- Email: [email protected]
Does surgical volume influence short-term outcomes of laparoscopic hysterectomy?
Research
www. AJOG.org
GENERAL GYNECOLOGY
Does surgical volume influence short-term outcomes of laparoscopic hysterectomy? Elena Tunitsky, MD; Ayse Citil, MD; Reyhan Ayaz, MD; Sertac Esin, MD; Alexander Knee, MS; Oz Harmanli, MD OBJECTIVE: To evaluate whether surgical volume has an impact on
short-term outcomes of laparoscopic hysterectomy. STUDY DESIGN: This is a retrospective analysis of 1016 laparoscopic
hysterectomies. RESULTS: The surgeons were divided into 2 groups based on a cutoff of 30
cases. Patient characteristics, the rates of laparotomy (4.5% vs 6.7%), and serious complications (3.6% vs 5.5%) were similar between 9 “high” and the remaining 39 “low volume” gynecologists, respectively (P ⬍ .05). Mean operating time was longer in the “low volume” group. Compared with their
first 29 hysterectomies, the “high volume” surgeons decreased their operating time significantly in their subsequent cases. The “high volume” surgeons improved their conversion rate (9.2% vs 2.4%; P ⬍ .0001) over time but not their serious complications. CONCLUSION: In laparoscopic hysterectomy, increasing the surgical
volume can reduce the operating time and the risk for conversion to laparotomy but not the rate of serious complications. Key words: complications, conversion, hysterectomy, laparoscopic hysterectomy, learning curve, surgical volume
Cite this article as: Tunitsky E, Citil A, Ayaz R, et al. Does surgical volume influence short-term outcomes of laparoscopic hysterectomy? Am J Obstet Gynecol 2010;203:24.e1-6.
A
s a minimally invasive approach, laparoscopic hysterectomy is gaining popularity among gynecologic surgeons. It offers a safe alternative to abdominal hysterectomy with less pain, reduced length of hospital stay, and faster postoperative recovery.1 Despite these clear advantages to laparotomy, it may be associated with serious complications and requires advanced skills.2 There has been an increasing interest in evaluation of the effect of surgeon’s experience on perioperative outcomes. We recently completed a large study evaluating the short-term surgical indices and complications of laparoscopic hysterectomies performed at our institution.3 Our overall complication rate was low; however, 1.3% of the patients had urinary tract injury, and 0.7% had vaginal cuff dehiscence. Serious complications, defined as life threatening or those reFrom the Department of Obstetrics and Gynecology, Baystate Medical Center, Tufts University School of Medicine, Springfield, MA. Received Aug. 12, 2009; revised Dec. 9, 2009; accepted Jan. 24, 2010. Reprints not available from the authors. 0002-9378/$36.00 © 2010 Mosby, Inc. All rights reserved. doi: 10.1016/j.ajog.2010.01.070
24.e1
quiring reoperation, occurred in 3.9% of all cases. Of all the surgeries, 4.8% were converted to abdominal hysterectomy. In this secondary analysis of the data from this previous study, we aimed to assess the influence of surgical volume on short-term outcomes and complication rates of laparoscopic hysterectomy.
M ATERIALS AND M ETHODS This is a post hoc analysis of the database that was generated to compare the shortterm outcomes between total (TLH) and supracervical laparoscopic hysterectomy (LSH). After obtaining an approval from the Institutional Review Board for this retrospective cohort study, we reviewed the medical records of all women who underwent a laparoscopic hysterectomy, TLH or LSH, for benign gynecologic problems at Baystate Medical Center between November 1999 and August 2008. During this period, slightly more than 5000 women underwent hysterectomy at our center, averaging 650 cases a year. Of those surgeries, approximately 30% were performed laparoscopically. The details regarding data collection and the results of that comparison can be found in our previous study.3 Exclusion criteria consisted of laparoscopically assisted vaginal hysterectomies, malignancies, and any other concomitant planned procedure
American Journal of Obstetrics & Gynecology JULY 2010
with exception of adnexal surgery, adhesiolysis, and intraoperative cystoscopy. The choice between TLH and LSH for each surgeon was so variable that we decided to combine the data for both to evaluate the effect of surgical volume on short-term outcomes for laparoscopic hysterectomy. To determine an appropriate cutoff for surgical volume, we categorized concurrent surgical cases in increments of 10 up to 100 cases and evaluated our data using a receiver operating characteristics (ROC) analysis for 2 of our main outcomes, serious complications, and conversions. Based on these results, we found that sensitivity and specificity were maximized at a cutoff of 40 for serious complications and 30 for conversions (Figure, A and B). When we looked at the number of surgeons that fell above or below these cutoffs, there was only the difference of 1 surgeon who had 36 cases. A cutoff of 30 cases was therefore chosen. Reviewing the literature, we noted that this number was consistent with a previously reported cutoff point.4 Surgeons who performed 30 or more surgeries were classified as “high volume,” whereas those who did less than 30 surgeries as “low volume.” We also compared the cases that were performed by the “high-volume” surgeons before they
General Gynecology
www.AJOG.org
FIGURE
Receiver operating characteristics (ROC) curve of surgical volume
Research
Data were analyzed using Stata version 10 (StataCorp LP, College Station, TX). All continuous variables are reported using means and standard deviations. Distributions were evaluated and determined to not follow a normal distribution, therefore the Wilcoxon rank-sum test was used to evaluate significant differences. Categorical variables are reported using number and percent. Significant differences were evaluated using Fisher’s exact test. Statistic significance was set at a P value of ⬍ .05 for all tests.
R ESULTS
A, ROC curve of surgical volume in increments of 10 cases for evaluation of serious complications from laparoscopic hysterectomies. B, ROC curve of surgical volume in increments of 10 cases for evaluation of the risk of conversion to laparotomy in laparoscopic hysterectomy cases. Tunitsky. Laparoscopic hysterectomies. Am J Obstet Gynecol 2010.
reached the volume cutoff with their subsequent cases. We evaluated baseline characteristics and comorbid conditions between the groups. We then examined the difference in operating time, rates of serious complications, and conversion to laparotomy. The definitions that were used for each
complication in this study can be found in our previous report.3 “Serious complications” were defined as complications that were either life threatening such as thromboembolic event and bleeding requiring transfusion, or those necessitating reoperation, which included visceral injury and vaginal cuff dehiscence.
There were 1110 consecutive laparoscopic hysterectomies identified. Of those, 94 cases were excluded because of concomitant major pelvic or abdominal surgery, leaving a total of 1016 cases that were accomplished by a total of 48 surgeons. Based on the cutoff of 30, we identified 9 surgeons as “high volume,” who performed 840 (83.4%) of all hysterectomies in this study. The remaining 39 surgeons were grouped as “low volume.” Of 9 “high volume” surgeons, 1 was fellowship trained in reproductive endocrinology, and the other 8 were general gynecologists. The majority of the patient characteristics including age, parity, body mass index, uterine weight, menopausal status, and adnexal removal rates were similar between the groups (Table 1). Race distribution was significantly different. More than 75% of all comparison groups were made up of white women. Among the comorbid conditions, endometriosis was the only one that significantly differed between the groups (Table 2). It was found more frequently in the first 29 cases of the “high-volume” surgeons as compared with their subsequent cases (17.6% vs 9.7%, P ⫽ .001). When we focused on the indications for surgery (Table 3), pelvic organ prolapse was more commonly recorded as an indication by the “high-volume” surgeons as compared with the “low-volume” surgeons (4.5% vs 0%; P ⫽ .002). Table 4 illustrates the complication rates and other perioperative parameters. The surgeries of the “low-volume” surgeons lasted significantly longer when compared
JULY 2010 American Journal of Obstetrics & Gynecology
24.e2
Research
General Gynecology
www.AJOG.org
TABLE 1
Patient characteristics High volume first 29 cases (n ⴝ 261)
High volume subsequent cases (n ⴝ 590)
Low volume (n ⴝ 165)
High volume (n ⴝ 851)
P valuea
43.4 ⫾ 6.2
44.3 ⫾ 7.0
.1080
44.0 ⫾ 6.6
44.5 ⫾ 7.2
.2804
Gravidity
2.4 ⫾ 1.6
2.4 ⫾ 1.6
.4980
2.4 ⫾ 1.6
2.5 ⫾ 1.6
.5331
Parity
1.9 ⫾ 1.3
1.9 ⫾ 1.2
.7200
1.8 ⫾ 1.2
1.9 ⫾ 1.2
.5092
28.6 ⫾ 7.5
28.1 ⫾ 6.6
.7898
27.4 ⫾ 5.8
28.4 ⫾ 6.9
.1911
176.3 ⫾ 132.7
212.3 ⫾ 194.3
.2213
176.0 ⫾ 125.7
227.0 ⫾ 214.4
.1586
Characteristic Age, y
P valuea
................................................................................................................................................................................................................................................................................................................................................................................ b ................................................................................................................................................................................................................................................................................................................................................................................ c ................................................................................................................................................................................................................................................................................................................................................................................ 2d
Body mass index, kg/m
................................................................................................................................................................................................................................................................................................................................................................................ e
Uterine weight, g
................................................................................................................................................................................................................................................................................................................................................................................
Postmenopausal, n (%)
11 (6.7)
60 (7.1)
⬎ .99
23 (8.9)
37 (6.3)
.192
................................................................................................................................................................................................................................................................................................................................................................................
Race, n (%)
.027
.030
.......................................................................................................................................................................................................................................................................................................................................................................
White
137 (83.1)
660 (77.6)
206 (78.9)
454 (77.0)
4 (2.4)
73 (8.6)
28 (10.7)
45 (7.6)
17 (10.3)
75 (8.8)
13 (5.0)
62 (7.6)
7 (4.3)
43 (5.1)
14 (5.4)
29 (4.9)
81 (49.1)
441 (51.8)
141 (54.0)
300 (50.9)
.......................................................................................................................................................................................................................................................................................................................................................................
Hispanic
.......................................................................................................................................................................................................................................................................................................................................................................
Black
.......................................................................................................................................................................................................................................................................................................................................................................
Other/unknown
................................................................................................................................................................................................................................................................................................................................................................................
Concomitant uni/bilateral adnexal removal, n (%)
.552
.414
................................................................................................................................................................................................................................................................................................................................................................................
Values are mean ⫾ standard deviation unless specified. a
P values calculated using Wilcoxon rank-sum test for continuous variables and Fisher’s exact test for categoric variables; b Low volume n ⫽ 159, high volume n ⫽ 822; c Low volume n ⫽ 159, high volume n ⫽ 823; d Low volume n ⫽ 163, high volume n ⫽ 808; e Low volume n ⫽ 93, high volume n ⫽ 444.
Tunitsky. Laparoscopic hysterectomies. Am J Obstet Gynecol 2010.
with those of the “high-volume” surgeons (188 ⫾ 73.7 minutes vs 163 ⫾ 59.0 minutes; P ⬍ .001). Furthermore, the “highvolume” providers were able to reduce their operating time and the length of hospital stay significantly after their first 29 cases (188.6 ⫾ 61.2 minutes vs 152.1 ⫾ 54.3 minutes; P ⬍ .001; 35 ⫾ 18.9 hours vs 27.9 ⫾ 11.2 hours; P ⬍ .001, respectively). The length of hospital stay was similar when the entire cohort of the “high-volume” group was compared with the “low-
volume” group. Other perioperative indices such as hemoglobin change and readmission rate were not significantly different. Overall, the surgical volume did not affect the complication rates, except for febrile morbidity, which was significantly more common in the initial 29 procedures of the “high-volume” group than in their latter cases (3.8% vs. 0.7%; P ⫽ .002). Febrile morbidity rate did not differ between the “low-volume” and the entire “high-
volume” groups. In all other comparisons we made, we were not able to show any statistically significant difference with respect to the rate of urinary tract injury, vaginal cuff dehiscence, and the overall “serious complications.” The “high-volume” gynecologists converted 9.2% of their first 29 cases. This significantly improved to 2.4% in their subsequent cases (P ⬍ .001). Interestingly, though not significantly different, the conversion rate in the “low-vol-
TABLE 2
Comorbid conditions and previous abdominal or pelvic surgery High volume subsequent cases (n ⴝ 590) n (%)
P valuea
47 (18.0)
107 (18.1)
⬎ .99
.380
14 (5.4)
21 (3.6)
.261
35 (4.1)
.663
12 (4.60
23 (3.9)
.708
21 (12.7)
103 (12.1)
.796
46 (17.6)
57 (9.7)
.001
42 (25.5)
223 (26.2)
.923
75 (28.7)
148 (25.1)
.273
Adnexal surgery
82 (49.7)
435 (51.1)
.799
140 (53.6)
295 (50.0)
.335
Other abdominal surgery
36 (21.8)
179 (21.0)
.835
56 (21.5)
123 (20.9)
.855
Characteristic
Low volume (n ⴝ 165) n (%)
High volume (n ⴝ 851) n (%)
P valuea
Hypertension
36 (21.8)
154 (18.1)
.276
Cardiovascular disease
4 (2.4)
35 (4.1)
Diabetes
5 (3.0)
Endometriosis
Uterine surgery
High volume first 29 cases (n ⴝ 261) n (%)
................................................................................................................................................................................................................................................................................................................................................................................ ................................................................................................................................................................................................................................................................................................................................................................................ ................................................................................................................................................................................................................................................................................................................................................................................ ................................................................................................................................................................................................................................................................................................................................................................................ b ................................................................................................................................................................................................................................................................................................................................................................................ ................................................................................................................................................................................................................................................................................................................................................................................ c ................................................................................................................................................................................................................................................................................................................................................................................ a
P values based on Fisher’s exact test; b Cesarean delivery, myomectomy; c Appendectomy, cholycystectomy, bowel resection, explorative surgery.
Tunitsky. Laparoscopic hysterectomies. Am J Obstet Gynecol 2010.
24.e3
American Journal of Obstetrics & Gynecology JULY 2010
General Gynecology
www.AJOG.org
Research
TABLE 3
Indications for hysterectomy Indication Uterine myomas
Low volume (n ⴝ 165) n (%)
High volume (n ⴝ 851) n (%)
P valuea
High volume first 29 cases (n ⴝ 261) n (%)
High volume subsequent cases (n ⴝ 590) n (%)
P valuea
88 (53.3)
422 (49.6)
.396
133 (51.0)
289 (49.0)
.604
116 (70.3)
579 (68.0)
.585
170 (65.1)
409 (69.3)
.233
Pelvic pain
64 (38.8)
363 (42.7)
.389
109 (41.8)
254 (43.1)
.764
Endometriosis
................................................................................................................................................................................................................................................................................................................................................................................
Menorrhagia
................................................................................................................................................................................................................................................................................................................................................................................ ................................................................................................................................................................................................................................................................................................................................................................................
11 (6.7)
70 (8.2)
.637
25 (9.6)
45 (7.6)
.346
Pelvic mass
7 (4.2)
44 (5.2)
.845
11 (4.2)
33 (5.6)
.502
Pelvic floor prolapse
0 (0.0)
38 (4.5)
.002
14 (5.4)
24 (4.1)
.471
Post menopausal bleeding
4 (2.4)
22 (2.6)
8 (3.1)
14 (2.4)
.640
Endometrial hyperplasia
5 (3.0)
31 (3.6)
12 (4.6)
19 (3.2)
.326
................................................................................................................................................................................................................................................................................................................................................................................ ................................................................................................................................................................................................................................................................................................................................................................................ ................................................................................................................................................................................................................................................................................................................................................................................
⬎ .99
................................................................................................................................................................................................................................................................................................................................................................................
.821
................................................................................................................................................................................................................................................................................................................................................................................ a
P values based on Fisher’s exact test.
Tunitsky. Laparoscopic hysterectomies. Am J Obstet Gynecol 2010.
ume” group (6.7%) is lower than in the initial 29 cases of the “high-volume” group. The most common causes for conversion were adhesions and large leiomyomas.
C OMMENT At our medical center, laparoscopic hysterectomy is a common procedure, practiced by a large number of gynecologic surgeons who have variable levels of experience. We recently evaluated shortterm outcomes for this procedure and found a relatively low rate of complications. The goal of this study was to examine if the surgical volume influenced these parameters. We did not note any significant difference between the shortterm surgical outcomes of the “low-” and “high- volume” gynecologists, except for the operating time. However, our analysis indicated that the “high-volume” surgeons significantly improved their operating time, length of hospital stay, conversion rate, and rate of febrile morbidity over time. Before further discussion on the duration of the surgeries, we must emphasize that operating time calculated in our database by taking the difference between the times “in” and “out” of the operating room, thus, does not reflect the actual surgical duration. This has to be taken into account when comparing our operating time with the other studies. It is not surprising that “low-volume” surgeons took longer time in the operating time
than “high-volume” surgeons. Likewise, the longer operating time in the first 29 cases of the “high-volume” surgeons may also be expected. These findings are also consistent with several other retrospective and prospective studies that had evaluated different versions of laparoscopic hysterectomy.5,6 The results of these studies attest to a learning curve in laparoscopic hysterectomies. In fact, this appears to be true for abdominal hysterectomy as well. In a recent study evaluating annual surgeon volume on outcomes for abdominal hysterectomies, Hanstede et al7 also found shorter operating times among the “high-volume” surgeons. Other studies, however, failed to demonstrate any significant change in the length of operating time with experience. Garrett et al8 when evaluating 120 cases of total laparoscopic hysterectomies, as well as Ou et al,9 in their analysis of 839 cases of laparoscopically assisted vaginal hysterectomies could not find any significant reduction in the operating time which was achieved with experience. Altgassen et al4 also studied the learning curve of laparoscopically assisted vaginal hysterectomies. Because these 3 studies did not find any improvement in operating time with increasing experience, they speculated that an experienced surgeon might not only tend to take on more complicated cases but also might be more likely to be in a role of an instructor rather than the primary surgeon. Thus, the efficiency gained by ex-
perience was counterbalanced by the complexity of the cases and time taken for teaching. Conditions that may potentially lead to complications are uterine weight, previous uterine surgery, and previous abdominal surgery, as well obesity or other medical comorbidities. In our cohort, these conditions did not generally differ between the “low-” and “high-volume” providers, and the first 29 and the subsequent cases of the “highvolume” gynecologists. Intuitively, one may think that a higher case volume leads to fewer complications. Brummer et al10 examined a 5-year national trend in hysterectomies in Finland and found a significant decrease in short-term complication rate for laparoscopic hysterectomy. Other retrospective studies, by Jones11 and Wattiez et al,12 evaluating laparoscopic hysterectomies, as well as Hanstede et al7 who studied abdominal hysterectomy, similarly demonstrated a decrease in complication rate over time. Contrary to these reports, for the most part we did not find a statistically significant decrease in complication rate with increase in case volume. Febrile morbidity was the only significant finding; statistically higher prevalence among the initial cohort of “high-volume” surgeons as compared with the later cohort. The hospital stay was also slightly, yet significantly, longer for this group. These 2 findings are logically connected as the patients that are found to be febrile postopera-
JULY 2010 American Journal of Obstetrics & Gynecology
24.e4
Research
General Gynecology
www.AJOG.org
TABLE 4
Perioperative complications and outcome measures Characteristic
Low volume (n ⴝ 165) n (%)
High volume (n ⴝ 851) n (%)
P valuea ⬎ .99
High volume first 29 cases (n ⴝ 261) n (%)
High volume subsequent cases (n ⴝ 590) n (%)
3 (1.1)
8 (1.4)
P valuea ⬎ .99
Urinary tract injury
2 (1.2)
11 (1.3)
Bowel injury
0 (0.0)
0 (0.0)
Vaginal cuff dehiscence
1 (0.6)
6 (0.7)
Thromboembolism
1 (0.0)
0 (0.0)
.162
Transfusion
5 (3.0)
12 (1.4)
.175
3 (1.2)
9 (1.5)
Febrile morbidity
4 (2.4)
14 (1.7)
.515
10 (3.8)
4 (0.7)
Ileus
1 (0.6)
5 (0.6)
1 (0.4)
4 (0.7)
⬎ .99
⬎ .99
................................................................................................................................................................................................................................................................................................................................................................................
—
—
—
—
................................................................................................................................................................................................................................................................................................................................................................................
1.0
1 (0.4)
5 (0.9)
.673
................................................................................................................................................................................................................................................................................................................................................................................
—
—
—
................................................................................................................................................................................................................................................................................................................................................................................
⬎ .99
................................................................................................................................................................................................................................................................................................................................................................................ b
.002
................................................................................................................................................................................................................................................................................................................................................................................
⬎ .99
................................................................................................................................................................................................................................................................................................................................................................................
Urinary retention
0 (0.0)
11 (1.3)
.228
3 (1.2)
8 (1.4)
Serious complications
9 (5.5)
31 (3.6)
.275
8 (3.1)
23 (3.9)
.692
11 (6.7)
38 (4.5)
.234
24 (9.2)
14 (2.4)
⬍ .001
7 (4.2)
32 (3.8)
.824
10 (3.8)
22 (3.7)
⬎ .99
⬍14 d
6 (3.7)
22 (2.6)
8 (3.1)
14 (2.4)
.641
Between 14 and 90 d
1 (0.6)
9 (1.1)
⬎ .99
1 (0.4)
8 (1.4)
.290
0 (0.0)
5 (0.6)
⬎ .99
1 (0.4)
4 (0.7)
................................................................................................................................................................................................................................................................................................................................................................................ c ................................................................................................................................................................................................................................................................................................................................................................................
Conversion to laparotomy
................................................................................................................................................................................................................................................................................................................................................................................
Readmission
.......................................................................................................................................................................................................................................................................................................................................................................
.438
....................................................................................................................................................................................................................................................................................................................................................................... ................................................................................................................................................................................................................................................................................................................................................................................
Exploratory laparotomy
⬎ .99
................................................................................................................................................................................................................................................................................................................................................................................
Length of hospital stay, h
31.0 ⫾ 20.9
30.1 ⫾ 14.4
.9363
35.0 ⫾ 18.9
27.9 ⫾ 11.2
⬍ .001
⬍ .001
................................................................................................................................................................................................................................................................................................................................................................................ d
Operating time, min
188 ⫾ 73.7
163 ⫾ 59.0
.0001
188.6 ⫾ 61.2
152.1 ⫾ 54.3
2.0 ⫾ 1.1
1.8 ⫾ 0.9
.1559
1.9 ⫾ 1.0
1.8 ⫾ 0.9
................................................................................................................................................................................................................................................................................................................................................................................ e
Change in hemoglobin, g
.3670
................................................................................................................................................................................................................................................................................................................................................................................
SD, standard deviation. a
P values calculated using Wilcoxon rank-sum test for continuous variables and Fisher’s exact test for categorical variables; b Postop fever, pelvic or cuff cellulitis; c Thromboembolism, urinary tract injury, bleeding requiring transfusion, vaginal cuff dehiscence, exploratory laparotomy at readmission; d High volume n ⫽ 846; e Low volume n ⫽ 93, high volume n ⫽ 438.
Tunitsky. Laparoscopic hysterectomies. Am J Obstet Gynecol 2010.
tively are more likely to stay longer, than those who are afebrile. Nevertheless, the difference in the febrile morbidity did not increase the risk of readmission or reoperation. In our analysis of the “high-volume” surgeons, we did note a higher rate of conversion to laparotomy in their initial 29 cases. Previous studies also demonstrate a drop in this rate parallel to an increase in case volume. Visco et al13 found that conversion rate halved after 5 cases and was predominant in the first 20 cases. When Jones11 examined the experience of a single surgeon, he also found a decrease in conversion rate from the first 250 hysterectomies to the subsequent 250. In our series, adhesions were blamed most frequently, followed by leiomyomas, both of which may pose a technical challenge by limiting exposure. Interestingly, there was a higher rate of endometriosis in the same group of patients and this might have contributed to 24.e5
the higher conversion rate. Arguably, conversion is not necessarily a complication; it may actually be a sign of prudence and caution. Perhaps the decrease in endometriosis and conversion rate over time, represents better foresight in patient selection. This study includes hysterectomies that were intended to be completed entirely laparoscopically by a large group of gynecologists in a single institution. We have commented on the possible shortcomings of our study in our previous report, which stem from its retrospective design. We conclude that, although the length of operating time decreases after 29 laparoscopic hysterectomies, the rate of complications does not significantly change. It is reassuring that, even in the hands of “low-volume” surgeons, the rate of complications for laparoscopic hysterectomy is very low. Changes in technology and surgical techniques over the years may compli-
American Journal of Obstetrics & Gynecology JULY 2010
cate comparison of earlier cases with later ones. Although Baystate Medical Center is an early adapter of new endoscopic technology, there has not been any remarkable change at our institution in gynecologic laparoscopic methods since 1999. That is why we specifically chose that year for the beginning of our patient inclusion in this research. With increasing number of emerging technologies, the effect of volume and experience should continue to be studied. f REFERENCES 1. Johnson N, Barlow D, Lethaby A, Tavender E, Curr E, Garry R. Surgical approach to hysterectomy for benign gynaecological disease. Cochrane Database Syst Rev 2006;19:CD003677. 2. Hakki-Siren P, Sjoberg J, Makinen J, et al. Finish national register of laparoscopic hysterectomies: a review and complications of 1165 operations. Am J Obstet Gynecol 1997;176: 118-22. 3. Harmanli OH, Tunitsky E, Esin S, Citil A, Ayaz R, Knee A. A comparison of short-term out-
www.AJOG.org comes between laparoscopic supracervical and total hysterectomies. Am J Obstet Gynecol 2009;201:536.e1-7. 4. Altgassen C, Michels W, Schneider A. Learning laparoscopic-assisted hysterectomy. Obstet Gynecol. 2004;104:308-13. 5. Rosen DMB, Cario GM, Carlton MA, Lam AM, Chapman M. An assessment of the learning curve for laparoscopic and total laparoscopic hysterectomy. Gynecol Endosc 1998; 7:289-93. 6. Melendez TD, Childers JM, Nour M, Harrigill K, Surwit EA. Laparoscopic staging of endometrial cancer: the learning experience. JSLS 1997;1:45-9.
General Gynecology 7. Hanstede MM, Wise LA, Stewart EA, Feldman S. The relation of annual surgeon case volume to clinical outcomes and resource utilization in abdominal hysterectomy. J Reprod Med 2009;54:193-202. 8. Garrett AJ, Nascimento MC, Nicklin JL, Perrin LC, Obermair A. Total laparoscopic hysterectomy: the Brisbane learning curve. Aust N Z J Obstet Gynaecol 2007;47:65-9. 9. Ou CS, Beadle E, Presthus J, Smith M. A multicenter review of 839 laparoscopic-assisted vaginal hysterectomies. J Am Assoc Gyneciol Laparosc 1994;1:S33. 10. Brummer TH, Seppälä TT, Härkki PS. National learning curve for laparoscopic hysterec-
Research
tomy and trends in hysterectomy in Finland 2000-2005. Hum Reprod 2008;23:840-5. 11. Jones RA. Complications of laparoscopic hysterectomy: comparison of the first 250 cases with the second 250. Gynaecol Endosc 2000;9:373-8. 12. Wattiez A, Soriano D, Cohen CB, et al. The learning curve of total laparoscopic hysterectomy: comparative analysis of cases. J Am Assoc Gynecol Laparosc 2002;3:339-45. 13. Visco AG, Barber MD, Myers ER. Early physician experience with laparoscopically assisted vaginal hysterectomy and rates of surgical complications and conversion to laparotomy. Am J Obstet Gynecol 2002;187:1008-12.
JULY 2010 American Journal of Obstetrics & Gynecology
24.e6
www. AJOG.org
GENERAL GYNECOLOGY
Does surgical volume influence short-term outcomes of laparoscopic hysterectomy? Elena Tunitsky, MD; Ayse Citil, MD; Reyhan Ayaz, MD; Sertac Esin, MD; Alexander Knee, MS; Oz Harmanli, MD OBJECTIVE: To evaluate whether surgical volume has an impact on
short-term outcomes of laparoscopic hysterectomy. STUDY DESIGN: This is a retrospective analysis of 1016 laparoscopic
hysterectomies. RESULTS: The surgeons were divided into 2 groups based on a cutoff of 30
cases. Patient characteristics, the rates of laparotomy (4.5% vs 6.7%), and serious complications (3.6% vs 5.5%) were similar between 9 “high” and the remaining 39 “low volume” gynecologists, respectively (P ⬍ .05). Mean operating time was longer in the “low volume” group. Compared with their
first 29 hysterectomies, the “high volume” surgeons decreased their operating time significantly in their subsequent cases. The “high volume” surgeons improved their conversion rate (9.2% vs 2.4%; P ⬍ .0001) over time but not their serious complications. CONCLUSION: In laparoscopic hysterectomy, increasing the surgical
volume can reduce the operating time and the risk for conversion to laparotomy but not the rate of serious complications. Key words: complications, conversion, hysterectomy, laparoscopic hysterectomy, learning curve, surgical volume
Cite this article as: Tunitsky E, Citil A, Ayaz R, et al. Does surgical volume influence short-term outcomes of laparoscopic hysterectomy? Am J Obstet Gynecol 2010;203:24.e1-6.
A
s a minimally invasive approach, laparoscopic hysterectomy is gaining popularity among gynecologic surgeons. It offers a safe alternative to abdominal hysterectomy with less pain, reduced length of hospital stay, and faster postoperative recovery.1 Despite these clear advantages to laparotomy, it may be associated with serious complications and requires advanced skills.2 There has been an increasing interest in evaluation of the effect of surgeon’s experience on perioperative outcomes. We recently completed a large study evaluating the short-term surgical indices and complications of laparoscopic hysterectomies performed at our institution.3 Our overall complication rate was low; however, 1.3% of the patients had urinary tract injury, and 0.7% had vaginal cuff dehiscence. Serious complications, defined as life threatening or those reFrom the Department of Obstetrics and Gynecology, Baystate Medical Center, Tufts University School of Medicine, Springfield, MA. Received Aug. 12, 2009; revised Dec. 9, 2009; accepted Jan. 24, 2010. Reprints not available from the authors. 0002-9378/$36.00 © 2010 Mosby, Inc. All rights reserved. doi: 10.1016/j.ajog.2010.01.070
24.e1
quiring reoperation, occurred in 3.9% of all cases. Of all the surgeries, 4.8% were converted to abdominal hysterectomy. In this secondary analysis of the data from this previous study, we aimed to assess the influence of surgical volume on short-term outcomes and complication rates of laparoscopic hysterectomy.
M ATERIALS AND M ETHODS This is a post hoc analysis of the database that was generated to compare the shortterm outcomes between total (TLH) and supracervical laparoscopic hysterectomy (LSH). After obtaining an approval from the Institutional Review Board for this retrospective cohort study, we reviewed the medical records of all women who underwent a laparoscopic hysterectomy, TLH or LSH, for benign gynecologic problems at Baystate Medical Center between November 1999 and August 2008. During this period, slightly more than 5000 women underwent hysterectomy at our center, averaging 650 cases a year. Of those surgeries, approximately 30% were performed laparoscopically. The details regarding data collection and the results of that comparison can be found in our previous study.3 Exclusion criteria consisted of laparoscopically assisted vaginal hysterectomies, malignancies, and any other concomitant planned procedure
American Journal of Obstetrics & Gynecology JULY 2010
with exception of adnexal surgery, adhesiolysis, and intraoperative cystoscopy. The choice between TLH and LSH for each surgeon was so variable that we decided to combine the data for both to evaluate the effect of surgical volume on short-term outcomes for laparoscopic hysterectomy. To determine an appropriate cutoff for surgical volume, we categorized concurrent surgical cases in increments of 10 up to 100 cases and evaluated our data using a receiver operating characteristics (ROC) analysis for 2 of our main outcomes, serious complications, and conversions. Based on these results, we found that sensitivity and specificity were maximized at a cutoff of 40 for serious complications and 30 for conversions (Figure, A and B). When we looked at the number of surgeons that fell above or below these cutoffs, there was only the difference of 1 surgeon who had 36 cases. A cutoff of 30 cases was therefore chosen. Reviewing the literature, we noted that this number was consistent with a previously reported cutoff point.4 Surgeons who performed 30 or more surgeries were classified as “high volume,” whereas those who did less than 30 surgeries as “low volume.” We also compared the cases that were performed by the “high-volume” surgeons before they
General Gynecology
www.AJOG.org
FIGURE
Receiver operating characteristics (ROC) curve of surgical volume
Research
Data were analyzed using Stata version 10 (StataCorp LP, College Station, TX). All continuous variables are reported using means and standard deviations. Distributions were evaluated and determined to not follow a normal distribution, therefore the Wilcoxon rank-sum test was used to evaluate significant differences. Categorical variables are reported using number and percent. Significant differences were evaluated using Fisher’s exact test. Statistic significance was set at a P value of ⬍ .05 for all tests.
R ESULTS
A, ROC curve of surgical volume in increments of 10 cases for evaluation of serious complications from laparoscopic hysterectomies. B, ROC curve of surgical volume in increments of 10 cases for evaluation of the risk of conversion to laparotomy in laparoscopic hysterectomy cases. Tunitsky. Laparoscopic hysterectomies. Am J Obstet Gynecol 2010.
reached the volume cutoff with their subsequent cases. We evaluated baseline characteristics and comorbid conditions between the groups. We then examined the difference in operating time, rates of serious complications, and conversion to laparotomy. The definitions that were used for each
complication in this study can be found in our previous report.3 “Serious complications” were defined as complications that were either life threatening such as thromboembolic event and bleeding requiring transfusion, or those necessitating reoperation, which included visceral injury and vaginal cuff dehiscence.
There were 1110 consecutive laparoscopic hysterectomies identified. Of those, 94 cases were excluded because of concomitant major pelvic or abdominal surgery, leaving a total of 1016 cases that were accomplished by a total of 48 surgeons. Based on the cutoff of 30, we identified 9 surgeons as “high volume,” who performed 840 (83.4%) of all hysterectomies in this study. The remaining 39 surgeons were grouped as “low volume.” Of 9 “high volume” surgeons, 1 was fellowship trained in reproductive endocrinology, and the other 8 were general gynecologists. The majority of the patient characteristics including age, parity, body mass index, uterine weight, menopausal status, and adnexal removal rates were similar between the groups (Table 1). Race distribution was significantly different. More than 75% of all comparison groups were made up of white women. Among the comorbid conditions, endometriosis was the only one that significantly differed between the groups (Table 2). It was found more frequently in the first 29 cases of the “high-volume” surgeons as compared with their subsequent cases (17.6% vs 9.7%, P ⫽ .001). When we focused on the indications for surgery (Table 3), pelvic organ prolapse was more commonly recorded as an indication by the “high-volume” surgeons as compared with the “low-volume” surgeons (4.5% vs 0%; P ⫽ .002). Table 4 illustrates the complication rates and other perioperative parameters. The surgeries of the “low-volume” surgeons lasted significantly longer when compared
JULY 2010 American Journal of Obstetrics & Gynecology
24.e2
Research
General Gynecology
www.AJOG.org
TABLE 1
Patient characteristics High volume first 29 cases (n ⴝ 261)
High volume subsequent cases (n ⴝ 590)
Low volume (n ⴝ 165)
High volume (n ⴝ 851)
P valuea
43.4 ⫾ 6.2
44.3 ⫾ 7.0
.1080
44.0 ⫾ 6.6
44.5 ⫾ 7.2
.2804
Gravidity
2.4 ⫾ 1.6
2.4 ⫾ 1.6
.4980
2.4 ⫾ 1.6
2.5 ⫾ 1.6
.5331
Parity
1.9 ⫾ 1.3
1.9 ⫾ 1.2
.7200
1.8 ⫾ 1.2
1.9 ⫾ 1.2
.5092
28.6 ⫾ 7.5
28.1 ⫾ 6.6
.7898
27.4 ⫾ 5.8
28.4 ⫾ 6.9
.1911
176.3 ⫾ 132.7
212.3 ⫾ 194.3
.2213
176.0 ⫾ 125.7
227.0 ⫾ 214.4
.1586
Characteristic Age, y
P valuea
................................................................................................................................................................................................................................................................................................................................................................................ b ................................................................................................................................................................................................................................................................................................................................................................................ c ................................................................................................................................................................................................................................................................................................................................................................................ 2d
Body mass index, kg/m
................................................................................................................................................................................................................................................................................................................................................................................ e
Uterine weight, g
................................................................................................................................................................................................................................................................................................................................................................................
Postmenopausal, n (%)
11 (6.7)
60 (7.1)
⬎ .99
23 (8.9)
37 (6.3)
.192
................................................................................................................................................................................................................................................................................................................................................................................
Race, n (%)
.027
.030
.......................................................................................................................................................................................................................................................................................................................................................................
White
137 (83.1)
660 (77.6)
206 (78.9)
454 (77.0)
4 (2.4)
73 (8.6)
28 (10.7)
45 (7.6)
17 (10.3)
75 (8.8)
13 (5.0)
62 (7.6)
7 (4.3)
43 (5.1)
14 (5.4)
29 (4.9)
81 (49.1)
441 (51.8)
141 (54.0)
300 (50.9)
.......................................................................................................................................................................................................................................................................................................................................................................
Hispanic
.......................................................................................................................................................................................................................................................................................................................................................................
Black
.......................................................................................................................................................................................................................................................................................................................................................................
Other/unknown
................................................................................................................................................................................................................................................................................................................................................................................
Concomitant uni/bilateral adnexal removal, n (%)
.552
.414
................................................................................................................................................................................................................................................................................................................................................................................
Values are mean ⫾ standard deviation unless specified. a
P values calculated using Wilcoxon rank-sum test for continuous variables and Fisher’s exact test for categoric variables; b Low volume n ⫽ 159, high volume n ⫽ 822; c Low volume n ⫽ 159, high volume n ⫽ 823; d Low volume n ⫽ 163, high volume n ⫽ 808; e Low volume n ⫽ 93, high volume n ⫽ 444.
Tunitsky. Laparoscopic hysterectomies. Am J Obstet Gynecol 2010.
with those of the “high-volume” surgeons (188 ⫾ 73.7 minutes vs 163 ⫾ 59.0 minutes; P ⬍ .001). Furthermore, the “highvolume” providers were able to reduce their operating time and the length of hospital stay significantly after their first 29 cases (188.6 ⫾ 61.2 minutes vs 152.1 ⫾ 54.3 minutes; P ⬍ .001; 35 ⫾ 18.9 hours vs 27.9 ⫾ 11.2 hours; P ⬍ .001, respectively). The length of hospital stay was similar when the entire cohort of the “high-volume” group was compared with the “low-
volume” group. Other perioperative indices such as hemoglobin change and readmission rate were not significantly different. Overall, the surgical volume did not affect the complication rates, except for febrile morbidity, which was significantly more common in the initial 29 procedures of the “high-volume” group than in their latter cases (3.8% vs. 0.7%; P ⫽ .002). Febrile morbidity rate did not differ between the “low-volume” and the entire “high-
volume” groups. In all other comparisons we made, we were not able to show any statistically significant difference with respect to the rate of urinary tract injury, vaginal cuff dehiscence, and the overall “serious complications.” The “high-volume” gynecologists converted 9.2% of their first 29 cases. This significantly improved to 2.4% in their subsequent cases (P ⬍ .001). Interestingly, though not significantly different, the conversion rate in the “low-vol-
TABLE 2
Comorbid conditions and previous abdominal or pelvic surgery High volume subsequent cases (n ⴝ 590) n (%)
P valuea
47 (18.0)
107 (18.1)
⬎ .99
.380
14 (5.4)
21 (3.6)
.261
35 (4.1)
.663
12 (4.60
23 (3.9)
.708
21 (12.7)
103 (12.1)
.796
46 (17.6)
57 (9.7)
.001
42 (25.5)
223 (26.2)
.923
75 (28.7)
148 (25.1)
.273
Adnexal surgery
82 (49.7)
435 (51.1)
.799
140 (53.6)
295 (50.0)
.335
Other abdominal surgery
36 (21.8)
179 (21.0)
.835
56 (21.5)
123 (20.9)
.855
Characteristic
Low volume (n ⴝ 165) n (%)
High volume (n ⴝ 851) n (%)
P valuea
Hypertension
36 (21.8)
154 (18.1)
.276
Cardiovascular disease
4 (2.4)
35 (4.1)
Diabetes
5 (3.0)
Endometriosis
Uterine surgery
High volume first 29 cases (n ⴝ 261) n (%)
................................................................................................................................................................................................................................................................................................................................................................................ ................................................................................................................................................................................................................................................................................................................................................................................ ................................................................................................................................................................................................................................................................................................................................................................................ ................................................................................................................................................................................................................................................................................................................................................................................ b ................................................................................................................................................................................................................................................................................................................................................................................ ................................................................................................................................................................................................................................................................................................................................................................................ c ................................................................................................................................................................................................................................................................................................................................................................................ a
P values based on Fisher’s exact test; b Cesarean delivery, myomectomy; c Appendectomy, cholycystectomy, bowel resection, explorative surgery.
Tunitsky. Laparoscopic hysterectomies. Am J Obstet Gynecol 2010.
24.e3
American Journal of Obstetrics & Gynecology JULY 2010
General Gynecology
www.AJOG.org
Research
TABLE 3
Indications for hysterectomy Indication Uterine myomas
Low volume (n ⴝ 165) n (%)
High volume (n ⴝ 851) n (%)
P valuea
High volume first 29 cases (n ⴝ 261) n (%)
High volume subsequent cases (n ⴝ 590) n (%)
P valuea
88 (53.3)
422 (49.6)
.396
133 (51.0)
289 (49.0)
.604
116 (70.3)
579 (68.0)
.585
170 (65.1)
409 (69.3)
.233
Pelvic pain
64 (38.8)
363 (42.7)
.389
109 (41.8)
254 (43.1)
.764
Endometriosis
................................................................................................................................................................................................................................................................................................................................................................................
Menorrhagia
................................................................................................................................................................................................................................................................................................................................................................................ ................................................................................................................................................................................................................................................................................................................................................................................
11 (6.7)
70 (8.2)
.637
25 (9.6)
45 (7.6)
.346
Pelvic mass
7 (4.2)
44 (5.2)
.845
11 (4.2)
33 (5.6)
.502
Pelvic floor prolapse
0 (0.0)
38 (4.5)
.002
14 (5.4)
24 (4.1)
.471
Post menopausal bleeding
4 (2.4)
22 (2.6)
8 (3.1)
14 (2.4)
.640
Endometrial hyperplasia
5 (3.0)
31 (3.6)
12 (4.6)
19 (3.2)
.326
................................................................................................................................................................................................................................................................................................................................................................................ ................................................................................................................................................................................................................................................................................................................................................................................ ................................................................................................................................................................................................................................................................................................................................................................................
⬎ .99
................................................................................................................................................................................................................................................................................................................................................................................
.821
................................................................................................................................................................................................................................................................................................................................................................................ a
P values based on Fisher’s exact test.
Tunitsky. Laparoscopic hysterectomies. Am J Obstet Gynecol 2010.
ume” group (6.7%) is lower than in the initial 29 cases of the “high-volume” group. The most common causes for conversion were adhesions and large leiomyomas.
C OMMENT At our medical center, laparoscopic hysterectomy is a common procedure, practiced by a large number of gynecologic surgeons who have variable levels of experience. We recently evaluated shortterm outcomes for this procedure and found a relatively low rate of complications. The goal of this study was to examine if the surgical volume influenced these parameters. We did not note any significant difference between the shortterm surgical outcomes of the “low-” and “high- volume” gynecologists, except for the operating time. However, our analysis indicated that the “high-volume” surgeons significantly improved their operating time, length of hospital stay, conversion rate, and rate of febrile morbidity over time. Before further discussion on the duration of the surgeries, we must emphasize that operating time calculated in our database by taking the difference between the times “in” and “out” of the operating room, thus, does not reflect the actual surgical duration. This has to be taken into account when comparing our operating time with the other studies. It is not surprising that “low-volume” surgeons took longer time in the operating time
than “high-volume” surgeons. Likewise, the longer operating time in the first 29 cases of the “high-volume” surgeons may also be expected. These findings are also consistent with several other retrospective and prospective studies that had evaluated different versions of laparoscopic hysterectomy.5,6 The results of these studies attest to a learning curve in laparoscopic hysterectomies. In fact, this appears to be true for abdominal hysterectomy as well. In a recent study evaluating annual surgeon volume on outcomes for abdominal hysterectomies, Hanstede et al7 also found shorter operating times among the “high-volume” surgeons. Other studies, however, failed to demonstrate any significant change in the length of operating time with experience. Garrett et al8 when evaluating 120 cases of total laparoscopic hysterectomies, as well as Ou et al,9 in their analysis of 839 cases of laparoscopically assisted vaginal hysterectomies could not find any significant reduction in the operating time which was achieved with experience. Altgassen et al4 also studied the learning curve of laparoscopically assisted vaginal hysterectomies. Because these 3 studies did not find any improvement in operating time with increasing experience, they speculated that an experienced surgeon might not only tend to take on more complicated cases but also might be more likely to be in a role of an instructor rather than the primary surgeon. Thus, the efficiency gained by ex-
perience was counterbalanced by the complexity of the cases and time taken for teaching. Conditions that may potentially lead to complications are uterine weight, previous uterine surgery, and previous abdominal surgery, as well obesity or other medical comorbidities. In our cohort, these conditions did not generally differ between the “low-” and “high-volume” providers, and the first 29 and the subsequent cases of the “highvolume” gynecologists. Intuitively, one may think that a higher case volume leads to fewer complications. Brummer et al10 examined a 5-year national trend in hysterectomies in Finland and found a significant decrease in short-term complication rate for laparoscopic hysterectomy. Other retrospective studies, by Jones11 and Wattiez et al,12 evaluating laparoscopic hysterectomies, as well as Hanstede et al7 who studied abdominal hysterectomy, similarly demonstrated a decrease in complication rate over time. Contrary to these reports, for the most part we did not find a statistically significant decrease in complication rate with increase in case volume. Febrile morbidity was the only significant finding; statistically higher prevalence among the initial cohort of “high-volume” surgeons as compared with the later cohort. The hospital stay was also slightly, yet significantly, longer for this group. These 2 findings are logically connected as the patients that are found to be febrile postopera-
JULY 2010 American Journal of Obstetrics & Gynecology
24.e4
Research
General Gynecology
www.AJOG.org
TABLE 4
Perioperative complications and outcome measures Characteristic
Low volume (n ⴝ 165) n (%)
High volume (n ⴝ 851) n (%)
P valuea ⬎ .99
High volume first 29 cases (n ⴝ 261) n (%)
High volume subsequent cases (n ⴝ 590) n (%)
3 (1.1)
8 (1.4)
P valuea ⬎ .99
Urinary tract injury
2 (1.2)
11 (1.3)
Bowel injury
0 (0.0)
0 (0.0)
Vaginal cuff dehiscence
1 (0.6)
6 (0.7)
Thromboembolism
1 (0.0)
0 (0.0)
.162
Transfusion
5 (3.0)
12 (1.4)
.175
3 (1.2)
9 (1.5)
Febrile morbidity
4 (2.4)
14 (1.7)
.515
10 (3.8)
4 (0.7)
Ileus
1 (0.6)
5 (0.6)
1 (0.4)
4 (0.7)
⬎ .99
⬎ .99
................................................................................................................................................................................................................................................................................................................................................................................
—
—
—
—
................................................................................................................................................................................................................................................................................................................................................................................
1.0
1 (0.4)
5 (0.9)
.673
................................................................................................................................................................................................................................................................................................................................................................................
—
—
—
................................................................................................................................................................................................................................................................................................................................................................................
⬎ .99
................................................................................................................................................................................................................................................................................................................................................................................ b
.002
................................................................................................................................................................................................................................................................................................................................................................................
⬎ .99
................................................................................................................................................................................................................................................................................................................................................................................
Urinary retention
0 (0.0)
11 (1.3)
.228
3 (1.2)
8 (1.4)
Serious complications
9 (5.5)
31 (3.6)
.275
8 (3.1)
23 (3.9)
.692
11 (6.7)
38 (4.5)
.234
24 (9.2)
14 (2.4)
⬍ .001
7 (4.2)
32 (3.8)
.824
10 (3.8)
22 (3.7)
⬎ .99
⬍14 d
6 (3.7)
22 (2.6)
8 (3.1)
14 (2.4)
.641
Between 14 and 90 d
1 (0.6)
9 (1.1)
⬎ .99
1 (0.4)
8 (1.4)
.290
0 (0.0)
5 (0.6)
⬎ .99
1 (0.4)
4 (0.7)
................................................................................................................................................................................................................................................................................................................................................................................ c ................................................................................................................................................................................................................................................................................................................................................................................
Conversion to laparotomy
................................................................................................................................................................................................................................................................................................................................................................................
Readmission
.......................................................................................................................................................................................................................................................................................................................................................................
.438
....................................................................................................................................................................................................................................................................................................................................................................... ................................................................................................................................................................................................................................................................................................................................................................................
Exploratory laparotomy
⬎ .99
................................................................................................................................................................................................................................................................................................................................................................................
Length of hospital stay, h
31.0 ⫾ 20.9
30.1 ⫾ 14.4
.9363
35.0 ⫾ 18.9
27.9 ⫾ 11.2
⬍ .001
⬍ .001
................................................................................................................................................................................................................................................................................................................................................................................ d
Operating time, min
188 ⫾ 73.7
163 ⫾ 59.0
.0001
188.6 ⫾ 61.2
152.1 ⫾ 54.3
2.0 ⫾ 1.1
1.8 ⫾ 0.9
.1559
1.9 ⫾ 1.0
1.8 ⫾ 0.9
................................................................................................................................................................................................................................................................................................................................................................................ e
Change in hemoglobin, g
.3670
................................................................................................................................................................................................................................................................................................................................................................................
SD, standard deviation. a
P values calculated using Wilcoxon rank-sum test for continuous variables and Fisher’s exact test for categorical variables; b Postop fever, pelvic or cuff cellulitis; c Thromboembolism, urinary tract injury, bleeding requiring transfusion, vaginal cuff dehiscence, exploratory laparotomy at readmission; d High volume n ⫽ 846; e Low volume n ⫽ 93, high volume n ⫽ 438.
Tunitsky. Laparoscopic hysterectomies. Am J Obstet Gynecol 2010.
tively are more likely to stay longer, than those who are afebrile. Nevertheless, the difference in the febrile morbidity did not increase the risk of readmission or reoperation. In our analysis of the “high-volume” surgeons, we did note a higher rate of conversion to laparotomy in their initial 29 cases. Previous studies also demonstrate a drop in this rate parallel to an increase in case volume. Visco et al13 found that conversion rate halved after 5 cases and was predominant in the first 20 cases. When Jones11 examined the experience of a single surgeon, he also found a decrease in conversion rate from the first 250 hysterectomies to the subsequent 250. In our series, adhesions were blamed most frequently, followed by leiomyomas, both of which may pose a technical challenge by limiting exposure. Interestingly, there was a higher rate of endometriosis in the same group of patients and this might have contributed to 24.e5
the higher conversion rate. Arguably, conversion is not necessarily a complication; it may actually be a sign of prudence and caution. Perhaps the decrease in endometriosis and conversion rate over time, represents better foresight in patient selection. This study includes hysterectomies that were intended to be completed entirely laparoscopically by a large group of gynecologists in a single institution. We have commented on the possible shortcomings of our study in our previous report, which stem from its retrospective design. We conclude that, although the length of operating time decreases after 29 laparoscopic hysterectomies, the rate of complications does not significantly change. It is reassuring that, even in the hands of “low-volume” surgeons, the rate of complications for laparoscopic hysterectomy is very low. Changes in technology and surgical techniques over the years may compli-
American Journal of Obstetrics & Gynecology JULY 2010
cate comparison of earlier cases with later ones. Although Baystate Medical Center is an early adapter of new endoscopic technology, there has not been any remarkable change at our institution in gynecologic laparoscopic methods since 1999. That is why we specifically chose that year for the beginning of our patient inclusion in this research. With increasing number of emerging technologies, the effect of volume and experience should continue to be studied. f REFERENCES 1. Johnson N, Barlow D, Lethaby A, Tavender E, Curr E, Garry R. Surgical approach to hysterectomy for benign gynaecological disease. Cochrane Database Syst Rev 2006;19:CD003677. 2. Hakki-Siren P, Sjoberg J, Makinen J, et al. Finish national register of laparoscopic hysterectomies: a review and complications of 1165 operations. Am J Obstet Gynecol 1997;176: 118-22. 3. Harmanli OH, Tunitsky E, Esin S, Citil A, Ayaz R, Knee A. A comparison of short-term out-
www.AJOG.org comes between laparoscopic supracervical and total hysterectomies. Am J Obstet Gynecol 2009;201:536.e1-7. 4. Altgassen C, Michels W, Schneider A. Learning laparoscopic-assisted hysterectomy. Obstet Gynecol. 2004;104:308-13. 5. Rosen DMB, Cario GM, Carlton MA, Lam AM, Chapman M. An assessment of the learning curve for laparoscopic and total laparoscopic hysterectomy. Gynecol Endosc 1998; 7:289-93. 6. Melendez TD, Childers JM, Nour M, Harrigill K, Surwit EA. Laparoscopic staging of endometrial cancer: the learning experience. JSLS 1997;1:45-9.
General Gynecology 7. Hanstede MM, Wise LA, Stewart EA, Feldman S. The relation of annual surgeon case volume to clinical outcomes and resource utilization in abdominal hysterectomy. J Reprod Med 2009;54:193-202. 8. Garrett AJ, Nascimento MC, Nicklin JL, Perrin LC, Obermair A. Total laparoscopic hysterectomy: the Brisbane learning curve. Aust N Z J Obstet Gynaecol 2007;47:65-9. 9. Ou CS, Beadle E, Presthus J, Smith M. A multicenter review of 839 laparoscopic-assisted vaginal hysterectomies. J Am Assoc Gyneciol Laparosc 1994;1:S33. 10. Brummer TH, Seppälä TT, Härkki PS. National learning curve for laparoscopic hysterec-
Research
tomy and trends in hysterectomy in Finland 2000-2005. Hum Reprod 2008;23:840-5. 11. Jones RA. Complications of laparoscopic hysterectomy: comparison of the first 250 cases with the second 250. Gynaecol Endosc 2000;9:373-8. 12. Wattiez A, Soriano D, Cohen CB, et al. The learning curve of total laparoscopic hysterectomy: comparative analysis of cases. J Am Assoc Gynecol Laparosc 2002;3:339-45. 13. Visco AG, Barber MD, Myers ER. Early physician experience with laparoscopically assisted vaginal hysterectomy and rates of surgical complications and conversion to laparotomy. Am J Obstet Gynecol 2002;187:1008-12.
JULY 2010 American Journal of Obstetrics & Gynecology
24.e6