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Mechanical Bowel Preparation for Gynecologic Laparoscopy: A Prospective Randomized Trial of Oral Sodium Phosphate Solution vs Single Sodium Phosphate Enema
Original Article
Mechanical Bowel Preparation for Gynecologic Laparoscopy: A Prospective Randomized Trial of Oral Sodium Phosphate Solution vs Single Sodium Phosphate Enema Linda C. Yang, MD, MSc*, Deborah Arden, MD, Ted T. M. Lee, MD, Suketu M. Mansuria, MD, Amy N. Broach, MD, Lori D’Ambrosio, and Richard Guido, MD From the Program of Minimally Invasive Gynecologic Surgery, Department of Obstetrics and Gynecology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts (Dr. Yang), and Division of Gynecologic Specialties, Minimally Invasive Gynecologic Surgery, Department of Obstetrics and Gynecology and Reproductive Sciences, Magee-Womens Hospital, University of Pittsburgh Medical School, Pittsburgh, Pennsylvania (Drs. Arden, Lee, Mansuria, Broach, D’Ambrosio, and Guido).
ABSTRACT Study Objective: To compare the effect of mechanical bowel preparation using oral sodium phosphate (NaP) solution vs single NaP enema on the quality of the surgical field in patients undergoing advanced gynecologic laparoscopic procedures. Design: Single-blind randomized controlled trial (Canadian Task Force classification I). Setting: Academic teaching hospital. Patients: Women undergoing gynecologic laparoscopic surgery. Interventions: Administration of either oral NaP solution or single NaP enema for preoperative bowel preparation. Measurements and Main Results: One hundred fifty-six women were enrolled, and 145 were randomized to receive either oral NaP solution (n 5 72) or NaP enema (n 5 73). Sixty-eight women in the oral solution group and 65 in the enema group completed the study. Assessment of the quality of the surgical field and bowel characteristics was performed using a surgeon questionnaire using Likert and visual analog scales. No significant differences were observed between the 2 groups in evaluation of the surgical field, bowel handling, degree of bowel preparation, or surgical difficulty. Surgical field quality was graded as excellent or good in 85% of women in the oral solution group and 91% of women in the enema group (p 5 .43). When surgeons were asked to guess the type of preparation used, they were correct only 52% of the time (k 5 0.04). Assessment of patient quality of life in the preoperative period was performed using a self-administered questionnaire using a visual analog scale. Severity of abdominal bloating and swelling, weakness, thirst, dizziness, nausea, fecal incontinence, and overall discomfort were significantly greater in the oral solution group. Women in the oral solution group also rated the preparation as significantly more difficult to administer, and were significantly less willing to try the same preparation in the future. Conclusion: Quality of the surgical field in patients undergoing advanced gynecologic laparoscopic procedures is similar after mechanical bowel preparation using either oral NaP solution and NaP enema. Adverse effects are more severe with oral NaP solution compared with NaP enema administration. Journal of Minimally Invasive Gynecology (2011) 18, 149–156 Ó 2011 AAGL. All rights reserved. Keywords:
Gynecology; Laparoscopy; Mechanical bowel preparation
The authors have no commercial, proprietary, or financial interest in the products and companies described in this article. Presented at the Annual Meeting of the American Society of Reproductive Medicine, October 23–27, 2010, Denver, CO, and the 39th AAGL Global Congress of Minimally Invasive Gynecology, November 8–12, 2010, Las Vegas, NV. Corresponding author: Linda C. Yang, MD, MSc, Program of Minimally Invasive Gynecologic Surgery, Department of Obstetrics and Gynecology, Beth Israel Deaconess Medical Center, 330 Brookline Ave, KS-319, Boston, MA 02215. E-mail: [email protected] Submitted August 6, 2010. Accepted for publication October 14, 2010. Available at www.sciencedirect.com and www.jmig.org 1553-4650/$ - see front matter Ó 2011 AAGL. All rights reserved. doi:10.1016/j.jmig.2010.10.007
Mechanical bowel preparation (MBP) is a common preoperative practice used by both general and gynecologic surgeons in patients undergoing elective abdominal and pelvic procedures. Several decades ago, the concept of bowel cleansing was introduced to minimize morbidity and mortality associated with intraoperative complications of colorectal surgery [1] and to decrease the risk of requiring a colostomy in the setting of large bowel injury. Use of preoperative MBP may provide several theoretical advantages. Intraoperative bowel manipulation during surgery may be improved by decreasing the bulky contents [1],
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reduction of postoperative infections due to intraoperative contamination may be achieved by emptying the bowel of its fecal load [2], and MBP may enable optimal visualization of the surgical field [3]. Another important issue related to MBP is that it can be associated with substantial patient discomfort including nausea, abdominal bloating, and diarrhea [4–6]. Recently, the role of MBP in gynecologic surgery has been questioned. Muzii et al [7] investigated the utility of MBP in gynecologic laparoscopic surgery and demonstrated no significant advantage of MBP over no bowel preparation in patients undergoing diagnostic laparoscopy with or without minor adhesiolysis or in patients undergoing laparoscopic procedures primarily limited to the adnexa. In more advanced laparoscopic procedures such as for treatment of endometriosis or hysterectomy because of bulky disease, visualization of and access to the pelvic organs is paramount, and may be impaired by suboptimal bowel conditions. To our knowledge, the benefit of MBP in advanced gynecologic laparoscopic procedures has not been studied. With evidence available from only 1 published trial relating predominantly to adnexal and other minor laparoscopic procedures, additional investigation of the role of MBP in advanced gynecologic laparoscopy procedures (i.e., laparoscopic hysterectomy and laparoscopic procedures to treat pelvic pain and endometriosis) becomes necessary. The primary objective of the present study was to compare the effect of MBP using oral sodium phosphate (NaP) solution vs single NaP enema on the quality of the surgical field in patients undergoing advanced gynecologic laparoscopic procedures. The secondary objective was to compare perioperative parameters and patient quality of life in the preoperative period between the 2 intervention groups. Materials and Methods Between September 2007 and May 2009, a single-blind, randomized, controlled trial was conducted in women undergoing advanced gynecologic laparoscopic procedures. Women aged 18 years or older undergoing laparoscopic surgery were enrolled from the offices of 3 minimally invasive gynecologic surgeons (T.L., S.M., R.G.) at Magee-Womens Hospital of the University of Pittsburgh Medical Center. Exclusion criteria were known or suspected gynecologic malignancy, pregnancy, suspected rectal endometriosis, any medical condition that represented a contraindication to the use of NaP bowel preparation, and inability to give informed consent. This protocol was approved by the University of Pittsburgh Institutional Review Board, and all participants provided informed consent. Participants were randomized to receive either oral NaP solution (Fleet Phospho-Soda) or single NaP enema (Fleet Enema) (both from C.B. Fleet Co., Inc., Lynchburg, VA) before undergoing the scheduled procedure. Block randomization was conducted using a computer-generated sequence, with allocation concealment maintained through the use of
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consecutively-numbered sealed opaque envelopes. The envelopes were opened by the research coordinator (L.D.) after the initial preoperative visit, and each study participant was provided with the assigned bowel preparation regimen. The primary surgeons remained blinded to the randomization assignments and were unaware of the exact details of the randomization method (i.e., block sizes were not revealed). Patients randomized to the oral group were instructed to ingest 45 mL of the NaP preparation in the morning and another 45 mL 3 hours after the first dose on the day before surgery. Patients randomized to the enema group were instructed to self-administer a single 133-mL NaP enema rectally at bedtime the evening before the scheduled surgery. Per standard preoperative surgical protocol, patients in both groups were allowed only clear liquids on the day before surgery, and were not to ingest anything by mouth including liquids after midnight. They were allowed a sip of water on the morning of surgery to take routine medications for chronic medical conditions. Participants were instructed to not reveal the bowel preparation assignment to the surgeon. Baseline participant characteristics including age, body mass index, race/ethnicity, indication for surgery, type of surgery, history of gastrointestinal conditions, and history of abdominal or pelvic surgery were recorded for each patient. Perioperative parameters including operative time, estimated blood loss, length of hospital stay, and complications were also obtained. After each surgery, the primary surgeon completed a selfadministered questionnaire to evaluate the intraoperative visual quality of the surgical field, assess the ease of intraoperative bowel manipulation, and rate the overall level of difficulty in performing the procedure. Using a 4-point Likert scale (excellent, good, fair, and poor), the surgeon assessed (1) the quality of the surgical field after initial laparoscopic port placement after positioning the patient in the Trendelenburg position, (2) quality of the surgical field at the conclusion of the surgery, (3) degree of small and large bowel preparation, (4) quality of bowel handling with laparoscopic instruments, and (5) visualization of the uterus, adnexal structures, and posterior cul-de-sac. The surgeon questionnaire also assessed additional large bowel characteristics, use of additional exposure techniques or instruments, and surgical difficulty. Patient quality of life in the preoperative period was assessed using a single self-administered questionnaire completed just before surgery. A visual analog scale scored from 0 (none) to 10 (worst possible) was used to evaluate severity of symptoms including abdominal cramps or pain, hunger, abdominal bloating or swelling, embarrassment, insomnia, weakness, thirst, dizziness, nausea, vomiting, fecal incontinence, fear, difficulty of administration, and overall discomfort. Additional questionnaire items included ability to complete bowel preparation regimen and willingness to repeat the assigned bowel preparation regimen in the future. Determination of the sample size for the primary outcome of the study, quality of the surgical field after MBP as
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assessed by the surgeon, was based on a reference rate of 87% for acceptable (excellent or good) bowel preparation after oral NaP as reported by Oliveira et al [4]. As in the study by Muzii et al [3], the objective of the present study was to detect a treatment difference of 20% between the treatment groups, with 80% power at the 5% significance level. The treatment-specific percentages used in the sample size determination were 87% for the oral solution group and 67% for the enema group. Using these treatment-specific percentages, the sample size for each group was calculated as 70 for each group, for a total of 140 participants. Statistical analysis was performed using commercially available software (STATA version 11; StataCorp LP, College Station, TX). Normality was determined by visually assessing the graphic display of the data distribution for each variable and by evaluating the value of the skewness and kurtosis statistics. Continuous variables were summarized using mean and standard deviation when normally distributed, and median and interquartile range when not normally distributed. Categorical variables were summarized using frequencies and percentages. Continuous variables were analyzed using the t test when normally distributed, and the Wilcoxon rank sum test when not normally distributed. Categorical variables were analyzed using the Fisher exact test. The k statistic was calculated to assess the degree of correctly predicting the assigned regimen. For all statistical analyses, a 5 .05 was considered significant.
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Results The study flow diagram is shown in Fig. 1. Over the 2-year study, 156 participants were enrolled, and 145 were randomized: 72 to the oral preparation arm, of whom 68 patients completed the study, and 73 to the enema preparation arm, of whom 65 patients completed the study. Baseline demographic data are given in Table 1. No significant differences were observed between the oral and enema groups insofar as age, body mass index, race/ethnicity, history of gastrointestinal conditions, or history of abdominal or pelvic surgery. Nineteen percent of patients in each group reported a preexisting gastrointestinal condition, primarily irritable bowel syndrome or gastroesophageal reflux disease. Seventy-four percent of patients in each group had undergone at least 1, and often multiple, previous abdominal or pelvic surgical procedures. The most commonly reported procedures were cesarean delivery, laparoscopy to treat endometriosis, and laparoscopic cholecystectomy. No statistical difference was observed between the 2 groups insofar as number of participants who completed the study. Surgical parameters are given in Table 2. No significant differences were observed between the oral and enema groups insofar as indication for surgery, type of surgery performed, estimated blood loss, length of hospital stay, surgical complications, or operating time. Indications for surgery were primarily pelvic pain, adnexal masses, myomas,
156 Participants signed informed consent
11 Participants not randomized Surgery not scheduled: 5 Patient missed surgery: 2 Bowel preparation not received: 2 Patient self-withdrew: 1 Surgery cancelled: 1
145 Participants randomized
72 Patients received oral NaP
4 Patients did not complete study Surgery not scheduled: 1 Bowel preparation not received: 1 Surgery cancelled: 2
68 Completed study
Fig. 1. Study flow diagram.
73 Patients received NaP enema
8 Patients did not complete study Surgery not scheduled: 1 Surgery cancelled: 4 Patient self-withdrew: 2 Surgery performed robotically: 1
65 Completed study
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Table 1
Baseline characteristics of participants randomizeda Bowel preparation Variable Age, mean (SD), y BMI, mean (SD) Race/ethnicity White African American History of GI condition History of previous surgery Patients completed the study
Oral NaP (n 5 72)
NaP enema (n 5 73)
40.8 (9.8) 27.1 (6.0)
38.1 (9.6) 26.3 (5.9)
.10 .46
67 (93) 5 (7) 14 (19) 53 (74) 68 (94)
64 (88) 9 (12) 14 (19) 54 (74) 65 (89)
.40
p Value
..99 ..99 .37
BMI 5 body mass index; GI 5 gastrointestinal; NaP 5 sodium phosphate. a Continuous data are normally distributed and given as mean (SD), and analyzed using the t test. Categorical data are given as frequency (%), and analyzed using the Fisher exact test. Unless otherwise indicated, data are given as No. (%).
abnormal bleeding, and other less common reasons including recurrent cervical dysplasia, risk-reducing prophylactic surgery, hydrosalpinges, pelvic organ prolapse, and urinary incontinence. The most commonly performed surgical procedures were unilateral or bilateral salpingooophorectomy, ovarian cystectomy, laparoscopic supracervical hysterectomy, total laparoscopic hysterectomy, and
excision of endometriosis with and without presacral neurectomy. The ‘‘other’’ category included 4 laparoscopy-assisted vaginal hysterectomies, 1 laparoscopic myomectomy, and 1 laparoscopic paravaginal repair, uterosacral ligament suspension, and Burch urethropexy. While the complication rate was 7% in the oral group and 15% in the enema group, this was not a statistically significant difference. Complications in the oral group included right lower quadrant port hematoma; readmission because of postoperative pyelonephritis; an emergency room visit because of nausea and vomiting, with negative findings at workup; an emergency room visit because of abdominal pain, with negative findings at workup; and postoperative vaginal cyst. Complications in the enema group included postoperative pelvic fluid collection requiring readmission for drainage via interventional radiology and antibiotic therapy, with subsequent Clostridium difficile infection; vaginal cuff cellulitis in 2 patients; urinary retention requiring prolonged catheterization in 2 patients; postoperative urinary tract infection; 1-day readmission because of nausea and vomiting, 1-day readmission because of abdominal pain; and 2 emergency room visits because of abdominal pain, with negative findings at workup. Results of the questionnaire filled out by the primary surgeon at the end of the case are given in Table 3. All but 2 of the surgeon questionnaires were completed. Surgeon responses
Table 2
Surgical data for participants who completed the studya Bowel preparation Variable Indication for surgery Pelvic pain Adnexal mass Myomas Dysfunctional uterine bleeding Other Surgical procedure Unilateral or bilateral salpingo-oophorectomy Cystectomy Laparoscopic supracervical hysterectomy Total laparoscopic hysterectomy Endometriosis excision Endometriosis excision with presacral neurectomy Other Operative time, median (interquartile range), min Blood loss, mL Minimal ,50 51–100 .100 Hospital stay, nights Outpatient 1 R2 Complications
Oral NaP (n 5 68)
NaP enema (n 5 65)
28 (41) 16 (24) 11 (16) 6 (9) 7 (10)
34 (52) 13 (20) 9 (14) 7 (11) 2 (3)
14 (21) 17 (25) 8 (12) 17 (25) 5 (7) 2 (3) 5 (7) 97 (70–140)
14 (22) 17 (26) 9 (14) 11 (17) 8 (12) 5 (8) 1 (2) 90 (66–143)
14 (21) 28 (41) 19 (28) 7 (10)
13 (20) 27 (42) 18 (28) 7 (11)
26 (38) 39 (57) 3 (4) 5 (7)
30 (46) 32 (49) 3 (5) 10 (15)
p Value .40
.46
.88 ..99
.61
.18
NaP 5 sodium phosphate. a Categorical data are given as frequency (%), and analyzed using the Fisher exact test. Continuous data (operative time) was not normally distributed, and was analyzed using the Wilcoxon rank sum test. Unless otherwise indicated, data are given as No. (%).
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Table 3
Surgeon assessment of quality of surgical field as reported using a postoperative questionnairea Bowel preparation Variable Initial quality of visualization ITT Excellent or good Fair, poor, or missing ATP Excellent or good Fair or poor Quality of visualization at conclusion Excellent or good Fair or poor Small bowel preparation Excellent or good Fair or poor Large bowel preparation Excellent or good Fair or poor Bowel handling Excellent or good Fair or poor Visualization of uterus Excellent or good Fair or poor Sugically absent Visualization of right adnexa Excellent or good Fair or poor Surgically absent Visualization of left adnexa Excellent or good Fair or poor Surgically absent Visualization of posterior cul-de-sac Excellent or good Fair or poor Large bowel assessment Collapsed Gas-filled Stool-filled Maneuver to improve exposure Fan retractor Additional ports Bowel suspension suture Bowel adhesiolysis Surgery compromised Surgical difficulty, mean (SD)
Oral NaP (ITT, n 5 72; ATP, n 5 68)
NaP enema (ITT, n 5 73; ATP, n 5 65)
p Value .69
56 (78) 16 (22)
59 (81) 14 (19)
56 (85) 10 (15)
59 (91) 6 (9)
62 (94) 4 (6)
62 (97) 2 (3)
65 (98) 1 (2)
62 (95) 3 (5)
56 (85) 10 (15)
55 (85) 10 (15)
65 (98) 1 (2)
63 (97) 2 (3)
61 (92) 0 5 (8)
60 (92) 0 5 (8)
62 (97) 2 (3) 0
64 (98) 0 1 (2)
58 (91) 4 (6) 2 (3)
59 (91) 5 (8) 1 (1)
53 (84) 10 (16)
55 (85) 10 (15)
43 (67) 20 (31) 1 (2)
39 (60) 21 (32) 5 (8)
0 0 2 (3) 12 (19) 1 (2) 3.94 (1.75)
0 0 1 (2) 15 (23) 3 (5) 4.29 (1.64)
.43
.68
.37
..99
.62
..99
.37
..99
..99
.29
.62 .67 .62 .25
ATP 5 according-to-protocol regimen; ITT 5 intent-to-treat regimen; NaP 5 sodium phosphate; VAS 5 visual analog scale. The primary outcome variable, initial quality of visualization, was analyzed using ITT and ATP methods. All other variables were analyzed using only ATP methods. Categorical data are given as frequency (%), and analyzed using the Fisher exact test. Continuous data (surgical difficulty) were rated on a VAS scale of 1 to 10, and analyzed using the t test. Unless otherwise indicated, data are given as No. (%). a
were dichotomized into 2 categories: excellent or good and fair or poor. No significant differences were observed between the 2 MBP groups in any of the surgeon assessments. The primary outcome, overall quality of visualization of the surgical field after initial laparoscopic port placement, was analyzed using both intent-to-treat and according-toprotocol analysis. In the intent-to-treat analysis, all missing data for patients who did not complete the study were
assumed to be failures, and put in the fair or poor visualization category. In the according-to-protocol analysis, only data for patients who completed the study were used. Neither analysis showed a significant difference in the primary outcome between the 2 groups. The remaining variables were analyzed according to protocol. There were no significant differences between the groups insofar as quality of visualization at the conclusion of the case, surgeon assessment of
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Table 4
Patient symptoms as reported using a self-administered questionnaire using a 10-point VASa Bowel preparation Variable
Oral NaP (n 5 68)
NaP enema (n 5 65)
p Value
Abdominal cramping or pain Hunger Abdominal bloating or swelling Embarrassment Insomnia Weakness Thirst Dizziness Nausea Vomiting Fecal incontinence Fear Overall discomfort Difficulty of administration Able to complete preparation, No. (%) Difficulty rating, No. (%) Easy Tolerable Slightly difficult Moderately difficult Very difficult Willing to use same preparation again, No. (%) Would rather try another preparation, No. (%)
1.6 (0.5–2.7) 4.3 (2.0–6.6) 2.7 (0.5–4.7) 0.4 (0.2–1.6) 0.3 (0.2–2.2) 1.7 (0.3–4.4) 5.3 (2.8–7.0) 0.8 (0.2–2.7) 2.0 (0.2–4.0) 0.2 (0.0–0.4) 1.5 (0.4–3.5) 0.4 (0.0–1.5) 2.6 (1.3–4.7) 5.0 (2.3–7.5) 66 (97)
1.7 (0.8–2.8) 5.0 (2.4–7.0) 0.9 (0.3–1.8) 0.5 (0.1–2.2) 0.5 (0.2–2.3) 0.5 (0.2–1.3) 3.0 (1.0–6.1) 0.2 (0.1–0.8) 0.4 (0.1–1.4) 0.3 (0.0–0.3) 0.3 (0.1–1.3) 0.3 (0.0–0.9) 1.2 (0.3–2.6) 0.6 (0.3–2.2) 65 (100)
.52 .63 ,.001 .88 .10 .005 .008 .001 ,.001 .37 ,.001 .65 ,.001 ,.001 .50 ,.001
18 (26) 29 (43) 11 (16) 5 (5) 5 (5) 51 (76) 44 (66)
43 (66) 13 (20) 7 (11) 2 (3) 0 63 (97) 20 (31)
.001 ,.001
IQR 5 interquartile range; NaP 5 sodium phosphate; VAS 5 visual analog scale. a All variables analyzed according to protocol. Continuous variables were not normally distributed, and are given as median (IQR), and analyzed using the Wilcoxon rank sum test. Categorical data are given as frequency (%), and analyzed using the Fisher exact test. Unless otherwise indicated, values are given as median (IQR).
small or large bowel preparation, quality of bowel handling with laparoscopic instruments, or visualization of the uterus, adnexal structures, and posterior cul-de-sac. When asked to assess the large bowel as collapsed, gasfilled, or stool-filled, there was no significant difference in the way the surgeons rated the 2 groups. No cases required the use of fan retractors or placement of additional ports to improve visualization of the operative field or bowel retraction. Only 2 cases in the oral group and 1 in the enema group warranted use of a bowel retention suture to manually displace the bowel during surgery. Adhesiolysis was performed in 19% of cases in the oral group and 23% in the enema group. None of these differences were statistically significant. Surgeons reported that they believed the surgery was compromised by the choice of bowel preparation in 1 case in the oral group and 3 cases in the enema group, which was not a statistically significant difference. Surgical difficulty as assessed by the primary surgeon was similar for the 2 groups. When asked to guess whether the patient had used an oral or enema preparation, the surgeon’s guess coincided with the actual allocation only 52% of the time (k 5 0.04). Results of the quality-of-life questionnaire completed by patients in the preoperative period are given in Table 4. Patients who used the oral preparation experienced significantly more severe symptoms of abdominal bloating and
swelling, weakness, thirst, dizziness, nausea, and fecal incontinence compared with those who used the enema preparation. Compared with the enema group, the oral group reported greater overall discomfort and significantly more difficulty with administration of the preparation. All patients in the enema group and all but 2 in the oral group were able to complete the assigned bowel preparation. The oral group rated preparation as significantly more difficult than the enema group. Significantly more patients in the oral preparation group reported that they would not be willing to undergo the same preparation in the future and would rather try another preparation if they had to undergo surgery again. Discussion Preoperative MBP is a routine procedure that is associated with significant patient burden and discomfort. In the past, the presumed benefit of fewer infectious sequelae was thought to offset the adverse effects and burden experienced by patients. Emerging data from published studies have not shown significant improvements in postoperative complications after MBP. Several trials comparing MBP with no preparation for elective colorectal surgery have not demonstrated reductions in anastomotic complications in both open and laparoscopic
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approaches. There has been some suggestion that the use of such an intervention may be associated with increased rates of anastomotic leakage and wound complications [1,8–10]. Despite the lack of convincing evidence supporting the use of MBP, a recent survey of colorectal surgeons showed that practice trends have not shifted from this longstanding surgical practice. More than 99% of survey respondents reported routine use of MBP [11]. The role of MBP in gynecologic laparoscopy procedures has not been clearly defined, and little has been published about this preoperative practice. For the gynecologic surgeon specializing in laparoscopic procedures, the risks of fecal spillage and subsequent septic and leakage complications inherent in colorectal surgery are generally less applicable. In 2003, Brosens et al [12] reported that diagnostic and minor gynecologic laparoscopy procedures are associated with a 0.08% risk of bowel injury and a 0.33% risk with major gynecologic laparoscopy procedures. Successful surgery relies on adequate visualization and exposure. Laparoscopic surgery involving pelvic structures poses an additional challenge to ensure a satisfactory surgical field, given the bony constraints of the pelvis [7]. The theoretical utility of bowel cleansing before gynecologic laparoscopy procedures is related to its potential ability to optimize visualization of pelvic structures within the surgical field. Bowel loops may compete with pelvic organs for space, interfering with deep pelvic dissection and use of laparoscopic instruments. Bowel manipulation during open surgery is technically feasible with retractors and packing, but may be more difficult with the intrinsic limitations of laparoscopic surgery. Evidence is available from only 1 published trial by Muzii et al [7], and is related predominantly to adnexal and other minor laparoscopic procedures. Thus, the objective of the present study was to investigate the role of MBP in advanced gynecologic laparoscopy procedures including hysterectomy, which often require additional laparoscopic training and pose greater surgical difficulty. The study by Muzii et al [7] found no difference in surgical field quality in patients randomized to MBP vs no MBP. A limitation of the design of the present study is the decision to not use a true control group of patients without any preoperative bowel preparation. This decision was made because of concerns about the unknown potential for significant impairment in surgical visualization during more complicated laparoscopic procedures, which would pose an unacceptable risk for study participants. The study design, comparing a rectal enema with an oral preparation, allowed assessment of whether a simpler and perhaps more tolerable MBP method enables acceptable surgical field conditions. Future studies with inclusion of a control group of patients who do not receive any bowel preparation would yield valuable observations that the present study was not able to provide. Another possible limitation is that not all randomized patients completed the study. Of the 72 patients randomized to
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the oral preparation group, 68 completed the study, and of the 73 patients randomized to the enema preparation, 65 completed the study. Two surgeon questionnaires, both from participants randomized to the oral preparation group, were not completed. To ensure that these missing data were not a source of bias, the number of participants from each group that failed to complete the study was compared, and was not statistically different (p 5 .37). Also analyzed was the primary outcome, overall quality of visualization of the surgical field after initial laparoscopic port placement, using both intent-to-treat and according-to-protocol methods. Neither analysis showed a significant difference in the primary outcome between the 2 groups, which lowers the suspicion of bias due to dropouts. The study demonstrates that MBP with oral NaP offered no significant improvement over the NaP enema regimen in visualization of the surgical field and pelvic structures or handling of the bowel with laparoscopic instruments. For both types of MBP, the overall quality of the surgical field was assessed as either excellent or good in most cases. We believe our study population is more representative of a minimally invasive gynecologic surgery practice than what had previously existed in the literature, which could enable more generalizable results. In contrast to the existing literature, exclusion criteria did not include obesity, history of previous surgery, or patients undergoing hysterectomy. Indeed, 26% of the sample had a body mass index greater than 30, 74% had a history of abdominal or pelvic surgery, and 35% of the surgical procedures performed in the present study were laparoscopic hysterectomies. In assessing operative parameters, no significant differences were observed between the 2 MBP groups. While the number of complications was not significantly different between the 2 groups, in the enema group, 2 patients had postoperative vaginal cuff cellulitis, and 1 had a pelvic abscess. It is not clear that these complications have any relation to the preoperative bowel preparation. The study was not powered to detect differences in complication rates between the 2 groups. Compared with the NaP enema group, patients in the oral NaP group experienced significantly more adverse effects including abdominal bloating and swelling, weakness, thirst, dizziness, nausea, fecal incontinence, and overall discomfort. In addition, the oral regimen was significantly more difficult to administer than the enema preparation, and significantly more patients in the oral preparation group reported that they would not be willing to undergo the same preparation in the future and would rather try another preparation if they had to undergo surgery again. In conclusion, NaP enema may be a reasonable MBP alternative to oral NaP solution in advanced gynecologic laparoscopic procedures because it achieves similar surgical field quality with less patient discomfort. The results of the present investigation serve as a valuable contribution to the limited body of knowledge that currently exists about this common preoperative practice.
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with oral sodium picosulphate (Picolax) for elective colorectal surgery and colonoscopy. Dig Surg. 2000;17:66–70. Muzii L, Bellati F, Zullo M, Manci N, Angioli R, Panici PB. Mechanical bowel preparation before gynecologic laparoscopy: a randomized, single-blind, controlled trial. Fertil Steril. 2006;85:689–693. Guenaga KF, Matos D, Castro AA, Atallah AN, Wille-Jorgensen P. Mechanical bowel preparation for elective colorectal surgery. Cochrane Database Syst Rev. 2005;CD001544. Wille-Jorgensen P, Guenaga KF, Matos D, Castro AA. Pre-operative mechanical bowel cleansing or not? an updated meta-analysis. Colorectal Dis. 2005;7:304–310. Zmora O, Lebedyev A, Hoffman A, et al. Laparoscopic colectomy without mechanical bowel preparation. Int J Colorectal Dis. 2006;21: 683–687. Zmora O, Wexner SD, Hajjar L, et al. Trends in preparation for colorectal surgery: survey of the members of the American Society of Colon and Rectal Surgeons. Am Surg. 2003;69:150–154. Brosens I, Gordon A, Campo R, Gordts S. Bowel injury in gynecologic laparoscopy. J Am Assoc Gynecol Laparosc. 2003;10:9–13.
Mechanical Bowel Preparation for Gynecologic Laparoscopy: A Prospective Randomized Trial of Oral Sodium Phosphate Solution vs Single Sodium Phosphate Enema Linda C. Yang, MD, MSc*, Deborah Arden, MD, Ted T. M. Lee, MD, Suketu M. Mansuria, MD, Amy N. Broach, MD, Lori D’Ambrosio, and Richard Guido, MD From the Program of Minimally Invasive Gynecologic Surgery, Department of Obstetrics and Gynecology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts (Dr. Yang), and Division of Gynecologic Specialties, Minimally Invasive Gynecologic Surgery, Department of Obstetrics and Gynecology and Reproductive Sciences, Magee-Womens Hospital, University of Pittsburgh Medical School, Pittsburgh, Pennsylvania (Drs. Arden, Lee, Mansuria, Broach, D’Ambrosio, and Guido).
ABSTRACT Study Objective: To compare the effect of mechanical bowel preparation using oral sodium phosphate (NaP) solution vs single NaP enema on the quality of the surgical field in patients undergoing advanced gynecologic laparoscopic procedures. Design: Single-blind randomized controlled trial (Canadian Task Force classification I). Setting: Academic teaching hospital. Patients: Women undergoing gynecologic laparoscopic surgery. Interventions: Administration of either oral NaP solution or single NaP enema for preoperative bowel preparation. Measurements and Main Results: One hundred fifty-six women were enrolled, and 145 were randomized to receive either oral NaP solution (n 5 72) or NaP enema (n 5 73). Sixty-eight women in the oral solution group and 65 in the enema group completed the study. Assessment of the quality of the surgical field and bowel characteristics was performed using a surgeon questionnaire using Likert and visual analog scales. No significant differences were observed between the 2 groups in evaluation of the surgical field, bowel handling, degree of bowel preparation, or surgical difficulty. Surgical field quality was graded as excellent or good in 85% of women in the oral solution group and 91% of women in the enema group (p 5 .43). When surgeons were asked to guess the type of preparation used, they were correct only 52% of the time (k 5 0.04). Assessment of patient quality of life in the preoperative period was performed using a self-administered questionnaire using a visual analog scale. Severity of abdominal bloating and swelling, weakness, thirst, dizziness, nausea, fecal incontinence, and overall discomfort were significantly greater in the oral solution group. Women in the oral solution group also rated the preparation as significantly more difficult to administer, and were significantly less willing to try the same preparation in the future. Conclusion: Quality of the surgical field in patients undergoing advanced gynecologic laparoscopic procedures is similar after mechanical bowel preparation using either oral NaP solution and NaP enema. Adverse effects are more severe with oral NaP solution compared with NaP enema administration. Journal of Minimally Invasive Gynecology (2011) 18, 149–156 Ó 2011 AAGL. All rights reserved. Keywords:
Gynecology; Laparoscopy; Mechanical bowel preparation
The authors have no commercial, proprietary, or financial interest in the products and companies described in this article. Presented at the Annual Meeting of the American Society of Reproductive Medicine, October 23–27, 2010, Denver, CO, and the 39th AAGL Global Congress of Minimally Invasive Gynecology, November 8–12, 2010, Las Vegas, NV. Corresponding author: Linda C. Yang, MD, MSc, Program of Minimally Invasive Gynecologic Surgery, Department of Obstetrics and Gynecology, Beth Israel Deaconess Medical Center, 330 Brookline Ave, KS-319, Boston, MA 02215. E-mail: [email protected] Submitted August 6, 2010. Accepted for publication October 14, 2010. Available at www.sciencedirect.com and www.jmig.org 1553-4650/$ - see front matter Ó 2011 AAGL. All rights reserved. doi:10.1016/j.jmig.2010.10.007
Mechanical bowel preparation (MBP) is a common preoperative practice used by both general and gynecologic surgeons in patients undergoing elective abdominal and pelvic procedures. Several decades ago, the concept of bowel cleansing was introduced to minimize morbidity and mortality associated with intraoperative complications of colorectal surgery [1] and to decrease the risk of requiring a colostomy in the setting of large bowel injury. Use of preoperative MBP may provide several theoretical advantages. Intraoperative bowel manipulation during surgery may be improved by decreasing the bulky contents [1],
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reduction of postoperative infections due to intraoperative contamination may be achieved by emptying the bowel of its fecal load [2], and MBP may enable optimal visualization of the surgical field [3]. Another important issue related to MBP is that it can be associated with substantial patient discomfort including nausea, abdominal bloating, and diarrhea [4–6]. Recently, the role of MBP in gynecologic surgery has been questioned. Muzii et al [7] investigated the utility of MBP in gynecologic laparoscopic surgery and demonstrated no significant advantage of MBP over no bowel preparation in patients undergoing diagnostic laparoscopy with or without minor adhesiolysis or in patients undergoing laparoscopic procedures primarily limited to the adnexa. In more advanced laparoscopic procedures such as for treatment of endometriosis or hysterectomy because of bulky disease, visualization of and access to the pelvic organs is paramount, and may be impaired by suboptimal bowel conditions. To our knowledge, the benefit of MBP in advanced gynecologic laparoscopic procedures has not been studied. With evidence available from only 1 published trial relating predominantly to adnexal and other minor laparoscopic procedures, additional investigation of the role of MBP in advanced gynecologic laparoscopy procedures (i.e., laparoscopic hysterectomy and laparoscopic procedures to treat pelvic pain and endometriosis) becomes necessary. The primary objective of the present study was to compare the effect of MBP using oral sodium phosphate (NaP) solution vs single NaP enema on the quality of the surgical field in patients undergoing advanced gynecologic laparoscopic procedures. The secondary objective was to compare perioperative parameters and patient quality of life in the preoperative period between the 2 intervention groups. Materials and Methods Between September 2007 and May 2009, a single-blind, randomized, controlled trial was conducted in women undergoing advanced gynecologic laparoscopic procedures. Women aged 18 years or older undergoing laparoscopic surgery were enrolled from the offices of 3 minimally invasive gynecologic surgeons (T.L., S.M., R.G.) at Magee-Womens Hospital of the University of Pittsburgh Medical Center. Exclusion criteria were known or suspected gynecologic malignancy, pregnancy, suspected rectal endometriosis, any medical condition that represented a contraindication to the use of NaP bowel preparation, and inability to give informed consent. This protocol was approved by the University of Pittsburgh Institutional Review Board, and all participants provided informed consent. Participants were randomized to receive either oral NaP solution (Fleet Phospho-Soda) or single NaP enema (Fleet Enema) (both from C.B. Fleet Co., Inc., Lynchburg, VA) before undergoing the scheduled procedure. Block randomization was conducted using a computer-generated sequence, with allocation concealment maintained through the use of
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consecutively-numbered sealed opaque envelopes. The envelopes were opened by the research coordinator (L.D.) after the initial preoperative visit, and each study participant was provided with the assigned bowel preparation regimen. The primary surgeons remained blinded to the randomization assignments and were unaware of the exact details of the randomization method (i.e., block sizes were not revealed). Patients randomized to the oral group were instructed to ingest 45 mL of the NaP preparation in the morning and another 45 mL 3 hours after the first dose on the day before surgery. Patients randomized to the enema group were instructed to self-administer a single 133-mL NaP enema rectally at bedtime the evening before the scheduled surgery. Per standard preoperative surgical protocol, patients in both groups were allowed only clear liquids on the day before surgery, and were not to ingest anything by mouth including liquids after midnight. They were allowed a sip of water on the morning of surgery to take routine medications for chronic medical conditions. Participants were instructed to not reveal the bowel preparation assignment to the surgeon. Baseline participant characteristics including age, body mass index, race/ethnicity, indication for surgery, type of surgery, history of gastrointestinal conditions, and history of abdominal or pelvic surgery were recorded for each patient. Perioperative parameters including operative time, estimated blood loss, length of hospital stay, and complications were also obtained. After each surgery, the primary surgeon completed a selfadministered questionnaire to evaluate the intraoperative visual quality of the surgical field, assess the ease of intraoperative bowel manipulation, and rate the overall level of difficulty in performing the procedure. Using a 4-point Likert scale (excellent, good, fair, and poor), the surgeon assessed (1) the quality of the surgical field after initial laparoscopic port placement after positioning the patient in the Trendelenburg position, (2) quality of the surgical field at the conclusion of the surgery, (3) degree of small and large bowel preparation, (4) quality of bowel handling with laparoscopic instruments, and (5) visualization of the uterus, adnexal structures, and posterior cul-de-sac. The surgeon questionnaire also assessed additional large bowel characteristics, use of additional exposure techniques or instruments, and surgical difficulty. Patient quality of life in the preoperative period was assessed using a single self-administered questionnaire completed just before surgery. A visual analog scale scored from 0 (none) to 10 (worst possible) was used to evaluate severity of symptoms including abdominal cramps or pain, hunger, abdominal bloating or swelling, embarrassment, insomnia, weakness, thirst, dizziness, nausea, vomiting, fecal incontinence, fear, difficulty of administration, and overall discomfort. Additional questionnaire items included ability to complete bowel preparation regimen and willingness to repeat the assigned bowel preparation regimen in the future. Determination of the sample size for the primary outcome of the study, quality of the surgical field after MBP as
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assessed by the surgeon, was based on a reference rate of 87% for acceptable (excellent or good) bowel preparation after oral NaP as reported by Oliveira et al [4]. As in the study by Muzii et al [3], the objective of the present study was to detect a treatment difference of 20% between the treatment groups, with 80% power at the 5% significance level. The treatment-specific percentages used in the sample size determination were 87% for the oral solution group and 67% for the enema group. Using these treatment-specific percentages, the sample size for each group was calculated as 70 for each group, for a total of 140 participants. Statistical analysis was performed using commercially available software (STATA version 11; StataCorp LP, College Station, TX). Normality was determined by visually assessing the graphic display of the data distribution for each variable and by evaluating the value of the skewness and kurtosis statistics. Continuous variables were summarized using mean and standard deviation when normally distributed, and median and interquartile range when not normally distributed. Categorical variables were summarized using frequencies and percentages. Continuous variables were analyzed using the t test when normally distributed, and the Wilcoxon rank sum test when not normally distributed. Categorical variables were analyzed using the Fisher exact test. The k statistic was calculated to assess the degree of correctly predicting the assigned regimen. For all statistical analyses, a 5 .05 was considered significant.
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Results The study flow diagram is shown in Fig. 1. Over the 2-year study, 156 participants were enrolled, and 145 were randomized: 72 to the oral preparation arm, of whom 68 patients completed the study, and 73 to the enema preparation arm, of whom 65 patients completed the study. Baseline demographic data are given in Table 1. No significant differences were observed between the oral and enema groups insofar as age, body mass index, race/ethnicity, history of gastrointestinal conditions, or history of abdominal or pelvic surgery. Nineteen percent of patients in each group reported a preexisting gastrointestinal condition, primarily irritable bowel syndrome or gastroesophageal reflux disease. Seventy-four percent of patients in each group had undergone at least 1, and often multiple, previous abdominal or pelvic surgical procedures. The most commonly reported procedures were cesarean delivery, laparoscopy to treat endometriosis, and laparoscopic cholecystectomy. No statistical difference was observed between the 2 groups insofar as number of participants who completed the study. Surgical parameters are given in Table 2. No significant differences were observed between the oral and enema groups insofar as indication for surgery, type of surgery performed, estimated blood loss, length of hospital stay, surgical complications, or operating time. Indications for surgery were primarily pelvic pain, adnexal masses, myomas,
156 Participants signed informed consent
11 Participants not randomized Surgery not scheduled: 5 Patient missed surgery: 2 Bowel preparation not received: 2 Patient self-withdrew: 1 Surgery cancelled: 1
145 Participants randomized
72 Patients received oral NaP
4 Patients did not complete study Surgery not scheduled: 1 Bowel preparation not received: 1 Surgery cancelled: 2
68 Completed study
Fig. 1. Study flow diagram.
73 Patients received NaP enema
8 Patients did not complete study Surgery not scheduled: 1 Surgery cancelled: 4 Patient self-withdrew: 2 Surgery performed robotically: 1
65 Completed study
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Table 1
Baseline characteristics of participants randomizeda Bowel preparation Variable Age, mean (SD), y BMI, mean (SD) Race/ethnicity White African American History of GI condition History of previous surgery Patients completed the study
Oral NaP (n 5 72)
NaP enema (n 5 73)
40.8 (9.8) 27.1 (6.0)
38.1 (9.6) 26.3 (5.9)
.10 .46
67 (93) 5 (7) 14 (19) 53 (74) 68 (94)
64 (88) 9 (12) 14 (19) 54 (74) 65 (89)
.40
p Value
..99 ..99 .37
BMI 5 body mass index; GI 5 gastrointestinal; NaP 5 sodium phosphate. a Continuous data are normally distributed and given as mean (SD), and analyzed using the t test. Categorical data are given as frequency (%), and analyzed using the Fisher exact test. Unless otherwise indicated, data are given as No. (%).
abnormal bleeding, and other less common reasons including recurrent cervical dysplasia, risk-reducing prophylactic surgery, hydrosalpinges, pelvic organ prolapse, and urinary incontinence. The most commonly performed surgical procedures were unilateral or bilateral salpingooophorectomy, ovarian cystectomy, laparoscopic supracervical hysterectomy, total laparoscopic hysterectomy, and
excision of endometriosis with and without presacral neurectomy. The ‘‘other’’ category included 4 laparoscopy-assisted vaginal hysterectomies, 1 laparoscopic myomectomy, and 1 laparoscopic paravaginal repair, uterosacral ligament suspension, and Burch urethropexy. While the complication rate was 7% in the oral group and 15% in the enema group, this was not a statistically significant difference. Complications in the oral group included right lower quadrant port hematoma; readmission because of postoperative pyelonephritis; an emergency room visit because of nausea and vomiting, with negative findings at workup; an emergency room visit because of abdominal pain, with negative findings at workup; and postoperative vaginal cyst. Complications in the enema group included postoperative pelvic fluid collection requiring readmission for drainage via interventional radiology and antibiotic therapy, with subsequent Clostridium difficile infection; vaginal cuff cellulitis in 2 patients; urinary retention requiring prolonged catheterization in 2 patients; postoperative urinary tract infection; 1-day readmission because of nausea and vomiting, 1-day readmission because of abdominal pain; and 2 emergency room visits because of abdominal pain, with negative findings at workup. Results of the questionnaire filled out by the primary surgeon at the end of the case are given in Table 3. All but 2 of the surgeon questionnaires were completed. Surgeon responses
Table 2
Surgical data for participants who completed the studya Bowel preparation Variable Indication for surgery Pelvic pain Adnexal mass Myomas Dysfunctional uterine bleeding Other Surgical procedure Unilateral or bilateral salpingo-oophorectomy Cystectomy Laparoscopic supracervical hysterectomy Total laparoscopic hysterectomy Endometriosis excision Endometriosis excision with presacral neurectomy Other Operative time, median (interquartile range), min Blood loss, mL Minimal ,50 51–100 .100 Hospital stay, nights Outpatient 1 R2 Complications
Oral NaP (n 5 68)
NaP enema (n 5 65)
28 (41) 16 (24) 11 (16) 6 (9) 7 (10)
34 (52) 13 (20) 9 (14) 7 (11) 2 (3)
14 (21) 17 (25) 8 (12) 17 (25) 5 (7) 2 (3) 5 (7) 97 (70–140)
14 (22) 17 (26) 9 (14) 11 (17) 8 (12) 5 (8) 1 (2) 90 (66–143)
14 (21) 28 (41) 19 (28) 7 (10)
13 (20) 27 (42) 18 (28) 7 (11)
26 (38) 39 (57) 3 (4) 5 (7)
30 (46) 32 (49) 3 (5) 10 (15)
p Value .40
.46
.88 ..99
.61
.18
NaP 5 sodium phosphate. a Categorical data are given as frequency (%), and analyzed using the Fisher exact test. Continuous data (operative time) was not normally distributed, and was analyzed using the Wilcoxon rank sum test. Unless otherwise indicated, data are given as No. (%).
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Table 3
Surgeon assessment of quality of surgical field as reported using a postoperative questionnairea Bowel preparation Variable Initial quality of visualization ITT Excellent or good Fair, poor, or missing ATP Excellent or good Fair or poor Quality of visualization at conclusion Excellent or good Fair or poor Small bowel preparation Excellent or good Fair or poor Large bowel preparation Excellent or good Fair or poor Bowel handling Excellent or good Fair or poor Visualization of uterus Excellent or good Fair or poor Sugically absent Visualization of right adnexa Excellent or good Fair or poor Surgically absent Visualization of left adnexa Excellent or good Fair or poor Surgically absent Visualization of posterior cul-de-sac Excellent or good Fair or poor Large bowel assessment Collapsed Gas-filled Stool-filled Maneuver to improve exposure Fan retractor Additional ports Bowel suspension suture Bowel adhesiolysis Surgery compromised Surgical difficulty, mean (SD)
Oral NaP (ITT, n 5 72; ATP, n 5 68)
NaP enema (ITT, n 5 73; ATP, n 5 65)
p Value .69
56 (78) 16 (22)
59 (81) 14 (19)
56 (85) 10 (15)
59 (91) 6 (9)
62 (94) 4 (6)
62 (97) 2 (3)
65 (98) 1 (2)
62 (95) 3 (5)
56 (85) 10 (15)
55 (85) 10 (15)
65 (98) 1 (2)
63 (97) 2 (3)
61 (92) 0 5 (8)
60 (92) 0 5 (8)
62 (97) 2 (3) 0
64 (98) 0 1 (2)
58 (91) 4 (6) 2 (3)
59 (91) 5 (8) 1 (1)
53 (84) 10 (16)
55 (85) 10 (15)
43 (67) 20 (31) 1 (2)
39 (60) 21 (32) 5 (8)
0 0 2 (3) 12 (19) 1 (2) 3.94 (1.75)
0 0 1 (2) 15 (23) 3 (5) 4.29 (1.64)
.43
.68
.37
..99
.62
..99
.37
..99
..99
.29
.62 .67 .62 .25
ATP 5 according-to-protocol regimen; ITT 5 intent-to-treat regimen; NaP 5 sodium phosphate; VAS 5 visual analog scale. The primary outcome variable, initial quality of visualization, was analyzed using ITT and ATP methods. All other variables were analyzed using only ATP methods. Categorical data are given as frequency (%), and analyzed using the Fisher exact test. Continuous data (surgical difficulty) were rated on a VAS scale of 1 to 10, and analyzed using the t test. Unless otherwise indicated, data are given as No. (%). a
were dichotomized into 2 categories: excellent or good and fair or poor. No significant differences were observed between the 2 MBP groups in any of the surgeon assessments. The primary outcome, overall quality of visualization of the surgical field after initial laparoscopic port placement, was analyzed using both intent-to-treat and according-toprotocol analysis. In the intent-to-treat analysis, all missing data for patients who did not complete the study were
assumed to be failures, and put in the fair or poor visualization category. In the according-to-protocol analysis, only data for patients who completed the study were used. Neither analysis showed a significant difference in the primary outcome between the 2 groups. The remaining variables were analyzed according to protocol. There were no significant differences between the groups insofar as quality of visualization at the conclusion of the case, surgeon assessment of
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Table 4
Patient symptoms as reported using a self-administered questionnaire using a 10-point VASa Bowel preparation Variable
Oral NaP (n 5 68)
NaP enema (n 5 65)
p Value
Abdominal cramping or pain Hunger Abdominal bloating or swelling Embarrassment Insomnia Weakness Thirst Dizziness Nausea Vomiting Fecal incontinence Fear Overall discomfort Difficulty of administration Able to complete preparation, No. (%) Difficulty rating, No. (%) Easy Tolerable Slightly difficult Moderately difficult Very difficult Willing to use same preparation again, No. (%) Would rather try another preparation, No. (%)
1.6 (0.5–2.7) 4.3 (2.0–6.6) 2.7 (0.5–4.7) 0.4 (0.2–1.6) 0.3 (0.2–2.2) 1.7 (0.3–4.4) 5.3 (2.8–7.0) 0.8 (0.2–2.7) 2.0 (0.2–4.0) 0.2 (0.0–0.4) 1.5 (0.4–3.5) 0.4 (0.0–1.5) 2.6 (1.3–4.7) 5.0 (2.3–7.5) 66 (97)
1.7 (0.8–2.8) 5.0 (2.4–7.0) 0.9 (0.3–1.8) 0.5 (0.1–2.2) 0.5 (0.2–2.3) 0.5 (0.2–1.3) 3.0 (1.0–6.1) 0.2 (0.1–0.8) 0.4 (0.1–1.4) 0.3 (0.0–0.3) 0.3 (0.1–1.3) 0.3 (0.0–0.9) 1.2 (0.3–2.6) 0.6 (0.3–2.2) 65 (100)
.52 .63 ,.001 .88 .10 .005 .008 .001 ,.001 .37 ,.001 .65 ,.001 ,.001 .50 ,.001
18 (26) 29 (43) 11 (16) 5 (5) 5 (5) 51 (76) 44 (66)
43 (66) 13 (20) 7 (11) 2 (3) 0 63 (97) 20 (31)
.001 ,.001
IQR 5 interquartile range; NaP 5 sodium phosphate; VAS 5 visual analog scale. a All variables analyzed according to protocol. Continuous variables were not normally distributed, and are given as median (IQR), and analyzed using the Wilcoxon rank sum test. Categorical data are given as frequency (%), and analyzed using the Fisher exact test. Unless otherwise indicated, values are given as median (IQR).
small or large bowel preparation, quality of bowel handling with laparoscopic instruments, or visualization of the uterus, adnexal structures, and posterior cul-de-sac. When asked to assess the large bowel as collapsed, gasfilled, or stool-filled, there was no significant difference in the way the surgeons rated the 2 groups. No cases required the use of fan retractors or placement of additional ports to improve visualization of the operative field or bowel retraction. Only 2 cases in the oral group and 1 in the enema group warranted use of a bowel retention suture to manually displace the bowel during surgery. Adhesiolysis was performed in 19% of cases in the oral group and 23% in the enema group. None of these differences were statistically significant. Surgeons reported that they believed the surgery was compromised by the choice of bowel preparation in 1 case in the oral group and 3 cases in the enema group, which was not a statistically significant difference. Surgical difficulty as assessed by the primary surgeon was similar for the 2 groups. When asked to guess whether the patient had used an oral or enema preparation, the surgeon’s guess coincided with the actual allocation only 52% of the time (k 5 0.04). Results of the quality-of-life questionnaire completed by patients in the preoperative period are given in Table 4. Patients who used the oral preparation experienced significantly more severe symptoms of abdominal bloating and
swelling, weakness, thirst, dizziness, nausea, and fecal incontinence compared with those who used the enema preparation. Compared with the enema group, the oral group reported greater overall discomfort and significantly more difficulty with administration of the preparation. All patients in the enema group and all but 2 in the oral group were able to complete the assigned bowel preparation. The oral group rated preparation as significantly more difficult than the enema group. Significantly more patients in the oral preparation group reported that they would not be willing to undergo the same preparation in the future and would rather try another preparation if they had to undergo surgery again. Discussion Preoperative MBP is a routine procedure that is associated with significant patient burden and discomfort. In the past, the presumed benefit of fewer infectious sequelae was thought to offset the adverse effects and burden experienced by patients. Emerging data from published studies have not shown significant improvements in postoperative complications after MBP. Several trials comparing MBP with no preparation for elective colorectal surgery have not demonstrated reductions in anastomotic complications in both open and laparoscopic
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approaches. There has been some suggestion that the use of such an intervention may be associated with increased rates of anastomotic leakage and wound complications [1,8–10]. Despite the lack of convincing evidence supporting the use of MBP, a recent survey of colorectal surgeons showed that practice trends have not shifted from this longstanding surgical practice. More than 99% of survey respondents reported routine use of MBP [11]. The role of MBP in gynecologic laparoscopy procedures has not been clearly defined, and little has been published about this preoperative practice. For the gynecologic surgeon specializing in laparoscopic procedures, the risks of fecal spillage and subsequent septic and leakage complications inherent in colorectal surgery are generally less applicable. In 2003, Brosens et al [12] reported that diagnostic and minor gynecologic laparoscopy procedures are associated with a 0.08% risk of bowel injury and a 0.33% risk with major gynecologic laparoscopy procedures. Successful surgery relies on adequate visualization and exposure. Laparoscopic surgery involving pelvic structures poses an additional challenge to ensure a satisfactory surgical field, given the bony constraints of the pelvis [7]. The theoretical utility of bowel cleansing before gynecologic laparoscopy procedures is related to its potential ability to optimize visualization of pelvic structures within the surgical field. Bowel loops may compete with pelvic organs for space, interfering with deep pelvic dissection and use of laparoscopic instruments. Bowel manipulation during open surgery is technically feasible with retractors and packing, but may be more difficult with the intrinsic limitations of laparoscopic surgery. Evidence is available from only 1 published trial by Muzii et al [7], and is related predominantly to adnexal and other minor laparoscopic procedures. Thus, the objective of the present study was to investigate the role of MBP in advanced gynecologic laparoscopy procedures including hysterectomy, which often require additional laparoscopic training and pose greater surgical difficulty. The study by Muzii et al [7] found no difference in surgical field quality in patients randomized to MBP vs no MBP. A limitation of the design of the present study is the decision to not use a true control group of patients without any preoperative bowel preparation. This decision was made because of concerns about the unknown potential for significant impairment in surgical visualization during more complicated laparoscopic procedures, which would pose an unacceptable risk for study participants. The study design, comparing a rectal enema with an oral preparation, allowed assessment of whether a simpler and perhaps more tolerable MBP method enables acceptable surgical field conditions. Future studies with inclusion of a control group of patients who do not receive any bowel preparation would yield valuable observations that the present study was not able to provide. Another possible limitation is that not all randomized patients completed the study. Of the 72 patients randomized to
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the oral preparation group, 68 completed the study, and of the 73 patients randomized to the enema preparation, 65 completed the study. Two surgeon questionnaires, both from participants randomized to the oral preparation group, were not completed. To ensure that these missing data were not a source of bias, the number of participants from each group that failed to complete the study was compared, and was not statistically different (p 5 .37). Also analyzed was the primary outcome, overall quality of visualization of the surgical field after initial laparoscopic port placement, using both intent-to-treat and according-to-protocol methods. Neither analysis showed a significant difference in the primary outcome between the 2 groups, which lowers the suspicion of bias due to dropouts. The study demonstrates that MBP with oral NaP offered no significant improvement over the NaP enema regimen in visualization of the surgical field and pelvic structures or handling of the bowel with laparoscopic instruments. For both types of MBP, the overall quality of the surgical field was assessed as either excellent or good in most cases. We believe our study population is more representative of a minimally invasive gynecologic surgery practice than what had previously existed in the literature, which could enable more generalizable results. In contrast to the existing literature, exclusion criteria did not include obesity, history of previous surgery, or patients undergoing hysterectomy. Indeed, 26% of the sample had a body mass index greater than 30, 74% had a history of abdominal or pelvic surgery, and 35% of the surgical procedures performed in the present study were laparoscopic hysterectomies. In assessing operative parameters, no significant differences were observed between the 2 MBP groups. While the number of complications was not significantly different between the 2 groups, in the enema group, 2 patients had postoperative vaginal cuff cellulitis, and 1 had a pelvic abscess. It is not clear that these complications have any relation to the preoperative bowel preparation. The study was not powered to detect differences in complication rates between the 2 groups. Compared with the NaP enema group, patients in the oral NaP group experienced significantly more adverse effects including abdominal bloating and swelling, weakness, thirst, dizziness, nausea, fecal incontinence, and overall discomfort. In addition, the oral regimen was significantly more difficult to administer than the enema preparation, and significantly more patients in the oral preparation group reported that they would not be willing to undergo the same preparation in the future and would rather try another preparation if they had to undergo surgery again. In conclusion, NaP enema may be a reasonable MBP alternative to oral NaP solution in advanced gynecologic laparoscopic procedures because it achieves similar surgical field quality with less patient discomfort. The results of the present investigation serve as a valuable contribution to the limited body of knowledge that currently exists about this common preoperative practice.
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References 1. Platell C, Hall J. What is the role of mechanical bowel preparation in patients undergoing colorectal surgery? Dis Colon Rectum. 1998;41: 875–883. 2. Zmora O, Mahajna A, Bar-Zakai B, et al. Colon and rectal surgery without mechanical bowel preparation: a randomized prospective trial. Ann Surg. 2003;237:363–367. 3. Muzii L, Angioli R, Zullo MA, Calcagno M, Panici PB. Bowel preparation for gynecological surgery. Crit Rev Oncol Hematol. 2003;48:311–315. 4. Oliveira L, Wexner SD, Daniel N, et al. Mechanical bowel preparation for elective colorectal surgery: a prospective, randomized, surgeonblinded trial comparing sodium phosphate and polyethylene glycol– based oral lavage solutions. Dis Colon Rectum. 1997;40:585–591. 5. Cohen SM, Wexner SD, Binderow SR, et al. Prospective, randomized, endoscopic-blinded trial comparing precolonoscopy bowel cleansing methods. Dis Colon Rectum. 1994;37:689–696. 6. Yoshioka K, Connolly AB, Ogunbiyi OA, Hasegawa H, Morton DG, Keighley MR. Randomized trial of oral sodium phosphate compared
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