Laparoscopic nephrectomy in the markedly obese living renal donor

ADULT UROLOGY

LAPAROSCOPIC NEPHRECTOMY IN THE MARKEDLY OBESE LIVING RENAL DONOR STEPHEN C. JACOBS, JR, EUGENE CHO, BRIAN J. DUNKIN, STEPHEN T. BARTLETT, JOHN L. FLOWERS, BRUCE JARRELL, AND STEPHEN C. JACOBS, SR

ABSTRACT Objectives. To determine whether laparoscopic living donor nephrectomy is safe and efficacious in markedly obese renal donors. Methods. From 1996 to 1999, 431 laparoscopic living donor nephrectomies were performed. The markedly obese group consisted of 41 patients with a body mass index (BMI) greater than 35. Forty-one controls with a BMI less than 30 were matched to the obese donors by sex, age, race, and date of surgery. Results. The markedly obese and control groups were closely matched in sex, race, age, serum creatinine level, creatinine clearance, HLA match to recipient, side of donated kidney, and experience level of the surgeons. The obese patients had a BMI range of 35.2 to 53.9 (mean 39.3), and the control patients had a BMI range of 18.4 to 29.0 (mean 24.3). Donor operations in the markedly obese were significantly longer by an average of 40 minutes. The greater intraoperative blood loss and longer extraction incision length seen in the markedly obese did not reach statistical significance. More and larger laparoscopic ports were used in the markedly obese. Obese donors were more likely to require conversion from laparoscopic nephrectomy to open nephrectomy than ideal-sized donors. The postoperative recovery of the gastrointestinal tract, hospitalization time, analgesic requirements, and total complications were equal in the two groups, although the obese donors’ complications tended to be cardiopulmonary problems. The recipient graft function was equivalent between the two groups. Conclusions. Laparoscopic living donor nephrectomy is more difficult to perform in the markedly obese but is associated with an equivalent donor morbidity and recipient renal outcome. UROLOGY 56: 926–929, 2000. © 2000, Elsevier Science Inc.

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he need for living donor kidneys to help alleviate the severe shortage of organs for transplantation has increased in recent years. The number of available cadaver kidneys has stagnated. In the United States, the population has been rapidly becoming heavier, and currently 54.9% of adults 20 years and older are classified as obese.1 As a result, many volunteers for living renal donation are obese. Surgery in obese patients is more difficult from the operative, anesthetic, and postoperative recovery perspectives. Laparoscopic surgery offers a greater potential for decreasing the incisional pain and immobilization for obese patients than for ideal-size patients. However, early experi-

From the Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland Reprint requests: Stephen C. Jacobs, Sr, M.D., University of Maryland Medical Systems, Room S8D18, 22 South Greene Street, Baltimore, MD 21201 Submitted: May 24, 2000, accepted (with revisions): July 18, 2000

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© 2000, ELSEVIER SCIENCE INC. ALL RIGHTS RESERVED

ence with laparoscopic urologic surgery pointed to a higher complication rate in patients with a body mass index (BMI) greater than 30.1.2 More recent experience has shown that the recovery parameters and complication rates may be superior for laparoscopic renal surgery compared with open renal surgery for patients with a BMI greater than 30.3 Is laparoscopic donor nephrectomy safe and efficacious in the obese? To answer this question, experience with laparoscopic nephrectomy in the markedly obese renal donor was compared with the experience with matched contemporaneous control renal donors with ideal body weights. MATERIAL AND METHODS From 1996 to 1999, 431 laparoscopic living donor nephrectomies were performed. The details of the preoperative evaluation and operative technique have been previously reported.4,5 An increased BMI alone was not a criterion for donor exclusion. Postoperative analgesia was by a morphine patientcontrolled analgesic device. The BMI was greater than 30 in 0090-4295/00/$20.00 PII S0090-4295(00)00813-X

TABLE I. Preoperative donor characteristics Donor

n

Age (yr)

BMI (kg/m2)*

Creatinine (mg/dL)

Creatinine Clearance (mL/min)

HLA Match

Obese Control

41 41

36.6 ⫾ 11.4 36.7 ⫾ 11.3

39.3 ⫾ 4.0 24.3 ⫾ 2.8

0.9 ⫾ 0.2 0.9 ⫾ 0.1

121.7 ⫾ 39.2 111.2 ⫾ 41.0

3.0 ⫾ 1.4 3.1 ⫾ 1.5

KEY: BMI ⫽ body mass index. Data presented as the mean ⫾ standard deviation. * P ⬍0.0001; all other differences were not significant.

TABLE II. Intraoperative data Donor

OR Time (min)

Warm Ischemia Time (s)

12-mm Ports

5-mm Ports

Incision Length (cm)

EBL (cc)

Obese Control P value

236.5 ⫾ 60.1 194.7 ⫾ 54.8 ⬍0.01

156.4 ⫾ 46.3 167.2 ⫾ 111.5 NS

2.5 ⫾ 1.0 2.0 ⫾ 1.0 ⬍0.05

1.3 ⫾ 0.6 1.8 ⫾ 0.9 ⬍0.01

7.3 ⫾ 1.4 6.8 ⫾ 1.0 NS

170.1 ⫾ 201.6 112.9 ⫾ 162.4 NS

KEY: OR ⫽ operating room; EBL ⫽ estimated blood loss; NS ⫽ not significant. Data presented as the mean ⫾ standard deviation.

114 donors (26%). The markedly obese group consisted of the 41 patients with a BMI greater than 35. A matched control donor was selected for each markedly obese donor from the pool of 317 patients with a BMI less than 30. The controls were matched in consecutive order to the obese donors by sex, age, race, and date of surgery. Recorded data are expressed as the mean ⫾ standard deviation. Significance was determined by the t test.

RESULTS The markedly obese and control groups were closely matched. The matching between the groups was 97.6% for sex and 92.7% for race, and 85.4% were less than 1 year apart in age. The average obese patient underwent donor nephrectomy 18 ⫾ 320 days before his control donor. Left kidneys were donated, except for two obese patients with a right renal donation. Table I shows the preoperative parameters age, serum creatinine level, creatinine clearance, and HLA match to the recipient, which were similar in the two groups. The obese patients had a BMI range of 35.2 to 53.9, and the control patients had a BMI range of 18.4 to 29.0. The actual body weight of the obese ranged from 80 to 138.2 kg and that of the controls from 61 to 88.4 kg. The intraoperative parameters are detailed in Table II. The donor operations in the markedly obese were significantly longer by an average of 40 minutes. Although the intraoperative blood loss was greater in the markedly obese, the difference was not statistically significant. No donor in either group received a blood transfusion. Similarly, the longer extraction site incision for the markedly obese donors did not reach statistical significance. The difference in the port sizes used was significant. In the obese, the surgeons used more 12-mm laparoscopic ports, rather than 5-mm ports. The UROLOGY 56 (6), 2000

TABLE III. Donor complications Complication Intraoperative Conversion to open nephrectomy Difficult intubation Enterotomy Postoperative Laryngeal edema Shortness of breath Atelectasis Peripheral edema Tachycardia Premature ventricular contractions Retroperitoneal hematoma Right thumb pain Right hip pain Urinary retention Cystitis Epididymitis Peyronie’s disease Incisional hernia Total

Obese Donors

Control Donors

3

0

1 0

0 1

1 1 1 1 1 1

0 0 0 0 0 0

0 0 0 0 0 1 0 1 12

1 1 1 1 1 2 1 1 10

larger ports accept larger lenses, which deliver better intraperitoneal visualization. Table III details the intraoperative and postoperative complications that occurred. Obese donors were more likely to require conversion from laparoscopic nephrectomy to open nephrectomy than ideal-size donors. The procedures of 3 obese donors were converted because of an iliac artery injury, a combination renal venous and arterial injury, and nonprogression of the surgery owing to a difficult bowel retraction. Obesity was described as playing a role in the difficult visualization in these 927

TABLE IV. Donor recovery Donor

MS (mg)*

MS/kg (mg/kg)

Obese Control

106.4 ⫾ 73.3 73.6 ⫾ 45.0

1.0 ⫾ 0.4 1.1 ⫾ 0.8

Oxycodone Tablets (n)

Resumption of Clear Liquid Diet (hr)

Resumption of Regular Diet (hr)

Hospital Stay (hr)

6.8 ⫾ 4.8 4.9 ⫾ 3.4

24.6 ⫾ 10.6 25.0 ⫾ 9.8

46.4 ⫾ 18.9 47.9 ⫾ 13.5

65.3 ⫾ 20.8 65.7 ⫾ 21.2

KEY: MS ⫽ morphine sulfate. Data presented as the mean ⫾ standard deviation. * P ⬍0.05; all other differences were not significant.

3 patients. Postoperative complications were equal in the two groups, although the obese donors’ complications tended to be cardiopulmonary problems. As shown in Table IV, the recovery of the markedly obese donors was equivalent to that of the ideal-size donors. The recovery of the gastrointestinal tract and the hospitalization time were similar. The obese patients gave themselves significantly more morphine using patient-controlled analgesia than the controls, but on a body weight basis, the consumption of morphine was not significantly different. The recipient graft function was equivalent between the two groups. The recipient creatinine value at 1 week was 2.5 ⫾ 2.0 mg% and 2.1 ⫾ 1.7 mg% for obese donors and control donors, respectively. Delayed graft function (DGF) was seen in two kidneys from obese donors and one from a control donor. COMMENT Obese patients in general are expected to have more complications, particularly of wound, pulmonary, and cardiovascular origin. Laparoscopic surgery is appealing in the obese because wound complications are reduced, pulmonary restriction due to pain is lessened, and early ambulation is improved. Obese patients who undergo laparoscopic surgery have been reported to have more intraoperative complications. For example, in many, but not all, series, the conversion rate for laparoscopic cholecystectomy,6 – 8 laparoscopic colectomy,9 and laparoscopic pelvic surgery10 –12 increases with the BMI. The reasons for this may be the decreased ability to see organs, vessels, or tissue planes covered with intra-abdominal fat. Robinson et al.13 reported that the increased thickness of the abdominal wall required an increased force to move the operating instrument tip, causing a decreased sensitivity felt by the surgeon. Insufflation of the abdomen with carbon dioxide is more difficult in the supine obese patient and results in more failures to insufflate. The flank position, however, allows abdominal subcutaneous fat to fall away from the 928

operative field, and failure to insufflate was not seen in the present series. The experience of the surgical team is important. An early (1995) multi-institutional report on laparoscopic nephrectomy showed that 71% of complications occurred in the first 20 cases done at an institution.2 In the current series, the matching of control patients to the markedly obese ensured that surgical experience of the team was equivalent in the two groups. From the total series of 431 donors, the conversions of the markedly obese patients to open nephrectomy were for patients 55, 65, and 371 (the 5th, 7th, and 34th markedly obese patient). The conversion rate for markedly obese donors was thus 7.3%. By comparison, although no control patients required conversion, the conversion rate for all patients with a BMI less than 35 (n ⫽ 390) was 1.3%. Adequate visualization was a major component of the decision to convert to open nephrectomy in the markedly obese patients, but not so in those not markedly obese. The difference in estimated blood loss (EBL) in the two groups did not reach statistical significance (P ⬎ 0.1) principally because of the wide standard deviations. If the patient with the largest EBL from each group was removed from consideration, the difference in EBL was significant (P ⫽ 0.015), and it certainly is the surgeon’s perspective that the markedly obese do lose somewhat more blood intraoperatively. Again, however, on a per-kilogram basis, the difference disappears. Otherwise, the markedly obese in this series had the same incidence of overall complications and an equivalent morbidity. Obese patients who undergo laparoscopic general urologic surgery have previously been noted to have a higher complication rate, longer operative time, and higher conversion rate.2 However, a laparoscopic approach did show an advantage over open surgery in a series of renal/adrenal cases by the Cleveland Clinic group.3 Kuo et al.14 recently reported a small series of laparoscopic renal donors (n ⫽ 12) with a BMI greater than 30 who had no differences compared with the nonobese donors, except for a slightly longer hospital stay of one-half day. The current series shows that a longer operaUROLOGY 56 (6), 2000

tive time, an increased port size requirement, a higher conversion rate, and an increased EBL of minor importance should be expected for markedly obese patients undergoing laparoscopic living donor nephrectomy. However, given the degree of obesity in these patients, with an average BMI of 39, the differences seen were fairly small, and the procedure of laparoscopic donor nephrectomy itself appears appropriate to consider for the markedly obese renal donor. ACKNOWLEDGMENT. To transplant coordinators Jessica Wilson, R.N., Lynn Heron, R.N., and Deborah Evans, R.N., who evaluated all of the donors both physically and psychologically before the renal transplants; and to Paula Buttner, R.N. and Sherry Dixon, who contributed substantial experience and expertise to the surgical procedures. REFERENCES 1. Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults. NIH Publication No. 98-4083. Bethesda, Maryland, National Institutes of Health, June 1998, p vii. 2. Mendoza D, Newman RC, Abala DM, et al: Laparoscopic complications in markedly obese urologic patients (a multi-institutional review). Urology 48: 562–567, 1996. 3. Fazelli-Matin S, Gill IS, Hsu THS, et al: Laparoscopic renal and adrenal surgery in obese patients: comparison to open surgery. J Urol 162: 665– 669, 1999. 4. Flowers JL, Jacobs SC, Cho E, et al: Comparison of open and laparoscopic live donor nephrectomy. Ann Surg 226: 483– 490, 1997. 5. Jacobs SC, Cho E, and Dunkin BJ: Laparoscopic donor nephrectomy: current role in renal allograft procurement. Urology 55: 807– 811, 2000. 6. Liu C, Fan S, Lai ECS, et al: Factors affecting conversion of laparoscopic cholecystectomy to open surgery. Arch Surg 131: 98 –101, 1996. 7. Alponat A, Kum CK, Koh BC, et al: Predictive factors for conversion of laparoscopic cholecystectomy. World J Surg 21: 629 – 633, 1997. 8. Phillips EH, Carroll BJ, Fallas MJ, et al: Comparison of laparoscopic cholecystectomy in obese and non-obese patients. Am Surg 60: 316 –321, 1994. 9. Schwandner O, Schiedeck TH, and Bruch H: The role of conversion in laparoscopic colorectal surgery: do predictive factors exist? Surg Endosc 13: 151–156, 1999. 10. Ostrezenski A: Laparoscopic total abdominal hysterectomy in morbidly obese women: a pilot-phase report. J Reprod Med 44: 853– 858, 1999. 11. Eltabbakh GH, Piver MS, Hempling RE, et al: Laparoscopic surgery in obese women. Obstet Gynecol 94: 704 –708, 1999. 12. Frankel J: Marked obesity and laparoscopic bladder neck suspension. Urology 50: 657, 1997.

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13. Robinson SP, Hirtle M, Imbrie JZ, et al: The mechanics underlying laparoscopic intra-abdominal surgery for obese patients. J Laparoendosc Adv Surg Tech A 8: 11–18, 1998. 14. Kuo PC, Plotkin JS, Stevens S, et al: Outcomes of laparoscopic donor nephrectomy in obese patients. Transplantation 69: 180 –182, 2000. EDITORIAL COMMENT This article demonstrates the feasibility of performing laparoscopic renal surgery in markedly obese individuals. Similar to “standard” patients, obese donors benefit from the lower amount of postoperative pain and the quicker convalescence associated with a laparoscopic approach. They also validate the difficulties encountered when applying laparoscopy to treat surgical pathologic features in obese people. The larger body size can increase the risk of intraoperative complications owing to difficulties with exposure and visualization. Vascular injuries are more likely to occur and can result in the need for open conversion. Several key points need to be emphasized to safely approach obese patients. Significant laparoscopic experience is recommended, as obese patients offer unique challenges related to organ exposure and visualization. The kidney should be accessed with the patient in a flank position to shift the panus medially. This maneuver will shorten the distance from the skin to the abdominal cavity. The use of longer trocars and instrumentation will permit optimal access to the operative field. In addition, one should avoid placing trocars through the panus by shifting trocar placement laterally. This will reduce mechanical resistance when manipulating the trocars and optimize visualization by moving the lens laterally to the bowel and omentum. Dissection should be slow and deliberate, with extra care taken to maintain orientation and identify structures before transection. Meticulous hemostasis is required, as injured vessels can retract and be difficult to locate in the fat. Most importantly, to avoid a catastrophic outcome, a plan for open conversion needs to be mapped out before initiating the procedure. The large body size will present challenges in rapidly performing an emergent laparotomy. Advances in video technology and instrument design have now allowed complex minimally invasive surgical procedures to be offered to patients with challenging body habiti. The authors illustrate that with experience, patience, and planning, laparoscopic donor nephrectomy can be safely offered to obese individuals.

Louis R. Kavoussi, M.D. Department of Urology Johns Hopkins Medical Institutions Baltimore, Maryland PII S0090-4295(00)00814-1 © 2000, ELSEVIER SCIENCE INC ALL RIGHTS RESERVED

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