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Enterocystoplasty vs Detrusorectomy: Outcome in the Adult with Spina Bifida
Enterocystoplasty vs Detrusorectomy: Outcome in the Adult with Spina Bifida Paul W. Veenboer,* Sven Nadorp, Tom P. V. M. de Jong, Pieter Dik, Floris W. A. van Asbeck, J. L. H. Ruud Bosch and Laetitia M. O. de Kort From the Department of Urology (PWV, SN, JLHRB, LMOdeK) and Department of Rehabilitation (FWAvanA), University Medical Center Utrecht, Utrecht and Pediatric Urology Center, University Children’s Hospitals, Wilhelmina Kinderziekenhuis Utrecht/Emma Kinderziekenhuis, Amsterdam (TPVMdeJ, PD), The Netherlands
Abbreviations and Acronyms BV ⫽ bladder volume CIC ⫽ clean intermittent catheterization EFP ⫽ end filling pressure GFR ⫽ glomerular filtration rate SB ⫽ spina bifida UTI ⫽ urinary tract infection Accepted for publication August 20, 2012. * Correspondence: Department of Urology, University Medical Center Utrecht, Room C.04.236, Heidelberglaan 100, P. O. Box 85500, 3508 GA Utrecht, Utrecht, The Netherlands (telephone: 00-31-887553348; e-mail: P.W.Veenboer-2@ umcutrecht.nl).
Purpose: Bladder augmentation by enterocystoplasty or detrusorectomy might prevent renal damage, help achieve dryness and decrease the need for antimuscarinics. We compared the long-term outcomes of enterocystoplasty and detrusorectomy in adults with spina bifida. Materials and Methods: A retrospective study using the hospital electronic database was performed. We identified 47 patients with spina bifida (median age at followup 26.8 years) who underwent either enterocystoplasty or detrusorectomy between 1988 and 2004. Median followup was 13.1 years in the detrusorectomy group and 15.3 years in the enterocystoplasty group. Results: In the detrusorectomy group 4 patients with treatment failure were identified. All 4 patients underwent secondary enterocystoplasty. No reoperation was necessary in the enterocystoplasty group. Preoperative bladder volume was approximately 100 ml higher in the detrusorectomy group (not significant). There was a significantly greater improvement of median bladder volume in the enterocystoplasty group (increase of 300 vs 77.5 ml, p ⫽ 0.006). No differences in continence rate, antimuscarinic use or condition of the upper tract were found. Conclusions: In this series of 47 patients long-term outcomes were good after enterocystoplasty and detrusorectomy, although bladder volume exhibited a greater increase in the enterocystoplasty group. No differences were observed among the other outcomes. If preoperative bladder volume is sufficient, detrusorectomy can be considered before enterocystoplasty is done. Key Words: spinal dysraphism; urinary bladder, neurogenic; urologic surgical procedures
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www.jurology.com
IN the spina bifida population with neurogenic bladder a limited bladder volume, low compliance and high pressures due to detrusor overactivity could cause problems in the upper and lower urinary tracts. Bladder augmentation in these patients serves the goals of 1) reducing pressures in the bladder and thereby protecting the kidneys, 2) achieving dryness and 3) decreasing the need for antimuscarinic agents. In the 1960s and 1970s most patients with
spina bifida underwent urinary diversion (eg ileal conduit) to protect the kidneys and treat urinary incontinence. Today detrusorectomy (also called autoaugmentation, which involves removing part of the detrusor muscle and thereby creating a pseudodiverticulum) or enterocystoplasty (adding an enteric segment to the bladder) is performed in these patients. Successful detrusorectomy was first reported in 1989 and has since been
0022-5347/13/1893-1066/0 THE JOURNAL OF UROLOGY® © 2013 by AMERICAN UROLOGICAL ASSOCIATION EDUCATION
http://dx.doi.org/10.1016/j.juro.2012.08.258 Vol. 189, 1066-1070, March 2013 RESEARCH, INC. Printed in U.S.A.
AND
ENTEROCYSTOPLASTY VS DETRUSORECTOMY IN ADULTS WITH SPINA BIFIDA
used with varying success rates.1,2 Proposed benefits in comparison to enterocystoplasty are the absence of mucous production and decreased incidence of stone formation, infections and electrolyte disturbances. Detrusorectomy is less invasive than ileocystoplasty and does not carry the risk of intestinal complications. Also since the pseudodiverticulum created with detrusorectomy is lined with transitional cell epithelium, the risk of malignancy is supposedly less.3 When comparing the 2 techniques, the question arises of whether detrusorectomy is sufficient or whether enterocystoplasty, although more complicated, is better in terms of continence and preservation of the upper tracts. To our knowledge no previous study has examined the long-term results of enterocystoplasty and detrusorectomy in comparable and concurrent cohorts. We examined the long-term clinical (eg use of antimuscarinics, kidney function, frequency of CIC) and urodynamic outcomes in an adult population with SB.
MATERIALS AND METHODS We analyzed 260 patients who were being followed at the adult spina bifida outpatient clinic between March 1999 and March 2009. This is a special clinic at our institution that is managed by a rehabilitation physician in conjunction with a urologist who checks these patients every 18 to 24 months, depending on their functional status. Of the patients 48 (18.5%) had undergone bladder intervention, with detrusorectomy being performed in 26 (10.0%) and enterocystoplasty in 22 (8.5%). One patient in the enterocystoplasty group was lost to followup after the first postoperative visit and, therefore, was excluded from further analysis, leaving 21 patients in that group. Median age at surgery was 14.0 years (IQR 11.0 –17.0). Procedures were performed between 1988 and 2006 at various centers, although mostly at our institution (especially in case of detrusorectomy). Data on the last preoperative urodynamic studies were retrieved. If not available at our hospital, other institutions were contacted to retrieve the data after written permission was obtained from the patient. Preoperatively BV was measured cystoscopically with the patient under anesthesia, and the capacity was used for making the decision as to which procedure to perform. Since most patients were operated on during puberty (when an adult BV was expected) absolute BV (ml) was reported instead of relative BV expected for age. Bladder compliance was retrieved as a numerical value (ml/cm H2O). Categories of compliance (poor, borderline and good) were also used, since they are generally used in daily practice. Compliance was considered improved if a patient went from poor or borderline compliance to borderline or good compliance postoperatively. End filling pressures were defined as detrusor pressure in cm H2O (detrusor pressure ⫽ bladder pressure - abdominal pressure) at the end of the filling phase during filling cystometry. EFP was chosen instead of leak point pressure be-
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cause leakage did not always occur. In most cases EFP equals the leak point pressure. The same method was used with postoperative urodynamic parameters. Postoperative parameters were retrieved from the most recent filling cystometry studies found. Detrusor overactivity of preoperative and postoperative urodynamic investigations, defined as any involuntary detrusor contraction during the filling phase, was noted. Condition of the upper tract was determined by ultrasound of the kidneys and serum creatinine. Findings of upper urinary tract ultrasonography were subdivided into 5 categories, which consisted of 1) no dilatation or scarring, 2) unilateral dilatation, 3) bilateral dilatation, 4) cortical scarring and 5) shrunken kidney. For renal function we retrieved the most recent serum creatinine values. We did not calculate GFR because none of the formulas used to calculate GFR is validated in this group of patients, and GFR estimations in these patients are often unreliable. Although 24-hour urine collection could overcome this problem, this evaluation was not available for any of the patients. Incontinence was subdivided into completely dry, socially continent (minimal urine loss or use of 1 pad daily) and incontinent. Any history of urolithiasis (kidney or bladder) during followup was reported. UTIs were subdivided into no clinical symptoms, and infrequent (less than 3 episodes yearly) and frequent infections (more than 3 episodes yearly).4 Patients who underwent enterocystoplasty after failed detrusorectomy were initially analyzed in the detrusorectomy group. Followup time was counted from detrusorectomy till enterocystoplasty. Clinical outcomes were compared using a 2-tailed Fisher exact test and contingency tables in case of discrete data. In case of more than 2 types of outcome a Pearson chi-square test was used. MannWhitney U test was used to compare 2 continuous variables and Kruskal-Wallis test for more than 2 continuous variables. Differences were considered statistically significant when the p value was less than 0.05. For statistical analysis commercially available software (SPSS®, version 20.0) was used. Most patients were operated on during puberty (median age 13.1 years at detrusorectomy and 15.3 years at enterocystoplasty). Patients were not randomized. Basically detrusorectomy was intended, and enterocystoplasty was performed only if detrusorectomy was not feasible (BV less than 80% of expected capacity for age).5 Surgeon preference and condition of the bladder wall also factored into decision making. A lower abdominal incision (Pfannenstiel) was made to enter the abdomen, and detrusor muscle tissue was removed. Cycling of the bladder started as soon as possible on postoperative day 1. For enterocystoplasty clam ileocystoplasty was performed in all but 2 cases, in which colocystoplasty was done. A 25 cm long ileum segment was isolated, after which a U-shaped cap was created to form a new bladder dome. In 1 patient sigmoidocystoplasty was done because of a short ileal mesenterium with severe lumbar lordosis. In 26 patients with a low leak point pressure the procedure was combined with a fascial sling procedure.
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ENTEROCYSTOPLASTY VS DETRUSORECTOMY IN ADULTS WITH SPINA BIFIDA
RESULTS Urodynamic and clinical outcomes are summarized in supplementary tables 1 and 2 (http://www.jurology. com), respectively. Of the 47 patients analyzed 26 had undergone detrusorectomy and 21 enterocystoplasty. In the detrusorectomy group 15 patients (57.5%) were male, and 25 (96.2%) had myelomeningocele and 1 occult SB. In the enterocystoplasty group 10 patients (47.6%) were male, and 19 (90.5%) had myelomeningocele and 2 occult SB. One female in the detrusorectomy group died during followup at age 32 years due to locally advanced bladder carcinoma.6 Three additional patients died during followup due to unrelated (nonurological) causes. Treatment failed in 4 patients (15.4%) who initially underwent detrusorectomy. These patients, who had a smaller BV postoperatively than preoperatively as well as poor compliance and persistent leakage, subsequently underwent enterocystoplasty. All 4 patients did well after reoperation. In another patient from the detrusorectomy group with recurrent strictures of the urethra and stenosis of the ureterovesical junction an Indiana pouch was constructed. In the enterocystoplasty group no reoperations were necessary. Median followup was 13.1 years in the detrusorectomy group and 15.3 years in the enterocystoplasty group (not significant). Urodynamic parameters are summarized in supplementary table 1 (jurology.com). Median preoperative BV was greater in the detrusorectomy group (297.5 vs 200.0 ml, not significant). There were no significant differences in preoperative detrusor overactivity, EFP or compliance. Postoperative BV did not differ between the groups, although there was a trend toward higher postoperative BV in the enterocystoplasty group. Median improvement in bladder capacity postoperatively was significantly greater in the enterocystoplasty group than in the detrusorectomy group (300.0 vs 77.5 ml, p ⫽ 0.006). More patients in the enterocystoplasty group had better compliance postoperatively (81% vs 46.2%, p ⫽ 0.019), although median improvement of compliance did not differ between the groups. Postoperative EFP and median improvement of EFP were not significantly different, although a trend toward lower EFP and more improvement of EFP was observed in the enterocystoplasty group. Clinical outcomes are summarized in supplementary table 2 (jurology.com). Median age in the enterocystoplasty group was significantly greater than in the detrusorectomy group (p ⫽ 0.002). Good longterm outcomes were noted in the upper and lower urinary tracts. End-stage renal disease did not manifest clinically in any patient. There were no significant differences between the 2 groups regarding postoperative ultrasonography findings. All abnor-
mal ultrasonography findings already existed preoperatively, and no new abnormalities were found. There was a trend toward a higher median serum creatinine in the enterocystoplasty group. There were no differences in continence, occurrence of UTIs or urolithiasis, frequency of CIC or use of prophylactic antibiotics between the groups. In the detrusorectomy group 21 patients (80.8%) were socially dry, as were 20 patients (95.2%) in the enterocystoplasty group. Postoperatively there was no significant difference in antimuscarinic drug use between the groups (76.9% for detrusorectomy vs 19.0% for enterocystoplasty, p ⫽ 0.003). An additional fascial sling procedure was performed in 65.4% and 42.9% of patients in the detrusorectomy and enterocystoplasty groups, respectively (not significant). The level of the lesion had no influence on outcome when analyzed separately for the 2 groups.
DISCUSSION Detrusorectomy and enterocystoplasty are the most commonly used forms of bladder surgery and have replaced the need for ileal conduits in patients with SB. To our knowledge this is the first study of the long-term outcomes of detrusorectomy and enterocystoplasty in comparable groups. Comparing enterocystoplasty and detrusorectomy is important because of the supposed disadvantages of enterocystoplasty. Enterocystoplasty involves isolating an enteric segment and thus interrupting the continuity of the gastrointestinal tract, carrying a greater risk of gastrointestinal complications such as postoperative ileus and leakage of the anastomosis. An incorporated enteric segment produces mucus and absorbs electrolytes and other metabolites from the urine, which may cause metabolic disturbances, malignancies and stone disease. Detrusorectomy is a much less invasive intervention that involves only the removal of muscle tissue of the bladder dome, without entering the peritoneal cavity. Therefore, if detrusorectomy appears to be as successful as enterocystoplasty, this technique is to be preferred, given the lower risk of postoperative complications in the shorter and longer terms. In both treatment groups we found a clinically stable upper urinary tract and comparable results concerning continence rates, although detrusorectomy failed in 4 patients and enterocystoplasty was always successful. Also there was no difference in the frequency of CIC, use of antimuscarinics or occurrence of UTIs. The most important finding of this study was that preoperative BV was larger in the detrusorectomy group, and the increase in BV was
ENTEROCYSTOPLASTY VS DETRUSORECTOMY IN ADULTS WITH SPINA BIFIDA
greater after enterocystoplasty, indicating that only bladders with a reasonable volume are suitable for detrusorectomy. Our findings are only partly consistent with earlier reports. According to the literature, detrusorectomy is not as successful as enterocystoplasty, and some authors even argue against the use of detrusorectomy.7 Success rates with detrusorectomy reportedly range from 7% to 80%.8 –14 However, these studies did not compare enterocystoplasty and detrusorectomy in the same cohort. Our study was not randomized. In patients with a BV that was too small enterocystoplasty was chosen and not detrusorectomy, as is reflected in the difference in preoperative BV between the groups. Detrusorectomy may be suitable for patients with a fairly good preoperative BV. At our institution 80% of expected capacity for age was used as a threshold, although this cutoff is rather arbitrary. To confirm this threshold value, a randomized study has to be done. No impairment of renal function was found. The upper tract was investigated by ultrasonography, which is considered sufficiently reliable.15 Creatinine is less reliable in patients with neuromuscular disease because less muscle mass is present, although a median creatinine level can still give an indication of kidney functioning. The trend toward a higher median serum creatinine in the enterocystoplasty group is probably related to reuptake of creatinine by the bowel segment in the bladder. A limitation of this study is its retrospective nature, with survival bias possibly influencing the results. A review of the entire cohort of children who presented at our pediatric renal center between 1986 and 2001 (reviewed by Dik et al16) revealed that only 3 of 143 did not survive until March 2012 (overall survival rate 97.9%). All of these cases were managed by CIC and antimuscarinics from birth onward, with surgical intervention only if conservative measures were insufficient to preserve lower
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and upper tract function. These data imply that the patients included in our series consist of those who were not doing well enough with conservative measures. These patients carry a worse prognosis than those who did not have to undergo surgery. A small number of patients included in this study were originally operated on elsewhere. However, we have no data from other centers in The Netherlands concerning survival into adulthood. From the literature it can be derived that currently 50% to 80% of all patients with SB reach adulthood.17–19 Another limitation is that both surgical groups were relatively small, which may have led to under powering and may contribute to the fact that not many differences were observed between the 2 groups. Moreover, since data in our small groups were not normally divided, nonparametric tests had to be used, which are less powerful in detecting significant differences. The most important information emerging from our study is that in patients with (congenital) neurogenic bladder disorder if an indication for bladder augmentation exists, detrusorectomy may be considered before performing enterocystoplasty, given its comparable longterm outcomes and its less invasive nature.
CONCLUSIONS In our series of 47 patients long-term clinical outcomes were good after enterocystoplasty and detrusorectomy, with 4 failures (all detrusorectomy) that necessitated reoperation. Since there was no difference in outcomes except for a smaller increase in capacity, we conclude that detrusorectomy may be preferable over enterocystoplasty (taking into account the invasiveness of the procedure), provided the bladder capacity is sufficient.
ACKNOWLEDGMENTS Esther Kok provided statistical and methodological advice.
REFERENCES 1. Cartwright PC and Snow BW: Bladder autoaugmentation: partial detrusor excision to augment the bladder without use of bowel. J Urol 1989; 142: 1050. 2. Dik P, Tsachouridis GD, Klijn AJ et al: Detrusorectomy for neuropathic bladder in patients with spinal dysraphism. J Urol 2003; 170: 1351. 3. Lindley RM, Mackinnon AE, Shipstone D et al: Long-term outcome in bladder detrusorectomy augmentation. Eur J Pediatr Surg, suppl., 2003; 13: S7. 4. O’Reilly M: Recurrent urinary tract infections. In: Urinary Tract Infection in the Female. Edited by
SL Stanton and PL Dwyer. London: Martin Dunitz 2000; pp 227–240. 5. Chrzan R, Dik P, Klijn AJ et al: Detrusorectomy reduces the need for augmentation and use of antimuscarinics in children with neuropathic bladders. J Pediatr Urol 2012; Epub ahead of print. 6. Veenboer PW and de Kort LM: Bladder carcinoma in a 31-year-old female spina bifida patient with an auto-augmented bladder. Int Urol Nephrol 2012; 44: 1027. 7. Karsenty G, Vidal F, Ruffion A et al: Treatment of neurogenic detrusor hyperactivity: detrusor myomectomy. Prog Urol 2007; 17: 580.
8. Kennelly MJ, Gormley EA and McGuire EJ: Early clinical experience with adult bladder auto-augmentation. J Urol 1994; 152: 303. 9. Stohrer M, Kramer A, Goepel M et al: Bladder auto-augmentation—an alternative for enterocystoplasty: preliminary results. Neurourol Urodyn 1995; 14: 11. 10. Stohrer M, Kramer G, Goepel M et al: Bladder autoaugmentation in adult patients with neurogenic voiding dysfunction. Spinal Cord 1997; 35: 456.
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11. Westney OL and McGuire EJ: Surgical procedures for the treatment of urge incontinence. Tech Urol 2001; 7: 126. 12. Marte A, Di Meglio D, Cotrufo AM et al: A long-term follow-up of autoaugmentation in myelodysplastic children. BJU Int 2002; 89: 928. 13. MacNeily AE, Afshar K, Coleman GU et al: Autoaugmentation by detrusor myotomy: its lack of effectiveness in the management of congenital neuropathic bladder. J Urol 2003; 170: 1643.
14. Aslam MZ and Agarwal M: Detrusor myectomy: long-term functional outcomes. Int J Urol 2012; 19: 1099. 15. Abrahamsson K, Jodal U, Stokland E et al: Ultrasonography to visualize the upper urinary tract in children with meningomyelocele. BJU Int 2006; 98: 858. 16. Dik P, Klijn AJ, van Gool JD et al: Early start to therapy preserves kidney function in spina bifida patients. Eur Urol 2006; 49: 908.
17. Bowman RM, McLone DG, Grant JA et al: Spina bifida outcome: a 25-year prospective. Pediatr Neurosurg 2001; 34: 114. 18. Tennant PW, Pearce MS, Bythell M et al: 20-Year survival of children born with congenital anomalies: a population-based study. Lancet 2010; 375: 649. 19. Hunt GM and Oakeshott P: Outcome in people with open spina bifida at age 35: prospective community based cohort study. BMJ 2003; 326: 1365.
Abbreviations and Acronyms BV ⫽ bladder volume CIC ⫽ clean intermittent catheterization EFP ⫽ end filling pressure GFR ⫽ glomerular filtration rate SB ⫽ spina bifida UTI ⫽ urinary tract infection Accepted for publication August 20, 2012. * Correspondence: Department of Urology, University Medical Center Utrecht, Room C.04.236, Heidelberglaan 100, P. O. Box 85500, 3508 GA Utrecht, Utrecht, The Netherlands (telephone: 00-31-887553348; e-mail: P.W.Veenboer-2@ umcutrecht.nl).
Purpose: Bladder augmentation by enterocystoplasty or detrusorectomy might prevent renal damage, help achieve dryness and decrease the need for antimuscarinics. We compared the long-term outcomes of enterocystoplasty and detrusorectomy in adults with spina bifida. Materials and Methods: A retrospective study using the hospital electronic database was performed. We identified 47 patients with spina bifida (median age at followup 26.8 years) who underwent either enterocystoplasty or detrusorectomy between 1988 and 2004. Median followup was 13.1 years in the detrusorectomy group and 15.3 years in the enterocystoplasty group. Results: In the detrusorectomy group 4 patients with treatment failure were identified. All 4 patients underwent secondary enterocystoplasty. No reoperation was necessary in the enterocystoplasty group. Preoperative bladder volume was approximately 100 ml higher in the detrusorectomy group (not significant). There was a significantly greater improvement of median bladder volume in the enterocystoplasty group (increase of 300 vs 77.5 ml, p ⫽ 0.006). No differences in continence rate, antimuscarinic use or condition of the upper tract were found. Conclusions: In this series of 47 patients long-term outcomes were good after enterocystoplasty and detrusorectomy, although bladder volume exhibited a greater increase in the enterocystoplasty group. No differences were observed among the other outcomes. If preoperative bladder volume is sufficient, detrusorectomy can be considered before enterocystoplasty is done. Key Words: spinal dysraphism; urinary bladder, neurogenic; urologic surgical procedures
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www.jurology.com
IN the spina bifida population with neurogenic bladder a limited bladder volume, low compliance and high pressures due to detrusor overactivity could cause problems in the upper and lower urinary tracts. Bladder augmentation in these patients serves the goals of 1) reducing pressures in the bladder and thereby protecting the kidneys, 2) achieving dryness and 3) decreasing the need for antimuscarinic agents. In the 1960s and 1970s most patients with
spina bifida underwent urinary diversion (eg ileal conduit) to protect the kidneys and treat urinary incontinence. Today detrusorectomy (also called autoaugmentation, which involves removing part of the detrusor muscle and thereby creating a pseudodiverticulum) or enterocystoplasty (adding an enteric segment to the bladder) is performed in these patients. Successful detrusorectomy was first reported in 1989 and has since been
0022-5347/13/1893-1066/0 THE JOURNAL OF UROLOGY® © 2013 by AMERICAN UROLOGICAL ASSOCIATION EDUCATION
http://dx.doi.org/10.1016/j.juro.2012.08.258 Vol. 189, 1066-1070, March 2013 RESEARCH, INC. Printed in U.S.A.
AND
ENTEROCYSTOPLASTY VS DETRUSORECTOMY IN ADULTS WITH SPINA BIFIDA
used with varying success rates.1,2 Proposed benefits in comparison to enterocystoplasty are the absence of mucous production and decreased incidence of stone formation, infections and electrolyte disturbances. Detrusorectomy is less invasive than ileocystoplasty and does not carry the risk of intestinal complications. Also since the pseudodiverticulum created with detrusorectomy is lined with transitional cell epithelium, the risk of malignancy is supposedly less.3 When comparing the 2 techniques, the question arises of whether detrusorectomy is sufficient or whether enterocystoplasty, although more complicated, is better in terms of continence and preservation of the upper tracts. To our knowledge no previous study has examined the long-term results of enterocystoplasty and detrusorectomy in comparable and concurrent cohorts. We examined the long-term clinical (eg use of antimuscarinics, kidney function, frequency of CIC) and urodynamic outcomes in an adult population with SB.
MATERIALS AND METHODS We analyzed 260 patients who were being followed at the adult spina bifida outpatient clinic between March 1999 and March 2009. This is a special clinic at our institution that is managed by a rehabilitation physician in conjunction with a urologist who checks these patients every 18 to 24 months, depending on their functional status. Of the patients 48 (18.5%) had undergone bladder intervention, with detrusorectomy being performed in 26 (10.0%) and enterocystoplasty in 22 (8.5%). One patient in the enterocystoplasty group was lost to followup after the first postoperative visit and, therefore, was excluded from further analysis, leaving 21 patients in that group. Median age at surgery was 14.0 years (IQR 11.0 –17.0). Procedures were performed between 1988 and 2006 at various centers, although mostly at our institution (especially in case of detrusorectomy). Data on the last preoperative urodynamic studies were retrieved. If not available at our hospital, other institutions were contacted to retrieve the data after written permission was obtained from the patient. Preoperatively BV was measured cystoscopically with the patient under anesthesia, and the capacity was used for making the decision as to which procedure to perform. Since most patients were operated on during puberty (when an adult BV was expected) absolute BV (ml) was reported instead of relative BV expected for age. Bladder compliance was retrieved as a numerical value (ml/cm H2O). Categories of compliance (poor, borderline and good) were also used, since they are generally used in daily practice. Compliance was considered improved if a patient went from poor or borderline compliance to borderline or good compliance postoperatively. End filling pressures were defined as detrusor pressure in cm H2O (detrusor pressure ⫽ bladder pressure - abdominal pressure) at the end of the filling phase during filling cystometry. EFP was chosen instead of leak point pressure be-
1067
cause leakage did not always occur. In most cases EFP equals the leak point pressure. The same method was used with postoperative urodynamic parameters. Postoperative parameters were retrieved from the most recent filling cystometry studies found. Detrusor overactivity of preoperative and postoperative urodynamic investigations, defined as any involuntary detrusor contraction during the filling phase, was noted. Condition of the upper tract was determined by ultrasound of the kidneys and serum creatinine. Findings of upper urinary tract ultrasonography were subdivided into 5 categories, which consisted of 1) no dilatation or scarring, 2) unilateral dilatation, 3) bilateral dilatation, 4) cortical scarring and 5) shrunken kidney. For renal function we retrieved the most recent serum creatinine values. We did not calculate GFR because none of the formulas used to calculate GFR is validated in this group of patients, and GFR estimations in these patients are often unreliable. Although 24-hour urine collection could overcome this problem, this evaluation was not available for any of the patients. Incontinence was subdivided into completely dry, socially continent (minimal urine loss or use of 1 pad daily) and incontinent. Any history of urolithiasis (kidney or bladder) during followup was reported. UTIs were subdivided into no clinical symptoms, and infrequent (less than 3 episodes yearly) and frequent infections (more than 3 episodes yearly).4 Patients who underwent enterocystoplasty after failed detrusorectomy were initially analyzed in the detrusorectomy group. Followup time was counted from detrusorectomy till enterocystoplasty. Clinical outcomes were compared using a 2-tailed Fisher exact test and contingency tables in case of discrete data. In case of more than 2 types of outcome a Pearson chi-square test was used. MannWhitney U test was used to compare 2 continuous variables and Kruskal-Wallis test for more than 2 continuous variables. Differences were considered statistically significant when the p value was less than 0.05. For statistical analysis commercially available software (SPSS®, version 20.0) was used. Most patients were operated on during puberty (median age 13.1 years at detrusorectomy and 15.3 years at enterocystoplasty). Patients were not randomized. Basically detrusorectomy was intended, and enterocystoplasty was performed only if detrusorectomy was not feasible (BV less than 80% of expected capacity for age).5 Surgeon preference and condition of the bladder wall also factored into decision making. A lower abdominal incision (Pfannenstiel) was made to enter the abdomen, and detrusor muscle tissue was removed. Cycling of the bladder started as soon as possible on postoperative day 1. For enterocystoplasty clam ileocystoplasty was performed in all but 2 cases, in which colocystoplasty was done. A 25 cm long ileum segment was isolated, after which a U-shaped cap was created to form a new bladder dome. In 1 patient sigmoidocystoplasty was done because of a short ileal mesenterium with severe lumbar lordosis. In 26 patients with a low leak point pressure the procedure was combined with a fascial sling procedure.
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ENTEROCYSTOPLASTY VS DETRUSORECTOMY IN ADULTS WITH SPINA BIFIDA
RESULTS Urodynamic and clinical outcomes are summarized in supplementary tables 1 and 2 (http://www.jurology. com), respectively. Of the 47 patients analyzed 26 had undergone detrusorectomy and 21 enterocystoplasty. In the detrusorectomy group 15 patients (57.5%) were male, and 25 (96.2%) had myelomeningocele and 1 occult SB. In the enterocystoplasty group 10 patients (47.6%) were male, and 19 (90.5%) had myelomeningocele and 2 occult SB. One female in the detrusorectomy group died during followup at age 32 years due to locally advanced bladder carcinoma.6 Three additional patients died during followup due to unrelated (nonurological) causes. Treatment failed in 4 patients (15.4%) who initially underwent detrusorectomy. These patients, who had a smaller BV postoperatively than preoperatively as well as poor compliance and persistent leakage, subsequently underwent enterocystoplasty. All 4 patients did well after reoperation. In another patient from the detrusorectomy group with recurrent strictures of the urethra and stenosis of the ureterovesical junction an Indiana pouch was constructed. In the enterocystoplasty group no reoperations were necessary. Median followup was 13.1 years in the detrusorectomy group and 15.3 years in the enterocystoplasty group (not significant). Urodynamic parameters are summarized in supplementary table 1 (jurology.com). Median preoperative BV was greater in the detrusorectomy group (297.5 vs 200.0 ml, not significant). There were no significant differences in preoperative detrusor overactivity, EFP or compliance. Postoperative BV did not differ between the groups, although there was a trend toward higher postoperative BV in the enterocystoplasty group. Median improvement in bladder capacity postoperatively was significantly greater in the enterocystoplasty group than in the detrusorectomy group (300.0 vs 77.5 ml, p ⫽ 0.006). More patients in the enterocystoplasty group had better compliance postoperatively (81% vs 46.2%, p ⫽ 0.019), although median improvement of compliance did not differ between the groups. Postoperative EFP and median improvement of EFP were not significantly different, although a trend toward lower EFP and more improvement of EFP was observed in the enterocystoplasty group. Clinical outcomes are summarized in supplementary table 2 (jurology.com). Median age in the enterocystoplasty group was significantly greater than in the detrusorectomy group (p ⫽ 0.002). Good longterm outcomes were noted in the upper and lower urinary tracts. End-stage renal disease did not manifest clinically in any patient. There were no significant differences between the 2 groups regarding postoperative ultrasonography findings. All abnor-
mal ultrasonography findings already existed preoperatively, and no new abnormalities were found. There was a trend toward a higher median serum creatinine in the enterocystoplasty group. There were no differences in continence, occurrence of UTIs or urolithiasis, frequency of CIC or use of prophylactic antibiotics between the groups. In the detrusorectomy group 21 patients (80.8%) were socially dry, as were 20 patients (95.2%) in the enterocystoplasty group. Postoperatively there was no significant difference in antimuscarinic drug use between the groups (76.9% for detrusorectomy vs 19.0% for enterocystoplasty, p ⫽ 0.003). An additional fascial sling procedure was performed in 65.4% and 42.9% of patients in the detrusorectomy and enterocystoplasty groups, respectively (not significant). The level of the lesion had no influence on outcome when analyzed separately for the 2 groups.
DISCUSSION Detrusorectomy and enterocystoplasty are the most commonly used forms of bladder surgery and have replaced the need for ileal conduits in patients with SB. To our knowledge this is the first study of the long-term outcomes of detrusorectomy and enterocystoplasty in comparable groups. Comparing enterocystoplasty and detrusorectomy is important because of the supposed disadvantages of enterocystoplasty. Enterocystoplasty involves isolating an enteric segment and thus interrupting the continuity of the gastrointestinal tract, carrying a greater risk of gastrointestinal complications such as postoperative ileus and leakage of the anastomosis. An incorporated enteric segment produces mucus and absorbs electrolytes and other metabolites from the urine, which may cause metabolic disturbances, malignancies and stone disease. Detrusorectomy is a much less invasive intervention that involves only the removal of muscle tissue of the bladder dome, without entering the peritoneal cavity. Therefore, if detrusorectomy appears to be as successful as enterocystoplasty, this technique is to be preferred, given the lower risk of postoperative complications in the shorter and longer terms. In both treatment groups we found a clinically stable upper urinary tract and comparable results concerning continence rates, although detrusorectomy failed in 4 patients and enterocystoplasty was always successful. Also there was no difference in the frequency of CIC, use of antimuscarinics or occurrence of UTIs. The most important finding of this study was that preoperative BV was larger in the detrusorectomy group, and the increase in BV was
ENTEROCYSTOPLASTY VS DETRUSORECTOMY IN ADULTS WITH SPINA BIFIDA
greater after enterocystoplasty, indicating that only bladders with a reasonable volume are suitable for detrusorectomy. Our findings are only partly consistent with earlier reports. According to the literature, detrusorectomy is not as successful as enterocystoplasty, and some authors even argue against the use of detrusorectomy.7 Success rates with detrusorectomy reportedly range from 7% to 80%.8 –14 However, these studies did not compare enterocystoplasty and detrusorectomy in the same cohort. Our study was not randomized. In patients with a BV that was too small enterocystoplasty was chosen and not detrusorectomy, as is reflected in the difference in preoperative BV between the groups. Detrusorectomy may be suitable for patients with a fairly good preoperative BV. At our institution 80% of expected capacity for age was used as a threshold, although this cutoff is rather arbitrary. To confirm this threshold value, a randomized study has to be done. No impairment of renal function was found. The upper tract was investigated by ultrasonography, which is considered sufficiently reliable.15 Creatinine is less reliable in patients with neuromuscular disease because less muscle mass is present, although a median creatinine level can still give an indication of kidney functioning. The trend toward a higher median serum creatinine in the enterocystoplasty group is probably related to reuptake of creatinine by the bowel segment in the bladder. A limitation of this study is its retrospective nature, with survival bias possibly influencing the results. A review of the entire cohort of children who presented at our pediatric renal center between 1986 and 2001 (reviewed by Dik et al16) revealed that only 3 of 143 did not survive until March 2012 (overall survival rate 97.9%). All of these cases were managed by CIC and antimuscarinics from birth onward, with surgical intervention only if conservative measures were insufficient to preserve lower
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and upper tract function. These data imply that the patients included in our series consist of those who were not doing well enough with conservative measures. These patients carry a worse prognosis than those who did not have to undergo surgery. A small number of patients included in this study were originally operated on elsewhere. However, we have no data from other centers in The Netherlands concerning survival into adulthood. From the literature it can be derived that currently 50% to 80% of all patients with SB reach adulthood.17–19 Another limitation is that both surgical groups were relatively small, which may have led to under powering and may contribute to the fact that not many differences were observed between the 2 groups. Moreover, since data in our small groups were not normally divided, nonparametric tests had to be used, which are less powerful in detecting significant differences. The most important information emerging from our study is that in patients with (congenital) neurogenic bladder disorder if an indication for bladder augmentation exists, detrusorectomy may be considered before performing enterocystoplasty, given its comparable longterm outcomes and its less invasive nature.
CONCLUSIONS In our series of 47 patients long-term clinical outcomes were good after enterocystoplasty and detrusorectomy, with 4 failures (all detrusorectomy) that necessitated reoperation. Since there was no difference in outcomes except for a smaller increase in capacity, we conclude that detrusorectomy may be preferable over enterocystoplasty (taking into account the invasiveness of the procedure), provided the bladder capacity is sufficient.
ACKNOWLEDGMENTS Esther Kok provided statistical and methodological advice.
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