Pediatric Urology Treatment of Pouch Stones After Augmentation Ileocystoplasty in Children: Is It Always Bothersome? Tamer E. Helmy, Mohammed M. Elawdy, Ahmed AbdelHalim, Hesham Orban, Hossam Nabeeh, Mohammed Dawaba, and Ashraf T. Hafez OBJECTIVE PATIENTS AND METHODS
RESULTS
CONCLUSION
To report our experience with different approaches for management of pouch stones in children with ileal-based urinary reservoir. Charts of children who underwent ileal-based urinary reservoirs between 2000 and 2009 were retrospectively reviewed. Patients who were diagnosed with reservoir calculi were identified; medical records were reviewed for patients’ demographics, diversion details, stone criteria, mode of treatment, perioperative complications, and recurrence rate. We identified 26 children with pouch stones after urinary diversion. There were 11 boys (42%) and 15 girls (58%). Mean age was 11 years (range, 4-16 years). Mean time for diagnosis was 42 months (24-120 months). Pouch stones were asymptomatic in 10 patients (38%). Fifteen cases were postbladder augmentation and 11 cases postcontinent cutaneous diversion. The mean stone size was 4 cm (range, 1-10 cm), and mean Hounsfield Unit was 585 (205-1090). Seventeen children (65%) had positive urine culture result, whereas 9 children were sterile. Seven children (27%) required open poucholithotomy, whereas 19 patients (73%) were managed endoscopically. Percutaneous approach was done in 5 children, whereas urethral access was used in 7 children. Mechanical extraction was performed in 12 cases, and stone disintegration was required in 7 cases. Eight children developed stone recurrence. Mean time for recurrence was 11 months (range, 3-19 months). Six children were after endoscopic disintegration, and all required redo endoscopic extraction. Stone analysis was available in 15 patients (struvite stones in 10 cases and calcium phosphate in 5 cases). Pouch stones are established long-term complication of urinary diversion. Open and endoscopic approaches are valid treatment strategies. UROLOGY 85: 195e198, 2015. 2015 Elsevier Inc.
I
t has been known that clean intermittent catheterization (CIC) together with antimuscarinics is the initial treatment model in patients with severely compromised lower urinary tract as in neurogenic bladder and extrophy-epispadias complex, when such methods fail to achieve continence or in presence of upper tract deterioration, urinary tract reconstruction comes down the road.1 Bladder stone is a well-known late complication after augmentation ileocystoplasty or total bladder substitution.2 Many factors are in favor for stone formation, mucus that acts as a nidus,3 urinary tract infection (UTI),4,5 urinary tract stasis, and bladder resistance procedures2 as well as metabolic abnormalities may play Financial Disclosure: The authors declare that they have no relevant financial interests. From the Department of Pediatric Urology, Urology and Nephrology Center, Mansoura University, Mansoura, Egypt Address correspondence to: Tamer E. Helmy, M.D., Department of Pediatric Urology, Urology and Nephrology Center, Mansoura University, Mansoura 35516, Egypt. E-mail: [email protected] Submitted: June 1, 2014, accepted (with revisions): September 16, 2014
ª 2015 Elsevier Inc. All Rights Reserved
a role in stone formation. Although many studies have been published about the overall experience of augmentation ileocystoplasty in children and its related complications,1,6,7 there are few studies that were published reporting pouch stone in detail,2,5,8,9 Most of the published series included patients in whom a different kind of gut has been used for cystoplasty,9,10 which could be a bias on studying the risk factors for stone formations. It has not been clear yet which is the most effective method for stone extraction after bladder reconstruction. Open cystolithotomy was reported to be the most successful means of removing the calculi11; others reported that the endoscopic approach is a safe and effective method even in the presence of a reconstructed bladder neck, and open vesicolithotomy should be reserved for the very large stone burden.10 We introduce our experience at a tertiary referral center regarding a homogenous group of patients to whom ileocystoplasty was done reporting the incidence of pouch stone, to further investigate the risk factors for http://dx.doi.org/10.1016/j.urology.2014.09.021 0090-4295/15
195
stone recurrence and reporting our experience in open and endoscopic procedure.
PATIENTS AND METHODS After approval from institutional review board, we retrospectively reviewed the records of all patients who underwent continent catheterizable ileal urinary reservoir in children between August 2000 and May 2009. Patients who developed pouch stones were filtered for further analysis. Medical records were reviewed for patients’ demographics data, age, sex, weight, and height. The indications for bladder reconstruction, time to pouch stone formation, mode of treatment, and subsequent recurrences were also recorded. We traced the different risk factors that favor stone formation and included urine pH, presence of UTI by urine culture, and presence of serum electrolytes. All data regarding the stones that included stone size, number, and radiologic characters as radio density and Hounsfield Unit (HU) were also included. Routine laboratory and radiologic workups were done for all patients. The surgical modality used for stone retrieval that was either open poucholithotomy or endoscopic approach were also recorded, in terms of operative time, blood loss, complications, hospital stay, and recurrence rate. The postoperative follow-up schedule was regular checkup visit every 3 months for physical examination, urine analysis, and pelvic ultrasonography. Patients were instructed to perform regular saline irrigation to avoid stone recurrence. Statistical analysis was performed using the commercial computer software Statistical Package for the Social Sciences version 16 (SPSS Inc, Chicago, IL). Data are reported as median (range).
RESULTS A total of 130 patients (58 boys and 72 girls) underwent ileal catheterizable urinary reservoir, from whom 26 patients (20%) developed pouch stones. Table 1 lists patient characteristics. They were 11 boys (42%) and 15 girls (58%). Median age was 11 years (range, 4-16 years), and the mean time for stone development was 42 months (24-120 months). Urinary diversion was done for nonmalignant causes in all cases. Augmentation ileocystoplasty with continent outlet was performed for 15 patients, whereas ileal neobladder substitution was performed in the remaining 11 patients. CIC was through the continent cutaneous outlet in 19 children, whereas CIC was through the urethra in the remaining 7 children. Pouch stones were incidentally discovered and asymptomatic in 10 patients (38%). Recurrent UTI was the second common presentation in 7 patients (26%). Others presented with abdominal pain or hematuria. Single pouch stone was found in 14 children (53%), whereas 12 children had multiple stones. Radiopaque stones were found in 22 patients (85%). The mean stone size was 4 cm (range, 1-10 cm). In patients to whom computed tomography scan was done, the HU was 585 (205-1090). Urine culture result was positive in 17 patients (65%). Escherichia coli and Klebsiella pneumoniae were the commonest among gram-positive bacilli that were detected. The serum creatinine level was normal in 196
Table 1. Patient characteristic Characteristics Mean age (range), y Mean follow-up (range), mo Sex Male Female Type of the reservoir Augmentation ileocystoplasty Neobladder substitution Voiding Continent outlet Urethra Urine culture Treatment Open Endoscopic Endoscopic route Urethra Cutaneous stoma Suprapubic Recurrence Open Endoscopic
Value 11 (4-16) 42 (24-120) 11 15 15 11 19 7 17 7 19 7 7 5 8 2 6
all patients (0.5 [0.2-1.4] mg/dL) and serum uric acid level was also within normal range (3.5 [2.4-5.3] mg/dL). Open surgery was done for 7 patients (27%) with mean hospital stay of 5 days (range, 3-7 days). In the 7 patients to whom open surgery was chosen (6 of them had multiple stones, 5 of them had radiopaque stones with >700 HU, and 4 of them with stones 7 cm in diameter). No perioperative complications were reported apart from small serosal injury that was adequately repaired in a 9year-old boy. On the other hand, endoscopic maneuver was commenced for the remaining 19 patients. Endoscopic approach was via the continent stoma in 7 children, the urethra in 7, and percutaneous in 5 patients. Mean hospital stay was 3 days (range, 2-10 days). Forceps extraction of the stone was satisfactory for 12 children, whereas electrohydraulic lithotripter was used for 7 patients for complete removal of the stones. Stone analysis was available in 15 patients (struvite stones in 10 cases and calcium phosphate in 5 cases). Bladder calculi recurred in 8 children (30%). Mean time to recurrence was 11 months (range, 3-19 months). Six of 8 patients were treated initially by endoscopic approach. The remaining 2 patients were after open poucholithotomy. All recurrent cases were treated by redo endoscopic procedure.
COMMENT Bladder reconstruction has become a standard technique for severe compromised lower urinary tact when other treatment modalities fail.12 Stone formation is a wellknown late complication after bladder reconstruction by either augmentation or total bladder substitution.1,7 Our patients have a tendency to develop more stones than what was reported in the literature. The incidence of pouch stones in our series is 20%, which is higher than UROLOGY 85 (1), 2015
that reported in many series (10%-11%),2,5 and the mean time of stone development in our series is 42 months (range, 24-120 months), which is shorter in comparison with what was reported (48-60 months),2,5 which can be explained by higher incidence of stone disease in general in our locality (stone built area). It is well known that adolescents are less compliant to intermittent selfcatheterization with inadequate bladder emptying and subsequently high risk of stone formation. Moreover, the prevalence of stone disease in Arabic people is higher than that of Europeans (odds ratio, 3.8; 95% confidence interval, 2.7-5.2).13 Also, high ambient temperature and sunlight exposure are independently associated with increased stone prevalence.14 Higher incidence of bladder calculi was recently reported; in 2831 children with augmentation cystoplasty, the cumulative incidence of bladder stones was 13.3%-36%,15 and Obermayr et al16 reported a 39% incidence of lower urinary tract calculi in their cohort of augmentation ileocystoplasty. Many factors are in favor of stone formation, intestinal mucous that acts as a nidus for stone formation and recurrent UTI especially with urea-splitting organisms.11 UTI was found in 17 patients in our series (65%), which was lower than what was published by Defoor et al5 as they found 26 of 29 patients had UTI with positive urine culture result containing urea-splitting organisms before they had developed pouch stones. Most of our patients who developed pouch stones have a Mitrofanoff outlet together with bladder neck closure or reconstruction that also was mentioned by.1,12 The fact that bladder neck procedure may lead to urine stasis is a well-known risk factor for pouch stone formation. Stone management in the augmented bladder has a special concern than the native bladder in many aspects; although endoscopic modality is safe in native bladder, it may jeopardize the reconstructed bladder neck or the Mitrofanoff outlet in the augmented bladder. On the other hand, if endoscopic procedure is performed by percutaneous approach, it carries the risk of injury to the mesentery of the augmented or the neobladder or even may cause intraperitoneal perforation. Most of our patients were operated by endoscopy (19 of 26) through urethra, the outlet or percutaneous approach without any reported major complications with the advantage of short hospital stay. Palmer et al4 recommended endoscopic maneuvers, which are safe, and open approach should be reserved only for large stone burden. In another series, percutaneous cystolithotomy was successfully performed in 12 of 13 patients in which the exit site of the suprapubic tube following the initial bladder augmentation was dilated with 1 case that required open exploration after bladder perforation.9 Seven of 26 patients in our series were operated by open approach with successful stone removal; most of those patients who were chosen have multiple or large stone burden in comparison with those who underwent endoscopy. Open surgery was reported with satisfactory results in many series. Ten of 14 patients were operated UROLOGY 85 (1), 2015
successfully by open surgery.8 Similarly, in another series of 26 patients, open cystolithotomy was the most successful means of removal of the calculi.11 We have 8 patients (30%) with reformed stone, interestingly 6 of them after endoscopy. Mean time to recurrence was 11 months (range, 3-19 months), which is similar to what was mentioned by Palmer et al4 with stone recurrence (18%) after endoscopy. The high recurrence after endoscopic maneuvers can be explained by residual fragments that could not be completely removed by endoscopy rather than open surgery. We acknowledge that the major limitation of this study is the retrospective nature and the small sample size. Additional large prospective studies are needed to establish the technical standpoints in such pathology.
CONCLUSION Pouch stones are a late complication after cystoplasty. Endoscopy and open surgery are viable options for management of pouch stones. Endoscopic procedures are safe, less invasive with short hospital stay, but with higher recurrence rate. Although open approach is more invasive, it is associated with low recurrence rate. The surgeon should tailor both techniques according to the patient’s condition as well as stone burden. Pouch stones are associated with high readmission rate, and prophylactic measures should be taken to decrease such complications.
References 1. Elshal AM, Abdelhalim A, Hafez AT, et al. Ileal urinary reservoir in pediatric population: objective assessment of long-term sequelae with time-to-event analysis. Urology. 2012;79:1126-1131. 2. Kronner KM, Casale AJ, Cain MP, et al. Bladder calculi in the pediatric augmented bladder. J Urol. 1998;160:1096-1098; discussion 103. 3. Khoury AE, Salomon M, Doche R, et al. Stone formation after augmentation cystoplasty: the role of intestinal mucus. J Urol. 1997; 158:1133-1137. 4. Palmer LS, Franco I, Kogan SJ, et al. Urolithiasis in children following augmentation cystoplasty. J Urol. 1993;150:726-729. 5. DeFoor W, Minevich E, Reddy P, et al. Bladder calculi after augmentation cystoplasty: risk factors and prevention strategies. J Urol. 2004;172:1964-1966. 6. DeFoor WR, Heshmat S, Minevich E, et al. Long-term outcomes of the neobladder in pediatric continent urinary reconstruction. J Urol. 2009;181:2689-2693; discussion 93-4. 7. Kaefer M, Tobin MS, Hendren WH, et al. Continent urinary diversion: the Children’s Hospital experience. J Urol. 1997;157: 1394-1399. 8. Mathoera RB, Kok DJ, Nijman RJ. Bladder calculi in augmentation cystoplasty in children. Urology. 2000;56:482-487. 9. Cain MP, Casale AJ, Kaefer M, et al. Percutaneous cystolithotomy in the pediatric augmented bladder. J Urol. 2002;168:1881-1882. 10. Palmer LS, Franco I, Reda EF, et al. Endoscopic management of bladder calculi following augmentation cystoplasty. Urology. 1994; 44:902-904. 11. Blyth B, Ewalt DH, Duckett JW, et al. Lithogenic properties of enterocystoplasty. J Urol. 1992;148:575-577; discussion 8-9. 12. Elshal AM, Abol-Enein H, Sarhan O, et al. Catheterizable serous lined urinary outlet in children and adolescents: a choice when other treatments fail. J Urol. 2011;185:1083-1087.
197
13. Mente A, Honey RJ, McLaughlin JR, et al. Ethnic differences in relative risk of idiopathic calcium nephrolithiasis in North America. J Urol. 2007;178:1992-1997. 14. Soucie JM, Coates RJ, McClellan W, et al. Relation between geographic variability in kidney stones prevalence and risk factors for stones. Am J Epidemiol. 1996;143:487-495.
198
15. Schlomer BJ, Copp HL. Cumulative incidence of outcomes and urologic procedures after augmentation cystoplasty [e-pub ahead of print]. J Pediatr Urol. 2014. doi: 10.1016/j.jpurol.2014.03.020. 16. Obermayr F, Szavay P, Schaefer J, et al. Outcome of augmentation cystoplasty and bladder substitution in a pediatric age group. Eur J Pediatr Surg. 2011;21:116-119.
UROLOGY 85 (1), 2015
RESULTS
CONCLUSION
To report our experience with different approaches for management of pouch stones in children with ileal-based urinary reservoir. Charts of children who underwent ileal-based urinary reservoirs between 2000 and 2009 were retrospectively reviewed. Patients who were diagnosed with reservoir calculi were identified; medical records were reviewed for patients’ demographics, diversion details, stone criteria, mode of treatment, perioperative complications, and recurrence rate. We identified 26 children with pouch stones after urinary diversion. There were 11 boys (42%) and 15 girls (58%). Mean age was 11 years (range, 4-16 years). Mean time for diagnosis was 42 months (24-120 months). Pouch stones were asymptomatic in 10 patients (38%). Fifteen cases were postbladder augmentation and 11 cases postcontinent cutaneous diversion. The mean stone size was 4 cm (range, 1-10 cm), and mean Hounsfield Unit was 585 (205-1090). Seventeen children (65%) had positive urine culture result, whereas 9 children were sterile. Seven children (27%) required open poucholithotomy, whereas 19 patients (73%) were managed endoscopically. Percutaneous approach was done in 5 children, whereas urethral access was used in 7 children. Mechanical extraction was performed in 12 cases, and stone disintegration was required in 7 cases. Eight children developed stone recurrence. Mean time for recurrence was 11 months (range, 3-19 months). Six children were after endoscopic disintegration, and all required redo endoscopic extraction. Stone analysis was available in 15 patients (struvite stones in 10 cases and calcium phosphate in 5 cases). Pouch stones are established long-term complication of urinary diversion. Open and endoscopic approaches are valid treatment strategies. UROLOGY 85: 195e198, 2015. 2015 Elsevier Inc.
I
t has been known that clean intermittent catheterization (CIC) together with antimuscarinics is the initial treatment model in patients with severely compromised lower urinary tract as in neurogenic bladder and extrophy-epispadias complex, when such methods fail to achieve continence or in presence of upper tract deterioration, urinary tract reconstruction comes down the road.1 Bladder stone is a well-known late complication after augmentation ileocystoplasty or total bladder substitution.2 Many factors are in favor for stone formation, mucus that acts as a nidus,3 urinary tract infection (UTI),4,5 urinary tract stasis, and bladder resistance procedures2 as well as metabolic abnormalities may play Financial Disclosure: The authors declare that they have no relevant financial interests. From the Department of Pediatric Urology, Urology and Nephrology Center, Mansoura University, Mansoura, Egypt Address correspondence to: Tamer E. Helmy, M.D., Department of Pediatric Urology, Urology and Nephrology Center, Mansoura University, Mansoura 35516, Egypt. E-mail: [email protected] Submitted: June 1, 2014, accepted (with revisions): September 16, 2014
ª 2015 Elsevier Inc. All Rights Reserved
a role in stone formation. Although many studies have been published about the overall experience of augmentation ileocystoplasty in children and its related complications,1,6,7 there are few studies that were published reporting pouch stone in detail,2,5,8,9 Most of the published series included patients in whom a different kind of gut has been used for cystoplasty,9,10 which could be a bias on studying the risk factors for stone formations. It has not been clear yet which is the most effective method for stone extraction after bladder reconstruction. Open cystolithotomy was reported to be the most successful means of removing the calculi11; others reported that the endoscopic approach is a safe and effective method even in the presence of a reconstructed bladder neck, and open vesicolithotomy should be reserved for the very large stone burden.10 We introduce our experience at a tertiary referral center regarding a homogenous group of patients to whom ileocystoplasty was done reporting the incidence of pouch stone, to further investigate the risk factors for http://dx.doi.org/10.1016/j.urology.2014.09.021 0090-4295/15
195
stone recurrence and reporting our experience in open and endoscopic procedure.
PATIENTS AND METHODS After approval from institutional review board, we retrospectively reviewed the records of all patients who underwent continent catheterizable ileal urinary reservoir in children between August 2000 and May 2009. Patients who developed pouch stones were filtered for further analysis. Medical records were reviewed for patients’ demographics data, age, sex, weight, and height. The indications for bladder reconstruction, time to pouch stone formation, mode of treatment, and subsequent recurrences were also recorded. We traced the different risk factors that favor stone formation and included urine pH, presence of UTI by urine culture, and presence of serum electrolytes. All data regarding the stones that included stone size, number, and radiologic characters as radio density and Hounsfield Unit (HU) were also included. Routine laboratory and radiologic workups were done for all patients. The surgical modality used for stone retrieval that was either open poucholithotomy or endoscopic approach were also recorded, in terms of operative time, blood loss, complications, hospital stay, and recurrence rate. The postoperative follow-up schedule was regular checkup visit every 3 months for physical examination, urine analysis, and pelvic ultrasonography. Patients were instructed to perform regular saline irrigation to avoid stone recurrence. Statistical analysis was performed using the commercial computer software Statistical Package for the Social Sciences version 16 (SPSS Inc, Chicago, IL). Data are reported as median (range).
RESULTS A total of 130 patients (58 boys and 72 girls) underwent ileal catheterizable urinary reservoir, from whom 26 patients (20%) developed pouch stones. Table 1 lists patient characteristics. They were 11 boys (42%) and 15 girls (58%). Median age was 11 years (range, 4-16 years), and the mean time for stone development was 42 months (24-120 months). Urinary diversion was done for nonmalignant causes in all cases. Augmentation ileocystoplasty with continent outlet was performed for 15 patients, whereas ileal neobladder substitution was performed in the remaining 11 patients. CIC was through the continent cutaneous outlet in 19 children, whereas CIC was through the urethra in the remaining 7 children. Pouch stones were incidentally discovered and asymptomatic in 10 patients (38%). Recurrent UTI was the second common presentation in 7 patients (26%). Others presented with abdominal pain or hematuria. Single pouch stone was found in 14 children (53%), whereas 12 children had multiple stones. Radiopaque stones were found in 22 patients (85%). The mean stone size was 4 cm (range, 1-10 cm). In patients to whom computed tomography scan was done, the HU was 585 (205-1090). Urine culture result was positive in 17 patients (65%). Escherichia coli and Klebsiella pneumoniae were the commonest among gram-positive bacilli that were detected. The serum creatinine level was normal in 196
Table 1. Patient characteristic Characteristics Mean age (range), y Mean follow-up (range), mo Sex Male Female Type of the reservoir Augmentation ileocystoplasty Neobladder substitution Voiding Continent outlet Urethra Urine culture Treatment Open Endoscopic Endoscopic route Urethra Cutaneous stoma Suprapubic Recurrence Open Endoscopic
Value 11 (4-16) 42 (24-120) 11 15 15 11 19 7 17 7 19 7 7 5 8 2 6
all patients (0.5 [0.2-1.4] mg/dL) and serum uric acid level was also within normal range (3.5 [2.4-5.3] mg/dL). Open surgery was done for 7 patients (27%) with mean hospital stay of 5 days (range, 3-7 days). In the 7 patients to whom open surgery was chosen (6 of them had multiple stones, 5 of them had radiopaque stones with >700 HU, and 4 of them with stones 7 cm in diameter). No perioperative complications were reported apart from small serosal injury that was adequately repaired in a 9year-old boy. On the other hand, endoscopic maneuver was commenced for the remaining 19 patients. Endoscopic approach was via the continent stoma in 7 children, the urethra in 7, and percutaneous in 5 patients. Mean hospital stay was 3 days (range, 2-10 days). Forceps extraction of the stone was satisfactory for 12 children, whereas electrohydraulic lithotripter was used for 7 patients for complete removal of the stones. Stone analysis was available in 15 patients (struvite stones in 10 cases and calcium phosphate in 5 cases). Bladder calculi recurred in 8 children (30%). Mean time to recurrence was 11 months (range, 3-19 months). Six of 8 patients were treated initially by endoscopic approach. The remaining 2 patients were after open poucholithotomy. All recurrent cases were treated by redo endoscopic procedure.
COMMENT Bladder reconstruction has become a standard technique for severe compromised lower urinary tact when other treatment modalities fail.12 Stone formation is a wellknown late complication after bladder reconstruction by either augmentation or total bladder substitution.1,7 Our patients have a tendency to develop more stones than what was reported in the literature. The incidence of pouch stones in our series is 20%, which is higher than UROLOGY 85 (1), 2015
that reported in many series (10%-11%),2,5 and the mean time of stone development in our series is 42 months (range, 24-120 months), which is shorter in comparison with what was reported (48-60 months),2,5 which can be explained by higher incidence of stone disease in general in our locality (stone built area). It is well known that adolescents are less compliant to intermittent selfcatheterization with inadequate bladder emptying and subsequently high risk of stone formation. Moreover, the prevalence of stone disease in Arabic people is higher than that of Europeans (odds ratio, 3.8; 95% confidence interval, 2.7-5.2).13 Also, high ambient temperature and sunlight exposure are independently associated with increased stone prevalence.14 Higher incidence of bladder calculi was recently reported; in 2831 children with augmentation cystoplasty, the cumulative incidence of bladder stones was 13.3%-36%,15 and Obermayr et al16 reported a 39% incidence of lower urinary tract calculi in their cohort of augmentation ileocystoplasty. Many factors are in favor of stone formation, intestinal mucous that acts as a nidus for stone formation and recurrent UTI especially with urea-splitting organisms.11 UTI was found in 17 patients in our series (65%), which was lower than what was published by Defoor et al5 as they found 26 of 29 patients had UTI with positive urine culture result containing urea-splitting organisms before they had developed pouch stones. Most of our patients who developed pouch stones have a Mitrofanoff outlet together with bladder neck closure or reconstruction that also was mentioned by.1,12 The fact that bladder neck procedure may lead to urine stasis is a well-known risk factor for pouch stone formation. Stone management in the augmented bladder has a special concern than the native bladder in many aspects; although endoscopic modality is safe in native bladder, it may jeopardize the reconstructed bladder neck or the Mitrofanoff outlet in the augmented bladder. On the other hand, if endoscopic procedure is performed by percutaneous approach, it carries the risk of injury to the mesentery of the augmented or the neobladder or even may cause intraperitoneal perforation. Most of our patients were operated by endoscopy (19 of 26) through urethra, the outlet or percutaneous approach without any reported major complications with the advantage of short hospital stay. Palmer et al4 recommended endoscopic maneuvers, which are safe, and open approach should be reserved only for large stone burden. In another series, percutaneous cystolithotomy was successfully performed in 12 of 13 patients in which the exit site of the suprapubic tube following the initial bladder augmentation was dilated with 1 case that required open exploration after bladder perforation.9 Seven of 26 patients in our series were operated by open approach with successful stone removal; most of those patients who were chosen have multiple or large stone burden in comparison with those who underwent endoscopy. Open surgery was reported with satisfactory results in many series. Ten of 14 patients were operated UROLOGY 85 (1), 2015
successfully by open surgery.8 Similarly, in another series of 26 patients, open cystolithotomy was the most successful means of removal of the calculi.11 We have 8 patients (30%) with reformed stone, interestingly 6 of them after endoscopy. Mean time to recurrence was 11 months (range, 3-19 months), which is similar to what was mentioned by Palmer et al4 with stone recurrence (18%) after endoscopy. The high recurrence after endoscopic maneuvers can be explained by residual fragments that could not be completely removed by endoscopy rather than open surgery. We acknowledge that the major limitation of this study is the retrospective nature and the small sample size. Additional large prospective studies are needed to establish the technical standpoints in such pathology.
CONCLUSION Pouch stones are a late complication after cystoplasty. Endoscopy and open surgery are viable options for management of pouch stones. Endoscopic procedures are safe, less invasive with short hospital stay, but with higher recurrence rate. Although open approach is more invasive, it is associated with low recurrence rate. The surgeon should tailor both techniques according to the patient’s condition as well as stone burden. Pouch stones are associated with high readmission rate, and prophylactic measures should be taken to decrease such complications.
References 1. Elshal AM, Abdelhalim A, Hafez AT, et al. Ileal urinary reservoir in pediatric population: objective assessment of long-term sequelae with time-to-event analysis. Urology. 2012;79:1126-1131. 2. Kronner KM, Casale AJ, Cain MP, et al. Bladder calculi in the pediatric augmented bladder. J Urol. 1998;160:1096-1098; discussion 103. 3. Khoury AE, Salomon M, Doche R, et al. Stone formation after augmentation cystoplasty: the role of intestinal mucus. J Urol. 1997; 158:1133-1137. 4. Palmer LS, Franco I, Kogan SJ, et al. Urolithiasis in children following augmentation cystoplasty. J Urol. 1993;150:726-729. 5. DeFoor W, Minevich E, Reddy P, et al. Bladder calculi after augmentation cystoplasty: risk factors and prevention strategies. J Urol. 2004;172:1964-1966. 6. DeFoor WR, Heshmat S, Minevich E, et al. Long-term outcomes of the neobladder in pediatric continent urinary reconstruction. J Urol. 2009;181:2689-2693; discussion 93-4. 7. Kaefer M, Tobin MS, Hendren WH, et al. Continent urinary diversion: the Children’s Hospital experience. J Urol. 1997;157: 1394-1399. 8. Mathoera RB, Kok DJ, Nijman RJ. Bladder calculi in augmentation cystoplasty in children. Urology. 2000;56:482-487. 9. Cain MP, Casale AJ, Kaefer M, et al. Percutaneous cystolithotomy in the pediatric augmented bladder. J Urol. 2002;168:1881-1882. 10. Palmer LS, Franco I, Reda EF, et al. Endoscopic management of bladder calculi following augmentation cystoplasty. Urology. 1994; 44:902-904. 11. Blyth B, Ewalt DH, Duckett JW, et al. Lithogenic properties of enterocystoplasty. J Urol. 1992;148:575-577; discussion 8-9. 12. Elshal AM, Abol-Enein H, Sarhan O, et al. Catheterizable serous lined urinary outlet in children and adolescents: a choice when other treatments fail. J Urol. 2011;185:1083-1087.
197
13. Mente A, Honey RJ, McLaughlin JR, et al. Ethnic differences in relative risk of idiopathic calcium nephrolithiasis in North America. J Urol. 2007;178:1992-1997. 14. Soucie JM, Coates RJ, McClellan W, et al. Relation between geographic variability in kidney stones prevalence and risk factors for stones. Am J Epidemiol. 1996;143:487-495.
198
15. Schlomer BJ, Copp HL. Cumulative incidence of outcomes and urologic procedures after augmentation cystoplasty [e-pub ahead of print]. J Pediatr Urol. 2014. doi: 10.1016/j.jpurol.2014.03.020. 16. Obermayr F, Szavay P, Schaefer J, et al. Outcome of augmentation cystoplasty and bladder substitution in a pediatric age group. Eur J Pediatr Surg. 2011;21:116-119.
UROLOGY 85 (1), 2015
