The ileal neobladder

Currently we are witnessing an increase of interest in bladder substitution enterocystoplasty. The goal of this presentation is to describe operative technique and first clinical results of a ileal neobladder for total bladder replacement. Creation of a ileal neobladder for total bladder replacement is described in 11 patients. To achieve a low pressure system, disruption of directional bowel peristalsis with a longitudinal incision at the antimesenteric border of a 70 cm ileal segment is performed. A spherical pouch, the neobladder, is fashioned and anastomosed to the urethra. The ureters are implanted according to Le Duc and Camey. Videourodynamic studies during various postoperative phases demonstrate this neobladder to be a urinary reservoir with a capacity approximating that of a normal bladder, good compliance during filling by maintaining pressures lower than 30 cm water and no reflux. Eight of the 11 patients with the neobladder are completely dry day and night. Three are stress incontinent grade I. All 11 patients developed recognizable sensations of bladder distension closely simulating those of their earlier bladders. The use of this ileal neobladder in male patients undergoing radical cystectomy offers a stoma free alternative to urinary diversion resulting in a highly compliant low pressure bladder. A urodynamic comparison between the most recent developments (Kock-pouch, Camey, Mainz-pouch, "Le Bag") is made and this clearly shows the ileal neobladder to have several distinct advantages: the ileocolonic junction and the terminal ileum are saved; the operative technique is safe, simple and reliable (no Kock valve, no 180 degree rotation of the reservoir, simple antireflux technique); development of recognizable sensations of bladder filling in all cases.(ABSTRACT TRUNCATED AT 250 WORDS)     

Ileal Neobladder for Bladder Substitution after Radical Cystectomy

Background: Studer's ileal neobladder is technically simple, and favorable clinical results have been reported. However, there have been only a few follow-up studies on this type of ileal neobladder. We reviewed the clinical outcomes of patients who received Studer's ileal neobladder, with a minor modification, in our institution.
Methods: Twenty-five men underwent bladder reconstruction with Studer's ileal neobladder after radical cystectomy. The function of the ileal neobladder and voiding status were evaluated during follow-up. The follow-up period ranged from 3 to 42 months (mean, 24 months).
Results: The ileal neobladder achieved a large capacity at a low basal pressure, associated with a relatively low complication rate directly related to the neobladder. At 12 months after surgery, daytime and nighttime continence rates were 90|X% and 74|X%, respectively. In 5 patients who were incontinent, the maximal urethral closure pressure was statistically lower than in patients with continence.
Conclusion: Studer's ileal neobladder is an easy operative procedure for bladder substitution, and has a relatively low complication rate directly related to the neobladder. Good compliance ofthe pouch and preservation of the external sphincter mechanism are the most important factors for achieving urinary continence, after construction of the ileal neobladder.     

CONTINENCE MECHANISM OF THE ORTHOTOPIC NEOBLADDER: URODYNAMIC ANALYSIS OF ILEOCOLIC NEOBLADDER AND EXTERNAL URETHRAL SPHINCTER FUNCTIONS

Background: The main objectives of bladder substitution are the preservation of the upper urinary tract and maintenance of urinary continence. Orthotopic bladder substitution makes it possible to achieve urinary continence as well as normal passage of urine through the urethra. Creation of a low pressure reservoir and careful preservation of the distal sphincter mechanism are considered to be of utmost importance for the maintenance of urinary continence after orthotopic bladder Substitution. However, sphincter behavior after orthotopic bladder substitution has not been fully elucidated. The purpose of this study was to evaluate the vesicourethral continence mechanism after orthotopic bladder substitution in male patients. Methods: Urodynamic evaluation was performed in 14 male patients after cystoprostatectomy for bladder cancer and an ileocolic neobladder using a cecourethral anastomosis. Results: Good continence was achieved in 86% (12/14) of the patients during the day and in 79% (11/14) at night. On cystometry, maximum capacity of the neobladders was 434 ± 21 ml (mean ± SEM), and basal pressure at maximum capacity was 15.6 ± 0.9 cm water. Phasic neobladder contraction with amplitudes ranging from 14 to 40 (26.6 ± 2.7) cm water were noted in 11 of 14 patients. Sphincter electromyography demonstrated an increase in the frequency of action potentials of the external urethral sphincter during neobladder filling from empty to 80% of capacity (from 8.9 ± 1.6 to 14.6 ± 2.1 spikes per second; mean percentage increase, 64%, in patients with daytime continence). Maximum urethral closure pressure on urethral pressure profile was 49.9 ± 3.5 (range, 30 to 64) cm water in patients with daytime continence, while in two patients who were incontinent during the day and at night maximum urethral closure pressure was lower (16 and 24 cm water) and the recruitment of action potentials of the external urethral sphincter during neobladder filling was impaired (percentage increase, 15% and 20%). Conclusions: An ileocolic neobladder has characteristics of a low pressure reservoir with a satisfactory continence rate. The vesicourethral continence reflex is well preserved in patients with continence after orthotopic bladder Substitution.     

腹腔镜下膀胱全切除、原位回肠新膀胱的尿流动力学分析

目的 探讨腹腔镜膀胱全切除、原位回肠新膀胱的临床效果。方法 对8例行腹腔镜膀胱全切除、原位回肠新膀胱患者进行排尿情况的记录和尿动力学检查。结果 8例患者均可自主控制排尿（1例夜间轻微尿失禁）,在新膀胱充盈过程中均可出现胀痛感觉,膀胱平均容量377．5ml,压力17．9cmH2O,最大尿流率18．1ml／s,最大尿道闭合压68．5cnH2O,功能性尿道长度3．7cm。结论 腹腔镜根治性全膀胱切除、原位回肠新膀胱术较传统的开放手术创伤更小,但贮尿囊一样具有容积较大、内压较低和可控性较好的优点,排尿良好,值得临床推广。     

The ileal neobladder

We improved the method of Hautmann's operation and an ileal neobladder was created in 7 male patients with bladder carcinoma and 1 female patient with tuberculous contracted bladder. Post-operative urodynamic studies demonstrated that the neobladder capacity was approximate to normal bladder, the maintaining pressure was lower than 25 cmH2O. No reflux and incontinence was noticed during the filling in all the patients. The patients not only could self-control micturate but also had the sensation of distension which was similar to normal bladder.     

Continence after total bladder replacement: urodynamic analysis of the ileal neobladder

Since April 1986 we have carried out 103 bladder substitutions with the ileal neobladder; 91 of these were performed after radical cystectomy in males (group 1) and 12 after subtotal bladder resection (group 2); 55 patients in group 1 and 8 in group 2 were followed up by long-term urodynamic investigations and by a questionnaire concerning micturition patterns and continence at home 3 months post-operatively. The maximum bladder capacity was approximately 770 ml with an absolute intravesical pressure of 23 to 30 cm H2O. Intravesical pressure waves with a mean amplitude of 20 cm H2O were found in 38% of patients in group 1 and 25% in group 2; 61% of these patients were asymptomatic. The results showed that 85% of patients were continent by day and by night. We attribute this to our operative technique: the ileal loop is folded 4 times in a "W" or "M" shape to achieve complete detubularisation of the bowel and the external urethral sphincter is carefully preserved. Altogether, these data show the ileal neobladder technique to be a reliable and safe method of bladder substitution.     

改良低压回肠代膀胱术的疗效评价

目的 总结改良原位低压回肠代膀胱术的疗效及患者生活质量。方法 膀胱癌患者53例，平均年龄61岁，均施行根治性膀胱全切术。截取末端35—45cm回肠，“U”形缝合形成代“膀胱”，并与输尿管形成抗返流的“乳头”缝合。结果 术后所有患者血生化及电解质均正常，随访3—6个月，51例患者白天完全可控排尿，完全夜间可控制排尿25例。47例无残余尿，5例有残余尿20-35mL。结论 改良低压回肠代膀胱术，膀胱容量大、压力低、无返流、效果好、无吸收性酸中毒，患者白天均能够控制尿液，夜间需定时排尿，生活质量高，多数患者满意。     

Carney Ⅱ式原位回肠膀胱术的远期疗效分析

目的 评价CarneyⅡ式原位回肠膀胱术后患者的远期疗效.方法 膀胱移行细胞癌行根治性膀胱切除CarneyⅡ式原位回肠膀胱术患者33例.采用美国癌症患者生命质量量表(FACT)和国际前列腺症状评分(IPSS)衡量患者术后生活质量,采用膀胱容量、最大尿流率、残余尿量,充盈期膀胱压力等尿动力学结果评估回肠膀胱功能.结果 33例患者中,术后10个月因肿瘤尿道复发死亡1例,失访2例.30例患者随访12～60个月.术后尿动力学检查回肠膀胱容量(380±65)ml、最大尿流率(12.6±2.3)ml/s、残余尿量(25±11)ml,充盈期膀胱压力明显低于尿道闭合压[(20.4±8.7)cm H2O(1 cm H2O=0.098 kPa))与(57.2±10.5)cm H2O,P<0.05].并发肾功能不全1例、尿瘘2例.术后1年28例患者白天控尿均满意,夜间控尿满意26例.FACT评分为(110.5±16.0)分,IPSS评分(14.5±4.2)分.结论 CarnyⅡ式原位回肠膀胱术式是一种效果良好、并发症较低的尿流改道术,有较好的临床应用价值.     

女性可控性回肠膀胱术的远期疗效分析

目的 探讨女性可控性回肠膀胱术的远期随访疗效.方法 女性膀胱肿瘤患者19例,年龄45～66岁,平均52岁.病程16 d～1.9年,平均4.4个月.临床表现均有间歇性无痛性全程血尿.肿瘤单发14例,多发5例.活检病理均为移行细胞癌.分级:G1 10例、G2 7例、G3 2例,UICC分期:pT1 5例、pT2 12例、pT3a 2例.肿瘤距膀胱颈部>2cm.尿道无肿瘤,无尿失禁.19例均采用改良根治性膀胱全切除术,不切除子宫及阴道前壁,保护支配尿道的神经,清除盆腔脂肪淋巴组织,切除近端尿道0.8～1.2cm.应用末端回肠30 cm制作新膀胱.原位尿道吻合.结果 19例手术及术后恢复顺利.术后失访3例.16例随访6～102个月,平均71个月.无瘤存活15例,术后17个月死于心肌梗死1例.术后9个月昼、夜控尿率分别为100%(16/16)和93%(14/15).术后9个月,15例行尿动力学测定,新膀胱容量(519.0±53.0)ml,残余尿量(29.2±4.9)ml,最大尿流率(18.6±2.8)ml/s;平均充盈压力和排尿压力分别为(16.7±3.5)和(53.0±5.0)cm H2O(1 cm H2O=0.098 kPa).术后9个月IVU检查单侧上尿路轻度积水1例,血BUN、Cr、电解质及二氧化碳结合力均正常.肿瘤无复发.结论 女性可控性回肠膀胱术后控尿功能良好,新膀胱容量大、压力低、顺应性好,并发症少,是女性膀胱原位重建的良好术式.     

CONTINENT ILEAL NEOBLADDER URINARY DIVERSION: AS AN ALTERNATIVE TO ILEAL CONDUIT DIVERSION

Total bladder replacement with an ileal neobladder was performed in five male patients undergoing cystoprostatectomy. The surgical technique and short-term results are reported. Four of these patients exhibited total urinary continence day and night. One patient was totally continent during the day but had difficulty with continence at night due to mucus leakage. All patients demonstrated satisfactory bladder emptying (average post-micturition residual < 40 mL) with a flow rate of 4–15 mL/s. Until 1989 the ileal conduit, first described by Bricker in 1950, was used as the preferred method of urinary diversion. We believe that the ileal neobladder in male patients is an excellent bladder substitute with an associated low operative and peri-operative morbidity and a high long-term continence rate, allowing the patient to be free from urostomy.     

Real-time MRI of orthotopic ileal neobladder voiding: preliminary findings

Objectives

The purpose of this preliminary study was to analyze the dynamic changes in the configuration of the neobladder and naïve bladder during voiding using real-time MRI.

Methods

This study included 10 male patients who had a radical cystectomy and an ileal orthotopic neobladder due to organ-confined bladder cancer and had good urinary function, and 5 male control volunteers. With the subjects in the lateral decubitus position, real-time MRI was performed during micturition. A sagittal slice orientation was used to depict the bladder and the entire length of the urethra; individual movements along the X-axis and Y-axis of the bottom and top of the neobladder and the naïve bladder were recorded and analyzed. Urodynamic studies (UDS) and video voiding cystourethrography were performed in patients.

Results

Five of the 10 neobladder patients could void in the lateral decubitus position. In normal controls and patients who could void, the bladder outlet bladder moved ventrocranially during micturition. The ileal bladder outlet moved a significantly longer distance than the naïve bladder during micturition (X-axis, −13.4 ± 1.5 vs. −3.6 ± 4.3 cm, p = 0.0014; Y-axis, −10.6 ± 0.5 vs. −2.0 ± 6.5 cm, p = 0.0187). The distance that the bladder top moved between the naïve bladders and the neobladder did not differ. UDS did not show a difference between patients who could and could not void at lateral position.

Conclusions

During micturition, the neobladder was found to rotate and move more dynamically than the naïve bladder. Real-time MRI is useful for assessing dynamic voiding function of orthotopic neobladders.     

腹腔镜下根治性膀胱切除回肠新膀胱术（附15例报告）

目的介绍腹腔镜下根治性膀胱切除回肠新膀胱术的方法及经验。方法本组15例，均为男性，年龄45～62岁，平均54岁。术前均明确诊断为浸润性膀胱癌。采用腹腔镜下行膀胱癌根治性切除，然后取长约40cm回肠于体外缝制贮尿囊及输尿管贮尿囊吻合，体内行贮尿囊尿道吻合术。结果手术时间5．5～8h，平均6．5h；出血量200～1100ml，平均550ml。术后8周静脉尿路造影以及代膀胱造影检查显示：双肾显影良好，无输尿管返流及梗阻，代膀胱充盈良好，容量约300ml。术后3个月全部患者日间控尿良好，7例患者夜间控尿良好，夜间排尿2～3次。结论腹腔镜下膀胱全切除、体外建成贮尿囊及输尿管再植、体内贮尿囊尿道吻合术创伤小、出血少、术后尿控率高、恢复快。     

机器人辅助腹腔镜体内原位U形回肠新膀胱术的临床疗效观察及尿动力分析

目的探讨采用da Vinci Xi机器人系统完成机器人辅助腹腔镜下根治性膀胱切除（RARC）加体内构建原位U形回肠新膀胱术的临床疗效,并结合术后尿动力分析评价该术式对排尿的影响及可能机制。 方法以2020年6月至2021年3月连续进行的8例机器人辅助腹腔镜下根治性膀胱切除+体内原位U形回肠新膀胱术患者为研究对象,其中男7例,女1例,年龄63（18）岁,极高危非肌层浸润膀胱癌1例,肌层浸润性膀胱癌7例,术后随访时间为3~12个月。记录随访期间患者的尿控恢复、分肾功能、上尿路影像学结构改变以及肿瘤学预后。 结果8例手术均成功完成,并发症发生率37.5%,术后3个月日间完全尿控率87.5%,夜间功能性尿控率75.0%,术后6个月尿动力分析示：最大尿流率和平均尿流率分别为19.8（3.97）ml/s、5.05（0.94）ml/s,最大尿道压81.5（28.75）cm H₂O,新膀胱顺应性26.5（12.75）ml/cm H₂O。 结论RARC术后实施体内原位U形回肠新膀胱术是可行的,具有可重复性,是一种疗效确切、尿控恢复理想的膀胱根治性切除术后新膀胱替代方案。     

机器人辅助全腹腔镜下"紫砂壶型"原位回肠新膀胱的临床疗效分析

目的探讨机器人辅助全腹腔镜下"紫砂壶型"原位回肠新膀胱患者的尿控和肿瘤学预后。 方法以2017年5月至2019年6月连续进行的10例机器人辅助根治性膀胱切除+回肠原位新膀胱术患者为研究对象，男9例，女1例，年龄（63±11）岁，极高危非肌层浸润膀胱癌5例，肌层浸润性膀胱癌5例；术后随访时间为12～37个月。记录手术视频、术后90 d内并发症、随访期间患者的尿控恢复、分肾功能、上尿路影像学结构改变以及肿瘤学预后。 结果10例患者均顺利完成全腹腔镜下机器人辅助根治性膀胱切除回肠原位新膀胱手术，手术时间（584±56）min，出血量（655±275）ml，术后进食时间1～3 d；1例患者术后6个月行切口疝修复术，其余无Ⅲ级以上并发症。5例（50%）患者术后6～12个月尿流动力学检查提示最大尿流率及平均尿流率分别为（6.3±4.5）ml/s、1.80（0.30）ml/s，术后新膀胱充盈尿量及残余尿量分别为（525±273）ml、161（227）ml，患者日间完全控尿9例（90%），夜间完全控尿8例（80%）。随访期间，发现4侧肾盂轻度扩张，监测分肾功能正常。1例患者术后18个月出现肺转移，其余患者未发现局部复发及转移。 结论"紫砂壶型"回肠原位新膀胱是在Studer型、VIP型回肠新膀胱基础上的储尿囊成型技术改进，术后新膀胱功能良好，能有效保护上尿路形态，恢复排尿功能。     

Significance of renal function in changes in acid–base metabolism after orthotopic bladder replacement: Colon neobladder compared with ileal neobladder

BACKGROUND: The objective of this study was to determine whether renal function influences the acid-base metabolism in patients undergoing orthotopic bladder replacement using intestinal segment. METHODS: Acid-base balance, serum electrolytes and renal function were studied in 30 patients with colon neobladder and 18 patients with ileal neobladder. Mean follow up was 51 months. Effects of renal function on acid-base metabolism in both types of bladder replacement were compared. Therapeutic efficacy of the sodium bicarbonate administration was also evaluated in cases with hyperchloremic acidosis. RESULTS: No significant differences were observed in any of the variables examined between the colon and ileal neobladder groups, except for potassium concentration. Although metabolic acidosis was detected using the Siggard-Anderson acid-base nomogram in eight (26.7%) and seven (38.9%) patients in the colon and ileal neobladder groups, respectively, this difference was not significant. In both the colon and ileal neobladder groups, the serum creatinine concentrations in patients diagnosed with metabolic acidosis were significantly higher than in those diagnosed with a normal metabolic status. Furthermore, as a result of severe metabolic acidosis, three (10.0%) and three (16.7%) patients in the colon and ileal neobladder groups, respectively, were administered sodium bicarbonate and their metabolic status was fully normalized. CONCLUSIONS: Despite there being no statistical difference, patients with ileal neobladder may more easily develop metabolic acidosis compared with those with colon neobladder. In addition, a close association between the serum creatinine level and the degree of metabolic acidosis was observed in both groups. However, even if severe metabolic acidosis occurs, it is relatively easy to correct using sodium bicarbonate. These findings suggest that it might be safe to use a colon segment for orthotopic bladder reconstruction in patients with higher serum creatinine levels, despite no significant difference in acid-base metabolism and detection rates of metabolic acidosis between the colon and ileal neobladder groups.     

Experience with the orthotopic ileal neobladder in women: a mid-term follow-up

OBJECTIVE: To report our experience with orthotopic bladder reconstruction in women, as currently the ileal orthotopic neobladder is the diversion of choice for women requiring a bladder substitute at our institution. PATIENTS AND METHODS: From February 1995 to March 2001, 29 women with muscle-invasive bladder carcinoma underwent a nerve-sparing radical cystectomy and had an orthotopic ileal neobladder reconstructed. The outcome was evaluated at 2 and 6 months and then yearly, by a clinical history, physical examination, voiding diary, stress test and estimate of functional neobladder capacity. RESULTS: All patients were followed for at least 14 months (mean 27.5); there were no major complications related to the surgery. The mean (range) neobladder capacity 2 months after surgery was 250 (190-320) mL; at 6 months it increased, remaining stable for the remaining follow-up, at 450 (350-700) mL. Four patients (14%) had nocturnal incontinence and one stress urinary incontinence, associated with using three pads per day. Three patients (10%) required catheterization for a postvoid urinary residual of >100 mL. Of the 29 patients, seven died with metastatic disease and three from causes unrelated to the reservoir or bladder cancer. Currently, 19 patients (65%) are alive and disease-free, with a mean follow-up of 35 months. CONCLUSION: Orthotopic neobladder reconstruction in women, using 40 cm of ileum, is safe and gives high continence and low urinary retention rates. Therefore, it should be advised as the first option in women with good renal function and a tumour-free bladder neck.     

Ileocaecal vs ileal neobladder after radical cystectomy in patients with bladder cancer: a comparative study

OBJECTIVE: To compare an ileocaecal orthotopic bladder, (which has been the standard procedure in Egypt for >30 years) with the ileal neobladder, as there is no ideal continent orthotopic bladder replacement for patients after cystectomy for bladder cancer. PATIENTS AND METHODS: Between June 1999 and December 2001, 60 patients with invasive bladder cancer were randomized into two groups. Group A comprised 29 patients who had radical cystectomy and reconstruction with an ileal neobladder (median age 50 years, 27 men and two women) and group B included 31 who had an ileocaecal bladder substitution after radical cystectomy (median age 51 years, 28 men and three women). RESULTS: The complication rate after surgery in group A was 17%, with two deaths, one from acute myocardial infarction and the other from haematemesis. In group B, the complication rate was 13%, with two deaths, one from a massive pulmonary embolism and the other from liver cell failure. Daytime continence was achieved in 93% of patients in group A and 90% in group B. The mean (sd) postvoid residual urine volume was larger in group A than group B, at 90 (72) vs 12 (20) mL. Acidosis and hyponatraemia were evident in the patients in group A but in none in group B (P < 0.05). The pelvicalyceal systems were preserved in 85% of patients in group A and 93% in group B during the 2-year follow-up. The mean (sd) renal cortical thickness was less in group A than in group B, at 1.8 (0.5) and 1.9 (0.2) cm, respectively. Although the cystometric capacity was greater and the basal pressure less in group A than B, these were not reflected in the degree of diurnal and nocturnal continence or back pressure on the renal units. CONCLUSION: Continence in both pouches was similar but the renal units were preserved better in the ileocaecal than in the ileal neobladder. Residual urine volume was greater in the ileal neobladder, with its potential complications of infection and stone formation, and acidosis was more evident.     

Orthotopic Ileal Neobladder Reconstruction after Renal Transplant

Radical cystectomy and urinary diversion is an effective curative treatment for muscle invasive bladder cancer. The orthotopic ileal neobladder has become a favorable choice of urinary diversion as it offers superior quality of life, cosmetic outcome and the potential for normal voiding. We treated two patients with bladder cancer who previously underwent renal transplant for end-stage renal disease. Radical cystectomy and orthotopic ileal neobladder reconstruction was performed in both patients. One patient had two renal transplants and underwent transplant nephrectomy at the time of cystectomy. In the other patient, the native kidneys were still present and the ureters were anastomosed to the neobladder. There is excellent function of the neobladder. There were no increased complications seen in these patients. Our cases demonstrate that an orthotopic ileal neobladder is safe and feasible after renal transplant and should be offered to these patients.     

d-Xylose absorption after urinary orthotopic bladder replacement: colon neobladder compared with ileal neobladder

BACKGROUND: To evaluate the digestive and absorptive status using the D-xylose test in patients who underwent radical cystectomy and orthotopic bladder replacement either by colon or ileal segment. METHODS: D-xylose serum levels after an oral load, nutritional status, plasma vitamin B12 levels, and acid-base and electrolyte balances were studied in 18 patients with colon neobladder and 12 patients with ileal neobladder. Mean follow-up period was 51 months. Results of both types of bladder replacement and a healthy control group were compared. RESULTS: Although no significant difference in the changes of plasma levels of D-xylose after oral load was observed between patients with colon neobladder and healthy controls, plasma levels of D-xylose 90 min after oral load in patients with ileal neobladder were significantly lower than those with colon neobladder. In contrast, there was no significant difference in nutritional status, plasma levels of vitamin B12, and acid-base and electrolyte balances between patients with colon and ileal neobladders. CONCLUSION: Despite acceptable nutritional status, intestinal malabsorption might be present in patients with ileal neobladder, as indicated by the plasma levels of D-xylose, while the colon neobladder group showed no significant differences compared with normal controls. Therefore, absorptive and metabolic status should be carefully monitored after ileal neobladder creation.     

Incontinence after augmentation cystoplasty and internal diversion

The collective published experience with continent urinary diversions, together with our own, indicates that there are certain basic principles with regard to continence, which is dependent on: (1) the pressure generated by the reservoir; (2) the outflow resistance of the outlet; and (3) detubularization, which is crucial to diminish the uninhibited involuntary bowel contractions. Detubularized ileal pouches provide the lowest pressures (less than 20 cm H2O). Although the majority of patients (approximately 85%) who have a low-pressure ileal neobladder are completely continent, a few experience persistent nocturnal incontinence as a result of low resting urethral pressure. Numerous continence methods have been described, each with its own unique set of problems. The most physiologic continence mechanism is the external urethral sphincter in men. It is clear that total continence with this mechanism is not assured. Other factors such as reservoir contractions, overflow incontinence, decreased sphincter tone, and loss of the normal vesicourethral reflex play an important role in nocturnal incontinence. However, understanding these contributing elements will allow us to refine the construction of a continent physiologic bladder substitute.