A model for a bladder replacement plasty by an ileal reservoir--an experimental study in dogs

Stem cells for urinary tract regeneration

Regeneration of the urinary bladder is a complicated task, due to organ dimensions and diseases (cancer, interstitial cystitis) when autologous bladder cells cannot be used. Cancer is the most frequent indication for bladder removal (cystectomy). Stem cells can be used with the guarantee of the sufficient cell number for the in vitro construction of the urinary bladder wall. Tissue engineering techniques hold great promise for regeneration of dysfunctional urinary sphincter. Denervation following surgical procedures or injuries results in weakness of the urethral sphincter and stress urinary incontinence. Injectable therapies and the potential of stem cells for sphincter restoration was presented in this review. The aim of this review was to present possibilities of urinary bladder regeneration with the use of stem cells and tissue engineering techniques.

Modified technique for the creation of an orthotopic neobladder in patients with shortened mesentery: making up the difference between the bladder and the urethral stump

OBJECTIVE

To describe an ileal neobladder reconstruction technique performed in 5 men who had previous abdominal surgeries and presented with a short mesoileum at the time of bladder replacement.

METHODS

The patients were 5 men scheduled for a radical cystoprostatectomy with bladder substitution and had a short mesoileum at the time of the surgery. All patients had a history of abdominal surgery. A neobladder was constructed in a "J" shape leaving the most proximal part of the ileum (8-10 cm) tubularized. We created a 3- to 4-cm flap from the surface of the most distal region of the reservoir. This flap was tubularized to lengthen the neobladder onto the urethral stump, resulting in a tension-free anastomosis. All patients underwent a complete clinical laboratory evaluation 12 months after the surgery.

RESULTS

At 1 year after surgery, all patients were able to void spontaneously. Day and night time continence were 80% and 60%, respectively. Urodynamic evaluation revealed a neobladder with good capacity (mean = 521 ml) and compliance (mean = 27.2 mL/cm H(2)O). Only 1 patient demonstrated a moderate hydronephrosis of the right kidney.

CONCLUSION

Candidates for orthotopic neobladders who have had previous abdominal surgeries and who have a short mesoileum at the time of the surgery are uncommon. Despite the small number of cases, our technique is noteworthy for having achieved good functional results during the short-term follow-up. This technique is advantageous because it is easy to perform and does not require any other bowel resection or anastomose.

Animal models in urinary diversion

We set out to critically assess the value of animal experimentation in urinary diversion through intestinal segments, as some authors question the effectiveness of animal research, criticising the methodological quality, lack of standardization, inadequate reporting and the few systematic reviews in this field. Based on a comprehensive MEDLINE literature search (MeSH database; search terms: urinary diversion, urinary reservoirs, continent, rat, dog, animal models) we retrieved and evaluated all full-length papers published in English, German, French, and Spanish languages from 1966 to 2011 reporting the use of animal models in the setting of urinary diversion. Studies were stratified according to the addressed research question. Within each category species, gender, number of animals, age at procedure, type of diversion, mortality, length of follow-up, experimental procedure and outcome were recorded and tabulated. In all, 159 articles were judged to be relevant and while there are numerous animal models only a few have been used in more than one study. Animals were used for the systematic study of new surgical techniques (93 articles) or metabolic and functional consequences of urinary reconstruction (66 articles). For the latter purpose, the most often used animal is the rat, whereas the dog model is preferred for technical experimentation. In many studies, the validity of the model is at least questionable. Animal experiments have repeatedly been conducted addressing the same question, often with striking discrepancies in outcome. Animal studies were even performed after a surgical technique had been pioneered in humans. The use of animal models in urinary diversion is far from standardized rendering the results less than ideal for comparison across studies. Due to differences in anatomy and physiology, the applicability of findings in animal experiments to clinical urology is limited. Continued effort is needed to optimise the use of animal models in experimental urology.

Strategies to treat children with end-stage renal dysfunction and severe lower urinary tract anomalies for receiving a kidney transplant

Dealing with children with bladder dysfunction and kidney transplant is certainly not a new issue. Nevertheless, it is still a matter of discussion and dilemma, based on few, not standardized, institutional center experiences. The authors perform a review of the techniques employed to restore the bladder condition in terms of storage and drainage of urine to receive a kidney transplant in a safer condition. Aspects of the etiology and the way of evaluation of such a group of patients are discussed. The strategies and individualized therapeutic options are presented and compared with the author's experience based upon 25 children with urinary anomalies who received 28 kidney transplants. Nevertheless, the number of complications, mainly UTI, graft and patient survival rates are equivalent to the group of children with non-urological causes of ESRD. Patients with severe lower urinary tract abnormalities and ESRD may receive a kidney transplant with comparable success.

Long-term results of standard procedures in urology: the ileal neobladder

Over the past 20 years orthotopic urinary reconstruction with the techniques developed at Ulm and Bern has become a widely accepted form of urinary diversion. So far, both centers together have performed more than 1,300 orthotopic bladder substitutions with an overall rate of neobladder formation in 58% of all cystectomized patients. Today, the absolute contraindications for this procedure are urinary stress incontinence, damaged rhabdosphincter, severely impaired renal and liver function, severe intestinal diseases or an oncologic situation requiring urethrectomy. In patients treated for transitional cell carcinoma of the bladder, the rate of urethral recurrence in both centers was 1.5 and 5%, respectively, and the rate of upper urinary tract recurrence was 2-3%. Local tumor recurrence usually did not affect neobladder function. The rate of outlet obstruction by local recurrence was 2%, that of gross hematuria 1%, and of entero-reservoir fistulas 1-2%. Daytime continence at 12 months was 92%, while nighttime continence was lower around 80%. Transient or permanent urinary retention was seen in 11-12% of male patients. In both series, long-term upper urinary tract safety was good. The risk of stenoses of the uretero-intestinal anastomosis with consecutive loss of renal function decreased with the introduction of non-refluxing implantation techniques. The rate of long-term metabolic complications remains low when adequate substitution with sodium bicarbonate is guaranteed in patients with impaired renal function. Patient selection and meticulous postoperative follow-up contributed to achieve good long-term results after cystectomy and orthotopic ileal neobladder substitution of the two large series of patients from the Universities of Ulm and Bern.

Twenty Years Experience With an Ileal Orthotopic Low Pressure Bladder Substitute—Lessons to be Learned

PURPOSE

We present the long-term results of a large consecutive series of patients undergoing ileal orthotopic bladder substitution following radical cystectomy.

MATERIALS AND METHODS

Between April 1985 and 2005 orthotopic bladder substitution with an ileal low pressure reservoir was performed in 482 patients (including 40 women) after radical and, if possible, nerve sparing cystectomy. In 447 cases the procedure was combined with an afferent ileal isoperistaltic tubular segment. The patients were followed prospectively.

RESULTS

In the 482 patients 61 early (less than 30 days) diversion related complications requiring prolonged hospital stay or readmission were noted and 115 late complications required treatment. At 1 year continence was good in 92% of patients during the day and in 79% at night. At last followup 93% of patients could void spontaneously. Of 442 evaluable men 99 (22.4%) reported having erections without and 68 (15.4%) with medical assistance. Ureteroileal stenosis was observed in 12 of 447 (2.7%) patients. Urethral recurrence was detected in 25 of 482 (5%) patients. A total of 15 (5%) patients received vitamin B12 substitution. Renal parenchyma decreased only in patients with preoperative or postoperative ureteral obstruction. After 10 years patients with normal renal function had no long-term acidosis and in 20 patients the incidence of osteoporosis resembled that of the normal population.

CONCLUSIONS

Ileal orthotopic bladder substitution combined with an afferent ileal tubular segment allows for good long-term functional results provided patients are restrictively selected, postoperative instructions are followed carefully, and typical complications such as outlet obstruction and hernias are treated early.

Orthotopic continent urinary diversion an ileal low pressure neobladder with an afferent tubular segment: how I do it

The surgical technique described here is not more complex than that of an ileal conduit but has significant advantages. The aboral end of an isolated portion of the distal ileum is formed into a low pressure, high capacity bladder substitute that combines Goodwin's 'cup-patch' technique and Couvelaire's ileo-urethral anastomosis. Although the neobladder is constructed from only about 40 cm of ileum, it achieves a capacity of 500 ml within a few weeks, simultaneously with rapid improvement of urinary incontinence. The procedure described is easy to perform and its long-term functional results have passed the test of time. Aside from the surgical technique per se, success with this method of bladder substitution is mainly ascribed to meticulous postoperative care and follow-up.

Augmentation cystoplasty in renal transplantation: a good and safe option--experience with 25 cases

OBJECTIVES

To assess the surgical and long-term results of renal transplantation in 25 patients with bladder dysfunction and augmentation cystoplasty.

METHODS

We retrospectively reviewed the evolution and surgical outcome of 25 renal transplants in 24 recipients with augmentation cystoplasty. The mean patient age at transplantation was 27.6 years. The etiology of bladder dysfunction was neurogenic bladder with detrusor hyperreflexia (11 patients), tuberculosis (5 patients), vesicoureteral reflux (4 patients), posterior urethral valves (3 patients), and interstitial cystitis (1 patient). Seventeen transplants were from living donors. Augmentation cystoplasty was performed before transplantation in 21 patients. The bowel segments used in the augmentation cystoplasty included ileum in 16, ileocecal segments in 2, and sigmoid in 5 patients. The donor ureter was anastomosed to the native bladder in 16 patients, to the bowel segment in 6, and to the native ureter in 3.

RESULTS

Twenty kidneys (80%) were functioning at a mean follow-up of 53.2 months (range 6 to 118). The mean serum creatinine was 1.56 mg/dL (range 0.7 to 2.6). Three patients died of unrelated causes and 1 of adenocarcinoma that originated at the vesicointestinal anastomosis. The actuarial graft survival at 1, 2, and 5 years was 96%, 92%, and 78%, respectively. Complications included symptomatic urinary infection, ureteral stenosis, and lymphocele.

CONCLUSIONS

Augmentation cystoplasty is a safe and effective method to restore function in noncompliant bladders. Renal transplantation can be performed safely after augmentation cystoplasty.

Laparoscopic orthotopic ileal neobladder

BACKGROUND AND PURPOSE

Orthotopic ileal neobladder is currently the preferred continent urinary diversion in suitable patients undergoing radical cystectomy for muscle-invasive bladder cancer. To our knowledge, presented herein is the initial report of laparoscopic orthotopic ileal neobladder following cystectomy that was performed completely intracorporeally in a porcine model.

MATERIALS AND METHODS

The laparoscopic technique was developed in seven pigs. Subsequently, a long-term survival study was performed in 12 consecutive animals. Laparoscopic cystectomy was performed, preserving the urethral sphincter. An ileal segment of 35 cm (first three animals), 45 cm (next four), or 55 cm (final five animals) with adequate mesentery was isolated; and ileal continuity was restored intracorporeally by a stapled anastomosis. Ileal detubularization for construction of an ileal neobladder, urethroileal anastomosis, and bilateral stented ileoureteral anastomoses to a tubular Studer limb extension were all created completely intracorporeally using only laparoscopic free-hand suturing and knot-tying. Biochemical data (preoperative and serial postoperative hemoglobin, renal panel, blood gases), radiologic studies (intravenous urogram, retrograde pouchgram), functional measures (neobladder urodynamics, Whitaker pressure-flow study of both ureters), and microscopic evaluation of the neobladder and ureteroileal and urethroileal anastomotic sites were obtained to evaluate the long-term functional and anatomic outcome.

RESULTS

Completely intracorporeal laparoscopic construction of an ileal orthotopic neobladder was successful in all 12 animals without intraoperative or early postoperative complications or open conversion. The mean operating time was 5.4 hours (range 4.5-6.5 hours), and the blood loss was minimal. All study pigs survived their predetermined follow-up period, ranging from 1 to 3 months. Late complications occurred in three animals: one port-site abscess and two cases of E. coli pyelonephritis and azotemia, leading to one death at 2 months. The mean serum creatinine concentrations were 1.33 mg/dL, 1.61 mg/dL, and 1.55 mg/dL at 1, 2, and 3 months, respectively. The mean neobladder capacity was 420 mL (range 250-700 mL) with pressures < or = 20 cm H2O (range 17-20 cm H2O). Pre-euthanasia Whitaker testing confirmed excellent drainage in all 24 ureters. No ileoureteral or ileourethral anastomotic strictures or leaks were noted on intravenous urography, retrograde pouchgram, or postmortem physical calibration of the anastomotic sites. Histologic examination confirmed excellent healing without obvious fibrosis.

CONCLUSION

Laparoscopic construction of an orthotopic neobladder is feasible. The anatomic and functional outcome is excellent and comparable to that of open surgery. Clinical application is imminent.

Isolation of human intestinal defensins from ileal neobladder urine

We describe the isolation of naturally occurring human intestinal defensins HD-5 and HD-6 from ileal neobladder urine and ileal mucosa. Using an antibody-based detection assay, we found multiple N-terminally processed forms of HD-5. The predominant HD-5 forms in tissue were longer than those in neobladder urine (amino acid (aa) 23-94 and 29-94 versus aa 36-94, 56-94 and 63-94) suggesting that Paneth cells store prodefensin that is processed to mature defensin during or after degranulation. Search for mature HD-6 yielded aa 69-100 as the predominant form in both sources. The ileal neobladder is a promising model to study human Paneth cell secretion.

Ileal orthotopic bladder substitutes. What we have learned from 12 years' experience with 200 patients

The perfect bladder substitute has not been devised yet. The ileal orthotopic bladder substitute, however, provides adequate capacity, convenient voiding patterns, optimal continence rate, preservation of renal function, acid-base balance, and calcium metabolism. The authors describe important surgical details based on experience with more than 200 patients. To achieve a good functional result, patient selection, postoperative voiding reeducation, and meticulous follow-up are important.

Summary of 10 years' experience with an ileal low-pressure bladder substitute combined with an afferent tubular isoperistaltic segment

We report on 10 years of experience with an ileal low-pressure bladder substitute combined with an afferent tubular segment following cystectomy in 100 consecutive men. The median follow-up period was 30 months (range 3-108 months), with a 2.5-year minimum in survivors. A total of 42 patients died, 33 of these dying of bladder cancer. The early complication rate was 11%, including 2 deaths due to postoperative sepsis. In all, 14 patients required reoperation for late complications. The reservoir's median functional capacity increased to 500 ml at 12 months and was paralleled by improving continence: 92% by day (after 1 year) and 80% by night (after 2 years). Four ureteric strictures occurred. No coordinated, isolated pressure rise developed in the reservoir during voiding, which was accomplished by pelvic floor relaxation with abdominal straining, if necessary. Raised intraabdominal pressure acted equally on the reservoir and ureters, preventing reflux during voiding. This technique is straightforward, allows radical cancer surgery, and protects the upper tract. The favorable functional results are comparable with those achieved by similar techniques, but meticulous follow-up is essential.

Urodynamic and clinical aspects of ileal low pressure bladder substitutes

Twenty-three patients with an ileal bladder substitute formed after cystectomy for invasive bladder cancer were evaluated clinically and urodynamically between 3 and 38 months post-operatively. The urodynamic measurements were compared with the clinical findings. After re-education of the patients' voiding habits the mean voiding volumes of the bladder substitutes stabilised 6-9 months post-operatively at 350 ml. The frequency of micturition was 3 to 5 times during the day and once or twice at night. The maximum functional capacity (maximum voiding volume) was about 490 ml. Ninety-one per cent of the patients were continent during the day 18 months after the operation and 82% were continent during the night. Micturition was problem-free with an average maximum flow of 25 ml/s and an average micturition time of 50 s. The mean voiding volume of ileal bladder substitutes was 50% of the measured cystometric capacity; the maximum functional capacity (= max. micturition volume) was 80% of the cystometric capacity. The average basal pressure was < 20 cm H2O from the third post-operative month onwards. Eleven of the 23 patients had contractions in the bladder substitute (average at 30 cm H2O) at 55-76% of the maximum cystometric capacity or at approximately 90% of the maximum functional capacity. Such spike waves had no clinical or radiological consequences. If the patients were shown how to increase the functional capacity of a reservoir made from only 40 cm of ileum, the clinical results were excellent.

Three years' experience with an ileal low pressure bladder substitute

At the beginning of this century it was realised that peristalsis would cause incontinence if bowel was used for augmentation or substitution of the bladder. Trans-section of the antimesenteric border and cross-folding of the intestinal segments (Goodwin's cup-patch technique) is an efficient means of solving this problem and has been successfully used in the Kock pouch. We anastomosed the ileal low pressure reservoir to the membranous urethra in 22 male patients following radical cystoprostatectomy for bladder cancer. The mean observation time was 16 months (range 3-36). The capacity of the bladder substitute increased with time, the average being 450 ml after 6 months. In the first 4 patients with a short (2-5 cm) intestinal segment between the pouch and the urethra, micturition was prolonged, residual urine varied from 50 to 300 ml and bacteriuria was found. Occasional expulsions of several ml of urine were caused by peristalsis within this short tubular segment. In the following 18 patients, the low pressure reservoir was anastomosed directly to the membranous urethra. Micturition was good, with no notable residual urine, no bacteriuria and no paroxysmal urinary incontinence. However, a safety pad is used by half of the patients because once or twice a week, mainly at night, a few ml of urine may be lost. No significant changes in serum electrolytes, bicarbonate or creatinine were noted. With the three different antireflux techniques used, no obstructive or inflammatory changes in the upper urinary tracts were found, although no long-term antibiotic prophylaxis was given.

100 cases of Mainz pouch: continuing experience and evolution

The surgical technique for creation of the Mainz pouch uses 10 to 15 cm. of cecum and ascending colon and 2 ileal loops of the same length for construction of a urinary reservoir. Initial applications of the Mainz pouch were for bladder augmentation after subtotal cystectomy and for continent urinary diversion. Current indications have been extended to complete bladder substitution after radical cystoprostatectomy with anastomosis of the pouch to the membranous urethra. For cosmetic reasons the umbilicus is used as a stomal site for continent urinary diversion, and the technique of intussuscepting the continence nipple has been modified accordingly. A total of 100 patients underwent a Mainz pouch procedure since 1983: 34 for bladder augmentation, 15 for total bladder substitution after cystoprostatectomy and 51 for continent urinary diversion. In the bladder augmentation group 1 patient underwent conversion to a continent stoma, 1 has urge and frequency, and the remaining 32 are completely dry day and night. These patients empty the bladder at normal intervals spontaneously except for 3 who rely on intermittent catheterization. In the bladder substitution group 1 patient has grade 1 stress incontinence and the remainder are completely dry during the day. However, at night 4 patients have leakage and they use a condom urinal. In the urinary diversion group all but 2 patients are completely dry and are on intermittent catheterization. The main problem of the initial series was prolapse of the continence nipple, which has been solved by staple fixation of the nipple to the bowel wall and to the ileocecal valve.

The ileal S-pouch for bladder replacement after cystectomy: preliminary report of 7 cases

In 7 patients with deeply infiltrating bladder cancer an ileal S-pouch was constructed for bladder replacement after radical cysto-vesiculo-prostatectomy and pelvic lymph node dissection. The operative technique and early clinical results are described.

A new technique for continent urinary diversion

Canine experimental surgery was used to investigate the feasibility of creating a new continent urinary reservoir. Remodelled ileum was used to fashion this reservoir like the Kock pouch, but without either of the intussuscepted nipple valves which it uses. Ureters were implanted directly into the wall of the reservoir using a nonrefluxing technique. Continence was obtained by plication of a short limb of intact ileum exiting from the reservoir through which intermittent catheterization was performed. Three of four animals which remained infection-free had good to excellent results. Reservoir infection in four additional animals was associated with failure due to ureteral obstruction. The advantages of this reservoir include the use of ileum to achieve a low-pressure reservoir, the absence of the complex nipple valves of the Kock pouch, and the absence of foreign bodies such as staples and artificial sphincters. While the followup in this study is recognized as relatively short-term, the successes seen in this difficult-to-use animal model suggest that further evaluation of this simplified procedure is warranted.

Bladder replacement with use of a detubularized right colonic segment: preliminary report of a new technique

Dissatisfaction with the long-term results of cutaneous urinary diversion and a demand for a more socially acceptable solution have prompted the development of procedures that allow continent urinary diversion. Creation of an internal reservoir from reconstructed bowel segments, which is anastomosed to the patient's urethra and allows continence and urination through the urethra, is a particularly attractive option. We describe a technique that is relatively easy to perform and that incorporates a detubularized right colonic segment. The advantages of this procedure are discussed.