Nonsecretory sigmoid cystoplasty: experimental and clinical results

Nonsecretory intestinocystoplasty: postoperative outcomes of 25 years

OBJECTIVE

The objective of bladder augmentation (BA) is to create a low-pressure reservoir with adequate capacity. Despite its benefits, the use of intestinal patches in bladder enlargement provides a high risk of developing complications and BA with demucosalised bowel represents a potential alternative. Therefore, this study evaluated urological parameters and long-term clinical follow-up of patients submitted to nonsecretory BA in a single center with 25 years of experience.

MATERIALS AND METHODS

Patients treated with BA underwent urological evaluation, which included history, physical examination and urodynamic study. The main urodynamic parameters (bladder capacity and bladder compliance) were assessed in the pre and postoperative moments, and compared by the Wilcoxon Signed Rank test. The main long-term complications were described.

RESULTS

269 patients (mean age 14±13 years, 47% male) underwent BA with the use of demucolised intestinal segments. Among the patients in the sample, 187 (69.52%) had neurogenic bladder, 68 (25.28%) had bladder exstrophy, nine had tuberculosis (3.34%), four had a posterior urethral valve (1.49%) and one with hypospadia (0.37%). After the surgical procedure, a significant increment in both urodynamic parameters was found, with a 222% increase in bladder capacity and 604% in bladder compliance (p < 0.001 in both analyzes). Mean follow-up time ranged from 2 to 358 months, with a median of 72 months (IQR 74-247). Among all patients, 5 presented spontaneous perforation.

CONCLUSION

The study showed statistically signifi cant increase in both compliance and bladder capacity after non-secretory BA, with a low rate of severe complications.

Outcomes of seromuscular bladder augmentation versus standard ileocystoplasty: A single institution experience over 14 years

INTRODUCTION

Ileocystoplasty is the standard technique used for bladder augmentation, and has been used widely for decades. However, it is known to be associated with complications such as stone formation, mucus production, metabolic acidosis, urinary tract infections, intestinal obstruction, and a long-term risk of bladder cancer. Seromuscular bladder augmentation (SMBA) is an alternative to the standard ileocystoplasty, and has been associated with a lower incidence of bladder stones. Few reports have been published on intermediate outcomes of SMBA. Herein, we report long-term outcomes of SMBA from a single institution compared with standard ileocystoplasty.

METHODS

After Institutional Review Board approval, a retrospective chart review of all patients who underwent bladder augmentation at our institution over a 14-year period was performed. The status of patients after SMBA (10 patients) was compared according to age, sex, and diagnosis with patients who underwent traditional ileocystoplasty (30 patients). Parameters such as demographic information, pre- and postoperative bladder capacity as assessed by urodynamic studies, urinary tract infections (UTIs), bladder calculi, incontinence, need for secondary surgical procedures, and spontaneous bladder perforation were compared in the two groups. All the patients were on a clean intermittent catheterization (CIC) regimen.

RESULTS

Over the study period, 10 patients underwent SMBA and 30 patients (according to age, sex, and diagnosis) underwent standard ileocystoplasty; the average age at surgery was 10.3 and 10 years respectively, with a mean follow up of 6.7 years in the SMBA group and 6 years in the ileocystoplasty group. There were no statistically significant differences in the rate of UTIs, urinary incontinence, subsequent surgery, or spontaneous bladder perforation. The mean bladder capacity increased significantly for both groups as assessed by pre- and postoperative urodynamic studies, although the difference in the rate of bladder calculi between the two groups (0 [0%] vs. 8 [27%], p = 0.06) did not reach statistical significance (Table).

CONCLUSIONS

SMBA is safe and efficacious and may result in a lower rate of stone formation than standard ileocystoscopy. SMBA should be considered as a viable alternative to standard ileocystoplasty.

The evolution of bladder augmentation: from creating a reservoir to reconstituting an organ

Bladder augmentation was first described in 1899. The goal at the time was to establish the ideal method to create a simple capacious reservoir for the safe storage of urine. That simple idea has over the last 100 years grown into one of the most dynamic areas in Pediatric Urology. Creative minds and hands from individuals in multiple disciplines have led us from creating a reservoir to the threshold of recreating a functional organ. In this review, we look at the historical evolution of bladder augmentation and how it exponentially grew in scope from those initial descriptions of intestinocystoplasty to the work being reported today in the field of tissue engineering.

Alternatives to conventional enterocystoplasty in children: a critical review of urodynamic outcomes

Alternatives to conventional enterocystoplasty have been developed in order to avoid the most common complications derived from contact of the urine with intestinal mucosa. In this article critically we review the literature on the topics: ureterocystoplasty, detrusorectomy, detrusorotomy, seromuscular gastroenterocystoplasty, use of off the shelf biomaterials, and bladder augmentation by bioengineering. Recognizing the difficulty of deciding when a child with a history of posterior urethral valves requires and augmentation and that the development of a large megaureter in cases of neurogenic dysfunction represents a failure of initial treatment, we conclude that ureterocystoplasty can be useful in selected cases when a large dilated ureter is available. Seromuscular colocystoplasty lined with urothelium (SCLU) has been urodynamically effective in several series when the outlet resistance is high and no additional intravesical procedures are necessary. Seromuscular gastrocystoplasty lined with urothelium seems to offer no distinct advantages and involves a much more involved operation. The use of seromuscular segments without urothelial preservation, with or without the use of an intravesical balloon has been reported as successful in two centers but strict urodynamic evidence of its effectiveness is lacking. The published evidence argues strongly against the use of detrusorectomy or detrusorotomy alone because of the lack of significant urodynamic benefits. Two recent reports discourage the use of small intestinal submucosa patches because of a high failure rate. Finally, research into the development of a bioengineered bladder constructed with cell harvested from the same patient continues but is fraught with technical and conceptual problems. In conclusion of the methods reviewed, only ureterocystoplasty and SCLU have been proven urodynamically effective and reproducible.

Seromuscular grafts for bladder reconstruction: extra-luminal demucosalisation of the bowel

Objective

To develop a robust sterile, fully demucosalized and vascularized seromuscular patch for use as an adjunct to novel bioengineering techniques aimed at augmenting, reconstructing, or replacing the bladder because of endstage disease. To eliminate deep colonic epithelial crypts to prevent the possibility of colonocyte regrowth. To maintain sterility by excluding the possibility of contamination from the bowel contents.

Methods

Pilot studies were performed on euthanized pigs to optimize the technique, with tissue samples examined by immunohistochemistry. In vivo, vascularized seromuscular colonic flaps were created from the bowel exterior in 7 large white hybrid pigs. The dissection was facilitated by placing an inflated Foley catheter within the colonic lumen. The seromuscular ends were approximated with 5/0 Vicryl sutures and excess mucosa intussuscepted within the lumen. Demucosalized flaps were used to augment the bladder by composite cystoplasty and were examined immunohistochemically at 3 months.

Results

Pilot studies showed that the technique was successful in creating seromuscular segments with no epithelial remnants. When applied surgically, the seromuscular flaps survived and showed no evidence of colonocyte regrowth at 3 months.

Conclusion

Extraluminal dissection creates robust seromuscular flaps and prevents both regrowth by colonic epithelial cells and contamination of the tissue by exposure to the bowel contents. This technique should find application in a range of bladder reconstruction techniques, including composite cystoplasty and autoaugmentation.

From Molecules to Matrix: Construction and Evaluation of Molecularly Defined Bioscaffolds

In this chapter, we describe the fundamental aspects of the preparation of molecularly-defined scaffolds for soft tissue engineering, including the tissue response to the scaffolds after implantation. In particular, scaffolds prepared from insoluble type I collagen fibres, soluble type II collagen fibres, insoluble elastin fibres, glycosaminoglycans (GAGs) and growth factors are discussed. The general strategy is to prepare tailor-made "smart" biomaterials which will create a specific microenvironment thus enabling cells to generate new tissues. As an initial step, all biomolecules used were purified to homogeneity. Next, porous scaffolds were prepared using freezing and lyophilisation, and these scaffolds were crosslinked using carbodiimides. Crosslinking resulted in mechanically stronger scaffolds and allowed the covalent incorporation of GAGs. Scaffold characteristics were controlled to prepare tailor-made scaffolds by varying e.g. collagen to elastin ratio, freezing rate, degree of crosslinking, and GAGs attachment. The tissue response to scaffolds was evaluated following subcutaneous implantations in rats. Crosslinked scaffolds maintained their integrity and supported the formation of new extracellular matrix. Collagen-GAG scaffolds loaded with basic fibroblast growth factor significantly enhanced neovascularisation and tissue remodelling. Animal studies of two potential applications of these scaffolds were discussed in more detail, i.e. for bladder and cartilage regeneration.

Autoaugmentation gastrocystoplasty: further studies of the sheep model

OBJECTIVE

To report our experience with autoaugmentation gastrocystoplasty (AAGC, reported to result in an inconsistent augmentation effect in children) in a sheep model, specifically addressing issues of surgical techniques and postoperative bladder drainage that may affect the augmentation result, as many factors have been implicated in the poor outcome.

MATERIALS AND METHODS

Ten 6-month-old male lambs had a suprapubic catheter placed by an open laparotomy. Intraoperative urodynamics were evaluated before and after detrusorotomy for autoaugmentation and after completing AAGC. The bladder was drained with no distension for 1 week after surgery and the urodynamic evaluation repeated on control and experimental animals 6 months after surgery. The animals were then killed and the bladders evaluated for gastric flap survival and histological changes in the native bladder and augmentation segments. The results were analysed using a one-sided Student's t-test.

RESULTS

The median (range) native bladder volume at leak-point pressure was 110 (40-490) mL. Intraoperative bladder volumes after completing AAGC confirmed adequate augmentation segments in all animals. The urodynamic evaluation at 6 months after AAGC showed increases in bladder volumes in nine of 10 animals (0-1336 mL), significantly greater than the increase in volume in the control sheep (median 337.5 vs 115.3 mL; P < 0.05). The bladder compliance (volume/pressure at leak capacity) 6 months after AAGC was slightly better but not significantly higher than in controls (median 17.3 vs 10.8 mL/cmH(2)O; P > 0.05). The median (range) ratio of surviving gastric flap to native bladder circumferences was 34.5 (31-53)%. Histology showed scarring of the submucosal layer in one of 10 augmentation segments and normal urothelium in all bladders.

CONCLUSION

AAGC produces reliable bladder augmentation and excellent bladder compliance in a sheep model of a non-neurogenic bladder. The gastric flap survived well and there was no bladder wall separation with simple postoperative catheter drainage.

A rabbit model to tissue engineer the bladder

A rabbit model was used for the evaluation of a collagen-based biomatrix of small intestinal submucosa (SIS, COOK) in comparison to a biochemically reconstructed biomatrix for bladder tissue regeneration. Rabbits underwent partial cystectomy and cystoplasty with SIS patch graft or with a biochemically defined collagen biomatrix. The grafts of the regenerated bladder wall were harvested at different intervals and tissue regeneration was evaluated. The results of the SIS and biochemically defined biomatrix grafts were comparable. At harvesting, we found five bladder stones and encrustation of the biomatrix in 21/56 animals. No stone formation was observed in the control group. The results of the molecularly defined biomatrix are thus far comparable to SIS. Both matrices show good epithelialization and ingrowth of smooth muscle cells. Both biomatrices show considerable encrustation, which appears to disappear in time. The rabbit model is suitable for bladder tissue engineering studies as it is an easy model to use. In this model, besides tissue regeneration, also some of the clinical problems are seen such as encrustation of foreign body material in the bladder. These aspects are subject for further pre-clinical studies in this animal model.

NONSECRETORY INTESTINOCYSTOPLASTY: A 10-YEAR EXPERIENCE

PURPOSE

We present long-term results on the use of demucosalized intestine for reconstructive surgery of the bladder.

MATERIALS AND METHODS

A total of 129 bladder augmentations with demucosalized intestine were performed in 123 patients (55% males and 45% females) 3 months to 53 years old during the last 10 years. Of the patients 82 presented with neurogenic bladder, 40 with bladder exstrophy, 3 each with tuberculosis and posterior urethral valves, and 1 with female hypospadias. Sigmoid was used in 104 cases and ileum in 25. In 105 cases a silicone balloon was left inside the augmented bladder for 2 weeks. In the remaining cases bladder mucosa was preserved and no mold was used. A silicone inflatable bladder neck cuff was implanted at the same time as augmentation in 32 patients.

RESULTS

Followup ranged from 3 to 135 months (median 51.0). There was a 329% increase in bladder capacity and compliance increased 7-fold. There were 13 (10.1%) cases considered failures, which were treated with reaugmentation using demucosalized ileum (6), different forms of augmentation (5) and no reaugmentation (2). There was no mucus formation, bladder perforation or neoplasia.

CONCLUSIONS

Based on our study we conclude that demucosalized intestine is a safe alternative for bladder augmentation and can be used for the same indications as total bowel segments.

Bladder augmentation with an omental pedicled gastric seromuscular flap without the necessity of gastric resection

Bladder augmentation using gastrointestinal segments requires gastric or intestinal resection. This has several risks. In a rat model, we aimed to test the efficacy of a new procedure in which a gastric seromuscular (GSM) flap is separated from the gastric mucosa without the necessity of gastric resection, and this GSM flap, based on an omentum pedicle, is transferred to the bladder. A GSM flap based on an omental leaf was dissected from the gastric mucosa and rotated 180 degrees counter-clockwise, after ligation of the vessels relating to the omentum, until the mid-duodenum. After urodynamic analysis for control levels of bladder capacity and pressure, the GSM flap was anastomosed to the bladder with a continuous suture. Because four rats died due to bladder calculi, only 21 of 25 rats were killed at 1 month (n = 10) and 4 months (n = 11) for histopathological and urodynamic evaluations of the augmented bladder. Bladder capacity increased significantly in the augmented bladders compared to preaugmentation (P < 0.001). There was no significant difference between end-filling pressures of the augmented bladders and preaugmentation. Histopathological findings demonstrated that the muscular surface of the flap was completely re-epithelialized in all rats. Squamous metaplasia was detected in 30% (3/10) of the 1 month group rats, and in 55% (6/11) of 4 month rats (P > 0.05). Gross calculi formation appeared in 20% (2/10) of the 1 month group rats, and in 34% (4/11) of 4 month rats (P > 0.05). Our data show that the use of the GSM flap in the bladder of a rat resulted in the complete re-epithelialization of the flap and sufficient bladder capacity. Despite significant complications such as death, metaplasia and calculi, this technique may be considered as an alternative experimental model to traditional full-thickness patching, which needs gastric or intestinal resection.

Detrusorectomy with rectus muscle hitch and backing

PURPOSE

Bladder autoaugmentation is a procedure that includes detrusoromyotomy or detrusorectomy with an aim to release intact urothelium, which then prolapses and increases bladder capacity and compliance. Covering of the prolapsed urothelium usually is done by using deepithelialized pedicled colonic or gastric patch. The authors present their first experiences with detrusorectomy using rectus muscle for hitch and backing.

METHODS

Between August 1999 and February 2002, autoaugmentation was performed in 19 patients (12 girls and 7 boys) aged 4 to 12 years (median, 8). All patients had a neurogenic bladder with small capacity and poor compliance. Detrusorectomy usually involves the whole upper half of the bladder to achieve regular shape of the huge prolapsed urothelium. Both rectus muscles are dissected from their anterior and posterior sheaths. Urothelium is sutured to the muscle at several points to prevent its retraction and shrinkage. This way, bladder is fixed and hanged on rectus muscles.

RESULTS

Follow-up was 6 to 35 months (median, 21). The new bladder capacity was increased in all patients and ranged from 190 to 411 ml (median, 313). All patients had clinical improvement and better compliance.

CONCLUSIONS

Detrusorectomy with rectus muscle hitch and backing is a safe and simple procedure. However, long-term results are needed to define value of this procedure.

Autoaugmentation by Detrusor Myotomy: Its Lack of Effectiveness in the Management of Congenital Neuropathic Bladder

PURPOSE

We present our long-term results in 17 patients with myelomeningocele undergoing autoaugmentation by vesicomyotomy.

MATERIALS AND METHODS

Surgery was performed from 1990 to 1994 on 17 patients with neurogenic bladder due to spinal dysraphism. Indications for autoaugmentation included upper tract deterioration and/or incontinence secondary to hypperreflexia, hypocompliance or low bladder volume. All patients had failed to respond to conservative medical and pharmacological treatments. Median patient age at surgery was 10.2 years (range 2.2 to 13.2). Outcomes were evaluated retrospectively according to changes in upper tract status, continence and urodynamic parameters. Median clinical and urodynamic followup is 75 months (range 4 to 126).

RESULTS

Progressive hydronephrosis developed in 5 patients, which required subsequent enterocystoplasty in 4. Of 13 patients 8 (62%) remain incontinent. Of the 17 cases 12 (71%) were considered clinical failures on the basis of upper tract deterioration and/or ongoing incontinence. There were few clinically significant improvements in urodynamic parameters, as 14 of 15 cases (93%) were considered urodynamic failures on the basis of persistent hypocompliance and/or less than expected gains in safe bladder capacity with somatic growth.

CONCLUSIONS

Although short-term reports of autoaugmentation have been promising, they do not appear durable. This procedure cannot be endorsed for the management of congenital neuropathic bladder.

Experience with demucosalized ileum for bladder augmentation

OBJECTIVE

To assess the use of demucosalized ileum for bladder augmentation, following the same principles previously used with the sigmoid colon.

PATIENTS AND METHODS

Eleven patients with bladder exstrophy or a neurogenic bladder had their bladders augmented with demucosalized ileum instead of the sigmoid colon, but following the same technique. The use of a Foley catheter with an inflated balloon greatly facilitated the dissection of the mucosa from the muscle. A silicone model, inserted in the bladder, was used to avoid shrinkage of the patch. An animal model was also used for total bladder replacement following the same principle.

RESULTS

The mean (range) follow-up was 15.4 (2-25) months. There was a significant increase in bladder compliance in all patients. A bladder of good shape and compliance was obtained in the animal model, with epithelial growth detected in all cases.

CONCLUSIONS

Demucosalized ileum can be used safely for bladder augmentation in the same way as with the sigmoid colon. The distension of the isolated patch greatly facilitates dissection between the mucosa and muscle. The animal model supported this method of bladder replacement.

Sigmoid cystoplasty with argon beam without mucosa

PURPOSE

Intestinal bladder augmentations have well recognized complications, including mucus production, metabolic abnormalities and perforation. These complications may be avoided if the intestinal mucosa is not incorporated in the urinary tract. We report our experience with sigmoid cystoplasty without mucosa using argon beam, and describe the clinical, urodynamic, ultrasound and pathological results.

MATERIALS AND METHODS

We performed sigmoid cystoplasty without mucosa in 26 patients and with argon beam over the mucosa before it was removed in 6 boys and 4 girls with a mean age of 8 years (range 3 to 14). All patients had neurogenic bladder as the initial disease. Indications for augmentation were poor bladder compliance, low bladder capacity, hydronephrosis and urinary incontinence. Mean followup was 18 months (range 8 to 40) and included ultrasound, urodynamic evaluation, renal function and clinical assessment. In all patients intraoperative biopsies were done. In 8 of the 10 patients endoscopic biopsies of the augmented segment were obtained between 6 months and 2 years postoperatively. The operation consisted of the Goodwin technique without mucosa, which was treated with argon beam before it was removed.

RESULTS

The 10 patients are dry on intermittent clean catheterization with intervals of greater than 4 hours. There have been no clinical urinary tract infections. Two patients presented with peristaltic contractions and no symptoms. Bladder capacity increased from 80 (range 45 to 200) to 300 (220 to 400) ml., and mean postoperative compliance was 15 ml./cm. H2O (range 9 to 38). There were no significant changes in the urodynamic data between patients treated with sigmoid cystoplasty without mucosa only and with argon beam. Intraoperative biopsies after treatment with argon beam showed damaged mucosa and muscularis mucosa, and intact serosa, muscularis and submucosa layers. On the 8 argon beam postoperative biopsies the sigmoid submucosa was covered with a pseudostratified metaplasia of connective tissue with collagen fibers without scars (trichromic technique).

CONCLUSIONS

Sigmoid cystoplasty without mucosa with argon beam is easy to perform. The clinical and urodynamic results have been satisfactory, and use of argon beam prevents postoperative bleeding and residual glands.

Sigmoid cystoplasty with argon beam without mucosa

PURPOSE

Intestinal bladder augmentations have well recognized complications, including mucus production, metabolic abnormalities and perforation. These complications may be avoided if the intestinal mucosa is not incorporated in the urinary tract. We report our experience with sigmoid cystoplasty without mucosa using argon beam, and describe the clinical, urodynamic, ultrasound and pathological results.

MATERIALS AND METHODS

We performed sigmoid cystoplasty without mucosa in 26 patients and with argon beam over the mucosa before it was removed in 6 boys and 4 girls with a mean age of 8 years (range 3 to 14). All patients had neurogenic bladder as the initial disease. Indications for augmentation were poor bladder compliance, low bladder capacity, hydronephrosis and urinary incontinence. Mean followup was 18 months (range 8 to 40) and included ultrasound, urodynamic evaluation, renal function and clinical assessment. In all patients intraoperative biopsies were done. In 8 of the 10 patients endoscopic biopsies of the augmented segment were obtained between 6 months and 2 years postoperatively. The operation consisted of the Goodwin technique without mucosa, which was treated with argon beam before it was removed.

RESULTS

The 10 patients are dry on intermittent clean catheterization with intervals of greater than 4 hours. There have been no clinical urinary tract infections. Two patients presented with peristaltic contractions and no symptoms. Bladder capacity increased from 80 (range 45 to 200) to 300 (220 to 400) ml., and mean postoperative compliance was 15 ml./cm. H2O (range 9 to 38). There were no significant changes in the urodynamic data between patients treated with sigmoid cystoplasty without mucosa only and with argon beam. Intraoperative biopsies after treatment with argon beam showed damaged mucosa and muscularis mucosa, and intact serosa, muscularis and submucosa layers. On the 8 argon beam postoperative biopsies the sigmoid submucosa was covered with a pseudostratified metaplasia of connective tissue with collagen fibers without scars (trichromic technique).

CONCLUSIONS

Sigmoid cystoplasty without mucosa with argon beam is easy to perform. The clinical and urodynamic results have been satisfactory, and use of argon beam prevents postoperative bleeding and residual glands.

Further experience with seromuscular colocystoplasty lined with urothelium

PURPOSE

We report our continuing experience with seromuscular colocystoplasty lined with urothelium. This procedure is designed to preserve the urothelium and potentially decrease the incidence of complications associated with standard bladder augmentation.

MATERIALS AND METHODS

We retrospectively reviewed the charts of 32 patients who underwent seromuscular colocystoplasty lined with urothelium between April 1994 and July 1999. Data were collected on patient demographics, surgical indications, previous and adjunctive surgical procedures, preoperative and postoperative urinary continence, upper urinary tract changes, urodynamic parameters, surgical complications and histological findings.

RESULTS

Mean patient age at surgery plus or minus standard deviation was 11.1 +/- 4.8 years. Mean followup was 1.6 +/- 1 years. A mean of 1.5 +/- 0.9 years postoperatively urodynamic studies available in 28 cases showed that total and safe bladder capacity increased by 1.8 and 2.4-fold, respectively. Continence was achieved in 71% of patients after the initial procedure, increasing to 81% after secondary procedures. Hourglass deformity developed in 7 cases (22%), augmentation failed in 4 (12.5%) and there were bladder calculi in 2 (6%). New onset or increased hydronephrosis and reflux were present in 6 of 62 (10%) and 9 of 60 (15%) evaluated renal units, respectively. Of the 7 interpretable biopsies 5 revealed various degrees of repeat colonic mucosal growth. There was no bladder perforation or metabolic abnormalities, and mucous production was not clinically significant.

CONCLUSIONS

Seromuscular colocystoplasty lined with urothelium is a viable alternative to standard bladder augmentation. The 2 procedures have a similar overall complication rate. Comparatively there appears to be a low incidence of bladder calculi, mucous production has not been clinically significant, metabolic disturbances have not developed and perforation has not occurred during short-term followup. We are enthusiastic about this technique and continue to apply it in select patients.

Bladder augmentation with different forms of intestinal grafts: an experimental study in the pig

OBJECTIVE

To create an experimental animal model to examine changes in bladder volume and histology after bladder augmentation in growing individuals and from the model, evaluate a method using demucosalized intestinal grafts and short-term bladder drainage.

MATERIALS AND METHODS

The study comprised 21 piglets: in group 1, seven underwent a sham operation; in group 2, seven piglets underwent bladder augmentation with full-thickness caecum after a major bladder resection; in group 3 seven underwent the same procedure but with demucosalized caecum. The bladder volume and area of the intestinal segment were measured peroperatively and when the animals were killed 2 months later. Bladder specimens were taken for histological examination.

RESULTS

The mean preoperative bladder volumes were similar among the groups; in the control group, volumes increased from 58 to 165 mL and in group 2 from 63 to 255 mL, with an increase in area of the intestinal segment from 59 to 138 cm2. In group 3 the volume was unchanged, from 63 to 71 mL, with a decrease in area from 58 to 5 cm2. Control bladders showed normal urothelium with neutral mucins and sialomucins. In group 2, there was metaplasia in the border between urothelium and colonic epithelium, with enhancement of sialo- and sulphomucins. Demucosalization resulted in extensive fibrosis, with a monolayer of urothelial cells showing metaplasia.

CONCLUSIONS

The experimental model was successful; the observed changes in bladder volume correlated well with the fate of the intestinal implant, because the bladder resection was major. This is essential, as the bladder remnant has some growth potential. Full-thickness grafts grew faster than the normal bladder. Mechanical demucosalization, including submucosa, results in shrinkage despite short-term drainage. Glandular metaplasia, with production of sialomucins and sulphomucins, occurs at the junction between bladder and colon, irrespective of mucosal removal.

Methods to enhance in vivo urothelial growth on seromuscular colonic segments in the dog

PURPOSE

We demonstrated survival and expansion in vivo of urothelial free autografts on demucosalized seromuscular segments.

MATERIALS AND METHODS

Four methods of in vivo urothelial expansion were investigated on demucosalized colonic segments in the canine model. Group 1 underwent colonic mucosal removal by manual stripping, group 2 underwent removal of colonic mucosa and submucosa, and group 3 underwent manual stripping of the colonic mucosa followed by treatment with protamine sulfate and urea. In the 3 groups urothelial autografts were then placed on the seromuscular segment and tubularized over a balloon splint. In group 4 the colonic mucosa was removed but the grafts were not tubularized. Instead the colonic segment was sutured to the parietal peritoneum.

RESULTS

Group 4 grafts had no epithelial growth and shrinkage of the bowel segment. Group 1 grafts had minimal growth with no expansion and colonic mucosal regrowth. Group 2 grafts demonstrated growth and expansion, although these colonic segments had a significant inflammatory response and fibrosis. Group 3 grafts had the best growth and expansion with the least inflammatory response, and 1 colonic segment was almost completely covered with urothelium.

CONCLUSIONS

We demonstrated in vivo expansion of urothelial autografts grown on seromuscular colonic segments. Preservation of the submucosa is essential to prevent fibrosis of the seromuscular colonic segment and a balloon stent is crucial to prevent graft contraction. Treatment of the demucosalized segment with protamine sulfate and urea results in better urothelial expansion and less colonic mucosal regrowth.

Enteric mucosal regrowth after bladder augmentation using demucosalized gut segments

PURPOSE

Regrowth of the enteric mucosa on a denuded muscular flap enterocystoplasty is an undesirable complication of demucosalized enterocystoplasty. This study was performed to understand how regrowth can be prevented and, thus, a complete urothelial lined enterocystoplasty can be achieved.

MATERIALS AND METHODS

We performed bladder augmentation on 30 sheep using demucosalized seromuscular gastric or colonic flaps with or without autoaugmentation. The epithelium and muscularis mucosae were completely removed from the gastric flap. Initial attempts to remove the muscularis mucosae and most of the submucosal layer from the colonic flap by cautery caused bleeding and muscle damage. Thus, demuscosalization was done by stripping with forceps, in which the muscularis mucosae and submucosa remained largely intact on the colonic flap. Sheep were sacrificed 4 to 12 months postoperatively and bladders were inspected for mucosal regrowth. Subsequently autoaugmentation with demucosalized seromuscular gastric or colonic flaps was performed clinically in 10 children in whom the enteric epithelium and muscularis mucosae were removed completely with part of the submucosa by dissection through the submucosal plane. These children were followed with urodynamic studies and mucin staining of urine up to 39 months postoperatively.

RESULTS

Regrowth of islands of enteric mucosa occurred in 4 of the 5 animals in which the muscularis mucosae and submucosal layers were preserved on a colonic flap. In all animals with mucosal regrowth the bowel was prepared by stripping the mucosa. Mucosal regrowth did not occur in any animal after complete removal of the muscularis mucosae and the inner portion of the submucosa from the stomach or colon. All patients had satisfactory urodynamic results and no evidence of enteric mucosal regrowth.

CONCLUSIONS

Removal of the muscularis mucosae with the inner portion of the submucosa appears necessary to prevent enteric mucosal regrowth on the muscular flap of a demucosalized enterocystoplasty. In addition, this level of dissection does not seem to interfere with the success of bladder augmentation in children.

Combined use of enterocystoplasty and a new type of artificial sphincter in the treatment of urinary incontinence

PURPOSE

We report the results of the combination of enterocystoplasty and a periurethral expander, a simplified type of artificial sphincter, in the treatment of urinary incontinence.

MATERIALS AND METHODS

The new 1-piece device has an adjustable cuff connected to a port positioned at the subcutaneous space in the abdomen. The cuff is adjusted to the bladder neck and the pins are fixed according to the diameter of the urethra. The port is punctured percutaneously and saline is injected until continence is achieved. Eight boys and 3 girls underwent nonsecretory sigmoid cystoplasty and placement of the device at a single operation. Nine patients had neurogenic bladder and in 2 exstrophy reconstruction had failed. Followup ranged from 4 to 26 months.

RESULTS

All patients were continent with improved bladder compliance 6 to 8 weeks after the operation, when the device was activated. In 1 case the device was extracted after 2 months due to frequent episodes of hematuria and edema at the port site. Two patients had erosion of the skin at the port site. Urodynamics were repeated at the time of activation. Maximal urethral closing pressure increased from 16.27 to 157.44%. Two patients needed a second injection to achieve continence. The patients with exstrophy void spontaneously and those with neurogenic bladder are on clean intermittent catheterization.

CONCLUSIONS

Although more followup is needed, the combination of these procedures seems to offer a new option for the treatment of urinary incontinence in children.

Bladder autoaugmentation

Autoaugmentation has proved effective in many patients in lowering bladder pressures, increasing bladder capacity, and improving their related symptoms. Patients with sever bladder hyperreflexia, uncontrolled with medications, have also benefited greatly from autoaugmentation procedures. Only patients who failed conventional medical management have undergone autoaugmentation at the authors' institution.

How to perform enterocystoplasty without opening the intestine

OBJECTIVES

To introduce a new technique for intestinal anastomosis when performing demucosalized enterocystoplasty.

METHODS

In 8 dogs, a vascularized seromuscular patch of sigmoid colon was harvested without opening the bowel lumen. The bowel mucosa was invaginated into the intestinal lumen and the sigmoid musculature was reapproximated. Twelve patients underwent a nonsecretory sigmoid cystoplasty following the same principle.

RESULTS

No complications occurred in the experimental animals. The animals were fed normally starting on the first postoperative day. Prolapse of the excess mucosa occurred in 3 cases and disappeared spontaneously. In the clinical group, the postoperative course was normal. Oral intake was resumed on the first day after the operation. The hospital stay was shorter than that of patients in whom the bowel lumen was opened.

CONCLUSIONS

The use of demucosalized intestinal patches without opening the intestinal lumen appears to be feasible and is expected to reduce perioperative morbidity. Extensive bowel preparation can be reduced, as can the prophylactic use of antibiotics.