The effect of ranitidine on urine mucus concentration in patients with enterocystoplasty

Ileal Neobladder With Mucous Plugs as a Cause of Obstructive Acute Kidney Injury Requiring Emergent Hemodialysis

Ileal neobladder is the preferred technique in the management of urinary diversion postradical cystectomy for bladder malignancy. The common complications associated with this procedure are atrophied kidney, chronic pyelonephritis, decreased renal function, ureteroileal or urethral anastomotic site stricture, urinary tract stones, incontinence, and hyperchloremic metabolic acidosis. Mucous plugs are also seen in 2%-3% patients. We present a rare presentation of a patient who required hemodialysis for severe hyperkalemia and acute kidney injury caused by mucous plugging of ileal neobladder.

The role of mucoregulatory agents after continence-preserving urinary diversion surgery

PURPOSE

The postsurgical use of N-acetylcysteine, octreotide, and other agents to reduce mucus accumulation after urinary diversion procedures is described.

SUMMARY

Patients undergoing continence-sparing bladder resection are at risk for infection and stone formation due to mucus accumulation. In addition to N-acetylcysteine, agents studied for mucoregulatory control in such patients include aspirin, urea, ranitidine, and octreotide. N-acetylcysteine has high mucolytic activity in vitro, and positive outcomes with instillations of 20% N-acetylcysteine solution have been reported in some patients. Significant mucus reductions were reported in small numbers of patients treated with oral ranitidine 300 mg daily or instillations of 30 mL of urea 40% solution, while the benefits of aspirin are more questionable. To date, there has been only one randomized controlled trial comparing various agents for mucus reduction after reconstructive bladder surgery; the results indicated no significant benefits with the use of N-acetylcysteine, aspirin, or ranitidine. In one small study (n = 40), the use of subcutaneous octreotide immediately before and for 15 days after surgery was reported to yield significant reductions in mucus production, the need for bladder irrigation to clear blockages, and the mean duration of hospital stays.

CONCLUSION

Various agents evaluated for mucus control after urinary diversion procedures (oral ranitidine or aspirin, N-acetylcysteine or urea instillations, and subcutaneous octreotide), while reportedly effective for some patients, remain of questionable benefit. More research is needed to define the optimal role of these agents for this indication.

The past, present and future of augmentation cystoplasty

What's known on the subject? And what does the study add? There is a wealth of evidence on the development, indications, outcomes and complications of augmentation cystoplasty (AC). Over the last decade, new evidence has been emerging to influence our clinical practice and application of this technique. AC is indicated as part of the treatment pathway for both neurogenic and idiopathic detrusor overactivity, usually where other interventions have failed or are inappropriate. The most commonly used technique remains augmentation with a detubularised patch of ileum (ileocystoplasty). Controversy persists over the role of routine surveillance following ileocystoplasty for the detection of subsequent bladder carcinoma; however the indication for surveillance after gastrocystoplasty is clearer due to a rising incidence of malignancy in this group. Despite a reduction in the overall numbers of AC operations being performed, it clearly still has a role to play, which we re-examine with contemporary studies from the last decade.

Combining gastric and ileal segments, does it overcome segment-related complications? An experimental study on rats

Bladder augmentation has revolutionized the care of children with neurogenic bladder but it is associated with certain short- and long-term complications. Using the combination of gastric and ileal segments to balance effects of these segments might be a solution for complications. A total of 39 female Spraque-Dawley rats randomly divided into four groups: ileocystoplasty (11), gastrocystoplasty (9), ileogastrocystoplasty (11) and control (8). Serum/urine electrolytes and pH values, and serum creatinine levels and urine mucus concentration were measured. Kruskal-Wallis non-parametric variance analysis was performed to compare the groups and p < 0.05 was accepted as significant. Metabolic alkalosis with significantly lower urine pH was observed in gastrocystoplasty group. Gastroileal group showed similar results with the ileal group in all parameters. No stone formation was detected in the sham and gastric cystoplasty groups. Metaplastic and hyperplastic changes were observed in all segments surrounding urothelium. In conclusion, combination of gastric and ileal segments does not significantly reduce the rate of metabolic impairments, stone and mucus formation. Besides it is not associated with significant improvement in histological outcome since urine is still in contact with the gastrointestinal mucosa.

Urinary Diversion

A consensus conference convened by the World Health Organization (WHO) and the Société Internationale d'Urologie (SIU) met to critically review reports of urinary diversion. The world literature on urinary diversion was identified through a Medline search. Evidence-based recommendations for urinary diversion were prepared with reference to a 4-point scale. Many level 3 and 4 citations, but very few level 2 and no level 1, were noted. This outcome supported the clinical practice pattern. Findings of >300 reviewed citations are summarized. Published reports on urinary diversion rely heavily on expert opinion and single-institution retrospective case series: (1) The frequency distribution of urinary diversions performed by the authors of this report in >7000 patients with cystectomy reflects the current status of urinary diversion after cystectomy for bladder cancer: neobladder, 47%; conduit, 33%; anal diversion, 10%; continent cutaneous diversion, 8%; incontinent cutaneous diversion, 2%; and others, 0.1%. (2) No randomized controlled studies have investigated quality of life (QOL) after radical cystectomy. Such studies are desirable but are probably difficult to conduct. Published evidence does not support an advantage of one type of reconstruction over the others with regard to QOL. An important proposed reason for this is that patients are subjected preoperatively to method-to-patient matching, and thus are prepared for disadvantages associated with different methods. (3) Simple end-to-side, freely refluxing ureterointestinal anastomosis to an afferent limb of a low-pressure orthotopic reconstruction, in combination with regular voiding and close follow-up, is the procedure that results in the lowest overall complication rate. The potential benefit of "conventional" antireflux procedures in combination with orthotopic reconstruction seems outweighed by the higher complication and reoperation rates. The need to prevent reflux in a continent cutaneous reservoir is not significantly debated, and this should be done. (4) Most reconstructive surgeons have abandoned the continent Kock ileal reservoir largely because of the significant complication rate associated with the intussuscepted nipple valve.

Mucus production after transposition of intestinal segments into the urinary tract

Following transposition into the urinary tract, intestinal segments continue to produce mucus and problems related to excessive production do not to diminish with time. Currently, 20 human mucin genes have been described and their protein products partially or fully characterised. As the use of transposed intestinal segments in urology increases, there is now a need for a better understanding of mucins at the gene and protein levels. There is also a need for urologists to be aware of the many complications related to excess mucus production. Whilst effective therapeutic measures to reduce mucus production and its related complications remain elusive, it is now clear that without such effective mucoregulatory agents the quality of life of patients will continue to be less than satisfactory. This review describes the biology of mucus and the problems related to continued production following transposition of intestinal segments into the urinary tract. Difficulties related to quantification of urinary mucus, in addition to the structural and mucin gene changes that occur in transposed segments, are addressed.

Experience with augmentation cystoplasty. A review

Good experience with clam cystoplasty is reported for 28 patients (14 female), 89% of whom had a neuropathic bladder. Prolonged conservative treatment had failed in all cases. The efficacy of the operation in terms of continence, increased bladder compliance, and bladder capacity was confirmed. Complications were common and included inability to void (70%) requiring clean intermittent catheterisation (CIC), recurrent urinary tract infection (59%) and stone formation (22%). Due to these complications, further surgery was required for 44% of the patients. Although clam enterocystoplasty is an efficient way to reconstruct a functionally disturbed urinary tract, careful patient selection is essential. Lifetime follow-up and recognition of the most frequent complications is mandatory.

W-stapled ileal neo-bladder formed entirely with absorbable staples

Orthotopic bladder replacement after total cystoprostatectomy for bladder cancer has gained broader use. Continent diversion has historically increased the complexity of the surgical procedure, often discouraging its adoption by many urologists. Absorbable staples on a GIA* instrument became available in 1992 and have been incorporated into reservoir formation in this preliminary study. A novel W-shaped ileal reservoir entirely fashioned from absorbable staples using the GIA and TA instruments has been developed and used in 15 patients undergoing cystoprostatectomy. The advantages of this technique are its simplicity and the speed with which the reservoir can be fashioned. In the first 15 patients operative time to construct the reservoir ranged from 12 to 21 minutes. Functional aspects of urodynamic studies and continence appear comparable to those of other ileal reservoirs. These preliminary data justify comparative trials on an expanded scale.