No evidence of osteopenia 5 to 8 years after ileal orthotopic bladder substitution

Is chronic alkali therapy in orthotopic ileal neobladders necessary? A prospective controlled study

PURPOSE

To evaluate the necessity of chronic alkali therapy in non-complicated orthotopic ileal neobladders with normal renal function.

MATERIALS AND METHODS

This is a prospective study that included 200 male patients who underwent radical cystectomy and ileal W neobladder for invasive bladder carcinoma between January 1993 and December 2013. The studied patients included 100 consecutive patients who were maintained on regular alkali therapy since surgery and 100 consecutive patients who stopped the use of alkali treatment after initial 3 months postoperative with minimum postoperative observation time of 1 year. All patients had satisfactory function of the reservoirs with normal upper tract. The patients were subjected to blood analysis for creatnine, electrolytes, pH and bicarbonate and urine chemical analysis. The study also included 40 healthy male age-matched volunteers who served as a control group.

RESULTS

Both groups were comparable as regard age, BMI, follow-up period and surgical technique. There were no significant differences between both groups as regard serum creatnine, electrolytes blood pH and bicarbonate and the mean values were within normal range; however, the neobladder patients are still toward the acidotic side in comparison to healthy volunteers. Also there were no significant differences between both groups of patients as regard urine pH and excretion of electrolytes, calcium, phosphorus and creatnine.

CONCLUSION

Patients with non-complicated ileal neobladders with normal upper tract who were not maintained on alkali prophylaxis for long period have a compensated acid base status. Therefore, the prolonged alkali prophylaxis is not mandatory.

Risk of fracture after radical cystectomy and urinary diversion for bladder cancer

PURPOSE

Radical cystectomy and urinary diversion may cause chronic metabolic acidosis, leading to long-term bone loss in patients with bladder cancer. However, the risk of fractures after radical cystectomy has not been defined. We assessed whether radical cystectomy and intestinal urinary diversion are associated with increased risk of fracture.

PATIENTS AND METHODS

Population-based study using SEER-Medicare-linked data from 2000 through 2007 for patients with stage 0-III bladder cancer. We evaluated the association between radical cystectomy and risk of fracture at any site, controlling for patient and disease characteristics.

RESULTS

The cohort included 50,520 patients, of whom 4,878 had cystectomy and urinary diversion. The incidence of fracture in the cystectomy group was 6.55 fractures per 100 person-years, compared with 6.39 fractures per 100 person-years in those without cystectomy. Cystectomy was associated with a 21% greater risk of fracture (adjusted hazard ratio, 1.21; 95% CI, 1.10 to 1.32) compared with no cystectomy, controlling for patient and disease characteristics. There was no evidence of an interaction between radical cystectomy and age, sex, comorbidity score, or cancer stage.

CONCLUSION

Patients with bladder cancer who have radical cystectomy and urinary diversion are at increased risk of fracture.

Metabolic consequences after urinary diversion

Metabolic disturbances are well-known, but sometimes neglected immediate consequences or late sequelae following urinary diversion (UD) using bowel segments. Whereas subclinical disturbances appear to be quite common, clinically relevant metabolic complications, however, are rare. Exclusion of bowel segments for UD results in loss of absorptive surface for its physiological function. Previous studies demonstrated that at least some of the absorptive and secreting properties of the bowel are preserved when exposed to urine. For each bowel segment typical consequences and complications have been reported. The use of ileal and/or colonic segments may result in hyperchloremic metabolic acidosis, which can be prevented if prophylactic treatment with alkali supplementation is started early. The resection of ileal segments may be responsible for malabsorption of vitamin B12 and bile acids with subsequent neurological and hematological late sequelae as well as potential worsening of the patient's bowel habits. Hence, careful patient and procedure selection, meticulous long-term follow-up, and prophylactic treatment of subclinical acidosis is of paramount importance in the prevention of true metabolic complications.

[Selection and perioperative management of patients undergoing an orthotopic ileal bladder substitution]

Orthotopic ileal bladder substitution (Studer pouch) has gained much popularity during the last decade, offering the best form of urinary diversion in appropriately selected patients. The superiority of this procedure is well known, with a low complication and high success rate. In the present study the most important details in patient selection, surgical technique, perioperative management with short- and long-term postoperative follow-up are described. Adequate preoperative assessment results in a proper indication for surgery and appropriate patient selection. The cystectomy should be performed with atraumatic dissection and preservation of the urethral autonomic innervation and sphincter apparatus. The bladder substitute is constructed from a terminal ileal segment of proper length formed into a spherical shape. Implantation of the ureters into the reservoir should not be performed using an anti- reflux technique to avoid a high stricture rate. Anastomosis of the bladder substitute to the urethra must be flat and wide open, avoiding a funnel-shaped outlet. In the immediate postoperative period, careful monitoring is necessary to minimize metabolic complications of acidosis and salt loss. To achieve successful voiding rehabilitation, with complete reservoir emptying, good functional reservoir capacity and satisfactory continence, it is necessary to educate the patients as to the physiological functioning of the bladder substitute. Careful lifelong follow up is essential for the successful outcome. Respecting strict patient selection criteria and proper surgical technique are of utmost importance for the successful outcome of the procedure, but only if combined with regular follow-up.

Bladder, bowel and bones--skeletal changes after intestinal urinary diversion

Impaired bone metabolism following urinary diversion through intestinal segments has always been a controversial subject of unclear clinical relevance. Whereas the perpetuated pathophysiological considerations seem conclusive in theory, the role of acidosis and malabsorption is less clear in animal experimentation and, even more so, in the clinical reality of modern continent diversion. In hardly any of the available contemporary case series was overt derangement of the acid-base balance, rickets or osteomalacia encountered. No consistent changes in osteotropic serum parameters could be found with normal calcium and phosphate in all patients. The assumption that colonic reservoirs have a higher risk of developing metabolic bone disease could not be confirmed by clinical data. As early correction of base excess is easy and probably a common policy in patients with intestinal urinary reservoirs, it will be virtually impossible to further study the natural history of bone metabolism after urinary diversion. While there is no need for a bone specific follow-up in asymptomatic adults with a normal acid-base balance, particular attention should be paid to children and to all patients with impaired renal function.

Bone mineral content and related biochemical variables in patients with ileal bladder substitution and colonic Indiana pouch

OBJECTIVES

To evaluate the effects of ileal bladder substitution or colonic Indiana pouch on skeletal bone density and various biochemical parameters related to bone metabolism.

PATIENTS AND METHODS

In 27 patients with urinary diversion and 14 controls with benign urologic disease, bone mineral density (BMD), assessed by dual-photon absorptiometry; serum electrolyte, creatinine, alkaline phosphatase and parathyroid hormone levels were determined, and capillary blood gas analysed. BMD was measured in the lumbar spine and the femur neck. The mean time since surgery was 33.6+/-10.1 months in 17 patients with an ileal bladder substitution and 56+/-9.1 months in 10 patients with a colonic Indiana pouch (p=0.001).

RESULTS

Although BMD did not change in the colonic Indiana pouch group, it was reduced in the patients with ileal bladder substitution compared to control group. The mean pH value was not statistically significant different in the both groups from the control group (p>0.2). The mean base excess value reduced in the substitution group (p<0.01). While alkaline phosphatase levels increased in both groups compared to control group (p<0.05), the mean parathyroid hormone level decreased only in the patients with ileal bladder substitution (p<0.05). The other biochemical parameters were similar in patients and control subjects. There was a statistically significant correlation between the base excess values and BMD values of the patients in both groups.

CONCLUSION

Although there is decreased BMD in patients with an ileal bladder substitute, there is no change in BMD in the patients with Indiana pouch. Alkaline phosphatase levels increased in both patient groups indicating increased bone turnover.

Metabolic changes and urodynamic findings after continent urinary diversion

Methods of creating continent urinary diversions were developed in the mid-1980s (neobladder, pouch) providing patients with continence and anatomically appropriate voluntary urine discharge. In a follow-up investigation on 18 patients, the question to be clarified was whether continent urinary diversion meets the demands of an ideal bladder substitute. Follow-up examination showed normal clinical test values almost without exception. Only five out of 18 patients had discrete acidosis. Neither malabsorption syndrome nor any disorder of vitamin D3 metabolism was found. Ultrasonography and X-ray diagnostics showed normal conditions, without stones and reflux. Urodynamic investigations revealed that bladder emptying was almost free of residual urine, and continence was largely undisturbed. In accordance with these data, there is almost perfect patient acceptance. At present, there are still no sufficient data on the risk of tumour induction, since the latency period required (about 20 years) in most cases has not yet been reached. Since there are currently numerous publications on "urinary diversion carcinoma", consistent follow-up is necessary comprising not only the metabolic, but also the oncological risks of urinary diversion via intestinal segments.