Gastrocystoplasty in pigs and effect of selective antral vagotomy on acid secretion of the reconstructed bladder

[Use of gastric segment in urinary bladder replacement after total cystectomy]

Drainage of urine by abnormal way is urinary derivation. Various forms of urinary derivations are available for urinary bladder replacement after radical cystectomy for invasive bladder tumor. Construction of continent urinary reservoir, so called pouch, from different bowel segments is named continent urinary derivations. If such urinary reservoir is connected with urethra, then it is about orthotopic derivation and reservoir is defined as neobladder. Upon satisfactory results of introduction of continent urinary derivations with Mainz pouch I and Orthotopic Mainz pouch, we performed continent orthotopic urine derivation with isolated gastric segment in 74-year old male patient who had previously undergone radical cystoprostatectomy because of the invasive urothelial cancer of the urinary bladder. Even though there were no major surgical complications in the near postoperative course, the patient had to be operated ten months later for ileus; 20 months after the procedure, significant loss of neobladder capacity, bilateral vesicoureteral reflux, persistent urinary infection and incipient renal failure were manifested. In the further course, reoperation was needed and neobladder augmentation by ileal pouch along with both ureteral reimplantations into the pouch wall was carried out. After this reintervention, the patient was alive in the following three years with satisfactory quality of life and preserved renal function. Our conclusion is that gastric neobladder should not be the first method of choice for urinary bladder replacement after radical cystectomy in older patients.

Acid secretion in urinary bladder of rats subjected to gastrocystoplasty

Urinary bladder augmentation with a segment of the stomach, i.e., gastrocystoplasty, has been used to improve capacity and compliance in patients with bladder dysfunction. In the present study, rats were subjected to gastrocystoplasty (using the oxyntic segment) with or without fundectomy (removal of the oxyntic part of stomach), and the acid secretion in the augmented bladder was measured. In freely fed rats, the pH values were neutral and not significantly decreased in the rats subjected to gastrocystoplasty with or without fundectomy compared to controls (no operation or sham operation). In response to food intake after being fasted, the rats subjected to gastocystoplasty + fundectomy produced significant amounts of acid. Immunohistochemical examination revealed that the ECL cells and parietal cells seemed to be normal in rats with gastrocystoplasty alone, and that micronodules of ECL appeared to develop in rats with gastrocystoplasty + fundectomy. We suggest that the rats subjected to gastrocystoplasty + fundectomy are capable of producing acid secretion in the bladder, probably due to the secretagogue and trophic effects of gastrin on the ECL cells in the segment of the oxyntic mucosal segment of the bladder.