Composite Antropyloric Valve and Gluteus Maximus Muscle Wrap for Neoanal Reconstruction: Initial Results.

BACKGROUND: Severe fecal incontinence has a significant negative impact on patient well-being. Current surgical methods of total anorectal reconstruction to substitute a colostomy have suboptimal results. A composite graft using antropyloric valve transposition and gracilis wrap has been described with good outcomes. However, this procedure requires extensive training of patients. Gluteus maximus, an accessory muscle for continence, may be better suited for this purpose. OBJECTIVE: The purpose of this study was to evaluate the outcomes of composite antropylorus-gluteus graft for intractable fecal incontinence. DESIGN: Patients underwent a 3-stage procedure: antropyloric transposition with diversion stoma followed by gluteus wrap. Stoma was closed after ensuring the anatomic and functional integrity of the graft. SETTINGS: This study was conducted at a single tertiary care institution. PATIENTS: Patients who were on permanent colostomy for intractable incontinence or would have had one after abdominoperineal resection were included. MAIN OUTCOME MEASURES: Endoultrasonography, MRI, loopogram, saline holding test, anal manometry, St. Mark's fecal incontinence score, and personal interviews were used for measurement. RESULTS: Eleven patients underwent the procedure with a median follow-up of 16 months (range, 13-34 mo). Digital rectal examination revealed a resting tone with a distinct squeeze provided by the composite graft. Radiological imaging confirmed healthy grafts. There was a significant improvement in mean anal manometry values (resting pressure: preoperative = 10.25 mm Hg vs postoperative = 20.45 mm Hg; squeeze pressure: preoperative = 22.63 mm Hg vs postoperative = 105.18 mm Hg) and mean incontinence score postprocedure (preoperative = 22.8 vs postoperative = 8.6). On personal interview, majority of the patients were continent and expressed satisfaction with the procedure. LIMITATIONS: The study was limited by its small sample size with no control group. CONCLUSIONS: Composite graft in patients with intractable fecal incontinence can serve as a viable novel method for total anorectal reconstruction. However, it should only be recommended for a highly select group of individuals in a surveillance setting. Its long-term outcomes remain to be determined as well as its risk versus benefit.

Gastrinaemia and G-cell density in the antral gastrocystoplasty: an experimental study in rats.

OBJECTIVE: To evaluate gastrinaemia and G-cell density in the antrum incorporated into the bladder of rats after antrocystoplasty. Materials and methods Thirty-two adult, female Wistar EPM-1 rats (body weight 200-220 g) were divided into four equal groups that underwent; group 1, no treatment (controls); group 2, a sham operation; group 3, antrectomy; and group 4, antrocystoplasty. The rats were assessed 2 months after treatment, and gastrinaemia and the G-cell density determined in the antrum mucosa incorporated into the bladder. RESULTS: Compared with group 1, serum gastrin was significantly lower in group 3 (P<0.05) and the G-cell density lower in group 4 (P<0.05), although there was no decrease in gastrinaemia in group 4. CONCLUSION: Antrocystoplasty in rats did not affect gastrinaemia but reduced the number of G cells in the antrum incorporated into the bladder.

New concepts of histological changes in experimental augmentation cystoplasty: insights into the development of neoplastic transformation at the enterovesical and gastrovesical anastomosis.

PURPOSE: To our knowledge the pathogenesis of malignancy associated with ileal cystoplasty, ureterosigmoidostomy and ileal conduits is currently unknown. To gain further insights into the mechanism of neoplastic transformation we studied histological changes in a canine augmentation cystoplasty model. MATERIALS AND METHODS: Enterocystoplasty and gastrocystoplasty were performed using a 5 to 7 cm. patch of ileum in 8 dogs and gastric antrum in 6. Specimens were harvested 4 months postoperatively. Representative 3 microm sections of the enterovesical and gastrovesical junctions were stained with hematoxylin and eosin. Uroplakin expression was assessed using an indirect peroxidase method subjected to double staining with alcian blue and periodic acid-Schiffreagent. RESULTS: The bladder portion of the augmentation cystoplasty had 3 to 4 stratified cell layers covered with a distinctive umbrella cell layer. Strong uroplakin staining was visible in all cell layers except the basal layer. At the enterovesical and gastrovesical junctions 6 to 10 layers of hyperplastic, urothelial appearing cells covered the glandular epithelium of the ileal and gastric segments. These cells expressed uroplakins. At this junction zone there was a marked decrease of underlying enteric glands, which had atrophied in proportion to the degree of urothelial hyperplasia. Double staining of uroplakin stained sections with alcian blue and periodic acid-Schiff reagent revealed mucosubstances in hyperplastic urothelial cells covering the enteral segments, indicating that the cells co-expressed uroplakins and mucins. CONCLUSIONS: Histological changes in this experimental canine model of augmentation cystoplasty indicated that the overgrowth of hyperplastic transitional epithelium develops at the enterovesical and gastrovesical junctions. These cells express not only uroplakins, but also mucosubstances. Our results suggest that the migrated hyperplastic urothelial cells have undergone changes characteristic of the enteric and gastric epithelium, which may have important implications in the pathogenesis of malignancy in bladder augmentations.

Use of the pylorus for preventing ileostomy complications. An experimental canine study.

PURPOSE: Conventional ileostomy, as it is well known, presents with persistent watery diarrhea, among other complications. The present-day modified methods of conventional ileostomy cannot effectively prevent these unpleasant consequences. The purpose of this study was to try to use the sphincter mechanism of the pylorus in ileostomy in dogs experimentally to prevent the above symptoms. METHOD: Following a highly selective vagotomy, the antrum with the pylorus and a 3-cm segment of the duodenum were separated from the gastrointestinal tract along with its vasculature and innervation, and the distal duodenal end was closed. Then, the terminal loop of ileum (before an ileostomy was performed) was dissected, and the distal segment was anastomosed with the proximal end of duodenum; the proximal segment of this loop was anastomosed with the stump of the antrum. The gastrointestinal continuity was established by anastomosis of the gastric stump to the first loop of the jejunum. RESULTS: After the procedure, the sphincter mechanism of the pylorus was preserved, and bowel movements became solid and infrequent, so a colostomy bag could be applied consistently. CONCLUSIONS: Similarity of anatomy and physiology of the alimentary tract in dogs and human favors possible application of this procedure to humans, with better results than with conventional ileostomy.

[Replacement continent bladder in dogs by opening an antro-pyloric graft onto the abdominal wall (seven cases between 1980 and 1983)]. / Etude d'une vessie continente de remplacement chez le chien par ouverture à la paroi abdominale d'un greffon antro-pylorique (sept cas réalisés de 1980 à 1983).

To determine the usefulness of antral bladder controlled by the pyloric sphincter denervated for urological applications, bladder replacement was performed in 17 dogs using the antral segment with its own sphincter, initially with the pylorus supplied by the left gastro-epiploic artery, and later by the right gastro-epiploic artery. The smooth pyloric muscle was denervated to obtain permanent spasm and pulled through the striated anterior abdominal muscle. Both ureters were anastomosed by a Cohen's procedure. The best results were obtained with a gastric pouch supplied by the right gastro-epiploic artery; dissection and reimplantation of the ureters in the gastric wall are difficult. IVP and cystography indicated good function of the antral pouch, with no reflux. The antral bladder controlled by the denervated pyloric sphincter could be a possible alternative in the surgical management of neurogenic or exstrophic bladder.

Technetium-pertechnetate uptake by ectopic antral mucosa. An experimental study.

The ability of ectopically placed fundic mucosa and retained antral mucosa to concentrate technetium has previously been demonstrated. The ability of ectopically placed antral mucosa to concentrate technetium was investigated. The denervated antrum implanted into the colon concentrated technetium in 5 dogs. However, this response was significantly less than that of parietal cell-containing mucosa (P less than 0.005) of the stomach. Technetium scanning may be useful in detecting ectopic and retained antral mucosa.

The effect of chronic acidification of the canine duodenum on gastrin release from the antrum transplanted into the colon.

Exogenous infusion of acid into the canine duodenum inhibits acid secretion stimulated by endogenously released and exogenously administered gastrin. The importance of this mechanism in normal acid homeostasis and in the inhibition of chronic endogenous acid hypersecretion is not established. In this study the classic Dragstedt model antral colonic transplant (ACT) was used to produce endogenous hypergastrinemia and acid hypersecretion. The effects of the ACT when the duodenum was retained in continuity with the stomach (gastroduodenostomy) were compared with those obtained when the duodenum was no longer in continuity with the stomach (gastrojejunostomy). The duodenum markedly suppressed gastrin release (p = 0.003) and gastric acid secretion (p = 0.005) in each of the four dogs. The dogs remained free of ulcers for 8 months after gastroduodenostomy and ACT. However, after conversion to gastrojejunostomy, large, chronic peptic ulcers developed after a mean of 3.5 months. The inhibitory effect of the duodenum on gastric release and gastric acid secretion protected the dog against ulceration for an extended period. The duodenum may be the major site of inhibitory control of acid secretion and endogenous gastrin release in dogs.

Inhibitory effect of prolonged administration of long-acting somatostatin on gastrin-stimulated fundic epithelial cell growth in the rat.

The effects of a 3-week administration of long-acting somatostatin were explored (a) in young rats under both normal and long-acting gastrin stimulation and (b) in adult rats with transposition of the antrum onto the colon and, therefore, chronically stimulated with endogenous gastrin. Histomorphometric parameters of the fundic mucosa were estimated at the end of the treatment. In young rats, somatostatin alone (390 micrograms/kg/day) only lowered parietal and peptic cell densities per cubic millimeter compared to controls. That it exerted an antitropic effect under physiological conditions remains questionable. However, in cases of chronic hypergastrinemia, the same dose of somatostatin obviously antagonized the growth-promoting effect of exogenous or endogenous gastrin.

Chemoneurolysis of the canine gastric submucosa: effects of surgically induced gastric hypersecretion in the Pavlov pouch.

Innervated (Pavlov) gastric fundic pouches were constructed in dogs. One group of dogs served as controls, and another group of dogs had their pouch submucosa infiltrated with 25 per cent ethyl alcohol. The alcohol infiltration of the gastric pouch submucosa eliminated the gastric secretory responses to histamine, pentagastrin, a meat meal, and insulin-induced hypoglycemia. The alcohol infusion of the gastric pouch submucosa did not modify the elevated serum gastrin levels to a meat meal, alter the basal or stimulated mean splenic arterial blood flow to the pouch, nor alter the histologic appearance of the pouch with hematoxylin and eosin or histochemical fluorescence of catecholamines. Transplantation of 75 per cent of the gastric antrum into the colon caused a basal and a meal-augmented hypergastrinemia in all dogs. In the control Pavlov pouches the hypergastrinemia induced elevated gastric secretory responses to histamine, pentagastrin, and insulin-induced hypoglycemia. In those Pavlov pouches in which the submucosa had been infiltrated with alcohol, the hypergastrinemia could not induce any gastric secretory response to histamine, pentagastrin, or insulin-induced hypoglycemia.

Experimental use of free gastric flaps for the repair of pharyngoesophageal defects.

The repair of large pharyngoesophageal defects was accomplished experimentally in 16 dogs with revascularized free flaps from the greater curvature of the stomach. These flaps were based on the gastroepiploic vessels, and they were anastomosed to the carotid artery and external jugular vein in the neck. The procedure had a low mortality and did not lead to peptic ulceration or hyperchlorhydria in these animals.