Autoaugmentation omentocystoplasty in a sheep model.

OBJECTIVE: To develop a sheep model of autoaugmentation omentocystoplasty and study the histologic appearance, and to compare the urodynamic results with a control group. METHODS: Ten male lambs underwent a bladder autoaugmentation reinforced with an omental patch. Three were culled early, to study urothelial survival and inflammatory changes. One was sacrificed at six months to assess late histologic changes; five sheep had a urodynamic study at that stage and two died of unknown causes without further investigation. A group of seven six-month-old male sheep, of similar weights, formed the control urodynamic group. RESULTS: The urothelial lining remained viable under the omentum, but marked inflammation and heterotopic calcification were seen within the subepithelial tissues in most of the animals. The histologic changes were reflected in the bladder dynamic data, which were no better than the control group; the average compliance value was 9.2 +/- 6.4 mL/cm H2O, compared to the control group figure of 11.8 +/- 5.2 mL/cm H2O. CONCLUSIONS: It would appear that autoaugmentation alone does not usually produce bladder augmentation in the sheep.

Autoaugmentation gastrocystoplasty and demucosalized gastrocystoplasty in a sheep model.

OBJECTIVES: To compare the normal sheep bladder at 6 and 12 months with bladders subjected to either an autoaugmentation gastrocystoplasty or a clam demucosalized gastrocystoplasty. METHODS: Twenty male lambs aged between 8 and 10 weeks had an autoaugmentation gastrocystoplasty in which de-epithelialized stomach muscle was added to an intact urothelium. The functional, radiologic, and histologic outcomes were compared with 11 animals who underwent a clam demucosalized gastrocystoplasty and 14 control animals. A total of 18 operated animals had a urodynamic study at 6 months and 9 at 12 months. RESULTS: The average bladder volume for the autoaugmentation gastrocystoplasty group at 12 months was greater than that of the control group (401 +/- 120 mL versus 205 +/- 77 mL). The demucosalized clam bladders had been less effectively enlarged (286 +/- 77 mL). The compliance values for autoaugmentation gastrocystoplasty animals were 14.7 +/- 11.3 mL/cm water (H2O) compared with 9.0 +/- 4.8 mL/cm H2O in the demucosalized gastrocystoplasty group, and 9.1 +/- 3.7 mL/cm H2O for the control animals. CONCLUSIONS: The addition of the autoaugmentation procedure improves the prospect of enlarging the normal sheep bladder when using demucosalized gastric muscle.

Autoaugmentation gastrocystoplasty: early clinical results.

OBJECTIVE: To assess the urodynamic and clinical outcome of five patients following an autoaugmentation gastrocystoplasty. PATIENTS AND METHODS: Four patients, two boys and two girls aged between 8 and 16 years, with a neuropathic bladder and incontinence, and one boy, aged 16 years, with an ileal conduit were included in the study. The bladder augmentation technique combined autoaugmentation and the addition of a demucosalized patch of gastric muscle to the created bladder diverticulum. RESULTS: All patients have improved bladder function, although one may require further surgery. Three had temporary difficulty tolerating full meals. CONCLUSIONS: This new technique seems to have a place in the management of the neuropathic bladder, but further laboratory study and cautious clinical application is required to ascertain its role in bladder augmentation.

Intraseptal procaine abolishes hypothalamic stimulation-induced wheel-running and hippocampal theta field activity in rats.

Rats were implanted chronically with hippocampal recording electrodes, a microinfusion guide cannula aimed at the medial septal nucleus, and an electrode for electrical stimulation of the posterior hypothalamic nucleus (PH). PH stimulation elicited running in rats placed in a wheel and simultaneously occurring hippocampal theta field activity (HPC-theta). In the preprocaine (PRE) testing condition, a positive linear relationship was demonstrated among the intensity of electrical stimulation of the PH, wheel-running speed, and the peak frequency of HPC-theta. HPC-theta amplitude reached an asymptote at the lowest levels of electrical stimulation of the PH. Procaine hydrochloride (1.5 microliters, 20% solution), a local anesthetic, was then infused into the medial septal nucleus (MS). Five minutes after the infusion, PH stimulation no longer induced wheel-running behavior or HPC-theta, and the remaining irregular field activity was significantly reduced in amplitude. Fifteen minutes after the procaine infusion, PH stimulation still did not elicit HPC-theta or running behavior in the majority of animals but did evoke large-amplitude sharp-waves. Thirty minutes after the procaine infusion, PH stimulation again elicited HPC-theta and running behavior, but HPC-theta peak frequency and running speeds were both significantly reduced compared with PRE values. Forty-five minutes after the infusion, HPC-theta amplitude had recovered to PRE values, but HPC-theta frequency and running speeds elicited by PH stimulation were still significantly reduced. By 60 min after procaine administration, the amplitude and frequency of HPC-theta and the running speeds elicited by PH stimulation recovered to PRE values. Multiple regression analysis revealed that the recovery pattern of running behavior reflected the frequency rather than the amplitude of HPC-theta. Neither saline control infusions into the MS nor procaine infusions into the lateral septum and paraventricular thalamic nucleus affected HPC-theta or running behavior. These findings are consistent with the notion that both the locomotor activity and "movement-related" HPC-theta frequency induced by electrically stimulating the PH were attributable to ascending activation of a hypothalamo-septal pathway and not to activation of descending brainstem or peripheral motor systems.

Urothelial lined colocystoplasty in a sheep model.

Nineteen lambs underwent colocystoplasty using a segment of demucosalised sigmoid colon, and were compared to 14 control animals. Nine animals had a procedure which included the addition of the muscle patch to an autoaugmented bladder, and 10 had a clam cystoplasty with the denuded colon. Six months after the procedure, the average compliance value for the autoaugmentation colocystoplasty bladders was 5.7 +/- 1.7 ml/cm H2O, compared to 6.9 +/- 2.2 ml/cm H2O for the clam-demucosalised colocystoplasty group, and 11.0 +/- 4.8 ml/cm H2O for the control group. Whereas at 12 months the compliance values were 9.2 +/- 3.5, 10.7 +/- 5.1 and 9.1 +/- 3.7 ml/cm H2O for each of the groups, respectively. The sheep colonic muscle tolerated the demucosalisation procedure poorly, reflected in an inflamed, haemorrhagic colonic segment in the animals sacrificed within 1 month; this may have been the reason for the poor results, and explain why the autoaugmentation did not improve the outcome. Colonic mucosal regrowth occurred in 5, and was related to the demucosalisation technique.

Late follow up of autoaugmentation omentocystoplasty in a sheep model.

Four male sheep were studied 12 months after an autoaugmentation omentocystoplasty (AAOC). The omentum was lined with urothelium, but continued inflammation and/or fibrosis were seen within the subepithelial tissues associated with a failure to achieve enlargement of the bladder when compared with a control group of six animals. The median compliance value was 5.9 mL/cm H2O for the AAOC animals and 9.8 mL/cm H2O for the control group, indicating that no improvement in bladder dynamic function had been achieved with the AAOC in sheep, and no significant improvement had occurred with time when the results were compared with those seen 6 months earlier.