Histological Changes following Two-Step Flap Gastrocystoplasty in Rats

Abstract

Introduction: A gastric segment used to increase bladder capacity can undergo considerable changes over time, as can all intestinal segments implanted in the urinary tract and in contact with urine. This experimental study reports the differences between the histological alterations observed in the gastric patch transposed in the bladder both with its own pedicle and after deafferentation from the stomach. Materials and Methods: A group of 30 young male Sprague-Dawley rats underwent gastrocystoplasty. Survivors were divided into 3 groups: gastrocystoplasty alone (8 rats); gastrocystoplasty with vascular deafferentation at 15 days (7 rats), and at 2 months (8 rats). 5 rats were used as controls. Urinary pH was evaluated during a 6-month follow-up. Results: Histology showed that early devascularization hindered the fusion of the two mucosae in the junctional area but reduced papillary hyperplasia (p = 0.013) of the gastric mucosa. No changes were observed in urinary pH after patch devascularization. Conclusions: Vascular deafferentation creates a gastric flap on the bladder which, even if it does not prevent urinary acidification, reduces the frequency of histologically detected changes susceptible for transformation into neoplasms.

Gastric neobladder: an experimental study in dog

“…A gastric segment used for bladder replacement can undergo considerable changes over time, due to direct contact with urine (Campodonico et al, 2002). The histopathological findings showed no pathological changes in the case of well-vascularized graft.…”

Histologic findings after gastrocystoplasty in rabbits

“…However, the oncogenic role of the abovementioned predisposing factors has not been documented in patients with gastrocystoplasty yet. Campodonico et al [11] described in rats that the devascularization hindered in fusion of the 2 mucosae in the junctional area but significantly reduced papillary hyperplasia of the gastric mucosa. The permanent bacterial presence in the urine, often existing in patients with colocystoplasty, may be a significant risk factor for malignancy after enterocystoplasties, but it is less relevant in patients with gastrocystoplasty because of lower incidence of bacteriuria owing to the acid production of the gastric segment.…”

“…However, only 1 case of transitional cell carcinoma had been reported in a 73-year-old woman 14 years after gastrocystoplasty [7]. Clinically manifested malignancies have not been reported after entero-or gastrocystoplasty in children or adolescents during a medium-term (10-year) follow-up, however, there is uncertainty about the development of malignancy after gastrocystoplasty in humans and only a few animal experiments dealing with this question [8][9][10][11]. Therefore, it is warranted to investigate possible histologic changes in 0022-3468/$ -see front matter D…”