Evaluation of alternative proximal gastric vagotomy techniques after a 9-month interval in a rat model

Proximal gastric vagotomy (PGV) is an accepted operation for patients with ulcers that are refractory to medical management. Results comparable to those of standard, operative PGV have previously been demonstrated using endoscopic chemoneurolytic injection or laparoscopic laser seromyotomy in a porcine model. In this study, we evaluated several PGV techniques in regard to long-term effects on acid secretion, ulcer prophylaxis, and permanent vagal denervation in a rat model. Trans-mucosal injection of chemoneurolytic agents (cobaltous chloride, benzalkonium chloride, and phenol) and seromyotomy by CO2 laser were performed. After 9 months, all rats received sub-serosal gastric injections of horseradish peroxidase (HRP) during laparotomy. Twenty-four hours later, an ulcerogenic dose of pentagastrin was administered sub-cutaneously. Three days after administration of HRP (to allow time for retrograde axonal transport and labeling of cells of the dorsal vagal nucleus with HRP), necropsy was performed. The pre-pyloric gastric mucosa was inspected for ulcerogenic changes, and a Congo red solution was applied to the gastric mucosa to map the acid-secreting areas. All PGV methods significantly diminished pentagastrin-induced ulceration when compared to sham controls. Benzalkonium chloride chemoneurolytic and laser methods were most effective for decreasing the size of acid-secreting areas. A reduced number of HRP-stained cells in the dorsal vagal nucleus indicated permanent denervation of vagal-gastric connections by operative and laser techniques.