The pathogenesis rectal stricture. II. Experimental salmonellosis and ischemic proctitis

Area of Science:

• Veterinary Pathology
• Gastroenterology
• Infectious Diseases

Background:

• Salmonella typhimurium infection in pigs can cause severe enterocolitis and ulcerative proctitis.
• Healed lesions may result in annular cicatricial ulcers and rectal strictures.
• The middle third of the rectum is a common site for these lesions.

Purpose of the Study:

• To investigate the pathogenesis of rectal strictures following Salmonella typhimurium-induced ulcerative proctitis in pigs.
• To explore the role of arterial supply and ischemic injury in the development of rectal strictures.

Main Methods:

• Experimentally induced oral Salmonella typhimurium infection in pigs.
• Surgical induction of rectal strictures via chlorpromazine injection into the cranial hemorrhoidal artery.
• Rectal perfusion studies using dye injection into the cranial hemorrhoidal artery.

Main Results:

• Salmonella typhimurium infection consistently caused severe enterocolitis with ulcerative proctitis.
• Healed lesions transformed into annular cicatricial ulcers, leading to rectal strictures.
• Chlorpromazine injection successfully produced strictures indistinguishable from naturally occurring lesions.
• Arterial dye perfusion was impeded at mucosal defects in pigs with strictures or proctitis.

Conclusions:

• The precarious arterial supply of the middle third of the rectum predisposes it to ischemic injury.
• Salmonella-induced ulcerative proctitis and subsequent strictures are linked to compromised blood flow and reduced reparative capacity.
• These findings elucidate the pathogenesis of rectal strictures in pigs, with implications for understanding similar conditions in other species.