RESUMEN
BACKGROUND: Cecal or colonic gas tympany of any cause may result in increased intraabdominal pressure, causing a significant decrease in venous return and cardiac output. Trocarization of the large colon or cecum in the event of large intestinal tympany may resolve gas distension and accompanying increased intraabdominal pressures sufficiently enough to promote resolution of a displaced large colon. Furthermore, trocarization of the medical colic may decrease morbidity and mortality associated with severe intraabdominal hypertension. DESCRIPTION: This how-to description details the technique of transcutaneous trocarization of the large colon and cecum in the standing horse using a 14-gauge catheter. SUMMARY: Trocarization is not a substitute for surgery in the severely gas-distended painful horse exhibiting signs of colic that require surgery; however, it is a viable medical therapy with minimal risk that alleviates gas distention and may assist with correction of a colonic displacement in the horse. KEY POINTS: The majority of colic episodes involving the large colon can be managed medically without surgical intervention. Auscultation and percussion of the paralumbar fossa area will solicit an audible "ping" (gas/fluid interface), thus targeting the appropriate site for trocarization. Percutaneous trocarization allows for rapid controlled decompression of colonic or cecal tympany, permitting improvement of both ventilation and perfusion. In situations where a displacement or primary colonic or cecal tympany is suspected, trocarisation is deemed successful if the horse has resolution of colic signs and the physical examination parameters return to normal. Trocarization may be clinically advantageous by requiring less pain medication, decreased time in the hospital, decreased costs, and avoidance of surgical intervention; yet, this therapy should not take place of surgical intervention if deemed necessary.