Intestinal histopathological changes in a porcine model of pneumoperitoneum-induced intra-abdominal hypertension

Surg Endosc. 2018 Sep;32(9):3989-4002. doi: 10.1007/s00464-018-6142-z. Epub 2018 May 17.

Abstract

Background: Low splanchnic perfusion is an immediate effect of pneumoperitoneum-induced intra-abdominal hypertension (IAH). Anatomical structure results in the intestinal mucosa being the area most sensitive to hypoperfusion. The relationship between intestinal injury and clinical parameters of tissue perfusion [abdominal perfusion pressure (APP), gastric intramucosal pH (pHi) and lactic acid (Lc)] has not been previously studied. This study aimed to monitorize intestinal pathogenesis through sequential ileal biopsies and to measure APP, pHi, and Lc levels at different pneumoperitoneum-induced intra-abdominal pressures (20, 30, and 40 mmHg) to evaluate the potential relationships between them.

Materials and methods: Fifty pigs were divided into four groups; a control group (C) and three experimental groups with different pneumoperitoneum-induced levels [20 mmHg (G20), 30 mmHg (G30), and 40 mmHg (G40)], that were maintained for 3 and 5 h. APP, pHi, and Lc were measured and ileal biopsies taken laparoscopically every 30 min. The mucosal damage was graded using the standardized Park's Score and animals were classified as injured (I+) or uninjured (I-).

Results: Different histopathological lesions were observed in groups G20, G30, and G40 but no damage observed in group C. A 33.3% of animals in G20 and G30 were I+ after 3 h, while 93.3% were injured in G40. After 5 h, histopathological lesions were no longer seen in some animals in G20 and only 10% were I+. Conversely, in G30 I+ pigs increased to 80% while those in G40 remained at 93.3% I+. The I+ animals had significantly lower APP and pHi than those I-. Lc was the clinical parameter that showed the earliest differences, with significantly higher figures in I+ animals.

Conclusions: The evolution of intestinal injuries from pneumoperitoneum-induced IAH depends on the degree of IAP. These damages may be associated with decreases in APP and pHi, and increases in Lc.

Keywords: Abdominal compartment syndrome; Histopathological changes; Intestinal injury; Intra-abdominal hypertension; Pneumoperitoneum; Porcine model.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abdominal Cavity / physiology
  • Animals
  • Biopsy
  • Blood Pressure / physiology
  • Gastric Mucosa / chemistry
  • Hydrogen-Ion Concentration
  • Ileum / pathology*
  • Intra-Abdominal Hypertension / etiology
  • Intra-Abdominal Hypertension / pathology*
  • Lactic Acid / metabolism
  • Models, Animal
  • Pneumoperitoneum, Artificial / adverse effects*
  • Swine

Substances

  • Lactic Acid