Microvascular blood flow changes in the small intestinal wall during conventional negative pressure wound therapy and negative pressure wound therapy using a protective disc over the intestines in laparostomy

Abstract

Objectives: Blood flow changes in the intestines during conventional negative pressure wound therapy (NPWT), and NPWT using a protective disc over the intestines in laparostomy.

Background: Higher closure rates of the open abdomen have been reported with NPWT compared with other kinds of wound management. However, the method has been associated with increased development of fistulae. We have compared the changes in blood flow in the intestinal wall using conventional NPWT and NWPT with a protective disc between the intestines and the vacuum source.

Methods: Midline incisions were made in 10 pigs and either conventional NPWT or NPWT with a disc over the intestines was applied. The microvascular blood flow was measured in the intestinal wall before and after the application of topical negative pressures of -50, -70, and -120 mmHg, using laser Doppler velocimetry.

Results: The blood flow was significantly decreased (by 24%) after the application of conventional NPWT at -50 mmHg, compared with a slight decrease (2%) after the application of NWPT with a protective disc (P < 0.05). The blood flow was significantly decreased (by 54%) after the application of conventional NPWT at -120 mmHg, compared with a slight decrease (17%) after application of NPWT using a protective disc (P < 0.001).

Conclusions: Inserting a disc between the intestines and the vacuum source in NPWT protects the intestines from ischemia. The decreased blood flow in the intestinal wall may induce ischemia, which could promote the development of intestinal fistulae.