Microvascular blood flow response in the intestinal wall and the omentum during negative wound pressure therapy of the open abdomen

Abstract

PurposeHigher closure rates of the open abdomen have been reported with negative pressure wound therapy (NPWT) compared with other wound therapy techniques. However, the method has occasionally been associated with increased development of intestinal fistulae. The present study measures microvascular blood flow in the intestinal wall and the omentum before and during NPWT.MethodsSix pigs underwent midline incision and application of NPWT to the open abdomen. The microvascular blood flow in the underlying intestinal loop wall and the omentum was recorded before and after the application of NPWT of −50, −70, −100, −120, −150, and −170 mmHg respectively, using laser Doppler velocimetry.ResultsA significant decrease in microvascular blood flow was seen in the intestinal wall during application of all negative pressures levels. The blood flow was 2.7 (±0.2) Perfusion Units (PU) before and 2.0 (±0.2) PU (*p < 0.05) after application of −50 mmHg, and 3.6 (±0.6) PU before and 1.5 (±0.2) PU (**p < 0.01) after application of −170 mmHg.ConclusionsIn the present study, we show that negative pressures between −50 and −170 mmHg induce a significant decrease in the microvascular blood flow in the intestinal wall. The decrease in blood flow increased with the amount of negative pressure applied. One can only speculate that a longstanding decreased blood flow in the intestinal wall may induce ischemia and secondary necrosis in the intestinal wall, which, theoretically, could promote the development of intestinal fistulae. We believe that NPWT of the open abdomen is a very effective treatment but could probably be improved.

Comparative study of the microvascular blood flow in the intestinal wall, wound contraction and fluid evacuation during negative pressure wound therapy in laparostomy using the V.A.C. abdominal dressing and the ABThera open abdomen negative pressure therapy system

“…Whether the application of NPWT to the open abdomen promotes the development of fistulae or not has been hotly debated. Our pre‐clinical studies indicate that ischaemia is induced in the intestinal loops lying close to the visceral protective layer when negative pressure is applied . The effect of these findings in the clinical situation is still not known.…”

Abdominal negative-pressure therapy: a new method in countering abdominal compartment and peritonitis - prospective study and critical review of literature

“…A study by Kaplan et al [5] clearly shows that, if the abdomen is not primarily closed within 7 to 10 days, adhesion formation and fascia retraction can render this impossible. If the application time is too long and the NPT system changes are too frequent, the rate of entero-cutaneous fistula formation, bowel obstruction, bleeding and other complications can increase [26,27,32-34]. Mortality rates vary between 7% and 38% [4,35] and can even reach 50% in patients with peritonitis, severe sepsis or septic shock [10,25].…”

Negative Pressure Wound Therapy in the Prevention of Infectious Wound Complications in Perineal Wound After Abdominoperineal Resection

“…Использование специ-альных защитных покрытий, располагаемых между органами брюшной полости и пенополиуретановой губкой, на которую подается отрицательное давление, снижает риски развития таких осложнений, как ише-мия кишечника, кишечные свищи и кровотечения [24][25][26].…”