Influence of Elevated Intra-abdominal Pressure on Suture Tension Dynamics in a Porcine Model

Abstract

Background: Inadequate suture tension is a risk factor for the failure of laparotomy closure. Suture tension dynamics in the abdominal wall are still obscure due to the lack of measuring devices. To answer the questions if intra-abdominal hypertension (IAH) influences suture tension in midline laparotomies and if IAH leads to a permanent loss of suture tension, microsensors were applied in a porcine model of IAH.

Material and methods: Microsensors measuring suture tension "on the thread" with a frequency of 1/s were developed and implanted in the suture lines of midline laparotomies in four pigs. During a 23-h experiment under general anesthesia, two intervals of IAH (30 mm Hg) were applied, interrupted by a 3-h interval without elevated intra-abdominal pressure.

Results: All sensors showed an immediate and reproducible response to changes of intra-abdominal pressure. The two 9-h periods of IAH resulted in a significant elevation of suture tension (P = 0.003 and P = 0.0009, respectively). Reducing the IAH lead to a significant loss of suture tension (P = 0.0005 and P = 0.0001, respectively). After the second interval with IAH, a complete loss of mean suture tension was observed. A statistically significant "recovery" of suture tension in the interval between the two phases with IAH was not observed.

Conclusions: Intervals with elevated intra-abdominal pressure have a direct influence on suture tension in midline laparotomy wounds. Intervals with IAH lead to a significant loss of suture tension in the suture line and to a complete loss of mean suture tension at the end of this experiment. A subsequent gaping of the fascia might contribute to either acute or chronic failure of laparotomy closure.

Keywords: Implantable sensor; Incisional hernia; Intra-abdominal hypertension; Laparotomy closure; Ruptured abdomen; Suture tension.