A prospective study of in vivo and ex vivo sealing of the human inferior mesenteric artery using an electrothermal bipolar vessel-sealing device.

Background: Mesenteric vascular ligation is a critical step in minimally invasive colorectal surgery. This study assessed the quality of in vivo and ex vivo sealing of the human inferior mesenteric artery (IMA), as well as the relation of IMA stump and bursting pressure.

Patients And Methods: This was a prospective experimental study in a tertiary-care teaching hospital. In total, 25 patients were included in the study. For the main outcome measures, bursting pressures were measured for each specimen. Ten freshly sealed specimens were histologically assessed for seal quality and lateral thermal damage.

Results: We evaluated 54 specimens from 25 patients for bursting pressure, of which 25 were primary sealed vessels (sealed in vivo at surgery) and 29 were secondary sealed vessels (sealed in the laboratory). The mean bursting pressure was 862 mm Hg. The mean diameter was 4 mm (range, 3-5 mm) with a standard deviation of 1 mm. Pearson correlation showed no correlation between diameter and bursting pressure (P=.187) or the length and bursting pressure (P=.247). There was no statistically significant difference in bursting pressures in the four groups of vessels based on length. One calcified vessel had a significantly lower bursting pressure of 89 mm Hg. There was no intraoperative or postoperative bleeding. Ten sealed specimens were sent for histological evaluation, which showed mean lateral thermal damage of 0.57 mm (range, 0-1.75 mm).

Conclusions: The bursting pressure in IMAs sealed with a bipolar device is significantly higher than physiological pressures; thus, the device can be safely used in sealing the vessel during colorectal surgery. Additionally, the length of the vessel stump does not correlate with the bursting pressures. Care needs to be taken when the vessel is calcified, which can be a potential cause of a weak seal.