Physiological Responses to Different Ischemic Periods during Laparoscopic Infrarenal Aortic Cross-Clamping: Evaluation in an Experimental Animal Model

Acute aortic wall injury caused by aortic cross-clamping: morphological and biomechanical study of the aorta in a swine model of three aortic surgery approaches

Background

Aortic cross-clamping and balloon occlusion of the aorta could lead to damage to the aorta wall.

Objective

The aim of this study was to investigate changes to the aorta wall related to the method used to interrupt flow (clamping or balloon) in the different techniques available for aortic surgery.

Methods

Experiments were performed on 40 female pigs, weighing 25-30kg, which were randomly allocated to 4 study groups: S (n=10), no intervention (sham group); C (n=10), midline transperitoneal laparotomy for infrarenal abdominal aortic access with 60 min of cross-clamping; L (n=10), laparoscopic infrarenal abdominal aortic surgery with 60 min of cross-clamping; EV (n=10), remote proximal aortic control with transfemoral arterial insertion of aortic occlusion balloon catheter, inflated to provide continued aortic occlusion for 60min. After euthanasia, the aortas were removed and cross-sectioned to obtain histological specimens for light microscopic and morphometric analyses. The remaining longitudinal segments were stretched to rupture and mechanical parameters were determined.

Results

We observed a reduction in the yield point of the abdominal aorta, decrease in stiffness and in failure load in the aortic cross-clamping groups (C and L) compared with the EV group.

Conclusions

Aortic cross-clamping during open or laparoscopic surgery can affect the mechanical properties of the aorta leading to decrease in resistance of the aorta wall, without structural changes in aorta wall histology.

Artificial tactile sensing approach in aortic-repair-laparoscopy: aorta cross clamping during surgery

Abdominal aortic aneurysm is one of the most common diseases of the vascular system for which the most definitive treatment is surgery. Laparoscopy is a primary method of minimally invasive surgery that could be useful in aortic repair surgeries. Although this method of surgery has significant advantages, the difficulty of exactly distinguishing the aorta from its surrounding tissues is its main drawback; this can cause many problems during the aorta cross clamping process. One of the most important limitations is that it is a time-consuming process; aorta cross clamping leads to increases in surgery duration. Artificial tactile sensing is an innovative technology aiming to make tactile data more available for surgeons, especially in situations where developments in technology make the surgeons less efficient. In this paper, considering the present problems during aortic repair laparoscopy, applicability of a novel tactile robotic system capable of cross clamping an artery during laparoscopy was evaluated. Having considered a small, 5-degree-of-planar-freedom robot and imitated surgeon's palpation using software, the path followed by the tip of the new tactile robotic system was extracted. It is shown that this new tactile robotic system is well capable of dissecting an artery from its adjacent tissues in a short time with an acceptable accuracy. The functional principles of the tactile robotic system capable of cross clamping the aorta during laparoscopy will also be presented.