Tissue damage with different surgical techniques in a porcine model of liver resection: implications for living-donor liver transplantation?

Abstract

Background/purpose: For living-donor liver transplantation (LDLT) it is of paramount importance to preserve as much viable liver tissue as possible to avoid postoperative complications in the donor and recipient. The depth of tissue damage caused by common surgical techniques for liver resection has not been studied so far.

Methods: Here we compared the depth of tissue damage and the immunohistochemical expression of heat shock protein (HSP) 70, a marker for tissue damage, in a porcine model of liver resection, to assess the effect of different surgical techniques, i.e., blunt dissection (BD), and dissection with an ultrasound aspirator (UA), an ultrasound scalpel (US), or a water-jet (WJ).

Results: Analysis with linear mixed effects models (LME) showed significantly less tissue damage with BD and UA than with US and WJ (joint p value <0.001). Damage also increased within 6 h after surgery (p value = 0.004). Semiquantitative evaluation of HSP 70 showed increased expression after resection with US compared to all other resection methods (p value <0.001), indicating increased tissue damage with this method.

Conclusion: We suggest that in cases of liver resection for LDLT surgeons should reevaluate using US and WJ because of possible excessive tissue damage compared to BD and UA. Overall we advocate the use of BD as it requires no special equipment and, hence, has considerably higher cost-effectiveness without compromising tissue preservation and clinical outcome and is readily available even in low-tech environments.

Fig. 1

Immunohistochemistry of heat shock protein (HSP) 70 in the degenerative zone of damaged liver tissue. Red staining indicates expression of HSP70. Cell nuclei have dark blue staining

Fig. 2

Hemalaun–eosin staining of liver tissue. In the upper part of the image the degenerative zone can be identified. Edematous hepatocytes with pale cytoplasm and karyopyknosis can be seen in parenchyma with preserved structural integrity and intraparenchymal hemorrhages. In the lower part normal parenchyma is seen with granulocyte infiltrates

Fig. 3

Observed depth of tissue damage over time stratified for resection method. Shown are median (open circles) and upper and lower quartiles (whiskers) of tissue damage depth

Fig. 4

Family-wise 95% confidence intervals for fixed effects on tissue damage depth according to linear mixed effects models (LME). The estimators are multiplicative and the reference for comparisons is tissue depth after blunt dissection at 0 h. If the confidence interval for a factor does not include 1, statistical significance is implied. UA Ultrasound aspirator, US ultrasound scalpel, WJ water-jet

Fig. 5

Frequency of “low”, “moderate”, and “high” maximum intensity scores of HSP70 immunohistochemistry stratified by method of resection