Influence of the water jet system vs cavitron ultrasonic surgical aspirator for liver resection on the remnant liver

BACKGROUND Several methods, such as finger fracture, Pean crush, cavitron ultrasonic surgical aspirator (CUSA), and water jet (WJ), are used for hepatic parenchymal dissection in liver surgery. CUSA is the conventional method in Japan. WJ is a relatively novel method for parenchymal dissection. Although it has several advantages, such as lower volume of blood loss and shorter operative time, the effect of the WJ system for hepatic dissection on the remnant liver has not yet been investigated. AIM To investigate and compare the effect of the WJ method vs CUSA on the remnant liver cut surface. METHODS This observational study compared the two types of parenchymal transection methods (WJ vs CUSA) in liver surgery. In total, 24 and 40 patients who underwent hepatectomy using the WJ method and CUSA, respectively, were included in the analysis. Accordingly, the clinicopathological characteristics and clinical outcomes of 24 and 40 patients were compared. Furthermore, postoperative contrast-enhanced computed tomography (CT) scan was performed to assess the cut surface length of the remnant liver and the degenerative thickness of the areas with a reduced contrast effect in the dissected plane. Then, the two groups were compared. RESULTS On CT scan, the median areas of denaturation in the liver dissection planes were 522 (range: 109.5-1242) mm(2) in the CUSA group and 324 (range: 93.6-1529) mm(2) in the WJ group. The area did not significantly differ between the two groups; however, the denaturation thickness of the WJ group was significantly lower than that of the CUSA group [5.8 (range: 0.7-11.1) mm vs 3.3 (range: 1.7-10.4) mm, P < 0.001]. CONCLUSION The WJ group had significantly thinner contrast-enhanced areas in the post hepatectomy detached section than the CUSA group.