Effects of Different 980-nm Diode Laser Parameters in Hepatectomy.

BACKGROUND AND OBJECTIVE: Despite the successful application of laser in animal experiments and clinics, the adjustment of laser parameters during surgery is still unclear. This study aimed to investigate the effect of different 980-nm diode laser parameters in hepatectomy. This could provide a clear protocol for using 980-nm diode laser in hepatectomy. STUDY DESIGN/MATERIALS AND METHODS: In total, 48 Sprague-Dawley rats were used to explore the effects of different 980-nm diode laser parameters in hepatectomy, by setting different parameter combinations. The rats were randomly divided into eight groups, including the continuous wave group and quasi-continuous wave group. The effects were assessed in terms of liver resection speed, extent of intraoperative bleeding, and thermal damage. RESULTS: In the quasi-continuous wave group, there was a significant difference in resection speed at the different laser parameters (P < 0.001); however, there was no significant difference in intraoperative bleeding and thermal damage. In the continuous wave group, there was a significant difference in resection speed, intraoperative bleeding, and thermal damage at different parameters. CONCLUSION: The study showed that the average power determined hemostasis efficiency and thermal damage, and peak power determined the liver resection speed, whereas the pulse width and repetition frequency are not independent factors. When using 980-nm diode laser in hepatectomy, the average power should be decreased to prove hemostasis efficiency in delicate operations, and the peak power should be decreased to accelerate the procedure without worsening thermal damage. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Warm ischemia time and elevated serum uric acid are associated with metabolic syndrome after liver transplantation with donation after cardiac death.

AIM: To describe the prevalence of posttransplant metabolic syndrome (PTMS) after donation after cardiac death (DCD) liver transplantation (LT) and the pre- and postoperative risk factors. METHODS: One hundred and forty-seven subjects who underwent DCD LT from January 2012 to February 2016 were enrolled in this study. The demographics and the clinical characteristics of pre- and post-transplantation were collected for both recipients and donors. PTMS was defined according to the 2004 Adult Treatment Panel-III criteria. All subjects were followed monthly for the initial 6 mo after discharge, and then, every 3 mo for 2 years. The subjects were followed every 6 mo or as required after 2 years post-LT. RESULTS: The prevalence of PTMS after DCD donor orthotopic LT was 20/147 (13.6%). Recipient's body mass index (P = 0.024), warm ischemia time (WIT) (P = 0.045), and posttransplant hyperuricemia (P = 0.001) were significantly associated with PTMS. The change in serum uric acid levels in PTMS patients was significantly higher than that in non-PTMS patients (P < 0.001). After the 1st mo, the level of serum uric acid of PTMS patients rose continually over a period, while it was unaltered in non-PTMS patients. After transplantation, the level of serum uric acid in PTMS patients was not associated with renal function. CONCLUSION: PTMS could occur at early stage after DCD LT with growing morbidity with the passage of time. WIT and post-LT hyperuricemia are associated with the prevalence of PTMS. An increased serum uric acid level is highly associated with PTMS and could act as a serum marker in this disease.

Hypothermic machine perfusion with metformin-University of Wisconsin solution for ex vivo preservation of standard and marginal liver grafts in a rat model.

AIM: To compare the effect of University of Wisconsin (UW) solution with or without metformin, an AMP-activated protein kinase (AMPK) activator, for preserving standard and marginal liver grafts of young and aged rats ex vivo by hypothermic machine perfusion (HMP). METHODS: Eighteen young (4 mo old) and 18 aged (17 mo old) healthy male SD rats were selected and randomly divided into three groups: control group, UW solution perfusion group (UWP), and UW solution with metformin perfusion group (MUWP). Aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), interleukin-18 (IL-18), and tumor necrosis factor-alpha (TNF-α) in the perfused liquid were tested. The expression levels of AMPK and endothelial nitric oxide synthase (eNOS) in liver sinusoidal endothelial cells were also examined. Additionally, microscopic evaluation of the harvested perfused liver tissue samples was done. RESULTS: AST, ALT, LDH, IL-18 and TNF-α levels in the young and aged liver-perfused liquid were, respectively, significantly lower in the MUWP group than in the UWP group (P < 0.05), but no significant differences were found between the young and aged MUWP groups. Metformin increased the expression of AMPK and eNOS protein levels, and promoted the extracellular release of nitric oxide through activation of the AMPK-eNOS mediated pathway. Histological examination revealed that in the MUWP group, the extent of liver cells and tissue damage was significantly reduced compared with the UWP group. CONCLUSION: The addition of metformin to the UW preservative solution for ex vivo HMP can reduce rat liver injury during cold ischemia, with significant protective effects on livers, especially of aged rats.