Hepatic ischemia/reperfusion injury is an important restricting factor of clinical liver resection and liver transplantation.When the liver is transiently deprived of blood followed by repeffusion,a large number of various mediators are released that can lead to cellular and,eventually,organ dysfunction.This review summarizes the pathogenesis and the protection mechanisms of hepatic ischemia/reperfusion injury.

Objective:To evaluate the clinical effects of posterior reduction in the treatment of acute severe traumatic lumbar spondylolisthesis.Methods:A retrospective study was conducted to analyze the clinical data of 12 patients with acute severe traumatic lumbar spondylolisthesis who had been treated by posterior reduction at Department of Spinal Surgery, Zhengzhou Orthopaedic Hospital from June 2010 to December 2018. There were 7 males and 5 females with an age of (25.7±1.8) years. The spondylolisthesis was at L4 in 4 cases and at L5 in 8 cases, and grade Ⅲ in 7 cases, grade Ⅳ in 4 cases and grade Ⅴ in 1 case according to the Meyerding classification. By the American Spinal Injury Association (ASIA) grading, the preoperative neurological function was at level B in 6 cases, at level C in 4 cases, and at level D in 2 cases. All the 12 patients underwent posterior reduction and internal fixation with pedicle screws, as well as intervertebral bone graft fusion. Operation time and intraoperative blood loss were recorded. Clinical efficacy was evaluated by visual analogue scale (VAS) and Oswestry disability index (ODI) before and after surgery, and neurological function was evaluated by ASIA grading. X-ray, CT plain scan and reconstruction were used to observe internal fixation and bone grafting.Results:All patients were followed up for (18.5±2.1) months. The operation time was (165.7±42.3) min and the blood loss (497.7±75.3) mL. The VAS pain scores [(2.7±0.3) points and (1.8±0.2) points] and ODIs (18.2%±2.3% and 14.5%±2.6%) at 2 weeks after operation and at the last follow-up were significantly lower than the preoperational values [(8.5±0.6) points and 72.3%±12.3%] ( P<0.05), but there was no statistically significant difference between 2 weeks after operation and the last follow-up ( P>0.05). At the last follow-up, X-rays and CT scans showed good fixation and adequate bone grafting; the spondylolisthesis was grade 0 in 10 cases and grade I in 2 cases; the ASIA level of neurological function was C in 2 cases, D in 3 cases, and E in 7 cases. Healing of surgical incision was delayed in 2 patients but responded to symptomatic treatment. Follow-ups observed no such complications as loosening or pulling out of internal fixation. Conclusion:In the treatment of acute severe traumatic lumbar spondylolisthesis, posterior reduction can effectively restore the spondylolisthesis sequence and restore spinal stability, leading to satisfactory curative outcomes.