Risk of Respiratory Complications in Obese Liver Transplant Patients: A Study of 343 Patients

Transfusion-Related Acute Lung Injury During Liver Transplantation: A Scoping Review

Liver transplantation is associated with significant blood loss, often requiring massive blood product transfusion. Transfusion-related acute lung injury (TRALI) is a devastating cause of transfusion-related deaths. While reports have investigated the general incidence of TRALI, the incidence of TRALI specifically following transfusion during liver transplant remains unclear. This scoping review summarizes existing literature regarding TRALI during the liver transplantation perioperative period. Databases were searched for all articles and abstracts reporting on TRALI after liver transplantation. Data collected included number of patients studied, patient characteristics, incidences of TRALI, TRALI characteristics, and patient outcomes. The primary outcome investigated was the incidence of TRALI in the setting of liver transplantation. Thirteen full-text citations were included in this review. The incidence of TRALI post-liver transplant was 0.68% (65 of 9,554). Based on reported transfusion data, patients diagnosed with TRALI received an average of 10.92 ± 10.81 units of packed red blood cells (pRBC), 20.05 ± 15.72 units of fresh frozen plasma, and 5.75 ± 10.00 units of platelets. Common interventions following TRALI diagnosis included mechanical ventilation with positive end-expiratory pressure, inhaled high-flow oxygen, inhaled pulmonary vasodilator, and pharmacologic treatment using pressors or inotropes, corticosteroids, or diuretics. Based on reported mortality data, 26.67% of patients (12 of 45) diagnosed with TRALI died during the postoperative period. This scoping review underscores the importance of better understanding the incidence and presentation of TRALI after liver transplant surgery. The clinical implications of these results warrant the development of identification and management strategies for liver transplant patients at increased risk for developing TRALI.

Obesity Management of Liver Transplant Waitlist Candidates and Recipients

Obesity is increasing in prevalence in liver transplant candidates and recipients. The rise in liver transplantation for nonalcoholic steatohepatitis reflects this increase. Management of obesity in liver transplant candidates can be challenging due to the presence of decompensated cirrhosis and sarcopenia. Obesity may increase peritransplant morbidity but does not have an impact on long-term post-transplant survival. Bariatric surgery may be a feasible option in select patients before, during, or after liver transplantation. Use of weight loss drugs and/or endoscopic therapies for obesity management ultimately may play a role in liver transplant patients, but more research is needed to determine safety.

Obesity in the Liver Transplant Setting

The obesity epidemic has resulted in an increased prevalence of obesity in liver transplant (LT) candidates and in non-alcoholic fatty liver disease (NAFLD) becoming the fastest growing indication for LT. LT teams will be dealing with obesity in the coming years, and it is necessary for them to recognize some key aspects surrounding the LT in obese patients. Obesity by itself should not be considered a contraindication for LT, but it should make LT teams pay special attention to cardiovascular risk assessment, in order to properly select candidates for LT. Obese patients may be at increased risk of perioperative respiratory and infectious complications, and it is necessary to establish preventive strategies. Data on patient and graft survival after LT are controversial and scarce, especially for long-term outcomes, but morbid obesity may adversely affect these outcomes, particularly in NAFLD. The backbone of obesity treatment should be diet and exercise, whilst being careful not to precipitate or worsen frailty and sarcopenia. Bariatric surgery is an alternative for treatment of obesity, and the ideal timing regarding LT is still unknown. Sleeve gastrectomy is probably the procedure that has the best evidence in LT because it offers a good balance between safety and efficacy.

Living donor liver transplantation in patients weighing ≥100 kg: Low graft weight and obesity do not impact outcomes

Living donor liver transplantation (LDLT) in obese patients raises concerns with regards to obtaining grafts of "adequate" graft-to-recipient weight ratio (GRWR) and the impact of obesity on the outcomes of LDLT. LDLT outcomes in patients weighing ≥100 kg were compared with those weighing <100 kg. Patients weighing ≥100 kg were divided into 3 categories based on the GRWR of the grafts they received. Groups 1, 2, and 3 included patients with GRWR ≥0.8%, between 0.65% and 0.8%, and <0.65%, respectively. The 56 (6.5%) adult liver transplants were performed in patients weighing 100 kg or more. Except for higher mean body mass index (35.8 versus 25.2 kg/m² ; P value < 0.01) and grafts of lower GRWR in obese patients (0.74% versus 1.02%; P value < 0.01), all other parameters were similar between the 2 groups. Despite obesity and smaller grafts, the posttransplant outcomes such as day to normal bilirubin and international normalized ratio; infective, respiratory, and biliary complications; and hospital mortality were similar between the 2 groups. On comparing obese patients in the 3 GRWR categories, except for graft weight (985 versus 769 versus 646 g; P value < 0.01), all the pretransplant parameters were comparable. There was no significant difference in terms of graft function, postoperative morbidity, and hospital mortality between patients with grafts of normal GRWR and those with grafts of low and very low GRWR. Grafts of low GRWR give satisfactory results in obese patients undergoing LDLT and obesity does not adversely impact the outcome of LDLT. Liver Transplantation 23:35-42 2017 AASLD.