study on the efficacy of prophylactic on lay mesh in preventing post-operative hernia in liver transplant patients

Conditions: Incisional Hernia of Anterior Abdominal Wall

Summary: study design: single-blinded, randomized, prospective clinical trial. study population: end-stage liver disease patients' candidates for liver transplantation. study procedures: consenting patients will be divided into two matched groups: 1. control group - receiving a standard running fascial closure with pds suture 2. treatment group - receiving a standard running fascial closure with pds suture plus a low molecular weight mesh. the mesh will be secured to the fascia extending 3 cm from the incisional site. there will be no modifications to routine post-operative wound care in both groups. however, the treatment group will have an additional drain placed at the incision site compared to the control group to reduce the risk of a seroma from placement of the mesh. wound dressing will be removed on post-op day 2 and the wound will be assessed. re-application of the dressing will occur thereafter until proper healing of the incision. an abdominal ultrasound will be done on all study participants at the 1- and 2-year mark postoperatively to look for objective evidence of a ventral incisional hernia. a ct scan will be performed if the abdominal ultrasound findings are inconclusive.

an incisional hernia is a common complication of abdominal surgery with an incidence of 4-20%. liver transplant patients represent a unique cohort of surgical patients with immediate immune suppression post-operatively. it is presumed that this immune suppression accompanied by significant co-morbidities have led to high incisional ventral hernia rates between 4.9%-34.3%. a recent 2018 retrospective review of 1044 liver transplant patients identified age \>55, high bmi \> 25, and immediate rejection were significant risk factors contributing to herniation. however, previously concerning considerations including gender, diagnosis, diabetes, child-pugh score, meld score, donor type, hepato-renal syndrome, varix bleeding, ascites, hepatic encephalopathy, ventilator use, spontaneous bacterial peritonitis (sbp), or bile leak were not identified as significant risk factors. moreover, the mortality for chronic liver disease patients for elective hernia repair is 3.7% at 90 days and morbidity is 27%. emergent hernia repair led to 10% 90-day mortality with 60% morbidity. the high incidence of herniation represents a common problem with significant morbidity and mortality post liver transplantation thereby requiring investigating a new preventative solution. a recent retrospective trial in the colorectal literature identified an institutional incidence of incisional hernia for colorectal patients of 39.9%. they recognized two high-risk populations, obese, and non-obese with a combination of several secondary risk factors. a follow-up prospective cohort study separated all colorectal patients undergoing laparotomy to standardized running pds closure versus those with bmi\>29 (the median in the prior study) and those bmi \ =2 risk factors to include standard closure with an on-lay ultrapro partially absorb-able mesh covering 3 cm adjacent to the incision placed with double down facial staples followed by a subcutaneous drain. the reported risk factors included bmi, smoking, serum creatinine, hemoglobin, serum albumin, copd diabetes, immune suppression with steroids or radiation/chemotherapy, and previous midline laparotomy. the results revealed a decrease in the incisional hernia rate from 43.9% to 10% (p=0.0001). this study also concluded the treatment was cost effective and safe.

Eligibility criteria:
inclusion criteria: • all patients above 18 years of age undergoing liver transplantation exclusion criteria: * non consenting patients * patients with skin or deep tissue infections at the time of surgery * prior mesh infection from hernia repair will be excluded * entry into the gastro-intestinal system (i.e., need for hepaticojejunostomy for transplantation versus just a standard biliary-biliary anastomosis) * prior biliary stent (causes colonization of the biliary track and increases surgical site infection) * patients that are unstable, requiring pressors, or required \>4 units of packed red blood cell transfusions intra-operatively will be excluded as to not prolong surgical time. * pregnant women * prior incisional hernia/history of ih and repair * death within 1-year * insufficient follow up * connective tissue disorders * prior significant wound dehiscence or infection * spontaneous bacterial peritonitis * primary sclerosing cholangitis (requires roux en y reconstruction thereby entry into the alimentary track)

Keywords: liver transplant incisional hernia