Defining Surgical Difficulty of Liver Transplantation.

Objective To define technically difficult liver transplantation (Diff-LT). Summary background data Currently, there is no acknowledged definition of Diff-LT. Methods This retrospective study included all first consecutive liver-only transplantations performed in two centers from 2011 to 2015. Diff-LT was defined as the combination of the number of blood units transfused, cold ischemia time, and duration of operation, all at or above the median value of the entire population. The correlation of Diff-LT with short- (including the comprehensive complication index [CCI]) and long-term outcomes was assessed. Outcomes were also compared to the 90-day benchmark cutoffs of LT. Predictors of Diff-LT were identified by multivariable analysis, first using only recipient data and then using all recipient, donor, graft, and surgical data. Results The study population included 467 patients. The incidence of Diff-LT was 18.8%. Diff-LT was associated with short-term outcomes, including the CCI and mortality, but not with patient or graft long-term survival. Previous abdominal surgery, intensive care unit-bound at the time of LT, split graft use, non-standard arterial reconstruction, and porto-systemic shunt ligation were independent predictors of Diff-LT. The proportion of variables below the corresponding LT 90-day benchmark cutoffs was 8/13 (61.5%) for non-Diff-LT, and 4/13 (30.8%) for Diff-LT. Conclusions Diff-LT, as defined, occurred frequently. Adjusting modifiable variables might decrease the risk of Diff-LT and improve the postoperative course. This definition of Diff-LT might be useful for patient information, comparison between centers and surgeons, and as a metric in future trials.