Minor Hepatectomies: Focusing a Blurred Picture: Analysis of the Outcome of 4471 Open Resections in Patients Without Cirrhosis.

To elucidate minor hepatectomy (MiH) outcomes.Liver surgery has moved toward a parenchyma-sparing approach, favoring MiHs over major resections. MiHs encompass a wide range of procedures.We retrospectively evaluated consecutive patients who underwent open liver resections in 17 high-volume centers.cirrhosis and associated digestive/biliary resections. Resections were classified as (Brisbane nomenclature): limited resections (LR); (mono)segmentectomies/bisegmentectomies (Segm/Bisegm); right anterior and right posterior sectionectomies (RightAnteriorSect/RightPosteriorSect). Additionally, we defined: complex LRs (ComplexLR = LRs with exposed vessels); postero-superior segmentectomies (PosteroSuperiorSegm = segment (Sg)7, Sg8, and Sg7+Sg8 segmentectomies); and complex core hepatectomies (ComplexCoreHeps = Sg1 segmentectomies and combined resections of Sg4s+Sg8+Sg1). Left lateral sectionectomies (LLSs, n = 442) and right hepatectomies (RHs, n = 1042) were reference standards. Outcomes were adjusted for potential confounders.Four thousand four hundred seventy-one MiHs were analyzed. Compared with RHs, MiHs had lower 90-day mortality (0.5%/2.2%), severe morbidity (8.6%/14.4%), and liver failure rates (2.4%/11.6%, P < 0.001), but similar bile leak rates. LR and LLS had similar outcomes. ComplexLR and Segm/Bisegm of anterolateral segments had higher bile leak rates than LLS rates (OR = 2.35 and OR = 3.24), but similar severe morbidity rates. ComplexCoreHeps had higher bile leak rates than RH rates (OR = 1.94); the severe morbidity rate approached that of RH. PosteroSuperiorSegm, RightAnteriorSect, and RightPosteriorSect had severe morbidity and bile leak rates similar to RH rates. MiHs had low liver failure rates, except RightAnteriorSect (vs LLS OR = 4.02).MiHs had heterogeneous outcomes. Mortality was low, but MiHs could be stratified according to severe morbidity, bile leak, and liver failure rates. Some MiHs had postoperative outcomes similar to RH.