Strategies to optimize donor safety with smaller grafts for adult-to-adult living donor liver transplantation

Purpose of review To describe our current understanding of adult-to-adult living donor liver transplantation (AA-LDLT) in terms of graft size. Recent findings Improved outcomes of small liver graft with the use of portal vein pressure (PVP) modulation. Summary AA-LDLT is viewed as a viable alternative to whole liver transplantation on the treatment of end-stage liver disease. Over the past two decades, right lobe AA-LDLT has been the standard because of concerns related to graft size. Small-for-size syndrome (SFSS) is an entity that presents in recipients of small grafts. It negatively affects patient and graft survival and recipients of grafts with a graft weight-to-recipient weight ratio (GW/RW) lower than 1.0 are at the highest risk. Over the last decade, our understanding of SFSS has identified PVP as a major determinant in the development of SFSS. Direct or indirect surgical PVP modulation has demonstrated a way to prevent the development of SFSS in recipients of small grafts and has improved the survival outcomes of small grafts. These improved outcomes coupled with concerns for donor safety have led to the renaissance of the use of left lobe grafts. Based on the current clinical data, the use of small grafts GW/RW greater than 0.6 is viewed as well tolerated when PVP is modulated to achieve a target PVP less than 15 mmHg after reperfusion and the left lobe is currently viewed as the ideal graft for AA-LDLT.