Living donor liver transplantation in maple syrup urine disease – Case series and world's youngest domino liver donor and recipient

Abstract

MSUD occurs due to deficiency of enzyme BCKAD required for metabolism of leucine, isoleucine, and valine leading to the accumulation of these and their ketoacids causing acute metabolic decompensation manifesting as encephalopathy or sudden death. The patient requires special protein-restricted diet to survive. As this enzyme is expressed in liver, liver transplantation has been successfully performed as a cure. We report two patients of MSUD who underwent LDLT while their livers were used as a domino graft for other biliary cirrhotic patients. A 22-month-old male child diagnosed as a case of classic MSUD underwent LDLT from an altruistic aunt as donor following which his serum leucine levels normalized on an unrestricted protein diet. His liver was used as a domino graft. A 38-month-old female child with diagnosed MSUD underwent LDLT from a swap donor, and her liver was used as a domino graft. Her DQ improved post-transplant. LDLT from non-heterozygous donors is a cure for classical MSUD. Their livers can be used as domino grafts for non-MSUD cases.

Domino liver transplantation for select metabolic disorders: Expanding the living donor pool

“…In contrast, recurrence of de novo disease has not been observed in MSUD DLT recipients, since the liver accounts for a minority of whole‐body BCKDH activity . Recent reports have established MSUD DLT as a safe, long‐term transplant intervention, rather than as a temporary bridge . We have previously reported a series with 100% patient and graft survival and no metabolic derangement following DLT using MSUD donors with short‐term follow‐up .…”

“…The technical aspects of DLT are reported in a large adult series and in limited pediatric cases, verifying feasibility and safety of the procedure without adding additional risk for donors and recipients. Younger donor age, shorter cold ischemia time, less intraoperative transfusion requirement, less graft dysfunction, and less ischemia preservation injury have been reported in DLT transplants . The technical issue of hepatic artery thrombosis in our patient may be related to pathophysiology of the underlying PA, as vascular thrombosis incidence has been reported to be increased in this population …”

“…2 Recent reports have established MSUD DLT as a safe, long-term transplant intervention, rather than as a temporary bridge. [19][20][21][22][23] We have previously reported a series with 100% patient and graft survival and no metabolic derangement following DLT using MSUD donors with short-term follow-up. 12 The literature and this series report recipients with normal plasma amino acid profiles and no metabolic decompensations following transplantation, confirming that sufficient extrahepatic BCKDH activity enables unrestricted protein intake with no clinical signs of MSUD.…”

“…12 The literature and this series report recipients with normal plasma amino acid profiles and no metabolic decompensations following transplantation, confirming that sufficient extrahepatic BCKDH activity enables unrestricted protein intake with no clinical signs of MSUD. 2,17,[20][21][22] MSUD DLT has been performed in patients with various enzyme deficiencies. Matsunami et al reported successful short-term results from transplanting MSUD liver to a patient with pyruvate carboxylase deficiency, 17 and this study confirms normal metabolic balance >1-year posttransplant.…”

“…Younger donor age, shorter cold ischemia time, less intraoperative transfusion requirement, less graft dysfunction, and less ischemia preservation injury have been reported in DLT transplants. [19][20][21][22] The technical issue of hepatic artery thrombosis in our patient may be related to pathophysiology of the underlying PA, as vascular thrombosis incidence has been reported to be increased in this population. 26 Successful DLT from a patient with one metabolic disease donor to one with a different metabolic disorder is a very complex clinical scenario necessitating a well-organized, multidisciplinary team, requiring detailed metabolic evaluation, care, and monitoring.…”