Effects of Hemi-Portocaval Shunts For Inflow Modulation on the Outcome of Small-for-Size Grafts in Living Donor Liver Transplantation

Abstract

Graft hyperperfusion in small-for-size grafts (SFSG) is considered the main causal factor of small-for-size syndrome (SFSS). We compared SFSG with a graft-torecipient body ratio ≤0.8, with and without graft inflow modulation (GIM) by means of a hemi-portocaval shunt (HPCS). Thirteen patients underwent adult-toadult living donor liver transplantation (AALDLT): G1, n = 5 [4 right livers (RL) and 1 left liver (LL)] without GIM, and G2, n = 8 (4 RL and 4 LL) with GIM. In G2 patients, portal vein flow (PVF) was significantly reduced by HPCS: 190 ± 70 mL/min/100 g liver in G2 vs. 401 ± 225 ml/min in G1 (p = 0.002). One-and 6-month post-transplantation graft volume/standard liver volume (GV/SLV) ratio was of 72% and 79.5% in G1; 80% and 101% in G2 (p = ns). SFSS was observed in three G1 recipients (who were retransplanted), but in none of the G2 patients. At 1-year, patient and graft survival was respectively of 40% and 20% in G1, 87.5% and 75% in G2 (p = 0.024 and 0.03).It is concluded that drastic reduction of PVF by means of HPCS improves overall patient and graft survival by averting the occurrence of SFSS. Graft inflow modulation through HPCS reduces the risk of complications when transplanting SFSG in adult recipients.

Splenectomy improves survival by increasing arterial blood supply in a rat model of reduced-size liver

“…This extent of pHx is followed by a transient small-for-size syndrome of minor degree, which usually resolves spontaneously within a few days. In contrast, major liver resection >75% is followed by a more pronounced and long-lasting smallfor-size syndrome with much higher morbidity and mortality [24]. However, occurrence and pathogenesis of small-for-size syndrome remain highly controversially discussed [26].…”

“…In humans, 60% pHx results in a doubling of the portal flow in the remnant liver tissue [24]. This extent of pHx is followed by a transient small-for-size syndrome of minor degree, which usually resolves spontaneously within a few days.…”

“…Modulation of liver inflow after segmental liver transplantation or massive liver resection was advocated as a way to overcome organ hyperperfusion, including splenic artery ligation and splenectomy or diversion of portal vein blood by means of portocaval and mesocaval shunts [24,[27][28][29]. However, these procedures have been used despite the lack of hemodynamic data [30,31].…”

“…Excessive portal blood flow is thought to contribute to the dysfunction and failure after extended liver resection, segmental liver transplantation as well as transplantation in patients with uncompensated severe portal hypertension [8,[22][23][24]. Whereas under normal conditions most cells have an adequate oxygen concentration, under critical conditions, hepatocytes may have an oxygen concentration at which mitochondrial respiration and ATP synthesis are partially oxygen limited [25].…”

Durability of small‐for‐size living donor allografts

“…Despites outflow optimization, portal hypertension persisted in some SFS grafts, where additional portal inflow modulations, including splenic artery ligation 21 and portocaval shunt 22 were employed. 23 In our series, 2 patients received splenic artery ligation with promising graft survival and good long-term graft function.…”