How far can we lower graft-to-recipient weight ratio for living donor liver transplantation under modulation of portal venous pressure?

Smaller size grafts for living donor liver transplantation (LDLT) can enhance donor safety and expand donor availability. We previously reported that modulation of portal venous pressure (PVP) was key for successful LDLT with small grafts, and that it actively lowered graft-to-recipient weight ratio (GRWR) for adult-to-adult LDLT. This retrospective study investigated the outcome of LDLT using small grafts with PVP modulation. This study analyzed 221 adult LDLT patients between March 2008 and December 2013 and divided them into 3 groups based on GRWR: large (L), GRWR ≥ 0.8% (n = 154), medium (M), ≥ 0.7% GRWR < 0.8% (n = 38); and small (S) GRWR < 0.7% (n = 29). Donor and recipient factors, PVP, pressure gradient between PVP and central venous pressure (CVP), occurrence of small for size syndrome (SFSS), ascites, and posttransplant laboratory data were compared across the 3 groups. Patient and graft survival were compared using Kaplan-Meier methods. There was no difference in patient or graft survival between the 3 groups. Amount of posttransplant ascites and posttransplant International Normalized Ratio were similar, but the S and M groups had more prolonged cholestasis. SFSS was identified in 17%, 13%, and 13% in the S, M, and L groups, respectively (P = NS). Patients with a final PVP of ≤15 mmHg had better survival than patients with a final PVP of >15 mmHg (P < .001). Multivariate analysis showed that donor age >40 years old, final PVP of >15 mmHg, and pressure gradient of PVP-CVP >5 mmHg were risk factors for inferior patient survival. We achieved satisfactory outcomes in LDLT with GRWR as low as 0.6% using PVP modulation. Thus, we currently set a lower limit of GRWR at 0.6% while protecting donor safety and expanding donor availability.

Uemura T ，Wada S ，Kaido T ，Mori A ，Ogura Y ，Yagi S ，Fujimoto Y ，Ogawa K ，Hata K ，Yoshizawa A ，Okajima H ，Uemoto S ... -  《-》

Lower limit of the graft-to-recipient weight ratio can be safely reduced to 0.6% in adult-to-adult living donor liver transplantation in combination with portal pressure control.

The goal of this study was to examine whether the lower limit of the graft-to-recipient weight ratio (GRWR) can be safely reduced to make better use of a left-lobe graft in adult-to-adult living donor liver transplantation (LDLT) in combination with portal pressure control. Beginning in December 2007, our institution actively selected left-lobe grafts for use in liver transplantation seeking to minimize the risks to healthy donors. We gradually decreased the lower limit of the GRWR to preferentially select a left-lobe over a right-lobe graft: from ≥0.7% beginning in December 2007 to ≥0.6% beginning in April 2009. A portal pressure control program, targeting final portal pressures below 15 mm Hg, was also introduced to overcome small-for-size graft problems. The ratio of left-lobe grafts among all adult-to-adult LDLT grafts and the donor complication rate (defined as Clavien grade ≥ III, excluding wound infection) were compared between two time periods: June 1999 to November 2007 (period 1, n = 541) and December 2007 to February 2010 (period 2, n = 119). Overall survival rates were also compared between those recipients of a GRWR < 0.8% and those with a GRWR ≥ 0.8% in 198 recipients who underwent LDLT at our institution between April 2006 and February 2010. Left-lobe grafts use increased from period 1 (65/541 recipients; 12.0%) to period 2 (50/119 recipients; 42.0%; P < .001). The donor complication rate tended to decrease from 13.8% in period 1 to 9.3% in period 2 (P = .115). The overall survival rate in 52 recipients with a GRWR < 0.8% did not differ from that in 146 recipients with a GRWR ≥ 0.8%. The lower limit of the GRWR can be safely reduced to 0.6% in adult-to-adult LDLT in combination with portal pressure control.

Kaido T ，Mori A ，Ogura Y ，Hata K ，Yoshizawa A ，Iida T ，Yagi S ，Uemoto S ... -  《-》

Graft-to-recipient weight ratio lower to 0.7% is safe without portal pressure modulation in right-lobe living donor liver transplantation with favorable conditions.

Lee SD ，Kim SH ，Kim YK ，Lee SA ，Park SJ ... -  《Hepatobiliary & Pancreatic Diseases International》

How transplant surgeons can overcome the inevitable insufficiency of allograft size during adult living-donor liver transplantation: strategy for donor safety with a smaller-size graft and excellent recipient results.

Small-for-size grafts are an issue in liver transplantation. Portal venous pressure (PVP) was monitored and intentionally controlled during living-donor liver transplantation (LDLT) in 155 adult recipients. The indocyanine green elimination rate (kICG) was simultaneously measured in 16 recipients and divided by the graft weight (g) to reflect portal venous flow (PVF). The target PVP was <20 mmHg. Patients were divided by the final PVP (mmHg): Group A, PVP < 12; Group B, 12 ≤ PVP < 15; Group C, 15 ≤ PVP < 20; and Group D, PVP ≥ 20. With intentional PVP control, we performed splenectomy and collateral ligation in 80 cases, splenectomy in 39 cases, and splenectomy, collateral ligation, and additional creation in five cases. Thirty-one cases received no modulation. Groups A and B showed good LDLT results, while Groups C and D did not. Final PVP was the most important factor for the LDLT results, and the PVP cutoffs for good outcomes and clinical courses were both 15.5 mmHg. The respective kICG/graft weight cutoffs were 3.5580 × 10(-4) /g and 4.0015 × 10(-4) /g. Intentional PVP modulation at <15 mmHg is a sure surgical strategy for small-for-size grafts, to establish greater donor safety with good LDLT results. The kICG/graft weight value may have potential as a parameter for optimal PVF and a predictor for LDLT results.

Hori T ，Ogura Y ，Ogawa K ，Kaido T ，Segawa H ，Okajima H ，Kogure T ，Uemoto S ... -  《-》

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

Campos BD ，Botha JF 《-》