Piggy-back versus conventional technique in liver transplantation: report of a randomized trial. Randomized trial comparing pulmonary alterations after conventional with venovenous bypass versus piggyback liver transplantation. Sequential versus contemporaneous portal and arterial reperfusion during liver transplantation.
Liver transplantation with preservation of the recipient vena cava (the "piggy-back" technique) has been proposed as an alternative to the traditional method. We performed a randomized study on 39 cirrhotic patients, 20 who underwent the piggy-back technique (group 1) and 19 the traditional method using venovenous bypass (group 2) to evaluate the feasibility and true advantages of the piggy-back technique compared to the traditional method. Two patients were switched to the conventional technique due to the presence of a caudate lobe embracing the vena cava in one patient and a caval lesion in the other. Statistically significant differences between the two groups were only found for the warm ischemia time (48.5 +/- 13 min for piggy-back vs 60 +/- 12 min for the conventional method) and for renal failure (zero cases in group 1 vs four cases in group 2). We therefore believe that liver transplantation with the piggy-back technique can easily be performed in almost all cases, and that only a few, specific situations, such as a very enlarged caudate lobe, do not justify its routine use. During the anhepatic phase of conventional liver transplantation (LT), the inferior vena cava (IVC) is cross-clamped and venovenous bypass (VVB) is usually indicated for diversion of IVC and portal blood flow. VVB can theoretically lead to pulmonary complications due to the contact of the blood with the surfaces of the circuit. In the piggyback method, preservation of the IVC avoids VVB. The aim of this study is to compare pulmonary alterations after conventional with VVB versus piggyback LT. Sixty-seven patients were randomized for conventional VVB (n = 34) or piggyback (n = 33) LT. Pulmonary static compliance (C(st)) and Pa(O2)/F(IO2) ratio were measured pre- and post-LT. Chest X-rays were obtained daily from the 1st to the 5th postoperative day. Pre- and post-LT C(st) were 73.4 +/- 36.0 mL/cm H(2)O and 59.7 +/- 22.0 mL/cm H(2)O in the conventional group and 69.1 +/- 20.0 mL/cm H(2)O and 58.7 +/- 27.1 mL/cmH(2)O in the piggyback group. The difference between the two groups was not significant (P =.702). C(st) significantly decreased after LT (P =.008). The pre- and post-LT Pa(O2)/F(IO2) were 455.6 +/- 126.6 mm Hg and 463.1 +/- 105.9 mm Hg in the conventional group and 468.9 +/- 114.1 mm Hg and 483.3 +/- 119.8 mm Hg in the piggyback group. The difference among the two groups was not significant (P = 0.331). There was no significant difference after LT (P =.382). Upon the radiological evaluation, piggyback group presented a higher frequency of pulmonary infiltrates (80.6% vs. 50.0%; P =.025). In conclusion, piggyback LT recipients have a higher rate of pulmonary infiltrates when compared to those operated upon using the conventional VVB method. Although sequential portal and arterial revascularization (SPAr) is the most common method of graft reperfusion at liver transplantation (OLT), contemporaneous portal and hepatic artery revascularization (CPAr) has been used to reduce arterial ischemia to the bile ducts. The aim of this study was to prospectively compare SPAr (group 1; n=19) versus CPAr (group 2; n=21) among 40 consecutive OLT from heart-beating donors. There were no differences in the demographics characteristics, Model for End-stage Liver Disease scores, indication for OLT and donor parameters between the groups. OLT was performed using the piggyback technique. The biliary anastomosis was performed in all cases by a duct-to-duct technique with a T-tube in 32% versus 29% of cases without a T tube (P=.83). In the CPAr group, the liver was reperfused simultaneously via the portal vein and hepatic artery. CPAr showed a longer warm ischemia (66 ± 8 vs 37 ± 7 minutes; P<.001), while SPAr had a longer arterial ischemia 103 ± 42 vs 66 ± 8 minutes (P=.0004). Recovery of graft function was similar. There was no primary nonfunction and delayed graft function occurred among 10% versus 9%. Liver function tests were similar between the two groups up to 90 days case of follow-up- One-year graft and patient survivals were, respectively, 89% and 95% versus 94% and 100% (P=.29). At a median follow-up of 13 ± 6 versus 14 ± 7 months, biliary complications included anastomotic stenoses in 15% versus 19% (P=.78) and intrahepatic non-anastomotic biliary strictures in 26% versus none (P=.01) for SPAr and CPAr, respectively. CPAr was safe and feasible, reducing the incidence of intrahepatic biliary strictures by decreasing the duration of arterial ischemia to the intrahepatic bile ducts.
                Copyright © 2011 Elsevier Inc. All rights reserved.
There is currently no evidence to recommend or refute the use of piggy-back method of liver transplantation.