Sonographic Differences in Venous Return Between Piggyback Versus Caval Interposition in Adult Liver Transplantations

The piggyback technique (PT) is being used more frequently than caval interposition (CI) in adult orthotopic liver transplants (OLT). It is unclear whether PT alters venous return compared with CI, therefore leading to postoperative complications. The aim of our study was to analyze our experience with PT and CI by comparing ultrasound results of hepatic vein flow on the first postoperative day. Patients and Methods: This retrospective analysis of consecutive OLTs performed between 2002 and 2005 included data from a single blinded radiologist who reviewed all postoperative day 1 ultrasound examinations. The hepatic vein waveforms were scored as all phasic, all flat, or partially phasic/flat. Results: During the study period, we performed, 465 OLT among which 270 had available ultrasound examinations. The etiologies of liver disease were similar between the PT and CI cohorts, hepatitis C and alcoholic liver disease accounted for more than 60%. Two hundred eight (77%) had undergone PT and 62 (23%) CI. Among the PT, 60% were phasic, 31.1% were partially phasic/flat, and 8% were flat. When a CI was performed, 56.5% were phasic, 35.5% were partially phasic/flat, and 8% were flat. Conclusions: There was no significant difference between PT and CI with regard to an effect on hepatic vein waveforms on the first operative day. Therefore, there do not appear to be early hemodynamic benefits of performing CI versus PT anastamoses of OLTs. Further studies may be needed to determine whether long-term sequelae follow the piggyback technique.