PURPOSE: The purpose of this study was to evaluate the Doppler spectral waveforms in the hepatic artery after liver transplantation and hepatic artery reconstruction by end-to-end anastomosis or aortohepatic bypass. The peak systolic velocities (PSVs), end-diastolic velocities (EDVs), and resistance indices (RIs) between the 2 reconstruction groups were compared to establish normal post-transplantation values.
METHODS: We retrospectively reviewed the Doppler sonograms and the sonographic reports from 48 patients who had undergone liver transplantation, 30 with end-to-end arterial anastomoses and 18 with aortohepatic bypasses. All aortohepatic bypasses had been performed using the infrarenal technique. All sonographic examinations had been performed 3-6 months after transplantation in patients with no clinical sign of transplant failure and whose liver function test results more normal. We compared the mean hepatic artery PSVs, EDVs, and RIs of the 2 groups.
RESULTS: Doppler spectral analysis allowed the detection of 2 types of arterial flow, a low-resistance pattern in the end-to-end anastomosis group and a high-resistance pattern with low diastolic flow in the infrarenal bypass group. The mean PSV +/- standard deviation (SD) was 57 +/- 16 seconds in the end-to-end anastomosis group and 62 +/- 16 cm/second in the infrarenal bypass group. The mean EDV +/- SD was 25 +/- 14 cm/second in the end-to-end anastomosis group and 12 +/- 4 cm/second in the infrarenal bypass group. The RIs ranged from 0.33 to 0.71 (mean +/- SD, 0.58 +/- 0.13) in the patients with end-to-end anastomoses and from 0.70 to 0.87 (mean +/- SD, 0.77 +/- 0.06) in those with infrarenal bypasses. The difference in the mean RIs between the 2 groups was statistically significant (p < 0.05).
CONCLUSIONS: Spectral waveform and RI are associated with the length and caliber of the type of hepatic artery anastomosis used. End-to-end anastomoses are short and have a uniform small caliber; aortohepatic bypasses are longer and have a progressively by smaller caliber. We must be cognizant of the method of anastomosis used when examining patients for complications after liver transplantation because the method used affects the resulting spectral waveform and RI.
