Role of Doppler Trasonography in Predicting Recovery From Early Allograft Dysfunction in Liver Postoperative Patients

OBJECTIVE

The aim of this study was to observe the recovery of liver function in patients with early allograft dysfunction (EAD) at one month postoperatively and explore whether early postoperative ultrasonic hemodynamic parameters can predict this outcome.

METHODS

Patients with EAD postoperatively, who underwent orthotopic liver transplantation (OLT) in our hospital from December 2012 to June 2021, were retrospectively collected. Based on the recovery of liver function within one month, patients were divided into two groups: the recovery group (FR-1M) and the non-recovery group (Non-FR-1M). Ultrasonic hemodynamic parameters within the first seven days postoperatively were compared between the two groups.

RESULTS

Among the 254 EAD patients included in this study, 158 (62%) patients recovered their liver function within one month. Of the 96 (38%) patients who did not recover, The RI of the non-FR-1M group was significantly lower than that of the FR-1M group on postoperative day 6 (POD6) and POD7. In the high resistance interval (RI all > 0.7), Group FR-1M represents a significant proportion (29/3, ratio 12/1), while in the low resistance interval (RI < 0.5 at least once), Group non-FR-1M accounts for a relatively high proportion (12/27, ratio 5/11). In the middle resistance interval (more than 1 time ≤ 0.7 and all ≥ 0.5), the proportions of the two groups are balanced (85/88, ratio 1/1).

CONCLUSION

Liver function typically recovers within 1 month in most patients with EAD. The high resistance state of the hepatic artery in the early postoperative period is illustrative an important role in its recovery. Low-resistance state is most unfavorable for the recovery of liver function.

Post-operative assessment in patients after liver transplantation: imaging parameters associated with 1-year graft failure

PURPOSE

To identify post-liver transplant CT findings which predict graft failure within 1 year.

MATERIALS AND METHODS

We evaluated the CT scans of 202 adult liver transplants performed in our institution who underwent CT within 3 months after transplantation. We recorded CT findings of liver perfusion defect (LPD), parenchymal homogeneity, and the diameters and attenuations of the hepatic vessels. Findings were correlated to 1-year graft failure, and interobserver variability was assessed.

RESULTS

Forty-one (20.3%) of the 202 liver grafts failed within 1 year. Graft failure was highly associated with LPD (n = 18/25, or 67%, versus 15/98, or 15%, p < 0.001), parenchymal hypoattenuation (n = 20/41, or 48.8% versus 17/161, or 10.6%, p < 0.001), and smaller diameter of portal veins (right portal vein [RPV], 10.7 ± 2.7 mm versus 14.7 ± 2.2 mm, and left portal vein [LPV], 9.8 ± 3.0 mm versus 12.4 ± 2.2 mm, p < 0.001, respectively). Of these findings, LPD (hazard ratio [HR], 5.43, p < 0.001) and small portal vein diameters (HR, RPV, 3.33, p < 0.001, and LPV, 3.13, p < 0.05) independently predicted graft failure. All the measurements showed fair to moderate interobserver agreement (0.233~0.597).

CONCLUSION

For patients who have CT scan within the first 3 months of liver transplantation, findings of LPD and small portal vein diameters predict 1-year graft failure.

KEY POINTS

•Failed grafts are highly associated with liver perfusion defect, hypoattenuation, and small portal vein. •Right portal vein < 11.5 mm and left portal vein < 10.0 mm were associated with poor graft outcome. •Liver perfusion defect and small portal vein diameter independently predicted graft failure.

Modulation of splanchnic circulation: Role in perioperative management of liver transplant patients

Splanchnic circulation is the primary mechanism that regulates volumes of circulating blood and systemic blood pressure in patients with cirrhosis accompanied by portal hypertension. Recently, interest has been expressed in modulating splanchnic circulation in patients with liver cirrhosis, because this capability might produce beneficial effects in cirrhotic patients undergoing a liver transplant. Pharmacologic modulation of splanchnic circulation by use of vasoconstrictors might minimize venous congestion, replenish central blood flow, and thus optimize management of blood volume during a liver transplant operation. Moreover, splanchnic modulation minimizes any high portal blood flow that may occur following liver resection and the subsequent liver transplant. This effect is significant, because high portal flow impairs liver regeneration, and thus adversely affects the postoperative recovery of a transplant patient. An increase in portal blood flow can be minimized by either surgical methods (e.g., splenic artery ligation, splenectomy or portocaval shunting) or administration of splanchnic vasoconstrictor drugs such as Vasopressin or terlipressin. Finally, modulation of splanchnic circulation can help maintain perioperative renal function. Splanchnic vasoconstrictors such as terlipressin may help protect against acute kidney injury in patients undergoing liver transplantation by reducing portal pressure and the severity of a hyperdynamic state. These effects are especially important in patients who receive a too small for size graft. Terlipressin selectively stimulates V1 receptors, and thus causes arteriolar vasoconstriction in the splanchnic region, with a consequent shift of blood from splanchnic to systemic circulation. As a result, terlipressin enhances renal perfusion by increasing both effective blood volume and mean arterial pressure.