Therapeutic Anticoagulation Does Not Prevent PVT Recurrence After Liver Transplant

In patients with cirrhosis who have portal vein thrombosis (PVT) and undergo liver transplantation, therapeutic anticoagulation was associated with significantly higher rates of bleeding and longer index hospitalization than in patients who did not receive anticoagulation. Additionally, anticoagulation did not prevent PVT recurrence after transplant, suggesting prophylactic use of this therapy is not effective in this patient population. This is according to recent study results published in the Journal of Thrombosis and Haemostasis.

When possible, therapeutic anticoagulation is recommended to manage PVT before liver transplant, but few studies have established the utility of this regimen for the prevention of PVT recurrence.

A retrospective study led by Isabel Bos, MD, of the University of Groningen in the Netherlands, examined all adult liver transplants performed at two high-volume liver transplant centers in Europe. All patients in the study had cirrhosis and thrombosis of the portal vein without complete extension in the spleno-mesenteric confluence or superior mesenteric vein.

Between the study years of 2003 and 2018, a total of 2,502 patients underwent liver transplantations at the European centers. Approximately 14.7% of these patients (n=369) had a PVT prior to or at the time of transplant.

Researchers selected 235 patients with PVT for the final analysis. In this cohort, 113 patients (48.1%) received anticoagulation for a median duration of three months and 122 patients (51.9%) did not receive anticoagulation. The overall median follow-up was 59.8 months, with significant difference observed between the two groups (72.3 vs. 49.4 months; p=0.34).

Therapeutic anticoagulation consisted of a short initial course of heparin started in the ICU as soon as possible, followed by oral administration of vitamin K antagonist with an international normalized ratio target between 2 and 3 for approximately three months. None of the patients received direct oral anticoagulants.

Patients who received therapeutic anticoagulation were significantly younger than those who didn’t receive anticoagulation (58 vs. 60 years, respectively; p=0.045).

The group of patients who received therapeutic anticoagulation had a higher rate of bleeding events (23% vs. 4.1%; p<0.01) and a longer initial hospitalization (21 vs. 17.5 days; p<0.01).

During the first year following liver transplantation, PVT recurrence was reported in 3.8% of cases, but there was no significant difference in recurrence between those who received anticoagulation and those who didn’t (5.1% vs. 2.5%; p=0.39).

At one year, residual thrombus was diagnosed in four patients who received therapeutic anticoagulation and three patients who did not. None of these patients experienced PVT recurrence.

While 10.6% of cases had arterial complications (n=25), no difference was found between the two groups in the arterial complication rate (12.4% vs. 9%; p=0.83). Additionally, 2.1% of patients experienced venous complications other than PVT recurrence, with no difference between the two groups (2.7% vs. 1.6%; p=0.67).

There was also no significant difference between the two groups in terms of graft (p=0.11), patient survival (p=0.44), or the incidence of arterial complications (12.4% vs. 9%; p=0.83).

In a univariate analysis, researchers found that the only significant risk factor for PVT recurrence was recipient age (odds ratio = 0.94; 95% CI 0.89-0.99; p=0.03).

In a subgroup analysis that considered only patients who presented with Yerdel grade 2 PVT (n=88), a significantly greater proportion of patients who received therapeutic anticoagulation experienced bleeding events (27.3% vs. 3%; p<0.01), but there were no differences in the need for surgical revision between the two groups (10.9% vs. 3%; p=0.25).

The study was limited by its retrospective nature, differences in recipient and graft characteristics between the two groups, and exclusion of patients with extensive grade III/IV PVT. Despite these limitations, the researchers concluded that the findings “provide valuable data regarding the usefulness of therapeutic anticoagulation in the pre- and post-transplant period that will help clinicians in their decisions.”

The authors report no relevant conflicts of interest.

Reference

Bos I, Blondeau M, Wouters D, et al. Therapeutic anticoagulation after liver transplantation is not useful among patients with pre-transplant Yerdel-grade I/II portal vein thrombosis: A two-center retrospective study [published online ahead of print, 2021 Jul 23]. J Thromb Haemost. doi: 10.1111/jth.15472.