Research on Portal Venous Hemodynamics and Influencing Factors of Portal Vein System Thrombosis for Wilson's Disease after Splenectomy

Objective: Splenectomy is one crucial solution for hypersplenism with portal hypertension. However, portal vein system thrombosis (PVST) caused by hemodynamic changes affects the prognosis of patients. We analyze the changes in portal vein hemodynamics following splenectomy for Wilson's disease combined with portal hypertension and the influencing factors that lead to PVST.

Methods: A retrospective cohort study was conducted, in which 237 Wilson's disease patients with hypersplenism underwent splenectomy. The hemodynamic indices of the portal vein were monitored before surgery and on the 1st, 7th, and 14th days around surgery. The patients were divided into PVST and non-PVST groups. The clinical factors were identified by univariate and multivariate logistic regression. The Logit P was calculated according to the logistic regression prediction model, and the ROC curve for each independent factor was plotted.

Results: The portal vein velocity, flow, and inner diameter showed a downward trend around surgery, with statistically significant differences between each time point (P < 0.01). The PVST incidence rate was 55.7%. Univariate analysis revealed that the platelet (PLT) levels on the postoperative 3rd and 7th days (P = 0.001; P < 0.001), D-dimer (D-D) on the postoperative 7th and 14th days (P = 0.002; P < 0.001), preoperative portal vein velocity, flow, diameter (P < 0.001), and splenic vein diameter (P < 0.001) were all statistically and significantly different between the two groups. Multivariate logistic regression revealed a significant increase in PLT on the postoperative 7th day (OR = 1.043, 95% CI, 1.027-1.060, P < 0.001) and D-D on the postoperative 14th day (OR = 1.846, 95% CI, 1.400-2.435, P < 0.001). Preoperative portal and splenic vein diameters (OR = 1.565, 95% CI, 1.213-2.019, P = 0.001; OR = 1.671, 95% CI, 1.305-2.140, P < 0.001) were the risk factors for PVST. However, preoperative portal vein velocity and flow (OR = 0.578, 95% CI, 0.409-0.818, P = 0.002; OR = 0.987, 95% CI, 0.975-0.990, P = 0.046) were protective factors for PVST. Logit P was calculated using a logistic regression prediction model with a cut-off value of -0.32 and an area under receiver operating characteristic curve of 0.952 with 88.61% accuracy.

Conclusions: Splenectomy relieves portal hypertension by reducing the hemodynamics index. PVST is linked to multiple factors, including preoperative portal vein diameter, velocity, flow, and splenic vein diameter, especially PLT on the postoperative 7th day and D-D on the postoperative 14th day. The predictive model is accurate in predicting PVST.