Risk factors of worsening kidney function and mortality in patients with renal vein thrombosis: a retrospective study.

Abstract

The outcome of renal vein thrombosis, in particular as for the long-termimpact on kidneyfunction, isnot fully known.We aimed to studythe natural course and outcomes of patients with renal vein thrombosis, ina large, single-center cohort. A single-center retrospective cohort study including patients who were diagnosed with renal vein thrombosis between January 2006 and September 2021was analyzed. The mainoutcomes analyzedwere worsening kidney function, defined as a decrease in eGFR of at least 40% from baseline, and all-cause mortality. Eighty-seven patients were included, 56.3% were female, median age was57years. Malignancy was the most common cause of renal vein thrombosis (60.9%), followed by post-surgery and trauma (16.1%) and nephrotic syndrome (12.6%). At initial presentation, 65.5% of the patientswere asymptomatic; the main signs andsymptoms were gross hematuria (20.7%), flank pain (18.4%), and flank tenderness (9.2%). During follow-up, 18 (21.4%) patients experienced worsening kidney function and 57 (65.5%) died. Multivariable analyses showed that the risk of worsening kidney function was higher in patients with nephrotic syndrome (hazard ratio [HR] 18.41; 95% confidence interval [CI], 1.57-216.04), body weight ≥ 60kg (HR 4.82; 95% CI 1.43-16.32), and malignancy (HR 9.10; 95% CI 1.05-78.63). Symptomatic acute renal vein thrombosis was associated with a lower risk of worsening kidney function compared to asymptomatic or symptomatic chronic renal vein thrombosis (HR 0.12; 95% CI 0.01-0.96). Malignancy (HR 5.45; 95% CI 2.58-11.54), age ≥ 75years (HR 3.44; 95% CI 1.49-7.93), and serum albumin < 3.0g/dL (HR 2.88; 95% CI 1.65-5.05) were associated with an increased mortality risk. Renal vein thrombosis is associated with a high rate of worsening kidney function and mortality. It is crucial to promptly identify patients at high risk and initiate early treatment to prevent negative outcomes.