Post-Thrombotic Syndrome Morbidity in Mechanical Thrombectomy Versus Pharmacomechanical Catheter-Directed Thrombolysis of Iliofemoral Deep Venous Thrombosis

Background: Iliofemoral deep venous thrombosis is strongly associated with post-thrombotic syndrome (PTS). Interventional treatment options include catheter-directed thrombolysis and pharmacomechanical thrombectomy. More recently, there has been a wide dissemination of large-bore devices for mechanical thrombectomy (MT). Both treatment types have been shown to be effective in clinical practice; however, the rates of PTS after MT are poorly characterized. Methods: We conducted a retrospective review of patients with acute iliofemoral deep venous thrombosis from 2007 to 2022. Patients were divided into 2 treatment groups: pharmacomechanical catheter-directed thrombolysis (PCDT) and MT with large-bore devices. Our primary endpoint was PTS (Villalta score > 4). Secondary outcomes included vessel patency, mortality, and moderate/severe PTS (Villalta score > 9). Predictors of PTS were analyzed using multivariable logistic regression. Results: The median age of our cohort (n- 349) was 49 (interquartile range 35-63) years, 54.2% were female. There were 294 (84.2%) patients treated with PCDT. There were no significant baseline characteristic differences between patients treated with PCDT versus MT aside from increased preoperative anticoagulant use in the MT cohort. The overall rate of PTS was 19.1%. There were no differences in rates of PTS, moderate-severe PTS, stent patency, mortality between groups, or hospital length of stay. However, patients treated with MT had higher rates of single operating room visit during their admission treatment relative to patients that underwent PCDT (33.3% vs. 9.0%, P < 0.01) and decreased intensive care unit length of stay (2 (1-3) vs. 0.5 (0-2), P < 0.01). MT treatment was not a risk factor for the development of PTS (adjusted odds ratio [aOR] 0.73; [95% confidence interval {CI} 0.30, 1.74]; P- 0.47) or associated with increased Villalta score (b:- 0.34; [95% CI- 1.28, 0.60]; P- 0.47). Infrainguinal deep venous thrombosis extension (aOR 2.18; [95% CI 1.16, 4.09]; P- 0.02), prior deep venous thrombosis (aOR 2.67; [95% CI 1.38, 5.13]; P < 0.01), and a hypercoagulable state (aOR 2.32; [95% CI 1.19, 4.50]; P = 0.01) were associated with increased risk of PTS. Conclusions: Treatment with large-bore MT was not a significant predictor for the development of PTS. MT appears safe, durable, and associated with greater rates of single operating room visit relative to PCDT, which suggests that rapid thrombus removal may be of value.