Iliac Vein Compression: A Protective Mechanism Against Symptomatic Pulmonary Embolism Following Lower Extremities Deep Vein Thrombosis

Objective To investigate the protective effect of iliac vein compression in patients with symptomatic pulmonary embolism (PE) of lower extremity deep vein thrombosis (LEDVT).

The clinical data of 82 patients with unilateral LEDVT including computed tomography of pulmonary angiogram (CTPA) and CT image data of common iliac vein from February 2020 to April 2023 were retrospectively analyzed. The patients were divided into two groups according to the presence or absence of PE. Univariate and multivariate logistic regression were used to analyze the risk factors of symptomatic PE in patients with LEDVT. The predictive value of severity of iliac vein compression for symptomatic PE with different measurements were further compared with receiver operating characteristics curve.

Univariate analysis showed that compression > 50% (OR = 0.19,95% CI = 0.07-0.51, P = .001) was a protective factor for symptomatic PE. Multivariate analysis showed that compression > 50% (OR = 0.21,95% CI = 0.07-0.64, P = .006) was a protective factor for symptomatic PE. Different compression measurements were compared. With affected caudal diameter as denominator, the area under curve (AUC) was 0.729, the cut-off value was 0.52, the sensitivity was 70.6%, and the specificity was 71.0%. Patent contralateral diameter as denominator, the AUC was 0.729, the cut-off value was 0.49, the sensitivity was 54.9%, and the specificity was 87.1%.

In patients with LEDVT, iliac vein compression greater than 50% is a protective factor for symptomatic PE. A larger sample is needed to determine the protective effect of iliac vein compression. Competing Interest Statement The authors have declared no competing interest. Funding Statement This study was funded by Xinjiang Uygur Autonomous Region Science fundation 2024D01C106 Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Ethics committee of People's Hospital of Xinjiang Uygur Autonomous Region waived ethical approval for this work I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Data Availability All data produced in the present study are available upon reasonable request to the authors.