This episode breaks down a 2026 JVIR letter to the editor describing intraprocedural heparin resistance during iliocaval thrombectomy in a 67-year-old man with stage IV diffuse large B-cell lymphoma and recurrent DVT.
- The Setup: A chest wall hematoma on therapeutic heparin forced cessation of anticoagulation and IVC filter placement. Two weeks later, thrombus extended from below the filter into the bilateral iliocaval and femoral segments (Villalta 15 to 18, VCSS 12).
- The Pharmacologic Wall: Despite 13,000 units of heparin (roughly 136 U/kg) targeting an ACT above 250 seconds, values sat at 133 to 138 with thrombus reaccumulating during active aspiration. Day two brought 21,000 units and a unit of FFP, moving the ACT only from 173 to 198.
- Why It Failed: The 4Ts score was 2, arguing against HIT. Antithrombin III fell from 89% at baseline to 52% post-procedure, pointing to acquired consumption rather than hereditary deficiency.
- The Algorithm: Confirm dosing, exclude sampling error, then escalate beyond repeat heparin. Options include anti-factor Xa-guided dosing, ATIII concentrate rather than FFP in a volume-overloaded patient, or a direct thrombin inhibitor that does not require ATIII.
- The Mechanical Half: Filter retrieval and femorotibial venoplasty addressed the thrombogenic nidus and the restricted inflow, since central clearance does not hold without runoff.
- Caveats: A single case with three problems corrected at once. Neither a direct thrombin inhibitor nor ATIII concentrate was actually given, leaving the recommended pathway untested.
Tune in to learn why escalating heparin against a flat ACT wastes table time, and what to reach for instead.
This podcast is generated using an AI model that has been trained in the context of endovascular surgery and interventional radiology in addition context of the article cited below. The content was reviewed and edited by multiple healthcare professionals in the field.