Collateral Saves the Day (Transplant)!

Inferior vena cava (IVC) filters are frequently placed but not removed as patients are lost to follow-up, decline future removal, or have persistent indications for filters to remain in place. Anticoagulant use can decrease the risk of filter thrombosis or other recurrent thrombotic events.



Methods:

This is a case report of an IVC filter occlusion more central to a renal transplant.

Results:

74-year-old male with a history of hypertension, diabetes mellitus type 2, obesity, hyperlipidemia, recurrent DVTs, noncompliance with medication, failure of DOAC therapy, and bipolar disorder. He is on cyclosporine and prednisone. Creatinine is 1.4-1.7. His filter was placed for DVGT in 1998. He has had recurrent thrombotic episodes in 2000, 2008, 2021, and now 2023. The patient's renal transplant was performed in 1989 on the left side. In May 2023, he underwent a duplex study to evaluate his kidney function which showed no thrombus in the transplanted renal vein, the kidney measured 13.4cm, the main renal artery peak systolic velocity was 100 cm/sec with a resistive index of 0.78.  Segmental resistive indices ranged from 0.65-1.0. Arcuate artery velocities in the renal cortex were 20.6 to 3.5 cm/sec. Later in the month he underwent a venous duplex scan which showed partial occlusion of the common femoral veins. Seven weeks later, he presents with bilateral increased swelling and new weeping ulcers in both lower extremities with duplex image showing complete occlusion of the bilateral common femoral, popliteal, and posterior tibial veins. A venogram was performed which demonstrated a large collateral draining the transplanted kidney preventing significant worsening of renal function. (Image 1) Patient was systemically heparinized and underwent venous mechanical thrombectomy. No lytic therapy was needed, and intervention time was 20 minutes.  Complete cava patency was restored. (Image 2) Edema has improved, and his ulcers have healed with wrap compression therapy.



Conclusions:

This case represents the importance of diligent follow-up and awareness of long-term indwelling IVC filters. It also demonstrates continued need for awareness by all providers to follow IVC filters with suspicion of potential occlusion in setting of sudden pelvic or lower extremity swelling. Fortunately, a collateral vein was present which prevented significant injury to the transplant kidney. The patient is now fully anticoagulated.