Suprarenal vena caval filter placement: follow-up of four filter types in 22 patients.

PURPOSE

To determine if suprarenal placement of inferior vena cava (IVC) filters is associated with renal dysfunction or other complications.

MATERIALS AND METHODS

Case files of all patients with suprarenal vena caval filter placement since 1985 were reviewed for clinical and biochemical evidence of renal dysfunction and renal vein thrombosis. The occurrence of associated complications, including IVC occlusion, filter fracture, device migration, and recurrence of pulmonary embolism was also recorded.

RESULTS

Twenty-two (2.9%) of 764 IVC filters were implanted above the renal veins: titanium Greenfield filter modified hook (TGF-MH) (n = 16), LGM type I (n = 2), LGM type II (n = 2), and Bird's Nest (BN) type I (n = 2). Reasons for suprarenal filter placement included thrombus to the level of the renal veins (n = 9), failure or poor position of the infrarenal filter (n = 6), pregnancy or intent of pregnancy (n = 4), and the malpositioning of BN filters above the renal veins (n = 2). A single patient demonstrated evidence of transient renal dysfunction. Pulmonary embolus was found at autopsy in one patient. Abdominal radiographs were obtained at follow-up of 18 patients and demonstrated a 2 cm or more migration of the filter in five patients (27.7%). This rate of migration was significantly different from the 3% migration rate reported by the authors' institution in the follow-up of 320 infrarenal IVC filters. There was one filter fracture (5.5%.) and penetration of the IVC occurred in one patient (5.5%).

CONCLUSION

Follow-up indicates suprarenal IVC filter placement is safe, and no evidence of permanent renal dysfunction after placement was found. Filter migration was the most frequent complication, but no clinical sequelae were noted with these patients.