Placement of the Greenfield filter above the renal veins was necessary in 71 (9%) of 821 total patients in the filter registries of two institutions. The status of 60 patients (85%) could be verified, with follow-up data ranging from 18 months to 16 years (average, 53 months). Of 24 deaths (34%), none was from recurrent embolism or renal failure; death was most commonly associated with a malignant neoplasm. The recurrent embolism rate was 4%, identical to the infrarenal experience. Duplex evaluation of the filters in 22 patients, representing the majority (61%) of living patients, showed that all the filters were patent. Sixteen patients (41%) had lower-extremity edema that predated filter insertion, and in no patient did the results of noninvasive venous studies worsen. Filter fracture (two patients) or distal migration (two patients) had no clinical sequelae, and there was no evidence of renal dysfunction. For thrombus extending to the level of the renal veins or within them and for pregnant patients or women of childbearing age, suprarenal placement of the Greenfield filter is safe and effective, with no filter obstruction seen in follow-up extending to 16 years.
We reviewed the limb and digit hemodynamics of 67 extremities of 48 patients evaluated for blue toe syndrome in our vascular laboratory during 7 years. These patients represented 1.4% of the arterial examinations during this period. Abnormal ankle/arm pressure indices (less than 0.9), signifying proximal arterial obstruction, were present in 31 limbs (47%). Toe/ankle indices were abnormal (less than 0.6) in 57 extremities (85%), indicating pedal or digital artery obstruction. Arteriograms were obtained in 40 of 64 extremities (63%) available for follow-up, which revealed atherosclerotic disease in 90% (aortoiliac 20%, femoropopliteotibial 30%, and combined 40%), aneurysm in 7.5%, and no disease in only one extremity (2.5%). Of 64 extremities followed for 1 to 84 months (mean, 26 months), only 28 (44%) manifested an uncomplicated outcome. Tissue loss was noted in 24 (38%), recurrent digital ischemia occurred in nine (14%), and 14 limbs (22%) required amputation of toe(s) (seven), forefeet (three) or legs (four). Nine patients (20%) died in the follow-up period. Outcomes did not correlate with limb or digit hemodynamics or with therapy (surgical in 31, medical in 11, or none in 22) except that tissue necrosis was more common in patients undergoing operation. The blue toe syndrome deserves recognition as an important sign of potential limb-threatening arterial disease, but the optimal therapy remains to be established.
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