Juan Ayerdi

Selective venography versus nonselective venography before vena cava filter placement: evidence for more, not less

OBJECTIVE We undertook this study to determine whether additional use of selective venography, compared with nonselective venography alone, reveals more abnormal anatomic venous findings that lead to changes in vena cava filter (VCF) position. METHODS From January 1998 to June 2002, 94 patients underwent VCF placement by vascular surgeons at a university tertiary care center. Indications, techniques, decision analysis, and complications were reviewed. Nonselective venography and selective venography of the inferior vena cava (IVC) were evaluated for image quality, abnormal findings, aberrant anatomy, and the anatomic relationship of vertebral bodies to major venous tributaries. RESULTS Absolute and relative indications for VCF placement were 44% and 56%, respectively. Jugular, femoral, and subclavian vein approach was used in 47%, 47%, and 6% of patients, respectively. Seventy-three percent of VCFs were placed in the catheterization laboratory, 21% in the operating room, and 5% at the bedside. Nonselective venography was performed in 80 patients (85%), of whom 44% had undergone selective venography. At nonselective venography plus selective venography 7.5% of patients had an abnormal finding (IVC compression, n = 3; IVC thrombus, n = 2; tortuosity, n = 1). Similarly, 17.5% of patients had aberrant anatomy (accessory renal vein, n = 8; IVC duplication, n = 3; large low right gonadal vein, n = 2; megacava, n = 2). Nonselective venography plus selective venography demonstrated that 16% of VCFs required a major change in position, 10% of which were placed above the renal veins. Compared with nonselective venography alone, selective venography enabled detection of significantly more abnormal and aberrant findings (9% vs 49%; P <.001). Changes in VCF placement were necessary significantly more often in patients undergoing additional selective venography compared with nonselective venography alone (31% vs 4%; P =.003). In one patient in the series, a VCF was malpositioned in the iliac vein with intravascular ultrasound visualization. CONCLUSION When nonselective venography plus selective venography were performed, 23% of patients had either an abnormal finding or aberrant anatomy, and most of these required a major change in VCF position. Nonselective venography plus selective venography redefines the criterion standard and, because of limitations of other methods of vena cava visualization for VCF deployment, should be performed in most patients.

Pancreatitis Caused by Rheolytic Thrombolysis: An Unexpected Complication

Two patients developed acute pancreatitis after mechanical thrombolysis with use of the AngioJet system. Patient 1 had undergone a remote complex revascularization of the lower extremities and presented with acute ischemia after thrombosis of his composite distal bypass. Patient 2 presented with superior vena cava (SVC) syndrome and had thrombosis of the SVC and innominate veins. Despite dissimilar presentations, both patients had renal insufficiency, were treated with mechanical and chemical thrombolysis, and had extensive thrombus burden. The pathophysiology of acute pancreatitis in this setting is believed to be secondary to massive hemolysis in the presence of chronic renal insufficiency. This phenomenon should be considered in patients whom develop abdominal pain after mechanical thrombolysis.