Comparison of streptokinase, urokinase, and recombinant tissue plasminogen activator in an in vitro model of venous thrombolysis.

PURPOSE: Presumed differences in the thrombolytic activity and fibrinolytic specificity of the three commonly used thrombolytic agents, streptokinase, urokinase, and recombinant tissue plasminogen activator (rt-PA), are based on clinical study results, where variability renders meaningful comparisons difficult. An in vitro model of catheter-directed venous thrombolysis was used to compare the three agents. METHODS: Retracted iodine 125-radiolabeled clots that simulate those observed in the venous system were infused with thrombolytic agents at doses analogous to those used clinically. Perfusion with heparinized, whole human blood was undertaken for 60 minutes, measuring the efficacy of thrombolysis through serial quantification of radio tracer released into the circuit. Fibrinolytic specificity was determined by following decrements in perfusate fibrinogen concentration. RESULTS: Streptokinase was the agent associated with the slowest rate of clot lysis (p = 0.01 vs urokinase and rt-PA). Urokinase was associated with an intermediate rate of lysis but appeared to be the agent with the greatest degree of fibrinolytic specificity (p = 0.02 vs streptokinase, p = 0.05 vs rt-PA). Although rt-PA was associated with improved efficacy early in the perfusions, the differences between rt-PA and urokinase dissipated after 30 minutes. CONCLUSIONS: These laboratory observations suggest that urokinase may be the most appropriate agent for catheter-directed venous thrombolysis, offering an advantageous compromise between fibrinolytic specificity and thrombolytic speed.

Operative management of coexistent aortic disease and horseshoe kidney.

The presence of horseshoe kidney in conjunction with abdominal aortic disease significantly increases the technical difficulty of aortic reconstruction. Preservation of the renal blood supply and collecting system during the surgical procedure is the goal of operative management. The pertinent issues that remain unresolved include the need for specific preoperative studies, the optimal operative approach and the safety of isthmus division. From 1979 to 1994 eight patients with horseshoe kidney underwent operative intervention for aortic disease. Five men and three women who had a mean age of 66 years underwent seven reconstructions for aneurysmal disease and one for aortoiliac occlusive disease. All operations were elective and the transperitoneal approach was used in all cases. In the patients with aneurysmal disease the mean maximal aortic diameter was 7.3 cm. The mean preoperative serum creatinine value was 1.1 mg/dl. Preoperative identification of horseshoe kidney was accomplished in all seven patients with aneurysmal disease but not in the patient with occlusive disease. The anomaly was correctly identified by CT scan in seven of seven (100%) patients, arteriography in two of eight (25%) patients, ultrasonography in two of seven (29%) patients, and renal scan in one patient. In the three patients who underwent intravenous pyelography (IVP) the caliceal system was demonstrated to be completely separate from the isthmus. Renal artery anomalies were present in six (75%) patients; in three (50%) these anomalies could be not visualized on the preoperative arteriogram. Renal revascularization was accomplished by a variety of techniques, including reimplantation of multiple (one patient) and single (four patients) renal arteries and branch grafting to an individual renal artery (one patient).(ABSTRACT TRUNCATED AT 250 WORDS)

Laser angioplasty in peripheral vascular disease: symptomatic versus hemodynamic results.

Most early reports on the efficacy of laser angioplasty have used subjective symptoms rather than objective hemodynamic parameters to evaluate clinical results. We reviewed our experience with hot tip laser-assisted balloon angioplasty in 99 occluded or stenotic arterial segments during 80 procedures in 71 patients, ranging from the aortic bifurcation to the tibial-peroneal trunk. Initial failure to successfully recanalize occluded or stenotic segments occurred in 13 instances (16%). Forty-one procedure-related complications occurred in 31 patients (39%). Functional results were evaluated by use of life-table methods on the basis of symptomatic versus hemodynamic improvement. Cumulative patency rates for symptomatic and hemodynamic improvement were 91% and 64% at 1 month, 71% and 48% at 6 months, and 57% and 34% at 1 year, respectively. These data suggest that symptomatic improvement alone gives a misleadingly high estimate of the efficacy of laser angioplasty when compared with more objective hemodynamic criteria (p less than 0.005). Hemodynamic success was more likely in aortoiliac lesions than femoropopliteal lesions (58% vs 18% at 1 year, p less than 0.01). Hemodynamic parameters should be used to evaluate the success of laser angioplasty, which in its present form, is associated with frequent complications and poor long-term success.

Acute aortic rupture from cross clamp injury.

We report a case of transmural disruption and perforation of the abdominal aorta secondary to clamp injury. The literature is reviewed in reference to the traumatic effects of vascular clamps. Steps are outlined to reduce the risk of this injury.

Vocal cord paralysis following carotid endarterectomy.

From 1964 to 1977, over 400 carotid endarterectomies were performed at the Rochester General Hospital. Two patients from this group experienced hoarseness secondary to vocal cord paralysis on the operated side, believed due to trauma to the vagus nerve. Although uncommon, it is important to stress the method of avoiding this complication.

Femoro-popliteal by-pass with bovine heterografts.

Modified bovine heterografts were used in 28 patients, primarily extremity salvage problems, found to have unavailable or unusable saphenous veins. The accumulated 3 year patency rate was 35%. Of the 18 graft failures, 11 required major amputation. A high failure rate of 39% in the first six-month interval was observed. Electromagnetic flowmeter recording were of limited value in predicting patency. Continued evaluation of bovine grafts for femoro-popliteal reconstruction in the absence of saphenous vein is recommended.