Complete MR angiography and Doppler ultrasound as the sole imaging modalities prior to carotid endarterectomy.

OBJECTIVE: To assess the combination of duplex Doppler ultrasound (DUS) and complete carotid magnetic resonance angiography (MRA) for the non-invasive imaging of carotid disease and their effect on outcomes. Determine inter-reader agreement of carotid MRA. MATERIALS AND METHODS: One-hundred and ten carotid bifurcations were evaluated using DUS, 2D and 3D time-of-flight MRA from the aortic arch to the Circle of Willis in 55 patients. Percentage stenoses were determined by two blinded readers using standardized criteria. Clinical follow-up was by chart review. RESULTS: Correlation of Doppler and MRA was excellent (r=0.903, P<0.001). Inter-reader agreement (K) for MRA was good: internal carotid artery (ICA) (0.750), external carotid artery (ECA) (0.674) and common carotid artery (CCA) (0.410). Differences in CCA readings were due to minor differences in categorizing lesions as CCA versus ICA or ECA. MRA and Doppler detected nine occluded ICAs. Two DUS occlusions had ICA flow by MRA; one due to a reconstituted precavernous ICA, one a near occluded vessel. Five patients (9%) had surgical management modified by MRA with four not having surgery: three distal ICA/Siphon occlusions and one less severe stenosis by MRA. One tandem lesion not visualized by DUS was surgically significant. Nine aortic arch abnormalities had no surgical impact, possibly due to small sample size. Of 41 endarterectomies, there were no complications from errors of diagnosis. CONCLUSION: Carotid MRA correlates well with DUS with good inter-reader agreement. MRA confirms Doppler findings, expands anatomical information and identifies tandem lesions from the aortic arch to the Circle of Willis which can affect surgical management. This approach to carotid artery imaging appears to have no negative effect on surgical outcome.

Early operative intervention after thrombolytic therapy for primary subclavian vein thrombosis: an effective treatment approach.

PURPOSE: Effective treatment of primary subclavian vein thrombosis focuses on restoration of venous patency, relief of intrinsic stenosis, and decompression of the thoracic inlet. The appropriate method and timing for surgery, however, have not been not well defined. We conducted a study to determine an acceptable treatment approach. METHODS: A retrospective review evaluated 11 patients seen at our institution in an 8-year period. Seven patients were male and four were female, with an average age of 30 years (range 15 to 54 years). Two patients who had symptomatic stenosis without occlusion were omitted from the study. All patients with occlusion received urokinase therapy and underwent surgical decompression within 5 days of thrombolytic therapy. Five percutaneous transluminal angioplasties were attempted before operative intervention. Eleven decompressions were performed, including nine first-rib resections and two scalenectomies. Five operative venous procedures, consisting of thrombectomy with patch closure (n = 3) and bypass (n = 2), and seven venolysis procedures were performed. All patients received coumadin for 3 to 6 months after the operation. RESULTS: Urokinase therapy established wide venous patency in nine of the 11 extremities treated, with the remaining two requiring thrombectomy for residual thrombus at the time of operation. One patient who underwent transluminal angioplasty before the operation had rethrombosis, and the remaining four showed no improvement in venous stenosis after the intervention. Eight of nine extremities treated by first-rib resection and one of two treated by scalenectomy were free of residual symptoms at follow-up. CONCLUSIONS: Preoperative use of percutaneous balloon angioplasty is ineffective and should be avoided in this setting. Surgical intervention within days of thrombolysis obviates the need for interim oral anticoagulation and enables patients to return to normal activity sooner.

Pulmonary embolism: comparison of cut-film and digital pulmonary angiography.

PURPOSE: To compare "cut-film" (film hard-copy) angiography (CFA) with digital pulmonary angiography in the detection of pulmonary embolism (PE). MATERIALS AND METHODS: Thirty-six adult patients (39 lungs) underwent selective digital pulmonary angiography for suspected PE. Imaging was repeated in one selected projection by using cut film. The standard was consensus interpretation of both CFA and digital angiographic images and clinical course. Three vascular radiologists subsequently reviewed the digital and cut-film images in a blinded fashion and ranked the likelihood of the presence of PE on a five-point scale. The two modalities were compared by means of receiver operating characteristic (ROC) analysis. Image quality (i.e., sharpness, opacification of subsegmental vessels, and exposure) was judged on a three-point scale. The highest-order pulmonary artery branch seen on each study was recorded. RESULTS: ROC curve analyses for all three operators showed similar diagnostic performance for digital pulmonary angiography and CFA, with one operator showing better performance with digital subtraction angiography than with CFA (P = .04). Compared with the final diagnosis, single-plane digital pulmonary angiography had higher sensitivity for the detection of PE than had CFA. The specificity was 100% for both modalities. The mean score in patients with findings positive for PE was higher in the digital pulmonary angiography group than in the CFA group (P < .005). There was no difference in the mean score in patients who did not have a PE. There also was no difference in the smallest detectable subsegmental branch (P = .87) or in the average estimate of image quality. CONCLUSION: Selective digital pulmonary angiography and CFA offer similar diagnostic performance and image quality. Digital pulmonary angiography is a reasonable alternative to CFA in the diagnosis of PE.

Risks and benefits of femoropopliteal percutaneous balloon angioplasty.

PURPOSE: The purpose of this study was to evaluate the efficacy of angioplasty in the treatment of femoropopliteal arterial disease. METHODS: From 1980 to 1991, 126 angioplasty procedures were performed in 131 limbs of 106 patients with 175 femoropopliteal lesions (26 common femoral, 118 superficial femoral, and 31 popliteal). Critical ischemia was present in 55 limbs (42%), and claudication was present in 76 (58%). Angioplasty was performed for a single lesion in 87 limbs (66%) and for multiple lesions in 44 (34%). In 13 limbs (10%) the most severe lesion was an occlusion; in 118 (90%) all lesions were stenoses. Distal runoff was good (2 or 3 vessels patent) in 72 limbs (55%) and poor (0 or 1 vessel patent) in 59 (45%). RESULTS: Death within 30 days occurred in 0.8%, nonfatal systemic morbidity in 7.1%, and local morbidity in 1.6% of procedures. Multivariate analysis revealed that indication and age were predictive of increased morbidity and mortality rates. Immediate success was achieved in 95% of limbs treated. Mean follow-up time was 2.0 years. The overall 5-year cumulative primary patency rate was 45% (+/- 5%). In a proportional hazards model indication and lesion type were predictive (p < 0.01) of long-term failure, with relative risks of 2.0 (1.2 to 3.3) and 2.7 (1.3 to 5.6), respectively. The 5-year primary patency rate after angioplasty for stenoses and claudication was 55% (+/- 7%), for stenoses and critical ischemia it was 29% (+/- 11%), and for occlusions it was 36% (+/- 14%). CONCLUSION: These results suggest that femoropopliteal angioplasty is a low-risk procedure with acceptable long-term results in patients with claudication and stenoses.

Superior mesenteric artery angioplasty with the TEGwire: usefulness and technical difficulties.

The TEGwire percutaneous transluminal angioplasty balloon on a guide wire was used successfully for dilation of a proximal superior mesenteric arterial stenosis that was not well suited to dilation by conventional angioplasty catheters. After the stenosis was dilated, however, the balloon deflated only partially due to a kink in the TEGwire as it coursed over the acute angle between the aorta and the superior mesenteric artery. Several unsuccessful attempts to correct this problem were made; finally, the partially deflated balloon and the guide catheter had to be withdrawn. Although the TEGwire was used within the guidelines and recommendations of the product, this experience supports the manufacturer's recommendation that the TEGwire system should not be used with narrow-radius vascular curves such as that formed between the superior mesenteric artery and the aorta.

Vena caval occlusion after Simon nitinol filter placement: identification with MR imaging in patients with malignancy.

The prevalence of inferior vena caval occlusion associated with the Simon nitinol filter (SNF) was studied at two institutions in the follow-up of filters placed over a 13-month period. Twenty-four consecutive patients with defined indications (contraindication to anticoagulation with pulmonary embolism or deep venous thrombosis [DVT], recurrent pulmonary embolism despite anticoagulation, or extensive DVT [eg, iliofemoral]) underwent placement of a SNF. This patient group includes a high proportion with pelvic or renal malignancy (54%, 13 of 24) or a history of other malignancy. Of these 24, physical examination at follow-up identified 10 symptomatic patients with unilateral or bilateral leg swelling. Of these 10, magnetic resonance imaging, with spin-echo and gradient-echo techniques, demonstrated IVC occlusion in five patients (50%). These data suggest that vena caval occlusion following SNF placement occurs more commonly than previously recognized. Possible contributing factors include reduced venous inflow in patients with prior nephrectomy or pelvic neoplasms, pelvic venous compression by tumor mass, and hypercoagulable states.

Effort thrombosis: role of interventional therapy.

Effort thrombosis, a form of axillary-subclavian vein occlusion in young people, was identified in patients referred over a 5-year period. Eleven of 120 patients (9%) with venous occlusion from many causes had effort thrombosis. They were treated acutely with heparin and then by thrombolysis, angioplasty, surgical bypass, or a combination. Five of the 10 patients with thrombolysis or surgery had patent veins on follow-up venography, but 9 of these later developed axillary-subclavian reocclusion. By later follow-up, however, all patients were asymptomatic at the time of collateral vein formation. We conclude that effort thrombosis leads to recurrent occlusion of the axillary-subclavian vein, short-term (12-month) recurrence of symptoms with exercise, and progressive compensatory collateral vein development. Radiographic documentation of reestablished venous flow is important, and can be used to guide the completion of treatment.

Axillary and subclavian venous thrombosis: follow-up evaluation with color Doppler flow US and venography.

Real-time ultrasonography (US) and color Doppler flow mapping were used to determine prospectively whether venous thrombosis in the upper extremity could be imaged as accurately as with conventional contrast venography. Thirteen patients were imaged. The diagnosis of spontaneous (or "effort") thrombosis was made clinically and confirmed initially at venography (n = 11) or at technetium-99m dynamic scintigraphy (n = 2). After therapy, follow-up imaging with color Doppler flow US and venography was performed in all 13 patients for correlation. Absence of flow signals was noted in five patients with complete occlusion of the subclavian vein, and decreased flow signal was seen in two patients with partial obstruction of the subclavian vein. In five patients, findings returned to normal at color Doppler flow US and venography, and patent collateral veins were seen in one patient. The authors conclude that color Doppler flow US is useful in evaluating venous thrombosis in the upper extremity and might be preferable to venography for follow-up because the discomfort of injection and risk of contrast material-induced phlebitis are eliminated.

Atherosclerosis, peripheral arterial disease and the vascular response to ketanserin.

Platelet activation releases thromboxane A2 and serotonin, which acts on blood vessels through a specific, 5-hydroxytryptamine (5-HT2) receptor. The development of ketanserin, the selective 5HT2 receptor blocker, has made it possible to explore the role of serotonin in patients with advanced atherosclerotic disease. Ketanserin in low doses (3 to 30 micrograms/kg) was administered intra-arterially to 23 patients with symptomatic peripheral occlusive vascular disease during peripheral angiography: an additional seven patients received a placebo. The angiographic response was evaluated by coded reading and by computer-assisted measurement of arterial segments in four anatomical regions (pelvis, thigh, knee, and lower leg). Hemodynamic changes were assessed by mercury strain gauge plethysmography and Doppler pressure measurement. Unequivocal vasodilatation was observed in zero of seven placebo-treated patients and in 13 of 23 (57%) treated patients primarily at the level of collateral vessels. Dilation of the geniculate arteries, a major source of collaterals to the calf, was associated with a significant increase in the blood flow delivery to the calf. There was a moderate drop of systemic blood pressure in patients who failed to respond with peripheral vasodilatation. Ketanserin induces hemodynamically significant vasodilatation in some patients with peripheral vascular disease, suggesting that serotonin may contribute to ischemia in some patients with advanced atherosclerosis.

Recombinant tissue-type plasminogen activator versus urokinase in peripheral arterial and graft occlusions: a randomized trial.

A randomized prospective trial was undertaken to compare intraarterial administration of recombinant human tissue-type plasminogen activator (rt-PA) with urokinase (UK) in 32 patients with peripheral arterial or bypass graft occlusions. Sixteen patients were randomized to receive rt-PA and 16 to receive UK. The rt-PA dose was administered as a 10-mg bolus into the thrombus, followed by 5 mg/h for up to 24 hours. The UK dose was administered as a 60,000 IU bolus into the thrombus, followed by 240,000 IU/h for 2 hours, 120,000 IU/h for 2 hours, and 60,000 IU/h for up to 20 hours. Serial arteriograms were obtained at baseline and at 4, 8 or 16, and 24 hours. The endpoint was defined as 95% of greater clot lysis. The cumulative numbers of patients with successful thrombolysis (rt-PA vs UK) were four vs none at 4 hours, seven vs one at 8 hours, seven vs three at 16 hours, and eight vs six at 24 hours. Lysis occurred more rapidly in the rt-PA group (P = .04). Major bleeding complications occurred in five rt-PA patients and two UK patients (P = .39). At 24 hours, fibrinogen levels were significantly lower in the rt-PA group than in the UK group (P = .01). There was no apparent difference in 30-day clinical success.

Observations on the use of thrombolytic agents for thrombotic occlusion of infrainguinal vein grafts.

Vein graft failure remains a major challenge for the vascular surgeon. Thrombolysis of occluded vein grafts has shown promising short-term results in restoring vein graft patency, however, the long-term results are not established. This study examines the long-term patency and limb salvage after successful thrombolysis and revision of 22 thrombosed vein grafts in 21 patients. There were 17 men and four women with an average age of 60 years (38 to 77 years). Failed vein grafts had an average primary patency of 19 months (1 to 84 months) and included eight in situ grafts and 14 non-in situ grafts. Twelve grafts were to the popliteal level, whereas 10 were infrapopliteal. Thrombolytic agents used included urokinase (15), tissue plasminogen activator (5), and streptokinase (2). After successful thrombolysis, 19 grafts underwent 26 additional procedures including percutaneous transluminal angioplasty (9), vein patch angioplasty (4), vein interposition or jump extension graft (9), or other procedures (4). Three patients had no additional procedure, but one was placed on sodium warfarin (Coumadin). After successful initial vein graft salvage, life-table analysis revealed a 36.6% +/- 11.9% patency at 1 year and a 22.9% +/- 11.6% patency at 3 years. After secondary failure six patients had further interventions contributing to an improved limb salvage of 66.9% +/- 11.6% at 1 year and 60.3% +/- 19.0% at 3 years. The results suggest that thrombosed vein grafts initially salvaged with thrombolysis and revision do not have a favorable long-term patency, and that a premium must be placed on the detection of the failing vein graft before thrombosis.

Modified gastrojejunostomy tube: percutaneous placement for gastric decompression and jejunal feeding.

A four-lumen, 20-F surgical gastrojejunostomy tube designed to incorporate separate lumens for both jejunal feeding and gastric decompression was modified for guide-wire use. This modification permits radiologic rather than intraoperative tube placement. The tube was successfully placed in six patients. Slow gastric leakage that developed at the stoma site in one patient immediately after tube insertion resolved after 24 hours. No catheter dislodgments or other complications occurred. At 4-month follow-up, five patients had fully functional tubes; the sixth patient had died with a functional tube.

Interruption of the inferior vena cava for prevention of pulmonary embolism: transvenous filter devices.

The availability of a safe, effective, and easily introducible percutaneous vena cava filter is crucial in the management of certain patients with pulmonary embolism. If thrombolytic or anticoagulant therapy for pulmonary embolism is contraindicated or fails, interruption of the inferior vena cava (IVC) blood flow is the logical alternative. Indications for filter insertion include a contraindication to anticoagulation, or recurrent pulmonary embolism despite adequate anticoagulation therapy. Common routes of filter insertion are from the right internal jugular vein, or the right or left femoral veins. The Mobin-Uddin umbrella filter (no longer available in the USA) and the Kimray-Greenfield filters have been the most widely used. Complications of vena cava filters include malpositioning, migration, venous thrombosis proximal or distal to the filter, hemorrhage at the percutaneous site of insertion, or sepsis. Despite these problems, IVC filters have been extremely useful in the management of pulmonary embolism among certain subsets of patients. Percutaneously inserted filters have now superseded surgical vena caval interruption in most US centers. Newer filters are currently under development in the US and Europe, and feature improved filtering function, anti-tilt abilities, retrievability, memory wire properties, and improved ease of insertion.

Ioversol. Double-blind study of a new low osmolar contrast agent for peripheral and visceral arteriography.

The new low-osmolar contrast agent ioversol was compared with the conventional ionic contrast agent diatrizoate in 60 patients undergoing routine abdominal (21 patients) and peripheral (39 patients) arteriography. The effects on hemodynamics, various laboratory parameters, and patient comfort were evaluated. In peripheral arteriography, there was less discomfort with ioversol as well as decreased magnitude and incidence of hypotension (P less than .001) after injection. In visceral arteriography, there was no significant difference between the two agents. Overall, the incidence of ECG changes was small in both groups (ioversol 2%, diatrizoate 8%). The two media were equivalent in incidence of adverse reactions (eg, nausea, vomiting, urticaria), the effect on laboratory parameters, and in the diagnostic adequacy of the radiographs. We conclude that ioversol is safe and efficacious for peripheral and visceral arteriography. In peripheral arteriography it causes less patient discomfort and, perhaps more importantly, fewer hemodynamic alterations than diatrizoate. These differences in hemodynamic effects may be important in patients with hemodynamic instability or limited cardiovascular reserve.