B.C. Eikelboom

Randomised comparison of primary stent placement versus primary angioplasty followed by selective stent placement in patients with iliac-artery occlusive disease

BACKGROUND Percutaneous transluminal angioplasty (PTA) is a safe, simple, and successful treatment for intermittent claudication caused by iliac-artery occlusive disease. Primary stent placement has been proposed as more effective than PTA. We compared the technical results and clinical outcomes of two treatment strategies-primary placement of a stent across the stenotic segment of the iliac artery, or primary PTA followed by selective stent placement when haemodynamic results were inadequate. METHODS We randomly assigned 279 patients with intermittent claudication, recruited from departments of vascular surgery, either to direct stent placement (group I, n=143) or primary angioplasty (group II, n=136), with subsequent stent placement in case of a residual mean pressure gradient greater than 10 mm Hg across the treated site. The main inclusion criterion was intermittent claudication on the basis of iliac-artery stenosis of more than 50%, proven by angiography. All patients had a clinical assessment before intervention and at 3, 12, and 24 months. Clinical success was defined as improvement of at least one clinical category. Secondary endpoints were initial technical results, procedural complications, cumulative patency as assessed by duplex ultrasonography, and quality of life. FINDINGS In group II, selective stent placement was done in 59 (43%) of the 136 patients. The mean follow-up was 9.3 months (range 3-24). Initial haemodynamic success and complication rates were 119 (81%) of 149 limbs and 6 (4%) of 143 limbs (group I) versus 103 (82%) of 126 limbs and 10 (7%) of 136 limbs (group II), respectively. Clinical success rates at 2 years were 29 (78%) of 37 patients and 26 (77%) of 34 patients in groups I and II, respectively (p=0.6); however, 43% and 35% of the patients, respectively, still had symptoms. Quality of life improved significantly after intervention (p<0.05) but we found no difference between the groups during follow-up. 2-year cumulative patency rates were similar at 71% versus 70% (p=0.2), respectively, as were reintervention rates at 7% versus 4%, respectively (95% CI -2% to 9%). INTERPRETATION There were no substantial differences in technical results and clinical outcomes of the two treatment strategies both at short-term and long-term follow-up. Since angioplasty followed by selective stent placement is less expensive than direct placement of a stent, the former seems to be the treatment of choice for lifestyle-limiting intermittent claudication caused by iliac artery occlusive disease.

Benefits of carotid patching: A randomized study☆

Advocates of carotid artery patching claim a reduced incidence of recurrent stenosis after endarterectomy. A prospective study was undertaken to determine its value with random selection between primary closure and saphenous vein patching. A consecutive series of 129 carotid endarterectomies was evaluated by duplex scanning at 3, 6, and 12 months after operation. Intravenous digital subtraction angiography (DSA) was performed in the first postoperative days for control of the surgical technique and after 1 year to serve as a reference for the duplex scanning. Sixty-two patients were selected to have primary closure and 67 were chosen for the patching technique. Both groups were identical with regard to risk factors (mean age 63 years, 74% were men, 57% had hypertension, 41% had coronary disease, 37% had peripheral arterial disease, and 9% had diabetes mellitus), side of operation (55% left), symptoms (18% were asymptomatic), and postoperative DSA (81% were normal, 17% had residual lesions, and 2% had occlusions). A complete 1-year follow-up was obtained in 105 cases (81%); duplex scanning showed recurrent stenosis of more than 50% in 12 cases (11%). This was significantly higher after primary closure (10 of 48 patients = 21%) compared with patch closure (2 of 57 = 3.5%; p = 0.006) and also in women (6 of 25 = 24%) compared with men (6 of 80 = 7.5%; p = 0.03). Recurrent stenosis was present in 6 of 11 women with primary closure (55%), 4 of 37 men with primary closure (11%), 2 of 43 men with patching (5%), and none of 14 women with patch closure (0%).(ABSTRACT TRUNCATED AT 250 WORDS)

Preoperative Diagnosis of Carotid Artery Stenosis Accuracy of Noninvasive Testing

Background and Purpose— Carotid endarterectomy has been shown to be beneficial in symptomatic patients with a severe stenosis (70% to 99%) of the internal carotid artery (ICA). Digital subtraction angiography (DSA) is the standard of reference in the diagnosis of carotid artery stenosis but has a relatively high complication rate. In a diagnostic study we investigated the accuracy of noninvasive testing compared with DSA. Methods— In a prospective diagnostic study we performed duplex ultrasound (DUS), magnetic resonance angiography (MRA), and DSA on 350 consecutive symptomatic patients. Stenoses were measured with the observers blinded for clinical information and other test results. Separate and combined test results of DUS and MRA were compared with the reference standard DSA. Only the stenosis measurements of the arteries on the symptomatic side were included in the analyses. Results— DUS analyzed with previously defined criteria resulted in a sensitivity of 87.5% (95% CI, 82.1% to 92.9%) and a specificity of 75.7% (95% CI, 69.3% to 82.2%) in identifying severe ICA stenosis (70% to 99%). Stenosis measurements on MRA yielded a sensitivity of 92.2% (95% CI, 86.2% to 96.2%) and a specificity of 75.7% (95% CI, 68.6% to 82.5%). When we combined MRA and DUS results, agreement between these 2 modalities (84% of patients) gave a sensitivity of 96.3% (95% CI, 90.8% to 99.0%) and a specificity of 80.2% (95% CI, 73.1% to 87.3%) for identifying severe stenosis. Conclusions— MRA showed a slightly better accuracy than DUS in the diagnosis of carotid artery stenosis. To achieve the best accuracy, however, both tests should be performed subsequently.

Site and pathogenesis of infarcts associated with carotid endarterectomy.

We analyzed perioperative strokes in 658 carotid endarterectomies with the purpose of explaining the pathogenesis from the morphologic aspect of the infarct on cerebral computed tomograms. All endarterectomies were performed with continuous electroencephalographic monitoring. Of the 42 ischemic strokes (6.4% of all endarterectomies), 34 could be studied. Seven infarcts were hemodynamically induced (five watershed infarcts, two patients with bilateral ischemia); all seven occurred during surgery. Twenty-three of the remaining 27 infarcts were within the territory of the middle cerebral artery (20) or anterior cerebral artery (three) and were probably of thromboembolic origin; 13 of these 23 occurred during surgery (57%). If intraoperative stroke was heralded by permanent electroencephalographic changes, these were not related to the moment of cross-clamping. In four patients the computed tomogram was normal. We believe these facts favor the hypothesis that thromboembolism is the most important factor in the pathogenesis of perioperative stroke associated with carotid endarterectomy under conditions of optimal cerebral monitoring.

Carotid endarterectomy with transcranial Doppler and electroencephalographic monitoring. A prospective study in 130 operations.

Background and Purpose We report the results of combined recording of hemodynamic and thromboembolic phenomena during carotid endarterectomy by means of computerized electroencephalography as well as transcranial Doppler ultrasonography. The study focuses on the additional value of transcranial Doppler to detect ischemia during surgery. Methods Combined monitoring was performed in 130 consecutive operations, using standard anesthe-siological, surgical, and neurophysiological procedures. Results A reduction of ≥70% of blood flow velocities in the middle cerebral artery during cross-clamping was measured in 16 patients. In seven of these cases there were no severe electroencephalographic changes and a shunt was not used, but one of the patients developed a subcortical infarct with slight disability. In 55 patients, 75 episodes of embolization were detected by transcranial Doppler. In one of these, with massive embolization after release of the clamp, an intraoperative stroke occurred without changes on cranial computerized tomography or neurological disability on follow-up. In the other 54 patients, intraoperative embolization did not cause clinical or neuroradiological symptoms. Electroencephalographic changes occurred in only two of the 75 episodes. In addition to the two nondisabling strokes during surgery (1.5%), six strokes occurred within 5 days of operation, including one hemorrhage. There was no significant relation between contralateral carotid occlusion and stroke (p=0.6). Conclusions During carotid endarterectomy, transcranial Doppler immediately provides information about thromboembolism and hemodynamic changes that are not detected by electroencephalography alone. Acoustic feedback from the transcranial Doppler monitoring unit has a direct influence on the surgical technique. Transcranial Doppler ultrasound may be a useful tool in the study and prevention of intraoperative stroke.

The potential of duplex scanning to replace aorto-iliac and femoro popliteal angiography

The ability of duplex scanning to assess haemodynamically significant lesions in the aorto-iliac and femoro-popliteal arteries was studied. Duplex scanning was prospectively and independently compared to intra-arterial digital subtraction angiography (ia. DSA) of the aorto-iliac and femoro-popliteal arteries and intra-arterial pressure measurements of the aorto-iliac tract before and after the administration of papaverine. In 40 patients 629 arterial segments were evaluated. A greater than 150% increase in peak systolic velocity had a sensitivity of 92% and a specificity of 98% in detecting greater than 50% diameter reducing lesions in the aorto-iliac arteries as compared to ia. DSA. The numbers for the femoro-popliteal arteries are 88% and 98% respectively. Detection of occlusion in the aorto-iliac arteries had a sensitivity and specificity of 100% and in the femoro-popliteal arteries 90% and 100% respectively. There was a poorer correlation between intra-arterial pressure measurements and duplex scanning or ia. DSA as compared to the correlation between ia. DSA and duplex scanning. Retrospective spectral analysis showed that an end diastolic velocity (EDV) of greater than 40 cm/s seems to be a valuable parameter to differentiate between 50% to 74% and 75% to 99% diameter reduction. It is concluded that duplex scanning can reliably differentiate between haemodynamically significant and insignificant lesions in the aorto-iliac and femoro-popliteal arteries and has the potential to replace angiography.

Thrombus regression in deep venous thrombosis. Quantification of spontaneous thrombolysis with duplex scanning

BackgroundThrombus regression in heparin-treated, acute deep venous thrombosis of the lower extremity is poorly documented in the literature; different rates of thrombus resolution and recanalization are reported. Methods and ResultsIn a prospective follow-up study, duplex scanning was used to evaluate the thrombus regression in patients with documented acute femoropopliteal thrombosis. Eighty vein segments in 20 legs of 18 patients were subjected to repeat duplex scans at 1, 3, 6, 12, and 26 weeks after diagnosis; 49 segments showed thrombus at diagnosis. The popliteal vein showed the highest thrombus load at diagnosis, followed in descending order by the superficial femoral, profunda femoris, and common femoral vein segments (p < 0.001). Thrombus regression was significant (p < 0.001) in all segments and proceeded at an exponential rate that was equal in the different vein segments of the upper leg. Both thrombus resolution and recanalization appeared to be a function of the initial thrombus load and could not be related to individual vein segments. Recanalization was seen in 23 of 31 initially occluded segments and occurred within the first 6 weeks after diagnosis in 20 of 23 segments. Extension of thrombus despite anticoagulant therapy was observed in 15 vein segments and was not related to the initial thrombosis score (p = 0.l) or individual vein segments (p = 0.23). Thrombus extension in seven patients with prethrombotic conditions was not different (p = 0.9) from the other patients. ConclusionsDuplex scanning is an important noninvasive tool to quantify thrombus regression in acute deep venous thrombosis in detail without unnecessary discomfort to the patient.

Duplex ultrasound scanning in the assessment of arteriovenous fistulas created for hemodialysis access: Comparison with digital subtraction angiography

The results of duplex ultrasound scanning for the diagnosis of stenoses in Brescia-Cimino arteriovenous fistulas and graft arteriovenous fistulas created for hemodialysis access are reported. Quantitative Doppler spectrum analysis of 64 arteriovenous fistulas was correlated with the outcome of digital subtraction angiography. The best Doppler parameter for the detection of a stenosis was the peak systolic frequency. In graft arteriovenous fistulas the use of this parameter resulted in a diagnostic accuracy of 86%, a sensitivity of 92%, and a specificity of 84% in the detection of stenoses. In Brescia-Cimino arteriovenous fistulas the diagnosis of anastomotic stenoses was possible with a diagnostic accuracy of 81%, a sensitivity of 79%, and a specificity of 84%. Measurement of peak systolic frequency ratios or end-diastolic frequencies had no additional diagnostic value for the detection of stenoses. The diagnosis of efferent vein stenoses was very accurate with duplex investigation (accuracy 96%, sensitivity 95%, and a specificity of 97%. We conclude that duplex scanning is a promising noninvasive method for the diagnosis of stenoses in arteriovenous fistulas created for hemodialysis access.

Screening for asymptomatic internal carotid artery stenosis and aneurysm of the abdominal aorta: comparing the yield between patients with manifest atherosclerosis and patients with risk factors for atherosclerosis only.

OBJECTIVE The purpose of this study was to investigate whether screening for internal carotid artery stenosis (ICAS) and aneurysm of the abdominal aorta (AAA) is indicated in patients with either manifest atherosclerotic disease or with only risk factors for atherosclerosis. STUDY DESIGN Data were obtained for 2274 patients enrolled in the SMART study, an ongoing single-center, prospective cohort study of patients referred to our vascular center with manifest atherosclerotic disease (peripheral atherosclerotic disease [PAD]; transient ischemic attack [TIA], stroke, or ICAS; AAA; angina pectoris; or myocardial infarction [MI]) or with only risk factors for atherosclerosis (diabetes mellitus, hypertension, hyperlipidemia). The presence of ICAS or AAA was determined with duplex scanning and ultrasonography. RESULTS The prevalence of ICAS 70% or greater is low in patients with risk factors for atherosclerosis only (1.8%-2.3%), intermediate in patients with angina pectoris or MI (3.1%), and highest in patients with PAD (12.5%) or AAA (8.8%). The prevalence of AAA 3 cm or larger is low in patients with risk factors for atherosclerosis only (0.4-1.6%), intermediate in patients with angina pectoris or MI (2.6%), and highest in patients with PAD (6.5%) or TIA, stroke, or ICAS (6.5%). The prevalence of AAA larger than 5 cm is low in all of the considered patient groups. The yield of screening can be optimized through selection on the basis of simple patient characteristics. In patients with PAD, selecting those with advanced age (>54 years) increased the prevalence of ICAS to 21.8%. Selecting patients with lower diastolic blood pressure (<83 mm Hg) increased the prevalence of ICAS to 17.9%. In patients with both advanced age and lower diastolic blood pressure, the prevalence of ICAS increased to 34.7%. Selecting patients with advanced age increased the prevalence of AAA 3 cm or larger to 9.6%. In patients with TIA, stroke, or ICAS, selecting those with advanced age increased the prevalence of AAA 3 cm or larger to 8.2%. Selecting patients with taller stature (>169 cm) increased the prevalence of AAA 3 cm or larger to 9.3%. In patients with advanced age and taller stature, the prevalence of AAA 3 cm or larger increased to 13.1%. CONCLUSIONS Screening for ICAS should be limited to patients referred with PAD or AAA, especially those with advanced age or with low diastolic blood pressure. Screening for AAA should be limited to patients referred with PAD or with TIA, stroke, or ICAS, particularly those with advanced age or tall stature. In patients referred with angina pectoris or MI and those referred with only risk factors for atherosclerosis, screening cannot be endorsed.

CT-angiography of abdominal aortic aneurysms after transfemoral endovascular aneurysm management

OBJECTIVE To evaluate short-term effect of Transfemoral Endovascular Aneurysm Management (TEAM) on aortic diameters and volumes after aneurysm exclusion, using CT-angiography. DESIGN Analysis of preoperative, 1 week postoperative and 6 months postoperative CT measurements. SETTING University Hospital. MATERIALS Nine patients treated with an endovascular tube prosthesis. CHIEF OUTCOME MEASURES True cross-sectional diameters of the aorta and the aneurysm, volume of the infrarenal aortic lumen, of the thrombus and of the iliac arteries and length of the aorta and of the endovascular prosthesis. MAIN RESULTS CT-angiography detected shrinkage of the aneurysm in seven patients. Aneurysm growth was observed in one patient with persistent flow outside the graft and in one patient with fully thrombosed aneurysm sac. In the two patients with increasing thrombus volume, the volume of the aortic lumen decreased. CONCLUSIONS Although successful aneurysm exclusion can be confirmed by maximum aneurysm diameter measurement, changes in aortic lumen volume and thrombus volume may be more appropriate to discriminate successful from failed exclusion.