Duplex Criteria for Grading of External Carotid Stenosis.

BACKGROUND: External carotid artery (ECA) stenosis is an independent mortality predictor. Additionally, concomitant ECA and internal carotid artery (ICA) stenosis progression has been associated with an increased risk of ipsilateral ischemic events in asymptomatic patients. Universally accepted ECA duplex velocity criteria, for the prediction of stenosis, do not exist. METHODS: Consecutive patients undergoing angiography and carotid duplex assessments were compared (n = 140). ICA, common carotid artery (CCA), and ECA peak systolic velocities (PSVs) were recorded. ECA/CCA PSV ratio was calculated. These parameters were compared with angiographic ECA measurements. Receiver-operator curve analysis was used to determine optimal criteria in identifying ECA stenosis of >50%. RESULTS: In patients with little ipsilateral ICA disease, for the detection of ECA stenosis of ≥50%, an ECA PSV >148 cm/sec provided a sensitivity of 80%, specificity of 76.2%, and an overall accuracy of 77.1%. An ECA/CCA PSV ratio of 1.45 demonstrated a sensitivity of 73.7%, specificity of 66.7%, and an accuracy of 68.2%.In patients with ICA stenosis ≥50%, for the detection of ECA stenosis of ≥50%, an ECA PSV >179 cm/sec provided a sensitivity of 50%, specificity of 79.6%, and overall accuracy of 71.3%. An ECA/CCA PSV ratio of ≥1.89 provided a sensitivity of 71.9%, specificity of 72.7%, and overall accuracy of 72.5%. CONCLUSIONS: ECA PSV and ECA/CCA PSV ratios appear as useful metrics for the prediction of unilateral high-grade ECA stenosis.

Are systolic velocity duplex metrics negatively affected by flow aliasing in areas of critical internal carotid artery stenosis.

Purpose: Duplex scanning is a useful noninvasive screening tool for the detection of carotid bifurcation disease. Internal carotid artery (ICA) peak systolic velocity (PSV) and ICA/common carotid artery (CCA) PSV ratios are proven metrics determining 70%-99% ICA stenosis. A potential disadvantage of using dramatically increasing systolic velocity measurements in areas of critical arterial stenosis is flow aliasing. Diastolic velocity should be less influenced by this flow artifact. We evaluate ICA and CCA end diastolic velocity (EDV) metrics in predicting severe ICA stenosis and document the prevalence of an aliasing artifact in a population of patients with critical ICA stenosis. Methods: Consecutive patients undergoing carotid duplex assessments and contrast angiography were compared (n = 140). ICA and CCA PSV and EDV were recorded as was evidence of the flow aliasing of ICA waveforms. ICA/CCA PSV and EDV ratios were calculated. Duplex parameters were compared with angiographic ICA measurements. Receiver-operator characteristic curve (ROC) analysis was used to determine optimal criteria to identify ICA stenosis of 70% to 99%. Results: Of 256 carotid bifurcation duplex studies, critical angiographic stenosis was present in 105 arteries. Only four completed arterial duplex scans demonstrated flow aliasing. In three of these patients, systolic metrics were non-diagnostic versus ICA/CCA EDV ratios. An ICA/CCA EDV ratio of 2.3 provided the best combination of sensitivity 73.8% and specificity 75.18%. Conclusion: ICA/CCA diastolic ratios reliably determine 70% or greater ICA stenosis. Flow aliasing infrequently complicates ICA PSV.

Gelatin-thrombin-based hemostatic sealant for intraoperative bleeding in vascular surgery.

Vascular surgical procedures may be prolonged because of intraoperative bleeding that is not easily controlled by cautery or suture ligation. This trial compared the ability of a new hemostat, FloSealTM Matrix (FM), with a known hemostat, Gelfoam(R) plus thrombin (GT), to control intraoperative bleeding. Patients undergoing vascular surgery procedures at four institutions were entered in the trial. After a bleeding site was identified, patients were randomized to one of the study agents: (1) FM, a cross-linked gelatin of bovine origin combined with thrombin, or (2) GT. The assigned agent was applied and the site observed for bleeding at 1, 2, 3, 6, and 10 min. The primary end point was cessation of bleeding within 10 min for the first identified site treated. Secondary end points were cessation of bleeding within 10 min for all sites and time to cessation of bleeding. Patients were assessed for morbidity at 30 days and 6-8 weeks after the operation. Analysis was performed on an intent-to-treat basis for analysis of hemostasis at 10 min and on protocol-valid patients for analysis of time to hemostasis. From our results we concluded that for patients undergoing vascular surgery procedures, the new topical hemostat, FloSeal Matrix, provides more rapid and effective hemostasis than Gelfoam plus thrombin.

Infrarenal rupture of an abdominal aortic aneurysm, previously repaired using an endoaneurysmorrhaphy technique.

Unusual as well as well-known complications can occur after aortic reconstruction. In an effort to heighten awareness of these possibilities, a case is presented of a 71-year-old male who was brought to the emergency department with severe back pain of 2 days duration and hypotension. He had undergone repair of an infrarenal abdominal aortic aneurysm 6 years earlier. An emergency computed tomography scan demonstrated a 10-cm abdominal aortic aneurysm extending from just above the celiac axis, through the aortic bifurcation, with retroperitoneal and intraperitoneal hematoma. He was found at operation to have extension of his aneurysmal disease proximally, with complete separation of the proximal suture line, and rupture of the distal aortic wall. Since the aneurysm had been closed around the graft at the time of the original operation, his aneurysm had essentially been restored, and the diseased wall was again exposed to the tensile stresses from the pulsatile column of blood. Emergency repair was successful, despite postoperative complications including myocardial infarction, and later rupture of an iliac artery aneurysm. Patients presenting with signs and symptoms consistent with a ruptured abdominal aortic aneurysm after previous repair should be addressed aggressively with computed tomography if it is immediately available and the diagnosis is in doubt. The patient should then undergo an immediate operation. Such recurrence, although rare, must always be considered a possibility. Similar scenarios may be encountered secondary to endoleaks occurring after endoluminal aortic repairs.