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.

Laparoscopic treatment of large true cysts of the liver and spleen is ineffective.

True epidermal cysts of the liver and spleen are uncommon and it has been recommended that laparoscopic management is appropriate. Often these cysts are large and centrally located by the time they reach clinical significance thereby making complete excision difficult without major liver resection or splenectomy. Definitive therapy consists of drainage and complete resection of the cyst wall. Three patients presented with upper abdominal pain. Workup revealed large non-parasitic true cysts of the liver (one) and spleen (two). All were initially treated with laparoscopic resection of their cysts with the primary objective being organ preservation. They were followed with periodic ultrasound/CT scanning. The pathology report in all three cases demonstrated benign congenital epithelial cysts and the patients did well postoperatively. Despite meticulous dissection and marsupialization of the cysts all three patients experienced recurrence that necessitated further therapy. We conclude that laparoscopic surgery is inadequate in the management of true cysts of the liver and spleen unless complete removal of all cyst wall can be assured.