Errol E. Erlandson

Atherosclerotic extracranial carotid artery aneurysms.

Twenty-four atherosclerotic extracranial carotid artery aneurysms were encountered in 21 patients during a 25-year period. These represented 46% of all extracranial carotid artery aneurysms diagnosed at the University of Michigan during this period. Neurologic symptoms including amaurosis fugax, transient ischemic attacks, and stroke were present in 50% of the patients. An asymptomatic pulsatile neck mass occurred in 33%. Surgical therapy was undertaken for 18 aneurysms, and nonoperative treatment was pursued in the remaining six aneurysms. Operative therapy included 14 aneurysmectomies and four aneurysmorraphies. There were no surgical deaths. Transient perioperative neurologic deficits affected three of these patients (17%), and one individual (5%) experienced a permanent deficit. Transient cranial nerve deficits occurred in three patients (17%), and a permanent deficit was noted in one patient (5%). During a 7.6-year follow-up period no late strokes occurred among patients who were operated on. Nonoperative therapy was associated with three ipsilateral strokes during a mean follow-up period of 6.3 years. Atherosclerotic extracranial carotid artery aneurysms were associated with an exceptionally high stroke rate (50%) if treated nonoperatively. Prevention of late stroke justifies surgery, although perioperative neurologic deficits may accompany this therapy more often than with nonatherosclerotic carotid artery aneurysms.

Developmental occlusive disease of the abdominal aorta and the splanchnic and renal arteries

Developmental occlusive disease of the abdominal aorta and the renal and splanchnic arteries represent an unusual vascular condition. When unrecognized or untreated this disease is associated with premature death, usually from severe secondary hypertension as a consequence of renovascular stenotic lesions. Strong circumstantial evidence indicates that developmental abnormalities occurring during the fetal union of the two dorsal aortae account for most of the occlusive lesions affecting the abdominal aorta and its visceral branches in these patients. Complete arteriographic studies are necessary to confirm and accurately delineate the disease process. Surgical treatment, which often encompasses complex vascular reconstructive efforts, affords excellent results when carefully planned and executed.

The Use of Preoperative Noninvasive Vascular Studies for the Evaluation of Radial Artery Conduits for Coronary Artery Bypass Grafting

Background: The increased use of the radial artery for coronary artery bypass conduits has heightened the awareness of potential resultant hand ischemia. The Allen test and subsequent modifications have been used to evaluate the patency of the superficial palmar arch (SPA). The purpose of this study was to determine if changes in blood flow patterns of the SPA assessed by the modified Allen test parallel changes in blood pressures of the first and second digits following radial artery occlusion. Methods: Continuous-wave Doppler ultrasound and photoplethysmography (PPG) were used to evaluate blood flow in the SPA and first and second digits, respectively, before and after manual occlusion of the radial artery in 60 extremities. A second continuouswave Doppler probe was used to ensure complete occlusion of the radial artery. Digit skin temperature was controlled between 36° and 37.5°0. A reduction of >20 mmHg in blood pressure was arbitrarily chosen to reflect a clinically significant change in digit arterial pressure. Results: Six of the 60 extremities (10%) studied showed a decrease in the audible Doppler signal over the SPA following radial artery occlusion. Reduction in digit arterial pressure following radial artery occlusion occurred in 13 of 60 extremities (21.7%). Digit arterial pressure reductions ranged from 20 to 58 mmHg (mean ±SD, 35.2 ±12.8 mmHg), demonstrating a 40% decrease in digital pressure. Changes in SPA flow did not parallel digital pressure changes following occlusion of the radial artery. Conclusion: Continuous-wave Doppler ultrasound of the SPA following radial artery compression alone does not accurately predict digit ischemia. Digit arterial pressure measurement of the first and second digits of upper extremities offers a relatively simple and objective method for evaluation of potential ischemic complications following radial artery harvest. This finding is important because many physicians only use a modified Allen test with radial artery compression to assess potential digit ischemia.

Popliteal Artery Occlusion Secondary to Cystic Adventitial Disease: A Rare Etiology of Lower Extremity Ischemia in a Marathon Runner A Case Report

A 44-year-old marathon runner was referred with a 2-week history of the sudden onset of severe left calf claudication. Angiography showed a 3- to 4-centimeter focal nearocclusion of the left midpopliteal artery. Magnetic resonance imaging showed a cystic structure in the left popliteal artery wall. A left popliteal artery exploration revealed popliteal artery occlusion secondary to cystic adventitial disease. Excision of the cyst resulted in restoration of pedal pulses. This rare disease of uncertain etiology should be suspected in young adults presenting with ischemia. Various noninvasive techniques in conjunction with arteriography result in reliably diagnosing cystic adventitial disease. Excision of the cyst usually provides adequate treatment. Resection of the diseased arterial segment with autogenous bypass may be required.

Duplex Ultrasonography to Predict Internal Carotid Artery Stenoses Exceeding 50% and 70% as Defined by NASCET: The Need for Multiple Criteria

Carotid duplex scanning is being used more frequently as the sole preoperative diagnostic imaging modality for patients considered candidates for carotid endarterectomy. The North American Symptomatic Carotid Endarterectomy Trial (NASCET) has demonstrated the benefit of surgical treatment in patients with carotid stenoses exceeding 70%. The purpose of this study was to determine duplex criteria that accurately predict carotid stenoses exceeding 50% and 70% as defined by NASCET arteriographic criteria. One hundred forty-one patients (264 carotid arteries) considered surgical candidates were prospectively studied over a 2-year period by use of both duplex scanning and digital subtraction cerebral arteriography. Carotid artery stenosis was determined by a single radiologist using NASCET arteriographic criteria. Peak systolic velocity (PSV) and enddiastolic velocity (EDV) were measured in the internal carotid (ICA) and common carotid (CCA) arteries by use of duplex scanning. ICA/CCA velocity ratios were calculated for PSV and EDV. Sensitivity, specificity, positive and negative predictive values, and accuracy were calculated. PSVICA/CCA provided the highest sensitivity, and EDVICA the highest specificity in this study. Arteriographic stenoses exceeding 50% and 70% were reliably predicted with use of these duplex criteria. It is concluded that duplex criteria can predict carotid stenoses exceeding 50% and 70% as defined by NASCET arteriographic criteria. These criteria should be independently validated by other vascular laboratories.