Noninvasive evaluation and management of the "asymptomatic" carotid bruit.

Cervical bruits in patients who are asymptomatic or who have nonhemispheric neurological symptoms present a universal challenge. Of 4,000 patients evaluated noninvasively for carotid occlusive disease, 1,287 presented with "asymptomatic" bruits (697 had nonhemispheric neurological symptoms and 590 were clinically asymptomatic). Carotid phonoangiography (CPA), the visual analysis of carotid bruits, identifies bruits indicative of significant stenosis, documents progression, and differentiates bruits of carotid bifurcation and sub-bifurcation origin. Sub-bifurication bruits were diagnosed in 619, insignificant bifurcation bruits in 426, and significant carotid bruits in 242 patients by CPA. Oculoplethysmography (OPG) evaluates the hemodynamic significance of carotid bruits by comparative timing of simultaneously recorded ocular and ear lobe pulses. OPG detected 273 asymptomatic bruit patients with significant internal carotid flow reduction and indicated 5% of the bifurcation bruits were of external carotid origin. An accuracy of 89% in determining greater than 40% stenosis by OPG/CPA in 295 patients having arteriography increases to 97% when both OPG and CPA are positive. Six-month to 70-month clinical follow-up of the 1,287 patients documented 154 carotid endarterectomies and 38 strokes. Analysis of the strokes favors arteriography and operation only for those patients with appropriately positive or progressive OPG/CPA or with focal transient ischemic attacks (TIAs).

Carotid occlusive disease as a risk factor in major cardiovascular surgery.

Carotid occlusive disease in patients undergoing major cardiovascular surgery raises the question of the perioperative risk factor of stroke. We evaluated 234 cardiovascular patients preoperatively by oculoplethysmography (OPG) to detect hemodynamically severe carotid occlusive disease. The perioperative stroke risk without flow-reducing carotid occlusive disease was 1%, in contrast to a 17% incidence of stroke when OPG studies indicated internal carotid artery stenosis of more than 60%. Oculoplethysmography is a reliable indicator of hemodynamically severe carotid occlusive disease with an associated high risk of stroke that warrants prophylactic carotid endarterectomy before major cardiovascular surgery.

A new method of preclotting fabric prostheses. A preliminary report.

A new method of preclotting arterial fabric prostheses is described. The preclotting process depends on infusion of blood into a polyethylene bag containing the prosthesis. Massage of the bag aids permeation of the graft, and a second infusion of blood over a 1 minute period seals the fraft completely. Rapid preclotting and asepsis are the unique features of this method.

Oculoplethysmography: an adjunct to arteriography in the diagnosis of extracranial carotid occlusive disease.

A four and a half year study documents that oculoplethysmography, in conjunction with carotid phonoangiography, fulfills the criteria of an effective noninvasive adjunct to arteriography in the diagnosis of extracranial carotid occlusive disease. The risk and expense of unnecessary arteriographic studies can be reduced and accuracy of arteriographic technics and interpretations can be enhanced by routine application of oculoplethysmography.

Wrapping of abdominal aortic aneurysms: a viable alternative.

Abdominal aortic aneurysm wrapping is an excellent procedure to use for poor-risk patients, calcified aneurysms, aneurysms extending above the renal arteries, and prophylaxis for small aneurysms. The procedure has a low operative mortality rate and a low long-term graft-related complication rate. It appears that aortic wrapping can be performed with a similar mortality and long-term survival rate as standard resection and grafting procedures, in spite of its application in generally poorer-risk patients. However, we do not believe that this procedure will replace aortic resection and grafting for most lumbar aortic aneurysms, but it should be considered for use in selected instances and should be in the armamentarium of all vascular surgeons.

Retroperitoneal unilateral ileofemoral thromboendarterectomy.

This clinical series of 145 operative procedures is presented to demonstrate that an aggressive approach in the management of ileofemoral arterial insufficiency utilizing a retroperitoneal approach for thromboendarterectomy is useful and appropriate. Considering the overall risk factors associated with this patient population, we have demonstrated that this method is well tolerated as supported by the low morbidity and mortality figures presented. The native vascular tree has been preserved, and excellent early and long-term revascularization goals have been obtained.

Guidelines for noninvasive evaluation of asymptomatic carotid bruits.

Basic recommendations for follow-up utilizing OPG/CPA results are as follows: Grade 1: Repeat studies in 12 months in the absence of specific focal TIAs or increase of bifurcation level bruit. Grade 2: Serial studies in 6 to 12 months in the absence of focal TIAs which provide their own indications for evaluation. If stability is established, 12-month interval testing is adequate. Grade 3: Serial studies in 3 to 6 months until a progression trend is established. Anticipation of major surgery with possible hypotension or severe blood loss is an indication for arteriography and possible endarterectomy. Grade 4: If repeat studies confirm grade 4 status, prophylactic carotid arteriography and endarterectomy should be seriously considered. If surgery is not employed, repeat OPG/CPA evaluation at 2 to 4 month intervals detects further progression toward total occlusion. Grade 5: Indications for arteriography in anticipation of surgery are tempered by the lower probability (30%) of a surgically correctable stenosis and the clinical status of the patient. In conclusion, we feel that OPG/CPA represents one valid means of noninvasively evaluating the presence and underlying hemodynamic significance of an asymptomatic bruit with sufficient reliability to justify angiography and prophylactic carotid endarterectomy on the basis of appropriate findings.

Thrombolysis of palmar and digital arterial thrombosis by intra-arterial Thrombolysin.

In nine patients, one with bilateral findings, impending gangrene of the hand due to thrombosis of the palmar arch or digital arteries did not respond to current surgical methods or to common nonsurgical measures and was treated by intra-arterial thrombolysin. The author's recommended diagnostic arteriography, direct surgical treatment, if indicated, and specific coagulation studies. Thrombolysin was given by perfusion at a rate of 100,000 U. per hour. Careful monitoring of the clotting process prevented any significant bleeding and excellent recovery occurred in eight hands and there was a good result in two.

Pressure and volume measurements from the eye for detecting possible arterial obstruction.

Detection and evaluation of functionally significant carotid occlusive disease are effectively achieved by noninvasive pressure and/or volume measurements from the eye. Ocular arterial blood pressure is measured by applying either direct compression or suction to evaluate intraocular pressure to the point of arterial collapse. Carotid blood flow is evaluated as it affects ocular volume waveforms, which result from the difference between pulsatile arterial flow and relatively constant venous flow. The relationship between noninvasive measurements from the eyes and carotid blood flow can be predicted using simple models of the cervical-cerebral circulatory system. Proper models verify clinically observed correlations between pressure and volume measurements from the eye and the underlying carotid occlusive disease. Electrical analog circuits provide a method for varying model parameters to simulate abnormalities, producing waveforms with good similarity to waveforms recorded from patients with known vascular or ophthalmic pathology. Further model refinements can be contributed by interested investigators. By using the improved models the strengths and weaknesses of current tests and techniques can then be better defined. Techniques that have been widely used for screening and evaluating potential stroke patients can thereby be modified to give improved functional analysis of these patients.

Oculoplethysmography and carotid phonoangiography for the noninvasive detection of extracranial carotid occlusive disease.

Clinical applications of imaging techniques and noninvasive physiological vascular evaluations provide useful assistance in the detection and management of stroke-prone patients by minimizing unnecessary carotid arteriography and surgery. Two such evaluation techniques are oculoplethysmography (OPG) and carotid phonoangiography (CPA). Developed, used, and proved highly reliable at the Tucson (Arizona) Medical Center, the techniques have been documented in 12,000 tests on approximately 8500 patients. OPG simultaneously records the bilateral ocular pulses concomitantly with external carotid pulses. Delays in timing of these pulses reflect reduction of flow in the internal and/or external carotid arteries, respectively. CPA consists of electronic stethoscopic auscultation, direct visualization, and photographic recording of carotid bruits or blood flow sounds.