Peripheral-arterial surgery

Retrograde Carotid Stenting for Isolated Stenosis of the Proximal Common Carotid Artery-Case Report-

A 49-year-old female with a history of systemic hypertension and diabetes mellitus suffered transient right hemiparesis. Carotid angiography with arch-aortography detected severe stenosis of the proximal portion of the left common carotid artery. The left carotid bifurcation was surgically exposed and retrograde catheterization was performed to approach the proximal common carotid artery stenosis. The lesion was dilated with a balloon catheter and successfully stented without complications. The left internal carotid artery was clamped during the procedure to avoid embolism. Retrograde carotid stenting for stenosis of the proximal common carotid artery is a safe and effective alternative to conventional surgery in selected patients.

Monitoring of end-tidal carbon dioxide partial pressure changes during infrarenal aortic cross-clamping: a non-invasive method to predict unclamping hypotension

BACKGROUND

To assess the variations in end-tidal CO2 in response to aortic cross-clamping and the relationship with systolic arterial pressure (SAP) changes induced by unclamping.

METHODS

Thirty-three patients undergoing infrarenal aortic abdominal aneurysm repair by aorto-aortic prothetic bypass were prospectively studied. All patients were anesthetized with i.v. midazolam (0.05 mg x kg(-1)), thiopentone (3-5 mg x kg(-1)), fentanyl (5 microg x kg(-1)), pancuronium (0.1 mg x kg(-1)) and the maintainance of anesthesia used was 1-1.5% end-tidal isoflurane and i.v. fentanyl. The perioperative management was standardized. End-tidal CO2 and SAP were measured 5 min before (Pre-XAA), 15 min after infrarenal aortic cross-clamping (XAA), 5 min before (Pre-UXAA) and immediately after unclamping (UXAA).

RESULTS

A total of 16 (48.5%) from 33 patients presented decrease in SAP following aortic unclamping, and 13 out of these patients had arterial hypotension defined as SAP<90 mmHg. End-tidal CO2 variation (PreXAA-PreUXAA) induced by aortic clamping was correlated with SAP variation (PreUXAA-UXAA) induced by unclamping (r=0.763; P=0.0001). An end-tidal CO2 reduction above 15% after aortic cross-clamping was found to have a 100% sensitivity to detect a SAP decrease greater than 20% after unclamping, with a 100% specificity and a negative predictive value of 1.0. Complete aortic occlusion duration was not correlated to SAP unclamping variation (deltaSAP). Intraoperative characteristics (fluid loading, hematocrits, urinary output) were comparable, although blood loss was higher in patients experiencing deltaSAP>20%.

CONCLUSIONS

End-tidal CO2 variation monitoring during aortic cross-clamping may provide a reliable and non-invasive method to predict unclamping hypotension. When the aortic clamp was released, systolic hypotension (>20%) occurred in those subjects who had a decrease in end-tidal CO2 greater than 15% during aortic cross-clamping.

Retrograde balloon angioplasty of brachiocephalic or common carotid artery stenoses at the time of carotid endarterectomy

OBJECTIVES

This study was performed to demonstrate the value and durability of intraoperative retrograde angioplasty for stenotic lesions of the aortic arch branches at the time of carotid endarterectomy for the treatment of tandem proximal and bifurcation carotid lesions.

DESIGN

Retrospective analysis of the clinical data.

METHODS

Forty-four patients were included in this study when they presented with symptomatic extracranial vascular disease due to stenosis of both a proximal aortic arch branch and carotid bifurcation disease. Tandem disease was detected in the vascular laboratory and confirmed by angiography. Each patient was subjected to conventional carotid endarterectomy, and at the time of operation, the proximal lesion was subjected to transluminal angioplasty through the endarterectomy arteriotomy (brachiocephalic 24; left common carotid 15; right common carotid artery five). Patients were then followed up clinically and by non-invasive tests at 6-monthly intervals.

RESULTS

Forty-three successful dilatations were achieved. The single initial technical failure was due to heavy calcification of a brachiocephalic artery. In the follow-up period restenosis was noted in four patients. All restenosis occurred within 24 months. No restenosis at the angioplasty site was noted on subsequent follow-up of the remaining 39 patients. No perioperative stroke or death was encountered. A surprisingly high mortality rate was noted on follow-up in this group of patients, suggesting the presence of more aggressive and advanced diffuse vascular disease.

CONCLUSION

Retrograde intraoperative angioplasty of the proximal component of a tandem extracranial lesion has in this series proven to be a safe and durable therapeutic option. This technique has an acceptable restenosis rate in a subset of patients who have been demonstrated to have a shortened life expectancy and a high mortality rate in the follow-up period.

Exercise testing and exercise rehabilitation for patients with peripheral arterial disease: status in 1997

Intermittent claudication is a common manifestation of peripheral arterial occlusive disease (PAOD). Patients with claudication are limited in terms of work, housework and leisure activities so that functional status is very impaired. Therefore, the goals for treatment should focus on improving the functional impairment as well as on modifying risk factors. Evaluation of the functional status is of critical importance before beginning any therapy so that any resultant changes can be assessed. A validated graded treadmill protocol and validated questionnaires are used for this purpose. Three questionnaires that are currently used include the Walking Impairment Questionnaire, the PAOD Physical Activity Recall and the Medical Outcomes Study SF-36. Exercise rehabilitation is a method that has been particularly efficacious for treating the functional impairment associated with intermittent claudication. Exercise rehabilitation has been shown to improve pain-free treadmill walking distance by 44% to 300% and absolute walking distance by 25% to 442%. In addition, improvements have also been reported (using questionnaire data) in the ability to walk distances and speeds, in amount of habitual physical activity and in physical functioning. Thus, exercise rehabilitation has caused improvements not only in exercise capacity but also in community-based functional status. Because of the benefits of this treatment, in addition to the low associated morbidity, exercise therapy is recommended as an important treatment option for people with intermittent claudication due to PAOD.

Dipyridamole thallium-201 single-photon emission computed tomography for prediction of perioperative cardiac events in patients with arteriosclerosis obliterans undergoing vascular surgery

The aim of the study was to determine whether or not dipyridamole thallium-201 single-photon emission computed tomography (201Tl-SPECT) has significant additive value for predicting perioperative cardiac events in patients with arteriosclerosis obliterans (ASO) undergoing vascular surgery. Routine preoperative 201Tl-SPECT was performed in 106 consecutive patients with ASO (age 68+/-8.9 years; 91 men and 15 women). The frequency of reversible defects in a clinical high-risk group (n=44) was significantly higher than in a low-risk group (n=62; 55% vs 24%, p<0.01). Perioperative cardiac events occurred in 9 patients, including 4 cardiac deaths, 1 non-fatal myocardial infarction, and 4 cases of unstable angina. Although clinical risk stratification was useful in predicting cardiac events (19% in the high-risk group vs 2% in the low-risk group, p<0.01), the positive predictive value was low. When considering a combination of 2 or more than 2 risk factors and a large reversible defect as a predictor, the positive predictive value and specificity increased from 19% to 47% and from 64% to 91%, respectively, whereas the sensitivity remained unchanged (89%). These results suggest that the addition of 201Tl-SPECT data to clinical risk-stratified patients with ASO allows better prediction of perioperative cardiac events.

Vascular disease in the elderly patient

At a time of potentially dramatic changes in health care policy in this country, and in view of the necessity for health care cost containment, physicians are expected to exercise serious introspection in the selection of treatment for the elderly patient with peripheral arterial disease. These decisions should be made while acknowledging that it is the goal of the health-care provider "to postpone chronic illness, to maintain vigor, and to slow social and psychological involution." For the elderly patient with an abdominal aortic aneurysm, with significant carotid disease, or with limb-threatening peripheral ischemia, the evidence is compelling that timely surgical intervention in properly selected patients is well tolerated and will satisfy this goal.

Prediction of late cardiac events by dipyridamole thallium imaging in patients undergoing elective vascular surgery

Dipyridamole thallium scintigraphy has previously been shown to have prognostic value in the preoperative assessment of patients scheduled to undergo vascular surgery, but its effect on the long-term outcome is less well-defined. In the largest series to date, dipyridamole thallium scanning was performed in 360 patients before elective vascular surgery and survivors were followed for a mean of 31 months. In the 327 patients who underwent vascular surgery, operative death and nonfatal myocardial infarction occurred in 4.9 and 6.7%, respectively. A cardiac event (nonfatal myocardial infarction or cardiac death) occurred in 14.4% of patients with a transient thallium defect, as opposed to 1% with a normal scan (p < 0.001). Logistic regression analysis revealed that the best predictor of a perioperative event was the presence of a reversible thallium defect, elevating the risk by 4.3-fold. Late cardiac events occurred in 53 (15.2%) surgical survivors or nonsurgically treated patients. Patients with a fixed perfusion abnormality had a 24% late event rate, compared with 4.9% in those with a normal dipyridamole thallium study (p < 0.01). Cox analysis demonstrated that a fixed thallium defect was the strongest factor for predicting a late event and increased the relative risk by almost fivefold. A history of congestive heart failure was the only significant variable that contributed additional value to that of a fixed defect alone. Life-table analysis confirmed the strong relation of a fixed defect to cardiac event free survival (p < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Perioperative and long-term prognostic value of intravenous dipyridamole thallium scintigraphy in patients with peripheral vascular disease

The prognostic value of long-term risk stratification of patients with peripheral vascular disease who undergo intravenous dipyridamole thallium scintigraphy has not been well studied. We screened 131 patients with peripheral vascular disease who underwent intravenous dipyridamole thallium testing to determine cardiac event rates over an average follow-up of 18 +/- 10 months. Of the 131 patients, 111 subsequently had peripheral vascular surgery. The patients with abnormal thallium scans after dipyridamole had a significantly higher risk of death or myocardial infarction, both in the perioperative phase (7% versus 0%; p less than 0.001) and at late follow-up (17% versus 6%; p less than 0.01). The risk of a cardiac event was two-fold greater when a reversible as compared to a fixed thallium defect was present. Multivariate analysis selected the number of thallium segments with perfusion defects, prior history of angina pectoris, and chest pain during dipyridamole testing as perioperative predictors of a cardiac event. A reversible thallium defect was the only predictor of death or nonfatal myocardial infarction during late follow-up. Thus intravenous dipyridamole thallium scintigraphy is a useful noninvasive test for risk stratification of patients before peripheral vascular surgery and provides prognostic information as to the risk of a cardiac event in the 2-year period after the test. A reversible thallium defect is associated with a significant increased risk and would indicate that coronary angiography should be considered and preoperative coronary revascularization.

Hypertension and renal artery aneurysm: spontaneous cure

An 18-year-old man is described with an aneurysm of the left renal artery diagnosed during study for hypertension. Medical treatment achieved control of the blood pressure. The patient voluntarily interrupted treatment 1 1/2 years after initial diagnosis but the blood pressure remained normal. Angiography at that time revealed almost complete thrombosis of the aneurysm and peripheral plasma renin activity returned to normal in contrast to the high figures registered initially (15 ng. per ml., normal values 0.51 to 2.64). The patient had normal blood pressure, received no medication and was on only a salt-free diet 1 year after this event.

Myocardial imaging using thallium 201 scintigraphy after dipyridamole infusion: a case history

Coronary artery disease frequently occurs in combination with peripheral vascular disorders and is an important cause of morbidity and mortality during or after peripheral vascular surgery. However, the detection of coronary artery disease in patients with peripheral vascular disease may be complicated, since most of these patients are unable to perform conventional exercise testing. The authors report a sixty-two-year-old man with an infrarenally located aneurysm of the abdominal aorta who underwent thallium 201 scintigraphy combined with dipyridamole infusion as an alternative exercise test. The subsequent thallium 201 images showed perfusion defects indicative of severe coronary artery disease. Coronary angiography showed an occluded right coronary artery and a significant proximal stenosis in the left anterior descending coronary artery. The patient underwent successful aortocoronary bypass surgery, and two months later, the aortic aneurysm was operated on without complications. As a result, dipyridamole thallium 201 scintigraphy should be considered as a valuable diagnostic test to detect coronary artery disease in patients with peripheral vascular disorders.

A look at 15 years of planar thallium-201 imaging

Extensive experience has been accumulated over the past 15 years regarding planar thallium-201 imaging. Quantitation of technically superior images provides a high sensitivity and specificity for the detection of CAD. In addition, planar thallium-201 images provide very important prognostic information in different clinical situations. Although single photon emission computerized tomography offers potential theoretical advantages over planar imaging, because of the problems involved in reconstruction, specifically the creation of artifacts, it may not be the ideal imaging modality in all situations. Good quality planar thallium-201 imaging still has an important role in clinical cardiology today.

Pitfalls during carotid endarterectomy

It is estimated that between 1971 and 1987 the number of carotid endarterectomies has increased from 15,000 to over 85,000 per year. Unless the procedure can be performed safely with a combined morbidity and mortality which is below the yearly risk of stroke (5%) for patients with symptomatic carotid artery disease, one should reconsider this operation as a therapeutic option. We review our experience with 891 carotid endarterectomies performed between January 1979 and June 1987. There were 579 (65%) men and 312 (35%) women of ages from 34 to 82 (median 65); risk factors included diabetes mellitus 213 (14%), hypertension 603 (68%), and smoking 630 (70%). Clinical presentation consisted of transient ischemic attacks 506 (57%), cerebral infarction with minimal neurological residual 252 (28%), stroke in evolution 3 (0.3%) and, asymptomatic stenosis 130 (15%). All patients were operated on under endotracheal anesthesia with transoperative monitoring of intra-arterial pressure, central venous pressure and arterial blood gases. Thiopental (3-5 mg/kg) and lidocaine (1 mg/kg) were given for induction and at 15 minute intervals during carotid cross-clamping. Intraluminal shunts were used in 13 (2%). A conventional (open) endarterectomy was performed in 561 (63%) and a limited endarterectomy (closed) in 330 (37%). Complications included 11 (1%) deaths, 26 (3%) developed a major neurological deficit that persisted, 30 (3%) had perioperative TIA's which resolved completely. Of the patients with preoperative neurological deficits, 33 (4%) recovered. Therefore, at one month after surgery, 854 (96%) were either as well or better than preoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)

Carotid endarterectomy in Great Britain and Ireland

A survey of the practice of carotid surgery by 245 vascular and neurological surgeons in Great Britain and Ireland was conducted with a 96 per cent response. Ninety-six surgeons (41 per cent) performed at least one carotid endarterectomy in 1984 and a total of 1374 such operations were carried out in that year. The indications for carotid endarterectomy in order of frequency were transient ischaemic attack, minor stroke and stroke. Operation was hardly ever undertaken for asymptomatic carotid bruit. Eighty-six per cent of surgeons who performed carotid endarterectomy generally assessed patients in the first instance using techniques less invasive than conventional angiography, principally Doppler ultrasonography or digital subtraction angiography. Nevertheless, conventional angiograms were usually performed before surgery by 89 per cent of surgeons. Almost all surgeons operated only under general anaesthesia, while opinion on the use of an intraluminal shunt during carotid endarterectomy was divided. Despite an increase in the number of carotid endarterectomies in recent years, this operation is currently performed nineteen times less frequently in Great Britain and Ireland than in the USA. The reasons for this are explored and certain controversies surrounding carotid endarterectomy are discussed.

The value of noninvasive investigation in the diagnosis of total occlusion of the internal carotid artery

A battery of simple noninvasive tests consisting of directional Doppler ultrasound and carotid phonoangiography has been used to detect carotid stenosis in 700 patients Forty four carotid occlusions in 42 patients were confirmed on angiography, and this study examines the accuracy of this noninvasive battery in predicting the presence of an occluded internal carotid artery. Although the sensitivity of the battery described has been 70% for occlusion, with a specificity of 98% (only five false positives), this relatively low sensitivity and the uniform requirement for surgery in the false positive group have led us to conclude that this battery should not be used as a substitute for angiography when the diagnosis of internal carotid occlusion requires to be confirmed. Nevertheless, these noninvasive tests do have a role in alerting the physician to the presence of carotid occlusion and contralateral carotid artery stenosis, allowing more specific planning of any subsequent arteriography required.

Use of a ringed intraluminal graft in the operative management of abdominal aortic aneurysms

The efficacy of a non-sutured technique of anastomosis has been assessed in 20 patients who had bifurcated grafts inserted for aneurysms of the infrarenal aorta. The grafts had rigid Dacron-covered metal rings incorporated at each end and the anastomoses were effected by securing these rings within the lumen of the vessel with a firmly tied Dacron tape. In order to allow access of the ring to the lumen of the aorta it was necessary to employ an intraluminal occlusion balloon catheter for proximal control. The patients included in the study formed a particularly high risk group. There were 12 emergency and 8 elective procedures. The mean duration of the operations was 134 +/- 34 min (+/- s.d.); the mean blood loss during surgery was 3498 +/- 2660 ml (+/- s.d.) and the mean length of inpatient stay after operation was 16 +/- 13 days (+/- s.d.). There were eight postoperative deaths and post-mortem examination, which was allowed in six cases, showed satisfactory appearances of the grafts and anastomoses. The surviving patients have remained free from complications for up to 18 months after operation. A non-sutured technique is possible for most aortic anastomoses but is of limited applicability for iliac and more distal anastomoses. With further technical refinements an intraluminal graft with a non-sutured aortic anastomosis may become a valuable alternative to the conventionally sutured prosthesis in the management of ruptured abdominal aneurysms.

Collagens, laminin, fibronectin, and cytoskeletal composition of cells in syngeneic aortal vein grafts in the rat

The supradiaphragmatic vena cava of the rat was transplanted to the abdominal aorta in syngeneic recipients. The cells and the connective tissue matrix of these grafts were studied 3 days to 12 weeks after transplantation by immunofluorescence staining of the cytoskeletal proteins desmin, vimentin, and myosin. The matrix proteins, collagen Types I and III, laminin, fibronectin, and fibrin(ogen) were similarly demonstrated. Blood coagulation Factor VIII was used as a marker for endothelial cells. Inflammatory cells invaded the graft during Week 1, but later on the grafts were crowded with cells containing vimentin. Intimal thickenings developed already after 1 week. Smooth muscle cells containing desmin proliferated in these thickenings. After transplantation collagen Type I increased in the graft, but collagen Type III rather decreased. During the phase of intense proliferation of smooth muscle cells the media contained a rich matrix of diffusely distributed laminin. The laminin of older grafts was confined mostly to the subintimal zone and to the intimal plaques.

Selection of patients for lumbar sympathectomy

We successfully predicted that patients presenting with critical ischemia of a limb and Doppler ratios greater than or equal to 0.3 would benefit from lumbar sympathectomy alone. However, we found that the procedure failed in 14 per cent of limbs whose ratios were greater than or equal to 0.3. In retrospect, all these patients were found to have deep infection. Had we known this fact prospectively, our predictions for success would have been close to 100 per cent. We were less than 50 per cent successful in predicting failure of the procedure, but the number of patients in this group is too small to draw reliable conclusions. We believe that patients with arm-ankle Doppler ratios greater than or equal to 0.3 whose manifestations of ischemia are limited to the skin will have a greater than 95 per cent chance of receiving a good result from lumbar sympathectomy alone and that this result will be maintained for many years.

Determination of cardiac risk by dipyridamole-thallium imaging before peripheral vascular surgery

To evaluate the severity of coronary artery disease in patients with severe peripheral vascular disease requiring operation, we performed preoperative dipyridamole-thallium imaging in 54 stable patients with suspected coronary artery disease. Of the 54 patients, 48 had peripheral vascular surgery as scheduled without coronary angiography, of whom 8 (17 per cent) had postoperative cardiac ischemic events. The occurrence of these eight cardiac events could not have been predicted preoperatively by any clinical factors but did correlate with the presence of thallium redistribution. Eight of 16 patients with thallium redistribution had cardiac events, whereas there were no such events in 32 patients whose thallium scan either was normal or showed only persistent defects (P less than 0.0001). Six other patients also had thallium redistribution but underwent coronary angiography before vascular surgery. All had severe multivessel coronary artery disease, and four underwent coronary bypass surgery followed by uncomplicated peripheral vascular surgery. These data suggest that patients without thallium redistribution are at a low risk for postoperative ischemic events and may proceed to have vascular surgery. Patients with redistribution have a high incidence of postoperative ischemic events and should be considered for preoperative coronary angiography and myocardial revascularization in an effort to avoid postoperative myocardial ischemia and to improve survival. Dipyridamole-thallium imaging is superior to clinical assessment and is safer and less expensive than coronary angiography for the determination of cardiac risk.

Continuous wave (CW) and pulsed laser effects on vascular tissues and occlusive disease in vitro

Human arterial segments with occlusive defects and acute dog hearts were exposed, in vitro, to high-energy pulsed and continuous wave (CW) laser beams at argon (514 nm) and Nd-YAG (1,064 nm) wavelengths, using various pulse powers, durations and pulse repetition rates. The laser effects included vaporization of plaques in the arterial segments and penetration of the pericardial sac, evaporation of pericardial fluid, and discoloration of tissue with crater-like lesions in the impact zone, all as a result of vaporization of heart muscle tissues. The areas affected and depth of penetration depended on the wavelength, power, pulse duration, and mode of energy deposition. Focused nanosecond Nd-YAG laser pulses at repetition rates of 40-50 Hz caused ablation or vaporization of hard plaques and kidney stones in air and saline. Picosecond (mode-locked) argon laser pulses at repetition rates of 3.8 MHz--average power 6.5 W, peak power of 230 W--caused effective vaporization of hard plaques and kidney stones in air and saline. Picosecond argon laser pulses--average power 1 W, peak power 250 W--were not effective in vaporization. Transmission characteristics of the various types of laser pulses through fiber optic waveguides were determined. The energy and power density required to vaporize fatty and hard plaques and kidney stones were tabulated as a function of laser wavelength, pulse energy, duration, and repetition rates.

Percutaneous transluminal angioplasty of the arteries of the lower limbs: a 5 year follow-up

A total of 482 percutaneous transluminal angioplasties (PTAs) of the arteries of the lower limbs were performed in 411 patients between 1977 and 1983. The 5 year patency rate, calculated by the life table method, was 83% for iliac and 58% for femoropopliteal PTA. Clinical improvement after the procedure was confirmed by a significant drop of the arm-ankle pressure difference: 48 +/- 5 mm Hg before vs 17 +/- 5 mm Hg 2 years after iliac PTA (p less than .01) and 73 +/- 5 mm Hg before vs 28 +/- 6 mm Hg after femoropopliteal PTA (p less than .01). The majority of reocclusions occurred within the first year after angioplasty. Patients with stenoses or occlusions of less than 3 cm had a favorable long-term patency rate of 74%. Conversely, patients with femoropopliteal occlusions presenting with pain at rest, diabetes, occlusions of greater than 3 cm, or poor distal runoff had an elevated rate of reocclusion. Complications, which occurred in 8% of the patients in whom PTA was attempted, included local hemorrhage, dissection, embolism, and spasm necessitating surgical intervention in 2%. No deaths or amputations were a direct consequence of PTA. PTA of arteries of the lower limbs may thus be regarded as a valid complementary treatment to vascular surgery in patients with occlusive disease of the peripheral arteries.

Decreased incidence and mortality of stroke

Dr. Whisnant argues persuasively that control of hypertension has played a major role in the decline of stroke. He offers a cohesive and logical overview on this decline and does so with data from his own vast experience and with the advantages of the Mayo Clinic system which includes a centralized population-based diagnostic index, neurological expertise and a high autopsy rate. However, neither Dr. Whisnant's arguments nor the Mayo Clinic data justify the conclusion that "treatment of hypertension is the only significant contributor to the decline of stroke."

Polyester prostheses as substitutes in the thoracic aorta of dogs. I. Evaluation of commercial prostheses

Using canine models, a representative selection of polyester or Dacron vascular prostheses, including woven, knitted, and velour types, were evaluated for their relative healing characteristics and for their structural changes during implantation. Following residence periods ranging from 4 h to 6 months at the site of the thoracic aorta, the dogs were sacraficed, and the grafts were excized for measurement of the thrombogenicity of the flow surface and for pathological examination by light microscopy and SEM. The kidneys were also removed and examined for infarcts caused by any trapped circulating emboli. The extent of healing, the presence of embolizing nuclei, and the thrombogenicity and morphology of the lumen surface were also assessed. The healing characteristics of each type of device proved similar. Velour fabrics exhibited more extensive encapsulation, but frequently their internal capsules failed to incorporate all the fibers. In all cases, cellular development on the lumen was limited to areas contiguous to the anastomoses. The initial porosity of the devices as measured by water permeability did not appear to influence the healing sequence to a significant extent. The grafts did exhibit differences in structural stability depending on whether they were of a knitted or woven construction. We suggest that users consider these different mechanical and structural properties when making their choice of a graft. Despite these differences, we believe that the healing process is far more host dependent than graft dependent.

Clinical use of noninvasive evaluation of the carotid artery

The noninvasive evaluation of carotid artery disease should include a battery of tests that includes one direct and one indirect assessment of the extracranial carotid arteries. The resulting data should be correlated with the clinical findings and the patient's general status so the risks and benefits of carotid endarterectomy may be determined. These studies are usually outpatient procedures and allow one to determine in the office which patients would benefit from carotid surgery and who should be followed serially. Carotid arteriography is reserved for those patients who will be subjected to surgery. In our hands, the combination of CPA, Kartchner-McRae OPG, and Echoflow fulfill these requirements. In a small number of patients the history, physical examination, and noninvasive studies are inconclusive. For most patients, we are able to make decisions as to the best therapy in the office and can discuss risks and benefits with patients and their families with an accuracy of approximately 95 per cent before hospitalization and arteriography are considered.