Spontaneous and chemically induced proliferative lesions in Tg.AC transgenic and p53-heterozygous mice

The prevention of stroke in patients with carotid pathology has been traditionally carried out with either medications that prevent clot formation (i.e., warfarin or antiplatelet agents) or revascularization of stenotic segments of the artery by surgical means (i.e., carotid endarterectomy). Recently, the use of percutaneous endovascular techniques, to treat lesions of the carotid artery has become increasingly popular. The most important techniques being used for this purpose are balloon angioplasty and stenting. Although still under intense investigation, it is already clear that endovascular therapy of the carotid artery is effective in the correction of lesions not readily accessible by surgery, those due to recurrent stenosis after endarterectomy, those not of an atherosclerotic nature, and those with unusually high surgical morbidity and mortality. The role of endovascular therapy in the treatment of type A lesions, which are perfect for endarterectomy, awaits the completion of prospective randomized trials. However, care must be exercised in the planning of these trials to allow a fair testing of the endovascular procedures.     

Elective stenting of carotid artery stenosis in patients with severe coronary artery disease

AIMS: To evaluate the feasibility and safety of elective carotid stent implantation in patients with carotid stenoses and concomitant coronary artery disease, as an alternative to combined carotid and coronary surgery. METHODS: We treated 50 patients with >70%, stenoses in 53 carotid arteries with balloon angioplasty followed by elective stent implantation. All patients had severe coronary artery disease, and/or mitral insufficiency, aortic stenosis, rhythm disorders or generalized arteriosclerosis. In three patients the opposite carotid artery was occluded; nine patients had bilateral stenoses of which two received stents bilaterally. RESULTS: Fifty-six successful stent implantations (42 Wallstents, eight BeStents, two AVE-Microstents, one Palmaz Schatz stent, three Sito stents) were performed, reducing the baseline percent stenosis from 78 +/- 18%, to 13 +/- 11%. Complications included three transient ischaemic attacks, one minor and one major stroke. Follow-up was available for 46 patients over a mean of 10 months. Three asymptomatic restenoses and one deformation of a BeStent occurred. CONCLUSION: Our preliminary results indicate that carotid artery stenting in patients with concomitant severe coronary artery disease is feasible, safe, and may be an alternative to combined carotid and coronary surgery.     

The effects of pictorial versus tangible stimuli in stimulus-preference assessments

OBJECTIVES: The purpose of this study was to compare 3-year risk-adjusted survival in patients undergoing coronary artery bypass graft (CABG) surgery and percutaneous transluminal coronary angioplasty. BACKGROUND: Coronary artery bypass graft surgery and angioplasty are two common treatments for coronary artery disease. For referral purposes, it is important to know the relative pattern of survival after hospital discharge for these procedures and to identify patient characteristics that are related to survival. METHODS: New York's CABG surgery and angioplasty registries were used to identify New York patients undergoing CABG surgery and angioplasty from January 1, 1993 to December 31, 1995. Mortality within 3 years of undergoing the procedure (adjusted for patient severity of illness) and subsequent revascularization within 3 years were captured. Three-year mortality rates were adjusted using proportional hazards methods to account for baseline differences in patients' severity of illness. RESULTS: Patients with one-vessel disease with the one vessel not involving the left anterior descending artery (LAD) or with less than 70% LAD stenosis had a statistically significantly longer adjusted 3-year survival with angioplasty (95.3%) than with CABG surgery (92.4%). Patients with proximal LAD stenosis of at least 70% had a statistically significantly longer adjusted 3-year survival with CABG surgery than with angioplasty regardless of the number of coronary vessels diseased. Also, patients with three-vessel disease had a statistically significantly longer adjusted 3-year survival with CABG surgery regardless of proximal LAD disease. Patients with other one-vessel or two-vessel disease had no treatment-related differences in survival. CONCLUSIONS: Treatment-related survival benefit at 3-years in patients with ischemic heart disease is predicted by the anatomic extent and specific site of the disease, as well as by the treatment chosen.     

Carotid artery repair for radiation-associated atherosclerosis is a safe and durable procedure

OBJECTIVE: The development of carotid atherosclerosis after neck irradiation is well documented. There has been concern about the safety and durability of carotid artery repair through a radiated field. The objective of this report is to describe the immediate and long-term results of a series of cases collected in a 13-year interval. METHODS: From 1984 to 1997, 24 patients underwent 26 carotid artery operations. All the patients had undergone prior radiation therapy at a mean interval of 17 years, with an average radiation dose of 6300 rad. Severe scarring of the skin or radiation fibrosis were present in two thirds of the patients, with 4 patients having permanent tracheostomies. The indications for carotid surgery included cerebral or monocular transient ischemic attack (58%), asymptomatic high-grade stenosis (27%), prior stroke (12%), and tumor invasion of the carotid artery (4%). General anesthesia was used with selective shunting on the basis of carotid artery back pressure or electroencephalography monitoring. Patch angioplasty closure was used in 79% of the patients. The operations included standard carotid endarterectomy (n = 20), external carotid endarterectomy (n = 2), carotid patch angioplasty alone (n = 2), aortocarotid bypass grafting (n = 1), and carotid interposition grafting (n = 1). Four patients required skin grafting or myocutaneous flaps. RESULTS: No deaths or strokes occurred within 30 days of the operations. Six patients had transient cranial nerve palsy, and two had wound infections. The patients were followed from 1 to 156 months, with six patients being followed for longer than 18 months. No strokes were seen at late follow-up examination. Duplex scan examination documented one occlusion, in a patient with primary closure, and two restenoses, one of which necessitated reoperation. The remainder of the grafts were widely patent. CONCLUSIONS: Carotid surgery after neck irradiation is safe and durable. The long-term patency rates and the protection against subsequent neurologic events are similar to the results obtained in the absence of radiation therapy. Problems of wound healing were not found in this series.     

Angioplasty of the occluded internal carotid artery

PURPOSE: To review patients who have presented with acute strokes from a middle cerebral artery occlusion in whom in addition to the middle cerebral artery thromboembolus, an internal carotid artery occlusion has been present, and in whom angioplasty of these totally occluded internal carotid arteries has bee n successful. METHODS: We reviewed retrospectively our experience in treating a cute stroke patients with intracranial, intraarterial urokinase. Six of 27 patients had internal carotid artery occlusions in addition to middle cerebral artery occlusions. Two patients presented with spontaneous carotid dissections for wh ich no further intervention from the ipsilateral internal carotid artery was attempted. In the remaining four internal carotid artery occlusions secondary to atherosclerotic disease, standard guide wires and catheters were negotiated across the level of the internal carotid artery occlusion, which expedited intracranial catheterization for thrombolysis. Subsequently, angioplasty of the internal carotid artery was performed. RESULTS: All four occluded internal carotid arteries could be traversed. No new neurologic deficits occurred. No vascular injuries occurred. No deaths occurred. Four- to 6-month follow-up showed all four internal carotid arteries remained patent. CONCLUSION: In acute occlusions of the internal carotid artery from atherosclerosis, the occluded vessel can sometimes be recanalized with low morbidity. In addition, endovascular access to the intracranial circulation can be expedited by using the recanalized internal carotid artery.     

Quantitative detection of Sphingomonas chlorophenolica in soil via competitive polymerase chain reaction

PURPOSE: To develop an ex vivo human carotid artery stenting model that can be used for the quantitative analysis of risk for embolization associated with balloon angioplasty and stenting and to correlate this risk with lesion characteristics to define lesions suitable for balloon angioplasty and stenting. METHODS: Specimens of carotid plaque (n = 24) were obtained circumferentially intact from patients undergoing standard carotid endarterectomy. Carotid lesions were prospectively characterized on the basis of angiographic and duplex findings before endarterectomy and clinical findings. Specimens were encased in a polytetrafluoroethylene wrap and mounted in a flow chamber that allowed access for endovascular procedures and observations. Balloon angioplasty and stenting were performed under fluoroscopic guidance with either a Palmaz stent or a Wallstent endoprosthesis. Ex vivo angiograms were obtained before and after intervention. Effluent from each specimen was filtered for released embolic particles, which were microscopically examined, counted, and correlated with various plaque characteristics by means of multivariate analysis. RESULTS: Balloon angioplasty and stenting produced embolic particles that consisted of atherosclerotic debris, organized thrombus, and calcified material. The number of embolic particles detected after balloon angioplasty and stenting was not related to preoperative symptoms, sex, plaque ulceration or calcification, or artery size. However, echolucent plaques generated a higher number of particles compared with echogenic plaques (p < 0.01). In addition, increased lesion stenosis also significantly correlated with the total number of particles produced by balloon angioplasty and stenting (r = 0.55). Multivariate analysis revealed that these two characteristics were independent risk factors. CONCLUSIONS: Echolucent plaques and plaques with stenosis > or = 90% produced a higher number of embolic particles and therefore may be less suitable for balloon angioplasty and stenting. This ex vivo model can be used to identify high-risk lesions for balloon angioplasty and stenting and can aid in the evaluation of new devices being considered for carotid balloon angioplasty and stenting.     

Carotid endarterectomy for asymptomatic carotid artery stenosis: patients with severe bilateral disease a high risk subgroup

Carotid endarterectomy if advised for asymptomatic disease must be associated with a low peri-operative morbidity and mortality and satisfactory long-term results. Over a 12 year period between 1978-1989 181 carotid endarterectomies were performed on 163 patients with asymptomatic carotid artery stenosis. There were 112 males and 51 females with a mean age of 64.9 years. All patients had a high-grade lesion (> 70% stenosis). The combined operative mortality and stroke rate was 2.8%. On long-term follow up six patients suffered a stroke. Only one patient however sustained a stroke in the same territory as the previously operated carotid artery. Four years following surgery 78% of patients were alive. Carotid restenosis or occlusion occurred in 8.3% of the remaining patients, all of whom were asymptomatic. All the immediate postoperative strokes occurred in patients with severe bilateral carotid artery disease. These patients with severe bilateral disease appear to constitute a high risk sub-group for peri-operative stroke. The role of 'normal pressure-hyperperfusion breakthrough' syndrome as the presumed aetiology of two of the postoperative cerebral haemorrhages is discussed.     

Renal artery angioplasty for renovascular hypertension and preservation of renal function: long-term angiographic and clinical follow-up

OBJECTIVE: Percutaneous transluminal angioplasty of stenoses of the renal artery can be used to treat hypertension and renal insufficiency. Although many studies have been published on the short-term results of this procedure, few long-term studies are available. SUBJECTS AND METHODS: One hundred ninety-five patients (123 men and 72 women 19-79 years old; mean age, 56 years) with stenosis of the renal artery and hypertension underwent renal percutaneous transluminal angioplasty at our institution. The stenosis was unilateral in 66% of patients, bilateral in 26%, and in a solitary functioning kidney in 8%. Renal insufficiency was present in 31% of patients. After renal percutaneous transluminal angioplasty, long-term clinical and angiographic follow-up was evaluated by life-table analysis. RESULTS: In patients with fibromuscular disease, blood pressure returned to normal in 57%, improved in 21%, and was unchanged in 21%. In patients with atherosclerotic stenosis, blood pressure returned to normal in 12%, improved in 51%, and was unchanged in 37%. After percutaneous transluminal angioplasty, renal function improved in 48% of patients with renal insufficiency due to bilateral stenosis or stenosis in the single functioning kidney, whereas none of the patients with unilateral stenosis of renal artery and renal insufficiency had any notable improvement. Long-term follow-up showed a high rate (82%) of patency of revascularized arteries and a low rate (21%) of hypertension recurrence at 5 years. CONCLUSION: Renal percutaneous transluminal angioplasty is useful for treating hypertension and for reestablishing renal function. Its effects on blood pressure and renal function are long-lasting in the large majority of patients.     

Stent deployment resolves a petrous carotid artery angioplasty dissection

A patient with a symptomatic petrous carotid artery stenosis underwent balloon angioplasty, which was complicated by a flow-limiting dissection. The problem was resolved by deploying a balloon-expandable coronary stent. The patient suffered no neurologic deficit, was discharged within 12 hours, and was asymptomatic at last follow-up, 5 months after the procedure, without warfarin therapy. This therapeutic option may prove useful as a means to correct endovascular procedural complications.     

Protease-catalyzed synthesis of Leu-enkephalin in a solvent-free system

Percutaneous transluminal angioplasty (PTA) is a well-established treatment for patients with stenosis of limb arteries. However, its efficacy for treatment of severe stenosis and occlusions of the subclavian artery is unclear. We attempted to recanalize the subclavian artery in 30 patients with severe stenosis or total occlusion of proximal subclavian artery and successful outcomes were seen in 27 cases (90%). In two patients the regional arterial thrombolysis with the PTA prcedure we used was found successful. There was no severe complications. During an average 6-month follow-up stenosis recurred in 2 patients, but the subclavian artery was recanalized by repedted PTA.     

Expanded polytetrafluoroethylene patch angioplasty in carotid endarterectomy

PURPOSE: This study retrospectively reviewed the experience with expanded polytetrafluoroethylene (ePTFE) patches for carotid endarterectomy in 924 consecutive procedures (753 patients) during a 17-year period. METHODS: The records of all patients who underwent ePTFE patch angioplasty for carotid artery stenosis performed by one surgeon were reviewed. The criterion for surgery was stenosis of 80% or greater. Follow-up by use of noninvasive methods was done by 6 months after operation the first year and annually thereafter. Recurrent stenosis was confirmed with angiography. Life-table analysis was used to estimate the risk of restenosis. RESULTS: Early morbidity and mortality included six deaths (0.6%), seven nonfatal strokes (0.9%), and 19 hemorrhages. Two postoperative infections occurred. There were no important aneurysmal dilations and no late hemorrhages. With a mean follow-up of 41.4 months (range 0 to 197), recurrent stenosis necessitating reoperation developed in 28 patients (3.7%). There were two late strokes. Life-table analysis indicated a 89% probability of freedom from stenosis at 120 months. CONCLUSIONS: In cases in which the decision to perform patch angioplasty is made at surgery, an ePTFE patch is an excellent alternative to autogenous saphenous vein, with a low rate of recurrences requiring operation and acceptable rates of perioperative and postoperative morbidity and mortality.     

Delayed full-thickness grafting of lower leg defects following removal of skin malignancies

Cerebral stroke is a serious complication related to carotid endarterectomy (CEA), being most frequently caused by thromboembolic events and less frequently on account of cerebral haemorrhage. The present series comprised five out of 857 (0.6%) patients who had undergone CEA at Oulu University Hospital between the years 1974 and 1993 and suffered a postoperative stroke four to 13 days after surgery due to intracerebral haemorrhage (IH). Preoperatively, all these patients were neurologically intact, with transient ischaemic attacked (TIA) as the main indication for CEA. All five patients had a history of arterial hypertension treated adequately preoperatively, and one patient had high blood pressure levels after surgery. Critical ipsilateral stenosis of the internal carotid artery (> 90%) was detected in the preoperative angiogram in all five cases. The primary outcome after CEA was uneventful in every case, without any signs of neurological deficiency. The symptoms, comprising severe headache, convulsions and/or hemiparesis occurred suddenly four to 13 days (mean seven days) after CEA. The diagnosis of IH was based on computed tomography (CT) findings. All five patients were treated conservatively. Three of them died. We conclude that even normotensive, neurologically intact patients without demonstrable cerebral infarction or postoperative hypertension may suffer cerebral haemorrhage after the relief of high-grade carotid stenosis. The role of possible insufficiency of the autoregulatory mechanisms of the cerebral vasculature on account of long-standing critical stenosis of the internal carotid artery and subsequent uncontrolled hyperperfusion following CEA are discussed.     

Extrathoracic bypass procedures for proximal common carotid artery lesions

During a 10-year period ending in December 1991, 31 extrathoracic bypass procedures were performed in 29 patients for proximal common carotid artery atherosclerotic stenosis or occlusion. This included 16 men and 13 women, with a mean age of 63 years. Indications for surgery included transient ischemic attacks in 23 patients (79%), nonfocal symptoms in 4 patients (14%), and asymptomatic proximal common carotid artery stenosis associated with near-total occlusion of the internal carotid artery in 2 patients (7%). Severe proximal stenosis or complete occlusion of the common carotid artery was demonstrated angiographically in all cases. Subclavian-to-carotid bypass was performed in 26 cases and carotid-to-carotid bypass in 5 cases. Seventy-four percent of the bypass procedures were to the common carotid artery and 26% to the external carotid artery. Endarterectomy of the common carotid bifurcation was performed in conjunction with the bypass procedure in 13 cases and vertebral artery transposition in 2 other cases. Saphenous vein was used as the bypass conduit in 65% and prosthetic grafts in 35% of cases. There were no perioperative strokes or deaths in this series, and the mean postoperative hospital stay was 5 days. Follow-up ranged from 2 to 118 months (mean: 38.4 months). Graft occlusion occurred in two cases during the follow-up period (3-year patency rate: 90%), with recurrence of symptoms in one patient, which necessitated revision. Three patients had persistence or recurrence of symptoms despite patency of the graft, one other patient sustained a posterior circulation infarct, and there was one death unrelated to carotid vascular disease during the follow-up period. This experience shows that extrathoracic bypass procedures are safe and well tolerated for symptomatic proximal common carotid artery stenosis or occlusion. This method of reconstruction has excellent long-term patency and protection against further anterior circulation neurologic events.     

Prevalence of asymptomatic carotid stenosis in patients undergoing infrainguinal bypass surgery

BACKGROUND: The prevalence of asymptomatic carotid stenosis in patients with lower-extremity ischemia is unknown. This report represents the largest carotid screening program to date of patients undergoing leg bypass. DESIGN: Patients undergoing infrainguinal bypass from 1987 through 1993 on the vascular surgery service at Oregon Health Sciences University, Portland, underwent routine carotid duplex examinations to detect the presence of asymptomatic carotid stenosis. PATIENTS: During the study period, 352 patients underwent infrainguinal revascularization for ischemia, of whom 225 (64%) had no prior carotid surgery, carotid arteriography, or cerebrovascular symptoms. There were 117 men and 108 women, with a mean age of 67 years. The indication for surgery was limb salvage in 67% and claudication in 33% of patients. RESULTS: Sixty-four patients (28.4%) who required lower-extremity revascularization had hemodynamically significant asymptomatic carotid artery stenosis or occlusion; 12.4% had stenosis of 60% or greater, the qualifying level for randomization in the Asymptomatic Carotid Atherosclerosis Study. Based on these findings, eight patients with carotid stenosis of 80% or greater underwent elective carotid endarterectomy. There were no postoperative neurologic events in the 225 leg bypass patients. By multivariate logistic regression analysis, the presence of carotid bruit (P < .001) and the presence of rest pain (P = .006) were associated with carotid stenosis of 50% or greater. Limiting screening to patients with carotid bruit, limb salvage indications for surgery, and/or advanced age excluded significant numbers of patients with stenosis; thus, these were not effective screening strategies. CONCLUSION: Screening carotid duplex scanning is indicated in patients who require lower-extremity revascularization.     

Atherosclerotic ischemic renal disease

Over the past decade, ischemic nephropathy has gained recognition as a distinct and treatable clinical entity. Atherosclerotic renal artery stenosis is the leading cause of ischemic renal disease. Among the aging population entering renal replacement programs, both renal artery and systemic atherosclerosis are common. Over recent years, patients with ischemic renal disease are presenting later and have diffuse atherosclerosis and other comorbid conditions. Improved screening techniques, patient selection, and interventional approaches have resulted in better outcomes in most centers. Percutaneous transluminal renal angioplasty has emerged as the treatment of choice in some centers for nonostial renal artery stenosis. Both percutaneous transluminal renal angioplasty and surgical repair have proven beneficial for renal function salvage. Many studies have elegantly demonstrated the pathophysiologic consequences of acute ischemia to the kidney. The concepts derived from acute studies have served as a springboard for considering the adaptive and maladaptive renal responses to chronic ischemia.     

Shortening and reimplantation for tortuous internal carotid arteries

PURPOSE: The purpose of this study was to assess the outcome after the shortening and reimplantation of tortuous internal carotid arteries to prevent kinking after endarterectomy. METHODS: Through a review of prospective records, we studied patients who underwent carotid endarterectomy (CEA) (n = 233) between 1993 and 1996 who had symptomatic stenosis of the internal carotid artery (ICA) of more than 70%. An elongated proximal ICA was excised, and the ICA was reimplanted into the bifurcation in 30 (13%) patients, with additional patch angioplasty in 5 patients. Of the remaining 203 patients, 50 (21%) had Dacron patch angioplasty, and the rest had conventional CEA with simple closure. RESULTS: In the reimplanted group, one patient had a minor stroke with complete recovery on discharge. Three patients (10%) had neck hematomas requiring reexploration, but in none of these was the bleeding from the artery. At mean follow-up of 15 months, 93% of the arteries were widely patent. Significant stenosis secondary to neointimal hyperplasia was detected in only two patients, for a restenosis rate of 6.7%, which is in line with other published reports. In the control group, 8 (3.9%) patients had perioperative transient ischemic attacks, 5 (2.5%) had strokes, and 13 (6.4%) had hematomas requiring evacuation. At follow-up, 14 (6.9%) of the arteries had restenosed. CONCLUSION: In carotid surgery, reconstructive techniques must be tailored to operative findings. Excision of a tortuous elongated proximal ICA with reimplantation is not associated with additional mortality or morbidity rates over those of conventional CEA alone and has the advantage of removing disease at the bifurcation. This procedure was carried out in 13% of our patients and should be a procedure with which the vascular surgeon is familiar.     

Radiation exposure of the population by roentgen diagnosis. II. The collective effective dosage of the population in former East Germany caused by 1987/1988 roentgen diagnosis

OBJECTIVES: To examine the relations between the development of neurologic events and the following variables: degree of stenosis of the contralateral carotid artery, prior neurologic symptoms and stump pressure of the ipsilateral internal carotid artery in patients undergoing carotid endarterectomy under regional anesthesia. PATIENTS AND METHODS: We undertook a prospective study of 92 patients undergoing carotid endarterectomy with a blockade of the superficial and deep cervical plexus. Neurological integrity was assessed and internal carotid artery stump pressure was monitored. Contralateral carotid artery stenosis and neurologic disease present before surgery were studied. RESULTS: Neurologic events developed when the carotid artery was clamped in 9.7% of patients. Mean stump pressure was significantly lower in symptomatic patients (43 +/- 11 mmHg) than in asymptomatic patients (74.6 +/- 24 mmHg) (p < 0.001). Neurologic symptoms developed during clamping of the carotid in 27.2% of the patients with stump pressure less than or equal to 50 mmHg, but in only 4.2% of those with stump pressure surpassing 50 mmHg. Stump pressure was significantly lower in patients with contralateral carotid stenosis. The incidence of neurologic events during clamping was unrelated to contralateral carotid condition, however. Likewise, neurologic symptoms before surgery was also unrelated. In six of the nine patients with neurologic events, internal carotid stump pressure was less than or equal to 50 mmHg, indicating that the sensitivity of this parameter to the development of neurologic events in our series was 66%. CONCLUSIONS: Although internal carotid artery stump pressure identifies a subset of patients likely to have a higher incidence of neurologic events during carotid artery clamping, it can not be considered the only criterion for placement of an intraluminal shunt to prevent such events. The state of the contralateral carotid artery and preexisting neurologic symptoms are not objective screening criteria for identifying patients at high risk of neurologic events during carotid clamping.     

Reduced visual acuity in elderly people: the role of ergonomics and gerontechnology

Branch pulmonary artery stenosis is a common problem in pediatric cardiology. Treatment has included surgery, balloon angioplasty, and balloon expandable stent placement. It was the purpose of this investigation to demonstrate the cost-effectiveness of each of these modes of treatment. From 1983 to 1994 there were 30 patients admitted for treatment of branch pulmonary artery stenosis only. Data included age at procedure, sex, primary diagnosis, acute and intermediate term success, and complications. Acute success was defined by results at the end of the procedure where intermediate term (IT) success was defined by results at follow-up. Success of a procedure was defined by at least one of the following: an increase in vessel diameter by >/=50% of predilation diameter, a decrease in right ventricular to left ventricular or aortic systolic pressure ratio by >/=20%, or a decrease in peak to peak pressure gradient by >/=50%. The procedure was considered a failure if the previously mentioned criteria were not met or if the patient required a second procedure for the same stenosis. The expense of the procedure (estimated by using the patient charges) were collected from the time of the procedure until December 1994. Because of differing lengths of follow-up, the patients were analyzed separately for procedures and outpatient charges. The total charges were corrected to 1994 dollars using the Medical Consumer Price Index. Thirty patients had 46 separate procedures (12 patients had >1 procedure and 3 had >2 procedures). There were 13 surgeries, 13 balloon angioplasties, and 20 stents. Stents were the most successful (90% acute and 85% IT), but were not statistically superior to surgery (62% acute and IT). Balloon angioplasty was significantly less successful as compared with stents (31% acute and 23% IT), and was not statistically different from surgery over the acute and intermediate term. The charge data showed balloon angioplasty was the least expensive followed by stents and then by surgery. The average total charges per procedure, including outpatient charges, were: surgery $58,068 +/- $4372 (standard error), balloon $21,893 +/- $5019, stents $33,809 +/- $3533 (p < 0.001); excluding outpatient charges: surgery $52,989 +/- $3649, balloon $15,653 +/- $1691, and stents $29,531 +/- $2241 (p < 0.001). Average total charges per patient, including all procedure types and grouped by initial procedure, were: surgery $53,707 +/- $6388, balloon $50,040 +/- $8412, and stent $34,346 +/- $3488 (p = 0.047). Stents were at least as effective as surgery and were more effective than balloon angioplasty in both acute and intermediate term follow-up. Balloon angioplasty was least expensive per procedure but was also least effective. Therefore, intravascular balloon expandable stents are the most cost-effective means available in the treatment of branch pulmonary artery stenosis.     

Risk factors for stroke after cardiac surgery: Buffalo Cardiac-Cerebral Study Group

PURPOSE: The purpose of this study was to identify risk factors for stroke in patients undergoing heart surgery. METHODS: A retrospective chart review of patients who underwent cardiac surgery in three hospitals of the State University of New York at Buffalo system over a 36-month period was completed. Demographics and risk factors were recorded, and stroke and death were determined by chart review. Carotid artery stenosis was determined by duplex examination. Data were analyzed by chi-squared and multiple logistic regression. RESULTS: One thousand one hundred seventy-nine cases were analyzed, with a mortality rate of 2.3%, stroke rate of 1.6%, and combined stroke/death rate of 3.1%. Four variables were found to be associated with an increased risk of stroke: carotid artery stenosis greater than 50%, redo heart surgery, valve surgery, and prior stroke. Five variables were associated with increased mortality rates:; carotid artery stenosis greater than 50%, redo surgery, peripheral vascular disease, longer pump time, and hypercholesterolemia. Carotid artery stenosis greater than 50% was present in 14.7% of cases. Carotid artery stenosis greater than 75% was not itself associated with increased stroke risk. Most strokes occurred more than 24 hours after surgery. Stroke distribution did not correlate with site of carotid artery stenosis greater than 50%. CONCLUSIONS: Most neurologic events after heart surgery occur in a subset of patients who can be defined before operation. Whereas carotid artery stenosis greater than 50% is a strong risk factor, the role of prophylactic endarterectomy is unclear. Future studies should focus on this high-risk subgroup. A prospective study of prophylactic carotid endarterectomy in patients undergoing coronary artery bypass grafting is needed.     

Three-dimensional ultrasound study of carotid arteries before and after endarterectomy; analysis of stenotic lesions and surgical impact on the vessel

BACKGROUND and PURPOSE: It has been proved that symptomatic patients with severe carotid stenosis benefit from endarterectomy. Currently used methods for quantitation of the severity of carotid stenosis have limitations, and the impact of endarterectomy on the operated region of carotid artery remains unknown. The purpose of this study was to examine the accuracy of a 3-D ultrasound system for quantitation of stenotic lesions and to evaluate changes in regional vessel volume and cross-sectional area after carotid endarterectomy. METHODS: We studied 14 patients with both carotid angiography and 3-D ultrasound. Of 13 patients who underwent surgery, 12 were reexamined with 3-D ultrasound after surgery. The length and volume of 20 randomly selected plaques were measured from 3-D data sets. The severity of stenosis was quantified by 3-D ultrasound using both a diameter method and an area method on cross-sectional views at the most stenotic site; the results were then compared with those from carotid angiography. The segmental vessel volume and average cross-sectional area of the operated artery both before and after endarterectomy were measured from 3-D ultrasound data. RESULTS: Good correlation was obtained between 3-D ultrasound and carotid angiography in quantitative analysis of carotid stenosis (SEE=12.4%, r=0.76, and mean difference=7.0+/-12.3% with the diameter method; SEE=10.5%, r=0.82, and mean difference=1.8+/-10.5% with the area method by 3-D ultrasound). 3-D ultrasound had excellent reproducibility and small intraobserver and interobserver variability in plaque length and volume measurements. No significant changes in segmental vessel volume and average cross-sectional area of the operated artery were observed after surgery in patients with suture closure. However, a significant increase in segmental vessel volume was obtained in patients with polyfluorethylene patches applied to the surgical opening of the artery. CONCLUSIONS: 3-D ultrasound can be used for both qualitative and quantitative analysis of plaques in the carotid artery and to detect and quantify significant carotid stenosis. Its volumetric potential has important clinical implications in serial follow-up studies for observing the progression or regression of stenotic lesions and for evaluating the outcome of interventional procedures such as endarterectomy or stent placement.