In-hospital mortality following carotid endarterectomy

OBJECTIVES: To determine population-based estimates of in-hospital mortality following carotid endarterectomy (CEA) and identify potential risk factors for in-hospital death. METHODS: Data from the Healthcare Cost and Utilization Project (HCUP-3) were analyzed for the year 1993. Nationally representative estimates of risk were calculated by age, sex, race, income, census region, hospital location (urban versus rural), teaching status of hospital, number of hospital beds, hospital ownership, third-party payer, principal procedure, and presence of surgical complications. Multivariate models were developed using stepwise logistic regression and a logit model fit by generalized estimating equations. RESULTS: There were 228 deaths among 18,510 CEAs performed in 17 states of the United States in 1993, yielding an estimated in-hospital mortality rate of 1.2%. Multivariate analysis showed that age, principal procedure, and presence of any surgical complication were significant predictors of in-hospital mortality. Mortality increased with increasing age (from 0.9% in those younger than 65 years to 1.7% in those age 75 and older) and was markedly higher with CEA performed as a secondary procedure (6.1% versus 0.9%) or with any surgical complication (5.9% versus 0.9%). CONCLUSIONS: Increasing age, CEA performed as a secondary procedure, and surgical complications are important predictors of in-hospital mortality following CEA.     

Significance of carotid restenosis following endarterectomy

The purpose of this study was to determine whether Vietnam veterans' risk for posttraumatic stress disorder (PTSD) was correlated with their premilitary school performance. The authors compared both primary and secondary school record data on hospitalized chemically dependent PTSD patients with those of both non-PTSD, chemically dependent and community controls. All participants were male Vietnam war combat veterans. The comparisons were made with MANCOVA analyses with the effects of combat and age differences between groups controlled. For the most part, primary-school grade point average, absenteeism, and tardiness data on three groups did not differ significantly. However, the mean secondary school grade points of the future PTSD patients were generally substantially lower than those of controls. Additionally, more secondary school absenteeism and tardiness were reported among future PTSD patients than in the controls. The groups did not differ significantly on number of extracurricular activities. Academic weakness, absenteeism, and tardiness in secondary school appear to be moderately strong predictors of vulnerability to PTSD after traumatization. It also supports the claim that chronic PTSD is, in part, the result of weaknesses present before exposure to trauma.     

Outcome of selective patching following carotid endarterectomy

OBJECTIVES: Routine patch angioplasty has been advocated following carotid endarterectomy but patching can be associated with complications. This study assesses the effect of a selective patching policy based on distal internal carotid diameter on the rate of restenosis and outcome following carotid endarterectomy. DESIGN, MATERIAL AND METHODS: A consecutive series of 213 patients underwent carotid endarterectomy performed by one surgeon. Preoperative carotid dimensions were measured intraoperatively using calipers. Following endarterectomy a 5mm Dacron patch was selectively employed if the distal internal carotid was 5mm or less (group 1, 95 patients) or 6mm or less (group 2, 118 patients). Patients underwent colour-coded Duplex scanning at 24 h, 1 week, 3, 6, 9, and 12 months, and yearly following this. RESULTS: Overall 27 restenoses (5 residual) of 50% or greater and two occlusions developed. Patching was performed in 47% of group 1 and 61% of group 2 arteries. In group 1 14% of patched compared with 24% of non-patched arteries developed restenosis at 24 months (p=0.4). In group 2 13% of patched compared to 11% of non-patched arteries developed restenosis at 12 months (p>0.5). Stroke rate at 24 months were similar for patched and non-patched patients in groups 1 (p>0.5) and 2 (p=0.4). CONCLUSIONS: This study suggests that patch angioplasty of larger carotid arteries may be unnecessary. Randomisation of larger arteries between patch and primary closure would be required to confirm this.     

Hyperperfusion syndrome following carotid endarterectomy: evaluation using diffusion-weighted magnetic resonance imaging--case report

OBJECTIVE: Epidemiological evidence suggests that resistance to insulin is the common nexus of the accumulation of factors in patients at high cardiovascular risk. To find a test which enables resistance to insulin to be identified in large populations will allow preventive and therapeutic measures to be taken. DESIGN: Crossover. SETTING: Carrascosa del Campo and Cuenca Health Centres. PARTICIPANTS: 408 patients (154 men and 254 women), all the non-diabetic obese patients at the two health centres, were studied. MEASUREMENTS AND MAIN RESULTS: Levels of cholesterol, triglycerides and uric acid were measured. Patients were medically examined, and blood pressure, waist and hip measurements, toxic habits and cardiovascular history were found. They were classified by pathology and normograms. The O'Sullivan and microalbuminuria tests were performed, and all the statistical associations with biochemical and medical characteristics were studied. The O'Sullivan test was significantly associated (p < 0.01) with cardiovascular risk and insulin-resistance factors such as hypercholesterolaemia (RR 1.63), hypertension (RR 1.92), hypertriglyceridaemia (RR 2.47), hyperuricaemia (RR 1.80), with the Berglund resistance index (RR 1.52) and the microalbuminuria test (RR 1.83). The association was more consistent when there were a number of factors combining. There was no relationship with the waist/hip index found. CONCLUSION: The O'Sullivan test, on its own or with the microalbuminuria test, seems very useful for identifying obese subjects with resistance to insulin.     

Cerebral Ischemia during carotid endarterectomy with severe but reversible changes

Electroencephalographic monitoring of a patient during carotid endarterectomy demonstrated severe ipsilateral voltage suppression with preservation of rhythms when the common carotid artery was clamped. Because the atheromatous plaque extended almost to the base of the skull, it was impossible to insert a shunt. Occlusion time was 19 minutes. After carotid flow was re-established, there was a rapid recovery of voltage. The patient awoke with a profound hemiparesis, but this cleared almost completely within a week. The EEG changes indicated severe ischemia, but, though function was transiently impaired, there was no apparent cerebral necrosis. This case represents the most severe yet reversible episode of ischemia during carotid clamping reported to date. Preservation of EEG rhythms, even in the face of voltage suppression, may have been a favorable sign.     

Cerebral hemodynamics during carotid massage in patients with carotid sinus syndrome

The effect of cardioinhibition and/or vasodepression on cerebral hemodynamics assessed by transcranial Doppler has been investigated during carotid massage in 11 patients (62-87 years, mean age 72) with carotid sinus syndrome. The patients were tested in the OOO mode (n = 11) with six tested in the DDD mode. Carotid massage in the OOO mode decreased mean arterial pressure by 44% (P < 0.01) and mean cerebral blood flow velocity by 50% (P < 0.01). Although not significant, cerebrovascular resistance increased transiently by 17% during massage, then decreased by 31% upon recovery. Carotid massage in the DDD mode decreased arterial pressure by 30% (P < 0.01), cerebral blood velocity by 23% (P < 0.01), and resistance by 15% (P < 0.05). The decreased cerebral perfusion induced by cardioinhibition and/or vasodepression results from the delayed onset of cerebral autoregulation. Pacing in the DDD mode temporarily assists the critical period preceding the onset of cerebral autoregulation that plays a key role in preventing the deleterious effects of vasodepression.     

Neuropsychologic effects of carotid endarterectomy

This study assessed neuropsychologic changes after internal carotid endarterectomy using a design that limited the confounding effects of surgical and anesthesiological stress. Twenty-eight patients (mean age = 65.9 years, SD = 8.4, range 45-79), underwent extensive neuropsychological assessment before and on the seventh day after carotid endarterectomy for symptomatic carotid stenosis greater than 75%. A similarly assessed control group of 30 patients underwent elective orthopaedic surgery. A third cognitive assessment was performed 4 months postoperatively on a subgroup of the study patients. No significant cognitive change occurred in the control group. The study patients showed significant improvement in verbal memory, constructive abilities, verbal attainment, and visual attention; a trend towards further improvement of verbal functions was evident at the late postoperative assessment. No side-specific cognitive change was observed. In conclusion, carotid endarterectomy performed for currently accepted indications significantly improves several cognitive functions.     

Prospective study of carotid endarterectomy and contralateral carotid occlusion

A total of 700 patients who had carotid endarterectomy (CEA) in the UK and Ireland during a 6-month interval between March and August 1994 were studied prospectively. Some 108 patients (15.4 per cent) had a contralateral internal carotid artery occlusion. Previous reports have shown an associated stroke rate of about 10 per cent in these patients. This study assessed complications and outcome for patients undergoing CEA with contralateral internal carotid artery occlusion compared with those without. The indications for surgery were comparable between the two groups although the patients with occlusion had a slightly higher incidence of arrhythmia and stroke. Intraoperative shunts were used in a significantly higher proportion of those with occlusion (83.3 versus 64.7 per cent, P = 0.0001). The combined death and stroke rate for patients with occlusion was 5.6 per cent compared with 2.4 per cent for the remainder (P not significant). On the basis of the present data, CEA with a contralateral carotid artery occlusion carries only a slight increase in the rate of postoperative stroke and death. This increase was not statistically significant and is lower than that reported previously.     

Plastic repair of the carotid artery in carotid endarterectomy

The work is based on an analysis of results of 70 carotid endarterectomies performed on 68 patients aged from 43 to 67 years. 53% of the patients were operated upon at the stage of a relative compensation of brain blood circulation. Multiple character of injuries of the brachiocephalic arteries took place in 70.5% of the cases. Plasty of the internal carotid artery is thought by the authors to be necessary by means of using a flap of lyophylized allopericardium, with the diameter of its orifice less than 8 mm.     

Determinants of outcome after carotid endarterectomy

BACKGROUND: The efficacy of carotid endarterectomy for selected patients has been evaluated with randomized controlled clinical trials. The generalizability of these studies to average surgical practice remains an important public health concern. OBJECTIVE: The objective of the study was to determine the predictors of outcome after carotid endarterectomy on a regional basis. Patients and Methods: The study was designed as a retrospective cohort study and included all consecutive patients presented for carotid endarterectomy at the 8 University of Toronto-affiliated hospitals in the period from January 1, 1994, to December 31, 1996. The main outcome measure was 30-day postoperative stroke or death rate. RESULTS: During the study interval, 1280 primary carotid endarterectomies were performed. The overall combined stroke and death rate was 6.3% for all patients who underwent endarterectomy (4.0% for patients who were asymptomatic). The significant predictors of poor outcome were the following: presenting symptoms (odds ratio, 1.74; 95% confidence interval [CI], 0.96, 3.12), low surgeon volume (<6 cases per year; odds ratio, 3.98; 95% CI, 1.65, 9.58), and left-sided surgery (odds ratio, 1.72; 95% CI, 1.07, 2.76). CONCLUSION: These data suggest that adoption of the recommendations of the symptomatic carotid endarterectomy trials is appropriate. However, endarterectomy for asymptomatic lesions remains of uncertain benefit on a regional basis and must be individualized to the experience of the specific surgeon. The surgeon volume/outcome relationship that is identified in this study suggests a need for a minimum volume threshold for this procedure.     

Mural thrombosis after experimental carotid endarterectomy

The incidence of mural thrombosis following three types of experimental intimal injuries at common carotid arteries, was investigated in a series of 12 dogs. Mural thrombosis was obtained at each of the intimal lesions. Moreover, obstructive thrombosis occurred in three instances. Further investigation of thrombi revealed that partial fragmentation occurred when exposed to hydrodynamic forces. These results suggest that mural thrombosis following carotid endarterectomy in humans, is possibly more frequent and significant than it is generally appreciated, thus leading to the consideration of postoperative anticoagulation after endarterectomy, as a means to minimize the incidence of postoperative embolic cerebrovascular accidents.     

Predictive value of carotid artery stump pressures during carotid endarterectomy

The ideal method of monitoring cerebral perfusion during carotid endarterectomy remains controversial. This article reviews many of the larger studies in the literature that have attempted to evaluate the usefulness of carotid artery stump pressure. Topics discussed include stump pressure alone, regional anesthesia, stump pressure and EEG, and stump pressures and transcranial Doppler ultrasonography.