Advanced carotid disease in patients requiring aortic reconstruction

Estenose carotídea acima de 70% em pacientes no pré-operatório de cirurgia da aorta abdominal: freqüência e fatores de risco

OBJETIVO: Analisar a freqüência e os fatores de risco associados à estenose carotídea acima de 70% em pacientes que serão submetidos a cirurgias de aorta abdominal. MATERIAL E MÉTODO: Foram analisados 94 pacientes que realizaram ultra-som Doppler de carótidas no pré-operatório de cirurgias de aorta abdominal entre janeiro de 2000 e janeiro de 2003, pela disciplina de Cirurgia Vascular da Santa Casa de São Paulo. RESULTADOS: Sessenta e sete pacientes (71%) eram homens. Dentre os 94 pacientes, 42 (44,6%) tinham doença oclusiva aorto-ilíaca, e 52 (53,4%), aneurismas da aorta abdominal (AAA). A análise dos dados mostrou uma prevalência de estenose de carótidas acima de 70% em 8,33% dos pacientes com AAA e em 13,51% dos pacientes com doença oclusiva aorto-ilíaca, diferença esta sem significância estatística (P = 0,5). Nos pacientes que apresentavam antecedente de isquemia cerebral - acidente vascular cerebral (AVC) ou ataque isquêmico transitório (AIT) -, houve uma prevalência estatisticamente maior de estenose carotídea entre 70 e 99%. Outros fatores de risco para aterosclerose, como sexo masculino, diabetes, hipertensão arterial e tabagismo, não foram preditivos da presença de estenose carotídea acima de 70%. CONCLUSÃO: A freqüência de estenose da carótida acima de 70% em pacientes no pré-operatório de cirurgia de aorta foi de 9,57%, e a presença de antecedente de AVC ou AIT na história foi preditiva de estenose acima de 70% neste grupo de pacientes.

Management of asymptomatic carotid stenosis in patients undergoing general and vascular surgical procedures

Current available data do not seem to support the strategy for carotid endarterectomy prior to surgical intervention in patients with asymptomatic carotid stenosis. However, in patients with coronary artery disease, synchronous carotid endarterectomy and coronary artery bypass grafting should be considered where there is a proven surgical risk of <3% with unilateral asymptomatic stenosis >60% or bilateral carotid stenosis >75% on the same side as the most severe stenosis. Clarification of the optimal strategy requires an adequately powered, multicentre, randomised clinical trial.

Preoperative construction of an extracranial arterial shunt for resection of an aortic arch aneurysm with occluded left carotid artery

A 68-year-old man with aortic arch aneurysm was referred to our department. Preoperative carotid echography and magnetic resonance angiography revealed occlusion of the left internal carotid artery. Single-photon emission computed tomography scanning indicated that cerebral blood flow was decreased and reactivity to acetazolamide was reduced in the left temporal lobe. A successful superficial temporal artery-middle cerebral artery anastomosis was first made by neurosurgeons. A postoperative single-photon emission computed tomography scan showed that cerebral blood flow and reactivity to acetazolamide were remarkably improved. Two months after the anastomosis, the aortic arch aneurysm was successfully repaired.

Cost of routine screening for carotid and lower extremity occlusive disease in patients with abdominal aortic aneurysms

OBJECTIVE

The burden of clinically relevant noncoronary atherosclerotic occlusive disease in patients with abdominal aortic aneurysms (AAAs) is poorly defined. Furthermore, the cost-effectiveness of routine versus selective preoperative noninvasive examination of the carotid and lower extremity arterial beds has not been established in patients who undergo elective AAA repair.

METHODS

Diagnostic vascular laboratory study results were reviewed in 206 patients who underwent evaluation before AAA repair from 1994 to 1998. The patients underwent routine preoperative carotid duplex scan examinations and lower extremity Doppler scan arterial studies with ankle-brachial index (ABI) determinations. The medical records were reviewed for the identification of clinical evidence consistent with cerebrovascular or lower extremity arterial occlusive disease. The costs of routine screening and selective screening were determined with Medicare reimbursement schedules.

RESULTS

The prevalence rate of advanced (80% to 100%) carotid artery stenosis (CAS) was 3.4%, and 18% of the patients had CAS between 60% and 100%. Advanced peripheral vascular occlusive disease (PVOD; ABI, <0.3) was found in 3% of the patients, and 12% of the patients had an ABI of less than 0.6. Most patients with advanced CAS (71%) or advanced PVOD (83%) had clinical indications of their disease. The absence of clinical evidence of disease had a negative predictive value of 99% for both advanced CAS and PVOD. The cost of routine screening for all patients for advanced CAS was $5445 per case. Routine screening for severe PVOD costs were $3732 per case discovered. In contrast, the costs for selective screening for advanced CAS or PVOD in patients with appropriate history or symptoms were $1258 and $785 per case found, respectively.

CONCLUSION

Routine noninvasive diagnostic testing for the identification of asymptomatic CAS and PVOD in patients with AAA may not be justified. Preoperative screening is more clearly indicated for patients with AAAs who have clinical evidence suggestive of CAS or PVOD.

Combined infrarenal aorta and carotid artery reconstruction: early and late outcome in 152 patients

Between January 1, 1985 and December 31, 1998, we performed combined infrarenal aorta and carotid artery reconstruction in 152 consecutive patients. The mean age of these patients was 65.4 +/- 8.6 years (range, 43-88 years). Infrarenal aortic disease involved abdominal aortic aneurysm in 78 patients (44.7%) and occlusive aortoiliac lesions in 84 (55.3%). Carotid artery disease was detected by performing routine Doppler ultrasonography prior to aortic reconstruction. A total of 121 carotid lesions were asymptomatic (79.6%). A total of 32 patients (21%) had a history of contralateral carotid repair. Eighty-one patients (53.2%) presented with coronary artery disease diagnosed on the basis of clinical and/or laboratory testing. Concurrent lesions were diagnosed in the renal arteries of 43 patients (28.3%) and in the visceral arteries of 16 (10.5%). Based on the results of cardiac evaluation, eight patients underwent coronary revascularization before combined reconstruction. Renal or visceral artery reconstruction was carried out during the same procedure in 30 (19.7%) and 10 (6.6%) patients, respectively. Univariate analysis demonstrated six factors that were significantly associated with perioperative mortality and morbidity: age, coronary artery disease, chronic obstructive pulmonary disease, procedure time, intraoperative blood loss, and creatinemia over 140 micromol/L. Multivariate analysis showed that only the first four of these factors were independent. Actuarial survival in the overall population, including the patients who died during the perioperative period, was 73.9 +/- 7.1% at 5 years and 50.9 +/- 10% at 10 years. From our experience, we conclude that combined infrarenal aorta and carotid artery reconstruction can be performed with no additional operative risks and consequently is the strategy of choice. In our series neither procedure had any effect on the early or late outcome of the other. Our experience suggests that combined surgery is a safe alternative to staged surgery in patients with concurrent lesions involving the infrarenal aorta and carotid artery bifurcation.

The haemodynamic effect of internal carotid artery stenosis on cerebral perfusion during aortic surgery

OBJECTIVES

to determine the impact of the extracranial internal carotid stenosis on cerebral perfusion during aortoiliac surgery.

DESIGN

prospective study.

MATERIAL AND METHODS

of 432 consecutive patients undergoing aortoiliac reconstruction, 16/86 (18%) with >70% internal carotid artery stenosis, underwent inverted surgical timing (aortic reconstruction first and carotid endarterectomy second). Preoperative Transcranial Doppler (TCD) with and without acetazolamide was used to evaluate cerebrovascular reserve capacity (CRC). Intraoperatively, middle cerebral artery flow velocity (mean MCAv) and systemic blood pressure (SBP) were recorded.

RESULTS

preoperatively, all 16 patients had good CRC (increase in mean MCAv: 66% right and 72% left). Intraoperatively, the mean MCAv (from 49+/-13 to 45+/-14 cm/s p=0.0249) and SBP decreased (from 127+/-25 to 113+/-22 mmHg p=0.0016). In patients with unilateral carotid disease, declamping had no effect on left mean MCAv despite a significant decrease of SBP (129+/-44 to 113+/-21 mmHg p=0.0211). In those with bilateral disease, declamping decreased both mean MCAv: from (48+/-12 to 39+/-10 cm/s p=0.011) and SBP (123+/-26 to 111+/-25 mmHg p=0.0479). No perioperative neurological deficit occurred.

CONCLUSIONS

if CRC is normal or still effective, aortoiliac reconstruction does not impair cerebral perfusion.

The prevalence of carotid artery stenosis in patients undergoing aortic reconstruction

BACKGROUND

Coronary artery disease occurs frequently in patients undergoing aortic reconstruction, and it has been presumed that internal carotid artery occlusive disease is also common. This has led to the practice of screening for and repairing significant carotid lesions in asymptomatic patients prior to aortic reconstruction. The purpose of this study was to determine the true prevalence of internal carotid artery disease in these patients.

METHODS

The records of 240 patients who underwent duplex ultrasound screening for carotid artery disease prior to aortic reconstruction were reviewed. Surgery was performed for aortic aneurysm (AA) or aorto-iliac occlusive disease (AO). The prevalence of hyperlipidemia and coronary artery disease was similar between the two groups, but tobacco use, hypertension, and diabetes mellitus differed.

RESULTS

Internal carotid artery stenosis > or = 50% occurred in 26.7% of the total group (64 of 240 cases). Stenosis > or = 50% was more common in the AO group (40 of 101 cases, 39.6%) than the AA group (24 of 139 cases, 17.3%, P = 0.0001). Severe disease (70% to 99%) was also more common in the AO group than the AA group (9.9% versus 3.6%, P = 0.0464).

CONCLUSION

Internal carotid artery disease occurs commonly in patients undergoing aortic reconstruction, and screening is worthwhile. Significant disease is more common in patients with aorto-iliac occlusive disease than in those with aortic aneurysm, although atherosclerotic risk factors occur with varying frequency in the two groups. These findings suggest that additional factors may contribute to the higher prevalence of internal carotid artery stenosis in aorto-iliac occlusive disease.

Selection and preparation of high-risk patients for repair of abdominal aortic aneurysms

OBJECTIVE

To discuss the most important risk factors in patients who undergo surgical repair of an abdominal aortic aneurysm (AAA).

DESIGN

This update in vascular surgical repair highlights the criteria that identify high-risk patients, the useful preoperative tests, and the perioperative measures that can aid surgical recovery.

MATERIAL AND METHODS

In elective repair of AAAs, high-risk patients are those with severe coronary or valvular heart disease, decompensated chronic obstructive pulmonary disease, severe cerebrovascular disease, chronic renal failure, hepatic cirrhosis with portal hypertension, and chronic hematologic disorders associated with bleeding dysfunction. Patients with unstable or severely symptomatic heart disease should undergo preoperative coronary angiography and ventriculography. Pharmacologic stress testing is recommended for patients with clinical markers of serious coronary artery disease and other medical or physical factors that prevent any type of standard exercise stress testing.

RESULTS

Our experience with high-risk patients supports conventional repair of AAAs. Our preference for the midline abdominal incision in high-risk patients is substantiated by an operative mortality rate of 5.7% in comparison with a reported 7% mortality rate for nonresective therapy. Approximately one in three high-risk patients will have a serious postoperative complication, the most common of which is a cardiac event. Most patients recover after a slightly prolonged hospital stay.

CONCLUSION

Despite an increased operative risk, patients with a stable medical condition and an AAA larger than 6 cm in diameter should be considered for elective repair. High-risk patients with smaller aneurysms (5 to 6 cm in diameter) should undergo efforts to stabilize or to improve their general medical condition before elective operation.