Cannulation of the extrathoracic left common carotid artery for thoracic aorta operations through left posterolateral thoracotomy.

The femoral artery is the usual site of arterial cannulation in thoracic aorta operations through left posterolateral thoracotomy that require cardiopulmonary bypass (CPB) with deep hypothermic circulatory arrest (DHCA). The advantage of this perfusion route is in limiting the duration of circulatory arrest. It is associated, however, with the risk of retrograde embolization or, in cases involving aortic dissection, malperfusion of vital organs. To prevent these risks, we have used the extrathoracic left common carotid artery as the perfusion route. From December 1999 to January 2003, we used cannulation of the left extrathoracic common carotid artery in 42 thoracic aorta operations through posterolateral thoracotomy with an open proximal anastomosis technique during DHCA. The indication for thoracic aortic repair was atherosclerotic ulcer in 7 cases, chronic aortic aneurysm in 18, acute type B dissection in 5, and chronic type B dissection in 12. Cannulation of the extrathoracic left common carotid artery was successful in all patients. Postoperative recovery was uneventful, with no cerebrovascular events in all cases. No cannulation-related complications were observed. One patient died from cardiac insufficiency on postoperative day 5. No peripheral neurological deficits (paraplegia or paraparesis) were observed. Postoperative complications included atrial fibrillation in five patients, reoperation to control hemorrhage in six, respiratory insufficiency in nine, and renal insufficiency in six. These results indicate that cannulation of the left extrathoracic common carotid artery is a useful, reliable method for proximal perfusion during CPB in patients undergoing repair of the descending thoracic aorta through left posterolateral thoracotomy. By providing effective perfusion of the brain, this technique can prolong safe DHCA time. Another advantage is the prevention of cerebral emboli, ensuring retrograde flow to the aortic arch.

Cerebral autoregulation after hypothermic circulatory arrest in operations on the aortic arch.

BACKGROUND: The purpose of this study was to determine whether patients who undergo thoracic aorta repairs with the aid of hypothermic circulatory arrest experience impairments in cerebral autoregulation, and to ascertain the influence of three different techniques of cerebral protection on autoregulatory function. METHODS: Sixty-seven patients undergoing elective aortic arch procedures with hypothermic circulatory arrest were tested for cerebral dynamic autoregulation using continuous transcranial Doppler velocity and blood pressure recordings. Twenty-three patients were treated using hypothermic circulatory arrest without adjuncts (group 1), 25 using antegrade cerebral perfusion (group 2), and 19 using retrograde cerebral perfusion (group 3). RESULTS: There were no hospital deaths. Two major strokes occurred in this series; 9 patients experienced temporary neurologic dysfunction: in all these patients severe impairment of cerebral autoregulation was observed. Cerebral autoregulation in the immediate postoperative period was preserved only in patients treated with antegrade cerebral perfusion. Severe impairments were observed in the other two groups in which the degree of autoregulatory response was inversely correlated to the duration of the cerebral protection time during hypothermic circulatory arrest. Postoperative improvement of autoregulatory function was observed in the majority of patients. Our data suggest the exposure to brain damage in the presence of autoregulation impairment, thus indicating that postoperative hypotensive phases may further contribute to neurologic impairment. CONCLUSIONS: The status of cerebral autoregulation in the postoperative period after hypothermic circulatory arrest procedures is profoundly altered. The degree of impairment is influenced by the cerebral protection technique. This study indicates the beneficial role of antegrade perfusion during hypothermic circulatory arrest for the preservation of this function and suggests that postoperative cerebral autoregulation impairment can be regarded as an expression of central nervous system injury.

Determinants of in-stent restenosis after carotid angioplasty: a case-control study.

PURPOSE: To report a retrospective study that sought to identify clinical factors contributing to the development of in-stent restenosis in the carotid arteries, to profile the patients at greatest risk, and to review the treatment modalities evolved from our experience. METHODS: Between December 2000 and April 2003, 195 carotid angioplasty/stenting (CAS) procedures (12 bilateral) were performed in 183 patients (131 men; median age 65.9 years, interquartile range 55.2-72.7). Stenting for de novo stenoses was performed in 119 (61%) carotid arteries; 76 (39%) vessels were treated for postsurgical restenosis. Nearly two thirds of the patients (117, 64%) were symptomatic. Patients were evaluated at 3 and 6 months and at 6-month intervals thereafter with duplex ultrasonography. Angiography was used to confirm any recurrent lesion detected on the ultrasound scan. RESULTS: Overall perioperative neurological complications included 4 (2.2%) minor strokes, 1 (0.5%) intracranial hemorrhage, and 1 (0.5%) major stroke; both patients with major neurological complications died at 5 and 12 days, respectively, after the procedure. During the 12.5-month follow-up (range 0-27.2), 3 non-procedure-related late deaths and another 9 (4.9%) neurological events occurred (2 strokes and 7 transient ischemic attacks). In-stent restenosis after CAS was present in 10 (5.2%) of 193 carotid arteries (9/181 patients) in follow-up; all but 1 artery had been treated for postsurgical restenosis. All lesions were treated secondarily with endovascular procedures. Statistical analysis demonstrated that postsurgical restenosis was the only predictive factor for the development of in-stent restenosis (OR 15.5, 95% CI 2.05 to 125.6, p=0.001) in this cohort. CONCLUSIONS: The present study, far from being exhaustive on the subject, indicates that patients who develop restenosis after carotid endarterectomy are also prone to develop restenosis after CAS; moreover, although strongly recommended for postsurgical restenosis, CAS carries a greater risk of in-stent restenosis in this subgroup, thus reducing the benefits of this procedure.

Extrathoracic cannulation of the left common carotid artery in thoracic aorta operations through a left thoracotomy: preliminary experience in 26 patients.

BACKGROUND: In aortic operations performed through a left thoracotomy, which require total bypass and deep hypothermic circulatory arrest, femoral artery cannulation is commonly used for arterial perfusion. This route limits the time of safe circulatory arrest and is associated with the risks of retrograde embolization or, in the case of aortic dissection, malperfusion of the vital organs. To overcome these problems, we have used cannulation of the extrathoracic left common carotid artery to ensure a central a route of arterial perfusion in these operations. The preliminary results are presented. METHODS: Between December 1999 and April 2001, we used left common carotid artery cannulation in 26 operations on the thoracic aorta performed through a posterolateral thoracotomy with an open technique during deep hypothermic circulatory arrest. Institutional review board approval and informed consent were obtained. The indications included perforating atherosclerotic ulcer (n = 5), chronic aortic aneurysm (n = 9), acute type B aortic dissection (n = 3), and chronic dissection of the thoracic aorta (n = 9). Transcranial Doppler ultrasonographic monitoring of both the right and left middle cerebral arteries was used to assess the adequacy of cerebral bihemispheric perfusion and to determine the differences in blood flow velocities throughout the procedure. RESULTS: Left common carotid artery cannulation was successful in all patients. All patients awoke from the operation, and none had cerebrovascular accidents. None died in the hospital, and complications related to carotid artery cannulation were not observed. None of the patients experienced postoperative paraplegia. In all patients transcranial Doppler monitoring indicated the absence of cerebral embolic phenomena throughout the entire procedure. Significant differences in middle cerebral artery flow velocities were observed at different phases of the procedures and between the right and left middle cerebral arteries during carotid cannulation and during selective cerebral perfusion. Nevertheless, the maximal drop of right middle cerebral artery blood velocity during selective perfusion through the left common carotid artery was within 50% of the left middle cerebral artery velocity, indicating adequate bihemispheric perfusion. CONCLUSIONS: In patients undergoing aortic operations through a left thoracotomy, extrathoracic left common carotid artery cannulation was a safe and effective means of providing proximal arterial inflow during cardiopulmonary bypass, which can be used to selectively perfuse the brain, as well as to prevent embolic phenomena in the arch vessels.