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Late stroke after carotid endarterectomy: the role of recurrent stenosis
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angiography were assumed to be always correct and without complications. Data regarding the natural history of asymptomatic high-grade carotid stenosis (death and stroke), risks of perioperative death, stroke, and TIA were retrieved only from prospective and/or randomized studies. Thesewere 5.3%, 18.6%, 1.9%, 2.4%, 2.4%, and4%, over a 4-year period, respectively. In each case, the worst reported risk of complications were used to bias against surgery, since a positive result would demonstrate the robustness of the final result. The outcome of measurement was clinical utility, a quantitative measure of the strength of the patient’s preference for an outcome. By use of a range from 0 to 1 (1 being the most preferred), utilities for death, stroke, TIA, and remaining asymptomatic was chosen as 0, 0.2, 0.8, and 1, respectively. Based on the reported risk probabilities and the above clinical utilities, the decision tree was folded back to yield an overall utility of 0.81 for surgery and 0.76 for nonoperative treatment. Sensitivity analysis demonstrated that surgery remains beneficial provided the operative death and stroke rates did not exceed 8% and lo%, respectively. Until definitive results are available from ongoing prospective randomized studies, our analysis suggests that surgery for asymptomatic carotid stenosis >75% is beneficial provided it can be accomplished within the above risk probabilities. Late stroke after carotid endarterectomy: the role of recurrent stenosis Kenneth Washburn, MD, William C. Mackey, MD, Michael Be&n, MD, and Thomas F. O’Donnell, Jr., MD, Tufts New England Medical Center, Boston, Mass. Perioperative stroke after carotid endarterectomy has been well studied, although little information is available regarding later strokes. We determined the cause of late stroke after carotid endarterectomy by examining the records of those patients in our carotid registry who had a stroke more than 30 days after surgery. Of the 689 patients in our registry 35 (5.1%) had a stroke more than 30 days after endarterectomy (mean follow-up, 59.3 months; SE, 1.8 months; range, 1 to 292 months). The cause of late stroke was established by input from consulting neurologists, head CT results, angiograms, noninvasive studies, and postmortem examinations. Eight of the 11 strokes of unknown origin were massive fatal events for which no further evaluation was undertaken. Strokes occurring between 1 and 36 months after endarterectomy are less likely to be related to recurrent stenosis than those occurring after 36 months. Restenosis
Journal of VASCULAR SURGERY
accounted for 3/20 (15%) strokes in the 1 to 36 month group and 8/15 (53.7%) events in the > 36 month group (p = 0.020 by Fischer exact method). These data support the hypothesis that the early pseudointimal fibrous hyperplastic lesion is less likely to result in stroke than is later recurrent stenosis, which is usually related to atherosclerosis. The current surgical management of carotid paragangliomas Glenn M. LaMuraglia, MD, Richard L. Fabian, MD, David C. Brewster, MD, John M. Pile-Spellman, MD, Richard P. Cambria, MD, and William M. Abbott, MD, Massachusetts General Hospital, Boston, Mass. The major technical challenge of carotid paragangliomas includes resection of a highly vascular, bulky lesion that is densely adherent to the splayed bifurcation of the carotid arteries and cranial nerves. We performed this review of our experience of the last decade to determine if recent advances in evaluation and therapy has improved the management of this problem. Eighteen carotid paragangliomas were identified in 5 men (average age, 40 years) and 11 women (average, 45 years). Ten patients underwent preoperative angiography and embolization of afferent arteries to the tumors without complications. Tumor surface area, as calculated from pathology measurements, did not differ between the embolized 67 ? 14 cm’ and nonembolized 63 i 20 cm’ tumors. Intraoperative blood loss was lower in the embolized (385 2 70 ml) patients than in their cohorts (610 rt 200 ml), but did not achieve statistical significance because of the wide ranges seen. However, the operative durations were equivalent 4.2 hours versus 4.5 hours. Intraoperative EEG monitoring was performed in seven patients; in one patient the EEG indicated intraoperative thrombosis of the carotid artery. Thrombectomy resulted in successful recanalization without a stroke. Six paraganglioma resections included division of the external carotid artery without sequellae. One patient developed transient aphasia 24 hours after a total carotid resection and bypass necessary to remove the entire tumor. The incidence of cranial nerve injury was 16%, with one ramus mandibularis, and two vocal cord paresis. We conclude that complete and careful preoperative embolization, intraoperative EEG monitoring, and external carotid resection, when necessary, facilitates this still challenging operation.
angiography were assumed to be always correct and without complications. Data regarding the natural history of asymptomatic high-grade carotid stenosis (death and stroke), risks of perioperative death, stroke, and TIA were retrieved only from prospective and/or randomized studies. Thesewere 5.3%, 18.6%, 1.9%, 2.4%, 2.4%, and4%, over a 4-year period, respectively. In each case, the worst reported risk of complications were used to bias against surgery, since a positive result would demonstrate the robustness of the final result. The outcome of measurement was clinical utility, a quantitative measure of the strength of the patient’s preference for an outcome. By use of a range from 0 to 1 (1 being the most preferred), utilities for death, stroke, TIA, and remaining asymptomatic was chosen as 0, 0.2, 0.8, and 1, respectively. Based on the reported risk probabilities and the above clinical utilities, the decision tree was folded back to yield an overall utility of 0.81 for surgery and 0.76 for nonoperative treatment. Sensitivity analysis demonstrated that surgery remains beneficial provided the operative death and stroke rates did not exceed 8% and lo%, respectively. Until definitive results are available from ongoing prospective randomized studies, our analysis suggests that surgery for asymptomatic carotid stenosis >75% is beneficial provided it can be accomplished within the above risk probabilities. Late stroke after carotid endarterectomy: the role of recurrent stenosis Kenneth Washburn, MD, William C. Mackey, MD, Michael Be&n, MD, and Thomas F. O’Donnell, Jr., MD, Tufts New England Medical Center, Boston, Mass. Perioperative stroke after carotid endarterectomy has been well studied, although little information is available regarding later strokes. We determined the cause of late stroke after carotid endarterectomy by examining the records of those patients in our carotid registry who had a stroke more than 30 days after surgery. Of the 689 patients in our registry 35 (5.1%) had a stroke more than 30 days after endarterectomy (mean follow-up, 59.3 months; SE, 1.8 months; range, 1 to 292 months). The cause of late stroke was established by input from consulting neurologists, head CT results, angiograms, noninvasive studies, and postmortem examinations. Eight of the 11 strokes of unknown origin were massive fatal events for which no further evaluation was undertaken. Strokes occurring between 1 and 36 months after endarterectomy are less likely to be related to recurrent stenosis than those occurring after 36 months. Restenosis
Journal of VASCULAR SURGERY
accounted for 3/20 (15%) strokes in the 1 to 36 month group and 8/15 (53.7%) events in the > 36 month group (p = 0.020 by Fischer exact method). These data support the hypothesis that the early pseudointimal fibrous hyperplastic lesion is less likely to result in stroke than is later recurrent stenosis, which is usually related to atherosclerosis. The current surgical management of carotid paragangliomas Glenn M. LaMuraglia, MD, Richard L. Fabian, MD, David C. Brewster, MD, John M. Pile-Spellman, MD, Richard P. Cambria, MD, and William M. Abbott, MD, Massachusetts General Hospital, Boston, Mass. The major technical challenge of carotid paragangliomas includes resection of a highly vascular, bulky lesion that is densely adherent to the splayed bifurcation of the carotid arteries and cranial nerves. We performed this review of our experience of the last decade to determine if recent advances in evaluation and therapy has improved the management of this problem. Eighteen carotid paragangliomas were identified in 5 men (average age, 40 years) and 11 women (average, 45 years). Ten patients underwent preoperative angiography and embolization of afferent arteries to the tumors without complications. Tumor surface area, as calculated from pathology measurements, did not differ between the embolized 67 ? 14 cm’ and nonembolized 63 i 20 cm’ tumors. Intraoperative blood loss was lower in the embolized (385 2 70 ml) patients than in their cohorts (610 rt 200 ml), but did not achieve statistical significance because of the wide ranges seen. However, the operative durations were equivalent 4.2 hours versus 4.5 hours. Intraoperative EEG monitoring was performed in seven patients; in one patient the EEG indicated intraoperative thrombosis of the carotid artery. Thrombectomy resulted in successful recanalization without a stroke. Six paraganglioma resections included division of the external carotid artery without sequellae. One patient developed transient aphasia 24 hours after a total carotid resection and bypass necessary to remove the entire tumor. The incidence of cranial nerve injury was 16%, with one ramus mandibularis, and two vocal cord paresis. We conclude that complete and careful preoperative embolization, intraoperative EEG monitoring, and external carotid resection, when necessary, facilitates this still challenging operation.