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Carotid endarterectomy—Is it safe in the community?
EDITORIAL
Carotid endarterectomy--Is it safe in the community? Wesley S. Moore, M.D., Los Angeles, Calif.
Most reported series of carotid endarterectomy reflect the experience of an individual surgeon or hospital, as reviewed by the principal involved. The report in the June issue of the Journal of Vascular Surgery (1986;3:911-6) by Kempczinski, Brott, and Labutta is unique in that it represents an independent audit of the experience of an entire community. Seven hundred fifty operations performed on 656 patients in 16 hospitals by 61 surgeons during a 12-month interval from July 1983 to June 1984 were meticulously reviewed by the authors. They found that more than half of the operations were done to treat asymptomatic lesions and that the overall combined neurologic morbidity (stroke) and mortality rate was 6.5% (7.8% in symptomatic and 5.3% in asymptomatic patients). Furthermore, the authors noted that the stated specialty among the various surgeons doing the operations (vascular surgery, cardiac surgery, neurosurgery, and general surgery) as well as individual caseload showed no significant differences in outcome. The authors concluded that the overall Cincinnati community experience (which they believe reflects the experience of other communities) demonstrates a morbidity and mortality rate unacceptably higher than that reported by a few surgeons working in specialized centers. Because of the far-reaching implications of these findings and the authors' conclusions, this report demands a careful analysis. First of all, what about the influence of a surgeon's stated specialty? The authors define a vascular surgeon as anyone completing a vascular surgery fellowship or anyone who belongs to a regional or one of the two major national vascular societies. Does that definition necessarily reflect judgment and surgical ability? Cardiac surgeons, neurosurgeons, and general surgeons may have had varying degrees of training in vascular surgery or experience in practice depending on the organization of their individual Reprint requests: WesleyS. Moore, M.D., Departmentof Surgery, UCLA Schoolof Medicine,Center for the Health Sciences,Los Angeles,CA 90024.
training programs, whether they have taken additional training, the length of time they have been in practice, and the individual referral patterns with respect to the type and difficulty of individual cases. Finally, although the morbidity and mortality rate for carotid endarterectomy averaged 6.5%, clearly many surgeons had better statistics to balance those who had worse. It would have been of interest if the authors had contrasted those surgeons with better results with those achieving a higher morbidity and mortality rate to determine whether there were identifiable characteristics that may have separated the safe surgeon from the unsafe surgeon (fellowship training, time in practice, and caseload). The next issue has to do with caseload or annual volume. Forty-four surgeons doing an average of 5.5 carotid endarterectomies a year had a combined morbidity and mortality rate of 9%; 14 surgeons doing an average of 19.7 carotid endarterectomies a year had a morbidity and mortality rate of 8%, and three surgeons doing an average of 76.6 operations a year had a morbidity and mortality rate of 4.8%. Although the authors state that these differences fail to achieve statistical significance, there is certainly an obvious trend in favor of better results as a function of higher volume. In fact, a Fisher exact test (onetailed) used to measure significance of difference revealed a p value less than 0.05, although the twotailed test yielded a p value equal to 0.07. I suspect that these differences are real and that a larger number of cases or more surgeons doing a larger number of cases would have resulted in an even better p value, indicating that the differences were statistically significant. Finally, do the results of the Cincinnati experience reflect the results of communities at large? Although reliable information is not available, the answer is probably in the affirmative. What message should we take away from this report and how should this information influence our practice? First of all, it is the responsibility of every surgeon performing carotid endarterectomy to monitor his 313
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experience with care. His records should include data on volume, morbidity, mortality, and outcome. Not every surgeon with exposure to vascular procedures during his training should do carotid endarterectomy. Only those surgeons with acceptable results are ultimately qualified. Mthough the information available in this report was lacking, it would seem self-evident that those surgeons receiving the most intensive training in the operation will be off to the best start once they enter practice. However, from that point on their results will be related to several factors that can only be documented with individual statistics. Many surgeons, including some in the Cincirmati community, can do carotid endarterectomy safely and have results comparable to the best reported in the literature. These surgeons should con-
Journal of VASCULAR SURGERY
tinue to do the operation. On the other hand, those surgeons with unacceptably high morbidity and mortality rates should either stop doing the operation or obtain additional training to improve their judgment in case selection, perioperative management, and results. Carotid endarterectomy, for several reasons, is coming under increasing scrutiny from several quarters. If the superiority of this operation over medical management in appropriately selected cases is to be proved, it must be done safely and with minimal morbidity and mortality risks. If we do not accept this challenge, the confidence of the public in the medical profession will suffer grievous and perhaps irreparable damage.
Carotid endarterectomy--Is it safe in the community? Wesley S. Moore, M.D., Los Angeles, Calif.
Most reported series of carotid endarterectomy reflect the experience of an individual surgeon or hospital, as reviewed by the principal involved. The report in the June issue of the Journal of Vascular Surgery (1986;3:911-6) by Kempczinski, Brott, and Labutta is unique in that it represents an independent audit of the experience of an entire community. Seven hundred fifty operations performed on 656 patients in 16 hospitals by 61 surgeons during a 12-month interval from July 1983 to June 1984 were meticulously reviewed by the authors. They found that more than half of the operations were done to treat asymptomatic lesions and that the overall combined neurologic morbidity (stroke) and mortality rate was 6.5% (7.8% in symptomatic and 5.3% in asymptomatic patients). Furthermore, the authors noted that the stated specialty among the various surgeons doing the operations (vascular surgery, cardiac surgery, neurosurgery, and general surgery) as well as individual caseload showed no significant differences in outcome. The authors concluded that the overall Cincinnati community experience (which they believe reflects the experience of other communities) demonstrates a morbidity and mortality rate unacceptably higher than that reported by a few surgeons working in specialized centers. Because of the far-reaching implications of these findings and the authors' conclusions, this report demands a careful analysis. First of all, what about the influence of a surgeon's stated specialty? The authors define a vascular surgeon as anyone completing a vascular surgery fellowship or anyone who belongs to a regional or one of the two major national vascular societies. Does that definition necessarily reflect judgment and surgical ability? Cardiac surgeons, neurosurgeons, and general surgeons may have had varying degrees of training in vascular surgery or experience in practice depending on the organization of their individual Reprint requests: WesleyS. Moore, M.D., Departmentof Surgery, UCLA Schoolof Medicine,Center for the Health Sciences,Los Angeles,CA 90024.
training programs, whether they have taken additional training, the length of time they have been in practice, and the individual referral patterns with respect to the type and difficulty of individual cases. Finally, although the morbidity and mortality rate for carotid endarterectomy averaged 6.5%, clearly many surgeons had better statistics to balance those who had worse. It would have been of interest if the authors had contrasted those surgeons with better results with those achieving a higher morbidity and mortality rate to determine whether there were identifiable characteristics that may have separated the safe surgeon from the unsafe surgeon (fellowship training, time in practice, and caseload). The next issue has to do with caseload or annual volume. Forty-four surgeons doing an average of 5.5 carotid endarterectomies a year had a combined morbidity and mortality rate of 9%; 14 surgeons doing an average of 19.7 carotid endarterectomies a year had a morbidity and mortality rate of 8%, and three surgeons doing an average of 76.6 operations a year had a morbidity and mortality rate of 4.8%. Although the authors state that these differences fail to achieve statistical significance, there is certainly an obvious trend in favor of better results as a function of higher volume. In fact, a Fisher exact test (onetailed) used to measure significance of difference revealed a p value less than 0.05, although the twotailed test yielded a p value equal to 0.07. I suspect that these differences are real and that a larger number of cases or more surgeons doing a larger number of cases would have resulted in an even better p value, indicating that the differences were statistically significant. Finally, do the results of the Cincinnati experience reflect the results of communities at large? Although reliable information is not available, the answer is probably in the affirmative. What message should we take away from this report and how should this information influence our practice? First of all, it is the responsibility of every surgeon performing carotid endarterectomy to monitor his 313
314
Moore
experience with care. His records should include data on volume, morbidity, mortality, and outcome. Not every surgeon with exposure to vascular procedures during his training should do carotid endarterectomy. Only those surgeons with acceptable results are ultimately qualified. Mthough the information available in this report was lacking, it would seem self-evident that those surgeons receiving the most intensive training in the operation will be off to the best start once they enter practice. However, from that point on their results will be related to several factors that can only be documented with individual statistics. Many surgeons, including some in the Cincirmati community, can do carotid endarterectomy safely and have results comparable to the best reported in the literature. These surgeons should con-
Journal of VASCULAR SURGERY
tinue to do the operation. On the other hand, those surgeons with unacceptably high morbidity and mortality rates should either stop doing the operation or obtain additional training to improve their judgment in case selection, perioperative management, and results. Carotid endarterectomy, for several reasons, is coming under increasing scrutiny from several quarters. If the superiority of this operation over medical management in appropriately selected cases is to be proved, it must be done safely and with minimal morbidity and mortality risks. If we do not accept this challenge, the confidence of the public in the medical profession will suffer grievous and perhaps irreparable damage.