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One hundred consecutive carotid reconstructions: Local versus general anesthesia
One Hundred Consecutive Carotid Reconstructions: Local Versus General Anesthesia
Charles G. Gabelman, MD, Providence, Rhode Island Donald S. Gann, MD, Providence, Rhode Island Charles J. Ashworth, Jr., MD, Providence, Rhode Island Wilfred I. Carney, Jr., MD, Providence, Rhode Island
A review of operative vascular procedure rates from 1970 to 1978 revealed that the incidence of all vascular procedures is increasing. Carotid endarterectomy has shown a 260 percent increase, the greatest increase among vascular procedures [I]. It therefore has become increasingly appropriate to consider the economic impact of variations in this surgical technique. Our experience with 100 carotid reconstructions at the Rhode Island Hospital has suggested that the use of local anesthesia is associated with diminished hospital costs primarily because of diminished utilization of the surgical intensive care unit and diminished length of postoperative hospital stay. In contrast, most researchers who have reported series of carotid endarterectomies have indicated the use of general anesthesia [2-g]. A smaller number have indicated their preference for local anesthesia [IO-131. In 1977 Bowen et al [14] reviewed before this society the use of local anesthesia in 587 patients with inguinal herniorrhaphy. They demonstrated that it provided substantial cost savings due to shortened hospital stay and early ambulation. In our retrospective series of 100 patients, the patients treated early in the series were given a general anesthetic. At that time we encountered a patient at high risk with the use of general anesthesia. Local anesthesia was employed and was found to be gratifyingly simple to administer. This stimulated our interest in local anesthesia and all subsequent patients were offered local anesthesia. We noted that local anesthesia seemed to decrease the magnitude From the Department of Surgery, Rhode Island Hospital, and the Section of Surgery, Brown University, Providence, Rhode Island. Requests for reprints should be addressed to Wilfred I. Carney, Jr., MD, 120 Dudley Street, Providence, Rhode Island 02905. Presented at the 63rd Annual Meeting of the New England Surgical Society, Bretton Woods, New Hampshire, October 15-17, 1982.
Volume 145, April 1983
of operative stress. In addition, the patients seemed to require less complex medical attention and to recover more rapidly. Material
and Methods
Between November 1977 and February 1982, carotid reconstruction was performed by surgical residents at the Rhode Island Hospital under the supervision of the senior author (WE) in 100 instances which involved 88 patients. The length of stay data were extracted from the hospital’s computerized medical information system. The medical records were then retrospectively reviewed. The patients were divided into two groups according to anesthesia type (general 46, local 54). The composition of the two groups was reviewed with regard to age, sex, the presence of organic heart disease, diabetes mellitus, hypertension, and aspirin use. Presenting symptoms, such as vertebrobasilar transient ischemic attack, carotid territory transient ischemic attack, amaurosis fugax, and established neurologic deficits were reviewed. The computerized information included duration of operating room time, recovery room time, and length of stay in the surgical intensive care unit and postoperative private or semiprivate room. Because the length of stay data tend to be normally distributed, a logarithmic transformation was applied to the length of stay data before the analysis of variance was applied. The patient cost determinations were calculated using length of stay data and 1982 hospital charges. Charges were as follows: operating room, $340 per hour; recovery room, $80 per hour; surgical intensive care, $550 per day; and semiprivate room, $188 per day. For comparison, length of stay data were obtained from two nearby hospitals. The records were surveyed for maximum and minimum systolic and diastolic blood pressures during surgery and for 24 hours postoperatively. The incidence of intraoperative use of the bifurcated Javid shunt and Dacron@ patch was tabulated. The records were also surveyed for postoperative complications including stroke, transient ischemic attack, wound hematoma, cranial nerve deficit,
477
Gabelman et al
and the need for intravenously antihypertensive drugs. dent’s t test for analysis termine any differences between the general and
administered pressor or Chi-square analysis and the Stuof variance were applied to dein the aforementioned categories local anesthesia groups.
Operative
Technique
The evening before surgery intravenous fluids are administered at 50 to 75 ml/h as appears appropriate. One hour or more before surgery silver/silver chloride electrodes for intraoperative electroencephalography are placed using collodion dried with compressed air. The normally uncomfortable stainless steel operating table is positioned for maximum patient comfort. The table is positioned to flex the hip and knee joints, the head rest is tilted back one notch for operative exposure, and the head is turned away from the side of intended surgery. The table is also tilted away from the side of surgery. These maneuvers bring the area of the wound as nearly as possible to a level plane at a point midway between the two surgeons. The patient’s arms are positioned close to his or her side. A toy squeaker, as described by Spielberger et al [IS], is placed in the patient’s contralateral hand to serve as an indicator of contralateral fine motor function during the procedure. A superficial cervical block is placed by infiltrating a 5 ml bolus of a half-and-half mixture of 1 percent lidocaine and 0.5 percent bupivacaine at the midpoint of the posterior border of the sternocleidomastoid muscle. The skin is then infiltrated subcutaneously along the proposed incision line anterior to the sternocleidomastoid muscle. After exposure of the carotid bifurcation a check of the patient’s neurologic status and electroencephalogram is made. When 5 minutes from administration of the heparin dose (5,000 to 7,000 units) have elapsed, the latex vessel loops on the internal and external carotid arteries are tightened. The common carotid artery is clamped and an anterolateral arteriotomy is made. If the patient’s neurologic status remains stable the endarterectomy proceeds. If there is any evidence of neurologic deterioration, a modified Javid bifurcated intraluminal shunt (C. R. Bard, Santa Ana, CA) is placed.
TABLE I
Percent of Preoperative Risk Factors and Symptoms
Anesthesia General
Local
59 30 65 72
56 38 70 72
Risk Factors Organic heart disease Diabetes mellitus Hypertension Tobaccouse Age (yr) Aspirin intake
61 f8 26
Symptoms Carotid TIA Vertebrobasilar TIA Amaurosis fugax Preoperative deficit Asymptomatic TIA = transient ischemic attack.
478
39 23 24 24 18
66 f 9 50
p
52 17 22 22 0
p <0.05
The endarterectomy is considered complete when most or all of the visible circular layers of media have been removed. The distal arteriotomy is extended to allow a clear view of the cut edge of distal plaque which is then sutured to the adventitia with double-armed 7-O prolene suture. One needle pierces the plaque within a millimeter of the cut edge and the other needle passes through the endarterectomized wall. A patch should be used in vessels that measure less than 4 mm or in vessels with thickened plaque at the distal cut edge. The patch is sutured into position with a running 6-O Dacron suture. Elastic Dacron (C. R. Bard) patch material 0.6 mm thick with 4,000 ml/min Hz0 porosity was used during most of the series. Because of occasional difficulty with excessive hemorrhage through the patch interstices, we switched to filamentous velour material (C. R. Bard) of lesser porosity (0.7 mm thick with 2,000 ml/min Hz0 porosity). After a 1 to 2 hour stay in the recovery area most patients were transferred to the surgical intensive care unit for overnight observation. Occasional patients who seemed extremely stable were transferred directly back to their rooms. The operative procedure in the general anesthesia group was the same except that the only local anesthetic employed was a 1 percent lidocaine solution infiltrated into the carotid body.
Results Chi-square analysis of the general and local anesthesia groups revealed no differences in age, sex, or incidence of hypertension, diabetes mellitus, organic heart disease, or tobacco use (Table I). There was a difference in preoperative intake of aspirin: 26% of the patients in the general anesthesia group had taken it preoperatively and 50 percent of those in the local anesthesia group did so (p
The American Journal of Surgery
Carotid Reconstruction:
from hypoglossal injury. Most of these deficits decreased markedly or resolved completely by the time of hospital discharge. Injuries to the mandibular branch of the facial nerve persisted longer. Two mandibular branch injuries appeared to be permanent (Table II). One patient complained that his larynx was no longer midline and had shifted away from the operated side. Examination confirmed his observation. It was attributed to operative division of the omohyoid muscle in a patient with a low carotid bifurcation. The larynx returned to the midline by 1 year follow-up. Estimated blood loss ranged from 50 to 800 ml with no significant differences between the local and general anesthesia groups. The postoperative incidence of wound hematoma was 7 percent in each group and no relation to aspirin use or hypertension could be demonstrated (Table II). Tabulation of the intraoperative and 24 hour postoperative high and low arterial pressures (Table III) revealed significantly higher systolic pressures in the local anesthesia group intraoperatively. Analysis of variance using the Student’s t test revealed both the mean highest and lowest systolic pressures to be significantly higher in the local anesthesia group. The use of intravenously administered pressor and antihypertensive drugs (general 15 percent, local 39 percent) was found to be significantly more prevalent in the local anesthesia group. The intraluminal Javid shunt was used significantly less frequently in the local anesthesia group (general 83 percent, local 20 percent, p
TABLE III
TABLE II
Local Versus General Anesthesia
Percent of Postoperative Complications Anesthesia General Local 4
Stroke TIA Myocardial infarction Hematoma Cranial nerve deficit Death (unrelated)
4 2 0 7 15 0
13 2 7 11 2
TIA = transient ischemic attack.
group (general 9.2 days, local 7.1 days, p <0.02). Mean length of time spent in the surgical intensive care unit was significantly reduced when local anesthesia was used (general 1.5 days, local 0.8 days, p
Perioperative Data Anesthesia General
Duration of Hospital Use Operating room time (h) Recovery room time (h) Surgical ICU [days) Postoperative (days) Hospital 1 Hospital 2 Technique lntraluminal shunt Patch angioplasty Systolic blood pressure (mm Hg) Maximum intraoperative Minimum intraoperative
Volume 145, April 1993
3.0 f 0.4 1.9 f 0.9 1.5 f 1.4 9.2 f 6.4 9.6 10.3
Local
2.7 2.6 0.6 7.1
f 0.6 f 1.6 f 0.6 f 6.2
p p p p
<0.02 <0.05
63% 63%
20% 69%
p <0.0001
179 f 24 114 f 16
193 f 30 131 f 24
p <0.02 p
479
Gabelman
et al
$ COST/ADMISSION
CALCULATED PcO.01
ACTUAL PLO.03
the general anesthesia group and $3,611 for those in the local anesthesia group. This represents a 29 percent savings when local anesthesia was employed (Figure 1). Comments In this study we originally had the intention of using general anesthesia and intraluminal shunts in all patients. When local anesthesia was adopted it became clear that many patients had no need for the shunt. Gradually we adopted an attitude of trying to avoid the intraluminal shunt in order to avoid the inconvenience of tubing and clamps in the operative field and to avoid the unneeded risks of intimal damage and thrombus formation in and around the shunt. This same adjustment of technique associated with the use of local anesthesia has been experienced and described by Connolly et al [II]. Very low stroke and mortality rates (in the 2 to 5 percent range) have been reported by researchers employing either local or regional anesthesia [11,16-181 or general anesthesia [7,9,19]. This report presents similar statistics with no measurable difference between local and general anesthesia groups. The one measurable consequence of the use of local anesthesia for carotid surgery was a reduction in intensive care unit usage and a reduction in the length of postoperative hospital stay. Length of stay data for patients who underwent carotid endarterectomy was obtained from two nearby hospitals in Rhode Island. The results were similar to results in our general anesthesia group (Table III). The local anesthesia group figures were lower in our study. When the length of stay data were converted to hospital charges, a significant 21 percent savings with
480
Figure 1. Cosi saving with iocai anesthesia. The “calculated” bars demonstrate cost savings with local anesthesia when the operating room, intensive care, and hospiiai room charges are totaled. 7Yte “actual” bars depict actual total patient bills which include laboratory, medication, and x-ray charges in addition to room
charges.
local anesthesia was noted. When the actual patient bills were reviewed, the savings with local anesthesia increased to 29 percent. Subtraction of the calculated room and operating room charges from the total actual bill revealed a miscellaneous category which consisted of x-ray, laboratory, and medication charges. This fraction of the bill was a 48 percent increase over the room rate in the general anesthesia group and represented only a 32 percent increase in the local anesthesia group. These findings suggest a diminished complexity of the postoperative care of patients in the local anesthesia group. The study incorporated several biases which might have acted against the results. The general anesthesia portion of the series was conducted from 1977 to 1980 when hospital charges were lower, yet the actual bills for the general anesthesia patients were 30 percent higher. The local anesthesia patients were significantly older than their general anesthesia counterparts, yet they needed less time in the intensive care unit and were discharged from the hospital earlier., Postoperative complications were not increased as might be expected in the older aged patients. Since asymptomatic patients are usually reported to have the least incidence of complications [19], the higher incidence of asymptomatic patients in the general anesthesia group should have been favorable for shorter length of stay and diminished complications. One might be concerned that the diminished operating time seen with local anesthesia could have been the result of increasing experience of the surgeon; however, we believe that the speed of surgery was largely regulated by the surgical residents who change from year to year. The procedure for local anesthesia for carotid endarterectomy is inherently
The American Journal of Surgery
Carotid Reconstruction: Local Versus General Anesthesia
faster than that for general anesthesia because there
is less need for extensive preparation by the anesthesiologist. Also, when the drapes are removed after completion of skin closure, the patient is ready and usually quite willing to move to a stretcher. The impact of quality assurance or the Professional Standards Review Organization (PSRO) in encouraging shorter hospital stay might be suspected as a bias factor in favor of the results. However, the greatest intensity of PSRO activity was during the early period of the study when the general anesthesia group was treated. In conclusion, the use of local anesthesia for carotid endarterectomy resulted in a diminished total hospital cost, shortened length of hospital stay, no change in the complication rate despite the older age of the local anesthesia group, and diminished complexity of postoperative care substantiated with billing data.
Summary One hundred consecutive patients who underwent carotid reconstructions were divided into two groups by anesthesia type (general 46, local 54) and retrospectively reviewed. Particular interest was paid to length of hospital stay and billing data. There were no differences in presenting symptoms, risk factors, incidence of stroke, cranial nerve injury, or wound hematoma. Significant reductions in length of operating time, intensive care unit time, and postoperative stay and intraluminal shunt usage were demonstrated. Calculated billings and actual billings were reviewed and found to be markedly diminished in the local anesthesia group. Acknowledgment: We gratefully acknowledge the programming and computer search assistance of John Pezzullo, Harvey Rosenblatt, and John Wallace of the Rhode Island Hospital Department of Data Processing, and Wentworth Boynton, Jr. of Rhode Island Health Services Research.
References 1. Rutkow I, Ernst CB. Vascular surgical manpower: too much? enou&? too lii? unknown?Arch Sug 1982;117:1537~2. 2. DeBakey ME. Successful carotid endarterectomy for cerebral arterial insufficiency, nineteen-year follow up. JAMA 1975;233:1083-5. 3. Eastcott HHG, Pickering GW, Rob CG. Reconstruction of internal carotid artery in a patient with intermittent attacks of hemiplegia. Lancet 1954;2:994-8. 4. DeWeese JA, Rob CG, Satran R, et al. Results of carotid endarterectomies for transient ischemic attacks-five years later. Ann Surg 1973; 178:258-84. 5. Baker JD, Gluecklich B, Watson CW, et al. An evaluation of electroencephalographic monitoring for carotid study. Surgery 1975;78:787-94. 8. Hays RJ, Levinson SA, Wylie EJ. lntraoperative measurement of carotid back pressue as a guide to operative management of carotid endarterectomy. Surgery 1972;72:953-80. 7. Sundt. TM Jr, Sharbrough FW, Piepgras DG, et al. Correlation of cerebral blood flow and electroence PhElrogaphic changes during carotid endarterectomy. Mayo Clin Proc 1981;58:
Volume 145,Apfil1983
533-43. 8. Moore WS, Yee JM, Hall AD. Collateral cerebral blood pressure: an index of tolerance to temporary carotid occlusion. Arch Surg 1973; 108:520-3. 9. Kelly JJ, Callow AD, O’Donnell TF, et al. Failure of carotid stump pressures. Arch Surg 1979;114:1361-6. 10. Hobson RW, Wright CB, Sublett JW, et al. Carotid artery back pressure and endarterectomy under regional anesthesia. Arch Surg 1974;109:682-7. 11. Connolly JE, Kwaan JHM, Stemmer EA. Improved results with carotid endarterectomy. Ann Surg 1977;186:334-42. 12. Riles TS, Kopelman I, lmparato AM. Myocardial infarction following carotid endarterectomy. Surgery 1979;85:249-52. 13. Peitzman AB, Webster MW, Loubeau JM, Crundy BL, Bahnson HT. Carotid endarlerectomy under regional (conductive) anesthesia. Ann Surg 1982;196:59-64. 14. Bowen JR, Thompson WR, Dorman BA, Soderberg CH Jr, Shahinian TK. Change in the management of adult groin hernia. Am J Surg 1978; 135:564-g. 15. Spielberger L, Turndorf H, Culliford A, lmparato A. Hand-held toy squeaker during carotid endarterectomy in the awake patient. Arch Surg 1979;114:103-4. 18. Rainer WG, McCrory CB, Feiler EM. Surgery on the carotid artery with cervical block anesthesia. Am J Surg 1966; 112:703-5. 17. Rich NM, Hobson RW. Carotid endarterectomy under regional anesthesia. Am Surg 1975;41:253-9. 18. Whittemore AD. Carotid endarterectomy. Arch Surg 1980; 115:940-2. 19. Thompson JE. Talkington CM. Camtii endarterectomy: surgical progress. Ann Surg 1976;184:1-15. 20. O’Donnell Jr TF, Callow AD, Willett C. Payne D. Cleveland RJ. The impact of coronary artery disease on carotid endarterectomy. Ann Surg 1983 (in press).
Discussion Allan Callow (Boston, MA): The authors have done something which each of us should strive to do; they have increased the safety of an operation while decreasing its cost. I do, however, have a strong sense of uneasiness because their implication is that the length of hospital stay, and then by extension, the complications of an operation, are related to the type of anesthesia employed. The trap in this may be that it diverts our attention from what are probably the true causes of complications, namely cardiac disease which, as Dr. O’Donnell pointed out previously [20], is present in about 60 percent of our carotid population and, in addition;hypertension. In our experience it is these factors, that is, major arrhythmias, congestive failure, and myocardial &hernia, rather than an operative mishap that prolong hospital stay and account for the need for extended time in the intensive care unit,. Such patients require exquisite, meticulous management of anesthesia. Dr. Carney noted that the carotid endarterectomy operation has increased in frequency by some 260 percent. Last year I had an occasion to review with a major third party the number of carotid endarterectomies performed in the state of Massachusetts in 1980, there were 1,000. One of the disquieting features of this finding was that 100 of these operations were performed by surgeons who do only one operation a year. John Mannick (Boston, MA): The authors have pointed out one safe and reasonable way of performing a carotid endarterectomy. I am not fully convinced, however, that they have shown this method to be safer or less costly for the patient than other methods. Our own vascular
481
Gabelmanet al
surgical service has recently undergone a reverse conversion. In the last few years we have performed 378 carotid endarterectomies in patients who were not operated on simultaneously for cardiac disease. We began by using general anesthesia and routine shunting or local anesthesia. We achieved about the same results with these two techniques. We have abandoned the routine use of local anesthesia because it is sometimes unacceptable to the patient and occasionally unacceptable to the surgeon because of patient movement. We now use general anesthesia with routine electroencephalographic monitoring with selective shunting based on electroencephalographic changes. This method has shown us clearly who needs a shunt and who does not, and whether or not the shunt is working. I do not think that we have seen an increase in costs by switching in the reverse direction. We seldom admit patients to the surgical intensive care unit after carotid endarterectomy, and the average length of stay is 4 days. Fiorindo Simeone (Providence, RI): We are now approaching the end of the third decade since the first operations for recurrent stroke or transient ischemic attacks were performed, and although there are many proponents of one form of anesthesia over another, the data are still being debated as to which is better and safer. I believe there are other important determinants of results, such as the selection of patients and the use of intraluminal or extraluminal shunts. Perhaps the manner in which the shunts are introduced, with care not to dislodge assorted emboli, is determinant. Most important is the gentle handling of the carotid arteries. The authors report a slightly longer stay in the recovery room but a shorter stay in the surgical intensive care unit for patients operated on under local anesthesia. This is difficult to understand in the absence of more overt morbidity in one group when compared with the other. The time at which a patient leaves the recovery room or intensive care unit is not always precisely conditioned by the patient’s general condition, but rather by such considerations as time of day, change in personnel, and the availability of space. The longer total postoperative stay is even more difficult to explain in the absence of increased morbidity for those operated on under general anesthesia. The two modes of anesthesia both have advantages and disadvantages. Under local anesthesia, the team can utilize patient consciousness as a monitor of cerebral circulation. Monitoring the ability of the patient to operate a hand-held toy squeaker is a nice trick. The effect of three minutes of carotid occlusion can he used as an indication for or against the use of a shunt. The disadvantage is that patients do get tired and sometimes make this manifest.
482
On the positive side, general anesthesia, especially halothane, is reported to improve cerebral circulation and to decrease the brain’s oxygen requirement by about 30 percent. The surgeon may feel less hurried and may more easily achieve a carefully executed procedure. H. Brownell Wheeler (Worcester, MA): I rise to support Dr. Carney on the selective use of local anesthesia. I have been through phases of doing them all under general and all under local, and I am thoroughly convinced now that there is a place for each. The crux is patient selection. The poor-risk patient, whether from the point of view of cardiac disease or the point of view of cerebral protection, is an ideal patient for local anesthesia. I would thoroughly agree with Dr. Carney that there is a big difference in what it means to the patient throughout his or her hospital stay. I agree with Dr. Mannick that these patients ought to be able to be discharged by the fourth postoperative day, irrespective of which method of anesthesia is used. When local anesthesia has been used, I have discharged at least some patients as early as the second postoperative day. Dr. Carney, why was the average length of stay in your study so long? Wilfred Carney (closing): In response to Dr. Callow’s comment, we did find similar distributions of hypertension and coronary artery disease in our two anesthesia groups and hoped that this would balance out the effects of these known risk factors. Dr. Mannick, I share your fear of that awful scene in the operating room when the patient becomes rambunctious, and this has happened to us. We have had to intubate two or three patients, particularly the two patients who suffered strokes during local anesthesia. This was an unpleasant experience but was manageable. I agree that there is a place for both local and general anesthesias. Local anesthesia can perhaps best be employed on a selective basis for the particularly high-risk patient. Dr. Mannick has noted that most of his patients are discharged on the fifth day or earlier, and he expressed concern that our mean length of postoperative stay is in the range of 7 to 9 days. The mean length of stay figure is inevitably skewed toward the high side by the occasional patient who has a long hospital stay. The median and the mode are somewhat better measures of the stay of the typical uncomplicated patient. Both the median and the mode in the general anesthesia group were 7 days and both the median and the mode were 5 days in the local anesthesia group. I do not have a good answer to the question of why general anesthesia was associated with an increased need for hospital care.
The American Journal of Surgery
Charles G. Gabelman, MD, Providence, Rhode Island Donald S. Gann, MD, Providence, Rhode Island Charles J. Ashworth, Jr., MD, Providence, Rhode Island Wilfred I. Carney, Jr., MD, Providence, Rhode Island
A review of operative vascular procedure rates from 1970 to 1978 revealed that the incidence of all vascular procedures is increasing. Carotid endarterectomy has shown a 260 percent increase, the greatest increase among vascular procedures [I]. It therefore has become increasingly appropriate to consider the economic impact of variations in this surgical technique. Our experience with 100 carotid reconstructions at the Rhode Island Hospital has suggested that the use of local anesthesia is associated with diminished hospital costs primarily because of diminished utilization of the surgical intensive care unit and diminished length of postoperative hospital stay. In contrast, most researchers who have reported series of carotid endarterectomies have indicated the use of general anesthesia [2-g]. A smaller number have indicated their preference for local anesthesia [IO-131. In 1977 Bowen et al [14] reviewed before this society the use of local anesthesia in 587 patients with inguinal herniorrhaphy. They demonstrated that it provided substantial cost savings due to shortened hospital stay and early ambulation. In our retrospective series of 100 patients, the patients treated early in the series were given a general anesthetic. At that time we encountered a patient at high risk with the use of general anesthesia. Local anesthesia was employed and was found to be gratifyingly simple to administer. This stimulated our interest in local anesthesia and all subsequent patients were offered local anesthesia. We noted that local anesthesia seemed to decrease the magnitude From the Department of Surgery, Rhode Island Hospital, and the Section of Surgery, Brown University, Providence, Rhode Island. Requests for reprints should be addressed to Wilfred I. Carney, Jr., MD, 120 Dudley Street, Providence, Rhode Island 02905. Presented at the 63rd Annual Meeting of the New England Surgical Society, Bretton Woods, New Hampshire, October 15-17, 1982.
Volume 145, April 1983
of operative stress. In addition, the patients seemed to require less complex medical attention and to recover more rapidly. Material
and Methods
Between November 1977 and February 1982, carotid reconstruction was performed by surgical residents at the Rhode Island Hospital under the supervision of the senior author (WE) in 100 instances which involved 88 patients. The length of stay data were extracted from the hospital’s computerized medical information system. The medical records were then retrospectively reviewed. The patients were divided into two groups according to anesthesia type (general 46, local 54). The composition of the two groups was reviewed with regard to age, sex, the presence of organic heart disease, diabetes mellitus, hypertension, and aspirin use. Presenting symptoms, such as vertebrobasilar transient ischemic attack, carotid territory transient ischemic attack, amaurosis fugax, and established neurologic deficits were reviewed. The computerized information included duration of operating room time, recovery room time, and length of stay in the surgical intensive care unit and postoperative private or semiprivate room. Because the length of stay data tend to be normally distributed, a logarithmic transformation was applied to the length of stay data before the analysis of variance was applied. The patient cost determinations were calculated using length of stay data and 1982 hospital charges. Charges were as follows: operating room, $340 per hour; recovery room, $80 per hour; surgical intensive care, $550 per day; and semiprivate room, $188 per day. For comparison, length of stay data were obtained from two nearby hospitals. The records were surveyed for maximum and minimum systolic and diastolic blood pressures during surgery and for 24 hours postoperatively. The incidence of intraoperative use of the bifurcated Javid shunt and Dacron@ patch was tabulated. The records were also surveyed for postoperative complications including stroke, transient ischemic attack, wound hematoma, cranial nerve deficit,
477
Gabelman et al
and the need for intravenously antihypertensive drugs. dent’s t test for analysis termine any differences between the general and
administered pressor or Chi-square analysis and the Stuof variance were applied to dein the aforementioned categories local anesthesia groups.
Operative
Technique
The evening before surgery intravenous fluids are administered at 50 to 75 ml/h as appears appropriate. One hour or more before surgery silver/silver chloride electrodes for intraoperative electroencephalography are placed using collodion dried with compressed air. The normally uncomfortable stainless steel operating table is positioned for maximum patient comfort. The table is positioned to flex the hip and knee joints, the head rest is tilted back one notch for operative exposure, and the head is turned away from the side of intended surgery. The table is also tilted away from the side of surgery. These maneuvers bring the area of the wound as nearly as possible to a level plane at a point midway between the two surgeons. The patient’s arms are positioned close to his or her side. A toy squeaker, as described by Spielberger et al [IS], is placed in the patient’s contralateral hand to serve as an indicator of contralateral fine motor function during the procedure. A superficial cervical block is placed by infiltrating a 5 ml bolus of a half-and-half mixture of 1 percent lidocaine and 0.5 percent bupivacaine at the midpoint of the posterior border of the sternocleidomastoid muscle. The skin is then infiltrated subcutaneously along the proposed incision line anterior to the sternocleidomastoid muscle. After exposure of the carotid bifurcation a check of the patient’s neurologic status and electroencephalogram is made. When 5 minutes from administration of the heparin dose (5,000 to 7,000 units) have elapsed, the latex vessel loops on the internal and external carotid arteries are tightened. The common carotid artery is clamped and an anterolateral arteriotomy is made. If the patient’s neurologic status remains stable the endarterectomy proceeds. If there is any evidence of neurologic deterioration, a modified Javid bifurcated intraluminal shunt (C. R. Bard, Santa Ana, CA) is placed.
TABLE I
Percent of Preoperative Risk Factors and Symptoms
Anesthesia General
Local
59 30 65 72
56 38 70 72
Risk Factors Organic heart disease Diabetes mellitus Hypertension Tobaccouse Age (yr) Aspirin intake
61 f8 26
Symptoms Carotid TIA Vertebrobasilar TIA Amaurosis fugax Preoperative deficit Asymptomatic TIA = transient ischemic attack.
478
39 23 24 24 18
66 f 9 50
p
52 17 22 22 0
p <0.05
The endarterectomy is considered complete when most or all of the visible circular layers of media have been removed. The distal arteriotomy is extended to allow a clear view of the cut edge of distal plaque which is then sutured to the adventitia with double-armed 7-O prolene suture. One needle pierces the plaque within a millimeter of the cut edge and the other needle passes through the endarterectomized wall. A patch should be used in vessels that measure less than 4 mm or in vessels with thickened plaque at the distal cut edge. The patch is sutured into position with a running 6-O Dacron suture. Elastic Dacron (C. R. Bard) patch material 0.6 mm thick with 4,000 ml/min Hz0 porosity was used during most of the series. Because of occasional difficulty with excessive hemorrhage through the patch interstices, we switched to filamentous velour material (C. R. Bard) of lesser porosity (0.7 mm thick with 2,000 ml/min Hz0 porosity). After a 1 to 2 hour stay in the recovery area most patients were transferred to the surgical intensive care unit for overnight observation. Occasional patients who seemed extremely stable were transferred directly back to their rooms. The operative procedure in the general anesthesia group was the same except that the only local anesthetic employed was a 1 percent lidocaine solution infiltrated into the carotid body.
Results Chi-square analysis of the general and local anesthesia groups revealed no differences in age, sex, or incidence of hypertension, diabetes mellitus, organic heart disease, or tobacco use (Table I). There was a difference in preoperative intake of aspirin: 26% of the patients in the general anesthesia group had taken it preoperatively and 50 percent of those in the local anesthesia group did so (p
The American Journal of Surgery
Carotid Reconstruction:
from hypoglossal injury. Most of these deficits decreased markedly or resolved completely by the time of hospital discharge. Injuries to the mandibular branch of the facial nerve persisted longer. Two mandibular branch injuries appeared to be permanent (Table II). One patient complained that his larynx was no longer midline and had shifted away from the operated side. Examination confirmed his observation. It was attributed to operative division of the omohyoid muscle in a patient with a low carotid bifurcation. The larynx returned to the midline by 1 year follow-up. Estimated blood loss ranged from 50 to 800 ml with no significant differences between the local and general anesthesia groups. The postoperative incidence of wound hematoma was 7 percent in each group and no relation to aspirin use or hypertension could be demonstrated (Table II). Tabulation of the intraoperative and 24 hour postoperative high and low arterial pressures (Table III) revealed significantly higher systolic pressures in the local anesthesia group intraoperatively. Analysis of variance using the Student’s t test revealed both the mean highest and lowest systolic pressures to be significantly higher in the local anesthesia group. The use of intravenously administered pressor and antihypertensive drugs (general 15 percent, local 39 percent) was found to be significantly more prevalent in the local anesthesia group. The intraluminal Javid shunt was used significantly less frequently in the local anesthesia group (general 83 percent, local 20 percent, p
TABLE III
TABLE II
Local Versus General Anesthesia
Percent of Postoperative Complications Anesthesia General Local 4
Stroke TIA Myocardial infarction Hematoma Cranial nerve deficit Death (unrelated)
4 2 0 7 15 0
13 2 7 11 2
TIA = transient ischemic attack.
group (general 9.2 days, local 7.1 days, p <0.02). Mean length of time spent in the surgical intensive care unit was significantly reduced when local anesthesia was used (general 1.5 days, local 0.8 days, p
Perioperative Data Anesthesia General
Duration of Hospital Use Operating room time (h) Recovery room time (h) Surgical ICU [days) Postoperative (days) Hospital 1 Hospital 2 Technique lntraluminal shunt Patch angioplasty Systolic blood pressure (mm Hg) Maximum intraoperative Minimum intraoperative
Volume 145, April 1993
3.0 f 0.4 1.9 f 0.9 1.5 f 1.4 9.2 f 6.4 9.6 10.3
Local
2.7 2.6 0.6 7.1
f 0.6 f 1.6 f 0.6 f 6.2
p p p p
<0.02 <0.05
63% 63%
20% 69%
p <0.0001
179 f 24 114 f 16
193 f 30 131 f 24
p <0.02 p
479
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et al
$ COST/ADMISSION
CALCULATED PcO.01
ACTUAL PLO.03
the general anesthesia group and $3,611 for those in the local anesthesia group. This represents a 29 percent savings when local anesthesia was employed (Figure 1). Comments In this study we originally had the intention of using general anesthesia and intraluminal shunts in all patients. When local anesthesia was adopted it became clear that many patients had no need for the shunt. Gradually we adopted an attitude of trying to avoid the intraluminal shunt in order to avoid the inconvenience of tubing and clamps in the operative field and to avoid the unneeded risks of intimal damage and thrombus formation in and around the shunt. This same adjustment of technique associated with the use of local anesthesia has been experienced and described by Connolly et al [II]. Very low stroke and mortality rates (in the 2 to 5 percent range) have been reported by researchers employing either local or regional anesthesia [11,16-181 or general anesthesia [7,9,19]. This report presents similar statistics with no measurable difference between local and general anesthesia groups. The one measurable consequence of the use of local anesthesia for carotid surgery was a reduction in intensive care unit usage and a reduction in the length of postoperative hospital stay. Length of stay data for patients who underwent carotid endarterectomy was obtained from two nearby hospitals in Rhode Island. The results were similar to results in our general anesthesia group (Table III). The local anesthesia group figures were lower in our study. When the length of stay data were converted to hospital charges, a significant 21 percent savings with
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Figure 1. Cosi saving with iocai anesthesia. The “calculated” bars demonstrate cost savings with local anesthesia when the operating room, intensive care, and hospiiai room charges are totaled. 7Yte “actual” bars depict actual total patient bills which include laboratory, medication, and x-ray charges in addition to room
charges.
local anesthesia was noted. When the actual patient bills were reviewed, the savings with local anesthesia increased to 29 percent. Subtraction of the calculated room and operating room charges from the total actual bill revealed a miscellaneous category which consisted of x-ray, laboratory, and medication charges. This fraction of the bill was a 48 percent increase over the room rate in the general anesthesia group and represented only a 32 percent increase in the local anesthesia group. These findings suggest a diminished complexity of the postoperative care of patients in the local anesthesia group. The study incorporated several biases which might have acted against the results. The general anesthesia portion of the series was conducted from 1977 to 1980 when hospital charges were lower, yet the actual bills for the general anesthesia patients were 30 percent higher. The local anesthesia patients were significantly older than their general anesthesia counterparts, yet they needed less time in the intensive care unit and were discharged from the hospital earlier., Postoperative complications were not increased as might be expected in the older aged patients. Since asymptomatic patients are usually reported to have the least incidence of complications [19], the higher incidence of asymptomatic patients in the general anesthesia group should have been favorable for shorter length of stay and diminished complications. One might be concerned that the diminished operating time seen with local anesthesia could have been the result of increasing experience of the surgeon; however, we believe that the speed of surgery was largely regulated by the surgical residents who change from year to year. The procedure for local anesthesia for carotid endarterectomy is inherently
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Carotid Reconstruction: Local Versus General Anesthesia
faster than that for general anesthesia because there
is less need for extensive preparation by the anesthesiologist. Also, when the drapes are removed after completion of skin closure, the patient is ready and usually quite willing to move to a stretcher. The impact of quality assurance or the Professional Standards Review Organization (PSRO) in encouraging shorter hospital stay might be suspected as a bias factor in favor of the results. However, the greatest intensity of PSRO activity was during the early period of the study when the general anesthesia group was treated. In conclusion, the use of local anesthesia for carotid endarterectomy resulted in a diminished total hospital cost, shortened length of hospital stay, no change in the complication rate despite the older age of the local anesthesia group, and diminished complexity of postoperative care substantiated with billing data.
Summary One hundred consecutive patients who underwent carotid reconstructions were divided into two groups by anesthesia type (general 46, local 54) and retrospectively reviewed. Particular interest was paid to length of hospital stay and billing data. There were no differences in presenting symptoms, risk factors, incidence of stroke, cranial nerve injury, or wound hematoma. Significant reductions in length of operating time, intensive care unit time, and postoperative stay and intraluminal shunt usage were demonstrated. Calculated billings and actual billings were reviewed and found to be markedly diminished in the local anesthesia group. Acknowledgment: We gratefully acknowledge the programming and computer search assistance of John Pezzullo, Harvey Rosenblatt, and John Wallace of the Rhode Island Hospital Department of Data Processing, and Wentworth Boynton, Jr. of Rhode Island Health Services Research.
References 1. Rutkow I, Ernst CB. Vascular surgical manpower: too much? enou&? too lii? unknown?Arch Sug 1982;117:1537~2. 2. DeBakey ME. Successful carotid endarterectomy for cerebral arterial insufficiency, nineteen-year follow up. JAMA 1975;233:1083-5. 3. Eastcott HHG, Pickering GW, Rob CG. Reconstruction of internal carotid artery in a patient with intermittent attacks of hemiplegia. Lancet 1954;2:994-8. 4. DeWeese JA, Rob CG, Satran R, et al. Results of carotid endarterectomies for transient ischemic attacks-five years later. Ann Surg 1973; 178:258-84. 5. Baker JD, Gluecklich B, Watson CW, et al. An evaluation of electroencephalographic monitoring for carotid study. Surgery 1975;78:787-94. 8. Hays RJ, Levinson SA, Wylie EJ. lntraoperative measurement of carotid back pressue as a guide to operative management of carotid endarterectomy. Surgery 1972;72:953-80. 7. Sundt. TM Jr, Sharbrough FW, Piepgras DG, et al. Correlation of cerebral blood flow and electroence PhElrogaphic changes during carotid endarterectomy. Mayo Clin Proc 1981;58:
Volume 145,Apfil1983
533-43. 8. Moore WS, Yee JM, Hall AD. Collateral cerebral blood pressure: an index of tolerance to temporary carotid occlusion. Arch Surg 1973; 108:520-3. 9. Kelly JJ, Callow AD, O’Donnell TF, et al. Failure of carotid stump pressures. Arch Surg 1979;114:1361-6. 10. Hobson RW, Wright CB, Sublett JW, et al. Carotid artery back pressure and endarterectomy under regional anesthesia. Arch Surg 1974;109:682-7. 11. Connolly JE, Kwaan JHM, Stemmer EA. Improved results with carotid endarterectomy. Ann Surg 1977;186:334-42. 12. Riles TS, Kopelman I, lmparato AM. Myocardial infarction following carotid endarterectomy. Surgery 1979;85:249-52. 13. Peitzman AB, Webster MW, Loubeau JM, Crundy BL, Bahnson HT. Carotid endarlerectomy under regional (conductive) anesthesia. Ann Surg 1982;196:59-64. 14. Bowen JR, Thompson WR, Dorman BA, Soderberg CH Jr, Shahinian TK. Change in the management of adult groin hernia. Am J Surg 1978; 135:564-g. 15. Spielberger L, Turndorf H, Culliford A, lmparato A. Hand-held toy squeaker during carotid endarterectomy in the awake patient. Arch Surg 1979;114:103-4. 18. Rainer WG, McCrory CB, Feiler EM. Surgery on the carotid artery with cervical block anesthesia. Am J Surg 1966; 112:703-5. 17. Rich NM, Hobson RW. Carotid endarterectomy under regional anesthesia. Am Surg 1975;41:253-9. 18. Whittemore AD. Carotid endarterectomy. Arch Surg 1980; 115:940-2. 19. Thompson JE. Talkington CM. Camtii endarterectomy: surgical progress. Ann Surg 1976;184:1-15. 20. O’Donnell Jr TF, Callow AD, Willett C. Payne D. Cleveland RJ. The impact of coronary artery disease on carotid endarterectomy. Ann Surg 1983 (in press).
Discussion Allan Callow (Boston, MA): The authors have done something which each of us should strive to do; they have increased the safety of an operation while decreasing its cost. I do, however, have a strong sense of uneasiness because their implication is that the length of hospital stay, and then by extension, the complications of an operation, are related to the type of anesthesia employed. The trap in this may be that it diverts our attention from what are probably the true causes of complications, namely cardiac disease which, as Dr. O’Donnell pointed out previously [20], is present in about 60 percent of our carotid population and, in addition;hypertension. In our experience it is these factors, that is, major arrhythmias, congestive failure, and myocardial &hernia, rather than an operative mishap that prolong hospital stay and account for the need for extended time in the intensive care unit,. Such patients require exquisite, meticulous management of anesthesia. Dr. Carney noted that the carotid endarterectomy operation has increased in frequency by some 260 percent. Last year I had an occasion to review with a major third party the number of carotid endarterectomies performed in the state of Massachusetts in 1980, there were 1,000. One of the disquieting features of this finding was that 100 of these operations were performed by surgeons who do only one operation a year. John Mannick (Boston, MA): The authors have pointed out one safe and reasonable way of performing a carotid endarterectomy. I am not fully convinced, however, that they have shown this method to be safer or less costly for the patient than other methods. Our own vascular
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surgical service has recently undergone a reverse conversion. In the last few years we have performed 378 carotid endarterectomies in patients who were not operated on simultaneously for cardiac disease. We began by using general anesthesia and routine shunting or local anesthesia. We achieved about the same results with these two techniques. We have abandoned the routine use of local anesthesia because it is sometimes unacceptable to the patient and occasionally unacceptable to the surgeon because of patient movement. We now use general anesthesia with routine electroencephalographic monitoring with selective shunting based on electroencephalographic changes. This method has shown us clearly who needs a shunt and who does not, and whether or not the shunt is working. I do not think that we have seen an increase in costs by switching in the reverse direction. We seldom admit patients to the surgical intensive care unit after carotid endarterectomy, and the average length of stay is 4 days. Fiorindo Simeone (Providence, RI): We are now approaching the end of the third decade since the first operations for recurrent stroke or transient ischemic attacks were performed, and although there are many proponents of one form of anesthesia over another, the data are still being debated as to which is better and safer. I believe there are other important determinants of results, such as the selection of patients and the use of intraluminal or extraluminal shunts. Perhaps the manner in which the shunts are introduced, with care not to dislodge assorted emboli, is determinant. Most important is the gentle handling of the carotid arteries. The authors report a slightly longer stay in the recovery room but a shorter stay in the surgical intensive care unit for patients operated on under local anesthesia. This is difficult to understand in the absence of more overt morbidity in one group when compared with the other. The time at which a patient leaves the recovery room or intensive care unit is not always precisely conditioned by the patient’s general condition, but rather by such considerations as time of day, change in personnel, and the availability of space. The longer total postoperative stay is even more difficult to explain in the absence of increased morbidity for those operated on under general anesthesia. The two modes of anesthesia both have advantages and disadvantages. Under local anesthesia, the team can utilize patient consciousness as a monitor of cerebral circulation. Monitoring the ability of the patient to operate a hand-held toy squeaker is a nice trick. The effect of three minutes of carotid occlusion can he used as an indication for or against the use of a shunt. The disadvantage is that patients do get tired and sometimes make this manifest.
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On the positive side, general anesthesia, especially halothane, is reported to improve cerebral circulation and to decrease the brain’s oxygen requirement by about 30 percent. The surgeon may feel less hurried and may more easily achieve a carefully executed procedure. H. Brownell Wheeler (Worcester, MA): I rise to support Dr. Carney on the selective use of local anesthesia. I have been through phases of doing them all under general and all under local, and I am thoroughly convinced now that there is a place for each. The crux is patient selection. The poor-risk patient, whether from the point of view of cardiac disease or the point of view of cerebral protection, is an ideal patient for local anesthesia. I would thoroughly agree with Dr. Carney that there is a big difference in what it means to the patient throughout his or her hospital stay. I agree with Dr. Mannick that these patients ought to be able to be discharged by the fourth postoperative day, irrespective of which method of anesthesia is used. When local anesthesia has been used, I have discharged at least some patients as early as the second postoperative day. Dr. Carney, why was the average length of stay in your study so long? Wilfred Carney (closing): In response to Dr. Callow’s comment, we did find similar distributions of hypertension and coronary artery disease in our two anesthesia groups and hoped that this would balance out the effects of these known risk factors. Dr. Mannick, I share your fear of that awful scene in the operating room when the patient becomes rambunctious, and this has happened to us. We have had to intubate two or three patients, particularly the two patients who suffered strokes during local anesthesia. This was an unpleasant experience but was manageable. I agree that there is a place for both local and general anesthesias. Local anesthesia can perhaps best be employed on a selective basis for the particularly high-risk patient. Dr. Mannick has noted that most of his patients are discharged on the fifth day or earlier, and he expressed concern that our mean length of postoperative stay is in the range of 7 to 9 days. The mean length of stay figure is inevitably skewed toward the high side by the occasional patient who has a long hospital stay. The median and the mode are somewhat better measures of the stay of the typical uncomplicated patient. Both the median and the mode in the general anesthesia group were 7 days and both the median and the mode were 5 days in the local anesthesia group. I do not have a good answer to the question of why general anesthesia was associated with an increased need for hospital care.
The American Journal of Surgery