Five-step protocol for carotid endarterectomy in the managed health care era

Completion Arteriogram Following Carotid Endarterectomy Yields Lower Perioperative Stroke Rate

Introduction: Completion imaging following carotid endarterectomy (CEA) remains controversial. We present our experience performing routine completion arteriography (CA). Methods: A retrospective review of our prospectively maintained institutional database was performed for patients undergoing isolated CEA. Results: 1439 isolated CEAs with CA were performed on 1297 patients. CEA was for asymptomatic lesions in 70% (1003) of cases. There were no complications related to arteriography. An abnormal arteriogram documented significant abnormalities in the internal carotid artery (ICA) and prompted revision in 1.7% (24/1439) of cases: 20 unsatisfactory distal endpoints of the endarterectomy (12 residual stenoses, 7 intimal flaps, and 1 dissection), 3 kinks or stenoses within the body of the patch, and 1 thrombus. Of the 20 distal endpoint lesions, stent deployment was used in 17 cases and patch revision in 3 cases. The other 4 cases were treated by patch angioplasty (3) or thrombectomy (1). None suffered a perioperative stroke. The overall 30-day stroke, death, and combined stroke/death rate for the 1439 patients in our series was 1.5% (22), .5% (7), and 1.9% (27), respectively. The combined stroke/death rate for asymptomatic lesions was 1.1% (11/1003) and for symptomatic lesions was 2.5% (11/436). Of the 22 strokes in the entire series (all with normal CA), 15 were non-hemorrhagic strokes ipsilateral to the CEA; 14 were confirmed to have widely patent endarterectomy sites by CT-A (13) or re-exploration and repeat arteriography (1). The occluded site was re-explored and underwent thrombectomy, but no technical problems were identified. The remaining strokes were hemorrhagic (4 reperfusion syndrome and 1 surgical site bleeding) or contralateral to the CEA (2). Conclusion: Although not all patients in this series who underwent intraoperative revision due to abnormal CA might have suffered a stroke, performing this simple and safe study may have halved our overall perioperative stroke rate from 3.2% to 1.5%.

Carotid endarterectomy with adjunctive cephalad carotid stenting: Complementary, not competitive, techniques

OBJECTIVE

Stenosis of the cephalad internal carotid artery (ICA) can present a challenge, making it difficult to obtain a technically satisfying distal end point during endarterectomy. Surgical revision of distal defects can be difficult and yield unsatisfactory results. The purpose of this review is to evaluate the efficacy of intraoperative carotid stenting as an adjunct to endarterectomy to salvage technical defects identified at the cephalad ICA endarterectomy site.

METHODS

Between January 2001 and February 2008, 14 patients were found to have technical defects located at the cephalad ICA endarterectomy site on intraoperative completion arteriogram. All defects were treated with adjunctive carotid stenting. Patient age ranged from 53 to 84 years (mean, 69 years). Indications for surgery were asymptomatic stenosis (nine), amaurosis fugax (two), and cerebrovascular accident (three). Operative time ranged from 2 to 5 hours (mean, 2.5 hours). Cervical block was used in all but two patients who received general anesthesia.

RESULTS

Technically satisfying results with stenting were achieved in all 14 patients. One patient suffered a perioperative transient ischemic attack; however, neurologic symptoms were noted before placement of the stent in this patient. There were no stent-related complications. All stents remained patent on duplex follow-up averaging 18 months.

CONCLUSION

Intraoperative salvage carotid stenting is an effective and safe adjunct to endarterectomy when unsatisfactory technical defects are identified at the cephalad ICA endarterectomy site.

Clinical-outcome-based demand management in health services

THE PROBLEM OF MANAGING DEMAND: Most healthcare systems have 'third-party payers' who face the problem of keeping within budgets despite pressures to increase resources due to the ageing population, new technologies and patient demands to lower thresholds for care. This paper uses the UK National Health Service as a case study to suggest techniques for system-based demand management, which aims to control demand and costs whilst maintaining the cost-effectiveness of the system.

TECHNIQUE FOR MANAGING DEMAND

The technique for managing demand in primary, elective and urgent care consists of managing treatment thresholds for appropriate care, using a whole-systems approach and costing the care elements in the system. It is important to analyse activity in relation to capacity and demand. Examples of using these techniques in practice are given.

CONCLUSION

The practical effects of using such techniques need evaluation. If these techniques are not used, managing demand and limiting healthcare expenditure will be at the expense of clinical outcomes and unmet need, which will perpetuate financial crises.

Correlation of carotid artery stump pressure and neurologic changes during 474 carotid endarterectomies performed in awake patients

PURPOSE

A carotid artery stump pressure (SP) of < 50 mm Hg and abnormal electroencephalography (EEG) changes have been suggested as indications for selective shunting in patients undergoing carotid endarterectomy (CEA) under general anesthesia. We attempted to determine the optimal SP threshold that correlated with neurologic changes in awake patients undergoing CEA using cervical block anesthesia (CBA) and performed a cost comparison with EEG monitoring.

METHODS

Between July 1, 1995, and December 31, 2004, SP was measured during 474 CEAs performed under CBA by inserting a 19-gauge butterfly needle into the common carotid artery. A saline-filled intravenous bag in the patient's contralateral hand was connected to pressure tubing to generate waveforms with hand squeezing that could be visualized on a monitor. Systemic pressure was maintained approximately 10 mm Hg higher than baseline. Accurate SPs were confirmed by the finding of flatline waveforms after internal carotid artery clamping. Selective shunting was performed when neurologic changes occurred (aphasia, inability to squeeze the contralateral hand, decreased consciousness), regardless of SP. During this same period, 142 patients underwent CEA using GA, and SP was also measured.

RESULTS

Shunting was necessary because of neurologic changes in 7.2% (34/474) of all CEAs performed using CBA: 0.9% (3/335) with SPs > or = 50 mm Hg systolic vs 1.0% (4/402) with SPs > or = 40 mm Hg systolic, and 22% (31/139) with SPs < 50 mm Hg systolic vs 42% (30/72) with SPs < 40 mm Hg systolic. If these 474 CEAs had been performed using GA, shunts would have been used in 29% (139/474) of patients for a SP < 50 mm Hg systolic vs 15% (72/474) for a SP < 40 mm Hg systolic. In patients not shunted, the perioperative stroke/death rate was 1.2% in patients (4/332) with SPs > or = 50 mm Hg vs 1.0% (4/398) with SPs > or = 40 mm Hg. Three of the four strokes occurred > 24 hours postoperatively and were unrelated to lack of shunting and ischemia. There was no significant difference in the percentage of patients with SPs > or = 50 mm Hg who underwent CEA using CBA (70%, 335/474) vs GA (67%, 96/142) during this time period. At our hospital, charges for SPe measurement, including anesthesia charges and tubing, were 229 dollars per case vs 3439 dollars per case for EEG monitoring. Use of SP measurements in these 474 patients would have resulted in reduced charges of 1,521,540 dollars compared with EEG monitoring if CEA had been performed under GA.

CONCLUSION

Using 40 mm Hg systolic as a threshold, the need for shunting (15%) and the false-negative rate (1.0%) for SP in our series were equivalent to the results of EEG monitoring during CEA reported in the literature. However, charges for SP measurements are dramatically lower compared with EEG monitoring. Our results suggest that a carotid artery SP > or = 40 mm Hg systolic may be considered as an equally reliable but more cost-effective method to predict the need for carotid shunting during CEA under GA compared with EEG monitoring, but further investigation is warranted.

A Comparison of Magnetic Resonance Angiography, Contrast Arteriography, and Duplex Arteriography for Patients Undergoing Lower Extremity Revascularization

The objective of this study was to compare magnetic resonance angiography (MRA), contrast arteriography (CA), and duplex arteriography (DA) for defining anatomic features relevant to performing lower extremity revascularizations. From March 1, 2001 to August 1, 2001, 33 consecutive inpatients with chronic lower extremity ischemia underwent CA, MRA, and DA before undergoing lower extremity revascularization procedures. The reports of these tests were compared prospectively and the differences in the aortoiliac segment, femoral-popliteal, and infrapopliteal segments were noted. The vessels were classified as mild disease (<50%), moderate disease (50-70%), severe disease (71-99%), and occluded. These studies and treatment plans based on these data were compared. During this time period, 11 patients were not able to undergo MRA and therefore were excluded from the study. Thirty-three patients were included in this study. These patients underwent 35 procedures, as 2 patients underwent bilateral procedures. The mean age of the 33 patients was 76+/-10 years (SD). Indications for the procedures included gangrene (20), ischemic ulcer (8), rest pain (4), and severe claudication (1). Patients' medical history included diabetes mellitus (25), hypertension (20), and end-stage renal disease (5). No differences were noted between intraoperative findings and CA in this series. Two of the three differences between DA and CA were felt to be clinically significant whereas 9 of the 12 differences between MRA and CA were felt to be clinically significant. On the basis of these data in this series, MRA does not yet seem to be able to obtain adequate data on infrapopliteal segments, at least not for this highly selected population. When severe tibial calcification or very low flow states are identified, CA may be necessary for patients undergoing DA.

Local versus general anaesthesia for carotid endarterectomy

BACKGROUND

Carotid endarterectomy reduces the risk of stroke in people with recently symptomatic, severe carotid artery stenosis. However, there are significant perioperative risks which may be lessened by performing the operation under local rather than general anaesthetic.

OBJECTIVES

The aim of this review was to assess the risks of endarterectomy under local compared with general anaesthetic.

SEARCH STRATEGY

We searched the Stroke Group trials register (April 2003), MEDLINE (1966 to April 2003), EMBASE (1980 to 2002), and Index to Scientific and Technical Proceedings (1980 to 1994). We handsearched 13 relevant journals up to 2002, and searched the reference lists of articles identified. We also advertised the review in Vascular News (a newspaper for European vascular specialists) in August 2001.

SELECTION CRITERIA

Randomised trials and non-randomised studies comparing carotid endarterectomy under local versus general anaesthetic.

DATA COLLECTION AND ANALYSIS

One reviewer selected studies for inclusion and another independently checked the decisions. Two reviewers assessed trial quality and independently extracted the data.

MAIN RESULTS

Seven randomised trials involving 554 operations, and 41 non-randomised studies involving 25622 operations were included. The methodological quality of the non-randomised trials was questionable. Eleven of the non-randomised studies were prospective and 29 reported on a consecutive series of patients. In nine non-randomised studies the number of arteries, as opposed to the number of patients, was unclear. Meta-analysis of the non-randomised studies showed that the use of local anaesthetic was associated with significant reductions in the odds of death (35 studies), stroke (31 studies), stroke or death (26 studies), myocardial infarction (22 studies), and pulmonary complications (7 studies), within 30 days of the operation. Meta-analysis of the randomised studies showed that the use of local anaesthetic was associated with a significant reduction in local haemorrhage (OR = 0.31, 95% CI = 0.12 to 0.79) within 30 days of the operation, but there was no evidence of a reduction in the odds of operative stroke. However, the trials were too small to allow reliable conclusions to be drawn, and in some studies intention-to-treat analyses were not possible because of exclusions.

REVIEWERS' CONCLUSIONS

There is insufficient evidence from randomised trials comparing carotid endarterectomy performed under local and general anaesthetic. Non-randomised studies suggest potential benefits with the use of local anaesthetic, but these studies may be biased. More randomised studies are needed.

Systematic review of the risks of carotid endarterectomy in relation to the clinical indication for and timing of surgery

BACKGROUND AND PURPOSE

Reliable data on the risk of carotid endarterectomy (CEA) in relation to clinical indication and timing of surgery are necessary to target CEA more effectively, to inform patients, to adjust risks for case mix, and to understand the mechanisms of operative stroke.

METHODS

We performed a systematic review of all studies published from 1980 to 2000 inclusive that reported the risk of stroke and death resulting from CEA. Pooled estimates of risk by type of presenting ischemic event and time since the last event were obtained by Mantel-Haenszel meta-analysis.

RESULTS

Of 383 published studies, only 103 stratified risk by indication. Although the operative risk for symptomatic stenosis overall was higher than for asymptomatic stenosis (odds ratio [OR], 1.62; 95% confidence interval [CI], 1.45 to 1.81; P<0.00001; 59 studies), risk in patients with ocular events only tended to be lower than for asymptomatic stenosis (OR, 0.75, 95% CI, 0.50 to 1.14; 15 studies). Operative risk was the same for stroke and cerebral transient ischemic attack (OR, 1.16; 95% CI, 0.99 to 1.35; P=0.08; 23 studies) but higher for cerebral transient ischemic attack than for ocular events only (OR, 2.31; 95% CI, 1.72 to 3.12; P<0.00001; 19 studies) and for CEA for restenosis than primary surgery (OR, 1.95; 95% CI, 1.21 to 3.16; P=0.018; 6 studies). Urgent CEA for evolving symptoms had a much higher risk (19.2%, 95% CI, 10.7 to 27.8) than CEA for stable symptoms (OR, 3.9; 95% CI, 2.7 to 5.7; P<0.001; 13 studies), but there was no difference between early (<3 to 6 weeks) and late (>3 to 6 weeks) CEA for stroke in stable patients (OR, 1.13; 95% CI, 0.79 to 1.62; P=0.62; 11 studies). All observations were highly consistent across studies.

CONCLUSIONS

Risk of stroke and death resulting from CEA is highly dependent on the clinical indication. Audits of risk should be stratified accordingly, and patients should be informed of the risk that relates to their presenting event.

Routine preoperative carotid duplex scanning in patients undergoing open heart surgery: is it worthwhile?

It has been reported that carotid screening may be cost-effective in patient populations in which the prevalence of severe carotid stenosis exceeds 4.5%. In order to identify potential patient populations who might benefit from carotid screening, we examined the results of preoperative duplex scanning in patients undergoing open heart surgery. Between January 1995 and July 1998, 3708 patients (59% male, 41% female) underwent open heart surgery at our institution. Of these, 3081 underwent coronary artery bypass grafting (CABG), 364 underwent valve replacement (VR), and 263 underwent CABG and VR. The ages of these patients ranged from 40 years to 98 years (mean 68 +/- 11 years). The risk factors analyzed included hypertension (HTN), 59%; smoking (Smk), 53%; and diabetes (DM), 33%. Patients were divided into three groups according to their age. Group A consisted of the 835 patients who were < or = 60 years old, group B consisted of 2474 patients ranging from 61 years to 80 years old, and group C consisted of 399 patients who were > or = 81 years old. All patients underwent bilateral preoperative carotid duplex scans at an Intersocietal Commission for the Accreditation of Vascular Laboratories (ICAVL)-accredited vascular laboratory. Statistical analyses were performed using chi-squared, Fisher's exact test, linear regression, and multivariate analysis. From our results we concluded that carotid screening is not recommended for patients under 60 years of age who are undergoing CABG unless they present with a minimum of two of the following major risk factors: hypertension, diabetes, or smoking. However, carotid screening is recommended for all patients undergoing open heart operations who are over the age of 60 years old, regardless of the absence of associated risk factors.

Carotid endarterectomy; local or general anaesthesia?

OBJECTIVES

to review the evidence for theoretical and clinical benefits of local or general anaesthesia for carotid endarterectomy.

METHODS

literature review.

RESULTS

animal studies suggest cerebral protection by a variety of general anaesthetic agents but clinical evidence is lacking. There is some clinical evidence that normal cerebral protective reflexes are preserved with local anaesthesia. Shunt insertion is the most widely used method of providing cerebral protection with awake testing the most reliable monitoring technique for the identification of ischaemia. There are therefore theoretical arguments for a reduced risk of perioperative stroke when local anaesthesia is used and this is supported by a meta-analysis of non-randomised studies. Intraoperative blood pressure is always higher with local anaesthesia but the incidence of postoperative haemodynamic instability seems to be independent of anaesthetic technique. There is little evidence that myocardial ischaemia is more common with either anaesthetic technique but meta-analysis of non-randomised again suggests fewer cardiac complications with local anaesthesia. Cranial nerve injury and haematoma formation may be less common with local anaesthesia but the evidence is weak. There is no evidence that surgery is more difficult with local anaesthesia or that it is poorly tolerated by the patients.

CONCLUSIONS

there are theoretical arguments and clinical evidence that the outcome from carotid endarterectomy may be better when local anaesthesia is used with no significant disadvantages. An appropriately designed randomised trial is required to confirm this.

Timing of postcarotid complications: a guide to safe discharge planning

OBJECTIVES

Currently, our standard of practice is that patients undergoing carotid endarterectomy (CEA) may be safely discharged on the first postoperative day. Because many patients do not appear to require overnight observation, we wanted to determine the safety and feasibility of same-evening discharge by establishing the timing of postoperative complications, which may potentially require operative intervention.

METHODS

A total of 835 consecutive patients undergoing CEA were retrospectively reviewed. Sixty-two patients had a postoperative wound hematoma or neurologic deficit (ND) (transient ischemic attack or stroke) within 24 hours of their operation, complications potentially requiring a second operation. Excluded were 64 patients not eligible for same-day discharge because of other reasons (eg, heparinization, CEA with coronary artery bypass grafting).

RESULTS

Sixty-two patients (8.0%) had ND (26 [3.4%]) or neck hematoma (NH) (36 [4.7%]) within 24 hours of their CEA. Nineteen (73%) of the NDs were diagnosed in the operating room or recovery room, 5 (19%) within 8 hours of the operation, and 2 (7.7%) after 8 hours but in less than 24 hours. Of the NHs, 23 (66%) were diagnosed in the recovery room, 11 (31%) within 8 hours, and 1 (2.7%) after 8 hours. Of the outliers, one patient experienced a blowout of the vein graft occurring on postoperative day 1, one patient had a delayed ipsilateral stroke, and one had a vertebrobasilar stroke. Overall, only three of 773 (0.4%) patients undergoing CEA had a complication occurring more than 8 hours after operation.

CONCLUSION

NDs and NHs in post-CEA patients occurred within 8 hours of operation in 95% of those patients experiencing these complications or 99.6% of all CEA patients. These data indicate that same-evening discharge may be safely performed without increasing the adverse effects of stroke or hematoma. This plan has cautiously been initiated at this institution.

Changing characteristics of carotid endarterectomy

We have noted significant differences in terms of our preoperative work-up, length of stay, morbidity, and mortality of patients undergoing carotid endarterectomy (CEA) from findings reported in large published randomized clinical trials. To further investigate these differences, we have reviewed our recent experience. CEA has proved to be the most effective approach to avert stokes caused by significant atherosclerotic disease of the carotid bifurcation. Between January 1, 1996 and December 31, 1998, 552 patients underwent CEA at our institution. Forty percent were performed in symptomatic patients with stenotic lesions > 60% in diameter by duplex ultrasonography. The remainder were performed for asymptomatic lesions > 60% in diameter. No patient underwent contrast angiography. Fifty-two percent of the patients were males. The mean age was 74 +/- 8 years old. General anesthesia was used in 97% of the cases and regional block, in 3%. All patients underwent routine postoperative measurement of serum creatinine phosphokinase (CPK) isoenzymes. Patients were discharged when deemed clinically stable. The patients' follow-up visits at 1 week and at 3-5 months after the procedure (mean, 3.4 months) included a neurological exam and duplex exam. Patient results suggest that CEAs can be performed in the modern era without contrast arteriography. Most patients can be discharged on the first postoperative day. In addition, previously acceptable rates of postoperative morbidity and mortality should perhaps be revised to meet current standards. Contrary to the previous concept that most postoperative strokes are due to embolic phenomena, hyperperfusion syndrome played an increasingly important role in this review.

Converting from general anesthesia to cervical block anesthesia for carotid endarterectomy

Between January 1, 1992 and June 30, 1998, vascular and general surgery residents performed 401 carotid endarterectomies (185 cervical block, 216 general anesthesia) under supervision of vascular attending surgeons. In January 1995, cervical block anesthesia was newly instituted. Initially anesthesiologists were randomly assigned to these cases and anesthetic technique was not standardized. At the surgeons' insistence later in the series, three specially trained anesthesiologists routinely administered cervical block anesthesia. As experience grew, surgeons realized that operating time greater than 2 hours and high neck dissections requiring mandibular retraction were poorly tolerated by cervical block anesthesia patients but that repeat carotid endarterectomies could be safely performed. Shunts were selectively inserted if significant electroencephalographic changes occurred or carotid stump pressures were less than 50 mm Hg systolic when general anesthesia was used; neurologic changes occurred when cervical block anesthesia was used; or there was a history of ipsilateral stroke for either anesthetic method. Despite an initial learning curve with cervical block anesthesia, the stroke-mortality rate was similar between the two groups (general anesthesia: 1.9% [four cerebrovascular accidents, two deaths]; cervical block anesthesia: 1.6% [two cerebrovascular accidents, two deaths]). Eight (12%) of the first 66 cervical block anesthesia patients were converted to general anesthesia compared to 2 (1.7%) of the most recent 119 patients with cervical block anesthesia (p = 0.03). After cervical block anesthesia was initiated, seven of the first eight repeat carotid endarterectomies were performed using general anesthesia compared to one of the most recent six repeat cases (p = 0.02). As surgeons' comfort with cervical block anesthesia increased, 94% (100) of the most recent consecutive 106 carotid endarterectomies were performed using this technique. These results suggest that carotid endarterectomy can be performed as safely using cervical block anesthesia as general anesthesia, specialized anesthesiologists are essential to achieve a successful outcome, selected repeat carotid endarterectomies can be performed using cervical block anesthesia, very cephalad lesions are best treated using general anesthesia, and surgical trainees can safely perform carotid endarterectomy under attending surgeon supervision if the operation is carried out expeditiously.

Short stay carotid surgery for veterans: an emerging standard

We have taken the short stay approach to carotid artery surgery to our VA setting over the past 5 to 6 years. Retrospectively, we reviewed the efficacy and safety of that approach in 201 consecutive carotid operations over the recent 4-year period (January 1, 1996-December 31, 1999). In 1996 we had already begun the transition to an algorithm to (1) utilize carotid color flow Doppler duplex exams for diagnosis, (2) same-day admission (SDA), (3) intensive care unit (ICU) only when deemed medically necessary, and (4) next-day discharge. Results of this approach have been a decrease in the utilization of diagnostic arteriograms and utilization of the ICU from 100% previous to the onset of this approach to 17 and 22%, respectively. SDA increased from 24 to 89%. Mean LOS decreased from 5.13+/-0.9 to 1.97+/-0.4 days. The percentage of patients completing the algorithm went from 15 to 72%. Stroke and/or death varied from 0 to 3.7% each year and was only 2.4% over the 4-year period. In conclusion, this approach to short stay carotid surgery in the veteran population has proven both efficacious and safe with results similar to those in university and community practices.

Cost Containment in Vascular Surgery

In the last decade, the delivery of health care and the role of the physician have undergone radical change. With the ad vent of managed care and the tightening of restrictions by Medicare and insurance companies, physicians have been required to review, re-engineer, and revitalize their role. Increasing financial pressures at the hospital level have caused administrators to cut costs at all levels. It is imper ative that physicians take an active role in cost containment so that the quality of care is not sacrificed. Cost containment in vascular surgery is an urgent priority in health care. Copyright © 2000 by W.B. Saunders Company.