Carotid endarterectomy under local anesthesia: single institutional experience
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《血管的通路杂志》
a Department of Cardiovascular Surgery, SB Vakf Gureba Hospital, Capa, 34390, Istanbul, Turkey
b Department of Thoracic Surgery, VKV American Hospital, Istanbul, Turkey
c Department of Anesthesiology, Vakf Gureba Hospital, Istanbul, Turkey
Abstract
The aim of this study is to review our experience and results of carotid endarterectomy performed under local anesthesia. We evaluated 300 patients who had undergone carotid endarterectomy with local anesthesia in our department. Surgical indication, outcome, operative technique, and complications were assessed. The patients were 58.20±2.76 years old and 153 (51%) were symptomatic. The perioperative course was uneventful. A shunt was inserted because of neurological deterioration in 20 patients (6.6%) with full recovery of the deficit after shunt insertion. Operative time was 52.02±12.86 min. There were 9 patients with postoperative neurological complications with one patient who died after 34 days. The remaining 8 patients with reversible neurological deficits recovered and were symptom-free on discharge. The mean length of hospital stay was 2.11±1.34 days. Carotid endarterectomy performed under local anesthesia is associated with low morbidity and mortality rates. The surgeon can assess the neurological status during the procedure and provide for a more meticulous endarterectomy. It is also associated with decreased shunt usage, decreased operative time and shorter length of hospital stay.
Key Words: Carotid endarterectomy; Local anesthesia; Awake patient
1. Introduction
With the recent refinements in cardiac surgery and anesthetic management, carotid atherosclerosis may be surgically treated today with very low morbidity and mortality rates. However, the maintenance of an adequate cerebral blood circulation during arterial clamping still remains the cornerstone of the procedure. After the introduction of carotid endarterectomy (CEA) in an awake patient without general anesthesia, the use of local anesthesia (LA) for carotid endarterectomy is rapidly increasing. Various series using local anesthesia carotid endarterectomy (LA CEA) for treatment of carotid stenosis had been reported in the literature in an attempt to decrease the risk of potential postoperative catastrophic complications [1–3]. The purpose of this study is to review our experience of LA CEA and determine whether the use of LA reduces postoperative morbidity and mortality.
2. Methods
Between November 2001 and September 2005, 300 consecutive patients underwent carotid endarterectomy without general anesthesia in SB Vakf Gureba Training Hospital, Cardiovascular Surgery Department. There was no patient in the series who refused to have carotid endarterectomy with local anesthesia. A carotid endarterectomy procedure was not carried out in symptomatic patients with a stenosis rate <50% and in asymptomatic patients with a stenosis rate <70%.
Clinical assessment, electrocardiogram and biochemical analysis were performed as an initial diagnostic work-up. In case of suspicion, further diagnostic evaluation was performed with echocardiography and cardiac catheterization. In patients with an established diagnosis of ischemic heart disease (IHD), a coronary bypass grafting and/or percutaneous angioplasty procedures were firstly carried out prior to carotid endarterectomy procedure. Duplex scanning and/or angiographic evaluation were the modalities used in all patients to establish a definitive diagnosis. Further investigations were undertaken as needed for assessment of any clinical abnormality.
Data evaluated retrospectively included patient age, sex, surgical indication, pre-operative characteristics, diagnostic methods used, degree of stenosis, shunt usage, primary or patch closure, operative time, any neurological deterioration during or after surgery, early postoperative problems and length of hospital stay.
2.1. Surgical technique
All operations were performed in an awake patient without general anesthesia and without premedication. Local anesthetic protocol consisted of local infiltration using a mixture of 0.5% bupivacaine (10 ml) and prilocaine (10 mg/ml, 10 ml). Additionally, local anesthetic was given during the dissection if required.
All patients were routinely monitored with non-invasive arterial blood pressure, pulse oximetry and electrocardiogram. In patients with blood pressure instability, arterial blood pressure was also continuously monitored throughout the operation with an indwelling catheter placed in the radial artery. Neurological status of the patient was evaluated by questioning before the incision. Direct neurological examination was also performed to confirm their level of consciousness throughout the procedure by asking the patients to answer the questions. The motor function of contralateral limb was closely monitored.
A standard carotid endarterectomy was performed in all patients. Briefly, following systemic heparinization (75 mg/kg), cross-clamps were applied. Systolic arterial blood pressure was kept between 170–210 mmHg during clampage. In the case of ST-changes, slow nitroglycerine infusion has been used without reducing systolic arterial blood pressure level below the desired levels. A shunt was inserted if there was a deterioration in the level of consciousness, an increased confusion and contralateral limb motor dysfunction. A long arteriotomy, beginning from below the plaque in the common carotid artery and extending to normal intima above the plaque in internal carotid artery (ICA), was done and the plaque was liberated by using an elevator. Following saline irrigation, the arteriotomy site was closed primarily with 6-0 polyprolene suture material if the internal carotid artery diameter was larger than 5 mm. Patch closure with a polytetrafluoroethylene (PTFE) patch material was undertaken in the remaining patients if any stenosis was thought to occur. Although obtaining hemostasis may be troublesome with PTFE material, no additional method of hemostasis has been required in these patients.
Patients were transferred to the surgical unit and closely monitored for non-invasive arterial blood pressure, heart rate, pulse oximetry and neurological status. Hemodynamically and neurologically unstable patients were admitted to the intensive care unit for close observation. All patients were evaluated daily by neurological staff until discharge and reviewed with clinical and Duplex examination at 3 months, 6 months and 1 year.
Neurologic events were classified as minor and major neurological deficits. Minor neurological deficits included transient ischemic attacks and any other neurological problem that resolved within 48 h. Major neurological deficits were defined as those deficits that lasted beyond 7 days. Myocardial infarction was defined as the occurrence of ST-changes and enzyme elevation during the postoperative period.
3. Results
Three hundred patients were operated on during a time period of 4 years. In our series, no patient required the conversion to general anesthesia. Forty patients (13.3%) had both sides operated. We firstly operated on the symptomatic site and after one week, the contralateral site was operated on. The patients ranged in age from 42 to 88 years at the time of diagnosis, with the mean age being 58.2±2.76 years. The female/male ratio was 60/240 and duration of the procedure was 52.02±12.86 min. There were 153 (51%) symptomatic patients in our series. Preoperative demographic data of patients are given in Table 1. There were 48 patients who underwent previous CABG operation in the series. The number of patients receiving medical therapy for ischemic heart disease was 53. Common symptoms in patients included transient ischemic attacks in 106 patients (35.3%), hemiplegia in 26 (8.6%) and amaurosis fugax in 8 (2.6%). The definitive diagnosis was established with carotid duplex in 80 patients (26.7%), carotid duplex and/or angiographic evaluation in the remaining (73.3%). Carotid artery stenosis rate was 50–70% in 80 patients (26.7%) and 70–99% in 220 patients (73.3%).
There were four cases of reoperation for postoperative bleeding. There were nine postoperative neurological complications during the study period (3%). One patient who had an ipsilateral stroke one day postoperatively died on day 34 from pulmonary complications (0.3%). Four patients had transient ischemic attacks (TIA), one patient had transient hemiplegia (TH), one patient had transient monoparesia (upper arm) (TM), two patients had transient facial nerve paralysis (TFP) during the early postoperative period. The Duplex scanning evaluation of the patients was normal. Except for the patients with facial nerve paralysis and monoparesia, all 5 patients recovered and they were event-free on discharge. There was no postoperative myocardial infarction or ECG abnormality indicating coronary ischemia.
A Pruitt-Inara type shunt (Pruitt-Inara Carotid Shunt, Out-lining model, Ideas for Medicine, Inc, USA) was placed in 16 patients (5.3%). The neurological deficit detected during arterial clamping was reversed by shunt insertion in all patients and there were no complications related to shunt insertion. The arteriotomy site was closed primarily in 260 patients (86.7%). In the remaining 40 patients (13.3%), a PTFE patch material was used because of the small diameter of the vessel. During the follow-up period, restenosis was detected in 15 patients in whom the arteritomy site was closed primarily (15/260, 5.76%). All these patients were reoperated and the stenotic area was enlarged with a PTFE patch material. The mean clampage time was 11.62±2.06 min. The mean operative time was 52.02±12.86 min. The mean length of hospital stay ranged from 2 to 14 days, with a mean of 2.11±1.34 days.
4. Discussion
After the accurate definition of surgical indications in patients with carotid atherosclerosis by the ECST, NASCET and ACAS, many surgeons have shown interest in attempts to reduce the risk of postoperative catastrophic neurological complications [4–6]. Although many methods including transcranial Doppler, stump pressure measurement, peri-operative EEG and somatosensorial evoked potentials have been proposed to monitor the level of cerebral perfusion during arterial clamping, there is no established consensus as to which is the superior technique. However, evidence from a large series suggested that local anesthesia reduces shunt placement, major morbidity, mortality and decreases the length of hospital stay [2,3,7,8].
Although shunt usage appears to reduce major events, shunting during carotid endarterectomy remains a dilemma. The use of shunting in carotid surgery itself can give rise to complications including shunt thrombosis, embolization and intimal damage [7,9]. We believe that selective shunting is the preferable policy in carotid surgery. Transcranial Doppler, stump pressure measurement, perioperative EEG and somatosensorial evoked potentials have been proposed, but none have been shown to be reliable in defining the exact criteria for shunting during arterial clamping. With local anesthesia, since reliable neurological assessment can be performed in an awake patient, we are able to closely monitor the neurological status of the patient throughout the operation. Although regional anesthesia seems to offer similar advantages, local anesthesia is quicker and more comfortable.
In our series, shunts have been used in 16 patients (5.3%) and our shunt rate was significantly less than that in literature [10,11]. Reduced shunt usage has been also reported in similar studies using LA CEA [12,13]. The most obvious advantage of local anesthesia is the avoidance of unnecessary shunt placement. Hafner and Evans reported that 86% of patients with stump pressures <50 mmHg would have been shunted unnecessarily [9]. As mentioned before, the methods used to predict which patients need a shunt are usually not reliable in assessing cerebral hypoperfusion and lead to unnecessarily increased shunt usage. LA enables awake cerebral monitoring and is associated with reduced neurological complications due to selective shunt usage.
Although local anesthesia offers many advantages, technical difficulties may occur in some group of patients. In our patients with short necks, we did not encounter any problem during the operation. On the other hand, we also believe that the use of local anesthesia in some patients with longer lesions extending into the siphon, the exposure requires more retraction and may be problematic. In this subset of patients, the cooperation with the patient gains more importance. In our series, we gave additional local anesthetic during the dissection if required to deal with pain. The use of minimal sedation may be considered in some patients; but, we generally try to avoid sedation during the operation since it may obscure neurological assessment.
The patients with carotid atherosclerosis also possess many co-morbid risk factors which directly increase surgical morbidity and mortality rates. Carotid stenting has been proposed by some centers; but, we do not have enough experience with this modality. The long-term results of percutaneous applications are not well-defined; therefore, we believe that surgical treatment still remains as a more reliable and durable procedure in these patients. In our series, there were 70 patients with a previous myocardial infarction and 46 patients with chronic obstructive pulmonary disease (COPD). Although endotracheal intubation is usually associated without significant complications, hemodynamic responses to tracheal intubation, tube suctioning and extubation may lead to myocardial ischemia and represent a risk for patients with known coronary artery disease [14,15]. Data from several studies suggest that LA is associated with greater cardiovascular stability throughout the peri- and post-operative periods. In their series of 1271 patients, Assadian et al. reported a 1.4% incidence of postoperative myocardial infarction [16]. In some other studies, it has been reported that the use of local anesthesia group was associated with a lower incidence of shunt placement, operative time, and perioperative hemodynamic instability compared to general anesthesia [17]. Rerkasem and colleagues reported that meta-analysis of studies showed that the use of local anesthetic was associated with significant reductions in the odds of death, stroke and myocardial infarction [18]. In our series, there was no postoperative myocardial infarction or ECG abnormality indicating coronary ischemia.
Although the advent of less invasive techniques for cardiovascular surgery affected the anesthetic approaches, individual patients with COPD vary in their susceptibility to endotracheal intubation. In the current surgical era, we believe that the avoidance of endotracheal intubation, especially in patients with co-morbid factors, offers significant benefits, including a reduction in morbidity, mortality and cost.
In conclusion, LA CEA has several advantages. Local anesthesia enables the surgeon to assess the neurological status during the procedure and provides for a more meticulous endarterectomy. It is also associated with decreased shunt usage, decreased operative time and shorter length of hospital stay.
References
Tangkanakul C, Counsell C, Warlow C. Local versus general anaesthesia for carotid endarterectomy. Cochrane Database Syst Rev 2002; 2: CD000126.
Love A, Hollyoak MA. Carotid endarterectomy and local anaesthesia: reducing the disasters. Cardiovasc Surg 2000; 8:429–435.
McCarthy RJ, Walker R, Mc Ateer P, Budd JS, Horrocks M. Patient and hospital benefits of local anaesthesia for carotid endarterectomy. Eur J Vasc Endovasc Surg 2001; 22:13–18.
Executive Committee for the Asymptomatic Carotid Atherosclerosis Study. Endarterectomy for asymptomatic carotid artery stenosis. J Am Med Assoc 1995; 273:1421–1428.
North American Symptomatic Carotid Endarterectomy Trial Collaborators. Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis. New Engl J Med 1991; 325:445–453.
European Carotid Surgery Trialists Collaborative Group. MRC European carotid surgery trial: interim results for symptomatic patients with severe (70–99%) or with mild (0–29%) carotid stenosis. Lancet 1991; 337:1235–1243.
Riles TS, Imparota AM, Jacobowitz GR, Lamparello PJ, Giangola G, Adelman MA, Landis R. The cause of perioperative stroke after carotid endarterectomy. J Vasc Surg 1994; 19:206–216.
Shah DM, Darling C, Chang B, Bock DE, Paty PS, Leather RP. Carotid endarterectomy in awake patients: its safety, acceptability and outcome. J Vasc Surg 1994; 19:1015–1020.
Hafner CD, Evans WE. Carotid endarterectomy with local anaesthesia: results and advantages. J Vasc Surg 1988; 7:232–239.
Benjamin ME, Silva MB Jr, Watt C, McCaffrey MT, Burford-Foggs A, Flinn WR. Awake patient monitoring to determine the need for shunting during carotid endarterectomy. Surgery 1993; 114:673–679.
Bowyer NW, Zierold D, Loftus JP, Egan JC, Inglis KJ, Halow KD. Carotid endarterectomy: a comparision of regional versus general anaesthesia in 500 operations. Ann Vasc Surg 2000; 14:145–151.
Allen BT, Anderson CB, Rubin BG, Thompson RW, Flye MW, Young-Beyer P, Frisella P, Sicard GA. The influence of anaesthetic technique on perioperative complications after carotid endarterectomy. J Vasc Surgery 1994; 19:834–841.
Donato AT, Hill SL. Carotid artery surgery using local anaesthesia. American Surgeon 1992; 58:447–450.
Paulissian R, Salem MR, Joseph NJ, Braverman B, Cohen HC, Crystal GJ, Heyman HJ. Hemodynamic responses to endotracheal extubation after coronary artery bypass grafting. Anesth Analg 1991; 73:10–15.
Mikawa K, Nishina K, Takao Y, Shiga M, Maekawa N, Obara H. Attenuation of cardiovascular responses to tracheal extubation: comparison of verapamil, lidocaine, and verapamil-lidocaine combination. Anesth Analg 1997; 85:1005–1010.
Assadian A, Senekowitsch C, Assadian O, Ptakovsky H, Hagmuller GW. Perioperative morbidity and mortality of carotid artery surgery under loco-regional anaesthesia. Vasa Feb 2005; 34:41–45.
Watts K, Lin PH, Bush RL, Awad S, McCoy SA, Felkai D, Zhou W, Nguyen L, Guerrero MA, Shenaq SA, Lumsden AB. The impact of anesthetic modality on the outcome of carotid endarterectomy. Am J Surg Dec 2004; 188:741–747.
Rerkasem K, Bond R, Rothwell PM. Local versus general anaesthesia for carotid endarterectomy. Cochrane Database Syst Rev 2004; 2: CD000126.(Yusuf Kalko, Unal Aydin, )
b Department of Thoracic Surgery, VKV American Hospital, Istanbul, Turkey
c Department of Anesthesiology, Vakf Gureba Hospital, Istanbul, Turkey
Abstract
The aim of this study is to review our experience and results of carotid endarterectomy performed under local anesthesia. We evaluated 300 patients who had undergone carotid endarterectomy with local anesthesia in our department. Surgical indication, outcome, operative technique, and complications were assessed. The patients were 58.20±2.76 years old and 153 (51%) were symptomatic. The perioperative course was uneventful. A shunt was inserted because of neurological deterioration in 20 patients (6.6%) with full recovery of the deficit after shunt insertion. Operative time was 52.02±12.86 min. There were 9 patients with postoperative neurological complications with one patient who died after 34 days. The remaining 8 patients with reversible neurological deficits recovered and were symptom-free on discharge. The mean length of hospital stay was 2.11±1.34 days. Carotid endarterectomy performed under local anesthesia is associated with low morbidity and mortality rates. The surgeon can assess the neurological status during the procedure and provide for a more meticulous endarterectomy. It is also associated with decreased shunt usage, decreased operative time and shorter length of hospital stay.
Key Words: Carotid endarterectomy; Local anesthesia; Awake patient
1. Introduction
With the recent refinements in cardiac surgery and anesthetic management, carotid atherosclerosis may be surgically treated today with very low morbidity and mortality rates. However, the maintenance of an adequate cerebral blood circulation during arterial clamping still remains the cornerstone of the procedure. After the introduction of carotid endarterectomy (CEA) in an awake patient without general anesthesia, the use of local anesthesia (LA) for carotid endarterectomy is rapidly increasing. Various series using local anesthesia carotid endarterectomy (LA CEA) for treatment of carotid stenosis had been reported in the literature in an attempt to decrease the risk of potential postoperative catastrophic complications [1–3]. The purpose of this study is to review our experience of LA CEA and determine whether the use of LA reduces postoperative morbidity and mortality.
2. Methods
Between November 2001 and September 2005, 300 consecutive patients underwent carotid endarterectomy without general anesthesia in SB Vakf Gureba Training Hospital, Cardiovascular Surgery Department. There was no patient in the series who refused to have carotid endarterectomy with local anesthesia. A carotid endarterectomy procedure was not carried out in symptomatic patients with a stenosis rate <50% and in asymptomatic patients with a stenosis rate <70%.
Clinical assessment, electrocardiogram and biochemical analysis were performed as an initial diagnostic work-up. In case of suspicion, further diagnostic evaluation was performed with echocardiography and cardiac catheterization. In patients with an established diagnosis of ischemic heart disease (IHD), a coronary bypass grafting and/or percutaneous angioplasty procedures were firstly carried out prior to carotid endarterectomy procedure. Duplex scanning and/or angiographic evaluation were the modalities used in all patients to establish a definitive diagnosis. Further investigations were undertaken as needed for assessment of any clinical abnormality.
Data evaluated retrospectively included patient age, sex, surgical indication, pre-operative characteristics, diagnostic methods used, degree of stenosis, shunt usage, primary or patch closure, operative time, any neurological deterioration during or after surgery, early postoperative problems and length of hospital stay.
2.1. Surgical technique
All operations were performed in an awake patient without general anesthesia and without premedication. Local anesthetic protocol consisted of local infiltration using a mixture of 0.5% bupivacaine (10 ml) and prilocaine (10 mg/ml, 10 ml). Additionally, local anesthetic was given during the dissection if required.
All patients were routinely monitored with non-invasive arterial blood pressure, pulse oximetry and electrocardiogram. In patients with blood pressure instability, arterial blood pressure was also continuously monitored throughout the operation with an indwelling catheter placed in the radial artery. Neurological status of the patient was evaluated by questioning before the incision. Direct neurological examination was also performed to confirm their level of consciousness throughout the procedure by asking the patients to answer the questions. The motor function of contralateral limb was closely monitored.
A standard carotid endarterectomy was performed in all patients. Briefly, following systemic heparinization (75 mg/kg), cross-clamps were applied. Systolic arterial blood pressure was kept between 170–210 mmHg during clampage. In the case of ST-changes, slow nitroglycerine infusion has been used without reducing systolic arterial blood pressure level below the desired levels. A shunt was inserted if there was a deterioration in the level of consciousness, an increased confusion and contralateral limb motor dysfunction. A long arteriotomy, beginning from below the plaque in the common carotid artery and extending to normal intima above the plaque in internal carotid artery (ICA), was done and the plaque was liberated by using an elevator. Following saline irrigation, the arteriotomy site was closed primarily with 6-0 polyprolene suture material if the internal carotid artery diameter was larger than 5 mm. Patch closure with a polytetrafluoroethylene (PTFE) patch material was undertaken in the remaining patients if any stenosis was thought to occur. Although obtaining hemostasis may be troublesome with PTFE material, no additional method of hemostasis has been required in these patients.
Patients were transferred to the surgical unit and closely monitored for non-invasive arterial blood pressure, heart rate, pulse oximetry and neurological status. Hemodynamically and neurologically unstable patients were admitted to the intensive care unit for close observation. All patients were evaluated daily by neurological staff until discharge and reviewed with clinical and Duplex examination at 3 months, 6 months and 1 year.
Neurologic events were classified as minor and major neurological deficits. Minor neurological deficits included transient ischemic attacks and any other neurological problem that resolved within 48 h. Major neurological deficits were defined as those deficits that lasted beyond 7 days. Myocardial infarction was defined as the occurrence of ST-changes and enzyme elevation during the postoperative period.
3. Results
Three hundred patients were operated on during a time period of 4 years. In our series, no patient required the conversion to general anesthesia. Forty patients (13.3%) had both sides operated. We firstly operated on the symptomatic site and after one week, the contralateral site was operated on. The patients ranged in age from 42 to 88 years at the time of diagnosis, with the mean age being 58.2±2.76 years. The female/male ratio was 60/240 and duration of the procedure was 52.02±12.86 min. There were 153 (51%) symptomatic patients in our series. Preoperative demographic data of patients are given in Table 1. There were 48 patients who underwent previous CABG operation in the series. The number of patients receiving medical therapy for ischemic heart disease was 53. Common symptoms in patients included transient ischemic attacks in 106 patients (35.3%), hemiplegia in 26 (8.6%) and amaurosis fugax in 8 (2.6%). The definitive diagnosis was established with carotid duplex in 80 patients (26.7%), carotid duplex and/or angiographic evaluation in the remaining (73.3%). Carotid artery stenosis rate was 50–70% in 80 patients (26.7%) and 70–99% in 220 patients (73.3%).
There were four cases of reoperation for postoperative bleeding. There were nine postoperative neurological complications during the study period (3%). One patient who had an ipsilateral stroke one day postoperatively died on day 34 from pulmonary complications (0.3%). Four patients had transient ischemic attacks (TIA), one patient had transient hemiplegia (TH), one patient had transient monoparesia (upper arm) (TM), two patients had transient facial nerve paralysis (TFP) during the early postoperative period. The Duplex scanning evaluation of the patients was normal. Except for the patients with facial nerve paralysis and monoparesia, all 5 patients recovered and they were event-free on discharge. There was no postoperative myocardial infarction or ECG abnormality indicating coronary ischemia.
A Pruitt-Inara type shunt (Pruitt-Inara Carotid Shunt, Out-lining model, Ideas for Medicine, Inc, USA) was placed in 16 patients (5.3%). The neurological deficit detected during arterial clamping was reversed by shunt insertion in all patients and there were no complications related to shunt insertion. The arteriotomy site was closed primarily in 260 patients (86.7%). In the remaining 40 patients (13.3%), a PTFE patch material was used because of the small diameter of the vessel. During the follow-up period, restenosis was detected in 15 patients in whom the arteritomy site was closed primarily (15/260, 5.76%). All these patients were reoperated and the stenotic area was enlarged with a PTFE patch material. The mean clampage time was 11.62±2.06 min. The mean operative time was 52.02±12.86 min. The mean length of hospital stay ranged from 2 to 14 days, with a mean of 2.11±1.34 days.
4. Discussion
After the accurate definition of surgical indications in patients with carotid atherosclerosis by the ECST, NASCET and ACAS, many surgeons have shown interest in attempts to reduce the risk of postoperative catastrophic neurological complications [4–6]. Although many methods including transcranial Doppler, stump pressure measurement, peri-operative EEG and somatosensorial evoked potentials have been proposed to monitor the level of cerebral perfusion during arterial clamping, there is no established consensus as to which is the superior technique. However, evidence from a large series suggested that local anesthesia reduces shunt placement, major morbidity, mortality and decreases the length of hospital stay [2,3,7,8].
Although shunt usage appears to reduce major events, shunting during carotid endarterectomy remains a dilemma. The use of shunting in carotid surgery itself can give rise to complications including shunt thrombosis, embolization and intimal damage [7,9]. We believe that selective shunting is the preferable policy in carotid surgery. Transcranial Doppler, stump pressure measurement, perioperative EEG and somatosensorial evoked potentials have been proposed, but none have been shown to be reliable in defining the exact criteria for shunting during arterial clamping. With local anesthesia, since reliable neurological assessment can be performed in an awake patient, we are able to closely monitor the neurological status of the patient throughout the operation. Although regional anesthesia seems to offer similar advantages, local anesthesia is quicker and more comfortable.
In our series, shunts have been used in 16 patients (5.3%) and our shunt rate was significantly less than that in literature [10,11]. Reduced shunt usage has been also reported in similar studies using LA CEA [12,13]. The most obvious advantage of local anesthesia is the avoidance of unnecessary shunt placement. Hafner and Evans reported that 86% of patients with stump pressures <50 mmHg would have been shunted unnecessarily [9]. As mentioned before, the methods used to predict which patients need a shunt are usually not reliable in assessing cerebral hypoperfusion and lead to unnecessarily increased shunt usage. LA enables awake cerebral monitoring and is associated with reduced neurological complications due to selective shunt usage.
Although local anesthesia offers many advantages, technical difficulties may occur in some group of patients. In our patients with short necks, we did not encounter any problem during the operation. On the other hand, we also believe that the use of local anesthesia in some patients with longer lesions extending into the siphon, the exposure requires more retraction and may be problematic. In this subset of patients, the cooperation with the patient gains more importance. In our series, we gave additional local anesthetic during the dissection if required to deal with pain. The use of minimal sedation may be considered in some patients; but, we generally try to avoid sedation during the operation since it may obscure neurological assessment.
The patients with carotid atherosclerosis also possess many co-morbid risk factors which directly increase surgical morbidity and mortality rates. Carotid stenting has been proposed by some centers; but, we do not have enough experience with this modality. The long-term results of percutaneous applications are not well-defined; therefore, we believe that surgical treatment still remains as a more reliable and durable procedure in these patients. In our series, there were 70 patients with a previous myocardial infarction and 46 patients with chronic obstructive pulmonary disease (COPD). Although endotracheal intubation is usually associated without significant complications, hemodynamic responses to tracheal intubation, tube suctioning and extubation may lead to myocardial ischemia and represent a risk for patients with known coronary artery disease [14,15]. Data from several studies suggest that LA is associated with greater cardiovascular stability throughout the peri- and post-operative periods. In their series of 1271 patients, Assadian et al. reported a 1.4% incidence of postoperative myocardial infarction [16]. In some other studies, it has been reported that the use of local anesthesia group was associated with a lower incidence of shunt placement, operative time, and perioperative hemodynamic instability compared to general anesthesia [17]. Rerkasem and colleagues reported that meta-analysis of studies showed that the use of local anesthetic was associated with significant reductions in the odds of death, stroke and myocardial infarction [18]. In our series, there was no postoperative myocardial infarction or ECG abnormality indicating coronary ischemia.
Although the advent of less invasive techniques for cardiovascular surgery affected the anesthetic approaches, individual patients with COPD vary in their susceptibility to endotracheal intubation. In the current surgical era, we believe that the avoidance of endotracheal intubation, especially in patients with co-morbid factors, offers significant benefits, including a reduction in morbidity, mortality and cost.
In conclusion, LA CEA has several advantages. Local anesthesia enables the surgeon to assess the neurological status during the procedure and provides for a more meticulous endarterectomy. It is also associated with decreased shunt usage, decreased operative time and shorter length of hospital stay.
References
Tangkanakul C, Counsell C, Warlow C. Local versus general anaesthesia for carotid endarterectomy. Cochrane Database Syst Rev 2002; 2: CD000126.
Love A, Hollyoak MA. Carotid endarterectomy and local anaesthesia: reducing the disasters. Cardiovasc Surg 2000; 8:429–435.
McCarthy RJ, Walker R, Mc Ateer P, Budd JS, Horrocks M. Patient and hospital benefits of local anaesthesia for carotid endarterectomy. Eur J Vasc Endovasc Surg 2001; 22:13–18.
Executive Committee for the Asymptomatic Carotid Atherosclerosis Study. Endarterectomy for asymptomatic carotid artery stenosis. J Am Med Assoc 1995; 273:1421–1428.
North American Symptomatic Carotid Endarterectomy Trial Collaborators. Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis. New Engl J Med 1991; 325:445–453.
European Carotid Surgery Trialists Collaborative Group. MRC European carotid surgery trial: interim results for symptomatic patients with severe (70–99%) or with mild (0–29%) carotid stenosis. Lancet 1991; 337:1235–1243.
Riles TS, Imparota AM, Jacobowitz GR, Lamparello PJ, Giangola G, Adelman MA, Landis R. The cause of perioperative stroke after carotid endarterectomy. J Vasc Surg 1994; 19:206–216.
Shah DM, Darling C, Chang B, Bock DE, Paty PS, Leather RP. Carotid endarterectomy in awake patients: its safety, acceptability and outcome. J Vasc Surg 1994; 19:1015–1020.
Hafner CD, Evans WE. Carotid endarterectomy with local anaesthesia: results and advantages. J Vasc Surg 1988; 7:232–239.
Benjamin ME, Silva MB Jr, Watt C, McCaffrey MT, Burford-Foggs A, Flinn WR. Awake patient monitoring to determine the need for shunting during carotid endarterectomy. Surgery 1993; 114:673–679.
Bowyer NW, Zierold D, Loftus JP, Egan JC, Inglis KJ, Halow KD. Carotid endarterectomy: a comparision of regional versus general anaesthesia in 500 operations. Ann Vasc Surg 2000; 14:145–151.
Allen BT, Anderson CB, Rubin BG, Thompson RW, Flye MW, Young-Beyer P, Frisella P, Sicard GA. The influence of anaesthetic technique on perioperative complications after carotid endarterectomy. J Vasc Surgery 1994; 19:834–841.
Donato AT, Hill SL. Carotid artery surgery using local anaesthesia. American Surgeon 1992; 58:447–450.
Paulissian R, Salem MR, Joseph NJ, Braverman B, Cohen HC, Crystal GJ, Heyman HJ. Hemodynamic responses to endotracheal extubation after coronary artery bypass grafting. Anesth Analg 1991; 73:10–15.
Mikawa K, Nishina K, Takao Y, Shiga M, Maekawa N, Obara H. Attenuation of cardiovascular responses to tracheal extubation: comparison of verapamil, lidocaine, and verapamil-lidocaine combination. Anesth Analg 1997; 85:1005–1010.
Assadian A, Senekowitsch C, Assadian O, Ptakovsky H, Hagmuller GW. Perioperative morbidity and mortality of carotid artery surgery under loco-regional anaesthesia. Vasa Feb 2005; 34:41–45.
Watts K, Lin PH, Bush RL, Awad S, McCoy SA, Felkai D, Zhou W, Nguyen L, Guerrero MA, Shenaq SA, Lumsden AB. The impact of anesthetic modality on the outcome of carotid endarterectomy. Am J Surg Dec 2004; 188:741–747.
Rerkasem K, Bond R, Rothwell PM. Local versus general anaesthesia for carotid endarterectomy. Cochrane Database Syst Rev 2004; 2: CD000126.(Yusuf Kalko, Unal Aydin, )