Francesco Speziale

Locoregional versus general anesthesia in carotid surgery: Is there an impact on perioperative myocardial ischemia? Results of a prospective monocentric randomized trial

PURPOSE The incidence of cardiac morbidity and mortality in patients who undergo carotid surgery ranges from 0.7% to 7.1%, but it still represents almost 50% of all perioperative complications. Because no data are available in literature about the impact of the anesthetic technique on such complications, a prospective randomized monocentric study was undertaken to evaluate the role of local anesthesia (LA) and general anesthesia (GA) on cardiac outcome. METHODS From November 1995 to February 1998, 107 patients were classified by the cardiologist as cardiac patients (IHD; history of myocardial infarction, previous myocardial revascularization procedures, or myocardial ischemia documented by means of positive electrocardiogram [ECG] stress test results) or noncardiac patients (NIHD; no history of chest pain or negative results for an ECG stress test). The patients were operated on after the randomization for the type of anesthesia (general or local). Continuous computerized 12-lead ECG was performed during the operative procedure and 24 hours postoperatively. The end points of the study were ECG modifications (upsloping or downsloping more than 2 mm) of the sinus tachycardia (ST) segment. RESULTS Fifty-five patients were classified as IHD, and 52 were classified as NIHD. Twenty-seven of the 55 IHD patients (49%) and 24 of 52 NIHD patients (46%) were operated on under GA. Thirty-six episodes of myocardial ischemia occurred in 22 patients (20.5%). Episodes were slightly more frequent (58%) and longer in the postoperative period (intraoperative, 10 +/- 5 min; postoperative, 60 +/- 45 min; P <. 001). As expected, the prevalence of myocardial ischemia was higher in the group of cardiac patients than in noncardiac group (15 of 55 patients [27%] vs 7 of 52 patients [13%]; P <.02). By comparing the two anesthetic techniques in the overall population, we found a similar prevalence of patients who had myocardial ischemia (GA, 12 of 52 [23%]; LA, 10 of 55 [18%]; P = not significant) and a similar number of ischemic episodes per patient (GA, 1.5 +/- 0.4; LA, 1.8 +/- 0.6; P = not significant). Episodes of myocardial ischemia were similarly distributed in intraoperative and postoperative periods in both groups. It is relevant that under GA, IHD patients represent most of the population who suffered myocardial ischemia (83%). On the contrary, in the group of patients operated on under LA, the prevalence was equally distributed in the two subpopulations. CONCLUSION The results confirm the different hemodynamic impact of the two anesthetic techniques. Patients who received LA had a rate of myocardial ischemia that was half that of patients who had GA. The small number of cardiac complications do not permit us to make any definitive conclusion on the impact of the two anesthetic techniques on early cardiac morbidity, but the relationship between perioperative ischemic burden and major cardiac events suggests that LA can be used safely, even in high-risk patients undergoing carotid endarterectomy.

Post-carotid endarterectomy hyperperfusion syndrome: Preliminary observations for identifying at risk patients by transcranial doppler sonography and the acetazolamide test

Patients at risk of hyperperfusion syndrome after carotid endarterectomy are often severely hypertensive and have a high grade internal carotid artery stenosis with disordered autoregulation due to a loss of reserve capacity (RC). Cerebral RC can be studied by sophisticated and expensive technical devices (SPECT, PET). Recently it has been demonstrated that the transcranial Doppler (TCD) and acetazolamide provocation test can be used to assess RC. From September 1991 to January 1992, 36 patients were studied by the TCD and acetazolamide test prior to carotid endarterectomy to identify patients at high risk of the hyperperfusion syndrome. Preoperatively, the patients were studied by TCD at rest and after vasolidation with acetazolamide 1 g intravenously (i.v.). Mean blood flow velocity on the middle cerebral artery (MCAv) was recorded for the following 20 min at 5 min intervals. MCAv at rest was 49 +/- 17 cm/s. After acetzaolamide infusion in 33 patients (92%), the mean MCAv was 62 +/- 19 cm/s with an increase of 19 +/- 13 cm/s (normal RC). In three patients (8%), the mean MCAv was 43 +/- 22 cm/s with a decrease of -6 +/- 3 cm/s with respect to base values (reduction of RC). (t = 3.30; p = 0.0022). All these patients were hypertensive (BP > 180/100 mmHg) and had a carotid artery stenosis > 90%. Postoperatively, the three patients with reduction of RC complained of homolateral headache. TCD showed a mean MCAv of 67 +/- 17 cm/s, an increase compared to the preoperative rest values of 17 +/- 8 cm/s, the 33 patients with normal RC showed a mean change in MCAv -2 +/- 12 cm/s.(ABSTRACT TRUNCATED AT 250 WORDS)

Detection of aortic graft infection with leukocytes labeled with technetium 99m—hexametazime

PURPOSE To reduce the rates of morbidity and mortality in aortic graft infection, a new diagnostic approach is needed to help identify low-grade stages, specifically when there are minimal or no clinical signs of overt infection. The aim of this study was to evaluate the role of technetium 99m--hexametazime white blood cell scanning (99mTc scanning) in detecting aortic graft infection, particularly in the low-grade stages. METHODS AND RESULTS Thirty-seven patients with suspected aortic graft infection were categorized into three groups according to their signs and symptoms on readmission. Ten patients (group A) had advanced graft infections that were correctly diagnosed by use of computed tomography (CT) scanning and 99mTc scanning and confirmed by intraoperative findings and culture results. Eighteen patients (group B) had nonspecific signs and symptoms of graft infection. Patients only underwent CT and 99mTc scanning for graft infection after standard clinical work-ups failed to reveal disease processes that accounted for the clinical symptoms. In this group of patients 99mTc scanning identified four cases of low-grade graft infection, which was confirmed by intraoperative findings and graft cultures. None of these four cases was confirmed by results of CT scanning. On an average 18-month follow-up in patients who did not undergo surgery graft infections developed. Nine patients (group C) had anastomotic aneurysms; CT scanning and 99mTc scanning correctly diagnosed five patients as being infected. The result of 99mTc scanning was false-positive in one patient. CONCLUSIONS The diagnostic accuracy of 99mTc scanning in patients who did not have specific signs of graft infection (groups B and C) was 100% for sensitivity, 94.4% for specificity, 90% for the positive predictive value, and 100% for the negative predictive value. 99mTc scanning seems to be a useful diagnostic technique for detecting aortic graft infection, particularly in low-grade stages.

General anaesthesia versus cervical block and perioperative complications in carotid artery surgery

PURPOSE To compare the influence of anaesthetic technique on perioperative complications in patients undergoing carotid endarterectomy. MATERIAL AND METHODS In a retrospective study of 1020 consecutive patients who underwent carotid artery surgery over 10 years, perioperative neurologic and cardiologic complications and the use of an internal carotid artery shunt were compared in 337 patients (33%) treated under general anaesthesia and 683 (67%) under cervical block. The two groups had similar characteristics. The most frequent surgical indication was symptomatic carotid artery disease (91.5%). The remaining patients had asymptomatic severe internal carotid lesions (> 70%). RESULTS The overall perioperative stroke rate was 1.9%, the death-stroke rate 0.7% and the cardiac complication rate 0.8%. The perioperative stroke rate was higher in the general anaesthesia group than in the cervical block group (3.2% vs 1.3%, p = 0.01). Cardiac complication rates were similar in the two groups. A carotid artery shunt was used in 75 patients (22%) receiving general anaesthesia and in 92 patients (13%) receiving cervical block (p = 0.0004). The causes of stroke in the cervical block group were intraoperative embolism (4 cases, 26%), perioperative thromboembolism (7 cases, 58%) and clamping ischaemia (1 case, 16%). Mechanisms causing stroke in the general anaesthesia group remained unidentified or uncertain. CONCLUSIONS Cervical block anaesthesia yields better perioperative results than general anaesthesia probably because it allows more reliable cerebral monitoring, reducing or even eliminating perioperative strokes related to clamping ischaemia. It facilitates detection of the mechanism underlying intraoperative stroke allowing surgical techniques and intraoperative management to be modified accordingly. Cervical block anaesthesia significantly reduces the need for internal carotid artery shunting.

Comparative study on carotid revascularization (endarterectomy vs stenting) using markers of cellular brain injury, neuropsychometric tests, and diffusion-weighted magnetic resonance imaging.

OBJECTIVE Subclinical alterations of cerebral function can occur during or after carotid revascularization and can be detected by a variety of standard tests. This comparative study assessed the relationship among serum levels for two biochemical markers of cerebral injury, postoperative diffusion-weighted magnetic resonance imaging (DW-MRI), and neuropsychometric testing in patients undergoing carotid endarterectomy (CEA) or carotid artery stenting (CAS) for high-grade asymptomatic carotid stenosis. METHODS Forty-three consecutive asymptomatic patients underwent carotid revascularization by endarterectomy (CEA, 20) or stenting (CAS, 23). They were evaluated with DW-MRI and the Mini-Mental State Examination (MMSE) test preoperatively and <or=24 hours after carotid revascularization. Venous blood samples to assess serum levels of neuron-specific enolase (NSE) and S100beta protein were collected for each patient preoperatively and five times in a 24-hour period postoperatively and assayed using automated commercial equipment. The MMSE test was repeated at 6 months. The relationship between serum marker levels and neuropsychometric and imaging tests and differences between the two groups of patients were analyzed by chi(2) test, with significance at P < .05. RESULTS No transient ischemic attacks or strokes were clinically observed. CAS caused more new subcortical lesions at postoperative DW-MRI and a significant decline in the MMSE postoperative score compared with CEA (P = .03). In CAS patients, new lesions at DW-MRI were significantly associated with a postoperative MMSE score decline >5 points (P = .001). Analysis of S100beta and NSE levels showed a significant increase at 24 hours in CAS patients compared with CEA patients (P = .02). The MMSE score at 6 months showed a nonsignificant increase vs the postoperative score in both groups. CONCLUSIONS Biochemical markers measurements of brain damage combined with neuropsychometric tests and DW-MRI can be used to evaluate silent injuries after CAS. The mechanisms of rise in S100beta and NSE levels at 24 hours after CAS may be due to increased perioperative microembolization rather than to hypoperfusion. Further studies are required to assess the clinical significance of those tests in carotid revascularization.

Contrast-Enhanced Ultrasound Imaging for Aortic Stent-Graft Surveillance

Purpose: To compare unenhanced and enhanced ultrasound imaging to computed tomographic angiography (CTA) or magnetic resonance angiography (MRA) for surveillance of aortic endografts. Methods: Thirty consecutive patients (29 men; mean age 69 years, range 50–82) who underwent endovascular aortic aneurysm repair agreed to participate in a follow-up program. Patients underwent CTA (26/30) or MRA (4/30), plain abdominal radiography, and unenhanced and enhanced ultrasound examinations at 3, 12, and 24 months to evaluate aneurysm diameter, endoleaks, and graft patency. The accuracy of ultrasound was compared with CTA or MRA as the reference standards. Results: Twenty-six patients reached the 24-month assessment (mean follow-up 30 months, range 6–60). All endoleaks detected by CTA or MRA were confirmed by enhanced ultrasound; the aneurysm diameter in these patients remained unchanged or increased. In patients without endoleaks on any imaging method, the sac diameter remained unchanged or decreased. Endoleaks disclosed by enhanced ultrasound alone, all type II, numbered 16 at 3 months, 6 at 12 months, and 3 at 24 months. In this group, the aneurysm diameter remained unchanged or increased. Enhanced ultrasound yielded 100% sensitivity in detecting endoleaks, but compared with CTA and MRA, all endoleaks detected by enhanced ultrasound alone were false positives (mean specificity 65%). Nevertheless, because changes in the postoperative aneurysm diameter were similar in patients with endoleaks detectable on CTA/MRA and on enhanced ultrasound (“true positives”) and in those with endoleaks detectable only on enhanced ultrasound (“false positives”), some endoleaks were possibly “true positive” results. Conclusions: Enhanced ultrasound is a useful method in the long-term surveillance of endovascular aortic aneurysm repairs, possibly in association with CTA or MRA. Enhanced ultrasound also seems able to identify endoleaks missed by other imaging techniques, but this conclusion awaits further investigation.

INFLAMMATORY ANEURYSMS OF THE ABDOMINAL AORTA INVOLVING THE URETERS: IS COMBINED TREATMENT REALLY NECESSARY?

PURPOSE Peri-aneurysmal fibrosis complicating inflammatory aneurysm of the abdominal aorta may involve the ureters, causing urological complications. We assessed patient anatomical and clinical outcomes after conservative ureteral management. MATERIALS AND METHODS From the operative records of 1,271 consecutive patients who underwent surgical repair of abdominal aortic aneurysms from 1980 to 1999 we identified 77 (6%) who had inflammatory aneurysms, which were complicated in 19 (24.6%) by dense peri-aneurysmal and ureteral fibrosis. Of these 19 patients 15 (78.9%) had coexisting monolateral hydronephrosis, 3 (15.7%) had bilateral hydronephrosis and 1 (5.2%) had renal atrophy. In 14 cases (73.6%) the fibrotic reaction severely impaired renal function. Only 1 patient underwent an emergency operation, while the others underwent elective repair. Only 2 patients (10.5%) underwent a specific urological procedure, including bilateral nephrostomy in 1 and ureterolysis plus ureterolithotomy in 1. Most ureteral complications were treated conservatively by aneurysmectomy only. RESULTS Immediate postoperative mortality was 7% (1 of 14 cases). Median followup was 48 months. In 1 of the 13 cases (7.7%) a ureteral stent was placed during followup. After aneurysmectomy in 9 of the 12 patients (75%) with renal dysfunction periaortic fibrosis disappeared or decreased as well as associated hydronephrosis. In 11 of the remaining 12 patients (91%) of the 14 with renal failure preoperatively kidney function returned to normal or improved. In the 2 patients who underwent a specific urological procedure renal function improved but did not return to normal. CONCLUSIONS Inflammatory abdominal aortic aneurysms involving the ureters and compressing the urinary structures respond well to aneurysmal resection only without a urological procedure.

Diagnosis of vascular graft infections with antibodies against staphylococcal slime antigens

Late-onset infections of synthetic vascular grafts (LO-SVGIs) are generally caused by staphylococci that produce a slime polysaccharide and grow as a biofilm on the graft surface. We developed an ELISA to detect serum antibodies against staphylococcal slime polysaccharide antigens (SSPA). Patients with an ongoing staphylococcal LO-SVGI had greater titres of IgM antibodies against SSPA than did patients in other groups. Antibody titres of 0.40 ELISA units (EU) or more, or 0.35 EU or more detected 97% and 100% of staphylococcal LO-SVGIs, respectively, 0% and 2% titre/unit false-positive results. Our findings suggest that such an ELISA represents a sensitive, specific, and non-invasive diagnostic test for staphylococcal LO-SVGIs.

Intraoperative Transcranial Doppler Sonography Monitoring during Carotid Surgery under Locoregional Anaesthesia

OBJECTIVES Studies comparing transcranial Doppler ultrasonography (TCD) with other intraoperative monitoring techniques for detecting clamping ischaemia during carotid endarterectomy under general anaesthesia suggest that a reduction of > two-thirds in the mean middle cerebral artery velocity (mMCAv) or a reduction of > 0.4 in the preclamping mMCAv: clamping mMCAv ratio warrants cerebral protection. Our aim was to study the relationship between mMCAvs and clamping ischaemia during carotid endarterectomy in awake patients. MATERIALS AND METHODS In a consecutive series of 57 patients undergoing carotid endarterectomy under locoregional anaesthesia 51 were monitored by intraoperative TCD, continuous EEG, and neurologic awake testing. RESULTS Five of the 51 (9.8%) patients had transient clamping ischaemia, which carotid shunting reversed. TCD showed that these five patients had significant lower mean mMCAvs than the other 46 patients, who had no deficits (1.8 +/- 1.1 cm/s vs. 26.2 +/- 8.5, p = 0.0003). Current TCD criteria indicated that four other patients (7.8%) should have been shunted. All four had significantly higher clamping mMCAvs than the five shunted patients (11.5 +/- 1.9 vs. 1.8 +/- 1.1, p = 0.0012). CONCLUSIONS Intraoperative TCD detected cerebral ischaemia and yielded no false-negative. An mMCAv of 10 cm/s or less may indicate the risk of clamping ischaemia better than the higher threshold currently proposed. This would avoid unnecessary shunting due to false-positives.

Urgent carotid endarterectomy to prevent recurrence and improve neurologic outcome in mild-to-moderate acute neurologic events

OBJECTIVES This study evaluated the safety and benefit of urgent carotid endarterectomy (CEA) in patients with carotid disease and an acute stable neurologic event. METHODS The study involved patients with acute neurologic impairment, defined as ≥ 4 points on the National Institutes of Health Stroke Scale (NIHSS) evaluation related to a carotid stenosis ≥ 50% who underwent urgent CEA. Preoperative workup included neurologic assessment with the NIHSS on admission or immediately before surgery and at discharge, carotid duplex scanning, transcranial Doppler ultrasound imaging, and head computed tomography or magnetic resonance imaging. End points were perioperative (30-day) neurologic mortality, significant NIHSS score improvement or worsening (defined as a variation ≥ 4), and hemorrhagic or ischemic neurologic recurrence. Patients were evaluated according to their NIHSS score on admission (4-7 or ≥ 8), clinical and demographic characteristics, timing of surgery (before or after 6 hours), and presence of brain infarction on neuroimaging. RESULTS Between January 2005 and December 2009, 62 CEAs were performed at a mean of 34.2 ± 50.2 hours (range, 2-280 hours) after the onset of symptoms. No neurologic mortality nor significant NIHSS score worsening was detected. The NIHSS score decreased in all but four patients, with no new ischemic lesions detected. The mean NIHSS score was 7.05 ± 3.41 on admission and 3.11 ± 3.62 at discharge in the entire group (P < .01). Patients with an NIHSS score of ≥ 8 on admission had a bigger score reduction than those with a lower NIHSS score (NIHSS 4-7; mean 4.95 ± 1.03 preoperatively vs 1.31 ± 1.7 postoperatively, NIHSS ≥ 8 10.32 ± 1.94 vs 4.03 ± 3.67; P < .001). CONCLUSIONS In patients with acute neurologic event, a high NIHSS score does not contraindicate early surgery. To date, guidelines recommend treatment of symptomatic carotid stenosis ≤ 2 weeks from onset of symptoms to minimize the neurologic recurrence. Our results suggest that minimizing the time for intervention not only reduces the risk of recurrence but can also improve neurologic outcome.