Brenno Fiorani

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.

Preoperative Angiotensin-Converting Enzyme Inhibitors and Acute Kidney Injury After Coronary Artery Bypass Grafting

BACKGROUND Angiotensin-converting enzyme (ACE) inhibitors confer renal protection in different clinical settings. No final conclusions are available on the renal benefits of ACE inhibitors after coronary artery bypass grafting (CABG). Because ACE inhibitors decrease glomerular perfusion pressure, they may exacerbate kidney injury during cardiopulmonary bypass (CPB)-related hypoperfusion. We evaluated the effect of preoperative ACE inhibitors on acute kidney injury (AKI) after CABG. METHODS A propensity score-based analysis of 536 patients undergoing CABG on CPB was performed, among which 281 received ACE inhibitors preoperatively. Patients with preoperative end-stage renal failure requiring dialysis were excluded. Postoperative AKI was defined as 50% or more decrease in the glomerular filtration rate from preoperative or postoperative mechanical renal support. RESULTS After CABG, AKI developed in 49 patients (9.1%), and 23 (4.2%) required dialysis. The incidence of AKI was 6.4% in patients who received preoperative ACE inhibitors and 12.2% in patients who did not (p = 0.02). The incidence of AKI requiring dialysis was 2.4% in the treatment group and 6.3% in controls (p = 0.03). After adjusting for propensity score and covariates, preoperative ACE inhibitors were found to reduce the incidence of postoperative AKI (odds ratio, 0.48; 95% confidence interval, 0.23 to 0.77; p = 0.04). Other independent predictors were age, preoperative glomerular filtration rate, left ventricular ejection fraction of less than 0.35, preoperative use of intraaortic balloon pump, emergency operation, and CPB time. CONCLUSIONS Preoperative ACE inhibitors are associated with a reduced rate of AKI after on-pump CABG surgery.

Emergency operation for acute type A aortic dissection: neurologic complications and early mortality.

BACKGROUND Acute type A aortic dissection is a surgical emergency still associated with high postoperative complications. The aim of this study was to investigate factors for hospital mortality and neurologic deficit in patients undergoing emergency operation for acute type A aortic dissection. METHODS Eighty-five consecutive patients (age range, 20 to 82 years) operated on for acute type A aortic dissection over a 6-year period were evaluated. Univariate and stepwise multiple logistic regression analyses were conducted among 32 perioperative variables. RESULTS All patients underwent surgical procedures under deep hypothermic circulatory arrest. Antegrade or retrograde cerebral perfusion was used in 23 patients (27.1%) and 18 patients (21.2%), respectively. Forty-three patients underwent arch/hemiarch replacement and the ascending aorta was replaced in 42 patients. Overall mortality rate was 25.9% (22 of 85 patients). Multiple logistic regression analysis showed that lack of cerebral perfusion (p = 0.021) and postoperative renal failure (p = 0.006) were the best predictors for hospital death. Twenty-one patients (24.7%) experienced neurologic accidents. The risk factor for postoperative neurologic complication was lack of cerebral perfusion (p = 0.013). Hospital mortality was 13% (3 of 23 patients) and 16.7% (3 of 18 patients) in the antegrade and retrograde cerebral perfusion groups (p > 0.05) and neurologic deficit was 13% (3 of 23 patients) and 11.1% (2 of 18 patients), respectively (p > 0.05). CONCLUSIONS Hospital mortality and neurologic complications in patients undergoing emergent operation for acute type A aortic dissection were reduced when cerebral perfusion was used with deep hypothermic circulatory arrest.

Reoperation After Surgical Correction of Acute Type A Aortic Dissection: Risk Factor Analysis

BACKGROUND Aortic dissection is an evolving process that may require one or several reoperations after its initial repair. We conducted a study to evaluate risk factors and define the incidence and locations of reoperations after surgical correction of acute type A aortic dissection (AAD). METHODS Between 1998 and 2008, 250 consecutive patients (mean age 62.5±12.4 years) underwent surgery for AAD at our institution. Replacement of the ascending aorta was done in 173 cases, composite graft replacement in 61 cases, separate aortic valve and ascending aorta replacement in 2 cases, and arch replacement required by distal repair in 14 cases. Mean follow-up time was 4.7±5.6 years. RESULTS Freedom from reoperation was 99%, 82%, and 79% at 1, 5, and 10 years, respectively. Twenty-five patients required 25 reoperations at a mean interval of 4.7 years after initial surgery for the correction of AAD. Reoperations included 21 procedures on the proximal aorta (ascending aorta, aortic root, or valve) and 4 procedures on the distal aorta (arch or descending aorta). Cox regression analysis identified the use of gelatin-resorcinol-formaldehyde (GRF) glue (p=0.0270), and nonreplacement of the aortic root at the time of initial AAD repair (p=0.0004), as a significant risk factor for proximal reoperation, and a patent false lumen (p=0.0107) as a significant risk factor for distal reoperation. CONCLUSIONS A patent false lumen, the use of GRF glue, and aortic root preservation at initial operation influence the risk for surgical correction in patients undergoing surgery for AAD. These patients need long-term follow-up.

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.

Effects of Preoperative Statin Treatment on the Incidence of Postoperative Atrial Fibrillation in Patients Undergoing Coronary Artery Bypass Grafting

BACKGROUND Postoperative atrial fibrillation is still a common complication in patients undergoing coronary artery bypass grafting. The aim of this study was to evaluate the effect of preoperative statin therapy on new onset of postoperative atrial fibrillation in patients undergoing coronary artery bypass grafting. METHODS Of 8,946 patients undergoing isolated coronary artery bypass grafting at the Bristol Heart Institute from April 1996 to September 2006, 6,321 (70.6%) received preoperative statins. Of these, 2,152 patients (statin group) were matched to a control group (no statin) by propensity score analysis. RESULTS Preoperative characteristics, number of distal anastomoses, and the use of off -pump procedures were similar in both groups. Hospital mortality was 1.3% (56 patients) with no difference between the two groups. Postoperative atrial fibrillation was significantly higher in the statin compared with the no statin group (411, 19.5%, versus 336; 15.8% respectively; p = 0.002). In a multivariate regression analysis, age (odds ratio [OR], 1.04; 95% confidence interval [CI], 1.02 to 1.05), pulmonary disease (OR, 1.42; 95% CI, 1.12-1.82), history of paroxysmal atrial fibrillation (OR, 3; 95% CI, 2.13 to 4.19), preoperative angiotensin-converting enzyme inhibitor therapy (OR, 1.26; 95% CI, 1.07 to 1.49), ejection fraction less than 0.30 (OR, 1.71; 95% CI, 1.22 to 2.38), emergency operations (OR, 4.5; 95% CI, 2 to 10.12), and preoperative statin treatment (OR, 1.31; 95% CI, 1.11 to 1.55) were all independent predictors of postoperative atrial fibrillation. CONCLUSIONS Preoperative statin is associated with a significantly higher incidence of postoperative atrial fibrillation compared with no statin treatment in patients undergoing isolated coronary artery bypass grafting.

Does combined mitral valve surgery improve survival when compared to revascularization alone in patients with ischemic mitral regurgitation? A meta-analysis on 2479 patients.

Objectives Optimal treatment of significant (≥2+ grade) ischemic mitral regurgitation remains controversial, and the impact of mitral valve surgery (MVS) at the time of coronary artery bypass grafting (CABG) on early and late results has to be still clarified. Methods A systematic literature search for studies comparing CABG combined to MVS (repair or replacement) compared with CABG alone in patients with ischemic mitral regurgitation and meta-analysis for late mortality, postoperative New York Heart Association functional class and late residual mitral regurgitation grade was performed. Risk ratios and the standardized mean difference (SMD) under the fixed or random effects model were reported. Results A total of nine observational nonrandomized studies were identified including 2479 patients with ischemic mitral regurgitation who underwent CABG alone (n = 1515) and CABG combined to MVS (n = 964). Meta-analysis of the pooled study population showed that MVS did not have advantages on late mortality [risk ratio 1.02; 95% confidence interval (CI) 0.90 to 1.14; P = 0.73] compared with CABG alone. Combined MVS was significantly associated with a lower residual mitral regurgitation grade compared with CABG alone (SMD = −0.9; 95% CI −1.250 to −0.559; P < 0.0001). However, postoperative New York Heart Association class was not significantly improved in the combined MVS group (SMD = −0.26; 95% CI −0.766 to −0.24; P = 0.30). Conclusion Most surgeons commonly use additional mitral valve procedure to treat moderate or severe ischemic mitral regurgitation, because it seems logical to assume that the volume overload associated with mitral regurgitation will be detrimental particularly to the patient with compromised left ventricular function. However, until definitive evidence about the superiority of this approach will be available, a tailored surgical strategy should be considered especially in mild ischemic mitral regurgitation.

Prophylactic intra-aortic balloon pump in high-risk patients undergoing coronary artery bypass grafting: a propensity score analysis

The optimal use of prophylactic intra-aortic balloon pump (IABP) to prevent postcardiotomy low cardiac output syndrome (LCOS) is still debated and poorly defined. The aim of this study was to evaluate whether prophylactic IABP reduces the rate of postcardiotomy LCOS and improves the early outcome in hemodynamically stable, high-risk patients undergoing coronary artery bypass grafting (CABG). From May 2004 to August 2007, 141 consecutive risk patients underwent CABG. Of these 38 (27%) received prophylactic IABP. The remaining 103 patients underwent operation without preoperative insertion of the device. Prophylactic IABP patients were more likely to be younger (P<0.0001), had a recent myocardial infarction (P<0.0001), lower ejection fraction (P=0.006), and higher New York Heart Association (NYHA) functional class (P=0.05). After risk-adjusting for propensity score, prophylactic IABP patients had a lower incidence of postcardiotomy LCOS (adjusted OR 0.07, P=0.006), postoperative myocardial infarction (adjusted OR 0.04, P=0.04), a shorter length of hospital stay (10.4+/-0.8 vs. 12.2+/-0.6 days, P<0.0001) than those who did not receive IABP. This study shows that prophylactic IABP treatment for hemodynamically stable high-risk patients undergoing CABG may improve postoperative course reducing postcardiotomy LCOS, postoperative myocardial infarction and length of hospital stay.

Weaning From Venovenous Extracorporeal Membrane Oxygenation Without Anticoagulation: Is it Possible?

A 19-year-old man affected with severe acute respiratory distress syndrome that was unresponsive to medical treatment was successfully weaned without anticoagulation therapy from venovenous extracorporeal membrane oxygenation (ECMO) because of life-threatening bleeding. The patient received venovenous ECMO with double peripheral cannulation. Heparin infusion was discontinued on day 10 for severe bleeding from thoracic and mediastinal drainages until the ECMO was removed. The weaning was performed while keeping the blood flow unchanged, only gas flows were gradually decreased. The patient was discontinued from ECMO and extubated after pulmonary function improved. Based on this single experience, management and weaning without any anticoagulant agent might be possible.

Ultrasound echo-enhancers in the evaluation of endovascular prostheses

Whereas conventional vascular surgical procedures are routinely monitored by ultrasound imaging, endovascular prostheses are usually monitored by radiographical imaging techniques. The aim of this study was to determine the safety, patient acceptance and role of ultrasound echo-enhancers (SHU 508 A) in the evaluation of endovascular devices. Nine patients were studied: six had stents (four in the internal carotid artery and two in the renal artery) and three had endoluminal prostheses (one in the abdominal aorta, one in the subclavian and one in the iliac artery). Endovascular patency and correct placement were studied with contrast angiography and ultrasound examination with and without contrast enhancement. Patients underwent angiography at the end of the endovascular procedure, and ultrasound examinations on the first postoperative day. Ultrasound contrast media (SHU 508 A) was injected through an antecubital vein at a rate of 1 ml/s. A total of 13 injections were given in nine patients. Ultrasonograms were obtained with 7.5 and 3.5 MHz transducers (Acuson 128 XP) and recorded on videotape for off-line visual inspection. Baseline and echo-enhanced sequences were assessed by two independent observers. None of the patients reported side-effects during or after the injection of the ultrasound echo-enhancer. Postoperative angiography showed endovascular patency and correct placement in all patients. The baseline ultrasound examination confirmed endoprosthesis patency in seven of nine patients: none revealed endoprosthesis malplacement. Contrast-enhanced ultrasound examination confirmed endoprosthesis patency. In two cases, the echo-contrast examination revealed persisting flow within the aneurysmal sac: in another patient it showed the incomplete adhesion of the distal portion of the endoprosthesis to the arterial wall. The preliminary findings suggest that ultrasound echo-enhancers are safe to use and induce no side-effects. Echo-enhanced sequences often provide additional information on the technical success of endovascular procedures. They promise to be useful in follow-up studies for assessing the functioning of endoprostheses.