Nicola Luciani

Composite arterial conduits for a wider arterial myocardial revascularization

From October 1991 to May 1993, 130 patients were submitted to myocardial revascularization using complex preformed arterial conduits. The age ranged from 29 to 75 years (mean age, 60.1 years); 121 patients were male. One hundred twenty-six patients had double- or triple-vessel disease. The mean ejection fraction was 0.53 (range, 0.22 to 0.79); only 6 patients had an ejection fraction less than 0.35. In 6 cases the procedure was a reoperation. We used 360 arterial conduits, 163 of which as free grafts (3 left internal mammary arteries, 16 right internal mammary arteries, 86 inferior epigastric arteries, 57 radial arteries, and 1 right gastroepiploic artery). One hundred fifty-four free grafts were anastomosed to one or both internal mammary arteries and one to a radial artery. We constructed 136 complex arterial conduits (branched, lengthened, or both). In 6 cases a double arterial system had to be used in a single patient. There was no operative mortality, and no inotropic or mechanical supports were used. The overall mortality rate was 1.5%. Early angiographic controls (between the 7th and 15th postoperative days) demonstrated 100% patency; late angiographic controls (at a mean interval of 9.5 months after operation) documented a mean patency rate ranging from 94.1% of the radial arteries to 100% of the left internal mammary arteries and right gastroepiploic arteries. At a mean follow-up of 7.2 months (range, 1 to 15 months) all patients are alive without recurrence of symptoms.

Long-Term Results of the Radial Artery Used for Myocardial Revascularization

Background—No information is available on the long-term results of radial artery (RA) grafts used as coronary artery bypass conduits. Methods and Results—In this report, we describe the long-term (105±9 months) angiographic results of a series of 90 consecutive patients in whom the RA was used as a coronary artery bypass conduit directly anastomosed to the ascending aorta. The long-term patency and perfect patency rates of the RA were 91.6% and 88%, respectively, versus 97.5% and 96.3% for internal thoracic artery grafts. The severity of stenosis of the target vessel clearly influenced long-term RA patency, whereas location of the target vessel and long-term use of calcium channel blockers did not influence angiographic results. Preserved endothelial function and absence of flow-limiting, fibrous, intimal hyperplasia were also documented. Conclusions—Ten years after surgery, RA grafts have excellent patency and perfect patency rates. Appropriate surgical technique and correct indication are the key factors for long-term RA patency.

Midterm clinical and angiographic results of radial artery grafts used for myocardial revascularization.

OBJECTIVE To evaluate the midterm angiographic results of the use of radial artery grafts for myocardial revascularization. METHODS The first 68 consecutive surviving patients who received a radial artery graft proximally anastomosed to the aorta at our institution were studied again at 5 years (mean 59 +/- 6.5 months) of follow-up; 48 of these patients had previously undergone an early angiographic examination. The response of the radial artery to the endovascular infusion of serotonin was evaluated 1 and 5 years after the operation, and the midterm status of the radial artery graft was correlated with the degree of preoperative stenosis of the target vessel and with calcium-channel blocker therapy. RESULTS The patency and perfect patency rates of the radial artery grafts 5 years after the operation were 91.9% and 87.0%, respectively. All radial artery grafts that were patent early after the operation remained patent at midterm follow-up, and early parietal irregularities in 7 patients were seen to have disappeared after 5 years. The early propensity toward graft spasm after serotonin challenge was markedly decreased at midterm follow-up. The continued use of calcium-channel antagonists after the first postoperative year did not influence the radial artery graft status, whereas the preoperative severity of the target-vessel stenosis markedly influenced the angiographic results. CONCLUSIONS The midterm angiographic results of radial artery grafts used for myocardial revascularization are excellent. The correct surgical indication is essential. Continued therapy with calcium-channel antagonists after the first year does not influence the midterm angiographic results.

Relation of the -174 G/C polymorphism of interleukin-6 to interleukin-6 plasma levels and to length of hospitalization after surgical coronary revascularization.

Interleukin (IL)-6 plasma levels are predictive of major cardiovascular events. The -174 G/C promoter polymorphism of the IL-6 gene affects basal levels in vivo and transcription rates in vitro, but its association with IL-6 acute phase levels among patients with coronary artery disease has not been investigated. In 111 patients with multivessel coronary artery disease undergoing elective coronary artery bypass graft surgery, we prospectively assessed genotype at position -174 and serial blood levels of IL-6 and other inflammatory indexes. Clinical and surgical characteristics did not differ among genotypic groups. IL-6 levels--measured daily up to 72 hours before surgery, after surgery, and at discharge--showed a mean 17-fold increase, peaking at 24 hours (p <0.0001). IL-6 levels (but not fibrinogen, white-blood cell count, and C-reactive protein values) differed significantly according to the -174 genotype (p = 0.042 for difference between areas under the curve), the 62 GG homozygotes exhibiting higher concentrations than the 49 carriers of the C allele (widest difference at 48 hours, p = 0.015 in multivariate analysis). GG homozygosity was associated with longer stays in the intensive care unit (2.5 +/- 3.4 vs 1.4 +/- 0.9 days, p = 0.02) and in the hospital (6.7 +/- 4.0 vs 5.3 +/- 1.4 days, p = 0.02) than C carriership. Rates of postoperative death, myocardial infarction, and stroke were 8% in GG homozygotes and 2% in C-carriers (p = 0.16). The IL-6-174 GG genotype is associated with higher acute phase levels of IL-6 and with longer stays in the hospital and in the intensive care unit than C allele carriership after surgical coronary revascularization.

Elevated levels of C-reactive protein before coronary artery bypass grafting predict recurrence of ischemic events

C-reactive protein was measured in 86 patients undergoing coronary artery bypass graft surgery. Patients were followed up for 3.2 years (range 1 to 6). Patients with C-reactive protein > or = 3 mg/L had significantly increased risk of recurrent ischemia at 1 to 6 years after intervention.

Risks of Using Internal Thoracic Artery Grafts in Patients in Chronic Hemodialysis via Upper Extremity Arteriovenous Fistula

Background—In patients in chronic hemodialysis via upper extremity arteriovenous fistula in whom ipsilateral internal thoracic artery graft was used for myocardial revascularization, hemodynamic interference between the fistula and the graft during dialysis can be hypothesized. Methods and Results—In 5 patients undergoing chronic hemodialysis via upper extremity arteriovenous fistula, ipsilateral to an internal thoracic to left anterior descending graft mammary flow was studied by means of transthoracic echo-color Doppler at baseline and during hemodialysis. Flow in the contralateral mammary artery was used as control. Transthoracic echocardiography was performed in concomitance with flow evaluation to assess eventual modifications of left ventricular segmental wall motion. Immediately after hemodialysis pump start there was a marked reduction of peak systolic and end-diastolic velocities and time average mean velocity and flow in the ITA ipsilateral to the fistula, whereas no substantial hemodynamic modification was evident in the contralateral artery. Dialysis-induced reduction of ipsilateral ITA flow was accompanied by evidence of hypokinesia of the anterior left ventricular wall. Three cases also experienced clinical angina. Conclusions—Hemodynamically evident flow steal and consequent myocardial ischemia develop during hemodialysis in patients with upper extremity arteriovenous fistula and ipsilateral internal thoracic artery to coronary graft. These data have major implications for patients’ management, both for nephrologists and cardiac surgeons.

Coronary artery bypass grafting in type II diabetic patients: a comparison between insulin-dependent and non-insulin-dependent patients at short- and mid-term follow-up

BACKGROUND Diabetes is a well-established risk factor for coronary artery disease, and it is associated with an increased rate of early and late adverse events after myocardial revascularization by coronary artery bypass grafting. METHODS A prospective follow-up study was done to evaluate the short-term and mid-term outcomes of type II diabetic patients who had coronary artery bypass grafting at our institution between 1996 and May 1999. A total of 200 patients, 100 insulin-dependent diabetic patients (group I) and 100 non-insulin-dependent diabetic patients (group II), met the inclusion criteria of the study and were included in the clinical follow-up study. RESULTS The characteristics of the patients of the two groups were similar for baseline clinical angiographic and operative characteristics. In particular, no significant differences in cardiopulmonary bypass and aortic cross-clamping times were noted between the two groups. The number grafts per patient was similar between the two groups. There were no in-hospital deaths, but postoperative complications were different among the two series. In fact, 33% of patients in group I had at least one major complication compared with 20% in group II (p = 0.037). The cumulative number of complications was 148 in group I and 69 in group II, and the mean number of complications per patient was 4.5 and 3.5 in groups I and II, respectively. The major differences in perioperative complication rates were found in the need for prolonged (> 24 hours) ventilation, occurrence of respiratory or renal insufficiency, and mediastinitis. The mean length of stay in the intensive care unit and for total hospitalization were longer in group I than group II (4.3 +/- 2.8 days versus 2.8 +/- 2.7 days [p = 0.010] and 11.1 +/- 2.2 days versus 7.2 +/- 2.4 group II [p < 0.05], respectively). At long-term follow-up, group I patients had a significantly higher mortality rate (29% versus 10%, p < 0.001). Moreover, overall late cardiac and noncardiac complication rates were significantly higher in group I than II (37% versus 22%, p = 0.02). In the multivariate analysis including several preoperative and operative variables, treatment by insulin, advanced age (> 75 years), left ventricular dysfunction (left ventricular ejection fraction < 35%), and complex lesions at coronary angiography (American Heart Association lesion classification type C lesion) were found as independent predictors of increased mortality. CONCLUSIONS Our data show that patients with insulin-dependent type II diabetes who had coronary artery bypass grafting have a significantly higher rate of major postoperative complications with an extremely unfavorable short- and long-term prognosis. Diabetic patients on insulin treatment should be considered high-risk candidates for coronary artery bypass grafting and require intense perioperative and long-term monitoring. Further studies will be necessary to investigate whether such conclusions may be appropriate for newer surgical strategies such as off-pump operation.

Extracorporeal circulation by peripheral cannulation before redo sternotomy: Indications and results

OBJECTIVES Cardiac reoperations are challenging and time-consuming, and have a high risk for reentry injuries. We discuss the indications, advantages, and technologic features of cardiopulmonary bypass by peripheral cannulation before resternotomy. METHODS Of 610 redo cardiac interventions from 2000 to 2006, 158 (25.9%) were performed with peripheral cannulation and ongoing cardiopulmonary bypass before resternotomy. This was indicated in the following: close adhesions between the sternum and the anterior cardiac surface; ascending aorta or bypass grafts (computed tomography scan); and patients with functional tricuspid regurgitation, hemodynamic/electric instability, previous mediastinitis, or depressed ejection fraction. Intraoperative transesophageal echocardiography was always performed. RESULTS Venous drainage was obtained by cannulation of the common femoral vein (Seldinger technique) and right internal jugular vein (percutaneously). Arterial nonocclusive cannula was placed in the femoral artery (Seldinger technique). Cardiopulmonary bypass time before cardiotomy was 35 +/- 14.7 minutes. There were 5 perioperative deaths, none due to reentry injury. Damage to mediastinal structures at resternotomy occurred in 4 cases. In all cases, peripheral cardiopulmonary bypass allowed adequate and comfortable repair. The operative time was 296 +/- 60 minutes. The average total postoperative bleeding was 264 +/- 38 mL/m(2). No patient experienced complications related to femoral cannulation. The Seldinger method allowed little vascular trauma and intraoperative patency of femoral vessels. CONCLUSION In selected patients, cardiopulmonary bypass before resternotomy is a valid and reproducible option to render cardiac reoperations safer and more expeditious in the reentry phase. The absence of cannulae in the operating field makes the procedure more comfortable. The liberal use of this strategy is recommended in redo cases.

Individualized surgical strategy for the reduction of stroke risk in patients undergoing coronary artery bypass grafting.

BACKGROUND This study was designed to evaluate the efficacy of a protocol of systematic screening of the ascending aorta and internal carotid arteries and individualization of the surgical strategy to the ascending aorta and internal carotid arteries status in reducing the stroke incidence among patients undergoing coronary artery bypass grafting. METHODS On the basis of a pre- and intraoperative screening of the ascending aorta and internal carotid arteries, 2,326 consecutive patients undergoing coronary artery bypass grafting were divided in low, moderate, and high neurologic risk groups. In the high-risk group dedicated surgical techniques were always adopted and the reduction of the neurologic risk was considered more important than the achievement of total revascularization. RESULTS The incidence of perioperative stroke in the high-risk group was similar to those of the other two groups (1.1 versus 1.3 and 1.1%, respectively; p = not significant); however, angina recurrence was significantly more frequent in the high-risk group. CONCLUSIONS The described strategy allows a low rate of perioperative stroke in high-risk patients undergoing coronary artery bypass grafting. Whether the reduction of the neurologic risk outweighs the benefits of complete revascularization remains to be determined.

Should severe monolateral asymptomatic carotid artery stenosis be treated at the time of coronary artery bypass operation

OBJECTIVE The optimal treatment of severe monolateral asymptomatic carotid artery stenosis (SMACS) in patients undergoing coronary artery bypass grafting (CABG) is still controversial. MATERIALS AND METHODS This study is based on the in-hospital and mid-term (>5 years) clinical results of a cohort of 139 consecutive CABG patients with SMACS operated at our Institution between January 1989 and December 1995. In the first 73 patients (no carotid surgery group), the SMACS was left untouched at the time of coronary surgery, whereas in the remaining 66 (carotid endoarterectomy group), the carotid stenosis was treated either immediately before or concomitantly with the CABG procedure (depending on the severity of the anginal symptoms). RESULTS The overall preoperative characteristics of the patients were comparable. The in-hospital results were similar between the two groups with regard to mortality, stroke and major postoperative complications. However, at mid-term follow-up, significantly more patients of the no carotid surgery group suffered cerebral events (transient or permanent) ipsilateral to the SMACS or the lesion had to be operated on. CONCLUSIONS The concomitant treatment (either staged or simultaneous) of SMACS at the time of CABG does not influence the in-hospital results, but confers significant neurological protection during the years after the operation.