Marco Contini

Left anterior descending coronary artery grafting via left anterior small thoracotomy without cardiopulmonary bypass

BACKGROUND We explored the possibility of anastomosing the left anterior internal mammary artery (LIMA) to the left anterior descending artery in a beating heart via a left anterior small thoracotomy. METHODS This procedure was performed in 155 of 162 scheduled patients; in 7 (4.3%) the left anterior descending artery was not suitable or was too small. The chest was opened in the fourth intercostal space (mean wound length, 10.5 cm) and the LIMA was harvested for about 4 cm. The left anterior descending artery was occluded by means of two 4/0 Prolene (Ethicon, Somerville, NJ) sutures, and the proximal suture was snared. The anastomosis was performed with two 8/0 Prolene sutures while the heart was beating. Early postoperatively all patients underwent repeat angiography or a Doppler flow assessment of the LIMA or both. RESULTS The LIMA was connected directly to the left anterior descending artery in 144 patients and with interposition of an inferior epigastric artery in 11. In 2 patients the diagonal branch was also grafted using an inferior epigastric artery from the LIMA. One patient (0.6%) died 38 days after the operation due to multiorgan failure. Nine patients (5.8%) had failure requiring a redo operation: 7 (4.5%) early and 2 (1.3%) late. One additional patient had a late percutaneous transluminal coronary angioplasty for anastomotic stenosis. At a mean 5.6 months of follow-up, 143 patients (92.2%) were alive, asymptomatic with or without medical treatment, and without cardiac events. CONCLUSIONS Left internal mammary artery-to-left anterior descending artery anastomosis performed on a beating heart via a left anterior small thoracotomy is a safe procedure. In selected patients the operation has good early and midterm results.

Impact of aortic manipulation on incidence of cerebrovascular accidents after surgical myocardial revascularization

BACKGROUND The impact of aortic manipulation on incidence of cerebrovascular accidents (CVAs) was evaluated in patients who underwent myocardial revascularization. METHODS From January 1988 to December 2000, 4,875 patients had coronary operations; 33 who survived less than 24 hours and 19 who had aortic cannulation without cross-clamping were excluded. According to the degree of aortic manipulation, patients were divided into two groups: group A, aortic cannulation, cross-clamping, with (A1, n = 597) or without (A2, n = 2,233) side-clamping, and group B, with (B1, n = 460) or without (B2, n = 1,533) side-clamping. Patients in group A (n = 2,830) were operated on with and patients in group B (n = 1,993) were operated on without cardiopulmonary bypass (CPB). Univariate and multivariate analyses were applied to identify independent predictors of higher incidence of CVAs. RESULTS Forty-nine patients (1.0%) had a postoperative CVA, 24 early and 25 delayed, with a 30-day mortality of 34.7%. Independent CVA predictors were low output syndrome, presence of extracoronary vasculopathy, conversion from off to on pump, and any aortic manipulation. This latter risk factor was significant in patients with extracoronary vasculopathy, but not in patients without. Side-clamping was not a risk factor in patients operated on with CPB, but it was in no-CPB cases. Patients in group B1 had the same CVA incidence as patients in group A2. Therefore CPB, per se, was not a risk factor for higher CVA incidence. CONCLUSIONS Aortic manipulation must be avoided in patients with extracoronary vasculopathy. Maintenance of a good hemodynamic status is crucial for any patient to reduce CVA incidence. Patients with extracoronary vasculopathy are at higher risk, and a correct surgical strategy should be tailored for each case. In no-CPB cases use of side-clamping provides the same CVA risk as in patients in whom CPB, aortic cannulation, and cross-clamping were used.

Myocardial revascularization with and without cardiopulmonary bypass in multivessel disease: impact of the strategy on early outcome

BACKGROUND The impact of myocardial revascularization without cardiopulmonary bypass (CPB) was evaluated in a series of consecutive patients with multivessel disease. METHODS From May 21, 1997 to November 30, 2000, 1,843 consecutive patients underwent isolated myocardial revascularization. From this total, 919 patients were done without CPB (group A, 49.9%) and 924 patients were done with CPB (group B, 50.1%). Patients that converted from without CPB to with CPB were included in group A. Thirty-three variables were evaluated with univariate and multivariate analysis to identify the independent variables predictive of higher incidence of early mortality, acute myocardial infarction, cerebrovascular accident, and early major events. RESULTS Early mortality was 2.2% (group A, 1.4%; group B, 3.0%; p = 0.016), acute myocardial infarction incidence was 1.8% (group A, 1.1%; group B, 2.6%; p = 0.027), cerebrovascular accident incidence was 0.9% (group A, 0.8%; group B, 1.0%; p = not significant), and early major events incidence was 6.7% (group A, 5.3%; group B, 8.2%; p < 0.001). Stepwise logistic regression analysis showed that CPB was an independent risk factor for higher mortality (odds ratio, 2.2; p = 0.0217), higher incidence of acute myocardial infarction (odds ratio, 2.5; p = 0.0185), and higher incidence of early major events (odds ratio, 1.8, p = 0.0034). CONCLUSIONS When CPB was not used, patients experienced lower early mortality and incidences of acute myocardial infarction were less complicated, both at univariate analysis and stepwise logistic regression analysis.

Midterm results after minimally invasive coronary surgery (last operation)

BACKGROUND Our experience with a left internal thoracic artery graft to the left anterior descending artery via a left anterior small thoracotomy is reviewed to evaluate midterm results. METHODS From November 1994 to April 1997, four hundred sixty patients were scheduled to undergo a left internal thoracic artery graft to the left anterior descending coronary artery via a left anterior small thoracotomy; 26 of these patients (5.7%) were converted and 434 of them had the operation. Two hundred fourteen patients (49.3%) had isolated disease of the left anterior descending artery, and 220 patients (50.7%) had multiple vessel disease. A sufficient length of the left internal thoracic artery was harvested to reach the left anterior descending artery. RESULTS Three hundred nine patients (71.2%) underwent extubation by hour 2. Mean intensive care unit stay was 4.2 +/- 4.5 hours; mean postoperative hospital stay was 66 +/- 29 hours; the 30-day mortality rate was 1.1%; the late mortality rate was 1.4%. Eighteen patients underwent reoperation early (< or = 30 days), and eight patients underwent reoperation late (> 30 days) because of conduit/anastomotic malfunction. Four patients underwent reoperation with patent anastomosis for progression of disease (n = 3) or pericarditis (n = 1). Three patients had a percutaneous transluminal coronary angioplasty. Cumulating angiographic and stress Doppler flow assessment results, a patent anastomosis was obtained in 417 patients and a nonrestrictive anastomosis in 404 patients. Twenty-nine months after surgery, survival was 97.1% +/- 0.7% (95% confidence interval 90.5% to 100%) and event-free survival 89.4% +/- 1.2% (95% confidence interval 78.2% to 100%). In the last 190 patients, with our increased experience and better instruments, we obtained a patent anastomosis in 188 patients (98.9%) and a nonrestrictive anastomosis in 185 (97.4%). CONCLUSIONS Left anterior small thoracotomy gives acceptable midterm results. Incidence of patent and nonrestrictive anastomoses was satisfactory, especially in the most recent part of our experience, when the learning curve ended.

Mitral Valve Surgery for Functional Mitral Regurgitation: Should Moderate-or-More Tricuspid Regurgitation Be Treated? A Propensity Score Analysis

BACKGROUND The aim of this retrospective study was to evaluate the clinical outcome of treating or not treating moderate-or-more functional tricuspid regurgitation in patients with functional mitral regurgitation undergoing mitral valve surgery. METHODS From January 1988 to March 2003, 110 patients with functional mitral regurgitation undergoing mitral valve surgery showed moderate-or-more functional tricuspid regurgitation, which was treated (group T) in 51 and untreated in 59 (group UT) patients. Propensity score was used to adjust midterm results. The tricuspid valve was always repaired using the DeVega technique. The mitral valve was repaired in 84 and replaced in 26 patients; no residual moderate-or-more functional mitral regurgitation was assessed at hospital discharge. RESULTS Thirty-day mortality was 5.5% (8.5% for group UT versus 2% for group T; p= 0.245). Adjusted 5-year survival was 45.0% +/- 6.1% in group UT and 74.5% +/- 5.1% in group T (p= 0.004), whereas the possibility to be alive in New York Heart Association class I or II was 39.8% +/- 6.0% in group UT versus 60.0% +/- 6.5% in group T (p= 0.044). Proportional Cox analysis, forcing propensity score into the model, demonstrated that untreated moderate-or-more tricuspid regurgitation was a risk factor for lower midterm survival (hazard ratio, 2.7; 95% confidence interval, 1.3 to 5.4) and survival in New York Heart Association class I or II (hazard ratio, 1.9; 95% confidence interval, 1.1 to 3.4). Follow-up functional tricuspid regurgitation progression rate (3+/4+) was 5% in group T versus 40% in group UT (p < 0.001). The progression of functional tricuspid regurgitation grade at follow-up was a risk factor for worse survival and the possibility to be alive in New York Heart Association class I or II. CONCLUSIONS Tricuspid annuloplasty is an easy and safe procedure, mandatory in case of at least moderate functional tricuspid regurgitation to achieve better mid-term outcome in patients with functional mitral regurgitation undergoing mitral valve surgery.

Off or on bypass: what is the safety threshold?

BACKGROUND To identify the technical profile of the patients operated on without cardiopulmonary bypass (CPB) and the benefit of the procedure. METHODS From May 21, 1997, to December 31, 1998, 785 patients had coronary artery bypass grafting through a median sternotomy (group A: 472 without CPB; group B: 290 with CPB; group C: 23 converted). Technical aspects, mortality rate, cerebrovascular accident (CVA) incidence (crude and risk-adjusted), and incidence of major complications were recorded. RESULTS Patients without CPB had mainly one to three grafts and one- or two-vessel disease. Multiple arterial grafting was not a limit, whereas sequential grafting was. Group A had lower complications rates, shorter intensive care unit and postoperative in hospital stays, and lower transfusion rates. Mortality rates and CVA incidence (crude and risk-adjusted) were similar in both groups and in each subgroup considered. In group A, a lower complications rate was present in some patients (aged greater than 70 years, female, with unstable angina). Group C showed higher mortality and complications rates. Failure of revascularization showed no difference between groups. CONCLUSIONS Primary endpoints are not affected by the surgical strategy, whereas some of the secondary endpoints are. However, patients in group A experienced fewer complications. Both techniques can give satisfying results and must be applied according to the surgeons preference.

Myocardial revascularization with and without cardiopulmonary bypass: advantages, disadvantages and similarities

OBJECTIVES Off-pump coronary artery bypass surgery is becoming increasingly popular although its effectiveness remains controversial. Our goal was to investigate the effectiveness of on-pump and off-pump coronary artery bypass surgery on early (30 days) and long-term (5 years) clinical outcome in two groups of patients selected using propensity scores. METHODS From November 1994 to December 2001, 4381 patients underwent isolated coronary surgery. Applying propensity score matching, 1922 patients were selected (off-pump n=961, on-pump n=961). RESULTS Stepwise logistic regression analysis showed that the use of cardiopulmonary bypass was an independent predictor for early death, cerebral vascular accident, early negative primary endpoints (ENPEP), and early major events (EME). Five years freedom from both events was similar in the two groups. However, freedom from acute myocardial infarction (AMI) in grafted areas was higher in the off-pump than in the on-pump patients, a possible explanation being the lower postoperative creatine kinase myocardial band (CKMB) release. Grouping all patients according to CKMB peak release also showed that patients with normal release values had higher freedom from all cardiac events investigated. A subgroup analysis of 59 patients converted from off-pump to on-pump showed higher early mortality, ENPEP, and EME. Conversion, however, did not affect late clinical outcome. CONCLUSIONS These results suggest that off-pump surgery reduces early mortality and morbidity. Conversion to on-pump carries high in-hospital mortality and morbidity. Long-term clinical outcome is similar in the two groups; however, off-pump patients seemed to have a higher freedom from AMI in the grafted area which might be related to the lower CKMB peak release when compared with patients undergoing on-pump surgery.

Persistence of Mammary Artery Branches and Blood Supply to the Left Anterior Descending Artery

BACKGROUND Partial harvesting of the left internal mammary artery (LIMA) is a widespread technique used during minimally invasive coronary operations performed through a left anterior small thoracotomy. The influence of persisting LIMA branches was investigated to evaluate their effect on the blood flow of the left anterior descending artery. METHODS Thirty patients, 15 with totally (group A) and 15 with partially (group B) harvested LIMAs, were evaluated. All the patients underwent postoperative angiography, during which a flow map of the LIMA was performed. The average peak velocity and the diastolic-to-systolic peak velocity ratio were recorded. The LIMA graft flow pattern was recorded in the proximal and distal thirds of the artery. Intramammary adenosine (12 to 14 microg) was injected and the average peak velocities before and after injection were calculated. RESULTS The average peak velocity was similar in both groups in the proximal and distal thirds of the LIMA (25 +/- 7 and 26 +/- 5 cm/sec, respectively, in group A versus 27 +/- 5 and 25 +/- 5 cm/sec, respectively in group B; p = NS). The diastolic-to-systolic peak velocity ratio was similar proximally (0.78 +/- 0.3 in group A versus 0.69 +/- 0.3 cm/s in group B; p = NS), but not distally (1.72 +/- 0.1 in group A versus 0.97 +/- 0.3 in group B; p < 0.0005). The LIMA graft flow reserve was similar both proximally and distally (2.6 +/- 0.6 and 2.5 +/- 0.3 cm/s, respectively, in group A versus 2.6 +/- 0.5 and 2.6 +/- 0.3 cm/s, respectively, in group B; p = NS). CONCLUSIONS The persistence of LIMA branches does not influence the blood flow of the left anterior descending artery after acute adenosine-induced myocardial hyperemia. If a left anterior small thoracotomy is used in left anterior descending artery direct revascularization, complete LIMA harvesting is not mandatory and depends on the personal preference of the surgeon.

Mitral valve surgery for functional mitral regurgitation: prognostic role of tricuspid regurgitation §

BACKGROUND The purpose of this study was to evaluate the impact of untreated moderate-or-more functional tricuspid regurgitation (FTR) on mid-term outcome of patients with functional mitral regurgitation (FMR) undergoing mitral valve surgery (MVS). METHODS From January 1988 to April 2003, 165 patients having FMR underwent MVS with untreated FTR. Patients with organic mitral or tricuspid valve disease were excluded. The entire population was divided into two groups, group A: 102 patients (FTR 0/1+), group B: 63 patients (FTR 2+/3+). No statistical difference was found between two groups concerning preoperative and operative variables. MV was repaired in 137 and replaced in 28 cases; the impact of untreated moderate-or-more FTR was estimated by Cox analysis. RESULTS Thirty-day mortality was 6.7 (5.9% group A vs 7.9% group B, p=0.607). Five-year actuarial survival was 73.5% (66.6-80.4%); 88.2% (83.0-93.4%) group A versus 46.0% (33.7-58.3%) group B, p<0.001; the possibility to be alive in NYHA class I-II was 65.8% (58.4-73.2%); 78.4% (72.3-84.5%) group A versus 41.2% (29.1-53.3%) group B, p<0.001. Cox analysis confirmed the impact of untreated moderate-or-more FTR on 5-year survival (HR=3.1, 95% CI=1.8-5.1, p<0.001) and possibility to be alive in NYHA class I-II (HR=3.0, 95% CI=1.8-4.9, p<0.001). After a median interval time of 28 months (IQR=11-60), TR grade was echocardiographically assessed in 122 (79.2%) of 154 patients surviving the first month. In group A (87 patients), TR grade decreased significantly from 0.7+/-0.5 to 0.3+/-0.5 (p<0.001) in the early postoperative period. Then, it increased again to 0.6+/-0.7 at follow-up (p<0.001); no difference was found between preoperative and follow-up time (p=ns). In group B (35 cases), TR grade decreased significantly from 2.2+/-0.4 to 1.3+/-0.7 in the early postoperative period (p<0.001), but then increased again to 2.2+/-0.9 (p<0.001 vs postoperative value; p=0.838 vs preoperative value). Cox analysis confirmed that the progression of TR grade at follow-up is a risk factor for lower survival and possibility to be alive in NYHA class I-II. CONCLUSIONS Patients with untreated moderate-or-more FTR had survival and survival in NYHA class I-II lower than patients with untreated less-than-moderate FTR at 5-year follow-up.

Current results in off pump surgery.

OBJECTIVE We reviewed our experience with myocardial revascularization without cardiopulmonary by-pass (CPB) to evaluate early- and mid-term results compared with those obtained using CPB. METHODS From May 21, 1997 to November 1998, 747 patients had isolated myocardial revascularization, 480 without CPB (Group A) and 267 with CPB (Group B). Exposure of the target vessels was obtained with four slings (two passed through the transverse sinus and two behind the inferior vena cava) and four deep pericardial sutures on the mobile pericardium around the left atrium (Lima stitches). The number of anastomoses/patient (when two or more conduits were used) was higher in Group B (3.1 +/- 1.0 vs 2.6 +/- 0.7, P < 0.001). More marginal branches were grafted in Group A (258 vs 239), but the percentage was higher in Group B (P < 0.001). Crude and risk adjusted mortality was similar in both groups, as well as cerebrovascular accident (CVA) and acute myocardial infarction incidences. Patients in Group A woke earlier, had less inotropes, lower creatinkinase myocardial band (CK-MB) peak, lower bleeding and less transfusion, shorter Intensive Care Unit (ICU) and postoperative stay in hospital than patients in Group B. 266 anastomoses were checked; of these 98.5% were patent and 97.0% were patent and not restrictive. CONCLUSIONS Myocardial revascularization without CPB can provide good early- and mid-term results in selected patients. Primary endpoints (death and acute myocardial infarction) were similarly independent from the technique used. Some of the secondary endpoints were favorable in Group A: however their importance is minor. Even if we feel that some high risk patients with severe comorbidities can benefit from CPB surgery; this aspect is difficult to demonstrate scientifically.