Left Anterior Descending Artery Graft Research Articles

Severity of coronary artery stenosis at preoperative angiography and midterm mammary graft status

Background. The purpose of this study was to evaluate the correlation between the midterm angiographic results of mammary artery grafts and the preoperative stenosis of the target vessel. Methods. We analyzed preoperative and postoperative angiograms of 93 patients who underwent postoperative midterm (≥3 years) angiograms of an internal mammary artery (IMA) to left anterior descending artery graft for clinical or study purposes. Patients were divided into three groups on the basis of the percentage of the coronary artery stenosis at preoperative angiography: <70%, 70% to 90%, and >90% stenosis. Results. Preoperative characteristics were similar in the three groups. The overall incidence of IMA occlusion was 19% in the entire population, without significant differences between groups (19% versus 29% versus 14%). The mean mammary artery diameter significantly increased in direct proportion to the severity of the coronary stenosis (2.0 ± 0.2 mm in the <70% versus 2.5 ± 0.3 mm in the 70% to 90% and 2.7 ± 0.4 mm in the >90% series; p < 0.05). Conclusions. Chronic native competitive flow does not significantly affect midterm graft status but does influence mammary graft diameter.

Did the introduction of a minimally invasive technique change the incidence of atrial fibrillation after single internal thoracic artery–left anterior descending artery grafting?

Objective: Atrial fibrillation after coronary artery bypass operations remains frequent and increases morbidity, as well as resource use. Its cause remains unclear. The introduction of a minimally invasive technique provides an opportunity to evaluate the effect of intraoperative factors, such as cardiopulmonary bypass, global myocardial ischemia, and myocardial protection technique, on the occurrence of this arrhythmia. Methods: All the patients undergoing isolated left internal thoracic artery–left anterior descending artery grafting between January 1994 and December 1999 were reviewed. Twenty possible risk factors for postoperative atrial fibrillation, including the choice of operative technique—minimally invasive technique was introduced in January 1997—were entered into univariate and multivariable logistic regression analysis. Results: Postoperative atrial fibrillation occurred in 36 (20%) of 183 patients. On univariate analysis, age (P <.001) and a history of supraventricular arrhythmia (P <.001) were found to be risk factors. In particular, 15 (22%) of 69 patients operated on with the minimally invasive technique had postoperative atrial fibrillation versus 21 (18%) of 114 in the standard group (P =.58). On multivariable analysis, including the operative technique, the same variables (P =.001 and.01, respectively) were identified as independent risk factors. Conclusions: The introduction of a minimally invasive technique for coronary artery bypass operations did not reduce the occurrence of postoperative atrial fibrillation in this study population. This suggests that prophylactic measures to reduce this arrhythmia should be focused on factors unrelated to cardiopulmonary bypass or myocardial preservation technique. (J Thorac Cardiovasc Surg 2001;121:683-8)

Exclusive Y graft operation for multivessel coronary revascularization

Background. The pedicled (in-situ) left internal mammary artery grafted to the left anterior descending artery has a very high late patency and reduces late mortality following coronary artery bypass surgery. A technique is described which achieves total arterial revascularization in patients with multivessel coronary disease and which is also entirely pedicled.Methods. Using the left internal mammary artery and radial artery joined as a composite Y graft, all coronary territories may be grafted.Results. One in-hospital death from 464 patients (0.2%) occurred. Age (mean ± standard error) was 64.7 ± 0.5 years and number of distal anastomoses 3.4 ± 0.04. Of 1,681 patients from Royal Melbourne Hospital, 346 had this operation. Comparison found no preoperative selection bias and no postoperative differences in complications. Actuarial survival was 0.98 ± 0.01 at 36.1 ± 0.3 months.Conclusions. Total arterial revascularization may be performed using the left internal mammary artery and radial artery as a composite Y graft. There was no increase in complications. This technique preserves the left internal mammary artery to left anterior descending artery graft.

Effect of coronary occlusion on left ventricular function with and without collateral supply during beating heart coronary artery surgery

OBJECTIVETo study the effects of coronary occlusion and collateral supply on left ventricular (LV) function during beating heart coronary artery surgery.DESIGNProspective intraoperative study, performed at baseline, during wall stabilisation, coronary...

Alternative approach to multivessel coronary disease with integrated coronary revascularization

Objective: Integrated coronary revascularization combines minimally invasive coronary artery bypass grafting (MICABG) with left internal thoracic artery–left anterior descending artery grafting and percutaneous coronary intervention. We hypothesized that integrated coronary revascularization could result in successful revascularization in suitable patients with multivessel coronary artery disease. Methods: Between September 1996 and January 1998, 31 consecutive patients underwent integrated coronary revascularization. Twenty-two were male; mean age was 69 years (46-86 years) and 42% were older than 75 years. Eight patients (26%) had a Parsonnet score greater than 20%. Left ventricular ejection fraction was 46.3% ± 12%; 6 patients (19%) had a left ventricular ejection fraction less than 35%. Results: The anastomosis time for MICABG with the internal thoracic artery was 14.6 ± 5.2 minutes and the operating time was 105 ± 20 minutes; 28 patients (90%) were extubated in the operating room. The internal thoracic artery anastomosis was patent in all 31 patients (100%). Percutaneous coronary intervention was performed before MICABG in 2 patients (7%), on the same day of MICABG in 16 patients (52%), on postoperative day 1 in 3 patients (9%), and on postoperative days 2 to 4 in 10 patients (32%). Postprocedure length of stay in the hospital was 2.7 ± 1.0 days and 13 patients (42%) were discharged home on postoperative day 1 or 2. Three patients (9.6%) required repeat target vessel revascularization in the distribution of the previous percutaneous coronary intervention. All patients are alive without angina at a follow-up of 10.8 ± 3.8 months. Conclusion: Our early results demonstrate that integrated coronary revascularization can be performed safely and effectively. Long-term results will be available from a prospective randomized trial now underway to compare integrated coronary revascularization with coronary artery bypass grafting for multivessel coronary artery disease. (J Thorac Cardiovasc Surg 1999;117:439-46)

Port-Access coronary artery bypass grafting: technical considerations and results.

This study reviews the results of an initial experience with minimally invasive coronary bypass surgery using the Port-Access approach in terms of early outcome and safety. Between October 1996 and July 1997 49 Port-Access minimally invasive coronary artery bypass grafting procedures were performed at our institution. The patients' mean age was 59.8 years (range 34 to 82 years). Sixteen patients received single vessel and 37 patients received multivessel bypass grafts. There were no operative deaths and no perioperative myocardial infarctions, neurological deficits, or conversions to sternotomy. Early complications included reoperation due to bleeding in 4 patients, reoperation for a pulmonary embolus in 1 patient, and angioplasty for occlusion of a right coronary artery graft in 2 patients. Postoperative angiograms were obtained in 86% (42/49) of the patients and showed 100% patency for left internal mammary artery to left anterior descending artery grafts and 96% patency for all grafts. These results demonstrate that Port-Access coronary artery bypass grafting using endovascular techniques for cardiopulmonary bypass and cardioplegic arrest can be performed safely with minimal morbidity and mortality. This technique allows multivessel revascularization on a protected, arrested heart with excellent anastomotic precision and reproducible early graft patency. Expanded use of Port-Access techniques is indicated in patients with multivessel coronary artery disease and the technique should be considered for patients with left anterior descending artery restenosis and patients with complex left anterior descending artery lesions where angioplasty results are suboptimal.

Left anterior small thoracotomy (LAST): mid-term results in single vessel disease.

Left anterior descending artery grafting using the left internal mammary artery via a left anterior small thoracotomy (LAST) gained new popularity in 1994. We review our experience in 250 of 512 patients who underwent a LAST in single vessel left anterior descending artery disease from November 1994 to October 1997. Left anterior descending artery stabilization was obtained pharmacologically and mechanically. Two patients (0.8%) had percutaneous transluminal coronary angioplasty at a mean of 23 +/- 5 days; 172 (68.8%) patients had early postoperative angiography. Eight conduits were occluded (patency rate 95.3%). There was only one late death. Cumulative angiography and Doppler flow evaluation showed that 96.8% of the anastomoses were patent and 95.6% were both patent and nonrestrictive. At a mean follow-up of 16.3 +/- 9.3 months, 9 (3.6%) patients had redo-surgery due to anastomotic/conduit failure and 249 (99.6%) patients were alive and asymptomatic. No patients had acute myocardial infarction. The 35-month actuarial survival rate was 99.6% +/- 0.4%, and the event-free survival rate for the entire experience was 93.7% +/- 1.3%. If only the last 157 patients are considered, at 18 months event-free survival was higher than in the entire group of patients (96.4% +/- 1.4% vs 93.7% +/- 1.3%, p = 0.05). New instrumentation has made the operation easier and has contributed to its spread, along with increased experience and the end of the learning curve. At the moment we consider the LAST a more anatomical and physiological surgical approach to single vessel coronary disease.

Atrial Septal Hematoma Immediately after Cardiac Surgery

Atrial Septal Hematoma Immediately after Cardiac Surgery

Surgical treatment of isolated left anterior descending coronary stenosis: Comparison of left internal mammary artery and venous autograft at 18 to 20 years of follow-up

To assess the long-term results of the surgical treatment of isolated left anterior descending coronary artery stenosis and compare surgical strategies for graft selection, we reviewed 100 consecutive patients receiving left internal mammary artery–to–left anterior descending artery grafts and 100 consecutive patients who received a saphenous vein autograft to the left anterior descending artery. All patients underwent operation from 1971 through 1973. The internal mammary artery and saphenous vein graft groups were equivalent with regard to preoperative clinical and angiographic variables, except that patients receiving left internal mammary artery grafts had a higher prevalence of noncritical disease (less than 50% stenosis) in the circumflex and right coronary arteries than did the saphenous vein graft group. Mean follow-up for the internal mammary artery and saphenous vein graft groups was 18.7 years and 20.7 years, respectively. The 18-year outcome was superior for the internal mammary artery group. Cox regression analysis confirmed that patients with left internal mammary artery grafts had superior survival, intervention-free survival, and event-free survival (all p < 0.01). The presence of noncritical disease in other vessels adversely affected intervention-free survival and event-free survival for both groups (all p < 0.03) and decreased survival for the saphenous vein graft group ( p = 0.01) but not for the internal mammary artery group ( p = 0.24). We conclude that in long-term follow-up of surgically treated isolated left anterior descending artery stenosis (1) the left internal mammary artery consistently yields better overall and intervention-free survival than does the saphenous vein graft, (2) outcome is influenced by the presence of noncritical disease in other vessels at the initial operation, and (3) deployment of the left internal mammary artery in the treatment of isolated left anterior descending artery stenosis yielded 18 years of intervention-free survival of 60.5% and provides a standard for comparison with other forms of therapeutic intervention. (J THORAC C ARDIOVASC S URG 1994;107:657-62)

The severity of atherosclerosis at sites of plaque rupture with occlusive thrombosis in saphenous vein coronary artery bypass grafts

Atherosclerotic plaque rupture with superimposed thrombosis is recognized as the lesion causing late, acute, thrombotic saphenous vein coronary artery bypass graft (CABG) occlusion. To determine the severity of atherosclerosis at the site of plaque rupture, 68 saphenous vein CABGs removed at the time of reoperation or at autopsy were studied. The study population consisted of 57 men, 64 ± 9 years old, and nine women, 70 ± 10 years old. The duration of graft implantation was 7.9 ± 2.7 years (mean ± S.D.). All CABGs were dissected from the hearts, fixed, decalcified, cut at 2 to 3 mm intervals, and processed routinely for histologic examination. A planimeter was used to measure total vessel, plaque, thrombus, and luminal cross-sectional areas at the site of plaque rupture with thrombosis in sections projected at 13.8 power magnification. At the site of atherosclerotic plaque rupture with superimposed thrombosis, the degree of stenosis due to plaque was: 90 ± 11% for the right coronary artery grafts ( n = 19); 94 ± 7% for the left anterior descending artery grafts ( n = 41), and 90 ± 14% for the left circumflex artery ( n = 8) grafts. Thus in saphenous vein CABGs, atheroscierotic plaque rupture with thrombosis usually occurs at sites of severe narrowing (mean = 93%) by preexisting atherosclerotic plaque.