Laser fluorescence angiography reveals perfusion defects in retrograde cardioplegia.

BACKGROUND: Adequate perfusion of the right ventricle with retrograde cardioplegia has always been questioned. However, clinical studies suggested sufficient protection and, up to now, intraoperative assessment of cardioplegia distribution has been difficult. METHODS: As a pilot study in 14 patients, we used indocyanine green laser fluorescence angiography (ICGLA) to assess vascular and myocardial perfusion of different areas of the right anterior ventricular wall. Regions of interest were analyzed quantitatively using a new software package. RESULTS: ICGLA allowed rapid and reliable visualization of cardioplegic flow and distribution. Retrograde cardioplegia revealed perfusion defects in the territory of the right anterior cardiac veins when compared to antegrade delivery and to areas close to the left anterior descending vein(s), confirmed by quantitative analyses of maximal fluorescence intensity. Five patients were excluded from quantitative analyses. The learning curve, pitfalls, limitations and special image details are described. CONCLUSION: A larger study is necessary to examine the relevance of perfusion defects to metabolic changes in affected myocytes and to global right ventricular function.

Comparison of Coapsys annuloplasty and internal reduction mitral annuloplasty in the randomized treatment of functional ischemic mitral regurgitation: impact on the left ventricle.

BACKGROUND: Functional mitral regurgitation is associated with both annular and ventricular distortion. Aggressive reduction annuloplasty for functional mitral regurgitation acts primarily at the annulus, with variable impact on the left ventricle. The Coapsys device externally reshapes the left ventricle to correct functional mitral regurgitation. Left ventricular reshaping was analyzed in a randomized study. METHODS: The RESTOR-MV study randomizes patients with coronary artery disease and functional mitral regurgitation to either reduction annuloplasty and coronary artery bypass grafting (the RA group) or Coapsys annuloplasty and bypass grafting (the CO group). The Coapsys device consists of epicardial pads connected by a cord. It was placed without cardiopulmonary bypass under echocardiographic guidance and sized to reduce annular dimension and improve leaflet coaptation. Internal reduction annuloplasty was performed by device placement. Intraoperative transesophageal echocardiograms were analyzed in 7 patients having reduction annuloplasty and 7 having Coapsys annuloplasty. RESULTS: Baseline mitral regurgitation (0-4 scale) was similar for the RA (3.0 +/- 0.6) and the CO groups (3.0 +/- 0.6). Intraoperative mitral regurgitation was reduced from 2.86 +/- 0.7 to 0.5 +/- 0.7 (P < .01 pre vs post) for the RA group and from 2.64 +/- 0.9 to 05 +/- 0.7 (P < .01 pre vs post) for the CO group. Annular anteroposterior diameter was reduced with both techniques: RA, 3.45 +/- 0.39 to 2.34 +/- 0.37 cm (P < .01 pre vs post); CO, 3.40 +/- 0.27 to 2.85 +/- 0.34 cm (P < .05 pre vs post). Long-axis dimensions were unchanged with both techniques. Short-axis dimensions measured at three levels were significantly reduced only in the CO patients: basal diameter 4.77 +/- 0.58 to 3.58 +/- 0.38 cm (P < .01 pre vs post); mid diameter 4.88 +/- 0.55 to 3.57 +/- 0.43 cm (P < .01 pre vs post); and apical diameter 4.39 +/- 0.46 to 3.38 +/- 0.34 cm (P < .01 pre vs post). CONCLUSIONS: Coapsys and reduction annuloplasty techniques both acutely reduce functional mitral regurgitation and annular dimension. The Coapsys device provided significantly greater left ventricular reshaping than did reduction annuloplasty. Further evaluation will assess the long-term valvular function and ventricular geometric stability associated with both techniques.

Endoscopic radial artery harvest: a new approach.

BACKGROUND: Although early attempts to use the radial artery (RA) as a conduit for cardiac revascularization met with disappointing results, recent data have shown the RA to achieve very good short-term patency as well as promising mid-term patency results. The recent increase in the frequency of coronary reoperations, with their limited options for vascular conduits, has also stimulated an interest in the RA graft. The success of minimally invasive vein harvesting techniques encouraged us to develop a minimally invasive technique for harvesting the RA from the forearm, which is reviewed in this article. METHODS: The endoscopic harvest technique was employed on more than 120 nonselected patients at our facility over a 12-month period. The procedure involved exposure of the RA under direct visualization and without direct manipulation, using an endoscopic dissector and harmonic shears. Side branches of the RA were isolated and divided, and the vessel was removed and side branch occlusion verified. The harvested RA was then prepared for the revascularization surgery. RESULTS: The patients who underwent the procedure showed no evidence of graft spasm or occlusion in the immediate postoperative period. Patients also preferred the small endoscopic incision to the full forearm incision of the "open" technique. CONCLUSIONS: Our experience indicates that endoscopic radial artery harvesting is a safe technique that achieves good short-term patency results and improved patient satisfaction. Evaluation of long-term vessel integrity is needed, and a comparison of the minimally invasive and the open technique has been initiated.

Current status of MIDCAB procedure.

The advent of cardiopulmonary bypass in the early 1960s allowed surgeons to safely perform complex reconstructions on the heart. Since then, the field of cardiac surgery has progressed to where surgical myocardial revascularization, or coronary artery bypass grafting (CABG), has become the most exhaustively studied operation in the history of surgery, and it has achieved widespread use because its benefits have been so thoroughly documented. The paradoxical fact is that more elderly and debilitated patients benefit the most from cardiac surgery compared with medical therapy, yet they sustain greater risk of morbidity and mortality after cardiac surgery. Most of the recent innovations and refinements in the treatment of coronary artery disease aim toward reduction of trauma without deviating much from the safety and efficacy of the conventional procedures. As a consequence, a greater number of high-risk elderly patients have become candidates for coronary artery bypass grafting (CABG). All of the amendments are caused by changing clinical scenarios brought on by an increased number of aging patients, a greater number of patients requiring re-operations, cost containment, increased discernment about outcome assessment, and also the dominance of coronary bypass being threatened by the success of interventional cardiology.

Transabdominal mimially invasive direct coronary artery bypass grafting (MIDCAB).

The major limitations of current minimally invasive direct coronary artery bypass (MIDCAB) techniques are multivessel and distal vessel disease frequently seen in patients with extensive stent restenosis ('full metal jacket syndrome') and reoperative surgery. Two separate minimal access incisions (minithoracotomy, lower partial sternotomy) have been used to bypass two separate arteries (left internal mammary artery (LIMA) to left anterior descending (LAD), right gastroepiploic artery (RGEA) to posterior descending artery (PDA)). To bypass multiple coronary arteries using multiple arterial conduits without violation of bony parts, we use a new minimal access incision by 'transabdominal approach'.

Cardiac hemangioma. A case report and discussion.

A cardiac hemangioma is a rare form of primary cardiac tumor. To our knowledge, only 34 cases of cardiac hemangioma have been discussed in the literature at the time of this writing. We report the case of a patient who presented with 1 episode of exertional dyspnea. The medical history, physical exam, work-up, surgical approach, and outcome are discussed. Other published reports on this topic are also reviewed.

Less invasive arterial CABG on a beating heart.

BACKGROUND: Competitive status of percutaneous transluminal coronary angioplasty and stenting has stimulated an interest in minimally invasive direct coronary artery bypass grafting. METHODS: Between April 1994 and September 1996,156 patients with a mean age of 67 +/- 10 years have undergone minimally invasive direct coronary artery bypass grafting via minithoracotomy, subxiphoid incision, or both with internal mammary artery, right gastroepiploic artery, and radial artery grafting using local coronary occlusion on a beating heart with immobilization of the coronary artery target sites with traction sutures and mechanical regional cardiac wall immobilization platform. RESULTS: Morbidity included wound infection (3), reoperation for bleeding (5), atrial fibrillation (12), central nervous system complication (1), and perioperative myocardial infarction (5). Cardiac-related operative mortality was 1.2% (2/156). Predominantly single grafting was done in 128 patients. Routine angiographic and Doppler echocardiographic flow assessment of anastomotic patency showed an overall patency rate of 92%. In 52 recent consecutive patients in whom the regional cardiac wall mechanical stabilization platform was used, the patency rate of the left internal mammary artery-to-left anterior descending coronary artery graft was improved to 96.2%. With a mean followup of 9.2 +/- 7.4 months, cardiac event-free interval (percutaneous transluminal coronary angioplasty, reoperative coronary artery bypass grafting, or death) in 111 patients was 91%. CONCLUSIONS: Minimally invasive direct coronary artery bypass grafting is safe and effective with good early and midterm clinical results, especially with left internal mammary artery-to-left anterior descending coronary artery grafting via minithoracotomy. Regional cardiac wall immobilization of coronary artery target sites enhances the early graft patency in a predictable manner (96.2%), and this method should be an essential part of all minimally invasive direct coronary artery bypass graft operations with left internal mammary artery-to-left anterior descending artery grafts via minithoracotomy. Further study is required to establish the long-term efficacy of minimally invasive direct coronary artery bypass grafting and the treatment of coronary artery disease.

Minimally invasive direct coronary artery bypass grafting: two-year clinical experience.

BACKGROUND: Interest in minimally invasive coronary artery bypass grafting has been increasing. METHODS: From April 1994 through December 1996, 199 patients (age, 36 to 93 years) underwent minimally invasive coronary artery bypass grafting through minithoracotomy, subxiphoid, and lateral thoracotomy incisions, with internal mammary artery, gastroepiploic artery, and composite grafts placed using local coronary artery occlusion. RESULTS: The conversion rate to sternotomy was 7% (14/199). Preoperative risk factors included unstable angina (n = 83), reoperative coronary artery bypass grafting (n = 54), low ejection fraction (n = 53), congestive heart failure (n = 44), renal insufficiency (n = 25), chronic obstructive pulmonary disease (n = 36), cerebrovascular accident (n = 22), and diffuse vascular disease (n = 47). Morbidity included wound infections (n = 5), reoperation for management of bleeding (n = 6) and acute graft occlusion (n = 2), perioperative stroke (n = 1), atrial fibrillation (n = 14), and perioperative myocardial infarction (n = 7). The operative mortality was 3.8% (7/185). The number of grafts placed in 185 patients was as follows: single, 156; double, 28; and triple, 1. Early (less than 36 hours) angiography and Doppler flow assessment of the coronary anastomoses in 85% of the patients showed that 92% were patent. Routine use of mechanical stabilization of the coronary artery since April 1996 was found to be associated with an increase in the patency rate of the left internal mammary artery-left anterior descending coronary artery anastomosis to 97%, versus 89% (p = 0.055) associated with conventional immobilization techniques. Of the 148 patients followed up beyond 1 month (range, 1 to 32 months; mean, 9.2 +/- 7.4 months) postoperatively, 3 have died (3 to 7 months), and of the 145 survivors the cardiac-related event (percutaneous transluminal coronary angioplasty, reoperation, readmission for recurrent angina, and congestive heart failure)-free interval was 93%. CONCLUSIONS: The minimally invasive coronary artery bypass grafting operation is safe and effective. Regional cardiac wall mechanical immobilization enhances the early graft patency and must be considered an essential part of this operation.

Clinical experience with minimally invasive reoperative coronary bypass surgery.

OBJECTIVE: To minimize the risk of standard and reoperative coronary artery bypass, we developed a minimally invasive approach. In this study we have evaluated the effectiveness of this technique. METHOD: Between April 1994 and September 1995, 12 men and 6 women, aged 55-84 years (mean, 69 years) with chronic stable angina (4) and recent post-myocardial infarction unstable angina (14), with left ventricular ejection fractions ranging 17-60% (mean 37%), underwent reoperative coronary artery bypass grafting using 7-cm mini-left and right anterior thoracotomy and subxiphoid incisions. Coronary artery anastomoses were carried out on beating hearts with local coronary occlusion. Ischemic preconditioning, beta and calcium channel blockers and the maintenance of mean arterial pressure at 75-80 mm Hg, were used as adjuncts for myocardial protection. The internal mammary artery was isolated under direct vision up to the second rib with excision of the fourth costal cartilage. Coronary artery target sites were the left anterior descending in 12, right coronary artery in 4, obtuse marginal in 3, posterior descending in 1 and diagonal branch in 1 patient. Arterial grafts (mammary, right gastroepiploic, radial), either as single or composite grafts, were used liberally. Preoperative risk factors included congestive heart failure (7), chronic renal insufficiency (5), second reoperation (2), third reoperation (1), cerebrovascular disease (5), prior angioplasty (8) and preoperative intra-aortic balloon pumping in two patients. RESULTS: There was no perioperative mortality with minimal morbidity. Twelve patients underwent patency study of the grafts 48-72 h postoperatively. Ten of the twelve grafts were patent; one internal mammary artery graft to the left anterior descending coronary artery (<1.5 mm) early in our series was occluded and one additional left internal mammary graft had a kink several centimeters away from the anastomosis, which was successfully opened by angioplasty. At a mean follow-up interval of 8 months all 16 surviving patients are in functional class I or II and all of them remain free of angina. CONCLUSION: In selected patients reoperative coronary artery bypass grafting can be performed with this minimally invasive approach with a low perioperative morbidity and mortality rate and satisfactory early graft patency rate with good symptomatic improvement.

Successful repair of combined septal and biventricular free wall rupture after acute myocardial infarction.

The following case is the first report of successful repair of combined left and right ventricular free wall and ventricular septal rupture. Reports of left ventricular free wall and septal rupture and reports of right ventricular free wall and septal rupture have been published both with and without successful surgical repair. This case demonstrates the presence of left and right ventricular free wall rupture along with septal rupture based upon cardiac catheterization and operative findings. In spite of her severe mechanical complications and prolonged hospital course, the patient is completely functional 1 year after surgical repair.

Valve injury and repair in balloon aortic valvuloplasty.

Aortic valves 0.5, and 4.5 months after successful percutaneous balloon aortic valvuloplasty (BAV) were examined. BAV caused macroscopic and microscopic fractures in calcific deposits. An inflammatory response was identified that may lead to valvular scarring. This process may be an important factor in the development of restenosis after BAV.

Preservation of myocardial ultrastructure after 24 hours of Klebsiella sepsis: histologic, functional, and biochemical correlations.

Myocardial function with ultrastructure and high energy phosphate levels in dogs was correlated after 24 hours of sepsis using live Klebsiella aerogenes. All animals developed progressive hemodynamic deterioration over a 24 hour period. Mean arterial pressure decreased from 148 +/- 7 mmHg to 85 (P less than 0.01) and cardiac output decreased from 3.43 +/- .31 to 1.6 +/- 0.5 L/min. Left ventricular stroke work decreased from 48.2 +/- 5 to 18.1 +/- 6 gm-meters (P less than 0.001). Systemic and pulmonary vascular resistances were increased at 24 hours (3,538 +/- 27 to 7,404 +/- 1,400 dyne/sec/cm-5 (P less than 0.01), and 185 +/- 20 and 619 +/- 90 dyne/sec/cm-5 (P less than 0.001), respectively. Left ventricular function curves at 24 hours showed a fixed low output. However, myocardial ultrastructure was preserved and high energy phosphate levels remained normal. These observations correlate well with the changes seen clinically in early gram negative sepsis in hypovolemic patients. Thus, this appears to be a suitable model for further investigation of the effects of gram negative sepsis on myocardial performance, ultrastructure, and maintenance of energy stores.

Effect of preoperative antiplatelet drugs on vascular prostacyclin synthesis.

Patients undergoing aortocoronary bypass using autogenous saphenous veins were randomly divided into three comparable groups. Group 1 (n = 10) acted as a control, Group 2 (n = 14) received 80 mg of aspirin at midnight before the operation, and Group 3 (n = 12) received 80 mg of aspirin and 75 mg of dipyridamole at midnight and an additional 75-mg dose of dipyridamole at 6 AM. The purpose was to determine which regimen would maximally inhibit platelet function without depressing vascular prostacyclin synthesis. Serum thromboxane A2, saphenous vein wall and aortic wall prostacyclin, platelet aggregation, and bleeding time were measured in all patients. None was restarted on a regimen of aspirin or dipyridamole postoperatively. Aspirin alone and in combination with dipyridamole significantly inhibited thromboxane A2 and platelet aggregation in all treated patients but spared venous prostacyclin synthesis. Aortic prostacyclin synthesis was partially inhibited in both treated groups. Chest tube drainage was comparable in all three groups. These results indicate that the combination of aspirin and dipyridamole offers no measurable advantage over aspirin alone in the perioperative period.

Prostacyclin production by internal mammary artery as a factor in coronary artery bypass grafts.

Long-term patency of coronary artery bypass grafts (CABG) with internal mammary artery (IMA) is better than with saphenous vein (SV) grafts. To determine if vascular prostacyclin (PGI2) produced by IMA might contribute to the improved outcome, we compared PGI2 generated by IMA and SV fragments from 26 patients undergoing CABG and tested the effect of preoperative, long-term ingestion of of aspirin. Fresh tissues were incubated in buffer +/- 25 mumol/L of sodium arachidonate at 37 degrees C for 5 minutes to stimulate PGI2 production, measured by radioimmunoassay of its major hydrolytic product, 6-keto-PGF1 alpha. Results were expressed in picograms of 6-keto-PGF1 alpha per milligram tissue wet weight for total PGI2 production by vascular segments and picograms per cm2 surface area for endothelial PGI2 production. Endothelial PGI2 production was compared for IMA and SV in template-stirring chambers that exposed only the luminal surface of the vessel, excluding underlying smooth muscle. Endothelial PGI2 production by IMA was significantly higher than production by SV under both basal (mechanical stimulation only 1436 +/- 224 versus 842 +/- 227 pg/cm2, mean +/- SEM, p greater than 0.05) and stimulated (25 mumol/L sodium arachidonate: 3343 +/- 347 versus 2032 +/- 465 pg/cm2, p less than 0.025) conditions in patients not receiving aspirin. For patients receiving aspirin, endothelial PGI2 production by IMA was significantly higher than production by SV in stimulated conditions (1382 +/- 526 versus 683 +/- 124 pg/cm2, p less than 0.05). Histologic examination of the tissue segments revealed intact endothelium after incubation in both IMA and SV. Thus a high capacity for PGI2 synthesis and diminished inhibition of PGI2 after aspirin were demonstrated for IMA compared with SV tissue and may be a factor in the improved patency of IMA grafts.