New graft holder for coronary artery bypass using arterial conduits.

An arterial graft holder was designed to facilitate coronary artery bypass surgery. It can be used to open the heel of arterial conduits and it immobilizes the graft with a spring clamp. The tip of the holder is made from flexible, silicon-coated vinyl chloride tubing, so that it can be inserted into the arterial lumen without causing endothelial injury.     

Early and mid-term results of all arterial graft coronary artery bypass grafting using bilateral internal thoracic and radial arterial conduits

From March 1996 to May 2000, 41 patients [age 39-78 (mean 63.5 +/- 8.8) years, 90.2% male] underwent all arterial multiple coronary artery bypass grafting (CABG) using bilateral internal thoracic (BiITA) and radial (RA) arterial conduits. The reason for using RA was that the right gastroepiploic artery (RGEA) was small or occluded on preoperative angiography, a history of upper abdominal surgery or disease, or the right coronary arterial lesion was proximal and mild. The BiITA were used as in situ grafts and the proximal anastomosis of RA was to the ascending aorta in all cases. All patients underwent conventional elective CABG with median sternotomy using cardiopulmonary bypass. The mean number of anastomoses was 3.3 +/- 0.5 branches and complete revascularization rate was 80.5%. Postoperative follow-up averaged 20 months and the longest was 50 months. There was no early death, and overall graft patency 2-3 weeks after surgery was 96.2% (LITA 94.0%, RITA 97.6%, RA 97.6%). Four-year actuarial survival rate was 96.4 +/- 3.5% (1 patient: 9 months, no cardiac death), and cardiac event-free rate after surgery was 89.7 +/- 4.9% [4 patients: percutaneous transluminal coronary angioplasty (PTCA)]. However, once patients were discharged from hospital, cardiac event-free rate was 100%. These excellent results suggest that all arterial graft CABG was satisfactory, and RA can be used as a third suitable arterial bypass conduit, if RGEA cannot be used or is unsuitable for use.     

Effect of ascorbic acid on endothelium-dependent vasodilatation of human arterial conduits for coronary artery bypass grafting.

OBJECTIVE: Techniques aimed at improving the performance of arterial conduits will maximize the clinical benefit achievable with coronary artery bypass surgery. Controlling oxidant stress could be a strategy for preventing early graft deterioration. We tested the effect of a free radical scavenger, ascorbic acid (vitamin C), on preserving the endothelium-dependent vasodilatation function in vitro of radial artery and internal thoracic artery. We also tested its effect on the amount of reactive oxygen species (ROS) generated by each graft. METHODS: Radial artery (RA, n=25) and internal thoracic (ITA, n=19) segments were obtained from coronary artery bypass grafting patients. Each segment was divided into 3-4 mm vascular rings and incubated with or without ascorbic acid (10(-3) mol/l) for 1 h or 72 h. Using the organ bath technique, the endothelium-dependent vasodilatation function was tested in vitro by the addition of cumulative concentrations of acetylcholine (10(-9)-10(-5) mol/l) following vasocontraction by endothelin-1 (3 x 10(-8) mol/l). ROS were measured by using chemiluminescence technique at 1-h and after 72 h incubation with or without ascorbic acid. RESULTS: There were no differences in the vasodilatation function between control and ascorbic acid group of both arteries in the 1-hour incubation experiment. However, in the 72 h incubation experiment, ascorbic acid preserved the endothelium-dependent vasodilatation function of RA compared with control group (35.8+/-2.2% vs. 25.9+/-2.1%; P=0.005), but not ITA (39+/-3.5% vs. 40.5+/-9.3%; P=0.438). After 72 h incubation, RA generated significantly more free radicals compared with 1 h (133.7+/-151.5 vs. 16.8+/-16.8 cps/mg x 100; P=0.01); however, AA has no statistically significant effect on decreasing the amount of free radicals generated by both arteries. CONCLUSIONS: In RA, ascorbic acid is able to preserve the endothelium-dependent vasodilatation function after 72 h incubation, but not after 1 h. However, the mechanism of action of AA is not completely understood. This finding could open the door for understanding the role of oxidant stress and antioxidants in preserving the endothelial function of coronary artery bypass grafts.     

Twenty-year outcomes of coronary artery bypass grafting utilizing 3 in situ arterial grafts

ObjectiveThe added value of total arterial revascularization in coronary artery bypass grafting becomes particularly apparent when evaluating long-term results. We previously reported on our 10-year outcomes of total arterial revascularization using bilateral internal thoracic and gastroepiploic arteries as in situ grafts in patients with 3-vessel disease. This study aimed to increase the follow-up period to 20 years.MethodsWe updated clinical outcomes of 201 patients operated on between 1992 and 2002. At that time, the technique was primarily performed in patients with a longer life expectancy. Primary end points were overall survival and freedom from the composite of major adverse cardiac events. Secondary end points were the separate cardiac events.ResultsExtended follow-up included all patients. The median follow-up time was 19.2 years (interquartile range, 16.2-20.0). The respective 15- and 20-year Kaplan-Meier estimated survival probabilities were 73.9% (95% confidence interval [CI], 67.2%-79.5%) and 63.5% (95% CI, 55.7%-70.4%) for overall survival and 57.9% (95% CI, 50.7%-64.5%) and 47.9% (95% CI, 40.1%-55.3%) for freedom from major adverse cardiac events. The respective estimated cumulative incidences at 15 and 20 years were 7.0% (95% CI, 3.5%-10.6%) and 7.8% (95% CI, 4.0%-11.6%) for myocardial infarction, 8.6% (95% CI, 4.7%-12.5%) and 9.3% (95% CI, 5.2%-13.3%) for percutaneous reintervention, 7.0% (95% CI, 3.5%-10.5%) and 7.0% (95% CI, 3.5%-10.5%) for reoperation, 8.6% (95% CI, 4.7%-12.6%) and 12.9% (95% CI, 7.6%-18.2%) for cardiac death, and 10.8% (95% CI, 6.5%-15.2%) and 15.2% (95% CI, 9.8%-20.6%) for death from other causes.ConclusionsThe use of in situ bilateral internal thoracic and gastroepiploic arteries provides outstanding 15- and 20-year survival and cardiac event-free survival probabilities. Further studies are needed in older patients with more severe comorbidities. Nevertheless, the results from this and scarce other studies on 15- to 20-year outcomes of total arterial revascularization suggest that cardiac surgeons should embrace the application of total arterial grafting to further reduce the risks of long-term cardiac events, especially during the second decade after surgery.     

Abdominal surgery following coronary artery bypass grafting using an in situ right gastroepiploic artery graft.

OBJECTIVE: The usefulness of the gastroepiploic artery (GEA) as arterial grafts in coronary artery bypass grafting (CABG) has been studied extensively. We report our experience performing abdominal surgery after CABG using in-situ GEA. METHODS: The subjects were eight patients who underwent abdominal surgery after CABG with an in situ GEA graft. The surgical indications were malignant tumors in five patients, an infrarenal abdominal aortic aneurysm in two patients and a diaphragmatic hernia in one patient. The interval from the CABG to the abdominal surgery ranged from 3 to 19 months. RESULTS: Operations included distal gastrectomy in two cases, total gastrectomy in one case, local excision of the stomach in one case, and excision of the transverse colon in one case. Aorto-biiliac artery bypass was performed in two cases, and the diaphragmatic hernia was reconstructed using standard techniques. When the skeletonization method has been used to harvest the GEA, GEA grafts were easily identified during a laparotomy, and the abdominal procedure was performed using routine methods. One patient died of cancer, and the other patients are alive 1 year 2 months to 4 years 5 months after surgery. No patient reported recurrence of angina. CONCLUSION: The risk of abdominal reoperations should be considered when using the in situ right GEA for CABG. We recommend the skeletonization method for GEA harvest to decrease the difficulty during second abdominal operations.     

Isoflurane produces only minor preconditioning in coronary artery bypass grafting

OBJECTIVE: To investigate whether administration of isoflurane prior to cardiopulmonary bypass (CPB) could partly account for the observed protection of the myocardial function and to decrease myocardial injury in patients undergoing coronary artery bypass grafting (CABG). METHODS: Thirty-four patients with stable angina who were scheduled for isolated elective CABG operations were randomized into the control group or isoflurane (ISO) group. In the ISO group, isoflurane was inhaled for 5 min followed by another 5-min washout period before commencing CPB. The control group did not receive isoflurane. Hemodynamic data and biochemical markers of myocardial injury were measured perioperatively. RESULTS: There were no adverse effects related to isoflurane. Cardiac index (CI) increased postoperatively as compared with the baseline. In the ISO group, there was a tendency for a greater increase of CI than that in the control group (p = 0.054, ANOVA for repeated measurements). At 1 h after CPB, the change of CI was much higher in the ISO group than that in the controls (p = 0.001). Both the creatine kinase cardiac isoenzyme (CK-MB) and troponin I (TnI) reached peak value at 6 h after CPB. Isoflurane patients released slightly less CK-MB than the controls postoperatively, but the difference was not significant (p = 0.16, ANOVA for repeated measurements). The release of TnI was similar in both groups (p = 0.65, ANOVA for repeated measurements). CONCLUSIONS: Administration of isoflurane prior to commencing CPB may bring an improvement in early hemodynamic performance after CABG operations.     

Remodeling of arterial conduits in coronary grafting

In the initial decade of coronary surgery, serial angiography of internal thoracic artery grafts revealed increased caliber in some, decreased caliber in others, and "string sign" in a few, which was occasionally documented to be reversible. Although we speculated on possible causes of these changes, it was not until discovery of the endothelial role in modulating arterial diameter to maintain shear stress in a narrow range that we began to gain insight into the mechanisms responsible for remodeling of the arterial wall. This review provides a glimpse of the physiology and biology of arterial remodeling and summarizes observations on the various arterial conduits when subjected to flow alterations.     

Off-pump coronary artery bypass grafting using in situ bilateral skeletonized internal thoracic arteries

Objective All arterial off-pump coronary artery bypass grafting (OPCAB) with in situ bilateral skeletonized internal thoracic arteries (ITAs) may become a standard procedure that would provide better long-term results without affecting early results. Methods Our study included 404 consecutive patients who underwent OPCAB with one or two ITAs. We compared the clinical results of 135 patients who underwent OPCAB using unilateral ITA (UITA group) to those of 269 patients using bilateral ITAs (BITA group). Results The average number of distal anastomoses was 3.07 in the UITA group and 3.47 in the BITA group (P < 0.01). Four operative mortalities occurred in the UITA group and two in the BITA group. There were no significant differences in morbidity between the two groups. Conclusion OPCAB using bilateral skeletonized ITAs is technically feasible, with good early results. Arterial OPCAB using in situ bilateral skeletonized ITAs may become a standard procedure in the future.     

Skeletonized arterial graft holder for coronary artery bypass grafting

A skeletonized arterial graft holder, designed for use during off-pump coronary artery bypass grafting, is described. This new holder is atraumatic and holds a skeletonized arterial graft securely during anastomosis. It helps the operator to make the first several stitches avoiding graft injuries, and the use of this instrument facilitates the use of skeletonized arterial grafts for coronary artery bypass grafting.     

Composite arterial grafts versus conventional grafting for coronary artery bypass grafting

OBJECTIVES: Composite arterial grafts for coronary artery bypass grafting surgery allow complete arterial revascularization but are limited by the inflow of a single internal thoracic artery supplying all the grafted vessels. We reviewed the safety of composite arterial grafts using either bilateral internal thoracic arteries or a single internal thoracic artery and radial artery. METHODS: From January 1999 to July 2002, 402 consecutive patients receiving composite grafts only were compared to a control group of patients (n = 542) undergoing coronary artery bypass grafting with internal thoracic artery and saphenous veins operated upon by the same surgeons. Two different statistical approaches were used to compare groups in this retrospective analysis. First, propensity score analysis with greedy matching technique was used to match patients from each group. Second, a multivariate analysis was performed looking at a combined patient outcome of death, intra-aortic balloon counterpulsation utilization, myocardial infarction, stroke, and prolonged ventilation on all patients in both groups. RESULTS: After matching by propensity score, the major clinical outcomes in composite arterial (n = 249) and control (n = 249) groups were found to be similar. The in-hospital mortality in the composite group was 1.2% as compared with 0.4% in matched patients (P =.62). However, patients in the composite group were found to have a significantly longer pump time (P <.0001), longer clamp time (P <.0001), increased incidence of prolonged mechanical ventilation (12.8% vs 4.8%; P =.002), and higher incidence of combined morbidity outcome (13.6% vs 6.4%; P =.007) as compared with matched patients. Multivariable analysis showed that composite arterial grafting was an independent predictor of the combined morbidity outcome with an odds ratio of 2.1 (1.2-3.7). CONCLUSIONS: These findings suggest that composite arterial grafting may be associated with an increase in risk-adjusted patient morbidity when compared with a conventional coronary artery bypass grafting group, although a mortality difference was not demonstrable.     

Mitral valve replacement through right thoracotomy after coronary arterial bypass grafting with functioning conduits.

A 67-year-old man who had undergone coronary artery bypass grafting 3 years previously suffered from severe mitral regurgitation associated with Streptococcal infective endocarditis. He was placed in New York Heart Association functional class III. Preoperative angiography demonstrated good opacification of all 3 conduits implanted in the previous operation. We replaced the mitral valve through an anterolateral right thoracotomy, approaching the mitral valve as an alternative to redoing sternotomy to minimize potential injury to patent grafts. His postoperative course was uneventful. After a 1-month course of antibiotics, the patient was discharged as New York Heart Association class II and at present, 3 months after discharge, is doing well. This approach is an effective alternative to redoing sternotomy for mitral valve operation, especially in patients undergoing a previous coronary arterial bypass grafting via median sternotomy.     

Combined aortic valve replacement and coronary artery bypass grafting with in situ arterial grafts for porcelain aorta.

Patients with porcelain aorta carry a high risk of cerebral as well as systemic embolism during cardiac surgery. Here we describe a case of severe aortic stenosis and coronary artery disease combined with the circumferentially calcified aorta. The patient was a 77-year-old man who successfully received four coronary artery bypass grafts with in situ arterial grafts without clamping the aorta and aortic valve replacement. Aortic valve replacement and two distal coronary artery anastomoses to the left circumflex artery and obtuse marginal branch were performed under cardiac arrest during hypothermic perfusion with endoaortic balloon occlusion, followed by partial endarterectomy and closure of the aorta buttressed with bovine pericardium under deep hypothermic circulatory arrest. While rewarming, the other two distal coronary anastomoses to the left anterior descending artery and diagonal branch were done on the beating heart in order to minimize cardiac arrest time. On-pump beating heart coronary artery bypass grafting (CABG) can be useful especially for combined complex cardiac surgery.     

Quadruple coronary artery bypass grafting.

In our last 150 consecutive revascularization operations, 30 patients (20%) have had 4 or more bypass grafts. One patient died after quadruple grafting (mortality, 3%). Twenty-two (75%) of the survivors have been rehabilitated to active work status and 25 (86%) were considered by their cardiologists to have improved function postoperatively by New York Heart Association criteria. Preoperatively 15 patients (50% of the group) had either a markedly diminished ejection fraction (EF) or extreme elevation in left ventricular end-diastolic pressure (LVEDP) or both. Complete revascularization, with resection of ventricular aneurysms when present, can be carried out successfully in a high-risk group of patients. Elevated LVEDP or diminished EF per se is not a valid contraindication to myocardial revascularization.