Claude M. Grondin

Discrepancies Between Cineangiographic and Postmortem Findings in Patients with Coronary Artery Disease and Recent Myocardial Revascularization

In 28 consecutive patients who died following coronary artery grafting and within 30 days of a previous coronary cineangiogram, a study was undertaken to compare the findings at autopsy and those at angiography. In five instances, such a comparison could not be made: in one instance, no postmortem examination was obtained, and in four additional cases, the quality of the cineangiographic document (three instances) or the pathological specimen (one instance) did not permit a reliable comparison. In the remaining 23 cases, there were nine specimens in which an appreciable difference (≥ 25%) was noted in the severity of the coronary artery lesions. In four of these nine cases, failure of cineangiography to assess the degree of coronary arterial narrowing led to incomplete myocardial revascularization and contributed, in retrospect, to the surgical failure. Most discrepancies occurred in the left coronary artery system, despite the fact that in all instances, four projections had been obtained of the left coronary artery in the transverse plane. Because of the particular orientation of the initial portion of the left coronary artery and its major divisions, it is recommended that additional projections in the sagittal plane be included to eliminate angiographic superimposition of multiple branches, which often cannot be properly separated in the standard transverse plane.

Loss of the improvement of angina between 1 and 7 years after aortocoronary bypass surgery: correlations with changes in vein grafts and in coronary arteries.

Improvement of effort angina following pure aortocoronary bypass graft surgery was related to postoperative control angiographic studies of grafts and coronary arteries in 75 unselected patients. Clinical and angiographic evaluations were carried out at approximately 1 year and at 5 to 7 years after surgery. At 1 year, 61 (81.3%) were improved (52 without angina and 9 with partial improvement by at least two functional classes), whereas 14 were unimproved (18.7%). At approximately 6 years, loss of improvement (reappearance of angina or aggravation by at least two functional classes) was observed in 22 of the 61 improved patients, representing an attrition of 36.1% over a 5-year period. Graft occlusion or a narrowing of over 50% was observed in two of the 39 patients in whom improvement had continued (5.1%), whereas it was found in six of the 22 patients (27.3%) whose results deteriorated (p less than 0.05). Similarly, progression to occlusion of a preexisting stenosis of over 50% or appearance of a new stenosis of over 50% in a major coronary artery (distal to a graft or in an unbypassed artery) was observed in five of the 39 patients with continued improvement (12.8%) and in 11 of the 22 patients whose condition deteriorated (p less than 0.01). Changes in a graft or in a coronary artery were noted in 63.6% (14/22) of the patients with loss of improvement as compared to only 18% (7/39) of the patients whose improvement did not deteriorate. Improvement of angina was also evaluated in all survivors among our first 500 cases who had preoperative effort angina and pure bypass surgery with or without angiographic studies. Of these 260 patients, 70.4% were angina-free or improved by two to three functional classes at 1 year, and only 41.9% at 7 years after surgery. It is concluded that the effect of aortocoronary bypass graft surgery is transient in a high proportion of patients and that deterioration of results is related to late graft modifications and progression of atherosclerosis, particularly in ungrafted coronary arteries.

Changes in grafts and coronary arteries after saphenous vein aortocoronary bypass surgery: results at repeat angiography.

We studied the patency of saphenous vein aortocoronary bypass grafts in nonconsecutive and consecutive subgroups of our first 600 patients. The patency rates were 87-93% within 1 month and 74-85% approximately 1 year after surgery. The attrition rate of grafts averaged 2.2% per year between I and 6 years. Early occlusion was due to thrombosis; occlusion at 1 year was caused by fibrous intimal proliferation of grafts, which also led to variable reduction in caliber and to significant (> 50%) segmental stenoses in 5-15% of patent grafts. The most important determinant of graft patency at 1 year was the runoff capacity of the recipient arteries, followed by the quality of the surgical techniques. Late occlusion was related to atherosclerosis that became manifest only after at least 2 years. Coronary atherosclerosis progressed in more than 50% of proximal segments of grafted arteries during the first year, but little additional deterioration occurred between 1 and 6 years. During the first year, only 10% of preexisting stenoses in nongrafted arteries showed progression of disease; progression in these vessels increased to 46% at 6 years and was no longer different, for preexisting lesions > 50%, from that of grafted arteries. A close correlation was observed between changes in grafts and in coronary arteries and long-term survival or relief of angina. Ninety-four percent of patients with all grafts patent and 98% with an optimal correction were alive at 6 years compared with 70% of patients without patent grafts or surgical correction. Changes in grafts or coronary arteries were observed in two-thirds of patients in whom functional deterioration occurred between 1 and 6 years, compared with 18% in whom improvement persisted after surgery.

Sequential Anastomoses in Coronary Artery Grafting: Technical Aspects and Early and Late Angiographic Results

The present study concerns itself with the early and late results obtained with aortocoronary vein grafts containing more than 1 coronary anastomosis per graft. The surgical technique is described in detail and some of the hazards are outlined. It is apparent that the use of side-to-side anastomoses (SSAs) leads to a marked increase in blood flow in the proximal portion of the graft (average flow,131 ml/min) and also increases the patency rate of the proximal anastomosis. Thus, 3 of 51 SSAs were obstructed on the early angiogram, and only 1 of the 28 SSAs restudied at one year had become occluded. Although the cumulative--early and late--patency rate (55/66, or 83.3%) of the distal end-to-side anastomoses (ESAs) was not significantly better than that usually seen with conventional vein grafts, it is believed that improvement in the technique and greater awareness of some of its pitfalls will further decrease awareness of some of its pitfalls will further decrease the occlusion rate of distal ESAs. Most occlusions of the ESA appeared related to angulation, which tended to occur in the segment of graft between the proximal and the distal anastomoses. Appropriate modifications in the technique are described that should help to eliminate this difficulty. The use of SSAs allows for grafting of small coronary arteries which, with the conventional single anastomosis technique, are not usually bypassed in view of the high expected failure rate. Thus, of the 9 SSAs performed to 1 mm arteries and studied on two occasions, 8 remained open early after operation and 7 were still patent a year later.

Aortocoronary Bypass Graft Initial Blood Flow through the Graft, and Early Postoperative Patency

Intraoperative measurements of blood flow were made in 70 patients in whom a total of 103 venous bypass grafts had been inserted from the aorta to the right, the left anterior descending, or the circumflex coronary artery. Cineangiographic evaluation of graft patency was performed in all patients. Overall patency rate was 90.3%. Flow in all bypass grafts averaged 68 ml/min. All grafts with flow of 20 ml or less or which failed to respond to the injection of 20 mg of papaverine became occluded. All grafts with flow greater than 45 ml/min remained open.

Progressive and Late Obstruction of an Aorto-Coronary Venous Bypass Graft

Progressive late obstruction of an aorto-coronary venous bypass graft is reported in a 44-year-old man who died of bi-ventricular failure 114 days after surgery. The first portion of the vein graft had a residual lumen of one mm. Histology showed marked intimal fibrosis. Mechanism for this occlusion and fibrosis is unclear. This representsc the first documented case of late obstruction of an aorto-coronary bypass graft with angiographic evidence of early postoperative patency.

Postoperative changes in aortocoronary saphenous vein grafts revisited: angiographic studies at two weeks and at one year in two series of consecutive patients.

Comparison of aortocoronary saphenous vein graft status at two weeks and at one year was made in two series of patients. The early postoperative evaluation includes 122 patients of the first 138 operated in our institution (182 grafts) and 83 subjects from a second series of 100 patients operated after modifications of surgical techniques (184 grafts). The one-year follow-up study was obtained in 105 patients of the first series (154 grafts) and in 67 of the second (152 grafts). The patency rate at two weeks was not significantly different between the two groups: 86.3% vs. 91.8%. A marked decrease of stenoses noted early at anastomotic sites was observed: 15% to 5.5% (P < 0.025). The patency rate at one year improved from 67% to 85.5% (P < 0.0005). Grafts having flows at operation of at least 50 ml/min had patency rates of 90% in both series. The patency in grafts with initial flows below 50 ml/min increased from 28% to 73% (P < 0.0005). The incidence of late localized graft stenoses ≧40% decreased from 16.5% to 6% (P < 0.025), and diffuse narrowing ≧40% was found in only 12% of the patent grafts at one year in the second series as compared to 31% in the first (P < 0.001). These improved results do not appear to have been influenced by selection favoring better distal run-off in grafted arteries nor by the introduction of sequential grafts to multiple coronary arteries in the second group. Modified surgical techniques may explain the improved results.

Myocardial Protection Through Cold Cardioplegia Using Diltiazem, a Calcium Channel Blocker

During two hours of aortic clamping, two groups of 10 dogs each were given an intermittent infusion of a cold solution in the aortic root. In one group, the solution contained 20 mEq per liter of potassium chloride (KCl) and in the other, a calcium channel blocker (diltiazem). Left ventricular (LV) performance was measured by calculation of LV pressure, left ventricular end-diastolic pressure (LVEDP), cardiac index (CI), and stroke-work index (SWI). Regional myocardial function was assessed through ultrasonic crystals implanted in the subendocardial areas of both the left anterior descending (LAD) and circumflex coronary arteries. Dogs receiving KCl displayed deterioration of LV performance as evidenced by a return of maximal LV pressure, maximal rate of rise of LV pressure (dP/dtmax), CI, and SWI to 74 +/- 4%, 87 +/- 5%, 74 +/- 6%, and 59 +/- 6%, respectively, of the initial (before clamping) values. Animals that received diltiazem, on the other hand, had for the same variables a return to 85 +/- 4%, 99 +/- 7%, 129 +/- 8%, and 111 +/- 10% of the initial values. The rate of relaxation (peak negative dP/dt) decreased in both groups but less in dogs receiving diltiazem. Regional function in the area of the LAD and circumflex arteries showed little change in either group. We conclude that cold cardioplegia with a solution containing KCl or diltiazem protects the myocardium during prolonged ischemic cardiac arrest. Return of LV function on the whole is superior when diltiazem is used.

Blood Flow Through Aorta-to-Coronary Artery Bypass Grafts and Early Postoperative Patency: A Study of 100 Patients

Abstract Blood flow through aorta-to-coronary artery bypass grafts was measured in 100 patients who underwent insertion of a total of 157 grafts to the right (RCA), left anterior descending (LAD), or circumflex (CIRC) coronary artery or to a combination of these arteries. Angiographic evaluation was obtained in all patients in the early postoperative period. The overall patency rate was 88.5%. Mean flow was 28 ml. per minute in occluded grafts and 66 ml. per minute in patent grafts. The mean flow doubled in both groups following injection of papaverine into the graft, although 5 of the 18 occluded grafts failed to respond to papaverine. This phenomenon was not observed in patent grafts. In all but 1 occluded graft, blood flow was less than 50 ml. per minute. Only 3 of 12 grafts with a flow of 25 ml. or less remained open. It is concluded that intraoperative measurement of blood flow provides a reliable index of early postoperative patency in aorta-to-coronary bypass grafts.

Sympathetic Denervation in Association with Coronary Artery Grafting in Patients with Prinzmetal's Angina

Myocardial revascularization in patients with Prinzmetals angina has yielded variable results. Two patients are presented who underwent partial cardiac sympathectomy in combination with coronary artery grafting for typical variant angina associated with severe organic obstructive coronary artery disease. Late results 12 and 18 months postoperatively have been excellent in both instances as shown by clinical and angiographic evaluation. Although the exact mechanism responsible for Prinzmetals angina is not known, it is believed that spasm through increased activity of vasomotor tone or of the autonomic nervous system plays a major role. Since this variant form of angina encompasses a whole spectrum at angiography, ranging from normal arteries to severely narrowed ones, including those with spasm, it is suggested that surgical treatment be planned accordingly. Thus, in patients who have organic stenoses with and without spasm, operative treatment may consist of removal of the preaortic or pretracheal plexus in association with conventional coronary artery grafting. In patients who have intractable episodes of ventricular arrhythmia or angina and who angiogram is normal or shows isolated spasm, coronary artery grafting should be abandoned, in view of the poor results reported in the literature in these circumstances, and cervicothoracic sympathectomy should be considered.