Comparison of myocardial preservation techniques for aortocoronary bypass surgery.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to G Schimert.
Explore the source record for details and available documents.
Perioperative and late follow-up hemodynamic cardiovascular studies to assess the effects of direct myocardial revascularization on cardiac function objectively have been completed on 51 patients. Analysis of the data delineated three distinct groups basedon the patterns of their early postoperative recovery. Group I patients (12) had a hyperdynamic cardiovascular response to operation and returned to a normal physiological range of cardiac function within 24 hours. Group II patients (24) initially had moderate to severe myocardial decompensation postoperatively but responded to inotropic support and moved into the normal physiological range within 24 to 48 hours. Group III patients (15) had severe, prolonged myocardial decompensation with little response to inotropic support. There were no early deaths in Group I, 1 early iatrogenic death in Group II, and 2 deaths from sepsis, 1 in Group I and 1 in Group II. All 7 cardiogenic deaths occurred in Group III patients. Late follow-up studies 4 to 23 months postoperatively have been completed on 29 patients. These showed cardiovascular stability in the mean values in Groups I and II. Significant improvement in mean cardiac function was seen in surviving Group III patients.
A technique is described for selective intracavitary and coronary hypothermic perfusion during cardiac bypass with cardioplegia to facilitate cardiac operations. A cold perfusate (Plasmalyte 148 and mannitol, 12.5 gm/L at 8 degrees to 10 degrees C) is administered with the aid of a low-flow perfusion pump into the left ventricular cavity and coronary circulation through an apical perfusion-venting (Per-Vent) catheter. This perfusate cools the myocardium rapidly and homogeneously to a temperature of 15 degrees to 20 degrees C. Within this temperature range, complete cardioplegia occurs and the safe ischemia period can be extended to 120 minutes. This method was applied in 50 unselected consecutive adult patients undergoing aortocoronary saphenous vein bypass grafting or aortic or mitral valve replacement. All patients survived and had excellent recovery of ventricular function.
Intraoperative myocardial protection was evaluated in two groups of patients undergoing coronary surgery in whom different techniques for cardiac arrest were utilized. In group A, profound selective myocardial hypothermic (15 to 18 C) arrest was achieved by perfusing a coolant (7 to 10 C) into the left ventricular cavity and the coronary circulation. The average anoxic arrest time was 82.5 +/- 27 minutes. In group B, ventricular fibrillation and moderate hypothermia were used. Group A patients showed rapid physiologic recovery, low average myocardial creatinine phosphokinase (MB-CK) isoenzyme levels (7.8 IU) , and a well-preserved myocardial ultrastructure. In group B, three patients showed abnormal physiologic recovery; six patients needed postoperative inotropic support; and in seven patients, electron-microscopy revealed irreversible focal changes. The average MB-CK isoenzyme level was 85.6 IU. Analysis of our data demonstrates that when myocardial protection during coronary bypass grafting is achieved by selective profound intracavitary and coronary cooling, there is physiological, ultrastructural, and biochemical evidence of less intraoperative myocardial damage than when ventricular fibrillation is applied.
An improved technique of free internal mammary artery (IMA) to ascending aorta anastomosis for coronary bypass is described. A small patch vein with a suitable side branch or branches is interposed, connecting the proximal end of a detached IMA to the ascending aorta. A single or double free IMA alone or in combination with an additional saphenous vein graft was performed in 77 patients. A total of 125 free IMA grafts were done. The hospital mortality was 2-7% and late mortality 1-4%. Seventy-one of the 74 surviving patients had no angina and returned to a normal life. Postoperative coronary arteriography in 65 patients showed a patency rate of 96%. On year's experience with this technique is very encouraging. However, prolonged follow-up is necessary to determine if free IMA, as used by us, will increase the long-term patency rate.
Mediastinal sepsis following open heart surgery is a significant cause of death. Open drainage of the mediastinumalone was employed originally in management of this problem. More recently, debridement, drainage, and reclosure have been used. Various irrigation solutions, such as antibiotics and Betadine, have been advocated to control severe mediastinal sepsis. Three principles of management in patients unresponsiveness to the above techniques have proved successful in two patients with life-threatening mediastinal sepsis: (1) radical, complete excision of the sternum and adjacent costal cartilages; (2) transposition of the greater omentum on a vascular pedicle to the mediastinum; and (3) primary closure with full-thickness rotational skin flaps. The radical excision of the sternum removes residual foci of sepsis in cartilage and sternal bone marrow. The transposition of the omentum provides a highly vascular, rapidly granulating covering for the contaminated great vessels and hase been successfully to prevent recurrence of suture line bleeding of an exposed ascending aortic anastomosis site. Primary closure of the wound with full-thickness skin flaps provides a suprisingly satisfactory covering for the heart. Preoperative and postoperative measurements of ventilatory mechanics have shown relatively small ventilatory impairment after the alteration of the thoracic cage imposed by excision of the sternum. Two patients have returned to active lives. A treatment failure probably due to incomplete adherence to these guidelines also is presented.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
An improved method of free internal mammary artery (IMA)-to-ascending aorta anastomosis for cornoary bypass is described. We interposed a small patch of vein with a suitable side-branch or brancyes in connecting the proximal end of a detached IMA or radial artery. Thirty-four free IMA-to-coronary artery bypasses were performed in 25 patients; 16 right IMA, 14 left IMA, and 4 radial arteries were used. Cornoary angiographic follow-up studies performed in all patients between two weeks and six months after operation proved that all grafts were patent and showing a larger lumen than is usually seen in undetached IMA grafts. Concomitantly marked relief of anginal pain was noted in all patients. Oour experience with this technique is very encouraging. All patients are being followed to evaluate long-term graft patency.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.