Hassan Najafi

Neurological Complications of Coronary Revascularization

In a series of 3,206 consecutive coronary artery bypass procedures performed between 1976 and 1981, 89 patients died (2.8% mortality) and 32 patients (1%) suffered major neurological syndromes. Among the latter patients, four distinct groups were identified. Group 1 consisted of 10 patients who remained unresponsive after operation. In Group 2 were 10 patients who awakened after operation but had clinical evidence of focal cerebral infarction. Group 3 included 6 patients who were initially intact neurologically but in whom neurological deficits later developed. In Group 4 were 6 patients who had severe mental aberration but no focal neurological deficits. The incidence of coma or focal deficit occurring without a lucid interval (Groups 1 and 2) was 0.62%, and these patients had a 30% mortality. Causative factors were suspected in 70% of the patients in Groups 1 and 2, and included atheromatous embolism, perioperative hypotension, carotid artery occlusive disease and air embolism. The outcome was poor for unresponsive patients, with 70% dying or remaining comatose, but nearly all of the patients with focal deficits or severe mental aberration demonstrated notable improvement.

Experience with antegrade bihemispheric cerebral perfusion in aortic arch operations

BACKGROUND Various techniques have been used for cerebral protection in aortic arch operations. Antegrade cerebral perfusion has lost its popularity to hypothermic circulatory arrest to overcome the so-called cluttered operative field. Hypothermic circulatory arrest has its own problems of coagulopathy, time constraints, and prolongation of cardiopulmonary bypass time. METHODS Since June 1986 we have used antegrade bihemispheric cerebral perfusion with moderate hypothermia in 20 patients with aortic arch disease. Twelve patients had aneurysm, 7 had dissection, and 1 had traumatic tear. Five patients had had previous sternotomy for ascending aortic replacement. In addition to arch reconstruction, 7 patients had aortic valve replacement or repair, 2 patients had Bentall procedure, and 3 had selective innominate reconstruction. The mean cerebral perfusion time was 51+/-29 minutes. In 7 patients the cerebral perfusion time was between 60 and 120 minutes. RESULTS There was no in-hospital or 30-day mortality. The blood product requirements were significantly less with moderate hypothermia. One patient suffered cerebrovascular accident (5%). None of the 7 patients with cerebral perfusion times of 60 to 120 minutes had any neurologic deficits. These results are superior to those reported for hypothermic circulatory arrest with or without retrograde cerebral perfusion. CONCLUSIONS Antegrade bihemispheric cerebral perfusion is an optimal adjunct for cerebral protection during aortic arch operations.

Acute Aortic Regurgitation Secondary to Aortic Dissection: Surgical Management Without Valve Replacement

Abstract Emergency operations were performed in 7 adult patients for severe aortic insufficiency caused by acute aortic dissection. Dissection beginning in the aortic root involved the entire thoracoabdominal aorta in at least 3 patients. The operative findings consisted of an arch of relatively normal caliber, supravalvular intimal tear, circumferential dissection, and prolapse of the aortic cusps into the left ventricle. Repair of the proximal dissected layers and elevation of the cusps to their normal position restored valve competence in every patient. Six survivors have retained normal aortic valve function four months to six years postoperatively. The review emphasizes the feasibility of restoring aortic valve competence without using a valve substitute in treating aortic insufficiency caused by acute aortic dissection.

Permanent transvenous balloon occlusion of the inferior vena cava: experience with 60 patients.

Traditional operations to obstruct the IVC are often unsatisfactory because the morbidity and mortality is appreciable; poor risk patients do not tolerate surgical and anesthetic trauma. Furthermore, if the patient is anticoagulated, an operation requires that such desirable treatment be stopped. Ten years ago a study was begun to develop a transvenous method of IVC occlusion in the awake anticoagulated patient. Animal studies were done prior to patient application. A technique was evolved wherein IVC interruption could be accomplished with a balloon bearing catheter inserted through the jugular vein. The balloon was positioned with venography and after inflation held in place by lateral pressure in the distensible IVC. The catheter was then removed, leaving the balloon in position. Balloon occlusion has been used in the management of 60 selected patients since 1970. Twenty-nine patients were simultaneously anticoagulated without complication. Very sick patients tolerated the procedure well. No patient experienced further pulmonary emboli. Nine hospital deaths occurred from a variety of causes, none related to the balloon catheter. Late follow-up shows that the occluding balloon gradually deflates in about 12 months. The remnant has remained stable in all patients, contained in a scar that permanently interrupts the IVC.

Extended aortic valvuloplasty for recurrent valvular stenosis and regurgitation in children.

Recurrent significant aortic valvular stenosis or regurgitation, or both, after balloon or open valvotomy in pediatric patients often necessitates aortic valve replacement. In an attempt to preserve the aortic valve, we performed extended aortic valvuloplasty in 21 children with recurrent aortic valve stenosis or regurgitation from January 1989 to March 1993. Previous related procedures were one open aortic valvotomy or more (n = 15), balloon valvotomy (n = 4), balloon valvotomy after surgical valvotomy (n = 1), and repair of iatrogenic valve tear (n = 1). Mean age at the time of the extended aortic valvuloplasty was 6 +/- 3.4 years. Mean pressure gradient across the aortic valve was 56 +/- 12 torr. Regurgitation was moderate (grade 2 to 3) in nine and severe (grade 4) in 12 patients. Extended aortic valvuloplasty techniques consisted of thinning of valve leaflets (n = 15), augmentation of scarred and retracted leaflets with autologous pericardium (n = 11), resuspension of the augmented leaflet (n = 14), release of the rudimentary commissure from the aortic wall (n = 5), extension of the valvotomy incision into the aortic wall on both sides of the commissure (n = 20), patch repair of the sinus of Valsalva perforation (n = 1), reapproximation of tears (n = 5), and narrowing of the ventriculoaortic junction (n = 2). No operative deaths occurred. The postoperative mean pressure gradient, assessed by most recent Doppler echocardiography or cardiac catheterization at a follow-up of 18 +/- 6 months, was 19 +/- 6 torr (p < 0.01 versus the preoperative gradient). Aortic regurgitation was absent in 13, mild in 6, and moderate-to-severe, necessitating subsequent aortic valve replacement, in 2. This short-term experience indicates that extended aortic valvuloplasty is a safe and effective surgical approach that minimizes the need for aortic valve replacement in children with significant recurrent aortic valve stenosis or regurgitation.

Left ventricular hemorrhagic necrosis. Experimental production and pathogenesis.

Abstract Left ventricular subendocardial hemorrhagic necrosis, a lesion different from myocardial infarction, has been considered a major cause of death in patients undergoing operation for valvular heart disease. To determine its pathogenesis, calves were placed on bypass and the myocardium was challenged by the unphysiological circumstances usually existing in clinical open-heart surgery. These consisted of total ischemia, total oxygenation (with equal or unequal pressures in the coronary vessels), and perfusion of one or different combinations of two coronary branches. Total and even myocardial oxygenation and total ischemia up to one hour were associated with minimal myocardial injury and no mortality, while uneven coronary perfusion, especially of an area of complete ischemia in the domain of the left coronary artery, was associated with significant myocardial damage resulting in a high mortality. The pitfalls and shortcomings of extracorporeal coronary perfusion are discussed along with certain hypotheses pertaining to the pathogenesis of the lesion in man.

Surgical Treatment of Cerebral Ischemia

Atherosclerotic lesions of the extracranial portion of the brachiocephalic system are segmental and amenable to surgical procedures currently available. The value of carotid endarterectomy in palliation of symptoms and in prevention of stroke has been demonstrated.

Inferior vena cava interruption with the hunter-sessions balloon: Eighteen years' experience in 191 cases***

Over a period of 18 years, 191 consecutive patients had interruption of the inferior vena cava with the Hunter-Sessions balloon for complications of deep venous thrombosis and pulmonary embolism. Causes of deep venous thrombosis and pulmonary embolism included the postoperative state (33%), cancer (32%), and stroke (11%). There were 93 females and 98 males; ages ranged from 17 to 90 years (average, 57 years). Indications for placement of the Hunter-Sessions balloon were as follows: contraindication to anticoagulants (33%), anticoagulant complications (24%), pulmonary embolism despite anticoagulants (45%), and others including inferior vena cava thrombus (12%). Sixty-eight percent had clinical phlebitis and 36% had positive venography results. Pulmonary embolism had occurred in 165 patients (86%). It was diagnosed by ventilation-perfusion scanning (75%), angiography (23%), or on clinical grounds (2%) in patients with confirmed deep venous thrombosis. At the time of the procedure 52% were in significant cardiopulmonary distress, and 10% were intubated and on respirators. Transjugular placement was done in 188 patients, and transfemoral placement was performed in three. All All tolerated inferior vena cava interruption. Thirty patients (15%) died while in the hospital an average of 21 days after balloon placement, which was unrelated to the deaths. Follow-up was 45 months. Ninety-four patients are dead, 95 are alive, and the status of two patients is unknown. Twenty-nine of 64 patients (45%) who died after they left the hospital died of cancer. At last follow-up, 75% of patients had legs free of edema and 25% had need for elastic stockings. No malfunction or migration has occurred with the device. No patient had a pulmonary embolism while in the hospital after insertion of the Hunter-Sessions balloon, and no patient died of pulmonary embolism. Late minor pulmonary embolism occurred in three patients.

Mitral Insufficiency Secondary to Coronary Heart Disease

Twenty-four patients were operated on for mitral regurgitation secondary to coronary heart disease. Their common features consisted of a history of myocardial infarction, congestive heart failure, coronary occlusive disease, left ventricular dysfunction, low cardiac output, pulmonary hypertension, and increased left ventricular end-diastolic pressure. Fourteen patients were in intractable congestive heart failure at the time of operation. The operative procedures employed consisted of aneurysmectomy in 4 patients; mitral valve replacement (MVR) in 7;MVR and revascularization in 4; MVR and aneurysmectomy in 5;MVR, revascularization, and partial ventricular resection in 3; and MVR with closure of ventricular septal perforation in 1 patient. Six patients died, a hospital mortality of 25%, and only 42% had good results. The degree of associated coronary artery disease and the status of the left ventricular myocardium were the most important prognostic factors.

Coronary Obstruction Secondary to Direct Cannulation

Four patients are reported with obstruction of the proximal left main coronary artery that developed following prosthetic replacement of the aortic valve. Angina pectoris and ventricular arrhythmias were the presenting clinical manifestations. Anterior descending coronary artery bypass was used in 3 of the patients and vein patch angioplasty in the fourth. One patient died in the hospital. The 3 survivors achieved reflief from angina and ventricular arrhythmias. One patient died from nephropathy 2 1/2 years later. Two patients remained asymptomatic 1 1/2 and 3 years later, respectively. This review emphasizes the need for prompt coronary angiography in patients experiencing angina pectoris after aortic valve replacement, and it shows that coronary revascularization can be performed with satisfactory results.