Advances in the Management and Surgical Treatment of Intracranial Aneurysms

Patients who have sustained a spontaneous subarachnoid hemorrhage are victims of a very serious illness. Not only are they subject at all times to the potentially catastrophic results of a recurrent bleed, but they are faced with the manifestations of the irritative effects of blood in the subarachnoid space where the blood may function as a poison to the vessel wall. These acutely ill individuals may suffer a composite of secondary effects from a bleed which may include a communicating hydrocephalus, cerebral edema (ischemic or chemically induced), sterile meningitis, inappropriate ADH syndrome (osmotic effects of blood in the cerebrospinal fluid), spasm, and the likelihood of a recurrent bleed

Advances in the Surgical Treatment of Patients with Extracranial Cerebral Vascular Disease

Since the subject of surgery for carotid artery occlusive disease is too broad to be covered in its entirety, we will dwell primarily on some results of cerebral blood flow measurements and electroencephalograms performed during this procedure, their meaning and relationship to states of cerebral ischemia, and some controversial aspects of the surgery. An understanding of cerebral hemodynamics and the tolerance of neural tissue to ischemia is of major importance to any surgeon or physician dealing with this illness

Conduit choice for coronary artery bypass grafting after mediastinal radiation

ObjectivePatients who have undergone prior mediastinal radiation might require coronary artery bypass grafting. However, there is some concern regarding potential radiation damage to the internal thoracic artery. Our objective was to assess the late patency of the internal thoracic artery and venous grafts in patients with prior mediastinal radiation.MethodsPatients undergoing coronary artery bypass grafting at our clinic after prior mediastinal radiation were identified, and medical records, including operative reports, clinical notes, and coronary angiography, were reviewed.ResultsBetween 1985 and 2005, 138 patients had coronary artery bypass grafting after mediastinal radiation. Of these, 25 underwent clinically indicated postoperative angiography. The mean patient age was 56.1 ± 13.8 years, and 24% were female. All patients received between 3000 and 6000 rads in fractionated doses. Seventy-two percent of patients had 3-vessel coronary artery disease. At late angiography (mean, 2.2 years), 6 (32%) of 19 internal thoracic arteries and 13 (27%) of 48 venous or radial arterial conduits showed stenosis of 70% or greater (P = .72). Assessing only grafts that were anastomosed to the left anterior descending coronary artery, 35% (6 of 17) of internal thoracic artery grafts and 60% (3 of 5) of non–internal thoracic artery grafts showed narrowing of 70% or greater (P = .61). Among patients who received a graft to the left anterior descending coronary artery (n = 113), however, age-adjusted survival at 5 years was superior among those receiving an internal thoracic artery graft to the left anterior descending coronary artery.ConclusionsInternal thoracic artery graft patency among patients with prior radiation was less than expected and similar to that for venous grafts, although the effect of conduit disease versus distal target vessel runoff is unknown. Despite this, late survival was superior among those receiving an internal thoracic artery graft to the left anterior descending coronary artery. These data support use of an internal thoracic artery graft to the left anterior descending coronary artery when it appears grossly to be an acceptable conduit

Does the dilated ascending aorta in an adult with congenital heart disease require intervention?

ObjectivesThere is increasing attention to prophylactic replacement of the moderately dilated ascending aorta at aortic valve surgery. Moderate ascending aortic dilatation is common in adult patients with conotruncal anomalies. There are no data outlining actual risk of progressive ascending aortic dilatation or dissection to provide management guidelines.MethodsFrom December 1973 through January 2008, 81 consecutive adults (median age, 34 years; range, 18--59 years) with conotruncal anomalies underwent operation on the aortic root, ascending aorta, or aortic valve. Primary cardiac diagnoses included tetralogy of Fallot with or without pulmonary atresia in 60 patients, truncus arteriosus in 12, double-outlet right ventricle in 6, and other in 3. Indications for operation included aortic regurgitation in 69 patients, supracoronary ascending aneurysm in 16, aortic stenosis in 5, and other in 8. Median ascending aortic size was 45 mm (23--80 mm).ResultsOperations included isolated aortic valve repair/replacement in 63 patients, combined aortic valve replacement and reduction aortoplasty in 9, aortic root replacement in 7, and isolated ascending aortic replacement in 2. Four patients required reoperation during a median follow-up of 3.8 years (maximum 31 years). There were no ascending aortic reoperations after previous reduction aortoplasties or supracoronary ascending aortic grafts, and there were no late aortic dissections.ConclusionsModerate ascending aortic enlargement is common among patients with conotruncal anomalies coming to operation, but aortic dissection is rare, as is subsequent need for aortic reoperation. Despite current enthusiasm for prophylactic operations on the ascending aorta in patients with acquired disease, these data suggest that the moderately dilated aorta in this setting may be observed

Fourteen-year experience with homovital homografts for aortic valve replacement

Two hundred seventy-five unprocessed, viable homograft (“homovital”) aortic valves were used for aortic valve replacement in patients aged 1.5 to 79 years (mean 45.8±19 years) with maximum follow-up of a 14-year period (mean 4.8 years). Ninety-two percent (252 patients) had New York Heart Association class III or IV functional status before operation and 25 underwent emergency operation. Valves were harvested under sterile conditions and kept in nutrient medium 199. Freehand (subcoronary) technique was used in 147 patients and freestanding root replacement was used in 128. Cumulative survival rates for the whole group were 92%±2% at 5 years and 85%±3% at 10 years, as compared with 96%±2% and 94%±4%, respectively, for the 98 patients who underwent isolated root replacement. Multivariate analysis determined that root replacement with associated procedures and operation for prosthetic endocarditis were risk factors for death, whereas previous xenograft valve, operation for endocarditis, and operation for aortic regurgitation were risk factors for reoperation. Actuarial rates for freedom from degenerative valve failure diagnosed at operation, by postmortem examination, or by routine echocardiography were 94%±2% at 5 years and 89%±3% at 10 years. Recipient age younger than 30 years and previous xenograft valve were risk factors for late degeneration. We conclude that homovital valves demonstrate good durability, particularly in patients older than 30 years, who had a 10-year freedom from degeneration rate of 97%

Ventricular function after coronary artery bypass grafting: Evaluation by magnetic resonance imaging and myocardial strain analysis

AbstractObjectiveMagnetic resonance imaging with radiofrequency tissue tagging permits quantitative assessment of regional systolic myocardial strain. We sought to investigate the utility of this imaging modality to quantitatively determine preoperative impairment and postoperative improvement in ventricular function in patients with ischemic heart disease.MethodsMagnetic resonance imaging with radiofrequency tissue tagging was performed on 6 patients (average age 60.2 ± 13.7 years) with coronary artery disease and 32 control subjects with no known heart disease. Patients with coronary artery disease underwent imaging before and 3 months after coronary artery bypass grafting. The ventricle was divided into 6 segments within a midventricular plane. Regional 2-dimensional left ventricular circumferential strain was calculated from tagged magnetic resonance images throughout systole. Circumferential strain results were compared in patients before and after and 3 months after coronary artery bypass grafting and also in control subjects.ResultsBefore the operation circumferential strain identified 100% (10/10) of all regional wall motion abnormalities seen by preoperative ventriculography. Postoperatively, improvements were demonstrated in 56% (20/36) of the regions, and these improvements agreed with viability testing by single-photon emission computed tomography when available. Additionally, preoperative global circumferential strain for the ischemic group was significantly depressed relative to that in control subjects (0.11 ± 0.05 vs 0.20 ± 0.03, P < .001). Global circumferential strain correlated with ejection fraction by ventriculography (r = 0.84, P < .01) and improved after coronary artery bypass grafting (0.14 ± 0.05 vs 0.11 ± 0.05, P < .01).ConclusionsMagnetic resonance imaging with radiofrequency tissue tagging permitted circumferential strain calculation. This technology quantitatively demonstrated improvements in left ventricular wall motion after coronary artery bypass grafting for both individual regions and the entire ventricle. This noninvasive method may prove useful in preoperative evaluation and postoperative serial assessment of left ventricular wall motion

Aortic valve replacement in patients aged 50 to 70 years: Improved outcome with mechanical versus biologic prostheses

ObjectiveImproved durability of bioprostheses has led some surgeons to recommend biologic rather than mechanical prostheses for patients younger than 65 years. We compared late results of contemporary bioprostheses and bileaflet mechanical prostheses in patients who underwent aortic valve replacement between 50 and 70 years old.MethodsIn this retrospective study, patients received either St Jude bileaflet valves or Carpentier–Edwards bioprostheses. Operations were performed between January 1991 and December 2000, and groups were matched one-to-one according to age, sex, need for coronary artery bypass grafting, and valve size.ResultsFour hundred forty patients were matched, and follow-up was 92% complete, with median durations of 9.1 years for patients who received mechanical valves and 6.2 years for patients who received bioprostheses. The 5- and 10-year unadjusted survivals were 87% and 68% for mechanical valves and 72% and 50% for bioprostheses, respectively (P < .01). Freedoms from reoperation at 10 years were 98% for mechanical valves and 91% for bioprostheses (P = .06). Rates of late stroke or other embolic events and of endocarditis were similar between groups. Hemorrhagic complications necessitating hospitalization occurred in 15% of patients with mechanical valves and 7% of patients with bioprostheses (P = .01). Notably, 19% of patients with bioprostheses were receiving warfarin sodium at last follow-up. After adjustment for unmatched variables, including diabetes, renal failure, lung disease, New York Heart Association functional class, ejection fraction, and stroke, the use of a mechanical valve was protective against late mortality (hazard ratio 0.46, P < .01).ConclusionIn this study, patients aged 50 to 70 years who underwent aortic valve replacement with mechanical valves had a survival advantage relative to matched patients who received bioprostheses. These findings question recommendations of bioprostheses for younger patients and suggest that a randomized trial may be warranted