Dextrorphan inhibits the release of excitatory amino acids during spinal cord ischemia

The release of excitatory amino acids, particularly glutamate, into the extracellular space plays a causal role in irreversible neuronal damage after central nervous system ischemia. Dextrorphan, a noncompetitive N-methyl-D-aspartate receptor antagonist, has been shown to provide significant protection against cerebral damage after focal ischemia. We investigated the changes in extracellular neurotransmitter amino acid concentrations using in vivo microdialysis in a swine model of spinal cord ischemia. After lumbar laminectomies were performed, all animals underwent left thoracotomy and right atrial-femoral cardiopulmonary bypass with additional aortic arch perfusion. Microdialysis probes were then inserted stereotactically into the lumbar spinal cord. The probes were perfused with artificial cerebrospinal fluid and 15-minute samples were assayed using high-performance liquid chromatography. Group 1 animals (n = 9) underwent aortic clamping distal to the left subclavian and proximal to the renal arteries for 60 minutes. Group 2 animals (n = 7) were treated with dextrorphan before application of aortic clamps, and during aortic occlusion and reperfusion. Five amino acids were studied, including two excitatory neurotransmitters (glutamate and aspartate) and three putative inhibitory neurotransmitters (glycine, gamma-amino-butyric acid, and serine). Somatosensory-evoked potentials and motor-evoked potentials were monitored. Glutamate exhibited a threefold increase in extracellular concentration during normothermic ischemia compared with baseline values and remained elevated until 60 minutes after reperfusion. In animals treated with dextrorphan, glutamate concentrations decreased to one-third of baseline levels before aortic clamping and remained unchanged during ischemia and reperfusion. There was early loss of somatosensory-evoked potentials and motor-evoked potentials during ischemia in group 1 animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Hypothermic circulatory arrest for cerebral protection during combined carotid and cardiac surgery in patients with bilateral carotid artery disease

OBJECTIVE

The authors evaluated the protective effect of hypothermic circulatory arrest for patients with bilateral carotid artery disease who underwent cardiac surgical procedures.

SUMMARY BACKGROUND DATA

Severe bilateral carotid artery disease coexisting with cardiac disease that requires surgical treatment is associated with a substantial incidence of stroke after operations that require cardiopulmonary bypass. The optimal method of management of patients with these coexisting conditions is not established clearly. Because hypothermia has a protective effect on neural and myocardial tissue during cardiac operations, a protocol employing profound hypothermia and a period of circulatory arrest was evaluated in a group of patients who underwent combined carotid and cardiac surgery who were considered to be at increased risk for the development of stroke.

METHODS

Fifty patients with bilateral carotid artery disease, including 24 patients with high-grade unilateral stenosis and contralateral occlusion and 6 patients with 80% to 99% bilateral stenosis, underwent combined carotid endarterectomy and cardiac surgery (coronary artery bypass grafting in all 50 patients and additional procedures in 8 patients). Profound systemic hypothermia (15 C) was instituted, and the carotid endarterectomy was performed during a period of circulatory arrest that averaged 30 minutes. The cardiac procedure was performed during the periods of cooling and rewarming.

RESULTS

The 30-day mortality rate was 6% (3 patients). There were no early postoperative strokes or reversible ischemic neurologic deficits. There have been seven late deaths in the postoperative period, which extends to 54 months. None of these deaths were caused by stroke. There has been one late stroke, which occurred in the distribution of the unoperated carotid artery.

CONCLUSIONS

This technique provides adequate protection of the brain and myocardium during combined carotid and cardiac surgical procedures and appears to reduce the frequency of stroke in the high-risk subgroup of patients with bilateral carotid artery disease.

Managed care involvement by cardiovascular specialists: prevalence, attitudes and influence on practice

OBJECTIVES

The purpose of this study was to determine the involvement in and attitudes toward managed care by cardiovascular specialists and the influence of such programs on their practices.

BACKGROUND

No in-depth study has measured the impact of managed care on cardiovascular specialists. Therefore, we conducted a mail survey to determine the prevalence of managed care arrangements among cardiovascular specialists and variations among pediatric and adult cardiologists and cardiovascular surgeons; the types of managed care arrangements in which cardiovascular specialists are engaged; the reasons why those not participating in managed care have chosen not to do so; and the general attitudes among cardiovascular specialists with regard to various aspects of managed care. In addition, we evaluated the impact of managed care among several aspects of cardiovascular practice.

METHODS

A questionnaire was mailed in the spring of 1993 to 4,577 practicing, domestic, American College of Cardiology (ACC) members selected at random from within each primary cardiovascular specialty group (adult cardiologists, pediatric cardiologists and cardiovascular surgeons). Additional data concerning practice characteristics were cross tabulated using results from the 1992 ACC membership profile survey.

RESULTS

In total, 1,961 of the 4,577 members responded to the survey, representing a 43% response rate. Of all survey respondents, 76% reported entering into at least one relationship with a health maintenance organization (HMO) or preferred provider organization (PPO). Of those not participating in managed care arrangements, the most frequently mentioned reason was "concern over the quality of care." This reason was cited by 51% of those not entering into HMO relationships and 41% of those not participating in PPOs. The majority of respondents indicated that they do not strongly object to the gatekeeper approach to managing nonemergent patients, although more than half indicated concern that gatekeepers may not be appropriate in the management of cardiac emergencies. In addition, cardiovascular specialists report that under managed care, referrals have not increased, income has decreased, and managed care formularies have not substantially affected their ability to prescribe appropriate medication to their patients.

CONCLUSIONS

Despite concerns over the quality of care and contract requirements and general philosophical opposition of cardiovascular specialists, most are becoming integrated into managed care environments.

Replacement of the aortic root with a pulmonary autograft in children and young adults with aortic-valve disease

BACKGROUND

The optimal substitute for severely diseased aortic valves in children and young adults is unknown. The use of a mechanical prosthesis requires permanent treatment of the patient with anticoagulants and is associated with thromboembolic and hemorrhagic complications. Aortic-valve allografts and porcine bioprostheses, which do not necessitate anticoagulant therapy, may deteriorate and have limited durability.

METHODS

We therefore evaluated the use of the autologous pulmonary valve (i.e., the patient's own pulmonary valve) and the adjacent pulmonary artery as a replacement for the aortic valve and aortic sinuses in 33 patients. Five of the patients were from 8 to 16 years of age, and 28 were from 20 to 47 years of age. The pulmonary valve and the main pulmonary artery were used to replace the diseased aortic valve and the adjacent aorta. The coronary arteries were detached from the aorta and implanted into the pulmonary artery. The pulmonary valve and artery were replaced with a cryopreserved pulmonary allograft.

RESULTS

There were no deaths during follow-up of up to 48 months (mean, 21 months). There were no episodes of infective endocarditis, and no reoperations on the aortic root were necessary. Also, there was no evidence on echocardiography of progressive dilatation of the autografts. With color-flow Doppler imaging, 22 patients were found to have only trivial regurgitation or none, 9 patients to have mild regurgitation, and no patients to have moderate or severe regurgitation across the autograft at the most recent follow-up visit. The mean peak velocity of flow across the autograft was 1.3 m per second (upper limit of normal, 1.8), indicating the absence of stenosis. One patient required reoperation for stenosis of the pulmonary allograft.

CONCLUSIONS

Although the pulmonary-autograft procedure is more complex than simple aortic-valve replacement, it has been safely applied in selected patients, including young adults. Intermediate follow-up indicates satisfactory function of the autografts, with no dilatation or progressive valvular regurgitation. Pulmonary-root autografts may thus be the best available substitute for diseased aortic valves in children and young adults.

Adjuncts to reduce the incidence of embolic brain injury during operations on the aortic arch

Two adjunctive techniques for operations involving the aortic arch, retrograde perfusion of cold oxygenated blood through the superior vena cava and establishment of antegrade flow after hypothermic circulatory arrest, are described. These techniques should reduce or possibly eliminate the embolization of air and particulate matter into the cerebral circulation and may reduce the incidence of brain injury.

Profound systemic hypothermia protects the spinal cord in a primate model of spinal cord ischemia

Spinal cord ischemia with resultant paraplegia or paraparesis remains an important clinical problem after operations on the thoracoabdominal aorta. Because hypothermia has a protective effect on ischemic neural tissue, we developed a baboon model of spinal cord ischemia to simulate the situation encountered clinically for resection of aneurysms of the thoracoabdominal aorta and to determine whether profound hypothermia produced by hypothermic cardiopulmonary bypass has a protective effect on spinal cord function. After cardiopulmonary bypass was established, the aorta was clamped distal to the left subclavian artery and proximal to the renal arteries for 60 minutes. Group I animals (n = 9) underwent aortic clamping at normothermia (37 degrees C), and group II animals (n = 9) were cooled to a rectal temperature of 15 degrees C before aortic clamping and underwent cardiopulmonary bypass at this temperature until the aorta was unclamped. Of the eight operative survivors in group I, six animals were paraplegic and two were paraparetic, whereas all six group II animals that survived the procedure were neurologically intact (p = 0.0002). The protective effect of hypothermia was associated with blunting of the hyperemic response of spinal cord blood flow (determined by the radioactive microsphere technique) in the lower thoracic and the lumbar segments of the spinal cord after unclamping of the aorta. Profound hypothermia produced by hypothermic cardiopulmonary bypass may be an effective method of protection of the spinal cord in patients undergoing repair of aneurysms of the thoracoabdominal aorta and may reduce the prevalence of ischemic injury to the spinal cord.

Strategy for the reduction of stroke incidence in cardiac surgical patients

Atherosclerosis of the ascending aorta (AAA) and severe carotid artery disease are risk factors for stroke in cardiac surgical patients. Twelve hundred of a consecutive series of 1,334 patients 50 years of age or older having a cardiac operation were screened for the presence of AAA by intraoperative ultrasonographic scanning and for the presence of carotid artery occlusive disease (791 of 798 patients > or = 65 years of age and younger symptomatic patients) by carotid duplex scanning. Coronary artery disease was present in 88% of the patients. Patients with moderate or severe AAA (n = 231; 19.3% of the total) were treated by ascending aortic replacement (n = 27) or by modified, less extensive techniques (n = 168) to avoid the atherosclerotic areas. Thirty-three patients had combined carotid endarterectomy and cardiac operation. Thirty-day mortality and stroke rates for the 1,200 patients were 4.0% and 1.6%, respectively. The stroke rate was low (1.1%) among the 969 patients with no or mild AAA. It was zero among 27 patients with moderate or severe AAA who had ascending aortic replacement and among the 33 patients who had carotid endarterectomy. The stroke rates were higher for 111 patients with moderate or severe ascending aortic disease who had only minor interventions (6.3%) and for 16 patients with severe carotid artery disease who did not have carotid endarterectomy (18.7%). Screening for AAA and carotid artery disease and aggressive surgical treatment of moderate or severe AAA and severe or symptomatic carotid artery disease appears to reduce the frequency of stroke in older cardiac surgical patients.

Renal dysfunction and intravascular coagulation with aprotinin and hypothermic circulatory arrest

High-dose aprotinin was used in 20 patients undergoing primary or repeat operations on the thoracic or thoracoabdominal aorta using cardiopulmonary bypass and hypothermic circulatory arrest. The activated clotting times immediately before the establishment of hypothermic circulatory arrest exceeded 700 seconds in all but 1 patient. Three patients (15%) required reoperation for bleeding. Seven patients died during hospitalization, and 5 had postmortem examination. Platelet-fibrin thrombi were present in multiple organs including the coronary arteries of 4 patients with myocardial infarction or failure, the pulmonary arteries of 2 patients, 1 of whom died of acute right ventricular failure, the brains of 2 patients who sustained a stroke, and the kidneys of 4 patients, 3 of whom had development of renal dysfunction. Renal dysfunction occurred in 13 patients (65%), and all were 65 years of age or older. Five of these patients required hemodialysis. Among 20 age-matched patients who had similar operations without aprotinin, there was one hospital death (5%) from myocardial infarction, and renal dysfunction developed in 1 patient (5%), who did not require dialysis. None of these 20 patients required reoperation for bleeding. Although aprotinin has been shown to reduce blood loss in patients having cardiac operations employing cardiopulmonary bypass, this benefit was not attained in this group of patients with thoracic aortic disease in whom hypothermic circulatory arrest was used. Use of aprotinin in elderly patients undergoing these procedures was associated with an increased risk of renal dysfunction and failure, and of myocardial infarction and death.

When and how to include arch repair in patients with acute dissections involving the ascending aorta

The arch should be included in the repair in patients with acute aortic dissection involving the ascending aorta when (1) the intimal tear is in the arch, (2) rupture of the arch has occurred, (3) the outer wall of the false channel in the arch is tenuous, and (4) the inner wall of the false channel is fragmented. A technique has evolved for patients with acute aortic dissection involving the arch that seems to minimize the difficulties and risks of including the arch, when indicated. Its place will best be determined by additional, prospective, and preferably multi-institutional testing.

Transesophageal echocardiography predicts successful withdrawal of ventricular assist devices

Transesophageal echocardiography has been found to be an effective technique for the real-time assessment of myocardial and valvular function in postoperative patients. To determine the value of transesophageal echocardiography in patients with mechanical assist devices, we performed daily, bedside transesophageal echocardiography on 16 patients with right (n = 3), left (n = 1), or biventricular assist devices (n = 12). We obtained four-chamber and short-axis views in all patients. Valvular function and the presence of left-to-right shunts were evaluated by means of color flow Doppler imaging. During the echocardiographic study ventricular assist device flow was diminished to less than 1.5 L/min, and inotropic agents (dobutamine or epinephrine) were given to assess ventricular reserve. Changes in day-to-day ventricular function were assessed in comparisons made by two observers (one unaware of the study sequence) using a semiquantitative method for wall motion analysis. The left ventricular wall motion scores in the patients successfully weaned from left or biventricular assist devices (n = 5) improved (14.2 +/- 1.6 versus 8.2 +/- 1.5, p < 0.0001). The scores did not improve in patients who remained dependent on the devices (n = 8). Two patients with only right ventricular assist devices were successfully weaned after documentation of improvement of right ventricular function by transesophageal echocardiography. Transesophageal echocardiography documented a clot compressing the heart in three patients; intracavitary thrombi were seen in two other patients. Marked hemodynamic improvement occurred after surgical decompression. In conclusion, transesophageal echocardiography is a safe, effective method for the assessment of ventricular function of patients on ventricular assist device support. In addition, it allows one to assess valvular function and the presence or absence of impaired ventricular filling.

Intraaortic balloon counterpulsation: patterns of usage and outcome in cardiac surgery patients

Between January 1, 1986, and May 6, 1991, 7,884 cardiac surgical procedures requiring cardiopulmonary bypass were performed at our institution, including 672 (9.8% of adult procedures) performed in 669 patients that were associated with preoperative (n = 240), intraoperative (n = 353), or postoperative (n = 79) use of an intraaortic balloon pump. The mean age of recipients was 65.3 years (range, 16 to 89 years). Intraaortic balloon pump usage increased during the study period from 6.4% of patients (83/1,298) in 1986 to 12.7% of patients (169/1,333) in 1990. The relative distribution between preoperative (mean, 35.7%), intraoperative (52.5%), and postoperative (11.8%) insertion remained nearly constant during the study period. The overall operative (30-day) mortality for patients with preoperative, intraoperative, or postoperative insertion of the intraaortic balloon pump was 19.6%, 32.3%, and 40.5%, respectively (X2 = 16.4; p less than 0.001). Although use of the intraaortic balloon pump in the intraoperative and postoperative settings is accompanied by a favorable outcome in most patients, the high associated mortality suggests the need for earlier use of the intraaortic balloon pump or other supportive measures such as the ventricular assist device.

Management of the severely atherosclerotic ascending aorta during cardiac operations. A strategy for detection and treatment

Embolization of atheroma from the ascending aorta is a principal cause of stroke after cardiac operations. We have previously shown that intraoperative ultrasonographic scanning of the aorta rapidly, safely, and accurately identifies atheromatous disease in the ascending aorta. Intraoperative ultrasonography of the ascending aorta was performed in 500 of a consecutive series of 540 patients 50 years of age or older (mean 68 years) who underwent a variety of cardiac operations. Eighty-nine percent required bypass grafting. Sixty-eight patients (13.6% of the total) with a mean age of 72 years (range 55 to 85 years) had significant atheromatous disease in the ascending aorta and were considered to be at increased risk for embolization. Palpation identified the atheromatous disease in only 26 (38%) of these patients and underestimated its severity. A total of 168 modifications in the standard techniques for cannulation and clamping of the aorta were implemented in the 68 patients (mean 2.5 per patient) and included alterations in the sites of aortic cannulation (50 patients), aortic clamping (54 patients), attachment of the vein grafts (35 patients), and cannulation for infusion of cardioplegic solution (29 patients). Ten patients with severe diffuse atheromatous disease underwent graft replacement of the ascending aorta with hypothermic circulatory arrest without aortic clamping. Fourteen patients with symptoms or with high-grade carotid artery occlusive disease were treated by concomitant carotid endarterectomy. Thirty-day mortality for the entire group was 3.4% (17 patients). Permanent neurologic deficits occurred in five (1.0%) of the patients in the entire group but in none of the 68 patients with significant atheromatous disease in whom modifications in technique were used. One patient in the latter group had a reversible ischemic neurologic deficit. Modification of standard cannulation and clamping techniques based on ultrasonography may reduce the frequency of stroke related to atheromatous embolization.

Management of the severely atherosclerotic ascending aorta during cardiac operations. A strategy for detection and treatment

Embolization of atheroma from the ascending aorta is a principal cause of stroke after cardiac operations. We have previously shown that intraoperative ultrasonographic scanning of the aorta rapidly, safely, and accurately identifies atheromatous disease in the ascending aorta. Intraoperative ultrasonography of the ascending aorta was performed in 500 of a consecutive series of 540 patients 50 years of age or older (mean 68 years) who underwent a variety of cardiac operations. Eighty-nine percent required bypass grafting. Sixty-eight patients (13.6% of the total) with a mean age of 72 years (range 55 to 85 years) had significant atheromatous disease in the ascending aorta and were considered to be at increased risk for embolization. Palpation identified the atheromatous disease in only 26 (38%) of these patients and underestimated its severity. A total of 168 modifications in the standard techniques for cannulation and clamping of the aorta were implemented in the 68 patients (mean 2.5 per patient) and included alterations in the sites of aortic cannulation (50 patients), aortic clamping (54 patients), attachment of the vein grafts (35 patients), and cannulation for infusion of cardioplegic solution (29 patients). Ten patients with severe diffuse atheromatous disease underwent graft replacement of the ascending aorta with hypothermic circulatory arrest without aortic clamping. Fourteen patients with symptoms or with high-grade carotid artery occlusive disease were treated by concomitant carotid endarterectomy. Thirty-day mortality for the entire group was 3.4% (17 patients). Permanent neurologic deficits occurred in five (1.0%) of the patients in the entire group but in none of the 68 patients with significant atheromatous disease in whom modifications in technique were used. One patient in the latter group had a reversible ischemic neurologic deficit. Modification of standard cannulation and clamping techniques based on ultrasonography may reduce the frequency of stroke related to atheromatous embolization.

Preoperative carotid artery screening in elderly patients undergoing cardiac surgery

The role of preoperative screening for carotid artery disease in elderly patients undergoing cardiac surgical procedures is not clearly established. This prospective study was designed to determine the prevalence of carotid disease in this population and to identify preoperative risk factors for carotid artery stenosis. During a 54-month interval, 1087 patients of a consecutive series of 1184 patients 65 years of age and older who underwent cardiac surgical procedures (91% had coronary artery disease) were evaluated before operation with carotid duplex ultrasonography. The prevalence of disease was 17.0% for 50% or greater stenosis and 5.9% for 80% or greater stenosis. With use of a stepwise, logistic regression model of 12 preoperative variables, five variables were found by multivariate analysis to be significant (p less than or equal to 0.05) predictors of 80% or greater stenosis: female sex, peripheral vascular disease, history of transient ischemic attack or stroke, smoking history, and left main coronary artery disease. If all patients with at least one risk factor were screened, then this model predicts that 95% of patients with 80% or greater stenosis and 91% of patients with 50% or greater stenosis would be identified before operation. The probability of carotid disease in a given patient can also be estimated (range, 5% to 65%). Carotid endarterectomy combined with cardiac surgical procedures was performed on 46 patients who were either symptomatic (16) or had 80% or greater stenosis (30). The overall stroke rate for the 1087 patients was 2.0% (22 patients), and the 30-day mortality rate was 5.2% (56 patients).(ABSTRACT TRUNCATED AT 250 WORDS)

Intraoperative ultrasonographic evaluation of the ascending aorta in 100 consecutive patients undergoing cardiac surgery

Dislodgement of atheromatous plaque from the ascending aorta following manipulation is one of the principal causes of stroke following cardiac surgery. To define clinical correlates that predict the presence of severe atherosclerosis, we performed ultrasonographic evaluation of the ascending aorta at the time of cardiac surgery in 100 consecutive patients. The ascending aorta was divided into three equal segments for analysis, and the severity of atherosclerosis was determined as mild when intimal thickening (less than 3 mm) was localized to one segment, moderate when intimal thickening (greater than 3 mm) was present in one or two segments, and severe when intimal thickening (greater than 3 mm) was present throughout the entire circumference in all three segments. Thirty-eight percent of the studies were normal, mild atherosclerosis was present in 33%, moderate atherosclerosis in 19%, and severe atherosclerosis in 10% of the patients. Palpation of the ascending aorta to detect atherosclerosis significantly underestimated the presence (p less than 0.001) and severity (p less than 0.001) of atherosclerosis when compared with ultrasonography. Age, carotid artery disease, diabetes, gender, smoking, and hypertension were evaluated for their ability to discriminate between normal and severely atherosclerotic aortas. Stepwise logistic regression analysis showed age (p less than 0.02) and diabetes (p less than 0.04) to be significant independent predictors of the presence of severe atherosclerosis in the ascending aorta. Based on the ultrasonographic findings, the operative procedure was altered to reduce the risk of embolization in 17% of the patients. We conclude that high-resolution images of the ascending aorta for identification of atherosclerosis can be obtained by ultrasonography.(ABSTRACT TRUNCATED AT 250 WORDS)

Sixteen-year experience with aortic root replacement. Results of 172 operations

During a 16-year interval ending in October 1990, 168 patients underwent 172 aortic root replacements. Thirty patients (18%) had Marfan syndrome. Annuloaortic ectasia (81 patients) and aortic dissection (63 patients) were the principal indications for operation. Twenty-seven patients (16%) had previous operations on the ascending aorta or aortic valve. The hospital mortality rate was 5% and the duration of cardiopulmonary bypass was the only significant independent predictor of early death (p = 0.017). Major modifications in technique were made in 1981, when the inclusion/wrap technique employing a composite graft (used in the first 105 procedures) was abandoned in favor of an open technique (used in 51 procedures), and in 1988, when aortic allografts and pulmonary autografts were introduced for selected conditions (reoperations, dissection, endocarditis, isolated aortic valve disease) in 16 patients. The mean duration of follow-up was 81 months. Forty-six patients were followed for more than 10 years. The actuarial survival rate was 61% at 7 years and 48% at 12 years. No significant difference in survival rate was observed between the patients with annuloaortic ectasia and aortic dissection, or between the inclusion/wrap and open techniques. However the frequency of pseudoaneurysm formation at suture lines and the frequency of reoperations on the ascending aorta and aortic valve were less with the open technique. The actuarial freedom from thromboembolism for the 152 patients with prosthetic valves was 82% at 12 years. One early and one late death occurred among the 16 patients with allograft or autograft root replacement. Anticoagulant therapy was not used in these patients and no thromboembolic episodes occurred in the follow-up period (mean, 7 months). The satisfactory results observed with extended follow-up support the continued use of the composite graft technique as the preferred method of treatment for patients with annuloaortic ectasia, persistent aneurysms of the sinuses of Valsalva following previous operations, and for patients with ascending aortic dissection who require aortic valve replacement. The availability of aortic root allografts and the perfection of techniques for safe implantation of the autologous pulmonary root into the aortic position have broadened the indications for aortic root replacement.

A model of right ventricular failure after global myocardial ischemia and mechanical left ventricular support

Postcardiotomy right ventricular (RV) failure after institution of mechanical left ventricular (LV) support is poorly understood. Using a canine model supported by cardiopulmonary bypass (CPB), the animals underwent 30 min of aortic clamping or no ischemia and were weaned to an LV assist device (LVAD). Echocardiographic measurements of LV and RV cavity size off support allowed calculation of percentage change in cavity area (fractional shortening). There were no differences at baseline. After 2 hrs on LVAD, there were significant differences between ischemic and control groups in both LV (38 +/- 12 vs. 61 +/- 6) and RV (15 +/- 3 vs. 55 +/- 12). The ischemic RV also had significantly decreased function compared with the LV (38 +/- 12 vs. 15 +/- 3). The control group demonstrated no differences in ventricular function. The authors concluded that global ischemia diminishes LV and RV function, and this effect is accentuated in the RV after LVAD support. In controls, RV function is not affected by LVAD support, but after ischemia, LVAD support alone often will be inadequate.

Aortic and vascular surgery

Diagnosis and treatment of thoracic vascular disease remain difficult problems for the clinician. These pathologic conditions often result in significant morbidity and mortality. Currently, published series document long-term treatment results and allow investigators to analyze both pre- and postoperative predictors of outcome. This review outlines some of the many significant publications over the past 12 months dealing with these disorders.