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BACKGROUND: Stroke remains a devastating complication of cardiac surgery, but stroke prevention remains elusive. Evaluation of early and long-term clinical outcomes and brain-imaging findings may provide insight into stroke prognosis, etiology, and prevention. METHODS: Five thousand nine hundred seventy-one cardiac surgery patients were prospectively studied for clinical evidence of stroke. Stroke and nonstroke patients were compared by early outcomes. Data collected for stroke patients included brain imaging results, long-term functional status, and survival. Outcome predictors were then determined. RESULTS: Stroke was diagnosed in 214 (3.6%) patients. Brain imaging demonstrated acute infarction in 72%; embolic in 83%, and watershed in 24%. Survival for stroke patients was 67% at 1 year and 47% at 5 years. Independent predictors of survival were cerebral infarct type, creatinine elevation, cardiopulmonary bypass time, preoperative intensive care days, postoperative awakening time, and postoperative intensive care days. Long-term disability was moderate to severe in 69%. CONCLUSIONS: Stroke after cardiac surgery has profound repercussions that are independently related to infarct type and clinical factors. These data are essential for clinical decision making and prognosis determination.

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The purpose of this study was to review the results of mitral and tricuspid valve replacement with mitral valve homograft. Twenty-two mitral homografts were used to replace cardiac valves in 20 patients. The mitral valve was replaced in 18 patients, applying the method described by Acar. The tricuspid valve was replaced in 2 patients, attaching one papillary muscle of the graft to the anterior papillary muscle and bringing the other papillary muscle of the graft through a tunnel in the anterior wall of the right ventricle. A concomitant Maze III procedure was performed in 3 patients. Accuracy of the repair was confirmed by intraoperative echocardiography. All patients survived operation and are currently alive. One patient was lost to follow-up. Patients have been followed for up to 3.25 years. All patients have good exercise ability (NYHA class I). Five homografts (25%) have been explanted from the mitral position and one from the tricuspid position. All events occurred during the first year after reoperation. Cardiac valve replacement with mitral valve homograft may be accomplished safely. A technically good operation does not guarantee that the valve will remain competent and an unacceptably high early explant rate may be expected. Use of mitral valve homograft for cardiac valve replacement should be restricted to young patients in whom anticoagulant medication is not indicated or undesirable and for those with resistant infection.

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BACKGROUND AND AIM: Operations on cardiac valves are being performed more frequently through smaller incisions than traditional midline sternotomy. A variety of alternate incisions have been used, but most of the interest appears to focus on partial sternotomy. The purpose of the study was to review results using a partial lower sternotomy for cardiac valve operations. METHODS: A standard partial lower one-half or two-thirds sternotomy was used for cardiac valve operations in 112 patients. The sternum was divided transversely in the third or second intercostal space and vertically from that point through the xyphoid process. Standard instruments and retraction devices were used. This incision provided adequate exposure for even complex operations to be performed. Small cannulae were placed into the aorta and heart through the primary incision for cardiopulmonary bypass. Vacuum-assisted venous drainage was used. RESULTS: Seventy-four single valve operations were performed. There were 35 double valve and 5 triple valve operations (35.4%) performed. Operative mortality (5.3%) and major complication rates were comparable to full the sternotomy approach. CONCLUSIONS: Partial sternotomy (lower half) provides a smaller incision through which virtually all cardiac valve operations may be performed. Results achieved with this approach are similar to those associated with full sternotomy. The smaller incision is appreciated by patients.

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BACKGROUND: Minimally invasive direct coronary artery bypass grafting with the gastroepiploic artery can be used in primary operations and reoperations to revascularize the inferior or anterior surface of the heart. METHODS: Patients who had symptomatic coronary artery disease limited to a single coronary distribution were selected. Coronary targets were grafted with the pedicled gastroepiploic artery through a small midline epigastric incision. Patients were followed with scheduled outpatient clinic visits, Doppler examination, and selective recatheterization. RESULTS: Between May 1995 and November 1997, 74 patients underwent gastroepiploic artery minimally invasive direct coronary artery bypass grafting; 33 (45%) had a primary operation and 41 (55%), a reoperation. Grafting was performed to the distal right coronary artery (n = 38), the posterior descending artery (n = 28), or the distal left anterior descending coronary artery (n = 8). There were six deaths (8%) within 30 days after operation. Twenty patients (28%) underwent recatheterization; there were two graft occlusions, two graft stenoses, and five anastomotic stenoses. Of 60 patients seen 2 or more weeks after operation, 53 (88%) had resolution of anginal symptoms at a mean follow-up of 10.9 months (range, 0 to 30 months). CONCLUSIONS: Inferior minimally invasive direct coronary artery bypass grafting with the gastroepiploic artery avoids the risks of repeat sternotomy, aortic manipulation, and cardiopulmonary bypass. Patency rates, however, were lower than expected, and there is significant morbidity and mortality associated with high-risk patients undergoing the procedure. Continued follow-up is essential to evaluate long-term graft patency and patient survival.

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BACKGROUND: Central nervous system dysfunction continues to produce significant morbidity and associated mortality in patients undergoing cardiac surgery. Using a closed-chest canine cardiopulmonary bypass model, dogs underwent 2 h of hypothermic circulatory arrest (HCA) at 18 degrees C, followed by resuscitation and recovery for 3 days. Animals were assessed functionally by a species-specific behavioral scale, histologically for patterns of selective neuronal necrosis, biochemically by analysis of microdialysis effluent, and by receptor autoradiography for N-methyl-D-aspartate (NMDA) glutamate receptor subtype expression. RESULTS: Using a selective NMDA (glutamate) receptor antagonist (MK801) and an AMPA antagonist (NBQX), glutamate excitotoxicity in the development of HCA-induced brain injury was documented and validated. A microdialysis technique was employed to evaluate the role of nitric oxide (NO) in neuronal cell death. Arginine plus oxygen is converted to NO plus citrulline (CIT) by the action of NO synthase (nNOS). CIT recovery in the cerebrospinal fluid and from canine cortical homogenates increased during HCA and reperfusion. These studies demonstrated that neurotoxicity after HCA involves a significant and early induction of nNOS expression, and neuronal processes leading to widespread augmentation of NO production in the brain. To further investigate the production of excitatory amino acids in the brain, we hypothesized the following scenario: HCA--> increased glutamate, increased aspartate, increased glycine--> increased intracellular Ca2+--> increased NO + CIT. Using the same animal preparation, we demonstrated that HCA caused increased intracerebral glutamate and aspartate that persists up to 20 h post-HCA. HCA also resulted in CIT (NO) production, causing a continued and delayed neurologic injury. Confirmatory evidence of the role of NO was demonstrated by a further experiment using a specific nNOS inhibitor, 7-nitroindazole. Animals underwent 2 h of HCA, and then were evaluated both physiologically and for NO production. 7-Nitroindazole reduced CIT (NO) production by 58.4 +/- 28.3%. In addition, dogs treated with this drug had superior neurologic function compared with untreated HCA controls. CONCLUSIONS: These experiments have documented the role of glutamate excitotoxicity in neurologic injury and have implicated NO as a significant neurotoxin causing necrosis and apoptosis. Continued research into the pathophysiologic mechanisms involved in cerebral injury will eventually yield a safe and reliable neuroprotectant strategy. Specific interventional agents will include glutamate receptor antagonists and specific neuronal NO synthase inhibitors.

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BACKGROUND: Previous midterm experience with the composite spiral saphenous vein graft to bypass the obstructed superior vena cava (SVC) has been favorable. This study looks at the long-term results in patients followed for up to 23 years. METHODS: Sixteen patients aged 17 to 68 years had operation for obstruction of the SVC with SVC syndrome caused by benign disease. Eleven patients had fibrosing mediastinitis with or without caseous necrosis, 4 had thrombosis caused by a catheter or a pacemaker electrode, and 1 had spontaneous thrombosis. All operations were performed using a composite spiral vein graft constructed from the patient's own saphenous vein. Graft diameter ranged from 9.5 to 15.0 mm. Ten grafts were from the left innominate vein, and six grafts were from the right or left internal jugular vein. The grafts were placed to the right atrial appendage in all patients except 1. Follow-up extends from 1 month to 23 years 8 months (mean follow-up, 10.9 years). RESULTS: Fourteen of 16 grafts remain patent for up to 23 years, and all patients but 1 are free from SVC syndrome. One patient required revision of the graft for thrombosis 4 days after operation. Two grafts closed during the first year after operation: one because of recurrence of spontaneous venous thrombosis and the other because of aggressive fibrosing mediastinitis requiring operation for graft revision three times over a 12-year period prior to death. CONCLUSIONS: These data demonstrate that a spiral vein bypass graft for treatment of the obstructed SVC relieves SVC syndrome and has excellent long-term patency.

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OBJECTIVE: Minimally invasive direct coronary artery bypass is performed under direct vision without sternotomy or cardiopulmonary bypass. The technique can be used in both primary and reoperative cases by employing the internal thoracic artery to perform arterial revascularization of the anterior surface of the heart. METHODS: Patients were selected who had significant coronary artery disease limited to 1 or 2 coronary distributions on the anterior surface of the heart. Coronary target vessels were grafted with the internal thoracic artery through a small anterior thoracotomy. After partial heparinization the anastomosis was facilitated by local coronary occlusion and handheld stabilization. RESULTS: Between August 1994 and July 1997, 162 patients underwent minimally invasive direct coronary artery bypass grafting with the internal thoracic artery. The left and right internal thoracic arteries were used for grafting of the left anterior descending artery in 142 patients (88%), the proximal right coronary artery in 7 patients (4%), existing saphenous vein grafts in 5 patients (3%), and diagonal branches in 2 patients (1%). Sequential grafting with the left internal thoracic artery was performed in 2 patients (1%) and bilateral internal thoracic artery grafting was performed in 4 patients (3%). Eight patients (4.9%) died within 30 days after the operation, 3 of cardiac causes. Seven additional patients died during the follow-up period. Nine patients (5.6%) required reintervention for graft stenosis or occlusion during follow-up. Of 141 patients seen 2 or more weeks after the operation, 135 (96%) had resolution of their anginal symptoms at a mean follow-up of 12 months (range 0-31 months). CONCLUSIONS: Anterior minimally invasive direct coronary artery bypass grafting with the internal thoracic artery avoids the risks of repeated sternotomy, aortic manipulation, and cardiopulmonary bypass. There was a low rate of reintervention, and patients had excellent resolution of anginal symptoms. Postoperative length of stay was comparatively short, and continued follow-up will be essential to evaluate long-term graft patency and patient survival.

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Penetrating cardiac trauma can result in a wide range of injuries to intracardiac structures. Missile injury, in particular, can cause damage in more than one cardiac chamber that may be difficult to identify at initial emergent operation. We report a case of late repair of traumatic ventricular septal defect and tricuspid valve perforation from gunshot wound. This case illustrates the importance of thorough examination of intracardiac anatomy during emergent and delayed repair for penetrating cardiac trauma.

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OBJECTIVE: Assessment of graft patency following minimally invasive direct coronary artery bypass (MIDCAB) surgery is essential in order to determine the efficacy of this technique. This study was conducted to evaluate the role of intraoperative and postoperative noninvasive flow and velocity measurements to follow and predict graft performance. METHODS: Between April 1996 and July 1997, 130 patients had 133 grafts placed using MIDCAB techniques. Intraoperative transit-time ultrasound was used to assess graft patency and flow prior to wound closure. Also, serial transcutaneous doppler examinations were performed to evaluate graft patency on the first postoperative day, at two weeks, and at three months. Peak values for systolic and diastolic waveforms were measured for both flow and velocity, and the diastolic-to-systolic ratio was calculated at each time interval. Recatheterization was performed selectively for inadequate ultrasound flow or doppler velocity, or for patient symptoms. RESULTS: Seven (5.3 %) grafts developed stenosis or occlusion. When compared to normal grafts, mean intraoperative flows, flow ratios, and velocity ratios were lower. Mean postoperative diastolic peak velocity (DPV) to systolic peak velocity (SPV) ratio remained stable over time for normal grafts; however, grafts with stenosis or occlusion demonstrated a diminished DPV/SPV ratio. CONCLUSIONS: Intraoperative transit-time ultrasound and outpatient transcutaneous doppler examinations did not reach a predictive value for graft stenosis or occlusion following MIDCAB surgery in this series of patients. However, these data demonstrate trends that may help identify patients at an increased risk for unfavorable events, guiding the use of postoperative recatheterization in such patients.

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Since 1989, 79 patients with benign or malignant cavernous sinus tumors, have been treated at Stanford University with linear accelerator (linac) radiosurgery. Radiosurgery has been used as (1) a planned second-stage procedure for residual tumor following surgery, (2) primary treatment for patients whose medical conditions preclude surgery, (3) palliation of malignant lesions, and (4) definitive treatment for small, well-localized, poorly accessible tumors. Mean patient age was 52 years (range, 18 to 88); there were 28 males and 51 females. Sixty-one patients had benign tumors; 18 had malignant tumors. Mean tumor volume was 6.8 cm(3) (range 0.5 to 22.5 cm(3)) covered with an average of 2.3 isocenter (range, 1 to 5). Radiation dose averaged 17.1 Gy. Mean follow-up was 46 months. Tumor control or shrinkage, or both, varied with pathology. Radiographic tumor improvement was most pronounced in malignant lesions, with greater than 85% showing reduction in tumor size; benign tumors (meningiomas and schwannomas) had a 63% control rate and 37% shrinkage rate, with none enlarging. We concluded that stereotactic radiosurgery is a valuable tool in managing cavernous sinus tumors. There was excellent control and stabilization of benign tumors and palliation of malignant lesions.

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The purpose of this study was to review the results of mitral valve replacement with mitral valve homograft, applying the method described by Acar, to determine if the method could be reproduced and was safe to use. Fourteen patients had replacement of the mitral valve with homograft. The diseased valve was excised and replaced with a cryopreserved homograft. The papillary muscles of the graft were attached to the papillary muscles of the patient in side-to-side fashion, using multiple stitches of fine monofilament suture. The annulus of the graft was attached to the patient annulus by continuous suture. The repair was supported by annuloplasty ring. All patients had intraoperative echocardiography. Patients were monitored clinically for up to 1.5 years. There were five men and nine women ranging in age from 16 to 70 years (mean = 43 years). Seven had rheumatic, six had degenerative, and one congenital morphology. Concomitant Maze III procedure was performed in three patients. All patients survived and are currently alive and in New York Heart Association functional class I. Thirteen patients have normal sinus rhythm. Only one patient has intermittent atrial fibrillation and is taking digoxin and warfarin. One patient had dehiscence of the recipient papillary muscle that required reoperation for mitral valve replacement with prosthesis. Three patients have moderate mitral valve regurgitation. Mitral valve replacement with homograft may be accomplished safely and reproducibly using the Acar method. Good short-term functional results and maintenance of normal sinus rhythm may be expected. Anticoagulant therapy should not be required.

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OBJECTIVE: The objective was to determine the course of the long thoracic nerve relative to the scapula as an aid to the prevention of proximal long thoracic nerve injuries. METHODS: Eighteen fresh cadavers (7 male, 11 female) were studied. Each was sequentially placed in the transaxillary and posterolateral thoracotomy positions, and the distance of the long thoracic nerve from the scapular tip and anterior scapular border was measured. The measurements were made bilaterally; the mean, standard deviation, and 99% confidence interval were calculated for each position by gender. RESULTS: Distances from the scapular tip to the long thoracic nerve are listed as mean/outer range: transaxillary thoracotomy, male 4.9/7.0 cm left, 5.2/7.5 cm right; female 4.3/5.0 cm left, 4.7/6.0 cm right; posterolateral thoracotomy, male 3.1/6.0 cm left, 4.5/5.1 cm right; female 3.2/4.5 cm left, 3.8/5.5 cm right. In all instances, the long thoracic nerve was furthest from the scapula at its tip. CONCLUSION: For patients positioned for a transaxillary thoracotomy, incision sites should be at least 7.5 and 6.0 cm anterior to the scapular tip for male and female patients, respectively. For patients in posterolateral thoracotomy positioning, incisions should be 6.0 and 5.5 cm anterior to the scapular tip for male and female patients, respectively. By using these anatomic guidelines, we believe that the incidence of iatrogenic proximal long thoracic nerve injury can be minimized.

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The change in the prevalence of esophageal cancer by cell type from predominantly squamous cell carcinoma to adenocarcinoma has been well documented in the USA, UK, and Western Europe. The objective of this study was to determine if this shift in cell type resulted in a change in survival in patients treated by esophagectomy without neoadjuvant therapy. Our study group included 106 consecutive esophageal cancer patients who underwent esophagectomy without neoadjuvant therapy. Cell type was adenocarcinoma in 76, and squamous cell in 30 patients. For stage 1 tumors there was a trend towards survival advantage for patients with adenocarcinoma, but this did not reach significance. For stage 2-4 tumors and overall, there was no statistical difference in survival as a function of cell type. Therefore, the observed shift in cell type to a higher prevalence of adenocarcinoma does not alter expected post-surgical outcome.

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The evolution of minimally invasive direct coronary artery bypass (MIDCAB) grafting has extended the role of this approach for limited coronary revascularization. MIDCAB techniques can now be used to address isolated stenoses in the inferior and lateral coronary distributions. MIDCAB techniques are increasingly being used in the reoperative setting, and multiple vessels can be bypassed during a single operation. This article reviews the expanded role of MIDCAB grafting in the treatment of coronary artery disease.

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The Cardiothoracic Surgery Network is an international collaborative effort among cardiothoracic surgeons that provides a common platform for the exchange of information. The Cardiothoracic Surgery Network website provides peer-reviewed journals, multimedia applications, and a database repository.

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OBJECTIVE: Immunosuppressive regimens for rejection after heart transplantation have been modified to reduce infectious complications without diminishing rejection treatment efficacy. A review of a single institutional series was performed to evaluate the influence of conservative management of grade 2 rejection on long-term outcomes after heart transplantation. METHODS: Before 1990, patients with late (>3 months after transplant) grade 2 rejection were treated with supplemental immunosuppressive drugs. Beginning in 1990, patients with late grade 2 rejection were treated conservatively by maintaining the current immunosuppressive regimen without additional therapy. The groups were compared for survival, incidence of subsequent rejection, and incidence of subsequent infection. RESULTS: One hundred twelve patients had one or more episodes of isolated, late grade 2 rejection; 39 (35%) were treated with supplemental immunosuppression (treated group) and 73 (65%) received no additional therapy (nontreated group). The mean time from transplantation to the first episode of isolated grade 2 rejection was 15.6 months in the treated group and 17.8 months in the nontreated group. Graft survival at 5 and 10 years was 69% and 51 %, respectively, in the treated group and 67% and 41 %, respectively, in the nontreated group (p = 0.77). The rates for overall subsequent rejection were 0.031 episodes/patient-month in the treated group and 0.029 episodes/patient-month in the nontreated group (p = 0.64). The rates for early rejection within 6 months of initial grade 2 rejection were 0.044 episodes/patient-month in the treated group and 0.035 episodes/patient-month in the nontreated group (p = 0.56). The rates for overall subsequent infection were 0.018 episodes/patient-month in the treated group and 0.012 episodes/patient-month in the nontreated group (p = 0.05). The rates for early infection within 6 months of initial grade 2 rejection were 0.070 episodes/patient-month in the treated group and 0.032 episodes/patient-month in the nontreated group (p = 0.04). Group comparisons demonstrated a significantly lower incidence of infection in the nontreated group. CONCLUSIONS: Conservative management of late grade 2 rejection neither adversely affects survival nor increases the incidence of subsequent short-term or long-term rejection. This approach lowers the early and late incidence of infection after rejection and may reduce other complications from aggressive supplemental immunosuppression.

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OBJECTIVE: Minimally invasive direct coronary artery bypass (MIDCAB) is performed under direct vision without sternotomy or cardiopulmonary bypass. The technique is used in reoperative patients through various incisions to revascularize one or two areas of the heart. The internal mammary artery, gastroepiploic artery, radial artery, or saphenous vein are used as graft conduits. METHODS: Anterior coronary targets are grafted with the internal mammary artery via a small anterior thoracotomy. Inferior coronary targets are grafted with the gastroepiploic artery via a small midline epigastric incision. Lateral coronary targets are grafted with radial artery or saphenous vein via a posterior thoracotomy. After partial heparinization, the anastomosis is facilitated by local coronary occlusion and stabilization. Graft follow-up consists of outpatient Doppler examination and selective recatheterization. RESULTS: Between January 1994 and August 1997, 81 patients underwent reoperative MIDCAB grafting. Twenty-one patients (25.9%) had internal mammary grafting, 39 (48.2%) had gastroepiploic grafting, and 21 (25.9%) had lateral grafting with radial artery or saphenous vein. There were nine early deaths (four cardiac, five non-cardiac), five late deaths (three cardiac, two non-cardiac), and nine myocardial infarctions in remaining patients. Sixteen patients underwent recatheterization; there were one graft occlusion, two graft stenoses, and eight anastomotic stenoses. Mean postoperative length of stay was 3.8 days. Ninety percent (55/61) of patients are free of symptoms at a mean follow-up of 7.8 months (range 0-39). CONCLUSIONS: Reoperative MIDCAB grafting avoids the risks of resternotomy, aortic manipulation, and cardiopulmonary bypass. The techniques yield an early patency rate of 94%, which includes eight patients who had postoperative catheter-based interventions. Reoperative MIDCAB grafting had lower rates of supraventricular arrhythmia and transfusion when compared with conventional coronary artery bypass grafting, but did not offer an advantage for mortality, stroke or myocardial infarction. This 3-year experience suggests that while reoperative MIDCAB grafting can effectively revascularize focal areas of the heart, patients should be carefully selected to minimize operative risk.

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Application of an external cross-clamp to an atherosclerotic ascending aorta increases the risk of an embolic event and traumatic injury of the aorta. Currently, there are limited management options in these patients when the clinical situation requires cardiac arrest during an operation. We present our approach to these patients using the Heartport Endoaortic Clamp (Heartport, Redwood City, CA).

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A technique is described in which most, if not all, cardiac operations may be performed through a standard small incision. A midline, lower half sternotomy is used. This provides traditional exposure of the heart and allows the surgeon to directly visualize the operating field and use familiar instruments. The complete spectrum of coronary revascularization and cardiac valve operations has been performed through this less-invasive incision.

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OBJECTIVE: Cryopreserved aortic allograft can be used for aortic valve replacement in congenital, rheumatic, degenerative, and infected native valve conditions, as well as failed prosthetic valves. This study was conducted to determine the long-term results of aortic valve replacement with cryopreserved aortic allografts. METHODS: Aortic valve replacement with cryopreserved aortic allografts was performed in 117 patients from July 1985 until August 1996. All patients requiring aortic valve replacement regardless of valve disease were considered for allograft replacement; the valve was preferentially used in patients under age 55 years and in the setting of bacterial endocarditis. Four operative techniques involving cryopreserved aortic allografts were used: freehand aortic valve replacement with 120-degree rotation, freehand aortic valve replacement with intact noncoronary sinus, aortic root enlargement with intact noncoronary sinus, and total aortic root replacement. Valve function was assessed by echocardiography during the operation in 78 patients (66%) and after the operation in 77 patients (65%). RESULTS: One-hundred eighteen aortic valve replacements with cryopreserved aortic allografts were performed on 117 patients; mean age was 45.6 years (range 15 to 83 years) and mean follow-up was 4.6 years (range up to 11 years). Intraoperative echocardiography disclosed no significant aortic valve incompetence. There were four operative deaths (3%) and seven late deaths; freedom from valve-related mortality at 10 years was 9:3% +/- 4.55%. New York Heart Association functional status at latest follow-up was normal in 98 (94%) patients. On postoperative echocardiography, 90% had no or trivial aortic valve incompetence. Freedom from thromboembolism at 10 years was 100% and from endocarditis, 98% +/- 2.47%. Seven (6%) patients required valve explantation, four for structural deterioration. At 10 years, freedom from reoperation for allograft-related causes was 92% +/- 3.47%. CONCLUSIONS: Aortic valve replacement with cryopreserved aortic allografts can be performed with low perioperative and long-term mortality. Most patients have excellent functional status, and reoperation for valve-related causes is unusual. Aortic valve replacement with cryopreserved aortic allografts demonstrates excellent freedom from thromboembolism, endocarditis, and progressive valve incompetence.

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