Comparison of allografts and prosthetic valves when used for emergency aortic valve replacement for active infective endocarditis.

Aortic valve replacement (AVR) using allografts is an established method of treating aortic valve disease. It is uncertain, however, whether the increased technical demands of allograft AVR can be justified in emergency operations. This study reports 15 patients treated between 1987 and 1990 for acute bacterial or fungal endocarditis involving the aortic valve. Patients underwent emergency AVR because of severe congestive failure, overwhelming sepsis or cerebral emboli. Eight patients received prosthetic valves (group I: 4 mechanical, 4 porcine) and 7 received human allografts (group II: 5 aortic and 2 pulmonary). The groups were comparable in age (group I, 55 years; group II, 51 years), intravenous drug abuse (group I, 1; group II, 3), and previous AVR (group I, 3; group II, 2). One group I and 4 group II patients had septal abscesses. Additional procedures in group I included mitral valve replacement (2), tricuspid valve replacement (1) and aortic root replacement (1). Additional procedures in group II were mitral valve repair (1), root replacement (1), atrial septal defect closure (1) and aortocoronary bypass (1). Mean bypass times (group I, 189 minutes; group II, 204 minutes) and cross-clamp times (group I; 108 minutes; group II, 121 minutes) were similar. Operative deaths occurred in 4 of 8 group I and 1 of 7 group II patients. All surviving patients have been successfully followed (group I, 28 months; group II, 18 months). No group I patient has required reoperation. One group II patients required reoperation for recurrent infection affecting the allograft, and another group II patient died 10 months postoperatively from noncardiac causes.(ABSTRACT TRUNCATED AT 250 WORDS)

Modern management of adult thoracic empyema.

Seventy adult patients with thoracic empyema were treated at the University of Michigan Medical Center between 1978 and 1982. Twenty-two (31%) of the empyemas were associated with pneumonia, 23 (33%) occurred as postoperative complications, and seven (10%) were iatrogenic. When used as the initial mode of drainage, repeat thoracentesis was successful in only four of 11 cases (36%). Similarly, closed tube thoracostomy, as initial treatment, was successful in only 14 of 40 cases (35%). Rib resection, however, provided cure or control in 10 of 11 patients (91%) when employed as the first treatment method. Eight of 12 patients (67%) with parapneumonic empyemas were treated successfully with closed tube thoracostomy, in contrast to only two of 17 patients (12%) with postoperative empyemas so treated. Eventual control or cure of empyema was achieved in 57 patients (81%), whereas 13 (19%) died (five from their empyema and eight with empyema as an active problem at the time of death). All of the five empyema-caused deaths occurred in patients who underwent chest tube drainage as the most invasive treatment modality. The mortality rate for immunosuppressed patients was 40% (four of 10 patients). This analysis of a large recent series of adult empyemas suggests that chest tube drainage is often inadequate and more aggressive management is likely to result in fewer treatment failures and fewer total procedures. Early rib resection, especially for postoperative empyemas and those in immunocompromised patients, is recommended.

Liver fibrosis (cardiac cirrhosis) five years after modified Fontan operation for tricuspid atresia.

A 15-year-old girl was found to have severe liver fibrosis on liver biopsy at the time of cholecystectomy, 5 1/2 years following a modified Fontan procedure (right atrial-right ventricular conduit) for tricuspid atresia. Postoperative right atrial pressures were consistently elevated above 13 mm Hg and this, in part, may have been due to progressive mild conduit stenosis. Because of increasing symptoms, the patient underwent successful revision of the conduit at the age of 15 years. It is suggested that sustained systemic venous hypertension caused the striking morphologic changes in the liver and that this serious complication may significantly affect the long-term prognosis of patients surviving the Fontan procedure.

Pedicled right atrial-pericardial tissue conduit for bypass of the obstructed superior vena cava in children.

Surgical relief of superior vena caval obstruction with flaps constructed from pedicled right atrium and pedicled pericardium has been performed successfully in 2 children aged 1 and 13 years. Long-term conduit patency 43 and 24 months after the operation has been achieved with this technique, despite continued growth of both patients.

Pericardial influence on internal defibrillation energy requirements.

There is no consensus regarding optimal positioning of patch leads for implantation of automatic implantable cardioverter defibrillators. We compared the energy (in joules) required for 50% and 80% successful termination of ventricular fibrillation with titanium-mesh patch leads outside intact normal pericardium and directly on the epicardium in 13 open-chest dogs. Talc was then instilled into the pericardial space to stimulate adhesion formation and pericardial thickening. After 3 weeks of recovery, thoracotomy and defibrillation testing were repeated in nine dogs with the patch leads outside the thickened, adherent pericardium. There were no significant differences in defibrillation energy requirements between locations (p greater than 0.10). In addition, a comparison of electrical impedance measurements at 10 joules showed no significant differences (p greater than 0.30). In this animal model, defibrillation energy requirements were not altered by positioning the patch leads outside normal intact pericardium rather than placing them directly on the epicardium. Furthermore, thickened, adherent pericardium interposed between the patch leads and the heart does not increase defibrillation energy requirements. These data suggest that placement of automatic implantable cardioverter defibrillator patch leads outside the pericardium in patients (including those with pericardial adhesions from previous cardiac operations) will not adversely affect defibrillation efficacy and thus can simplify the implantation procedure.

Aprotinin for coronary bypass operations: efficacy, safety, and influence on early saphenous vein graft patency. A multicenter, randomized, double-blind, placebo-controlled study.

The purpose of this study was to evaluate the efficacy and safety of aprotinin in a U.S. population of patients undergoing coronary artery bypass grafting. Early vein graft patency rates were assessed by ultrafast computed tomography. A total of 216 patients at five centers were randomized to receive either high-dose aprotinin or placebo during the operation; 151 patients underwent primary operation, and 65 underwent repeat procedures. Total blood product exposures in the primary group were 2.2 per patient receiving aprotinin as compared with 5.7 per patient receiving placebo (p = 0.010). The repeat group had 0.3 exposures per patient receiving aprotinin as compared with 10.7 per patient receiving placebo (p = < 0.001). Consistent reductions in the percent of patients requiring donor red blood cells and in the number of units of platelets, fresh frozen plasma, and cryoprecipitate required were associated with the use of aprotinin in both primary and repeat groups. Mortality was 5.6% in the aprotinin group and 3.7% in the placebo group (p = 0.517). In the primary group, clinical diagnoses of myocardial infarction were made in 8.9% of patients receiving aprotinin as compared with 5.6% of the patients receiving placebo (p = 0.435). In the repeat group, infarctions occurred in 10.3% of patients receiving aprotinin and 8.3% of patients receiving placebo (p = 1.000). Secondary analysis of electrocardiograms and available enzyme data showed no significant difference in infarction rates between the treatment groups. There was no difference in clinically significant renal dysfunction. The early vein graft patency rates were 92.0% in the aprotinin group and 95.1% in the placebo group (p = 0.248). In this study, aprotinin was effective in reducing bleeding and blood product transfusion rates, and its use was not associated with an increase in complications. An adverse effect on early vein graft patency rates was not demonstrated, but the number of grafts assessed was insufficient for absolute conclusions in this regard.

Presentation and perioperative management of arterioportal fistulas.

Arterioportal fistulas (APFs) are usually traumatic in origin and may result in portal hypertension and its complications. Over six years, six patients (aged 20 to 59 years) presented with APFs. Two APFs developed after percutaneous liver biopsy, but only one was complicated (hemobilia). Neither patient was treated operatively. Four APFs occurred two days to three years after gunshot wounds. Three patients presented with gastrointestinal tract hemorrhage. All patients had abdominal bruits. Two patients underwent primary repair. One patient underwent APF resection and replacement of the superior mesenteric artery with autogenous vein. Another patient underwent APF and bowel resection. Three patients survived. One patient died of liver failure. The development of an abdominal bruit in a patient with penetrating abdominal trauma suggests APF and should prompt angiography. Elective repair is recommended before complications of portal hypertension develop.

Limited lateral thoracotomy. Improved postoperative pulmonary function.

A prospective randomized controlled study was designed to determine differences in early postoperative pulmonary function, pain, and complications between patients undergoing limited lateral muscle-sparing thoracotomy. Fifteen patients underwent standard thoracotomy and 13 underwent limited incision with the same anesthetic technique. During the first 24 hours after operation, there were large decreases in the results of spirometric tests of pulmonary reserve (forced expiratory volume in 1 second and forced vital capacity), but these decrements were consistently significantly smaller in the limited-incision group. Other tests of pulmonary function (mid-expiratory phase forced expiratory flow, alveolar-arterial oxygen gradient, and PaCO2), however, demonstrated similar postoperative changes in both groups. Similarly, there were no differences in pain scores, postoperative morphine requirements, complications, or length of hospital stay. Use of the limited muscle-sparing incision resulted in improved postoperative pulmonary reserve, but this did not translate into differences in other measures of postoperative convalescence.

Surgical cure of cardiac arrhythmia. 1969.

The first surgical procedure undertaken for the intended purpose of curing a patient with recurrent tachycardia was performed by Sealy in 1968, and the report of that operation was published in The Annals of Thoracic Surgery in 1969. The first attempted accessory bundle ablation was successful, marked the beginning of cardiac arrhythmia surgery, and has set the standard against which other methods of arrhythmia control must be measured.

Clinical experience in coronary bypass surgery for abciximab-treated patients.

Abciximab effectively inhibits platelet aggregation and, therefore, there is considerable concern regarding bleeding complications in patients who require coronary artery bypass graft (CABG) surgery while affected by the drug. This presentation reviews the available published literature regarding CABG in abciximab-treated patients, the clinical results of emergency CABG in 12 patients, and management suggestions for the abciximab-treated patient requiring emergency surgery.

Coronary artery spasm following coronary artery surgery.

Coronary artery spasm during the early postoperative period following cardiopulmonary bypass for coronary artery surgery can be an unrecognized cause of sudden, severe cardiopulmonary collapse. The literature regarding perioperative coronary artery spasm is reviewed, and methods of prevention, diagnosis, and treatment are suggested. Preoperative angina at rest appears to be an important identifying factor in patients who experience postoperative coronary spasm. Anatomically, the presence of a relatively normal, dominant right coronary may also indicate increased risk for early post-coronary bypass spasm. Acute hypotension is often the first sign of coronary artery spasm, and conventional treatment methods may only worsen the vasospastic reaction. Peripheral intravenous nitroglycerin infusion has often been unsuccessful treatment while intragraft or intracoronary nitroglycerin injection or administration of calcium channel-blocking drugs, or both, has proven to be effective in reversing the coronary artery spasm and ventricular dysfunction. Reluctance to use vasodilating agents must be overcome, even in the face of hypotension, when evidence of spasm is present.

Early dilation in the treatment of esophageal disruption.

During the past four years, 11 patients with disruption of esophageal continuity have received dilation therapy prior to the healing of the fistula. In 7 patients undergoing transhiatal esophagectomy with a cervical esophagogastric anastomosis, anastomotic leaks within 2 to 13 days (average, 8 days) after operation were treated by drainage, bedside esophageal dilations to at least a 46F bougie, and supplemental jejunostomy tube feedings. Bougienage was performed within 1 to 12 days (average, 6 days) of the diagnosis of a leak, and oral intake was not discontinued for more than 72 hours average. Fistula drainage stopped within 1 to 12 days (average, 6 days) of dilation in all patients. Four patients referred with chronic intrathoracic esophageal disruptions (2, middle third and 2, distal third) following resection of diverticula (2), esophageal dilation (1), and trauma from Harrington rods (1) were also treated successfully by drainage, esophageal dilation, or both. Periesophageal inflammation associated with an esophageal leak, esophageal spasm due to local irritation, or relative anastomotic narrowing may all contribute to obstruction distal to an esophageal disruption and adversely affect spontaneous closure. Dilation of the leaking esophagus is not dangerous if performed carefully and selectively, and in fact may promote healing of the injury.

Rapid technique of occlusion of the venae cavae for total cardiopulmonary bypass during repeat cardiac operations.

A new technique of occlusion of the venae cavae utilizing a cannula with an inflatable balloon cuff is described.

Surgical implications of atrial septal defect complicating aortic balloon valvuloplasty.

An 80-year-old man underwent percutaneous transluminal balloon valvuloplasty for critical aortic stenosis. The procedure was performed by the antegrade atrial transseptal approach and was complicated by a persistent atrial septal defect. Symptoms recurred 6 months later, restenosis of the aortic valve was confirmed, and the atrial septal defect yielded a substantially greater left-to-right shunt. This complication of percutaneous transluminal balloon valvuloplasty poses important problems in hemodynamic assessment and operative management of patients who undergo subsequent aortic valve replacement.

Obstruction to left coronary artery blood flow secondary to obliteration of the coronary ostium in supravalvular aortic stenosis.

Supravalvular aortic stenosis is characterized by obstruction of the left ventricular outflow tract distal to the aortic valve, and may result in diminished coronary artery blood flow. This report describes the cases of 2 patients in whom obstruction to left coronary artery flow was caused by obliteration of the coronary ostium itself. This mechanism differs from the more commonly recognized cause--valve leaflet adhesion to the obstructing ridge of aortic tissue. The coronary artery obstruction found in these 2 patients required direct enlargement of the left coronary ostium in both. This mechanism of impaired coronary artery flow deserves emphasis, as traditional methods of extended patch aortoplasty may fail to relieve the coronary ostial narrowing.

Embolectomy for acute pulmonary artery occlusion following Fontan procedure.

A 5-year-old child experienced acute hemodynamic decompensation and hypoxia four weeks following an uneventful Fontan procedure for univentricular heart. Cardiac catheterization revealed complete occlusion of the left pulmonary artery, and emergent pulmonary artery embolectomy was performed. The source of the embolus was the atrial septal patch. Because of the altered hemodynamics following the Fontan procedure, stasis of right atrial blood and thrombus formation may occur. Routine anticoagulation immediately following operation is recommended. Prompt diagnosis and treatment with embolectomy may be lifesaving.

Surgical treatment of cardiac myxomas: long-term results.

Between 1965 and 1988, 22 patients underwent 24 operations for cardiac myxomas. Two patients had the complex myxoma syndrome. Mitral valve replacement was required at initial operation in 2 patients. One patient died perioperatively, and 5 others died subsequently. The 16 surviving patients recently underwent evaluation at a mean duration of 9 years after operation. Ten are asymptomatic and 6 have New York Heart Association class II symptoms. Nine patients continue to be employed. Eleven are in sinus rhythm, 3 have permanent pacemakers, and 2 have chronic atrial arrhythmias. Echocardiography showed atrioventricular valve insufficiency in 3 patients and reduced contractility in 4, but no new tumor recurrences. The long-term prognosis of this relatively large group of patients with cardiac myxomas has been good. Patients without the complex myxoma syndrome had no recurrence, whereas 2 patients did require reoperation for mitral valve replacement. Long-term disability and chronic arrhythmias have been infrequent, and functional status and employability of these patients have been very good.

Norepinephrine plus phentolamine improves regional blood flow during experimental low cardiac output syndrome.

A complication of cardiac surgical procedures is postoperative low cardiac output syndrome. Treatment with norepinephrine plus phentolamine (N + P) is beneficial, but the effect of these agents on regional organ blood flow has not been evaluated. Therefore, in 6 dogs with long-term instrumentation, pentobarbital was infused to simulate low cardiac output (32 + 10% of the conscious control level). Infusions of N + P at 0.2, 0.5, and 1.0 microgram/kg/min restored cardiac pump performance to conscious control levels. Regional blood flows, determined with tracer-labeled microspheres, were substantially reduced in the low cardiac output state but increased to values not markedly different from control levels in all organs studied except stomach fundus during infusion of N + P. The pressure-work index, an indirect measure of myocardial oxygen consumption, did not increase to more than the conscious level except at the highest dose. The data demonstrate that simultaneous infusion of N and P is capable of successfully improving cardiac pump performance with restoration of vital organ perfusion and without evidence of excessive myocardial oxygen consumption.

Aprotinin for coronary artery bypass grafting: effect on postoperative renal function.

Two hundred sixteen patients undergoing coronary artery bypass graft procedures were randomized to receive either high-dose aprotinin or placebo. Clinically important postoperative renal insufficiency was infrequent, with a single patient (0.9%) from each group requiring dialysis. Although increases in the serum creatinine level occurred postoperatively in more patients who received aprotinin (20/108) than in those given placebo (13/108), the difference between the two groups was not statistically significant (p = 0.186), and the increases were generally small and transient. Likewise, there was no difference between the groups in terms of the incidence of abnormal serum electrolyte levels, blood urea nitrogen levels, or urinalysis findings, or in the frequency of abnormal creatinine clearance rates. Under the conditions described, aprotinin use does not appear to be associated with a significant risk of serious renal toxicity.

Coronary vasodilator reserve in young dogs with moderate right ventricular hypertrophy.

The effects of experimental right ventricular (RV) pressure overload and RV hypertrophy on coronary vasodilator reserve in young animals is not well established. Therefore, we measured coronary vasodilator reserve in the right ventricle of dogs from 7 to 12 months old with moderate RV hypertrophy due to pulmonary artery banding performed 3 to 7 days after birth. In the 5 dogs with pulmonary artery banding, substantial RV hypertension developed (RV pressure at rest, 73 +/- 11 mm Hg) as did RV hypertrophy (ratio of RV free wall/left ventricular free wall weight, 1.86 +/- 0.41 gm/kg). The reactive hyperemic response following brief coronary occlusions was used as an index of coronary vasodilator reserve. The ratios of peak reactive hyperemic response to resting flow, however, were not significantly different in the 5 banded dogs compared with 7 control animals (3.6 +/- 1.0 versus 2.6 +/- 0.6); this implies that the extent of vasodilator reserve was similar with or without moderate RV hypertrophy. In addition, myocardial blood flow, as determined using radioactive microspheres, was not significantly different at rest: 0.57 +/- 0.09 ml/min per gram in the banded dogs versus 0.48 +/- 0.12 ml/min per gram in the controls. Uniform transmural distribution of blood flow was maintained during infusion of isoproterenol, which was used to increase myocardial oxygen requirements in both groups. Minimum coronary vascular resistance was significantly lower in the banded than the control dogs (1.5 +/- 0.6 versus 6.2 +/- 2.3; p less than 0.01). This difference suggests that the cross-sectional area of the right coronary vascular bed increased with the development of RV hypertrophy.