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The role of porcine bioprostheses in cardiac valve replacement has been under review for several years. The literature deals primarily with age as a determinant of durability, as well as the intermediate-term performance of various prostheses. The performance of the Carpentier-Edwards first-generation standard porcine bioprosthesis is presented over the long-term with further documentation on age determinants.The "Guidelines for Reporting Morbidity and Mortality After Cardiac Valvular Operations" were used for definitions of valve-related complications, categorization, and statistical methods. The valve-related complications were evaluated in a time-related manner by actuarial life-table techniques. The Lee-Desu statistic test was used for comparison of performance by valve positions and age groups. Hazard function rates were demonstrated for complications and composites.Of the Carpentier-Edwards porcine bioprostheses implanted in 1,195 patients (1,214 operations, 1,315 valves) commencing in 1975 the early mortality was 7.6% (92). The early mortality without concomitant procedures was 6.1% and with 11.7%. The late mortality was 5.3% per patient-year; 4.6% patient-year without and 7.5% per patient-year with concomitant procedures. The valve-related causes of late mortality (131) were thromboembolism (41), antithromboembolic hemorrhage (14), prosthetic valve endocarditis (20), nonstructural dysfunction (12), and structural valve deterioration (44). The valve-related deaths (early, 7; late, 124) were 21.2% of the total 617 total deaths. Reoperation for valve-related complications was performed in 406 patients (4.1% per patient-year), of which 327 were for structural valve deterioration (3.3% per patient-year). Mortality for reoperation was 0.5% per patient-year (49 patients) or 12.1%. Of the 49 deaths, 33 were caused by structural valve deterioration. The linearized occurrence rate for thromboembolism was 1.6% per patient-year (major, 0.9% per patient-year, and minor, 0.7% per patient-year). The fatal thromboembolic rate was 0.4% per patient-year (41), undifferentiated by valve position. The freedom from thromboembolism was 76% at 17 years (p = not significant by valve position) (major, 87%; fatal, 93%). The freedom from prosthetic valve endocarditis was 92% at 17 years (p = not significant by valve position). The freedom from reoperation, at 15 years, was 38%: aortic (AVR), 55%; mitral (MVR), 20%; and multiple valve replacement (MR), 24% (p0.05 AVRMVR, MR). The freedom from structural valve deterioration, at 15 years, was 41%; AVR, 58%; MVR, 21%; MR, 36% (p0.05 AVRMVR, MR). The freedom from structural valve deterioration was greater for advancing age groups (p0.05); AVRor = 70 years 96% at 12 years, and 65 to 69 years 94% at 12 years and 82% at 15 years; MVRor = 70 years 85% at 12 years, and 65 to 69 years 54% at 12 years. The freedom from valve-related mortality was 73% at 17 years: AVR, 80%; ; MVR, 61%; and MR, 67% (p0.05 AVRMVR, MR). The freedom valve-related residual morbidity was 94% (p = not significant by valve position).The Carpentier-Edwards standard porcine bioprosthesis continues to provide satisfactory clinical performance to 17 years. Thromboembolism is a more serious problem than structural failure: 92 major thromboembolic events with 41 fatalities compared with 44 fatalities of which 33 occurred with reoperation. The prosthesis is especially recommended for patients more than 65 years of age for AVR and more than 70 years of age for MVR.

Cystosarcoma phyllodes is an uncommon breast tumor that rarely metastasizes. A case of dumbbell cystosarcoma phyllodes metastatic to the heart and lung diagnosed antemortem is described. The roles of diagnostic echocardiography and surgical excision are discussed. Atrial extension of a lung malignancy through a pulmonary vein is not an absolute contraindication to operation, but careful patient selection and operative planning are required.

Isolated nonworking and working heart preparations are described and recent modifications that increase their reliability and scope are reviewed. Isolated perfused tissues are superior to other models for screening myocardial preservation techniques. The metabolic and functional differences between anoxia and ischemia are stressed, myocardial glycolysis is reviewed, and from basic studies potentially fruitful avenues for investigation of myocardial preservation techniques are outlined. Better application of available knowledge of myocardial metabolism could further reduce the risks of cardiac operation.

After years during which pacers of very similar design and capabilities were provided by a small number of manufacturers, many different lithium, halogen, rechargeable, and nuclear power sources are now available. The variety of chemistries, methods of construction, and sealing techniques used in the batteries of the different manufacturers is almost unlimited. This has made it necessary for physicians who implant and follow pacers to acquire a general knowledge of the field if they are to make an informed choice of pacemaker power source for implantation and if they are to manage recalls with a minimum of patient and physician trauma. More experience is required before it can be definitely determined which of the new pacer power sources will prove superior, but when coupled with well-designed, hermetically sealed pulse generators, all are capable of providing continuous pacing for at least 5 years and the 10-year pacemaker is now a probability.

For 80 elective clinical cardiopulmonary bypasses we alternately used either a commercial microporous Teflon membrane oxygenator or a commercial hybrid bubble-film oxygenator. Setup time was a little longer with the membrane unit (20 minutes), but priming volume (2,250 ml) was the same. No problems were encountered with the hybrid oxygenator. However, despite our monitoring of additional variables, including shim and inlet pressure and recirculation flow, gas exchange abnormalities were encountered in 5 patients on whom the membrane oxygenator was used; in 4 of these cases the abnormalities were encountered prior to our recognition of the potential for occasional internal shunting with this device. There were no hospital deaths. When the two groups, matched except for oxygenator selection, were compared, there were no significant differences clinically or hematologically. For cardiopulmonary bypass of 2 hours or less, both oxygenators studied are definite improvements over previous silicone membrane and high-gas-flow bubble oxygenators. However, lower cost and reduced complexity favor the hybrid oxygenator.

An improved technique for cannulating the ascending aorta has been developed and used in 229 consecutive open-heart procedures without complication. Advantages of the method include speed and ease of cannula insertion, elimination of the need for partial-occlusion clamping of the aorta, minimization of the risk of introducing air, minimization of blood loss, and facilitation of distal cannulation in patients with short aortas.

If the original electrode is damaged during pacemaker replacement for battery depletion, the operation becomes substantially more involved and hazardous. By drilling a hole in the back of the electrode connector housing and inserting an Allen wrench into the drill hole, an impacted electrode hub can be pushed free without placing stress on the electrode components. This technique is recommended whenever an electrode hub cannot be easily removed from a pacemaker during a replacement operation, as traction on the electrode not infrequently results in gross or occult damage to the Silastic sheath or conductive elements.

Spontaneous pneumothorax has been reported with increasing frequency in patients with acquired immunodeficiency syndrome and Pneumocystis carinii pneumonia. In the past year, we treated 4 patients with spontaneous pneumothorax. All of them were treated with closed tube thoracostomy, and 1 patient with bilateral apical cysts eventually required bilateral thoracotomies and pleurectomies. Only 1 patient had an uncomplicated hospital course. The remaining patients had prolonged air leaks, and 2 had synchronous pneumothoraces. Pneumothorax appears to be associated with P. carinii pneumonia. We recommend closed tube thoracostomy as the initial treatment in symptomatic patients. Pleurectomy for air leaks persisting longer than seven days can be safely performed in patients fit for thoractomy.

Selection of valve type for predominant usage is obscured by limiting the analysis to prosthesis-related rather than patient-oriented failure modes. In this report, "treatment failure" is defined as a valve-related death or permanent patient disability; successful reoperations are excluded, and emboli with permanent residua are included. Results with the Starr-Edwards Silastic ball valve (Oregon) and the Hancock (Stanford) and Carpentier-Edwards (Vancouver) porcine valves are compared using this new definition of treatment failure. Evaluated according to structural failure, the mechanical valve is superior to the tissue valve, and using the Stanford definition of valve failure, it becomes so between 5 and 10 years. Using treatment failure, tissue valves are superior at 5 years; at 10 years in the aortic position, the results are comparable; and in the mitral position at 8 to 10 years, tissue valves show a continued but small advantage.

With exposed metal at the electrode tissue interface (8 mm2, 28 mm2, 57 mm2), myocardial threshold stimulation impedance increased as pulse duration was lengthened, with left ventricular intramyocardial stimulation, and with the smaller surface area electrode. An 0.5 mm2 differential-current-density electrode, which eliminated direct metal-to-tissue contact at the electrode-myocardial interface, was associated with notably higher impedances than each of the three metal tip electrodes and did not show increasing impedance levels with changes in pulse duration, confirming the minimization of polarization energy losses with this device. The majority of electrode, electrode tissue interface, and myocardial variables that are characterized by high threshold stimulation impedance are associated with low threshold energy requirements for pacing and reduced pacemaker power source drain. No accurate information about sensing impedances can be derived from current knowledge of pacing impedance.

Procaine, hypocalcemia, magnesium, fluoride, adrenochrome, and tetrodotoxin have been used to induce metabolic arrest of the heart and increase its tolerance to ischemia. Prolonged periods of ischemic cardiac arrest without measurable deterioration of cardiac function are possible. The application of these techniques in the repair of intracardiac lesions deserves further study.

Twelve patients with tuberculous pericarditis were found among 1,194 patients with tuberculosis treated at the University of Texas Medical Branch over a 10-year period, an incidence of 1%. Surgical treatment was undertaken in 4 patients, and the rest were treated medically. The surgically treated patients had no major complications, and none of them died. In the medically treated group, however, 1 patient died, 1 had an anaerobic empyema, and 1 experienced respiratory arrest. In addition, the average hospital stay was 33 days less in the surgically treated group. Early surgical intervention should be carried out in patients with tuberculous pericarditis who do not respond promptly to adequate antituberculosis chemotherapy.

To evaluate the effect of a cardioplegic solution on the endothelium of the saphenous vein, portions of this vein were harvested from each of 5 patients undergoing coronary artery bypass operation. Each sample was divided into five segments. One segment was distended with heparinized saline solution, one with heparinized blood, and one with heparinized cardioplegic solution (25 mEq of potassium per liter). All of the distending solutions were kept at 10°C, and pressure was carefully limited to 200 mm Hg. The fourth segment of vein was distended with heparinized saline solution but no effort was made to limit distending pressure, and the fifth segment was not distended. All samples were then examined with light and scanning electron microscopy. There were no great morphological differences in the endothelium of veins distended to 200 mm Hg with saline solution, blood, or cardioplegic solution. The morphology of these samples compared favorably with the control vein endothelium although scattered areas of endothelial disruption were present in every sample. Veins distended without pressure control showed massive endothelial disruption. The particular solution used to distend the saphenous veins is not as important as limiting the distending pressure.

We used intrapleural instillation of quinacrine hydrochloride in 20 patients (Group A) with recurrent spontaneous pneumothorax (one bilateral) and compared their clinical course with 19 patients who underwent thoracotomy and scarification or pleurectomy (Group B) and 63 patients treated by tube thoracostomy alone (Group C). In Group A, there was one complication of treatment, a pneumothorax immediately following tube removal, which necessitated repeat tube thoracostomy, and there was one late ipsilateral recurrence 2 years after treatment. These 20 patients with 21 recurrent spontaneous pneumothoraces treated with intrapleurally administered quinacrine have been followed for from 6 months to more than 4 years with only one late recurrence on the treated side. Eight patients in Group B had postoperative complications: 2 patients who had had pleurectomy required reoperation for postoperative bleeding; lobar pneumonia developed in 3; 1 had lack of total expansion of the lung; an intrathoracic hematoma developed in 1; and an ipsilateral pneumothorax necessitating tube thoracostomy developed in 1. In Group C, the rate of recurrence of pneumothorax was 23% during the first year following treatment. Intrapleural instillation of quinacrine is a simple, low-risk, reliable, and effective treatment for recurrent spontaneous pneumothorax, and is equally as effective as thoracotomy and scarification.

To evaluate an apparent perception that there is no difference in reliability among the products of the major cardiac pacing system manufacturers, an extensive review of US Food and Drug Administration regulatory actions was performed. The study period was July 1974 through June 1987. The total number of affected devices was collected for each manufacturer. Available sales data were used to calculate their percentage of recalled products during two time periods. The percentage of potentially high-risk devices (Food and Drug Administration class I and II recalls) was high for one company, moderate for one, and relatively low for the rest. Potential biases in some other sources of reliability information, as well as implications for regulatory policies, are discussed. The data reported establish that there have been past deficiencies in recall management. Although further pacing device recalls are probable, appropriate early regulatory and manufacturer action should help to assure that both the immense cost and patient distress caused by pacer and related product problems in the past can be minimized in the future.

The Carpentier-Edwards porcine valve prosthesis has afforded our patients a satisfactory quality of life and a low incidence of valve-related complications at follow-up periods of up to five years. From December, 1975 to March, 1980, 768 prosthesis were implanted in 700 patients (aortic valve replacement [AVR], 334; mitral valve replacement [MVR], 292; tricuspid valve replacement [TVR), 6; and multiple valve replacement, 68). One hundred and thirty-seven patients (19.6%) had had previous cardiac operations. Concomitant aortocoronary bypass was performed in 127 patients (18.1%). There were 52 hospital deaths, for a mortality of 7.4% (AVR, 4.8%; MVR, 9.2%; multiple valve replacement, 11.8%). Total follow-up was 1,047 patient-years (range, 6 to 60 months, mean, 19.4 months). There were 33 late deaths (AVR, 1.7% per patient-year; MVR, 4.0% per patient-year; multiple valve replacement, 8.1% per patient-year). Eight percent of AVR patients and 47% of MVR and multiple valve replacement patients were taking anticoagulants. The valve-related complications (expressed as events per 100 patient-years) were as follows: (1) thromboembolism (AVR, 0.94; MVR,. 1.42; multiple valve replacement, 4.62); (2) infective endocarditis (AVR, 0.94; MVR, 0.24; multiple valve replacement, 2.31); (3) periprosthetic leak (AVR, 0.94; MVR, 0.71; multiple valve replacement, 3.46); and (4) valve dysfunction (MVR, 0.24). The only case of valve dysfunction was a calcified mitral prosthesis in a 13-year-old girl. Actuarial survival, including operative deaths, was as follows: AVR, 90.5% at 36 months; MVR, 84% at 36 months; and multiple valve replacement, 74% at 24 months. Of surviving patient, 93.6% were in New York Heart Association Class I or II at follow-up evaluation.