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Biomedical subjects

W G Wolfe

Publications and source records attributed to W G Wolfe.

At least 37 records · Page 2Linked to original sources

The significance of c-erb B-2 and p53 immunoreactivity in patients with adenocarcinoma of the esophagus.

OBJECTIVE: Studies in breast cancer suggest that p53 and c-erb B2 protein overexpression are predictive of outcome. The authors determined whether these molecular markers correlated with treatment response and survival in patients with adenocarcinoma of the esophagus and esophagogastric junction. METHOD: Immunostaining for p53 and c-erb B2 was performed on paraffin-embedded specimens from 42 patients with esophageal adenocarcinoma. All patients received neoadjuvant chemotherapy (cisplatin and fluorouracil [5-FU] x 3 cycles) and irradiation (4500 rads) followed by resection. RESULTS: In this cohort of patients, 79% (33/42) were positive for p53, and 43% (18/42) were positive for c-erb B2. p53 positivity correlated with residual disease in the resection specimen but not with disease-free survival. Although c-erb B2 negatively correlated with residual disease after resection and a 5-year survival of 10%, c-erb B2 positivity was associated with a 5-year actuarial survival of 60%. CONCLUSIONS: Although p53 protein overexpression is commonly observed in adenocarcinoma of the esophagus, its prognostic value appears limited. In contrast, c-erb B2 protein expression predicts a favorable response to therapy and improved survival.

Actuarial Analysis↗

Right thoracotomy for reoperative right coronary artery bypass procedures.

The use of a right thoracotomy is a safe alternative approach for reentering the mediastinum for reoperative right coronary artery bypass grafting. This technique was used in 9 patients and allowed minimal dissection, reducing the risks of hemorrhage and injury to previously placed patent grafts. Cardiopulmonary bypass was used in 4 patients in whom myocardial protection was accomplished with systemic hypothermia. Right atrial cannulation provided adequate venous return, with arterial inflow established via the femoral artery (n = 2) or ascending aorta (n = 2). In 5 patients, revascularization was accomplished by temporary coronary artery occlusion without cardiopulmonary support. There were no deaths, and postoperative recovery was not delayed. Postoperative chest drainage (mean +/- standard deviation, 1,076 +/- 718 mL) was significantly less (p < 0.01) than redo median sternotomy (1,352 +/- 602 mL) in a similar population. Eight of 9 patients remain free of angina 29 +/- 24.8 months postoperatively.

Aged↗

Progressive alveolar septal injury in primates exposed to 60% oxygen for 14 days.

Moderate exposures to hyperoxia are becoming increasingly common in clinical medicine as advancing technology allows O2 to be more effectively delivered to nonintubated patients. The sensitivity of the lung to injury by a subchronic exposure to 60% O2 was investigated, using baboons and serial lobar biopsies. Because results obtained from different regions of the lung were compared, the alveolar architecture of different lung lobes of three controls was studied, with the use of electron microscopic morphometric analyses, to assess possible lobar differences in volume, surface, and numerical densities of cells and tissues. In animals exposed to 60% O2, the same techniques were used to assess specific tissue changes in the epithelial, interstitial, and endothelial compartments of the alveolar septa. All six lobes of the normal baboon lung were found to be identical with respect to alveolar architecture. Thus, for gases of low reactivity and given in high concentrations, such as O2, cross-comparisons between different lobes are appropriate. Exposure to 60% O2 was found to cause proliferation of alveolar type II epithelium, suggesting a low-grade, chronic epithelial injury. Animals allowed to recover for 8 wk in room air showed progressive changes in the alveolar interstitium, involving increases in both cells and matrix. Because sequential lobar resections were done, animals were exposed both to 60% O2 and to the effects of general anesthesia and thoracotomies. The exposure to 60% O2 for 2 wk in this experimental setting leads to an alveolar septal injury that includes a progressive interstitial fibrotic response.

Animals↗

Comparison of anticoagulation regimens after Carpentier-Edwards aortic or mitral valve replacement.

BACKGROUND: To identify the optimal use of anticoagulants after Carpentier-Edwards valve replacement, a retrospective study of all patients undergoing Carpentier-Edwards aortic (N = 378) or mitral (N = 370) valve replacement was done. METHODS AND RESULTS: At the time of hospital discharge, 103 patients were managed with warfarin, 509 with aspirin alone, and 136 with no anticoagulation or antiplatelet therapy. Over the first 90 days after aortic or mitral valve replacement, the linearized rate of hemorrhage was greater for warfarin than for aspirin or no therapy (16.7 +/- 7.6%, 3.4 +/- 1.7%, and 3.1 +/- 3.1% per patient-year, respectively; P = .03). After aortic valve replacement, aspirin provided a low rate of thromboembolism (0.8 +/- 0.2% per patient-year), not significantly different from warfarin or no treatment (2.9 +/- 1.6% and 1.5 +/- 0.6% per patient-year) (P = .07). After mitral valve replacement, no single treatment was most advantageous because the rate of hemorrhage over the first 90 days for warfarin was equivalent to the 90-day rate of thromboembolism with aspirin or no therapy. CONCLUSIONS: Anticoagulation after Carpentier-Edwards mitral valve replacement may be best guided by individual patient characteristics. Within the limits of a retrospective analysis, these data support the routine use of aspirin alone after Carpentier-Edwards aortic valve replacement, both in the first 90 days and long-term.

Aortic Valve↗

Determinants of reoperation after 960 valve replacements with Carpentier-Edwards prostheses.

During the period of 1977 to 1990, 960 Carpentier-Edwards standard prostheses (Baxter Healthcare Corp., Santa Ana, Calif.) were placed in 875 operations. Freedom from reoperation at 10 years was 57% +/- 4%, 76% +/- 3%, and 95% +/- 5% for mitral, aortic, and tricuspid valve replacement, respectively. Age was the only independent determinant of reoperation for both aortic and mitral valves. Likelihood of reoperation decreased with age, with freedom from reoperation after 10 years in patients aged less than 60 years versus 60 or more years being 65% +/- 5% versus 90% +/- 4% after aortic valve replacement and 48% +/- 5% versus 75% +/- 6% after mitral valve replacement. For mitral valve replacement, larger valve size made reoperation more likely, with freedom from reoperation at 10 years being 71% +/- 6% for sizes median less than 31 mm and 57% +/- 5% for sizes 31 mm or larger. For aortic valve replacement, prior median sternotomy reduced freedom from reoperation at 10 years from 80% +/- 3% to 25% +/- 5%. The low prevalence of reoperation affirms the suitability of the Carpentier-Edwards prosthesis for selected elderly patients and for tricuspid valve replacement. Because of their influence on the probability of reoperation, valve size and prior cardiac procedures also merit consideration in the choice of valvular prosthesis.

Aged↗

Effects of muscle contraction on cytochrome a,a3 redox state.

The relationships among mitochondrial O2 availability, O2 delivery, and lactate formation in exercising skeletal muscle remain unclear. Some data suggest that muscle O2 provision is sufficient at maximal O2 consumption (VO2max) to challenge the concept of a mitochondrial O2 limitation at VO2max. The relationships among VO2, mitochondrial O2 availability, and net lactate production were studied over a wide range of exercise intensities. Using near-infrared spectroscopy, the oxidation-reduction state of cytochrome a,a3 was monitored in the canine gracilis in vivo. Twenty adult dogs were anesthetized with alpha-chloralose, intubated, and mechanically ventilated on room air. Five-minute stimulation periods at rates of 2, 3, 4, 5, 7, 8, 10, or 12 stimuli/s were performed. VO2max generally was achieved at a stimulation rate of 8 stimuli/s; mean VO2max was 0.12 +/- 0.09 (SE) ml.min-1 x g-1. The concentration of oxidized mitochondrial cytochrome a,a3 decreased at all work loads relative to resting state and demonstrated a near-linear relationship with muscle VO2 (r2 = 0.99). Muscle lactate efflux and the lactate-pyruvate ratio also were correlated positively with cytochrome a,a3 reduction, suggesting a common regulatory mechanism coupling the processes of aerobic glycolysis and oxidative phosphorylation. At VO2max, the corresponding cytochrome oxidation was not significantly different from that observed at death. Thus, in the gracilis maximal exercise leads to near-complete reduction of cytochrome a,a3 secondary to deficient O2 provision. We conclude that VO2max is limited primarily by O2 delivery to this muscle and not by other factors limiting mitochondrial ATP production or substrate oxidation.

Animals↗

Survival of patients with carcinoma of the esophagus treated with combined-modality therapy.

Since 1985, 229 cases of carcinoma of the esophagus have been considered for entry into a protocol with the use of preoperative chemotherapy and radiation therapy followed by surgical intervention as the primary element of treatment. One hundred sixty-five patients (93 with adenocarcinoma and 72 with squamous cell carcinoma) had esophagogastrectomy. The 5-year survival of the protocol patients who underwent resection was 25% for both groups--squamous cell carcinoma and adenocarcinoma. Of the protocol patients with squamous cell carcinoma who underwent resection, 40% had a sterilized specimen, whereas of those with adenocarcinoma, 20% had a sterilized specimen. If the patient had a sterilized specimen, the 5-year survival was approximately 60% for adenocarcinoma and 40% for squamous cell carcinoma. Those patients with adenocarcinoma and Barrett's esophagus had a 5-year survival of 55%. Of the patients who underwent only esophagectomy and esophagogastrectomy and had not been entered into the protocol, none lived beyond 3 years. The operative mortality rate for those who had esophagogastrectomy was 5%. Sixty-four patients completed the radiation therapy and chemotherapy but did not undergo surgical procedures because of progressive disease or refusal. Of those patients who completed chemotherapy and radiation therapy without surgical intervention, 5-year survival was 18% in patients with squamous cell carcinoma, whereas no patients with adenocarcinoma survived beyond 3 years. The finding of a sterilized specimen after esophagectomy is a favorable prognostic factor in patients with adenocarcinoma or squamous cell carcinoma. The finding that patients with Barrett's esophagus and adenocarcinoma have an improved chance for survival is perhaps related to an earlier diagnosis. It is clear that some patients with squamous cell carcinoma who did not undergo surgical procedures did have a sterilized specimen, because the survival in this group approached 20% at 5 years.

Adenocarcinoma↗

Sensitive and specific detection of the 4B5 antigen in bronchial lavage specimens from patients with primary bronchogenic carcinoma.

The monoclonal antibody 4B5 binds to a mucin-like antigen elaborated by respiratory epithelium of patients with non-small cell bronchogenic carcinoma. Several immunoassay formats were used to determine the presence of the antigen in lavage specimens. A qualitative immunodrop binding assay showed immunoreactivity in 37 (64%) of 58 specimens from patients with non-small cell lung cancer. In contrast, only 11 (12%) of 93 specimens from patients with either metastatic carcinoma or benign pulmonary diseases exhibited 4B5 immunoreactivity. A quantitative radioimmunoassay using standardized amounts of mucin exhibited similar sensitivity and specificity. Positive immunoreactivity was associated significantly with tobacco use and the cytopathologic diagnoses of squamous metaplasia, atypia, or dysplasia. Conversely, no significant association was found between 4B5 immunoreactivity and age, gender, race, benign cytologic findings, frankly malignant cytologic findings, or stage of disease. The expression of 4B5 antigen in bronchial secretions from patients with bronchogenic carcinoma deserves additional evaluation as a potential marker of pulmonary carcinogenesis.

Adult↗

Bronchial carcinoid tumors: a retrospective analysis of 126 patients.

From 1970 until 1990, 8,958 cases of primary carcinoma of the lung were diagnosed at the Duke University Medical Center. During the same period, 126 patients (mean age, 53 +/- 13 years) were diagnosed with bronchial carcinoid. The overall survival was 78% for 5 years and 71% for 10 years. Surgical treatment in 106 patients included pneumonectomy (15), lobectomy (63 with 9 bronchoplastic procedures), stapled wedge resection (22), and bronchoscopic laser resection (6). The method of diagnosis was chest roentgenography (121), chest computed tomography (77), mediastinal tomography (31), bronchoscopy (81), bronchoscopic brushing and washing (50), bronchoscopic biopsy (40), transthoracic needle biopsy (27), thoracotomy (100), and autopsy (5). Univariate analysis of the medical history, presenting signs and symptoms, diagnostic test results, and pathologic data predicted improved survival (p less than 0.001) for: female sex (n = 58), asymptomatic presentation (n = 47), normal serum serotonin or urinary hydroxyindoleacetic acid levels (n = 76), peripheral location of the primary tumor (n = 50), pathologic stage I or II (n = 91), negative lymph nodes (n = 80), primary tumor 2 cm or less in diameter (n = 67), and typical histology (n = 80). No significance (p greater than 0.1) was observed for age, smoking history, race, family history of carcinoid, environmental exposure, or hemoptysis. The most important factors affecting survival defined by multivariate analysis were (p less than 0.01) pathologic stage, atypical histology, and asymptomatic presentation. Bronchial carcinoid tumors are unique, making up 1% to 2% of primary lung neoplasms and having an excellent prognosis after resection with a 95% 5-year and 93% 10-year survival for pathologic stage I disease.

Analysis of Variance↗

Acute traumatic aortic aneurysm: the Duke experience from 1970 to 1990.

Improvements in the operative management of acute traumatic thoracic aortic aneurysm have resulted in safe and expeditious repair. Nonetheless, multisystem injuries continue to inflict significant numbers of deaths. From 1970 to 1990, 108 patients with acute traumatic thoracic aortic aneurysm were evaluated. Mean injury severity score, excluding aortic injury, was 17.5. Ninety-three patients (86%) survived beyond initial resuscitation and came to operation. Median interval from injury to aortic repair was 8 hours (range, 2 hours to 19 days); there were five operative deaths. Lethal nonaortic injuries included 18 closed head injuries, four myocardial contusions, two intraabdominal vascular injuries, and one pulmonary contusion. The overall mortality rate was 39% of total admissions (42 of 108), and 29% of survivors of resuscitation (27 of 93). It is significant that only 11 of the 42 deaths (26%) were directly attributable to thoracic aortic aneurysm. Adjuncts to prevent spinal cord ischemia (shunt/bypass) were used in 76 patients, whereas 12 underwent clamp/repair. Postoperative paraplegia developed in 5 of 79 patients (6.8%, including 4 of 68 (5.9%) repaired with shunt/bypass and 1 of 11 (9.1%) repaired with clamp/repair (p = NS). Among those who developed paraplegia, the injury severity score was 27.0, and the median interval from injury to repair was 4.9 hours (range, 2 to 6.5). Intraoperative hypotension occurred in three of five patients with paraplegia. Death in patients with thoracic aortic aneurysm is due primarily to associated injuries and has remained relatively constant over the 20-year period of review. Overall injury severity, intraoperative hypotension, and extensive aortic tissue destruction may correlate with the development of postoperative paraplegia; however, a larger population sample is required to confirm this conclusion. A plea is made for standardized reporting of all patients with thoracic aortic aneurysm.

Acute Disease↗

Analysis of 945 cases of pulmonary metastatic melanoma.

From 1970 to 1990, 7564 patients with melanoma were seen at Duke University Cancer Center. Complete follow-up data were available in all patients. The estimated probability of a pulmonary metastasis developing 5, 10, or 20 years after initial diagnosis was 0.13, 0.19, and 0.30, respectively. Pulmonary metastases were documented in 945 patients (12%), these having 1-, 3-, and 5-year survival rates of 30%, 9%, and 4%, respectively. The methods of diagnosis were chest radiograph (n = 544), computed tomography (n = 157), transthoracic needle biopsy (n = 121), bronchoscopy (n = 14), thoracotomy (n = 112), and autopsy (n = 7). Evidence of advanced pulmonic spread included bilateral disease in 543 and more than two nodules in 595. Univariate predictors for early formation of pulmonary metastases (p less than 0.001) were male sex, black race, increased primary thickness (millimeters), higher Clark's level, nodular or acral lentiginous histology, location on trunk or head and neck, and regional lymph nodes positive for metastasis. Multivariate predictors of improved survival (p less than 0.001) in order of importance were complete resection of pulmonary disease, longer time for formation of metastases, treatment with chemotherapy, one or two pulmonary nodules, lymph nodes negative for metastasis lymph nodes (p less than 0.005), and histologic type (p less than 0.04). Additionally, survival in patients with one nodule and resection (n = 84) was better than in those with similar disease and no resection (n = 142 months, p less than 0.001). These data comprise the largest series to date and emphasize the importance of long-term follow-up, as well as supporting the selective use of resection for isolated pulmonary metastases, increasing the 5-year survival rate from 4% to 20%.

Adult↗

Management and long-term outcome of aortic dissection.

All 163 patients admitted to one institution between 1975 and 1988 with aortic dissection were reviewed. Type I and type II patients received grafting of the ascending aorta, with an intraoperative mortality rate of 11%. For type III dissection, management was medical in 53 patients, while 19 required surgery for aortic rupture or expansion, with an intraoperative mortality rate of 11%. The 9- or 10-year survival rates were 29%, 46%, and 29% for types I, II, and III respectively. Of 135 patients with primary aortic dissection, 17 (13%) required subsequent aortic surgery. Cause of late death was other cardiovascular disease in 38%, rupture of another aortic segment in 18%, sudden death in 24%, and other medical conditions in 21%. Although operative therapy for types I and II dissections and reserving operation for selected type III dissections provides acceptable long-term survival, careful follow-up is necessary due to concurrent cardiovascular disease and residual aortic disease.

Academic Medical Centers↗

Responses of baboons to prolonged hyperoxia: physiology and qualitative pathology.

Cardiopulmonary responses to prolonged hyperoxia and their relationships to the development of lung pathology have not been fully characterized in primates. In this study, circulatory hemodynamics and pulmonary function, vascular permeability, and leukocyte sequestration were measured in male baboons after 100% O2 exposure and related to ultrastructural changes of lung injury by electron microscopy. Three groups of animals were exposed to 100% O2 in an exposure cage for 40, 66, and 80 h, respectively. A fourth group of animals was exposed in a cage for 80 h and then anesthetized and ventilated with 100% O2 for additional time. These animals were exposed for a total duration of 110 h or until death from the injury. Physiological responses to hyperoxia were characterized by decreases in total lung capacity and inspiratory capacity at 80 and 110 h. A significant increase in pulmonary leukocyte accumulation was noted by 80 h. Extravascular lung water and permeability surface-area product increased at 80 and 110 h. Cardiac output and stroke volume also decreased, and systemic vascular resistance increased after 80 and 110 h of hyperoxia. Histopathological changes were present in the lungs of all but the 40-h exposure group. Animals exposed for 66 h showed endothelial injury and neutrophil accumulation. By 80 h, animals showed endothelial cell destruction, interstitial edema, and type I cell injury. At 110 h, animals showed substantial destruction of endothelial and type I epithelial cells, exposure of alveolar basement membrane, congestion of capillaries, and substantial interstitial edema. The data indicate that histological changes by electron microscopy precede physiological responses to hyperoxic pulmonary injury in baboons by as much as 14 h and that the physiological responses to early hyperoxic injury are relatively insensitive to the pathological injury.

Animals↗

Aortic dissection resulting from tear of transverse arch: is concomitant arch repair warranted?

Forty-seven patients with aortic dissection resulting from a primary tear located in the transverse aortic arch underwent surgical treatment. Twenty-six patients had acute type A, 7 had acute type B, 7 had chronic type A, and 7 had chronic type B aortic dissections. Of the 33 patients with acute dissections, 11 (7 acute type A and 4 acute type B) underwent concomitant arch repair with an operative (less than or equal to 30 days) mortality rate of 55% (35% to 73%, +/- 1 asymmetric 70% confidence limit) (2 of 7 acute type A and 4 of 4 acute type B). Concomitant arch repair was omitted in 22 patients with acute dissections (19 acute type A and 3 acute type B); the operative mortality rate was 41% (29% to 54%) (7 of 19 acute type A and 2 of 3 acute type B) (p = not significant versus arch repair). The overall survival rate for those with arch repair was 45% +/- 15% (+/- 1 standard error of the estimate) at 4 years, compared with 43% +/- 11% for patients without arch repair (p = not significant). Considering the type of dissection, the 4-year survival estimate for patients with acute type A dissections who underwent arch repair (5 hemiarch and 2 total arch) was 71% +/- 17% (versus 44% +/- 12% for acute type A patients without arch repair). There were no survivors among the 4 patients with acute type B dissections who had an arch repair (1 hemiarch and 3 total arch), whereas patients with acute type B dissections who did not undergo concomitant arch repair had a 4-year survival estimate of 33% +/- 27% (p = not significant versus arch repair). Four other patients with acute type B dissections resulting from an arch tear were managed medically and tended to have a slightly better prognosis (2-year survival estimate of 75% +/- 22% versus 14% +/- 13% for all surgically treated acute type B patients), but again this difference was not statistically significant. Multivariate analysis of the 47 surgical patients revealed that advanced age (p = 0.0008), preoperative dissection complications (p = 0.02), and other coexistent medical problems (p = 0.03) were the only significant, independent determinants of overall mortality. Initial arch repair was not a significant predictor. Nine percent (2/22) of patients with acute type A dissections who initially underwent isolated ascending aortic replacement required subsequent arch replacement; 1 died after reoperation.(ABSTRACT TRUNCATED AT 400 WORDS)

Actuarial Analysis↗

Barrett's esophagus and adenocarcinoma of the esophagus and gastroesophageal junction.

Since 1985, 57 patients with adenocarcinoma of the esophagus and gastroesophageal (GE) junction have undergone surgical resection. In this group, 16 of the tumors arose in a Barrett's esophagus. There was a significant predilection toward white men above the age of 55 (15/16; 94%) in this subgroup. The mean proximal extent of abnormal columnar involvement was 5.4 cm above the gastroesophageal junction (range 2.5 to 11 cm). The mean location of the neoplasm centered in the distal esophagus 1.8 +/- 0.5 cm above the gastroesophageal junction. During the same time period, 30 patients with Barrett's esophagus were seen without associated adenocarcinoma. There were no statistical differences in the proximal extent of columnar involvement or the presence of reflux symptoms between the two groups. There were no significant differences in age, smoking history, and alcohol consumption between patients with benign or malignant Barrett's esophagus as compared to those with adenocarcinoma of the gastroesophageal junction not associated with Barrett's mucosa. The marked male predominance seen in the group with malignant Barrett's esophagus was in contrast to the benign cases (16/30; 53%) but was similar to the adenocarcinoma group, without recognized Barrett's esophagus (38/41; 93%). The mean location of the tumor in the latter was 0.9 +/- 1.2 cm above the gastroesophageal junction and was comparable to the location in the group with Barrett's adenocarcinoma. The 4-year survival rate of patients in the non-Barrett's adenocarcinoma group is approximately 30%. Of those with Barrett's adenocarcinoma, the present 4-year survival rate is 60%. The demographic and morphometric similarities between the Barrett's and non-Barrett's adenocarcinoma groups may be of primary importance in determining the true clinical prevalence of Barrett's adenocarcinoma. Our findings suggest that the sensitivity of endoscopic surveillance may be improved if biopsy specimens are concentrated within the distal 3 cm of the esophagus and the esophagogastric junction. Finally, the reason for the current difference in survival between the Barrett's and non-Barrett's adenocarcinoma groups is uncertain but may be related to endoscopic surveillance permitting earlier diagnosis and treatment.

Adenocarcinoma↗

Preservation of aortic valve in type A aortic dissection complicated by aortic regurgitation.

Two hundred fifty-two patients underwent operation for type A aortic dissection at Stanford University Medical Center from 1963 to 1987 and Duke University Medical Center from 1975 to 1988. Sixty-seven percent had an acute type A dissection and 33% had a chronic type A dissection. In addition to repair or replacement of the ascending aorta, 121 patients (48%) required an aortic valve procedure. Valve resuspension was performed in 46 (39 acute type A and 7 chronic type A), with an operative mortality rate of 13% +/- 5% (+/- 70% confidence limits), and aortic valve replacement in 75 (36 acute type A and 39 chronic type A), with an operative mortality rate of 20% +/- 5% (p = not significant versus resuspension). The operative mortality rate for patients requiring only repair or replacement of the ascending aorta was 32% +/- 4%. Indications for valve replacement included coexistent (nonacute) aortic valve disease, Marfan's syndrome, annuloaortic ectasia, and cases in which successful resuspension could not be accomplished. The overall actuarial survival rate for all patients was 59% +/- 3% (+/- 1 standard error of the mean), 40% +/- 4%, and 25% +/- 5% at 5, 10, and 15 years, respectively. Survival rates at these same times for patients with valve resuspension were 67% +/- 8%, 52% +/- 10%, and 26% +/- 19%, respectively; for patients who required aortic valve replacement, these survival rates were 70% +/- 5%, 39% +/- 8%, and 21% +/- 11%; finally, patients who received only an ascending aortic procedure had survival probabilities of 51% +/- 5%, 37% +/- 6%, and 23% +/- 6% (p = not significant versus resuspension versus aortic valve replacement). Multivariate analysis showed advanced age (p less than 0.001), previous cardiac or aortic operation (p less than 0.001), more preoperative dissection complications (p = 0.002), and earlier operative date (p = 0.038) to be the only significant, independent factors that increased the likelihood of early or late death. The type of aortic valve procedure (resuspension versus aortic valve replacement versus none) was not a significant predictor of mortality. Two of 46 patients with valve resuspension required late aortic valve replacement (freedom from aortic valve replacement: 100% and 80% +/- 13% at 5 and 10 years, respectively), as did 4 of 75 patients with initial aortic valve replacement (freedom from repeat aortic valve replacement: 98% +/- 2% and 73% +/- 13%, respectively).(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗

Effects of standard mitral valve replacement on left ventricular function.

Recent studies have suggested that excision of the mitral valve apparatus during mitral valve replacement impairs left ventricular performance. However, functional measurements in humans have been difficult to obtain in a load-independent fashion. To investigate this concept, 12 patients (mean age, 65 +/- 8 years; mean New York Heart Association functional class, 3.3 +/- 0.7) with 4+ mitral regurgitation (n = 8) or mitral stenosis (valve area, 1.2 +/- 0.2 cm2) (n = 4) underwent prosthetic valve replacement using crystalloid cardioplegia. No patient required therapeutic inotropic support, every patient had at least the anterior mitral leaflet excised, and paced heart rate was maintained constant throughout. Left ventricular volume was measured with radionuclide angiocardiography, left ventricular pressure with a 3F micromanometer, and left ventricular wall volume with two-dimensional transesophageal echocardiography. Left ventricular preload was varied over a mean end-diastolic pressure range of 9 to 20 mm Hg and an end-diastolic volume range of 134 to 170 mL to generate four to five steady-state pressure-volume loops before and ten minutes after cardiopulmonary bypass. Left ventricular performance was estimated with the stroke work/end-diastolic volume relationship, which is insensitive to load. After bypass, no significant change (p greater than 0.1) was noted in wall volume for patients with mitral regurgitation or mitral stenosis (175 +/- 68 to 189 +/- 63 mL/m2 and 130 +/- 22 to 127 +/- 19 mL/m2, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗