Graduate education in thoracic surgery and the American College of Surgeons.
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Accreditation↗
Biomedical subjects
B R Wilcox
Publications and source records attributed to B R Wilcox.
Anatomically sound, simplified approach to repair of "complete" atrioventricular septal defect.
BACKGROUND: There are few congenital anomalies of the heart that have benefited more from thorough anatomic analysis than the complex anomaly known as atrioventricular septal defect in the setting of common atrioventricular junction. Recent advances in understanding the anatomy of this lesion have led to alternative methods of repairing these defects. METHODS: The medical records of 21 consecutive patients undergoing repair of complete atrioventricular septal defect have been reviewed. Nine of these patients had a standard one- or two-patch repair, and 12 had direct closure of the ventricular element of the defect. RESULTS: Direct closure resulted in significantly shorter pump and cross-clamp times. Follow-up for an average of 34 months suggests that when direct closure can be performed, the results are comparable with those of the more standard technique. CONCLUSIONS: Our initial success with this approach is encouraging; however, longer follow-up is required to establish whether it will be broadly applicable.
Cardiac Surgical Procedures↗
Graduate education in surgery: too long?
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Clinical Competence↗
Volume requirements for cardiac surgery credentialing: a critical examination. The Ad Hoc Committee on Cardiac Surgery Credentialing of The Society of Thoracic Surgeons.
New volume requirements for coronary artery bypass grafting are being imposed on cardiac surgeons by hospitals, managed care groups, and others. The rationale for this is unclear. The available literature as well as additional sources relating volume and outcomes in cardiac surgery were extensively reviewed and reexamined. There are no data to conclusively indicate that outcomes of cardiac operations are related to a specific minimum number of cases performed annually by a cardiac surgeon. Each cardiothoracic surgeon should participate in a national database that permits comparison of his or her outcomes on a risk-adjusted basis with other surgeons. Until conclusive data become available that link volume to outcome, volume should not be used as a criterion for credentialing of cardiac surgeons by hospitals, managed care groups, or others. Instead, each surgeon should be evaluated on his or her individual results.
Cardiac Surgical Procedures↗
One hundred consecutive thymectomies for myasthenia gravis.
BACKGROUND: Between June 1997 and November 1993, 100 consecutive thymectomies for myasthenia gravis were performed at University of North Carolina Hospitals in Chapel Hill. METHODS: A consistent, planned protocol involving preoperative, intraoperative, and postoperative care was followed. All thymectomies were performed through a median sternotomy with removal of all visible thymus and perithymic fat in the anterior mediastinum. RESULTS: There was no perioperative mortality or longterm morbidity. Mean postoperative hospital stay was 6.3 days (range, 3 to 18 days). Ninety-six percent of the patients were extubated the day of the operation, and all patients were extubated within 24 hours. Mean postoperative intensive care unit stay was 1.2 days (range, 1 to 4 days). After a mean follow-up of 65 months (range, 1 to 199 months), 78% of all patients are improved by at least one modified Osserman classification when their current status is compared with their worst preoperative disease severity. In fact, 69% of patients with mild disease preoperatively (class I, II, or III maximal severity) are in pharmacologic remission (asymptomatic without regular medication), whereas 29% of patients with severe disease (class IV or V) are in remission (p = 0.0001). CONCLUSIONS: Our programmatic approach to thymectomy through a sternotomy has shown minimal morbidity and mortality. It is beneficial to myasthenics at both ends of the age and severity spectrum.
Adult↗
Understanding cardiac anatomy: the prerequisite for optimal cardiac surgery.
If advances in cardiac surgery are to continue into the twenty-first century, it will be necessary to concentrate on details of matters such as the anatomy of the heart. This will be achieved best when anatomy is described as it is observed. This approach is obscured when words are used in inappropriate fashion, or else assigned a function separate from their everyday meaning. Examples of how the congenitally malformed heart and the normal heart have been described in the past are examined within the framework of using words in their vernacular meaning. Suggestions are made to improve descriptions and understanding for the 21st century. Using the example of the "univentricular heart", it is shown how conventions debarring ventricular status to discrete chambers within the ventricular mass are, of necessity, artificial. Similar examples are used to distinguish septal from parietal structures within the heart and to elucidate the structure of some congenital malformations. For values, it is shown how proper description requires assessment of these structures in their closed as well as their open positions. Understanding of cardiac anatomy, truly a prerequisite for successful cardiac surgery, will be facilitated in future if words are used in their generally accepted sense, and if artificial conventions are avoided.
Anatomy↗
The Thoracic Surgery Residency Program at Chapel Hill.
The success of the cardiothoracic surgery residency program in Chapel Hill is due to a number of contributing factors. The first important ingredient is the faculty. Their ability, stability, and dedication, with each faculty member developing an area of expertise, has contributed greatly to the success of our program. The second important aspect is the program design itself--all three years: the first to allow the resident time to reflect on educational priorities and do some innovative thinking; the second and third as chief resident on their respective services--for an entire, continuous year. The third and most important aspect of our program is the quality of the residents we have been able to attract--uniformly a splendid group of individuals who regularly gave more than they received and who continue to be a source of inspiration, hope, and pride for those of us who have been privileged to be their teachers.
Boston↗
The surgical anatomy of ventricular septal defects with univentricular atrioventricular connection.
Hearts that do not possess one-to-one connections at the segmental junctions almost always produce a univentricular atrioventricular connection. One ventricle is usually large and dominant and the other small, lacking one or two of its components. The ventricular septal deficiency forms part of the circulatory pathway. We take the stance that only hearts that possess a truly solitary ventricular chamber are univentricular. They cannot have a ventricular septal defect, and so are excluded from this study. This review, therefore, is concerned with the morphology of septal defects in hearts in which both atrioventricular junctions are connected exclusively to a dominant left or a dominant right ventricle, and those lacking one atrioventricular connection, where the remaining valve is connected to a dominant ventricle. This morphology in the absence of one atrioventricular connection can be modified when there is overriding of the solitary atrioventricular valve. The ventricular septal defects are analyzed and categorized for the various groups, and the position of the conduction axis is described for the well-recognized entities.
Heart Atria↗
Effects of chronically elevated pulmonary arterial pressure and flow on right ventricular afterload.
The effects of pulsatile hemodynamics on right ventricle-pulmonary circulation interactions were studied in control lambs and in two lamb models of altered pulmonary hemodynamics induced at infancy: elevated pulmonary arterial pressure (PAP) was created by the infusion of monocrotaline pyrrole (MCTP), and elevated pulmonary arterial blood flow was obtained by the creation of an arteriovenous fistula (Shunt). High-fidelity PAP, midvessel Doppler blood velocity (PAV), and cardiac output (CO) were measured in open-chest, anesthetized lambs. PAV waveforms were normalized to match the measured CO. Measured pressure and flow signals were separated in the time domain into forward and backward components. Pulmonary input impedance and indexes quantifying the timing of the reflected wave pulse (beginning of reflected pulse, duration of reflected pulse in systole, and duration of reflected wave in diastole) were calculated for each group. Results indicate that in control animals the reflected wave returned late in systole and extended through much of diastole, thereby increasing diastolic pressure like a counterpulsation balloon. No significant differences in the timing indexes were found between Shunt and control animals. In the MCTP group, the reflected wave returned significantly earlier than normal with the peak reflected pulse occurring before valve closure. The resulting augmentation of systolic pressure and, therefore, large pulse pressure is consistent with pressure waveforms observed in clinical pulmonary hypertension. We conclude that early wave reflection exerts a detrimental effect in pulmonary hypertension by unfavorably loading the still-ejecting right ventricle.
Animals↗
Cadaver lung donors: effect of preharvest ventilation on graft function.
The pulmonary donor pool would increase substantially if lungs could be safely transplanted after cessation of circulation. To determine whether ventilation of cadaver lungs could improve graft function, canine donors were sacrificed and then ventilated with 100% oxygen (n = 6) or 100% nitrogen (n = 6); 6 served as nonventilated controls. Four hours after death, the lungs were flushed with modified Euro-Collins solution and harvested. Controls were ventilated with 100% oxygen only during flush and harvest. Recipients were rendered dependent on the transplanted lung by occlusion of the right pulmonary artery and bronchus 1 hour after transplantation. Ventilation was maintained at a constant inspired oxygen fraction of 0.4. Four controls died of pulmonary edema shortly after occlusion of the native lung. The mean arterial oxygen tensions in the oxygen-ventilated, nitrogen-ventilated, and control groups at the end of 8 hours were 81 mm Hg (n = 4), 88 mm Hg (n = 3), and 55 mm Hg (n = 2), respectively. Postmortem oxygen ventilation improved early recipient survival and gas exchange. Postmortem nitrogen ventilation improved early gas exchange and delayed recipient death compared with non-ventilated controls. The mechanics of ventilation appears to confer a functional advantage independent of a continued supply of oxygen. Transplantation of lungs harvested from cadavers after cessation of circulation might be feasible.
Animals↗
Systematic survey of opinion regarding the thoracic surgery residency.
To summarize this rather wide-ranging study, let us review the high points. The future practice of thoracic surgery will be increasingly affected by governmental factors and will have even greater technological dimensions. To do this work, we must continue to attract high-caliber individuals, and this is best accomplished by the early and continuing involvement in the educational process of strong role models from our field. These future surgeons must be motivated to do good work and should have high ethical standards as well as maturity and high intelligence. Experienced, involved faculty leading the residents through a broad program that offers graduated assumption of clinical and leadership responsibilities will facilitate the development of mature clinical judgment. Residents must be taught the clinical skills necessary to do all thoracic operations, leaving subspecialization to postresidency fellowships. The educational program should be humane in its demands and collegial in its application. It should incorporate experiences beyond the operating room, including the opportunity to read, think, and interact with local mentors and colleagues from around the country. The requirements of certification should not be so rigid as to preclude the development of different pathways to the same end. Likewise, although the accreditation process must protect the resident from exploitation, it must not be so restrictive that it does not allow for educational innovation and justifiable differences among programs. These are the thoughtful opinions of our colleagues. They deserve serious consideration.
Accreditation↗
Profile of the contemporary thoracic surgery resident.
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Academic Medical Centers↗
Curriculum change for graduate education in thoracic surgery.
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Accreditation↗
Anomalous course of the left brachiocephalic vein.
An anomalous course of the left brachiocephalic vein beneath the aortic arch was identified in 7 patients undergoing surgical repair of congenital cardiac malformations. Six of these patients had the morphologic features of tetralogy of Fallot including severe obstruction to the right ventricular outflow tract and a right aortic arch. A review of the literature reveals this to be an uncommon anomaly. When it is present, however, it is frequently associated with a ventricular septal defect, obstruction of the right ventricular outflow, and aortic arch anomalies. This anomaly can be documented by echocardiography, at cardiac catheterization, or intraoperatively. The presence of a subaortic left brachiocephalic vein may have implications for the conduct of surgical procedures, especially in the setting of tetralogy of Fallot.
Abnormalities, Multiple↗
Effect of a free radical scavenger on cadaver lung transplantation.
The pulmonary donor pool would increase substantially if lungs could be safely transplanted after cessation of circulation. To determine whether the addition of the free radical scavenger dimethylthiourea to the perfusate of cadaver lungs could improve graft function, canine donors were sacrificed, and lungs retrieved 2 hours after death. In a blinded fashion, dimethylthiourea was added to the modified Euro-Collins solution and infused into recipients (n = 9) perioperatively; a placebo was included in the perfusate of control animals (n = 9). Donor animals were ventilated with 100% oxygen only during flush and harvest. Recipients were rendered dependent upon the single left transplanted lung by occlusion of the right pulmonary artery and bronchus 1 hour after transplantation. Ventilation was maintained at a constant inspiratory oxygen fraction of 0.4. Recipients were followed up for 8 hours or until death. Three of 9 control animals survived the 8-hour observation period, whereas 6 of 9 recipients of cadaver lungs harvested with dimethylthiourea survived the observation period. Two deaths in the dimethylthiourea group occurred after 7 hours, implying that the effects of the ischemia and reperfusion injury were ameliorated by the use of this agent in this model. This study supports the notion that perfusate modification may improve the yield of cadaver lung retrieval and may allow for transplantation of lungs harvested from cadavers after cessation of circulation.
Animals↗
The surgical anatomy of ventricular septal defects associated with overriding valvar orifices.
This is the second review in a three-part series concerned with the description and categorization of ventricular septal defects. By viewing the defects from the right ventricular aspect, they can be placed into one of three classes: perimembranous, muscular, or doubly committed and juxta-arterial. According to the posteroinferior margin of the third group, these could extend to become perimembranous or muscular. In this review, the complications produced by malalignment of the septal structures associated with overriding of an arterial or atrioventricular valve are described in detail. It shows that although there are problems in defining the extent of any interventricular communication, these ventricular septal defects can be classified with the same categorization as developed for those not associated with overriding. The nosology developed is able to serve as a guide to the surgeon to the site of the specialized axis for atrioventricular conduction.
Atrioventricular Node↗
Isolated lung transplantation for end-stage lung disease: a viable therapy.
Since January 1990, we have performed 29 isolated lung transplantations in 28 patients with end-stage lung disease (12 single, 16 bilateral). Recipient diagnoses were: cystic fibrosis (11), chronic obstructive pulmonary disease (6), pulmonary fibrosis (6), eosinophilic granulomatosis (1), postinfectious lung disease (1), adult respiratory distress syndrome (1), and primary pulmonary hypertension (2). There have been four deaths, two in patients with pulmonary fibrosis and two in patients with primary pulmonary hypertension. Four patients have undergone transplantation while on ventilatory support for respiratory failure (2 with cystic fibrosis, 1 having redo lung transplantation with cystic fibrosis, and 1 with adult respiratory distress syndrome); all of these have survived. Six patients required cardiopulmonary bypass, which was associated with increased transfusion requirement. All patients 2 months after discharge have returned to an active life-style, except for 2 patients who currently await retransplantation. Preoperative pulmonary rehabilitation has resulted in significant improvement in exercise performance in all patients. Immunosuppression consists of cyclosporine, azathioprine, and antilymphoblast globulin (University of Minnesota), withholding systemic steroids in the early postoperative period. We have employed bronchial omentopexy in all but four transplants; there has been one partial bronchial dehiscence, two instances of bronchomalacia requiring internal stenting, and one airway stenosis. Cytomegalovirus disease has been seen frequently (15 cases), but has responded well to treatment with ganciclovir. Other complication shave included one drug-related prolonged postoperative ventilation, thrombosis of a left lung after bilateral lung transplantation requiring retransplantation, five episodes of unilateral phrenic nerve palsy after bilateral lung transplantation (4 resolved), and the requirement of massive transfusion (greater than 10 units) in 5 patients.(ABSTRACT TRUNCATED AT 250 WORDS)
Adolescent↗