Donald G. Mulder

Effect of thymectomy in patients with myasthenia gravis: A sixteen year experience

Abstract Thymectomy was performed in 100 patients with myasthenia gravis who were selected for operation because of poor medical control of the disease or the presence of thymic tumor. Significant improvement occurred in fifty-two of the fifty-eight females who did not have thymoma (89 per cent) and in ten of the fifteen males in the same category (66 per cent). Of the twenty-seven patients who had thymic tumor, twelve of the sixteen females were improved (75 per cent), as were five of the eleven males (45 per cent). There were two operative and ten late deaths during a follow-up period of sixteen years. It is concluded that in selected patients with myasthenia gravis, thymectomy favorably influences the course of the disease in most cases.

Thymectomy for myasthenia gravis

Abstract 1. 1. Myasthenia gravis appears to be related to an abnormality of the thymus. 2. 2. A significant number of patients with myasthenia gravis benefit from thymectomy. 3. 3. After thymectomy for myasthenia gravis, about one-third of patients are much improved, one-third somewhat improved and one-third unimproved. 4. 4. Young myasthenic women with a relatively short history of the disease, gradually losing ground, and without a tumor of the thymus benefit most from thymectomy. 5. 5. Patients with thymomas should have resection of the tumor regardless of the presence or absence of myasthenia. 6. 6. Thymectomy, with the patient under cyclopropane anesthesia, performed through a sternal-splitting approach in itself causes little risk. Deaths result after operation from pulmonary complications characteristic of myasthenia. 7. 7. The edrophonium test differentiates myasthenic crisis from cholinergic crisis, a dangerous and lethal complication of cholinergic treatment.

Intraoperative measurement of pericardial constraint: Role in ventricular diastolic mechanics

The pressure of pericardial constraint was measured in 20 patients undergoing elective cardiac surgery (10 in Group I with normal cardiac size; 10 in Group II with cardiomegaly) using a catheter with a collapsible latex end balloon. Right atrial pressure and other hemodynamic variables including right ventricular stroke work index were also measured before and after the pericardium was widely opened. The pericardium was grossly normal in all patients and only small physiologic effusions were present. In Group I mean pericardial pressure was 8 +/- 2 mm Hg as was mean right atrial pressure. In Group II mean pericardial pressure was 6 +/- 2 mm Hg versus mean right atrial pressure of 10 +/- 5 mm Hg (p less than 0.05). Excluding 2 of the 20 patients with outlying data, pericardial pressure showed linear correlation with right atrial pressure (r = 0.689). In Group I right ventricular stroke work index rose from 5.0 +/- 2.0 to 6.4 +/- 2.1 g-m/m2 (p less than 0.01) after pericardiotomy with no significant increase in mean right atrial pressure; similar findings in Group II were consistent with removal of external constraint. Thus, even in the absence of an abnormal effusion the normal pericardium exerts a significant pressure on the heart, which is often similar in magnitude to right atrial pressure. In certain notable exceptions, however, right atrial pressure far exceeds pericardial pressure. Such pericardial constraint has important implications for ventricular diastolic mechanics.

A Syndrome Featuring Defects of the Heart, Sternum, Diaphragm, and Anterior Abdominal Wall

Three patients featuring a syndrome of defects of the heart, sternum, diaphragm, and anterior abdominal wall are presented. The striking similarity of the anomalies manifested by the 3 cases posed a question whether or not a recognized syndrome previously existed. In order to determine this, a search was made to find other such cases, and an attempt was made to establish a common embryologic pathogenesis. Review of the literature as well as extensive personal communication was carried out. Embryology of the involved organs was considered in order to determine a specific phase of defective development.

Tetralogy of Fallot in the adult

Abstract The anatomic, clinical, roentgenographic, electrocardiographic and hemodynamic findings in 25 adult patients with tetralogy of Fallot not previously operated upon revealed many differences from the classic description of this lesion in children. Distinctive features in the adult were (1) very large ventricular septal defect; (2) greater frequency of combined infundibular and valvular pulmonary stenosis with decreased frequency of isolated valvular stenosis; (3) congestive heart failure in 33 percent of cyanotic and 38 percent of acyanotic patients; (4) characteristic chest pain occurring in early adult life in both cyanotic and acyanotic patients; (5) a symptomatic quiescent period during the second decade; (6) normal or increased pulmonary vascularity in 42 percent of cyanotic patients and absence of hypervascularity in 70 percent of acyanotic patients; (7) electrocardiographic evidence of right bundle branch block in 58 percent and tall peaked P waves in 66 percent of cyanotic patients, and predominant right ventricular hypertrophy in 46 percent of acyanotic patients. The life history and clinical manifestations of those patients with tetralogy of Fallot who reach adulthood without benefit of surgical palliation or total correction suggest that longevity in tetralogy of Fallot is determined predominantly by early development of collateral circulation to the lungs and the progressive narrowing of the initially mild infundibular stenosis with age. It is concluded that these dynamic factors are responsible for the altered manifestations of tetralogy of Fallot in the adult.

Scientific paperEffect of thymectomy in patients with myasthenia gravis: A sixteen year experience

Abstract Thymectomy was performed in 100 patients with myasthenia gravis who were selected for operation because of poor medical control of the disease or the presence of thymic tumor. Significant improvement occurred in fifty-two of the fifty-eight females who did not have thymoma (89 per cent) and in ten of the fifteen males in the same category (66 per cent). Of the twenty-seven patients who had thymic tumor, twelve of the sixteen females were improved (75 per cent), as were five of the eleven males (45 per cent). There were two operative and ten late deaths during a follow-up period of sixteen years. It is concluded that in selected patients with myasthenia gravis, thymectomy favorably influences the course of the disease in most cases.

Thymectomy for myasthenia gravis in children

Abstract Thymectomy was performed on 14 children under 20 years of age with myasthenia gravis during the past 12-years. Objective pre- and postoperative evaluation was accomplished by determining blub ergograph responses, oropharyngeal and general muscle strength and vital capacity. The decision for prophylactic or concomitant tracheostomy was also based on this information. Significant objective improvement following thymectomy occurred in all but one of the patients (Groups A and B). The average age of the patient at the time of thymectomy was 13.3 years and the average duration of symptoms prior to thymectomy was 2.5 years. One child underwent thymectomy at the age of 2.5 years and has experienced substantial improvement (Group B) subsequently. Two patients, each 19 years of age, had a benign thymoma. One of these patients died two years after thymectomy, the only death in the series. The severity of symptoms prior to thymectomy did not influence the clinical response obtained from operation. Postoperative respiratory complications are common and fastidious care is imperative. Thymectomy appears to provide a good opportunity for improvement in symptoms of selected children with myasthenia gravis and may be attended with a low risk of mortality.

Superior Vena Cava Syndrome Following Complete Correction (Mustard Repair) of Transposition of the Great Vessels

Abstract An unusual complication is reported of a superior vena cava syndrome secondary to a Mustard repair for transposition of the great vessels. The central portion of the pericardial baffle underwent constrictive changes presumably due to bacterial infection of the baffle. The patient was reoperated upon, and an elliptical gusset of pericardium was used to widen this constricted area. More than a year following the second operation the patient is asymptomatic.

Aneurysm of the left atrium

Abstract Congenital left atrial aneurysm is a rare anomaly that has been reported only five times previously. The usual presenting features include an abnormal chest roentgenogram, an apical systolic murmur and supraventricular tachycardia. Even with cineangiocardiography the diagnosis is uncertain, and the lesion is commonly confused with cardiac tumor. Aneurysmectomy is the preferred treatment and has been successful in all patients undergoing operation. The presence of thrombi in the aneurysm necessitates circulatory assistance during excision.

Management of huge epiphrenic esophageal diverticula.

Epiphrenic diverticula occur in association with motor disorders of the distal esophagus, including achalasia and diffuse esophageal spasm. Four patients with huge symptomatic epiphrenic diverticula are presented to emphasize the need for complete radiographic and manometric studies of the esophagus to document this motor dysfunction prior to performing combined diverticulectomy and esophagomyotomy. Each patient had achalasia with symptoms extending from 4 to 25 years. Diverticulectomy and esophagomyotomy were performed in every patient. One patient had previously undergone diverticulectomy alone, with prompt recurrence of the lesion. During a follow-up period extending from 2 to 10 years, three patients were alive and well. One patient developed recurrent dysphagia due to reflux esophagitis and stricture requiring dilatation. It is essential that esophagomyotomy be part of the initial operative procedure. In selected patients, an antireflux procedure may also be indicated.