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Biomedical subjects

T B Ferguson

Publications and source records attributed to T B Ferguson.

At least 109 records · Page 6Linked to original sources

Thymectomy for myasthenia gravis in the young adult. Long-term results.

An 8 year experience with a prospective treatment program for patients with myasthenia gravis is reviewed with particular focus on the results in patients less than 35 years of age. Twenty myasthenic young adults with an average age of 24 years and a duration of symptoms of 22 months, excluding two with the juvenile form, had thymectomy followed by short-term anticholinesterase and long-term prednisone therapy. All of the 18 patients with a short duration of symptoms are in markedly improved condition and 61% of them are in remission after a mean postoperative period of 32 months. The longest follow-up period is 7.3 years. Two patients have mild improvement. There was no correlation between thymic disease and clinical result. Complete en bloc extirpation of all thymic and adjacent tissue through a median sternotomy is advocated. The patients were treated postoperatively with prednisone, 100 mg/day, a regimen which gradually is changed to every other day medication and finally a gradual reduction of dosage. There have been no operative or late deaths and no serious complications of therapy. The effects have been long lasting, with not a single instance of significant recurrence of symptoms of myasthenia gravis 6 months after thymectomy.

Adolescent↗

Atrial myxoma with intellectual decline and cerebral growths on CT scan.

A woman with left atrial myxoma had progressive disturbance of intellectual function, headache, and prominent constitutional symptoms. The absence of stroke is noteworthy. Multiple high-density lesions with contrast enhancement were seen by CT scan, suggesting metastatic neoplasms, hematomas, or hemorrhagic infarcts. Serial study showed progressive enlargement of the lesions. The only cerebral lesion examined histologically proved to be an organizing hematoma, originating most likely from adjacent small arteries found to be plugged by embolic myxoma.

Brain Neoplasms↗

Comparison of bubble and membrane oxygenators in short and long perfusions.

Eighty patients had cardiopulmonary bypass (CPB), half having short (109 +/- 11 minutes) perfusions and half having long (188 +/- 14 min) perfusions. Twenty patients in each group were perfused with bubble oxygenators (Bentley, Harvey, or Galen) and 20 with membrane oxygenators (Modulung or Teflo). Hemodilution to a hematocrit value of 22.5% +/- 1.4% and hypothermia to 28 degrees +/- 2 degrees C were used in all patients. Complete hemograms, sequential multiple analyzer 18 tests, coagulation profiles, blood gases and pH, three immunoglobulins, and two complement fraction proteins were sampled as follows: three times before perfusion, one to ten times during perfusion, 1 hour immediately after perfusion, and 4, 24, and 48 hours postoperatively. Data in concentration terms were compared statistically and reported as mean and standard error for each subset. Additionally, rates of gain or loss were calculated in terms of quantity per liter of blood pumped per minute. During perfusion for both duration sets, use of a membrane oxygenator resulted in greater pump flows (4.55 +/- 0.15 L/min versus 3.75 +/- 0.11 L/min), lower total peripheral resistances (1,125 +/- 63 dynes.sec.cm-5 versus 1,652 +/- 115 dynes.sec.cm-5), and greater urinary outputs (9.4 +/- 1.1 ml/min versus 2.2 +/- 0.6 ml/min) than in the bubble oxygenator subsets. Comparisons of measured and calculated data in the immediate postperfusion interval showed no differences between bubble and membrane oxygenator subsets for short perfusions. In long perfusions, the membrane subset had lower plasma hemoglobin and white cell concentrations and generation rates, smaller (3 to 8 1/2 times) losses of IgG, IgM, C3 and shed blood necessitating less transfusion, and greater C4 losses. The membrane oxygenator systems used were more complex and costly and offered no advantages for short perfusion in adults. In anticipated long perfusions or where bleeding may be a problem, a membrane oxygenator appears more efficacious than bubble systems. For perfusions of less than 2 hours, membrane oxygenators had no biochemical or hematologic advantage over the bubble devices used in this study.

Blood Cell Count↗

Arterial hypoxemia following the administration of sublingual nitroglycerin.

The effect of nitroglycerin on arterial blood gases and cardiovascular hemodynamics were studied in patients with coronary artery disease. In 13 premedicated patients blood gases and cardiovascular hemodynamics were studied before and 10 minutes after sublingual nitroglycerin (0.6 mg). In eight unpremedicated patients only blood gases were determined before and 10 minutes after sublingual nitroglycerin 0.6 mg. All studies were performed before induction of anesthesia with the patients in the supine position breathing room air. In both groups, arterial PO2 decreased significantly (p less than 0.001); pH and pCO2 did not change. In the 13 patients on which hemodynamic studies were performed, the mean arterial pressure (p less than 0.001), cardiac index (p less than 0.001), central venous pressure (p less than 0.001), pulmonary artery (p less than 0.001) and pulmonary artery wedge pressure (p less than 0.001) decreased. Calculated values for systemic and pulmonary vascular resistance were not significantly altered (p greater than 0.4). This study gives conclusive evidence that nitroglycerin reduces arterial PO2 in most patients with coronary artery disease breathing room air in the supine position. The possible mechanisms and clinical implications are discussed.

Administration, Oral↗

Percutaneous transthoracic aspiration needle biopsy.

An experience based on 1,211 patients has shown aspiration needle biopsy to be a valuable technique for diagnosing bronchogenic carcinoma and other localized intrathoracic lesions that are beyond the reach of the fiberoptic bronchoscope. In 896 patients with malignant intrathoracic neoplasm, the aspirate demonstrated malignant cells in 96%. A false cytological diagnosis of carcinoma occured in 2 patients, for a true positive rate of 99%. However, the true negative rate was only 87%. In 77% of 31 immunosuppressed patients, the causative agent of a focal infectious process was diagnosed. Pneumothorax was the only notable complication, occuring in 24% of patients, with 14% requiring chest tube drainage. The procedure is relatively simple and rapid, generally causes little patient discomfort, and can be performed in virtually any hospital.

Adolescent↗

Left ventricular aneurysm resection: indications and long-term follow-up.

Forty-four patients had resection of a chronic postinfarction left ventricular aneurysm. Operative indications were heart failure, angina, and ventricular arrhythmias. Twenty-six patients (59%) had coronary grafting in addition to aneurysmectomy. The operative mortality rate was 4.5% (2/44), and late mortality (mean follow-up, 31 months) was 17.9% (7/39). Preoperatively all patients were in New York Heart Association Functional Class III or IV; 91% were Class I or II postoperatively. Coronary bypass grafting did not increase the operative mortality rate, and long-term survival was similar between those receiving coronary grafts and those not receiving grafts. Postoperative ventriculograms were evaluated in 10 patients by means of a system of internal grids. Amount of regional myocardial contraction correlated well with the patient's postoperative functional capacity. It is concluded that ventricular aneurysmectomy in combination with coronary bypass grafting is safe and effective, resulting in marked improvement in the patients' functional capacity and longevity.

Adult↗

Multiple valve replacement: changing status.

Review of our experience with multiple valve replacement over a 6-year-period revealed a recent marked reduction in operative risk. Operative mortality for 62 patients operated on before 1974 was 34%; for 44 patients operated on since 1974, mortality was only 11%. In both groups, mortality was clearly related to the preoperative cardiac functional status. Several recent technical advances including myocardial protection by topical hypothermia, shortened perfusion time, and the intraaortic balloon pump may all have contributed to the reduced operative risk.

Aortic Valve↗

Myocardial infarction due to tumor embolization following pulmonary resection.

A fatal case of massive systemic tumor embolization, with involvement of the coronary arteries, which occurred following resection of a metastatic pulmonary fibroliposarcoma, is presented. Elevation of the cardiac specific creatine kinase isoenzyme (MB-CK) documented myocardial damage due to obstruction of the coronary arteries by tumor emboli. The preoperative computed tomography scan demonstrated contiguity between the pulmonary mass, the inferior pulmonary vein and left atrium. In future cases this finding should alert the surgeon that cardiopulmonary bypass and removal of the left artial extension of the tumor under direct vision may be required to prevent embolization during pulmonary resection.

Adult↗

Pharmacological preservation of the ischemic heart.

This study was based on the concept that intracellular accumulation of calcium plays a role in mediating ischemic myocardial injury and that inhibition of entry of calcium into cells may have a salutary effect on the ischemic heart. Nifedipine, a potent vasodilator and inhibitor of transmembrane calcium flux, was infused into the aortic root of 6 dogs (5 microgram/kg/hr) during 2 hours of myocardial ischemia while on cardiopulmonary bypass. Seven control animals received normal saline at the same flow rate and temperature (20 degrees C). The results showed that none of the 7 control animals were able to maintain adequate aortic pressure or cardiac output after 30 to 60 minutes of normothermic reperfusion. All had marked left ventricular failure and were unresponsive to large doses of inotropic agents. In contrast, the 6 dogs treated with nifedipine were weaned from bypass either without difficulty or requiring small doses of calcium chloride and norepinephrine. Light microscopy demonstrated more marked ischemic damage in the control group than in the group of drug-treated dogs. We conclude that the concept of inhibition of transmembrane calcium flux offers a new and potent method for myocardial preservation during ischemia.

Animals↗

A new operation for far-advanced cystic medial necrosis of the aortic root.

Three patients with far-advanced cystic medial necrosis of the aorta, which had produced giant bulbous enlargement of the aortic root and severe aortic regurgitation, were operated on using a procedure not previously described. Measurements of the aortic valve annulus and ascending aorta were made from aortograms. A knitted polyester arterial prosthesis was sewn together to form a circle. This circular prosthesis was sewn to a 31 mm Björk-Shiley aortic valve prosthesis in the way that a tire is fitted onto a wheel. The resulting composite prosthesis, which had the same diameter as the aortic root, was used to replace the excised valve. In all cases a composite prosthesis measuring greater than 50 mm in diameter was used. In 2 of the 3 patients the ascending aorta was replaced with a tubular graft reshaped as a truncated cone. This reshaping was done by inserting multiple gussets into one end of the aortic prosthesis so that the flanged end fit precisely to the transverse aortic arch. Two patients are asymptomatic more than two years following operation. The third patient died suddenly of a ventricular arrhythmia on the twenty-third postoperative day.

Adult↗

Guilds, boards, and hobgoblins.

The American specialty board system is viewed in the historical perspective of a quest for quality assessment of surgical trainees. Beginning with the American Board for Ophthalmic Examinations in 1916, a system of 22 boards has developed which, by their training requirements and examinations, essentially dictate the length and content of all postgraduate educational programs. The time has come for the boards, as a powerful force in postgraduate education and in organized medicine, to reassess their position and to be sensitive to the responsibilities they have for the future. The events of history suggest six changes that might be profitable. (1) Recognize their purpose to be broader than the administration of certifying examinations. (2) Recognize that the certificate is now a license, and deal squarely with this issue. (3) Initiate and support needed medical reforms while the private sector can still do so. (4) Assume a leadership role in the shaping and future direction of graduate medical education. (5) Relinquish a degree of autonomy in order to strengthen the American Board of Medical Specialties. (6) Define their place in the medical scene and reorganize their board structures accordingly. The primary responsibility of the boards should be to make certain all aspects of resident training in approved programs are sound. Long-range goals should be the elimination of the certifying examination, and public recognition and approval of specialty status attainment.

Certification↗

Postoperative investigation of left ventricular aneurysm resection.

We reviewed 35 patients undergoing resection of a chronic postinfarction left ventricular aneurysm. There was 5.7% operative mortality. Of the long-term survivors, 80% are functional class I or II. Ten patients had postoperative left ventriculograms studied by means of a computerized analysis of endocardial motion using internal orthogonal and radial grids. Postoperative end-diastolic volumes were much greater than normal and large akinetic areas were present although there was good improvement in the patient's functional capacity. Grid analysis of endocardial motion correlated better with the patient's postoperative clinical status than did measurements of end-diastolic pressure and volume, ejection fraction, or visual inspection of the postoperative left ventriculogram.

Adult↗