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Biomedical subjects

J P Marbarger

Publications and source records attributed to J P Marbarger.

15 recordsLinked to original sources
PubMed1996

Treatment of refractory ventricular fibrillation by combined internal (epicardial) and external (transthoracic) defibrillation.

This report describes a modified defibrillation technique used successfully in a patient with an implanted epicardial cardioverter defibrillator who developed refractory ventricular fibrillation. During operative testing at the time of generator replacement, two episodes of intractable ventricular fibrillation were terminated by using a combined internal (epicardial)-external (transthoracic) defibrillation system that delivered a 360-J shock between the anterior epicardial patch and a large posterior skin electrode.

Defibrillators, Implantable↗
PubMed1994

Publishing the Journal of the Aerospace Medical Association: 1929-1981.

The author served as Editor-in-Chief of this Journal from 1959 through 1980, a period which included two title changes and an explosion of information about aerospace medicine and related fields. He reviews the history of the Journal from its establishment in 1929 through the periods of growth during World War II and the coming of the Space Age.

Aerospace Medicine↗
PubMed1986

Aneurysmal bone cyst of the cervicothoracic spine: computed tomographic evaluation of the value of preoperative embolization. Case report.

In this report, the management of an aneurysmal bone cyst in the cervicothoracic region of an 8-year-old girl is described. Aneurysmal bone cyst is a histologically benign lesion that is often extremely vascular. In the spine, it can cause extensive bone destruction and compress neural structures. Because this lesion may involve all parts of a vertebra, full delineation of the lesion before its excision is important in planning the surgical approach. The value of preoperative embolization to reduce tumor vascularity, allowing total excision, and the improved radiological evaluation of this lesion with computed tomographic scanning are demonstrated.

Angiography↗
PubMed1983

Ultrasonic assessment of the St. Jude prosthetic valve: M mode, two-dimensional, and Doppler echocardiography.

To determine whether the flow characteristics of aortic and mitral St. Jude Medical valves could be defined noninvasively, we analyzed Doppler transprosthetic flow velocity spectra in 23 relatively asymptomatic patients. Results were interpreted in the framework of M mode and two-dimensional echocardiographic data and were compared with Doppler transvalvular flow velocity spectra from native valves of healthy subjects. Although the morphologic characteristics of Doppler spectra were similar, peak and mean transprosthetic mitral flow velocities were higher than values obtained across native valves (1.38 +/- 0.3 m/sec and 0.73 +/- 0.1 m/sec vs 0.78 +/- 0.1 m/sec and 0.35 +/- 0.06 m/sec, respectively; p less than .001). However, calculated pressure half-times were not different (61.2 +/- 16.9 msec vs 57.2 +/- 13.2 msec; p greater than .05) and calculated transprosthetic mitral gradients were small (2.3 +/- 0.9 mm Hg). Similarly, the morphologic characteristics of aortic Doppler flow spectra in St. Jude and native valves were analogous. However, prosthetic valves exhibited higher peak and mean velocities (p less than .01) and slightly prolonged time-to-peak flow (p = .02). M mode and two-dimensional studies did not show useful quantitative measures of prosthetic function and did not demonstrate evidence of paravalvular leaks, which were detected in four cases by Doppler techniques. Thus Doppler echocardiography provides quantitative information about transprosthetic flow characteristics in patients with implanted St. Jude valves and is useful in identifying patients with prosthetic dysfunction.

Adult↗
PubMed1982

The clinical life history of explanted prosthetic heart valves.

This report analyzes 118 prosthetic heart valves obtained from 97 patients at reoperation (96) or at postmortem examination (22). The number obtained from the mitral, aortic, and tricuspid positions were 78, 32, and 8, respectively. Duration of implant ranged from one day to 12.3 years. Valves showing the least long-term wear were the Starr-Edwards metal strut-silicone bell and the Björk-Shiley. Moderate long-term durability was provided by the Beall and Starr-Edwards cloth-covered composite-seat prostheses while short-term durability was given by Hancock and Carpentier valves. Reoperation for valve-related causes was performed for 46 of 47 Beall valves, which demonstrated stenosis, hemolysis, and incompetence from component wear, 6 of 27 Björk-Shiley prostheses for valve thrombosis or thromboembolism or both, and 11 of 17 porcine prostheses because of calcification (4) or cusp perforation or rupture. Analyses of wear and fatigue of mechanical valves demonstrated that use of ultrahard materials (pyrolyte carbon, titanium, stellite 21) provided superior durability in contrast to polymeric solids or fabrics with poor abrasion and impact characteristics. Further, cloth and disc wear were evident as early as 0.5 year after implant and appeared to be complete by 4 years. Completeness of healing after 24 months was not related to the type of fabric material used or its construction. This study suggests that mechanical valves made from hard materials have long durability when properly implanted and require fastidious prophylaxis against infection and thromboembolism. The findings of early cusp perforation or rupture in the aortic position and leaflet calcification, stiffening, or disruption in the mitral position for porcine prostheses suggest that frequent and careful examinations of patients with these prostheses are required to detect early signs of stenosis or incompetence and that early reoperation is required before catastrophic valve failure necessitates emergency prosthetic valve replacement.

Aortic Valve↗
PubMed1982

Computed tomography in the preoperative evaluation of bronchogenic carcinoma.

Preoperative determination of the extent of bronchogenic carcinoma at presentation was assessed by CT using a 4th generation scanner with a 3-second scan time in 98 patients whose disease was later surgically staged. Prospective CT interpretations correctly staged 33 of 35 (94%) resectable lesions, and disease in 41 of 45 (91%) patients who had lesions that were not resectable for cure. No definite opinion was rendered on the scans of the remaining 18 patients. Retrospectively analysis using slightly modified criteria resulted in a correct prediction of resectability in 28 of 30 (93%) patients (scans showed a normal mediastinum with no lymph node larger than 1 cm in diameter), and nonresectability for cure in 34 of 34 (100%) patients (scans showed either direct extension of the primary neoplasm into the mediastinum or mediastinal lymph-node enlargement greater than 2 cm in diameter). However, scans of 34 of 98 (35%) patients showed inconclusive findings (mediastinal lymph-nodes with 1-cm to 2-cm diameters, neoplasms abutting but not definitely invading the mediastinum, pleural or pericardial thickening, or additional noncalcified nodules).

Adenocarcinoma↗
PubMed1981

Esophagogastrostomy with the EEA stapler.

Esophagogastric anastomosis was performed with the EEA stapler in 31 patients who underwent esophageal resections. Anastomoses were accomplished at all levels of the thoracic and cervical esophagus by a variety of approaches. Routine barium cine-esophagograms obtained at seven days after operation failed to demonstrate an anastomotic leak in any patient. The operative mortality rate was 3% (1 of 31 patients). Technical problems occurred during the operation in three patients; in two of these an incomplete anastomosis may have resulted from the surgeon's error. All patients were able to swallow normally at the time of discharge. Late anastomotic stricture occurred in five patients, and responded to dilatation in all but one patient who had local tumor recurrence. We conclude that the EEA stapler allows rapid and reliable esophagogastric anastomosis. Successful use of the instrument requires strict attention to technical detail and awareness of possible pitfalls.

Adult↗
PubMed1981

Laboratory and initial clinical studies of nifedipine, a calcium antagonist for improved myocardial preservation.

This report summarizes five years of laboratory investigations and the initial six-month clinical experience with a calcium antagonist, nifedipine, added to a cold hyperkalemic cardioplegic solution for enhancement of myocardial protection. Regional ischemia was created in 112 dogs and global ischemia in 98 dogs, under normothermic and two hyperthermic states. Control solutions, two clinical cardioplegic solutions, and nifedipine solutions were compared. Infusion of nifedipine during regional ischemia and reperfusion intervals resulted in a two-to-threefold reduction in injury volume and maintenance of normal left ventricular function in contrast infusion of nitroprusside. Nifedipine solutions (0.2 microgram/ml) provided superior preservation of left ventricular function in comparison to the two cardioplegic solutions after one hour of global ischemia at 37 degrees C and two hours at 18 C. In a clinical trial of nifedipine in cold potassium cardioplegia, 38 high risk patients with poor ventricular function have been treated; 22 of which were intensively studied serially with radionuclide ventriculography and pyrophosphate scans, myocardial isoenzyme determinations, 24 hour EKG recordings and intra- and postoperative hemodynamic studies. Of the 35 patients admitted to the intensive care unit (ICU), 33 have survived. Stroke work and cardiac indices return promptly to near normal levels after operation. The time-isoenzyme activity curves are low and radionuclide determined ejection fractions show no change for the study group. Death from acute postischemic cardiac failure did not occur in treated patients and the usage of intra-aortic balloon pump (IABP) has decreased threefold in comparison with 40 similar high risk patients treated concurrently with cardioplegic solution alone. It is concluded that nifedipine is a potent adjunct to cold hyperkalemic cardioplegic solution in high risk patients.

Adult↗
PubMed1980

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↗
PubMed1978

Blalock-taussig anastomosis: the preferred shunt in infants and newborns.

The Blalock-Taussig anastomosis (B-T shunt) has been regarded as an unsatisfactory procedure for infants and newborns with severe pulmonary oligemia. With use of microsurgical technique, B-T shunts were constructed in 11 infants under 6 months of age, six of whom were less than 1 month old (2 to 30 days). Weights ranged from 2.4 to 5.6 kg. Diagnoses included transposition of the great arteries (4), tetralogy of Fallot (4), pulmonary arterial atresia (2), and Taussig-Bing syndrome (1). There was no operative mortality; perioperative morbidity included paralysis of the diaphragm (2), Horner's syndrome (1), superficial wound dehiscence (1), congestive heart failure (1), and prolonged respiratory failure requiring ventilation assistance for more than 5 days (2). There has been one late death in the group at 2 months post-shunt. All surviving patients have had satisfactory palliation of cyanosis and hypoxemia. In view of the pulmonary artery scarring and kinking that follows the Waterston and Potts shunts, it is concluded that the Blalock-Taussig shunt is a reliable and preferable technique for palliation of pulmonary oligemia in infants and newborns.

Anastomosis, Surgical↗