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Biomedical subjects

D J Keenan

Publications and source records attributed to D J Keenan.

At least 19 recordsLinked to original sources
PubMed2001

Left cervical aortic arch associated with pseudocoarctation and aortic and mitral regurgitation: one-stage surgical repair.

Cervical aortic arch is rare with a prevalence of less than 1/10000 live births (Pediatr Cardiol 10 (1989) 205); but may occur with other cardiovascular congenital abnormalities. We report pseudocoarctation of a left-sided cervical aortic arch with an aberrant right subclavian artery and aortic and mitral regurgitation, corrected by an anterior mediastinal shunt from ascending to descending aorta and aortic and mitral valve replacements, as a one-stage procedure.

Adult↗
PubMed1999

Hypoglycaemia associated with a solitary fibrous tumour of the pleura.

We report the interesting case of an elderly woman who presented with hypoglycaemic episodes and weight loss. She was found to have a solitary fibrous tumour weighing more than 1.7 kg arising from the diaphragmatic pleura, which had been producing insulin-like growth factor II. After surgical removal of this well-encapsulated, pedunculated tumour her hypoglycaemia resolved and she returned to normal both clinically and biochemically.

Aged↗
PubMed1999

Overdose of tetracycline for pleurodesis leading to chemical burns of the pleura.

Chemical pleurodesis using tetracycline is an accepted and commonly employed treatment of pneumothorax and pleural effusions. We describe a case of chemical burn of the pleura in a ventilated 41-year-old who came to thoracotomy after 3 days of continuous intrapleural infusion of tetracycline at another hospital. To our knowledge this has not been previously reported although other adverse effects of this procedure are documented. We suggest that damage to the pleura and underlying lung may occur if excessive amounts of tetracycline are used in attempted pleurodesis.

Adult↗
PubMed1999

Good outcomes from cardiac surgery in the over 70s.

OBJECTIVE: To determine the early mortality and major morbidity associated with cardiac surgery in the elderly. DESIGN: Retrospective case record review study of 575 patients >/= 70 years old who underwent cardiac surgery at the Manchester Heart Centre between January 1990 and December 1996. SETTING: Regional cardiothoracic centre. SUBJECTS: Patients >/= 70 years old who underwent cardiac surgery. MAIN OUTCOME MEASURES: Comparison of 30 day mortality and incidence of major morbidity between patients >/= 70 years old and patients < 70 years old. RESULTS: Of 4395 cardiac surgical operations, 575 operations (13.1%) were in patients aged >/= 70 years (mean (SD) 73.1 (3.2) years). The proportion of elderly patients rose progressively from 7.9% in 1990 to 16.5% in 1996. 334 patients (58.1%) had coronary artery bypass grafting alone, 91 patients (15.8%) had valve surgery alone, and 129 patients (22.4%) had combined valve surgery and bypass grafting. For isolated coronary artery bypass grafting, 30 day mortality in patients >/= 70 years was 3.9% compared with 1.3% in patients < 70 years (p < 0.001). 30 day mortality for isolated valve surgery in patients >/= 70 years was 7.7%. Isolated aortic valve replacement was the most common valvar procedure in patients >/= 70 years and carried the lowest mortality (4.3%). Additional coronary artery bypass grafting increased the mortality rate in patients >/= 70 years to 9.3% for all valve surgery and to 8.0% for aortic valve replacement. Major morbidity in patients >/= 70 years was low for all procedure types (stroke 1.9%, acute renal failure requiring dialysis 1.6%, perioperative myocardial infarction 0.5%). CONCLUSIONS: Early mortality and major morbidity is low for cardiac surgery in elderly patients. Concerns over the risk of cardiac surgery in the elderly should not prevent referral, and elderly patients usually do well. However, unconscious rationing of health care may affect referral patterns, and studies that assess the cost effectiveness of cardiac surgery versus conservative management in such patients are lacking.

Age Factors↗
PubMed1997

The effect of cardiopulmonary bypass on circulating megakaryocytes.

Megakaryocytes (Mks) are found in the lungs and the blood stream as well as in the bone marrow. We modified a whole blood filtration method for Mks by immunostaining for CD61 using biotin streptavidin, and used this technique to study Mks and their morphology in the central venous and arterial circulations before, during and after cardiopulmonary bypass (CPB) in haematologically normal patients undergoing routine cardiac surgery. Blood samples were taken immediately after the insertion of central venous (V) and arterial (A) catheters and after thoracotomy, immediately before bypass. Further samples were taken after 60-90 min on-CPB and 180-240 min post-bypass. In comparison with the steady state before bypass, circulating Mk levels in blood on bypass increased dramatically, from (V) 10.93 +/- 3.94/ml (mean +/- SD) to 36.48 +/- 11.52/ml and from (A) 8.37 +/- 4.39/ml to 38.65 +/- 20.68/ml. This effect was still present, to a lesser extent, 180-240 min post-bypass. Circulating levels of Mks were consistently lower in the arterial circulation than in the venous circulation off bypass, but levels in the two circulations were comparable during CPB, confirming previous suggestions that the lungs are net removers of Mks from the circulation. Type 4 Mks, the largest and most normal morphologically, were rarely seen in arterial blood, but increased significantly during CPB, indicating that the lungs selectively remove large Mks. The lungs appear to play an active role in the regulation of Mk levels. This is lost during CPB and despite the extracorporeal 40 microm arterial line filter, large Mks enter the systemic circulation. More effective extracorporeal filtration of large Mks might reduce the neurological impairment seen in some patients who have undergone CPB.

Adult↗
PubMed1995

Comparison of propafenone to atenolol for the prophylaxis of postcardiotomy supraventricular tachyarrhythmias: a prospective trial.

To compare the efficacy of propafenone to atenolol in the prevention of supraventricular tachyarrhythmias (SVT) following cardiac surgery, 207 consecutive patients were randomly allocated to receive either propafenone 300 mg twice daily (105 patients) or atenolol 50 mg once daily (102 patients) orally for 7 days after operation. Double blinding was achieved using placebos. The end point was the development of a SVT which was symptomatic, recurrent, or lasting over 2 minutes, or the occurrence of adverse effects possibly attributable to the drugs. The groups were well matched for age, sex, bypass- and cross-clamp times, and other data. Thirteen patients in the propafenone group and 11 in the atenolol group developed SVT during the first week after operation. (P = 0.89, non significant, chi-squared with Yates' correction). In our study propafenone and atenolol were of approximately equal efficacy in preventing post cardiotomy SVT. Propafenone may have an advantage in being less negatively inotropic than atenolol; it could therefore be used in patients with poor left ventricular function or marginal haemodynamics when a beta blocker is contraindicated.

Adult↗
PubMed1995

Determinants of early and late mortality in patients with end-stage renal disease undergoing cardiac surgery.

To determine factors influencing early and late mortality associated with cardiovascular surgery in end-stage renal disease, 48 consecutive patients (mean age 56.3 years) were reviewed: 30 underwent coronary and 18 valvular surgery. There were eight early deaths, three in the former and five in the latter group. Factors significantly related to early mortality in univariate testing included infective valvular disease, emergency vs elective surgery (both p = 0.02) poor left ventricular function and prolonged clamping and bypass times (all p = 0.001). When these factors were included in a stepwise logistic regression analysis, infective valvular disease (p = 0.02), poor left ventricular function (p = 0.01) and long cross-clamping (p = 0.01) were independently associated with early mortality. There were six late deaths. Survival for the whole cohort at 1, 5 and 7 years was 95%, 60.4% and 42.6%, respectively. Related to late mortality at univariate testing were age (p = 0.03), smoking (p = 0.04), diabetes (p = 0.03) and poor left ventricular function (p = 0.02), and stepwise logistic regression analysis showed independent association with age, diabetes and impaired left ventricular function. Mortality associated with cardiac surgery in patients with end-stage nephropathy can be reduced by better patient selection, early operation in patients with infective endocarditis, and minimized cross-clamping and bypass times.

Adult↗
PubMed1994

Bicoronary-pulmonary fistulae with coexistent mitral valve prolapse: a case report and literature review of coronary-pulmonary fistula.

Bicoronary-pulmonary artery fistulae are rare congenital coronary artery fistulae. We report the case of a 57-year-old man who presented with biventricular failure and angina pectoris. At angiography the coronary arteries were normal, but bicoronary-pulmonary fistulae were noted; severe mitral regurgitation secondary to mitral valve prolapse was also present. At right heart catheterization the calculated left to right shunt was 2.1. Fistula ligation and repair of both mitral and tricuspid valves was undertaken. The literature regarding coronary-pulmonary fistula is also reviewed.

Arterio-Arterial Fistula↗
PubMed1993

Type I aortic dissection in a patient with osteogenesis imperfecta.

The previously undescribed association between aortic dissection and osteogenesis imperfecta is reported in a 39-year-old man with known osteogenesis imperfecta, who presented with a type I aortic dissection. His ascending aorta was repaired using a Dacron tube graft under hypothermic circulatory arrest but the patient died 12 h later, following re-dissection around the left coronary ostium resulting in massive myocardial infarction of the left ventricle.

Adult↗
PubMed1986

Closure of ventricular septal defect through the pulmonary artery.

A transpulmonary arterial approach to the closure of a high ventricular septal defect (VSD) has been used, between 1978 and 1982, in eight patients. The reasons were ease of access and the wish to overcome the problems associated with right ventriculotomy. The patients' ages ranged from three weeks to 15 months, their weight from 2.9 kg to 9 kg. The approach was used both when the VSD was an isolated anomaly and when there were major associated defects. It is in this latter group, four with aortic arch anomalies, two with additional double outlet right ventricle (DORV), that avoidance of ventriculotomy was most helpful. It was especially important in the two patients with DORV and a perimembranous, outlet subpulmonary VSD, where it was possible to close off the left ventricular outflow tract and pulmonary valve using a patch, without opening the right ventricle, which was subsequently to become the systemic ventricle. This technique obviates the need for ventriculotomy in the closure of some perimembranous outlet and doubly committed subarterial VSDs, and is the approach of choice for the closure of a perimembranous, outlet, subpulmonary VSD in DORV.

Double Outlet Right Ventricle↗