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Biomedical subjects

J C Callaghan

Publications and source records attributed to J C Callaghan.

At least 19 recordsLinked to original sources
PubMed1993

Long term clinical outcomes following isolated mitral valve replacement.

OBJECTIVE: This study reviews the short and long term outcomes of patients who underwent isolated mitral valve replacement at the University of Alberta Hospitals during the past decade. DESIGN: Data were obtained retrospectively by review of patients' hospital charts, cardiologists' follow-up charts, contact with patients' physicians, and direct telephone or mail contact with patients and/or their surviving relatives. RESULTS: The clinical outcomes of 198 consecutive patients (124 women and 74 men) who underwent isolated mitral valve replacement from January 1981 to December 1990 at the University of Alberta Hospital were reviewed. Overall early operative mortality was 11%. Deaths were mainly related to pump failure and previous mitral valve replacement. Late mortality was 17%. Follow-up data were available except in five patients. Average follow-up was 6.3 years. Overall cumulative survival was 72.9 +/- 3.4% at five years and 63.1 +/- 4.8% at 10 years. The cumulative freedom from complications was 64.3 +/- 3.9% and 36.4 +/- 4.9% at five and 10 years, respectively. Long term survival rates obtained after isolated mitral valve replacement are higher than those reported in series of medically treated patients with mitral valve disease. CONCLUSIONS: Mitral valve replacement can prolong survival as well as improve symptoms in patients with symptomatic mitral valve disease.

Female↗
PubMed1990

Antimicrobial prophylaxis for open heart operations.

Between 1986 and 1988, 450 adults undergoing coronary artery bypass, cardiac valve replacement, or both were enrolled into a prospective, randomized, comparative trial of cephalothin versus cefamandole as perioperative prophylaxis. They were assessed during their hospitalization and at 6 weeks and 6 months after discharge for postoperative infectious complications. Eleven patients had major postoperative infections including 5 with sternal wound infections (three bacteremic), 6 with bacteremia, 1 with prosthetic valve endocarditis, and 3 with severe venous donor graft site infections. Eight major infections occurred in patients receiving cephalothin prophylaxis and three in patients receiving cefamandole, with all five sternal wound infections occurring in the cephalothin group. Postoperative pathogens responsible for the major infections included gram-negative aerobes in 5 patients, Staphylococcus aureus in 4, and Staphylococcus epidermidis in 2. Preoperative colonizing staphylococcal isolates were not predictive of postoperative staphylococcal pathogens. Although there was no statistically significant difference in rate of major postoperative infectious complications using either cephalothin or cefamandole prophylaxis, there was a trend in favor of cefamandole. Gram-negative aerobes are becoming increasingly important pathogens in this setting.

Aged↗
PubMed1989

Transiliac bypass for infected femoral end of an aortofemoral graft.

Infection of an aortofemoral fabric graft is among the most serious complications of vascular surgery and necessitates removal of the graft. The authors chose a transosseal (iliac bone) approach to permit a new graft to be carried down to the periphery without the risk of contamination or pressure on it from the patient's position. They performed this procedure in a 71-year-old man. He underwent a transiliac bypass before the infected limb of an aortobifemoral graft was removed. He was well 11 months after the operation and the graft was functioning well with no evidence of infection.

Aged↗
PubMed1987

Six year clinical study of use of the Omniscience valve prosthesis in 219 patients.

A 6 year experience of cardiac valve replacement with the Omniscience prosthesis is described. A total of 253 valves were inserted in 219 patients. The survivors were followed up for a total of 536 patient-years and for a mean of 2.8 years. The follow-up was 97.6% complete. Analyses were performed in accordance with recommended criteria regarding definitions of complications and grading thromboembolic events for severity and analysis of anticoagulant status. Results are described both in terms of actuarial and linearized rates. For the patients at risk, actuarial survival at the end of 5 years was 87.9 +/- 3.1% overall, 90.4 +/- 3.0% for single valve (aortic 88 +/- 5%, mitral 93.3 +/- 4%) replacement and 71 +/- 11% for multiple valve replacement. The actuarial rates of freedom from complications were as follows: endocarditis 95.7 +/- 1.8% (aortic 94 +/- 3.5%, mitral 100%), periprosthetic leak 98 +/- 1% (aortic 96.2 +/- 2.6%, mitral 100%), thromboembolism 95.2 +/- 2.3% (aortic 90.9 +/- 4.6%, mitral 96.7 +/- 3.3%), valve thrombosis 98.7 +/- 0.9% (aortic 100%, mitral 100%), anticoagulant-induced bleeding 90.3 +/- 2.6% and all valve-related complications 79.4 +/- 3.6% (aortic 78.8 +/- 3.6%, mitral 85.9 +/- 4.5%). The functional improvement in patients was very satisfactory and the risk of reoperation was 1.1% per patient-year. Over a 6 year time frame, the Omniscience valve has given excellent clinical performance.

Actuarial Analysis↗
PubMed1983

Coronary artery bypass in patients under 40 years of age.

Coronary artery bypass surgery was performed in 92 patients, ranging in age from 20 to 40 years. The male-to-female ratio was 5:1. The operative mortality was 3.3%. Sixty-two patients were followed up for a mean of 3.5 years. Complete relief of angina was reported by 79% of patients and an additional 10% experienced some improvement. The survival rate at 3.5 years was 97%. The results favour myocardial revascularization in young adults.

Adult↗
PubMed1982

Infective endocarditis: surgical treatment of 41 patients.

Forty-one patients with infective endocarditis were treated surgically at the University of Alberta Hospital, Edmonton, between 1961 and 1980. Their ages ranged from 10 to 67 years and the male to female ratio was 4:1. A wide variety of organisms were cultured but gram-positive organisms predominated. Bicuspid aortic valves, normal valves and valves affected by rheumatic heart disease, were the most common sites of infection. The aortic valve was most frequently involved. The onset of left ventricular failure was the major indication for surgery. The overall mortality at 30 days was 19.5%. The mortality after 30 days was 9.8%. Eleven of 12 patients who died had left ventricular failure preoperatively. The mortality in patients who had valve replacement during the first 4 weeks of infection did not differ from those who had valve replacement after 4 weeks of infection. Hemodynamic studies following operation in six patients showed that pulmonary arterial and wedge pressures had returned to normal levels. Nineteen of 26 patients who were followed up were asymptomatic. One had a malfunctioning prosthesis, one chronic heart failure and one had reoperation for paravalvular leak. Four patients diet during the follow-up period. The authors conclude that all patients with infective endocarditis who suffer left ventricular failure should have prompt valve replacement regardless of the duration of antibiotic therapy.

Adolescent↗
PubMed1981

Carcinoid tumor of the thymus associated with recurrent pericarditis.

A 49-year-old man with carcinoid tumor of the thymus presented with the clinical picture of acute pericarditis. Recurrent bouts persisted after removal of the tumor without other evidence to indicate tumor recurrence. There were no associated manifestations of an endocrine disorder.

Carcinoid Tumor↗
PubMed1981

Pulmonary resection in cystic fibrosis: a case report.

There is limited experience world wide in the management of patients with cystic fibrosis who undergo thoracotomy. Because of their shortened life-span and the diffuse nature of pulmonary involvement, resection is seldom performed for uncontrolled pulmonary infections. An 8-year-old boy with cystic fibrosis and a chronic infection of the right lung with abscess formation underwent pulmonary resection after 1 week of antibiotic therapy with tobramycin, ticarcillin and cloxacillin, and physiotherapy. Postoperatively, he was kept in the intensive care unit for 48 hours. Physiotherapy was begun immediately after operation and continued every 2 hours for the first day. The preoperative antibiotic therapy was continued. The postoperative course was smooth and the boy did well for 1 year. Over the next 6 months his condition deteriorated and he died 18 months after operation. Pulmonary resection should not be used in patients whose pulmonary infections can be controlled medically but may be of value for those with uncontrollable localized infections.

Anti-Bacterial Agents↗
PubMed1981

Intramyocardial arteriovenous shunting of blood with nonpulsatile perfusion.

Coronary blood drains through three types of channels: the subepicardial veins, the thebesian veins, and the arteriosinusoidal vessels. In this study the changes in the blood draining through the subepicardial and thebesian veins were measured in relation to time, up to 180 minutes. Analysis of the data yielded useful information about the relatively inaccessible microcirculation in the working heart. The first group of eight dogs was subjected to pulsatile perfusion and the second to nonpulsatile perfusion. The arteriovenous oxygen difference decreased at an identical rate of 0.01 ml of oxygen per minute per 100 ml of blood in both groups. Spontaneous increase in drainage (milliliters of blood per 100 gm of myocardium per minute) occurred as follows: Subepicardial venous drainage increased at a rate of 0.34 +/- 0.03 (mean +/- SE) with pulsatile perfusion and at a rate of 0.23 +/- 0.03 with nonpulsatile perfusion; the values were significantly different (p < 0.025). Corresponding values for thebesian venous drainage were 0.08 +/- 0.01 with pulsatile perfusion and 0.06 +/- 0.01 with nonpulsatile perfusion (p < 0.05). As a result, there was a linear increase in total myocardial oxygen utilization (MVO2) with pulsatile perfusion and a decrease with nonpulsatile perfusion. The increase in drainage with nonpulsatile perfusion, therefore, may have been due predominantly to abnormal shunt activity. The difference in drainage increase may then represent nutritive flow, the absence of which led to a fall in MVO2 with nonpulsatile perfusion. There was also some evidence that the "thebesian system" may play a compensatory role during shunting. Abnormal shunting of blood may be partly responsible for the perfusion-related myocardial damage reported in the literature.

Animals↗
PubMed1980

Extended aortic bypass.

At the University of Alberta Hospital, six patients recently underwent placement of Dacron bypass grafts from the ascending aorta to the infrarenal abdominal aorta or femoral arteries for a variety of vascular problems. The operations were performed in patients with (1) multiple aortic coarctations, (2) congenital aortic arch interruption and congenital mitral stenosis, (3) recoarctation of the thoracic aorta after previous coaractation repair (two patients), (4) aortoiliac occlusive disease in a patient with multiple previous abdominal operations including an abdominal-perineal resection and left lower quadrant colostomy, and (5) idiopathic retroperitoneal fibrosis and multiple previous operations on the abdominal aorta. Surgical access was through midline sternotomy and laparotomy incisions, and groin incisions were used as required. Careful attention was paid to placing as much graft as possible in an extraperitoneal position. All patients survived the operation and had essentially uneventful postoperative courses with good results. This technique has previously been described. However, attention is drawn to it once again as an excellent means of bypassing the thoracic and abdominal aorta in selected patients with complex vascular problems.

Adult↗
PubMed1980

Perfusion in cardioplegia: an experimental study.

A new myocardial support system has been developed and a study of this system is reported. Cardioplegia was induced by continuous infusion of potent "cardioplegic" agents (potassium chloride and potassium chloride with propranolol) at the aortic root in 12 dogs subjected to cardiopulmonary bypass with total body hypothermia (20 degrees C). A low-flow normal-pressure perfusion was maintained with the aid of a norepinephrine drip. During the period of hypothermia the blood pH was maintained at 7.6 and serum magnesium concentration was increased to an average of 2.1 mmol/l by parenteral infusion of magnesium sulfate. At no time was ischemia induced and the aorta was not cross-clamped. The functional recovery to normal and preservation of the ultrastructure of the subendocardium after 4 hours of perfusion in cardioplegia were remarkable. The control hearts from hypothermic dogs that were allowed to fibrillate spontaneously showed severe damage.

Animals↗
PubMed1978

Hypothermic coronary perfusion for myocardial protection during aortocoronary bypass.

Numerous methods have been used in an attempt to prevent myocardial injury that results from the interruption of aortic flow during cardiac operations. The authors describe a relatively simple means of inducing cardioplegia during coronary bypass surgery by coronary perfusion with cold lactated Ringer's solution through the aortic root. When the results following the employment of hypothermic coronary perfusion for intraoperative cardioplegia were compared with those obtained without its use, the procedure was found to confer a degree of intraoperative myocardial protection and appeared to lead to a decrease in intraoperative myocardial infarction, subendocardial ischemia and intraoperative mortality.

Coronary Artery Bypass↗
PubMed1978

Myocardial protection during aortic valve replacement: normothermia versus hypothermia.

The operative results in 32 patients who underwent aortic valve replacement with aortic occlusion and normothermic myocardium (group 1) were compared with 54 similar patients in whom the myocardium was protected by hypothermic coronary perfusion through the aortic root (group 2). The operative mortality and the incidence of heart failure, subendocardial ischemia and myocardial infarction were the same in the two groups. The maximal concentrations of cardiac enzymes after operation in group 2 patients were significantly lower than those in group 1. The postoperative cardiac performance was significantly different in that only 5.6% of group 2 patients required inotropic agents after operation compared with 25% of group 1 patients. The patients in group 2 were easier to defibrillate after cardiopulmonary bypass.

Adult↗
PubMed1978

Survival after late disc dislodgement of a mitral Wada-Cutter prosthesis.

A 33-year-old woman, 6 years after placement of a Wada-Cutter prosthesis, suffered from free mitral regurgitation secondary to the dislodgement of the disc occulder into the left atrium. She was operated on approximately 14 hours after the onset of symptoms and survived; this patient is the third reported survivor following dislodgement of a Wada disc.

Adult↗
PubMed1977

Hypothermic coronary perfusion for intraoperative cardioplegia.

Hypothermic asanguineous perfusion has been used to arrest 170 hearts at the beginning of 1/2 to 2 hours of intraoperative coronary ischemia. This method of producing cardioplegia has facilitated valve replacement and coronary artery bypass operations. Inadequate myocardial protection has not been experienced since we began using this method of arresting the heart for cardiac operations.

Adult↗