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Biomedical subjects

D S Esmore

Publications and source records attributed to D S Esmore.

52 records · Page 3Linked to original sources
PubMed1991

Technique and results of cardiac transplantation using "domino-donor" hearts.

Heart-lung transplantation is now well established for treatment of patients with terminal cardiopulmonary disease. More than 50% of heart-lung transplant recipients have normal or near normal hearts, with the majority having some degree of right ventricular hypertrophy. This potential source of "prepared" cardiac allografts remained untapped until the introduction of the "domino-donor" operation, a procedure in which the heart-lung recipient serves as a cardiac donor. The implantation of these available allografts contributes to the alleviation of the short supply of donor organs for cardiac transplantation. Aspects of the surgical technique, results, and potential benefits of this procedure are presented.

Adult↗
PubMed1990

Reproducibility of radionuclide left ventricular ejection fraction in patients awaiting cardiac transplantation.

Radionuclide-derived left ventricular ejection fraction (LVEF) is used to assess LV systolic function, to follow trends in the natural history of dilated cardiomyopathy, and to prioritize patients waiting for cardiac transplantation. Reproducibility of LVEF at extremely low levels has not, however, been reported. To assess the reproducibility of radionuclide LVEF at levels below 0.30 EF U, 17 highly symptomatic patients (NYHA Class III/IV) with dilated cardiomyopathy were studied on two occasions, 72 hours apart. Sequential scans were analyzed by two independent observers. Mean LVEF was 0.18 +/- 0.06 U (scan 1) and 0.17 +/- 0.06 U (scan 2). Interoperator reproducibility (SD) was 0.03 U (R = 0.76), interscan reproducibility (SD) was 0.03 U (R = 0.62), and overall reproducibility (SD) was 0.04 U (R = 0.50). The interobserver variation of 0.03 (actually 0.027) was just over one half that seen in normal volunteers (variation 0.05, n = 29) studied previously in this department. A change of greater than or equal to 0.08 U (2SD) in either direction is highly likely to represent a real change in LV function in those with LVEF less than or equal to 0.30 units, compared with the change of at least 0.10 units required in those with normal LV function. Lower interobserver and interscan reproducibility should be taken into account when interpreting sequential scans in patients with severe LV dysfunction.

Adolescent↗
PubMed1989

Repeat myocardial revascularization surgery: an analysis of 169 cases.

One hundred and sixty-nine patients who underwent repeated myocardial revascularization surgery between 1982 and 1987 were studied. The mean interval between operations was 91.6 +/- 7.3 months. The indications for repeated surgery were graft failure in 37.2% of patients, progressive coronary atherosclerosis in 40.2% of patients and a combination of the two causes in 22.5% of patients. The mean number of grafts that were inserted was 2.74 +/- 0.61 grafts per patient at the second operation. Coronary endarterectomy as an adjunctive procedure was necessary in 17.1% of patients. The hospital mortality rate was 4.1%, with a 1.8% incidence of perioperative myocardial infarctions. Of the surviving patients, 96.3% were available for follow-up at a mean of 19 +/- 6.4 months. Of these patients, 68.5% were well and could be categorized into the New York Heart Association's functional class I. We conclude that both progression of coronary atherosclerosis in native vessels and obstruction of venous grafts cause recurrent angina and that repeated myocardial revascularization surgery is a feasible treatment option in these patients.

Adult↗
PubMed1989

Ascending aortic aneurysms associated with aortic valve regurgitation: St Vincent's Hospital's experience.

This report represents a retrospective analysis of the St Vincent's Hospital experience with combined replacement of the aortic valve and ascending aorta using a composite conduit and coronary artery reimplantation, in 44 patients, from 1 January 1981 to 30 June 1988. The mean age at operation was 48 years. Annuloaortic ectasia was the most common indication for operation in 24 patients (54%). There were three hospital deaths (7%). Forty-one patients were discharged from hospital and were followed up for a total of 1,106 patient months (mean = 26.5 months). There were three late deaths (7%). One death was due to a new dissection, one to a cerebrovascular accident and one to a drug overdose. So far, no patients have required reoperation. Of the 36 surviving patients available for follow-up, 28 are in New York Heart Association class I, seven patients are in class II and one in class III. Composite graft replacement reduces the risk of recurrent dissection and aneurysm formation and of periprosthetic leak. In the present experience, it is the method of choice in patients with degenerative lesions in the ascending aorta and aortic valve and particularly for annuloaortic ectasia. The exact surgical technique currently used has been the result of an evolution of different techniques.

Adolescent↗
PubMed1989

Open cardiac compression in the postoperative cardiac intensive care unit.

Thirty-nine patients required heroic resuscitative measures for sudden hypotension and cardiac arrest in the first 72 hours following cardiac surgery between January 1, 1984 and May 31, 1988. Emergency sternotomy with open cardiac compression was performed in twenty-four of these patients when external cardiac compression failed. These were categorised as Group A. Group B comprised the fifteen patients in whom resuscitation was entirely by means of external compression and adjuvant measures. Survival with NYHA Functional Class I and II status was noted in 75% of patients in Group A, compared with 20% in Group B (P less than 0.002). Emergency sternotomy with open cardiac compression is an effective way of resuscitating patients in the intensive care unit in the first few days following open heart surgery.

Cardiac Surgical Procedures↗
PubMed1986

Rationale for simultaneous carotid endarterectomy and aortocoronary bypass.

Seventy-eight patients were treated for coexistent carotid and coronary stenosis by simultaneous reconstructions. Five patients died (6.4%), one from a stroke contralateral to the carotid reconstruction. Four others suffered a perioperative stroke (total stroke incidence 6.4%). Three myocardial infarctions occurred (3.8%) including one fatal infarct. Analysis of the most recent 36 combined reconstructions indicates that the extramorbidity in this group increased the stroke or death rate for all carotid endarterectomies carried out in the same period by only 1%. Alternatively if these patients had been operated upon by aortocoronary grafting alone the mortality would have increased by 0.1% assuming no neurologic complications. Since these 36 patients had severe carotid stenosis and would have been refused carotid endarterectomy as an isolated procedure the results seem better than would have been achieved by staged operations.

Adult↗
PubMedDate not supplied

Circadian rhythms of heart rate and blood pressure after heart transplantation.

Blood pressure and heart rate were recorded over 24-hour periods on 39 occasions in 20 subjects 5 to 72 weeks after heart transplantation. All patients were receiving cyclosporine, azathioprine, and prednisolone. In 38 of the 39 records the mean nighttime heart rate was lower than the mean daytime rate, with a peak difference of 20.1 +/- 1.8 beats/min. Blood pressure responses were, however, of two patterns. In 15 of the 39 recordings (approximately 50% of patients) the mean nighttime systolic pressure was higher than the mean daytime systolic pressure; in the remainder the converse was observed. The pattern was generally consistent on repeated recordings from the same patient and was not related to time since transplantation, renal function, or other therapy. Echocardiographic/Doppler studies were available at the time of 31 of these recordings. No differences in left ventricular diameters, systolic function, or transmitral filling patterns were present between patients whose blood pressure was higher or lower at night. Left ventricular posterior wall thickness and the ratio between wall thickness and ventricular diameter at end diastole were greater in the group showing nighttime pressure falls. Blood pressure responses after heart transplantation show the presence of nighttime "dippers" and "nondippers." At least early after transplantation, however, nondipper status is not preferentially associated with the development of left ventricular hypertrophy. The mechanisms accounting for the different circadian blood pressure responses in heart transplant recipients are not known.

Blood Pressure↗
PubMedDate not supplied

Successful heart transplantation with cardiac allografts exposed to carbon monoxide poisoning.

The procurement of cardiac allografts from brain-dead donors who have suffered acute carbon monoxide poisoning has, in the past, been considered inadvisable. Two patients have recently undergone successful transplantation at our institution with cardiac allografts from donors who had suffered acute carbon monoxide poisoning. Carbon monoxide poisoning is not a contraindication to cardiac allograft procurement in the setting of clinical and objective evidence of satisfactory cardiac function.

Adult↗
PubMedDate not supplied

Right ventricular assist and prostacyclin infusion for allograft failure in the presence of high pulmonary vascular resistance.

The presence of high pulmonary vascular resistance (PVR) greater than 4 Wood units contributes to significant early posttransplant mortality, and remains a negative predictor of long-term survival. Current trends have been toward exclusion of the recipient with high PVR from the orthotopic procedure; elective heterotopic allograft placement is increasingly advocated. A patient with a PVR of 6 Wood units underwent orthotopic transplantation; the cardiac allograft from a 12 kg heavier donor was implanted after an ischemic time of 115 minutes. Early graft failure at 4 hours and subsequent cardiac arrest were followed by reinstitution of cardiopulmonary bypass, during which time optimal pharmacologic manipulation of the pulmonary vasculature was undertaken, including the use of high-dose prostacyclin. Refractory right heart failure indicated the requirement for right ventricular assistance (RVA) for patient survival. RVA with a Bio-Medicus pump was instituted in association with high-dose prostacyclin; an intraaortic balloon pump was inserted 12 hours later. Maintenance immunosuppression consisted of cyclosporine and azathioprine alone. RVA was maintained for 3 days; during this time the patient was totally pump dependent. Over an 18-hour period the patient was weaned and successfully withdrawn from RVA. Intraaortic balloon pump counterpulsation and the prostacyclin infusion were continued for 6 and 10 days, respectively. The clinical implications of the various interventions that resulted in the patient's survival are discussed.

Cardiac Output, Low↗
PubMedDate not supplied

Cyclosporine and azathioprine immunosuppression without maintenance steroids: a prospective randomized trial.

Since the commencement of the St. Vincent's Transplant Programme, 41 patients have undergone orthotopic heart transplantation, with low-dose cyclosporine and prednisolone as maintenance immunosuppression. An actuarial survival rate of 75% at 1 year resulted. To reduce early rejection-related death, azathioprine was chosen as an augmenting immunosuppressive agent to be administered as a prospective randomized trial. Sixty patients were randomized; 29 received low-dose cyclosporine plus azathioprine plus prednisolone (group A). Thirty-one patients received cyclosporine and azathioprine alone (group B). Both groups received a 7-day course of antithymocyte gamma globulin. One group B patient who underwent retransplantation was not analyzed. Actuarial survival for group A was 92% and group B 93%. The overall incidence of rejection for group A was 1.1 per patient and group B, overall, 2.3 episodes per patient. Group B patients who had persistent rejections were converted to group A protocol. Nine group B patients (30%) required conversion to maintenance steroids (group C). The overall incidence of infection was 1.6 episodes per patient and 1.3 episodes per patient for group A and group B, respectively. Two early deaths in group B and one in group A were unrelated to immunosuppressive protocol. One group A patient died at day 280 of multiorgan failure. There were no rejection- or infection-related deaths in the series. Hypertension occurred with equal frequency in both study groups. The cyclosporine and azathioprine protocol produces actuarial survival and morbidity rates comparable to those of a matched triple-therapy group. Thirty percent of patients in this protocol, however, will require maintenance steroids.

Actuarial Analysis↗
PubMedDate not supplied

The Bentall procedure: a surgical option in Ehlers-Danlos syndrome.

The Ehlers-Danlos syndrome (EDs) is one of the most frequently encountered inherited disorders of connective tissue. The arterial-ecchymotic type IV is notorious for large vessel involvement associated with spontaneous catastrophic bleeding. Most of these patients who require cardiovascular surgical procedures have a poor prognosis. Our experience of two patients, with aneurysmal dilatation of the ascending aorta is presented. The first patient presented with an aortic dissection extending from the ascending aorta to the common iliac arteries. The second patient presented with asymptomatic but progressive aneurysmal dilatation of the aortic root. Both patients underwent the Bentall procedure using a 25 mm St. Jude composite valved conduit. Despite increased vascular friability, both of these patients tolerated the operative procedure without complication and are doing well on early follow-up. This experience suggests that the Bentall procedure may be used to decrease the risks of dissection and rupture of the ascending aorta in patients with Ehlers-Danlos syndrome.

Adult↗
PubMedDate not supplied

Myocardial revascularisation in patients over seventy five years.

A consecutive series of 73 patients aged 75 years and above underwent coronary artery bypass graft surgery during a 6 year period. Pre-operatively unstable angina (61.6%) and congestive heart failure (10.9%) were significant presenting features. Triple vessel disease accounted for 61.6% of cases while 26% had left main coronary obstruction. The mean number of grafts per patient was 3.2 +/- 0.9. Combined procedures such as valve replacement were done in 16.2% of patients. The hospital mortality rate was 2.7% and there was not a single recordable case of peri-operative myocardial infarction. Significant complications post-operatively were atrial arrhythmias (43.8%), segmental pulmonary atelectasis (43.8%) and renal problems (15%). Of the sixty patients followed up at an average of 27.7 months, 58 were in NYHA Functional Class I. Good patient selection and careful monitoring leads to encouraging results with coronary artery bypass grafting in the elderly.

Aged↗
PubMedDate not supplied

Preliminary experience with inhaled nitric oxide for acute pulmonary hypertension after heart transplantation.

BACKGROUND: Substantial interest has developed in the physiologic and therapeutic role of nitric oxide in the last few years. In patients with pulmonary hypertension it appears to be a useful selective pulmonary vasodilator; however, many issues of both staff and patient safety remained unanswered. METHODS: This study examines further safety issues and also presents preliminary clinical experience in patients after orthotopic heart transplantation with pulmonary hypertension and right-sided ventricular failure. RESULTS: Atmospheric levels of nitric oxide and nitrogen dioxide are 100 times less than occupational health standards. When nitric oxide is used at 70 parts per million in the presence of a fraction of inspired oxygen greater than 0.60, nitrogen dioxide levels in the circuit exceed the published short-term exposure limit of the American Conference of Government Industrial Hygienist of 5 parts per million. CONCLUSION: Staff safety appears confirmed, but despite encouraging clinical results, further longer term safety and efficacy studies are indicated.

Administration, Inhalation↗
PubMedDate not supplied

Successful long-term outcome with prolonged ischemic time cardiac allografts.

BACKGROUND: The limited availability of cardiac allografts together with the increasing number of patients on the waiting list restricts treatment of this population with heart transplantation. An increase in the available donor pool has been facilitated by the use of allografts with prolonged ischemic time (> 240 minutes). METHODS: Short- and long-term outcomes were compared in 150 heart transplant recipients on the basis of allograft ischemic time (< 241 minutes, 241 to 300 minutes, and > 300 minutes). RESULTS: No difference was found in allograft functional capacity, the development of transplant-associated coronary disease, or actuarial survival in the short and long term. CONCLUSIONS: Improved population treatment with prolonged ischemic time cardiac allografts can be safely undertaken without long-term risk to heart transplant recipients.

Adolescent↗