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Biomedical subjects

F B Hoy

Publications and source records attributed to F B Hoy.

8 recordsLinked to original sources
PubMed2001

Ventricular assist device use with mechanical heart valves: an outcome series and literature review.

BACKGROUND: Management of postcardiotomy cardiogenic shock with a ventricular assist device (VAD) is a common and accepted therapeutic option. However, VAD use in patients with mechanical heart valves (MHVs) is thought to carry an increased risk of thromboembolus. We report a series of 7 patients with combined VAD-MHV and review the literature. METHODS: A retrospective review was performed on all patients who were supported with a ventricular assist device with a mechanical heart valve in place. A literature review was also performed from 1966 to 2000. RESULTS: Seven patients were identified from April 1988 to June 2000 as having VAD support with a MHV. One thromboembolic event was documented in the 7 patients (14%). Five of the 7 patients (71%) underwent VAD explantation. Overall survival rate was 3 of 7 (43%). Causes of death included heart failure, renal failure, multisystem organ failure, adult respiratory distress syndrome, and cerebral hypoxia. All patients who died had support withdrawn at the request of the family. All patients discharged are currently alive with length of survival of 3, 26, and 84 months. CONCLUSIONS: This study suggests that this population's rate of survival to discharge and risk of thromboembolus compare favorably to that of the general VAD population. We believe that anticoagulation can be managed as with any MHV patient and that flow rates can be kept slightly lower, which may encourage valve washing.

Aged↗
PubMed2001

Intracranial bleed during bridge to transplant may not preclude a successful result.

We report the case of a 29-year-old man who suffered sub-arachnoid bleeding while stabilized on a biventricular assist device as a bridge to cardiac transplantation. We adjusted his anti-coagulation therapy to control the bleeding and to concurrently minimize thrombosis while on support. He underwent 2 craniotomy operations to evacuate sub-arachnoid hematomas, and he underwent a subsequent operation to debride and close the dura. Eighteen days later, he underwent successful orthotopic heart transplant and was discharged to home 3 weeks post-transplant.

Adult↗
PubMed2000

Bridge to recovery for postcardiotomy failure: is there still a role for centrifugal pumps?

BACKGROUND: Early implantation of centrifugal devices in patients with postcardiotomy cardiogenic shock may provide a bridge to recovery and allow subsequent long-term survival. METHODS: Since January 1989, 62 patients were supported with centrifugal pumps because of failure to wean from cardiopulmonary bypass. Indications were postcardiotomy cardiogenic shock (PCCS) (n = 60), bridge to cardiac retransplantation (n = 1), and right ventricular failure (n = 1). Patients' ages ranged from 23 to 78 years; 40 were men (65%), and 22 were women (35%). Twenty-two patients (35%) had a left ventricular assist device; 9 patients (15%) had a right ventricular assist device; and 31 patients (50%) had a biventricular assist device. Length of support ranged from 1 day to 19 days. RESULTS: Forty-two patients (68%) were weaned successfully; 27 patients survived to discharge (44%). Complications included bleeding (n = 41, 66%), renal failure (n = 28, 45%), and respiratory failure (n = 26, 42%). Currently, 23 patients survived 10 or more years (n = 1), 6 to 10 years (n = 7), 1 to 5 years (n = 10), and less than 1 year (n = 5). CONCLUSIONS: Centrifugal pumps are available, easy to use, and relatively inexpensive. Our experience justifies their continued use as a bridge to recovery for patients with postcardiotomy cardiogenic shock, despite the availability and increasing use of more expensive devices.

Adult↗
PubMed1989

Prolonged ventricular support using a centrifugal pump.

The Biomedicus centrifugal pump was required to provide prolonged ventricular support to 13 patients with hemodynamic instability: 11 after cardiovascular surgical procedures, 1 after myocardial infarction and 1 after failure of a heart transplant. The duration of support ranged from 3.5 hours to 9 days (mean 72 hours). Complications included bleeding in six patients, renal insufficiency in three and central nervous system deficit in three. Six patients (46%) were successfully weaned from the pump. The patient with graft failure had hyperacute rejection of a second heart. Five patients were discharged from the hospital. There was one death 8 months postoperatively. Prolonged ventricular support with the centrifugal pump may allow recovery of potentially reversible ventricular dysfunction in selected patients after cardiac surgical procedures.

Adolescent↗
PubMed1989

Concomitant vascular procedures in conjunction with myocardial revascularization: all or none? A report of a case.

Patients with coronary artery atherosclerosis usually have concomitant peripheral vascular lesions. The authors describe the case of a 65-year-old woman who had multiple symptomatic lesions: severe stenosis of the left main coronary artery and the carotid arteries, a large abdominal aortic aneurysm and bilateral renal artery occlusion. To manage these and to avoid myocardial infarction and cerebrovascular accident at operation, concomitant procedures were performed as follows: coronary artery bypass grafting, aneurysm resection, carotid endarterectomy and revascularization of the larger kidney. Although the patient's hospital stay was prolonged, there was no major morbidity and her recovery was good. She returned to a normal life-style, requiring only hemodialysis on an outpatient basis.

Aged↗
PubMed1983

Improved myocardial protection during a prolonged cross-clamp period.

Severe coronary stenoses limit delivery of cardioplegic solution to ischemic regions in patients undergoing bypass operations. A prospective randomized trial was undertaken to determine whether the construction of proximal as well as distal anastomoses during a prolonged cross-clamp period would provide more uniform cardiac cooling and better myocardial protection. Ninety-one consecutive patients undergoing elective coronary bypass operations were randomized into two groups. The long cross-clamp technique was used in 46 patients (Group 1), and a proximal anastomosis was constructed after each distal anastomosis. The short cross-clamp technique was employed in 45 patients (Group 2), and distal anastomoses were constructed during aortic occlusion. Cardiopulmonary bypass time was identical, but the cross-clamp period was longer in Group 1 (59 +/- 15 minutes versus 46 +/- 17 minutes in Group 2; p less than 0.001). The mean temperature in the most ischemic region was colder with the long cross-clamp technique (12.5 +/- 3.1 degrees C in Group 1 versus 14.8 +/- 3.2 degrees C in Group 2; p less than 0.01). The total amount of the myocardial isoenzyme of serum creatine kinase released was greater in Group 2 than in Group 1 (332 +/- 34 IU/L per hour in Group 1 versus 469 +/- 45 IU/L per hour in Group 2). Thirty-six patients had coronary sinus catheters inserted (18 patients in each group). Myocardial lactate extraction returned to normal sooner in the patients who had a long cross-clamp period; time to a normal lactate extraction was 0.8 +/- 0.8 hours in Group 1 versus 2.2 +/- 2.1 hours in Group 2 (p less than 0.001). Volume loading and atrial pacing 2 to 4 hours postoperatively produced a similar hemodynamic response in the two groups, but myocardial lactate extraction increased in Group 1 and decreased in Group 2 (p less than 0.05). The construction of proximal as well as distal anastomoses during a prolonged cross-clamp period produced more uniform cooling and improved myocardial protection.

Constriction↗
PubMed1983

Comparison of alternative cardioplegic techniques.

Cold potassium cardioplegia provides adequate protection for coronary bypass operations, but severe coronary stenoses limit cardioplegic delivery to ischemic regions. The traditional technique delivers cardioplegic solution into the aortic root during the performance of distal anastomoses. The proposed alternative technique constructs proximal as well as distal anastomoses during a prolonged cross-clamp period, but permits more uniform cooling. The two techniques were compared in a prospective concurrent trial of 45 patients undergoing elective coronary bypass grafting. The traditional technique was employed in 26 patients (Group A) and the alternative technique in 19 patients (Group B). In both groups, 700 to 1,000 ml of a crystalloid cardioplegic solution was infused into the aortic root after application of the aortic cross-clamp. In Group A (traditional technique), 500 ml was infused into the aortic root after each distal anastomosis. In Group B (alternative technique), cardioplegic solution was administered through the vein graft after each distal anastomosis, and a proximal anastomosis was constructed after distal anastomoses to the most ischemic regions to permit continued cardioplegic delivery to these regions. The cross-clamp period was shorter in Group A than in Group B (44 +/- 15 versus 60 +/- 18 minutes, p less than 0.01), but the mean temperature in the most ischemic region was warmer (Group A, 19 degrees +/- 3 degrees C; Group B, 15 degrees +/- 3 degrees C, p less than 0.05). The postoperative CK-MB was higher in Group A (Group A, 47 +/- 36; Group B, 21 +/- 9 IU/L, p less than 0.01). Cardiac lactate production persisted longer in Group A (Group A, 4 +/- 1; Group B, 1 +/- 1 hours postoperatively, p less than 0.05). Volume loading 4 hours postoperatively produced a similar increase in left atrial pressure and cardiac index in both groups. In response to volume loading, Group A patients produced lactate, but Group B patients extracted lactate (change in cardiac lactate extraction: Group A, -1.7 +/- 2.3; Group B, +2.5 +/- 5.1 mg/dl, p less than 0.05). The construction of proximal as well as distal anastomoses during a prolonged cross-clamp period permits more uniform cooling and immediate reperfusion. This alternative technique resulted in less injury (CK-MB release) and more rapid recovery of myocardial metabolism.

Aged↗