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Biomedical subjects

M P Holden

Publications and source records attributed to M P Holden.

At least 19 recordsLinked to original sources

Fifteen-year experience with the mitral Carpentier-Edwards PERIMOUNT pericardial bioprosthesis.

BACKGROUND: This multicenter study concerning the mitral PERIMOUNT valve previously reported clinical results at 12 years; this report updates the performance to 15 years postoperatively. METHODS: The 435 patients (mean age 60.7+/-11.6 years; 41.1% male) underwent implantation with the PERIMOUNT valve between 1984 and 1989 at seven institutions. Follow-up was complete for 96.1% of the cohort. The mean follow-up was 8.1+/-4.4 years (range 0 to 15.4 years) for a total of 3492 patient-years. RESULTS: There were 34 (7.8%) operative deaths, one (0.2%) valve related. The late mortality rate was 5.3%/patient-year (2.2%/patient-year valve related). At 14 years, the overall actuarial survival rate was 37.1%+/-3.3% (63.1%+/-4.4% valve related). Actuarial freedom from complications at 14 years was as follows: thromboembolism, 83.8%+/-3.2% (1.1%/patient-year); hemorrhage, 86.6%+/-3.2% (1.1%/patient-year); and explant due to structural valve deterioration (SVD), 68.8%+/-4.7%. Actual freedom from explant due to SVD was 83.4%+/-2.3%. Rates of structural failure decreased with increasing age at implant. CONCLUSIONS: The Carpentier-Edwards PERIMOUNT Pericardial Bioprosthesis is a reliable choice for a tissue valve in the mitral position, especially in patients more than 60 years of age.

Actuarial Analysis↗

Structural valve deterioration in mitral replacement surgery: comparison of Carpentier-Edwards supra-annular porcine and perimount pericardial bioprostheses.

BACKGROUND: Bioprostheses preserved with glutaraldehyde, both porcine and pericardial, have been available as second-generation prostheses for valve replacement surgery. The performance with regard to structural valve deterioration with the Carpentier-Edwards supra-annular (CE-SAV) porcine bioprosthesis and the Carpentier-Edwards Perimount (CE-P) pericardial bioprosthesis (Baxter Healthcare Corp, Edwards Division, Santa Ana, Calif) was evaluated to determine whether there was a difference in mitral valve replacement. METHODS: The CE-SAV bioprosthesis was implanted in 1266 overall mitral valve replacements (isolated mitral, 1066; mitral in multiple, 200) and the CE-P bioprosthesis in 429 overall mitral valve replacements (isolated mitral, 328; mitral in multiple, 101). The mean age of the CE-SAV population was 64.2 +/- 12.2 years and that of the CE-P population, 60.7 +/- 11.7 years (P =.0001). For the study, structural valve deterioration was diagnosed at reoperation for explantation. RESULTS: The freedom from structural valve deterioration was evaluated to 10 years, and the freedom rates reported are at 10 years. For the overall mitral valve replacement groups, the actuarial freedom from deterioration was significant (P =.0001): CE-P > CE-SAV for 40 years or younger, 80% versus 60%; 41 to 50 years, 91% versus 61%; 51 to 60 years, 84% versus 69%; 61 to 70 years, 95% versus 75%. The older than 70-year group was 100% versus 92% (no significant difference). The actual freedom from structural valve deterioration also demonstrated the same pattern at 10 years: 40 years or younger, CE-P 82% versus CE-SAV 68%; 41 to 50 years, 92% versus 70%; 51 to 60 years, 90% versus 80%; 61 to 70 years, 97% versus 88%; and older than 70 years, 100% versus 97%. The independent risk factors of structural valve deterioration for the overall mitral valve replacement group were age and age groups and prosthesis type (CE-SAV > CE-P). The prosthesis type either in isolated replacement or in multiple replacement was not predictive of structural valve deterioration. The pathology of structural valve deterioration was different: 70% of CE-P failures were due to calcification and 57% of CE-SAV failures were due to combined calcification and leaflet tear. CONCLUSION: The actuarial and actual freedom from structural valve deterioration, diagnosed at reoperation, is greater at 10 years for CE-P than for CE-SAV bioprostheses. The mode of failure is different, and the cause remains obscure. Long-term evaluation is recommended, because the different modes of failure may alter the clinical performance by 15 and 20 years.

Adolescent↗

Packing the chest: a useful technique for intractable bleeding after open heart operation.

Mediastinal bleeding can be a problem after cardiac surgery, either as a result of coagulation derangements or technical problems. We evaluated 100 patients, treated with temporary chest packing for intractable bleeding, of 9,383 undergoing open heart operations during a 10-year period. Preoperatively, 60 of these patients had one or more predisposing factors for bleeding. There were four predominant sites of hemorrhage: general ooze, needle holes of the aortic and atrial suture lines, inaccessible origin, and another specific place. The chest was packed in the operating room in 84 patients and in the intensive care unit in 16. Four methods of temporary chest closure were used: the skin alone, partial sternal approximation plus skin closure, full closure, and the wound open and covered by a Steri-drape dressing. The bleeding was controlled in 65 patients who had been packed once, and in 29 patients after reexploration and multiple packings, for a total of 94 patients (94%). Sternal wound infection, generalized sepsis, and sternal dehiscence was present in 24 patients, 8 of whom died. The venue for inserting or removing the packs did not affect the incidence of infections. Our experience suggests that packing of the chest after cardiac procedures for intractable bleeding allows a reasonable patient salvage rate and complication risks.

Adolescent↗

Mechanical, but not infective, pacemaker erosion may be successfully managed by re-implantation of pacemakers.

OBJECTIVE: When a pacemaker box causes erosion it is usually removed and a new pacemaker implanted at a contralateral site. In this study when there was no evidence of systemic infection an attempt was made to clean and reimplant the same pacemaker in the same site. RESULTS: Over 10 years 62 patients had pacemaker reimplantation. In 18 patients the procedure was repeated a second time. Reimplantation was successful after at least six months follow up in 38 patients (61%): in nine two attempts had been made. Mean hospital stay for all patients was 21.3 days; for patients in whom the procedure was successful it was 12.5 days and for those in whom it was unsuccessful it was 35.4 days. 31 (82%) of the 38 patients in whom reimplantation was successful had no bacterial growth from wound swabs from 17/24 (71%) patients in whom reimplantation was unsuccessful (p < 0.001). Bacteria were grown from swabs from 7/8 patients with a protruding wire compared with 9/23 patients with a protruding pacemaker (p = 0.05). Thin patients and those who were older were more likely to have successful reimplantation: neither association reached statistical significance. A clinical impression of infection was not helpful. If re-implantation had been attempted only in the patients with negative wound swabs or intact skin the success rate would have been 74% at a cost of 5010 pounds per patient compared with a cost of 6509 pounds per patient for explantation and a reimplantation of a new contralateral pacemaker. CONCLUSION: These data support the hypothesis that pacemaker erosion is caused by primary infection or by a non-infective process (probably mechanical pressure). Pacemaker erosion that is not caused by infection can be successfully managed by ipsilateral reimplantation and this approach saves money.

Adult↗

Early bioprosthesis calcification in an octogenarian.

Pericardial valves have been advocated for use in the older age group of patients as they avoid the need for anticoagulation and are less liable to calcification than they are in the young. We report here a case of early valve calcification in a Sorin pericardial valve in the aortic position.

Aged↗

Open heart operation in patients suffering from hereditary spherocytosis.

Hereditary spherocytosis is a clinically heterogeneous, genetically determined red blood cell membrane disorder resulting in hemolytic anemia. Structural or functional disorders of the cytoskeletal proteins result in the formation of spherocytes, which lack the strength, durability, and flexibility to withstand the stresses of the circulation. This problem can be accentuated by the deleterious effects of the heart-lung machine. Three patients with hereditary spherocytosis underwent open heart operation with no deaths and no serious complications resulting from the hematologic defect. Splenectomy is recommended, although not essential, before a cardiac operation, and mechanical valves should perhaps be avoided.

Aged↗

Fracture of the wire stent in a Carpentier-Edwards porcine bioprosthesis.

A 60-year-old woman underwent mitral and aortic valve replacement with Carpentier-Edwards supra-annular bioprosthesis in 1986. Six years later rapidly progressing exercise dyspnea and orthopnea made hospital admission necessary. At chest x-ray and cardiac catheter examination one of the wire struts of the mitral bioprosthesis was found completely broken causing cusp prolapse. Surgical findings at reoperation confirmed the diagnosis. No apparent cause of the stent fracture was found.

Animals↗

Peripheral and intracardiac levels of atrial natriuretic factor during cardiothoracic surgery.

Immunoreactive atrial natriuretic factor (ANF) levels were measured in blood taken from superior vena cava, right atrium, pulmonary artery, pulmonary vein, left atrium, and radial arteries in patients undergoing cardiac surgery. Significant (p less than 0.05) differences were seen between sites. Levels of atrial natriuretic factor were seen to rise from superior vena cava (27.5 pmol/L) to right atrium (54.3 pmol/L) and then fall in pulmonary artery (38.5 pmol/L). A further significant fall was seen in pulmonary vein (32.7 pmol/L) samples. There was no significant change in levels in left atrium (32.1 pmol/L) or radial artery (30 pmol/L). The fall between radial artery levels and superior vena caval levels was also significant. The rise from superior vena cava to right atrium is to be expected as this represents the major site of addition of atrial natriuretic factor to the circulation. We propose that the fall in levels from right atrium to pulmonary artery and from pulmonary artery to pulmonary vein suggests uptake and therefore possible local hormonal action on both right ventricle and pulmonary vasculature. The fall from radial artery to vena cava would be in keeping with atrial natriuretic factor's known systemic uptake and action.

Arm↗

Atrial natriuretic factor release in postoperative cardiothoracic surgical patients.

Immunoreactive atrial natriuretic factor (ANF) levels were measured preoperatively and for 5 days postoperatively in 22 patients undergoing cardiothoracic surgery. They were studied in 4 groups according to surgical procedure (mitral valve replacement, aortic valve replacement, coronary artery bypass grafting, and lung resection). The highest preoperative ANF levels were observed in the aortic valve group (mean 40.9 pmol/L) which were 2.5 (95% CI: 0.7 to 8.6) to 3.5 (95% CI: 0.9 to 13.9) times higher than the other groups. Values tended to peak on the 3rd and 4th postoperative days in all groups, although significantly elevated postoperative ANF concentrations occurred only in the coronary artery bypass group where the levels increased by a factor of 3.2 (95% CI: 1.3 to 7.5). As a separate part of the study, measurement of ANF release before, during, and after cardiopulmonary bypass in 6 patients tended to show a fall in ANF levels when on bypass, with a return to baseline levels on cessation of bypass.

Atrial Natriuretic Factor↗

Pacemaker-induced superior vena cava syndrome: report of four cases and review of the literature.

Superior vena cava syndrome due to transvenous pacing leads is a rare event. We describe four cases. One occurred among 3,100 primary pacemaker insertions performed at our institution. In the other three cases the primary insertion had been performed elsewhere. Over 30 cases have been reported previously. Local infection, which preceded the development of superior vena cava syndrome in each of our four cases, and the presence of a severed retained lead, as in three of our cases, are important predisposing factors. There is no strong evidence that multiple lead insertion, if each lead remains intact, significantly increases the risk. The pathology at the site of obstruction includes thrombosis and in some cases fibrotic narrowing. Venous angiography is useful to show the site of obstruction, the extent of collateral circulation and to assess the response to treatment. Treatment should include removal of any infected pacemaker apparatus, anticoagulation and, if symptoms are of recent onset, thrombolytic therapy. Most patients improve but in those who do not angioplasty or surgical relief of the obstruction may be helpful.

Aged↗

Candida endocarditis: report of four cases.

Four patients who developed left-sided endocarditis due to infection with Candida species are reported. Three of them had had previous prosthetic valve replacement, and the fourth one developed endocarditis on a normal valve following pancreaticoduodenectomy. The difficulties presented in diagnosis and management are discussed.

Adolescent↗

Continuous monitoring of blood glucose concentration during open-heart surgery.

Continuous monitoring of blood glucose concentration was compared with frequent intermittent sampling in 12 non-diabetic adult patients undergoing open-heart surgery with cardiopulmonary by-pass using priming fluids free of glucose. Continuous monitoring revealed several changes which were not detected on intermittent sampling. Blood glucose concentration decreased by 2 mmol litre-1 +/- 0.5 (SEM) (P less than 0.01) immediately on the institution of CPB, and increased during the succeeding minutes. Rewarming from hypothermic by-pass was associated with a 3 (+/- 0.5)-mmol litre-1 increase in blood glucose concentration (P less than 0.01). Commencement of infusions of sympathomimetic agents resulted in a similar increase.

Blood Glucose↗