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Biomedical subjects

M Mathison

Publications and source records attributed to M Mathison.

15 recordsLinked to original sources
PubMed2001

Off-pump bypass grafting is safe in patients with left main coronary disease.

BACKGROUND: Because of a concern about the ability to tolerate beating heart grafting, patients with left main coronary artery stenosis have been excluded from off-pump bypass. We reviewed our experience with off-pump coronary artery bypass grafting for patients with left main coronary artery disease. METHODS: Eight hundred twenty-three patients underwent bypass grafting for left main coronary artery disease from January 1998 to October 1999. One hundred patients were revascularized without the use of cardiopulmonary bypass and compared with a contemporaneous cohort of 723 patients who underwent grafting with the aid of cardiopulmonary bypass. All patients had multivessel grafting performed through a sternotomy. RESULTS: There was one death (1%) in the group undergoing off-pump grafting as compared with a 30-day mortality of 4.7% (p = 0.059) in the on-pump group. Univariate analysis established that patients revascularized without cardiopulmonary bypass were significantly less likely to require postoperative inotropic support (23% versus 62%, p < 0.001) and transfusion (35% versus 67%, p < 0.001). Logistic regression analysis revealed that cardiopulmonary bypass was an independent risk factor for mortality (odds ratio, 7.3; 95% confidence interval, 1.34 to 138.4). CONCLUSIONS: Coronary artery bypass grafting using off-pump techniques are safe and effective in left main coronary artery disease.

Adult↗
PubMed2001

The influence of female gender on the outcome of endovascular abdominal aortic aneurysm repair.

PURPOSE: Women appear to have a greater risk of death than men after open surgery for abdominal aortic aneurysm (AAA). The aim of this study is to compare outcomes after endovascular AAA repair in men and women. MATERIALS AND METHODS: From March 1994 to November 2000, 305 patients (281 men and 24 women) underwent AAA repair with use of endovascular techniques. Outcomes measured included perioperative mortality, percentage of procedures aborted or converted to open abdominal AAA repair, deployment success rate, angiographic success rate, major complication rate, and percentage of patients with endoleaks. RESULTS: Patients of both genders were comparable with respect to mean age (74.4 in men vs 75.9 in women; NS). According to the Society for Vascular Surgery/International Society of Cardiovascular Surgery risk stratification method, men and women were also comparable in age risk score (0.60 vs 0.67; NS), pulmonary risk score (0.50 vs 0.83; NS), and renal risk score (0.28 vs 0.17; NS). However, the cardiac risk score was higher in men (1.31 vs 0.80; P <.05) and maximum AAA diameter was greater in men (57.0 mm vs 52.1 mm; P <.01). Eight perioperative deaths (2.6%) occurred (2.8% of men, 0% of women; NS). Proportionately more procedures were aborted in women than men: four (16.7%) versus six (2.1%; P <.01). Conversion to open repair occurred in four men (1.4%) and no women (NS). Deployment success was achieved in 96.4% of men and 83.3% of women (P <.01). Angiographic success was achieved in 84.1% of men and 80% of women (NS). Of 46 major complications, 42 (14.9%) occurred in 281 men and four (16.7%) occurred in 24 women (NS). Sixty-seven patients had endoleaks: 60 were men (22.1%) and seven were women (35%; NS). CONCLUSIONS: There was no difference between men and women with respect to perioperative mortality and major complication rates. These findings indicate that being a woman does not adversely influence the outcome of endovascular AAA repair. However, women had a higher rate of aborted procedures. Precise preoperative evaluation may help reduce this problem in women.

Aged↗
PubMed2000

Analysis of hemodynamic changes during beating heart surgical procedures.

BACKGROUND: Coronary artery bypass grafting on the beating heart causes significant hemodynamic compromise during displacement of the heart. The precise mechanisms causing altered hemodynamics have not been clearly understood. The purpose of this study was to define the hemodynamic changes caused by displacing the heart in patients undergoing beating heart surgical procedures. METHODS: Forty-four patients (35 men, 9 women; mean age, 64.5 +/- 9.6 years) underwent off-pump coronary artery bypass grafting. The hemodynamic variables were collected before and after positioning the heart for anastomosis of the left anterior descending, circumflex, and posterior descending coronary arteries. RESULTS: There was a significant increase in right ventricular end-diastolic pressure during positioning for all vessels, and in left ventricular end-diastolic pressure during positioning for the left anterior descending and circumflex coronary arteries. Positioning for the circumflex artery showed the largest increase of left and right ventricular end-diastolic pressure, resulting in the greatest hemodynamic compromise. CONCLUSIONS: In the clinical setting of diseased human hearts, there is a biventricular contribution to altered hemodynamics. The increase of right ventricular end-diastolic pressure in all positions suggests that the major cause of hemodynamic changes is disturbed diastolic filling of the right ventricle, especially by direct ventricular compression.

Aged↗
PubMed2000

Right heart circulatory support facilities coronary artery bypass without cardiopulmonary bypass.

BACKGROUND: Revascularization of the posterior wall often causes hemodynamic instability in beating heart coronary artery bypass (CAB). Our previous clinical studies have shown that tilting the heart primarily alters right-heart hemodynamics. The purpose of this study was to evaluate right-heart support in clinical cases. METHODS: Seventeen patients underwent beating heart CAB with right-heart support. The right-heart support system (A-Med Systems, West Sacramento, CA) consisted of a coaxial cannula placed through the right atrium and the tip of the cannula positioned in main pulmonary artery. Blood was removed from the right atrium and returned to the main pulmonary artery. RESULTS: Elective beating heart CAB was accomplished successfully in 17 patients with right-heart support. Anastomoses performed were left anterior descending coronary artery (11), diagonal (3), circumflex (5), obtuse marginal artery (11), and right coronary artery (10). Right-heart support between 1 and 3 L/min improved hemodynamics especially in the circumflex position. No device-related patient incidents occurred, nor were there incidents of infection or air embolism. All 17 patients were discharged to their homes. CONCLUSIONS: The right-heart support system was safe without complications. Exposure of the posterior wall was possible in all cases without hemodynamic compromise.

Aged↗
PubMed1998

[Two cases of surgical treatment of recrudescent Stanford type A dissection after early thrombogenic closure without intimal tear].

We reported two cases of thrombosed, Stanford A type acute aortic dissection, initially without intimal tear, later operated upon because of recrudescence. They admitted to our hospital with the symptoms of aortic dissection. Early examination of computed tomography and angiography demonstrated thrombosed type A aortic dissection showing a normal aortic figure, although accompanied by pericardial effusion, that was drainaged. Under strict BP control, however, repeat CT examination revealed recrudescent dissection of ascending aorta, making dissecting aneurysms. Graft replacement of ascending aorta was performed, on the 55th and 153th day after admission, and they were discharged.

Aged↗
PubMed1996

Risk factors in heart transplantation. A statistical study of New Zealand cases.

The first heart transplantation in New Zealand was performed on December 2, 1987. This study covers all forty-five transplantations that were performed in New Zealand at Green Lane Hospital from that time through January 1994. Eleven patients from that group have died. The 30 day and 1, 2 and 4 year survival rates were found to be 91.1, 86.7, 80.0 and 75.6%, respectively. The mean waiting period of the patients for heart transplantation was 61.9 days. Only pulmonary vascular resistance was a statistically significant risk factor for early death after cardiac transplantation. Ischemic time was not a significant risk factor in this study.

Adult↗
PubMed1996

Aneurysm of a branch of the subclavian artery with multiple arteriovenous fistulae.

A rare case is reported of an 83-year-old woman with an aneurysm of a branch of the subclavian artery with multiple arteriovenous fistulae. The patient was admitted to our hospital with a pulsatile mass in the supraclavicular space and a prominent continuous murmur which radiated to the anterior chest, right forearm and right neck. She first noticed a pulsatile 2 cm mass in 1972, 1 year following a subtotal gastrectomy. At that time, she had intravenous therapy through a right neck vein. In 1993, the mass became larger, and she developed a shunt murmur. Digital subtraction angiography (DSA) demonstrated an aneurysm of the right subclavian artery and an arteriovenous fistula between the right subclavian artery and vein. The right common carotid artery and right subclavian artery arose from the aortic arch separately. The aneurysm arose from a branch of the subclavian artery which may be the costocervical trunk. The 5 x 4 cm aneurysm was resected and the arteriovenous fistula was divided. On postoperative day 5, a new murmur was ausculated. A repeat DSA detected a new fistula between the axillary artery and vein. Reoperation was performed to ligate and divide the fistula. Pathological examination revealed an atherosclerotic aneurysm.

Aged↗
PubMed1993

[A role of valvuloplasty in surgical treatment of isolated tricuspid regurgitation].

Seven surgical cases of isolated tricuspid regurgitation were reviewed. From pathological point of view, the patients were classified into three groups. Two were due to abnormalities of subvalvular system, four to annular dilatation and one to anomalous leaflet. Among four cases of annular dilatation, two were diagnosed as dilated cardiomyopathy. In one, it was very rare myopathy confined to right ventricle. Three cases, two subvalvular and one leaflet abnormalities, underwent valvuloplasty which included chordal reconstruction using Gore-Tex suture. Among annular dilatation group, three underwent valve replacement (two with mechanical valve and one with bioprosthetic valve), while fourth underwent annuloplasty. When We look at 89 surgical patients with secondary tricuspid regurgitation, thrombosed mechanical valve was seen in two cases, one of them necessitating re-valve replacement. On the other hand, late results of tricuspid annuloplasty with Carpentier-Edwards ring was excellent without re-operation. Although isolated tricuspid regurgitation has very complicated pathological features, we now think it very important to manage to repair regurgitant tricuspid valve utilizing all available techniques including redundant valve tissue resection, chordal reconstruction, and annuloplasty, thus avoiding valve replacement especially with mechanical valve.

Adolescent↗
PubMed1992

[Congenital bicuspid aortic valve: stenotic type and insufficient type].

Two-hundred and eighty-one patients underwent surgical treatment of the aortic valves during a 10-year period of 1981 to 1991, 32 of whom (11%) had bicuspid aortic valve. Bicuspid aortic valve is well known to cause calcified aortic stenosis, however, some of these cases develop pure aortic insufficiency of unknown etiology. In our studies of 32 patients with bicuspid aortic valve, 28 patients had aortic stenosis, 2 were aortic insufficiency and 2 were infective endocarditis. Pathogenesis of aortic insufficiency in patients with bicuspid aortic valves was discussed and compared with that of aortic stenosis.

Adult↗
PubMed1990

Diagnosis of cardiac allograft rejection by the detection of circulating plasma cardiac myosin light chains.

Twenty adult male Japanese monkeys of the species Macaca fuscata were randomly paired and subjected to heterotopic cardiac transplantation performed by the Ono-Lyndsey method. Without immunosuppression, graft survival ranged between 8 and 27 days, with a mean survival of 14 days. Plasma cardiac myosin light chains were measured by radioimmunoassay, which showed transient increases in myosin levels just following transplantation. Three hearts showed high values at this period and stopped beating when the myosin levels decreased (type 1). The other 7 hearts showed low myosin values after transient increases and 5 of them were rejected with a preceding reincrease in the myosin levels (type 2). Pathological study revealed myocardial necrosis, perivascular cuffing of mononuclear cells and/or neutrophils and/or plasma cells in the type 1 hearts. Measurement of the plasma myosin light chain level was therefore revealed to be of great value in the monitoring of cardiac allograft rejection.

Animals↗
PubMed1990

[Successful resection of mediastinal and abdominal recurrent tumors of esophageal leiomyosarcoma 12 years after surgery].

A 57-year-old woman admitted to our hospital in October, 1988 because of the tumor of the abdominal wall and abnormal shadows of right chest wall and right upper mediastinum. Her esophagus had been resected and reconstructed by the stomach roll because of the esophageal leiomyosarcoma in May, 1976. Clinical examinations revealed that the abdominal mass and chest shadows were the recurrence of the leiomyosarcoma. The abdominal tumor was resected on 17th October, 1988. On 14th December, 1988 right thoracotomy was performed. Chest wall tumor (40 x 30 x 20 mm) and mediastinal tumor (45 x 40 x 35 mm) were resected completely. The mediastinal tumor was adhered to the remnant esophageal muscle layer. Microscopic section of the tumor showed spindle cell sarcoma with fine calcification, and it was diagnosed as the metastatic leiomyosarcoma.

Abdominal Muscles↗
PubMed1990

[Quadricuspid aortic valve: case reports].

Two cases of quadricuspid aortic valve with aortic regurgitation are reported. Case 1, a 66-year-old woman was operated on because of aortic regurgitation, and an aortic valve replacement with a bioprosthesis was performed. When the valve was exposed during the operation, it showed four cusps, three of which were of equal size and one smaller cusp which was interposed between the right and left coronary cusp. Case 2, a 46-year-old man was diagnosed, using echocardiography and aortography before surgery, as suffering from aortic regurgitation because of a quadricuspid aortic valve. During surgery, two larger cusps and two smaller cusps and a displacement of the right coronary artery ostium, (which was placed in a lower position and close to the commissure between the right coronary and the right posterior cusps) were found. The four cusps were excised and replaced by a tilting disc prosthesis. In both cases, the postoperative recovery was uneventful. Using the 24 cases from the literature and two of our own cases, the correlation between the size or the position of the accessory cusp and the occurrence of aortic regurgitation was analyzed. The larger the accessory cusp was, the higher the incidence of aortic regurgitation occurred (p less than 0.05).

Aged↗
PubMed1988

Doppler analysis of flow velocity profile at the aortic root.

This study of aortic root flow velocity profiles suggests that the flow velocity pattern is parabolic rather than flat as has been widely supposed. To analyze the distribution of flow velocity, a special ultrasound pulsed Doppler velocity flow meter, with a direct probe on the aortic wall, was designed. Sixteen patients, none with a diagnosis of aortic valve disease, were examined just before undergoing open heart surgery. Parabolic velocity patterns were always found, and it was determined that the parabola was skewed rightward toward the anterior wall. Furthermore, it was shown that the flow velocity vector was initially directed toward the commissure of the right coronary and the noncoronary cusps.

Adult↗