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Biomedical subjects

O K Hansen

Publications and source records attributed to O K Hansen.

33 records · Page 2Linked to original sources
PubMed1991

Prognosis and risk factors in acute, dialysis-requiring renal failure after open-heart surgery.

Of 1988 patients who underwent open-heart surgery from 1980 through 1988, 68 (3.4%) developed postoperative acute renal failure requiring dialysis (2.5% of adult and 8.3% of pediatric patients). Isolated aortocoronary bypass grafting was the operation with lowest incidence of this complication (0.6%). Acute renal failure usually appeared during the first 3 postoperative days. It carried a mortality rate of 63%, with half of the deaths occurring during the first few postoperative days, due to low cardiac output and progressive multiple organ failure. Logistic regression analysis in cases of aortic valve replacement demonstrated that significant independent preoperative risk factors for acute renal failure were renal insufficiency (serum creatinine greater than 110 mumol/l in greater than or equal to 2 samples) and increased cardiothoracic index/left ventricular end-diastolic dimension. Data from the literature indicated no time-related trend towards reduction of acute renal failure incidence or mortality. Prevention of low cardiac output is of major importance in these respects. Operative intervention before development of advanced disease with left ventricular dilatation and secondary kidney failure is advocated.

Acute Kidney Injury↗
PubMed1987

Primary malignant pericardial mesothelioma mimicking left atrial myxoma. Case report.

In a 32-year-old man with clinical and echocardiographic signs mimicking left atrial myxoma, thoracotomy revealed a highly malignant pericardial mesothelioma with an intraatrial pendulous extension and haemorrhagic pericardial exudate. CT scanning of the thorax is useful when an intracavitary cardiac mass is associated with pericardial exudate and/or with suspected extracavitary involvement.

Adult↗
PubMed1985

Anomalous origin of the left coronary artery from the pulmonary artery in an adult.

Anomalous origin of the left coronary artery from the pulmonary artery is a rare, almost universally fatal form of congenital heart disease. A case was diagnosed in a 19 year old woman who had exercise induced syncope and ST segment displacement during exercise stress testing. The anomaly was successfully treated with ligation of the anomalous left coronary artery combined with saphenous vein grafting. Young adults with exercise induced syncope should be examined by exercise stress testing, and if it induces ST segment displacement coronary angiography should be undertaken.

Adult↗
PubMed1978

Direct evidence that the greater contractility of resistance vessels in spontaneously hypertensive rats is associated with a narrowed lumen, a thickened media, and an increased number of smooth muscle cell layers.

The mechanical and morphological properties of segments of certain precisely defined resistance vessels (approximately 150 micrometer lumen diameter) in the mesenteric bed of spontaneously hypertensive (SHR) and normotensive (WKY) rats have been compared in vitro under carefully controlled conditions and also after fixation. At a given transmural pressure, the relaxed SHR vessels (compared with the WKY vessels) would have had a 16% smaller lumen diameter (P less than 0.01) and a 49% thicker media (P less than 0.005), so that the media volume per unit segment length was 31% greater (P less than 0.05). The smooth muscle cells were arranged circumferentially in about four layers in the SHR vessels and in about three layers in the WKY vessels. The SHR active wall tension in response to potassium was 53% greater (P less than 0.02) and to norepinephrine was 50% greater (P less than 0.01) than for WKY. However, the ED50 values for the norepinephrine dose-response curves were similar (approximately 5 micrometer). Activation with potassium plus norepinephrine gave greater responses in both vessel types, than with either agent alone, but the SHR responses were on average only 19% greater than the WKY (P less than 0.10). However, under these conditions, the SHR vessels would have been able to contract against 45% greater transmural pressures (P less than 0.001) because of their smaller lumen. On maximal activation, the mean force developed by each cell (approximately 3.85 micro N) was the same in both vessel types, even though on average (P = 0.10) the SHR cells had a 21% greater cross-sectional area. The results support the Folkow hypothesis that in genetic hypertension the increased peripheral resistance is associated with structural changes in the resistance vessels.

Animals↗
PubMedDate not supplied

Pediatric multiplane transesophageal echocardiography in congenital heart disease: new possibilities with a miniaturized probe.

In recent years, transducers for multiplane Doppler echocardiography have demonstrated their superior imaging performance in adult patients. To date, the size of these probes has limited their use in pediatric patients. In this article, we report our initial experience with a recently developed miniaturized transducer with all conventional imaging and Doppler modalities. The study focused primarily on imaging performance by comparing standard biplane images with those obtained in oblique planes. The investigations were carried out intraoperatively or during interventional catheterization in patients with congenital heart disease. We observed no complications in a study population of 15 children (weight range of 5 to 63 kg and an age range of 96 days to 11 years). The probe was easy to handle and provided excellent images. Additional information was obtained in several cases and documentation of clinical findings was easier because an optimal image plane almost always could be displayed. We concluded that pediatric multiplane Doppler echocardiography has considerably improved investigative performance compared with the conventional monoplane or biplane studies normally available for this age group. In neonates, however, investigation with the multiplane technique is limited by the size of the patient.

Child↗
PubMedDate not supplied

Acute or delayed surgical treatment of traumatic rupture of the descending aorta.

During a 20 year period, 33 patients with traumatic rupture of the descending thoracic aorta were operated upon. In the absence of an indication for acute surgery our policy was to defer operation at least 4 weeks after the trauma. Six patients were operated upon within 24 hours (Group I), 5 after 4-13 days due to suspected expansion of mediastinal widening (Group IIa), 10 were operated upon electively after 4-12 weeks (Group IIb), and 12 were operated upon for chronic traumatic aneurysms (Group III). The number of operative deaths/reoperations due to bleeding were: Group I, 2/1; Group IIa, 1/2; Group IIb, 0/0; and Group III, 1/0. There were no late deaths related to the operation or the inserted prosthesis. Of 26 survivors, 21 underwent a follow-up study 1.5-20 years (mean 8.2 years) postoperatively. Except for 6 patients with paralysis of the left recurrent laryngeal nerve none of the patients had sequelae which could be related to the operation or the inserted prosthesis. CT-scanning of the chest revealed neither pseudoaneurysms nor significant stenosis in the suture lines or prosthetic areas. The results indicate that delayed operation of traumatic thoracic aortic ruptures on selected patients may be performed with acceptable results.

Adult↗