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Biomedical subjects

S Mellander

Publications and source records attributed to S Mellander.

69 records · Page 4Linked to original sources
PubMed1967

The effects of stimulation of the hepatic nerves, infusions of noradrenaline and occlusion of the carotid arteries on liver blood flow in the anaesthetized cat.

1. In anaesthetized cats, the hepatic artery, portal vein and inferior vena cava pressures and the hepatic artery and portal vein flows were recorded using pressure transducers and electro-magnetic flowmeters.2. The hepatic nerves were stimulated with maximal stimuli for periods of 2-5 min. The magnitude of the response varied with the frequency of stimulation over the range 1-10 impulses/sec. The resistance to flow increased in both the hepatic artery and the portal vein.3. In the hepatic artery, mean pressure remained virtually constant, while the flow showed an initial marked decrease followed by a return towards the control level. In the portal vein, the flow remained constant while portal pressure showed a maintained increase. These responses were unaffected by previous administration of atropine and propranolol, but were blocked by phenoxybenzamine.4. Infusions of noradrenaline into the hepatic artery produced changes similar to those following stimulation of the nerves. In contrast, when the hepatic arterial pressure was maintained constant, intravenous infusions of noradrenaline produced a maintained decrease in hepatic artery flow.5. The occurrence of autoregulation of the hepatic artery flow at arterial pressures above 80-100 mm Hg was confirmed.6. Occlusion of the carotid arteries caused a rise in arterial pressure with little change in hepatic artery flow, but when the hepatic artery pressure was maintained at the pre-occlusion level the flow showed an abrupt decrease, usually followed by a recovery towards the control level. This decrease was abolished by section of the hepatic nerves and removal of the adrenal glands.7. It is concluded that the increase in hepatic artery resistance during occlusion of the carotid arteries was dependent on the hepatic nerves, the adrenal medullary secretions and an intrinsic autoregulatory mechanism.

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Treatment of descending thoracic aneurysms by endovascular stent grafting.

PURPOSE: Endovascular stent-graft treatment for true aneurysms of the descending thoracic aorta is a valid and effective alternative to conventional surgery. A review of our experience with 21 consecutive patients is reported and technical considerations are discussed. METHODS: Twenty-one patients (mean age 73 years) with true aneurysms of the descending thoracic aorta (n = 14) or contained rupture (n = 7) were treated between October 1999 and July 2001. Seven patients (33%) underwent emergency endovascular procedure. Postoperatively, the patients were followed with CT scans at 1, 3, 6, and 12 months. Follow-up, which averaged 17 months, was 100% complete. THIRTY-DAY RESULTS: No conversions to open repair were necessary. Two patients died (10%), one of acute intestinal ischemia and the other because of multiorgan failure. Four patients showed endoleaks immediately after stenting. Two patients required new endovascular stentgrafts, while the remaining two were treated conservatively. Besides endoleaks, eight major complications occurred in six patients (two stroke, two paraplegia, two respiratory insufficiency, and one renal failure). MID-TERM RESULTS: Three more patients died during the follow-up period. One patient died of heart failure after a complicated postoperative course, 91 days after stenting. The second patient died because of aortic rupture, 139 days after stenting. The third patient died of heart failure, 15 months after the endovascular procedure. The remaining 16 patients are alive and have been regularly controlled by CT scans. No late migration or endoleaks have been detected. In all the survivors, the size of the aneurysm was unchanged or diminished. CONCLUSIONS: Treatment of descending thoracic aortic aneurysms by endovascular stentgraft devices has good early and mid-term results. More accurate selection of patients may further reduce mortality and morbidity.

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