PubMed Health⌕ Search

Biomedical subjects

L von Segesser

Publications and source records attributed to L von Segesser.

At least 73 records · Page 4Linked to original sources
PubMed1992

Treatment of mycotic aneurysm of the aorta and its branches: the location determines the operative technique.

Twenty-seven patients with mycotic aneurysms of the aorta and its major branches were operated on between 1969 and 1991. There were 24 males and three females ranging in age from 6 to 84 years (mean age for adults 63 years). Sixteen of the 27 (59%) aneurysms were ruptured and in situ repair was undertaken in 20 (74%) patients. The mean follow-up was 5.8 years (range: 8 months to 16 years). Four patients (15%) died during the hospital stay and 23 survived. There were eight late deaths, two of which were a direct result of the aneurysm. The estimated 1- and 5-year survival rates were 62 and 36%, respectively. Extra-anatomic reconstruction is the method of choice for the majority of patients with mycotic aneurysm of the infrarenal abdominal aorta and iliac arteries. In situ repair after an extensive debridement of the aneurysmal wall and all infected tissue combined with antibiotic therapy is a satisfactory method of treating mycotic aneurysms of other locations, and for a highly selected group of patients with infrarenal mycotic aortic aneurysms.

Adult↗
PubMed1992

Valve replacement in octogenarians: increased early mortality but good long-term result.

Between January 1983 and December 1990, 20 patients aged 80 years or older underwent valvular surgery. The patients' ages varied from 80 to 87 years (mean, 82 +/- 1.5 years). The indication for operation was aortic stenosis in 19 patients, and mitral insufficiency after previous mitral valve replacement with a bioprosthesis in one. There were 15 elective, two urgent, and three emergency operations. Four of these patients had aortic valve replacement plus coronary artery bypass grafting. Six patients (30%) had an uneventful hospital stay, and the other 14 (70%) experienced several post-operative complications. The operative mortality rate was 15% (three patients). All patients before operation were in NYHA (New York Heart Association) class III and IV and all survivors remained in NYHA class I or II. The survivors have been followed from 6 to 70 months (mean 20 +/- 8 months). The actuarial survival rate at 1 and 5 years was 78.5% and 67%, respectively. Valvular replacement in octogenarians can be performed, despite the high rate of post-operative complications, with increased but acceptable mortality. Long-term results are good.

Aged↗
PubMed1991

[Aortocoronary bypass surgery in patients older than 70 years].

From January 1981 to December 1990, 204 patients aged between 70 and 81 years underwent aortocoronary bypass surgery. Operative mortality (30-day mortality) was 6.8%. Actuarial survival rate at 1 and 5 years was 92% and 86% respectively. A higher incidence of postoperative complications was observed (arrhythmias in 19%, reoperation for bleeding in 5.4%, respiratory and neurological complications in 13% and 3% respectively, perioperative infarction in 4.4%). The mean follow-up was 25 months. Preoperatively most patients (71%) were in New York Heart Association (NYHA) functional class III and IV, and at the end of following-up in NYHA functional class I and II (95%) (p less than 0.001). A rapid rise in coronary artery surgery in the elderly is evident. It is associated with an increased but acceptable operative risk. Long-term results and postoperative improvement of functional status are very satisfactory.

Age Factors↗
PubMed1991

[Vascular complications associated with aortic dissection].

Aortic branch occlusion may constitute the mode of presentation or become an important focus of treatment in patients sustaining acute aortic dissection. The optimal therapeutic approach in patients with acute aortic dissection complicated by cerebral, visceral and peripheral vascular problems, and the implications of such complications, are not well established. We review the outcome in 187 consecutive patients (149 males and 38 females, mean age 58 years) with acute dissection of the thoracic aorta who were admitted and operated on in our department over a 13-year period. We assess the incidence, consequences and specific management of significant stenotic and obstructive lesions of the aorta and its branches. Noncardiac vascular complications occurred in 59 patients (32%); of these complications, 38 were associated with type A dissection (incidence 28%) and 21 with type B dissection (incidence 48%). A trend towards decreasing overall surgical mortality was observed in the second part of the study (1983-1989) compared with the first part (1977-1982) i.e. 28% versus 12%. Although aortic rupture and cardiac tamponade were the strongest correlate of morbidity and mortality, death specifically related to vascular complication was more common when such malperfusion occurred in the carotid, celio-mesenteric and renal circulation. Proximal aortic repair at the site of the intimal tear with obliteration of the false lumen may have restored adequate distal circulation in 27 patients in whom improvement of the visceral or peripheral ischemia was observed after the thoracic aortic repair. Additional procedures (immediately after the thoracic repair or later) were necessary in 15 patients to restore adequate perfusion in the compromised area.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

[Heart tumors: incidence, distribution, diagnosis. Exemplified by 20,305 echocardiographies].

The occurrence, type and location of cardiac tumors as detected by Doppler-echocardiography are reviewed. In a series of 20,305 consecutive echocardiographic studies performed at our institution over a four-year period, cardiac tumors were identified in 30 patients (0.15%; 17 male and 13 female, mean age 53 years). Primary cardiac tumors were detected in 21/30 patients (70%; mean age 50 years), secondary tumors in 5/30 patients (17%; mean age 58 years); however, in 4/30 patients (13%) the tumors could not be classified (mean age 59 years). In the group with primary tumors, benign cardiac tumors were found in 18/21 patients (86%) and malignant tumors in 3/21 (14%). All benign cardiac masses were myxomas (18/18) and accounted for 60% of all tumors; they were mainly located in the left atrium (16/18 or 89%) and rarely occurred in the right atrium (2/18 or 11%). One patient had a recurrence of a left atrial myxoma and a second patient of a biatrial myxoma. Three patients had a primary malignant cardiac tumor detectable either in the right atrium (leiomyosarcoma and synovial sarcoma; 2/21) or in the left ventricle (epitheliocellular sarcoma; 1/21). The group of secondary cardiac tumors consisted of different types of metastatic processes which were most often detected in the right atrium (4/5; 80%) and in one case in the left ventricle (1/5; 20%). Overall, the most frequent tumors found in this series were benign cardiac tumors represented by atrial myxoma in 18/30 patient (60%); they resided most often in the left atrium (16/30 or 53% of all tumors). All the cardiac chambers and all main adjacent cardiac vessels must be visualized and inspected carefully to detect the magnitude, origin and recurrence of cardiac tumors.

Echocardiography, Doppler↗
PubMed1991

Different interactions of platelets with arterial and venous coronary bypass vessels.

We studied the interaction of platelets with the wall of human internal mammary arteries and saphenous veins, suspended in organ chambers for measurement of isometric tension. Vessels were obtained during coronary bypass surgery and cut into 5 mm rings; in some the endothelium was chemically removed. Rings from several patients were randomly chosen for each experiment, and in each ring six concentrations of platelets (from healthy blood donors; 1-75 x 10(3)/microliters) were tested consecutively and concentration-response curves constructed; the areas under these curves were used for statistical comparisons. In rings of internal mammary artery contracted in response to noradrenaline, aggregating platelets induced endothelium-dependent relaxation which was prevented by apyrase (0.67 U/ml ADPase activity) and L-NG-monomethylarginine (1 mmol/l). By contrast, in saphenous vein rings contracted in response to noradrenaline, aggregating platelets induced only a further increase in tension. In quiescent vessels, the platelet-induced contraction did not occur in arteries with endothelium but that in veins was greater and facilitated by endothelium. Preincubation of platelets with aspirin (10 mumol/l) reduced the contraction in both vessels, but contraction was abolished only in the presence of both the thromboxane receptor antagonist SQ-30741 and the serotoninergic (5HT2) receptor antagonist ketanserin. These findings show that platelet-derived ADP causes release of nitric oxide by the endothelium of internal mammary artery but not of saphenous vein; thromboxane A2 and serotonin mediate contraction in vein but not artery with endothelium. These differences may contribute to differences in graft function and the clinical efficacy of antiplatelet drugs.

Apyrase↗
PubMed1991

Bronchial neuroendocrine (carcinoid) tumor causing unilateral left-sided carcinoid heart disease.

A female patient suffering from a bronchial neuroendocrine tumor with unilateral left-sided carcinoid heart disease is reported. Repeated x-ray films of the chest showed a slowly growing lung tumor in the left lower lobe. The patient refused any diagnostic or therapeutic procedure to define the type of the tumor. During the follow-up of 24 years she developed severe mitral and moderate to severe aortic insufficiency, both invasively quantified by thermodilution techniques. During surgery for double valve replacement the patient died from left ventricular heart failure. Necropsy revealed the typical pattern of a bronchial neuroendocrine tumor without metastases. Examination of the heart disclosed the characteristic deposits of fibrous tissue on the cusps of both the mitral and the aortic valves whereas the right heart showed no abnormalities. Review of the literature suggests the unilateral left-sided carcinoid heart disease to be a very rare finding, its pathogenesis remains to be elucidated.

Aged↗
PubMed1991

Perioperative myocardial perfusion scintigraphy at rest with technetium 99m methoxyisobutylisonitrile before and after coronary bypass operations.

Eighteen patients were examined at rest by technetium 99m methoxyisobutylisonitrile (99mTc-MIBI) myocardial scintigraphy 1 day before and 1 week after aorto-coronary bypass operation with planar and single photon emission tomography (SPET) imaging. One day postoperatively, a planar scintigraph in the intensive care unit (ICU) was done. Inter-observer variability was 3.8% for all examinations and for SPET alone, 3.9%. The quality of the planar images taken under emergency conditions in the ICU was quite comparable with those taken under routine conditions. The postoperative myocardial infarction in a patient who died 6 days later could clearly be demonstrated. In 16.2% of all segments which were hypoperfused at rest on preoperative scintigraphy, an amelioration of perfusion could be shown in the 1st week after the bypass operation. 99mTc-MIBI proved to be a useful agent to assess perioperative perfusion, in the ICU as well as under standard conditions.

Adult↗
PubMed1991

Simultaneous revascularization for critical coronary and peripheral vascular ischemia.

Patients with coronary artery disease can exhibit substantial vascular involvement, and patients with vascular disease have a high incidence of coronary disease. Simultaneous coronary artery bypass grafting and treatment of vascular disease was performed in 32 patients with strong indications for surgical treatment of coronary artery disease and critical peripheral vascular ischemia operated on from 1980 until 1990. Overall hospital mortality was 3.1%; 1 patient died of myocardial infarction 2 days after urgent combined revascularization because of unstable angina pectoris and subacute occlusion of the aortoiliac bifurcation. Early mortality was 0% in patients undergoing elective operations. Eight-year actuarial survival was 87.5%. Combined procedures can be performed with acceptable risk and with encouraging long-term results in this special group of patients; they may improve prognosis in patients with diffuse atherosclerosis.

Adult↗
PubMed1991

Dealing with dilated ascending aorta during aortic valve replacement: advantages of conservative surgical approach.

Five to fifteen percent of patients undergoing aortic valve replacement (AVR) will have an ascending aortic aneurysm requiring a concomitant surgical procedure. On the other hand, a dilated ascending aorta is known to be a potential source of complications after AVR. From 1972 to 1988, 2278 AVR, either isolated or combined with a second cardiac procedure, were performed in our institution. In the same time interval, a dilated ascending aorta was treated in additional 291 consecutive patients during AVR. Three different surgical options were employed: aortic remodelling and external wall support in 164 patients (56.4%), composite graft replacement in 81 patients (27.8%) and a supracoronary graft in 46 patients (15.8%). Early mortality was 4.8%. Aortic remodelling plus external wall support had the lowest early mortality (1.8%) and the best 8-year survival (89.6%). Supracoronary grafting had a higher early mortality (6.4%) and lower 8-year survival (73.2%). The results of the composite graft were least favourable: early mortality was 9.8% and 8-year survival 76.5%. The results point out the necessity for instituting the appropriate surgical procedure for a dilated ascending aorta during AVR. They show that conservative aortic surgery with preservation of endothelial lining gives excellent early and late results.

Actuarial Analysis↗
PubMed1991

Preoperative assessment of the likelihood of infection of the lower respiratory tract after cardiac surgery.

Lower-respiratory-tract infections are among the most frequent complications observed in the intensive care unit, leading to delayed postoperative recovery time and increased costs and mortality. We have tried to evaluate the prognostic value of perioperative bacteriology of tracheal aspirates in assessing the risk of such complications. In a prospective study aspirates of 100 patients undergoing cardiac surgery were taken immediately after intubation and were analysed for microorganisms by Gram-stain and microbiological cultures using standard procedures. All patients received perioperative antibiotic prophylaxis with a single dose of 2 g ceftriaxone intravenously. From 26 patients with bacteriologically positive tracheal secretion, 8 (30.7%) developed lower respiratory tract infection whereas only 1 of 72 patients (1.4%) with negative bacteriological results developed this complication. Smoking (p less than 0.01) and abnormal preoperative lung function (p less than 0.01) were significantly more frequent in patients developing postoperative pneumonia. Regarding the results of this study, the risk of developing pulmonary infection in the early postoperative course after cardiac surgery can be estimated from the tracheal aspirates.

Adult↗
PubMed1991

Predictability of aortic dissection as a function of aortic diameter.

The role of aortic diameter on the occurrence of type A dissection was investigated in 73 patients with dilated ascending aorta at the time of pre-operative evaluation. Using transthoracic echocardiography for diagnosis and measurements, 54 patients were identified with type A dissection (group 1) and 19 without dissection (group 2). The true mean aortic diameters were identical (6.0 +/- 1.3 cm in group 1 and 6.4 +/- 1.4 cm in group 2; mean +/- SD; ns) as were the indexed aortic diameters (ratio of diameter/body surface area; 3.2 +/- 0.8 cm.m-2 and 3.4 +/- 0.7 cm.m-2, respectively; ns). However, the individual diameters showed a pronounced scatter in both groups (range from 3.6 +/- 11.0 cm). Of the 73 patients, 66 had surgery (47/54 with and 19/19 without dissection) and seven patients were treated medically. Emergency surgery was performed in 45/66 patients (all with acute type A dissection) and elective repair in 21/66 (19 without and two with chronic type A dissection). In-hospital mortality was 18% in the emergency group, 5% in the elective group and 57% in the medical group. It is concluded that patients with dilated ascending aorta have a substantial incidence of acute dissection. Their clinical course is unpredictable: acute dissection occurs in some, and in others the ascending aorta continues to enlarge without dissection. Because patients with dissection often arrive too late for elective repair and have to be operated on as emergencies with a higher operative risk, we recommend elective surgery before the diameter of the ascending aorta has reached 6 cm.

Aortic Dissection↗
PubMed1991

Different activation of the endothelial L-arginine and cyclooxygenase pathway in the human internal mammary artery and saphenous vein.

The endothelium releases substances controlling vascular tone and platelet function. We investigated mediators of endothelium-dependent responses in human internal mammary arteries and saphenous veins. The inhibitor of nitric oxide formation, NG-monomethyl L-arginine, enhanced the sensitivity to norepinephrine (fivefold) and evoked more pronounced endothelium-dependent contractions in internal mammary arteries (19 +/- 6% of 100 mM KCl) than in saphenous veins (2 +/- 1%; p less than 0.005). In internal mammary arteries, NG-monomethyl L-arginine, but not indomethacin, markedly reduced endothelium-dependent relaxations to acetylcholine (from 95 +/- 2% to 39 +/- 7%; p less than 0.005) and prevented those to histamine (78 +/- 6% to 4 +/- 3%; p less than 0.005). In saphenous veins, endothelium-dependent relaxations to acetylcholine were weak (24 +/- 11%), while nitric oxide caused comparable relaxations (85 +/- 3%) as in internal mammary arteries (80 +/- 5%; NS). NG-Monomethyl L-arginine prevented the relaxations to acetylcholine and unmasked endothelium-dependent contractions (30 +/- 10%). Indomethacin and the thromboxane synthetase inhibitor CGS-13080 augmented relaxations of saphenous veins to acetylcholine from 24 +/- 11% to 46 +/- 9% (p less than 0.05). Histamine-evoked contractions were converted to endothelium-dependent relaxations by indomethacin and the thromboxane A2/endoperoxide receptor antagonist SQ-30741 (38 +/- 3% and 40 +/- 6%; p less than 0.05) but not CGS-13080. Thus, 1) nitric oxide mediates endothelium-dependent relaxations in human arteries and veins; 2) internal mammary arteries release more nitric oxide than do saphenous veins, and 3) in saphenous veins, the effects of nitric oxide are reduced by endothelium-derived contracting factors originating from the cyclooxygenase pathway.

Acetylcholine↗
PubMed1991

[Reduction of postoperative blood loss and donor blood use in heart surgery with aprotinin: experience with various dosages].

The effect of high dose aprotinin was evaluated in a prospective study on 100 patients undergoing cardiopulmonary bypass. Special attention was made on postoperative blood loss and transfusions of bank blood postoperatively. In the first part of the study, after induction of anesthesia, a loading dose of 2,000,000 kallikrein-inhibiting-unit (KIU) = 280 mg aprotinin was given intravenously over a 30-min period. Immediately afterward, a continuous infusion of 500,000 KIU/h was started and maintained until skin closure. Another 2,000,000 KIU was added to the priming volume of the heart-lung machine. A control group of 50 patients was randomized with similar indication for surgery and past cardiac history. The total loss from the thoracic drains was significantly reduced in the aprotinin group as compared with the loss in the control group (490 +/- 265 ml versus 1045 +/- 380 ml). In a separate group of risk patients (redo-operations, infective endocarditis) the total blood loss was even more significant reduced in the aprotinin group (690 +/- 195 ml versus 1585 +/- 290 ml). Patients of the aprotinin group received markedly less bank blood postoperatively (350 +/- 100 ml versus 900 +/- 240 ml without aprotinin). Part II of the study (36 patients) consisted of lower dosage (2,000,000 KIU intravenously during induction of anesthesia only or 2,000,000 KIU in the priming volume of the heart-lung machine only). Patients who received aprotinin in the heart-lung machine only showed no significant difference regarding blood loss and blood requirement to patients with high dose aprotinin. It appears possible that aprotinin reduces the activation of the coagulation during cardiopulmonary bypass and preserves platelet function without affecting platelet consumption during the extracorporeal circulation. The results of our study demonstrate that high dose aprotinin markedly reduces blood loss as well as homologous blood requirement in the early postoperative course of cardiosurgical patients. Similar effects due to reduced aprotinin dose have been observed in patients receiving aprotinin in the extracorporeal circulation only.

Aged↗
PubMed1991

[Simultaneous coronary and vascular surgery interventions: indications,technique and results].

Atherosclerosis is often a generalized disease, affecting not only coronary circulation, but other parts of vascular system as well. Vascular diseases most commonly encountered in patients with coronary atherosclerosis are carotid disease, abdominal aortic aneurysm and obliterative atherosclerosis in aortoiliac segment. In such situation two options are available: to treat the more significant, life-threatening manifestation first and postpone the other operation--staged approach; or to perform coronary artery bypass grafting (CABG) and other vascular procedures during one single operation--synchronous surgery. The advantages of this latter approach are obvious: patient has to undergo only one operation; there is no additional risk in the waiting period for second operation; surgical treatment is greatly accelerated. From 1978 until July 1990 a total of 123 synchronous CABG and vascular procedures were carried out in our clinic. In the same period, CABG was performed in 3867 pts in the same institution; combined procedures amount to 3.5% of all coronary revascularisations performed in the same period. CABG was done together with carotid endarterectomy (CEA) in 45 pts, associated with resection of abdominal aortic aneurysm (AAA) in 31 and in 28 pts it was combined with vascular procedures in aorto-iliac or femoral segment. In 4 pts a triple procedure--CABG, CEA and peripheral vascular reconstruction--were undertaken. Thoracic aortic aneurysm and CABG were performed in 15 pts. CEA is performed immediately prior to CABG in symptomatic carotid disease, past history of transient ischemic attack, severe bilateral carotid disease and unilateral carotid obstruction with contralateral stenosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Aneurysm↗