PubMed Health⌕ Search

Biomedical subjects

L von Segesser

Publications and source records attributed to L von Segesser.

At least 55 records · Page 3Linked to original sources
PubMed1993

[Clinical late results following surgical ablation of an accessory atrioventricular connection in Wolff-Parkinson White syndrome].

All patients operated because of WPW-syndrome between 1980 and 1990 at the University clinics of Zürich were followed up by clinical examination and by electrocardiography. Relief from symptoms (tachycardia, vertigo and/or syncopes) was defined as "symptomatic" success, lack of preexcitation in the ECG at rest as "surgical" success. Overall 56 patients (40 men, 16 women) aged from 13 to 66 years had been operated in the stated time period. Before operation 52 of these patients had pre-excitations in the ECG, 54 had tachycardia and 23 had syncopes. None of the patients died from the operation. In order to localize the AAVVs epicardial cartography was performed in all patients during operation before the AAVVs were cut through an endocardial access. The follow-up was possible after an average interval of 5.5 years (1-120 months) in 50 of the 56 patients. One patient died 10 years after operation from heart failure. 6 patients were reported to be out of the country. The follow-up revealed symptomatic success of the intervention, defined as absence of tachycardia, in 88% (44 out of 50). In 84% (42 out of 50) also a surgical success of the operation was found. In these patients the accessory atrio-ventricular bundle had been successfully ablated, and they were free of tachycardia and of preexcitation in the ECG. Two patients with persisting preexcitation remained free of clinical symptoms. Insofar the rate of symptomatic success was higher than the rate of surgical success. Summarizing the results surgical transsection (ablation) of an accessory atrioventricular bundle in patients with WPW-syndrome is a good therapeutic option with favorable long term success. It has today still its place--in selected cases--as alternative to the now available radio-frequency ablation.

Adolescent↗
PubMed1993

Retrograde ascending aortic dissection: a diagnostic and therapeutic challenge.

Aortic dissection with an entrance tear in the transverse aorta is generally considered to have the highest acute fatality rate of any type of dissection and the direction of its extension is the most difficult to predict. In a prospective study, we evaluated 61 consecutive patients (mean age 56.7 years, ranging from 21 to 75 years), presenting with ascending aortic dissection during a 36-month-period and tried to clarify the incidence of retrograde ascending aortic dissection. In 49 patients (80.3%), the intimal tear was located in the ascending aorta, whereas the dissection originated in the transverse aorta in 12 patients (19.7%); in this latter group, extension was strictly retrograde in 5 patients and in both directions in 7 patients. Three patients died before operation; 58 patients underwent aortic replacement/repair under moderate hypothermia; if the primary tear extended into the transverse aorta or was not found in the ascending aorta, the aortic arch was explored during a brief period of deep hypothermic circulatory arrest. The overall operative mortality was 12.1% (7/58); it was 10.4% (5/48) in ascending aortic dissection and 20% (2/10) in dissection of the transverse aorta. Age (P < 0.005), concomitant coronary artery disease (P < 0.01) and the site of intimal tear (P < 0.01) were significant predictive factors of operative risk. A tear in the transverse aorta is almost always associated with retrograde dissection and may simulate dissection with the entrance tear in the ascending aorta. Localization of the entrance tear remains a diagnostic challenge in aortic dissection but Doppler-echocardiography had a high sensitivity in this series (96.7%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Immediate shear stress resistance of endothelial cell monolayers seeded in vitro on fibrin glue-coated ePTFE prostheses.

The shear stress resistance of endothelial cells (EC) previously seeded onto ePTFE grafts was assessed by morphometric determination of the number of cells per cm2 of graft surface before and after exposure of 6 h of arterial blood flow interposed in the canine femoral artery. Autologous venous endothelial cells (AVEC) were harvested from the extrajugular veins of five dogs. The AVEC were cultured in vitro and seeded at a density of 150 x 10(3) cells per cm2 onto 4 mm ID ePTFE grafts precoated with fibrin glue and human fibronectin. Subsequently, the AVEC monolayers on the grafts were cultured for 8 days using a perfusion system and then implanted end-to-end in the femoral artery. All grafts remained patent (5/5). Scanning electron microscopy demonstrated complete, thrombus-free monolayers of AVEC after 6 h of arterial blood flow. The cell densities were 124 +/- 14 and 129 +/- 7 x 10(3) cells per cm2 respectively before and after implantation. It is concluded that in vitro lining of 4 mm ePTFE vascular prostheses is feasible and results in EC monolayers on the graft surface which are shear stress resistant and athrombogenic.

Animals↗
PubMed1993

Steal syndrome after internal mammary artery bypass grafting--an entity with increasing significance.

Stenosis of proximal subclavian artery (SCA), malformations of the internal mammary artery (IMA) at its origin, or large IMA side branches may cause myocardial ischemia due to blood-steal through a patent IMA graft. Thirty-one cases of postoperative steal syndromes have been reported in the literature, 23 due to proximal SCA stenosis, seven due to large IMA side branches and one due to an IMA malformation. We report two additional cases and discuss them in conjunction with the cases in the literature. Thirty patients suffered from recurrent angina pectoris, three had asymptomatic reversal of flow in the IMA as diagnosed by coronary angiography during routine follow-up examination. Carotid-subclavian bypass grafting is the treatment of choice for the management of proximal SCA stenosis. IMA malformations or large side branches are treated by interruption of the responsible vessel, either by ligation or by transarterial catheter embolization. In 82% (27 of 33), steal syndrome could have been prevented by preoperative angiography of the IMA. We advocate it as a routine procedure in combination with coronary arteriography.

Humans↗
PubMed1993

Regional diastolic dysfunction in postischaemic myocardium in calf: effect of nisoldipine.

OBJECTIVE: The aim was to assess the effect of nisoldipine on left ventricular systolic and diastolic function during prolonged myocardial ischaemia. METHODS: The left circumflex coronary artery was ligated for 2 h and reperfused for 4 h in 12 calves. The animals were randomised to a control group (n = 6) or to treatment with 1.25 mg.h-1 intravenous nisoldipine (n = 6) during 2 h of ischaemia. Circulatory support by a ventricular assist device was performed throughout the experiment except for the time of haemodynamic measurements. Regional wall thickening of a normal and an ischaemic left ventricular region was determined using pairs of ultrasonic crystals. Left ventricular pressure was measured by micromanometry. Left ventricular wall thickness and regional wall stiffness at a common preload of 10 mm Hg were calculated using an elastic model with shifting asymptote. RESULTS: Ten animals survived after 6 h. No difference was observed in systolic function between controls and nisoldipine treated animals. Systolic thickening of the ischaemic wall remained depressed 4 h after reperfusion and showed some recovery after dopamine infusion. Ischaemic wall stiffness at a common preload was lower after nisoldipine during ischaemia and reperfusion than in controls. Control wall stiffness remained unchanged during the whole experiment with and without nisoldipine. Diastolic thinning of the ischaemic wall was prevented by nisoldipine during ischaemia and after reperfusion. CONCLUSIONS: Prolonged myocardial ischaemia is associated with increased myocardial stiffness of the ischaemic wall. Mechanical unloading can help to bridge the acute phase but cannot prevent postischaemic diastolic dysfunction of the ischaemic wall. Nisoldipine has a beneficial effect on regional diastolic function during ischaemia and reperfusion by decreasing regional wall stiffness and preventing diastolic thinning of the ischaemic wall.

Animals↗
PubMed1993

Different effects of angiotensin-converting enzyme inhibition in human arteries and veins.

The renin-angiotensin system (RAS) participates in the regulation of vascular tone; its effects were studied in human internal mammary artery (IMA) and saphenous vein (SV) suspended in organ chambers for isometric tension recording. The angiotensin-converting enzyme (ACE) inhibitor enalaprilat (10(-7) M) markedly augmented endothelium-dependent relaxations to bradykinin in SV (concentration shift: 10-fold; n = 6; p < 0.005), but not in IMA; in both blood vessels, it had no effect on endothelium-dependent relaxations to acetylcholine. The contractions to angiotensin I (Ang I; 10(-7) M) were markedly inhibited by enalaprilat (10(-7) M) in SV (control: 34 +/- 6% of 100 mM KCl; treatment: 18 +/- 6%; n = 7; p < 0.05) but not in IMA (control: 33 +/- 4%; treatment: 30 +/- 6%; n = 7; NS) and abolished by the Ang II receptor antagonist DuP 753 (10(-7) M) in both blood vessels. Ang II (10(-7) M) induced more pronounced contractions than Ang I in IMA (63 +/- 4%) and SV (63 +/- 5%; n = 5-6; p < 0.05 vs. Ang I), which was markedly inhibited by DuP 753 (10(-7) M; IMA: 21 +/- 5%; SV: 32 +/- 5%; p < 0.05). Thus, in SV but not IMA, ACE inactivates bradykinin and thereby blunts endothelium-dependent relaxations to the peptide and converts Ang I to Ang II.

Acetylcholine↗
PubMed1993

Mycotic aneurysm of the abdominal aorta: extra-anatomic versus in situ reconstruction.

Between 1973 and 1991, 12 patients with mycotic aneurysm of the abdominal aorta underwent operation. There were four elective and eight emergency procedures. In situ reconstruction was performed in six patients and extra-anatomic reconstruction with axillobifemoral bypass grafting in six. The hospital mortality rate was 25% (three patients) and another three died during the follow-up period of mean 5.5 years. Descending aorta-bifemoral bypass was performed in two patients without signs of chronic local infection 1 and 2 years after previous axillobifemoral bypass. Late complications were peripheral embolization in one patient after in situ reconstruction and a total of five thromboses of the axillofemoral bypass in three patients. Extra-anatomic bypass grafting remains the method of choice for the majority of patients with mycotic aneurysm of the abdominal aorta. In situ reconstruction seems to be an appropriate procedure for a highly selected group of patients.

Aged↗
PubMed1993

Anomalous left pulmonary artery (pulmonary sling): result of a surgical approach.

Between 1977 and 1992, four infants with an anomalous left pulmonary artery and subsequent compression of the tracheobronchial tree were operated on at the University Hospital Zurich. The operation consisted of mobilization of the abnormal left pulmonary artery with reimplantation into the main pulmonary trunk in three patients; the left pulmonary artery was transected and restored in front of the trachea by end-to-end anastomosis in one. Mean follow-up was 7 years (range 2 months to 14.3 years). There were no early and no late deaths. All patients have shown significant symptomatic improvement without respiratory infection or disturbance of normal life activities. Surgical therapy in this rare condition can be safely undertaken with good long-term results. In symptomatic patients the operation should be performed early before occurrence of severe respiratory symptoms and bronchial collapse.

Airway Obstruction↗
PubMed1993

[Differential diagnosis of ischemia of the lower extremities in young adults].

Lower-extremity arterial occlusive disease in individuals younger than 50 years is rare. We report on 4 young adults with lower limb ischemia, each of them with a different cause. According to literature premature atherosclerosis is the most common cause and is followed by thromboangiitis obliterans, coagulation abnormalities and popliteal artery entrapment syndrome. We suggest a diagnostic concept which could help to avoid undue delay.

Adult↗
PubMed1993

Transcaval liver resection with hepatoatrial anastomosis for treatment of patients with the Budd-Chiari syndrome. Late results.

Between 1980 and 1990 transcaval liver resection with hepatoatrial anastomosis was performed in 17 patients with the Budd-Chiari syndrome. There were two early deaths (early mortality 11.7%). Hepatic function returned to normal and hepatosplenomegaly disappeared in all but two patients with preexisting cirrhosis. All survivors regained normal working capacity after the operation. During an average follow-up of 6 years (7 months to 11 years) there were three late deaths due to progression of the underlying disease. The actuarial 1-, 5-, and 10-year survivals were 82%, 76%, and 57%, respectively. Hepatoatrial anastomosis represents an optimal treatment for patients with the Budd-Chiari syndrome and obstruction of major hepatic veins. Patients with compression of the inferior vena cava, very common in this disease, were treated by simultaneous transcaval stenting. The late results are very satisfactory, with excellent quality of life. With adequate hepatic function, results of hepatoatrial anastomosis are superior to those of liver transplantation, which represents the only alternative for patients with the advanced form of the Budd-Chiari syndrome.

Adult↗
PubMed1993

In situ repair of mycotic aneurysm of the ascending aorta.

Between 1969 and 1990 six patients (aged 14 to 64 years, mean 43 years) underwent in situ reconstruction for mycotic aneurysm of the ascending aorta. The primary source of infection was endocarditis in three patients (subacute bacterial endocarditis [n = one patient], sepsis with acute endocarditis [n = one patient]), sepsis with sternal osteomyelitis in one, sepsis with purulent pericarditis in one, and generalized febrile illness in one. In five of six patients the treatment consisted of the excision of changed tissue combined with a composite graft (n = one patient), a xenopericardial patch repair (n = one patient), a Dacron graft repair and aortic valve replacement (n = one patient), a Dacron graft repair alone (n = one patient), and a lateral suture combined with double valve replacement (n = one patient). In one patient with perforation of the mycotic aneurysm into the pulmonary artery, the place of rupture was oversewn without excision of the aortic or pulmonary artery tissue. Two patients with local pericardial inflammation were reoperated on during the hospital stay; one of them because of recurrent mycotic aneurysm of the ascending aorta at the other location and the other because of infection of the suture line after the Dacron patch repair. Antibiotic therapy was intravenously administered for 2 to 12 weeks postoperatively and continued orally for 4 to 8 weeks. The mean observation time was 6 years (range 4 months to 16 years). There was no late graft infection, except the chronic infection of the suture line in one patient who died suddenly 4 months after the operation. There was no early death, and there were three late deaths (chronic myocardial failure, one patient, chronic renal failure, one patient, sudden death, one patient). We concluded that in situ reconstruction for mycotic aneurysm of the ascending aorta combined with prolonged antibiotic therapy is an appropriate procedure with satisfactory early and good long-term results.

Adolescent↗
PubMed1992

[Immediate and long-term results of carotid endarterectomy: the Zurich experience].

Extracardial carotid artery disease is a frequent cause of transient ischemic attack and of cerebral infarction. The records of 485 patients who underwent carotid endarterectomy between 1978 and 1991 were reviewed, with special attention to both cardiac and neurological complications. 432 patients had symptomatic carotid disease whereas 53 were asymptomatic but presented with significant carotid stenosis or a large ulceration at doppler-duplex examination and/or angiography. These examinations showed the following lesions in symptomatic patients: unilateral stenosis > 75% (331; 68.5%), ulceration (41; 8.5%), bilateral stenosis (61; 12.5%) and unilateral stenosis with contralateral occlusion (51; 10.5%). Intraluminal shunt was used in nearly all patients whereas special management of cerebral metabolism (intraoperative electroencephalogram, somatosensory evoked potentials) were used in high-risk patients only. Overall early mortality was 1.8%. Three patients died from the sequelae of a neurologic injury, whereas six patients died from myocardial infarction or intractable arrhythmia. Mortality decreased from 2.4% between 1978 and 1984 to 0.8% between 1985 and 1991. At 6 and 8 years, actuarial survival rates of 88.1% and 76.1% and stroke-free survival rates of 86% and 81.5% were observed. Late mortality was essentially due to ischemic cardiac complications (38.5% of the actuarial late mortality at 8 years). Review of the literature shows that carotid endarterectomy is the treatment of choice for symptomatic high-grade extracranial carotid stenosis in patients who are not high-risk candidates.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Implications of pulsatile stretch on growth of saphenous vein and mammary artery smooth muscle.

Internal mammary artery (IMA) coronary bypass grafts have a higher patency than saphenous vein (SV) grafts. Intimal hyperplasia and occlusion of venous grafts result from smooth muscle proliferation. Mechanical factors, such as pulsatile stretch, are potential mediators of this process. Smooth muscle cells from IMA and SV were cultured on deformable membranes and exposed to pulsatile stretch (60 cycles/min). This stimulus increased 3H-thymidine incorporation into venous (a two-fold increase) but not arterial smooth muscle cells after 24 h. Smooth muscle cell numbers from SV, but not IMA, were increased (p less than 0.05) after 6 days of stretch. Thus, pulsatile stretch stimulates smooth muscle cell proliferation in SV, but not IMA, and may contribute to venous bypass graft disease.

Cell Division↗
PubMed1992

Implantation of antibiotic-releasing carriers and in situ reconstruction for treatment of mycotic aneurysm.

Four patients with mycotic aneurysm of the extracranial carotid artery, the innominate artery, the ascending aorta, and the infrarenal aorta were treated with local implantation of antibiotic-releasing carriers after resection of the aneurysm, excision of all infected tissue, and in situ reconstruction by prosthetic graft replacement in two patients and patch plasty in two patients. The patient with a mycotic aneurysm of the ascending aorta was operated on again 1 month after the first operation because of a second mycotic aneurysm located on the aortic arch. No early or late signs of recurrent infection were seen on clinical and laboratory postoperative follow-up done between 9 and 16 months or on duplex scan or computed tomography done at these times. Implantation of antibiotic-releasing carriers after débridement of all infected tissue and in situ reconstruction for treatment of mycotic aneurysm was performed successfully in four patients with this life-threatening condition.

Aged↗
PubMed1992

Ruptured congenital aneurysm of the sinus of Valsalva: surgical technique and long-term follow-up.

Congenital ruptured aneurysm of the sinus of Valsalva is a rare anomaly usually causing decrease of cardiac performance. Eight patients with a ruptured congenital aneurysm of the sinus of Valsalva were operated upon at the University Hospital Zurich between 1970 and 1991. There were four female and four male patients aged from 15 to 48 years (mean, 36 years). Three patients were asymptomatic and five symptomatic. Associated congenital cardiac defects were found in six patients. Surgical techniques consisted of direct suture in seven patients and closure with a Dacron patch in one. A secondary Dacron patch closure was performed on the second postoperative day in a patient with suture insufficiency after direct closure. Associated operations were closure of ventricular septal defect in two patients, aortic valve replacement in two, aortic valve reconstruction in one and aortic valve commissurotomy in one patient. There were no operative deaths. The mean follow-up was 9 years, range 7 months to 17 years. There were two late deaths due to endocarditis and recurrent cerebral embolisation. An operation for a ruptured aneurysm of the sinus of Valsalva has a low operative risk, but patients remain prone to development of late valvular complications.

Adolescent↗
PubMed1992

Severe tricuspid regurgitation following blunt chest trauma: indication for emergency surgery.

A 24-year-old man with polytrauma and severe posttraumatic tricuspid regurgitation due to rupture of all three papillary muscles was subjected to emergency operation 3 days after a car accident. At operation, all three papillary muscles of the tricuspid valve were reinserted. Severe tricuspid regurgitation after blunt chest trauma is an indication for emergency surgical treatment, and can be performed with a low operative risk.

Adult↗
PubMed1992

Surgical treatment of cardiovascular complications in Marfan syndrome: a 27-year experience.

Fifty-two patients with Marfan syndrome and ascending aortic pathology were treated surgically between 1964 and 1990. The indication for primary operation was true aneurysm of the ascending aorta with or without aortic insufficiency in 35 patients (67%) and dissection in 17 (33%). Composite grafts were used in 28 patients (54%; group I) and other procedures on the ascending aorta in 24 patients (46%; group II). The latter included supracoronary graft replacement with or without aortic valve replacement or reconstruction (n = 13), and reconstruction of the ascending aorta with or without aortic valve replacement (n = 11). Composite graft insertion was combined with mitral valve surgery at the same operation in 3 patients (6%). The early mortality after primary operations was 7.7% (4 deaths) and the late mortality was 27% (14 deaths). Eight late deaths were related to cardiovascular complications. The mean follow-up was 6.7 years (range 1-27 years). The actuarial 5-, 10-, and 15-year survival rates for all patients were 82%, 63%, and 44%, respectively; for group I (composite grafts) they were 87%, 76%, and 57%; and for group II (other types of operations) they were 73%, 53%, and 37%. The incidence of late complications was much higher in group II than in group I (50% vs. 16%). At 5 and 10 years, the actuarial rates of freedom from late complications related to the primary operation were 88% and 80%, respectively, in group I and 65% and 18% in group II. Composite graft insertion is the operation of choice when approaching the ascending aorta and/or aortic valve in Marfan syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗