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Biomedical subjects

L von Segesser

Publications and source records attributed to L von Segesser.

At least 19 recordsLinked to original sources
PubMed2001

[Coronary artery bypass by mini-thoracotomy: noticeable benefits with clinical experience of the treatment team].

AIM OF THE STUDY: Minimally invasive coronary artery bypass surgery is fundamentally different as compared to open sternal approach under cardiopulmonary bypass. Modifications of the surgical, anesthesiologic and post-operative techniques are necessary before evaluation of its real benefit. We analyze the potential effect of a learning period on the short term results of this technique. METHODS: From July 1997 to February 1999, 20 patients were operated using this method. We compare the results of the first 10 patients (group 1: 8M/2F, 59.6 +/- 13.8 years) to those of the last 10 patients (group 2: 8M/2F; age = 63.2 +/- 6.1 years). DISCUSSION: Progress between the two groups is striking. Left anterior descending coronary clamping time could be reduced from 28.5 +/- 2.4 min. in group 1 to 22.2 +/- 1.8 min. in group 2 (p < 0.05), and operative time was reduced from 125 +/- 4 min. to 97 +/- 5 min. (p < 0.005). The post-operative atrial fibrillation rate diminished from 4/10 in group 1 to 1/10 in group 2.3/10 patients in group 1 suffered a post-operative pneumonia whereas none in group 2 had pulmonary complication. The stay in the intensive care unit could be reduced from 2.3 +/- 0.3 days to 1.4 +/- 0.2 days (p < 0.05) and the total post-operative stay diminished from 8.5 +/- 0.9 days to 4.7 +/- 0.5 days (p < 0.005). CONCLUSION: There are evidence for a learning period in minimally invasive cardiac surgery. Short term benefits of this technique are then evident as demonstrated by a reduction in the ICU stay and the hospital stay.

Adult↗
PubMed1999

Five-year outcome in patients with isolated proximal left anterior descending coronary artery stenosis treated by angioplasty or left internal mammary artery grafting. A prospective trial.

BACKGROUND: Percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass surgery (CABG) improve the clinical status of patients with isolated proximal left anterior descending coronary artery stenosis. At 2 years, only additional revascularization was more frequently required after PTCA. METHODS AND RESULTS: We monitored 134 patients randomized to PTCA (n=68) or CABG (n=66) for </=5 years. End points were death, myocardial infarction, need for additional revascularization, clinical status, and medical treatment. At 5 years, 6 patients (9%) had died in the PTCA group versus 2 (3%) in the CABG group (P=0.12). One patient in each group died of a cardiac cause. Myocardial infarction was more frequent after PTCA (15% versus 4%; P=0.0001), but Q-wave infarction was not (6% in the PTCA group versus 3% in the CABG group; P=0.8). Additional revascularization was required in 38% of patients in the PTCA group versus 9% in the CABG group (P=0.0001). Functional status was comparable, with 6% of patients after PTCA and 3% after CABG in functional class III or IV. Finally, after PTCA or CABG, 62% and 91% of patients, respectively, were free of events (P=0.0001). CONCLUSIONS: The 5-year prognosis of patients with isolated proximal left anterior descending coronary artery stenosis is good. Both PTCA and CABG improve clinical status, but revascularization was needed more frequently after PTCA. There is an excess incidence of non-Q-wave myocardial infarction in the PTCA group that does not affect the vital or symptomatic outcome.

Angioplasty, Balloon, Coronary↗
PubMed1999

Vascular surveillance after peripheral artery interventions.

Prospective studies have shown that intensive vascular surveillance with echo-Doppler significantly improves arterial graft patency rate in the lower limbs although no conclusive data have demonstrated associated improvement in limb salvage. The lack of randomised controlled studies makes it difficult to advocate such intensive surveillance programmes to reduce limb loss after arterial reconstruction. Nevertheless, it appears that measures maintaining good graft patency in the lower limb have the best chance to be accompanied by improved life quality. Therefore, a fair protocol for graft surveillance should take into consideration early flow disturbances, intrinsic risks related to comorbidities and technical aspects of the graft material. Strict control of cardiovascular risk factors will greatly contribute to reducing the risk of late occlusive events by slowing or halting the evolution of the atherosclerotic process.

Arteries↗
PubMed1999

Renal function one year after switching from Sandimmun to Neoral.

BACKGROUND: The replacement of Sandimmun by Neoral in 1995 was thought to cause subsequent renal function deterioration due to the better bioavailability of the new drug. We prospectively analyzed the effect of a dose-to-dose drug replacement on renal function over 12 months. METHODS AND RESULTS: The renal function of 47 consecutive heart transplanted patients was prospectively evaluated before (T0), at 1 (T1), 3 (T3), and 12 (T12) months after drug replacement. Mean serum creatinine was not significantly different at T0 and T12 (142 +/- 55 and 154 +/- 60 micromol/L, p = 0.1). We were able to reduce cyclosporine total and weight-indexed doses by, respectively, 11% and 14% between T0 and T12 (274 +/- 86 to 244 +/- 72 mg/d, p = 0.0003; and 3.7 +/- 1.4 to 3.2 +/- 1.2 mg/kg/d, respectively, p = 0.0005). CONCLUSIONS: This study demonstrates that the dose-to-dose replacement of Sandimmun by Neoral is feasible, with no direct influence on renal function over a 1-yr follow-up.

Cyclosporine↗
PubMed1999

Hemodynamic properties of the hemopump HP14.

BACKGROUND: The Hemopump HP14 is a catheter-mounted, transvalvular, left ventricular assist device intended for femoral percutaneous insertion. The pump was developed for patients with postoperative or postinterventional low cardiac output and for CABG surgery on the beating heart. Little is known about the effect of afterload and hematocrit on the pump performance. METHODS: The influence of hematocrit and afterload on the pump flow was tested using an in vitro model filled with heparinized bovine blood. Regression analysis of the pump flow with respect to three hematocrit values (20%, 30%, 40%) and ten afterload levels (30 mmHg-120 mmHg in 10 mmHg increments) was performed for all pump speed levels (n = 7). RESULTS: At all pump speed levels reduction of afterload and hematocrit were significant predictors for increasing pump flow (p<0.001). For hematocrit values between 40% and 20% and highest pump speed, mean pump flow at lowest afterload ranged between 2.34 and 2.53 L/min; and at highest afterload between 1.31 and 1.53 L/min. For speed level 1, afterload of 120 mmHg and hematocrit of 40% there was a maximal retrograde flow of 230+/-35 ml/min. CONCLUSIONS: Pump performance is significantly improved by both afterload and hematocrit reduction. In the weaning phase and during the removal of the device, the pump should run at a speed level of at least three to prevent retrograde flow in the pump. Estimates for pump flow in vivo can be extrapolated from our diagrams. Our results show that the Hemopump HP14 is a valuable alternative to intra-aortic balloon counterpulsation.

Animals↗
PubMed1999

[Three different types of atrial septal defects in the same family].

Most of the time atrial septal defects (ASD) are sporadic. Familial forms are characterised by the same type of the ASD, and are frequently associated by other cardiac, osteoarticular (Holt-Oram syndrome) or atrioventricular conductions abnormalities (ostium secundum ASD with prolonged PR, sinus venosus ASD with sinusal bradyarrhythmia). This report describes a family in which the father and his two children present an ASD, each one of a different type (ostium primum ASD, ostium secundum ASD, sinus venosus ASD), without any other associated malformations. To the best of our knowledge, this is the first report of a family in which three different ASD types are present.

Adult↗
PubMed1998

Incidence and prognostic value of electrocardiographic abnormalities after heart transplantation.

BACKGROUND: The improvement of surgical techniques and the use of immunosuppressive drugs within the past 15 years has made heart transplantation an increasingly performed procedure and an accepted treatment for end-stage cardiac failure. HYPOTHESIS: The aim of this study was to describe the changes of the 12-lead electrocardiogram (ECG) after heart transplantation and to determine their prognostic value on complications such as rejection or graft coronary artery disease during follow-up. METHODS: The ECGs of 62 consecutive patients were analyzed for 5 years at follow-up periods of 1, 2, 3, 6 months and yearly after transplantation. RESULTS: The most prevalent abnormality was the presence of complete or incomplete right bundle-branch block (RBBB). New RBBB appeared in 69% (43/62) of the patients, mainly during the first month (21/43). There was no left bundle-branch block. We detected nine episodes of supraventricular arrhythmias: one atrial fibrillation, six atrial flutter, one junctional tachycardia, one orthodromic tachycardia on a Wolff-Parkinson-White syndrome; all appearing during the first 3 months. Three of the six episodes of atrial flutter occurred during an episode of acute rejection. There was no relation between RBBB and the gender and age of recipients and donors, nor with the graft ischemic time and the pretransplantation hemodynamic values. Right bundle-branch block was not associated with acute rejection nor with graft coronary artery disease. CONCLUSION: The ECG abnormalities after heart transplantation have no predictive value on the long-term evolution. Right bundle-branch block is very frequent and is not associated with adverse prognosis.

Adult↗
PubMed1998

Spiral CT aortography: an efficient technique for the diagnosis of traumatic aortic injury.

The objective of this study was to assess the efficiency of spiral CT (SCT) aortography for diagnosing acute aortic lesions in blunt thoracic trauma patients. Between October 1992 and June 1997, 487 SCT scans of the chest were performed on blunt thoracic trauma patients. To assess aortic injury, the following SCT criteria were considered: hemomediastinum, peri-aortic hematoma, irregular aspect of the aortic wall, aortic pseudodiverticulum, intimal flap and traumatic dissection. Aortic injury was diagnosed on 14 SCT examinations (2.9 %), five of the patients having had an additional digital aortography that confirmed the aortic trauma. Twelve subjects underwent surgical repair of the thoracic aorta, which in all but one case confirmed the aortic injury. Two patients died before surgery from severe brain lesions. The aortic blunt lesions were confirmed at autopsy. According to the follow-up of the other 473 patients, we are aware of no false-negative SCT examination. Our limited series shows a sensitivity of 100 % and specificity of 99.8 % of SCT aortography in the diagnosis of aortic injury. It is concluded that SCT aortagraphy is an accurate diagnostic method for the assessment of aortic injury in blunt thoracic trauma patients.

Accidental Falls↗
PubMed1997

Outcome of survivors of accidental deep hypothermia and circulatory arrest treated with extracorporeal blood warming.

BACKGROUND: Cardiopulmonary bypass has been used to rewarm victims of accidental deep hypothermia. Unlike other rewarming techniques, it restores organ perfusion immediately in patients with inadequate circulation. This study evaluated the long-term outcome of survivors of accidental deep hypothermia with circulatory arrest who had been rewarmed with cardiopulmonary bypass. METHODS: Deep hypothermia (core temperature, <28 degrees C) with circulatory arrest was found in 46 of 234 patients with accidental hypothermia. In 32 of the 46 patients, rewarming with cardiopulmonary bypass was attempted, resulting in 15 long-term survivors. In most of these patients, deep hypothermia developed after mountaineering accidents or suicide at tempts. After an average (+/-SD) of 6.7+/-4.0 years of follow-up, we obtained the patients' medical histories and performed neurologic and neuropsychological examinations, neurovascular ultrasound studies, electroencephalography, and magnetic resonance imaging of the brain. RESULTS: The average age of the patients was 25.2+/-9.9 years; seven were female and eight were male. The mean interval from discovery of the patient to rewarming with cardiopulmonary bypass was 141+/-50 minutes (range, 30 to 240). At follow-up there were no hypothermia-related sequelae that impaired quality of life. Neurologic and neuropsychological deficits observed in the early period after rewarming had fully or almost completely disappeared. One patent had cerebellar atrophy on magnetic resonance imaging with mild clinical signs, a condition that may have been caused by hypothermia. Other clinical abnormalities were either preexisting or due to injuries not related to hypothermia CONCLUSIONS: This clinical experience demonstrates that young, otherwise healthy people can survive accidental deep hypothermia with no or minimal cerebral impairment, even with prolonged circulatory arrest. Cardiopulmonary bypass appears to be an efficacious rewarming technique.

Accidents↗
PubMed1997

[Pulmonary arteriovenous fistula: a rare cause of progressive asymptomatic cyanosis in neonates].

A six month old girl with no significant medical history was admitted to hospital for progressive cyanosis of recent onset refractory to oxygen therapy. There were no detectable cardiac murmurs. Chest X-ray showed an irregular left posterior parahilar infiltration. Echocardiography showed dilatation of the left atrium and ventricle but no cardiac malformation. The diagnosis of pulmonary arteriovenous fistula was suspected. Chest CT scan, magnetic resonance imaging and pulmonary angiography demonstrated the arteriovenous fistula in the lower lobe of the left lung. It was much bigger than the appearances of the chest X-ray suggested. After the left lower lobectomy, the cyanosis completely disappeared. Progressive cyanosis refractory to oxygen therapy without any apparent cardiac or pulmonary disease is strongly suggestive of pulmonary arteriovenous fistula. Surgical treatment is curative whereas the spontaneous outcome of this condition may be lethal.

Angiocardiography↗
PubMed1996

[Heart surgery in acute heart infarct. Indications and results].

The therapy of acute myocardial infarction has made major advances in the last 10 years. Cardiac surgeons have to adapt their strategies to the more aggressive management of acute myocardial infarction. Only in mechanical complications of acute myocardial infarction is cardiac surgery nowadays the therapy of choice. In cardiac rupture and ventricular septal defect, surgery is the only therapeutic option. In ischemic mitral regurgitation, cardiac surgery is required in the event of concomitant cardiogenic shock and pulmonary edema after intra-aortic balloon pump placement. Coronary artery bypass surgery my be indicated at low risk in patients with unstable angina pectoris when PTCA is not feasible or has failed, or in catheter emergencies.

Acute Disease↗
PubMed1996

Endothelial cell seeding improves patency of synthetic vascular grafts: manual versus automatized method.

Lack of an endothelial surface is the most important variable causing the relatively poor patency of synthetic bypass grafts. This study was designed to investigate the effect of endothelial cell seeding on small-diameter Dacron grafts seeded with microvascular endothelial cells from omentum, and to evaluate two methods (manual vs automatized) for one-stage seeding in a canine carotid artery model. In 30 mongrel dogs microvascular endothelial cells were harvested from omentum, either by a manual or an automatized method, and seeded onto 6-mm internal diameter Dacron prostheses prior to the graft interposition into the common carotid arteries. Non-seeded Dacron grafts were used as control grafts. All dogs received dipyridamole (75 mg/day) and acetylsalicylic acid (325 mg/day) for 4 weeks. The prostheses were explanted between 2 and 26 weeks after insertion. The results were assessed by patency, angiography, light and scanning electron microscopy, transmission electron microscopy, and morphometry. Endothelial cell seeding improved the patency rate significantly, regardless of the seeding methods used. The overall actuarial patency rates at 5, 12, and 26 weeks were 98%, 94% and 94%, respectively, for the seeded Dacron grafts, and 92%, 62% and 54%, respectively, for the non-seeded grafts. The automatized method yielded more endothelial cells per gram of omental tissue than the manual method (P = 0.0002), but there was no difference (P = 0.34) between the seeding densities per square centimeter of the graft surface. The harvesting and seeding by the automatized method took 55 min for the whole procedure, 20 min less than the manual method. We concluded that one-stage endothelial cell seeding with omental microvascular endothelial cells improved the patency of small-diameter Dacron grafts in a canine model. The automatized method obtained excellent results comparable to the manual procedure, and also reduced the time necessary for the cell seeding.

Animals↗
PubMed1996

[32 years of Senning's correction for transposition of the great vessels].

Between 1962 and 1994 342 patients with transposition of the great arteries (TGA) were treated by atrial correction. Since 1992 the atrial switch operation is the treatment of choice for TGA. We reviewed our 32 year experience. Average age of the patients at operation was 69 months (7 days--8.5 years). 177/342 (52%) patients had a complex TGA: 74 patients with ventricular septal defect (VSD), 49 patients with pulmonary stenosis (PS) and 54 with both (VSD and PS). The 30 day mortality was for the whole series 15.7%. In the last 4 years 7.5%. The actuarial survival rate for all patients was 88% after 10 years and 82% after 20 years. For simple TGA 91% after 10 years and 83% after 20 years, for complex TGA 84% and 81%. The most important cause of death during our longterm observation were heart failure (19 patients) and sudden death (7 patients). Average follow-up for the whole group was 13.4 years. Most of the survivors are functionally symptom free (66% NYHA I) or they have slight symptoms (29% NYHA II). Only 5% were NYHA III or IV. Arterial switch operation has replaced the atrial correction for TGA. Nevertheless the longterm results after atrial correction remains encouraging. The main threat to the patients is the failure of the systemic ventricle.

Cardiac Surgical Procedures↗
PubMed1995

Aneurysm of the superior mediastinal veins.

A case of true venous aneurysm with saccular dilation of the proximal half of the superior vena cava, the right innominate vein, and the distal two thirds of the left innominate vein in an 18-year-old white woman is presented. At surgery part of the aneurysmal wall was resected, and subsequently the mediastinal venous system was reconstructed with use of the rest of the aneurysmal wall. The postoperative course was uneventful. Operative treatment of mediastinal venous aneurysms is indicated to prevent possible major complications. We strongly suggest performance of this surgery only by means of a heart-lung machine.

Adolescent↗
PubMed1995

Severe respiratory insufficiency complicating Epstein-Barr virus infection: case report and review.

We report a case involving a young adult who had life-threatening bilateral pneumonitis in the course of an acute Epstein-Barr virus (EBV) infection. Because of severe hypoxemia, the patient required mechanical ventilation and additional oxygenation by an intravascular oxygenator. The patient was treated with corticosteroids and survived without sequelae. Severe pulmonary involvement associated with EBV infection is a rare but potentially fatal complication of infectious mononucleosis. Similar cases reported in the literature are reviewed, and the therapeutic options for this particular complication are discussed.

Acute Disease↗
PubMed1995

Pseudoaneurysm following aortic homograft: clinical implications?

OBJECTIVE: To determine the prevalence of pseudoaneurysm formation after aortic (left ventricular outflow tract) homograft implantation and to evaluate predisposing factors. METHODS: Echocardiographic data were analysed in 30 patients for evidence of pseudoaneurysm formation after homograft implantation. Pseudoaneurysm was characterised as a perfused echo-free space between the homograft and the native aortic wall communicating with the left ventricular outflow tract. Clinical data were analysed for potential predisposing factors for pseudoaneurysm formation. RESULTS: Pseudoaneurysms were found in 22 of 30 patients. Mean age, length of follow up after surgery, aortic systolic pressure gradient (15 (SD 12) v 10 (4) mm Hg), aortic root diameter, and size of the homografts were comparable in patients with and without pseudoaneurysm. preoperative infection, operating techniques, and whether first or reoperation did not affect pseudoaneurysm formation. However, pseudoaneurysms were often localised at the site of an abscess or a paravalvular leak after eradicated prosthetic valve endocarditis. CONCLUSIONS: (1) Doppler echocardiography demonstrates that pseudoaneurysm formation is common after aortic homograft implantation. (2) A prospective study is needed to clarify the prognostic importance of pseudoaneurysms. (3) The high incidence of pseudoaneurysm formation may lead to an improvement of surgical technique (application of fibrin glue).

Adult↗