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Biomedical subjects

P Vogt

Publications and source records attributed to P Vogt.

At least 55 records · Page 3Linked to original sources
PubMed1999

Corrective use of the 2.5-mm GFX stent for suboptimal angioplasty results in small coronary arteries.

To evaluate the clinical efficacy of endoluminal stenting in the setting of percutaneous intervention for small coronary artery lesions, we reviewed our results on stenting with the 2.5-mm GFX stent (Arterial Vascular Engineering, Santa Rosa, CA) during an 18-month study period. A total of 120 patients with significant coronary artery disease in vessels </=2.6 mm were followed up clinically. Procedural success (defined as angiographic residual stenosis <20% without clinical complications) was obtained in 94% of cases. In-hospital complications were death (1%), non-Q-wave myocardial infarction (5%), and urgent repeat percutaneous intervention because of stent thrombosis (3%). During a mean follow-up of 9.8 months (range, 6-23 months), the following complications were noted: myocardial infarction (1%), clinical need for repeat intervention (13%) requiring repeat percutaneous treatment (12%) and surgical revascularization (1%). In conclusion, transcatheter application of a specifically designed stent for coronary artery disease in small vessels seems safe and efficient with a low incidence of adverse events during follow-up. Cathet. Cardiovasc. Intervent. 48:157-161, 1999.

Adult↗
PubMed1999

Immobility as a major cause of bone remodeling in residents of a long-stay geriatric ward.

Residents of a long-stay geriatric ward at the University Hospital Basel were included in a study to investigate the effects of hypovitaminosis D and immobility. All 91 women (mean age 82.5 years) and 92 men (mean age 78.7 years) were enrolled in the study. Measurements included bone resorption, as measured by urinary deoxypyridinoline (dpd), serum 25-hydroxyvitamin D (25OHD), serum intact parathyroid hormone (iPTH), and their correlations with a four grade mobility score. Mobility score reflected the degree of weight bearing, ranging from walking independently to primarily bed bound. In 86% of all residents, serum 25OHD levels were below the normal limit of 12 ng/ml. Secondary hyperparathyroidism (HPT) was detected in 24% of all patients, using 55 pg/ml as the upper limit for serum iPTH. No significant correlation was found between urinary dpd and serum 25OHD or serum iPTH. Mobility index and both urinary dpd (f: P = 0.001, r = 0.37; m: P < 0.0001, r = 0.47) and serum calcium (female: P = 0.007, r = 0.28; male: P = 0.02, r = 0.24) were positively related. In institutionalized elderly people with a high prevalence of vitamin D deficiency serum intact PTH levels did not correlate with bone resorption as measured by urinary deoxypyridinolin. However, more immobile subjects had significantly higher excretion rates for urinary dpd and higher serum calcium levels. Our results suggest that in elderly people immobility may contribute to bone loss that might preempt the development of secondary HPT through elevation of serum calcium.

Activities of Daily Living↗
PubMed1999

Congenital subaortic stenosis by accessory mitral valve tissue, recognition and management.

Accessory mitral valve tissue as the single cause for left ventricular outflow tract obstruction is a very rare cardiac malformation in normally connected hearts. We report a case in which this condition was present as single cause for left ventricular outflow tract obstruction. The surgical technique is described and a review of the literature presented.

Aortic Valve Stenosis↗
PubMed1999

Tissue engineering in cardiovascular surgery: MTT, a rapid and reliable quantitative method to assess the optimal human cell seeding on polymeric meshes.

OBJECTIVE: Currently used valve substitutes for valve replacement have certain disadvantages that limit their long-term benefits such as poor durability, risks of infection, thromboembolism or rejection. A tissue engineered autologous valve composed of living tissue is expected to overcome these shortcomings with natural existing biological mechanisms for growth, repair, remodeling and development. The aim of the study was to improve cell seeding methods for developing tissue-engineered valve tissue. METHODS: Human aortic myofibroblasts were seeded on polyglycolic acid (PGA) meshes. Cell attachment and growth of myofibroblasts on the PGA scaffolds with different seeding intervals were compared to determine an optimal seeding interval. In addition, scanning electron microscopy study of the seeded meshes was also performed to document tissue development. RESULTS: There was a direct correlation between cell numbers assessed by direct counting and MTT(3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltertra-zoliu m bromide) assay. Both attach rate and cell growth seeded on meshes with long intervals (24 and 36 h) were significantly higher than those seeded with short intervals (2 and 12 h) (P<0.01), there was no significant difference between 24- and 36-h seeding interval. Scanning electron microscopy also documented more cell attachment with long seeding intervals resulting in a more solid tissue like structure. CONCLUSION: It is feasible to use human aortic myofibroblasts to develop a new functional tissue in vitro. Twenty-four hours is an optimal seeding interval for seeding human aortic myofibroblasts on PGA scaffolds and MTT test is a rapid and reliable quantitative method to assess the optimal human cell seeding on polymeric meshes.

Biomedical Engineering↗
PubMed1999

Conservative treatment of the aortic root in acute type A dissection.

OBJECTIVE: In acute type A dissection long-term results of conservative aortic root surgery were compared with the outcome of primary valve and/or root replacement. METHODS: Between 1985 and 1995, 199 patients (mean age 59 years, 154 men) were operated on. The aortic root was involved in the dissection process and valve incompetence of varying degree was present without exception. Replacement of a proximal aortic segment was standard procedure in all patients. The aortic valve was preserved in 126 patients: commissural suture resuspension (12 patients), root reconstruction with GRF-glue (gelatine-resorcin-formaldehyde/glutaraldehyde-glue) (114 patients). Valve replacement was performed in 73 patients (50 composite grafts, 23 valve prostheses with separate supracoronary grafts). Preoperative risk factors (valve replacement vs. preservation): coronary artery disease (11 vs. 8%, NS), tamponade (18 vs. 17%, NS), unstable hemodynamics (22 vs. 15%, NS), renal failure (4 vs. 6%, NS), neurologic disorder (19 vs. 32%, NS). RESULTS: The overall early mortality was 23.6% (47/199 patients) and increased after commissural suture resuspension compared with GRF-glue reconstruction (P = NS). Parameters of the early postoperative period did not differ between conservative treatment and root/valve replacement: low cardiac output, 34 versus 38% (P = NS); myocardial infarction, 10 versus 11% (P = NS); hemorrhage, 25 versus 23% (P = NS); duration of intensive care (P = NS). Survival was 61% after 8 years without difference between the two principal treatment groups (P = NS) and between the two conservative subgroups (P = NS). At 2 years, GRF-glue reconstruction had an increased freedom from reoperation on the aortic root (92 vs. 70%, P = 0.0253) and event free survival (77 vs. 41%, P = 0.0224) compared with suture resuspension. Commissural suture resuspension was an independent, significant predictor for reoperation (P = 0.0221, relative risk = 4.7130). CONCLUSION: Surgery for acute type A dissection still carries a considerable early risk. Preservation of the aortic root is safe in the absence of Marfan or annuloaortic ectasia, but a certain incidence of reoperations on the aortic valve and the aortic root has to be accepted. Root reconstruction using GRF-glue is the method of choice and is superior to suture resuspension, with a significantly better reoperation-free and event-free survival.

Acute Disease↗
PubMed1999

[Cardiovascular disease in pregnancy].

There is a heterogeneous population of young women with cardiovascular disease contemplating pregnancy. Many of the conditions are rare and require teams with expertise in the management of such patients. A specific congenital or acquired cardiovascular anomaly and its physiology must be understood. The nature of prior surgical procedures and the residua and sequelae following therapy are essential to manage a pregnant woman with cardiovascular disease. Physiologic changes during pregnancy and after delivery must be known. Counseling includes maternal and fetal risk stratification and genetic counseling regarding inherited disorders. The outcome of pregnancy is favourable in many women with good functional class. These patients can be reassured. A multidisciplinary approach may be crucial to manage this population during pregnancy, labour, delivery and in the postpartum period to avoid serious maternal and fetal complications. Women with intermediate and high risk pregnancy must be followed and managed in a high risk pregnancy unit and a team from obstetricians, cardiologists, anesthetists, pediatricians, neonatologists and cardiac surgeons who are skilled in high risk pregnancies. Vaginal delivery is the method of choice in many women (class 1 woman) and cesarean section is seldom a cardiac indication. Contraindications for pregnancy are: poor maternal functional class, poor ventricular function, severe cyanosis without pulmonary hypertension (oxygen saturation < or = 85%), pulmonary vascular disease, severe mitral stenosis, severe left ventricular outflow tract obstruction, Marfan syndrome with aortic dilatation (> 40 mm) and aortic valve involvement (moderate to severe aortic regurgitation), symptomatic hypertrophic obstructive cardiomyopathy. Preconception counseling must be offered if unfavourable outcome is likely. Tubal ligation is probably the safest and most appropriate method of sterilization if there is a high risk pregnancy.

Adult↗
PubMed1999

Bronchiolitis obliterans organizing pneumonia associated with polymyalgia rheumatica.

The association of bronchiolitis obliterans organizing pneumonia (BOOP) with polymyalgia rheumatica is rare, and only one case has previously been described. This study reports on the case of an 80 yr-old male who presented with malaise, nonproductive cough and exertional dyspnoea for several weeks, along with a history of bilateral shoulder and pelvic girdle pain of several months' duration. The chest radiograph revealed a pneumonic infiltrate in the right lower lobe, which was unresponsive to antibiotics. Bronchoscopy, bronchoalveolar lavage and a transbronchial lung biopsy established the diagnosis of BOOP. The patient improved consistently on steroids. As in other connective diseases, organizing pneumonia may be one of the early manifestations of polymyalgia rheumatica.

Aged↗
PubMed1999

Composite graft replacement of the aortic root: long-term results, incidence of reoperations.

BACKGROUND: Long-term results after composite graft replacement of the aortic root may depend on the insertion technique. METHODS: 181 consecutive patients (mean age 53 years; 153 men) operated on between 1983 and 1993 were studied. Indications for surgery were annuloaortic ectasia (n=98), acute aortic dissection (n = 46), other indications (n = 12), and various indications after previous aortic valve replacement (n = 25). Mean follow-up was 28 months. The open-button technique was performed in 74 patients (41 %) and the Bentall inclusion technique in 107 patients (59%), with a Cabrol shunt to the right atrium in 16 patients. RESULTS: Overall survival was 75% after 7 years, significantly decreased in acute aortic dissection (p = 0.0019) and without difference between the two surgical techniques (p = 0.3166). Reoperation-free survival was 69% at 7 years and significantly decreased after acute dissection (p = 0.0421 ). Pseudoaneurysm formation only occurred in 3 patients operated with the Bentall technique not including a Cabrol shunt. CONCLUSIONS: Long-term results are satisfactory. In acute aortic dissection survival is decreased and late reoperations more frequent. The open technique is safe in non-dissection and in acute dissection and avoids pseudoaneurysm formation. The Bentall technique combined with Cabrol shunt is indicated if there is a high risk of hemorrhage. Long-term monitoring of the aorta is mandatory in patients with acute dissection and/or Marfan disease.

Acute Disease↗
PubMed1999

Pregnancy after atrial repair for transposition of the great arteries.

OBJECTIVE: To investigate the risk of pregnancy in patients with transposition of the great arteries (TGA) who have undergone atrial repair. DESIGN: Retrospective analysis (1962-94) of 342 TGA patients who underwent atrial repair. Of 231 known late survivors, 48 were women over 18 years old who were interviewed about possible reproductive plans and previous pregnancies. As a control, comparison was made with data of 57 500 women (mean age 26 years) obtained from the Swiss Statistical Bank in Bern. RESULTS: Mean follow up was 13.7 years; 66% remained asymptomatic, 29% had mild to moderate cardiac symptoms, and 5% suffered from severe cardiac symptoms (New York Heart Association grade III-IV). Thirty six of the 48 women wished to bear children and, to date, there have been 10 live births, two spontaneous first trimester abortions, and one induced abortion at 16 weeks. During pregnancy there was one case of cardiac deterioration and two cases of pneumonia. There was no evidence of congenital heart disease in the children. CONCLUSIONS: In this relatively small series the completion of pregnancy in women with TGA who had undergone atrial repair and who had normal functional cardiac status was uncomplicated

Abortion, Spontaneous↗
PubMed1999

Optimized performance of the Abiomed BVS 5000: adjustment of the pump height based on Doppler control of the flow pattern.

The Abiomed BVS 5000 is an automatic volume-driven paracorporeal pulsatile assist device providing left, right or biventricular support. The paracorporeal position allows optical adjustment of filling volumes of the device, which determines the output of the system. A procedure to adjust for maximal stable flow has not yet been established. In vitro measurements have been performed to assess the flow and pressure characteristics of the Abiomed BVS 5000 by raising the preload in 5 mmHg steps before running the system. Doppler probes were placed at the inflow and outflow lines of the pump. After setting the afterload at 80 mmHg the assist device was started. Two measurements were performed to find optimal flow (based on Doppler control and optical adjustment). (1) By Doppler control a stable flow pattern was found at a preload of 25 mmHg with a mean atrial pressure of 5 mmHg and a mean flow of 5.3 +/- 0.7 l/min (mean +/- standard deviation) at the inflow and outflow sites (the console flow was 4.8 +/- 0.4 l/min with a frequency of 61.8 +/- 2.0 l/min). (2) Optical adjustment of the pump height gave rise to a preload of 35 mmHg where we recorded a maximal atrial pressure of 107 +/- 5.8 mmHg, a maximal retrograde flow of -4.3 +/- 1.2 l/min at the inflow and -1.2 +/- 0.4 l/min at the outflow site. The mean flow at the inflow and outflow sites was 5.1 +/- 0.5 l/min (the console flow was 4.6 +/- 0.3 l/min with a frequency of 59.6 +/- 2.6 Hz). At an initial afterload of 60 and 40 mmHg the system showed the same qualitative behaviour, but the results were less accurate. Optical adjustment of the pump height may result in an atrioventricular valve insufficiency with undetected retrograde flow and high atrial pressures. We conclude that a Doppler flow probe must be placed at the inflow site to guarantee maximal stable flow.

Equipment Design↗
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↗
PubMed1998

[Minimally invasive surgery for coronary disease: a new alternative].

To avoid the inflammatory syndrome generated by cardiopulmonary bypass, a new surgical technique, minimal invasive direct coronary artery bypass (MIDCAB), has been developed. An anastomosis is performed between the left internal mammary artery (LIMA) and the left anterior descending artery (LAD) on a beating heart, through a limited anterior thoracotomy. We describe our experience with this technique. Ten consecutive patients underwent a MIDCAB procedure. (9 males, age 65.9 +/- 9 years). There were 8 bypasses of the LIMA on the LAD, one bilateral mammary bypass on the LAD and the right coronary artery, and one conversion to a standard sternotomy with CPB for a saphenous vein bypass on the LAD because of injury to the LIMA (2nd case). There was one redo for haemostasis of the mammary artery bed (3rd case). The first 3 patients required postoperative blood transfusion. From the 4th operation onwards, with the introduction of new instrumentation which was better adapted to the narrowness of the surgical field, there were no further surgical complications. During the follow-up (mean 5 months; range 2-9), no patient suffered anginal recurrence. With the improvement of instrumentation, the MIDCAB technique offers satisfactory short- and mid-term results, while avoiding CPB with its adverse effects. Lastly, the cosmetic result is far better than with the conventional procedure.

Aged↗
PubMed1998

[Surgical management of soft tissue sarcomas: principles of resection and reconstructive plastic procedures].

1. Adequate complete surgical resection with a oncologic radical or wide margin of normal tissue represents the most important measure to prevent a local recurrence. Limited excision with "shelling-out" of the tumor, through its "pseudocapsule" almost invariably means positive microscopic margins. The pathohistologically or macroscopically marginal or intralesional positive resection margins make a salvage surgery necessary. 2. A close safety margin of < 1 cm due to neighboured anatomic structures indicates a high risk of local recurrence and makes an adjuvant radiotherapy mandatory. Plastic-reconstructive surgery should prepare the radiotherapy fields, to avoid cavities or ulcerations. 3. Facts should be stated in the clinical record and the operation report, e.g. the safety margin should be defined by the surgeon and the pathologist; the histopathologic stage and grade are absolutely basic requirements. If necessary, a second histopathologic review should be asked for. 4. Tumor resection and reconstructive oncoplastic measures should correspond individually to the oncologic parameters, to the functional demands and to the age of the patient. 5. Multidisciplinary cooperation in a tumorboard is a precondition for an adequate treatment.

Humans↗
PubMed1998

Prognosis of medically treated patients referred for cardiac transplantation.

OBJECTIVES: To assess prognosis and factors influencing survival of transplant candidates in whom continued medial therapy was recommended in comparison to that of immediately listed patients. METHODS: Retrospective analysis of clinical, echocardiographic and hemodynamic data as related to survival or listing for transplantation of medically treated transplant candidates. PATIENTS: 160 patients considered 'too well' for cardiac transplantation and 133 patients immediately listed for transplantation. RESULTS: Forty-one of the medically treated patients deteriorated clinically and were listed after 10.7+/-12.3 months after initial evaluation. Mid-term prognosis (2 years) of patients never listed was comparable to that of immediately listed patients (74% vs. 70%) but long-term prognosis (5 years) was worse (41% vs. 54%, p<0.001). Cardiothoracic ratio and pulmonary capillary wedge pressure were independent predictors of survival (multivariate analysis) in patients whose NYHA class and physical working capacity improved and cardiothoracic ratio decreased significantly after adjustment of medical therapy. CONCLUSIONS: Mid-term prognosis of selected patients considered 'too well' for transplantation is comparable to patients immediately listed. Lower left ventricular filling pressures, smaller hearts on chest X-ray on initial evaluation, and improvement of symptoms during follow up may identify a subgroup of patients who do well on optimized therapy.

Actuarial Analysis↗
PubMed1998

Randomised comparison of Micro Stent I with Palmaz-Schatz stent placement for the elective treatment of short coronary stenoses.

This randomised trial compared the Micro Stent I and the Palmaz-Schatz stent for the elective treatment of short (<8 mm long), new-onset coronary stenoses. The primary endpoints were restenosis rate and minimal luminal diameter at 6 mo angiographic follow-up. The secondary endpoints were angiographic and procedural success of stenting and a composite clinical endpoint at 6 mo (death, myocardial infarction, and target site revascularisation). A total of 93 patients were randomised. Clinical and angiographic characteristics of the two groups were comparable. Angiographic success of stenting was 96% in both groups, and there were no complications so that the procedural success was also 96% in both groups. The restenosis rate was 29% for Micro Stent I and 27% for the Palmaz-Schatz stent (P = NS). The minimal luminal diameter at 6 mo was 1.75 +/- 0.72 mm in the Micro Stent I group and 1.84 +/- 0.59 in the Palmaz-Schatz group (P = NS). At 6 mo, a clinical endpoint was reached by 21% of the patients in the Micro Stent I group and by 11% in the Palmaz-Schatz group (P = NS). In conclusion, the elective treatment of short coronary stenosis with the Micro Stent I or the Palmaz-Schatz stent resulted in similar early and late outcomes. In particular, the late angiographic results were very similar.

Aged↗
PubMed1998

Stent by stent crush: procedural outcome and angiographic follow-up.

Rewiring of an occluded and incompletely deployed coronary stent with a sharp and/or tortuous entrance angle may be difficult in the emergency setting. We report the case of a patient who experienced subacute stent thrombosis in the proximal right coronary artery. Incorrect rewiring resulted in stent crush after conventional balloon angioplasty at lesion site. In order to improve the angiographic result parallel stent placement was performed. Repeat angiography at 6 months demonstrated vessel patency without restenosis.

Angioplasty, Balloon, Coronary↗