Biomedical subjects

Gernot Seebacher

Publications and source records attributed to Gernot Seebacher.

18 recordsLinked to original sources

PubMed2006

Cystic formation of the foramen ovale mimicking a right atrial myxoma.

A 65-year-old woman presented with shortness of breath, stenocardia, and tachycardia. She underwent several steps of examination. Echocardiography showed a suspicious formation in the right atrium extending into the inferior caval vein. The lesion was suspicious for a myxoma, a thrombus, or a malformation. Intraoperatively this formation presented as a cystic formation connected to the right atrial wall in the area of the foramen secundum and filled with blood and five calcified thrombi. We hypothesize that a slit-like opening in the foramen ovale produced a valve-like mechanism bulging parts of the septum secundum and produced this cystic formation.

Aged↗

PubMed2006

Decellularization does not eliminate thrombogenicity and inflammatory stimulation in tissue-engineered porcine heart valves.

BACKGROUND AND AIM OF THE STUDY: In tissue engineering of heart valves using decellularized xenogenic valves, it has been suggested that cell elimination would result in a biologically inert matrix. The aim of this in-vitro investigation was to evaluate different decellularization methods in regard to the completeness of cell removal, inflammatory response, and thrombocyte activation. METHODS: Decellularized porcine Synergraft valves were compared with porcine pulmonary conduits decellularized with Triton X-100, sodium deoxycholate, Igepal CA-630 and ribonuclease. Completeness of decellularization was evaluated with staining for nuclei and alpha-Gal epitope. Decellularized heart valves with and without seeding with endothelial cells (ECs) were incubated with human platelet-rich plasma and stained for CD41 and PAC-1 to evaluate thrombocyte activation. Samples were processed for laser scanning microscopy (LSM) and scanning electron microscopy (SEM). Migration of human monocytic cells towards extracted valve proteins was tested. RESULTS: In contrast to the Synergraft, complete cell removal and elimination of the alpha-gal epitope was achieved with the new decellularization method. Numerous adherent and activated platelets were found on the decellularized matrix. This was inhibited by seeding with ECs. Even in completely cell-free valve tissue extracellular matrix proteins attracted human monocytic cells as in early inflammation, depending on whether porcine or human tissue was used. CONCLUSION: Important differences were found in the decellularization efficacy of treatment methods. However, even complete elimination of cells and their remnants did not result in a biologically inert matrix. The decellularized porcine heart valve matrix has the potential to attract inflammatory cells and to induce platelet activation. These findings suggest that it will be important to control the different inflammation-stimulating factors if porcine tissues are to be used successfully in tissue engineering.

Animals↗

PubMed2005

Tissue engineering of heart valves: decellularized porcine and human valve scaffolds differ importantly in residual potential to attract monocytic cells.

BACKGROUND: Tissue-engineered or decellularized heart valves have already been implanted in humans or are currently approaching the clinical setting. The aim of this study was to examine the migratory response of human monocytic cells toward decellularized porcine and human heart valves, a pivotal step in the early immunologic reaction. METHODS AND RESULTS: Porcine and human pulmonary valve conduits were decellularized, and migration of U-937 monocytic cells toward extracted heart valve proteins was examined in a transmigration chamber in vitro. Homogenized tissue specimens were size fractionated by SDS-PAGE. The decellularization procedure effectively reduced the migration of human monocytes toward all heart valve tissue. However, only the antigen reduction of human pulmonary valves abolished the monocytic response (wall, 0.88+/-0.19% versus 30.20+/-3.93% migrated cells [mean+/-SEM]; cusps, 0.10+/-0.06% versus 10.24+/-1.83%) and was significantly lower (P<0.05) than that of the decellularized porcine equivalent (wall, 5.03+/-0.14% versus 24.31+/-2.38%; cusps, 3.18+/-0.38% versus 10.24+/-1.83%). SDS-PAGE of the pulmonary heart valve tissue revealed that considerable amounts of proteins with different molecular weights that were not detected in the human equivalent remain in the decellularized porcine heart valve. CONCLUSIONS: We describe for the first time that the remaining potential of decellularized pulmonary heart valves to attract monocytic cells depends strongly on whether porcine or human scaffolds were used. These findings will have an important impact on further investigations in the field of heart valve tissue engineering.

Animals↗

PubMed2005

Bronchial stump coverage with a pedicled pericardial flap: an effective method for prevention of postpneumonectomy bronchopleural fistula.

BACKGROUND: Bronchopleural fistula is a serious complication after pneumonectomy. The aim of this retrospective study was to investigate the efficacy of bronchial stump reinforcement with a pedicled flap of whole pericardium. METHODS: The bronchial stump of 93 consecutive patients who underwent pneumonectomy between July 1988 and March 2003 was covered with a pedicled pericardial flap. Pneumonectomy was performed for primary lung cancer in 89.2% of patients. The study patients received concomitant extensive mediastinal lymphadenectomy, resection of adjacent structures (aorta, vena cava, thoracic wall), and neoadjuvant or planned adjuvant chemotherapy or radiotherapy, or both. Operative and perioperative complications were recorded, and patients were followed up for a mean of 15 +/- 21.2 months (range, 9 to 126). RESULTS: Perioperative mortality was 4.3% (n = 4; pulmonary embolism, sepsis, cardiac arrest, and sudden death in 1 patient each). Perioperative complications occurred in 2 patients: renal failure and hemiplegia in 1 patient and cardiac tamponade in 1 patient. The latter complication, caused by tight reconstruction of the pericardium, was directly related to the applied method and required reoperation. No evidence of postpneumonectomy bronchopleural fistula was observed perioperatively and during the whole follow-up. One-year and 2-year survival was 65.7% and 44.8%, respectively. CONCLUSIONS: Bronchial stump reinforcement with a pericardial flap is a highly effective method for preventing postpneumonectomy bronchopleural fistula in selected patients.

Aged↗

PubMed2005

Extended donor criteria for lung transplantation--a clinical reality.

OBJECTIVE: Standard lung donor criteria have been established on opinions and individual experiences rather than on existing evidence. Since the scarcity of donor organs is one of the major limitations to lung transplantation, extension of donor lung criteria might considerably increase the donor pool. This study therefore evaluates the outcome, achieved with the use of extended donors versus standard donors and aims to redefine lung donor criteria. METHODS: We performed a retrospective analysis of 98 consecutive primary lung transplantations from 94 donors from 1/2001 to 12/2002. Donors were classified as extended if they fulfilled at least one criteria: age >55 years, PaO(2) at FiO(2)/PEEP 5 <300mmHg, tobacco history >20 pack years, inhalative drug abuse, presence of infiltration on chest X-ray or purulent secretions at bronchoscopy. Recipients were stratified in two groups according to whether they received a 'standard' or 'extended' organ. Postoperative complications, extubation time, ICU and hospital stay and survival were compared. RESULTS: Twenty-three (24.5%) donors were extended. Twenty-six recipients (26.55%) received organs from extended donors. Differences in intubation times (12+/-2 days standard vs. 14+/-5 days extended, P=0.70), ICU stay (16+/-2 days standard vs. 18+/-5 days extended, P=0.74) and hospital stay (38+/-4 days standard vs. 40+/-6 days extended, P=0.71) were not statistically significant. Postoperative bleeding rates were comparable (n=14 standard vs. n=3 extended) as well as bronchial anastomotic complications (n=7 standard vs. n=3 extended). Three months survival was 88.89% in the standard group vs. 92.31% in the extended group. One year survival is comparable as well with 81.94 vs. 84.62%, respectively. CONCLUSIONS: The use of lung donors who fail to meet standard criteria does not impair short and medium term results compared to standard lung donors. The impact on long term development of BOS has yet to be evaluated. The strict application of standard lung donor criteria excludes a considerable number of lungs potentially suitable for transplantation, thus liberalisation of donor criteria might help to overcome donor shortage.

Adult↗

PubMed2005

Quality of life after lung transplantation: a cross-sectional study.

BACKGROUND: The increase in life expectancy has raised the importance of quality of life after lung transplantation, although this issue has not yet been systematically investigated. The aim of this cross-sectional study was to provide an overview of quality of life in lung transplant patients. METHODS: Between April and July 2001, a set of 4 questionnaires were given to all adult, German-speaking lung transplant recipients (n = 108; response rate 87% [n = 94]): St. George's Respiratory Questionnaire (SGRQ), a lung-specific health status instrument; the Short Form-36 (SF-36), a general quality of life measure; the Hospital Anxiety and Depression Scale (HADS-D) and a self-reported questionnaire concerning sexual functioning, physical symptoms, adverse effects of immunosuppression and satisfaction with outcome. RESULTS: With regard to the SGRQ, all lung transplant recipients had significantly better scores, which reflected an enhanced quality of life compared with the reference value for patients with obstructive pulmonary disease (SGRQ: p < 0.001 in all sub-scales). The Hospital Anxiety and Depression Scale and the Mental Component Summary Scale of the SF-36 did not differ significantly compared with published normative data in the healthy population. However, the side effects of immunosuppression proved to be a major factor influencing the quality of life of lung transplant recipients (11% influenced strongly and 24% moderately). Seventy-six percent of lung transplant patients were highly satisfied with the transplant outcome and 92% would opt for the procedure again. Among all lung transplant recipients, those with cystic fibrosis were most satisfied (significantly) with their quality of life. CONCLUSIONS: Although lung transplant patients must cope with the side effects of immunosuppression, they report a highly satisfying quality of life with regard to physical and emotional well-being and social and sexual function.

Adult↗

PubMed2005

The decellularized porcine heart valve matrix in tissue engineering: platelet adhesion and activation.

An approach in tissue engineering of heart valves is the use of decellularized xenogeneic matrices to avoid immune response after implantation. The decellularization process must preserve the structural components of the extracellular matrix to provide a biomechanically stable scaffold. However, it is known that in vascular lesions platelet adhesion to extracellular matrix components occurs and platelet activation is induced. In the present study we examined the effects of a decellularized porcine heart valve matrix on thrombocyte activation and the influence of re-endothelialisation in vitro. Porcine pulmonary conduits were decellularized using Triton X-100, Na-deoxycholate and Igepal CA-630 followed by a ribonuclease digestion. Cryostat sections of decellularized heart valves with and without seeding with human umbilical vein endothelial cells (HUVEC) were incubated with platelet rich plasma. Samples were either stained with fluorescent antibodies for CD41 and PAC-I (recognizing the activated fibrinogen receptor) or fixed with glutaraldehyde. Thereafter, the samples were processed for laser scanning microscopy (LSM) or scanning electron microscopy (SEM). Examination by LSM showed numerous platelets with co-localized staining for CD41 and PAC-1 on the nonseeded decellularized heart valve matrix whereas after seeding with endothelial cells no platelet activation was detected. SEM revealed platelet adhesion and aggregate formation only on the surface of the non-seeded or partially denuded matrix specimens. We show in this study that the decellularized porcine matrix acts as a platelet-activating surface. Seeding with endothelial cells effectively abolishes the platelet adhesion and activation and therefore is necessary to eliminate thrombogenicity in tissue engineered heart valves.

Animals↗

PubMed2004

Cystic fibrosis and lung transplantation--determination of the survival benefit.

INTRODUCTION: Cystic fibrosis is a well acknowledged indication for lung transplantation; however, the optimal timing for transplantation remains debatable. Liou et al. described a score for calculating 5-year probability of survival for patients with cystic fibrosis and concluded that only patients with a probability of survival < 30% gained a survival benefit from transplantation; those between 30% and 50% had equivocal survival effects from transplantation and those > 50% suffered negative effects. The aim of the present study was to determine the validity and applicability of this model. METHODS: Data from patients with cystic fibrosis transplanted between January 1995 and July 2001 were retrospectively reviewed. Survival score according to Liou was calculated from data collected before transplantation. Patients were classified according to 5-year probability of survival (group 1: < 30%, group 2: 30%-50%, groups 3-5: > 50%). Actuarial survival rates were calculated separately for each group and compared with the predicted probability of survival. RESULTS: During the observation period 27 patients were transplanted for cystic fibrosis. Three patients had to be excluded from further analysis because of incomplete pretransplant data. Fifteen patients were classified as group 1 and nine patients as group 2. No patients were eligible for groups 3 to 5. There were nine female patients and six males in group 1, mean age 22.1 +/- 4.9 years. Mean survival time was 918 +/- 787 days; 1-, 3- and 5-year survival rates were 66.6%. Three male patients and six females were classified as group 2, mean age 26.2 +/- 12.2 years. Mean survival time for this group was 701 +/- 617 days, and 1-, 3- and 5-year survival rates were 66.6%. CONCLUSION: We found that only patients with a 5-year probability of survival < 50% had been transplanted. For patients in groups 1 and 2 we report identical 5-year survival rates of 66.6%. According to our experience, cystic fibrosis patients with a 5-year probability of survival < 30% and also those between 30% and 50% gain a clear survival benefit from bilateral lung transplantation.

Actuarial Analysis↗

PubMed2004

Upregulated hypoxia-inducible factor-1 DNA binding activity to the vascular endothelial growth factor-A promoter mediates increased vascular permeability in donor lung grafts.

BACKGROUND: Transplantation-induced hypoxia results in enhanced vascular permeability and tissue vascular endothelial growth factor (VEGF) and endothelin-1 (ET-1) overexpression in donor lung grafts. Promoter studies have uncovered a hypoxia-inducible factor (HIF)-1 binding site (HBS) in 5'-flanking region of VEGF gene that regulates the hypoxia-induced expression of VEGF; and ET-1 potently stimulates VEGF-A production. We hypothesized that HIF-1 regulates VEGF-mediated vascular permeability in lung grafts. METHODS: We studied the mRNA and protein expression of HIF-1 and its protein-binding capacity to the HBS of the VEGF gene in biopsies of preserved donor and control lungs, using real-time reverse transcription-polymerase chain reaction, Western blotting, and electrophoretic mobility shift assay. Wet-to-dry lung weight ratio was measured in donor and control lungs. RESULTS: While HIF-1 alpha mRNA expression was unchanged, HIF-1 beta was downregulated (p < 0.05) in donor versus control lungs. Protein expression of both, HIF-1 alpha and -beta was significantly upregulated in donor lung grafts. HIF-1 binding to the HBS of the VEGF promoter as well as tissue fluid content were increased in donor lung biopsies versus controls (p < 0.05). CONCLUSIONS: These data indicate that upregulated HIF-1 DNA binding activity to the HBS of VEGF-A most likely contributes to elevated VEGF levels in preserved lung grafts. Unchanged HIF-1 alpha mRNA expression did not affect HIF-1 alpha protein levels. Endothelin-1 increases HIF-1 alpha accumulation and activates HIF-1 transcription complex in vitro. Therefore, ET-1-mediated increased HIF-1 alpha protein stability most likely leads to transcriptional activation of VEGF during lung graft preservation. Targeting HIF might be of benefit to counteract edema formation in preserved lung grafts.

Aryl Hydrocarbon Receptor Nuclear Translocator↗

PubMed2004

Lobar transplantation, split lung transplantation and peripheral segmental resection--reliable procedures for downsizing donor lungs.

OBJECTIVES: The increasing scarcity of donor lungs, especially for small and pediatric recipients has stimulated the development of new operative techniques, which allow larger lungs to be downsized for use in smaller recipients. This approach has only recently gained widespread use-especially for highly urgent recipients-however, it is still not considered a standard procedure. METHODS: This report reviews the Vienna University experience with cadaveric split lung transplantation, lobar transplantation and by means of peripheral resection size reduced lung transplantation within the years 2001-2002. Peri-operative complications and outcome of those patients were retrospectively analysed and compared to the patients undergoing standard single or double lung transplantation during the observation period. RESULTS: During the observation period 98 primary lung transplantations were performed, of which 27 (27.6%) were size reduced transplantations. Size reduction was achieved by lobar transplantation (n=9), split lung transplantation (n=2) or peripheral segmental resection (n=16). There was no statistically significant difference between the size reduced and standard lung transplantation group with regard to the rate of bronchial healing problems (n=3/7; P=0.85) and the rate of post-operative bleeding (n=5/12; P=0.85). No other major thoracic surgical complications were observed. Three months survival rate was 85.2% in the size reduced group, compared to 92.9% in the standard group (P=0.13). CONCLUSIONS: Size reduced lung transplantation, including split lung transplantation, lobar transplantation and peripheral segmental resection, is a reliable procedure providing equal results compared to standard lung transplantation.

Adolescent↗

PubMed2004

Relation between size of prosthesis and valve gradient: comparison of two aortic bioprosthesis.

OBJECTIVES: The outcome of patients undergoing aortic valve replacement (AVR) may be affected by the influence of prosthesis-patient mismatch on left ventricular mass regression. However, due to the discrepancies in labeled valve size, size of sizer and actual valve dimension, it is difficult to compare different valve types. In order to perform an objective comparison, this study was designed to compare the hemodynamics of the Edwards Lifescience pericardial (ELP) and the Medtronic Mosaic porcine (MM) bioprosthesis between patients receiving the same valve size and between patients with the same aortic annulus diameter. METHODS: This prospective, randomized study was performed on 81 hospital survivors out of 86 patients undergoing AVR with either the ELP (n=39) or the MM (n=42) bioprosthesis. Intra-operative randomization was performed after the surgeon had excised the aortic valve, measured the size of the aortic annulus with three different sizers (ELP, MM and a set of metric sizers), and decided which size he would implant for either of the valve types. All valves were implanted in supra-annular position with the same implantation technique. Echocardiographic follow-up was performed early postoperatively and 6 months thereafter. RESULTS: In 12 (31%) of the patients receiving the ELP-valve, as compared to 3 (7.1%) of the patients receiving the MM-valve, the labeled valve size was smaller than the aortic annulus diameter (P<0.05). Early postoperatively, mean (17.4+/-3.1 vs 20.3+/-3.6 mmHg) and peak gradients (30.1+/-4.8 vs 37.6+/-9.6 mmHg) for the 21 mm ELP-valve were lower than for the 21 mm MM-valve (P<0.05). All other hemodynamic parameters did not show significant differences at any time point. When the same aortic annulus diameter was taken as a reference, there were no significant hemodynamic differences between either valve type at any time point, regardless of the valve size implanted. CONCLUSIONS: This study demonstrates that the hemodynamic performance of the ELP and the MM bioprosthesis are comparable when the same aortic annulus diameter is taken as a reference. The significant variabilities between different valve types with regard to labeled valve size, valve-sizer size and actual valve size have to be taken into account, when hemodynamic comparisons are performed.

Aged↗

PubMed2004

Reverse cardiac remodelling in patients with primary pulmonary hypertension after isolated lung transplantation.

OBJECTIVE: Pulmonary hypertension eventually leads to severe distortion of the cardiac geometry with consequent impact on cardiac function. The purpose of this study was to prove reverse cardiac remodelling after isolated bilateral lung transplantation (LuTX) in patients with advanced primary pulmonary hypertension (PPH) and severe alterations of cardiac morphology and function. METHODS: In the period of 2000-2002 17 (10 female, seven male) patients with advanced PPH underwent isolated bilateral LuTX. Median age was 30 years (range 16-53). All patients were in NYHA III or IV, most of them with intractable ascites, established renal impairment, malnutrition and immobility, continuously deteriorating despite various forms of pharmacological treatment including i.v. and inhalative prostacyclin, diuretics, Ca-antagonists, bosentan and catecholamines. Echocardiography and Doppler echocardiography measurements were performed before and 3 months after transplantation. Left and right ventricular diameters and function were assessed and tricuspid valve regurgitation was determined. RESULTS: Mortality after 3 months was 17.5% (cerebral bleeding, multi-organ failure and diffuse myocardial infarction in one patient each). Three months after LuTX the 14 surviving patients were in NYHA I or II. Echocardiography showed normal left ventricular function and markedly improved right ventricular function with normal size of the RV. The leftward shifted flattened interventricular septum had returned in its physiological position and the high-grade tricuspid insufficiency had disappeared in all patients. CONCLUSIONS: Advanced alterations of cardiac morphology and function normalize completely and pre-existing tricuspid insufficiency disappears in PPH patients after isolated bilateral LuTX. Quality of life is excellent. Therefore, LuTX is preferred and safe in patients with advanced PPH even with severe cardiac dysfunction.

Adolescent↗

PubMed2004

Decellularization protocols of porcine heart valves differ importantly in efficiency of cell removal and susceptibility of the matrix to recellularization with human vascular cells.

OBJECTIVE: We compared 3 different decellularization protocols in porcine heart valves for efficiency of complete cell removal and potential for recellularization. METHODS: Porcine aortic and pulmonary roots were treated with trypsin, sodium-dodecyl-sulphate, or a new method using 0.25% tert-octylphenyl-polyoxyethylen in combination with sodium-deoxycholate. After a subsequent ribonuclease digestion, specimens were seeded with in vitro expanded human saphenous vein endothelial cells and myofibroblasts. RESULTS: After treatment with trypsin and subsequent ribonuclease digestion, endothelial attachment took place; however, xenogenic cells were still visible within the matrix. Unexpectedly, when human cells were seeded onto specimens that had been decellularized with sodium-dodecyl-sulphate, the matrices were surrounded by nonviable endothelial cell fragments, indicating a toxic influence of the ionic detergent; 0.25% tert-octylphenyl-polyoxyethylen together with sodium-deoxycholate completely removed porcine cells and enabled host recellularization. CONCLUSION: Compared with trypsin and sodium-dodecyl-sulphate involving decellularization procedures, reported to be effective in cell removal and susceptible to recellularization with human cells, only the porcine matrix treated with a new detergent-based decellularization method using 0.25% tert-octylphenyl-polyoxyethylen/sodium-deoxycholate followed by nuclease digestion presented an excellent scaffold for recellularization with human cells.

Aortic Valve↗

PubMed2004

Heterotopic tracheal transplantation with omentum wrapping in the abdominal position preserves functional and structural integrity of a human tracheal allograft.

OBJECTIVES: Transplantation of a human trachea has been reported only twice in the literature with limited documentation of the functional and structural properties of the allograft. PATIENTS AND METHODS: A 57-year-old patient with chronic obstructive pulmonary disease with low segment tracheal stenosis was accepted for lung transplantation and 2-stage tracheal allotransplantation. Standard bilateral sequential lung transplantation was performed with the transfer of the donor trachea into the recipient's abdomen, which was wrapped in the greater omentum and sutured into the abdominal wall, similar to a stoma. The patient received immunosuppression consisting of cyclosporine A, mycophenolate mofetil, and cortisone. Sixty days later, the tracheal allograft presented with macroscopically normal appearance with maintained elasticity and rigidity. The patient underwent a cricotracheal resection 6 months after lung transplantation. However, reconstruction with direct end-to-end anastomosis was achievable. The tracheal allograft, therefore not needed for reconstruction, was harvested and underwent complete investigations. RESULTS: Cross-section of the graft revealed a mechanically stable and macroscopically intact trachea. Hematoxylin-eosin staining demonstrated vital cartilage covered by respiratory epithelium. Angiography, followed by corrosion studies and electromicroscopy, demonstrated excellent vascularization of the tracheal wall. CONCLUSION: The patient is alive 31 months posttransplantation and remains in bronchiolitis obliterans syndrome stage 0. Human trachea wrapped in omentum maintains its functional and structural integrity and may be used for 2-stage allotransplantation.

Abdominal Wall↗

PubMed2004

Reconstructed bicuspid aortic valve after 10 years: clinical and echocardiographic follow-up.

BACKGROUND: Sixteen patients (mean age, 30.9 +/- 12.9 years; range, 9-79 years) with incompetent bicuspid aortic valves underwent valve-sparing correction between 1992 and 1995. METHODS: All patients underwent triangular resection of the enlarged leaflet. In addition, 13 patients underwent commissuroplasty. In 3 patients leaflet perforations were corrected with glutaraldehyde-fixed autologous pericardial patch. All patients underwent annual echocardiographic and clinical examinations at our institution. RESULTS: During follow-up 1 patient died of heart failure, and 3 patients underwent reoperations because of valve incompetence or dilatation of the sinus. Two patients underwent reoperation perioperatively. At long-term follow-up (mean, 10.06 +/- 1.01 years) the remaining 10 patients were in New York Heart Association class I. No patient was receiving anticoagulation, and no thromboembolic, bleeding, or endocarditis events were observed in 107.2 cumulative patientyears of follow-up. Mean grade of regurgitation was 0.7 +/- 0.5; mean aortic flow velocity was 2.29 +/- 0.47 m/s. Optimal valvular function led to normal ventricular diameters (left ventricular end systolic diameter, 39.2 +/- 4.3 mm; left ventricular end diastolic diameter, 56.2 +/- 5.9 mm) and normal ventricular function (fractional shortening, 31.5% +/- 0.1%). The dimensions of the aortic root were stable from 1-year to late followup (mean aortic annulus, 27.1 +/- 6.8 mm; sinus of Valsalva, 33.0 +/- 7.1 mm; sinotubular junction, 34.1 +/- 7.7 mm; ascending aorta, 31.6 +/- 7.4 mm). CONCLUSION: In contrast to early follow-up results of 5 reoperations, clinical and echocardiographic results were excellent for 10 patients who had undergone reconstruction of bicuspid incompetent aortic valves, and the patients were in stable condition after 10 years. However, the mode of early failure is unknown. Reconstruction of bicuspid valves is possible in selected patients.

Adolescent↗

PubMed2003

Lung transplantation. Donor selection.

The demand for donor lungs currently exceeds the supply of suitable grafts by a significant margin. Legal backgrounds and organizational and logistic issues are of major impact on the available donor pool. Re-evaluation of the donor criteria currently in use and new, innovative approaches such as living donor lung transplantation and non-heart-beating donation will hopefully contribute to improve this situation and reduce waiting time and waiting list mortality.

Brain Death↗

PubMed2002

Dilatation of the autograft root after the Ross operation.

OBJECTIVE: Structural differences of the pulmonary root may predispose it to progressive dilatation in the systemic circulation after the Ross operation. We identified the incidence and risk factors of pulmonary autograft root dilatation. METHODS: One hundred and seven adult patients (mean age of 36+/-11 years) were followed after the Ross operation since 1991 including an echocardiogram within 3 months of surgery and yearly clinical assessment and echocardiography. The autograft was measured at the maximum diameter of the sinus (SV) and aortic insufficiency (AI) assessed. A SV of >37 mm was considered as root dilatation and the incidence over time was calculated using the Kaplan-Meier method. Clinically relevant dilatation was defined as a root diameter of >42 mm. In addition, we determined the percentage change of the sinus diameter between the early and latest echocardiogram. Furthermore we tested the influence of patient variables and risk factors on dilatation. RESULTS: By 1 year, dilatation was found in 21 patients (20%). The SV was >42 mm in eight patients (7%). By 7 years, only 45% of patients were free of dilatation. Eleven patients (10%) had a SV of >42 mm. Increase in SV was time related and linear. However, 90% of patients showed <25% dilatation during follow-up. Time from operation, early SV diameter, male gender and surgical technique were identified as significant risk factors of dilatation. However, dilatation has not lead to reoperation due to aneurysm formation or development of significant AI. CONCLUSIONS: We conclude that time dependent autograft root dilation occurs but does not cause an increase in AI and need for reoperation up to 7 years. These findings warrant the pursuit of the concept of the Ross operation in young patients who regain excellent functional status and life style without anticoagulation.

Adult↗

PubMed1990

[The determination of trace amounts of protein in solutions containing surface-active substances].

A rapid and sensitive method for protein determination (0.5-16 micrograms) in samples of any volume containing various surfactants in concentration up to 1% is suggested. The method includes the protein acid denaturation, the solution of acid insoluble precipitate of detergent in ethanol (25-30%), the protein determination on nitrocellulose filter, dyeing by aminoblack 10 B, elution of dyed complex and colorimetric determination at 630 nm.

Amido Black↗