Biomedical subjects

Peter Jaksch

Publications and source records attributed to Peter Jaksch.

17 recordsLinked to original sources

PubMed2007

Institutional experience with extracorporeal membrane oxygenation in lung transplantation.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) is currently accepted in lung transplantation either to bridge patients to transplantation or to treat postoperatively arising severe primary graft failure. Based on promising initial experiences we have since 2001 implemented ECMO as the standard of intraoperative extracorporeal support in lung transplantation (LuTX) patients with haemodynamic or respiratory instability with the potential to prolong ECMO support into the perioperative period. The aim of this paper is to summarise our total experience with the use of ECMO in LuTX. METHODS: We retrospectively reviewed all 306 patients undergoing primary lung transplantation from 1/2001 to 1/2006 with regard to the different forms of ECMO use. Results of all patients requiring ECMO were compared to those without ECMO during the observation period. RESULTS: ECMO was used in 147 patients in total. Two patients were bridged to transplantation. A total of 130 patients received intraoperative ECMO support. In 51 of these patients ECMO was prolonged into the perioperative period. Five of these patients required ECMO support again in the postoperative period due to graft dysfunction. Contrary cardiopulmonary bypass was used in 27 patients mainly with concomitant cardiac defects. Eleven of these patients needed therapeutic ECMO in the further course. A total of 149 patients without relevant risk factors were transplanted without any intraoperative extracorporeal support. Six of these patients required ECMO support in the postoperative period for treatment of primary graft dysfunction. Overall 3-month, 1-year and 3-year survival rates were 88.6%, 82.1% and 74.63%. The mentioned survival rates were 85.4%, 74.2% and 67.6% in the intraoperative+/-prolonged ECMO group; 93.5%, 91.9% and 86.5% in the no support group and 74.0%, 65.9% and 57.7% in the CPB group. CONCLUSION: ECMO is a valuable tool in lung transplantation providing the potential to bridge patients to transplantation, to replace CPB with at least equal results and to overcome severe postoperative complications. Favourable survival rates can be achieved despite the fact that ECMO is used in the more complex patient population undergoing lung transplantation as well as to overcome already established severe complications.

Adult↗

PubMed2006

Relationship between cytomegalovirus DNA load in epithelial lining fluid and plasma of lung transplant recipients and analysis of coinfection with Epstein-Barr virus and human herpesvirus 6 in the lung compartment.

Cytomegalovirus (CMV) is a significant cause of morbidity and mortality in lung transplant recipients (LTRs). The aim of the present study was to elucidate the relationship between the CMV DNA load in the lung compartment and that in plasma. For CMV load determination, the level of CMV DNA in plasma and bronchoalveolar lavage (BAL) samples was measured in a total of 97 paired BAL and plasma samples obtained from 25 LTRs. The original virus concentration in the epithelial lining fluid (ELF) was calculated from the BAL samples by correcting for dilution using the urea dilution method. In addition, the load of Epstein-Barr virus (EBV) and that of human herpesvirus 6 (HHV-6) DNA also were determined in BAL samples, recalculated for their concentrations in the ELF, and compared with the CMV DNA load. CMV DNA was found more frequently and at significantly higher levels in the lung compartment than in plasma (P<0.001, Wilcoxon test), and the CMV load in the ELF was associated with symptomatic CMV disease. EBV and HHV-6 were detected in 43.6% and 21.7% of the ELF samples, respectively. A statistically significant association was found between the CMV and EBV DNA loads in the ELF (P<0.001; Spearman's rho=0.651). Thus, in LTRs, determination of the CMV DNA load in the lung compartment may be advantageous compared to monitoring only viremia. The significant relationship between EBV and CMV DNA loads in the ELF of LTRs and its clinical impact require further investigation.

Adult↗

PubMed2006

Emergence of multiple cytomegalovirus strains in blood and lung of lung transplant recipients.

BACKGROUND: Cytomegalovirus (CMV) is a major pathogen in lung transplant recipients (LTRs). The emergence of different CMV strains in lung and blood after transplantation has not yet been analyzed. METHODS: In total, 75 serum and 91 broncheoalveolar lavage (BAL) samples obtained from 25 LTRs in the follow-up after transplantation were tested for the presence of different CMV strains. The gB, gN, and gO genes of the CMV isolates were analyzed by subtype-specific PCR, restriction fragment length polymorphism (RFLP), sequencing, and phylogenetic analysis. RESULTS: Mixed CMV-strain populations were detected after cessation of antiviral prophylaxis in up to 80% and 90% of the patients' BAL and serum, respectively, and this was independent of the CMV serostatus of donor and recipient. In five patients, the same single CMV strain was consistently detectable over at least 1 year in lung and blood, although in two of these cases donor and recipient had both been CMV-seropositive. Most CMV strains were distributed in the lung and blood compartment. Symptomatic CMV infection within the first year after transplantation was observed only in patients with mixed CMV-strain populations (P<0.05). CONCLUSION: Most LTRs harbor more than one CMV strain in their lung and blood compartment after cessation of prophylaxis, but the CMV strain distribution within and between the compartments varies between individuals and is not associated with the donor/recipient serostatus. The data further show that compartmentalization of CMV strains in lung versus blood seems to be a rare event and that the presence of mixed CMV-strain infections within the first year after transplantation may be disadvantageous for LTRs.

Adolescent↗

PubMed2005

Donor total lung capacity predicts recipient total lung capacity after size-reduced lung transplantation.

BACKGROUND: Size-reduced lung transplantation has only recently undergone widespread use, especially in highly urgent cases. However, it is still not considered standard procedure at most centers. It has the potential to alleviate the donor organ shortage by allowing the use of oversized grafts for small and pediatric recipients. Limited data exist on pre-operative parameters predicting functional outcome after lung transplantation in general, especially after size-reduced lung transplantation. METHODS: All 98 patients undergoing primary lung transplantation during a 2-year period, including 27 size-reduced lung transplantations, were analyzed retrospectively. Pre-operative functional parameters were-after correction of estimated values according to the amount of size reduction-correlated with post-operative functional assessment. Actual and predicted total lung capacity (TLC) of transplant recipients and predicted TLC of donors was compared with the best post-operative TLC achieved within 12 months after transplantation. RESULTS: Size-reduced lung transplantation was performed in 27 cases. Downsizing was achieved by lobar transplantation (n = 9), split-lung transplantation (n = 2) or peripheral segmental resection (n = 16). There was a statistically highly significant (p < 0.01) correlation between donor TLC and best recipient TLC achieved after transplantation (Pearson's correlation coefficient = 0.675). No statistically significant correlation was seen between pre-operative recipient actual TLC and best post-operative TLC (p = 0.87; Pearson's correlation coefficient = 0.415). In standard lung transplant recipients post-operative TLC was correlated with both donor predicted TLC (p < 0.01; Pearson's correlation coefficient = 0.509) and actual pre-operative recipient TLC (p < 0.01; Pearson's correlation coefficient = 0.667). CONCLUSIONS: Post-operative recipient TLC in size-reduced lung transplantation can be predicted by donor TLC rather than pre-operative recipient TLC.

Adolescent↗

PubMed2005

Initial experience with oral valganciclovir for pre-emptive cytomegalovirus therapy after lung transplantation.

BACKGROUND: The most common opportunistic viral pathogen after lung transplantation is cytomegalovirus (CMV). Oral valganciclovir, a prodrug of ganciclovir, has been introduced as a potential drug for prophylaxis and treatment of CMV infection and disease in lung transplantation. The goal of this study was to describe our initial experience with oral valganciclovir for pre-emptive treatment of CMV infections after lung transplantation. METHODS AND PATIENTS: We summarize our experience with 19 patients who underwent lung transplantation and received pre-emptive oral valganciclovir therapy in the situation of positive CMV polymerase chain reaction (PCR) in either plasma or bronchoalveolar lavage. None of the patients presented with manifest CMV disease. Treatment dosage of valganciclovir was 450 mg to 1800 mg daily, depending on renal function and white blood count. Treatment was continued until the CMV PCR became negative, in any case for a period of at least 14 days. RESULTS: Three patients received two courses of pre-emptive oral valganciclovir; 16 patients were treated once. Eleven patients (57.9%) were treated because of a positive plasma CMV PCR; in eight patients (42.1%) the PCR was positive only in bronchoalveolar lavage. Therapy was initiated 896 +/- 1186 days (range, 108-3911) after transplantation with a mean CMV PCR of 45,536 +/- 149,294 copies (range, 426-706,000). In all cases the PCR fell below detectability (<400 copies) after a period of 22 +/- 10 days of treatment (range, 7-50 days). Mild to moderate leucopenia was observed in seven patients (36.8%) during treatment. None of the patients developed new onset of other potentially drug-related disorders such as neutropenia, anemia, deterioration of renal function or gastrointestinal disorder. CONCLUSIONS: Pre-emptive therapy with oral valganciclovir for CMV infections detected by PCR in either plasma or bronchoalveolar lavage after lung transplantation seems to be efficacious and safe. However, regular blood counts should be performed to detect developing leucopenia.

Administration, Oral↗

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

Monitoring C2 level predicts exposure in maintenance lung transplant patients receiving the microemulsion formulation of cyclosporine (Neoral).

BACKGROUND: Dosing of the microemulsion formulation of cyclosporine (Neoral) is conventionally based on trough levels (C(0)). However, experience in renal transplantation has shown that cyclosporine exposure during the absorption phase (AUC(0-4)) is critical for optimizing immunosuppression, and that cyclosporine (CsA) concentration at 2 hours post-dose (C(2)) shows the closest correlation with AUC(0-4). This study evaluated whether C(2) values correlate more closely with AUC(0-4) than C(0) in lung transplant patients. METHODS: Pharmacokinetic data were collected prospectively from 20 clinically stable adult lung allograft recipients receiving CsA, mycophenolate mofetil and steroids. Indications for transplantation were emphysema (n = 15), idiopathic fibrosis (n = 2), primary pulmonary hypertension (n = 1), cystic fibrosis (n = 1) and lymphangioleiomyomatosis LAM (n = 1). Blood samples were collected at 0, 1, 2, 3 and 4 hours after administration of CsA, and then AUC(0-4) was calculated. The Correlation between cyclosporine concentration at each time-point and AUC(0-4) was also calculated. RESULTS: C(2) showed the closest correlation with AUC(0-4) (r(2) = 0.85). C(0) had the poorest correlation of all time-points (r(2) = 0.64). Two patients with radiologic signs of gastroparesis had no peak cyclosporine levels at all and were excluded from the correlation analysis. Mean AUC(0-4) was 3,700 ng . h/ml during Year 1 post-transplant, 2,400 ng . h/ml during Years 1 to 3, and 1,500 ng . h/ml thereafter. Mean C(2) values were 1.2 microg/ml during Year 1, 0.8 microg/ml during Years 1 to 3, and 0.5 microg/ml thereafter. CONCLUSIONS: C(2) is the single time-point that correlates most closely with AUC(0-4) in lung transplant recipients without gastroparesis. It remains to be demonstrated whether monitoring CsA based on C(2) levels results in a lower incidence of rejection without additional toxicity.

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

Broncho-alveolar lavage matrix metalloproteases as a sensitive measure of bronchiolitis obliterans.

Bronchiolitis obliterans (BO) is a survival-limiting factor in lung transplantation. There are no common BO markers in use. Since BO is associated with extracellular matrix remodeling, we asked whether matrix metalloproteases (MMPs) and their tissue inhibitors (TIMPs) could serve as BO markers. In 72 lung transplant patients (34 BO syndrome (BOS) 0, 15 BOS 0-p, and 23 BOS 1) serum and broncho-alveolar lavage (BAL) MMP and TIMP levels were examined by ELISA. The BAL cell counts were additionally analyzed. The serum MMP-2, MMP-8, MMP-9 and TIMP-2 levels were not different in all groups. In contrast, the BAL MMP-8, -9 and TIMP-1 levels were significantly elevated in BOS 0-p (p = 0.003; p = 0.007; p = 0.0003, respectively) and BOS 1 (p = 0.003; p = 0.001; p = 0.0004, respectively) as compared to BOS 0 patients. The BAL MMP-8, -9 and TIMP-1 levels were significant predictors of BOS 0-p (p = 0.01; p = 0.01; p = 0.01, respectively) and BOS-1 (p = 0.007; p = 0.01; p = 0.006, respectively) in receiver operating characteristic analysis. Except for BAL macrophages that were significantly decreased in BOS 0-p versus BOS 0 patients; other cell counts were not different between the groups. BAL MMP-8, -9 and TIMP-1 might be useful markers to detect BO in lung transplant patients.

Adult↗

PubMed2005

In vivo measurement of levofloxacin penetration into lung tissue after cardiac surgery.

Nosocomial pneumonia is a severe complication after cardiac surgery (CS). Levofloxacin, a fluoroquinolone, qualifies for the therapy of postoperative pneumonia. However, penetration properties of levofloxacin into the lung tissue could be substantially affected by CS: atelectasis, low cardiac output after CS, high volume loads, and inflammatory capillary leak potentially influence drug distribution. The aim of our study was to gain information on interstitial antibiotic concentrations in lung tissue in patients undergoing coronary artery bypass grafting with cardiopulmonary bypass. Therefore, six patients undergoing elective CS participated in this prospective study. A dose of 500 mg of levofloxacin was administered intravenously in addition to standard antibiotic prophylaxis immediately after the end of surgery. Time versus concentration profiles of levofloxacin in the interstitial lung tissue and plasma were determined. A microdialysis technique was used for lung interstitial concentration measurements. The microdialysis procedure was well tolerated in all patients and no adverse events were observed. The median area under the concentration curve (AUC) of levofloxacin in interstitial lung fluid was 18.6 microg.h/ml (range, 10.1 to 33.6). The median AUC for tissue (AUC(tissue)) of unbound levofloxacin/AUC(total) in plasma was 0.6 (range, 0.4 to 0.9). The median unbound AUC(tissue)/MIC was 2.4 (range, 1.3 to 4.2) for Pseudomonas aeruginosa. Our study demonstrated the feasibility and safety of microdialysis in human lung tissue in vivo after CS. The unbound AUC/MIC ratio revealed that levofloxacin used in the described manner was borderline sufficient for the treatment of nosocomial pneumonia caused by Klebsiella pneumoniae and insufficient for the treatment of pneumonia caused by Pseudomonas aeruginosa, because the breakpoint of 30 to 40 for AUC/MIC could not be reached by the conventionally used dosage schema in our post-CS setting. Penetration was lower than in previous reports.

Aged↗

PubMed2004

Association of cytomegalovirus DNA concentration in epithelial lining fluid and symptomatic cytomegalovirus infection in lung transplant recipients.

BACKGROUND: The authors have investigated the effectiveness of virus detection from bronchoalveolar lavage (BAL) samples for the identification of symptomatic cytomegalovirus (CMV) infection in lung transplant recipients. METHODS: Thus, 275 BAL samples taken from 105 lung transplant recipients during follow-up were analyzed by quantitative polymerase chain reaction (PCR) and virus isolation. RESULTS: Quantitative PCR detected virus in all 24 BAL samples taken at onset of symptomatic disease, and virus culture in only 7 samples (29.2%). Twenty-three of 251 BAL samples (9.2%) were positive by PCR, although they were obtained in an asymptomatic phase. Quantitation of CMV DNA from BAL allowed no discrimination between symptomatic and asymptomatic infection in individual cases. However, when the urea dilution method was used to recalculate the CMV DNA concentration for the epithelial lining fluid (ELF) diluted in the BAL, a CMV DNA level of more than 10 copies/mL ELF was clearly associated with symptomatic disease. CONCLUSION: The CMV DNA level in ELF may be a marker for symptomatic CMV infection.

Bronchoalveolar Lavage Fluid↗

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

Treatment of severe acute lung allograft rejection with OKT3 and temporary extracorporeal membrane oxygenation bridging.

OBJECTIVES: The use of OKT3 for treatment of advanced high-grade acute rejection episodes eventually can result in cytokine release and consecutive pulmonary edema. Temporary extracorporeal membrane oxygenation (ECMO) bridging can be used to overcome this crucial period before the beneficial effects of OKT3 can be observed. METHODS: We summarize our experience with three patients, who underwent lung transplantation and presented with severe acute rejection episodes. OKT3 had to be initiated due to insufficient response to standard rejection therapy with corticosteroids. Upon initiation of OKT3 treatment, a massive life-threatening deterioration of lung function in spite of heavily invasive respirator treatment was seen and temporary ECMO support was imperative to support graft function. Results of this treatment were retrospectively reviewed. RESULTS: In all cases femoro-femoral veno-arterial ECMO was used for support of the impaired graft and after a period of 4-5 days led to a massive improvement of graft function. In the further course two patients could be discharged from hospital and are still alive 30 and 36 months, respectively, after the described incident. One patient died 4 months later due to liver failure. CONCLUSIONS: We conclude that the use of ECMO support in patients experiencing significant side effects from OKT3 therapy is a useful and effective therapeutic tool to overcome the initial critical period until the lung has sufficiently recovered.

Acute Disease↗

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

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↗

PubMed2003

Eigenvector approximation leading to exponential speedup of quantum eigenvalue calculation.

We present an efficient method for preparing the initial state required by the eigenvalue approximation quantum algorithm of Abrams and Lloyd. Our method can be applied when solving continuous Hermitian eigenproblems, e.g., the Schrödinger equation, on a discrete grid. We start with a classically obtained eigenvector for a problem discretized on a coarse grid, and we efficiently construct, quantum mechanically, an approximation of the same eigenvector on a fine grid. We use this approximation as the initial state for the eigenvalue estimation algorithm, and show the relationship between its success probability and the size of the coarse grid.

Journal Article↗

PubMed2002

Successful lung volume reduction surgery brings patients into better condition for later lung transplantation.

OBJECTIVES: Lung volume reduction surgery (LVRS) is accepted as a potential alternative therapy to lung transplantation (LTX) for selected patients. However, the possible impact of LVRS on a subsequent LTX has not been clearly elucidated so far. We therefore analyzed the course of 27 patients who underwent LVRS followed by LTX in our institution. METHODS: Twenty-seven patients (11 male, 16 female, mean age 51.9+/-2.2 years) out of 119 patients who underwent LVRS between 1994 and 1999 underwent LTX 29.7+/-3.2 months (range 2-57 months) after LVRS. Based on the postoperative course of FeV1 after LVRS (best value within the first 6 months postoperatively compared with the preoperative value) patients were divided into two groups: Group A (n=11) without any improvement (FeV1 <20% increase), and Group B (n=16) with FeV1 increase > or = 20% after successful LVRS which declined to preoperative values after 8-42 months. Subsequent LTX was performed 22.9+/-5.6 months after LVRS in Group A and 34.3+/-4.9 months after LVRS in Group B (P<0.05). Patients were analyzed according to the course of their functional improvement and of their body mass index (BMI) after LVRS and to survival after LTX, respectively. Values are given as the mean+/-SEM and significance was calculated by the chi(2)-test whereas continuous values were estimated by Student's t-test. RESULTS: Patients in Group A without improvement in FeV1 after LVRS had no increase in BMI as well and this resulted in a high perioperative mortality of 27.3% after LTX. On the contrary, patients in Group B, who had a clear increase of FeV1 after LVRS, experienced a significant increase of BMI of 23.2+/-4.5% as well (P<0.05). This improvement in BMI remained stable despite a later deterioration of FeV1 prior to LTX. After LTX, these patients had a significantly lower perioperative mortality of 6.3% as compared to Group A (P=0.03). CONCLUSIONS: Successful LVRS delays the need for transplantation, improves nutritional status and brings patients into a better pretransplant condition, which results in decreased perioperative mortality at LTX. Patients after failed LVRS, however, should be considered as poor candidates for later transplantation.

Body Mass Index↗