Biomedical subjects

W Wisser

Publications and source records attributed to W Wisser.

53 records · Page 3Linked to original sources

PubMed1996

Influence of human leukocyte antigen matching on long-term outcome after lung transplantation.

BACKGROUND AND METHODS: The importance of human leukocyte antigen matching for long-term outcome after lung transplantation is uncertain. We therefore analyzed retrospectively 78 consecutive primary, isolated lung transplantations (37 female, 41 male; 40 single, 38 bilateral) performed between October 1989 and October 1995 for which human leukocyte antigen typing of both donor and recipient was available. The follow-up ranged from 1 day to 60.3 months. Graft failure, defined as retransplantation or patient death, served as end point. RESULTS: Graft survival was significantly better with one mismatch at the B locus than with two mismatches (p = 0.046): 67% versus 51% and 61% versus 25% graft survival at 12 and 36 months, respectively. For the B and DR loci combined, a marked matching effect was also observed (p = 0.21 for zero to two mismatches versus three to four mismatches: 81% versus 62% and 51% versus 29% graft survival at 12 and 36 months, respectively. The sum of mismatches at the A, B, C, and DR loci combined showed a similar effect (p = 0.17 for zero to four mismatches versus five to eight mismatches: 83% versus 62% and 58% versus 29% graft survival at 12 and 36 months, respectively. Although no clear effect could be shown for the isolated DR locus, the outcome for the three patients with zero mismatches was notably good: one patient is alive at 27 months, two died 37 and 48 months after transplantation. The number of acute rejection episodes showed a clear but insignificant correlation to the number of mismatches. A similar trend was observed for the incidence of bronchiolitis obliterans syndrome. CONCLUSIONS: In summary, a strong influence of human leukocyte antigen matching on the long-term outcome after lung transplantation is suggested by our results. A clear trend toward improved graft survival with better human leukocyte antigen matching was observed, with the most significant effect occurring at the B locus.

Adolescent↗

PubMed1996

[Lung volume reduction in emphysema--experience and results of the first 2 years].

Between September 1994 and August 1996 Lung Volume Reduction Surgery (LVRS) was performed through median sternotomy, videoendoscopically or by thoracotomy in 60 patients (age 33 to 80 years, mean 56.7 years). All these patients had severe emphysema despite maximal conservative and physical therapy. The areas with the most destroyed lung parenchyma were resected by means of linear stapling devices, 3 patients (20%) out of 15 who were operated via sternotomy died postoperatively due to aspiration pneumonia, multiorgan failure and acute hepatic failure. In the videoendoscopic group with 45 patients, 2 patients (4.4%) died due to multiorgan failure and cardiorespiratory failure. 72.7% of the remaining patients showed a significant functional improvement (postoperative FEV1 > 130% of the preoperative value) with a marked decrease of dyspnea. There was no significant improvement in 23.7% of the patients (postoperative FEV1 = 90 to 110% of the preoperative value) and 3.6% of the patients had a functional deterioration. Residual volume decreased from 317.0 +/- 12.4% of predicted (%p) preoperatively to 226.2 +/- 8.8 %p within the first month (p = 0.0001). FEV1 significantly increased from 23.7 +/- 1.3 %p preoperatively to 36.6 +/- 4.1 %p during the first 6 months postoperatively (p = 0.0016). Radiological signs of hyperinflation and distention of the thorax preoperatively improved to narrowed intercostal spaces and a more shaped diaphragm. These morphological changes resulted in better ventilatory muscle function. The intrinsic PEEP significantly decreased from 5.92 +/- 0.64 cm H2O preoperatively to 1.70 +/- 0.25 cm H2O postoperatively (p = 0.0001). The work of breathing decreased from 1.58 +/- 0.09 J/l preoperatively to 0.99 +/- 0.07 J/l postoperatively (p = 0.0001). In conclusion, LVRS is an excellent therapeutic option for patients with severe emphysema and additional signs of severe hyperinflation with significant postoperative functional improvement and marked increase in quality of life.

Female↗

PubMed1996

[Surgical technique and results of bilateral volume reduction in patients with pulmonary emphysema].

Between 9/94 and 3/96 volume reduction was performed on 29 patients by a median sternotomy or videoendoscopic approach. Perioperative mortality occurred in three patients. The residual volume decreased within the first month from preoperative 308.8 +/- 13.4% of predicted (%p) to 217.9 +/- 12.7%p (p < 0.05). FeV1 significantly improved to 37.9 +/- 4.6%p after 3 months, versus 23.5 +/- 1.8%p preoperatively (p < 0.05). Intrinsic PEEP substantially decreased from 6.69 +/- 0.91 cm H2O preop to 0.93 +/- 0.28 cm H2O initially after surgery (p < 0.005). This was paralleled by the work of breathing: 1.78 +/- 0.2 J/l preoperatively versus 0.77 +/- 0.04 J/l postoperatively (p < 0.005). In conclusion, VR is a safe and successful option for patients with pulmonary emphysema, who show signs of marked hyperinflation.

Female↗

PubMed1995

The pulmonary nodule after lung transplantation. Cause and outcome.

In the immunocompromised patient, the pulmonary nodule remains a diagnostic and therapeutic challenge. We studied the incidence, cause, diagnosis, and therapy of pulmonary nodules after lung transplantation (LTx). Eight out of 64 patients (12.5%) developed pulmonary nodules after a median follow-up of 5.8 months (range, 1 to 10 months). The median age was 30.5 years (range, 21 to 62 years). Solitary pulmonary nodules (n = 2) disappeared spontaneously within 3 weeks and were suspected to be of infectious origin. The cause of multiple nodules (n = 6) was posttransplant lymphoproliferative disorder (PTLD [n = 3]), aspergillosis (n = 2), and abscesses caused by Pseudomonas aeruginosa and Staphylococcus aureus (n = 1). After an initial chest radiograph, CT with fine-needle biopsy was the most valuable diagnostic tool. In six patients, nodules resolved within 10 weeks (median, 8 weeks). Two patients, however, died of sepsis (P aeruginosa and S aureus and Aspergillus, respectively). The differential diagnosis of pulmonary nodules after LTx primarily comprises PTLD and infection (bacterial or fungal). To improve the outcome, early, aggressive treatment is mandatory; therefore, serial CT scans are strongly recommended to be part of the diagnostic armamentarium in LTx recipients.

Adult↗

PubMed1994

Hemodilution reduces early reperfusion injury in an ex vivo rabbit lung preservation model.

We sought to reduce early ischemia-reperfusion injury after lung preservation by an initial brief period of hemodilute reperfusion. Left lungs of New Zealand White rabbits were ventilated with room air and reperfused in an ex vivo ventilation-perfusion apparatus after 18 hours of storage at 10 degrees C. Lungs were randomly assigned to one of three groups (n = 6) according to the composition of initial reperfusate. In group 1 (control), preserved lungs were reperfused with whole blood for 20 minutes (hematocrit, 38%). In the experimental groups, blood was diluted to a hematocrit of 10% with Ringer's lactate (group 2) or low-potassium-dextran solution (group 3) for the first 10 minutes of reperfusion, followed immediately by whole blood for 10 minutes. Oxygen tension of left ventricular effluent at the end of the 20-minute assessment period was significantly higher in both hemodiluted groups (mean +/- standard error of the mean: group 2, 81.3 +/- 6.6 mmHg; group 3, 77.0 +/- 9.5 mmHg, versus Group 1, 46.3 +/- 7.4 mmHg; p < 0.006). Similarly, mean tracheal airway pressure was reduced in the hemodiluted groups, suggesting improved compliance (group 2; 3.1 +/- 0.3 mmHg; group 3, 2.8 +/- 0.6 mmHg; versus group 1, 6.5 +/- 1.4 mm Hg; p < 0.05). An initial 10-minute period of hemodilute reperfusion appears to reduce early pulmonary ischemia-reperfusion injury in this 18-hour ex vivo rabbit lung preservation model.

Airway Resistance↗

PubMed1993

[Cytomegalovirus infection following lung transplantation].

The significance of cytomegalovirus (CMV) infection after lung transplantation was investigated in 20 patients (ten women and ten men; mean age 46 [21-67] years). Indications for transplantation were emphysema (n = 6), cystic fibrosis (n = 2), primary pulmonary hypertension (n = 2), pulmonary fibrosis (n = 5), obliterating bronchiolitis (n = 2), cystic lung (n = 2) and bronchiectasis (n = 1). Incidence, diagnostic parameters (serology, virus isolation and histology) and efficacy of prophylactic and therapeutic measures were recorded. 16 of the 20 patients developed a CMV infection, which in 12 was clinically significant. CMV pneumonia developed in two patients, proving fatal in one. The infection occurred a median of 47 (17-200) days after the transplantation. Administration of Ganciclovir (5 mg/kg twice daily intravenously) brought about remission of symptoms in all but one of the patients and improved the clinical parameters.--This experience demonstrates that regular monitoring of the patients for possible CMV infection and its early therapy can achieve a low death rate.

Adult↗

PubMed1993

Closed circuit perfusion of an isolated rabbit lung. A new model for the evaluation of preservation quality of stored lungs.

The comparison of different preservation methods in lung transplantation demands a well standardized and reproducible animal model. The aim of this study was to establish as in vitro model in which the oxygenation capacity of the lung can be investigated over an extended period of time. Heart-lung blocks from 6 New Zealand white rabbits were harvested, the pulmonary artery and the left ventricle cannulated and the lungs perfused with whole rabbit blood by means of a roller pump and ventilated with room air. A dialyser was installed into the closed circuit perfusion for continuous deoxygenation of the oxygen-saturated blood gained from the left ventricle. Throughout the stable perfusion period the average arterial and venous partial oxygen pressure (pO2) levels were 105.8 +/- 15.5 mmHg and 55.2 +/- 6.2, respectively (P < 0.05). The average peak airway pressure steadily increased from 10.7 +/- 1.2 mmHg at the start of reperfusion to 21 +/- 14.4 mmHg after 180 minutes (P = NS). With this experimental setting it is possible to maintain stable conditions (i.e. constant venous and arterial blood gases) for at least 180 minutes. It is therefore feasible to compare the influences of different preservation methods on the quality of lung function.

Animals↗

PubMed1993

Early experience with sequential bilateral lung transplantation.

We performed 20 sequential bilateral lung transplantation in 19 consecutive patients from April 1990 to May 1992. Perioperative mortality was low (2 patients). One-year actuarial survival was 70%. All survivors had normal blood oxygen tension (82 mm Hg, mean) while breathing room air and continuing improvement of pulmonary function. Bronchial dehiscence did not occur. Stents were implanted in 7 patients to control bronchial stenosis. Aggressive treatment of graft rejection has been effective in preventing obliterative bronchiolitis.

Bronchial Diseases↗

PubMed1992

Management of severe bronchial ischemia after bilateral sequential lung transplantation.

A case of severe diffuse bronchial ischemia after bilateral sequential lung transplantation is presented. A combination of initial conservative treatment with silicone stenting and late bilateral retransplantation under stable conditions resulted in good clinical outcome. Factors in decision making and technical aspects of the stenting procedure are discussed.

Adult↗

PubMed1992

One and one-half year experience with unilateral and bilateral lung transplantation.

Lung transplantation has now become an established form of treatment for end-stage pulmonary parenchymal and vascular diseases. Despite its wide acceptance, technical aspects are still in discussion. We report on the initiation of our own lung transplant program and the technical changes we have performed during our first 1 1/2-year experience. During that period of time, we have performed 26 lung transplantations (16 single lung [SLTX] and 10 bilateral lung transplantations [BLTX]). Three-month survival for the whole group was 74% (69% for the SLTX group and 77% for the BLTX group). No instance of bronchial dehiscence was observed; however, there were eight cases of bronchial stenosis: six were managed by silicone stent insertion, one by bronchoplastic correction, and one by retransplantation. Changes in the technique of the bronchial anastomosis together with the addition of prednisone to the immediate postoperative immunosuppressive regime resulted in almost complete avoidance of these problems.

Adult↗

PubMed1991

Low-potassium UW solution for lung preservation. Comparison with regular UW, LPD, and Euro-Collins solutions.

University of Wisconsin solution has been used successfully in clinical kidney and liver preservation. The object of this study was to determine if low-potassium UW (LPUW) solution could be applied to pulmonary preservation. Rabbit lungs were stored after hypothermic pulmonary artery (PA) flush with four different solutions (group 1: low-potassium dextran (LPD) solution, group 2: high-potassium UW (HPUW) solution, group 3: LPUW solution, group 4: modified Euro-Collins (E-C) solution). The lungs were preserved at 10 degrees C for 30 hr and evaluated in an ex vivo ventilation/perfusion apparatus using fresh pooled venous rabbit blood. Mean PA flush pressures (MFP) during harvesting were significantly lower in groups 1 and 3 (8.1 +/- 1.0 mmHg and 7.3 +/- 0.6 mmHg, respectively; mean +/- SEM) than in groups 2 and 4 (15.5 +/- 1.7 mmHg and 12.3 +/- 0.9 mmHg, respectively). Lungs in groups 1 and 3 showed significantly higher PaO2 (103.5 +/- 8.0 mmHg and 89.3 +/- 7.2 mmHg) than groups 2 and 4 (48.3 +/- 7.7 mmHg, 66.7 +/- 4.7 mmHg). Groups 1 and 3 showed significantly lower wet/dry weight (W/D) ratios after reperfusion (6.21 +/- 0.15 and 6.39 +/- 0.23) than groups 2 and 4 (7.70 +/- 0.57 and 7.13 +/- 0.21, respectively). There were no significant differences in MFP, PaO2, PaCO2, mean pulmonary artery pressure, or W/D ratio between groups 1 and 3. These results suggest that LPUW solution may be as beneficial as LPD solution for pulmonary arterial flush and lung preservation.

Adenosine↗

PubMed1991

[Uni- and bilateral lung transplantation: functional results. Vienna Lung Transplant Group].

At the end of December 1990 11 patients had survived lung transplantation at the 2nd Department of Surgery, University of Vienna. In these patients 7 single lung (SLTX) and four bilateral lung transplantations (DLTX) were performed. The indication for operation in 6 cases was emphysema, in 2 cases mucoviscidosis, in 2 cases pulmonary fibrosis, and in 1 case secondary pulmonary hypertension, following operation of a ductus Botalli. By means of fitness tests, blood-gas analysis, pulmonary function tests and ventilation respectively perfusion scan a marked improvement of the clinical status of the patients following lung transplantation could be shown.

Adult↗

PubMed1990

Release and detection of dental corrosion products in vivo: development of an experimental model in rabbits.

An experimental animal model was developed to investigate the release of metal ions from nonprecious dental alloys. Cast specimens of five Ni-Cr-alloys and Co-Cr-alloys were implanted intramuscularly in rabbits for periods of 2, 4, 8, and 12 weeks. The concentrations of nickel, chromium, cobalt, and molybdenum in the implant-loaded muscles were determined by electrothermal atomic absorption spectrometry (AAS) and neutron activation analysis (NAA). Reference muscle samples of each animal were analyzed to determine the individual control values. Significant increases in the tissue concentrations of these metals occurred in the immediate vicinity of the implants. Concentration gradients of the corrosion products were found between the implant contact tissue and the implant periphery (p less than 0.001). Tissue concentrations of nickel and chromium correlated (r less than 0.7). Microprobe analysis before and after implantation of the alloy specimens indicated an even corrosive loss of the alloy surfaces and changes in the surface element distributions. Advantages and limitations of this animal model are discussed, as well as its application in future studies.

Animals↗

PubMed1990

Pulmonary surfactant in bronchoalveolar lavage after canine lung transplantation: effect of L-carnitine application.

Pulmonary surfactant during lung transplantation was investigated in the control group of a canine single lung transplantation model by measuring dipalmitoyl-phosphatidylcholine, the main phosphocholine fraction of surfactant in bronchoalveolar lavage. In a second group of dogs, L-carnitine, an essential cofactor for transfer of long-chain fatty acids into the mitochondria, was applied. Organ function after pulmonary artery flushing with modified Euro-Collins solution and hypothermic storage for 4 hours was adequate in both groups, with significantly higher arterial oxygen pressure levels in the L-carnitine group after 12 (p less than 0.05) and 24 (p less than 0.025) hours, respectively. In the control group, a reduction of the dipalmitoyl-phosphotidylcholine portion on total phosphotidylcholines was observed 4 and 12 hours after transplantation of the left lung (p less than 0.005 and p less than 0.01, respectively, both specified by Student's t test for dependent data, not significant by Bonferroni correction). In the simultaneously stored right lungs, a constant fall of the dipalmitoyl-phosphotidylcholine portion was demonstrated. In the L-carnitine group, significantly higher dipalmitoyl-phosphotidylcholine levels were observed in the transplanted left lungs after 4 hours (p less than 0.01) and in the continuously stored right lungs after 24 hours (p less than 0.005), when compared with the control group. These results suggest that dipalmitoyl-phosphotidylcholine portion on total phosphotidylcholine decreases parallel to the extent of the ischemic damage. Furthermore, the application of L-carnitine improved pulmonary function after transplantation, possibly by reducing the impairing effect of ischemia on alveolar type II cell metabolism and thereby on pulmonary surfactant system.

1,2-Dipalmitoylphosphatidylcholine↗

PubMed1989

Beneficial effect of iloprost on early pulmonary function after lung preservation with modified eurocollins solution.

Prostacyclin (PGI2) has proven beneficial effects on organ preservation. Iloprost (ZK 36 374), a stable synthetic analogue with a longer half-life of 14 minutes is reported to have less hypotensive effects than PGI2 while offering increased cytoprotective and antiaggregation action. In this study its effects on lung-preservation were investigated. The heart lung block of 12 Beagle dogs was harvested after flushing of the pulmonary artery with 60 ml/kg modified Eurocollins (MEC) solution, the left lung was stored for 4 hours and then transplanted into 12 weight-matched dogs. Prior to operation the animals were randomized into two groups with MEC solution as the only preservative in group A and an additional i.v. infusion of 1 microgram/kg/min Iloprost during 15 minutes prior to flushing and 15 micrograms/kg Iloprost administered to the perfusate in group B. Arterial pO2, alveolo-arterial oxygen difference (AaDO2) and pulmonary artery pressure (PAP) of the transplanted lungs were measured 1, 4, 12, and 24 hours after transplantation during occlusion of the contralateral pulmonal artery. The application of Iloprost resulted in a significant improvement of pO2 (p = 0.047), AaDO2 (p = 0.002) and PAP (p = 0.018) after 1 hour. Results in group B at later time points were improved without reaching statistical significance. Iloprost therefore showed beneficial effects on pulmonary function early after lung preservation with MEC.

Animals↗

PubMedDate not supplied

[The influence of major connectors of partial dentures of phonation: an instrumental analysis of speech].

After the insertion of removable dentures for restoring partially edentulous arches, phonation is affected by many factors, of which many influences are not completely understood. The aim of this study was to investigate the influence of various construction elements of maxillary and mandibular partial dentures on the formations of plosives, nasals, lateral approximates and fricatives. Twenty-four patients were included in the study. For each patient five different test dentures were constructed. Over a period of 24 h, six digital tape records were made for each patient. By this time, the patient had worn the dentures maximally 6 h. With the help of a computer-supported frequency analysis based on the principle of fast Fourier transformation (FFT), it was possible to demonstrate the differences in phonation in regard to denture design. During the test period, the patients were asked to fill in a questionnaire on denture comfort and phonation. This study also quantifies the influence of the sublingual bar on phonation. It can be assumed that the speaker tries to retain his habitual way of articulation despite the inserted test denture. Therefore, a phonation test immediately after insertion of a new constructed partial denture should be interpreted with caution because of the assumed compensation process. The results of this study could have consequences for dental therapy plans.

Adolescent↗

PubMedDate not supplied

A new flush solution for extended lung preservation.

BACKGROUND: The aim of this study was to compare the effect of the most frequently used clinical preservation solution (Euro-Collins, group I) with a newly composed low potassium, glucose- and insulin-containing preservation solution (141 mmol/L sodium, 6.4 mmol/L potassium, 119 mmol/L chloride, 5 mmol/L magnesium, 10 gm/L glucose, 10 gm/L dextrane and 20 U/L insulin) (group II) on postischemic lung function. METHODS: We studied 12 isolated New Zealand White rabbit lungs in a closed circuit model during the first 4 hours of reperfusion after 24 hours of ischemic hypothermic storage. RESULTS: Oxygenation capacity, defined by the difference between the arterial and venous oxygen tension was significantly higher in group II compared with group I after 10 (58.7 +/- 5.8 versus 34.9 +/- 7.5 mm Hg), 30 (63.5 +/- 7.8 versus 27.3 +/- 10.4 mm Hg) and 180 minutes (77.7 +/- 7.2 versus 8.8 +/- 5.6 mm Hg). Ventilatory pressure was significantly lower in group II after 1 minute (11.3 +/- 1.3 mm Hg versus 13.7 +/- 0.5 mm Hg, p < 0.05), with no significant difference thereafter. No significant difference was found in pulmonary vascular resistance except after 20 minutes (30.8 +/- 1.2 dyns/cm5 [group I] versus 27.1 +/- 1.1 dyns/cm5 [group II], p < 0.05). CONCLUSION: These data suggest that this new solution provides superior lung function after 24 hours ischemic time compared with Euro-Collins solution.

Animals↗