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Biomedical subjects

W Klepetko

Publications and source records attributed to W Klepetko.

At least 145 records · Page 8Linked to original sources
PubMed1989

[Intrathoracic splenosis].

Intrathoracic splenosis is an unusual event after diaphragmatic and splenic rupture, which causes intrathoracic mass lesions. It results from spontaneous autotransplantation of splenic tissue to serous surfaces. On chest X-rays, three different radiological appearances were distinguished: pulmonary mass lesions, pleural lesions and mediastinal tumors. Since the radiological appearance is nonspecific, a diagnosis may only be suspected together with the characteristic anamnesis. In those case scintigraphy should be performed because this method may verify the diagnosis. Here we report the radiological and clinical appearances of this entity by one of our own and 13 well-documented cases in the literature.

Adult↗
PubMed1989

Leaflet fracture in Edwards-Duromedics bileaflet valves.

Two cases of leaflet fracture in the Edwards-Duromedics valve at 36 and 38 months after implantation are reported. Both patients were immediately reoperated on and recovered well. In one valve an older housing fracture with partial tissue ingrowth was noted beside a recent transverse leaflet fracture. In the other valve the leaflet was fractured near the pivot mechanism. All larger embolized parts were detected in the iliac artery region by computed tomographic scan and were subsequently removed. Problems in diagnosis and the importance of immediate reoperation, even without exact diagnosis, are discussed. Technical evaluation of the valve revealed crack growth and arrest, giving evidence of fatigue fracture. Scanning electron microscopic examination revealed several areas of pitting and erosion. Although the exact cause of mechanical disruption remains speculative, pyrolytic carbon seems to have the characteristic of fatigue fracture as well as erosion damage. A connection between the two might exist.

Adolescent↗
PubMed1989

Blood platelets in cardiopulmonary bypass operations. Recovery occurs after initial stimulation, rather than continual activation.

The ultrastructure of blood platelets was related to platelet function and secretion products before, during, and after cardiopulmonary bypass. Circulating platelets from 15 patients undergoing aorta-coronary bypass operations were investigated at ten predetermined points of time by scanning and transmission electron microscopy. Simultaneously, platelet adenosine triphosphate, diphosphate, and serotonin, as well as plasma levels of platelet factor 4, beta-thromboglobulin, serotonin, thromboxane B2, lactic dehydrogenase, and free hemoglobin were measured. Moreover, platelet responsiveness toward adenosine diphosphate and collagen was determined by optical aggregometry. By scanning electron microscopy, the number of unactivated platelets dropped from 96% +/- 4% to 54% +/- 19% (p less than 0.05) 8 minutes after the onset of bypass. Simultaneously, the percentage of "shape changed" platelets significantly increased. No major release reaction was detected at this time. After the initial activation, platelet morphology began to recover although the bypass continued. During the late period of bypass, a highly significant correlation between increasing plasma levels of alpha-granule compounds (platelet factor 4 and beta-thromboglobulin) and lysis parameters (lactic dehydrogenase and free hemoglobin) was found. However, transmission electron microscopic analysis of the arterial filter and scanning electron microscopic findings of circulating platelets indicated that the release products in plasma were due not only to platelet lysis but also to a limited extent to secondary aggregation. In an inverse and probably causative manner, platelet morphology recovered, whereas the sensitivity of platelets to adenosine diphosphate and collagen decreased toward the end of bypass.

Adenosine Triphosphate↗
PubMed1988

Plasma atrial natriuretic factor in cirrhotic patients with ascites. Effect of peritoneovenous shunt implantation.

Human atrial natriuretic factor (ANF) levels were measured before and after peritoneovenous shunt implantation in 10 cirrhotic patients with ascites, in whom sodium retention is a major clinical problem. The mean preoperative plasma level of ANF was 82 ng/L (normal range, 5-80 ng/L). Peritoneovenous shunting resulted in a significant rise in plasma ANF to 308 ng/L (p less than 0.0025) immediately after operation. This was followed by a constant fall until the seventh postoperative day, when mean plasma ANF was still significantly elevated (149 ng/L) compared with the preoperative value (p less than 0.01). Three months after shunt implantation mean plasma ANF had returned to the preoperative level (75 ng/L). Mean sodium excretion increased from 2.6 mEq/h preoperatively to 10.2 mEq/h at the second postoperative day (p less than 0.025). No direct relationship was noted between changes in plasma ANF level and changes in urinary sodium excretion after shunt implantation. These data demonstrate an intact ANF release response to intravascular volume expansion in cirrhotic patients with ascites, but exclude ANF as the diminished natriuretic factor as proposed by the overflow theory of ascites formation. Sodium excretion and fluid retention seem to be the result of vascular underfill and fluid maldistribution, and hormonal changes are likely to be secondary to them.

Aged↗
PubMed1988

Phenotypic and functional analysis of cellular cytotoxicity after splenectomy.

Phenotypic and functional aspects of cellular cytotoxicity were investigated in patients after splenectomy. While assays testing for natural killer cell (NK) activity and antibody-dependent cellular cytotoxicity showed a significantly reduced (p less than 0.005 and p less than 0.025, respectively) activity of the relevant cell populations, lectin-dependent cellular cytotoxicity was either normal or, in one dilution of phytohemagglutinin, even significantly increased (p less than 0.025), as compared to healthy control persons. In a search for a possible explanation for this phenomenon, it was found that the total lymphocyte count was significantly increased (p less than 0.01) in patients after splenectomy, when compared with healthy control individuals. However, neither the absolute cell count nor the percentage of Leu7+ lymphocytes showed significant differences between splenectomized patients and controls. In contrast, the percentages of (Leu7+Leu2)+, OKT11+, OKT4+ and Leu2a+ lymphocytes were significantly decreased (p less than 0.0025, p less than 0.01 and p less than 0.005, respectively) in splenectomized patients with not only the percentage, but also the absolute number of DR+ lymphocytes being significantly increased (p less than 0.005 and p less than 0.05, respectively). We thus conclude that in patients after splenectomy NK activity is decreased which may possibly be due to the lack of a NK subset. In contrast, the overall percentages of T cells (OKT11+), T helper/inducer (OKT4+) and T suppressor cells (Leu2a+) were significantly decreased in patients after splenectomy, although this defect could be compensated by a significant increase in the absolute lymphocyte number.

Adult↗
PubMed1988

[Long-term bougienage treatment of corrosive strictures of the esophagus].

The value of long term bougienage of corrosive esophageal strictures is analysed in 21 patients. 67 bougienages have been performed with a 7.4 percent risk of perforation (5 cases), 4 patients whose symptoms were refractory to bougienage underwent operative therapy. Esophageal cancer developed in 2 patients and was operated in one of them. 70 percent of the 14 patients, who are still in the bougienage program report a good quality of life. We believe bougienage therapy of chronic corrosive esophageal strictures to be the method of choice in patients with high operative risk and satisfying response to the dilatations.

Adolescent↗
PubMed1988

[Experimental bile duct replacement using deep seromuscular stomach wall grafts].

Numerous materials and experimental designs were tested hitherto concerning their usefulness as a substitute of the ductus choledochus. However, an ideal substitute to discover failed. We had tested a serous muscular stomach wall patch, flapped at the gastroepiploic vasa, in 6 pigs. Choledochus epithelium did not grow in every case. A scarred shrinking with following stenosis of the transplant resulted in all cases with a longer observation period. We concluded from that a serous muscularly flapped stomach wall transplant does not suit as a bile duct substitute.

Animals↗
PubMed1987

Surgical therapy of radiation-induced small-bowel lesions. Report of 34 cases with a high share of patients with combined chemotherapy.

Operations on irradiation-injured bowel are rare, bear a high postoperative mortality, and the procedure of choice (resection vs bypass) is still controversial. Thirty-seven operations on small bowel for late effects of irradiation in 16 years were analyzed retrospectively. Fifty-one percent of the operations were performed in the last four years. Ovarian cancer treated by a combination of radiotherapy and chemotherapy was the most frequent underlying disease of 20 patients (58%) followed by carcinoma of the cervix (eight [24%] of the patients). The median latent period between irradiation and surgery was eight months after the combined radiotherapy/chemotherapy, and 12 months after radiotherapy alone. Thirty operations (81%) were done for small-bowel stricture, four for fistula, and three for perforation. Bypass was performed in 17 patients and resection in 16. Complications (fistula, peritonitis, perforation) occurred after 13 operations (35%). All three patients who developed peritonitis died (mortality, 8.1%): two after resection and one after bypass. Suture-associated complications occurred in three (23%) of 13 cases after single-layer and in three (35%) of 17 cases after two-layer anastomoses. Ten patients are still alive two to 76 months (median, 32 months) after operation, six of them free of tumor. All are underweight and suffer from diarrhea (four to 12 stools per day). Pernicious anemia developed in all six patients surviving more than two years.

Adult↗
PubMed1987

[Diagnosis of peritoneovenous shunt occlusion].

Reaccumulation of ascitic fluid after peritoneovenous shunt implantation demands accurate diagnostic procedure. Between 1973 and 1985 81 peritoneovenous shunts have been implanted at the IInd Surgical Department of the University of Vienna. In the same time 34 reoperations in 17 patients have been performed for reasons of shunt-dysfunction. Besides thorax x-ray, diagnosis was established in 11 cases by means of Doppler ultrasound investigation, in 26 cases by technetium scan and in 15 cases by shunt angiography. Shuntography proved to be the method of choice, with no false results. Doppler ultrasound results were unclear in a high percentage, thus this method is not used any more.

Ascites↗
PubMed1987

[Effect of endoscopic hydrothermo- and laser coagulation on the human stomach wall in vivo].

Effect of thermic and laser energy applied onto human in vivo gastric wall has not yet been reported in literature. In our study we evaluated the maximum amount of energy not harming the patient as well as principles for secure and sufficient therapy. In 8 patients hospitalized for gastric resection we applied vaporization by laser- and hydrothermosounds in this part of the stomach which should be resected. Endoscopic pictures were taken. We used a NdYAG laser (maximum performance 70 W, time of application 1-3 s) and hydrothermosounds (maximum performance 170 W, time of application 1-3 s). The stomach was resected 3-8 days following application. Comparing laser- and hydrothermosounds marks we observed a bigger area of necrosis at hydrothermosounds marks using the same amount of energy. In histological investigation correlation between depth and diameter of necrosis was found. After the same application time both depth and diameter of necrosis were bigger by hydrothermosounds than by laser. Lesions reached serosa at the maximum time of application of 3 s. Serosal lesion itself did not appear. Endoscopic treatment of tissue lesion by laser and thermic irradiation (vaporization of bleeding polyp pedicles, treatment of tumors) is secure using the maximum energy mentioned above. Serosal lesion did not appear. Bleeding lesions must be treated by higher energy because of absorption of energy by escaped blood.

Electrocoagulation↗
PubMed1987

Implantation of the Duromedics bileaflet cardiac valve prosthesis in 400 patients.

From September, 1983, to April, 1986, 451 Duromedics bileaflet cardiac valve prostheses were implanted in 400 patients at our institution in Vienna. Aortic valve replacement was done in 190 patients, 157 underwent mitral valve replacement (1 patient also underwent tricuspid valve replacement), 52 underwent double valve replacement, and 1 patient underwent isolated reoperation for tricuspid valve replacement. Concomitant procedures were performed in 86 patients (21.5%). Sixty-one patients (15.2%) had undergone previous cardiac surgery; 32 (8%) had undergone earlier valve replacement. The early mortality rate (within 30 days) was 6.25% (25 patients). Follow-up was done on 337 surviving Austrian citizens; this represents 429 patient-years. The late mortality rate was 2.1% per patient-year (9 patients). We observed paravalvular leak in 3 patients (0.7% per patient-year), thromboembolism in 4 (0.9%), prosthetic valve endocarditis in 5 (1.2%), and anticoagulant-related hemorrhage in 10 (2.3%). Valve failure occurred in 8 patients (1.8%). We conclude, therefore, that good clinical results and a low complication rate can be achieved with this new type of valve.

Anticoagulants↗
PubMed1987

Implantation of the left ventricular assist device.

Development of mechanical devices for support of the failing heart is a major goal in cardiac surgery. The application of left ventricular assist device (LVAD) is a promising approach in the case of severe and otherwise untreatable cardiac failure. In our experience we have used two external centrifugal pumps for the extracorporeal biventricular cardiac support in a post-transplantation patient who experienced severe rejection six months after heart transplantation. Our own series includes a total of ten implantations of LVAD's with six patients who could be weaned from the device but only one long-term survivor. The clinical results are not encouraging which suggests that the heart of the patient who needs an LVAD has been damaged beyond any chance for later recovery. Obviously timing is the most crucial aspect of the decision to implant the device. It would appear that orthotopic implantation of the transplanted heart remains the method of definitive treatment.

Cardiac Surgical Procedures↗
PubMed1987

Plaque ablation by excimer laser irradiation using a movable energy-transmitting device.

During the past 2 years, excimer laser energy has been shown to provide a highly suitable type of atherosclerotic plaque ablation, especially in small-diameter vessels such as coronary or crural arteries. Nevertheless, transmission of far-ultraviolet pulsed laser power has remained a major problem in animal studies and clinical trials. In an attempt to solve this problem, we constructed an energy-transmitting device for use with a Lambdaphysics EMG 102 excimer laser. The transmission system, which was housed in a rigid articulated arm, allowed movement in all directions and rotation along the long axis, thus permitting easy handling and guiding of the laser beam in the operating field. To test whether this device could deliver enough energy to remove atherosclerotic plaques within a period that would meet the requirements for intraoperative use, we obtained fresh human cadaver coronary arteries both with and without atherosclerotic disease, and irradiated them vertically and coaxially. A power meter was used to determine the effective amount of energy delivered at the distal end of each vessel. Energy densities up to 3 J/cm(2)/pulse were obtained, owing to energy focussing within the transmitting device. At 5 Hertz (Hz), tissue ablation consisted of approximately 20 microm/pulse. Areas of normal vascular tissue, as well as fibrohyalinous and lipid plaque components, were promptly ablated. Macroscopically, the "lasered holes" appeared well-circumscribed, with clear-cut surfaces and no carbonization. Light microscopy revealed no thermal damage to the boundary tissue. With this new energy-transmitting device, the surgeon can use excimer laser irradiation intraoperatively. There is no significant loss of energy between the generator and the tip, and energy densities of 3 J/cm(2)/pulse are available for sufficient plaque removal.

Journal Article↗
PubMed1987

[Human atrial natriuretic factor (hANF) in liver cirrhosis].

Mean plasma levels of hANF at admission were significantly higher in liver cirrhosis (LC) patients with ascites (93 +/- 11 ng, n = 20; p less than 0.05) than in LC-patients without ascites (32 +/- 14 ng/l, n = 11) or healthy controls (31 +/- 15 ng/l; range: 5-80 ng/l; n = 106). Diuretic treatment of patients with LC and ascites normalised hANF plasma concentrations (44 +/- 14 ng/l; p less than 0.05). Increase of plasma hANF in LC-patients with ascites after acute volume expansion was lower (relative rise: 159%) than in those without ascites (relative rise: 223%). Volume redistribution into the vascular compartment, induced by peritoneovenous shunt implantation in LC-patients with diuretic treatment-refractory ascites, resulted in a sharp increase of plasma hANF levels (344 +/- 87 ng/l = 420% of preoperative concentration). Normal and slightly increased levels of plasma hANF and the appropriate regulation to volume changes suggest an intact control of the hormone in LC-patients. Neither a lack nor an inappropriate secretion of hANF as a cause for sodium retention as postulated by the overflow theory of ascites accumulation could be found in liver cirrhosis.

Ascites↗
PubMed1987

[Transplantation of gastrointestinal tumors to immunodeficient nude mice as an in vivo model of tumor biology].

Serial transplantation of ten different types of tumours, both primary tumours and their metastases, to 170 nude mice was conducted for biological analysis of human gastro-intestinal carcinomas, with particular reference being made to the aspect of tumour growth. The types transplanted included seven colorectal carcinomas, one oesophageal carcinoma, one gastric lymphoma, and two gastric carcinomas.--Tumour growth was quantitatively monitored by means of a standardised measuring method and was statistically evaluated. The qualitative aspects of tumour growth were micromorphologically investigated. Tumour transplants were allowed to reach a defined size and were then retransplanted within the nude mouse system, with up to six tumour passages being conducted. The investigations were evaluated, with particular reference being made to comparison between primary tumours, on the one hand, and their metastases, on the other.--The average primary tumour take rate amounted to 83 per cent and was generally higher for metastatic tumours. Statistically significant findings were obtained to the effect of growth of metastases which was faster than that of their own primary tumours (p 0.05), where as no qualitative differentiation between primary tumour and metastases was possible on the basis of the micromorphological aspect. Growth of metastases.

Adenocarcinoma↗
PubMed1987

[Prognostic factors in cardia cancer].

Among 164 patients operated upon for adenocarcinoma of the cardia 102 (61%) were resected, 87 of them with curative intent. The mortality within 30 days was 20%, and the 5-year survival 15%. A total gastrectomy was performed in 36 patients, whereas a proximal partial gastrectomy was carried out in 66 cases. The median survival was 19 months after total gastrectomy, and 11 months after proximal resection (Breslow: 0.22). Only in stages N0 and N1 total gastrectomy resulted in a significantly longer (32 months) median survival than proximal resection (11 months; p = 0.03). The impact of total gastrectomy was more pronounced in the diffuse type according to Lauren, whereas lymphadenectomy was more effective in stages N0 and N1 and in Lauren's intestinal type. It is concluded that total gastrectomy should be carried out in all cases of carcinoma of the cardia.

Adenocarcinoma↗