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Biomedical subjects

B Luther

Publications and source records attributed to B Luther.

At least 19 recordsLinked to original sources

[Tasks and function of the German Medical Review Board of the Statutory Health Insurance (MDK). Latest aspects in dermatology in view of social medicine].

The German Medical Review Board of the Statutory Health Insurance (MDK) is a sociomedical service for impartial medical opinion and consultation. Together with the statutory health insurance companies it takes part in shaping the public health care system. Many recent developments are changing the german health insurance system. This article illustrates the complex sociomedical framework of MDK's activities in relation to current issues in dermatology. The article focuses on: new diagnostic and therapeutic methods, drugs (off-label-use), out-patient and in-patient dermatological rehabilitation and hospital treatment.

Dermatology↗

[Cost comparison of different graft materials in femoropopliteal bypass: experience with G-DRG].

BACKGROUND: The German DRG classification refrains from medical accuracy of different surgical procedures by concentrating mainly on economic aspects. The process cost calculation of femoropopliteal bypass should as an example illuminate the charge of a surgical procedure under hospital conditions. METHODS: From 07/03 to 03/04 we analysed out of 71 peripheral arterial reconstructions 10 alloplastic grafts (PBP) and 10 autologous vein grafts (VBP) for femoropopliteal above-knee bypass through the process cost calculation. This required a classification of the procedure in different diagnostic and treatment sections (ward, intensive care, diagnosis, treatment (surgical procedure)). RESULTS: The average length of hospitalisation with VBP amounted to 12.2 +/- 3.6 (7-19) days, and with PBP to 14.0 +/- 8.0 (8-35) days. The duration of the surgical procedure was almost identical with 118 +/- 26 minutes (VBP) compared to 110 +/- 31 minutes (PBP), but in average 0.4 more assistants participated in VBP. One bleeding caused revision in VBP; one PBP led to extended length of hospitalisation because of wound complication. We diagnosed one asymptomatic bypass occlusion in VBP. The average total costs in VBP amounted to 4 368.10 euro (profit: 4 468.15 euro), in PBP to 5 069.50 euro (profit: 3 802.94 euro). CONCLUSION: The reconstruction of the superficial femoral artery with alloplastic or autologous vein graft is profitable in G-DRG. Although less medical staff in required in PBP the price of the prosthesis weakens the profit. The autologous vein graft shows furthermore a shorter length of hospitalisation. Further investigation into cost-effectiveness regarding long-term follow-up and patency rates could lead to consequences for the German health system.

Arteriovenous Shunt, Surgical↗

[Homologous vein transplantation in cruropedal arterial reconstruction].

Allogenic venous transplantation represents an alternative procedure for preventing leg amputation. This study reviewed the question of whether immunologic monitoring and immunosuppressive therapy provide results close to those of autologous reconstructions. Twenty-eight patients received 31 homologous venous transplants. The average age in this group of 15 women and 13 men was 64.5 years. Limbs in danger of amputation could be kept longer in two thirds of them. These promising results show the superiority of this method over the use of alloplastic material in regions with cruropedal vessels. Therefore, it can be recommended in acute leg ischemia with lack of autologous vascularity. Improving guidelines for indication will be an interesting research field, and more contributions are needed.

Adult↗

[Interdisciplinary operative procedure-pelvis and abdomen].

Surgery for tumors in the abdomen, retroperitoneum, and pelvis requires technical skills and expertise sometimes beyond the capability of a single surgeon. This holds especially true if curative tumor resection involves replacement of arteries and veins, which needs careful planning to avoid long periods of ischemia, and the selection and provision of vascular substitutes according to anatomical position, postsurgical therapy, and adjuncts to avoid thrombosis and infection of vascular grafts. Since the works of Fortner, the value of close collaboration between general and vascular surgeons has been demonstrated, but many of the former even today continue to attempt the operation alone, although the result is not always a masterpiece. The authors refer to their experience in major tumor surgery in either the single management of vascular complications or collaboration. The potential value of close collaboration is presented by negative examples, and a plea is made for a less "eminence"-based management of these sometimes difficult cases, which is based on vast positive experience with vascular diseases of the aorta and the visceral and iliac arteries and veins, including safety measures and adjuncts.

Abdominal Neoplasms↗

Outcome of critical foot ischaemia in longstanding diabetic patients: a retrospective cohort study in a specialised tertiary care centre.

BACKGROUND: We sought to establish risk factors predicting the outcome of foot lesions in longstanding diabetic patients with critical foot ischaemia (CFI). PATIENTS AND METHODS: We investigated retrospectively 98 consecutive diabetic patients with ischaemic foot lesions. The patients (mean age 70 years, duration of diabetes 21 years) were jointly cared for by specialised diabetologists and vascular surgeons; 75 patients were treated by arterial revascularisation. RESULTS: Good outcome (lesions healing) was observed in 53 patients (54%). Bad outcome was observed in 45 patients: not healing lesions (n = 5), major amputation (n = 19), and death in relation to the foot lesion (n = 21). Patients with good and bad outcome did not differ regarding age, sex, smoking status, type, duration and treatment of diabetes mellitus, presence of neuropathy, coronary heart disease, stroke, previous amputations, current revascularization, and localization of the foot lesion. The risk of bad outcome was increased 8.9 times in patients on dialysis for end-stage renal disease; 7.0 times if surgical complications were present; and 5.4 times with C-reactive protein (CRP) above the second quintile (cut-off value 8 mg/dl). CONCLUSION: Management of longstanding diabetic patients with ischaemic foot lesions leaves room for improvement. Dialysis treatment, elevated CRP levels and surgical complications were strongly predictive of non-healing lesions, major amputation and death.

Aged↗

Donor-specific sensitization by cadaveric venous allografts used for arterial reconstruction in peripheral arterial occlusive vascular disease.

The use of allogeneic venous grafts from postmortal organ donors allows for the reconstruction of critically affected arteries in patients with peripheral occlusive vascular disease. We were interested to determine the prevalence and specificity of anti-HLA antibodies in patients after allogeneic vein transplantation. Anti-HLA class I and II alloantibodies were analyzed by flowcytometric analysis using color-coded microbeads coated with HLA antigens including recombinant single antigens. Nine out of 10 patients involving 12 venous allografts were positive for anti-HLA alloantibodies. All antibody-positive patients carried both anti-HLA class I and II alloantibodies. Anti-donor HLA specificity of the anti-HLA alloantibodies was seen in seven out of nine patients for anti-class I antibodies and in eight out of nine patients for anti-HLA class II antibodies. A high rate of donor-specific allosensitization was seen after allogeneic venous transplantation. In conclusion, allosensitization not only includes a humoral response against the constitutively expressed class I antigens but also extends to class II antigens.

Aged↗

[Reconstruction of the inferior vena cava for extended resection of malignant tumors].

OBJECTIVES: Malignant tumor invasion in the inferior vena cava (IVC) has for a long time been the limiting factor in the resection of retroperitoneal tumors. The clinical outcome in these patients depends on vascular surgical techniques, the central role of which is played by IVC reconstruction. METHODS: Within the last 7 years, 9,085 vascular reconstructive procedures were performed in our department. Six patients suffered from retroperitoneal invasion of tumor into the IVC. After tumor resection, the involved IVC segments were replaced by polytetrafluorethylene (PTFE) grafts to restore IVC continuity. In three patients, an adjunctive arteriovenous (AV) fistula was constructed. RESULTS: The graft patency after a mean follow-up of 30.2 months (range 1 to 79) was 83.3%. The only graft occlusion occurred in a patient without AV fistula. There were no perioperative deaths and no major complications demanding reoperation. CONCLUSION: In patients with tumor involvement of the IVC, clinical outcome depends on vascular surgical coprocedure. After resection of the IVC, a PTFE graft should be interposed in combination with an AV fistula. Anticoagulation and CT scan are recommended after 3 months before ligation of the AV fistula.

Adult↗

[Current diagnosis and therapy of non-occlusive mesenteric ischemia].

PURPOSE: Non-occlusive mesenteric ischemia (NOMI) is a life threatening disease. Therapy and prognosis depend upon the length of time elapsed between primary clinical manifestation and the time of definitive diagnosis and treatment. MATERIALS AND METHODS: NOMI was diagnosed by intraarterial selective angiography in four patients. After a bolus administration of 20 g Alprostadil (Prostavasin) into the superior mesenteric artery, intraarterial perfusion was continued with 60 microg Alprostadil/day via the catheter for three days. RESULTS: The mesenteric ischemia resolved in all patients. One patient recovered completely. Three patients recovered from mesenteric ischemia, but died subsequently due to complications of their primary diseases. CONCLUSION: When NOMI without perforation or necrosis of the bowel wall is suspected clinically, immediate intraarterial angiography is the diagnostic method of choice. If NOMI is confirmed, the appropriate treatment is the intraarterial application of potent vasodilators for several days. The diagnostic work-up in suspected NOMI and the impact of different radiological examinations are explained. The literature is reviewed.

Aged↗

[Survey of therapy of deep venous thrombosis among members of the German Society of Vascular Surgery].

INTRODUCTION: In the literature of the past 15 years, deep venous thrombectomy has been rarely described. The only indications reported for thrombectomy seem to be recurrent pulmonary embolisation and phlegmasia coerulea dolens. Many contraindications and severe complications are making decisions concerning thrombolysis very difficult. At present, anticoagulation therapy is preferred over fibrinolysis. There is no conclusive concept for the standardization of treatment for deep venous thrombosis. As a first step towards achieving this, it was necessary to know what therapy is performed in hospitals throughout Germany. METHODS: In 1999, we sent letters of enquiry to the members of the "Deutsche Gesellschaft für Gefässchirurgie". We wrote to 341 members (hospitals), and the information gained by means of a questionnaire was analysed and evaluated. RESULTS: We received answers from 39.9% (n = 136) of the members. In all, 69% of the hospitals had an independent vascular department. In 1999, 6,718 patients underwent treatment for deep venous thrombosis, on average, 51 patients per hospital. Overall, 7,665 therapies were performed in one year (15.9% thrombectomy, 18.6% fibrinolysis, and 65.5% only anticoagulation). Only 23.5% of the hospitals had their own data about the outcome of their patients. The patency rate was 71.8% for thrombectomy and 48.9% for fibrinolysis. A severe postthrombotic syndrome was seen in 6.2% after thrombectomy, in 8.1% after fibrinolysis, and in 10.4% after singular anticoagulation. CONCLUSION: At present, there is still no standardized concept for the treatment of patients with deep venous thrombosis. It seems that there are better results for some indications with thrombectomy than with other methods. For the establishment of a concept of treatment, a prospective randomised study is necessary.

Anticoagulants↗

[Aortoiliac reconstruction after kidney transplantation. Strategies to avoid ischemic damage of the transplant].

INTRODUCTION: The rising life expectancy of patients undergoing kidney transplantation and the improvement in the function rate of the allografts have led to an increasing number of patients suffering from arteriosclerosis-related diseases of the aortoiliac arteries. In these particular cases, an interruption of the blood supply of the allograft is always necessary for operative repair of the aortic and iliac arteries. This means a high risk of ischemic damage to the transplanted kidney. PATIENTS AND METHODS: Between 1987 and 2000, 1,076 kidney transplantations were performed in our department. During this time, 14 reconstructive operations of the aortoiliac arteries were performed in 12 patients (6 women, 6 men, average age 55.2 (45-71) years). Operations were indicated in patients suffering from occlusive disease with imminent extremity or allograft loss, and symptomatic or asymptomatic aneurysms with a maximum diameter of more than 4 cm. In patients presenting with thoracoabdominal (1) and abdominal aortic aneurysms (3), protection of the transplanted kidney was performed by axilloiliac or axillofemoral bypass. Hypothermic flush-perfusion of the allograft containing PGE1 and heparin was performed in seven of nine operations for occlusive disease. RESULTS: None of the patients presented with a permanent decrease in kidney function, six patients showed temporary creatinine elevation, and in nine patients creatinine levels at discharge were lower than they were preoperatively. None of the patients died. CONCLUSION: Reviewing all reported methods of allograft protection, we recommend a three-step strategy including sequential clamp technique (ischemia < 30 min.), hypothermic flush-perfusion (ischemia < or = 60 min.), and temporary axilloiliac/femoral shunt (ischemia > 60 min), depending on the expected renal ischemia time.

Aged↗

[The acute mesenteric ischemia - not understood or incurable?].

PURPOSE: Despite surgical research and progress, the high mortality of acute intestinal ischemia seems to be improved insignificantly over the past fifty years. In this study we analyzed the specific diagnostic and therapeutic problems of the disease in order to improve further management of acute mesenteric ischemia. METHODS: From 1979 until 2000 64 patients (female 31, male 33) with a mean age of 64 (30-89) years underwent operation for primary intestinal ischemia at our institution. All medical and surgical records and imaging studies were reviewed retrospectively. Follow up consisted of clinical examination and duplex sonography. RESULTS: Only in 26 patients (41 %) a preoperative diagnostic work-up including angiography 12 and CT 14 was performed, whereas in 42 cases the intestinal ischemia was diagnosed during surgical exploration. Intestine malperfusion was caused primarily by venous thrombosis in 9 cases (14 %) and by arterial occlusive disease in 55 cases (86 %). Arterial disorders consisted of arterial thrombosis in 19 cases (30 %), arterial embolism in 18 cases (28 %), aortic or mesenteric artery dissection in 10 cases (15 %), non occlusive disease (NOD) in 5 cases (8 %), trauma 3 cases (5 %). Five different therapeutic strategies were applied: group I: Intestinal resection: 24 patients, anastomotic insufficiency 5 (39 %), mortality 11 (46 %), group II: intestinal artery revascularization: 5 patients, secondary patency rate 80 %, mortality 40 %, GROUP III: Intestinal artery revacularization and perfusion with Ringer's solution: 11 patients, mortality 8 (73 %), group IV intestinal artery revascularization and intestinal resection: 3 patients, mortality 100 %, group V intestinal artery revascularization and perfusion and intestinal resection: 3 patients, mortality 33 %. A second look operation was performed in 29 cases (40 %) and displayed malperfusion in 72 %. Only 21 of 64 patients survived the acute intestinal ischemia (in hospital mortality was 67 %). Delayed diagnostic and operation caused higher mortality (interval 10 hours: mortality 59 %, interval 37 hours mortality; 71 %, p = 0,06). Follow up after 61 (4-72) months of 21 patients (100 %) could be achieved. Ten patients (48 %) had meanwhile died, 5 patients (50) % as consequence of mesenteric ischemia, the others of unrelated reasons. Eleven patients are still alive without clinical signs of intestinal ischemia. CONCLUSIONS: Early diagnosis before hospitalisation and in-hospital (arteriography) and operation are essential to improve the outcome of patients with acute intestinal ischemia. To avoid short bowel syndrome bowel resection should be combined with mesenteric revascularization. Resection of malperfused bowel should be done cautiously and should be followed automatically by second look operations. Special expertise and good team work of visceral and vascular surgeons are required to achieve better therapeutic results.

Acute Disease↗

Eurotransplant Senior Program 'old for old': results from 10 patients.

More frequently there is the need for renal transplantation of older patients. Against the background of an increasing number of old donors and recipients, Eurotransplant Leiden started the Eurotransplant Senior Program (ESP) 'old for old' in 1999. The ESP works with donors and recipients both over 65 yr. The kidneys are transplanted with short cold ischaemia time regardless of the human leukocyte antigen (HLA) compatibility. Compatibility of blood groups, negative crossmatch and less than 5% cytotoxic antibodies are required. First experiences from 10 patients at Heinrich Heine University hospital are reported here. The course of 10 transplanted patients is described from January 1999 until November 1999 (28.4+/-15.8 wk). Age of donor and recipient, cause of dialysis and concomitant diseases from recipients, function of the transplanted kidney and complications are analysed. Immunosuppression consisted initially of cyclosporin A, mycophenolic acid and steroids. The results of these 10 patients were compared to 14 patients who were transplanted according to the ordinary Eurotransplant criteria (Eurotransplant Kidney Allocation System) in the same period of time. Kidneys from six donors (70.5+/-3.3 yr) were transplanted to 10 different recipients (66.9+/-2.2 yr). The control group consisted of 14 patients (47.6+/-14.4 yr) who received kidneys from 14 donors (48.3+/-10.1 yr). One double kidney transplantation was performed in the senior group, i.e. two kidneys from a marginal donor were transplanted to one recipient ('two in one'). In the ESP group, cold ischaemia time was reduced by 5 h and mean of HLA mismatches was more than doubled. Mean length of hospitalisation of ESP and control groups was 47.2+/-28.2 and 34.2+/-11.6 d, respectively. Intraoperatively, no complications were seen, post-operative care was performed on a normal ward. ESP patients suffered more often from delayed graft function, which led to further need for haemodialysis for 11.2 d. Finally, 9 of 10 patients acquired a satisfactory renal graft function. A total of 13 biopsies were performed in eight cases. Altogether seven acute rejections in 6 patients were found (four interstitial, one vascular, one interstitial+vascular, one clinical). The 9 patients with sufficient renal graft function were discharged with a mean serum creatinine level of 2.3+/-0.5 mg/dL (control: 1.9+/-0.8 mg/dL). Comparing these 10 recipients to a control group consisting of 14 patients, the results are comparable and encouraging. In conclusion, the short-term results of the ESP are promising. Nevertheless, the post-operative care requires more attention due to several complications. Though the HLA compatibility was not considered, all rejections were coped with effectively. Quality of life was improved.

Age Factors↗

An algebraic/graphical tool to compare ecosystems with respect to their pollution V: cluster analysis and Hasse diagrams.

In case of large data matrices comparative evaluations of objects/regions with the technique of Hasse diagrams may be troublesome due to a messy system of lines in the graphical representation. Here fuzzy clustering leads to useful simplifications because regions with slightly different pollution pattern are grouped together. However, fuzzy clustering implies to introduce a threshold value for the membership of an object to a cluster and to select the best number of clusters. Therefore many arbitrarities evolve. Within the systematic study presented here we found that some objects are very stable against variations of the threshold value and the number of cluster whereas other objects behaves different. According to their behaviour we investigated a classification of the objects. Formal Concept Analysis shows that in some cases specific pollution pattern imply the membership to one of these classes. For example objects which are characterized by high Pb-, Zn-concentration and moderate S-concentration imply a high stability against variants of the clustering process. Further implications are described in the paper.

Cadmium↗

Surgical treatment of 50 carotid dissections: indications and results.

PURPOSE: This article analyzes the course of 48 patients with 49 chronic carotid dissections (who were treated surgically at our institution after a median anticoagulation period of 9 months because of a persistent high-grade stenosis or an aneurysm) and the course of one additional patient with acute carotid dissection (who underwent early operative reconstruction 12 hours after onset because of fluctuating neurologic symptoms). METHODS: All medical and surgical records and imaging studies were reviewed retrospectively. All histologic specimens were reevaluated by a single pathologist to assess the cause of dissection. Follow-up of 41 patients (85%) after 70 months (range, 1-190 months) consisted of an examination of the extracranial vessels in the neck by Doppler ultrasound scanning and a questionnaire about the patients' medical history and their personal appraisals of cranial nerve function. RESULTS: Seventy percent of the dissections had developed spontaneously; 18% were caused by trauma; 12% of all patients (22% of the women) had a fibromuscular dysplasia. Indication for surgery was a high-grade persisting stenosis and a persisting or newly developed aneurysm. Flow restoration was achieved by resection and vein graft replacement in 40 cases (80%) and thromboendarterectomy and patch angioplasty in three cases (6%). Gradual dilatation was performed and effective in two cases (4%). Five internal carotid arteries (10%) had to be clipped because dissection extended into the skull base. One patient died of intracranial bleeding. Five patients (10%) experienced the development of a recurrent minor stroke (ipsilateral, 4 patients; contralateral, 1 patient). Cranial nerve damage could not be avoided in 29 cases (58%) but were transient in most of the cases. During follow-up, one patient died of unrelated reasons, and only one patient had experienced the development of a neurologic event of unknown cause. CONCLUSION: Chronic carotid dissection can be effectively treated by surgical reconstruction to prevent further ischemic or thromboembolic complications, if medical treatment for 6 months with anticoagulation failed or if carotid aneurysms and/or high-grade carotid stenosis persisted or have newly developed.

Anticoagulants↗

[Controlled reperfusion of ischemic extremity musculature to prevent free radical induced lesions].

Tissue injury following reperfusion represents an essential problem of reconstructive vascular surgery. Pathogenetically toxic oxygen radicals are considered to play a pivotal role. Pharmacotherapeutical approaches are based particularly on antioxidants and vasodilators. However, a standardized regimen is not yet clinically introduced. In 48 adult Lewis-rats lower limb ischemia was induced by aortal cross-clamping. Following 3.5 hours of ischemia intravascular flushing perfusion via the distal aorta with a heparinized electrolyte solution (group B). Group C received additionally oxypurinol, group D alprostadil and group E sodium selenite into the flushing solution. At 4 hours recirculation was established. After 10 min, 30 min and 24 hours of reperfusion we determined lactate, creatine kinase, lactate dehydrogenase, urea, malondialdehyde and the laser Doppler flux. At the end of the experiments biopsies were taken from M. tibialis anterior. In comparison to control animals (group A) we observed an attenuation of reperfusion injury in the groups treated with flushing perfusion. Free oxygen radical reactions measured by malondialdehyde release were significantly reduced (30 min: A-209.1 +/- 45.4, B-127.3 +/- 36.9, C-113.2 +/- 14.1, D-99.6 +/- 24.5, E-123.6 +/- 11.2 mmol/l, p < 0.05). The laser Doppler flux measurements corresponded with the biochemical analyses (30 min: A-52.4 +/- 11.1, B-48.0 +/- 11.0, C-72.6 +/- 12.0, D-74.4 +/- 13.3, E-62.6 +/- 10.8% of baseline). Histologically, treatment with alprostadil (PGE1) and oxypurinol revealed superior results. Standardized intraarterial flushing perfusion with antioxidants and vasodilators reduces reperfusion injury. Clinical trials are urgently required to confirm the experimental findings and to optimize the therapy of extremity ischemia/reperfusion injury in humans.

Animals↗

Reference typing report for complement component C4.

During the 7th Complement Genetics Workshop, Mainz, Germany, May 1998, a complement component C4 typing exercise took place with the aim of applying present technologies to the definition of reference C4 alleles/phenotypes and the recognition of nonexpressed (Q0) C4 alleles within expressed haplotypes. Eleven samples were submitted from 3 laboratories and tested by 14 participating laboratories with basic protein-typing technologies; in addition, each laboratory contributed data from local expertise. The samples were introduced to the reference typing for one or more characteristic allotype or for partial or total nonexpression of one isotype. The blinded samples were centrally evaluated and the results discussed among the participants at a plenum meeting. From the results, the samples could be classified into a group of common, easy to diagnose pheno-/allotypes, less common but still unanimously recognised variants, and a third group with difficult pheno-/allotypes. Within the latter group, the allotypes were either new (C4A '92'; C4B '93') and/or showed partial or total reversed antigenicity and unusual Rodgers/Chido (Rg/Ch) PCR subtypes (C4A '92'; C4A 12; C4B '35'; C4B '13'). Semiquantitative C4-alpha-chain estimates of relative isotype levels correlated well with the number of alleles seen at each locus by agarose gel electrophoresis, and were superior to other isotype quantitation methods. From the evaluation of the reference typing it was concluded that the recognition of rare, aberrant or hybrid C4 alleles with partial or total reversed Rg/Ch antigenicity or monoclonal reactivity is still difficult in most instances; besides isotype-dependent lysis, relative migration values, immunoblots with Rg- and Ch-specific monoclonal antibodies, Rg/Ch PCR typing, side-by-side comparison with already described allotypes will ultimately be required. The recognition of nonexpressed alleles within C4A and C4B expressed phenotypes remains the major obstacle in C4 genetic typing. Finally, a conclusive interpretation of DNA typing results will be achieved only in the context of complete allotyping results at the protein level, and at present cannot replace conventional protein allotyping.

Alleles↗