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Biomedical subjects

F Liewald

Publications and source records attributed to F Liewald.

At least 19 recordsLinked to original sources
PubMed2002

[Endoluminal stent-assisted management of acute traumatic aortic rupture].

INTRODUCTION: Open repair of traumatic descending aortic rupture in trauma patients is associated with a mortality rate of 15-20% and a risk of paraplegia of 5-10%. Stent grafts may decrease the morbidity and mortality of these procedures by reducing blood loss and aortic occlusion time. MATERIAL AND METHODS: Within an experience of 52 thoracic stent grafts between 1995 and 2000, eight men with acute traumatic descending aortic rupture were conducted as emergencies without delay. All patients had severe coinjuries and presented with acute onset of mediastinal hematoma due to periaortic bleeding. Successful stent deployment was performed in all eight patients, seven of them required one single stent and one required two stents; within the aortic arch all stents covered the origin of the left subclavian artery. RESULTS: All acute aortic ruptures were sealed successfully. One death occurred in hospital from multiorgan failure. There was no conversion to open repair. Not one patient's condition resulted in temporary or permanent paraplegia. One endoleak required treatment by overstenting. Two patients required secondary surgical procedures (iliac access complication and revascularisation of left subclavian artery). Mean follow-up was 11 months (1-21 months). Mid-term freedom from endoleak was monitored in all patients. CONCLUSION: The treatment of acute traumatic descending aortic rupture with an endovascular approach is feasible and safe and may offer the best means of therapy. The mortality rate and risk of paraplegia are low compared with the risks associated with open operations. Continued surveillance is essential.

Acute Disease↗
PubMed2002

[What is the cost of vascular operations? A prospective cost analysis of conventional and combined endovascular interventions].

Current and future legislation demand improved efficiency in the medical services. The aim of this study was to analyse the costs of vascular surgery in order to reveal potential ways of reducing expense. Taking into account the staff, equipment and operating theatre supplies, we analyzed 58 elective operations comprising 47 conventional and 11 combined endovascular procedures. The mean overall costs calculated for the different operations were: 5.269 DM for a transfemoral embolectomy (n = 3), 8.504 DM for a patchplasik of the profunda arteria (n = 8), 10.265 DM for a femoro-popliteal bypass with a prosthesis (n = 6)--13.180 DM with a vein (n = 2), 9.864 DM for conventional iliac artery reconstruction (n = 7)--iliac endovascular combined procedure (n = 4) 14.494 DM, 14.951 DM for a Y-prosthesis in case of stenosis (n = 3)--13.288 DM in case of infrarenal aortic aneurysm (IAA, n = 4), 11.954 DM for a tube prosthesis in case of IAA (n = 3), 23.571 DMY-stent prothesis for IAA (n = 5), 19.914 DM stent for a thoracic aneurysm (n = 2), 7.153 DM a carotid thrombendarterectomy (n = 6), 5.503 DM for varicosis surgery (n = 5). Because of the high cost of materials, the total outlay for combined endovascular procedures appeared to be high when compared to conventional vascular surgery. Substantial savings concerning the operation may only be achieved if facility structure and qualification of staff meets the particular requirements.

Adult↗
PubMed2002

Endovascular repair of aortic rupture due to trauma and aneurysm.

OBJECTIVES: to report a single centre experience with endovascular repair of the ruptured descending thoracic and abdominal aorta. DESIGN: prospective non-randomised study in a university hospital. MATERIAL AND METHODS: between 1995 and 2000, endovascular treatment was utilised for 231 aortic repairs; in 37 cases (16%) endografting was conducted on an emergency basis for 21 ruptured infrarenal aortic aneurysms, 15 ruptured descending thoracic aortic lesions, and 1 ruptured thoracoabdominal aortic aneurysm. The feasibility of endovascular treatment and the prostheses' size were determined, based on preoperative spiral CT and intraoperative angiography, both obtained in each patient. RESULTS: endografting was successfully completed in 35 patients (95%). Primary conversion to open repair was necessary in 2 patients (5%). Postoperative 30-day mortality rate was 11% (4 deaths). No patient developed postoperative temporary or permanent paraplegia. In 2 patients (5%) primary endoleaks required overstenting and in 6 patients (16%) secondary surgical interventions were required. Mean follow-up was 19 months (1-70 months); three deaths occurred within three months postoperatively (1-year survival rate 81+/-6%). In one case, secondary conversion to open repair was necessary 14 months postoperatively. CONCLUSION: the feasibility of endoluminal repair of the ruptured aorta has been demonstrated. Endoluminal treatment may reduce morbidity and mortality, and may in time become the procedure of choice in certain centres. However, further follow-up is required to determine the long-term efficacy.

Adolescent↗
PubMed2001

Endograft treatment of anastomotic aneurysms following conventional open surgery for infrarenal aortic aneurysms.

OBJECTIVE: to evaluate the use of endograft therapy for treating anastomotic aneurysm following open surgical repair of infrarenal aneurysms of the abdominal aorta. METHODS: four male patients (age 47-75 years) at high surgical risk (ASA IV n=3, ASA III n=1) developed secondary aneurysms at the site of the central (four aneurysms) and additional peripheral (two aneurysms) anastomosis of their tube or bifurcation prosthesis an average of 13 years (range 1-23 years) after conventional open surgical correction of infrarenal aneurysm of the abdominal aorta. In two patients, there was covered rupture of the aneurysm sac. The aneurysm diameter was 4.8 cm, 8.0 cm, 7.4 cm, 7.0 cm, respectively (mean 6.8 cm). Follow-up included helical CT imaging at 1 week, 3 months and 6 months postoperatively. RESULTS: anastomotic aneurysm was successfully treated in all four cases. No evidence of endoleak was observed during the follow-up period. Two patients died 14 and 18 days after surgery due to myocardial infarction and cerebrovascular accident. The endovascular repair of the two patients who died was intact. CONCLUSION: although no long-term results are available, the use of a graft-in-graft method to repair anastomotic aneurysms following conventional implantation of tube or bifurcation prostheses appears to be effective, particularly in patients at high surgical risk.

Aged↗
PubMed2001

Influence of treatment of type II leaks on the aneurysm surface area.

OBJECTIVE: to determine whether interventional treatment of type II endoleaks leads to a decrease in aneurysm surface area. MATERIAL AND METHOD: type II endoleaks were detected in a group of 14 male patients (median age: 70.2 years) following endovascular repair of a total number of 160 infrarenal aneurysms of the abdominal aorta. The surface area of the aneurysm was determined by computed tomography (CT) pre- and postoperatively and at subsequent follow-up examinations. If type II endoleaks were documented at CT, patients underwent treatment by means of coil embolisation. RESULTS: interventional treatment resulted in successful occlusion of type II endoleaks in eight patients. One of the cases exhibited spontaneous occlusion. Occlusion was associated with an average decrease in aneurysm surface area of 3.3 cm(2)( p =0.01). In one of these patients, treatment resulted in a temporary occlusion of the endoleak, also with associated decrease in aneurysm size. After recurrence of the type II endoleak, however, the patient experienced an increase in aneurysm surface area. In the remaining four patients the type II endoleaks persisted, resulting in a non significant increase in aneurysm surface area. CONCLUSION: only complete occlusion of endoleaks results in decrease in the size of the aneurysm sac. Because of endotension and the risk of rupture we favour an early interventional treatment of type II endoleaks.

Aged↗
PubMed2001

Intraoperative, perioperative and late complications with endovascular therapy of aortic aneurysm.

PURPOSE: To describe the incidence and management of the intraoperative, perioperative and late complications of endovascular aortic aneurysm repair. METHODS: Endovascular aneurysm repair was attempted in 130 patients between October, 1995 and January, 2000. Follow-up including computed tomography (CT) was performed in the immediate postoperative period and then at 3, 6, 9 and 12 months and biannually thereafter. The median follow-up period was 20 months. RESULTS: Intra- and perioperative problems occurred in 26 patients (20%). Conversion to open surgery was required in five cases (4%). The primary technical success rate was 86%. Three patients (2%) died within the first 30 postoperative days. Late problems occurred in 28 patients (26%). These included: endoleaks (type I: 5%; type II: 10%; type III: 1%) and limb occlusion (3%). The cumulative rate of freedom from secondary intervention was in the first 65 patients treated: 86% and 65% after 1 and 3 years, respectively, and in the last 65 patients: 90% at 1 year. CONCLUSIONS: Endovascular aneurysm repair is associated with a higher complication rate than open surgery.

Adult↗
PubMed2001

[Chances in surgical treatment of bronchial carcinoma under palliative conditions].

UNLABELLED: Palliative surgery aims at symptomatic relief in patients in whom curative therapy seems not feasible. When diagnostic imaging techniques describe advanced stage IIIa, IIIb or IV malignancy, despite of palliative intention curative resection may still be possible. Objective of the present study was to investigate lung cancer patients undergoing surgery with palliative intent and to compare their prognosis with patients whose tumor resection had been complete (R0) or incomplete (R1/R2). PATIENTS AND METHOD: Patients were assigned to one of the three groups on the basis of the following criteria: palliative intention with subsequent complete resection (group I, n = 11); curative intention with subsequent incomplete resection (group II, n = 38), palliative intention with incomplete resection (group III, n = 23). Additionally 3 patients were operated on by explorative thoracotomy. A total number of 75 patients was therefore investigated. Median follow-up period was 34.5 months. Survival rates were calculated using the Kaplan-Meier method. RESULTS: The following procedures involving resection of pulmonary tissue were performed: pneumonectomy (n = 10), extended pneumonectomy (n = 32), lobectomy (n = 5), extended lobectomy (n = 11), sleeve lobectomy (n = 7), bilobectomy (n = 3), extended bilobectomy (n = 4). The 30 days hospital mortality rate was 13%. Median survival times were 25.5 months in group I, 12.8 months in group II and 7.7 months in group III (statistical significance: group I vs. group II/III, p < 0.05). CONCLUSIONS: Results of the present study show that patients with bronchial carcinoma in advanced tumor stages III and IV may still benefit from pulmonary resection, particularly when reduction of their somatic complaints is considered. In 11 patients, R0 resection was feasible leading to a statistically significant prolongation of their survival rates.

Adenocarcinoma↗
PubMed2000

How useful is positron emission tomography for lymphnode staging in non-small-cell lung cancer?

UNLABELLED: The introduction of positron emission tomography (PET) raises the question of the new method's capabilities in the staging of mediastinal lymphnodes, since PET differentiates between metabolically active and inactive tissues. 80 patients with histologically confirmed non-small-cell lung cancer (NSCLC) underwent PET scanning with 18-F-marked fluorodeoxyglucose (FDG). Extensive dissection of mediastinal lymphnodes (18-28 lymphnodes recovered) was performed in 78 cases. Metastasis to mediastinal lymphnodes were observed in 25 patients (N2: 22; N3: 3). RESULTS: Primary Tumor: FDG-PET showed significant enhancement of the primary tumor in 78 of 80 patients (sensitivity: 97%). Lymphnode Involvement: FDG-PET was positive in 23 of 25 patients with surgically confirmed lymphnode involvement (sensitivity: 92%). After a median follow up interval of 18 months, 11 patients with false positive lymphnode uptake were still alive; 10 of them showed no tumor recurrency. On the basis of these findings, enlarged mediastinal lymphnodes visualized at CT, but negative at FDG-PET are free of metastatic involvement with a sensitivity of 92%. FDG uptake of mediastinal lymphnodes at PET, however, should not be interpreted as proof of malignancy.

Adult↗
PubMed2000

FDG positron emission tomography in the diagnosis of peripheral pulmonary focal lesions.

Positron emission tomography (PET) using fluoride-18-marked fluoride deoxyglucose (FDG) represents a metabolically based imaging technique capable of providing information on the potential malignancy of peripheral pulmonary focal lesions. In the present prospective study, we investigated the effectiveness of FDG-PET in determining the dignities of 67 such lesions in 35 patients. Findings of FDG-PET were compared with those of computed tomography (CT), as well as with surgical and histological reports, and the value of FDG-PET as a diagnostic method evaluated. FDG-PET correctly identified 38 lesions as positive for malignancy, 18 correctly as negative, 7 incorrectly as negative, and 4 incorrectly as positive. Based on lesions, this yields a sensitivity of 84.4% and a specificity of 81.8%. All malignant focal lesions with a diameter of over 1.2 cm were correctly identified (sensitivity: 100%). In cases of intense FDG uptake, differentiation between a primary lesion, a metastasis, and an acute inflammation is often not possible.

Adolescent↗
PubMed2000

Expression of myosin heavy chain isoforms in skeletal muscle of patients with peripheral arterial occlusive disease.

PURPOSE: Peripheral arterial occlusive diseases (PAODs) not only compromise blood flow but lead to a series of subsequent metabolic and structural changes in the relevant muscles. Changes in myofibrillar proteins (eg, of myosin heavy chain [MHC] isoforms), one of the determinants of muscle structure as well as of muscular function, have not been reported in patients with PAOD and were therefore the aim of this study. METHODS: Thirteen consecutive patients with PAOD were examined (clinical stage according to Fontaine II, three patients; III, three patients, and IV, seven patients) and compared with five age-matched control patients who had been in traffic accidents. A calf muscle sample (gastrocnemius muscle) in the ischemic region was taken for MHC isoform analysis by sodium dodecyl sulfate polyacrylamide gel electrophoresis and silver stain, and the relative content of MHC isoforms was measured. RESULTS: Compared with the control patients, there was no significant change of MHC isoforms in patients with PAOD II. In patients with PAOD III, MHC IIb decreased significantly (P <.05) although MHC IIa remained unchanged; in patients with PAOD IV, both MHC IIa and IIb decreased significantly (P <.05). Accordingly, there was a progressive increase of the relative amount of MHC I with more critical ischemia in PAOD. CONCLUSION: In patients with PAOD, the content of MHC II decreased with a higher grade of ischemia. That seems to be consistent with an increased resistance to ischemia for myosin isoforms in the order of I more than in IIa more than IIb. Whether the decrease of MHC II in patients with PAOD is related to atrophy of muscle fibers or to muscle-fiber transition must be investigated further.

Aged↗
PubMed1999

[In Process Citation]

Since 1996 thoracic surgery has been invoiced according to fixed reimbursement rates (Sonderentgelte, SE). The legislator argues that fixed reimbursement rates cover operation costs and justify a 20% reduction in reimbursement for nursing. In order to examine this assumption we performed a cost analysis of thoracic surgery. Taking into account the staff, equipment, and operating theatre supplies, we analyzed 30 cases of five different types of operation prospectivly: wedge resections with more than three wedges (AR: n = 8), lobectomies (LE: n = 8), pneumonectomies (PE: n = 5), thoracoscopic wedge resections (VR: n = 6) and resections of mediastinal tumors (MR: n = 3). Then we calculated the overall costs for each operation. The costs for a LE amounted to DM 9,927, which is DM 4,904 more than the corresponding fixed reimbursement rate. The costs were DM 11,562 for a PE, DM 12,477 for a VR and DM 7,532 for a MR. Thus the costs were DM 5,539, DM 2,435 or DM 1,907 higher than the corresponding fixed reimbursement rates. The fixed reimbursement rate for an AR was DM 866 higher than the actual cost of DM 6,922. Only for a small number of cases do the fixed reimbursement rates cover the actual costs of thoracic surgery. Thus operation costs still need to be at least partly covered by the reimbursement for nursing.

Journal Article↗
PubMed1998

Comparison of virtual and fiberoptic bronchoscopy.

Preoperative diagnostic procedures in the treatment of non-small-cell lung carcinoma (NSCLC) include fiberbronchoscopy (FBS) and CT scanning of the thorax and abdomen. The introduction of double-detector helical computed tomography has led to improved image resolution which allows three-dimensional reconstruction of the bronchial tree. A special computer simulation provides a virtual endoscopic view into the inner surface of the bronchial system. In order to determine whether the so-called virtual bronchoscopy (VBS) accurately reflects the anatomic situation of the bronchial tree, neoplastic lesion, and postoperative control of sleeve resections, we performed a virtual bronchoscopy in 24 patients with NSCLC and in 6 patients following sleeve resections and compared the results with the findings of fiberoptic bronchoscopy. An anatomic computer simulation of the bronchial tree was created in 100% of the investigated patients. Central tumor stenosis or occlusion was visualized by VBS as well as by FBS. In peripheral tumorous lesions VBS revealed the correct diagnosis in only 75%. VBS, however, enables viewing beyond the stenosis. FBS remains the gold standard in the endoscopic diagnostic procedures, showing not only airway patency but also mucosal changes in the vicinity of the tumorous lesion. VBS, however, gives further information about the poststenotic area in occlusive main bronchus stenosis. Furthermore, adequate control investigation of airway patency in patients following sleeve resections or stent implantation can be performed by VBS.

Bronchoscopy↗
PubMed1997

Effect of felodipine on regional blood supply and collateral vascular resistance in patients with peripheral arterial occlusive disease.

This double-blinded, randomized, placebo-controlled study was designed to investigate the acute effect of felodipine on regional blood supply and collateral vascular resistance in patients with peripheral arterial occlusive disease (PAOD). Thirty men with PAOD were treated with a single dose of 5 mg felodipine or placebo. Systolic blood pressure (SBP), Doppler ankle pressure (DAP), calf blood flow (CBF) by venous occlusion plethysmography and calf transcutaneous oxygen tension (tcpO2) were measured during a cycle ergometry. Felodipine reduced SBP significantly (from 149 to 136 mmHg, p < 0.05), while placebo did not. DAP increased slightly but not significantly in both groups. The pressure gradient between SBP and DAP fell significantly in the felodipine group (60 vs 39 mmHg, p < 0.01) but not in the placebo group (59 vs 56 mmHg). There was a trend for lower velocity in tcpO2 decrease during the stress test and higher velocity of tcpO2 increase during recovery from exercise in the felodipine group although the differences between both groups were not significant. In the felodipine group, CBF increased by 35.6% (p < 0.05) whereas it did not change in the placebo group. In conclusion, while lowering SBP, felodipine increased slightly, or at least maintained, the blood supply to the calves in PAOD patients, which probably results from reducing collateral vascular resistance.

Adult↗
PubMed1997

Comparison of real-time virtual and fiberoptic bronchoscopy in patients with bronchial carcinoma: opportunities and limitations.

OBJECTIVE: Both helical CT and fiberoptic bronchoscopy are used in the staging of pulmonary tumors for therapeutic decision making. The improved resolution offered by helical CT has led to the clinical use of three-dimensional reconstruction techniques such as virtual bronchoscopy. We tested this new simulated endoscopic view of inner organ surfaces and compared it with corresponding fiberoptic examinations of the tracheobronchial system. SUBJECTS AND METHODS: Twenty patients with malignancies of the lung and mediastinum were examined with both virtual bronchoscopy and fiberoptic bronchoscopy. Both examinations were reviewed by radiologists and surgeons familiar with fiberoptic bronchoscopy. Virtual bronchoscopy was calculated and reconstructed from the cross-sectional images on a separate workstation. Stenoses and tumor infiltration were classified from the fiberoptic examination. These results were compared with the virtual bronchoscopy findings. RESULTS: Virtual bronchoscopy of diagnostic quality was achieved in 19 of 20 patients. High-grade stenoses were revealed equally well with virtual and fiberoptic techniques. Virtual bronchoscopy offered the advantage of being able to visualize areas beyond even high-grade stenoses. However, on virtual bronchoscopy discrete infiltration or extraluminal impression was not visible in five patients. In another patient, strong heart pulsation produced motion artifacts that prevented evaluation of the reconstruction. CONCLUSION: Virtual bronchoscopy represents a new noninvasive method for evaluating helical CT findings. In comparison with fiberoptic bronchoscopy, virtual bronchoscopy offers the advantage of being able to visualize areas beyond even high-grade stenoses. In addition to the limited view of fiberoptic bronchoscopy, extraluminal causes of lumen compressions can be analyzed in the cross-sectional images and evaluated together with the virtual representation. However, it was not possible to detect small infiltrations with virtual bronchoscopy. This new representation of helical CT data might be helpful for postoperative follow-up examinations, such as after stent implantation, and can be carried out without additional risk to the patient. Radiologists do need special fiberoptic bronchoscopy knowledge and experience with three-dimensional-reconstructions to differentiate between real stenoses and artificial stenoses that might be caused by pulsation artifacts.

Artifacts↗
PubMed1995

[Inflammatory pseudotumors of the lung and trachea].

Inflammatory pseudotumors (synonym: plasma cell granulomas) of the lung and trachea are a group of non-neoplastic lesions of unknown etiology which may occur at any age. The complex histomorphology und proliferative capacity of these pseudotumors may result in diagnostic difficulties during intraoperative frozen section analysis. Four cases of inflammatory pseudotumors of the respiratory tract (three pulmonal, one tracheal pseudotumors) are reported. One patient (16 years, female) suffered from sudden chest pain with dyspnoe, caused by obstruction of the right main bronchus due to an intraluminal pseudotumor. Because of the intraoperative diagnosis of a malignant histiocytoma, sleeve resection of the right main bronchus with bronchotracheal anastomosis was performed. Eight years postoperative, the patient is still disease-free. Another patient (52 years, male) developed multiple inflammatory pseudotumors in both lungs with direct infiltration of the mediastinum. After three thoracotomies, there is still residual disease in the mediastinum. The third patient (52 years, male) developed an inflammatory pseudotumor in the right upper lobe after irradiation therapy for hypopharyngeal carcinoma several years before. The last case in this series is a patient (43 years, male) with suspected bronchial carcinoma in the left lower lobe. The intraoperative frozen section analysis interpreted this lesion as an bronchioloalveolar carcinoma, but the diagnosis was corrected in the paraffin embedded specimens. Clinical presentation, size and number of these tumors are very variable. Despite their rarity, inflammatory pseudotumors should be considered in the differential diagnosis.

Adolescent↗
PubMed1994

Integrated optical density (IOD), syntactic structure analysis, and survival in operated lung carcinoma patients.

Histological sections of formalin fixed, paraffin-embedded tissue comprising 195 specimens of human lung carcinomas were Feulgen stained. The nuclei of the histomorphological images were segmented using an automated image analyzing system, and the attributed minimum spanning trees (MST) were calculated. Features related to the DNA-content of the nuclei (integrated optical density (IOD), IOD-entropy, S-phase related fraction, percentage > 5C, etc.), and structural parameters (minimum distance between tumor cell nuclei, minimum distance between tumor cells and neighboring lymphocytes, MST-entropy, MST-current of entropy (entropiefluss), distance between neighboring proliferating tumor cells, etc.) were measured. The following results were obtained: the measured IOD and MST features showed significant differences between the primary carcinomas and metastatic carcinomas in the intrapulmonary lymph nodes. The survival of patients was remarkably improved if the carcinomas displayed a low S-phase related fraction, a low percentage of tumor cells > 5C, a low number of stem lines, and a low MST-current of entropy.

Carcinoma, Bronchogenic↗
PubMed1994

[Percutaneous aspiration thromboembolectomy in the treatment of acute occlusion of the lower leg arteries].

Percutaneous aspiration thrombembolectomy (PAT) is a very suitable method for the recanalization of the popliteal and lower limb arteries after embolic occlusion. In thrombotic occlusion in patients with arteriosclerotic disease, PAT can easily be combined with other interventional procedures, yielding good results. With the use of PAT the dose of regionally effective fibrinolytic drugs, which may be additionally administered, can be significantly reduced.

Adult↗