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Biomedical subjects

C Düber

Publications and source records attributed to C Düber.

At least 73 records · Page 4Linked to original sources
PubMed1996

[Thromboendarterectomy in chronic thromboembolic pulmonary hypertension. Hemodynamics and right-heart function over the long term].

OBJECTIVE: To find out whether pulmonary thromboendarterectomy (PTE) can achieve lasting reduction of pulmonary vascular resistance in patients with pulmonary arterial hypertension due to chronic thromboembolism. PATIENTS AND METHODS: 45 patients (25 women, 20 men; mean age 45 +/- 24 [19-67] years) were re-investigated a mean of 21 (13-32) months after successful PTE. Two patients had then been in New York Heart Association (NYHA) stage II, 26 in stage III, and 17 in stage IV. In addition to clinical examination and chest radiogram 36 patients had right heart catheterization, 28 pulmonary angiography and 44 echocardiography. RESULTS: Definite improvement of symptoms had occurred in all. 34 were now in NYHA stage I, nine in stage II, and two in stage III. The pulmonary vascular resistance was significantly lower than before and immediately after PTE (pre-PTE: 1052 +/- 472 dyn.s.cm-5; post-PTE: 293 +/- 175 dyn.s.cm-5; at follow-up: 187 +/- 92 dyn.s.cm-5; P < 0.001 for follow-up vs pre-PTE; P < 0.05 for follow-up vs post-PTE). Correspondingly, cardiac index had significantly increased (3.0 +/- 0.5 vs 2.0 +/- 0.7 l/min.m2; P < 0.001). Radiological and echocardiographic examinations showed a definite decrease in right ventricular dimensions and improvement in right ventricular function. CONCLUSION: In patients with pulmonary arterial hypertension due to chronic pulmonary thromboembolism PTE can achieve a reduction in pulmonary vascular resistance with lasting improvement in right heart function and clinical symptoms.

Adult↗
PubMed1996

[Anesthesia in endovascular treatment of aortic aneurysm. Results and perioperative risks].

UNLABELLED: Surgical treatment of aortic aneurysms carries significant cardiovascular risks. Transvascular insertion of endoluminal prostheses is a new, minimally invasive treatment for aortic aneurysms. The pathophysiology of this novel procedure, risks and benefits of different anaesthetic techniques, and typical complications need to be defined. METHODS: With their informed, written consent, 19 male patients aged 48-83 years of ASA physical status III and IV with infrarenal (n = 18) or thoracic (n = 1) aortic aneurysms underwent 23 stenting procedures under general endotracheal (n = 9), epidural (n = 8), or local anaesthesia with sedation (n = 6). Intra-anaesthetic haemodynamics, indicators of postoperative (p.o.) oxygenation and systemic inflammatory response, and perioperative complications were analysed retrospectively and compared between anaesthetic regimens. RESULTS: Groups were well matched with regard to morphometry and preoperative risk profiles (Table I). The use of pulmonary artery pressure monitoring, incidence of intraoperative hypotensive episodes, and p.o. intensive care was more frequent with general anaesthesia. Groups did not differ in total duration of anaesthesia care, incidence and duration of intraoperative hypertensive, brady-, or tachycardic periods, incidence of arterial oxygen desaturation, use of vasopressors, colloid volume replacements, or antihypertensives (Table 2). Postoperatively, all groups showed a similar, significant systemic inflammatory response, i.e., rapidly spiking temperature (p.o. evening: mean peak 38.5 +/- 1.0 degrees C). leucocytosis, and rise of acute-phase proteins without bacteraernia (Table 3). During this period, despite supplemental oxygen, pulse oximetry revealed temporary arterial desaturation in 13 of 18 patients (70%) (Table 3). In 3 patients, hyperpyrexia was associated with intermittent tachyarrhythmias (n = 3) and angina pectoris (n = 1). There was no conversion to open aortic surgery, perioperative myocardial infarction, or death. CONCLUSIONS: Regional and local anaesthesia with sedation are feasible alternatives to general endotracheal anaesthesia for minimally invasive treatment of aortic aneurysms by endovascular stenting. However, invasive monitoring and close postoperative monitoring are strongly recommended with either method. Specific perioperative risks in patients with limited cardiovascular or pulmonary reserve are introduced by the abacterial systemic inflammatory response to aortic stent implantation. Hyperpyrexia increases myocardial and whole-body oxygen consumption, and can precipitate tachyarrhythmias. Hyperfibrino-genaemia may increase the risk of postoperative arterial and venous thromboses. Close monitoring of vital parameters and prophylactic measures, including oxygen supplementation, low-dose anticoagulation, antipyretics, and fluid replacement are warranted until this syndrome resolves.

Aged↗
PubMed1996

Extrathoracic arteriosclerotic vascular changes preclude the use of the internal thoracic artery for coronary artery bypass grafting.

During a two-years period we have treated 6 patients where use of the internal thoracic artery for coronary artery grafting was precluded because of extrathoracic arteriosclerotic vascular lesions. In four patients with severe aorto-iliac occlusive disease preoperative digital angiography demonstrated collateralisation of the lower extremity by either the left, right, or both internal thoracic arteries (ITA). In these cases use of the ITA was excluded in order to preserve the collateral supply and coronary bypass grafting was performed using only saphenous vein. In two patients with proximal occlusion of the left subclavian artery the right ITA was used as in-situ bypass to graft the left anterior descending artery. All patients survived the operation without development of a perioperative myocardial infarction, neurological deficit, or peripheral ischemia. Although they rarely do, extrathoracic vascular disorders can exclude the use of the ITA for grafting. Especially in the case of aorto-iliac occlusive disease or proximal arteriosclerotic subclavian lesions angiographic evaluation is mandatory to prevent the development of life-threatening peripheral ischemia by harvesting an ITA and to avoid the use of an inadequate ITA graft with in-flow occlusion.

Aged↗
PubMed1996

[Intravascular therapy of aortic aneurysms: initial clinical results].

PURPOSE: A clinical study aiming at examining the implantation technique and the clinical results of a new vascular prosthesis in endovascular therapy of aneurysms of the aorta. MATERIAL AND METHODS: In 21 patients (20 men of 55 to 87 years of age, average age 70 years) with aneurysms of the infrarenal abdominal aorta (AAA n = 19) and the thoracic aorta (n = 2), a self-expanding nitinol stent with outer Dacron sheath (tubular prosthesis n = 4; bifurcation prosthesis n = 17) was implanted by means of an F-18 introductory set after surgical opening of the inguinal artery. RESULTS: By means of the 4 tubular prostheses and 13 of the 17 bifurcation prostheses the aneurysm was bypassed completely. In 4 cases residual perfusion through leaks (n = 3) or collateral blood supply (n = 1) was seen. In 6 patients 7 complications occurred which did not require to be operated on. No patient died in consequence of the surgical intervention or during the hospital stay. Follow-ups up to 8 months after surgery did not reveal any late complications to date. CONCLUSIONS: Endovascular implantation of vascular prostheses is a promising new method for interdisciplinary treatment of aneurysms of the aorta.

Aged↗
PubMed1996

[Stent implantation as a palliative therapeutic measure in stenosing tumors of central airways].

PURPOSE: Stent implantation was used to treat patient with malignant tracheobronchial obstructions to determine the effectiveness in producing symptomatic palliation. METHODS: 18 patients (15 men and three women; median age 57 years) with malignant tracheobronchial stenosis were treated by application of metal stents (15 Palmaz-, 10 Gianturco-, 4 Wallstents). The indication for stent implantation was given in 13 patients by clinically significant dyspnea, besides in 5 patients by therapy resistant postobstructive pneumonia. RESULTS: In 17 patients correct positioning of the stents was achieved and the symptoms completely disappeared until tumor related death. Median survival was 137 days (min. 10 days to max. 322 days). In one patient symptoms recurred three months after stent implantation. CONCLUSION: The application of metal stents in patient with malignant tracheobronchial obstruction appears to be a useful palliation procedure. The treatment was well tolerated and very effective.

Adult↗
PubMed1996

[CT angiography versus intra-arterial DSA in abdominal aortic aneurysms].

PURPOSE: To evaluate if CT angiography is able to image all features necessary for the preoperative planning of abdominal aortic aneurysms (accessory renal arteries, stenoses or occlusions of renal and iliac arteries, patency of inferior mesenteric artery). METHODS: CT angiography and DSA were performed on 27 patients with abdominal aortic aneurysms. CT angiography was performed using a protocol that covered the abdominal aorta and the pelvic arteries with a single spiral acquisition (contrast dose: 150 ml, collimation: 5 mm, table feed: 7.5 mm/s, increment of reconstruction: 2 mm). Maximum intensity projections (MIP) and axial scans were compared with the results of intraarterial DSA. RESULTS: Using axial scans and subvolume MIP, CTA accurately defined 7/8 accessory renal arteries, 13/13 occlusions and 9/12 high grade stenoses of renal and pelvic arteries. High-grade stenoses of the iliac arteries were underestimated in two cases and overlooked in one case. CT angiography was superior to DSA in imaging the inferior mesenteric artery. CT angiography precisely diagnosed 33 aneurysms of the iliac, renal and coeliac arteries. CONCLUSION: CT angiography using a single administration of intravenous contrast may replace preoperative DSA in most cases of abdominal aortic aneurysm.

Aged↗
PubMed1996

[Radiologically assisted percutaneous gastro-/enterostomy--a retrospective analysis of 90 procedures].

PURPOSE: To analyse retrospectively the indications, technique and results of radiologically induced gastrostomies or enterostomies. PATIENTS AND METHOD: Radiologically assisted gastrostomies or enterostomies were induced in 90 patients, mostly with high grade obstructions due to head and neck tumours or oesophageal tumours. 19/90 patients had had previous resection of the oesophagus or gastric operations. RESULTS: A catheter was successfully introduced in all patients. In 11/90 patients this was followed by a two-stage procedure. In 16/90 patients puncture was performed under CT control because of some anatomical peculiarity. Serious complication occurred in 9/90 patients but in only one was surgery necessary. There were no deaths resulting from the procedure but mortality after 30 days was 6.7%. CONCLUSION: Radiologically assisted gastrostomies or enterostomies are a reliable and effective form of treatment even amongst difficult patients. The results and complications are comparable to those from endoscopic procedures.

Adult↗
PubMed1996

Abdominal aortic aneurysms: preliminary technical and clinical results with transfemoral placement of endovascular self-expanding stent-grafts.

PURPOSE: To evaluate treatment of infrarenal abdominal aortic aneurysm (AAA) with a new endoluminal stent-graft. MATERIALS AND METHODS: In 26 male patients, straight or bifurcated nitinol stents covered with woven Dacron graft material were implanted to treat eccentric saccular AAA (n = 3) or AAA involving the bifurcation and common iliac arteries (n = 23), with follow-up from 8 days to 8 1/2 months. RESULTS: Implantation was technically successful in all but one of the 26 (96%) patients (leak of the stent-graft for more than 3 months necessitated implantation of an additional covered stent). In seven of the 26 patients, minor residual perfusion persisted immediately after implantation, but complete thrombosis occurred within 7 days. Five procedure-related complications occurred: distal embolization (n = 2); local hematoma, which necessitated surgery (n = 1); acute hepatic failure due to gastric bleeding, in a patient with liver cirrhosis (n = 1); and stent-graft occlusion due to emboli originating from the left atrium (n = 1). CONCLUSION: Exclusion of AAA from circulation was feasible, safe, and clinically effective with the new stent-graft.

Aged↗
PubMed1996

Prospective comparison of CT angiography of the legs with intraarterial digital subtraction angiography.

OBJECTIVE: The aim of this study was to determine the accuracy of CT angiography (CTA) with a single spiral acquisition for the diagnosis of arterial stenoses and occlusion in patients with peripheral vascular occlusive disease. SUBJECTS AND METHODS: In a prospective study, intraarterial digital subtraction angiography and i.v. CTA from the groin to the lower calves were performed on 50 patients with vascular occlusive disease. Maximum-intensity-projection images in multiple views were produced. The accuracy of CTA with and without analysis of the axial scans was determined with digital subtraction angiography as the standard. RESULTS: The sensitivities of CTA were 100% for the diagnosis of femoral artery occlusion, 100% for the detection of popliteal artery (including tibial-peroneal arterial trunk) occlusion, and 94% for the detection of tibial artery occlusion. The specificities were 100%, 99%, and 98%, respectively. When maximum-intensity-projection images were interpreted without axial scans, sensitivities were 98%, 85%, and 92% and specificities were 100%, 99%, and 97%, respectively. For the accurate grading of high-grade (75-99%) stenoses of the superficial femoral artery and the popliteal artery (including tibial-peroneal arterial trunk), the sensitivities of CTA were 88% and 73% and the specificities were 94% and 100%, respectively. When maximum-intensity-projection images alone were used, the sensitivities for the correct grading of high-grade stenoses were 58% and 36% and the specificities were 99% and 100%, respectively. CONCLUSION: CTA from the groin to the lower calves is feasible, and the short examination time is a significantly advantage over the time required for other noninvasive techniques. CTA is particularly accurate in the depiction of femoral artery occlusions. Maximum-intensity-projection images are useful, but analysis of axial scans is more accurate for the grading of arterial stenoses. The results of CTA are encouraging enough to warrant further studies. A CTA protocol covering the pelvic and pedal vessels remains to be established and evaluated.

Aged↗
PubMed1996

[Is preoperative site diagnosis in organic hyperinsulinism from the viewpoint of the surgeon still necessary today? Results of a consecutive series and analysis of the literature].

To answer the open question whether a preoperative localization diagnostic is necessary in organic hyperinsulinism we prospectively investigated our 28 patients with an organic hyperinsulinism who were operated on between September 1, 1985 and December 31, 1994. Additionally we performed an analysis of the literature. In case of a solitary adenoma the preoperative localization diagnostic had a sensitivity between 28.4% (sonography) and 84% (endosonography). The combination of all preoperative localization procedures had a sensitivity between 70% (literature) and 90% (own patient material). With palpation and intraoperative sonography 97.1% (own patient material 100%) of all solitary adenomas could be found during first exploration. Multiple adenomas and reoperations have special problems. The pre- and intraoperative localization diagnostic failed in every fourth patient. In conclusion, in case of a primary operation without a MEN syndrome a preoperative localization procedure is not necessary due to the high sensitivity of the intraoperative diagnostic. In case of a MEN syndrome or reoperation a preoperative localization diagnostic is still advisable although the sensitivity is low.

Adenoma, Islet Cell↗
PubMed1995

[Diagnosis of the origin and therapy of organic hyperinsulinism].

BACKGROUND: The need for preoperative localization of an insulinoma is still under discussion. The aim of the present study was to determine the usefulness of preoperative localization of the tumour, to investigate the operative risk and to analyse the long-term course. PATIENTS AND METHODS: The sensitivity of the diagnostic workup was investigated prospectively in 26 patients operated on between 1. 9. 1985 and 31. 8. 1994 for hyperinsulinism at the surgical department of the university hospital in Mainz. RESULTS: In the case of solitary adenomas the sensitivity of preoperative sonography was 43%, that of CT 57%, and that of angiography 85%. Intraoperatively, all solitary adenomas were palpable and were to be seen at sonography. In a patient with multiple adenomas, only one tumour was seen sonographically. The postoperative course was unremarkable in 18 out of 27 operations on the pancreas; two patients died later. After a mean follow-up of 51 months, all patients were free of hypoglycaemic attacks. CONCLUSIONS: The results show that localization of the tumour prior to the first operation is no longer necessary in patients with no MEN syndrome. In the presence of the latter, however, it is recommended despite its low sensitivity. Although a permanent cure is possible with surgery, the morbidity of the operation is not negligible.

Adult↗
PubMed1995

Malignant peripheral neuroectodermal tumors in urology.

During the past few years, a new tumor type has emerged in the pediatric and adolescent group of cancer patients, which has been designated malignant peripheral neuroectodermal tumor (MPNT). This tumor has some clinical and pathological signs in common with either soft-tissue sarcomas or classic Ewing's sarcoma, but is defined as a distinct entity because of its immunohistological characteristics. The tumor expresses neuronal markers, but the pattern varies: chromogranin, neuron-specific enolase, synaptophysin, protein S-100 and others. MPNT can occur in the urogenital region. The differential diagnosis on clinical grounds must include Ewing's and soft tissue sarcomas, and also Wilms' tumor and its variants. MPNT are often wide spread in the urogenital region when first diagnosed. Response to radiotherapy and combination chemotherapy is limited. Radical surgery is not always possible. The prognosis therefore remains rather poor at this time. A selection of MPNT patients is presented to demonstrate the various problems associated with this diagnosis. MRI and CT of all patients showed large tumors with direct infiltration of the surrounding structures. MRI is the best imaging modality for diagnosis and therapy monitoring in these tumors, because of its high soft-tissue contrast.

Adult↗
PubMed1995

[Popliteal aneurysms: clinical aspects and diagnosis].

PURPOSE: To identify clinical and radiological features allowing an early diagnosis of popliteal aneurysms. MATERIAL AND METHODS: History, clinical features and radiological findings of 23 patients with 37 aneurysms were reviewed. RESULTS: 14 patients presented with a history of a sudden onset of rest pain localised in the calf or foot. Arteriography found popliteal artery occlusion in 12 of them. Amputation was necessary in one patient in spite of immediate diagnosis and therapy. In two cases embolisation of the tibial vessels caused intermittent claudication. In at least 7 patients the underlying disease was not suspected until arteriography was performed. In 16/23 patients the presence of thrombus prevented direct visualisation of the aneurysm and there were only secondary angiographic signs of the underlying condition. Thus, arteriography may fail to diagnose popliteal aneurysms. In 21/22 cases colour Doppler sonography was quick and accurate in the assessment of patent and thrombosed aneurysms. CONCLUSION: In any patient with ischaemic symptoms of the lower extremity a thorough palpation of the popliteal fossa should be performed. In patients with a prominent popliteal pulse, in pulseless popliteal tumours and in patients arteriographically shown to have popliteal artery occlusion, a sonographic study of both popliteal fossae should be performed.

Adult↗
PubMed1995

[Radiation exposure in diagnostic CT: comparison between spiral CT and standard CT].

CT-Dose-Index of Standard-CT corresponds to CT-Dose-Effect-Index of Spiral-CT. Spiral-CT provides a continuous data acquisition with well balanced dose profiles. Increasing pitch reduces radiation dose and nevertheless an unbroken reconstruction of scanned volume is possible. In contrast to Standard-CT, small parts at both ends of the volume scan are not reconstructed. Volume-Dose-Index therefore is elevated in short scan times but corresponds to that of Standard-CT in long scan times. 1 mm slices cause more radiation exposure due to their broadened dose profiles.

Equipment Design↗
PubMed1995

[CT and MRI in malignant peripheral neuroectodermal tumors].

To evaluate the diagnostic accuracy of CT and MRI in the diagnosis of malignant peripheral neuroectodermal tumors (MPNT), the imaging data of nine patients with immunehistochemically proven MPNT were retrospectively analyzed. The average age was 24 years (ranging from 5 to 63 years). MRI and CT of all patients showed large tumors with direct infiltration of the surrounding structures. Intratumoral calcifications were not identified. All tumors showed equal to less high signal intensity in T1- and high signal intensity in T2-weighted images. Because of its high soft-tissue contrast, MRI is the most capable imaging modality in the diagnosis and therapy-monitoring in these tumors.

Adolescent↗