Biomedical subjects

R Dorffner

Publications and source records attributed to R Dorffner.

At least 37 records · Page 2Linked to original sources

PubMed1998

[Treatment of arterial aneurysms of the pelvic leg vessels using dacron covered nitinol stents].

PURPOSE: To evaluate the success rates of the implantation of stent grafts in the treatment of peripheral aneurysms. MATERIALS AND METHODS: In 13 patients with 15 aneurysms at the common iliac artery (n = 6), external iliac artery (n = 1), hypogastric artery (n = 2), femoral artery (n = 2) or popliteal artery (n = 4), implantation of dacron-covered nitinol stents was performed. The patients were followed up for three to 20 months (mean, 8.8 months) with intravenous digital subtraction angiography, CT or colour-coded Doppler sonography. RESULTS: In all cases, the aneurysm was successfully occluded after stent implantation. In one case with a popliteal aneurysm, kinking of the vessel caused thrombosis of the stent. The stent was successfully reopened. The aneurysm however, had to be surgically treated 9 months later. The primary and secondary patency rates at 6 months were 93% and 100%, respectively. CONCLUSION: The method described might be an alternative therapy to surgery. There are some limitations in respect of treatment of popliteal aneurysms.

Adult↗

PubMed1998

MR imaging in children with nonperforated acute appendicitis: value of unenhanced MR imaging in sonographically selected cases.

OBJECTIVE: The aim of this study was to describe the MR appearance of acute appendicitis and to determine the value of MR imaging for diagnosis of acute appendicitis. SUBJECTS AND METHODS: Forty-five children (28 girls, 17 boys), 7-16 years old (mean age, 13 years old), with clinically diagnosed acute appendicitis underwent independently graded compression sonography by two radiologists. MR imaging was performed when sonography revealed acute appendicitis (observer 1, 16 [36%] patients; observer 2, 18 [40%] patients), was inconclusive (observer 1, two [4%] patients; observer 2, one [2%] patient), and was interpreted as normal (observer 1, two [4%] patients; observer 2, one [2%] patient) (n = 20). Axial T1-weighted turbo spin-echo sequences, T2-weighted turbo spin-echo sequences in the axial and coronal planes, and fat-suppressed short inversion time inversion recovery turbo spin-echo sequences in the axial plane (4-mm slice thickness) were obtained and evaluated independently by two radiologists. The ability to see acute appendicitis with MR imaging was evaluated, the appearance and morphologic changes were described, and the most accurate sequence was determined. All children in whom MR imaging was performed underwent surgery. RESULTS: MR imaging revealed acute appendicitis in all cases (100%) by both observers. On T2-weighted ultra turbo spin-echo images, acute appendicitis appeared with a markedly hyperintense center, a slightly hyperintense thickened wall, and markedly hyperintense periappendiceal tissue. Unenhanced axial T2-weighted spin-echo imaging was the most sensitive sequence. CONCLUSION: In this study group, MR imaging was a valuable technique for depiction of acute appendicitis.

Acute Disease↗

PubMed1997

[MRI diagnosis of lesions of the anterior cruciate ligament--comparison of 1.0 Tesla and 0.2 Tesla. Initial results].

The purpose of our study was to compare the diagnostic performance of a 0.2-T MRI unit and a 1.0-T MRI unit in the evaluation of the anterior cruciate ligament in patients with clinically suspected lesions of this ligament. Twenty four patients with clinically suspected lesions of the anterior cruciate ligament underwent MRI of the knee on both 0.2-T and 1.0-T MRI units. Three independent observers evaluated the examinations for primary and secondary signs of a tear of the anterior cruciate ligament. Frequency of these signs was determined for both modalities, and observer agreement was assessed using the kappa statistic. Sixteen of 24 patients had signs of tears of the anterior cruciate ligament on the 1.0-T unit; the 0.2-T unit detected primary signs in 15/16 (93%) patients and secondary signs in 7/12 (43%) patients. In 8 patients the 1.0 T unit showed neither primary nor secondary signs for tears of the anterior cruciate ligament; in these patients the 0.2-T unit detected primary signs in 1/8 cases (12%), and secondary signs in 3/8 cases (37%). Observer agreement was very good for the 1.0-T unit and fair for the 0.2-T unit. There is no substantial difference between 1.0-T units and 0.2-T MRI units in the visualisation of primary signs of tears of the anterior cruciate ligament. In the visualisation of secondary signs, 1.0-T units are superior to 0.2-T units, and there is a surprisingly high rate of false-positive results with the 0.2-T unit. As to the reproducibility of the results, the 1.0-T unit is far superior to the 0.2-T unit.

Adult↗

PubMed1997

Intraoperative and early postoperative colour Doppler sonography after carotid artery reconstruction: follow-up of technical defects.

We studied 50 patients with intraoperative colour-coded Doppler sonography (CCDS) after carotid artery reconstruction. Technical defects could be detected in 19 cases (38 %): residual plaques in 9, flaps in 8 and strictures in 2. In 9 cases (18 %) the carotid endarterectomy was revised. One residual plaque and one residual stricture caused thrombosis at the operative site a few hours postoperatively. One of the patients with residual plaques developed a high-grade stenosis within the follow-up period. Of the patients with residual plaques two had a medium-grade stenosis at follow-up. Six flaps decreased in size or disappeared within 1 week after operation. No patient with a flap developed a stenosis within the follow-up period. Our findings seem to indicate that correction of intimal flaps less than 10 mm in size is not necessary.

Aged↗

PubMed1997

Reduction of adverse events in MRI of the breast by personal patient care.

PURPOSE: To determine the difference in anxiety reactions in patients undergoing standard (non-breast) magnetic resonance imaging (MRI) compared to breast magnetic resonance imaging (MRM) and to evaluate the influence of patient information before the breast imaging examination on the rate of premature termination of the procedure. MATERIALS AND METHODS: Over 2 years, 5837 non-breast and 336 breast magnetic resonance examinations were performed at our institution. One group of breast MRM patients (n = 144) received detailed information and a second group (n = 189) received only routine information before MRI. The rates of premature termination were recorded for all groups. RESULTS: In 0.5% (27/5837) of patients undergoing standard MRI examinations the study had to be stopped prematurely. Of the breast MRM patients, those who had received only routine information had a significantly higher rate of premature termination when compared to the better-informed patients and those undergoing standard MRI (5.5%, 10/189, P= 0.01). A significantly lower rate of premature termination occurred in the better-informed breast group (0%, 0/144). CONCLUSION: MRM is associated with an increase in patient anxiety and higher rates of incomplete examination than other MR procedures. We recommend careful patient preparation including detailed verbal information before MRM and support during the procedure to obtain optimal patient compliance.

Anxiety↗

PubMed1997

Lymph node sonography versus palpation for detecting recurrent disease in patients with malignant melanoma.

The aim of this study was to examine the efficacy of lymph node palpation versus high resolution lymph node sonography for the detection of lymph node metastases in patients with malignant melanoma. We retrospectively evaluated 2256 pairwise lymph node examinations of the cervical, axillary and inguinal region by palpation and sonography in 264 patients with resected melanomas greater than 0.75 mm of invasion thickness. Lymph node metastases occurred in 50 patients (19%) which were detected in 38 (76%) by both methods in agreement. In 7 cases (14%) palpation failed, in 3 cases (6%) sonography failed and in 2 cases both methods failed to identify metastases. The overall sensitivity of detecting metastatic disease was 82% for palpation and 90% for sonography which was statistically not different. The overall specificity by sonography (99%) was significantly better than for lymph node palpation (88%). Taking into account the results of this analysis, we conclude that patients with a negative result by lymph node palpation do not need further sonography for verification. However, any suspect result by palpation should be additionally evaluated by lymph node sonography in order to rule in or out metastatic disease.

Adolescent↗

PubMed1997

Treatment of abdominal aortic aneurysms with transfemoral placement of stent-grafts: complications and secondary radiologic intervention.

PURPOSE: To determine the rate of complications of transluminally placed endovascular stent-grafts in patients with abdominal aortic aneurysms and to assess efficacy of secondary radiologic intervention. MATERIALS AND METHODS: In 28 patients, covered nitinol stents were implanted. Frequency and outcome of complications were evaluated after stent-graft placement (mean follow-up, 8.2 months). RESULTS: In 27 patients, 11 tube and 16 bifurcated grafts were implanted successfully. In one (4%) patient, distal migration of a bifurcated graft necessitated conversion to standard open repair. Technical success rates (successful deployment of the device and complete exclusion of the aneurysm at intraoperative angiography) for bifurcated and tube grafts were 24% (four of 17 patients) and 91% (10 of 11 patients). After surgery, leaks were seen in six bifurcated and five tube grafts. After secondary intervention, the final exclusion rate for bifurcated and tube grafts was 88% (15 of 17 patients) and 100% (11 of 11 patients), respectively; the overall success rate was 93% (26 of 28 patients) for exclusion of aortic abdominal aneurysms. Stent-graft thrombosis necessitated local thrombolysis in one patient. Overlapping of accessory renal arteries occurred in two patients. CONCLUSION: Complications after stent-graft placement in abdominal aortic aneurysms are frequent. Secondary radiologic intervention is successful in most cases.

Aged↗

PubMed1997

Evaluation of abdominal aortic aneurysm for stent-graft placement: comparison of gadolinium-enhanced MR angiography versus helical CT angiography and digital subtraction angiography.

PURPOSE: To determine whether magnetic resonance (MR) angiography can be used alone to evaluate abdominal aortic aneurysms (AAAs) for endovascular placement of stent grafts. MATERIALS AND METHODS: Sixty-one patients with AAAs underwent gadolinium-enhanced MR angiography of the abdominal aorta and pelvic arteries. Measurements of the size and extent of the AAAs were compared with helical computed tomographic (CT) and digital subtraction angiographic measurements; 95% confidence intervals for the differences in the means were determined. RESULTS: Because of the larger field of view, MR angiography was superior to CT angiography in assessing visceral iliac artery disease. Both modalities were equal in evaluating the proximal extent of the AAA (mean difference, -0.16 mm; 95% CI, -0.31, 0.64) and in measuring all aortic dimensions (e.g., mean difference in the proximal neck diameter, -0.74 mm; 95% CI, -0.98, -0.49). MR angiography was inferior to CT angiography in depicting accessory renal arteries (seven of 12) and in grading renal artery stenoses (sensitivity, 100% [95% CI, 0.90, 1.00]; specificity, 84% [95% CI, 0.74, 0.91]). CONCLUSION: Gadolinium-enhanced MR angiography is a fast, reliable means of providing all the information relevant to the preoperative assessment of endovascular aortic stent-graft placement.

Adult↗

PubMed1997

Diaphragmatic dysfunction after heart or lung transplantation.

BACKGROUND: The aim of this study was to evaluate the incidence and outcome of diaphragmatic dysfunction in patients after heart or lung transplantation and to assess the value of bedside sonography for the detection of diaphragmatic dysfunction. METHODS: We prospectively evaluated 33 heart transplant recipients and 27 lung transplant recipients by use of sonography of the diaphragm and fluoroscopy. RESULTS: Diaphragmatic dysfunction, diagnosed with ultrasonography and confirmed with fluoroscopy, was present in four heart transplant recipients (12.1%) and two lung transplant recipients (7.4%) and such dysfunction led to a statistically significant higher incidence of pneumonia during hospitalization and a nonstatistically significant increased length of intubation compared with patients with normal diaphragmatic function. CONCLUSION: Diaphragmatic dysfunction, which can be reliably diagnosed with bedside sonography, is common after heart and lung transplantation and seems to have a negative influence on patient recovery.

Adult↗

PubMed1996

Pseudopericardial effusions in heart transplant recipients.

BACKGROUND: The objective of this study was to determine the nature of sonographically observed band-shaped, homogeneous, almost echo-free structures located ventral to the right ventricle of the heart in heart transplant recipients. METHODS: A total of 212 consecutive heart transplant recipients was evaluated sonographically. RESULTS: In 18 of the 212 patients (8.5%) band-shaped structures were detected, and these structures were proved with computed tomography or magnetic resonance imaging to be caused by mediastinal fat. CONCLUSIONS: A sonographically demonstrable, almost echo-free band-shaped structure located ventral to the heart should not be misinterpreted as localized pericardial effusion.

Adult↗

PubMed1994

[Rate of thrombosis after cava filter implantation. Long-term results].

Thrombosis of the access site and occlusion of the inferior vena cava after placement of an inferior vena caval filter are known complications of caval interruption. 30 patients were evaluated with colour-coded Doppler sonography 4 to 66 months (average 2.5 years) after percutaneous placement of either a Günther filter, a Bird's Nest filter or a Simon-Nitinol filter. One right internal jugular vein had post-thrombotic alterations. One inferior vena cava was found to be occluded 15 months after Simon-Nitinol filter placement. The long-term occlusion rates of access site and inferior vena cava after percutaneous filter introduction are low. These two factors need not be considered if implantation of a caval filter is contemplated.

Adult↗

PubMed1994

Quantification of pleural effusions: sonography versus radiography.

PURPOSE: To develop a practical method of estimating the volume of pleural effusions with sonography. MATERIALS AND METHODS: Fifty-one patients underwent sonography of the pleural space while supine. Sonographic results and results of lateral decubitus radiography were compared with actual effusion volumes. The maximum thickness of the pleural fluid layer was measured with both modalities, while actual effusion volume was determined by means of complete drainage. RESULTS: Sonographic measurements correlated statistically significantly better with actual effusion volume (r = .80) than did radiographic measurements (r = .58) (P < or = .05). With sonographic measurement, an effusion width of 20 mm had a mean volume of 380 mL +/- 130 (standard deviation), while one of 40 mm had a mean volume of 1,000 mL +/- 330. Prediction error with sonographic measurement (mean, 224 mL) was statistically significantly less (P < or = .002) than that with radiographic measurement (mean, 465 mL). CONCLUSION: In quantification of pleural effusions, the sonographic measurement method presented is preferable to radiographic measurement.

Adult↗

PubMed1993

[Stenoses and occlusions of the abdominal aorta in patients less than 40-years old].

Stenosis or occlusion of the abdominal aorta in patients under 40 years of age is either due to a congenital malformation (abdominal aortic coarctation) or due to idiopathic aortitis (Takayasu's arteritis). Some authors, however, consider abdominal aortic coarctation as a subtype of Takayasu's arteritis. We evaluated 9 of our cases and 108 well-documented cases from the literature to help decide the question whether abdominal aortic coarctation is an entity of its own or a subtype of Takayasu's arteritis. In coarctation there is a slight male predominance, patients are usually younger than 20 years of age, and the short aortic stenosis is suprarenal with involvement of the renal arteries. In Takayasu's arteritis females are predominantly affected, patients are usually over 20 years of age, and the long aortic stenosis or occlusion is infrarenal without involvement of the renal arteries. Abdominal aortic coarctation must therefore be considered as a separate disease. Aortography is important, because the morphology of aortic alterations often allows a radiological diagnosis.

Adult↗

PubMed1992

Fotemustine plus dacarbazine in advanced stage III malignant melanoma.

19 patients with advanced malignant melanoma were treated with fotemustine and dacarbazine. Data recorded and available for evaluation in all patients included clinical and histopathological parameters of the primary melanoma, blood chemistry, blood cell count, chest X-ray, ultrasound and bone scan for initial staging of the site of metastases and follow-up during treatment. Dosage was fotemustine 100 mg/m2 and dacarbazine 200 mg/m2 intravenously twice monthly on days 1 and 8, repeated for a maximum of six courses. There were two complete and three partial responses in 5/19 patients (26%), and 8 patients (42%) had stable disease. 6 (32%) patients had no response. Median length of complete and partial responses was 3.9 months, and that of stable disease 4.2 months. The main side-effects were thrombocytopenia in 10 patients (53%) and nausea in 6 (32%); the nausea was easily suppressed by ondasetron. Thus, fotemustine-dacarbazine may be new treatment in advanced melanoma.

Adult↗

PubMedDate not supplied

Successful exclusion of a large femoropopliteal aneurysm with a covered nitinol stent.

A 70-year-old woman presented with a large femoro-popliteal aneurysm. A covered nitinol stent was implanted successfully and complete exclusion of the aneurysm was achieved. At follow-up 5 months later the stent was still patent and the patient was free of symptoms. However, moderate stenosis was seen at the proximal end of the stent.

Aged↗

PubMedDate not supplied

Embolization of iatrogenic vascular injuries of renal transplants: immediate and follow-up results.

PURPOSE: To evaluate the outcome in seven patients in whom iatrogenic vascular complications were treated with catheter embolization. METHODS: Angiography showed an arteriovenous fistula in six of the seven patients, a pseudoaneurysm in three patients, and an arteriocaliceal fistula in three patients. Embolization was performed with GAW coils or microcoils in all cases. In three patients enbucrilate, polyvinyl alcohol, or absorbable gelatin powder was administered as an adjunct to the coils. RESULTS: Angiographic success with total occlusion of the vascular injury was achieved in five of the seven patients and clinical success was achieved in four of seven cases. In two cases, nephrectomy after embolization was necessary because of renal artery occlusion or acute hemorrhage at the renal artery anastomosis, respectively. Infarction of 30%-50% of the renal parenchyma was seen in two cases. CONCLUSION: Angiographically successful embolization is not necessarily associated with clinical success. The complication rate is high.

Adult↗

PubMedDate not supplied

Spiral CT during selective accessory renal artery angiography: assessment of vascular territory before aortic stent-grafting.

We evaluated the vascular territory of accessory renal arteries in cases where the vessel might be overlapped by an aortic stent-graft. Spiral CT during selective accessory renal artery angiography was performed in four patients with abdominal aortic aneurysms (including one with a horseshoe kidney). The volume of the vascular territory of each renal artery was measured using a software program provided by the CT unit manufacturer. The supernumerary renal arteries perfused 32%, 37%, 15%, and 16% of the total renal mass, respectively. In two patients, stent-grafts were implanted, which resulted in occlusion of the supernumerary renal artery. The volume of the renal infarction was equal to the volume perfused by the artery as calculated before implantation of the stent-graft. The method proposed is accurate for estimating the size of the expected renal infarction. It might help to determine whether placement of a stent-graft is acceptable.

Aorta, Abdominal↗

PubMedDate not supplied

Spiral CT angiography in the assessment of abdominal aortic aneurysms after stent grafting: value of maximum intensity projections.

PURPOSE: Our goal was to evaluate the value of maximum intensity projections (MIPs) rendered from spiral CT in the assessment of abdominal aortic aneurysms after stent graft implantation. METHOD: Spiral CT of the aorta was performed in 28 patients 1 week after implantation of covered aortic stent grafts. MIPs were evaluated in a blinded fashion. Transaxial scans and intravenous angiographs were considered the reference standard. RESULTS: Stent deformity was evident on the MIPs in 5 cases and stent angulation was seen in 24 cases. The excluded aneurysmal sac was visualized in 14 (50%) cases. MIPs depicted the patent inferior mesenteric artery in 20 of 23 cases (87%). Renal artery occlusion (n = 3), leaks (n = 8), and parietal thrombi, (n = 3) were detected on the MIPs in all cases. CONCLUSION: MIPs are a valuable tool in the assessment of aortic stent grafts.

Aged↗