PubMed Health⌕ Search

Biomedical subjects

R Dorffner

Publications and source records attributed to R Dorffner.

At least 19 recordsLinked to original sources
PubMed2005

[Technical feasibility of the implantation of a monorail stent system into the renal arteries without pre-dilatation].

PURPOSE: To evaluate the technical feasibility of the implantation of the monorail RX Herculink system into the renal arteries without pre-dilatation. MATERIALS AND METHODS: Forty-two patients (mean age 71 years) from four centers with a total of 44 renal artery stenoses underwent implantation of the RX Herculink stent. The mean grade of the stenosis was 83.8 %, the mean length 7.5 mm. The stenoses were ostial in 38 cases and in immediate proximity to the ostium in 6 cases. The mean follow-up-period was 57 weeks (24 - 176 weeks). RESULTS: In 42 cases, the implantation was successful without pre-dilatation. In 2 cases, pre-dilatation was carried out. In none of the cases, detachment of the stent from the balloon was observed. In one stenosis with a length of 17 mm, implantation of two stents was performed. In 9 cases, post-dilatation with a larger balloon or higher balloon pressure was necessary. Residual stenoses exceeding 30 % were not observed. Two patients developed local bleeding at the puncture site. During the follow-up, restenoses were observed in 5 stents after 26 to 126 weeks, which necessitated a second intervention in 3 cases (PTA in 2 cases, re-stenting in 1 case). The primary patency rate after 6 and 12 months was 0.92 +/- 0.056 according to Kaplan-Meier, the secondary patency rate after 6 and 12 months was 1.0 +/- 0.0. CONCLUSION: Implantation of the RX Herculink stent system into the renal arteries without pre-dilatation is technically feasible and safe. Even without pre-dilatation, the stent-system can be advanced through the stenosis without detachment. The complication rate is low. Our clinical results are comparable to previous studies.

Aged↗
PubMed2005

[Lung nodule detection with ultra-low-dose CT in routine follow-up of cancer patients].

PURPOSE: To evaluate the value of an ultra-low-dose CT protocol (ULD-CT) in the dectection of lungnodules in follow-up of cancer patients. MATERIAL AND METHODS: Between April and August 2003, 72 consecutive patients with a history of malignancy were prospectively examined on a single-slice helical CT scanner (Aquilion, Toshiba) with ULD-CT (120 kV, 5 mAs, D-eff 0.12 mSv) and regular-dose CT (R-CT) (120 kV, 150 mAs, D-eff 4.8 mSv). The ULD-CT examinations were independently evaluated by two radiologists. Afterwards, consensus reading of the ULD-CT and R-CT examinations was done. Individual nodules were classified benign (benign calcifications) and non-benign. The studies were classified in 4 subgroups: 1) non-benign nodule evident; 2) non-benign nodule probable; 3) non-benign nodule possible, but not likely; 4) no-non benign nodule. RESULTS: ULD-CT detected 180 nodules in 47 patients, while R-CT showed 168 nodules in 39 patients. The sensitivity of ULD-CT was 87 % in detecting nodules regardless of size and 94 % in detecting nodules > or = 5 mm. Regarding the prediction of a case with non-benign nodules (subgroups 1 to 3), the sensitivity of ULD-CT was 94 % and the specificity 75 %. CONCLUSION: ULD-CT is a good diagnostic tool in detecting lung nodules > or = 5 mm. Radiation dose can be markedly reduced. A negative ULD-CT study excludes non-benign nodules in R-CT with a high probability. In case of a positive ULD-CT, R-CT can be immediately followed.

Adult↗
PubMed2002

[First experience with a non-covered CHOO enteral stent in the stomach,duodenum, and jejunum].

AIM: To evaluate the technical performance of the non-covered CHOO enteral stent in the stomach, duodenum and jejunum. METHODS: In 8 patients (two men, 6 women) with malignant tumors of the stomach (n = 4), duodenum (n = 3) and jejunum (n = 1) stent implantation was performed under fluoroscopic control. In two patients endoscopy was needed additionally. The patients were followed for 1 to 168 days. RESULTS: Stent implantation was technically successful in 7 of 8 patients. In 6 patients symptoms improved. In two patients a second stent implantation was necessary 35 and 161 days after primary implantation, respectively. There was no stent migration or tumor ingrowth. CONCLUSION: The implantation of the non-covered CHOO enteral stent into the upper gastrointestinal tract is safe and effective.

Adult↗
PubMed2001

Treatment of a malignant stenosis of the corpus of the stomach with a self-expanding stent.

In a 50-year-old man, a self-expandable stent was implanted under fluoroscopic guidance to treat symptoms of an inoperable carcinoma of the corpus of the stomach. Foreshortening of the stent necessitated implantation of a proximal extension stent 5 weeks later. Secondary symptoms of advanced stage of the disease negatively influenced clinical success of the procedure, although free passage through the stents was achieved. We conclude that stent implantation for palliation of a carcinoma of the corpus of the stomach seems to be a viable method. The operator has to be aware of the special limitations and problems associated with the procedure.

Esophageal Stenosis↗
PubMed2001

Inferior mesenteric artery as outflow vessel in endoleaks after abdominal aortic stent-graft implantation: 36-month follow-up CT study.

The aim of this study was to determine the role of the inferior mesenteric artery (IMA) as an outflow vessel in endoleaks after abdominal aortic stent-graft implantation. Forty consecutive patients in whom abdominal aortic aneurysms (AAA) had been treated with stent-graft implantation were evaluated retrospectively. Spiral-CT examinations and angiographies up to 36 months after implantation were analyzed. In 29 (73%) of the 40 patients the IMA was perfused prior to implantation. In 5 (17%) of these 29 cases, the artery remained perfused after stent-graft insertion. In all 5 cases, endoleaks were detected; however, in none of these cases was the IMA the sole cause. In 3 of these 5 cases, angiography showed antegrade flow in the IMA. Implantation of extension stent grafts caused thrombosis of the aneurysmal sac and the IMA. There were no secondary endoleaks caused by the IMA at the 36-month follow-up examinations. The majority of IMAs which are patent prior to intervention occlude after successful stent-graft insertion. In cases with leaks and angiographically proven antegrade flow in the IMA, implantation of extension stent grafts is a therapeutic alternative to embolization. In this study, the IMA was not responsible for secondary endoleaks.

Aged↗
PubMed1999

Immunotherapy of metastatic malignant melanoma by a vaccine consisting of autologous interleukin 2-transfected cancer cells: outcome of a phase I study.

We performed a phase I trial to evaluate the safety and tolerability of repeated skin injections of IL-2-transfected autologous melanoma cells into patients with advanced disease. Cell suspensions, propagated from excised metastases, were IL-2 gene transfected by adenovirus-enhanced transferrinfection and X-irradiated prior to injection. Vaccine production was successful in 54% of the patients. Fifteen patients (37%) received two to eight skin vaccinations of either 3 x 10(6) (intradermal) or 1 x 10(7) (half intradermal, half subcutaneous) transfected melanoma cells per vaccination (secreting 140-17,060 biological response modifier program units of IL-2/10(6) cells/24 hr). Analyses of safety and efficacy were carried out in 15 and 14 patients, respectively. Overall, the vaccine was well tolerated. All patients displayed modest local reactions (erythema, induration, and pruritus) and some experienced flu-like symptoms. Apart from newly appearing (4 of 14) and increasing (5 of 14) anti-adenovirus and newly detectable anti-nuclear antibody titers (1 of 15), recipients developed de novo or exhibited increased melanoma cell-specific delayed-type hypersensitivity (DTH) reactions (8 of 15) and vitiligo (3 of 15) and showed signs of tumor regression (3 of 15). This supports the idea of a vaccine-induced or -amplified anti-cancer immune response. None of the patients exhibited complete or partial regressions, but five of them experienced periods of disease stabilization. Three of these individuals received more than the four planned vaccinations and their mean survival time was 15.7 +/- 3.5 months as compared to 7.8 +/- 4.6 months for the entire patient cohort. These data indicate that IL-2-producing, autologous cancer cells can be safely administered to stage IV melanoma patients and could conceivably be of benefit to patients with less advanced disease.

Adult↗
PubMed1999

[Management of abdominal aortic and peripheral aneurysm using stent grafts].

The implantation of stent grafts is a relatively new method for the treatment of aneurysms of the aorta or peripheral aneurysms. Before the implantation precise measurements are mandatory to obtain the necessary information about the aneurysm. The numerous contraindications must be observed strictly to successfully exclude the aneurysmal sac. The stent graft is inserted via a percutaneous puncture or, in the case of an aortic graft, through a surgical arteriotomy. After the implantation rigorous follow-up is mandatory to detect complications such as leaks or thrombi: Spiral CT angiography is the method of choice. Some of the complications require secondary interventions such as the implantation of additional stent grafts. The results are encouraging, with a secondary exclusion rate of the aneurysm of up to more than 95%; however, long-term results are not available.

Angiography↗
PubMed1999

Amplitude-coded color doppler: clinical applications.

Amplitude-coded color Doppler sonography (ACD) has become an useful adjunct to gray-scale US and conventional color Doppler sonography (CD) for the assessment of vascular diseases and pathologic conditions that might affect or alter tissue vascularization or perfusion. Basically, all US units that generate conventional color Doppler information through autocorrelation technique are capable of displaying ACD. This technique is also referred to as power Doppler, amplitude-mode color Doppler US, color Doppler energy (CDE), or US angiography. Amplitude-coded color Doppler sonography has already emerged as a valuable adjunct to conventional CD, particularly for evaluating flow in parts of the body where CD signal is weak because of slow flow, small blood vessels, or both.

Blood Flow Velocity↗
PubMed1999

Pseudoaneurysm of the internal carotid artery after shrapnel injury in World War II: demonstration by CT angiography with 3D MIP reconstruction.

A case of pseudoaneurysm of the left internal carotid artery (ICA) after shrapnel injury is demonstrated by intra-arterial digital subtraction angiography (DSA) and computed tomography angiography (CTA) with subtraction technique. Although the pseudoaneurysm was well demonstrated by intra-arterial DSA, CTA was the only modality to demonstrate the three-dimensional shape of the perfused part of pseudoaneurysm and the aneurysmal neck, which affected the therapeutic strategy. The CTA technique is useful in the assessment of large pseudoaneurysms and for therapeutic planning.

Aged↗
PubMed1999

Dental vertical root fractures: value of CT in detection.

PURPOSE: To determine the value of computed tomography (CT) in the diagnosis of dental vertical root fractures relative to the value of conventional dental radiography. MATERIALS AND METHODS: Thirty-seven patients with 42 teeth in which vertical root fracture was clinically suspected underwent dental radiography and axial CT. Two radiologists evaluated the images independently and by consensus for a fracture line. The results were compared with intraoperative findings. RESULTS: Twenty-eight of the 42 teeth were proved intraoperatively to be fractured. The sensitivity and specificity averaged for the two reviewers in the assessment of vertical fractures were 23% and 70%, respectively, with dental radiography and 100% and 100%, respectively, with CT. Consensus reading showed sensitivities of 25% for dental radiography and 75% for CT. Eight (reviewer A) or nine (reviewer B) false-negative CT findings were encountered in cases in which metallic artifacts obscured parts of the root and in cases in which the root was very small in diameter. Interobserver agreement was 95% for dental radiography and 93% for CT. CONCLUSION: CT is superior to dental radiography in the detection of dental vertical root fractures.

Adult↗
PubMed1998

Venous contrast fluid level in computed tomography.

OBJECTIVE: To evaluate the clinical significance of a venous contrast fluid level during computed tomography (CT). METHODS: An incidentally found contrast fluid level in the left internal jugular vein during CT in an otherwise healthy patient was the reason for investigation of this phenomenon. We collected data over a 4-year period at our institution and reviewed the case notes of seven patients exhibiting this CT finding. We also performed conventional radiography, CT, venography and colour-coded Doppler sonography to rule out an underlying pathology in those patients. Additional in-vitro CT studies were performed to define conditions of flow leading to a contrast fluid level. Flow dynamics in the internal jugular veins were studied in vivo by using colour-coded Doppler sonography in 20 normal volunteers. RESULTS: In addition to our first patient, we found seven patients with a venous contrast fluid level among a total of 58400 contrast-enhanced CT examinations performed in our institutions. The investigations were performed on various CT-units, with different scan protocols, injection rate, dose and manufacturer of non-ionic contrast agent. The contrast fluid level was encountered unilaterally in the left internal jugular vein in seven patients and in the inferior vena cava in one patient. All patients were free of symptoms and the outcome of all other examinations was unremarkable. In-vitro and in-vivo studies showed that pure contrast agent entering a vessel (in case of the internal jugular vein due to physiological flow and/or stasis) can produce a contrast fluid level. CONCLUSION: The occurrence of a venous contrast fluid level during contrast enhanced CT is an incidental finding of no pathological significance and need not initiate costly further examinations.

Adult↗
PubMed1998

Endovascular management of "endoleaks" after transluminal infrarenal abdominal aneurysm repair.

PURPOSE: To investigate the reasons for endoleaks after transluminal infrarenal abdominal aneurysm management and the potential for transluminal interventions in subsequent management. METHODS: Prospective analysis of 50 consecutive patients undergoing endovascular aneurysm repair at a single institution with Stentor and Vanguard grafts from March 1995 to March 1997. SETTING: Academic teaching hospital. RESULTS: Two procedures were converted for other reasons than leak. In the remaining 48 successful procedures endoleaks were detected in 11 (22.9%): proximal aortic leak (2.1%), distal aortic leak (8.3%), iliac leak (12.5%). Leaks were treated at the initial procedure in five patients, resulting in 87.5% excluded aneurysms. Twelve and a half per cent were discharged with a primary leak. Redo was performed on all iliac leaks within 7 weeks. All aortic leaks showed spontaneous thrombosis within 3 months, but reappeared with local aneurysm expansion. Aortic redo-procedures were performed by proximal tubular extension or converting a tube graft into a bifurcation graft. All rescue procedures were successful. Secondary leaks have been observed twice in this series, both treated by endovascular means. CONCLUSIONS: Endovascular treatment of primary and secondary endoleaks is possible, and may be a safe alternative to a difficult open procedure.

Aged↗
PubMed1998

[The value of sonography in the intensive care unit for the diagnosis of diaphragmatic paralysis].

PURPOSE: To assess the value of bedside sonography in the detection of diaphragmatic paralysis in patients in the intensive care unit. METHODS: In this study, 100 patients who were admitted to the intensive care unit after thoracic operations were evaluated. Sonography of each hemidiaphragm was performed with coronal scans at the mid-axillary line on both sides with the patient supine. Absent and paradoxical diaphragmatic movement was considered to be indicative of diaphragmatic paralysis. All patients underwent additional fluoroscopy within 5 days. RESULTS: In 13 patients (13%) sonography revealed diaphragmatic paralysis. All these results were confirmed with fluoroscopy resulting in a sensitivity and specificity for sonography of 100%. CONCLUSION: Bedside sonography of the diaphragm at the intensive care unit is a reliable tool for diagnosing diaphragmatic paralysis.

Adult↗