Biomedical subjects

H Seifarth

Publications and source records attributed to H Seifarth.

5 recordsLinked to original sources

PubMed2003

Virtual intra-arterial angioscopy (VIA) of the carotid artery based on helical CT data.

The purpose of this study was to visualize both the vessel wall and atherosclerotic plaques in virtual intra-arterial angioscopy (VIA) based on helical CT data sets. To achieve this in vitro, the optimal reconstruction threshold of the vessel wall was determined to be 56.4% of the maximum enhancement. Using this threshold, 20 patients suffering from symptomatic carotid disease were examined in a helical CT scanner. The degree of stenosis was defined using the North American Symptomatic Endarterectomy Trial (NASCET) criteria and compared with results from digital substraction angiography (DSA). Grading of stenoses was only possible by adding the separately computed plaque geometry to the geometry of the vessel wall in a second step. Correlation between VIA and DSA in low grade, medium grade and high grade stenosis was 88%, 93% and 71%, respectively. Complete occlusions were diagnosed correctly in all patients. Sensitivity and specificity for the correct diagnosis of high grade stenosis was 93.7% and 91.3%, respectively. A realistic depiction of intraluminal structures in carotid arteries can only be generated by displaying both the vessel wall and plaque structures simultaneously.

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

Geometric changes in aortic endografts over a 2-year observation period.

PURPOSE: To report geometric changes in bifurcated aortic endografts observed over a 2-year follow-up period. METHODS: Twenty-two patients (21 men; mean age 68 years, range 57-83) with abdominal aortic aneurysms were treated with an endovascular stent-graft. Follow-up examinations included spiral computed tomographic scanning postoperatively and at 3, 6, 9, 12, 18, and 24 months after treatment. Geometric changes were measured using 3-dimensional reconstructed images in anteroposterior (AP) and lateral projections. Locations for the measurements were the proximal neck, the midportion of the endograft, and the graft limbs at the origin of the iliac arteries. RESULTS: Lateral changes predominated, demonstrating maximum angles on the side of the inserted left limb. For the proximal neck, the stent angle changed by a mean -0.71 degrees in the AP and 4.0 degrees in the lateral projection. At the midgraft, changes were -0.56 degrees for AP and 12.5 degrees for lateral. The right limb showed an angle of 6.43 degrees in AP and -0.43 degrees in lateral, whereas the left limb angles changed 1.38 degrees in AP and 11.71 degrees in the lateral plane after 2 years. There was no statistically significance difference in these changes from baseline. CONCLUSIONS: Aortic endografts are exposed to a significant amount of movement after insertion, but the resultant changes are very inhomogeneous, unpredictable, and ongoing even after 2 years. The most vulnerable location seems to be the attachment zone of the modular graft limb. These geometric changes might be one cause for late complications, including leaks and limb dislocations.

Aged↗

PubMed2001

Endovascular grafting of traumatic aortic aneurysms in contaminated fields.

PURPOSE: To evaluate the potential of endovascular stent-grafts to treat traumatic aortic lesions in contaminated areas. METHODS: Four patients (3 women; ages 26-78 years) underwent stent-grafting to repair an aortic rupture sustained in a motorcycle accident, aortic lacerations secondary to surgical treatment of spondylitis in 2 patients, and an aortobronchial fistula following surgical thoracic aortic repair 10 years earlier. Stent-grafts (2 Corvita, 1 Talent, and 1 Vanguard) were placed endoluminally into the infected areas via a transfemoral approach. Follow-up included erythrocyte sedimentation rate, white blood count, C-reactive protein, blood cultures, and computed tomography (CT). RESULTS: The stent-grafts were successfully placed in all cases and excluded the aortic lesion. Under supportive antibiotic therapy, inflammation parameters returned to normal. CT imaging showed no evidence of paraprosthetic infection, nor were there any other complications over a follow-up that ranged from 3 to 34 months. CONCLUSIONS: Endovascular therapy may be an alternative in the acute management of aortic ruptures in the setting of infection. Long-term results are required for definitive evaluation of the method.

Adult↗

PubMed1998

[High-resolution virtual laryngoscopy based on spiral CT data].

This pilot study investigated the feasibility and clinical value of high-resolution virtual real-time laryngoscopy based on helical CT data sets. Nine patients with laryngeal pathology (three with tumors of the vocal cords, two laryngeal carcinomas, one with invasion of the larynx by thyroid carcinoma and six subglottic stenoses) underwent examination by helical CT at a collimation of 1 mm. Following acquisition, the images were processed at a workstation with standard visualization software, such that virtual endoscopy (VE) in real time was possible. The images were then compared with the findings of conventional endoscopy. Because of swallowing artifacts, reconstruction failed in 2 of 12 patients. None of the carcinomas of the vocal cords was recognized at VE or in the cross-sectional CT images. VE provided the correct diagnosis in 8 of 12 cases (laryngeal tumors, subglottic stenoses). Virtual laryngoscopy is capable of simulating the visual findings of endoscopy in cases of laryngeal tumors and subglottic stenoses. Small tumors of the vocal cords are not adequately visualized. The major problem affecting results is motion artifacts resulting from involuntary swallowing.

Aged↗