ABSTRACT
OBJECTIVES: To document the mechanism of percutaneous transluminal angioplasty (PTA) and stenting of the iliac arteries, and to relate the effect to patency. MATERIALS AND METHODS: Thirty-seven stenotic iliac arteries were examined by intravascular ultrasound (IVUS) and arteriography before and after PTA, and after stent deployment (n = 16). The patients were followed prospectively by duplex scanning at 3, 6, 12, 18 and 24 months after the intervention. RESULTS: The effect of PTA was established by both compression and stretching with the major contribution arising from stretching. There were differences in the effect of PTA dependent on plaque morphology: in homogeneous eccentric lesions, stretching contributed significantly more than compression to the luminal gain, while stretching and compression contributed equally in concentric or heterogeneous plaques. Stenting of the arteries had no effect on the free luminal area as measured by IVUS. The primary 1-year patency rate was 72%. The patency was related to the free luminal area and diameter and the heterogenicity of the plaque as evaluated by IVUS. The arteriographic measurements did not have any predictive value. CONCLUSION: IVUS was able to document the effect of PTA and stenting in the iliac arteries, and predict the outcome. The luminal gain and reduction in degree of stenosis seemed to be accomplished primarily by stretching of the arteries and to a lesser extent by plaque compression. Stenting did not change the IVUS measurements. Patency was related to the size of the free lumen and the heterogenicity of the plaque.
Subject(s)
Angioplasty, Balloon , Arterial Occlusive Diseases/therapy , Iliac Artery/diagnostic imaging , Stents , Ultrasonography, Interventional , Aged , Arterial Occlusive Diseases/diagnostic imaging , Arteriosclerosis/diagnostic imaging , Arteriosclerosis/therapy , Female , Follow-Up Studies , Humans , Male , Middle Aged , Prospective Studies , Ultrasonography, Doppler, DuplexABSTRACT
The composition of the radioiodine species that is released in a hospital by nuclear medical therapy is investigated. More than 90% are found to be organic iodine. This leads to a reduction of the calculated radiation exposure in the environment by more than a factor of ten with regard to pure elemental iodine releases. The organic iodine is not formed by chemical reactions in the air of the rooms butoriginates in patients, who are treated with 131I. Effective half-lives and release factors for exhalation were determined by monitoring the exhaled air of the patients.
