Natalia Majewska

Patients' Radiation Doses During Thoracic Stent-Graft Implantation: The Problem of Long-Lasting Procedures

BACKGROUND This article investigates patient radiation doses during implantation of thoracic stent-graft. Aortic stengraft implantation can be disturbed by many factors, which, in turn, lead to prolongation of the procedure time and, as a consequence, increase the radiation dose. METHODS Measurements of radiation length (fluoroscopy and exposure), air kerma (AK) in grays, and dose-area product in grays·square centimeters were conducted simultaneously in 100 patients. The patients were analyzed retrospectively, regarding their body mass index (BMI), type of aneurysms, number of stent-graft parts, angulation of aorta, and coverage of the left subclavian artery. RESULTS Mean total dose-area product value for this kind of treatment was 361 Gy·cm2. This was caused by the fact that total mean AK was high for the cohort analyzed and reached 797 mGy. For 23 patients total AK was between 1 and 2 Gy, and for 3 it exceeded 2 Gy. In the remaining group, the maximal radiation dose was very high and exceeded 3 Gy. The total AK of patients with BMI within the range of 25 to 29.9 kg/m2 and with BMI greater than 30 kg/m2 significantly increased in comparison with the group of patients with BMI between 18 and 24.9 kg/m2 (p=0.00005 and 0.000001, respectively). During the study, a good correlation between AK and fluoroscopy time (r=0.6) and for AK (or dose-area product) and exposure time (r=0.66 or 0.81, respectively) was observed. CONCLUSIONS The main factors contributing to a high radiation dose being acquired by patients during thoracic stent-graft were BMI greater than 25 kg/m2, number of parts of the stent-graft, and angulation of the neck of aneurysm exceeding 60 degrees.

Clinical factors increasing radiation doses to patients undergoing long-lasting procedures: Abdominal stent-graft implantation

Summary Background An important negative factor of EVAR is the radiation acquired during long-lasting procedures. The aim of the study was to document the radiation doses of EVAR and to discuss potential reasons for prolongation of radiological procedures. Material/Methods Dose-area product (DAP) (Gy cm2) and air kerma (AK) (Gy) obtained during EVAR from 92 patients were analyzed retrospectively in regards to body mass index (BMI), angulations of aneurysm neck, length of aneurysm neck and occurrence of tortuosity of iliac arteries. Results Total AK for fluoroscopy differed significantly between normal BMI (373 mGy) and BMI 25–29.9 (1125 mGy) or BMI >30 (1085 mGy). Iliac artery tortuosities >45° and short aneurysm necks caused higher doses of total AK (1097 mGy and 1228 mGy, respectively) than iliac artery tortuosities <45° and long aneurysm necks (605 mGy and 720 mGy, respectively). Conclusions The main factors contributing to a high radiation dose being acquired by patients during EVAR are: BMI >25, tortuosity of iliac arteries >45° and short aneurysm necks.

Patient radiation exposure during carotid artery stenting

Objectives The main purpose of this study was to document the radiation doses to patients during carotid stenting. Material and method Fluoroscopy and exposure time, air kerma and dose-area product during carotid artery stenting in 160 patients were retrospectively reviewed with regard to body mass index, degree of stenosis and use of cerebral protection devices. Results Total air kerma was lower than 0.5 Gy in 80%, 0.5–1 Gy in 17% and higher than 1 Gy (maximum 1.2) in 3% of patients. Mean total dose-area product value for carotid stenting was 54 Gy cm2. The mean air kerma (fluoroscopy), air kerma (exposure), total air kerma and dose-area product (fluoroscopy), dose-area product (exposure), total dose-area product of patients with body mass index within the range 25–29.9 and with body mass index >30 were significantly increased compared to that of patients with body mass index 18–24.9 (H = 40.2, df = 2; p = 0.0000001 and p = 0.000003, respectively). Conclusion Carotid artery stenting is a relatively safe radiological procedure in terms of the radiation dose acquired by the patient. The main factors contributing to possible radiation overdosing are body mass index value and complexity of the carotid lesion. Proper preoperative planning in obese and complicated patients may reduce the fluoroscopy time and contribute to reduced dose acquisition.

Endovascular treatment of renal artery occlusion caused by aortic stentgraft migration.

Renal function impairment during interventional procedures became a real clinical problem. Contrast related nephropathy is the most common cause of renal failure, however, the procedure-related technical troubles may cause unexpected renal dysfunction.Technical failure of EVAR resulting in acute renal dysfunction is presented. The postprocedural occlusion of the right renal artery was treated in chimney technique. Early reintervention allowed the kidney preservation and renal function restoration. It is impossible to avoid all the complications following treatment of aortic aneurysm, but they can be anticipated and comprehensively treated in collaboration with other specialists.

Fenestrated stent graft in treatment of type IV thoracoabdominal aneurysm involving all visceral arteries.

Conventional open surgical repair of thoracoabdominal aortic aneurysm (TAAA) is associated with high perioperative mortality and morbidity risk. Our report of successful treatment of a 56-year-old patient with TAAA involving all visceral arteries and with many comorbidities with a fenestrated stent graft supports its application in high-risk TAAA patients.

Visceral arteries thrombosis as a fatal complication of intraaortic balloon malposition

1Department of General and Interventional Radiology, Poznan University of Medical Sciences, Poznan, Poland 2Department of Cardiac Surgery and Transplantology, Poznan University of Medical Sciences, Poznan, Poland 3Department of Hypertensiology, Angiology and Internal Medicine, Poznan University of Medical Sciences, Poznan, Poland 4Department of Cardiac Surgery and Transplantology, Poznan University of Medical Sciences, Poznan, Poland

Multiple complications after aortic stent-graft placement in a patient with preexisting nephrostomy and atherosclerosis of the lower extremities

Summary Background: Aortic stent-graft placement is intended to be a procedure with minimal perioperative risk in com -parison to the open procedure. However, the 1.5% mortality rate and the possibility of procedure-related complications should be taken into account. Case Report: This paper presents multiple procedure-related complications including acute limb ischemia and bowel necrosis in a patient with preexisting nephrostomy operated on with EVAR (endovascular aortic repair). Issues regarding proper anatomical planning and imaging are discussed, and ways to avoid such complications are highlighted. Conclusions: Multiple complications during EVAR may significantly reduce the early benefit of the procedure. Correct preoperative assessment of CT scans can avoid making an inappropriate decision regard-ing use of EVAR. In cases of concomitant urological pathology, any surgical intervention should be decided upon in cooperation with the vascular surgeon and urologist. key words: abdominal aortic aneurysm complications • aortic stentgrafts • nephrostomy • bowel necrosis • acute limb ischemia