How Sensitive Is the Upper Gastrointestinal Tract to 90Y Radioembolization? A Histologic and Dosimetric Analysis in a Porcine Model.

In 90Y radioembolization, nontarget embolization to the stomach or small bowel can result in gastrointestinal injury, a rare but difficult to manage clinical complication. However, dosimetric thresholds for toxicity to these tissues from radioembolization have never been evaluated in a controlled setting. We performed an analysis of the effect of 90Y radioembolization in a porcine model at different absorbed-dose endpoints. METHODS: Six female pigs underwent transfemoral angiography and infusion of 90Y-resin microspheres into arteries supplying part of the gastric wall. Esophagogastroduodenoscopy was performed after 4 wk to assess interim gastrointestinal health. Animals were monitored for side effects for 9 wk after 90Y infusion, after which they were euthanized and their upper gastrointestinal tracts were excised for analysis. Histologic sections were used to map microsphere location, and a microdosimetric evaluation was performed to determine the absorbed-dose profile within the gastrointestinal wall. RESULTS: 90Y radioembolization dosages from 46.3 to 105.1 MBq were infused, resulting in average absorbed doses of between 35.5 and 91.9 Gy to the gastric wall. No animal exhibited any signs of pain or gastrointestinal distress through the duration of the study. Excised tissue showed 1-2 small (<3.0 cm2) healed or healing superficial gastric lesions in 5 of 6 animals. Histologic analysis demonstrated that lesion location was superficial to areas of abnormally high microsphere deposition. An analysis of microsphere deposition patterns within the gastrointestinal wall indicated a high preference for submucosal deposition. Dosimetric evaluation at the luminal mucosa performed on the basis of microscopic microsphere distribution confirmed that 90Y dosimetry techniques conventionally used in hepatic dosimetry provide a first-order estimate of absorbed dose. CONCLUSION: The upper gastrointestinal tract may be less sensitive to 90Y radioembolization than previously thought. Lack of charged-particle equilibrium at the luminal mucosa may contribute to decreased toxicity of 90Y radioembolization compared with external-beam radiation therapy in gastrointestinal tissue. Clinical examples of injury from 90Y nontarget embolization have likely resulted from relatively large 90Y activities being deposited in small tissue volumes, resulting in absorbed doses in excess of 100 Gy.

Bariatric embolization of the gastric arteries for the treatment of obesity.

Obesity is a public health epidemic in the United States that results in significant morbidity, mortality, and cost to the health care system. Despite advancements in therapeutic options for patients receiving bariatric procedures, the number of overweight and obese individuals continues to increase. Therefore, complementary or alternative treatments to lifestyle changes and surgery are urgently needed. Embolization of the left gastric artery, or bariatric arterial embolization (BAE), has been shown to modulate body weight in animal models and early clinical studies. If successful, BAE represents a potential minimally invasive approach offered by interventional radiologists to treat obesity. The purpose of the present review is to introduce the interventional radiologist to BAE by presenting its physiologic and anatomic bases, reviewing the preclinical and clinical data, and discussing current and future investigations.

Effect on examination ordering by physician attitude, common knowledge, and practice behavior regarding CT radiation exposure.

PURPOSE: We surveyed ordering physician attitudes, knowledge, and behavior with regard to computed tomography (CT)-related radiation exposure at a large medical center. METHODS: Sixteen questions were sent via electronic survey to 350 physicians. RESULTS AND CONCLUSION: The ability to quickly rule in or rule out conditions effectively strongly influenced the decision to order CT (85%-99%). Fear of litigation influenced CT ordering for those with less experience [odds ratio (OR)=2.3, P<.05]. Residents and primary care physicians were less likely to discuss risks/benefits of CT with patients (P ≤.03) compared to those with >5 years of experience (OR=4.0, P=.04).

Long-term efficacy and safety of uterine artery embolization in young patients with and without uteroovarian anastomoses.

PURPOSE: To assess long-term clinical efficacy of uterine artery embolization (UAE) in young women and the clinical significance of patent anastomoses between uterine and ovarian arteries. MATERIALS AND METHODS: Consecutive women no older than 39 years of age treated with UAE for symptomatic uterine leiomyomata with at least 3 years of follow-up were included in the study. Analysis includes angiographic images, pre- and postoperative magnetic resonance (MR) images, and symptom evaluations. Clinical evaluation and symptom severity scores (SSSs) were obtained at 6 months and yearly. Leiomyomata volume change, SSS, and repeat intervention rates were compared for patients with and without anastomoses between uterine and ovarian arteries. RESULTS: The study cohort included 87 patients, including 30 white patients (34.4%), 49 black patients (56.3%), and eight patients of other ethnicities (9.2%). Anastomoses were demonstrated in 41 patients (47.1%). Seventy patients (80.5%) completed the long-term follow-up, of whom 35 had an anastomosis (85.4% of the 41 patients with anastomoses) and 35 did not (76.1% of the 46 patients without anastomoses). Mean leiomyoma volume reduction was 49.1% (P = .018), and reduction of uterine volume was 36.0% (P < .001). Mean clinical follow-up duration was 45 months. Overall, 18 of 70 patients (25.7%) underwent repeat interventions, including 13 (37.1%) with anastomoses and five (14.3%) without anastomoses (P = .029). One patient (1.4%) developed natural amenorrheic change in the long term after UAE. Nineteen patients (27.1%) attempted pregnancy after UAE, and 12 patients had 15 pregnancies, with six pregnancies to full term. CONCLUSIONS: UAE in young patients achieves significant dominant leiomyoma volume reduction and symptomatic improvements, with overall repeat intervention rates of 25.7% in the long term. Uteroovarian anastomoses in young patients are associated with higher rates of repeat intervention after UAE.

Safety and utility of uterine artery embolization with CO2 and a gadolinium-based contrast medium.

The authors evaluated the safety and clinical outcomes of uterine artery embolization (UAE) without the use of conventional iodinated contrast media for symptomatic uterine leiomyomata. Patients underwent UAE with use of CO(2) gas and a gadolinium-based contrast medium. The safety and feasibility of the technique were assessed. Patients were followed up at 24 hours, 1 month, and 6 months after UAE and yearly thereafter. UAE without iodinated contrast medium was attempted in eight patients (mean age, 42.7 years +/- 4.1), and bilateral UAE was successful in all patients. The mean fluoroscopy time was 14.9 minutes. The mean amount of gadolinium-based contrast medium used was 30.6 mL or 0.181 mmol/kg. No major complications were noted. The mean improvement in the symptom severity score was 53.8. The mean reduction in leiomyoma volume was 42%. To date, no repeat interventions have been performed. UAE with CO(2) and a gadolinium-based contrast medium is a viable treatment option for patients with a severe allergy to iodinated contrast media or renal insufficiency.

Development of a hypertrophic ovarian artery after uterine artery embolization with polyvinyl alcohol particles.

Uterine artery embolization (UAE) for the treatment of symptomatic leiomyomata has shown excellent short-term clinical efficacy and minimal complications, yet recurrences after successful treatments at mid- and long-term follow-up have been reported. Exact etiologies for such recurrences have not been fully understood. We present a case of symptom recurrence with the development of a hypertrophic ovarian artery after successful UAE with polyvinyl alcohol particles, successfully treated with ovarian and repeat UAEs.

Treatment of intrauterine and large pedunculated subserosal leiomyomata with sequential uterine artery embolization and myomectomy.

Successful clinical outcomes were obtained after a combined therapy of uterine artery embolization (UAE) and subsequent myomectomy for gigantic subserosal leiomyoma exceeding 1,000 cm3 in volume on a short stalk and multiple intrauterine leiomyomata in young patients who desired fertility and uterine preservation. UAE effectively treated symptomatic multiple intramural and submucosal leiomyomata for menorrhagia symptoms, which also facilitated uncomplicated subsequent myomectomy with devascularized gigantic leiomyoma for the treatment of bulk symptoms.

Endovenous laser ablation of the great saphenous vein with a 980-nm diode laser in continuous mode: early treatment failures and successful repeat treatments.

PURPOSE: To investigate the efficacy of lower-energy endovenous laser treatment for great saphenous vein (GSV) incompetence and treatment parameters associated with early treatment failure. MATERIALS AND METHODS: Sixty consecutive endovenous laser treatments (32 left, 28 right; 57 initial treatments, three repeat treatments) in 48 patients (13 men, 35 women; mean age, 55.2 +/- 12.9 years), with bilateral treatments in nine patients, were studied. Preprocedural clinical signs, etiology, anatomy, and physiologic classifications demonstrated class 2 limbs in 11.7% of cases, class 3 limbs in 25.0%, class 4 limbs in 48.3%, and class 5 limbs in 15.0%. All initial and repeat treatments were performed with lower-energy with use of a 980-nm diode endovenous laser at 11 W in continuous mode. Patients wore class II compression stockings for 2 weeks and were followed up at 1, 3, and 6 months with clinical and duplex ultrasound examinations. Treatment failures were diagnosed at 3 months on the basis of GSV patency or lack of clinical improvement. Diameter and length of GSV treated, treatment energy parameters, and clinical outcomes were prospectively measured and compared between successful and failed treatments. RESULTS: The initial treatment success rate was 94.7% (54 of 57). The mean maximum diameter of successfully treated GSVs was 1.12 +/- 0.52 cm, and the mean maximum diameter of GSVs in which treatment failure occurred was 2.05 +/- 0.23 cm (P = .008). Mean total energy applied for successful treatments was 1,131.3 +/- 248.1 J, and mean total energy applied for failed treatments was 1,439.6 +/- 425.0 J (P = 0.053). Mean unit energy applied for successful treatments was 32.7 +/- 7.5 J/cm, and that for failed treatments was 32.8 +/- 4.9 J/cm (P = .986). All patients in whom treatment failed were successfully treated again with a mean total energy of 1,393.0 +/- 81.0 J and a mean unit energy of 29.4 +/- 4.9 J/cm. There were no significant differences in mean total energy or unit energy applied among successful, failed, and repeat treatments (P > .05). Mean follow-up duration was 6.8 months. CONCLUSIONS: Endovenous laser treatment with lower energy appears to be safe and effective. Larger GSV diameter is associated with early treatment failures.