Ben E. Paxton

Adjunctive percutaneous mechanical thrombectomy for lower-extremity deep vein thrombosis: clinical and economic outcomes.

PURPOSE To assess the clinical and economic benefits of catheter-directed thrombolysis (CDT) alone versus CDT with rheolytic percutaneous mechanical thrombectomy (PMT) for lower-extremity deep vein thrombosis (DVT). MATERIALS AND METHODS Consecutive patients with acute iliofemoral DVT treated with CDT with urokinase between 1997 and 2003 were identified. Demographic characteristics and clinical and economic outcomes were compared between patients treated with CDT alone versus CDT plus PMT. RESULTS Twenty-six limbs in 23 patients received CDT with urokinase, whereas 19 limbs in 14 patients were treated with CDT plus PMT. Mean treatment duration for CDT was 56.5 +/- 27.4 hours, compared with 30.3 +/- 17.8 hours for CDT plus PMT (P = .001). Mean urokinase dose for CDT was 6.70 +/- 5.9 million U compared with 2.95 +/- 1.82 million U for CDT plus PMT (P = .011). Urokinase CDT achieved complete clot lysis in 80.7% of limbs (n = 21) compared with 84.2% of limbs (n = 16) treated with CDT plus PMT (P = .764). The incidences of major bleeding (CDT, 7.7%; CDT plus PMT, 5.3%; P = .749) and pulmonary embolism (CDT, 3.8%; CDT plus PMT, 5.3%; P = .818) were similar. The mean urokinase and PMT device cost for CDT alone was

Catheter-Directed Thrombolysis with Percutaneous Rheolytic Thrombectomy Versus Thrombolysis Alone in Upper and Lower Extremity Deep Vein Thrombosis

10,127 compared with

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

5,128 for CDT plus PMT (P = .026). CONCLUSIONS Percutaneous CDT with rheolytic PMT is as effective as CDT alone for acute iliofemoral DVT but requires significantly shorter treatment and lower lytic agent dose, resulting in lower costs. Randomized studies to confirm the benefits of pharmacomechanical thrombolysis in the treatment of DVT are warranted.

Bariatric Embolization for Suppression of the Hunger Hormone Ghrelin in a Porcine Model

PurposeTo compare the efficacy of catheter-directed thrombolysis (CDT) alone versus CDT with rheolytic percutaneous mechanical thrombectomy (PMT) for upper and lower extremity deep vein thrombosis (DVT).MethodsA retrospective cohort of consecutive patients with acute iliofemoral or brachiosubclavian DVT treated with urokinase CDT was identified, and a chart review was conducted. Demographic characteristics, treatment duration, total lytic dose, clot lysis rates and complications were compared in patients treated with urokinase CDT alone or combined CDT and rheolytic PMT.ResultsForty limbs in 36 patients were treated with urokinase CDT alone. Twenty-seven limbs in 21 patients were treated with urokinase CDT and rheolytic PMT. The mean treatment duration for urokinase CDT alone was 48.0 ± 27.1 hr compared with 26.3 ± 16.6 hr for urokinase CDT and rheolytic PMT (p = 0.0004). The mean urokinase dose required for CDT alone was 5.6 ± 5.3 million units compared with 2.7 ± 1.8 million units for urokinase CDT with rheolytic PMT (p = 0.008). Complete clot lysis was achieved in 73% (29/40) of DVT treated with urokinase CDT alone compared with 82% (22/27) treated with urokinase CDT with rheolytic PMT.ConclusionPercutaneous CDT with rheolytic PMT is as effective as CDT alone for acute proximal extremity DVT but requires significantly shorter treatment duration and lower lytic doses. Randomized studies to confirm the benefits of pharmacomechanical thrombolysis in the treatment of acute proximal extremity DVT are warranted.

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

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.

Physician Self-Referral of Lumbar Spine MRI With Comparative Analysis of Negative Study Rates as a Marker of Utilization Appropriateness

PURPOSE To prospectively test in a porcine model the hypothesis that bariatric embolization with commercially available calibrated microspheres can result in substantial suppression of systemic ghrelin levels and affect weight gain over an 8-week period. MATERIALS AND METHODS The institutional animal care and use committee approved this study. Twelve healthy growing swine (mean weight, 38.4 kg; weight range, 30.3-47.0 kg) were evaluated. Bariatric embolization was performed by infusion of 40-μm calibrated microspheres selectively into the gastric arteries that supply the fundus. Six swine underwent bariatric embolization, while six control animals underwent a sham procedure with saline. Weight and fasting plasma ghrelin and glucose levels were obtained in animals at baseline and at weeks 1-8. Statistical testing for differences in serum ghrelin levels and weight at each time point was performed with the Wilcoxon signed rank test for intragroup differences and the Wilcoxon rank sum test for intergroup differences. RESULTS The pattern of change in ghrelin levels over time was significantly different between control and experimental animals. Weekly ghrelin levels were measured in control and experimental animals as a change from baseline ghrelin values. Average postprocedure ghrelin values increased by 328.9 pg/dL ± 129.0 (standard deviation) in control animals and decreased by 537.9 pg/dL ± 209.6 in experimental animals (P = .004). The pattern of change in weight over time was significantly different between control and experimental animals. The average postprocedure weight gain in experimental animals was significantly lower than that in control animals (3.6 kg ± 3.8 vs 9.4 kg ± 2.8, respectively; P = .025). CONCLUSION Bariatric embolization can significantly suppress ghrelin and significantly affect weight gain. Further study is warranted before this technique can be used routinely in humans.

Treatment of Intrauterine and Large Pedunculated Subserosal Leiomyomata with Sequential Uterine Artery Embolization and Myomectomy

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.

Bacteriophage K for reduction of Staphylococcus aureusbiofilm on central venous catheter material

OBJECTIVE Financial interest in imaging equipment may affect the imaging referral patterns of ordering physicians. The purpose of this article is to determine whether ownership of MRI equipment by ordering physicians predicts the likelihood and prevalence of positive findings on lumbar spine MRI as a metric for comparison of utilization. MATERIALS AND METHODS A retrospective review was performed of 500 consecutive diagnostic lumbar spine MRI examinations in one radiology practice ordered by two separate referring physician groups serving the same geographic community: one with financial interest in the MRI equipment used (financial-interest group) and one without financial interest in the MRI equipment used (no-financial-interest group). Negative examinations and total number of lesions per positive study were recorded for each group. RESULTS Five hundred scans met inclusion criteria during the study period (250 in the financial-interest group and 250 in the no-financial-interest group). The negative scan frequency was 86% higher in the financial-interest group (p < 0.0001). Among positive scans, there was no significant difference in the average total number of positive lesions per scan (3.93 for the financial-interest group and 4.31 for the no-financial-interest group; p = 0.132). The average age of patients imaged by the financial-interest group was 49.8 years, versus 56.9 years for the no-financial-interest group (p < 0.0001). CONCLUSION Lumbar spine MRI examinations referred by the financial-interest group were significantly more likely to be negative than those referred by the no-financial-interest group. Lesion frequency among positive scans suggests similar severity of disease between the two patient populations. Patients imaged by the financial-interest group were significantly younger than those imaged by the no-financial-interest group.

Histopathologic and Immunohistochemical Sequelae of Bariatric Embolization in a Porcine Model

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.

Bariatric Embolization of the Gastric Arteries for the Treatment of Obesity

The purpose of this project was to determine whether bacteriophage can reduce bacterial colonization and biofilm formation on central venous catheter material. Twenty silicone discs were inoculated for 24 h with broth culture of Methicillin sensitive staphylococcus aureus (0.5 McFarland standard). The inoculate was aspirated and discs placed into two equal groups for 24 h: (1) untreated controls; (2) bacteriophage treatment (staphylococcal bacteriophage K, propagated titer > 108). At the completion of the experiment discs were processed for quantitative culture. Statistical testing was performed using the rank sum test. Mean colony forming units (CFU) were significantly decreased in experimental compared with controls (control 6.3 × 105 CFU, experimental 6.7 × 101, P ≤ 0.0001). Application of bacteriophage to biofilm infected central venous catheter material significantly reduced bacterial colonization and biofilm presence. Our data suggests that bacteriophage treatment may be a feasible strategy for addressing central venous catheter staph aureus biofilm infections.