Bariatric Embolization: Pilot Study on the Impact of Gastroprotective Agents and Arterial Distribution on Ulceration Risk and Efficacy in a Porcine Model.

PURPOSE: To assess whether the number of fundal arteries embolized and use of gastroprotective agents have an impact on ghrelin suppression and gastric ulceration rates. MATERIALS AND METHODS: Twenty-two healthy, growing swine (mean, 38.4 kg; range, 30.3-47.0 kg) were evaluated. Six control swine underwent a sham procedure. Gastric embolization was performed by the infusion of 40-µm microspheres selectively into some or all gastric arteries supplying the gastric fundus. In group 1, 6 swine underwent embolization of all 4 arteries to the gastric fundus. In group 2, 5 swine underwent embolization of 2 gastric fundal arteries. In group 3, 5 swine underwent embolization of 1 gastric fundal artery. Animals in groups 2 and 3 were treated with gastroprotective agents (sucralfate and omeprazole). Weight and fasting plasma ghrelin levels were analyzed at baseline and at week 4. Upon animal euthanasia, gross analysis was performed for identification of ulcers. RESULTS: Only group 1 animals exhibited changes in serum ghrelin levels that rendered them significantly lower than those in control animals (P = .049). Group 3 animals exhibited marked elevations in serum ghrelin levels compared with control animals (P = .001). Gross pathologic evaluation revealed 0 ulcers in the control animals, 3 ulcers (50%) in group 1, 2 ulcers (40%) in group 2, and 2 ulcers (40%) in group 3. CONCLUSIONS: Administration of gastroprotective agents and embolization of fewer arteries to the gastric fundus did not prevent gastric ulceration in treated animals. Only animals that underwent embolization of all gastric arteries exhibited significant decreases in serum ghrelin levels.

Bariatric Radioembolization: A Pilot Study on Technical Feasibility and Safety in a Porcine Model.

PURPOSE: To evaluate feasibility of left gastric artery (LGA) yttrium-90 ((90)Y) radioembolization as potential treatment for obesity in a porcine model. MATERIALS AND METHODS: This study included 8 young female pigs (12-13 weeks, 21.8-28.1 kg). Six animals received infusions of (90)Y resin microspheres (46.3-105.1 MBq) into the main LGA and the gastric artery arising from the splenic artery. Animal weight and serum ghrelin were measured before treatment and weekly thereafter. Animals were euthanized 69-74 days after treatment, and histologic analyses of mucosal integrity and ghrelin immunoreactive cell density were performed. RESULTS: Superficial mucosal ulcerations < 3.0 cm(2) were noted in 5 of 6 treated animals. Ghrelin immunoreactive cell density was significantly lower in treated versus untreated animals in the stomach fundus (13.5 vs 34.8, P < .05) and stomach body (11.2 vs 19.8, P < .05). Treated animals gained less weight than untreated animals over the study duration (40.2 kg ± 5.4 vs 54.7 kg ± 6.5, P = .053). Average fundic parietal area (165 cm(2) vs 282 cm(2), P = .067) and average stomach weight (297.2 g vs 397.0 g, P = .067) were decreased in treated versus untreated animals. Trichrome staining revealed significantly more fibrosis in treatment animals compared with control animals (13.0 vs 8.6, P < .05). No significant differences were identified in plasma ghrelin concentrations (P = .24). CONCLUSIONS: LGA (90)Y radioembolization is promising as a potential treatment for obesity. A larger preclinical study is needed to evaluate the safety and efficacy of this procedure further.

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.

Bacteriophage K antimicrobial-lock technique for treatment of Staphylococcus aureus central venous catheter-related infection: a leporine model efficacy analysis.

PURPOSE: To determine whether a bacteriophage antimicrobial-lock technique can reduce bacterial colonization and biofilm formation on indwelling central venous catheters in a rabbit model. MATERIALS AND METHODS: Cuffed central venous catheters were inserted into the jugular vein of female New Zealand White rabbits under image guidance. Catheters were inoculated for 24 hours with broth culture of methicillin-sensitive Staphylococcus aureus. The inoculum was aspirated, and rabbits were randomly assigned to two equal groups for 24 hours: (i) untreated controls (heparinized saline lock), (ii) bacteriophage antimicrobial-lock (staphylococcal bacteriophage K, propagated titer > 10(8)/mL). Blood cultures were obtained via peripheral veins, and the catheters were removed for quantitative culture and scanning electron microscopy. RESULTS: Mean colony-forming units (CFU) per cm(2) of the distal catheter segment, as a measure of biofilm, were significantly decreased in experimental animals compared with controls (control, 1.2 × 10(5) CFU/cm(2); experimental, 7.6 × 10(3); P = .016). Scanning electron microscopy demonstrated that biofilms were present on the surface of five of five control catheters but only one of five treated catheters (P = .048). Blood culture results were not significantly different between the groups. CONCLUSIONS: In a rabbit model, treatment of infected central venous catheters with a bacteriophage antimicrobial-lock technique significantly reduced bacterial colonization and biofilm presence. Our data represent a preliminary step toward use of bacteriophage therapy for prevention and treatment of central venous catheter-associated infection.

Histopathologic and immunohistochemical sequelae of bariatric embolization in a porcine model.

PURPOSE: To evaluate the histopathologic sequelae of bariatric embolization on the gastric mucosa and to correlate with immunohistochemical evaluation of the gastric fundus, antrum, and duodenum. MATERIALS AND METHODS: This study was performed on 12 swine stomach and duodenum specimens after necropsy. Of the 12 swine, 6 had previously undergone bariatric embolization of the gastric fundus, and the 6 control swine had undergone a sham procedure with saline. Gross pathologic, histopathologic, and immunohistochemical examinations of the stomach and duodenum were performed. Specifically, mucosal integrity, fibrosis, ghrelin-expressing cells, and gastrin-expressing cells were assessed. RESULTS: Gross and histopathologic evaluation of treatment animals showed healing or healed mucosal ulcers in 50% of animals, with gastritis in 100% of treatment animals and in five of six control animals. The ghrelin-immunoreactive mean cell density was significantly lower in the gastric fundus in the treated animals compared with control animals (15.3 vs 22.0, P < .01) but similar in the gastric antrum (9.3 vs 14.3, P = .08) and duodenum (8.5 vs 8.6, P = .89). The gastrin-expressing cell density was significantly lower in the antrum of treated animals compared with control animals (82.2 vs 126.4, P = .03). A trend toward increased fibrosis was suggested in the gastric fundus of treated animals compared with controls (P = .07). CONCLUSIONS: Bariatric embolization resulted in a significant reduction in ghrelin-expressing cells in the gastric fundus without evidence of upregulation of ghrelin-expressing cells in the duodenum. Healing ulcerations in half of treated animals underscores the need for additional refinement of this procedure.

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

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.

Physician self-referral: frequency of negative findings at MR imaging of the knee as a marker of appropriate utilization.

PURPOSE: To determine whether ownership of magnetic resonance (MR) imaging equipment by ordering physicians affects the likelihood of positive findings at MR imaging of the knee and to evaluate rates of knee abnormalities seen at MR imaging as a metric for comparison of utilization. MATERIALS AND METHODS: The institutional review board approved this retrospective HIPAA-compliant study and waived the need for informed consent. A retrospective review was performed of consecutive diagnostic MR images of the knee interpreted by one radiology practice between January and April 2009 for patients who had been referred by two separate physician groups serving the same geographic community: one with financial interest (FI) in the MR imaging equipment used and one with no FI (NFI) in the MR imaging equipment used. The percentage of examinations with negative results was tabulated for both groups, and the relative frequency of each abnormality subtype was calculated among the studies with positive findings in each group. To examine frequency differences among groups, χ(2) tests were used, and to examine mean differences among groups, t tests were used. RESULTS: Of 700 examinations, 205 had negative results (117 of 350 in the FI group and 88 of 350 in the NFI group, P = .016). Among the examinations with positive results, the mean total number of positive abnormality subtypes per image did not significantly differ between groups: 1.52 for the FI group and 1.53 for the NFI group (P = .96). CONCLUSION: MR images of the knee among patients referred by the FI group were significantly more likely to be negative than those among patients referred by the NFI group. Frequency of abnormality subtype and distribution among examinations with positive results suggests a highly similar distribution and severity of abnormalities between the two patient groups.

Journal Club: Shoulder MRI utilization: relationship of physician MRI equipment ownership to negative study frequency.

OBJECTIVE: The purpose of this article is to determine whether ownership of MRI equipment by ordering physicians influences the frequency of negative shoulder MRI scans. MATERIALS AND METHODS: A retrospective review was performed of 1140 consecutive shoulder MRI scans ordered by two separate referring physician groups serving the same geographic community. The first group (financially incentivized) owned the scanners used and received technical fees for their use. The second group (non-financially incentivized) did not own the scanners used and had no direct financial interest. All examinations were performed with identical protocols and were interpreted by a single radiologist group without financial interest in the imaging equipment used. The frequency of negative examinations and the number of abnormalities in each positive study was tabulated for each group. RESULTS: A total of 1140 shoulder MRI scans met inclusion criteria; 255 were negative (142 for the financially incentivized group and 113 for the non-financially incentivized group). There were 25.6% more negative scans in the financially incentivized group (p=0.047). There was no statistically significant difference in the average number of lesions per positive scan (1.67 for the financially incentivized group and 1.71 for the non-financially incentivized group; p=0.34). No statistically significant difference was found in the frequency of 19 of 20 examined lesions. CONCLUSION: Shoulder MRI examinations referred by physicians with a financial interest in the imaging equipment used were significantly more likely to be negative. Positive examinations exhibited no statistically significant difference in the number of lesions per scan or in the frequency of 19 of 20 lesion subtypes. This finding suggests a highly similar distribution and severity of disease among the two patient groups.

Bariatric embolization for suppression of the hunger hormone ghrelin in a porcine model.

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.

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).

Physician self-referral of lumbar spine MRI with comparative analysis of negative study rates as a marker of utilization appropriateness.

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.

Self-referral in medical imaging: a meta-analysis of the literature.

PURPOSE: In the current political and economic climate, there is a desire to reduce health care costs; diagnostic imaging expenditure is one area of particular interest. The authors present a meta-analysis of the relative frequency of imaging utilization in the setting of self-referral compared with that of non-self-referral and a simulation of increased cost to Medicare Part B on the basis of this relative frequency. METHODS: The MEDLINE database was searched systematically. Specific inclusion criteria for relative frequency calculations were a numerator (number of patients imaged) and denominator (number of total patients seen) in each group (self-referrers and radiologist referrers). The relative risk of self-referral was determined for each group and is defined by the "relative frequency" of imaging utilization for the self-referrers divided by the frequency for the radiologist referrers. Relative frequency represents the increased (if >1) or decreased (if <1) chance of imaging by self-referrers over radiologist referrers. The meta-analysis was used to combine imaging frequencies for each referral condition of the individual studies that met inclusion criteria for an overall estimate of relative frequency, using a random-effects model to account for the variations among the studies. Relative frequency data were then used to perform a cost simulation to Medicare Part B using 2006 data. RESULTS: The initial search yielded 334 articles, 5 of which met the threshold for inclusion. In these 5 studies, 76,905,162 total episodes of care were analyzed. The individual relative frequency of imaging in the setting of self-referral ranged from 1.60 to 4.50. The combined relative frequency was 2.16 (95% confidence interval, 2.15-2.16) using the fixed-effects model and 2.48 (95% confidence interval, 1.90-3.24) using the random-effects model. For 2006 Government Accountability Office (GAO) data, the estimated cost of increased imaging in the setting of self-referral was $3.6 billion, but a range of costs was also provided to account for potential inaccuracies in the GAO data. CONCLUSIONS: The existing literature yields a combined relative frequency of imaging of 2.48 (95% confidence interval, 1.90-3.24) for self-referrers compared with non-self-referrers. Precise extrapolation of Medicare Part B costs attributable to self-referral would require changes in reporting requirements for imaging equipment ownership. Cost simulation results total billions of dollars annually and may be irrespective of potential inaccuracies in the GAO data as a result of Current Procedural Terminology(®) coding ambiguity and nontransparent reporting of equipment ownership.

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.

Catheter-directed thrombolysis with percutaneous rheolytic thrombectomy versus thrombolysis alone in upper and lower extremity deep vein thrombosis.

PURPOSE: To 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). METHODS: A 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. RESULTS: Forty 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. CONCLUSION: Percutaneous 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.