Quantum Phase Transitions for an Integrable Quantum Rabi-like Model with Two Interacting Qubits.

A two-interacting-qubit quantum Rabi-like model with vanishing transverse fields on the qubit pair is studied. Independently of the coupling regime, this model can be exactly and unitarily reduced to two independent single-spin quantum Rabi models, where the spin-spin coupling plays the role of the transverse field. This transformation and the analytical treatment of the single-spin quantum Rabi model provide the key to prove the integrability of our model. The existence of different first-order quantum phase transitions, characterized by discontinuous two-spin magnetization, mean photon number, and concurrence, is brought to light.

Rilpivirine plus cobicistat-boosted darunavir as a two-drug switch regimen in HIV-infected, virologically suppressed subjects on steady standard three-drug therapy: a randomized, controlled, non-inferiority trial (PROBE 2).

BACKGROUND: We explored the combination of rilpivirine plus cobicistat-boosted darunavir [a two-drug regimen (2DR)] when switching from standard triple combined ART. METHODS: In this randomized, open-label, non-inferiority trial, participants had an HIV-RNA <50 copies/mL on a stable (>6 months) three-drug regimen. The primary endpoint was proportion with HIV-RNA <50 copies/mL at Week 24 (snapshot algorithm), with a -12% non-inferiority margin. ClinicalTrials.gov: NCT04064632. RESULTS: One hundred and sixty patients were allocated (1:1) to 2DR or to continue current ART (CAR). At Week 24, 72 (90.0%) of participants with 2DR and 75 (93.8%) with CAR maintained HIV-RNA <50 copies/mL [difference -3.75% (95% CI = -11.63 to 5.63)], confirming non-inferiority. Non-inferiority was confirmed considering an HIV-RNA >50 copies/mL (0% for 2DR; 3.7% for CAR; 95% CI = -0.4 to 7.9). Four patients reported adverse events not leading to treatment discontinuation (one patient in the 2DR group and three patients in the CAR group); eight subjects discontinued therapy in the 2DR group and three in the CAR group. With 2DR, lipid serum concentrations increased, but differences were statistically significant only for tenofovir disoproxil fumarate-containing CAR and in 2DR patients receiving a pre-switch regimen including tenofovir disoproxil fumarate. Median bone stiffness decreased in the CAR group from 86.1 g/cm2 (IQR = 74-98) to 83.2 g/cm2 (IQR = 74-97) and increased in the 2DR group from 84.9 g/cm2 (IQR = 74-103) to 85.5 g/cm2 (IQR = 74-101). The reduction within the CAR group was significant (P = 0.043). CONCLUSIONS: Once-daily rilpivirine plus cobicistat-boosted darunavir is an effective 2DR that combines a high virological efficacy with a potential to avoid major NRTI toxicities.

Are strong opioids equally effective and safe in the treatment of chronic cancer pain? A multicenter randomized phase IV 'real life' trial on the variability of response to opioids.

BACKGROUND: Guidelines tend to consider morphine and morphine-like opioids comparable and interchangeable in the treatment of chronic cancer pain, but individual responses can vary. This study compared the analgesic efficacy, changes of therapy and safety profile over time of four strong opioids given for cancer pain. PATIENT AND METHODS: In this four-arm multicenter, randomized, comparative, of superiority, phase IV trial, oncological patients with moderate to severe pain requiring WHO step III opioids were randomly assigned to receive oral morphine or oxycodone or transdermal fentanyl or buprenorphine for 28 days. At each visit, pain intensity, modifications of therapy and adverse drug reactions (ADRs) were recorded. The primary efficacy end point was the proportion of nonresponders, meaning patients with worse or unchanged average pain intensity (API) between the first and last visit, measured on a 0-10 numerical rating scale. (NCT01809106). RESULTS: Forty-four centers participated in the trial and recruited 520 patients. Worst pain intensity and API decreased over 4 weeks with no significant differences between drugs. Nonresponders ranged from 11.5% (morphine) to 14.4% (buprenorphine). Appreciable changes were made in the treatment schedules over time. Each group required increases in the daily dose, from 32.7% (morphine) to 121.2% (transdermal fentanyl). Patients requiring adjuvant analgesics ranged from 68.9% (morphine) to 81.6% (oxycodone), switches varied from 22.1% (morphine) to 12% (oxycodone), discontinuation of treatment from 27% ( morphine) to 14.5% (fentanyl). ADRs were similar except for effects on the nervous system, which significantly prevailed with morphine. CONCLUSION: The main findings were the similarity in pain control, response rates and main adverse reactions among opioids. Changes in therapy schedules were notable over time. A considerable proportion of patients were nonresponders or poor responders. CLINICAL TRIAL REGISTRATION: NCT01809106 (https://clinicaltrials.gov/ct2/show/NCT01809106?term=cerp&rank=2).

Combined sorafenib and yttrium-90 radioembolization for the treatment of advanced hepatocellular carcinoma.

BACKGROUND AND AIMS: In this pilot study, we assessed the safety and tolerability of combining sorafenib with 90Y radioembolization for the treatment of unresectable hepatocellular carcinoma (hcc). METHODS: The study, conducted prospectively during 2009-2012, included eligible patients with unresectable hcc and a life expectancy of at least 12 weeks. Each patient received sorafenib (400 mg twice daily) for 6-8 weeks before 90Y treatment. Safety and tolerability were assessed. RESULTS: Of the 40 patients enrolled, 29 completed treatment (combined therapy). In the initial cohort, the most common cause of hcc was hepatitis C (32.5%), and most patients were staged Child A (82.5%). The 29 patients who completed the study had similar baseline characteristics. Grades 1 and 2 toxicities accounted for 77.8% of all adverse events reported. The most common toxicities reported were fatigue (19.0%), alteration in liver function (7.9%), and diarrhea (6.3%). There were 12 grade 3 and 2 grade 4 toxicity events reported. One patient died of liver failure within 30 days after treatment. During the study, the sorafenib dose was reduced in 6 patients (20.7%), and sorafenib had to be interrupted in 4 patients (13.8%) and discontinued in 4 patients (13.8%). The disease control rate was 72.4% per the modified Response Evaluation Criteria in Solid Tumors, and tumour necrosis was observed in 82.8% of patients. Overall survival in patients undergoing combined therapy was 12.4 months. CONCLUSIONS: Preliminary results demonstrate the safety and tolerability of combining 90Y radioembolization and sorafenib for advanced hcc. A larger prospective study is needed to determine the extent of the survival benefit.

Portal vein embolization and its effect on tumour progression for colorectal cancer liver metastases.

BACKGROUND: The aim of this study was to evaluate the long-term outcomes of patients with colorectal cancer liver metastasis (CRCLM) exhibiting disease progression after portal vein embolization (PVE). METHODS: Patients with CRCLM requiring PVE before hepatectomy between 2003 and 2014 were included. Clinical variables, and liver and tumour volumes determined by three-dimensional CT volumetry were assessed before and after PVE. Overall and disease-free survival data were obtained. Univariable and multivariable logistic regression analyses were performed to identify predictors of tumour progression after PVE. RESULTS: Of 141 patients who underwent PVE, 93 (66.0 per cent) had tumour progression and 17 (12.1 per cent) developed new contralateral lesions. Significantly fewer patients had resectable disease in the group with disease progression than among those with stable disease: 43 (46 per cent) of 93 versus 36 (75 per cent) of 48 respectively (P = 0.001). Median survival was similar in patients with and without tumour growth after PVE: 22.5 versus 26.0 months for patients with unresectable tumours (P = 0.706) and 46.2 versus 52.2 months for those with resectable disease (P = 0.953). However, disease-free survival for patients with tumour progression after PVE was shorter than that for patients with stable disease (6.0 versus 20.2 months; P = 0.045). Response to neoadjuvant chemotherapy was the only significant factor associated with tumour progression in multivariable analysis. CONCLUSION: Tumour progression after PVE did not affect overall survival, but patients with resected tumours who had tumour growth after embolization experienced earlier recurrence. A borderline response to neoadjuvant chemotherapy seemed to be associated with tumour progression after PVE.

The role of interventional radiology in the management of hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (hcc) is one of the most common causes of cancer-related death worldwide. Overall, liver transplantation and resection are the only available treatments with potential for cure. Various locoregional therapies are widely used to manage patients with advanced hcc or as a bridging therapy for patients with early and intermediate disease. This article reviews and evaluates the role of interventional radiology in the management of such cases by assessing various aspects of each method, such as effect on rates of survival, recurrence, tumour response, and complications. METHODS: A systemic search of PubMed, medline, Ovid Medline In-Process, and the Cochrane Database of Systematic Reviews retrieved all related scientific papers for review. RESULTS: Needle core biopsy is a highly sensitive, specific, and accurate method for hcc grading. Portal-vein embolization provides adequate expansion of the future liver remnant, making more patients eligible for resection. In focal or multifocal unresectable early-stage disease, radiofrequency ablation tops all other thermoablative methods. However, microwave ablation is preferred in large tumours and in patients with Child-Pugh B disease. Cryoablation is preferred in recurrent disease and in patients who are poor candidates for anesthesia. Of the various transarterial modalities-transarterial chemoembolization (tace), drug-eluting beads, and transarterial radio-embolization (tare)-tace is the method of choice in Child-Pugh A disease, and tare is the method of choice in hcc cases with portal vein thrombosis. CONCLUSIONS: The existing data support the importance of a multidisciplinary approach in hcc management. Large randomized controlled studies are needed to provide clear indication guidelines for each method.

Magnitude of change in alpha-fetoprotein in response to transarterial chemoembolization predicts survival in patients undergoing liver transplantation for hepatocellular carcinoma.

BACKGROUND: Downsizing strategies are often attempted for patients with hepatocellular carcinoma (hcc) before liver transplantation (lt). The objective of the present study was to determine clinical predictors of favourable survival outcomes after transarterial chemoembolization (tace) before lt for hcc outside the Milan criteria, so as to better select candidates for this strategy. METHODS: In this retrospective study, patients with hcc tumours either beyond Milan criteria (single lesion > 5 cm, 3 lesions with 1 or more > 3 cm) or at the upper limit of Milan criteria (single lesions between 4.1 cm and 5.0 cm), with a predicted waiting time of more than 3 months, received carboplatin-based tace treatments. Exclusion criteria for tace included Child-Pugh C cirrhosis or the presence of portal vein invasion or extrahepatic disease on imaging. Only patients without tumour progression after tace underwent lt. RESULTS: Of 160 hcc patients who received liver grafts between 1997 and 2010, 35 were treated with tace preoperatively. The median of the sum of tumour diameters was 6.7 cm (range: 4.8-8.5 cm), which decreased with tace to 5.0 cm (range: 3.3-7.0 cm) at transplantation (p < 0.0004). The percentage drop in alpha-fetoprotein (αfp) was a positive predictor (p = 0.0051) and the time from last tace treatment to transplantation was a negative predictor (p < 0.0001) for overall survival. CONCLUSIONS: The percentage drop in αfp and a shorter time from the final tace treatment to transplantation significantly predicted improved overall survival after lt for hcc downsized with tace. As a serum marker, αfp should be followed when tace is used as a strategy to stabilize or downsize hcc lesions before lt.

Investigating coping and stigma in people living with HIV through narrative medicine in the Italian multicentre non-interventional study DIAMANTE.

Antiretroviral therapy (ART) significantly reduced Human Immunodeficiency Virus (HIV) morbidity and mortality; nevertheless, stigma still characterises the living with this condition. This study explored patients' coping experience by integrating narrative medicine (NM) in a non-interventional clinical trial. From June 2018 to September 2020 the study involved 18 centres across Italy; enrolled patients were both D/C/F/TAF naïve and previously ART-treated. Narratives were collected at enrolment (V1) and last visit (V4) and then independently analysed by three NM specialist researchers through content analysis. One-hundred and fourteen patients completed both V1 and V4 narratives. Supportive relationships with clinicians and undetectable viral load facilitated coping. Conversely, lack of disclosure of HIV-positive status, HIV metaphors, and unwillingness to narrate the life before the diagnosis indicated internalised stigma. This is the first non-interventional study to include narratives as patient reported outcomes (PROs). Improving HIV awareness and reducing the sense of guilt experienced by patients helps to overcome stigma and foster coping.

Effect of topical clay application on the synthesis of collagen in skin: an experimental study.

BACKGROUND: Clay is often used in cosmetic treatments, although little is known about its action. AIM: To evaluate the effect of topical clay application on the histoarchitecture of collagen fibres in rat skin. METHODS: Animals received a daily application of clay and retinoic acid (RA) 0.025% to the dorsal skin over 7 and 14 days, under vaporization at 37 °C for 40 min. Control skin was not vaporized. Samples from each region were excised, and stained with picrosirius red for collagen evaluation. RESULTS: Seven days after clay treatment, an increase in the number of collagen fibres was observed in treated skin compared with control skin (51.74 ± 1.28 vs. 43.39 ± 1.79%, respectively, P < 0.01), whereas RA did not alter the collagen level (45.66 ± 1.10%). Clay application over 14 days did not induce a further increase in skin collagen, whereas treatment with RA did (58.07 ± 1.59%; P = 0.001 vs. control). CONCLUSION: Clay application promotes an increase in the number of collagen fibres, which may account for its beneficial effects.

Environmental car exhaust pollution damages human sperm chromatin and DNA.

OBJECTIVE: The adverse role of traffic pollutants on male fertility is well known. Aim of this study was to evaluate their effects on sperm chromatin/DNA integrity. METHODS: To accomplish this, 36 men working at motorway tollgates and 32 unexposed healthy men (controls) were enrolled. All of them were interviewed about their lifestyle. Hormone, semen samples, and environmental and biological markers of pollution were evaluated. Sperm chromatin and DNA integrity were evaluated by flow cytometry following propidium iodide staining and TUNEL assay, respectively. RESULTS: LH, FSH, and testosterone serum levels were within the normal range in tollgate workers. Sperm concentration, total sperm count, total and progressive motility, and normal forms were significantly lower in these men compared with controls. Motorway tollgate workers had a significantly higher percentage of spermatozoa with damaged chromatin and DNA fragmentation, a late sign of apoptosis, compared with controls. A significant direct correlation was found between spermatozoa with damaged chromatin or fragmented DNA and the length of occupational exposure, suggesting a time-dependent relationship. CONCLUSION: This study showed that car exhaust exposure has a genotoxic effect on human spermatozoa. This may be of relevant importance not only for the reproductive performance of the men exposed, but also for the offspring health.

Profunda femoris mycotic aneurysm as a complication of bacterial endocarditis: a case report and review of the literature.

Profunda femoris aneurysms account for only 0.5% of all peripheral artery aneurysms. This case documents a profunda femoris mycotic aneurysm (MA) in a 47-year-old woman, three years post-treatment of bacterial endocarditis. The patient underwent an open surgical excision of the aneurysm with antibiotic cover and made a successful recovery. A literature review was carried out to look at other MA cases to summarise the most common presentations, infective agents and management strategies.

Optimized nerve block techniques while performing percutaneous hepatic ablation: Literature review and practical use.

Percutaneous image guided thermal ablation has become a cornerstone of therapy for patients with oligometastatic disease and primary liver malignancies. Evolving from percutaneous ethanol injection (PEI), thermal ablation utilizing radiofrequency ablation (RFA) and microwave ablation (MWA) have become the standard approach in the treatment of isolated lesions that fit within the size criteria for curative intent therapy (typically 3-4cm). With the evolution of more intense thermal ablation, such as MWA, the dramatic increase in both the size of ablation zone and intensity of heat generation have extended the limits of this technique. As a result of these innovations, intra-procedural and post-procedural pain have also significantly increased, requiring either higher levels of intravenous sedation or, in some institutions, general anesthesia. In addition to the increase in therapeutic intensity, the use of intravenous sedation during aggressive ablation procedures carries the risk of over-sedation when the noxious insult (i.e. the ablation) is removed, adding further difficulty to post-procedural recovery and management. Furthermore, high subdiaphragmatic lesions become challenging in this setting due to issues relating to sedation and compliance with breath hold/breathing instructions. Although general anesthesia may mitigate these complications, the added resources associated with providing general anesthesia during ablation is not cost effective and may result in substantial delays in treatment. The reduction of Aerosol Generating Medical Procedures (AGMP), such as intubation due to the COVID-19 Pandemic, must also be taken into consideration. Due to the potential increased risk of infection transmission, alternatives to general anesthesia should be considered when safe and possible. Upper abdominal regional nerve block techniques have been used to manage pain related to trauma, surgery, and cancer; however, blocks of this nature are not well described in the interventional radiology literature. The McGill University group has developed experience in using such blocks as splanchnic, celiac and hepatic hilar nerve blocks to provide peri-procedural pain control [1]. Since incorporating these techniques (along with hydrodissection with tumescent anesthesia), we have also observed in our high volume ablation center a dramatic decrease in the amount of sedatives administered during the procedure, a decrease in patient discomfort during localization and ablation, as well as decreased pain post-procedure. Faster time to discharge and overall reduction in room procedural time serve as added benefits. The purpose of this publication is to outline and illustrate the practical application and use of nerve block/regional anesthesia techniques with respect to percutaneous hepatic thermal ablation.

Resveratrol proniosomes as a convenient nanoingredient for functional food.

Proniosomes are free-flowing powders composed of water-soluble carriers blended with surfactants, which form niosomes upon hydration. In this work, proniosomal formulations containing the natural antioxidant resveratrol (RSV) were prepared and fully characterized. A pre-formulation study on RSV-loaded niosomes was carried out to determine the most promising ratio between the two surfactants, Tween 20 and Span 60, in terms of entrapment efficiency and antioxidant activity. The optimized formulae were subsequently adapted to be prepared as proniosomes by the slurry method, including lactose or maltodextrin as carriers. The impact of surfactants and carriers properties on size, entrapment efficiency and release kinetics of proniosomes were evaluated. In vitro release of RSV in simulated gastric and intestinal media was determined, as well as the vesicular stability. Moreover, the biocompatibility of the formulations was determined on intestinal cells in vitro. Overall, the developed proniosomes provide promising nanoingredient for functional food, improving resveratrol stability and bioavailability.

Vascular calcifications in homozygote familial hypercholesterolemia.

BACKGROUND: Patients with homozygous familial hypercholesterolemia (hmzFH) attributable to LDL receptor gene mutations have shown a remarkable increase in survival over the last 20 years. Early onset coronary heart disease (CHD) and calcific aortic valve stenosis are the major complications of this disorder. We now report extensive premature calcification of the aorta in patients with hmzFH. METHODS AND RESULTS: We examined 25 hmzFH patients from Canada; mean age was 32 years (range 5 to 54), and mean baseline cholesterol before treatment was 19+/-5 mmol/L (737+/-206 mg/dL). Aortic calcification was quantified using computed tomography (CT). An elevated mean calcium score was found in patients by age 20 and correlated with age (r(2)=0.53, P=0.001). One quarter (24%) of patients underwent aortic valve surgery. CONCLUSIONS: We document premature severe aortic calcifications in all adult hmzFH patients studied. These presented considerable surgical management challenges. Strategies to identify and monitor aortic calcification in hmzFH by noninvasive techniques are required, as are clinical trials to determine whether additional or more intensive therapies will prevent the progression of such calcifications. Whether vascular calcifications in hmzFH subjects are related to sustained increases in LDL-C levels or to other mechanisms, such as abnormal osteoblast activity, remains to be determined.

Autogenous brachial-brachial fistula for vein access. Haemodynamic factors predicting outcome and 1 year clinical data.

UNLABELLED: Two-stage autogenous brachial vein-brachial artery access (ABBA) has been proposed as an option where adequate superficial vein is not available for the creation of conventional haemodialysis fistulae. METHODS: This report depicts the clinical outcome of a series of 17 consecutive patients who underwent ABBA in a single centre. Of the 17 patients, nine had had at least one previous arterioventricular (AV) fistula or graft, and eight were new to haemodialysis. Patencies were assessed using the Kaplan-Meier survival analysis. RESULTS: In 14 patients, the brachial vein was transposed (82%) and the time to transposition ranged from 4 to 26 weeks (median time: 6 weeks). The functional patency rate was 45.75% at 12 months. After stage one, all fistulas that went on to develop well had a brachial vein flow of at least 900 ml min(-1), and this was significantly higher than in fistulas that failed to develop (p=0.005). The maturation rate in our study was 65% and the median time to cannulation of the fistula was 8 weeks from the stage 1. Of the 17 patients, 12 (71%) experienced at least one complication. Ten (59%) demonstrated moderate-to-severe stenoses; eight of which necessitated angioplasty and/or percutaneous mechanical thrombolysis. CONCLUSIONS: ABBA was characterised by a high incidence of complications and a long period to achieve maturation. Despite close monitoring and a high rate of secondary interventions, the patency rate was low. With this experience, we now only consider it an alternative in patients without adequate superficial veins, who have had failed grafts or where there is a very high risk of infection.

Zenith abdominal aortic aneurysm endovascular graft: a literature review.

The early experience of endovascular aneurysm repair (EVAR) using ''first generation'' devices was disappointing. There was an appreciable incidence of delayed, post-EVAR, aneurysm rupture. This was primarily a consequence of structural device failure. These failures provided important lessons for re-design and the modern ''second generation'' devices, including the Zenith (Cook Inc, Bloomington, IN, USA) endograft, are thought to be more reliable, particularly providing better fixation and sealing and also a more durable stent/fabric structure. This article comprises a review of the English literature detailing the endovascular treatment of abdominal aortic aneurysms using the Zenith endograft. It focuses on clinical studies or trials with intermediate to long-term follow-up, and related the literature to our own experience. In the series examined (N.=2 017 patients) the early mortality rate ranged from 0% to 4.1% and the technical success rate from 97.7% to 100%. The re-intervention rate was related to the length of follow-up (6.8% to 14%). Conversion rates were consistently <1%. There was a low incidence of device migration, limb thrombosis, component separation and stent fracture. These data support the ongoing use of the Zenith endovascular graft in patients with abdominal aortic aneurysms suitable for EVAR.

Liposomes as carriers for verbascoside: stability and skin permeation studies.

In this study the influence of liposomal incorporation on both the stability and the in vitro (trans) dermal delivery of verbascoside was evaluated. The effect of drug entrapment into vesicles on its radical scavenging activity was also studied. Liposomes were obtained from soy phosphatidylcholine and cholesterol according to the film hydration method. Stability of verbascoside-loaded vesicles was studied over 6 months. Results showed that verbascoside can be incorporated in liposomes (E% = 57-66%), preventing its degradation. Stability studies (dynamic lager light scattering [DLLS] measurements and transmission electron microscopy [TEM] visualization) pointed out that vesicles were stable for 90 days and neither verbascoside leakage nor vesicle size alteration occurred during this period. The effects of vesicular incorporation on verbascoside diffusion through skin were investigated in vitro using newborn pig skin. Results showed that liposomes promoted drug accumulation into the stratum corneum but they did not give rise to any significant transdermal verbascoside delivery. Finally, results obtained from a 1, 1-diphenyl-2-pierylhydrazyl (DPPH) radical assay demonstrated that liposomes did not interfere with the radical scavenging activity of verbascoside.

The effect of physiotherapy on fatigue and physical functioning in chronic fatigue syndrome patients: A systematic review.

OBJECTIVE: The objectives of this work were to fill the gap in the scientific literature and to evaluate the results of physical therapy treatments in individuals affected by chronic fatigue syndrome, considering only studies that employed a randomized controlled trial. METHODS: A systematic review was carried out according to PRISMA guidelines. Three bibliographic databases were searched: MEDLINE, Cochrane Library, and PEDro. The minimum prerequisites for papers to be included in the systematic review were that they had to (a) employ a randomized controlled trial; (b) be published in English; and (c) be published during the last ten years (2007-2017). The studies were evaluated according to Jadad score. RESULTS: Four studies were included. This systematic review suggests that a treatment that is more effective than all the others cannot be defined. This conclusion is related to the low number of investigated studies; therefore, the collected results cannot be generalized. CONCLUSION: Chronic fatigue syndrome is not yet a well-understood pathology, and the physical mechanisms that influence the outcomes still need more study. Rehabilitation programs that promote physiotherapy techniques such as exercise, mobilization, and body awareness (e.g., MRT and GET) are the most effective in reducing medium and long-term fatigue severity in CFS patients.

Predicting inferior vena cava (IVC) filter retrievability using positional parameters: A comparative study of various filter types.

PURPOSE: To compare changes in inferior vena cava (IVC) filter positional parameters from insertion to removal and examine how they affect retrievability amongst various filter types. MATERIALS AND METHODS: A total of 447 patients (260 men, 187 women) with a mean age of 55 years (range: 13-91 years) who underwent IVC filter retrieval between 2007-2014 were retrospectively included. Post-insertion and pre-retrieval angiographic studies were assessed for filter tilt, migration, strut wall penetration and retrieval outcomes. ANCOVA and multiple logistic regression models were used to analyze factors affecting retrieval success. Pairwise comparisons between filter types were performed. RESULTS: Of 488 IVC filter retrieval attempts, 94.1% were ultimately successful. The ALN filter had the highest mean absolute value of tilt (5.6 degrees), the Optease filter demonstrated the largest mean migration (-8.0mm) and the Bard G2 filter showed highest mean penetration (5.2mm). Dwell time of 0-90 days (OR, 11.1; P=0.01) or 90-180 days (OR, 2.6; P=0.02), net tilt of 10-15 degrees (OR 8.9; P=0.05), caudal migration of -10 to 0mm (OR, 3.46; P=0.03) and penetration less than 3mm (OR, 2.6; P=0.01) were positive predictors of successful retrievability. Higher odds of successful retrieval were obtained for the Bard G2X, Bard G2 and Cook Celect when compared to the ALN and Cordis Optease filters. CONCLUSION: Shorter dwell time, lower mean tilt, caudal migration and less caval wall penetration are positive predictors of successful IVC filter retrieval.