Correlation of body mass index with recanalization risk after endovenous thermal ablation.

OBJECTIVE: Chronic venous insufficiency (CVI) has an increased prevalence among obese individuals with body mass indices (BMI) over 30. A safe, efficacious, and evidence-based recommended treatment for CVI due to superficial venous reflux (SVR) in great saphenous veins (GSVs), small saphenous veins (SSVs), accessory saphenous veins (ASVs), and reflux in the perforator veins (PVs) is endovenous thermal ablation (EVTA). We sought to identify if BMI is an independent risk factor for recanalization after EVTA. METHODS: All patients with CVI were initially managed conservatively, and those with pathologic SVR refractory to compression therapy were offered EVTAs depending on the site of reflux. Sonographic confirmation of SVR was defined as >500 milliseconds of reflux in the GSVs, SSVs, and ASVs and a diameter >4 mm. PV reflux was confirmed as >350 milliseconds of reflux and a diameter >2.5 mm. All patients received a follow-up duplex ultrasound 1 week after the procedure, every 3 months for the first year, and every 6 months thereafter. Multivariate analysis with logistic regression was performed regarding patients' age, ablation modality (laser vs radiofrequency ablation), vein location and laterality, BMI, and recanalization. RESULTS: From 2013 to 2018, 9739 endovenous ablations were performed on 3070 patients. Endovenous laser was used in 3862 procedures and radiofrequency ablation in 5831 procedures. Veins treated with EVTA were distributed as follows: 6182 GSVs, 2509 SSVs, 597 ASVs, and 451 PVs. The mean patient age was 61.1 years (15-99, standard deviation [SD] ±15.6) with a mean BMI of 31.2 kg/m2 (13.7-69.5, SD ±7.3). A total of 68.4% patients were women and 31.4% men. The mean follow-up was 25.8 months (0-65.9, SD ±12.9). Multivariate statistical analysis with logistic regression was used to determine potential statistical significance between BMI and vein recanalization after EVTA. Overall, obese patients experienced more recanalizations than nonobese patients (P = .032), with an average BMI of 33 kg/m2 for recanalizations. PVs were statistically more likely to recanalize than any other vein (P = .0001). A secondary analysis was performed with the exclusion of PVs, due to their five times increased risk of recanalization, and showed no significant difference of recanalization across all BMI subgroups (P = .127). CONCLUSIONS: BMI does not predict recanalization risk after EVTA, except for ablations performed on PVs.

Correction: Chronic Methamphetamine Effects on Brain Structure and Function in Rats.

[This corrects the article DOI: 10.1371/journal.pone.0155457.].

Chronic Methamphetamine Effects on Brain Structure and Function in Rats.

Methamphetamine (MA) addiction is a growing epidemic worldwide. Chronic MA use has been shown to lead to neurotoxicity in rodents and humans. Magnetic resonance imaging (MRI) studies in MA users have shown enlarged striatal volumes and positron emission tomography (PET) studies have shown decreased brain glucose metabolism (BGluM) in the striatum of detoxified MA users. The present study examines structural changes of the brain, observes microglial activation, and assesses changes in brain function, in response to chronic MA treatment. Rats were randomly split into three distinct treatment groups and treated daily for four months, via i.p. injection, with saline (controls), or low dose (LD) MA (4 mg/kg), or high dose (HD) MA (8 mg/kg). Sixteen weeks into the treatment period, rats were injected with a glucose analog, [18F] fluorodeoxyglucose (FDG), and their brains were scanned with micro-PET to assess regional BGluM. At the end of MA treatment, magnetic resonance imaging at 21T was performed on perfused rats to determine regional brain volume and in vitro [3H]PK 11195 autoradiography was performed on fresh-frozen brain tissue to measure microglia activation. When compared with controls, chronic HD MA-treated rats had enlarged striatal volumes and increases in [3H]PK 11195 binding in striatum, the nucleus accumbens, frontal cortical areas, the rhinal cortices, and the cerebellar nuclei. FDG microPET imaging showed that LD MA-treated rats had higher BGluM in insular and somatosensory cortices, face sensory nucleus of the thalamus, and brainstem reticular formation, while HD MA-treated rats had higher BGluM in primary and higher order somatosensory and the retrosplenial cortices, compared with controls. HD and LD MA-treated rats had lower BGluM in the tail of the striatum, rhinal cortex, and subiculum and HD MA also had lower BGluM in hippocampus than controls. These results corroborate clinical findings and help further examine the mechanisms behind MA-induced neurotoxicity.