Intercepción de las lluvias por la cubierta de bosques y efecto en los caudales de crecida en una cuenca experimental en Malalcahuello, IX Región, Chile

Abstract

OBJECTIVEThe objective of this randomized, prospective, blinded study was to determine the relative effects of two laser wavelengths in the treatment of great saphenous vein (GSV) insufficiency.METHODSFifty-one male and female patients scheduled for routine laser treatment of GSV insufficiency provided signed informed consent for the procedure. Patients were randomized to receive endovenous laser treatment with a wavelength of 810 or 980 nm. The same surgeon, blinded to the wavelength, performed all procedures. Nonoperating study staff, blinded to the laser wavelengths, evaluated patients before and after the procedure regarding physical signs and symptoms. Patients were monitored within 72 hours after the procedure (via duplex ultrasonography), at 1 week (by procedural site photos scored for bruising, as well as a pain score), at 3 weeks, and at 4 months for bruising, physical and emotional effects of the procedure (scored by patients on a five-point visual analogue scale), and symptoms (scored by the physician), along with adverse events. Patients were followed up for a year to determine the long-term efficacy of the procedure.RESULTSThe 51 patients (38 women and 13 men; mean age, 52.4 ± 11.7 years) completed treatment and follow-up examination (30 legs for each wavelength). At 72 hours after the procedure, no significant differences were noted between patient outcomes, physical conditions, and symptoms and or possible adverse events. At 1 week after the procedure, bruising scores were significantly different (P < .005): patients in the 980-nm group showed less bruising of the procedure site than the patients in the 810-nm group. Only three physical or symptom parameters presented with significant differences (P < .05) over time—less itching was noted by 810 nm–treated patients at 3 weeks after the procedure, lower levels of pain intensity were seen in the 980 nm–treated patients at the 4-month follow-up visit, and lower varicose vein ratings were seen for the 980 nm–treated patients at the 4-month follow-up visit. Thirteen legs were phlebitic at 7 days after the procedure (10 in the 810-nm group and 3 in the 980-nm group). Two treatment failures occurred (one patient in each treatment group); both patients exhibited flow in the treated venous segment at the 4-month follow-up visit. Two other patients (one in each group) had treatment failure at the 1-year follow-up, demonstrating venous insufficiency in the treated segment.CONCLUSIONSBoth laser wavelengths were effective in treating GSV insufficiency, with no major complications and a paucity of adverse outcomes.