['Complex forms of congenital venous malformation have defied proper classification and confounded therapy. Through a newly designed multidisciplinary approach, these venous defects were properly diagnosed and classified according to the Hamburg classification. Absolute ethanol was adopted as a new scleroagent for this complex form of venous defects to improve overall treatment results with acceptable morbidity and recurrence rates.', 'Among 318 patients aged 2 months to 60 years (130 men: mean age, 24.6 years; 188 women: mean age, 24.5 years), 143 patients were confirmed as having venous defects predominantly (45%). We conducted diagnostic evaluation with magnetic resonance imaging, whole body blood pool scan, duplex scans, transarterial microalbumin lung scans, air plethysmography, bone x-ray film, and angiography. Thirty of 143 patients were indicated for the absolute ethanol sclerotherapy for the complex form of venous defects, and they completed 98 sessions of multistage therapy with direct puncture technique. Follow-up assessment (minimum, 6 months; average, 10.2 months) was made as early results after completion of therapy.', "The immediate success rate at the completion of treatment through 98 sessions on 30 patients was 92% (90/98). The reason for the failure of 8% (8/98 sessions) was mainly due to the lesion's inaccessibility to the nidus to deliver the alcohol safely. On follow-up assessment available on 28 of 30 patients, overall improvement of the lesions with good to fair response on clinical assessment was obtained in 27 (96%) of 28 patients. Similar good to fair responses were obtained on whole body blood pool scan assessment (14 [93%] of 15 patients) and also on magnetic resonance imaging assessment (12 [93%] of 13 patients). Various major to minor acute complications developed during the procedure in eight (26.7%) of 30 patients through 16 (16.3%) of 98 sessions of the therapy: ischemic bullae, tissue fibrosis, deep venous thrombosis, pulmonary embolism, peripheral nerve palsy, and temporary pulmonary hypertension. All 24 incidences of complication were successfully managed with full recovery except one case of permanent peroneal nerve palsy that was present during 18 months of follow-up. No single recurrence has been detected to date."] Does new experience with absolute ethanol sclerotherapy in the management of a complex form of congenital venous malformation?