I had foam sclerotherapy a while back and I quizzed my consultant on causes. He said he'd never heard of alcohol being a contributory factor. So drink your beer with a clear conscience!! Incidentally have you heard of Inclined Bed Therapy (IBT)? I've just read about it on a website.
Even one of my friend was suffering from varicose vein problem and she consulted a doctor at USA Vein Clinics. She had intolerable pain in legs due to that and doctors advised her Endovenous Laser Therapy (EVLT). She had undergone this surgery from USA Vein Clinics and is perfectly alright.