A minimally invasive method for treating varices in especially sensitive areas, including pelvic varices in females, varicoceles, and also oesophageal varices is presented. The method comprises the steps of making a micro incision into the blood vessels of a patient, endoscopically inserting a catheter device into the blood vessel of a patient and advancing the distal end of the catheter to reach the varix or varices. For treatment of male varicocele, insertion is preferably made directly at the testicle. Alternatively, insertion can be made in the femoral vein and advanced using a catheter. Preferably, x-ray, angiography, or other imaging techniques are used to visualize and position the catheter. An optical fiber is then inserted into the catheter and the distal end is advanced to a predetermined point near the varix or varices. Optical fiber distal end is preferably a slim, radial 360 degree emitting fiber end. Laser energy of preferably 1470±30 nm is then transmitted to the varix to close the blood vessel. Other wavelengths with similar or greater absorption in blood/water than at 1470 nm are also effective. Imaging techniques such as angiographies may again be performed to confirm closure of the vein. The laser source linked to a radial emitting fiber allows for thermo occlusion of varicoceles using about 2-3 W of emitting power with little or no pain or discomfort for patient. The present invention is an out-patient procedure that requires no anesthesia and minimal recovery time, and does not require that any foreign objects be left in the body. This method has been shown to have a high success rate and minimum pain or side effects for the patient.