Hi, This is a great question. All mastoid surgeries may not be fully successful. With the modern instruments and optical improvements like in high resolution microscope and endoscopes the surgery has become very such successful in expert hands. You can take a second opinion of another ENT surgeon if you have doubts. Get operated if indicates as there is no chance of any brain injury at all, so no worry. As for facial paresis; the chances are least as one may not go to that area. Surely a few courses of antibiotics, anti-inflammatory medicines and decongestant can help a lot in some cases and worth trying to avoid surgery. Go for surgery if medical treatment fails to give results. Also, watch for any problems in nose, sinuses and throat as primary cause and if present should be treated as well. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. T. Chandrakant, General Surgeon