Do the complications of mastoid surgery differ from those of the disease?

During mastoid surgery there is a risk to the facial nerve and hearing but at present it is unclear how substantial this risk is. This information is necessary for adequate informed consent to be given, as consent requires information about both the potential risks of the surgery as well as the risks of leaving the disease untreated. The aim of this study is to establish the risks of mastoid surgery and the incidence of complications as a consequence of mastoid disease. The records of all patients undergoing mastoidectomy between 1985 and 1994 were reviewed for preoperative and intra-operative complications. Preoperatively there were 21 (2%) facial nerve palsies, 67 (6.5%) dead ears and 58 (5.7%) intracranial complications of the mastoid disease. If this risk is extrapolated for the population of the Western Cape over a 40-year period (average expected life-span after presentation), the risk of developing a serious complication (facial palsy, dead ear or intracranial) from mastoid disease during this period was 3.8%. The incidence of intra-operative iatrogenic facial nerve palsy was 1.7% (n = 17) and of dead ear was 1.7% (n = 17). Although the comparative risk of developing a severe complication from untreated disease was similar to the risks of surgery (facial palsy, dead ear), the number (58) of intracranial life-threatening preoperative complications presenting in the 10-year period reviewed was significant. These figures provide a base from which otologists can inform patients about the possible risk of mastoid surgery as well as allowing these risks to be compared with the risks of leaving the disease untreated.