LAUSR

Background Between 2010 and 2014, microscopic transsphenoidal surgery (mTSS) was performed more frequently than endoscopic TSS (eTSS) in the USA. However, few epidemiological studies on pituitary surgery are currently available. Methods We performed a retrospective study on patients who had undergone pituitary surgery between July 2010 and March 2016. To this end, a nationwide inpatient database in Japan was used. Patients’ characteristics, diagnoses, types of surgery, complications, and discharge status were examined. Results A total of 16,253 inpatients who received pituitary surgery were identified. Patients were diagnosed with diseases for insurance claims described below: pituitary adenoma, hyperprolactinemia, other pituitary disorders (e.g., Rathke’s cleft cyst), hyperpituitarism, craniopharyngioma, acromegaly, Cushing’s disease, and pituitary cancer. Among them, pituitary adenomas, primarily the non-functioning ones, were the most frequent (66.9%). A total of 14,285 (88%) patients underwent TSS, while 1968 (12%) patients were treated using transcranial surgery. The number of patients undergoing TSS increased each year. The number of eTSS operations was 8140 (77%) and that of mTSS operations was 2419 (23%). Of note, eTSS increased each year. We found that high-volume hospitals more frequently selected eTSS. Compared with mTSS, eTSS was associated with a reduction of hyponatremia incidence (odds ratio, 0.69; p  = 0.019). Additionally, it was not associated with other major complications. Conclusion The present study showed that both TSS and eTSS increased on a yearly basis. We believe that the present study will be the basis of future epidemiological investigations of pituitary surgery.