Frequency and Pattern of Diabetes Insipidus following Hypophyseal Adenectomy in Baqyiatallah Hospital, 1991-2001

Adenoma is one of the most common pituitary tumors, with diabetes Insipidus (DI) being one of the most common complications. This study was conducted with the following a) determination of relative frequency of DI following hyphophyseal adenectomy, b) assessment of correlation between DI and some variables, c) study the clinical course of DI development after surgery of hyphophyseal adenoma. Matherials and This prospective study was conducted between 1991-2001 in Baqyiatallah Hospital, Tehran, 50 Patients with pituitary adenoma without diabetes underwent trans-Sphenoidal (n = 35) or trans-cranial adenectomy (n = 15). Development, time of onset, duration of DI, and need to use Minirin was assessed in patients. DI was categorized to Immediate DI (IDI, ≤ day 10) and Delayed DI (DDI, >day 10). DI occurred in 15 cases (30%), of which, 10 had IDI (67%) and 5 cases had DDI (33%). DI developed in 5 (33.3%), 7 (46.6%), and 1 (6.6%) subjects, on days 1, 2 and 7 following their operation, respectively. DI was not correlated with sex, age and kind of surgery (p>0.05). DDI was seen more after trans-Cranial surgery than after trans-Sphenoid surgery (26.6% vs 2.8%, p=0.024). Of 15 cases of DI, 5 (33%) did not need Minirin, 5 (33%) needed it just for one day, and 5 (33%) received it for 4-180 days (4, 11, 15, 62 and over 180 days). This study reported the relative frequency of hypophyseal adenectomy to be 33%. According to this study, one third of patients have self-limited DI and do not need drug therapy. However, we recommend that in patients with DI after these surgeries, early and routine prescription of Minirin should be avoided and treatment should be based on fluid replacement. This study also reported trans-Sphenoid surgery to be less frequently accompanied by DI, which seems to be an important factor in the selection of operation techniques for these surgeries.