Specific focus on the basal dura for improving Cushing's disease surgery: a cohort study.

Background and objectives: In Cushing's disease, the rate of endocrine remission after surgery reaches 80% in expert centers. However, due to the tumor's capacity to invade surrounding dural structures, hypercortisolism persists in 20% of patients or recurs in 15%. To improve the likelihood of remission, tumor resection can be extended to the dura in patients who show basal dura invasion. The objective was to evaluate the benefit of a surgical strategy based on a systematic focus on the basal dura.

Methods: Endoscopic surgery was performed in 89 adult patients with no obvious cavernous invasion. The basal dura was systematically removed whenever a macroscopic invasion was suspected. Three groups were defined: (i) resected but noninvaded dura (n = 14); (ii) resected and invaded dura (n = 16); and (iii) nonresected dura (n = 59). The studied cohort was compared to a control personal series of Cushing's patients with no systematic focus on the basal dura.

Results: The mean follow-up duration was 19.9 ± 9.4 months. Endocrine remission was achieved in 15/16 (94%) patients with invaded dura, 14/15 (93%) patients with resected noninvaded dura and 50/59 (85%) patients with nonresected dura. Anterior pituitary deficits and diabetes insipidus occurred in 3% and 9% of patients respectively. Compared to the control series, our remission rate was significantly higher (88% vs. 75%, P =.019).

Conclusion: Tumorectomy extended to the basal dura is a safe procedure that maximizes surgical resection. Despite dura invasion, endocrine remission is high when the dura is removed. A systematic focus on the basal dura can optimize endocrine outcomes.