Pituitary surgery for Cushing's disease: the use of per-operative ACTH sampling
Paul Menheere1, Erwin Cornips2 & Jean-Pierre Sels3
Background: Treatment of choice of ACTH producing pituitary adenoma is transsphenoidal resection. Owing to difficult visual demarcation of the adenoma, peroperative feedback about the completeness of the resection would be desirable. We investigated if rapid per-operative ACTH measurements is useful in surgical strategy.
Methods: Thirteen patients with pituitary adenomas were operated. An modified ACTH-assay delivered results within 30 min. Catheters were inserted in the internal jugular veins at the site of the adenoma (four patients) or in both internal jugular veins (eight patients). A third catheter permitted sampling in femoral vein. Once the surgeon thought the adenoma was completely removed, surgery was suspended and ACTH was repeatedly sampled in all catheters for 20 min. Next, results were judged if they showed complete removal of adenoma or whether re-inspection was indicated. Surgery was terminated only after visually satisfactory removal of the adenoma together with biochemical confirmation.
Results: In three patients it was impossible to finish the procedure, sampling being impossible due to clotting. Four patients showed complete removal of the adenoma. Owing to initial insufficient decline of ACTH, re-exploring was decided in five out of nine patients; in three patients additional visual remnants were removed. In remaining patients, there was doubt if any additional adenoma was removed.
Conclusions: Per-operative ACTH measurements seem useful to decide for more aggressive approach to gain complete but selective resection of adenoma. Furthermore, the ACTH concentrations proved to be predictive for the long-term follow-up. Results are promising in increasing rate of cure in Cushings disease.