Volumetric classification of pituitary macroadenomas predicts outcome and morbidity following endoscopic endonasal transsphenoidal surgery

Abstract

Endoscopy in combination with extended approaches allow for resection of large pituitary adenomas via a transsphenoidal route. The objective of the current study was to determine a volumetric threshold for lesions with high perioperative morbidity and high rate of subtotal resection following endonasal endoscopic surgery. Thus, we analyzed a prospectively collected database of 71 patients who underwent endoscopic transsphenoidal approaches for macroadenomas (diameter >1 cm). Extend of resection (EOR) was calculated based on volumetric analysis of pre-and post-operative contrast-enhanced MRI. Average EOR was 97.8% and a gross total resection (GTR) was achieved in 76.1% of all patients. GTR was accomplished in 92.0% versus 38.1% of adenomas either without or with CS invasion, respectively. Likewise, GTR was accomplished in 90.2% versus 40.0% of lesions less than or greater then 10 cm(3) respectively. However, even if only subtotal resection was achieved, 90.3% of tumor volume was removed. At 17 months follow-up, visual field defects improved in 80.8% of patients. Complications included permanent diabetes insipidus (5 patients), panhypopituitarism (4 patients), injury to the ophthalmic artery (1 patient) and CSF leak (1 patient). On multivariate logistic regression, two factors negatively predicted GTR: invasion of the CS and volume greater than 10 cm(3). A 10 cm(3) threshold was a stronger predictor of EOR and complication risk than diameter-based measurements. A volume greater than 10 cm(3) and CS invasion may help to identify pituitary lesions associated with a higher likelihood of subtotal resection and post-operative morbidity.

Surgical outcomes of the endoscopic endonasal transsphenoidal approach for large and giant pituitary adenomas: institutional experience with special attention to approach-related complications

“…It is worth emphasizing that only one purely endoscopic surgical series was included in their analysis, since the manuscript by de Paiva Neto et al 24 was mainly microscopic transphenoidal. Thereafter, few studies came out in the literature addressing the outcomes of patients undergoing resection for large and giant pituitary adenomas by the endoscopic approach 6,8,10,11,13,14,15,16 . Their main surgical outcomes and complications rates are detailed on Tables 3 and 4 …”

“…Such higher rates of GTR are quite encouraging in comparison to the open and microscopic transsphenoidal groups (9.6% and 30.9%, respectively) 7 . It is worth discussing that cavernous sinus involvement is reported by most of the studies as the major limitation to GTR with the endoscopic approach 6,8,14,16 , whereas for the microscopic transsphenoidal approach is the suprasellar extension multilobular configuration and extension to the middle fossa 15 are also reported to have a negative impact on surgical resection rates by the endoscopic technique.…”

“…Even though a fair comparison cannot be performed, because of a different definition for STR (residual tumor > 10-20%) 7 , the endoscopic rates of decompression are at least similar to open and microscopic transsphenoidal groups (78.8% and 81.2%, respectively) 7 . Finally, the surgical technique used by most of the endoscopic endonasal series is the standard approach, in which a wide exposure of the sellar floor is obtained from the medial walls of the cavernous sinus laterally, the tuberculum sellae cranially and the dural indentation of the clivus/inferior transcavernous sinus caudally 6,8,10,11,14,16 . Some studies have used the extended transplanum/transtuberculum endonasal approach to address some dumbbell-shaped or suprasellar adenomas or even fibrous tumors 6,8,10,13,14,15 .…”

“…Finally, the surgical technique used by most of the endoscopic endonasal series is the standard approach, in which a wide exposure of the sellar floor is obtained from the medial walls of the cavernous sinus laterally, the tuberculum sellae cranially and the dural indentation of the clivus/inferior transcavernous sinus caudally 6,8,10,11,14,16 . Some studies have used the extended transplanum/transtuberculum endonasal approach to address some dumbbell-shaped or suprasellar adenomas or even fibrous tumors 6,8,10,13,14,15 . The role of the extended approach is yet to be defined, but the results are promising taken into consideration the higher rates of GTR in comparison to the standard endonasal approach (average of 41.3% vs. 27.3%, respectively; Table 3).…”

“…Some recent reports have described the usefulness of the endoscopic endonasal route in the their management, even though its safety and effectiveness of treating large and giant pituitary adenomas is yet to be established in the literature 6,8,10,11,13,14,15,16 . Herein, we sought to investigate our institutional experience of patients who underwent endoscopic endonasal transsphenoidal approach for treatment of large and giant pituitary adenomas emphasizing the surgical results and approachrelated complications.…”