gms | German Medical Science

Objective: Intraoperative visualization of cavernous sinus (CS) is difficult despite advances in microsurgical and endoscopic technique. For this purpose we describe the use of intraoperative direct contact ultrasound in pituitary surgery and correlate sonographic findings to anatomical landmarks as identified in corresponding MRI slices.

Methods: During transnasal pituitary surgery for 8 non-secreting macroadenomas (18-38 mm in diameter; 3 recurrent adenomas; age 57–80 years), and 1 recurrent meningeoma originating from right CS (age 82 years), a side fire ultrasound-probe (B-mode frequency 4–13 MHz, linear field of view 10 mm, penetration 20 mm, colour coded flow mode 6 MHz) was introduced after wide opening of sellar floor und after tumor removal. The parasellar and suprasellar space was scanned in direct contact to the sellar envelope perpendicular to the line between nostril and center of the sella. To describe anatomical landmarks corresponding T1-weighted 1.5 T 3D-MR images of a patient without sellar pathology were evaluated.

Results: Anatomical details as found with MRI are described and are correlated to sonographic findings. Using colour coded flow mode it was possible to identify the intracavernous course of the ICA in all cases and to operate safely close to the artery. In 2 cases intraoperative scanning revealed residual tumor, which was than completely resected. Parasellar tumor remnants due to infiltrative growth pattern were seen intraoperatively in 2 cases (one Knosp Grade IV adenoma, one meningeoma). The extent of suprasellar tumor resection was correctly predicted in 8 cases (complete in 7 adenomas, incomplete in the meningeoma), and was false negative in one recurrent adenoma with 3 previous transcranial operations.

Conclusions: Intraoperative ultrasound scanning of the parasellar and suprasellar space enables the surgeon to identify tumor remnants intraoperatively and to perform tailored resection even in infiltrative tumors.