Intrasellar ultrasound in transsphenoidal surgery: a novel technique.
OBJECTIVE
Residual tumor masses are common after transsphenoidal surgery. The risk of a residual mass increases with tumor size and parasellar or suprasellar growth. Transsphenoidal surgery is usually performed without image guidance. We aimed to investigate a new technical solution developed for intraoperative ultrasound imaging during transsphenoidal surgery, with respect to potential clinical use and the ability to identify neuroanatomy and tumor.


METHODS
In 9 patients with pituitary macroadenomas, intrasphenoidal and intrasellar ultrasound was assessed during transsphenoidal operations. Ultrasound B-mode, power-Doppler and color-Doppler images were acquired using a small prototype linear array, side-looking probe. The long probe tip measures only 3 x 4 mm. We present images and discuss the potential of intrasphenoidal and intrasellar and ultrasound in transsphenoidal surgery.


RESULTS
We present 2-dimensional, high-resolution ultrasound images. A small side-looking, high-frequency ultrasound probe can be used to ensure orientation in the midline for the surgical approach to identify important neurovascular structures to be avoided during surgery and for resection control and identification of normal pituitary tissue. The image resolution is far better than what can be achieved with current clinical magnetic resonance imaging technology.


CONCLUSIONS
We believe that the concept of intrasellar ultrasound can be further developed to become a flexible and useful tool in transsphenoidal surgery.
Solheim
Ole
O
Department of Neuroscience, Norwegian University of Science and Technology, Department of Neurosurgery, St. Olavs University Hospital, Trondheim, Norway. ole.solheim@ntnu.no
Selbekk
Tormod
T
Løvstakken
Lasse
L
Tangen
Geir A
GA
Solberg
Ole V
OV
Johansen
Tonni F
TF
Cappelen
Johan
J
Unsgård
Geirmund
G
D000236:Adenoma / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D000328:Adult; D000368:Aged; D015150:Echocardiography, Doppler / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods*; D010911:Pituitary Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D012658:Sella Turcica / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D013101:Sphenoid Sinus / Q000473:pathology / Q000601:surgery*