Practical Use of a Simple Technique, Insertion of Wet Cotton Pledgets into the Tumor Resection Cavity in Transsphenoidal Surgery of Pituitary Tumors, for a Better Comparison between Pre- and Intraoperative High-Field Magnetic Resonance Images

Abstract

Background Intraoperative high-field magnetic resonance imaging (iMRI) is a useful modality for immediate intraoperative quality control. With iMRI, a surgeon can confirm whether tumor remnants exist during surgery; which makes it possible to add further resection, obtain a higher resection rate, and improve the cure rate. It is sometimes difficult to evaluate the existence of tumor remnants when the tumor resection cavity is collapsed. In this study, we reported a simple technique for comparing pre- and intraoperative MR images.

Patients and Methods Thirty-five consecutive patients with pituitary adenoma underwent endoscopic endonasal transsphenoidal surgery using iMRI. Twenty-six patients had adenomas with suprasellar extension, and 9 had intrasellar adenomas. Nine adenomas had cavernous sinus invasion. Eight patients had endocrine-active, and 27 endocrine-inactive tumors. The simple technique included wet cotton pledgets inserted into the resection cavity to easily and precisely compare pre- and intraoperative MR images. Furthermore, we evaluated the efficacy of iMRI using our method on determining the extent of tumor resection in this study.

Results The first iMRI scan showed that 12 of 35 patients had some tumor remnants, and 23 patients did not. Eight of these 12 patients with tumor remnants had cavernous sinus invasion. Three cases received further tumor resection after iMRI and had a gross total removal.

Conclusions We presented our initial results after using a simple method in high-field iMRI during endoscopic transnasal transsphenoidal pituitary surgery. This procedure allowed us to obtain valuable information to determine the extent of tumor resection and to precisely visualize the parasellar structures.

Keywords

transsphenoidal approach - endoscopy - intraoperative high field MRI

• References

• 1 Sakurada K, Matsuda K, Funiu H , et al. Usefulness of multimodal examination and intraoperative magnetic resonance imaging system in glioma surgery. Neurol Med Chir (Tokyo) 2012; 52 (8) 553-557
• 2 Cottier JP, Destrieux C, Brunereau L , et al. Cavernous sinus invasion by pituitary adenoma: MR imaging. Radiology 2000; 215 (2) 463-469
• 3 Knosp E, Steiner E, Kitz K, Matula C. Pituitary adenomas with invasion of the cavernous sinus space: a magnetic resonance imaging classification compared with surgical findings. Neurosurgery 1993; 33 (4) 610-617 , discussion 617–618
• 4 Ahn JY, Jung JY, Kim J, Lee KS, Kim SH. How to overcome the limitations to determine the resection margin of pituitary tumours with low-field intra-operative MRI during trans-sphenoidal surgery: usefulness of Gadolinium-soaked cotton pledgets. Acta Neurochir (Wien) 2008; 150 (8) 763-771 , discussion 771
• 5 Baumann F, Schmid C, Bernays RL. Intraoperative magnetic resonance imaging-guided transsphenoidal surgery for giant pituitary adenomas. Neurosurg Rev 2010; 33 (1) 83-90
• 6 Bellut D, Hlavica M, Schmid C , et al. Intraoperative magnetic resonance imaging-assisted transsphenoidal pituitary surgery in patients with acromegaly. Neurosurg Focus 2010; 29 (4) 1-9
• 7 Bohinski RJ, Warnick RE, Gaskill-Shipley MF , et al. Intraoperative magnetic resonance imaging to determine the extent of resection of pituitary macroadenomas during transsphenoidal microsurgery. Neurosurgery 2001; 49 (5) 1133-1143 , discussion 1143–1144
• 8 Darakchiev BJ, Tew Jr JM, Bohinski RJ, Warnick RE. Adaptation of a standard low-field (0.3-T) system to the operating room: focus on pituitary adenomas. Neurosurg Clin N Am 2005; 16 (1) 155-164
• 9 Fahlbusch R, Ganslandt O, Buchfelder M, Schott W, Nimsky C. Intraoperative magnetic resonance imaging during transsphenoidal surgery. J Neurosurg 2001; 95 (3) 381-390
• 10 Fahlbusch R, Keller Bv, Ganslandt O, Kreutzer J, Nimsky C. Transsphenoidal surgery in acromegaly investigated by intraoperative high-field magnetic resonance imaging. Eur J Endocrinol 2005; 153 (2) 239-248
• 11 Gerlach R, du Mesnil de Rochemont R, Gasser T , et al. Feasibility of Polestar N20, an ultra-low-field intraoperative magnetic resonance imaging system in resection control of pituitary macroadenomas: lessons learned from the first 40 cases. Neurosurgery 2008; 63 (2) 272-284 , discussion 284–285
• 12 Martin CH, Schwartz R, Jolesz F, Black PM. Transsphenoidal resection of pituitary adenomas in an intraoperative MRI unit. Pituitary 1999; 2 (2) 155-162
• 13 Nimsky C, Ganslandt O, Fahlbusch R. Comparing 0.2 tesla with 1.5 tesla intraoperative magnetic resonance imaging analysis of setup, workflow, and efficiency. Acad Radiol 2005; 12 (9) 1065-1079
• 14 Nimsky C, von Keller B, Ganslandt O, Fahlbusch R. Intraoperative high-field magnetic resonance imaging in transsphenoidal surgery of hormonally inactive pituitary macroadenomas. Neurosurgery 2006; 59 (1) 105-114 , discussion 105–114
• 15 Pergolizzi Jr RS, Nabavi A, Schwartz RB , et al. Intra-operative MR guidance during trans-sphenoidal pituitary resection: preliminary results. J Magn Reson Imaging 2001; 13 (1) 136-141
• 16 Schwartz TH, Stieg PE, Anand VK. Endoscopic transsphenoidal pituitary surgery with intraoperative magnetic resonance imaging. Neurosurgery 2006; 58 (1, Suppl): ONS44-ONS51 , discussion ONS44–ONS51