title: The Value of Intraoperative Magnetic Resonance Imaging in Endoscopic and Microsurgical Transsphenoidal Pituitary Adenoma Resection.
abstract: BACKGROUND
  The routine use of intraoperative magnetic resonance imaging (iMRI) helps to achieve gross total resection in transsphenoidal pituitary surgery. We compared the added value of iMRI for extent of resection in endoscopic versus microsurgical transsphenoidal adenomectomy.
  
  
  METHODS
  A total of 96 patients with pituitary adenoma were included. Twenty-eight consecutive patients underwent endoscopic transsphenoidal tumor resection. For comparison, we used a historic cohort of 68 consecutive patients treated microsurgically. We evaluated the additional resection after conducting iMRI using intraoperative and late postoperative volumetric tumor analysis 3 months after surgery. Demographic data, clinical symptoms, and complications as well as pituitary function were evaluated.
  
  
  RESULTS
  We found significantly fewer additional resections after conducting iMRI in the endoscopic group (P = 0.042). The difference was even more profound in Knosp grade 0-2 adenomas (P = 0.029). There was no significant difference in Knosp grade 3-4 adenomas (P = 0.520). The endoscopic approach was associated with smaller intraoperative tumor volume (P = 0.023). No significant difference was found between both techniques in postoperative tumor volume (P = 0.228). Satisfactory results of pituitary function were significantly more often associated with an endoscopic approach in the multiple regression analysis (P = 0.007; odds ratio, 17.614; confidence interval 95%, 2.164-143.396).
  
  
  CONCLUSIONS
  With the endoscopic approach, significantly more tumor volume reduction was achieved before conducting iMRI, decreasing the need for further resection. This finding was even more pronounced in adenomas graded Knosp 0-2. In the case of extensive and invasive adenomas with infiltration of cavernous sinus and suprasellar or parasellar extension, additional tumor resection and increase in the extent of resection was achieved with iMRI in both groups. The endoscopic approach seems to result in better endocrine outcomes, especially in Knosp grade 0-2 pituitary adenomas.
authors.affiliation: Department of Neurosurgery, University of Ulm, Günzburg, Germany. Electronic address: andrej.pala@uni-ulm.de.
authors.forename: Andrej
authors.initials: A
authors.lastname: Pal'a
authors.affiliation: Department of Neurosurgery, University of Ulm, Günzburg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Knoll
authors.affiliation: Department of Neurosurgery, University of Ulm, Günzburg, Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Brand
authors.affiliation: Endokrinologiezentrum Ulm, Ulm, Germany.
authors.forename: Gwendolin
authors.initials: G
authors.lastname: Etzrodt-Walter
authors.affiliation: Department of Neurosurgery, University of Ulm, Günzburg, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Coburger
authors.affiliation: Department of Neurosurgery, University of Ulm, Günzburg, Germany.
authors.forename: Christian Rainer
authors.initials: CR
authors.lastname: Wirtz
authors.affiliation: Department of Neurosurgery, University of Ulm, Günzburg, Germany.
authors.forename: Michal
authors.initials: M
authors.lastname: Hlaváč
mesh_terms: D000236:Adenoma / Q000000981:diagnostic imaging* / Q000601:surgery*; D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D015331:Cohort Studies; D004724:Endoscopy / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008866:Microsurgery / Q000379:methods*; D008875:Middle Aged; D009666:Nose / Q000601:surgery; D010911:Pituitary Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery*; D013100:Sphenoid Bone / Q000000981:diagnostic imaging / Q000601:surgery*; D016896:Treatment Outcome; D055815:Young Adult
keywords: Endoscopic transsphenoidal surgery; Intraoperative MRI; Microsurgical technique; Pituitary adenoma; Tumor volume