title: Diaphragma sellae: a surgical reference for transsphenoidal resection of pituitary macroadenomas.
abstract: OBJECTIVE
  To classify patterns of descent of the diaphragma sellae (DS) to the sella turcica after transsphenoidal resection of pituitary macroadenomas and to determine whether there is any correlation between type of descent and volume or growth pattern of the tumor, as well as the presence of any postoperative hormone alteration, cerebrospinal fluid leak, and/or residual tumor.
  
  
  METHODS
  One hundred patients with pituitary macroadenomas in which microsurgical transsphenoidal approach was indicated were prospectively included. We classified patterns of descent of the DS into four types: type A: symmetrical descent with a central fold corresponding to the pituitary stalk; type B: asymmetrical with a lateralized fold; type C: symmetrical and uniform descent without any fold; and type D: minimal or no descent in absence of visible residual tumor. A correlation was made between these types of descent and clinical and radiological findings.
  
  
  RESULTS
  The largest tumors were types A and B; endocrine deficit was more frequent in types A and C, whereas the possibility of residual tumor was more elevated in types B and D. No statistically significant differences were found regarding tumor morphology and cerebrospinal fluid leakage.
  
  
  CONCLUSIONS
  Our results suggest that pattern of descent of the DS may serve as a reference to determine the risk of leaving residual tumor as well as the possibility of developing postoperative endocrine deficit. It is apparent that tumor volume, more than morphology, is the main factor determining type of descent of the DS.
authors.affiliation: Department of Neurosurgery, Hospital de Especialidades, Centro Médico Nacional Siglo XXI, México City, México. gguinto@prodigy.net.mx
authors.forename: Gerardo
authors.initials: G
authors.lastname: Guinto Balanzar
authors.forename: Miguel
authors.initials: M
authors.lastname: Abdo
authors.forename: Moises
authors.initials: M
authors.lastname: Mercado
authors.forename: Patricia
authors.initials: P
authors.lastname: Guinto
authors.forename: Elisa
authors.initials: E
authors.lastname: Nishimura
authors.forename: Norma
authors.initials: N
authors.lastname: Arechiga
mesh_terms: D000236:Adenoma / Q000453:epidemiology / Q000473:pathology / Q000601:surgery*; D000328:Adult; D000368:Aged; D004388:Dura Mater / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018365:Neoplasm, Residual / Q000453:epidemiology / Q000473:pathology / Q000601:surgery; D019635:Neurosurgical Procedures / Q000592:standards*; D010902:Pituitary Gland / Q000033:anatomy & histology*; D010911:Pituitary Neoplasms / Q000453:epidemiology / Q000473:pathology / Q000601:surgery*; D011183:Postoperative Complications / Q000453:epidemiology / Q000517:prevention & control; D012015:Reference Standards; D012307:Risk Factors; D012658:Sella Turcica / Q000033:anatomy & histology; D013100:Sphenoid Bone / Q000601:surgery; D055815:Young Adult