title: Delayed Cerebrospinal Fluid Rhinorrhea After Gamma Knife Radiosurgery with or without Preceding Transsphenoidal Resection for Pituitary Pathology.
abstract: BACKGROUND
  Skull base cerebrospinal fluid (CSF) leak after gamma knife radiosurgery (GKRS) is a very rare complication. In patients who were treated with both GKRS and transsphenoidal resection (TSR) for pituitary lesions, early CSF leak occurs at a comparable rate with the general TSR population (4%). Delayed CSF leak occurring more than a year after TSR, GKRS, or dual therapy is exceedingly rare.
  
  
  METHODS
  Retrospective chart review and review of the literature.
  
  
  RESULTS
  We present 2 cases of delayed CSF leak after GKRS to treat pituitary adenoma. One patient developed CSF rhinorrhea 16 years after GKRS for growth hormone-producing pituitary adenoma. The patient had previously undergone TSR surgery 7 years prior to GKRS without complication. Additionally, a second patient developed high-flow CSF rhinorrhea 2 years after GKRS for a prolactinoma that failed dopamine agonist therapy. Both patients underwent a complicated clinical course after presentation, requiring multiple revisions for definitive CSF leak repair.
  
  
  CONCLUSIONS
  Delayed CSF leak is a rare but serious complication after GKRS independent of TSR status; urgent repair is the treatment of choice. Based on our experience, these leaks have the potential to be refractory, and we recommend aggressive reconstruction, preferably with a vascularized flap, and potentially supplemented by placement of a lumbar drain and acetazolamide. Current evidence is scant and provides little insight regarding an underlying mechanism, which may include bony destruction by the tumor, delayed radiation necrosis, or a secondary empty sella syndrome.
authors.affiliation: Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Avital
authors.initials: A
authors.lastname: Perry
authors.affiliation: Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Graffeo
authors.affiliation: Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: William R
authors.initials: WR
authors.lastname: Copeland
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Van Abel
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Carlson
authors.affiliation: Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota, USA; Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Pollock
authors.affiliation: Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota, USA; Department of Otolaryngology-Head and Neck Surgery, Mayo Clinic, Rochester, Minnesota, USA. Electronic address: Link.Michael@Mayo.edu.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Link
mesh_terms: D000236:Adenoma / Q000150:complications / Q000628:therapy*; D000368:Aged; D002559:Cerebrospinal Fluid Rhinorrhea / Q000175:diagnosis / Q000209:etiology* / Q000628:therapy*; D003131:Combined Modality Therapy / Q000009:adverse effects; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010027:Osteotomy / Q000009:adverse effects*; D010911:Pituitary Neoplasms / Q000150:complications / Q000628:therapy*; D011832:Radiation Injuries / Q000209:etiology / Q000628:therapy; D016634:Radiosurgery / Q000009:adverse effects*; D013100:Sphenoid Bone / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome
keywords: Acromegaly; Cerebrospinal fluid leak; Gamma knife; Late outcomes; Transsphenoidal surgery