=====Endoscopic transnasal external fistulation=====
Solanki et al. present a technique for the persistent external drainage of intractable subdiaphragmatic cystic recurrences with the creation of a fistula between the cyst wall epithelium and epithelium on the nasal cavity, using a [[pedicled nasoseptal flap]] as a conduit. The long-term efficacy of endoscopic transnasal external fistulation (ETEF) in controlling cystic recurrences in this patient group is addressed through a retrospective observational review of 3 male patients aged 8, 22, and 45 years with the diagnosis of recurrent cystic [[subdiaphragmatic craniopharyngioma]] who underwent the ETEF procedure between 2006 and 2009. Clinical presentation, neuroimaging, surgical interventions, and follow-up were recorded. The main outcome measure was cyst reaccumulation on MRI. Patients had a mean follow-up of 76 months (range 5-8 years) with no incidence of cystic recurrence. Follow-up imaging revealed sustained cyst involution contrary to the usual recurrent enlargement commonly seen in this patient group. Symptoms of headache and visual field defects improved post-ETEF. Long-term theoretical complications of a persistent fistula such as [[intracranial abscess]], [[meningitis]], or [[cerebrospinal fluid leak]] were not observed. ETEF promotes nasalization of cystic recurrences in subdiaphragmatic craniopharyngioma. It is safe and effective, causing long-term involution of cysts and can be considered a definitive procedure
((Solanki SP, Sama A, Robertson IJ. Endoscopic transnasal external fistulation
in recurrent cystic subdiaphragmatic craniopharyngioma: a novel technique. J
Neurosurg Pediatr. 2015 Oct 16:1-6. [Epub ahead of print] PubMed PMID: 26474101.
)).