Relationship between Recurrence Rates of Rathke's Cleft Cysts and Surgical Approaches to Sellar Reconstruction

Introduction: Rathke’s cleft cysts are rare, benign lesions that can present due to local compression upon the pituitary gland, stalk, and optic chiasm. Following initial surgical management, recurrence rates can be high; reportedly up to 40% in some studies. The modern era of endoscopic transsphenoidal surgery has afforded the skull base surgeon improved methods of reconstructing the pituitary fossa floor (or sellar face) following cyst drainage. However, an issue not fully resolved in the literature is whether specific surgical techniques are associated with higher rates of cyst recurrence, and/or iatrogenic complications.

Study Aim: To specifically address the question of whether reconstructing the pituitary fossa floor following cyst drainage or excision results in increased rates of recurrence.

Methods: A retrospective case series was compiled from examination of medical records and radiological investigations at a single institution (The Royal Melbourne Hospital, Melbourne, Australia) over a time period spanning 25 years. The presence and timing of cyst recurrence was determined from previous MRI scans and outpatient encounters. Details regarding type of surgical procedure, and absence or presence of fossa floor reconstruction (and technique) were obtained from operation notes. The other outcome measure was morbidity (specifically pertaining to CSF leak and meningitis rates).

Results: A total of 23 patients were treated surgically for a Rathke’s cleft cyst at the study institution between 1992 and 2017. The overall cyst recurrence rate was 48%, with 39% of all patients requiring redo surgery within the timeframe of the study. The mean time to redo surgery for recurrence was 4 years (range: 2 months–20 years). The total number of procedures performed among this group of patients was 38 (5 transcranial, 14 microscopic transsphenoidal, and 19 endoscopic transsphenoidal). Among the transsphenoidal procedures, 6 (18%) involved no reconstruction, and 27 (82%) involved fossa floor reconstruction using variations of fat graft, bone or plastic sellar implant, and vascularized nasoseptal flap.

Cyst recurrence rates were 0% post transcranial procedures, 57% post microscopic procedures, and 26% post endoscopic procedures. In the nonreconstructed group, there was a recurrence rate of 17%, whereas in the reconstructed group the recurrence rate was 41%. Notable surgical morbidity included prolapse of the optic chiasm into the pituitary fossa with deterioration in vision requiring multiple endoscopic “Chiasmopexy” procedures to correct. Complications specifically arising after non-reconstructive procedures were as follows: development of CSF rhinorrhea 3 weeks postoperatively, spontaneous pneumocephaly 2 months postoperatively after sneezing, and multiple episodes of meningitis. All of these patients required return to theater for secondary reconstruction of the pituitary fossa floor.

Conclusion: Although the small and skewed numbers of this study preclude reliable statistical analysis, the results suggest that reconstruction of the pituitary fossa floor, and microscopic rather than endoscopic techniques, may be associated with a higher rate of Rathke’s cleft cyst recurrence. However, complication rates among patients undergoing the alternative procedure of nonreconstruction may be higher, and such patients may be more likely to require repeat surgery to address this. Further studies involving greater numbers of patients are still required to answer this question.