1326. Posterior Fusion for Treatment of Pannus and Anterior Brainstem Compression in Chiari I Children

Authors: Bruno Perocco Braga, MD; Muhammad Janjua; bradley weprin, MD; dale swift, MD; Kamran Urgun, MD (Dallas, TX)


There is still controversy regarding the best option for surgical treatment of Chiari I malformation which is somewhat expected given the debate regarding its pathophysiology. We present a retrospective series of Chiari I patients that were found to have pannus and anterior brainstem compression. Patients who underwent surgery that included a posterior fusion were found to have regression of the pannus and resolution of anterior brainstem compression.


From May 2001 to July 2016, one-hundred-and-forty-two Chiari I patients underwent surgical treatment either because of symptoms or presence of syringomyelia through at least a standard suboccipital decompression. A high cervical or occipito-cervical fusion was also recommended in case of anterior brainstem compression by pannus, basilar invagination, abnormal occipitocervical facet joints or skull base angles. Pre- and postoperative MRIs were used to determine outcomes regarding resolution of pannus and syrinx.


Thirty-five patients were identified as having pannus in preoperative MRIs. Out of the 24 patients who underwent a standard suboccipital decompression alone, pannus was still present in 23 of them as shown in the postoperative MRIs. Out of the eleven patients who underwent a high cervical or occipitocervical fusion in addition to the decompression, there was resolution of pannus in all of them as confirmed by postoperative MRI. Syrinx was either resolved or improved in all patients who underwent fusion (11/11). Out of the patients who did not undergo fusion, syrinx improved or resolved in all but one (23/24). There was no significant change in CSF leak, infection, need for transfusion, neurological injury. Time of operation was significant longer in the fusion group.


Posterior fusion is a safe and effective option for treatment of pannus and associated anterior brainstem compression in patients with Chiari I malformation and it does not lead to higher complication rates.