Decompression of Chiari malformation with and without duraplasty: morbidity versus recurrence

Clinical article

Restricted access


The optimal surgical management of Chiari malformation (CM) is evolving. Evidence continues to accrue that supports decompression without duraplasty as an effective treatment to achieve symptomatic relief and anatomical decompression. The risks and benefits of this less invasive operation need to be weighed against decompression with duraplasty.


The authors performed a retrospective review of all CM decompressions from 2003 to 2007. All operations were performed by a single surgeon at a single institution. Data were analyzed for outcome, postoperative morbidity, and recurrence.


Of 121 unique patients, 56 underwent posterior fossa decompressions without duraplasty (PFD) and 64 patients underwent posterior fossa decompressions with duraplasty (PFDD). Of the 56 PFD patients, 7 (12.5%) needed a subsequent PFDD for symptomatic recurrence. Of the 64 patients who underwent a PFDD, 2 (3.1%) needed a repeated PFDD for symptomatic recurrence. Patients treated with PFDD had an average operative time of 201 minutes in contrast to 127 minutes for those who underwent PFD (p = 0.0001). Patients treated with PFDD had average hospital stays of 4.0 days, whereas that for patients treated with PFD was 2.7 days (p = 0.0001). While in the hospital, patients treated with PFDD used low-grade narcotics, intravenous narcotics, muscle relaxants, and antiemetic medications at statistically significant differing rates.


While PFD was associated with a higher rate of recurrent symptoms requiring repeated decompression, this may be justified by the significantly lower morbidity rate. Clearer delineation of the trade-off between morbidity and recurrence may be used to help patients and their families make decisions regarding care.

Abbreviations used in this paper: CM = Chiari malformation; PFD = posterior fossa decompression; PFDD = PFD with duraplasty.

Article Information

Address correspondence to: Thomas M. Moriarty, M.D., Ph.D., Department of Neurosurgery, Norton Neuroscience Institute, 210 East Gray Street, Suite 1102, Louisville, Kentucky 40202. email:

© AANS, except where prohibited by US copyright law.



  • View in gallery

    Bar graph showing the percentage of patients with selected signs and symptoms. The comparison involves all patients versus PFDD versus PFD without duraplasty. Abn gag = abnormal gag reflex; coord = coordination; dyph = dysphagia; HA = headache; incont = incontinence; N/T = numbness and tingling; N/V = nausea and vomiting.

  • View in gallery

    Bar graphs demonstrating mean postoperative, weight-appropriate, administrations of low-grade narcotics (LGN), and intravenous narcotics (IVN) on each of postoperative Days 1, 2, and 3. PFDD compared with PFD without duraplasty.

  • View in gallery

    Bar graphs demonstrating postoperative, weight-appropriate, administrations of muscle relaxants (MR) and antiemetic medication (AE) on each of postoperative Days 1, 2, and 3. PFDD compared with PFD without duraplasty.



American Academy of Orthopaedic Surgeons: Changing patient expectations new procedures change view of knee replacement ( [Accessed January 21 2010]


Appleby AFoster JBHankinson JHudgson P: The diagnosis and management of the Chiari anomalies in adult life. Brain 91:1311401968


Caldarelli MNovegno FVassimi LRomani RTamburrini GDi Rocco C: The role of limited posterior fossa craniectomy in the surgical treatment of Chiari malformation Type I: experience with a pediatric series. J Neurosurg 106:3 Suppl1871952007


Dawn AGLee PP: Patient expectations for medical and surgical care: a review of the literature and applications to ophthalmology. Surv Ophthalmol 49:5135242004


D'Errico A: Surgical procedure for hydrocephalus associated with spina bifida. Surgery 4:8568661938


Durham SRFjeld-Olenec K: Comparison of posterior fossa decompression with and without duraplasty for the surgical treatment of Chiari malformation Type I in pediatric patients: a meta-analysis. J Neurosurg Pediatr 2:42492008


Feldstein NAChoudhri TF: Management of Chiari I malformations with holocord syringohydromyelia. Pediatr Neurosurg 31:1431491999


Galarza MSood SHam S: Relevance of surgical strategies for the management of pediatric Chiari type I malformation. Childs Nerv Syst 23:6916962007


Gardner WJ: Hydrodynamic mechanism of syringomyelia: its relationship to myelocele. J Neurol Neurosurg Psychiatry 28:2472591965


Gardner WJGoodall RJ: The surgical treatment of Arnold-Chiari malformation in adults; an explanation of its mechanism and importance of encephalography in diagnosis. J Neurosurg 7:1992061950


Haddad FSGarbuz DSChambers GKJagpal TJMasri BADuncan CP: The expectations of patients undergoing revision hip arthroplasty. J Arthroplasty 16:87912001


Isu TSasaki HTakamura HKobayashi N: Foramen magnum decompression with removal of the outer layer of the dura as treatment for syringomyelia occurring with Chiari I malformation. Neurosurgery 33:8448501993


List CF: Neurologic syndromes accompanying developmental anomalies of the occipital bone, atlas and axis. Arch Neurol Psychiatry 45:5776161941


Malis LICohen IGross SW: Arnold-Chiari Malformation. Arch Surg 63:7837981951


McConnell AAParker HL: A deformity of the hind-brain associated with internal hydrocephalus. Its relation to the Arnold-Chiari malformation. Brain 61:4154291938


Munshi IFrim DStine-Reyes RWeir BKHekmatpanah JBrown F: Effects of posterior fossa decompression with and without duraplasty on Chiari malformation-associated hydromyelia. Neurosurgery 46:138413902000


Nguyen Thi PLBriançon SEmpereur FGuillemin F: Factors determining inpatient satisfaction with care. Soc Sci Med 54:4935042002


Sitzia JWood N: Patient satisfaction: a review of issues and concepts. Soc Sci Med 45:182918431997


Toyone TTanaka TKato DKaneyama ROtsuka M: Patients' expectations and satisfaction in lumbar spine surgery. Spine 30:268926942005




All Time Past Year Past 30 Days
Abstract Views 36 36 15
Full Text Views 37 37 10
PDF Downloads 88 88 11
EPUB Downloads 0 0 0


Google Scholar