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New Study Reveals Outcomes and Complications of Decompression Surgery for Chiari Malformation and Syringomyelia

September 23, 2022

Research teams from the multicenter Park-Reeves Syringomyelia Research Consortium (PRSRC) published new findings on outcomes and complications from posterior fossa decompression with and without duraplasty in cases of Chiari I malformation and syringomyelia.

The study was published in the July 2022 issue of The Journal of Neurosurgery: Pediatrics and was one of this edition's Editor's Choice features.

The work of the PRSRC is designed to help further the medical community’s understanding of syringomyelia and Chiari malformation. Through the collection of data on 1,000 individuals by 25 medical centers in the United States, this study examines the underlying causes, natural history, and optimal treatment of syringomyelia and Chiari malformations.

UPMC Children’s Hospital of Pittsburgh Division of Pediatric Neurosurgery is a contributing member of the PRSRC. Its work with the consortium is led by site principal investigator Stephanie Greene, MD,  professor of Neurosurgery, who was a co-author of the study. Dr. Greene is the director of Vascular Neurosurgery and Perinatal Neurosurgery at UPMC Children’s.

Study Overview and Findings in Brief

In the new paper, the PRSRC research team analyzed combined prospective and retrospective outcomes and complications data from the registry encompassing 692 patients who underwent posterior fossa decompressive surgery with and without duraplasty for Chiari I malformation and syringomyelia.

This is the first large-scale, multicenter study to compare outcomes and complication rates in posterior fossa decompression with and without duraplasty (PFDD; PFD).

Of the 692 patients, 117 were cases of PFD, and 575 were PFDD. The mean age of patients at the time of surgery was 9.86 years, and the mean duration of follow-up was 2.73 years, neither of which varied in statistical significance between the two cohorts. The only statistically significant presenting symptom difference between PFD and PFDD patients was in holocranial headaches, which occurred in 26.5% of PFD patients versus 14.6% underdoing PFDD.

Intraoperative complication rates were low and similar for both groups: PFD 0.0% and PFDD 07%, as were postsurgical complications after 6 months with a rate of 0.9% in the PFD group and 2.8% in the PFDD group.

However, postsurgical complication rates from 0 to 6 months significantly favored the PFD group with a 13.7% rate of complications versus a 24.3% rate observed in PFDD patients. Also, the PFDD group had a much higher incidence of postoperative pseudomeningocele than the PFD group – 7.7% versus 2.6%.

When examining procedure time, the research team uncovered a shorter mean operating time in PFD patients – 1.98 hours – versus 2.92 hours for the PFD group. Blood loss greater than 50 mL during surgery occurred in a higher percentage (18.3%) of PFDD patients.

Length of stay in the hospital, another metric compared between the two groups, was shorter for patients undergoing PFD.

Effects of PFD and PFDD on Symptom Management/Resolution

Patients undergoing PFDD had higher rates of improvements in symptoms or resolution of symptoms related to headaches. The PFDD group reported improvements in this area in 89.6% of cases, while in the PFD group, headache symptom improvement or resolution was only reported in 80.8% of cases.

Radiological findings of syrinx size after surgery favored those who underwent PFDD versus PFD.

"These new data give surgeons new insights into expected outcomes and complications for patients with Chiari I malformation and syringomyelia and will aid in case planning and discussions with patients and their families," says Dr. Greene. "

Learn more about the study and its complete analysis and findings using the link below.


Akbari SHA, Yahanda AT, Ackerman LL, et al. Complications and Outcomes of Posterior Fossa Decompression With Duraplasty Versus Without Duraplasty for Pediatric Patients With Chiari Malformation Type I and Syringomyelia: A Study From the Park-Reeves Syringomyelia Research Consortium. J Neurosurg Pediatr. 2022; 30: 39-51.