Closing the dura: dural hitching versus surgicel and tisseel overlay graft in craniocervicaldecompression for Chiari 1 malformation.

BACKGROUND: This study compares dural hitching to surgicel and tisseel overlay graft following craniocervical decompression and C1 laminectomy with simple durotomy for Chiari I malformation. Outcome measures were syrinx decompression, headache resolution and complication rates. METHODS: A retrospective analysis of case notes was conducted. Patients who had undergone craniocervical decompression (CCD) were grouped by method of dural closure. Outcomes compared were rates of syrinx decompression, headache resolution, and post-operative complications. Statistical analysis was conducted using SPSS v20. RESULTS: We identified 32 adult patients for inclusion in this study. 53.1% (n = 17) had asyrinx, and 78.1% (n = 25) had a pre-operative headache. All were treated with suboccipital craniectomy, C1 laminectomy (with or without C2 laminectomy), and durotomy. The dura was either left open by dural hitching (n = 23) or closed with surgicel and tisseel overlay graft (n = 9). We found a statistically significant association between the method of dural closure and the rate of syrinx resolution. Resolution occurred in 91.7% (n = 11) of the hitching group, compared to 20.0% (n = 1) of the overlay graft group: Χ2(1) = 5.6, p = .018. There were no statistically significant differences between the two groups in the rates of headache resolution or other complications. CONCLUSIONS: In patients with symptomatic Chiari I malformation and associated syringomyelia, syrinx resolution is more likely if the dura is hitched open rather than closed bysurgicel and tisseel overlay graft after durotomy.

Mycophenolate and methotrexate are better tolerated than azathioprine in myasthenia gravis.

Azathioprine is recommended as the first-line steroid-sparing immunosuppressive agent for myasthenia gravis. Mycophenolate and methotrexate are often considered as second-line choices despite widespread consensus on their efficacy. We aimed to gather real-world data comparing the tolerability and reasons for discontinuation for these agents, by performing a national United Kingdom survey of side effects and reasons for discontinuation of immunosuppressants in myasthenia gravis. Of 235 patients, 166 had taken azathioprine, 102 mycophenolate, and 40 methotrexate. The most common side effects for each agent were liver dysfunction for azathioprine (23 %), diarrhoea for mycophenolate (14 %), and fatigue for methotrexate (18 %). Women were generally more likely to experience side effects of immunosuppressants. Azathioprine was significantly more likely to be discontinued than mycophenolate and methotrexate due to side effects. There was no significant difference in treatment cessation due to lack of efficacy. This study highlights the significant side-effect burden of treatment for myasthenia gravis. Mechanisms to reduce azathioprine toxicity should be utilised, however mycophenolate and methotrexate appear to be good treatment choices if teratogenicity is not a concern. Women are disadvantaged due to higher frequency of side effects and considerations around pregnancy and breastfeeding. Treatments with improved tolerability are needed.