Background: Cerebrospinal fluid (CSF) leak may occur after CSE labor analgesia, and can be a cause of Post Dural Puncture Headache (PDPH). If headache persists after treatment measures, continual leakage of CSF should be considered. Although rare, this leakage may lead to a fistulous tract - a cerebrospinal fistula1. 
Case report: 22 year-old woman, with no underlying diseases and an uneventful pregnancy underwent CSE labor analgesia. Three punctures were necessary for a successful technique, but no accidental dural puncture was reported. 24 hours after labour, the patient complained of nausea and headache that worsened after standing position. Conservative treatment was initiated: paracetamol, caffeine, hydratation and bed rest. After 72 hours with no improvement, a successful blood patch was performed and she was discharged. The patient returned to the hospital 2 days later, with the same symptoms. She was again given conservative therapy and 2 more blood patches with no success. Her spine CT-scan and MRI were normal. A myelography computerized tomography was performed, showing a CSF fistula in the CSE puncture site. Neurosurgery was contacted and it was decided to attempt a fluoroscopic guided blood patch, before any surgical approach. The blood patch was successful and the patient was asymptomatic at the time of discharge.
Discussion: Although most cases of CSF leakage are iatrogenic2, it is very rare to encounter CSF fistulas as a complication of CSE puncture. During CSE, no accidental dural puncture was reported, but 3 punctures were necessary, indicating a higher risk of lesion. Orthostatic headaches are the main symptom of CSF fistulas2. Initially fistulas can be hard to detect on spinal CT or MRI. Myelography-CT was essential to the diagnosis3.Treatment is at first conservative. If symptoms persist, targeted blood patch is a safe technique and was more effective than blindly placed blood patch in this case.2
References: 
1Couture D, Branch CL., Jr Spinal pseudomeningoceles and cerebrospinal fluid fistulas. Neurosurg Focus. 2003;15(6):E6.
2Gottschalk A. Cerebrospinal fluid leakage. Indications, technique and results of treatment with a blood patch. Radiologe. 2015;55(6):471-478
3Schievink WI. Spontaneous spinal cerebrospinal fluid leaks: a review. Neurosurg Focus, 2000Jul15;9(1):e8.
Learning Points: Although CSE labour analgesia is often performed with no associated complications, the anesthesiology must be able to recognize and manage iatrogenic lesions.

Cerebrospinal fluid fistula after combined spinal-epidural labor analgesia (CSE) – a very rare case report