Pneumocephalus Following Endoscopic Retrograde Cholangiopancreatography

Case Description

A 54-year-old male with no prior history of traumatic brain injury or nasopharyngeal disease underwent endoscopic retrograde cholangiopancreatography (ERCP) for a pancreatic space-occupying lesion. The procedure was performed under general anesthesia. In the postanesthetic recovery period, the patient rapidly developed severe neurological symptoms, presenting with left-sided mydriasis and a coma. An emergency computed tomography scan revealed pneumocephalus ([Fig. 1A] and [B]). Review of the intraprocedural imaging was then conducted. We noted that the pancreatic duct guidewire, after navigating the neck of the pancreas, had aberrantly protruded downwards ([Fig. 2]). The multidisciplinary team subsequently ruled out other potential etiologies. They concluded that the most likely cause was iatrogenic CO₂ migration into the cranial cavity through an enterospinal fistula, a tract created by the initial puncture injury. Fortunately, the patient showed a full neurological recovery, regaining consciousness after 4 days with no lasting deficits. This case represents the first reported instance of pneumocephalus following an ERCP procedure.

Fig. 1 Point bubble and patchy air shadow in the bilateral pterygoid process, pterygoid muscle,(A) bilateral parapharyngeal space,(B) mandibular ramus, and left submandibular area.

Fig. 2 After the guidewire passed through the duodenal papilla, the pancreatic duct guidewire, after navigating the neck of the pancreas, had aberrantly protruded downwards.

Practical Implications for Endoscopists

• Be aware that pneumocephalus, while extremely rare, is a potential life-threatening complication of ERCP.

• While CO₂ insufflation is preferred for its rapid absorption and reduced discomfort, careful monitoring of insufflation pressure is crucial for preventing complications.[1] In this case, although we had strictly controlled the CO₂ flow pressure below 0.4 MPa, pneumocephalus still occurred inevitably.

• The primary preventive measure is to operate with extreme caution when advancing the guidewire to avoid aberrant protrusion outside the pancreatic duct wall, particularly in the pancreatic neck area. Excessive force can create a puncture injury that may lead to unusual fistulous tracts allowing CO₂ migration.[2]

Conflict of Interest

None declared.

• References

• 1 Shi H, Chen S, Swar G, Wang Y, Ying M. Carbon dioxide insufflation during endoscopic retrograde cholangiopancreatography: a review and meta-analysis. Pancreas 2013; 42 (07) 1093-1100
• 2 Schömig B, Seliger C, Schulte-Mattler W. et al. Clinical reasoning: pneumocephalus and pneumorrhachis in a 67-year-old man. Neurology 2016; 86 (21) e218-e221

Publication History

Article published online:
31 October 2025