Gas accumulation in the spinal canal: a systematic review and a novel CT-based classification

This systematic review aims to further explore the relationship between image and clinical features of spinal gas accumulation, propose a novel clinical classification based on CT images and clinical outcomes of surgical treatment and provide insights for new therapeutic strategies.

Studies with data on gas accumulation in the spinal were retrieved by searching PubMed, Embase, and Web of Science from inception to August 20, 2023, and screened following the PRISMA guidelines. Characteristic information, CT and MRI morphologic features, and surgical results of patients with gas accumulation in the spinal were reviewed, and patients were categorized according to preoperative CT findings.

A total of 41 articles were retrieved from the works of literature, including 53 patients with complete data. Among them, there were 29 males (59.70%) and 24 females (40.30%), with an average age of 65.8 years. We identified four types of gas accumulation in the spinal: Pseudocyst as pure gas (TypeI) with 34 cases (64.1%), Air cyst as epidural gas with a thin wall (TypeII) with 7 cases (13.2%), Air-contained disc herniation as epidural gas with disc herniation (Type III) with 3 cases (5.7%), intradural type (Type IV) with 9 cases(17.0%). 25 patients with Type I underwent non-conservative treatment and mild adhesions were observed in three patients. Adhesions were observed in 5 of the 6 Type II patients treated operatively. No adhesion was observed in three Type III patients. Adhesion was observed in 4 of 9 Type IV patients.

Gas accumulation in the spinal canal is a common clinical disease, which can be identified by CT and MRI. The classification based on CT scans helps guide clinical treatment.