ObjectiveTo summarize the experience in management of occult cerebrospinal fluid leakage (CSFL) in posterior thoracolumbar surgeries, and to explore the best drainage duration, as well as to analyse the ways to reduce the risk of CSFL. MethodsA retrospective analysis was made on the clinical data of 26 patients with occult CSFL in posterior thoracolumbar surgeries between January 2011 and January 2013. There were 15 males and 11 females, with the average age of 48.7 years (range, 36-59 years). Headache occurred in 19 cases, and 5 cases had nausea with 3 cases also having vomiting after operation. Drainage tube unobstructed and no CSFL from the skin incision were observed in 23 cases at the postoperative 2nd day, and the drainage pipe clamp test was performed at the 3rd day. Twenty-one patients had no CSFL and were given extubation; 2 cases having CSFL were given extubation after conservative treatments for 10 days. Three patients had CSFL with ineffective conservative treatments at the postoperative 2nd day, then received reoperation, incision suture, and drainage. At the postoperative 3rd day, if no CSFL was observed, these patients were given extubation and stayed in bed for 3-5 days. ResultsAll incisions healed and the healing time was 7-15 days (mean, 8 days). No incision infection, persistent CSFL, and other complications occurred. After extubation, headache, nausea, vomiting, and other symptoms were alleviated immediately. All patients were followed up 12-24 months (mean, 16 months). MRI at the postoperative 6th month showed no subcutaneous epidural pseudocyst. ConclusionThe quality of suturing is the key factor to prevent occult CSFL in posterior thoracolumbar surgery. Under the premise of good suture quality, extubation can be given at the postoperative 3rd day. Before extubation, the drainage pipe clamp test can be performed to make sure no CSFL and to reduce the risk of CSFL from the surgical incision after extubation.