Risk factors of the cerebrospinal fluid leakage after posterior circumferential decompression for thoracic ossification of posterior longitudinal ligament

English Keywords:Cerebrospinal fluid leakage  Circumferential decompression  Ossification of posterior longitudinal ligament  Thoracic  Risk factors

English Abstract:

  【Abstract】 Objectives: This study aimed to retrospectively evaluate the related risk factors of the cerebrospinal fluid leakage after posterior transarticular osteotomy and circumferential decompression for thoracic ossification of posterior longitudinal ligament(OPLL). Methods: A total of 50 patients with thoracic OPLL underwent posterior transarticular osteotomy and circumferential decompression from August 2015 to December 2019, including 26 males and 24 females. The age ranged from 27 to 82 years old, with an average age of 53.0±13.3 years. The patients were divided into CSLF group and non-CSFL group according to whether they suffered cerebrospinal fluid leakage. The incidence and outcomes of CSFL was analyzed, and to compare the demographic characteristics，radiological and surgical data between CSFL group and non-CSFL group. the risk factors were obtained according to the multivariate Logistic regression analysis used indexes with statistic differences. Results: All patients underwent surgery. The operation time was 80-354min, average operation time was 173.7±68.7min. The mean blood loss was 1019.8±746.3ml(range 50-3500ml). There were 14 patients(28%) underwent CSFL postoperatively, including 6 males and 8 females, with an average age of 49.4±11.8 years. There were statistical differences in smoking history, number of laminectomy, segment of circumferential decompression, ossification of ligamentum lavum(OLF), Occupying ratio, base ratio of OPLL between CSFL group and non-CSFL group(P<0.05). Multivariate Logistic regression analysis showed that smoking history, segment of circumferential decompression and base ratio of OPLL were risk factors for CSFL. The probability of CSFL in smokers was 43.8 times that of non-smokers. The incidence of CSFL was 21.9 and 33.1 times higher if the circumferential decompression were underwent at the upper and middle thoracic than that at the lower thoracic, respectively. Besides, the ratio of OPLL base(OR=1.09, P=0.012) could be risk factors for CSLF. Conclusions: Smoking history, upper and middle thoracic circumferential decompression and broad-based OPLL are risk factors for postoperative CSFL. If any of these factor exist in patients, surgeons need to pay more attention to protecting the dural sac to prevent postoperative cerebrospinal fluid leakage.