Location Distribution of Fistulas and Surgical Strategies for Spinal Extradural Meningeal Cysts: A Retrospective Analysis of 30 Cases at a Single Center

Objective

This study aimed to illustrate the features of fistula location distribution, surgical strategies, and outcomes in spinal epidural meningeal cysts (SEMCs).

Methods

The authors searched and reviewed the medical records for cases of SEMCs. Imaging features, operative reports, and media were reviewed to accurately describe the surgical techniques employed. We recorded the level and laterality of the fistula according to the operative report and the media. Consistency analysis was performed on the dominant laterality of the cyst on preoperative axial magnetic resonance imaging and laterality of the fistula in the operative media or report. When cyst and fistula lateralities were the same, they were considered consistent. Finally, the Japanese Orthopedic Association (JOA) score was used to obtain patient-reported results at each follow-up.

Results

Thirty patients with SEMCs were identified. Fistula repair was performed in all patients. Two patients experienced cyst recurrence after surgery and were repaired during the second surgery. Based on imaging findings, SEMCs mostly occurred in the thoracolumbar junction. Most of the fistulas (87.88%) were at the T12 or L1 levels. In patients with multiple adjacent SEMCs, the fistula may be at one end of the cyst rather than in the middle level of the cyst. A fistula laterality of 72.72% was consistent with cyst laterality. The JOA improvement rate was 61.84%±26.63%.

Conclusion

Most fistulas were always located at the T12–L1 level as well as the middle level of the cyst, which is always consistent with cyst laterality. In patients with multiple adjacent SEMCs, the fistula may be at one end of the cyst. Cleft closure is key to healing SEMCs.

A Single Vertebral Surgical Approach for Spinal Extradural Meningeal Cysts Spanning Multiple Vertebral Segments by Auxiliary Neuroendoscope

BACKGROUND

Spinal extradural meningeal cysts (SEMCs) are rare lesions, especially those spanning multiple vertebral segments, and the surgical strategy has remained controversial. In the present study, we have described the outcomes of 4 patients with SEMCs treated with dural defect repair alone assisted by neuroendoscopy.

METHODS

From January 2018 to January 2020, 4 patients with SEMCs spanning multiple vertebral segments had undergone single-vertebral laminectomy or hemilaminectomy.

RESULTS

The SEMCs in all 4 patients had spanned multiple vertebral segments, from T11 to L2. Using magnetic resonance imaging, the location of the dural defect was predicted correctly for 3 patients. Single-vertebral laminectomy was used in 2 patients and single-vertebral hemilaminectomy in 2 patients. Intraoperatively, the entire cyst, including the upper pole, lower pole, and middle segment of the cyst, was explored using neuroendoscopy. In each patient, only 1 dural defect was found, which had been located in the middle segment of the cyst (T12-L1). All cyst dural defects had been sutured under a microscope. In all cases, the cyst wall was not removed. Postoperatively, the symptoms for all the patients had improved significantly, and subsequent magnetic resonance imaging studies showed obvious cyst regression. During the follow-up period of 15-44 months, no recurrence was observed.

CONCLUSIONS

For SEMCs spanning multiple vertebral segments, dural defect repair without cyst wall resection through single-vertebral hemilaminectomy or laminectomy can be effective. Intraoperative neuroendoscopy can assist, not only in finding the dural defect, but also in avoiding the omission of multiple dural defects as much as possible.

Spinal extradural meningeal cyst in klippel-trenaunay syndrome

A case of a symptomatic spinal extradural meningeal cyst (SEMC) in Klippel-Trenaunay syndrome (KTS) is introduced. A 38-year-old woman presented with right L2 radiculopathy. She underwent operations for varicose veins in both her lower extremities. She had port-wine nevi on her trunk and extremities. The edematous change in both legs had waxed and waned. Magnetic resonance imaging showed an 11.8×13 mm extradural meningeal cyst growing through the intervertebral foramen in L2-3. Multiple meningeal cysts were located in the dorsal aspect of the spinal cord from T3 to T10. A 5.8×6.2 mm cyst was also found in left pleural cavity. The extradural meningeal cyst was completely excised and the preoperative symptom was improved. KTS is a congenital disorder due to a mesodermal abnormality, which may predispose the dura to weakness. The SEMC may occur through the dural defect or weakened point.