The patient is a middle-aged male who has experienced soreness in his coccyx, right buttock, and lower limbs for the past year, with a recent deterioration in symptoms over the past month. During a recent examination at a local hospital, giant sacral cysts were detected. Following the advice of a local physician, an appointment was arranged to consult with Dr. Zheng at his outpatient clinic.
Our preoperative magnetic resonance examination found two huge sacral cysts in the sacrum 1-3, with the left sacral cyst being larger, but the symptoms were on the right side.
Dr. Zheng carefully reviewed the film and found that although the cyst in the right sacral canal is relatively small, there is an abnormal gray signal at the cerebrospinal fluid leak (neck of the cyst), suggesting the possibility of an internal hernia of the nerve root.
Furthermore, the patient’s sacrum has undergone extensive erosion as a result of prolonged compression from the substantial sacral cyst. Consequently, there has been significant loss of both the vertebral body and laminae, with numerous areas already perforated.
After preoperative preparation, Dr. Zheng’s team performed a sacral cyst leak closure surgery under neurophysiological monitoring.
As anticipated prior to the surgery, we found that the leakage from right side sacral cyst was remarkably large. Beyond the nerve roots that traversed the area, two additional nerve roots herniated into the leakage in an M-shape and adhered severely to it. This accounts for the paradoxical presentation where despite the relatively small size of the cyst in the right sacral canal, the symptoms experienced by the patient are severe.
With neurophysiological monitoring ensuring precision, Dr. Zheng meticulously dissected the adhesion between the nerve root and the leakage under microscope. Subsequently, he repositioned the herniated nerve root back into the subarachnoid space and sealed the leakage using microsurgical suturing techniques, all without causing any harm to the nerve root throughout the procedure.
Postoperative magnetic resonance imaging showed good occlusion of bilateral sacral cysts. And titanium plates were used to repair the posterior wall of the sacral canal, avoiding bulging of the contents of the sacral canal.
The patient’s symptoms improved significantly after surgery, and they were discharged after two weeks.
Dr. Zheng emphasized that sacral cysts are not true cysts but rather cerebrospinal fluid leaks. When the leakage is substantial, the rapid influx and efflux of cerebrospinal fluid can draw nearby nerve roots into the cyst, resulting in an internal herniation of nerve roots. If numerous nerve roots herniate and become compressed at the leakage site, leading to entrapment and adhesion, the symptoms will exacerbate significantly. This mechanism is analogous to hernias in general surgery, and prompt intervention is crucial to prevent severe damage or necrosis of the nerve roots.