Intradural disc herniation at the L1-2 level

Background: Intradural disc herniations (IDHs) are rare, are difficult to diagnose on preoperative MR/CT imaging, and typically, are most readily confirmed at the time of surgery. However, one of the greatest challenges posed by these lesions, is the repair of the ventral dural rent. Case Description: A 55-year-old male with a 20-year history of lumbago presented with low back pain and right lower extremity sciatica of 3 months’ duration. The MR and CT studies showed a compressive lesion at the L1-2 level. There was no original suspicion that this was an IDH. At surgery, performed under the operating microscope, a subtotal L1-L2 laminectomy was performed (i.e. while lysing severe adhesions between the posterior longitudinal ligament and the ventral dura, a traumatic durotomy occurred. White, spongious, friable, soft tissue, and free-floating disc fragments extruded through the durotomy site. Notably, it was initially considered to be a tumor rather than a disc. Once all fragments had been delivered, unsuccessful attempts were made to repair the ventral dura. Further efforts were curtailed due to concern that they would result in damage to multiple ventral nerve rootlets. Despite the lack of primary dural repair, the secondary measures resulted in no postoperative recurrent cerebrospinal fluid leakage (CSF) and a smooth postoperative surgical course. Conclusion: IDH at the L1-2 level is rare, and preoperative MR/CT studies may not always document their intradural location. Ideally, ventral dural tears attributed to these lesions should be directly repaired and/or managed with additional adjunctive CSF leak repair techniques (i.e. muscle patch grafts, microfibrillar collagen, and fibrin sealants).

Intradural Dorsolumbar Disc Herniation: Case Report and Literature Review

Intradural disc herniation is a rare entity, representing between 0.26% and 0.30% of all herniated discs. 92% of cases occur in the lumbar spine, more frequent at the L4-L5 level. The diagnostic and therapeutic conduct performed in a 61-year-old male patient who came to the office with a one-year and six-month history of dorsolumbar pain is described, accompanied by sensory alterations in the lower limbs. In view of the exacerbation of symptoms, a simple magnetic resonance study was performed, observing an intraspinal, intradural, extramedullary lesion at the D12-L1 space. An intradural disc herniation is suspected.After being evaluated the case in the group of Neurosurgeons (Group of Spinal Surgery) of the Institute of Neurology and Neurosurgery of Havana, it is proposed to carry out surgical treatment, which consisted of the extraction with microsurgical technique of the Herniated disc, preserving the vertebral anatomy through the laminoplasty technique, an open book variant. The patient evolved satisfactorily after three months of follow-up. It is concluded that intradural disc herniation should be included among intradural, extraxial lesions of the spine. By means of the magnetic resonance study, a group of imaging signs that support the preoperative diagnosis of this lesion can be described. Surgery is the definitive therapeutic method and allows an accurate diagnosis of spinal herniation to be established.

Posterior Transdural Approach for a Calcified Thoracic Intradural Disc Herniation Using a 3-Dimensional Exoscope: 2-Dimensional Operative Video

This video depicts the removal of an intradural thoracic disc herniation through a purely transdural approach. Thoracic disc herniations are rare, and less than 5% are intradural. Though thoracic disc herniations are removed through a posterolateral or transthoracic corridor, there is literature to support a transdural approach for central herniations.1-3 Although the transdural approach has been selectively adopted for central soft herniations, calcified herniations have been regarded as less suitable.1,2 Intradural thoracic herniations have not been specifically addressed by a transdural approach in the limited literature, though it has been utilized in conjunction with a larger transthoracic approach.4 Our case features a 72-yr-old female presenting with worsening left leg weakness. Computed tomography (CT) identified a multilobulated ventral calcified mass at T11-12. Magnetic resonance imaging was not possible because of an incompatible pacemaker. Our impression was that this likely represented an intradural meningioma though a calcified intradural disc herniation was considered. Given the apparent intradural location, we opted for a transdural approach only via T11-12 laminectomy and a midline dural opening. Dentate ligament sectioning allowed a clear corridor to the now apparent disc material. Postoperative CT confirmed near complete resection, and the patient showed neurological improvement. Ultimately, the transdural approach alone led to complete discectomy while avoiding the morbidity of an invasive transthoracic approach and instrumented fusion. To our knowledge, this is the first video documenting a purely transdural approach for resection of an intradural disc herniation. The patient consented to the surgical procedure and to the use of intraoperative video for education purposes.

Case report of a cervical myelomalacia caused by a thoracolumbar intradural disc herniation leading to intracranial hypotension

A 50-year-old patient was admitted with symptoms of intracranial hypotension. MRI revealed a cervical myelomalacia caused by engorged epidural veins leading to a stenosis of the spinal canal. This condition is rarely described in patients with hydrocephalus and ventricular shunts suffering from chronic overdrainage. However, the reason in this patient was a CSF leak caused by an intradural disc herniation at T12/L1. After surgery, symptoms resolved and the cervical myelomalacia and the swollen epidural veins disappeared on postoperative MRI. In patients with engorged cervical epidural veins without a ventricular shunt, a CSF leak has to be considered.