Minimally invasive endoscopic spinal cord untethering: case report

Surgical management of tethered spinal cord syndrome through biportal endoscopic approach: a novel technical note

This video article explores a case of tethered cord release through a minimally invasive biportal endoscopic approach. A 24-year-old female with chronic back pain and thigh numbness underwent surgery. The chosen approach involved biportal endoscopic technique, demonstrating precision with minimal bone excision. Preoperative imaging revealed a midline fusion defect at L5 and abnormal conus medullaris termination. The surgical procedure involved one-sided hemilaminectomy, durotomy, and careful filum terminale separation. Postoperatively, radiological exams confirmed success with minimal bone defect. Emphasizing minimal invasiveness, reduced bone excision, and muscle sparing, this technique showcased successful outcomes, enabling the patient's rapid postoperative recovery without complications. The video can be found here: https://stream.cadmore.media/r10.3171/2024.1.FOCVID23228.

Endoscopic spinal cord untethering using a 1 cm skin incision technique in pediatrics: a technical case report

BACKGROUND

Spinal cord untethering by sectioning the filum terminale is commonly performed in tethered cord syndrome patients with minor abnormalities such as filar lipoma, thickened filum terminale, and low conus medullaris. Our endoscopic surgical technique, using the interlaminar approach, allows for sectioning the filum terminale through a very small skin incision. To our knowledge, this procedure has not been previously reported. This is the first case report involving a 1 cm skin incision.

CASE PRESENTATION

A 9-month-old male patient was referred to our neurosurgical department due to a coccygeal dimple. MRI revealed a thickened fatty filum. After considering the treatment options for this patient, the parents agreed to spinal cord untethering. A midline 1 cm skin incision was made at the L4/5 vertebral level. Untethering by sectioning the filum terminale was performed by full endoscopic surgery using the interlaminar approach. The procedure was uneventful and there were no postoperative complications.

CONCLUSIONS

In terms of visibility and minimizing invasiveness, our surgical technique of using the interlaminar approach with endoscopy allows for untethering by sectioning the filum terminale through a very small skin incision.

Flexible thecoscopy for extensive spinal arachnoiditis

OBJECTIVE

Chronic adhesive spinal arachnoiditis (SA) is a complex disease process that results in spinal cord tethering, CSF flow blockage, intradural adhesions, spinal cord edema, and sometimes syringomyelia. When it is focal or restricted to fewer than 3 spinal segments, the disease responds well to open surgical approaches. More extensive arachnoiditis extending beyond 4 spinal segments has a much worse prognosis because of less adequate removal of adhesions and a higher propensity for postoperative scarring and retethering. Flexible neuroendoscopy can extend the longitudinal range of the surgical field with a minimalist approach. The authors present a cohort of patients with severe cervical and thoracic arachnoiditis and myelopathy who underwent flexible endoscopy to address arachnoiditis at spinal segments not exposed by open surgical intervention. These observations will inform subsequent efforts to improve the treatment of extensive arachnoiditis.

METHODS

Over a period of 3 years (2017-2020), 10 patients with progressive myelopathy were evaluated and treated for extensive SA. Seven patients had syringomyelia, 1 had spinal cord edema, and 2 had spinal cord distortion. Surgical intervention included 2- to 5-level thoracic laminectomy, microscopic lysis of adhesions, and then lysis of adhesions at adjacent spinal levels performed using a rigid or flexible endoscope. The mean follow-up was 5 months (range 2-15 months). Neurological function was examined using standard measures. MRI was used to assess syrinx resolution.

RESULTS

The mean length of syringes was 19.2 ± 10 cm, with a mean maximum diameter of 7.0 ± 2.9 mm. Patients underwent laminectomies averaging 3.7 ± 0.9 (range 2-5) levels in length followed by endoscopy, which expanded exposure by an average of another 2.4 extra segments (6.1 ± 4.0 levels total). Endoscopic dissection of extensive arachnoiditis in the dorsal subarachnoid space proceeded through a complex network of opaque arachnoidal bands and membranes bridging from the dorsal dura mater to the spinal cord. In less severely problematic areas, the arachnoid membrane was transparent and attached to the spinal cord through multifocal arachnoid adhesions bridging the subarachnoid space. The endoscope did not compress or injure the spinal cord.

CONCLUSIONS

Intrathecal endoscopy allowed visual assessment and safe removal of intradural adhesions beyond the laminectomy margins. Further development of this technique should improve its effectiveness in opening the subarachnoid space and untethering the spinal cord in cases of extensive chronic adhesive SA.

Congenital Spinal Lipomatous Malformations. Part 2. Differentiation from Selected Closed Spinal Malformations

BACKGROUND

Congenital spinal lipomatous malformations (spinal lipomas, lipomyeloceles, and lipomyelomeningoceles) are closed neural tube defects over the lower back. Differentiation from some other closed neural tube defects in this region can be problematic for pathologists.

MATERIALS AND METHODS

This review is based on PubMed searches of the embryology, gross and histopathologic findings, and laboratory reporting requisites for retained medullary spinal cords, coccygeal medullary vestiges and cysts, myelocystoceles, true human vestigial tails, and pseudotails for comparison with congenital spinal lipomatous malformations.

RESULTS

Embryology, imaging, gross and histopathology of these closed neural tube lesions have different but overlapping features compared to congenital spinal lipomatous malformations, requiring context for diagnosis.

CONCLUSION

The lipomyelocele spectrum and to some degree all of the malformations discussed, even though they may not share gross appearance, anatomic site, surgical approach, or prognosis, require clinical and histopathologic correlation for final diagnosis.

Use of an endoscope for spinal intradural pathology

The endoscope has been increasingly used to treat various spinal diseases. However, the application of spinal endoscopy in an intradural lesion has been less common compared to that of an epidural counterpart. The authors reviewed existing literature describing spinal endoscopy as an aid in surgical treatment for intradural pathologies. Importantly, available literature indicated the safety and feasibility of spinal endoscopy for intradural lesions. Especially, an endoscope was utilized for intradural subarachnoid cystic lesions, tethered cord syndrome, extramedullary tumors, spinal arteriovenous malformations, and cordectomy for intractable pain. The results of this review should enhance further development and broaden application of an endoscope for various intradural pathologies.

Congenital Spinal Lipomatous Malformations. Part 1. Spinal Lipomas, Lipomyeloceles, and Lipomyelomeningoceles

Background: Lumbosacral spinal lipomas and lipomyeloceles are usually identified in early childhood. Terminology, histopathology, and diagnosis for these malformations can be confusing. Materials and Methods: This is a PubMed review with comparison of embryology, gross, and histopathology, and reporting requisites for these and related closed spinal malformations. Results: The spinal lipoma group (congenital spinal lipomatous malformations) includes subcutaneous, transdural, intradural, and noncontiguous malformations stretching through the entire lower spinal region. This lipomyelocele trajectory overlaps the embryonic tail's caudal eminence. Histopathologically, the lipomyelocele spectrum is a heterogeneous, stereotypical set of findings encountered from dermis to spinal cord. Diagnosis requires detailed correlation of images, intraoperative inspection, and histopathology. Conclusions: Appropriate terminology and clinicopathologic correlation to arrive at a diagnosis is a critical activity shared by pathologist and clinician. Prognostic and management differences depend on specific diagnoses. Familial and genetic influences play little if any role in patient management in closed spinal malformations.

A Transforaminal Endoscopic Surgical Technique for Treating Lumbar Disc Herniation in the Setting of Spina Bifida

Recent literature suggests that adult patients with spina bifida receive surgery for degenerative disc disease at higher rates than the general population. However, sometimes the complex anatomic features of co-occurring spina bifida and lumbar disc herniation can significantly challenge standard surgical techniques. Here, the technical steps are presented for treating a foraminal lumbar 4-5-disc herniation in the setting of a patient with multifaceted degenerative and spina bifida occulta anatomy. Utilized is a minimally invasive approach that does not require general anesthesia or fusion and allows the patient to leave the same day. To the best of our knowledge, this is the first-reported case of endoscopic surgical decompression of a lumbar disc in a patient with spina bifida.

The benefit zone of full-endoscopic spine surgery

Minimally invasive spine procedures have undergone rapid development during the last decade. Efforts to decrease muscle crush injuries during prolonged retraction, avoid significant soft tissue stripping and minimize bony resection are surgical principles that are employed to prevent iatrogenic instability and provide patients with decreased post-operative pain and disability. Full-endoscopic spine surgery represents a tool for the spine surgeon to provide targeted access to spinal pathology utilizing these principles. Endoscopic techniques have seen over 30 years of evolution and innovation, however, early iterations of these techniques largely focused on transforaminal lumbar microdiscectomies. Currently, endoscopic techniques are utilized for approaching pathology in the cervical, thoracic and lumbar spine. There has been a growing body of literature that not only confirms the efficacy of these procedures but also underscores the advantages these procedures offer with respect to less morbidity and safer complication profiles. Endoscopic decompressions have been utilized in the settings of degenerative spinal stenosis, spondylolisthesis, scoliosis, previous fusion, tumor and infection. Furthermore, endoscopic interbody fusion has also been utilized in the lumbar spine as technology continues to advance. As technological innovation continues to facilitate reproducible surgical technique and expand the indications for use, we believe that endoscopic spine surgical techniques will provide surgeons with a more powerful and less morbid approach to spinal pathology that ultimately elevates the standard of care when treating our patients. We present a brief review of the history of endoscopic spine surgery, an overview of current techniques and review current outcomes of endoscopic spine surgical procedures in the context of an invasiveness/complexity index to elucidate the benefit zone of these newer techniques.

Minimally Invasive Surgical Approach to Filum Lipoma

Filum terminale lipoma (FTL) causes various spinal symptoms known as tethered cord syndrome. The treatment for FTL is surgical untethering by sectioning the FTL, which can prevent symptom progression and often results in improvement of symptoms. This report describes a minimally invasive surgical strategy that we have introduced for FTL sectioning. The pediatric patients with FTL since 2007 were treated using this minimally invasive surgical strategy, which we refer to as an interlaminar approach (ILA). In summary, the surgical technique involves: minimal skin incision to expose the unilateral ligamentum flavum in the lower lumbar region; ligamentum flavum incision to expose the dural sac, and dural incision followed by identification and sectioning of the filum. Postoperatively, no bed rest was required. Prior to introducing ILA, we had used standard one level laminectomy/laminotomy (LL) with more than 1 week of postsurgical bed rest until 2007, providing an adequate control group for the benefit of the ILA. A total of 49 consecutive patients were treated using ILA. While 37 patients were treated using LL. Surgical complications that need surgery were seen only in one patient, who developed cerebrospinal fluid (CSF) leak in LL patients. No retethering or additional neurological symptoms were seen during follow-up. All patients complained of minimal postsurgical back pain, but no patients required postoperative bed rest in ILA patients, while LL patients need postsurgical bed rest because of back pain. The ILA strategy provides the advantage of a minimal tissue injury, associated with minimal postoperative pain, blood loss, and bed rest.