The Role of Minimal Invasive Split Laminotomy, the Alternative Parasplit Approach and the “Arch bone” Technique in Surgical Removal of Axial Longitudinal Pathologies in the Spinal Canal

Conventional approaches to open the spinal canal carries the risk of spinal deformities, instability, subluxation, and invariably separate the muscle attachments from the spinous processes and laminae. Damage to these muscles and bony connections can lead to persistent axial pain and cervical malalignment. With the aim of preserving and reconstructing the posterior structures, the authors developed a novel minimal invasive multilevel spinous process splitting and distraction laminotomy approach, the “arch bone” and the additional rescue parasplit technique.Patients and Methods These novel techniques were used in 70 adult patients with mainly midline located intramedullary pathologies of the cervical, thoracic, and thoracolumbar spine. All muscle attachments on the spinous processes and laminas, as well as the laminas themselves, were completely preserved. With the aim of moderate enlargement of the spinal canal, a spacer was placed between the bony parts facing each other in case of total resection of an intramedullary tumor was not possible. When midline splitting is not feasible or convenient because of anatomical differences of the spinous processes and laminas, we used the parasplit approach. The patients were followed with regular MRI, CT scans, fluoroscopy, and neurological examinations.Results The midline opening of the spinal canal gave a key-hole approach, achieving an adequate view of the intraspinal space for surgery in its entire longitudinal extension. The approach used did not affect the extent of resection proved by MRI evaluation or neurological outcome. The numbers of splitted laminae were 3 to 10. The incidence of postoperative local pain was lower, within acceptable limits (VAS: 2–4). The average length of hospital stay was 6.7 days. Average follow-up was 58 months. Instability and deformity was detected in none of the patients on the flexion–extension lateral radiographs during the follow-up period.Conclusion These surgical approaches suitable for exploring and removing different intramedullary pathologies, help in preventing damage to crucial posterior stabilizers of the spine. Its major advantage is that unnecessary exposure and tissue trauma is reduced, and structures not directly involved in the pathologic process are preserved. In contrast to conventional spinal canal approaches, leaves the muscle attachments intact, disintegration of vertebral arches and facet joints is reduced. Furthermore, these techniques are suitable methods for all spinal segments in all age group. Although the clinical and radiological results are very promising, the limited follow-up period precludes conclusions regarding the long-term results of the procedure, especially with respect to kyphotic deformity.