Interlaminar Approach

The interlaminar technique uses a posterior approach and accesses the epidural space through the interlaminar window. This is essentially the same approach used in open and microdiscectomy procedures, except with significantly less tissue disruption. The skin is incised and the muscle dilated just enough for the passage of an 8 mm working sleeve. Likewise, resection of the laminae, if necessary, and incision of the ligamentum flavum, are significantly reduced when using the endoscope.

The interlaminar approach provides direct access to central and paracentral herniations, as well as the medial facet to address lateral recess stenosis. The interlaminar approach especially facilitates access to the L5-S1 level where the interlaminar window is naturally very large and the iliac crest can obstruct the transforaminal approach. The interlaminar approach can be easily extended with additional bone resection or, when necessary, conversion to an open procedure to address remotely sequestered fragments or in the case of complications.

Technique Summary:

  • Using fluoroscopy, target the interlaminar window with the tip of the dilator
  • Incise the skin and insert the dilator and working sleeve
  • Insert the endoscope and visualize the interlaminar window and ligamentum flavum 
  • Using burrs under direct visualization, resect lamina and medial facet in order to enlarge the interlaminar window enough to allow passage of the 8 mm working sleeve
  • Resect the ligamentum flavum from medial to lateral to allow passage of the working sleeve
  • Identify the exiting nerve and retract it medially with the beveled tip of the working sleeve by rotating the sleeve
  • Identify and remove the herniation under direct visualization
  • Resect the medial facet as necessary to address stenosis