Contralateral “Keyhole” Endoscopic Surgery

Abstract

Spinal stenosis is the most common disorder of the lumbar spine in elderly patients (Deyo et al., Spine 18:1463–70,193). Decompressive surgery is currently the best choice in the treatment for symptomatic lumbar spinal stenosis (Weinstein et al., N Engl J Med 358:794–810, 2008). Percutaneous endoscopic decompression (PED) in progression has become a reasonable alternative to open microsurgery for lumbar spinal stenosis (Thongtrangan et al., Neurosurg Focus 16:1–10, 2004; Johnsson et al., Spine 11:107–110, 1986; Young et al., Neurosurgery 23:628–633, 1988; Sanderson et al., Bone Joint J 75:393–397, 1993; Poletti et al., Neurosurgery 37:343–347, 1995; Weiner et al., Spine 24:2268, 1999). PED has several advantages, including less paraspinal muscle injury, less postoperative back pain, and early discharge. Regarding postoperative spinal instability, however, PED surgery whether the uniportal or the biportal endoscopic technique is based on the unilateral laminectomy for bilateral decompression (so-called “over-the-top technique”). Thus the possibility of postoperative spinal instability due to extensive removal of the ipsilateral medial facet joint or the isthmus remains. A contralateral interlaminar approach is an unfamiliar method. But some microscopic tubular decompressions via a contralateral interlaminar approach for lumbar spinal stenosis or disc herniations have been reported (Niggemeyer et al., Eur Spine J 6:423–429, 1997; Ahn et al., Expert Rev Med Devices 11:605–616, 2014; Hwa Eum et al., J Neurosurg Spine 24:602–607, 2016; Komp et al., Clin Spine Surg 24:281–7, 2011; Minamide et al., J Neurosurg Spine 19:664–671, 2013; Ruetten et al., J Neurosurg Spine 10:476–485, 2009; Torudom et al., Asian Spine J 10:335–342, 2016). They emphasized that the contralateral approach procedures provided easier access to the lateral recess pathology than the ipsilateral approach, and it maintained biomechanical stability by preserving facet joints. Following the evolution of surgical instruments including development of the high-speed endoscopic drill, we can perform PED surgery via the contralateral interlaminar approach for lumbar spinal stenosis. In this chapter, we describe the technical methods of the contralateral keyhole endoscopic surgery that makes it possible to maximize preservation of facet joints and prevent segmental instability.