Surgical Technique for Percutaneous Endoscopic Laser Annuloplasty/Nucleoplasty

6 Surgical Technique for Percutaneous Endoscopic Laser Annuloplasty/Nucleoplasty

Akarawit Asawasaksakul and Gun Choi

6.1 Introduction

Diskogenic pain is one of the most difficult back pains to distinguish by clinical symptoms. The pathophysiology of diskogenic back pain involves granulation tissue ingrowth into the disk space via an annular defect (fissure, tear, or cleft) resulting from either degenerative disease or trauma. The granulation tissue results in angiogenesis, free nerve ingrowth, and a chronic intradisk inflammatory process that irritates free nerve endings in the area.1,2 There are many procedures for coping with disk-ogenic pain, such as fusion surgery or total disk replacement, but since the advent of minimally invasive techniques, there are more options.

The era of intradiskal treatment began in 1975 when Hijikata et al reported on percutaneous posterolateral intradiskal nucleotomy for indirect nerve root decompression³ and advanced again in 1983 with Kambin et al’s report on the outcome of percutaneous lateral diskectomy of the lumbar spine.⁴ The nonvisualized methods continued to be developed by many surgeons,^5,6,7,8 but after the introduction of the endoscope, many spine surgeons applied and developed the use of endoscopic spinal treatment, including Kambin et al, who used the arthroscope for microdiskectomy in 1997;⁹ Yeung et al, who introduced transforaminal endoscopic decompression in 2002;^10,11 and Choi et al, who introduced percutaneous endoscopic diskectomy via the interlaminar approach in 2005.¹² This led to the concept of using endoscopic procedures to treat diskogenic back pain by direct visualization of the inflammation and annular defect, nucleoplasty to manage inflammation, and annuloplasty to narrow the annular defect.

In 2002, Yeung et al introduced thermal discoplasty and annuloplasty using the YESS endoscope via a transforaminal approach;¹¹ they were followed in the same year by Tsou et al’s description of the surgical technique for posterolateral transforaminal diskectomy and annuloplasty for chronic lumbar diskogenic back pain¹⁰ and in 2010 by Lee’s introduction of the use of laser for nucleoplasty and annuloplasty (Video 6.1).¹³

6.2 Diagnosis

There are many causes of low back pain, such as mechanical instability, intervertebral disk pathology, facet joint pain, neurogenic pain, and miscellaneous causes,¹³ but usually 40% of low back pain is diskogenic.¹⁴ The clinical challenges with diskogenic back pain start with how to make the most accurate diagnosis with the least invasive method. As is well known, the characteristics of diskogenic back pain include sitting intolerance, difficulty in lifting heavy objects, extension catch, increased pain after a hard working day, and loss of ability to maintain a posture for 30 minutes, but all of these symptoms are mostly nonspecific. Because of this, MRI and provocative diskography are very helpful diagnostic tests for diskogenic back pain.

MRI can show an annular defect on both T1 and T2, and it can show thickening of the posterior portion of the annulus and the disk trapped inside the defect. The HIZ (high intensity zone) is also a helpful finding in T2 MRI (Fig. 6.1). If the characteristics of the pain and the MRI findings correlate, the diagnosis can be confirmed using provocative diskography.¹⁵ During diskography, a sharp, shooting pain is present upon injection at the pathologic level due to the increase in intradiskal pressure that stimulates the nerve endings. Furthermore, dye leakage from the annular defect can be found. If the symptoms of the back pain are clearly established, diskography can be done in the same setting with the percutaneous endoscopic laser annuloplasty/nucleoplasty. The important thing about provocative diskography is that the examiner also obtains a normal reference from a normal disk level (Table 6.1).

Fig. 6.1 (a,b) High intensity zone (HIZ), annular defect. (c,d) Annular defect.

Table 6.1 Summary of investigation findings

Diagnostic Tool	Positive Finding
Clinical symptoms	Sitting intolerance Difficulty lifting heavy objects Extension catch Increased pain after hard working day Loss of ability to maintain posture for 30 minutes
MRI	Annular defect with both T1 and T2 imaging Thickening of posterior annulus HIZ (high intensity zone) on T2 imaging
Provocative diskography	Positive with sharp, shooting pain