Image Guided Spine Interventions

Abstract

This book is written by an interventional radiologist. His preface states that interventional radiology is under considerable pressure as cardiology and vascular surgery appropriate existing vascular interventions, and interventional radiologists need to be looking constantly for new procedures to replace this loss. This book has therefore been written about spine intervention procedures that are possible rather than necessary or even desirable. In Chapter 2, the author discusses corticosteroids for use in spine interventions, including depo-medrol (depomedrone, methylprednisolone), and especially the epidural controversy, but makes no comment on the product data sheet that specifies that it is not for spinal use. Chapter 3 discusses the assessment of the chronic pain patient. This is by necessity oversimplified, including as it does a very physical approach using all investigational approaches, and diagnostic nerve blockade, before considering the psychological assessment. This chapter also includes treatment, including discussion of ‘therapeutic’ neural blockade. Steroids are again pushed as being safe and effective in epidurals for radiculopathy, but no evidence is cited, not even the current evidence that epidural steroid injections can be useful in the short term, although less often in the longer term. The discussion of image-guided therapy in relation to surgical management does become evidence-based, and points out that success rates for fusion are variable, 46% rising to 96% if fusion is sound. This highlights the problem of such surgery. Similar discussion leaves the role of facet blockade uncertain when considering surgical procedures, but does suggest that facet denervation might be a viable treatment. Similarly, no convincing study demonstrates the ability of conventional surgery such as lateral recess decompression or foraminotomy to treat referred pain reliably diagnosed on the basis of selective nerve root blocks. Again, the efficacy of intradiscal therapy remains to be proven. Vertebroplasty is considered to be a reasonable method to treat symptomatic vertebral compression fractures that have failed to respond to time-limited conservative care. The common sense shown in this chapter is laudible, and Todd Wetzel and Frank Phillips are to be congratulated. They conclude that a diagnostic test must be sensitive, specific, and reproducible, and in many such tests their very nature precludes the achievement of full sensitivity. They state that ‘the exercise of compassionate restraint may be the greatest challenge facing clinicians today’. Various procedures are specifically described in individual chapters, including image-guided percutaneous spine biopsy, discography, intradiscal electrothermal annuloplasty, and automated percutaneous lumbar discectomy. Epidural steroid injections and selective nerve blocks are again described, but selection is vague. It appears to be offered for any neck or back pain, not purely for radicular pain, despite the lack of evidence of efficacy for back pain. The references quoted for efficacy in back pain are in fact for sciatica, not back pain. Diagnostic epidurography and therapeutic epidurolysis are similarly discussed. Further procedures covered are facet joint injections, autonomic nerve blockade, sacroiliac joint injection, percutaneous vertebroplasty, implanted drug delivery systems, endovascular therapy of the spine, epidural blood and fibrin patches, balloon kyphoplasty, and intradiscal oxygen-ozone in the treatment of herniated lumbar disc. This book is therefore essential reading for the interventional radiologist looking to keep in employment as he loses procedures to cardiologists and vascular surgeons. It will be of interest to interventional pain specialists, as a ‘how to do it’ manual with excellent illustrations, and to warn them to guard their territory against interventional radiologists. The critical interventionalist will appreciate the illustrations and the techniques described, but will be disappointed in the evidence presented, and the lack of a critical approach.