The role of endoscopic surgery in the treatment of painful conditions of an ageing spine: State of the art

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Comment by Anthony T YeungThe major gap between fusion-oriented spinal surgeons and pain management physicians is bridged by endoscopic spinal surgeons. Current surgical philosophy by traditionally-trained spinal surgeons focuses on fusion as the ultimate “cure” for a painful spinal segment caused by instability, while pain management uses techniques such as neuromodulation to relieve pain. Endoscopic surgery—the least invasive of current minimally invasive options—offers a path between traditional surgical fusion and the less invasive techniques of pain management, writes Anthony T Yeung.

Fusion has evolved throughout its history, with new concepts changing every few years since the pedicle screw revolution for instrumented stabilisation. Current emphasis is on attaining sagittal alignment—another phase in the evolution of fusion techniques. For pain management, current focus is on injection techniques, radiofrequency rhizotomy, neuromodulation of the spinal cord and, more recently, neuromodulation of the dorsal root ganglion as a salvage technique following failed back surgery syndrome.

Endoscopic surgeons support “full endoscopic” decompression procedures as the least invasive of the surgical trends promoting minimal invasiveness in spinal surgery.

Transforaminal decompression is still undervalued and underutilised because formal training in academic centres is lacking, and advancements have mainly been made in private practice settings which compete with traditionally-trained surgeons. Some surgeons have adopted translaminar endoscopic decompression due to the greater familiarity with the translaminar approach. The transforaminal approach has advanced significantly for experienced endoscopic surgeons; as many as 80–90% of painful degenerative conditions can now be treated transforaminally.

The current healthcare environment in the USA aims to stem the escalating cost of spine care to government and insurance payers. Payers tend to prioritise cost management, rather than what may be the most effective treatment for a particular patient.

Payment is increasingly governed by guidelines developed by each payer and stakeholder using evidenced-based medicine (EBM) through Level I and II validation. Each stakeholder focuses on EBM studies to dole out shrinking reimbursement. Treatment decisions can become more dictated by EBM studies, struggles for complex payment codes, and the “reimbursement game”, than by the most effective and least invasive treatment of the patient’s pain.

All competing factions need new directions, with cooperation between physicians and other healthcare providers. We all need to be aware of each other’s contributions as a multidisciplinary team. Specialties need to coordinate care in cooperation with each other, or there could become a need for competing providers to warranty their procedures, much like consumer products are warrantied.

Our response to the individual needs of our patients can be restricted by the use of guidelines that limit payments, and therefore physicians’ autonomy to treat our patients for their individual needs. By focusing on the patho-anatomic source of pain by endoscopic visualisation, surgical pain management of pain is a viable treatment option validated in open-access peer-reviewed publications.1 The treatment algorithm in spine is evolving and changing due to a better understanding of the patho-anatomy, well-correlated with its pathophysiology. I have written about my own evolving technique in publications including a series of articles in Surgical Technology International.2

Richard Wolf’s articulated burr in foraminoplasty cannula

Pain is better understood with in vivo visualisation and probing of the pain generators using endoscopic transforaminal access, rather than just relying on a symptom diagram and image correlation.3 This culminates in a shared decision-making process involving patient and surgeon, focused on a broader spectrum of surgical as well as non-surgical treatments, and not just masking the pain generator.

Transforaminal endoscopic decompression, irrigation, and ablation have moved away from decisions based on imaging confirmation alone. Image abnormalities cannot, by themselves, explain the pain and disability experienced by each individual patient. Images do not always show variations in nerve supply and patho-anatomy, nor do they quantify the pain experienced by a patient.

The ability to isolate and visualise “pain” generators in the foramen, and to treat persistent pain by visualising inflammation and compression of nerves, serves as the basis for transforaminal endoscopic (TFE) surgery.3,4 This has also resulted in better pre-surgical planning with more specific and defined goals in mind.

There are various surgical philosophies and techniques proposed by other pioneers in endoscopic surgery, but I choose to embrace the “inside out” philosophy of TFE surgery as safe and precise in well-trained surgical hands. It provides basic access to the disc and foramen that cover a large spectrum of painful pathologies with the least surgical risk.

Yeung’s preoperative MRI
The author’s preoperative MRI

My own experience with the endoscopic approach for spine began in 1991, when I took an arthroscopic spinal surgery course taught by Parviz Kambin (Philadelphia, USA). With extensive personal experience in joint arthroscopy, I began using the endoscope to explore intradiscal and foraminal anatomy, and studying Rauschning’s cadaver cryo-anatomy. It seemed natural to me to utilise the endoscope to examine patho-anatomy in the spine. I quickly decided to visualise the epidural space through the foramen with the “inside out” technique to obtain confirmation that the spinal nerves were decompressed.

In 1991, the laser was introduced for the lumbar spine, and I became a fan of the tool under endoscopic visualisation, because it had the tissue effect of decreasing bleeding, and ablating soft tissue and bone through a 6mm working cannula with a 2.8mm working channel scope. This experience caused me to develop my own endoscopic system in conjunction with Richard Wolf’s surgical instrument system. In 1997 the Yeung endoscopic spine system (YESS) was cleared by the US Food and Drug Administration (FDA) and marketed in the USA.

I have not deviated from this surgical philosophy since then, except to evolve the technique, aided by the recognition of spinal patho-anatomy. I have customised my surgical instrumentation to facilitate decompression, ablation, and irrigation of the pain generator; documented patho-anatomy identified by the endoscope, and monitored the effect by probing, decompression, ablation or transection.

Yeung’s postoperative MRI
The author’s postoperative MRI

My original endoscope design is still the state-of-the-art configuration for intradiscal therapy, where the degenerative process begins. It has been reproduced to some extent in designs of other endoscope manufacturers. As the procedure evolved, different scope sizes, designs and working channels have been augmented by better endoscopic instrumentation and modified approach techniques. Instruments have evolved to make endoscopic spinal surgery a staple of the surgical treatment of the future.

The author immediately following surgery
The author immediately following surgery

I end with a personal account of my own spinal condition, which had deteriorated rapidly over the past five years. True to my career-long focus on treating pain generators with transforaminal endoscopic surgery, I underwent the surgery I had helped develop, performed by my son, Chris Yeung, an associate at our group practice.

With the current interest in biologics, we are destined to improve spine care by moving away from fusion as a first-line surgical treatment because of the techniques available in the endoscopic platform. To attain this level of surgical expertise, appropriate training is paramount for the efficacy of the technique as described—this is not a “see one, do one” procedure.

Anthony T Yeung is a spinal surgeon at the Desert Institute for Spine Care, Phoenix, USA, a volunteer professor at the University of New Mexico School of Medicine, Albuquerque, USA, and the executive director of the International Endoscopic Therapy Spine Society.

References

1. Yeung AT, Gore SR. In-vivo Endoscopic Visualization of Patho-anatomy in Symptomatic Degenerative Conditions of the Lumbar Spine II: Intradiscal, Foraminal, and Central Canal Decompression. Surgical Technology International 2011; XXI: 299–319

2. Yeung et al, various articles, Surgical Technology International 1999–2011; VIII, XI, XV, XXI editions.

3. Yeung AT, Gore SR. Evolving methodology in treating discogenic back pain by Selective Endoscopic Discectomy (SED) and thermal annuloplasty. Journal of Minimally Invasive Spinal Technique 2001; 1:8–16.

4. Gore SR, Yeung AT. Identifying sources of discogenic pain. Journal of Minimally Invasive Spinal Technique 2003; 3(1): 21–24.

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