Aware State Endoscopic Laser Foraminoplasty in thr Treatment of Chronic Lumbar Spondylosis and Failed Back Surgery

Martin T.N. Knight

The Spinal Foundation, Arbury Consulting Centre, Manchester Road,

Rochdale OL11 4LZ, UK

Study Design. This study evaluates the results of Endoscopic Foraminoplasty on 250 consecutive patients followed for a minimum of 2 years, reviewed and assessed by an external independent assessor.

Objectives.

The objective has been to assess the clinical outcomes and morbidity following Spinal Probing and Discography pain source definition and their treatment by Endoscopic Laser Foraminoplasty with decompression of the foramen, mobilisation and neurolysis of the exiting and transiting nerves and ablation of osteophytes in patients with Chronic Lumbar Spondylosis (CLS) and Failed Back Surgery (FBS).

Summary of Background Data.

Recent appreciation of lumbar pain mechanisms reveals that Magnetic Resonance scans cannot reliably establish the source and cause of back pain.

This diagram depicts some of the foraminal pain sources found by aware state posterolateral endoscopy to be the site of hitherto unappreciated pain pathogenesis

 

 

The function of the foramen is a delicate balance between the size of the foraminal boundaries and the status of their contents.  This balance is easily compromised by pathology, irritation or sensitisation of tethered tissues and abnormal motion.

Since 1994 an endoscopic system has been developed to explore the intervertebral foramen and the intradiscal epidural space via the postero-lateral route.  The system has been used to address lateral recess stenosis, epidural scarring, osteophytosis, settlement, degenerate and spondylolytic olisthesis, disc extrusion and sequestration and ‘failed back syndrome’ and ‘failed back surgery syndrome’.

Outcome Study Methodology. This prospective study involved “daycase” Endoscopic Laser Foraminoplasty performed on 121 males, and 129 females with an average age of 48 years (21-86 years).  They were followed for an average period of 30 months (26-43 months).  The average preoperative duration of symptoms was 6.1 years (5 -11 years).  75 Patients had had 1 – 3 previous open operations.  19 patients were on narcotic analgesics prior to surgery. At other centres, 142 patients were evaluated and open surgical procedures were not deemed appropriate or likely to be of benefit.

Outcome Study Results. 97% cohort integrity was maintained at the final follow up.  Back, buttock and leg pain were separately compared and analysed using the percentage change in Oswestry Disability Index, and percentage change in visual analogue pain (VAP) scores, a Patient Satisfaction Scoring Scale and a patient Target Achievement Score. Clinically appreciable change was observed in 74% patients with back pain, 77% buttock pain, and 75% leg pain. Using a percentage change in Oswestry Disability Index of 50 or more to determine good and excellent outcomes, 61% of patients exceeded this score for back pain; 66% for buttock pain; and 65% for leg pain.  95% patients required no further surgical intervention.

Outcome Study Conclusions.

These results indicate that Endoscopic Laser Foraminoplasty provides a minimalist means of exploring the extraforaminal zone, the foramen and the epidural space and performing discectomy, lateral recess decompression, osteophytectomy and perineural neurolysis. It incorporates the prophylactic advantage of foraminal undercutting with discectomy and provides a promising means of identifying and treating back pain and sciatica of indeterminate origin and the pain of ‘failed back surgery’.  Done in an aware state, it serves to precisely identify and localise the source of pain generation.  Endoscopic Laser Foraminoplasty avoids the morbidity associated with open spinal surgery and serves as a useful means of effecting ‘keyhole’ neurolysis, osteophytectomy, discectomy and decompression without extensive exploration and fusion.  Current improvements in equipment promise wider application and more encouraging results in the future.

Morbidity Study Objective

To analyse the incidence and gravity of reported complications that arise in spinal surgery and assess the comparative safety, or otherwise, of Endoscopic Laser Foraminoplasty.

Morbidity Study Methodology

The Spinal Foundation, Rochdale has performed 958 Endoscopic Laser Foraminoplasty procedures and holds a comprehensive database of the results of all operations carried out in this manner. The records of these procedures provided the basis for a comparison of the safety of Endoscopic Laser Foraminoplasty to that found for other spinal surgical techniques as reported in the literature.

958 procedures have been performed on 716 patients. Complications that arose during the operation and the postoperative phase of 6 weeks following the procedure were elicited from patient records. This data was correlated and compared to a meta-analysis of randomised controlled trial data available on complications arising during and after conventional spinal surgery. The ‘SPSS’ and ‘CIA’ statistical packages were used to draw conclusions as to the safety of endoscopically assisted laser spinal surgery.

Morbidity Study Results

The cohort integrity of operative and review records at 6 weeks after surgery was 100%. In 958 ELFs performed  24 complications occurred in 23 patients. There were 9 cases of discitis (1 infective) (0.9%), 1 dural tear (0.1%), 1 deep wound infection (0.1%), 2 patients suffered a foot drop (1 transient) (