Spinal Surgery

Introduction

In one sense spinal surgery is the ‘poor relation’ of neurosurgical activity. It is less dramatic than brain surgery and is perceived as being less complicated. While it is true that outcome from spinal pathology or the complications of surgery are rarely life threatening as they often are with brain surgery, nevertheless the consequences of getting things wrong in spinal surgery are just as serious or even more so. As a junior neurosurgeon I found spinal surgery the hardest discipline to learn and I now find it hard to teach. It is a field where techniques are changing constantly which makes it difficult to evaluate them in comparison to established methods of treating patients. The fact that something is new does not necessarily make it better. The adage ‘if it is not broken, don’t fix it’ certainly applies in spinal surgery.

Personal experience

I was fortunate to be trained by some first rate spinal surgeons. My late colleague from Bristol, Huw Griffith was a great innovator who pioneered minimally invasive spinal surgery and whose technique for lumbar microdiscectomy I still use today. Working with Brian Cummins (retired colleague from Bristol) exposed me to the management of complex spine problems and I learnt from him how to manage these in the context of an individual patient’s lifespan. With progressive disease, one has to take a long term view and support patients over many years. Richard Cowie (Manchester) is a first rate technical surgeon whose efficient approach matched my own. ‘Learn to do the simple things well’ was his regular advice. In a field like spinal surgery where there is no one technique that is better than another, one learns something from everyone, not least from my present colleagues, Ian Nelson, Steve Gill and Ciaran Bolger to name three with whom I have operated with from time to time.

The major part of my pain surgery practice involved the management of benign persistent pain in patients whom spinal surgery has failed. This practice influenced my approach to spinal surgery in two ways. Firstly it made me very conservative, If there is a way to manage a problem that does not involve surgery then I have no doubt that this should be tried first. Secondly it convinced me that the optimum management of spinal problems should be multidisciplinary. The more complex a problem the more important it is to take a multidisciplinary team approach. This is very hard to do in an environment where everyone is so busy.

Throughout my early consultant practice the management of routine spinal problems was difficult as the department has never been well enough resourced to allow emergency work, regional tertiary referral work and GP referral work to take place side by side. The emergency and tertiary referral activity inevitably takes preference. My spinal practice was biased towards this. I treated intrinsic spinal disease with my neurology colleagues (Ian Ormerod). I worked with the spinal injuries unit in Salisbury (Tony Tromans) treating the complications of spinal cord injury. 30% of the operating generated by the pain surgery service was ‘conventional’ spinal surgery. Where I identified problems that required spinal fusion I generally referred patients to my spinal orthopaedic colleagues Ian Nelson providing the most considered, often conservative opinion on management. He has now retired.

In the early 2000's the waiting times for routine NHS spinal surgery were quite unacceptable. The waiting time for urgent spinal surgery in my practice was 16 weeks while routine cases could wait over a year. In order to rectify this I set up a spinal assessment service - SWIS Ltd. This service and its demise is described separately on this web site. Nevertheless the service did change practice fundamentally. The 'one stop shop' principle on which it was based became widely established at least in the private sector. The price of scanning came down - at least halved. Sadly the NHS service that replaced it - assessment by general physiotherapists without access to scanning completely failed to match the service we provided.

In terms of the service that SWIS provided, no one knew what they had got until it had gone! I have been asked a number of times if the service could be reproduced - of course it could. 250k population generates 100 referrals per month, easily managed by a clinic a week day evening with the 10 operations and 10 root blocks managed with a decdicated list every week end. Referrals from SWIS to the pain clinic are fully worked up so the pain physicians can focus on therapy rather than diagnosis. However I no longer have the energy to drive this myself. So much effort went into setting the service up against resistance from every quarter that once the business was closed down I have been unable to find the incentive to do it all again.

Recently, since the move to Southmead, I have continued my input to spinal surgery in the following ways. The spinal physios refer me the urgent cases that are referred to them; I have been picking up long waiters stranded on a generic waiting list, I have been helping out the pain surgery service in between definitive appointments to that service and I have helped out individual colleagues as needed.

I am unable to predict what will happen in 2018. The activity described above has come to an end. The generic spinal waitinng list no longer exists. My colleagues are now motivated ot manage their own long waiters and the pain surgery servic eis fully staffed again. My services in spinal surgery may no longer be needed.

Below are descriptions of some of the common spinal surgical procedures that I perform.

Lumbar Microdiscectomy

One of the commonest spinal operations is Lumbar Microdiscectomy. The technique I employ was pioneered by Huw Griffith in the early 1980’s when he advocated ‘day case’ disc surgery for the first time. This was viewed almost as heresy at the time although is quite commonplace now. Personally I prefer patients to have at least one night’s in patient stay after this operation. The average post operative stay is 2 nights.

The operation is performed under general anaesthetic and with X Ray control. A small (2-4cm) midline skin incision is made at the appropriate level and the ligament between the spines of the vertebrae exposed. The key to Huw Griffith’s technique was the disconnection of as few muscle insertions to the adjacent bone as possible and the avoidance of the use of cutting diathermy (which produces postoperative pain!) Done carefully, this gives more than adequate exposure to the bones and ligaments superficial to the disc space. A microscope is essential at this stage as it provides the necessary illumination as well as magnification to proceed to removal of the ligament and if necessary some bone to expose the dura, the nerve root and the disc prolapse. I learnt from Sandy Strang (retired neurosurgeon from Manchester) the importance of approaching the nerve root from a lateral approach. This allows removal of the disc prolapse with minimal retraction of the nerve root. If there is an element of bony entrapment of the nerve root as well I then remove the part of the joint that is producing the compression. (my technique, learnt from Richard Cowie is to use microchisels for this). There is no agreement as to how much disc material within the disc space should be removed. My approach is to be as thorough as I can about removing loose material within the disc but I do not try to remove the whole disc. The balance is between the risk of reprolapse of disc if loose material is left behind and the risk of discitis (inflammation / infection of the disc space) and the very rare complication of major blood vessel damage from over zealous clearance of the disc space. Once the nerve root has been decompressed it is a straightforward process to close the wound, infusing local anaesthetic into the muscle to reduce post operative discomfort. I like patients to mobilize as soon as they have recovered from the anaesthetic. The routine is to get out of bed the same day as surgery, mobilize with the physiotherapists on the flat on day 1 post surgery, do stairs on day 2 and then go home either on day 2 or day 3 post surgery.

How rapidly patients can return to normal activities depends on a number of factors, not least what constitutes normal activities for an individual patient! In general I prefer patients to take at least a month out of their lives to recover from disc surgery. They can gradually increase their activities with the proviso that if things hurt, they rest. The worst possible thing to do is to work through discomfort that is inevitable in the early postoperative days and weeks. I specifically ask patients to avoid heavy lifting, twisting their backs and sitting in soft armchairs. The act of standing up from a sitting position in a soft armchair inevitably tenses the erector spinae muscles and disrupts the muscle insertions that were disconnected during surgery. After six weeks or so patients can gradually return to normal activities although it is three months from surgery before the back fully recovers and is as strong as it is going to be.

Cauda Equina Syndrome

In most series of lumbar disc prolapse, presentation with cauda equina syndrome is relatively uncommon - c3-4%. This occurs when pathology, usually a disc prolapse compromises the sacral nerve roots acutley causing loss of bladder and bowel function. In this series the iincidence of this is 20%, much higher than normal.

Results of lumbar microdiscectomy