• Wrong level spinal surgery-surgical risk or negligence?

    28 September at 20:45 from atlas

    The decision by a patient to undergo spinal surgery is a major event in their life. It is a time of sever and chronic pain, disability, time off work and suffering.The surgeon will have addressed the options, diagnosis, and appropriateness of surgery i.e.. (i) benefits.risks and correct surgery for diagnosis.In Neurosurgery the surgeon will consider the patient's symptom distribution, neurological signs, CT/MR/NCS/myelography (usually an appropriate combination) and determine the correct spinal LEVEL or SEGMENT (and side) for surgery.There is a not unreasonable expectation by the patient that the CORRECT level (and side) will be operated on.Unfortunately, this does not always eventuate and usually results in the break-down of the relationship between surgeon and patient.There is a need for re-operation and added pain,risk and expense and inevitably the question of 'a surgical complication' versus ' 'surgical negligence' arises. This issue is important both for the surgeon and the patient.

    To put this matter into some perspective we need to look at the prevalence of incorrect level surgery(ILS). Mody MG et al (Spine 2008 Jan 14;33(2):194-8) surveyed members of the prestigious American academy of Neurologic Surgeons (n=3505) and assessed some 1.3 million spinal operations. From 1.3 million operations examined there were 418 incorrect level operations performed ,i.e. a prevalence of 1 in 3110 operations(0.32%).The majority were in the lumbar region(71%), cervical (21%) and thoracic (8%).The authors concluded that there is a 'high prevalence of ILS among spine surgeons'; 1 of every 2 spine surgeons may perform an ILS during their career and recommended preventitive measures including improved communication, side marking and intra-operative Xray confirmation.

    Kraemer R et al in Herkowitz& Bell's standard text 'The Lumbar Spine' report a 1.2& prevalence of ILS among very experienced surgeons and a 3.3% among less experienced surgeons. Most ILS occur at L4/L5 rather than at L5/S1. again, an intra-operative radiograph with the needle in the upper interlaminar corner prior to ligamentum flavectomy is advised.

    Lewis BD refers to the Canadian Orthopaedic Associationn's guidelines to 'reduce' ILS including : pre-operative patient discussion to confirm the symptoms, signing the affected leg with the surgeon's initials in ink, reading both radiology reports AND viewing of the actual films in the O.R.. , being vigilant to the possibility of congenital anomalies (e.g. spina bifida occulta) or other anomalies such as osteo-arthritic lipping of the L5/S1 facets making the last inter-laminar space determination difficult/ misleading, having radiology films on view in O.R. and performing an intra-operative cross-table radiograph with a metal marker in situ.

    the various surgical colleges and professional groups have recommended hospital check lists, team time outs etc-but at the end of the day it is the surgeon who must select and operate on the correct level(and side)-this is not a delegatable responsibility.That being said, it is NOT always predictable outcome.The radiographer & radiologist may have mentioned a lumbarised S1 or sacralised L5.There may be 6 , not 5, lumbar vertebral segments on the X-ray(in theatre) but CT/MR (pre-op plain Xrays are usually NOT performed nowadays!) only examined L3 to S1 (or C2& C3 were fused partially) and this raises the potential for the radiologist to use a differnt level nomenclature.To compound the problem , the radiologist may not discuss the observation of an extra LV and the surgeon receives an MR film with tiny mini-boxed scout view 9if at all( and must rely on the report.As I emphasided above patients nowadays get a CT or MR , not plain Xray from GP and the first plain Xray is the lateral Xray in OR.I emphasise that performing a pre-op plain Xray coes NOT always solve the problem as there is no marker on that X-ray, obviously.Thus, the cross table Xray in theatre is the only palin Xray that the surgeon may have and the surgeon must correlate a CT or MR with a lateral Xray, often a poor quality one on OR at times due to multiple factors.

    The reader may wonder how can a patient could have an intra-operative Xray and the operation YET the ILS occurs and is identified ONLY on the post-op check Xray, or if the patient fails to improve as expected.Having discussed the technical difficulties of an intra-op cross table II (or even C arm technology) and correlation with a CT/MR , the reader must understand that a stenosis disappears with the laminectomy, and at many times the surgeon is guided by the II rather than SEEING pathology.The laminae & facetys of a stenotic level may appear similar to a non-stenosed level from the back & removing them does not result in finding of 'confirmatory' pathology. This point is LESS applicable for discectomy. here an experienced surgeon will recognise that the ubiquitous BULGE is different at time of display to a HERNIATIONof nucleus. The surgeon MUST be experienced and vigilant.

    There are more issues to consider. The on table Xray may be non-ideal due to patient build( truncal & shoulder girdle obesity), lack of Xray penetration due to the pelvis and hips-and even a radiographer 'blasting full power' with a Bucky collimator in use may produce unhelpful images with large pelvic/hip and shoulder girdle bones in the way.The thoracic region is even more difficult due to a lack of landmarks(sacrum in lumbar surgery and skull base in cervical surgery)- pre-operative marking with a wire AND dye are advised(not cross table II in OR).

    If the surgical findings do not match the CT/MR findings in respect of a disc protrusion despite the cross table II showing the needle in the 'correct' disc level , then another II must be performed, with the needle in the disc space.One MUST not forget that small disc herniations may resolve prior to surgery-hence the need for 'fresh' MR if an extended course of conservative treatments was undertaken.A telephone call to the radiologist to come to OR and sort out the images is another option , if after repeat II the surgeon is not happy...and the 'team' is becoming tired and disorientated and the anaesthetist is raising duration of anaesthesia concerns.Another, less favoured( and used by the older surgeons in the old days as a routine), is to check the level above and below by laminectomy.Another surgeon with 'fresh' eyes ' may be summonsed to help.If all this fails and the surgeon is NOT satisfied in finding the discal pathology on the CT/MR and especially if the anaesthetic duration risks are mounting-the patient is closed and an early pre-discharge Xray, CT and MR is performed, and if necessary re-operation can be considered after consulting with the patient, family , radiologist and anaesthetist.Concealing the ILS is NEVER a wise option.

    So, do I warn patients of the chance of ILS? YES.This is because it can occur and is thus a risk rather than a mistake or negligencePROVIDING : (i)careful pre-operative reporting and reviewing of imaging.,(ii)the theatre team has performed a team time out , (iii) the surgeon & assistant have reviewed the pre-op films and reports in the O.R., (iv)intro-operative II (with hard copies& reports) were performed , (v) checking for spina bifida occulta, large facets making the most caudal inter-laminar deceptive level, recognising obesitynad insisting on concerted efforts at the best possible II techniques,and (vi) obtaining a radiologist's or surgical colleague's assistance in O.R. I do warn of ILS as a RISK and discuss the difficulties and measures undertaken to minimise it and always perform both intra-operative II and check post0op X-rays in the Radiology department. If the discussed measures are NOT performed THEN ILS could arguably be considered a MISTAKE, ERROR or even NEGLIGENCE, which is RARE.

    Spinal surgery is complex and difficult-it must be carefully offered with appropriate INDICATIONS and APPROPRIATENESS as risks, including ILS do exist, even in the most senior and experienced of hands.patients, I believe SHOULD be warned of this risk and how it can occur and measures that will be undertaken to reduce it's likelihood..as distressing and perplexing as it may be to the patient at the commencement of the announcement.