Complications of Spine Surgery & Consent

About consent

Consenting for an operation means that you agree to have it done, understand why and accept the possible complications. You should therefore only sign the consent form if you agree to all aspects. You should also have taken enough time to make this decision. Therefore, consenting to a procedure is not just signing the dotted line but a process of having sufficient information about your condition, treatment options, the specific procedure you are consenting to and the chance to weigh up ‘pros and cons’ and ask questions where it is not clear. In particular, make sure you are understanding the ‘medical language’ often used and ask the surgeon to translate this into plain English. Do not be embarrassed if you do not understand a specific word, a condition or feel overwhelmed with all the information. Ask again!

Note: If you are an adult, you are the only person, who can sign your consent form! Another person cannot do this unless they are a registered guardian or if you have indicated your consent but are physically unable to sign (e.g. if you have fractured your arm and cannot sign the consent for the operation to fix it). If a patient is unable to understand, comprehend or retain the information given (e.g. if the patient is unconscious or has dementia but no official guardian, the treating doctor can do this in the best interest of the patient. Commonly, a second doctor will sign as well. If possible, a relative should sign to document it has been discussed with the family or next of kin but this is not instead of the patient. This is usually only necessary in emergency situations rather than planned operations.

For further information about consent click here.


About complications

Any surgery or intervention carries risks. Some may have hardly any consequences and others could be life-changing. When considering any procedure, you should discuss these in full with your surgeon or specialist and take sufficient time to think about these. In urgent situations where time is of the essence (e.g. urgent/ emergency surgery for  cauda equina syndrome, unstable fractures or tumours causing spinal cord compression), there might be very little time which can make this process very difficult. However, do not hesitate to ask questions, in particular those who might be frightening such as risk of paralysis or even risk to life. Where possible, get a person you trust to be with you. Even in Covid-times having somebody on the phone on loudspeaker is usually possible when you are talking to your surgeon.

When discussing complications, there are a few questions you should consider:

How common is the complication?

You are likely to be quoted a percentage which gives you an idea how often this can occur. These are average estimates. They do not answer the question if you will suffer this or not so even a small number does not mean it should be disregarded. There are also certain factors which will vary from patient to patients which might make it very difficult to estimate the risk for your operation (e.g. the risk of a CSF leak often depends of the severity of existing scar tissue in a revision operation). 

 

How serious is the complication?

Some complications might not need any specific treatment and have little consequences. Others can be life changing such as a spinal cord injury. Some patients hesitate to ask questions about this - and some surgeons might also find it difficult to talk about a risk to life. It is important to cover these as some patients sadly suffer these often rare complications. The surgeon should be able to put this in the context of your particular case.


What are the consequences?

This is important. Even minor complications can increase the number of days you spend in hospital even if it has no other consequences. It can therefore have an impact on how you have set up your recovery or return to work. Discuss whether complications might have transient or permanent consequences.


What are the strategies if a complication occurs?

When doing an operation, a surgeon should not only know how to do it but also how to deal with complications. Although most surgeons will be able to handle most complications such as recurrent disc protrusions, infections and CSF leaks, it is sometimes necessary to involve other specialties such as vascular surgeons, general surgeons or medical specialists such as pain consultants. Treating some complications can be more difficult than the operation itself, e.g. a revision fixation if implants have failed. Some complications might occur with some delay such as an infection. Ask the surgeon who to contact in  case there is a problem after you have been discharged including the case where you cannot contact the surgeon directly (weekend or if surgeon is on leave).


General points about complications

Although it might sound trivial, all operations, even minimal invasive operations require a cut in the skin. The healing of a wound can be effected by a number of conditions such as diabetes. Certain drugs or radiotherapy can have an effect, too. A previous operation in the same area might also alter the healing process. 

Most operations are done under a general anaesthetic and complications can arise from this as well. These will be discussed with you by the anaesthetist.

Specific complications

Listed below are just the main complications of spinal surgery but do not cover all spinal operations. Some are very specific to the condition (e.g. risk of tumour recurrence) or approach of the operation (e.g. going to the spine through the chest or abdomen. These are not listed here but the surgeon should explain these beforehand.


Bleeding

As soon as the skin is penetrated, even in so-called minimal invasive or percutaneous procedures, bleeding can occur. This can be just from the skin or muscles leading to a blood clot (haematoma) under the skin or from the wound, or major vessels. A deep seated clot can press on a nerve or spinal cord and cause neurological problems or in the neck might cause breathing difficulties. Bleeding can be difficult to stop in some cases and a patient might require a blood transfusion during or after surgery. If you do not consent to have a blood transfusion during or after surgery (e.g. if you are a Jehovah's witness or any other reason) you must raise this with your surgeon well in advance. In some operations, so-called cell savers can be used so you get your own blood transfused during surgery, but this is not always available and should be planned beforehand.

There are several factors which can influence this form specific medical conditions to taking certain blood-thinning medication such as Aspirin, Clopidrogrel and Warfarin. It is very important to discuss all the medication you take, even the 'baby-Aspirin' you might take just now and again, with your surgeon.


Infection

Any operation, as for bleeding, carries a risk of infection. For clean / elective, i.e. planned surgery, this should be small and well <5%. It can be higher in certain cases, e.g. if you had radiotherapy to a tumour in the same area before or in trauma. Certain medical conditions such as diabetes or a disease lowering the immune system can also make an infection  more likely. The same applies for certain drugs/ medication including steroids. Therefore, it is important that you discuss all your medication with the surgeon.


CSF-leak

CSF stands for cerebro-spinal fluid. It is in the sac (dura) containing the nerves and this sac can be injured during surgery or sometimes the underlying condition (e.g. a spinal fracture). Sometimes, the defect can be directly repaired during surgery but this is not always possible. A small leak might even go unnoticed and only causes a problem at a later stage. As long as the nerves or spinal cord inside this sac are not injured, it is usually not a problem but is likely to require a longer hospital stay. As long as the CSF does not come through a wound and is otherwise not causing symptoms like pain or nerve compression, it might not require any specific treatment. Occasionally, a patient needs to be taken back for further surgery or a repair. 

If you notice any clear fluid leaking through a spinal wound you should get in touch with the surgeon or hospital urgently! This usually happens within the first 10-14 days, i.e. before the wound has healed. It can also manifest itself as a swelling underneath the skin. An excessive CSF leak causes headaches (it is in the end brain fluid) and if you experience this, get in touch with the surgeon.


Nerve or spinal cord damage

Any spinal operation has a risk or nerve or spinal cord damage, depending on the location / level of surgery. Spinal cord damage can cause a devastating and permanent paralysis , which can effect the arms and legs depending on the level of surgery. The risk depends also on the underlying condition and the surgeon should specify this for the operation you are having. 


Incomplete decompression 

When removing discs or bone/ ligaments compressing nerves, it is possible to leave bits behind. Most surgery is carried out with the help of a microscope and special instruments are used to feel if a nerve is still under pressure. However, the patient is not in the same position on the surgical operating table than when standing for example and a disc might appear to  be bulging less during surgery than in real life. Sometimes, the risk of damaging the nerve by retracting it to get to a fragment might be so great that the surgeon has to leave it behind.


Recurrent disc protrusion

During a lumbar discectomy, only the part which has protruded and obvious loose fragments, are removed. There is a small risk, that another fragment breaks loose inside before the ring of the disc has healed. This risk is about 5-7% and most commonly occurs within the first 3 months after surgery. However, it can also happen after many years.


Implant loosening, misplacement, failure /or breakage

Implants can fail for various reasons. If a spinal segment does not grow together with the bone graft often used, screws can become loose. Certain conditions such as osteoporosis weaken the bone and implants can pull out. 


Swallowing difficulties

In surgery through the front of the neck, such as anterior cervical discectomies, the food- and windpipes need to be retracted. this can lead to some swallowing difficulties which usually resolves within a short period of time (days). It is very uncommon to suffer an injury of the food pipe (oesophagus).


Hoarse voice

A nerve (called recurrent laryngeal nerve) runs along the food- and windpipe and can be stretched or rarely directly injured during surgery from the front of the neck. This can lead to a hoarse voice which usually improves or resolves again unless the nerve has been severely injured.