Post-surgical fibrosis is a condition that occurs by making any type of cut in the body, such as spinal surgery, causing excessive scarring of the tissues which can cause great pain by compressing tissues, nerves and nerve roots.
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- 1 Post-surgical fibrosis
- 1 What is
- 2 How it occurs
- 3 Prevention Methods
- 4 Symptoms
- 5 Risks
- 6 Diagnosis
- 7 Treatment
- 2 Source
What is it
Any cut in the body involves subsequent healing , which consists of repairing the tissue that was cut with fibrous tissue . The postsurgical fibrosis , strictly speaking, corresponds to secondary healing all surgery , but the term is often used to refer to cases in which healing is excessive, so that it forms more fibrous tissue necessary. If after a spinal operation that excessive scar compresses a nerve, it causes great pain.
How it occurs
It is accepted that the main risk factors for developing post-surgical fibrosis depend on: 1. The scar: The more blood the surgical wound has and the larger it is, the greater the risk that it will generate fibrosis. 2. Individual propensity: Some people have a spontaneous tendency to heal more than necessary and even small cuts on the skin lead to large scars ( keloids ).
Preventing the risk of post-surgical fibrosis is very important, since it is a painful situation whose treatment is complex and not always possible. The best way to prevent the risk of post-surgical fibrosis is: 1. To be operated only when it is essential. 2. The use of less aggressive surgical techniques whenever possible, such as microsurgery, which generate less bleeding and smaller scars.
As drugs that inhibit cellular response, the most widely used are corticosteroids . By stopping the inflammatory reaction, in addition to achieving a highly desirable analgesia for the post-operative patient, it reduces scarring reactions. Small doses of cytostatics and immunosuppressants (better known for their use in tumors and transplants) have also been experimented with , although these substances seem to increase the risk of infections, so their use is not standardized. In the chapter on anti-fibrosis barriers , the first element that was used and continues to be used with relative success is the patient’s own fat, obtained from the subcutaneous tissue. Subsequently, the industry has developed different insulating gels and membranes that are used normally today. The truth is that there have been no clinical trials to support the validity of these methods , but the current trend is a progressive increase in their use.
The pain that typically causes post-surgical fibrosis is pain in which the component of pain radiating to the leg, in case of operation of the lumbar spine , or to the arm, in case of cervical operation , is more intense than the pain Located in the back, and in which the pain, although it may worsen in some positions, can be almost constant. Not all pains that appear after a spinal operation are due to post-surgical fibrosis. For example, an operation for a herniated disc, although performed perfectly, does not prevent pain from involvement of the facet joint or muscle contraction after the operation; only acts on the herniated disc. Those pains would be due to a cause other than the operation or its healing.
What we call fibrosis is the scar tissue or connective tissue, which appears in any wound and serves to unite the tissues that have been separated. In the case of lumbar surgery , it is necessary to separate the muscle to reach the spinal canal, manipulate the fat that surrounds the nerves, coagulate some epidural veins …, ultimately, damage some tissues that surround one or more sciatic nerve roots . All damaged tissues tend to be repaired with scar formation.
The fibrous tissue is very sticky and tends to anchor any nearby structure (that is its mission). It is true that scarring is very variable between patient and patient. In the perfect patient, the damaged tissues are restructured without emitting more adhesive “tentacles” than necessary. The muscle is reattached to the bone and there is almost no foreign tissue in the spinal canal. This situation is the least common. Inflammatory reactions commonly occur in muscle and other injured tissues with chemical mediators that stimulate the growth of connective tissue to the manipulated area of the nerve, surrounding it and replacing genuine epidural fat with fibrous tissue.
Although this mechanism has always been an argument to explain the poor results of surgery, the truth is that fibrosis is not usually capable of displacing other tissues in its growth, but only occupies the available spaces, therefore it would not act as a compression process. However, we have seen that it is a very resistant and adhesive tissue, being able to anchor the nerve roots to the surrounding tissues (vertebral bone, disc and muscle). The healthy roots are surrounded by a very soft fat that protects and lubricates them, allowing small movements that are accompanied by the movements of the body.
Sometimes post-surgical fibrosis can compress a motor nerve fiber, causing loss of strength. Radiologically fibrosis can be confused with a herniated disc and give the impression of compressing the nerve, but with the use of intravenous contrasts, the difference is very clear: fibrosis shines because it is a tissue that receives blood supply, unlike the disc tissue. It is also well distinguished from the nerve root, since it contains liquid inside.
In certain flexion positions, the sciatic needs to stretch several millimeters so that the ” alarm ” of impending damage, the sciatic pain, does not go off. An anchored root lacks this ability to move, so each movement of the sciatic acts as a ” tug ” at the root root. The pain caused by these movements is usually momentary, but the sum of these attacks can start an inflammatory process that leads to chronic radiculitis .
Magnetic resonance imaging can detect post-surgical fibrosis. A medical history and physical examination are essential to determine if fibrosis detected on MRI is the cause of the pain. Neurophysiological tests can detect the existence of compression of the nerve fibers.
In the past, when the cause of pain was diagnosed as nerve compression due to post-surgical fibrosis, the patient was re-operated to “release” the compressed nerve. But after a few months the scar from the second operation used to produce even more compression, and the more times the patient was operated on, the worse the problem was. Today, with some exceptions, it is preferred to treat post-surgical fibrosis with other treatments or with methods specific to pain surgery, such as implantation of stimulation electrodes or morphine pumps.
Once the surgical procedure is finished, there are two things that surgeons have considered useful as preventives: applying inhibitory substances and isolating the nerve root from the tissues that cause fibrosis, especially muscle and epidural veins cauterized during surgery, using non-adherent agents .
Once fibrosis is suspected of causing postoperative symptoms, physical therapy should be the first action. This section includes progressive hamstring stretches to lengthen the sciatic nerve and make it more tolerant to daily activities. Also the physical means of deep anti-inflammation like laser or microwave can help.
When the symptoms are rebellious, selective root infiltrations or epidurolysis can be attempted with corticosteroids and antifibrosis agents such as hyaluronidase, generally practiced in Spinal Units or Chronic Pain Units. A more advanced technique is epiduroscopy , which consists of navigating the epidural space with a fiber optic camera and detaching the adhesions from the nerve by means of mechanical, pharmacological or radiofrequency actions. The epiduroscopy is performed in few centers because of the difficulty and uncertainty that arise in the medical community results.
Another way to control symptoms without acting directly on fibrosis is to partially desensitize the nerve so that it does not transmit painful signals. This is accomplished with pulsed radio frequency .
Finally, when other methods have failed, palliative pain techniques such as spinal neurostimulation or the implantation of automatic infusion devices ( intrathecal morphine pump ) may be the last step.