Dr. Iliev, what is chronic subdural hematoma?
- Chronic subdural hematomas are one of the most common neurosurgical diseases. They represent the end product of the breakdown of pathologically collected blood in the subdural space, beginning with an insidious onset and progression over time. Chronic subdural hematoma consists of an outer membrane (capsule), a hematoma cavity and an inner membrane.
Hematoma fluid usually does not clot. Depending on various circumstances, this blood grows and expands its volume, thereby pressing on the brain and leading to neurological complaints. Surgical evacuation remains the gold standard for the treatment of symptomatic chronic subdural hematomas. Evacuation of the hematoma facilitates rapid prevention of neurologic deficit and results in a favorable outcome in most patients.
Subdural hematomas represent an economic and social burden to societies worldwide, due to the significant morbidity and mortality they cause. Current trends indicate that given the aging population and the widespread use of anticoagulant and antiplatelet therapy, chronic subdural hematomas will double by the middle of this century, possibly becoming the most common intracranial diagnosis requiring surgical intervention by 2030.
Which risk group is most prone to this condition?
- People over the age of 65 are most often affected, with male gender being a potential risk factor. The tendency to develop chronic subdural hematoma in the elderly can also be explained by the shrinkage of brain volume within the cranial vault (brain atrophy). Therefore, tension on the bridging parasagittal veins that drain the cortical surface are prone to injury and hemorrhage.
In addition to demographic risk factors, anticoagulant or antiplatelet therapy is also considered a risk factor for both chronic subdural hematoma formation and recurrence. The risk of developing a chronic subdural hematoma is greater in patients who are prone to falls and hitting the head, most often people with epilepsy, dementia or addictions, mainly to alcohol. The frequency of chronic subdural hematoma is also greater in the presence of an arachnoid cyst.
How does the disease progress and what are its main symptoms?
- Symptomatic subdural hematoma, which has a chronic nature, can manifest in a different way, earning it the nickname - "great imitator". This hematoma can occur over a prolonged period with isolated cognitive decline mimicking dementia or present acutely in the context of focal neurologic deficits as seen in stroke. It can progress dramatically and lead to coma, even death – as a result of the symptoms of increased intracranial pressure or mass effect on important structures.
Since chronic subdural hematomas develop slowly and in the context of marked cerebral atrophy, they may not become clinically significant until they are large enough that compensation from the cerebral cortex is no longer possible. Symptoms most commonly include: headache, nausea, vomiting, drowsiness, vertigo, seizures, mental deterioration, unsteadiness of gait, and paresis of the limbs. When symptoms are vague, diagnosis can sometimes be difficult because there is often no history of a traumatic event that warrants routine imaging.
Due to this fact, my advice, especially to younger medical colleagues, is when they have the slightest suspicion of any pathology, to do an imaging study - a brain scan or magnetic resonance. A scanner in the context of urgency is the better choice of investigation because it is more accessible and done quickly.
Magnetic resonance examination is very informative, but it is quite lengthy, and most patients are restless and psychomotor agitated. In order to have an imaging study, the patient can use a referral from a neurologist, but as you know, these referrals are limited in our he alth system and are usually paid for by relatives.
As an option for performing an imaging study, usually a scanner, is to admit the patient to the hospital, through the emergency center and through a clinical pathway, which, according to my observations, is the most common. After examination by a neurologist, at discretion, the patient also consults with a neurosurgeon, and then a decision is made whether to proceed with surgical treatment. There are also cases with chronic subdural hematomas (effusions), usually with a layer thickness of less than 1 cm, which do not affect the clinical condition of the respective patient. In them, an operative intervention would lead to clinical deterioration or even worse results.
Conservative treatment in these patients is an option. In patients with pronounced neurological symptoms and a subdural hematoma causing significant brain compression, the gold standard is surgical treatment. In these cases, any conservative treatment would lead to a tragic outcome. Usually, these patients come to us at the last moment, and this happens most often in the evening or at the end of the work week, when their relatives come home from work or pay more attention to them.
Operative intervention in people who are on anticoagulant or antiplatelet therapy is somewhat delayed. Most often they take aspirin, clopidogrel, syntrom and similar blood thinning medications. The risk of surgical intervention is associated with intraoperative bleeding or in the postoperative period – with the formation of a recurrence. In such cases, before surgery, it is better to stop taking these drugs and wait for some time. Practice, unfortunately, shows that this is possible in few cases and therefore it is necessary to act preventively and urgently.
What operative methods of treatment are applied?
- In most operations of chronic subdural hematomas in our clinic, we perform a neuroendoscope-assisted mini-invasive intervention with a burr - 2-3 cm. It can be said that this is an innovation, since there is not much practice to use a neuroendoscope in these conditions. The neuroendoscope is an expression of entry and integration of high technologies in modern neurosurgery, and with its help we have the opportunity to examine the subdural cavity very well for residual clots or bleeding vessels.
In this way, we minimize risks during surgery or in the postoperative period. In some patients, usually with multiple septa, this minimally invasive intervention cannot be performed. Then a larger operative access should be made by craniotomy or craniectomy, with removal of the bone flap.
Another high-tech equipment we use in selected patients is neuronavigation. It allows the integration of structural, anatomical and functional data. As well as real intraoperative protection, not only of structures, but also of functions. Its only drawback is that it takes longer, and in some conditions it is vital.
What more serious complications could occur with this type of intervention?
- The most common complications of such surgery are recurrences or, to put it simply, repeated bleeding. It is usually operated minimally invasively, field visibility is minimal, and if additional tools such as neuroendoscope and neuronavigation are not used, the risk of bleeding is high. To flush the subdural space from the accumulated fluid, a special catheter is inserted.
During this procedure, it is possible to tear a blood vessel, which will subsequently cause a relapse or lead to damage to the cerebral cortex itself. There is a potential risk of pneumocephalus – air collection – following all surgical techniques in the treatment of chronic subdural hematomas.
What is conservative therapy?
“Conservative therapy worldwide is still under investigation for certain medications. There are articles and reports that indicate that certain drugs or procedures work well for certain patients. But in general, there is still no drug or therapy that has been proven to be superior to, equivalent to, or even close to the results of surgical treatment. Conservative therapy has the best effect when it is carried out together with operative treatment
The most time-tested conservative drugs are corticosteroids (dexamethasone). They have a proven effect only after surgery, as they are anti-inflammatory. Dexamethasone alone would not cure the patient. In addition to corticosteroids, statins have also been tried - atorvastatin, which also do not have a good effect. Tranexamic acid is currently being tested, but it is expensive and not as effective as a single agent. The benefit of middle meningeal artery embolization has been reported in the literature, especially for recurrent chronic subdural hematomas," the doctor explained