What is the reason for a recurrent haematoma?
Q: My diabetic father was diagnosed to have a chronic subdural haematoma in his head for which he was operated a few months back. But when he went for scanning recently, he was found to have developed a re-accumulated haematoma. What is the cause for this? Will surgery be required again?
A:The coverings of the brain called meninges are composed of 3 layers - the dura mater, arachnoid mater, and pia mater. There is a potential space between the arachnoid and dura (called the subdural space) and bridging veins cross this space. Bleeding from these veins results in accumulation of blood called subdural haematoma. The presence of brain atrophy or loss of brain tissue due to any cause, such as old age, alcoholism, or stroke, provides a potential space between the dura and the brain surface. Such bleeds are more common in the elderly and in infants because of their larger subarachnoid space, which permits more movement between the brain and dura, predisposing these age groups to the formation of subdural haematomas (SDH). The haematoma may be acute if less than 72 hours old, subacute when 3-20 days old or chronic if older than 20 days. The commonest cause is secondary to trauma but spontaneous haematomas may be seen in the aged, those receiving anticoagulation treatment, or patients with intracranial hypotension. Subdural haematomas after lumbar puncture, epidural injection, and puncture of spinal meningeal cysts have also been reported. Rarely they may occur due to rupture of an aneurysm or dural arteriovenous malformations. Such malformations often cause unexplained and recurrent bleeds. The risk factors for a chronic SDH include chronic alcoholism, epilepsy, coagulopathy, arachnoid cysts, anticoagulant therapy (including aspirin), cardiovascular disease (hypertension, arteriosclerosis), thrombocytopenia, and diabetes. Subdural haematomas may be clinically silent when small and are discovered only incidentally. Some patients may present with headache or dizziness while larger haematomas may give rise to symptoms caused by mass effect on the brain tissue in the form of decreased mental status, unsteady gait, headache, deviated gaze, or respiratory depression. The treatment of liquefied chronic SDHs is by drainage through burr holes or drainage via a small catheter. Nonliquified chronic SDH requires removal by craniotomy. Post-operative residual haematoma may be seen in more than 90% patients on a CT scan but patients continue to improve regardless of the size of this collection. Re-operation for reaccumulation of haematoma may be required in 12-22% cases. Early diagnosis before significant neurologic deterioration correlates with a favourable prognosis. There is no correlation between preoperative CT scan and postoperative outcome.