Chronic subdural hematoma treatment
Surgical therapies involve the irrigation and removal of the blood products, sometimes with partial resection of these vascular membranes 1).
Investigational medical therapies have employed various strategies, which include reducing the rate of microhemorrhage from the membranes, changing the osmotic environment, or altering angiogenesis 2).
Endovascular therapies are aimed at de-vascularizing these membranes 3) 4) 5) 6).
Providing a high level of evidence to propose a standard of care for this frequent pathology is of utmost importance. However, two surveys in the UK and in France have shown a wide range of practice, without major rationale 7) 8).
A variety of clinical factors must be taken into account in the treatment of chronic subdural hematoma (cSDH), and the multifaceted treatment paradigms continue to evolve 9).
There is lack of uniformity about the treatment strategies, such as the role of burr hole, twist drill, craniotomy, etc., in CSDH amongst various surgeons. There is also disagreement about the use of drain, irrigation, and steroid 10) 11).
Surgery is usually the treatment of choice, but conservative treatment may be a good alternative in some situations.
Chronic subdural hematoma surgery
Middle Meningeal Artery Embolization
Systematic reviews
Chronic subdural hematoma recurrence after evacuation occurs in approximately 10% of chronic subdural hematomas, and the various Chronic subdural hematoma surgery interventions are approximately equivalent. Corticosteroids are associated with reduced recurrence but also increased morbidity. Drains reduce the risk of recurrence, but the position of drain (subdural vs subgaleal) did not influence recurrence. Middle meningeal artery embolization is a promising treatment warranting further evaluation in randomized trials 12).
Soleman et al., provide a systematic review of studies analysing the conservative treatment options and the natural history of cSDH. Of 231 articles screened, 35 were included in this systematic review. Studies evaluating the natural history and conservative treatment modalities of cSDH remain sparse and are predominantly of low level of evidence. The natural history of cSDH remains unclear and is analysed only in case reports or very small case series. “Wait and watch” or “wait and scan” management is indicated in patients with no or minor symptoms (Markwalder score 0-1). However, it seems that there are no clear clinical or radiological signs indicating whether the cSDH will resolve spontaneously or not (type C recommendation). In symptomatic patients who are not worsening or in a comatose state, oral steroid treatment might be an alternative to surgery (type C recommendation). Tranexamic acid proved effective in a small patient series (type C recommendation), but its risk of increasing thromboembolic events in patients treated with antithrombotic or anticoagulant medication is unclear. Angiotensin converting-enzyme inhibitors were evaluated only as adjuvant therapy to surgery, and their effect on the rate of recurrence remains debatable. Mannitol showed promising results in small retrospective series and might be a valid treatment modality (type C recommendation). However, the long treatment duration is a major drawback. Patients presenting without paresis can be treated with a platelet activating factor receptor antagonist (type C recommendation), since they seem to promote resolution of the haematoma, especially in patients with subdural hygromas or low-density haematomas on computed tomography. Lastly, atorvastatin seems to be a safe option for the conservative treatment of asymptomatic or mildly symptomatic cSDH patients (type C recommendation). In conclusion, the knowledge of the conservative treatment modalities for cSDH is sparse and based on small case series and low grade evidence. However, some treatment modalities seem promising even in symptomatic patients with large haematomas. Randomised controlled trials are currently underway, and will hopefully provide us with good evidence for or against the conservative treatment of cSDH 13).
Surveys
The aim of a study was to survey aspects of current practice in the UK and Ireland. A 1-page postal questionnaire addressing the treatment of primary (i.e. not recurrent) CSDH was sent to consultant SBNS members in March 2006. There were 112 responses from 215 questionnaires (52%). The preferred surgical technique was burr hole drainage (92%). Most surgeons prefer not to place a drain, with 27% never using one and 58% using drain only in one-quarter of cases or less. Only 11% of surgeons always place a drain, and only 30% place one in 75% of cases or more. The closed subdural-to-external drainage was most commonly used (91%) with closed subgaleal-to-external and subdural-to-peritoneal conduit used less often (3 and 4%, respectively). Only 5% of responders claimed to know the exact recurrence rate. The average perceived recurrence rate among the surgeons that never use drains and those who always use drains, was the same (both 11%). Most operations are performed by registrars (77%). Postoperative imaging is requested routinely by 32% of respondents and 57% of surgeons prescribe bed rest. Ninety four per cent surgeons employ conservative management in less than one-quarter of cases. Forty-two per cent of surgeons never prescribe steroids, 55% prescribe them to those managed conservatively. This survey demonstrates that there are diverse practices in the management of CSDH. This may be because of sufficiently persuasive evidence either does not exist or is not always taken into account. The current literature provides Class II and III evidence and there is a need for randomized studies to address the role of external drainage, steroids and postoperative bed rest 14).
Cenic et al. developed and administered a questionnaire to Canadian Neurosurgeons with questions relating to the management of chronic and subacute subdural hematoma. Our sampling frame included all neurosurgery members of the Canadian Neurosurgical Society.
Of 158 questionnaires, 120 were returned (response rate = 76%). The respondents were neurosurgeons with primarily adult clinical practices (108/120). Surgeons preferred one and two burr-hole craniostomy to craniotomy or twist-drill craniostomy as the procedure of choice for initial treatment of subdural hematoma (35.5% vs 49.5% vs 4.7% vs 9.3%, respectively). Craniotomy and two burr-holes were preferred for recurrent subdural hematomas (43.3% and 35.1%, respectively). Surgeons preferred irrigation of the subdural cavity (79.6%), use of a subdural drain (80.6%), and no use of anti-convulsants or corticosteroids (82.1% and 86.6%, respectively). We identified a lack of consensus with keeping patients supine following surgery and post-operative antibiotic use.
The survey has identified variations in practice patterns among Canadian Neurosurgeons with respect to treatment of subacute or chronic subdural hematoma (SDH). Our findings support the need for further prospective studies and clinical trials to resolve areas of discrepancies in clinical management and hence, standardize treatment regimens 15).