Chronic subdural hematomas: What a decade in practice has taught me
Over the past ten years, my practice has been quietly transformed by a condition that most medical students meet only briefly in their neurology rotation. Chronic subdural hematomas rarely make headlines, yet they fill operating lists in every major Australian neurosurgical unit and account for a steady stream of acute admissions. With an ageing population, the volume of cases I see in Sydney each year has climbed noticeably, and conversations with colleagues in Melbourne and Brisbane suggest the pattern is uniform nationally. The lessons I have gathered are not original to this specialty, but they deserve a single gathering place for trainees, general physicians, and patients who want to understand what modern care looks like.
What follows is not a systematic review but a working surgeon's account of what has changed, what has held up, and where the evidence still trails behind instinct. Some lessons are technical refinements I learned the hard way in theatre. Others concern how we counsel families, when we operate, and when we hold back. I have tried to be honest about the failures, because those have shaped my decisions more than the successes.
The shifting demographics behind these collections
When I began as a consultant, chronic subdural hematomas were still described in textbooks as a disease of the elderly alcoholic. That caricature is now thoroughly misleading. The typical patient on my Sydney list is a septuagenarian or octogenarian who fell at home, often in the garden or getting out of bed, and presented two to four weeks later with confusion or a slow gait. Brain atrophy, widespread anticoagulant use for atrial fibrillation, and the simple fact that Australians are living longer with more comorbidities have all converged to swell the caseload. The Australian Institute of Health and Welfare has documented the demographic shift repeatedly, and the operating theatres reflect the statistics.
A second demographic is harder to quantify but equally real. Middle-aged patients on dual antiplatelet therapy after coronary stents now present with sizeable collections following relatively minor trauma, and the conversation about whether to operate, when to reverse their medications, and how long to wait is increasingly common. Even in regional Queensland, where colleagues fly patients out from smaller centres, the age mix has broadened. The lesson is straightforward: any patient with a gradually progressive neurological change and a history of a head knock weeks earlier deserves imaging, regardless of age or the apparent triviality of the injury.
Surgical technique has become gentler and more deliberate
A decade ago, the default operation for many chronic subdural hematomas was a small craniotomy with membranectomy. Today, burr hole irrigation with a closed-system drain is the workhorse in most Australian units I have worked in, including those within the Royal Prince Alfred and Royal Melbourne networks. The shift is not merely cosmetic. Randomised trials have shown that simpler is at least as good, with shorter anaesthetic times, fewer complications, and comparable recurrence rates. I have moved with the evidence, and operating lists are noticeably calmer as a result.
That said, the gentler approach has its limits. Organised haematomas and acute-on-chronic collections still demand a more generous exposure. I now read the preoperative CT more carefully than I once did: membrane thickness, midline shift, and acute components all shape the incision I plan. I spend longer in clinic explaining why a small hole is usually enough but why we sometimes need to do more. The conversations are fuller, the consent forms longer, and the satisfaction, when recovery is smooth, is greater.
Anticoagulation decisions are now the hardest part
If there is one area where my practice has changed most, it is in managing anticoagulants and antiplatelets around the time of surgery. Warfarin was once the only real consideration, and reversal with vitamin K and prothrombin complex concentrate was straightforward. The arrival of direct oral anticoagulants has complicated everything. Rivaroxaban and apixaban are prescribed to enormous numbers of older Australians for atrial fibrillation, and delaying surgery while waiting for renal clearance has cost some patients weeks of hospital bed rest.
My current practice is to operate within 24 to 48 hours of presentation in symptomatic patients, using idarucizumab for dabigatran reversal when available and accepting a slightly elevated rebleed risk in others. The haematology teams I work with have developed pragmatic local protocols, and I would encourage any clinician to know theirs. The lesson is that procrastination is often the greater risk; a drained collection under imperfect anticoagulation is usually safer than an undrained collection in a deteriorating patient.
Recognising the presentations that fool us
Chronic subdural hematomas are sometimes called the great mimic, and the reputation is deserved. Headaches are common but nonspecific. Some patients present with what looks like a stroke, others with a slowly evolving dementia mistaken for Alzheimer's disease. I have seen misdiagnoses in general practice from Sydney's inner west to the Gold Coast, where atypical presentations include subtle personality change, gait disturbance mistaken for normal ageing, and isolated seizures in patients with no prior epilepsy history.
The lesson I keep relearning is to image early. A non-contrast CT is cheap, fast, and definitive in most cases. The cost of a scan in a public Australian hospital is trivial compared with the cost of a missed diagnosis that progresses to a fatal midline shift. Junior trainees sometimes apologise for requesting imaging they consider low yield. I tell them the opposite: in this condition, the yield is almost always worth the radiation and the waiting room.
Recurrence remains the most humbling outcome
No technique has eliminated recurrence, and my recurrence rate over the decade has hovered stubbornly around five to ten percent, broadly consistent with published Australian series. Some recurrences are technical: an inadequately drained cavity, an obstructed drain, a membrane that re-bleeds early. Others are biological: fragile neovascular membranes, ongoing brain atrophy that prevents re-expansion, and persistent anticoagulant use.
The lesson is to warn patients. Everyone I consent for surgery now hears the word "recurrence" and the possibility of a second operation. I also tell them about middle meningeal artery embolisation, which has emerged in recent years as a useful adjunct in recurrent or high-risk cases. Interventional neuroradiology colleagues are increasingly involved early rather than late, and that has changed outcomes. Patients who join the discussion on the forum often ask whether embolisation is right for them, and the honest answer is that it depends on anatomy, comorbidity, and local availability.
Training the next generation of Australian neurosurgeons
A working knowledge of these collections is part of the core curriculum for trainees sitting the Royal Australasian College of Surgeons neurosurgery examinations, yet exposure varies enormously. Trainees at high-volume metropolitan centres see dozens; those in rural rotations may see only a handful. The tyranny of distance, so often invoked in Australian medicine, applies here too. I have taught registrars via telehealth, supervising burr hole placements by camera from Brisbane out to remote towns, and the results have been reassuring.
The lesson is that technique is transferable but judgement is not. A trainee can be taught to drill a burr hole in an afternoon. Teaching them when to operate on a minimally symptomatic patient, when to reverse anticoagulation, and when to wait is a longer apprenticeship. Anyone wanting a deeper framework for perioperative decision-making in brain-injured patients may find the neurocritical care piece useful, since the same principles apply.
Comparing the main options at a glance
| Option | Typical indication | Recurrence risk | Average length of stay | Suitability in elderly |
|---|---|---|---|---|
| Burr hole irrigation with drain | First-line for most symptomatic cases | 5–10% | 1–3 days | Very good with careful anaesthesia |
| Mini-craniotomy with membranectomy | Organised, multilayered, or acute-on-chronic | 8–12% | 2–5 days | Acceptable but more invasive |
| Middle meningeal artery embolisation | Recurrent or high-risk cases, often as adjunct | 3–6% when combined | 1–2 days | Excellent when anatomy permits |
| Conservative management | Minimal symptoms, thin collections, high surgical risk | Not applicable | Variable, often weeks | Selected patients only |
The table is a snapshot, not a rule book. Local resources, radiology support, and patient preference all shift the choice. In rural Western Australia, for example, embolisation may simply not be available within a safe timeframe, and burr hole drainage remains the default.
Keep the conversation going
If this reflection has raised questions about your own practice, your training, or a relative's care, I would warmly invite you to bring them to the open peer forum on this site. Cases, complications, and disagreements are all welcome, because the senior lessons in chronic subdural hematoma surgery are still being written. For ongoing updates and clinical notes from my own list, subscribe by email and you will not miss the next instalment.