Is Trephination Still Used Today? Yes, and Why

Trephination, the practice of making a hole through the skull, remains one of the most commonly performed neurosurgical procedures worldwide. Modern surgeons call the openings “burr holes” and use high-speed drills instead of hand-scraped stone tools, but the core idea is identical to what healers were doing thousands of years ago: remove a disc of bone to access or relieve pressure inside the cranium. Far from being an obsolete relic, the technique has branched into a surprisingly wide range of applications across emergency medicine, intensive care, elective surgery, and even fields that have nothing to do with the brain.

A Very Old Idea That Never Went Away

The oldest known trephined skulls date back to the Neolithic period. Excavations in southwestern Germany, for instance, have turned up skulls with neat holes that show clear signs of bone healing, meaning the patients survived long enough afterward for their bodies to begin repairing the wound.¹ And these were not flukes. Studies of Late Iron Age skulls from Switzerland found a survival rate of about 78%, suggesting the procedure was performed skillfully and often successfully even without anesthesia, antibiotics, or imaging.² What the ancients used the procedure for is debated: some skulls show trauma near the hole, implying treatment for head injuries, while others show no obvious pathology, hinting at ritual or spiritual purposes.

What matters for the modern story is that the underlying principle proved sound enough to survive every revolution in medicine since. When antiseptic technique, general anesthesia, and neuroimaging arrived, trephination did not become obsolete. It became safer and more precise, and its indications expanded rather than contracted.

Emergency Evacuation of Blood Clots

The most urgent modern use of a burr hole is to drain blood that has collected between the skull and the brain after head trauma. An epidural hematoma, where blood pools between the skull and the tough outer membrane covering the brain, can compress the brain rapidly and become fatal within hours. The classic emergency treatment is a full craniotomy, where a larger flap of bone is temporarily removed, but in certain situations a simpler burr hole can be enough. A case series of eight patients with epidural hematomas that were developing relatively slowly found that all were successfully drained through burr holes alone, with consciousness improving within the first day and none needing a follow-up craniotomy.³

This is not the go-to approach for every brain bleed. In patients whose condition is deteriorating quickly or whose hematoma is large and complex, a full craniotomy gives the surgeon better visibility and control. But the burr hole option matters in two important scenarios: when the patient’s blood does not clot well (making a bigger surgery riskier), and when neurosurgical facilities are limited or far away. A published guide on emergency burr holes describes the technique as a lifesaving measure that can be performed when specialist neurosurgical intervention is simply not available.⁴

The Most Common Reason for Burr Holes Today

If emergency hematomas are the dramatic use case, chronic subdural hematomas are the bread-and-butter one. A chronic subdural hematoma is a slow bleed that builds up between the brain and its membranes over weeks, often after a seemingly minor bump to the head. It is increasingly common in older adults, partly because the aging brain shrinks slightly within the skull, stretching the delicate veins that bridge the gap. Blood thinners, widely prescribed in the same age group, raise the risk further.

The standard treatment is burr-hole craniostomy: one or two small holes drilled through the skull under local anesthesia, through which the collected blood is drained. A retrospective study of 322 elderly patients (average age 76) who underwent burr-hole craniostomy found that favorable neurological outcomes were achieved in the majority, with overall surgical mortality of under 3%.⁵ Even among patients over 80, mortality and complication rates were comparable to younger age groups, and age alone was not an independent risk factor for worse outcomes.⁶ A systematic review confirmed that surgery for chronic subdural hematomas in older adults was superior to conservative management, with recurrence and reoperation rates similar to those in younger patients.⁷

The same procedure works in very young patients, though the causes differ. In children under two, chronic subdural collections can develop after birth trauma or non-accidental injury. A study of 25 such children found that burr-hole craniotomy without continuous drainage resolved the problem in 80% of cases on the first attempt, with no procedure-related complications.⁸

Relieving Pressure from Fluid Buildup

Hydrocephalus, an abnormal accumulation of cerebrospinal fluid inside the brain’s ventricles, is another condition that regularly calls for a burr hole. The most common neurosurgical treatment for acute hydrocephalus is to drill a small hole and thread a thin catheter through it into the ventricle, creating an external ventricular drain (EVD) that diverts the excess fluid into a collection bag at the bedside.⁹ The entry point is usually a landmark on the skull called Kocher’s point, identified using surface measurements.¹⁰

Getting the catheter tip into the right spot matters: if it lands in the wrong place, the drain does not work properly. Refinements to the technique have included endoscopic guidance and modified entry points. A study of 200 patients who underwent ventriculostomy through a modified Kocher’s point demonstrated that small adjustments to the standard approach could improve placement precision.¹¹ This is one area where the ancient principle of “make a hole, relieve the pressure” has been refined with modern imaging and navigation technology but remains fundamentally the same act.

Precision Access for Deep Brain Stimulation

Not every burr hole is about emergencies or draining fluid. In deep brain stimulation (DBS), a treatment for Parkinson’s disease, essential tremor, and certain psychiatric conditions, surgeons drill small holes in the skull to insert electrodes into specific targets deep within the brain. The electrodes deliver continuous electrical pulses that modulate abnormal neural circuits. Here, the burr hole is not the therapy itself but the gateway for it, and precision matters enormously: even a millimeter of error can mean the difference between symptom relief and side effects.

A recently described technique creates partial burr holes, drilled only about 8 mm deep, with the remaining bone perforated by a much narrower drill bit. This “half burr hole” approach, used with a robotic surgical system, aims to reduce the amount of brain shift that occurs when the skull is fully opened, improving the accuracy of electrode placement in targets like the anterior thalamic nucleus.¹² It is a good example of how the basic concept keeps being reinvented to meet new clinical demands.

Smarter Drills and Safer Bedside Procedures

One of the practical challenges of drilling through a skull has always been knowing when to stop. Push too far and you risk injuring the brain tissue underneath. Traditional pneumatic drills used in operating rooms have a mechanical clutch that disengages once bone resistance drops, but newer portable drills designed for bedside use take a different approach. A safety analysis of one such device described an electrical “smart autostop” mechanism that halts the bit the moment it senses breakthrough, making it suitable for single-use bedside procedures in intensive care units where bringing the patient to a full operating room is impractical or risky.¹³

The development of bedside-friendly tools reflects how common burr-hole procedures have become in neurocritical care. When a patient in the ICU develops sudden hydrocephalus or a new bleed, there is real clinical value in being able to perform the procedure right there rather than transporting a critically ill patient through hospital corridors. The COVID-19 pandemic added another dimension to this: a comparative study of different craniotomy techniques during the pandemic found that traditional hand trephination produced far fewer aerosolized droplets than electric drills or saw methods, and none of the surgical team members assisting the trephination group tested positive for COVID-19 in the week following surgery, compared to 13 positive team members in the groups using powered instruments.¹⁴

Burr Holes in Battlefield and Remote Medicine

Perhaps the starkest modern parallel to ancient trephination is the military use case. When a soldier sustains a traumatic brain injury in a combat zone, the nearest neurosurgeon may be hours or even days away. A recent practical guide published in a military health journal lays this out bluntly: experience from the war in Ukraine and planning for large-scale combat operations have reinforced the need for non-neurosurgeons, including general surgeons and emergency physicians, to be capable of performing emergency burr-hole craniostomy in resource-constrained settings without imaging or electrical power.¹⁵

The guide describes a manual technique that would be recognizable, in broad strokes, to a surgeon from centuries past. The key difference is the standardized training, the understanding of neuroanatomy, and the knowledge of when the procedure is and is not appropriate. Military medicine accepts a trade-off that civilian medicine usually does not have to make: the procedure carries risks, but doing nothing in a patient with a rapidly expanding blood clot inside the skull is almost always worse.

Trephination Beyond the Skull

The word “trephine” in medical language refers to any cylindrical cutting tool that removes a disc of tissue, and the concept has migrated well beyond neurosurgery. In ophthalmology, corneal trephines are used during corneal transplant procedures to cut precise circular discs from donor and recipient corneas. A guided trephine system allows surgeons to cut the recipient cornea to a specific depth, then replace it with a matching donor disc.¹⁶ Comparative studies have evaluated different trephine designs, including vacuum-assisted metal blade trephines and laser-based alternatives, to minimize damage to the delicate inner cell layer of the cornea.¹⁷

In veterinary medicine, trephination of the paranasal sinuses is a routine procedure for horses with chronic sinusitis. Because a horse’s sinuses are large and deeply recessed, surgeons drill through the facial bones to access them for drainage and inspection. A review of 229 horses treated by sinus trephination found that the technique is commonly combined with modern imaging like computed tomography and sinoscopy to guide the placement of holes and improve drainage.¹⁸ The horses typically stand for the procedure under sedation, which is about as far from the dramatic image of brain surgery as you can get while still technically performing trephination.

What It Actually Feels Like for the Patient

Many people are surprised to learn that burr-hole surgery for chronic subdural hematomas is typically performed while the patient is awake, under local anesthesia only. A study of 50 patients (average age around 73) who underwent awake burr-hole trepanation surveyed their experience both shortly after surgery and six months later. About half reported some pain during the procedure, with an average pain score of roughly 4 out of 10. Postoperative pain was milder, averaging about 3 out of 10. Satisfaction with how the surgical team communicated during the operation was high, averaging over 8 out of 10.¹⁹

One cosmetic concern that patients sometimes raise is the visible or palpable dent left in the scalp after the procedure. Without a cover, the soft tissue over the burr hole tends to sink inward as it heals. A pilot study compared covered and uncovered burr holes and found that skin depressions occurred over roughly 92% of uncovered holes but only about 7% of those fitted with a small titanium plate. Patient satisfaction with the cosmetic result was significantly higher when covers were used, and the covers did not increase infection risk or interfere with hematoma recurrence monitoring.²⁰

Repairing the Skull Afterward

When burr holes are small, they often heal on their own or are left as is, especially in elderly patients for whom an additional procedure may not be worth the risk. But when larger portions of skull are removed during a full craniotomy (for tumor surgery, severe trauma, or decompressive procedures), the resulting defect needs to be repaired. This follow-up surgery, called cranioplasty, aims to restore the skull’s protective function and normal contour. A variety of materials have been used throughout the history of the procedure, including the patient’s own stored bone flap, titanium mesh, and various synthetic polymers and ceramics. Despite decades of research, there is still no consensus on the ideal material: each has trade-offs in terms of infection risk, long-term durability, and how well the body tolerates it.²¹ The psychological benefit of cranioplasty is worth noting. Patients with large skull defects often report anxiety, social withdrawal, and a sense of vulnerability from having an unprotected area of their brain. Restoring the skull’s shape can meaningfully improve quality of life beyond the purely structural repair.

Self-Trepanation and the Fringe

No article about modern trephination is complete without addressing its strangest chapter. Since the 1960s, a small subculture has promoted voluntary trepanation as a way to increase cerebral blood flow, elevate consciousness, or achieve a permanent high. The movement traces largely to a Dutch former medical student who published writings suggesting that opening a hole in the skull could reverse the supposed loss of brain pulsation that occurs when the skull’s fontanelles close in infancy. Dozens of people have sought out trepanation for these purposes over the decades, and some have attempted it on themselves.²²

The medical community has no time for these claims. There is no credible evidence that drilling a hole in a healthy skull improves cognitive function, mood, or spiritual awareness. The risks, on the other hand, are very real. A case report described a 56-year-old woman with schizophrenia who chronically excavated her own scalp and skull due to delusional beliefs, resulting in exposed brain tissue, a polymicrobial bone infection, bilateral subdural hematomas, and a brain abscess with significant swelling.²³ While this case involved psychiatric illness rather than a wellness-motivated trepanation, it illustrates the catastrophic potential of breaching the skull outside of a sterile, controlled surgical environment. The skull exists for a reason, and opening it safely is the domain of trained surgeons with imaging, instruments, and a defensible clinical indication.