"Endoscopic" is one of those words that arrives in a consulting room already carrying more promise than it can reasonably deliver. Patients hear it and think "easier". Like "keyhole" and "minimally invasive".

Sometimes that is close to true. Often it is more complicated, and the complexity is worth understanding before you agree to anything.

So, it is worth setting out what the word actually describes, what changes for the person having the operation, and what does not change at all.

What the technique is

Most spinal surgery has historically been done through an "open" incision. The surgeon literally makes a cut as big as is required to do what comes next. When I was training I vividly remember a very senior mentor of mine (who made big cuts himself) remark on how his old boss used to say "big surgeons make big cuts" - now the inverse appears true - interpret this how you will. Following the skin incision - the only thing a patient really sees - we move the muscle off the bone to see the anatomy directly - as in with our eyes, and then work under direct vision, using a microscope for particularly precise manoeuvres.

Endoscopic spine surgery works differently. Instead of opening a corridor wide enough to look down directly, the surgeon passes a narrow tube through the tissue to the target - the endoscope shaft is around 6 to 7 mm across, through a skin incision of 8 to 10 mm. A camera and a light sit at the end of it, and the operating instruments pass down a working channel of about 4 mm. The surgeon works watching a screen rather than looking into the wound.

At this point I want to highlight that there are two endoscopic "schools of thought" - uniportal and biportal. It's exactly as it sounds - one technique uses a single port, the other, two. The pros and cons of these different, yet ultimately extremely similar approaches, are currently the source of many a publication by rival cohorts of surgeons who advocate for one over the other. As it stands, the literature is supportive of both, inasmuch as both demonstrate reliable efficacy and safety as compared to traditional techniques (Zhou et al), and in some ways it is akin to asking which of two football teams a surgeon supports. Both teams play the same sport, are closely matched in terms of their ability, but the reasons surgeons will give for why they support their individual team will probably have more to do with the other people they have trained with, than from having made an objective appraisal of the two teams and deciding based on the clear superiority of one over the other. What's more important is a practitioner's experience with either technique, and its judicious use for the specific indication a patient may have.

In addition, currently there are two well established endoscopic approaches or "routes" to the lumbar spine - interlaminar and transforaminal (as distinct from the difference between uniportal and biportal techniques, which relates to the hardware involved) - these describe the anatomical corridors that the endoscope itself will traverse, i.e. where the cut will be. While the interlaminar route is familiar to both open and endoscopic practitioners, it is a near technical impossibility to approach the neural foramen directly via an open incision, thus the transforaminal endoscopic technique is a somewhat novel and increasingly useful surgical approach to problems previously thought only amenable to an interlaminar one. Your surgeon will decide the appropriateness of each approach in your individual case, as each has its own advantages over the other, and multiple factors go into deciding which may be suitable. The transforaminal approach will result in a small incision on the flank, whereas an interlaminar one will be situated more recognisably in the small of the back.

The important difference here is not the camera. It is that the muscle is dilated and pushed aside rather than stripped off the bone. In a conventional open approach, the muscle has to be detached to give you a view. In an endoscopic approach, much of it never is.

That is the accepted explanation for why early recovery differs, and it has some direct support. Creatine kinase, the blood marker of muscle injury, runs lower after "MIS discectomy" (a predecessor of endoscopy, performed using muscle splitting tubes) than after microdiscectomy. MRI series also show less fatty replacement of the paraspinal muscle a year on.

It is worth saying plainly that the mechanism is not settled. The studies favouring endoscopy on this point are small, and several were authored by its most enthusiastic proponents.

So, I would put it this way: reduced tissue handling is the most plausible reason for the early difference, not a proven one. Anecdotally, I can confidently assert that most of the time, an endoscopic approach requires substantially less soft tissue disruption than an equivalent open procedure.

What changes for the patient

Three things, realistically.

The wound is smaller. Usually a centimetre or so per incision, rather than the 3 to 5 cm of an open microdiscectomy. Note "per incision" - some endoscopic techniques use two (or more, infrequently). That matters less cosmetically than people expect. Its practical value is narrower than the cosmetic one: wound infection is uncommon after either operation, running at roughly three or four in a hundred after open surgery and about one in a hundred after endoscopic, and the pooled analyses consistently favour the smaller wound even where the confidence intervals are wide.

Less muscle is disturbed. The muscles either side of your spine are not passive padding. They are part of what holds the spine upright and controls it. The muscle will heal after being detached, but the healing takes time and some of what returns is fat and fibrous tissue rather than working muscle.

Early recovery is usually quicker, and this is the best-evidenced benefit. Hospital stay is around a day or two days shorter. Opioid requirements in the first day are lower. In a Dutch randomised trial of 613 patients, 94% of the endoscopic group went home the same day, against 6% of the open group. Pain scores in the first 24 hours favour endoscopy by about one point on a ten-point scale.

Those are genuine advantages. But note what I have not said. I have not said it is painless, because it is not. I have not said it is risk-free. And I have not said the long-term result is better.

That last point deserves its own section.

What does not change

The nerve, the disc and the bone do not care how the surgeon reached them.

If the operation is a decompression - taking pressure off a nerve - then the objective is to take the pressure off the nerve. The decompression either achieves that or it does not, and the honest qualification is that achieving it is certainly harder through a port, particularly during the early phase in a surgeon's experience. Leaving disc material behind is the commonest reason an endoscopic operation has to be done again. In one national series of a technique's first 172 cases, 14% needed a second operation, and more than half of those were for residual disc.

Beyond that learning period, the picture converges. By six months there is no measurable difference between endoscopic and open decompression in pain or function, and that holds at one, two and five years. Where long-term differences do reach statistical significance they are too small to be noticeable to the patient. The access route changes your first fortnight considerably. It changes your second year very little.

The risks

The risks that matter in spinal surgery are largely the same either way: injury to the nerve or the dura, the membrane holding the spinal fluid; infection; bleeding; a disc recurring at the same level; and not getting the symptom relief you hoped for. Recurrent herniation runs at about 3 to 5% either way. Dural tears at about 1 to 3%.

Endoscopic access removes none of those, and it adds several of its own that patients are rarely told about.

Nerve irritation afterwards. Dysaesthesia - burning, tingling or hypersensitivity in the leg, from irritation of the nerve's sensory ganglion as the instruments pass it - is the signature complication of the transforaminal endoscopic route (not the interlaminar one). Reported rates vary enormously, from around 1.5% in some pooled reviews to over 20% in a large multi-centre series, with meaningful variation between surgeons. That spread is itself worth knowing: it is an unresolved question rather than a settled small number, and although it is usually temporary, this is not always the case.

Irrigation-related problems. Full-endoscopic surgery runs under continuous saline flow. If the pressure is too high it can raise pressure inside the skull, causing headache, neck pain, blurred vision or drowsiness, and in rare cases seizures. Rare.

Radiation. The percutaneous route is guided by X-ray. Fluoroscopy times are typically longer than for open surgery, so the trade for less tissue trauma is more radiation - to the patient, and cumulatively to the surgeon. In reality the increased radiation exposure to patients themselves is negligible however.

Less room to solve a problem. The working space is small, the image is two-dimensional - so you lose depth perception, and most tactile feedback. Additionally, the instruments used are necessarily altered to facilitate use down the scope, usually with the tradeoff that they are at least somewhat less effective. The practical consequence is that a problem which may be manageable in an open field is harder to deal with through a port. A tear in the dura is the clearest example: under a microscope it can usually be repaired directly, however through an endoscope it often cannot. The significance of this fact is unclear, as this approach is an altogether complete reimagining of the original procedure; I can say anecdotally that dural tears which would otherwise require repair in the open setting often don't in the endoscopic setting, due to other differences in the surgical field owing to the approach.

That said, an endoscopic operation occasionally needs to be converted into an open one (i.e. the operation you would have got anyway) - a decision your surgeon makes during the operation, while you're still asleep - most often for bleeding that cannot be controlled through the port. Published series report this only sporadically and there is no reliable figure for how often it happens, which is itself worth knowing. A patient consenting to an endoscopic operation should understand conversion as a possibility rather than a failure - and if it happens, it was for a good reason.

Who it suits, and who it does not

The endoscopic technique is best utilised for a well-localised problem, in a reachable place. A single disc fragment pressing on a single nerve root is close to the ideal case.

It suits the situation less well when the problem is spread across several levels, when multiple pathological structures need decompressing, or when the spine needs stabilising rather than a simple decompression alone. Roughly two-thirds of the degenerative spinal work I have performed over my career was decompression alone; the remaining third involved stabilisation or fusion. Endoscopy speaks much more directly to that first two-thirds.

Although many would instinctively think the limitations of endoscopic techniques would preclude revision surgery, a review of the literature suggests otherwise. A published meta-analysis comparing endoscopic versus "conventional" discectomy for recurrent disc herniation found outcomes comparable to open revision, with fewer complications and shorter operating times (Lu et al). Another systematic review demonstrated the efficacy and safety of exploiting the transforaminal route for revision cases, whereby the recurrent disc material can be reached while avoiding the scarred plane of the first operation, though this study did not compare the two techniques side by side; a study comparing transforaminal endoscopic discectomy versus microendoscopic discectomy for non-recurrent pathology also showed comparable results (Chen et al).

For more complex reconstructive work, the case is much less settled. Endoscopic fusion techniques do better than open surgery on blood loss, hospital stay and early back pain, but show no advantage in complication rates, fusion rates or disability scores, and most of that evidence is non-randomised. Anyone telling you the question is closed is ahead of the literature. Ultimately, endoscopic fusion techniques are substantially more involved than those used for decompression alone, and fall outside the purpose of this topic beyond this mention.

The bit nobody mentions

There is a learning curve, and it is steeper than it looks from the outside.

This is not a small adjustment to an existing skill - such as turning a screw left instead of right. Working from a two-dimensional screen, through a narrow port, with instruments that move differently, and anatomy that looks unfamiliar (both due to their presentation on screen and their infrequently seen anatomical relationships), is a distinct skill that has to be learned largely from the beginning.

The numbers on this are sobering and they are the most important thing in this article. Studies putting a figure on competence land somewhere between roughly 20 and 50 cases depending on the technique. Inside one randomised trial, a surgeon still on the learning curve had a one-year reoperation rate of 17%, against 2% for the experienced surgeon in the same trial - and 6% for conventional open surgery.

Structured training with an experienced surgeon measurably shortens that curve.

Neurosurgeons do use endoscopes in the brain, and orthopaedic surgeons similarly use arthroscopes (endoscopes by another name) in most other joints. My own impression is that the arthroscopic habit transfers more usefully to a working-channel endoscope than intracranial endoscopy does, though this perhaps only confers benefit early on in the learning curve. I should be clear that this is an impression: I am not aware of any study comparing learning curves by a surgeon's prior endoscopic background.

Adoption has divided the field, and in my observation it has not divided along the lines you would expect - some senior surgeons have taken it up readily, and some much younger ones remain unconvinced. That is an impression too. Nobody has published adoption data.

For a patient, all of this translates into a reasonable question, politely asked: how many of these has the surgeon done, and what do they do if it needs converting? A surgeon who is confident about the technique will not mind being asked.

Would I undergo an endoscopic procedure myself - all things being equal, yes. But I would approach it with a clear understanding that whilst there are potential short term benefits over the more established techniques, these benefits are small. I would also be realistic about the fact that there are limitations with any technique, and that my ultimate goal is relief of my symptoms for which I sought treatment - not to just end up with a smaller scar.

The point

Endoscopic spine surgery is a real advance, most clearly in the first two weeks, and I expect a smaller wound to prove an advantage in infection risk as the data mature. It is not a different operation with better odds. It is a better-tolerated route to the same operation, carrying a few risks of its own, and only worth considering when that operation is the right one to be doing in the first place.

Which is the harder question, and the more important one.

Disclosure: since 2017 I have worked as a proctor for Medtronic, teaching oblique lateral interbody fusion (OLIF) technique. Readers should weigh that when I write about surgical access. I have not performed endoscopic spinal surgery in my own right; I have assisted on it, watched it closely, and intend to take it up - which is the vantage point this article is written from.

This article is general information about a surgical technique. It is not advice about your own care, and it is not a substitute for the consent discussion, which covers the general risks of surgery and anaesthesia as well as those described here.

Principal sources: Chin et al., Spine Journal 2024; Tang et al., Annals of Palliative Medicine 2021; Gadjradj et al., Spine 2021 and BMJ 2022; Gadjradj et al., Neurospine 2022 (learning curve); Ju & Lee, Neurospine 2023 (complications); Lewandrowski et al., Clinical Neurology and Neurosurgery 2020 (dysaesthesia); Arts et al., European Spine Journal 2011 (muscle injury); Lu et al., Indian Journal of Orthopaedics 2022 (revision); Musa et al., International Journal of Spine Surgery 2025 (transforaminal endoscopic discectomy for recurrent herniation); Chen et al., Spine 2023 (five-year randomised comparison, transforaminal endoscopic versus microendoscopic discectomy); Zhou et al., Journal of Orthopaedic Surgery and Research 2025 (uniportal versus biportal); Terkelsen et al., Acta Neurochirurgica 2024.