Revision TELD

When a disc herniates and a fragment is removed, a defect is left in the tough outer wall of the disc. In most people that settles, but in a minority a fresh fragment pushes out through the same weakened area at some point in the future — a recurrent disc herniation, bringing the sciatica back. This is not, in itself, a sign that the first operation was done poorly; it is a feature of the disc and the defect that any discectomy leaves behind. Certain factors, such as smoking, a large tear in the disc wall and diabetes, raise the risk.

Here is the heart of it. In a traditional open revision, the surgeon has to cut back down through the scar tissue of the first operation — scar that is stuck to the covering of the nerves — to reach the disc again, and that raises the risk of tearing the dura and irritating the nerve. The transforaminal endoscopic route approaches from the side of the body, through a virgin corridor that the previous operation never entered. It arrives at the disc from the front of the foramen, largely bypassing the posterior scar altogether, so the recurrent fragment can be reached and removed without dissecting through old adhesions stuck to the nerve. Less scar disturbed, less risk to the dura and the nerve, and a genuinely cleaner path to the target. For a re-do disc at a suitable level, this is, in my view, one of the most compelling uses of the transforaminal technique.

The operation follows the principles of a primary transforaminal discectomy, planned carefully from the imaging. Under x-ray guidance, and often with the patient awake enough to report sensation, the working sleeve is docked at the foramen through fresh tissue, a foraminoplasty is performed if needed to open the way, and the recurrent fragment — often stained with dye to distinguish it — is removed under direct magnified vision. Where scar is encountered, it is defined and separated under continuous irrigation, which lifts and floats the tissues and makes the plane between scar and nerve clearer than the naked eye allows. Decompression is confirmed when the nerve returns to its natural position and lies free.

Revision endoscopic surgery asks for particular judgement: recognising when the transforaminal corridor offers a clean path around the scar, handling the altered anatomy of a previously operated level, and knowing when a recurrence is better treated by removing the fragment alone versus stabilising the level with a fusion. These are decisions I make individually, and they draw on exactly the subspecialty experience in endoscopic technique that I have built my practice around. When the approach fits the problem, a recurrent disc that would otherwise mean a larger open re-operation can be dealt with through a few-millimetre corridor, around the scar rather than through it.

The evidence here is unusually clear. A randomised trial by Ruetten and colleagues compared full-endoscopic with microsurgical revision for recurrent disc herniation and found equivalent re-recurrence rates — around six percent — with fewer complications and less tissue trauma in the endoscopic group. Later cohorts and a recent systematic review confirm that endoscopic revision, and particularly the transforaminal route through fresh tissue, achieves good outcomes with low complication rates, and comparative studies favour it over open re-operation for tissue preservation and recovery. It is honest to note that a disc which has recurred once carries some risk of recurring again, and that revision surgery is, on average, a little less predictable than first-time surgery — points I discuss frankly with patients.

Because the endoscopic approach spares the tissues and largely avoids the old scar, recovery from a revision is often quicker than people expect from a re-do operation — many go home the same day or the next, walking, with relief of the leg pain often early. Some temporary nerve sensitivity can occur in the first weeks and usually settles; numbness and long-standing weakness may take longer and do not always resolve fully. Care is taken with lifting and bending early on, and the spine is followed up over the longer term.

• —Ruetten S, et al. Full-endoscopic versus microsurgical revision for recurrent lumbar disc herniation (RCT). (PMID 19342934)
• —Yoshikane K, et al. Full-endoscopic discectomy for recurrent lumbar disc herniation: patient-reported outcomes. (PMID 34435151 / PMC8356243)
• —Percutaneous endoscopic lumbar discectomy for recurrent disc herniation: systematic review and meta-analysis. (PMID 40242820 / PMC11998055)
• —Percutaneous endoscopic versus open microdiscectomy for recurrent lumbar disc herniation. (PMID 20062565)
• —Akmal S, et al. Risk factors for recurrent lumbar disc herniation: systematic review and meta-analysis. (PMID 26765413 / PMC4718239)
• —Gadjradj PS, et al. Full-endoscopic transforaminal versus open microdiscectomy: systematic review and meta-analysis. (PMID 35867477)