Biportal and uniportal are the two endoscopic approaches to the spine. Uniportal surgery passes the camera and instruments through a single working channel, which suits disc herniations and small focal decompressions but limits what else can be done through it. Biportal surgery, also called unilateral biportal endoscopy (UBE) or BESS, uses two portals of about 7 to 10 mm, one for the camera and one for instruments, so the surgeon works with standard spine instruments. That freedom lets biportal endoscopy address what open spine surgery addresses, including discectomy, laminectomy, foraminotomy, and fusion, through ultra-minimally invasive incisions.
Side by side
| Category | Biportal (UBE / BESS) | Uniportal |
|---|---|---|
| Portals | Two: one for the camera, one for instruments | One: camera and instruments share a single channel |
| Instruments | Standard spine instruments, moving independently of the camera | Specialized instruments sized to pass through the single channel |
| Field of view | Camera angle and instrument angle adjust separately | Camera and instruments share one axis |
| Incisions | Two of about 7 to 10 mm | One of about 8 to 10 mm |
| Discectomy | Yes | Yes, its strongest indication |
| Laminectomy and bilateral decompression | Yes, including bilateral decompression worked from a single side | Limited to small, focal decompressions |
| Fusion | Yes, performed endoscopically as an endoscopic TLIF | Not routinely performed |
| Overall range | The full range of degenerative cervical and lumbar pathology | Disc herniation and small focal decompression |
What biportal endoscopy can do
The practical question is not which technique is newer or which uses fewer incisions. It is what each one can actually accomplish once the surgeon is inside the spine.
Uniportal endoscopy does one job very well. A contained disc herniation, or a small focal area of nerve compression, can be addressed cleanly through a single channel. Beyond that, the shared channel becomes the constraint: the camera and the instruments travel the same path, and the instruments are limited to those that fit alongside the scope.
Biportal endoscopy removes that constraint. Because the camera has its own portal, the surgeon uses standard spine instruments and moves them independently of the view. That is what makes the technique versatile enough to cover the range of degenerative spine work: discectomy, laminectomy and decompression for spinal stenosis, foraminotomy, posterior cervical decompression, and fusion performed endoscopically as an endoscopic TLIF.
Laminectomy is the clearest illustration. Decompressing a stenotic segment, including bilateral decompression worked from a single side, is routine biportal work and is not what the uniportal approach is built for. It is done through the same two 7 to 10 mm incisions, with the paraspinal muscles dilated through their natural planes rather than stripped off the bone.
The result is a technique that addresses what open spine surgery addresses, through an ultra-minimally invasive exposure.
Turning a fusion into a non-fusion operation
Some patients are told they need a fusion not because the segment is already unstable, but because the decompression required is more than a traditional approach can accomplish without destabilizing it. Taking enough bone and joint to free the nerve through an open exposure can leave the segment needing to be fused.
Biportal endoscopy changes that calculation. Working through small portals with an angled, magnified view, the decompression can often be completed while preserving the facet joint, the bone, and the muscle that keep the segment stable. When those structures are preserved, the fusion may no longer be necessary.
Converting a planned fusion into a non-fusion operation is one of the most valuable things this technique offers, because it preserves motion at the segment and avoids the longer recovery and hardware that fusion involves. Where a fusion genuinely is required, it can still be performed endoscopically.
Why Dr. Kazarian performs the biportal technique
Dr. Erick Kazarian performs biportal endoscopic spine surgery (UBE/BESS) at NYU Langone Health in New York City. He is the lead author of a peer-reviewed technical primer on unilateral biportal endoscopic spine surgery published in The Spine Journal. He is an invited AAOS lecturer on the biportal learning curve and serves as an instructor at national training labs where practicing spine surgeons are taught the biportal technique.
I offer endoscopic spine surgery to my patients because it is versatile enough to handle almost anything, it is exceptionally well tolerated, and it often lets me avoid a fusion entirely in patients who would otherwise need one.
Common questions
What is the difference between biportal and uniportal endoscopic spine surgery?
The difference is versatility. Uniportal surgery sends the camera and instruments down one shared channel, so they move together and the surgeon is limited to instruments that fit that channel. Biportal surgery separates them into two portals, which means standard spine instruments can be used and angled independently of the camera. That is why biportal endoscopy covers discectomy, laminectomy, foraminotomy, and fusion, while uniportal is best suited to disc herniations and small focal decompressions.
Can a laminectomy be done endoscopically?
Yes, with the biportal technique. Biportal endoscopy performs laminectomy and decompression for spinal stenosis, including bilateral decompression worked from a single side, through two incisions of about 7 to 10 mm. The muscles that support the spine are dilated rather than stripped from the bone. This is one of the clearest areas where biportal endoscopy does work that the uniportal approach is not well suited to.
Can endoscopic surgery avoid a fusion?
In selected patients, yes, and it is one of the most valuable things the biportal technique offers. Some patients are told they need a fusion because the decompression required is too extensive for a traditional approach to accomplish without destabilizing the spine. Biportal endoscopy can often achieve that decompression while preserving the bone, joint, and muscle that hold the segment stable, which can turn a planned fusion into a non-fusion operation. When a fusion genuinely is required, it can also be performed endoscopically as an endoscopic TLIF.
Is biportal endoscopy limited compared with open surgery?
In terms of what can be accomplished, no. Biportal endoscopy addresses the same pathology that open spine surgery addresses, including disc herniation, spinal stenosis, foraminal narrowing, and instability requiring fusion. The difference is the footprint: incisions of about 7 to 10 mm, muscles dilated through natural planes rather than cut from the bone, and typically same-day discharge.
Which technique does Dr. Kazarian perform?
Dr. Erick Kazarian performs biportal endoscopic spine surgery (UBE/BESS) at NYU Langone Health in New York City. He is the lead author of a peer-reviewed technical primer on unilateral biportal endoscopic spine surgery published in The Spine Journal and an invited AAOS lecturer on the biportal learning curve.
Am I a candidate for biportal endoscopic surgery?
Candidacy depends on your imaging and symptoms rather than on a fixed list of diagnoses, and the range of conditions the biportal technique can treat is wide. Dr. Kazarian reviews every patient's MRI personally and will tell you directly whether an endoscopic approach fits your case.
References
- Kazarian ER, et al. Primer on Unilateral Biportal Endoscopic Spine Surgery: Technical Overview for Beginners. The Spine Journal, 2025.
- Uniportal versus biportal endoscopic spine surgery: a comprehensive review. Expert Review of Medical Devices, 2023;20(7).
Related reading: Biportal endoscopic spine surgery in depth, am I a candidate?, and endoscopic spine surgery in New York City.