Biportal or Uniportal? How Gangseo-gu Endoscopic Spine Surgery Approach Is Chosen-Seoul One Hospital

For lumbar disc herniation with months of leg pulling, how does Seoul One Hospital decide between uniportal and biportal endoscopic surgery?

Key Answer

For lumbar disc herniation with leg pulling that has lasted for months, if the area of compression is narrow and only the disc has herniated, I choose uniportal endoscopic surgery. If the stenosis is widespread or the foraminal area is also narrowed, I choose biportal endoscopic surgery.

With both approaches, the compressed area is first identified on MRI, and the decision is made only after observing the response to non-surgical (conservative) treatment.

The current evidence shows that, in terms of relieving leg pain, there is no major mid- to long-term difference among the two endoscopic approaches and open microscopic discectomy.

Questions This Article Answers

• If leg pulling has lasted for months, should I get endoscopic surgery right away?
• What criteria distinguish uniportal from biportal endoscopic surgery?
• If several spinal segments look abnormal at once, do all of them need surgery?
• What complications can occur after endoscopic surgery?
• In what order does Seoul One Hospital make these decisions?

I am Dr. Chang-Hee Cho, a board-certified orthopedic surgeon and Director of the Spine Center at Seoul One Hospital.

I frequently see patients from the Hwagok-dong area who have endured leg pulling and tingling for months and finally come in, exhausted, in the late afternoon or evening.

Many start out managing the pain with patches or heat packs, and only visit the hospital once they notice the area of leg pulling expanding or their walking distance shrinking.

Today I'd like to lay out the criteria I actually use to decide between uniportal and biportal endoscopic surgery for patients who have been struggling with leg pulling for months.

If Leg Pulling Has Lasted for Months: What to Check First-Location and Extent of Compression

Leg pulling and tingling present similarly whether the cause is lumbar disc herniation or lumbar spinal stenosis, so symptoms alone cannot distinguish between the two conditions.

After listening to the patient's history, I always check MRI to identify which spinal segment and nerve root are compressed, and the extent of that compression.

If the disc has herniated to one side and is compressing only a single nerve root, the area requiring treatment tends to be small. If the stenosis is widespread or both neural foramina are narrowed, the area requiring decompression is itself large.

Whether the area of compression is narrow or wide is the first criterion that separates uniportal from biportal endoscopic surgery.

This initial judgment is made at the point the MRI is reviewed, and is then adjusted further based on the response to conservative treatment.

That's why, from the initial MRI interpretation stage, I record the extent of compression by segment and use it to design the treatment plan.

What's the Difference Between Uniportal and Biportal Endoscopic Surgery?

Uniportal endoscopic surgery (UED) uses only a single incision site, so there is less damage to the skin and muscle, but because the endoscope and instruments both enter through the same single portal, the field of view and instrument angles are somewhat limited.

For this reason, it is suitable for cases where only the disc has herniated, or where the area requiring treatment is narrow and symptoms are relatively mild.

Biportal endoscopic surgery (BESS, biportal endoscopic spine surgery) uses two incision sites, but because the portal for viewing through the endoscope is separate from the portal for handling instruments, it allows a wider field of view and more flexible maneuvering.

This is the approach I choose more often when stenosis is severe and requires extensive decompression, or when there is a possibility that the area of compression will turn out to be wider than expected during surgery.

Both approaches use continuous irrigation with saline during surgery, which helps reduce infection risk, and the incisions are made at under 1cm.

At the level of evidence, a non-inferiority study of 613 patients found that at 12 months, leg pain scores were actually lower in the endoscopic group than in the open microscopic discectomy group, and reoperation rates were similar between the two groups at 5% and 6%. Source

A meta-analysis pooling 14 studies also found no statistically significant difference between endoscopic and open microscopic discectomy in either leg pain or functional recovery over the mid- to long-term (moderate-quality evidence). Source

However, some reports note that minimally invasive surgery showed slightly worse back pain scores than open surgery, so while relief of leg pain is comparable or slightly better, this does not mean back pain improves equally well with both approaches.

I make the final decision on whether uniportal is sufficient or whether to expand to biportal by considering both the extent of compression and the condition of the nerve as confirmed during surgery.

That's why, at Seoul One Hospital, we adjust the approach by combining the pre-surgical MRI interpretation with the endoscopic field of view confirmed during surgery.

How We Differentiate When Several Segments Appear Abnormal at Once

Even when two or three lumbar segments appear degenerated together on MRI, the segment actually causing the symptoms is usually just one.

A patient who recently visited had disc degeneration findings at 2-3 segments on MRI, but when I matched the pattern of leg pulling and tingling with the neurological exam findings, the causative segment narrowed down to just one.

In such cases, I do not set the entire area shown on imaging as the surgical scope. Instead, I compare the pattern of symptoms, nerve distribution, and physical exam findings to identify the actual causative segment.

Conversely, when multiple segments are severely affected together and the spine itself is unstable, as in spondylolisthesis, I make a different judgment.

In such spines, decompression alone via endoscopy may have insufficient effect, or symptoms may worsen again not long after surgery.

So in these cases, I consider spinal fusion rather than endoscopic surgery from the outset.

Even when multiple segments look abnormal, identifying the actual causative segment comes first, and if the spine itself is unstable, the judgment shifts from endoscopic surgery toward fusion.

That's why I go through the process of re-comparing the MRI findings against the clinical symptoms every time.

Limitations and Precautions: Endoscopic Surgery Is Not Suitable for Everyone

Endoscopic surgery is not suitable for every case of lumbar disc herniation or lumbar spinal stenosis.

Please check the following items for self-assessment.

• Has leg pulling lasted more than 3 months and is the area gradually expanding?
• Is the distance you can walk before needing to rest gradually shortening?
• Do you feel weakness in your ankle or toes?
• Does pain shoot down your leg when you cough or sneeze?
• Does the pain return within 2-3 weeks even after medication, injections, or physiotherapy?

If several of these apply, and especially if there is weakness in the ankle or toe muscles or a persistent decrease in walking distance, it is time to actively consider endoscopic decompression.

Conversely, in the following cases, an approach other than endoscopic surgery alone is needed.

• Cases where several segments are severely unstable at once, accompanied by spondylolisthesis
• Cases where surgery itself must be minimized due to general anesthesia risk or prior surgical history, but the compression is too extensive for decompression alone to secure stability

You should also be aware of warning signs. Sudden bowel or bladder dysfunction, rapid weakness in both legs, or new numbness or weakness caused by nerve root injury are signals requiring emergency evaluation.

Even after surgery, sudden worsening of pain accompanied by neurological symptoms may indicate a post-surgical hematoma, which is one of the reported complications — if such changes occur, immediate evaluation is needed. Source

The pooled complication rate for uniportal endoscopic spine surgery is reported at 9.79%, broken down into dural tear at 3.75%, nerve palsy at 2.69%, post-surgical hematoma at 0.24%, infection at 0.01%, and reoperation at 2.39%. Source

Complications are rare but are actually reported figures, so I design the surgical scope and approach in a way that minimizes them.

That's why, at Seoul One Hospital, we prioritize minimally invasive approaches that minimize complications such as bleeding, infection, and dural injury, and immediately reassess if warning signs appear.

How Is Seoul One Hospital's Approach to Care Different?

I design spinal care as a step-by-step structure that escalates from medication and physiotherapy, to nerve block injections and neural blockade, to percutaneous epidural neuroplasty (including balloon decompression), to minimally invasive endoscopic spine surgery, and finally to spinal fusion.

For patients who improve sufficiently with medication and physiotherapy, treatment ends there, and we move to the next step only if there is no effect.

In practice, if pain decreases by 60-80% after 2-3 rounds of injection treatment and that improvement is maintained for 2-3 months or longer, I judge that conservative treatment is sufficient. But for patients whose pain returns within 1-2 weeks of an injection and who need repeated injections, I recommend moving up to a procedure or surgery.

For cases where MRI shows a severely ruptured disc with worsening symptoms or signs of paralysis, I do not insist on conservative treatment alone from the start, and instead recommend active decompression.

I once had a patient who wanted medication-only treatment despite having paralysis symptoms. After confirming the degree of nerve compression on MRI, I performed decompression surgery, and the pain decreased noticeably first after the surgery.

The sensory and motor paralysis showed a gradual course of recovery over 2-3 months, and in some cases over a year or longer.

Our hospital has operated an integrated nursing care ward since November 2022, with nursing staff present 24 hours a day, so patients can be admitted without a caregiver or family member present.

At Seoul One Hospital, we track each patient's area of compression and response to conservative treatment step by step, and select only the minimum necessary treatment — whether that is uniportal or biportal endoscopic surgery, or fusion.

As of 2024, I apply this same step-by-step principle to patients from the Hwagok-dong and Gangseo-gu areas who are considering endoscopic spine surgery.

Frequently Asked Questions

If leg pulling has lasted for months, should I go straight to biportal endoscopic surgery?

The duration of symptoms alone does not determine the approach.

After confirming the extent of compression on MRI and observing the response to conservative treatment, I consider biportal surgery if the area is wide, and uniportal surgery if it is narrow.

Why is uniportal endoscopic surgery said to leave a smaller scar?

Because there is only one incision and access pathway, the route through the skin and muscle ends at that single portal.

However, this also means the field of view and instrument angles are limited, which may make it unsuitable for widespread stenosis requiring a larger treatment area.

When should endoscopic surgery be considered?

It becomes a candidate option when there is no improvement despite sufficient conservative treatment such as medication, physiotherapy, and nerve block injections, or when weakness in the ankle or toe muscles or a decrease in walking distance is progressing.

If there are signs of paralysis, we do not prolong conservative treatment and instead proceed directly to testing and a decision on surgery.

For whom is endoscopic surgery not suitable?

In cases where several segments are severely unstable at the same time, accompanied by spondylolisthesis, decompression via endoscopy alone may have insufficient effect, so fusion is considered first.

For patients with significant concerns about general anesthesia or prior surgical burden, the surgical scope and approach are discussed even more carefully.

Key Takeaways

• If leg pulling has lasted for months, the starting point is to first check the extent of compression on MRI.
• If the compression is narrow and only the disc has herniated, uniportal surgery is considered; if the stenosis is widespread, biportal surgery is considered.
• The mid- to long-term evidence shows no major difference in relief of leg pain between endoscopic surgery and open microscopic discectomy.
• Even when several segments appear abnormal, identifying the actual causative segment comes first, and if the spine is unstable, fusion is considered.
• Seoul One Hospital follows a step-by-step approach, from medication to fusion, selecting the most minimal treatment necessary at each stage.

Dr. Chang-Hee Cho, a board-certified orthopedic surgeon, completed a spine fellowship at Seoul St. Mary's Hospital, The Catholic University of Korea, and is a spine specialist certified by the Korean Spinal Society. Profile

Seoul One Hospital is located at Dongmyeong M Building, 179 Gangseo-ro, Gangseo-gu, Seoul, a 1-minute walk from Exit 8 of Hwagok Station.

Clinic hours are weekdays from 9:00 AM to 6:00 PM (lunch break 1:00-2:00 PM), and Saturdays from 9:00 AM to 1:00 PM. Closed Sundays and public holidays.

If your leg pulling has been persisting, we recommend starting with an MRI to check the area of compression.