Biportal Endoscopy in the Aging Spine

The population presenting to spine clinics in Korea has changed during my career, and the change is not subtle. In the early 2000s, a typical operative candidate for lumbar decompression was a working-age adult with a focal disc herniation. The same clinic today sees a different profile: patients in their seventies and eighties with multi-level degenerative stenosis, often with comorbidities that complicate not only the choice of operation but the very decision to operate. Korea's demographic trajectory—among the fastest-aging societies in the OECD—has translated, in the operating room, into a steadily older mean age at the time of spine surgery.

This shift has occurred at the same time that surgical technique has evolved. The question of whether biportal endoscopic spine surgery has a particular role in elderly patients is therefore not abstract. It is being asked in clinic, in radiology rounds, and in preoperative anesthesia consultation every week.

The case for considering biportal endoscopy in this population rests on several observations, none of which are unique to elderly patients but which acquire additional weight in their context.

The first is the preservation of the posterior musculoligamentous complex. Conventional open laminectomy requires detachment and retraction of the paraspinal musculature, with predictable consequences for postoperative axial pain, recovery time, and the subsequent biomechanics of the lumbar spine. In a patient in her thirties, this trade-off is often acceptable; in a patient in her eighties, it carries different weight. Reduced muscular disruption may shorten the period of inpatient immobility, during which the risks of pneumonia, deep venous thrombosis, and functional decline accumulate with each additional day.

The second is the reduction of intraoperative blood loss. Elderly patients on antiplatelet agents—a substantial proportion of the candidates I see—have physiologic margins that do not tolerate the blood loss of an extensive open exposure. The continuous saline irrigation of the biportal endoscopic field, in addition to its optical function, has the practical effect of limiting hemorrhage from the bony surfaces and the epidural venous plexus. This is, in itself, a modest advantage in younger patients; it can be a meaningful one in patients whose physiologic reserve is limited.

The third is the bony and ligamentous restraint of the approach. In our 2022 systematic review of biportal endoscopic decompressive surgery for lumbar stenosis (Heo DH, Park DY, Hong HJ, et al. World Neurosurgery), my colleagues and I noted that the technique permits decompression of the central canal, the lateral recess, and the foramina with limited resection of the facet joint complex. In an osteoporotic spine, where the facets are already mechanically compromised, this preservation may reduce the secondary risk of postoperative instability—a complication that, in the elderly patient, is often the precipitant of further surgery.

The argument for biportal endoscopy in the aging spine is most compelling, in my reading of the evidence, in the setting of thoracic spinal stenosis secondary to ossification of the ligamentum flavum (OLF). OLF is a disease of older Asian populations, and the conventional surgical option—open posterior thoracic laminectomy with en bloc removal of the ossified ligament—carries a non-trivial risk of intraoperative spinal cord injury. In our 2023 series (Kim JY, Ha JS, Lee CK, Lee DC, Hong HJ, et al. Neurospine), we documented that the outside-in, en bloc decompression technique via biportal endoscopic approach can be performed with limited bony resection and with avoidance of the inside-out piecemeal removal that, in our early experience, was associated with neural injury. The technique remains demanding; it is not a beginner's procedure. But for this specific pathology in this specific demographic, it has appeared to me to offer a meaningful advantage.

Several caveats must accompany this argument.

The first is patient selection. Severe deformity, multi-level fusion needs, or anatomy distorted by prior surgery may move the case outside the comfortable indications of the biportal approach. There is no virtue in fitting a patient to a procedure rather than the reverse.

The second is the learning curve. The technique is unforgiving in its early stages, and the consequences of intraoperative complications are not less serious in elderly patients—they are more serious. A surgeon who is in transition to this approach should not be doing so on the most fragile patients in the practice. The literature on early-learning outcomes, including our own comparative analysis of uniportal and biportal TLIF (Kim JY, Hong HJ, et al. JMISST, January 2024), suggests that the technique requires deliberate, paced acquisition. This is a clinical and ethical fact, not only a technical one.

The third is the limits of what surgery itself can accomplish. The aging spine is, often, the aging patient: cardiac disease, pulmonary insufficiency, cognitive change, polypharmacy. Decompression of a stenotic canal does not address these. A surgeon who proposes operation to an elderly patient should be confident not only that the procedure is appropriate but that the patient is. This is the older clinical question, and it remains the more important one.

What I think the biportal endoscopic approach offers, in the right cases, is an additional tool for situations in which the surgical morbidity of the conventional alternative is itself a significant concern. It does not lower the threshold for operation. It alters, in some cases, the terms on which operation is considered.

The relevant question for the aging spine is not whether the technique is new or modern but whether it serves the patient who is in front of us. That patient, increasingly, is older than the patients on whom most of our surgical assumptions were originally formed. We owe them an honest assessment of the options that match their physiology, their anatomy, and their preferences. Biportal endoscopy is one of those options, in selected circumstances. It is not all of them.