Biportal endoscopic L7–S1 foraminotomy shows promise in dogs

CURRENT FULL VERSION: A newly published Veterinary Surgery study reports that biportal endoscopic foraminotomy may offer a more effective minimally invasive option for decompressing the L7–S1 neuroforamen in dogs with lumbosacral foraminal stenosis. In an ex vivo comparison, the arthroscope-based biportal technique produced greater neuroforaminal enlargement than conventional open dorsolateral foraminotomy, and the authors paired those findings with a first clinical case in which a client-owned dog had immediate improvement and remained symptom-free 8 months later. The article was published online ahead of print on March 12, 2026. (pubmed.ncbi.nlm.nih.gov)

The paper lands amid rising interest in minimally invasive canine spine surgery. Lumbosacral foraminal stenosis is a subtype of degenerative lumbosacral disease that can compress the exiting nerve root and cause lower back pain, root-signature lameness, and pelvic limb dysfunction. Traditional decompression methods can be effective, but they also have recognized drawbacks, including limited access to the foramen and greater soft tissue disruption. That has pushed researchers to adapt biportal endoscopic methods already used in human spine surgery for veterinary patients. (pmc.ncbi.nlm.nih.gov)

In the new study, the Zurich-led group developed the procedure using standard arthroscopic equipment and compared three approaches across 24 neuroforamina in 12 cadaveric lumbosacral specimens: open dorsolateral foraminotomy, biportal endoscopic foraminotomy with a 3.0 mm 30° arthroscope, and biportal endoscopic foraminotomy with a 1.9 mm needle arthroscope. According to the conference abstract that preceded the full paper, both open and biportal approaches significantly enlarged the neuroforamen, but the 3.0 mm arthroscope technique achieved a larger increase than open surgery, about 76% versus 46%, while also improving visualization and reducing nerve root manipulation. The same report described immediate clinical resolution in the first treated dog, with CT and MRI showing persistent enlargement 8 months after surgery. (pubmed.ncbi.nlm.nih.gov)

That result fits with other recent veterinary reports. A 2025 cadaveric study of biportal endoscopic lumbosacral foraminotomy found the approach could be completed in all specimens without conversion to open surgery, with significant postoperative enlargement at the entry, middle, and exit zones of the foramen. Another Veterinary Surgery report extended the concept cranially: in 14 normal beagle cadavers, unilateral biportal endoscopic partial cervical laminectomy and facetectomy at C3–4 and C6–7 allowed consistent probing of anatomic landmarks with visualization scores of 2 out of 2, though dural injuries were noted at three sites. Median surgical time was 31.5 minutes, portal sizes were about 1.2 cm and 1.0 cm, and a 5-year-old Doberman with wobbler syndrome treated with UBE laminectomy plus vertebral distraction and fusion at C5–6 had resolution of proprioceptive ataxia within 1 month and a normal neurologic exam at 6 months. Separate 2025 work in Veterinary Surgery also described biportal endoscopic spine surgery for thoracolumbar disc disease in dogs, suggesting the platform may have applications beyond the lumbosacral junction. Taken together, those studies suggest the field is moving from proof-of-concept toward procedure-specific refinement. (pubmed.ncbi.nlm.nih.gov)

The trend is not limited to small animals. In horses, UC Davis recently began offering minimally invasive endoscopic cervical foraminotomy for cervical foraminal stenosis, a procedure still performed by only about a dozen veterinarians nationwide. The service expansion was enabled by installation of a large-bore equine CT scanner that can image the lower cervical spine and nerve root exits, an anatomic region that has historically been difficult to assess. The equine reports describe similar goals to the canine lumbosacral work: using endoscopic instruments to burr the foramen larger and relieve nerve root compression, with some horses reportedly improving in pain and neurologic signs within 24 hours. That cross-species momentum underscores how much advanced imaging and endoscopic access are reshaping referral-level spine care.

Direct outside commentary on this specific paper was limited in public sources, but the broader message from the literature is consistent: biportal endoscopy is being explored because it can widen the surgical field while limiting collateral tissue trauma. The 2025 Frontiers cadaver paper noted that the two-portal setup allows one portal for visualization and one for instrumentation, which improves maneuverability and fluid outflow, and may make the technique more intuitive for surgeons already comfortable with arthroscopy or open spinal decompression. That interpretation supports why the 3.0 mm arthroscope performed better than the needle arthroscope in the new study. (pmc.ncbi.nlm.nih.gov)

The minimally invasive theme is also showing up outside spine surgery. A recent Journal of Small Animal Practice case report described endoscopic-guided electrosurgical snare cauterization of a nasopharyngeal sialocele in a 9-year-old spayed Pug that presented with marked obstructive apnea and intermittent sneezing. The procedure took about 5 minutes, cytology confirmed the diagnosis, and there was no recurrence on repeat endoscopy 4 months later. The authors also advised screening for nasopharyngeal sialoceles in brachycephalic breeds undergoing brachycephalic obstructive airway syndrome surgery and noted that CT characteristics may be less typical than previously reported. It is a very different disease process, but it reflects the same broader push toward shorter, targeted, endoscopic interventions when anatomy and equipment allow.

Why it matters: For veterinary professionals, this is less about one successful case and more about a possible shift in how selected dogs with foraminal lumbosacral disease are approached surgically. Better visualization of the exiting L7 nerve root, less manipulation, and more targeted bone removal could translate into less morbidity and faster recovery, though that still needs to be proven clinically. The practical upside is that the technique uses arthroscopic principles and equipment many specialty surgeons already know. The practical constraint is that adoption will likely depend on training, case selection, imaging support, and whether outcomes hold up in larger prospective cohorts. The same pattern is emerging in cervical canine surgery and even equine neurology, where access to advanced CT appears to be a major enabler of these minimally invasive procedures. (pubmed.ncbi.nlm.nih.gov)

There are also important caveats. The main comparison was cadaveric, not clinical, and the live-animal evidence in this paper is a single dog. That means unanswered questions remain around complication rates, bleeding control, operative time in routine practice, revision options, cost, and long-term neurologic and pain outcomes. The cervical cadaver study’s three dural injuries are also a reminder that endoscopic access does not eliminate technical risk. As with many minimally invasive techniques, early technical success does not automatically guarantee broad clinical benefit. (pubmed.ncbi.nlm.nih.gov)

What to watch: The next signals will be multicenter case series, surgeon learning-curve data, and longer follow-up showing whether biportal endoscopic decompression can deliver durable outcomes for pet parents and patients, not just cleaner cadaver metrics. Also worth watching is whether the same endoscopic toolkit keeps spreading across veterinary specialties, with imaging capability and surgeon training likely to determine how quickly these techniques move from early adopters into wider referral practice. (pubmed.ncbi.nlm.nih.gov)