Biportal endoscopic foraminotomy of the L7-S1 neuroforamen in dogs: Description of surgical technique and ex vivo comparison with conventional open dorsolateral foraminotomy.

Abstract

OBJECTIVE: (1) To establish a surgical technique for minimally invasive biportal endoscopic foraminotomy (BEF) of L7-S1 in dogs using arthroscopic equipment. (2) To compare BEF and dorsolateral foraminotomy (DF) and (3) to provide clinical results of the first client-owned dog treated by way of BEF. STUDY DESIGN: Ex vivo cadaveric study, case report. SAMPLE POPULATION: A total of 18 cadaveric lumbosacral spinal specimens (L3-S3). A 4-year-old mixed breed dog with lumbosacral foraminal stenosis. METHODS: A surgical technique using a 3.0&#x2009;mm 30&#xb0; arthroscope (BEF-A) or a 1.9&#x2009;mm 0&#xb0; needle arthroscope (BEF-N) was developed in six cadaveric spines. Bilateral L7-S1 foraminotomy was performed in 12 spinal specimens (24 neuroforamina) by (1) DF, (2) BEF-A or (3) BEF-N (n&#x2009;=&#x2009;8/group). Visualization, iatrogenic nerve root damage, and foraminal enlargement were compared between the three procedures. RESULTS: BEF-A provided superior visualization compared to DF and BEF-N (p&#x2009;<&#x2009;.05). Iatrogenic nerve root damage was not observed in any of the procedures. All procedures resulted in significant enlargement of the neuroforamen (58&#x2009;&#xb1;&#x2009;33%, p&#x2009;<&#x2009;.01). BEF-A (81.3&#x2009;&#xb1;&#x2009;30.0%) resulted in significantly more enlargement compared to DF (59.7&#x2009;&#xb1;&#x2009;33.7%, p&#x2009;=&#x2009;.03) and BEF-N (51.1&#x2009;&#xb1;&#x2009;38.8%, p&#x2009;=&#x2009;.04). BEF-A was successfully used to treat a client-owned dog with L7-S1 foraminal stenosis. CONCLUSION: BEF-A provided superior visualization and efficacy compared to DF. CLINICAL SIGNIFICANCE: BEF-A is a safe and effective surgical technique for treating dogs with L7-S1 foraminal stenosis. The technique should be evaluated in larger clinical studies.