The large working channel (LWC) uniportal endoscope offers significant advantages over the traditional unilateral biportal endoscopy for obese patients at lower lumbar levels. The LWC features a broader working channel (diameter > 5.5 mm) that accommodates larger surgical instruments, enhancing its ability to perform complex procedures with greater precision and efficiency. This expanded channel reduces the need for multiple incisions, minimizes surgical trauma, provides clear vision due to good water outflow channels, and increases surgical precision, which is particularly beneficial in patients with obesity who may have more challenging anatomy and an increased risk of complications. The improved instrument mechanism of LWC and enhanced visibility also enable better access and navigation within the restricted operative field, leading to more effective and less invasive interventions in patients with obesity. Overall, the design addresses the specific challenges of obesity, making it a superior choice for endoscopic procedures in this patient population at lower lumbar levels (L4–5 and L5–S1).

Patients with degenerative lumbar spinal stenosis and double crush syndrome often require decompression of the nerve root at multiple levels. Traditional approaches are limited by the need for extensive bony resection and the risk of iatrogenic instability. The endoscopic contralateral approach offers a minimally invasive alternative, but has primarily been applied to single-level decompressions. This study evaluated the feasibility of an "extended" biportal endoscopic contralateral approach for 2-level decompression in a patient with double crush syndrome, detailing the surgical technique and outcomes. A 69-year-old female patient presented with bilateral leg pain and numbness attributed to severe stenosis at L4–5 and L5–S1. The patient underwent a single biportal endoscopic procedure utilizing an extended contralateral approach to decompress the L4–5 central canal, lateral recess, and the L5–S1 foramen. The technique involved careful planning of incision placement, sublaminar drilling, and decompression of the L5 nerve root across both levels. The second illustrative case is a patient with L4 double crush syndrome who was managed similarly. Postoperative imaging demonstrated successful decompression of the L4–5 central canal and L5–S1 foramen, with preservation of the L5 pars interarticularis. The patient experienced complete symptom resolution. The approach resulted in minimal soft tissue dissection and bony preservation, enhancing surgical efficiency. The extended biportal endoscopic contralateral approach effectively addresses double crush root syndrome through a single minimally invasive approach. This technique improves operating room efficiency, while still achieving good neural decompression without causing iatrogenic instability, and may be a viable surgical option for selected cases.