1. What is lumbar spinal stenosis? Lumbar spinal stenosis is defined as a clinical syndrome that causes pain in the lumbosacral region or lower extremities, with or without back pain, due to reduced space for the movement of tissues such as lumbar nerves and blood vessels. It follows that the main compression after space reduction is due to lumbar spinal nerves and blood vessels, and local ischemia and hypoxia. The hallmark manifestations are: intermittent claudication, i.e., soreness, numbness, and weakness of both lower limbs after walking three to five hundred meters, which can be relieved after squatting and resting for a while, and is not affected when riding a bicycle. The incidence is about 30%, and the incidence is higher above the age of 60. It is usually divided into congenital and degenerative, with the latter accounting for the majority. 2.Traditional treatment of lumbar spinal stenosis As patients age, their symptoms gradually worsen, and those who are ineffective with conservative treatment need to undergo surgery. However, due to the lack of clear clinical signs and imaging criteria, at present, clinicians can only diagnose and determine whether surgery is needed by combining multiple methods. Posterior lumbar laminectomy and decompression with or without interbody fusion is the standard procedure for the treatment of lumbar spinal stenosis. However, the decision to intervene surgically is based on a combination of the patient’s clinical symptoms and imaging findings. In other words, no matter how severe a patient’s lumbar spinal canal or nerve root canal stenosis is shown to be on imaging, as long as the patient has no clinical symptoms or minimal symptoms, hands are not considered first. Similarly, if a patient’s clinical symptoms lacked strong imaging evidence to support them, surgical intervention was likewise not considered first, regardless of how severe the symptoms were. In addition, surgical treatment is only considered if conservative treatment is not sufficiently effective in relieving the patient’s clinical symptoms. The core of minimally invasive treatment for lumbar spinal stenosis should be “decompression based on complete reduction of collateral damage”. The traditional simple decompression surgery can perform osseous decompression of the central spinal canal and subtle decompression of the lateral saphenous fossa (or nerve root canal) by removing the ligamentum flavum on both sides, and many reports have proved its efficacy. However, decompression alone is not effective in patients with bony stenosis of the lateral saphenous fossa, because stenosis of the nerve root canal, including the lateral saphenous fossa, is the cause of many patients with spinal stenosis, so that complete lateral decompression is valued as the “basis for complete decompression. The so-called “reduction of collateral damage” means not destroying too much muscle, bone and ligament tissue. “and “degree” of surgery. 4.The development and status of minimally invasive treatment for lumbar spinal stenosis Lumbar spinal stenosis is one of the early recognized diseases and one of the first diseases to which various minimally invasive methods and tools were applied, so after decades of development, there are numerous minimally invasive treatment methods. (1) Simple decompression This procedure was widely used before the emergence of intervertebral fusion, but with the deeper understanding of the disease and reflection on cases with poor outcomes, its indications were redefined, and on this basis, “limited decompression”, “continuous open decompression”, and “indirect decompression” were proposed. The concepts and techniques of “limited decompression”, “continuous open window decompression” and “indirect decompression” have been proposed. In recent years, the application of endoscopy and supporting tools has made decompression less invasive with foraminoscopy, discoscopy, and access systems. However, the research evidence supporting minimally invasive surgery as an alternative to open decompression surgery is currently limited. A large series of studies conducted by ClevelandClinic showed that minimally invasive surgery can reduce the use of anesthetics and shorten the length of hospital stay compared to traditional open decompression surgery, with comparable clinical outcomes. A purely comparative retrospective analysis by Rahman et al. found that the prognosis was similar for minimally invasive surgery and traditional open reduction surgery, but the former resulted in shorter operative times, reduced bleeding, and facilitated early mobility. (2) Fusion versus fixation The use of internal fixation allows the operator to perform extensive decompression without the concern of causing lumbar instability; however, complications associated with internal fixation such as nerve injury, lumbar stiffness, and degeneration of adjacent segments remain insurmountable problems; therefore, it is recommended that fusion be performed without the routine use of instrumentation during the treatment of lumbar degenerative stenosis. Currently, the literature also lacks evidence that instrumentation use significantly improves outcomes. In conclusion, minimally invasive treatment of lumbar spinal stenosis is not defined by “fusion”, but also by intervertebral fusion (e.g., MIS-TLIF, discoscopic fusion, etc.) and open continuous minimally invasive decompression with small incisions. mind, on the basis of their experience and technique.