Lumbar synovial cysts are fluid-filled lesions arising from the facet joints that can cause lateral recess stenosis and neurogenic claudication. While surgical decompression is the gold standard for symptomatic cysts, patients with significant comorbidities, such as chronic obstructive pulmonary disease (COPD) and emphysema, face elevated perioperative risks under general anesthesia and delayed wound healing. This case report describes the successful application of the minimally invasive lumbar decompression (MILD) procedure as a safe alternative for a high-risk surgical candidate. A 68-year-old male with a history of hypertension and severe COPD/emphysema presented with chronic, progressive lower back pain and fluctuating bilateral radiculopathy, which was initially worse on the left before migrating to the right and subsequently alternating sides. Lumbar MRI revealed a 6 mm × 5 mm synovial cyst arising from the left L4-L5 facet joint, causing severe subarticular narrowing and nerve root compression. To mitigate anesthetic risks, the patient underwent the MILD procedure under moderate sedation. Using a bone Kerrison and tissue sculptor, mechanical decompression of the lamina and hypertrophied ligamentum flavum was achieved, followed by an adjunct epidural injection of betamethasone. The patient reported immediate symptomatic improvement. At the six-month follow-up, he maintained 100% relief of his primary radicular symptoms. A follow-up MRI confirmed successful decompression of the L4-L5 lateral recess and a significant reduction in cyst size. Although imaging later noted minimal residual tissue, the patient maintained sustained clinical improvement through March 2023 at his final follow-up. The MILD procedure provides an effective alternative for symptomatic synovial cysts in patients who are poor candidates for open surgery. By combining mechanical decompression with anti-inflammatory measures under moderate sedation, clinicians can achieve sustained functional improvement while bypassing the respiratory risks associated with general anesthesia and invasive surgical excision.
Lynch et al. (Sat,) studied this question.