Lumbar spinal stenosis (LSS) is one of the most frequent etiologies of chronic back pain, neurogenic claudication, and lumbar radiculopathy. Bilateral dissection and retraction of the paraspinal muscles, wide laminectomy, medial facetectomy and foraminotomy were traditional decompression strategy involved in treatment of LSS. Excessive disruption of supraspinous/interspinous ligament complex and posterior bony contribute to spinal instability, which eventually increase the rate of surgical failures and revision surgery12, 13. Meanwhile, minimally invasive laminectomy approaches have been widely recognized to be associated with decreased approach related morbidity.
Eventhough PEID was associated with less blood loss, narcotic use, and satisfactory clinical outcomes in previous studies. However, there is a lack of clinical evidence to comfirm its safety and efficacy comparing PEID to TLIF. The current study shows that ULBD technique is a viable option for patients with moderate and severe LSS14. Absence of muscle dissection with the endoscope and instruments over the lamina and preservation of the soft tissue structures, could alleviate the muscle atrophy and spinal instability15. Furthermore, another advantage of ULBD lies in its mitigation the risk of adjacent segment fusions postoperative, while adjacent segment disease following fusion involves fusing a second level in traditional revision surgery16.Also, the reduction in duration of hospitalization was observed.The complication rates in the literature for TLIF have an average of 36,7%, whereas minimally invasive laminectomy approaches have 28,4%17. The present study found that patients underwent PEID approach show good clinical outcomes and pain scores at 3 and 12 months after operation. Even though decompression with instrumented fusion was widely used in the past, clinical experience demonstrate that decompression alone can lead to satisfactory patient-reported outcomes18.Complex MIS surgeries, such as microdiscectomy, transforaminal lumbar interbody fusion, are built on the foundation of simple laminotomy. At present, there is no consensus providing a treatment algorithm for LSS due to sagittal imbalance and severity of stenosis. While there is sort of a big academic debate on surgical indications of fusion for LSS, TLIF was proven to be improve lumbar function and spinal stabilization3, 19. TLIF allow weight-bearing through the anterior column and would prevent the stress concentration that may increase the instability of the adjacent vertebra20, 21.
PEID was reported to treat several degenerative lumbar disease, such as degenerative scoliosis and spondylolisthesis, lumbar stenosis, and thoracic disc herniations14, 22, 23. Previous reports have already demonstrated that ULBD is a effective and safe approach to treat degenerative spondylolisthesis10.Several clinical study focused attentionon the clinical efficacy of ULBD for the treatment of severe lumbar stenosis. Komp et al24 conducted a prospective, randomized, controlled research and demonstrated that full-endoscopic ULBD is an is safe and effective strategy for treating LSS. In this study, 71 patients demonstrated constantly and obviously improved back pain and leg pain and daily activities. even though slight deterioration was observed.No patient suffered worsening of back pain. Postoperative pain symptom and analgesics, such as ibuprofen and paracetamol, show significant improvement.Furthermore, the rate of complications related to the procedure was significantly reduced during the follow-up. The maximum duration of hospitalization was shortened as a result of using the full-endoscopic technique. Referring to complications, we found the incidence of dural tears increased slightly in the in the ULBD group. Mobbs et al. showed that incidental durotomy rates was 3.7% in ULBD group and open surgery group25,whereas incidence of dural tears in classic laminectomy may range from 5% to 15%26. Only 1 incidental durotomy happened in our study and we found it challenging to identificate and suture the dural tears through a smaller surgical channel. In addition, postoperative lumbar instability was not observed in the PEID group. This study confirm that length of hospitalization and estimated blood loss were less in our operation, which is consist with the previous literature.
When it comes to clinical outcomes, the success rate demonstrated no significant difference between the 2 groups, although a slightly better patient-reported outcome after PEID can be seen; in the long term, PEID showed equally effection in improving pain and function when compared to fusion. ULBD facilitates neural decompression while preserving stabilizing osseoligamentous structures and may be uniquely suited for the treatment of LSS with concurrent mild to moderate degenerative deformity. Thus, the main advantages of this less invasive technique lie in the reduction of postoperative instability and more suitable for patients with lumbar spinal stenosis and severe osteoporosis. This study found that PEID did not have any advantage in patient-reported outcomes compared with TLIF techniques after surgery.
Additionally, this surgical procedure can be an effective treatment of other degenerative lumbar diseases.Thoracic disc herniations were first reported by Yüce et al23 to be alleviatied by ULBD approach. A previous study reported that patients with thoracic disc herniation should undergo fusion27. However, fusion surgery inflicts traumatic injury than ULBD, leading to a longer hospitalization. Other methods, such as physical therapy, medication treatment, and nerve root block could ease the back pain caused by disc herniation28, 29. We strongly recommended PEID to alleviate pain if the conservative treatment has no any effect on patient.
Some limitations should be addressed in current study. First, this retrospectively study has less creditability. Hence, future prospective studies should be performed to evaluate the effectiveness and safety of the PEID procedure. Second, only 10 patients, a small sample size, were enrolled in this study, which makes the results inaccurate. Third, patients who underwent PEID procedure were not compared with control procedure in this study.