Comparison of Clinicoradiological Outcomes in Patients Undergoing Transforaminal Lumbar Intervertebral Fusion via Unilateral Biportal Endoscopy vs Open approach; an Open Non-Inferior Randomised controlled trial study

TLIF stands for Transforaminal Lumbar Interbody Fusion, which is a widely performed spine surgery. TLIF corrects a variety of spinal conditions, such as disc herniation, degenerative disc disease, and spondylolisthesis. The purpose of this procedure is to stabilize the vertebra to prevent dangerous movement between the bones. TLIF creates a solid bone between neighbouring vertebra and eliminates abnormal movement between them; hence, it is widely used for stabilization and treatment of degenerative lumbar disease following failed conservative treatment.

 For many years, the standard posterolateral lumbar interbody fusion (LIF) technique has been a successful surgical treatment for LDD. It involves a posterior or transforaminal approach. Transforaminal LIF (TLIF) and posterior LIF (PLIF) might cause a considerable loss of posterior anatomic features, requiring a lengthy recovery period, even though they may stabilize the operated spinal segments and relieve neurologic issues.

 The recently developed biportal endoscopic (BE) spinal surgical approach divides the working and viewing channels by making two independent incisions, thereby enabling continuous fluid perfusion. This technique allows for a broad field of vision and dynamic manipulation of the instruments. BE surgery can be used to treat spinal discectomy, spinal decompression, and additional LIF surgery (BE-LIF). BE-LIF and the minimally invasive

TLIF (MI-TLIF), which is based on tubular retractor devices, are similar techniques. It allows for direct neural decompression by facetectomy, discectomy, and laminectomy (ipsilateral and contralateral), as well as indirect neural decompression via spondylolisthesis reduction and disc space restoration.

 The extra benefit of UBE surgery not requiring blind endplate preparation, which removes the possibility of endplate violation, is one significant advantage of UBE TLIF over uniportal fusion when the cage insertion is aided by fluoroscopic guidance. Moreover, a more thorough disc preparation can be carried out by directly seeing the endplate. Furthermore, compared to uniportal trans-Kambin methods, there is a reduced risk of exiting nerve root injury since direct visibility can be acquired during cage insertion. Less muscle injury and surgical insult to the patient compared to open and tubular procedures is another possible advantage of UBE fusion. According to Kang et al.’s research, on postoperative days 1 and 2, UBE TLIF results in a lower inevitable systematic inflammatory response (CRP and CPK). Others have also discovered that the UBE fusion group’s post-operative CRP is noticeably lower than the MT-TLIF group’s.These findings suggest that by reducing soft tissue trauma, UBE surgery reduces systemic inflammatory response. UBE surgeons think that because there is less systemic inflammation, patients may experience less pain following surgery and have a better quality of life in the early postoperative phase. The published research supports this notion by demonstrating the benefits of UBE fusion in the early post-operative phase. When it comes to back discomfort in the first month following surgery, UBE fusion groups score higher on the VAS scores than the MI TLIF group. Nevertheless, there is no discernible difference in these two groups’ back pain VAS scores at the final follow-up.

 In their study, Gatam et al. also found that the UBE fusion group had statistically significant improvements in back pain,VAS levels up to three months after surgery. There was no discernible difference between MIS-TLIF and VAS back pain at 6 and 12 months.

 Although some studies published that only VAS back pain showed differences in early follow-up period, other studies found a bigger improvement in ODI in the UBEgroup up to 1 month. In addition to patient report outcome, the UBE fusion group’s length of stay was shown to be significantly less than that of the MI-TLIF and open PLIF surgical groups due to decreased subjective discomfort.

 The fusion rate in UBE TLIF is a concern because of the constant fluid irrigation pressure. Osteoblast-rich cells at the fusion bed may be washed off by constant fluid. Luckily, the literature does not support this belief. Comparable to MIS-TLIF, acceptable fusion rates have been obtained with UBE TLIF.

 The UBE TLIF procedure is a novel surgical approach that carries a steep learning curve and may lead to increased rates of complications. On the other hand, the available data does not indicate a statistically significant difference between the MT-TLIF group and the UBE fusion group with respect to the rates of neurological impairment, cage subsidence, epidural hematoma, dural rupture, and overall surgical complications. If the irrigation fluid outflow is blocked, pressure from the fluid may accumulate in the paraspinal muscles. Muscle death similar to compartment syndrome may happen when the compartment pressure rises. A rise in intracranial pressure is another possible outcome. Seizures, headaches, neck stiffness, and vomiting are some of the signs of elevated ICP. It’s important to maintain a steady outflow and avoid raising the irrigation fluid pressure above 50 mmHg.

 Unlike uniportal endoscopic spine operations, UBE transforaminal endoscopic fusion offers accurate surgery without instrument size limitations, thereby addressing the fundamental problem of mobility in tubular minimally invasive spinal surgery. This suggests a hopeful future for the procedure. This is particularly helpful during fusion surgery when precise intervertebral disc management is needed and additional bony work is involved. The development of robotic surgery and navigation may help reduce the learning curve in UBE fusion,

and advances in intervertebral cage technology, including expandable cage systems, ultrasonic knives, and improved biologics, could ultimately lead to better fusion outcomes.

 With less post-operative pain and a shorter hospital stay, UBE lumbar fusion is a relatively recent approach to lumbar fusion that primarily offers less intraoperative blood loss and faster recovery. Still, there is no greater risk of problems with long-term clinical and radiological results compared to open and MIS fusion procedures. None of the recently published research had a longer than one-year follow-up period, and the majority are retrospective studies. Therefore, additional high-quality randomized control trials with extended follow-up are required to corroborate these results and assess the safety and effectiveness of UBE fusion in situations of multilevel fusion, adjacent segment illness, and revision scenarios.