Ultimately, all patients in the study had fusion on follow-up imaging. The author believed that MI-TLIF is at least equivalent if not a marked improvement over its open counterpart. A variation of the accepted microendoscopic discectomy was completed by Isaacs and colleagues, which was termed METLIF [6]. METLIF was completed on 20 patients who had lumbar spondylolisthesis or AP24534 mechanical back pain. This unique procedure compared favorably to patients who underwent PLIF at the same institutions. METLIF resulted in less blood loss, shorter hospital stays, and decreased postoperative narcotic administration. There were no associated procedural complications associated with the multicenter study. Ultimately, this new variation showed promise. Schizas et al.

examined their institutional experience executing both MITLIF and open midline transforaminal lumbar interbody fusion [5]. Their 36 patient cohort had isthmic spondylolisthesis or DDD which indicated for TLIF. The study found that length of surgery, postoperative pain, analgesia requirements, and VAS/ODI scores were not significantly different between the MI and open procedures. However, they did find that the MI-TLIF did result in significantly less blood loss and a shorter hospital stay. Complications found in the MI-TLIF group, three pseudorthrosis, may have likely been due to the surgeon’s gradual adjustment to the novel instrumentation and visualization techniques associated (Table 5). Table 5 MI-TLIF complication types and complication rates. 5.

Discussion Lumbar arthrodesis is an effective method for treating spinal pathology such as spondylolisthesis, DDD, and spinal instability. As minimally invasive spine procedures have emerged, variants such as minimally invasive discectomy and minimally invasive cervical foraminotomies have allowed for reduced complications related to tissue trauma, while reducing blood loss and shortening recovery time [4, 8, 19, 20]. However, no procedure comes without inherent risks. Due to MI-TLIF being a novel procedure for some surgeons, it takes increasingly longer for them to become effective in carrying it out. Villavicencio et al. compared safety and effectiveness of MI-TLIF and open TLIF, showing similar long-term outcomes over the course of the 37.5-month follow-up period [8].

Assigning 63 patients to the open arm and 76 patients to the minimally invasive arm of the study, the authors matched by prior lumbar surgery, diagnosis, and levels at which fusion was performed. They found significant improvement in mean estimated blood loss (P < .0001) for MI (163.0mL) versus the open TLIF (366.8mL). The study found improvements (P = 0.02) in mean duration of hospitalization in MI-TLIF (3 days) relative to their open counterparts (4.2 days). In addition, rates of neurological Brefeldin_A deficit were significantly higher (P = 0.02) in the minimally invasive arm of the study (10.2%) compared to the open cohort (1.6%).