Biportal endoscopic transforaminal lumbar interbody fusion (TLIF) may have advantages of minimally invasive fusion surgery as well as those of endoscopic surgery. The purpose of this study was to present the biportal endoscopic TLIF technique along with video presentations and a review of the literature on this technique. Basically, the biportal endoscopic TLIF technique is similar to minimally invasive TLIF with a tubular retractor. There were 2 options in the biportal endoscopic TLIF procedures. The first was the insertion of one long TLIF cage and the other was the insertion of 2 short posterior lumbar interbody fusion (PLIF) cages. After the interbody fusion procedures, percutaneous pedicles screw fixation was performed. Biportal endoscopic TLIF achieved complete neural decompression through laminectomy and facetectomy like conventional TLIF. Endplate preparation was performed completely under a clear and magnified endoscopic view. It was also feasible to insert a large TLIF cage or 2 cages for PLIF without exiting nerve root injury. Biportal endoscopic TLIF might have the advantages of endoscopic surgery as well as minimally invasive fusion surgery. Direct neural decompression, endplate preparation under endoscopic guidance, and the insertion of a large TLIF cage or 2 PLIF cages may be the merits of biportal endoscopic lumbar fusion procedures.

Objective: The aim of this study was to compare the clinical and radiologic outcomes of 3 types of minimally invasive posterior cervical foraminotomy (PCF): uniportal endoscopic surgery, biportal endoscopic surgery, and microsurgery.Methods: Between January 2019 to January 2020, PCF was performed using 3 different approaches to treat foraminal stenosis. The foraminal expansion rate, facet resection rate, and surgical foraminal approach angle were measured using magnetic resonance imaging. Visual analogue scale (VAS) scores for neck and arm pain, neck disability index (NDI), MacNab criteria, operation time, hospital stay, and complications were assessed. Clinical and radiologic parameters were compared among the 3 surgical groups.Results: There were 38, 30, and 50 patients in the uniportal endoscopy, biportal endoscopy, and microscopy groups, respectively. Microscopy group displayed significantly higher foraminal expansion compared to uniportal endoscopy group (p = 0.001). Facet resection rates and inclination angle for facet joint undercutting were significantly different among the 3 groups. Uniportal endoscopy group had the highest inclination angle and the least facet resection. On the 6 months and final follow-up, VAS scores and NDI were significantly lower in the uniportal endoscopy group than in the microscopy group (p = 0.000).Conclusion: All 3 types of PCF displayed favorable clinical outcomes and sufficient expansion of the midforaminal area. Two endoscopy groups showed a significantly higher inclination angle for undercutting the facet joint and a lower facet resection rate than the microscopy group. Reduced facet joint resection using an inclinatory approach did not interfere with sufficient foraminal expansion and enhanced the clinical result after 6 months of follow-up.

Technical report. Dural tear is one of the most common complications of endoscopic spine surgery. Although endoscopic dural repair of the durotomy area may be difficult, we successfully repaired the dural tear area using nonpenetrating clips during biportal endoscopic surgery. We introduce the surgical technique of dural repair using nonpenetrating titanium clips in biportal endoscopic spine surgery and report its clinical outcome. We retrospectively reviewed and analyzed 5 patients who were treated via primary dural repair using nonpenetrating titanium clips during biportal endoscopic lumbar surgery. The 2 methods of dural clipping and repair include 2 or 3 portals. We analyzed radiological parameters such as cerebrospinal fluid collection as well as clinical parameters, including postoperative clinical outcomes. Five patients underwent biportal endoscopic dural repair using nonpenetrating clips. Incidental durotomy was successfully repaired using nonpenetrating titanium clips in all 5 patients. No cerebrospinal fluid collection was detected in the postoperative magnetic resonance images. Clinically, preoperative symptoms improved significantly after surgery (P < .05). We repaired the dural tear area completely using nonpenetrating titanium vascular anastomosis clips in biportal endoscopic lumbar surgery. Dural repair via clipping method may be an effective alternative for incidental durotomy.