This work was supported by the Third Affiliated Hospital of Sun Yat-Sen University, Clinical Research Program (Grant Number: YHJH202203).

The Institutional Review Board of the Third Affiliated Hospital at Sun Yat-sen University approved the protocols (ID:[2022]02-356-01). All included patients were required to sign an informed consent form.
1. Surgical indications
<ol>
	<li>Include patients with lumbar spinal stenosis who have contra-lateral recess stenosis or disc herniation or who have contra-lateral neural compression.</li>
</ol>
2. Surgical method
<ol>
	<li>Perform bilateral endoscopic spinal canal decompression via UBE-ULBD technique and endoscopic discectomy via T-UBE.</li>
</ol>
3. Preoperative procedure
<ol>
	<li>Anesthesia and surgical position:
	<ol>
		<li>Under general anesthesia, position the patient prone on a spinal frame, avoiding any discomfort. Flex the lumbar spine slightly to open up the interlaminar space. 
		NOTE: General anesthesia with endotracheal intubation or combined spinal-epidural anesthesia is used for surgical procedures to minimize intraoperative pain.</li>
	</ol>
	</li>
	<li>Desired portals position (L4-5, for example):
	<ol>
		<li>Obtain a standard anteroposterior (AP) X-ray view, and let the target intervertebral space be vertical to the ground in the X-ray lateral view by adjusting the surgical table.</li>
		<li>Mark the bilateral pedicles of L5 and the ipsilateral pedicle of L4. Draw a line along the midline of the L4/5 intervertebral disc and the posterior midline of the spine.</li>
		<li>On the ipsilateral side, mark two incisions 1.5 cm above and below the midline of the intervertebral disc for manipulation and endoscopic portal, respectively. Locate the third channel incision on the contra-lateral midline of the L4/5 intervertebral disc space.</li>
	</ol>
	</li>
</ol>
4. Surgery procedure (L4-5, for example)
<ol>
	<li>Sterilize the surgical site with iodine tincture and 75% alcohol, and prepare the site with waterproof drapes.</li>
	<li>Establish UBE endoscopic channel and ipsilateral working channel.
	<ol>
		<li>Insert two syringe needles from the medial edge of the line of the ipsilateral pedicle shadow, one at 15 mm cranial and the other at 15 mm caudal, to the midline of the L4/5 intervertebral disc. The inserted needles will form a triangle and meet at the L4/5 interlaminar.</li>
		<li>Then, make two 8-10 mm longitudinal skin incisions for endoscopic and manipulated portals based on the location of the aforementioned needles.</li>
		<li>After dissecting the extralaminal soft tissue with a curette, insert serial dilators to expand the surgical field. Then, establish the endoscopic channel and working channel, converging along the sublaminar edge.</li>
	</ol>
	</li>
	<li>Establish endoscopic operating space (Figure 1A-C)
	<ol>
		<li>Insert a 30-degree endoscope via the viewing channel, connected to a continuous gravity saline irrigation positioned 50-60 cm high above the patient.</li>
		<li>After that, insert the surgical instruments and a radiofrequency ablation blade via the working channel to remove the soft tissue on the laminar surface until exposure of the lower edge of the L4 lamina, the ligamentum flavum, and the medial edge of the ipsilateral L4/5 facet joint. Establish the endoscopic operating space.</li>
	</ol>
	</li>
	<li>Ipsilateral laminotomy and neural decompression (Figure 2A-D, Figure 3A-D)
	<ol>
		<li>Remove the ipsilateral lower part of the L4 lamina, the upper part of the L5 lamina, and the medial inferior facet by a 3.5-mm high-speed drill (8000 rotations/s) and Kerrison punches until the ligamentum flavum is fully mobilized.</li>
		<li>Then, separate the ligamentum flavum from the dural sac and gradually remove it from the cranial to the caudal end with Kerrison punches or forceps.</li>
		<li>After that, carefully remove the medial facet joint of L4/5 and the hyperplastic facet joint bone with a soft-tissue protection drill or punches until the traversing nerve root is completely decompressed.</li>
		<li>Ensure that more than 50% of the medial facet is preserved, avoiding the possibility of spinal instability.</li>
	</ol>
	</li>
	<li>Contra-lateral dorsal neural decompression (Figure 4A-E)
	<ol>
		<li>Remove the base of the L4 spinous process with a drill (8000 rotations/s) and adjust the working channel obliquely towards the contralateral spinal canal.</li>
		<li>Undercut the medial part of the contralateral L4 inferior facet, fully expose the contralateral ligamentum, separate from the dural sac, and remove it using Kerrison punches (4 mm) until adequate dorsal neural decompression.</li>
	</ol>
	</li>
	<li>Contralateral third channel-assisted discectomy (Figure 5A-C, Figure 6A-E)
	<ol>
		<li>Make an 8-mm longitudinal skin incision adjacent (5 mm) to the spinous process at the midline of the contralateral disc. Insert a K-wire, followed by serial dilators under endoscopic view, to establish the contra-lateral working channel.</li>
		<li>After the thecal sac and contra-lateral traversing nerve root (L5) are retracted and well protected, expose the contralateral herniated disc fragment. Then, insert forceps or other instruments vertically into the contra-lateral disc space and remove the herniated disc tissues through the third channel.</li>
		<li>At last, use a blunt nerve hook to explore the dural sac and bilateral nerve roots to ensure sufficient spinal decompression.</li>
	</ol>
	</li>
	<li>Place a drainage tube outside the lamina and suture each incision to complete the operation. 
	NOTE: The surgical instruments used in the T-UBE technique are essentially the same as those used in the conventional UBE technique and traditional open spinal surgery. There is no need to purchase specialized instruments. T-UBE instruments include a 30-degree, 4-mm-diameter arthroscope, an endoscopic sheath, standard laminectomy instruments such as Kerrison punches, forceps, and nerve hooks, as well as a bipolar flexible radiofrequency probe, and a 3.5-mm radiofrequency electrode.</li>
</ol>

A 3-Channel Endoscopic Technique for Lumbar Stenosis and Contralateral Herniation

<ol>
	<li>Suvithayasiri, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+and+clinical+outcomes+of+endoscopic+spine+surgery+of+treating+spinal+metastases;+Outcomes+of+29+cases+from+8+countries.">The role and clinical outcomes of endoscopic spine surgery of treating spinal metastases; Outcomes of 29 cases from 8 countries.</a> Neurospine. 20 (2), 608-619 (2023).</li><li>Choi, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Small+is+beautiful,+less+is+better.">Small is beautiful, less is better.</a> Neurospine. 16 (1), 3 (2019).</li><li>Yu, K. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Brief+history,+global+trends,+and+Chinese+mission+of+unilateral+biportal+endoscopy+technique.">Brief history, global trends, and Chinese mission of unilateral biportal endoscopy technique.</a> Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 36 (10), 1181-1815 (2022).</li><li>Xie, X., Zhang, G., Liu, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Clinical+effect+of+unilateral+biportal+endoscopy+in+the+treatment+of+lumbar+diseases:+a+systematic+review+and+meta-analysis.">Clinical effect of unilateral biportal endoscopy in the treatment of lumbar diseases: a systematic review and meta-analysis.</a> Wideochir Inne Tech Maloinwazyjne. 17 (1), 61-68 (2022).</li><li>Wang, B., He, P., Liu, X., Wu, Z., Xu, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Complications+of+unilateral+biportal+endoscopic+spinal+surgery+for+lumbar+spinal+stenosis:+A+systematic+review+of+the+literature+and+meta-analysis+of+single-arm+studies.">Complications of unilateral biportal endoscopic spinal surgery for lumbar spinal stenosis: A systematic review of the literature and meta-analysis of single-arm studies.</a> Orthop Surg. 15 (1), 3-15 (2023).</li><li>Kim, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biportal+endoscopic+spinal+surgery+for+lumbar+spinal+stenosis.">Biportal endoscopic spinal surgery for lumbar spinal stenosis.</a> Asian Spine J. 13 (2), 334-342 (2019).</li><li>Lin, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+systematic+review+of+unilateral+biportal+endoscopic+spinal+surgery:+Preliminary+clinical+results+and+complications.">A systematic review of unilateral biportal endoscopic spinal surgery: Preliminary clinical results and complications.</a> World Neurosurg. 125, 425-432 (2019).</li><li>Heo, D. D., Lee, D. C., Park, C. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+analysis+of+three+types+of+minimally+invasive+decompressive+surgery+for+lumbar+central+stenosis:+biportal+endoscopy,+uniportal+endoscopy,+and+microsurgery.">Comparative analysis of three types of minimally invasive decompressive surgery for lumbar central stenosis: biportal endoscopy, uniportal endoscopy, and microsurgery.</a> Neurosurg Focus. 46 (5), E9 (2019).</li><li>Kim, J., Park, C., Yeung, Y., Suen, T., Jun, S. G., Park, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Unilateral+bi-portal+endoscopic+decompression+via+the+contralateral+approach+in+asymmetric+spinal+stenosis:+A+technical+note.">Unilateral bi-portal endoscopic decompression via the contralateral approach in asymmetric spinal stenosis: A technical note.</a> Asian Spine J. 15 (5), 688-700 (2021).</li><li>Hawker, G. A., Mian, S., Kendzerska, T., French, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measures+of+adult+pain:+Visual+Analog+Scale+for+Pain+(VAS+Pain),+Numeric+Rating+Scale+for+Pain+(NRS+Pain),+McGill+Pain+Questionnaire+(MPQ),+Short-Form+McGill+Pain+Questionnaire+(SF-MPQ),+Chronic+Pain+Grade+Scale+(CPGS),+Short+Form-36+Bodily+Pain+Scale+(SF-36+BPS),+and+Measure+of+Intermittent+and+Constant+Osteoarthritis+Pain+(ICOAP).">Measures of adult pain: Visual Analog Scale for Pain (VAS Pain), Numeric Rating Scale for Pain (NRS Pain), McGill Pain Questionnaire (MPQ), Short-Form McGill Pain Questionnaire (SF-MPQ), Chronic Pain Grade Scale (CPGS), Short Form-36 Bodily Pain Scale (SF-36 BPS), and Measure of Intermittent and Constant Osteoarthritis Pain (ICOAP).</a> Arthritis Care Res (Hoboken). 11, S240-S252 (2011).</li><li>Smeets, R., K&#246;ke, A., Lin, C., Ferreira, M., Demoulin, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measures+of+function+in+low+back+pain/disorders:+Low+Back+Pain+Rating+Scale+(LBPRS),+Oswestry+Disability+Index+(ODI),+Progressive+Isoinertial+Lifting+Evaluation+(PILE),+Quebec+Back+Pain+Disability+Scale+(QBPDS),+and+Roland-Morris+Disability+Questionnaire+(RDQ).">Measures of function in low back pain/disorders: Low Back Pain Rating Scale (LBPRS), Oswestry Disability Index (ODI), Progressive Isoinertial Lifting Evaluation (PILE), Quebec Back Pain Disability Scale (QBPDS), and Roland-Morris Disability Questionnaire (RDQ).</a> Arthritis Care Res (Hoboken). 11, S158-S173 (2011).</li><li>Zhang, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Decompression+using+minimally+invasive+surgery+for+lumbar+spinal+stenosis+associated+with+degenerative+spondylolisthesis:+A+review.">Decompression using minimally invasive surgery for lumbar spinal stenosis associated with degenerative spondylolisthesis: A review.</a> Pain Ther. 10 (2), 941-959 (2021).</li><li>Chen, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+learning+curve+of+unilateral+biportal+endoscopic+(UBE)+spinal+surgery+by+CUSUM+analysis.">The learning curve of unilateral biportal endoscopic (UBE) spinal surgery by CUSUM analysis.</a> Front Surg. 9, 873691 (2022).</li><li>Xu, H., Ni, J., Li, H., Fu, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microsurgical+technique+in+the+treatment+of+lumbar+disc+prolapse.">Microsurgical technique in the treatment of lumbar disc prolapse.</a> Hunan Yi Ke Da Xue Xue Bao. 23 (4), 395-399 (1998).</li><li>Park, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biportal+endoscopic+versus+microscopic+lumbar+decompressive+laminectomy+in+patients+with+spinal+stenosis:+a+randomized+controlled+trial.">Biportal endoscopic versus microscopic lumbar decompressive laminectomy in patients with spinal stenosis: a randomized controlled trial.</a> Spine J. 20 (2), 156-165 (2020).</li><li>Park, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biportal+endoscopic+versus+microscopic+discectomy+for+lumbar+herniated+disc:+a+randomized+controlled+trial.">Biportal endoscopic versus microscopic discectomy for lumbar herniated disc: a randomized controlled trial.</a> Spine J. 23 (1), 18-26 (2023).</li><li>Aygun, H., Abdulshafi, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Unilateral+biportal+endoscopy+versus+tubular+microendoscopy+in+management+of+single+level+degenerative+lumbar+canal+stenosis:+A+prospective+study.">Unilateral biportal endoscopy versus tubular microendoscopy in management of single level degenerative lumbar canal stenosis: A prospective study.</a> Clin Spine Surg. 34 (6), E323-E328 (2021).</li><li>Zheng, B., Xu, S., Guo, C., Jin, L., Liu, C., Liu, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficacy+and+safety+of+unilateral+biportal+endoscopy+versus+other+spine+surgery:+A+systematic+review+and+meta-analysis.">Efficacy and safety of unilateral biportal endoscopy versus other spine surgery: A systematic review and meta-analysis.</a> Front Surg. 9, 911-914 (2022).</li><li>Ma, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+percutaneous+endoscopic+interlaminar+discectomy+and+open+fenestration+discectomy+for+single-segment+huge+lumbar+disc+herniation:+A+two-year+follow-up+retrospective+study.">Comparison of percutaneous endoscopic interlaminar discectomy and open fenestration discectomy for single-segment huge lumbar disc herniation: A two-year follow-up retrospective study.</a> J Pain Res. 15, 1061-1070 (2022).</li><li>Sasai, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microsurgical+posterior+herniotomy+with+en+bloc+laminoplasty:+alternative+method+for+treating+cervical+disc+herniation.">Microsurgical posterior herniotomy with en bloc laminoplasty: alternative method for treating cervical disc herniation.</a> J Spinal Disord Tech. 18 (2), 171-177 (2005).</li></ol>

The authors declare that they have no competing financial interests.

The UBE technique is an innovative endoscopic surgery that has rapidly advanced in recent years for the treatment of spinal disorders12. In contrast to PELD, UBE does not require specialized instruments and is similar to conventional surgical procedures. This may reduce costs and eliminate the need for extensive training, particularly for surgeons experienced in arthroscopic surgery13. Therefore, the UBE technique has been widely used for discectomy, spinal canal decompression, and intervertebral fusion, particularly in East Asia. The benefits of this procedure include reduced damage to the paravertebral musculature, less bleeding, a clear surgical view, quicker recovery, and fewer postoperative complications14.
The UBE technique has the distinct advantage of decompressing the spinal canal. Recently, two randomized controlled trials (RCTs) reported that the UBE technique has comparable clinical outcomes to traditional microscopic open surgery in the procedures of discectomy and spinal canal decompression. In 2020, Park et al.15 reported that UBE decompressive laminectomy is an alternative approach to microscopic open surgery in patients with symptomatic lumbar spinal stenosis, offering comparable clinical outcomes. More recently, Park et al.16 (from the same team) also reported that UBE discectomy was non-inferior to microscopic discectomy over a 12-month period. They concluded that UBE discectomy can be a relatively safe and effective surgical technique for lumbar disc herniation, with the added advantage of reduced muscle damage.
Compared to other minimally invasive surgical (MIS) techniques, Aygun et al. found that UBE was superior to microendoscopic discectomy (MED) in terms of improving the ODI and Zurich Claudication Questionnaire (ZCQ) over various follow-up periods. UBE surgery also resulted in shorter hospital stays, reduced operative times and blood loss, and higher patient satisfaction rates17. In another study, although back pain relief was better on post-op day 1, the UBE technique was reported to be similar to the MED technique regarding leg pain relief, long-term efficacy, and safety. As for percutaneous endoscopic lumbar discectomy (PELD), UBE was comparable to PELD in providing relief for low back or leg pain, demonstrating long-term effectiveness, and ensuring safety18.
Although the UBE technique has many advantages in surgical neural decompression of lumbar spinal stenosis, it still has some limitations. Age-related degeneration of the spine, including facet hypertrophy or ipsilateral spinous process deviation, may hamper ipsilateral access and require partial facetectomy to expose the lateral recess9. To overcome this limitation, Kim et al. reported that UBE decompression via the contralateral approach could offer more manipulative freedom and also allow safer decompression and facet preservation9. Although UBE can do very well with dorsal and lateral spinal decompression via endoscopic ULBD procedure, It is difficult to perform ventral neural decompression or discectomy when bilateral or contra-lateral recess stenosis or disc herniation exists.
In this study, we proposed the third channel-assisted UBE technique (T-UBE) to overcome this limitation. During the operation, the assistant utilizes a nerve hook to retract and protect the nerve root and dural sac via the original operation channel. Subsequently, the chief surgeon performs a discectomy through the third channel. The contralateral ventrally herniated intervertebral disc can be well exposed and easily removed, which can also be applied to contralateral stenosis decompression. In this situation, the T-UBE technique may prevent the need for an additional UBE operation on the opposite side. This can help to reduce the overall operation time, minimize soft tissue damage, and potentially lower the risk of nerve injury during surgery. Discectomy should not only remove the prolapsed or herniated nucleus pulposus tissue but also eliminate any loose nucleus pulposus tissue in the intervertebral disc19. The operating device is positioned vertically from the contralateral third channel in the T-UBE. In this way, the nucleus pulposus forceps can access the deep intervertebral disc and remove it, thereby reducing the recurrence rate of intervertebral disc herniation and avoiding dural sac injury caused by excessive inclination of the operating device. However, similar to conventional UBE decompression surgery, the T-UBE technique requires careful attention to preserving more than 50% of the bilateral facets, maintaining lumbar stability, and avoiding postoperative lumbar instability.
For cases of spinal stenosis combined with central disc herniation, the conventional UBE technique can effectively achieve spinal canal decompression and herniated disc resection through ULBD20. For cases of spinal stenosis combined with contralateral paracentral or foraminal disc herniation, the conventional UBE technique is often hindered by the dural sac and contralateral nerve roots. It becomes challenging for the operating device to access the contralateral herniated disc or reach the deep disc without causing nerve injury. However, the T-UBE technique can address this limitation. Under the protection of the nerve retractor in the original operating channel, the operating device was inserted vertically through the third channel to successfully extract the herniated disc and remove the loose nucleus pulposus from the innermost part of the disc. This approach is more efficient and safer (Figure 11).
The disadvantage of the T-UBE technique is that it requires an additional surgical incision and needs an assistant to complete the procedure. Maybe an automatic nerve retractor can be developed to serve as a surgical aid in the future. In addition, the visual field of TUBE is easily affected by intraoperative bleeding, and even a little bleeding can interfere with the surgeon&#39;s operation. Some skills may be useful, such as avoiding a large fluctuation of blood pressure and controlling blood pressure to 100-110 mmHg during operation, maintaining relatively stable hydrostatic pressure by gravity water irrigation, intraoperative preventive hemostasis, static hemostasis or compressive hemostasis with gelatin sponge or hemostatic drugs. Furthermore, anticoagulants should be discontinued before surgery, and patients with cardiovascular diseases should receive heparin replacement therapy.
This study primarily introduces the surgical procedure and advantages of the T-UBE technique. This technique will be used for patients with lumbar spinal stenosis who have contralateral recess stenosis or disc herniation or who have contra-lateral neural compression. Nonetheless, it is pivotal to acknowledge that the current study presents only a limited number of clinical cases. To establish its true efficacy, an expanded array of cases and prospective studies are required.
In conclusion, the T-UBE technique, developed from the conventional UBE technique, can address the limitations of the conventional UBE technique. It improves the efficiency of spinal decompression, reduces operative time, minimizes tissue damage, and leads to better clinical outcomes. Therefore, it is expected to be a significant alternative to the conventional UBE technique.

In the field of spine surgery, minimally invasive spine surgical (MISS) techniques have evolved significantly in recent years, transitioning from open surgery to microscopic, microendoscopic, and endoscopic surgery. Endoscopic spine surgery is an advanced form of MISS technique that has been widely used to treat spinal diseases and achieve satisfactory clinical outcomes1. Compared with traditional open surgery, it has the advantages of less tissue damage, less bleeding, quicker recovery, and fewer postoperative complications2. 
Endoscopic spine surgery can be performed using single or two portals. Unilateral biportal endoscopic (UBE) spine surgery is an innovative type of MISS technique that was first reported for performing lumbar discectomy in Argentina. It has since been refined to also perform decompression or fusion surgery in South Korea3. The surgical procedure of the UBE technique is similar to conventional open surgery. However, the UBE technique is less invasive and provides a clearer field of view compared to traditional open surgery4,5. 
The conventional UBE technique not only enables unilateral decompression but also achieves bilateral decompression for spinal stenosis6,7. In 2019, Heo et al.8 reported that the UBE technique could significantly expand the stenotic dural areas through unilateral laminotomy for bilateral decompression (ULBD). This technique also preserved more of the ipsilateral facet joint by undercutting the medial facet joint, compared to conventional microscopic decompression. In 2021, Kim et al.9 described a new decompression procedure for UBE in cases of asymmetric spinal stenosis using a contralateral approach. The contralateral approach UBE technique was able to achieve adequate decompression of the contralateral recess and spinal stenosis. It had advantages such as better manipulative freedom, a more accessible target approach, and more facet preservation.
The advantage of the UBE technique is dorsal and lateral spinal decompression through the endoscopic ULBD procedure. However, It is challenging to perform ventral neural decompression or discectomy when there is bilateral recess stenosis or disc herniation. Although bilateral UBE can be performed, it will significantly prolong the operation time, increase intraoperative bleeding, and elevate the risk of dural injury. Here, a third channel was developed in the UBE technique to perform the discectomy within the same endoscopic field of view. This allows the instruments to be inserted vertically into opposite discs, making the discectomy process easier. This technique can not only achieve adequate decompression of the bilateral spinal canal but also effectively remove contralateral herniated disc fragments.

<table><tbody><tr><td>Bone dissector</td><td>Hengsheng Medical Instrument Co., Ltd.</td><td>PMT-BLQ001</td><td>Used for soft tissue expansion and laminar bone surface soft tissue stripping. Curved streamline design, better hand holding, one device and two uses, one end as soft tissue expansion, the other end as bone tissue dissection, fully expand and dissect the lamina and facet soft tissue.</td></tr><tr><td>Electric surgical equipment for osseous tissue</td><td>Viewall</td><td>VP7110</td><td>Used to grind off vertebral plate and partial facet bone; in the device channel, it is used for processing bone tissue; grind bone tissue at high speed, without damage to soft tissues such as nerve vessel; even grind close to nerve root, without damage to nerve; it is safer and faster.</td></tr><tr><td>Expandable Channel</td><td>Hengsheng Medical Instrument Co., Ltd.</td><td>PMT-KZG001</td><td>Perform channel dilation</td></tr><tr><td>Handle of scalpel</td><td>Hengsheng Medical Instrument Co., Ltd.</td><td>PMT-DB001</td><td>Used to Install scalpel</td></tr><tr><td>Mouth gag</td><td>Hengsheng Medical Instrument Co., Ltd.</td><td>PMT-KKQ001</td><td>Used to handle annulus breaks prior to disc</td></tr><tr><td>Nerve hook</td><td>Hengsheng Medical Instrument Co., Ltd.</td><td>PMT-LG001</td><td>Used for traction of nerve root in surgery; under endoscopic surgical field, pull apart and protect nerve root in instrument channel and can simultaneously enter other instruments for processing intervertebral disc.</td></tr><tr><td>Nucleus pulposus forceps</td><td>Hengsheng Medical Instrument Co., Ltd.</td><td>PMT-SHQ003</td><td>Used for clamping soft tissue and nucleus pulposus tissue of intervertebral disc during operation. Different angles and sizes allow easier grasping of soft tissue in various locations during surgery, and the finger loop design is ergonomic and easy to perform, along with gunshot forceps.</td></tr><tr><td>Osteotome</td><td>Hengsheng Medical Instrument Co., Ltd.</td><td>PMT-GZ001</td><td>During the operation, handle the lamina and facet, osteotomes with different angles and sizes can efficiently and flexibly chisel the facet and laminar bone</td></tr><tr><td>Radiofrequency electrode</td><td>GAOTONG</td><td>DZX-T2430-A160</td><td>Used for hemostasis ablation, cutting and cleaning soft tissue under endoscope during operation</td></tr><tr><td>Rongeur</td><td>Hengsheng Medical Instrument Co., Ltd.</td><td>PMT-YGQ002</td><td>During the operation, the laminar and facet bones were bitten and cut, the bone window was enlarged, and different sizes and angles were different. The bitewing mouth of the large incision easily bitewed off different bony tissues and calcified tissues, greatly saving the operation time, gun design, better hand holding sensation, and more forceful biting of bony tissues during the operation</td></tr><tr><td>Scalpel</td><td>Hengsheng Medical Instrument Co., Ltd.</td><td>PMT-SSD001</td><td>Used to cut the annulus fibrosus</td></tr><tr><td>Tissue Liberator</td><td>Hengsheng Medical Instrument Co., Ltd.</td><td>PMT-BLQ002</td><td>Used for stripping soft tissue in surgery, bidirectionally at different angles; used for stripping and separating mucosal tissue under instrument channel.</td></tr></tbody></table>

the third channel-assisted unilateral biportal endoscopic technique for lumbar spinal stenosis combined with contralateral disc herniation

Unilateral biportal endoscopic (UBE) spine surgery is an emerging minimally invasive surgical (MIS) technique that has gained popularity for treating lumbar spinal stenosis, particularly in Eastern Asia. The traditional UBE technique, with two portals on one side, can achieve successful unilateral laminotomy for bilateral decompression (ULBD) and, therefore, demonstrates favorable clinical outcomes. However, in the case of lumbar spinal stenosis combined with contralateral disc herniation, it is very difficult to remove the contralateral disc herniation, especially the loose disc fragment within the deep disc. Here, a third channel of the traditional UBE technique was developed to do the discectomy within the ipsilateral endoscopic vision, with which the instruments can go vertically into the contralateral disc, allowing easy discectomy. This technique can not only achieve adequate decompression of the bilateral spinal canal but also effectively remove contralateral herniated disc fragments. This technique avoids performing another UBE procedure on the opposite side, which can potentially shorten the duration of the operation, minimize blood loss and tissue damage, and ensure sufficient neural decompression. This paper will introduce the indications and surgical operation procedures, as well as present a classical case report and follow-up data, to facilitate the application of the third channel-assisted UBE (T-UBE) technique for spine surgeons.

The T-UBE technique will be demonstrated in a typical case. A 65-year-old male complained of low back pain with bilateral numbness in his lower limbs for 10 months. The numbness is more pronounced on the right side and is accompanied by intermittent claudication, which occurs after walking 50 m. The symptoms on the left side were relieved by analgesic and neurotrophic drug treatment, but the symptoms on the right side persisted. Physical examination revealed mild tenderness of the spinous process and pain upon percussion at the lumbar L4-5 level. There was a slight limitation in lumbar flexion and extension. The patient also exhibited mild hypoesthesia on the dorsum of the right foot and grade 5 extensor strength in both hallux. The right straight leg raise test (SLR) was negative, while the left SLR was positive at 60&#176;. The preoperative visual analog scale (VAS)10 scores for low back pain and leg pain were both 5, and the Oswestry disability index (ODI)11 score was 42% (Figure 7). The preoperative X-ray showed lumbar degeneration but no instability (Figure 8A-D). Magnetic resonance imaging (MRI) revealed L4-5 spinal stenosis, right facet cyst formation, left disc herniation, and severe bilateral nerve compression (Figure 9A-C). Computed tomography (CT) showed L4-5 central canal and bilateral recess spinal stenosis, as well as severe bilateral nerve compression (Figure 9D-F). The diagnosis was lumbar spinal stenosis (bilateral at L4/5) and left-sided lumbar disc herniation (at L4/5). The patient underwent surgical treatment for T-UBE L4/5 spinal canal decompression (ULBD) with contralateral discectomy through the third channel.
The patient started walking on the second day after the surgery, and the symptoms in his lower limbs nearly disappeared. Physical examination showed that the muscle strength of the lower limbs was grade V, and the sensation was the same as before the operation. The bilateral SLR test was negative. The VAS score for low back pain was 1, for leg pain was 0, and the ODI was 6% on postoperative day 3. Follow-up at 3 months, the VAS score for low back pain was 0, the VAS score for leg pain was 0, and the ODI was 4%. Follow-up at 6 months showed that the VAS for low back pain and leg pain was 0, and the ODI was 4%. The postoperative modified Macnab score was excellent. Postoperative CT showed adequate bilateral decompression at the L4-5 level, with more than 50% preservation of facet joints, thus avoiding the possibility of lumbar instability. Postoperative MRI showed adequate bilateral decompression at the L4-5 level using a unilateral approach. The procedure successfully removed the contralateral disc herniation, and there was no compression of the dural nerve (Figure 10). The dural sac area increased from 63.55 mm2 (preoperative, Figure 9C) to 100.80 mm2 (postoperative, Figure 10B). Additionally, the nerve root sedimentation sign changed from positive before the surgery to negative after the surgery.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/65262/65262fig01.jpg" /> 
Figure 1: Establish endoscopic operating space (A) Photograph capturing the operator&#39;s involvement during the procedure. (B) Utilization of a radiofrequency ablation blade to delicately remove soft tissue from the laminar surface. (C) Visual exposure of the lower edge of the L4 lamina and the medial aspect of the L4/5 right facet joint. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/65262/65262fig01large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/65262/65262fig02v2.jpg" /> 
Figure 2: Performing ipsilateral laminotomy. (A) Schematic representation of the procedure&#39;s microscopic operating space setup. (B) Operator engagement documented through gross photography. (C) Systematic grinding of the L4 lamina&#39;s lower inner edge to the tip of the ligamentum flavum insertion utilizing a micropowered burr, operating at a rotation rate of 8000 rotations per second. (D) Employing a micropowered burr to meticulously remove the lateral margin of the L4 inferior facet. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/65262/65262fig02largev2.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/65262/65262fig03.jpg" /> 
Figure 3: Achieving neural decompression. (A) Utilization of a nerve elevator to meticulously separate the ligamentum flavum at the lower edge of the L4 lamina and at its insertion point. (B) Careful removal of the ligamentum flavum from its cranial to caudal and lateral dimensions utilizing a 4 mm Laminar rongeur. (C) Removal of the ligamentum flavum within the right lateral recess at the L4/5 level, accompanied by the resection of hyperplastic cohesive facet joint bone and facet joint cyst. (D) Culmination of nerve root decompression to ensure comprehensive resolution. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/65262/65262fig03large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 4" class="xfigimg" src="/files/ftp_upload/65262/65262fig04.jpg" /> 
Figure 4: Contra-lateral dorsal neural decompression. (A) Controlled abrasion of a portion of the base of the L4 spinous process, employing a micropowered burr. (B) Precise exposure of the contralateral L4 inferior facet, culminating in the full visualization of the left border of the ligamentum flavum. (C) Meticulous removal of the left ligamentum flavum along with a section of the medial wall of the left facet at the L4/5 level, accomplished through the use of a 4 mm Laminar rongeur. (D) Attainment of dorsal decompression for the contralateral nerve root. (E) Schematic representation of the base of the L4 spinous process abrasion process. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/65262/65262fig04large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 5" class="xfigimg" src="/files/ftp_upload/65262/65262fig05.jpg" /> 
Figure 5: Establishing the third channel. (A-C) A sequence of sub-figures depicting the procedural progression of establishing the third channel. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/65262/65262fig05large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 6" class="xfigimg" src="/files/ftp_upload/65262/65262fig06.jpg" /> 
Figure 6: Contralateral third channel-assisted discectomy. (A) Gross photographic documentation of the operator&#39;s active involvement during the procedure. (B) Methodical retraction of the thecal sac and the left L5 nerve root utilizing a nerve retractor, leading to optimal exposure of the contralateral herniated disc. (C) Precise cutting of the disc using a sharp knife. (D) Removal of the nucleus pulposus achieved through the utilization of a nucleus pulposus forceps. (E) Successful realization of an adequate release of the nerve root. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/65262/65262fig06large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 7" class="xfigimg" src="/files/ftp_upload/65262/65262fig07.jpg" /> 
Figure 7: Visual analog scale (VAS) and Oswestry disability index (ODI) scores. (A) Visualization of the variations in Visual Analog Scale (VAS) scores pertaining to low back pain, both before surgery and throughout the postoperative follow-up. (B) Depiction of the alterations in VAS scores relating to leg pain, pre-surgery and during the postoperative follow-up. (C) Comprehensive representation of the shifts in Oswestry Disability Index (ODI) scores, prior to surgery and within the postoperative follow-up period. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/65262/65262fig07large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 8" class="xfigimg" src="/files/ftp_upload/65262/65262fig08.jpg" /> 
Figure 8: Preoperative radiographs. (A) Lumbar reoperative anteroposterior radiograph of the patient. (B) Preoperative lumbar lateral radiograph of the patient. (C) Preoperative lumbar hyperflexion radiograph of the patient. (D) Preoperative lumbar hyperextension radiograph of the patient. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/65262/65262fig08large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 9" class="xfigimg" src="/files/ftp_upload/65262/65262fig09.jpg" /> 
Figure 9: Preoperative MRI and CT. (A) Preoperative left sagittal MR image of the lumbar region for the patient. (B) Preoperative right sagittal MR image of the lumbar region for the patient. (C) Preoperative horizontal MR image of the L4/5 level for the patient. (D,E) Preoperative lumbar coronal CT images for the patient. (F) Preoperative horizontal CT image of the L4/5 level for the patient. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/65262/65262fig09large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 10" class="xfigimg" src="/files/ftp_upload/65262/65262fig10.jpg" /> 
Figure 10: Postoperative MRI and CT. (A) Postoperative sagittal MR image of the lumbar region for the patient. (B) Postoperative horizontal MR image of the L4/5 level for the patient. (C) Postoperative sagittal CT image of the lumbar region for the patient. (D) Postoperative horizontal CT image of the L4/5 level for the patient. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/65262/65262fig10large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 11" class="xfigimg" src="/files/ftp_upload/65262/65262fig11.jpg" /> 
Figure 11: The comparison between conventional UBE and T-UBE. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/65262/65262fig11large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>

Watch this Scientific Journal Video about The Third Channel-Assisted Unilateral Biportal Endoscopic Technique for Lumbar Spinal Stenosis Combined with Contralateral Disc Herniation at JoVE.com

Author Spotlight: Unveiling the Potential of TUBE Technique in Spinal Surgery

Here, we present the third channel-assisted UBE technique, which allows for the vertical removal of herniated disc fragments. This technique can effectively address the limitations of traditional UBE techniques. This article will systematically elaborate on this procedure.

The Third Channel-Assisted Unilateral Biportal Endoscopic Technique for Lumbar Spinal Stenosis Combined with Contralateral Disc Herniation

Unilateral biportal endoscopic (UBE) spine surgery is an emerging minimally invasive surgical (MIS) technique that has gained popularity for treating ...

the-third-channel-assisted-unilateral-biportal-endoscopic-technique

Nanyang Technological University

Research

JoVE Journal

Medicine

1.2K Views.  The Third Affiliated Hospital of Sun Yat-sen University. Ons onderzoek richt zich op unilaterale bipolaire endoscopie UBE voor spinale gedegenereerde ziekten. De traditionele UBE-techniek met twee dragers aan één kant kan unilaterale laminectomie bereiken voor bilaterale decompressie, ULBD, en daarom gunstige klinische resultaten laten zien. Hier proberen we deze techniek te verbeteren om het efficiënter en veiliger te maken.De UBE-techniek wordt steeds vaker gebruikt bij spinale decompressie of discectomie als een nieuwe endoscopische te...

Video: Auteur in de schijnwerpers: onthulling van het potentieel van de TUBE-techniek in spinale chirurgie

Acute and Chronic Tactile Sensory Testing after Spinal Cord Injury in Rats

Spinal cord injury (SCI) impairs sensory systems causing allodynia1-8. To identify cellular and molecular causes of allodynia, sensitive and valid sensory testing in rat SCI models is needed. However, until recently, no single testing approach had been validated for SCI so that standardized methods have not been implemented across labs. Additionally, available testing methods could not be implemented acutely or when severe motor impairments existed, preventing studies of the development of SCI-induced allodynia3. Here we present two validated sensory testing methods using von Frey Hair (VFH) monofilaments which quantify changes in tactile sensory thresholds after SCI4-5. One test is the well-established Up-Down test which demonstrates high sensitivity and specificity across different SCI severities when tested chronically5. The other test is a newly-developed dorsal VFH test that can be applied acutely after SCI when allodynia develops, prior to motor recovery4-5. Each VFH monofilament applies a calibrated force when touched to the skin of the hind paw until it bends. In the up-down method, alternating VFHs of higher or lower forces are used on the plantar L5 dermatome to delineate flexor withdrawal thresholds. Successively higher forces are applied until withdrawal occurs then lower force VFHs are used until withdrawal ceases. The tactile threshold reflects the force required to elicit withdrawal in 50% of the stimuli. For the new test, each VFH is applied to the dorsal L5 dermatome of the paw while the rat is supported by the examiner. The VFH stimulation occurs in ascending order of force until at least 2 of 3 applications at a given force produces paw withdrawal. Tactile sensory threshold is the lowest force to elicit withdrawal 66% of the time. Acclimation, testing and scoring procedures are described. Aberrant trials that require a retest and typical trials are defined. Animal use was approved by Ohio State University Animal Care and Use Committee.

We describe two tactile sensory testing methods for acute or chronic periods of spinal cord injury in rats. These validated procedures can detect the development and maintenance of allodynia-like sensations.

Spinal cord injury (SCI) impairs sensory systems causing allodynia1-8. To identify cellular and molecular causes of allodynia, sensitive and valid sensory ...

A Contusive Model of Unilateral Cervical Spinal Cord Injury Using the Infinite Horizon Impactor

While the majority of human spinal cord injuries occur in the cervical spinal cord, the vast majority of laboratory research employs animal models of spinal cord injury (SCI) in which the thoracic spinal cord is injured. Additionally, because most human cord injuries occur as the result of blunt, non-penetrating trauma (e.g. motor vehicle accident, sporting injury) where the spinal cord is violently struck by displaced bone or soft tissues, the majority of SCI researchers are of the opinion that the most clinically relevant injury models are those in which the spinal cord is rapidly contused.1 Therefore, an important step in the preclinical evaluation of novel treatments on their way to human translation is an assessment of their efficacy in a model of contusion SCI within the cervical spinal cord. Here, we describe the technical aspects and resultant anatomical and behavioral outcomes of an unilateral contusive model of cervical SCI that employs the Infinite Horizon spinal cord injury impactor.
Sprague Dawley rats underwent a left-sided unilateral laminectomy at C5. To optimize the reproducibility of the biomechanical, functional, and histological outcomes of the injury model, we contused the spinal cords using an impact force of 150 kdyn, an impact trajectory of 22.5&deg; (animals rotated at 22.5&deg;), and an impact location off of midline of 1.4 mm. Functional recovery was assessed using the cylinder rearing test, horizontal ladder test, grooming test and modified Montoya's staircase test for up to 6 weeks, after which the spinal cords were evaluated histologically for white and grey matter sparing.
The injury model presented here imparts consistent and reproducible biomechanical forces to the spinal cord, an important feature of any experimental SCI model. This results in discrete histological damage to the lateral half of the spinal cord which is largely contained to the ipsilateral side of injury. The injury is well tolerated by the animals, but does result in functional deficits of the forelimb that are significant and sustained in the weeks following injury. The cervical unilateral injury model presented here may be a resource to researchers who wish to evaluate potentially promising therapies prior to human translation.

A reliable and repeatable way to produce a cervical unilateral spinal cord injury using the Infinite Horizon impactor is described. The method takes advantage of a custom designed frame and clamp to stabilize the spine. The standardized procedure and biomechanical injury parameters result in sufficient and sustained injuries.

While the majority of human spinal cord injuries occur in the cervical spinal cord, the vast majority of laboratory research employs animal models of ...

Topical Airway Anesthesia for Awake-endoscopic Intubation Using the Spray-as-you-go Technique with High Oxygen Flow

A patient&#39;s willingness to cooperate is an absolute precondition for successful awake intubation of the trachea. Whilst drug-sedation of patients can jeopardize their spontaneous breathing, topical anesthesia of the airway is a popular technique. The spray-as-you-go technique represents one of the simplest opportunities to anesthetize the airway mucosa. The application of local anesthetic through the working channel of the flexible endoscope is a widespread practice for anesthetists as well as pulmonologists. There is neither need for additional devices nor special training as a pre-requisite to perform this technique. However, a known clinical problem is the coughing and gagging reflex that may occur when the liquid anesthetic strikes the airway mucosa and other sensitive structures like the vocal cords. This can be avoided by the use of oxygen applied through the working channel with the aim of fogging the local anesthetic into finer particles. Furthermore, the oxygen flow provides a higher oxygen supply and contributes to a better view, dispersing mucus secretions and blood away from the lens. Using an atomizer with a high oxygen flow of 10 L/min we maximized these benefits, caused less coughing and had more satisfied and therefore cooperative patients. Possible, but very rare complications of using oxygen flow including gastric insufflation, organ rupture or barotrauma did not arise. We attribute the complication-free use of high oxygen flow to the design of the set, which permits flow and pressure release.

The topical anesthetic lidocaine was atomized using a high oxygen flow through the working channel of a flexible intubating endoscope to achieve topical airway anesthesia for awake endotracheal intubation. We prefer this modified spray-as-you-go technique for endoscopic intubation to classical bolus application because of higher patient satisfaction and better compliance.

A patient&#39;s willingness to cooperate is an absolute precondition for successful awake intubation of the trachea. Whilst drug-sedation of patients can ...

Ovine Lumbar Intervertebral Disc Degeneration Model Utilizing a Lateral Retroperitoneal Drill Bit Injury

Intervertebral disc degeneration is a significant contributor to the development of back pain and the leading cause of disability worldwide. Numerous animal models of intervertebral disc degeneration have been developed. The ideal animal model should closely mimic the human intervertebral disc with regard to morphology, biomechanical properties and the absence of notochordal cells. The sheep lumbar intervertebral disc model fulfils these criteria. We present an ovine model of intervertebral disc degeneration utilizing a drill bit injury through a lateral retroperitoneal approach. The lateral approach significantly reduces the incision and potential morbidity associated with the traditional anterior approach to the ovine spine. Utilization of a drill-bit method of injury affords the ability to produce a consistent and reproducible injury, of precise dimensions, that initiates a consistent degree of intervertebral disc degeneration. The focal nature of the annular and nucleus pulposus defect more closely mimics the clinical condition of focal intervertebral disc herniation. Sheep recover rapidly following this procedure and are typically mobile and eating within the hour. Intervertebral disc degeneration ensues and sheep undergo necropsy and subsequent analysis at periods from eight weeks. We believe that the drill bit injury model of intervertebral disc degeneration offers advantages over more conventional annular injury models.

Intervertebral disc degeneration is a significant contributor to back pain and a leading cause of disability worldwide. Numerous animal models of intervertebral disc degeneration exist. We demonstrate an ovine model of intervertebral disc degeneration, utilizing a drill bit, which achieves a consistent disc injury and reproducible level of disc degeneration.

Intervertebral disc degeneration is a significant contributor to the development of back pain and the leading cause of disability worldwide. Numerous ...

A Mobile Outside-in Technique of Transforaminal Lumbar Endoscopy for Lumbar Disc Herniations

Percutaneous endoscopic transforaminal lumbar discectomy (PETLD) has now become a standard of care for the management of lumbar disc disease. There are two techniques for the introduction of a working cannula with respect to disc&#8212;outside-in and inside-out. The aim of this prospective study is to describe the technical aspects of a novel mobile outside-in method in dealing with different types of disc prolapse. A total of 184 consecutive patients with unilateral lower limb radiculopathy due to lumbar disc prolapse were operated on with the mobile outside-in technique of PETLD. Their clinical outcomes were evaluated based on the type of disc prolapse they had, a visual analog scale (VAS) leg pain score, the Oswestry Disability Index (ODI), and the Macnab criteria. The completeness of the decompression was documented with a postoperative magnetic resonance imaging. The mean age of the patients was 50 &#177; 16 years and the male/female ratio was 2:1. The mean follow-up was 19 &#177; 6 months. A total of 190 lumbar levels were operated on (L1&#8211;L2: n = 4, L2&#8211;L3: n = 17, L3&#8211;L4: n = 27, L4&#8211;5: n = 123, and L5&#8211;S1: n = 19). Divided into types, the patient distribution was central: n = 14, paracentral: n = 74, foraminal: n = 28, far lateral: n = 13, superior-migrated: n = 8, inferior migrated: n = 38, and high canal compromise: n = 9. The mean operative time was 35 &#177; 12 (25 - 56) min and the mean hospital stay was 1.2 &#177; 0.5 (1&#8211;3) days. The VAS score for leg pain improved from 7.5 &#177; 1 to 1.7 &#177; 0.9. The ODI improved from 70 &#177; 8.3 to 23 &#177; 5. According to the Macnab criteria, 75 patients (40.8%) had excellent results, 104 patients (56.5%) had good results, and 5 patients (2.7%) had fair results. Recurrence (including early and late) was seen in 15 out of the 190 levels that were operated on (7.89%). This article presents a novel outside-in approach that relies on a precise landing within the foramen in a mobile manner and does not solely depend upon the enlargement of the foramen. It is more versatile in application and useful in the management of all types of disc prolapse, even in severe canal compromise and high migration.

Here we present a protocol of a novel outside-in technique of transforaminal endoscopic discectomy for lumbar disc herniations. The technical aspects of the technique, the wide indications of use, and the results of the treatment in 184 patients are described in detail.

Percutaneous endoscopic transforaminal lumbar discectomy (PETLD) has now become a standard of care for the management of lumbar disc disease. There are ...

Targeting Gray Rami Communicantes in Selective Chemical Lumbar Sympathectomy

Chemical lumbar sympathectomy (CLS) is a commonly used, minimally invasive procedure for the treatment of conditions including ischemic diseases of the lower extremities, hyperhidrosis, etc. It is commonly practiced to position the puncture needle tip in front of the anterior fascia of the psoas major muscle and inject the inactivating agent around the sympathetic trunk, which is defined as conventional CLS. Although relatively rare, ureteropelvic damage is the most frequently reported complication of conventional CLS and can cause serious harm to patients. We found that injecting the inactivating agent behind the anterior fascia, which only targets gray rami communicantes, helped achieve therapeutic efficacy in&#160;vasodilation, sweat reduction, and pain relief comparable to conventional CLS, and serious complications were largely reduced. We define this procedure as selective CLS. Here, we present a protocol of selective CLS. The precise needle tract and accurate evaluation of the spreading of the contrast agent are critical to ensure that the drug is injected behind the anterior fascia of the psoas major muscle. The needle tip is at approximately one-third the dividing line of the vertebral body in the lateral view of a lumbar X-ray. The contrast is mainly confined around the needle tip and spreads outward and downward along the psoas muscle fibers. In this way, the anterior fascia provides a natural barrier for the ureteropelvic area, and the psoas major muscle provides a natural barrier for the lumbar nerve root. There are several highlights of this article, including 1) a detailed description of the selective CLS procedures, 2) an explanation of the anatomical basis for the implementation of selective CLS, and 3) an explanation of the differences between selective and conventional CLS.

We present a protocol for selective chemical lumbar sympathectomy (CLS), which inactivates only gray rami communicantes and not the sympathetic trunk. Selective CLS can help achieve therapeutic efficacy in vasodilation, sweat reduction, and pain relief that are comparable to conventional CLS, and serious complications, particularly ureteropelvic damages, can be reduced.

Chemical lumbar sympathectomy (CLS) is a commonly used, minimally invasive procedure for the treatment of conditions including ischemic diseases of the ...

Modified Posterior Vertebral Column Resection for Patients with Thoracolumbar Kyphotic Deformity

Old compression vertebrae fracture or congenital kyphoscoliosis with abnormal vertebral body development and other diseases that invade the spine may cause severe thoracolumbar kyphotic deformity, often accompanied by intractable low back pain or compression of the spinal cord, leading to severe neurological symptoms or even paralysis. If conservative treatment cannot relieve the symptoms or correct the deformities, surgical treatment is usually needed. For severe kyphotic deformity, reconstruction of the physiological curvature and rigid fixation determine the prognosis of the patients. Osteotomy and orthopedics are the standard procedure for deformities with severe compression of the front and middle column, but the trauma to the patients is high, with a long operation time and massive blood loss. To avoid these disadvantages, we have developed a modified technique to remove the diseased vertebra unilaterally. In this technique, we use a modified trephine to resect the vertebral columns like in the pedicle screw technique by adding a locking instrument that can restrict the trephine to lower the risk of osteotomy and shorten the surgery time and blood loss.

We describe a modified technique for resecting the posterior vertebral column unilaterally based on a modified trephine for patients with thoracolumbar kyphotic deformity.

Old compression vertebrae fracture or congenital kyphoscoliosis with abnormal vertebral body development and other diseases that invade the spine may ...

Modified Laparoscopic Anatomic Hepatectomy: Two-Surgeon Technique Combined with the Simple Extracorporeal Pringle Maneuver

Laparoscopic anatomic hepatectomy (LAH) has become increasingly prevalent worldwide in recent years. However, LAH remains a challenging procedure due to the anatomical characteristics of the liver, with intraoperative hemorrhage being a primary concern. Intraoperative blood loss is the leading cause of conversion to open surgery; therefore, effective management of bleeding and hemostasis is crucial for a successful LAH.
The two-surgeon technique is proposed as an alternative to the traditional single-surgeon approach, with potential benefits in reducing intraoperative bleeding during laparoscopic hepatectomy. However, there remains a lack of evidence to determine which mode of the two-surgeon technique yields superior patient outcomes. Besides, to our knowledge, the LAH technique, which involves the use of a cavitron ultrasonic surgical aspirator (CUSA) by the primary surgeon while an ultrasonic dissector by the second surgeon, has been rarely reported before.
Herein, we present a modified, two-surgeon LAH technique, wherein one surgeon employs a CUSA while the other uses an ultrasonic dissector. This technique is combined with a simple extracorporeal Pringle maneuver and low central venous pressure (CVP) approach. In this modified technique, the primary and secondary surgeons utilize a laparoscopic CUSA and an ultrasonic dissectorconcurrently to achieve precise and expeditious hepatectomy. A simple extracorporeal Pringle maneuver, combined with the maintenance of low CVP, is employed to regulate the hepatic inflow and outflow in order to minimize intraoperative bleeding. This approach facilitates the attainment of a dry and clean operative field, which allows for the precise ligation and dissection of blood vessels and bile ducts. The modified LAH procedure is simpler and safer due to its effective control over bleeding as well as the seamless transition between the roles of primary and secondary surgeons. It holds great promise for future clinical applications.

Here, we present a protocol to perform a modified laparoscopic anatomic hepatectomy using improved techniques and instruments.

Laparoscopic anatomic hepatectomy (LAH) has become increasingly prevalent worldwide in recent years. However, LAH remains a challenging procedure due to ...

Unilateral Biportal Endoscopy for the Treatment of Lumbar Disc Herniation

Unilateral biportal endoscopy (UBE) is a minimally invasive spinal surgery technique increasingly employed in treating degenerative lumbar diseases, such as lumbar disc herniation, lumbar spinal stenosis, and spondylolisthesis. In UBE, two independent yet interconnected surgical channels are established-one for the endoscope and the other for surgical instruments-providing a broad and clear surgical field of view. UBE offers several advantages over traditional open surgery, including reduced tissue damage, shorter hospital stays, and faster recovery times. Additionally, it combines the benefits of microscopic surgery and interlaminar endoscopy, enhancing flexibility, accuracy, and reliability during the procedure. The learning curve for UBE is shorter than that for transforaminal endoscopy, as the surgical processes closely resemble those of conventional open surgery. Despite its favorable clinical outcomes, such as reduced blood loss and shorter hospitalization, UBE carries potential complications, including epidural hematoma, dural injury, and compression of the outlet nerve root. To mitigate these risks, it is crucial to ensure appropriate patient selection, apply the correct surgical technique, and engage in careful postoperative monitoring. This article provides a detailed summary of the step-by-step surgical techniques used in UBE for treating lumbar disc herniation. It serves as a comprehensive guide to enhance practitioners' understanding of UBE. The presentation also underscores the importance of rigorous training and expertise to ensure optimal patient outcomes.

Presented here is a step-by-step surgical protocol of unilateral biportal endoscopy (UBE), a minimally invasive approach for treating lumbar disc herniation. By using two ports, surgical accuracy and flexibility are enhanced. This article provides a comprehensive description of UBE and highlights the practical application of this approach in clinical practice.

Unilateral biportal endoscopy (UBE) is a minimally invasive spinal surgery technique increasingly employed in treating degenerative lumbar diseases, such ...

Treating Lumbar Spinal Stenosis with a Minimally Invasive Spine Surgery

Percutaneous Endoscopic Unilateral-Approach Bilateral Decompression for Lumbar Spinal Stenosis

Lumbar spinal stenosis (LSS) involves the narrowing of the spinal canal due to degenerative changes in the vertebral joints, intervertebral discs, and ligaments. LSS encompasses central canal stenosis (CCS), lateral recess stenosis (LRS), and intervertebral foramen stenosis (IFS). The utilization of lumbar endoscopic unilateral laminotomy for bilateral decompression (LE-ULBD) has gained popularity in the treatment of CCS and LRS. This popularity is attributed to the rapid development of endoscopic instruments and the progress of endoscopic philosophy.
In this technical report, a detailed introduction to the steps and key points of LE-ULBD is provided. Simultaneously, a retrospective review of 132 consecutive patients who underwent LE-ULBD for central canal and/or lateral recess stenosis was conducted. The outcomes after more than two years of follow-up were assessed using the visual analogue score (VAS), Oswestry Disability Index (ODI), Japanese Orthopaedic Association (JOA) scores, and the modified MacNab criteria to evaluate surgical efficacy. All 132 patients underwent LE-ULBD successfully. Among them, 119 patients were rated as "excellent," while 13 patients were rated as "good" based on the modified MacNab criteria during the last follow-up. Incidental dural tears occurred in four cases, but there were no post-operative epidural hematomas or infections. The experience demonstrates that LE-ULBD is a less invasive, effective, and safe approach. It can be considered as an alternative option for treating patients with lumbar central canal stenosis and/or lateral recess stenosis.

Author Spotlight: Scope of LE-ULBD as a Safe, Effective, and Minimally Invasive Approach to Treat Lumbar Spinal Stenosis

The present protocol describes the steps and key points of lumbar endoscopic unilateral laminotomy for bilateral decompression for the treatment of degenerative lumbar spinal stenosis.

Lumbar spinal stenosis (LSS) involves the narrowing of the spinal canal due to degenerative changes in the vertebral joints, intervertebral discs, and ...

The Third Channel-Assisted Unilateral Biportal Endoscopic Technique for Lumbar Spinal Stenosis Combined with Contralateral Disc Herniation

Samenvatting

Meer video's verkennen

Hoofdstukken in deze video