The retrospective study was approved by our institutional review board (STUDY2021000113),&#160;and an informed consent waiver was granted because of the nature of the study. The procedure demonstrated in the video was performed on a human specimen that was obtained and utilized following the ethical guidelines and protocols established by our institution. The specimen was handled respectfully and in compliance with all relevant ethical standards.
1. Patient selection
<ol>
	<li>Select patients with degenerative lumbar disease and failed non-surgical treatment.</li>
	<li>Assess segment hypermobility or instability with flexion-extension X-ray images in addition to regular anteroposterior (AP) and lateral views (Figure 2). In cases of segment instability, perform an additional posterior fixation.</li>
	<li>Obtain a computed tomography (CT) and magnetic resonance (MR)-scan of the lumbar spine.</li>
</ol>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/66878/66878fig02.jpg" /> 
Figure 2: Pre-operative and follow-up X-ray images in A.P and lateral view. (A-B) Multilevel degenerative lumbar spine disease with collapsed disc space L3/4 as well as L4/5 and neuroforaminal stenosis. No signs of instability or hyperflexible were observed. (C-D) One-year post-operative follow up. Correct position of PEEK cages in L3/4 and L4/5 disc space without subsidence. Both disc and neuroforaminal height are restored. <a href="https://www.jove.com/files/ftp_upload/66878/66878fig02large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
2. Positioning
<ol>
	<li>Position the patient, under general anesthesia, in a right-sided decubitus position with partially flexed hips and knees on a radiolucent operating table. Pad bony prominences to avoid soft tissue damage due to pressure.</li>
	<li>Secure the patient with surgical tape and belts/pads to prevent movement and ensure safety.</li>
	<li>Flex the operating table to generate more space if needed.</li>
</ol>
3. Preoperative phase
<ol>
	<li>Confirm the desired surgical level with AP/lateral fluoroscopy images.</li>
	<li>Use skin markers to visualize the disc space and vertebral bodies of the desired level on the skin surface (Figure 3).</li>
	<li>Place electrodes for electromyography (EMG) on reference muscles for nerves that could be at risk during surgery17.</li>
</ol>
4. Approach
<ol>
	<li>After disinfecting the skin and covering the area with the surgical drape, according to institutional standards, make a 3-5 cm long skin incision using a sterile scalpel over the disc space in a single-level surgery.</li>
	<li>Use electrocautery to dissect the fascia abdominalis.</li>
	<li>Open the fascia and use clamps/retractors to bluntly split the three layers of the obliques until the retroperitoneal space is reached.</li>
	<li>Identify the psoas and split it in the longitudinal direction (for example, using retractors).</li>
</ol>
5. Neuromonitoring
<ol>
	<li>Look out for any changes in somatosensory evoked potentials (SSEP), motor evoked potentials (MEP), and spontaneous electromyography (EMG) during approach and when dissecting the psoas17.</li>
	<li>Using a handheld EMG probe, identify the exiting nerve root at the desired level.</li>
</ol>
6. Retractors
<ol>
	<li>After fluoroscopically confirming the desired level, place a self-retaining retractor system (Figure 4).</li>
</ol>
7. Preparation of intradiscal space
<ol>
	<li>Use a scalpel to perform an annulotomy and resect all discal material using a rongeur. 
	NOTE: In severe degeneration, the disc space may be obscured by osteophytes. These may need resection before evacuation of the discal space.</li>
	<li>Place a spreader to open the collapsed intervertebral space. 
	NOTE: In cases of severe degeneration, only partial restoration of the intervertebral space may be possible.</li>
	<li>Carefully remove disc material and cartilage from both endplates using Curettes or Cobb elevators (Figure 4).</li>
</ol>
8. Placement of trail cage
<ol>
	<li>Use different trial components to restore normal disc height and to relieve any pressure on nerve roots. 
	NOTE: The trial position is verified using fluoroscopy from both the AP and lateral views. The endplates should be symmetrically elevated (Figure 4).</li>
</ol>
9. Cage implantation
<ol>
	<li>After identifying the correct size, implant the cage under fluoroscopic guidance (Figure 5).</li>
	<li>Obtain final fluoroscopic images in A.P. and lateral view.</li>
</ol>
10. Closure
<ol>
	<li>Use irrigation and perform a final hemostasis check.</li>
	<li>Carefully remove all retractors and spreaders.</li>
	<li>Close the wound in a multilayered fashion.</li>
</ol>
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/66878/66878fig03.jpg" /> 
Figure 3: Identification of disc level. (A-B): Marking the desired level in anteroposterior (AP) and lateral view. (C) Identification of the desired level in the lateral view fluoroscopy. <a href="https://www.jove.com/files/ftp_upload/66878/66878fig03large.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/66878/66878fig04.jpg" /> 
Figure 4: Interoperative view during LLIF. (A) Position of Retractors on AP view. (B) Intraoperative verification of the correct level using fluoroscopy lateral view with retractors in place. (C) View on disc-level through Retractors. The disc was removed, with some cartilage left. (D) Intraoperative fluoroscopy AP view, with a trial cage in place. <a href="https://www.jove.com/files/ftp_upload/66878/66878fig04large.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/66878/66878fig05.jpg" /> 
Figure 5: Intraoperative view with implanted cage. (A) Intraoperative view through retractors.&#160;Visualization of the implanted cage. (B-C) Fluoroscopy with the cage in place. Correct positioning of the cage with restoration of disc height. <a href="https://www.jove.com/files/ftp_upload/66878/66878fig05large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
11. In-hospital postoperative phase
<ol>
	<li>Encourage patients to mobilize without a brace within hours by providing adequate pain medication or other pain management techniques.</li>
	<li>Provide the patient with a clear diet until the patient has passed flatus, then advance to a regular diet.</li>
	<li>Perform a recommended inspection and manual palpation of the flanks and a formal dressing check before discharge.</li>
</ol>
12. Outpatient postoperative phase
<ol>
	<li>After two weeks, perform a formal wound check.</li>
	<li>Advise the patients not to perform bending/lifting/twisting movements greater than 15 lbs.</li>
</ol>
13. Follow up
<ol>
	<li>At six weeks obtain postoperative X-rays and initiate 6 weeks of formalized physical therapy and education in trunk mechanics (Figure 2).</li>
	<li>At 3 months perform a formal evaluation. If concern for pseudoarthrosis arise obtain a CT with MPR (multiplanar reformatting) or MIP (maximum intensity projection) post-processing tools to assess for continuity of the fusion.</li>
	<li>At six months, perform a neurological evaluation and obtain standard radiographs.</li>
	<li>Release patient from care after a last clinical and radiological follow-up one-year post-surgery.</li>
</ol>

<ol>
	<li>Luoma, 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=Low+back+pain+in+relation+to+lumbar+disc+degeneration.">Low back pain in relation to lumbar disc degeneration.</a> Spine. 25 (4), 487-492 (2000).</li><li>Rabau, O., 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=Lateral+lumbar+interbody+fusion+(LLIF):+An+update.">Lateral lumbar interbody fusion (LLIF): An update.</a> Global Spine J. 10 (2_suppl), 17S-21S (2020).</li><li>Pimenta, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Less-invasive+lateral+lumbar+interbody+fusion+(XLIF)+surgical+technique:+video+lecture.">Less-invasive lateral lumbar interbody fusion (XLIF) surgical technique: video lecture.</a> Eur Spine J. 24 Suppl 3 (S3), 441-442 (2015).</li><li>Pimenta, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lateral+endoscopic+transpsoas+retroperitoneal+approach+for+lumbar+spine+surgery.">Lateral endoscopic transpsoas retroperitoneal approach for lumbar spine surgery.</a> Presented at VIII Brazilian Spine Society Meeting. , (2001).</li><li>Ozgur, B. M., Aryan, H. E., Pimenta, L., Taylor, W. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extreme+lateral+interbody+fusion+(XLIF):+a+novel+surgical+technique+for+anterior+lumbar+interbody+fusion.">Extreme lateral interbody fusion (XLIF): a novel surgical technique for anterior lumbar interbody fusion.</a> Spine J. 6 (4), 435-443 (2006).</li><li>Lamartina, C., Berjano, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prone+single-position+extreme+lateral+interbody+fusion+(Pro-XLIF):+preliminary+results.">Prone single-position extreme lateral interbody fusion (Pro-XLIF): preliminary results.</a> Eur Spine J. 29, 6-13 (2020).</li><li>Walker, C. T., 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=Single-position+prone+lateral+interbody+fusion+improves+segmental+lordosis+in+lumbar+spondylolisthesis.">Single-position prone lateral interbody fusion improves segmental lordosis in lumbar spondylolisthesis.</a> World Neurosurg. 151, e786-e792 (2021).</li><li>. XLIF Nuvasive Available from: <a target="_blank" href="https://www.nuvasive.com/procedures/spine/xlif20/">https://www.nuvasive.com/procedures/spine/xlif20/</a> (2025)</li><li>. DLIF Metronic Available from: <a target="_blank" href="https://thespinemarketgroup.com/wp-content/uploads/2020/07/Direct-Lateral-Surgical-Technique-Medtronic.pdf">https://thespinemarketgroup.com/wp-content/uploads/2020/07/Direct-Lateral-Surgical-Technique-Medtronic.pdf</a> (2025)</li><li>. OLIF Medtronic Available from: <a target="_blank" href="https://www.medtronic.com/me-en/healthcare-professionals/therapies-procedures/spinal-orthopaedic/olif.html">https://www.medtronic.com/me-en/healthcare-professionals/therapies-procedures/spinal-orthopaedic/olif.html</a> (2025)</li><li>Alonso, F., 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+subcostal+nerve+during+lateral+approaches+to+the+lumbar+spine:+an+anatomical+study+with+relevance+for+injury+avoidance+and+postoperative+complications+such+as+abdominal+wall+hernia.">The subcostal nerve during lateral approaches to the lumbar spine: an anatomical study with relevance for injury avoidance and postoperative complications such as abdominal wall hernia.</a> World Neurosurg. 104, 669-673 (2017).</li><li>Godolias, P., 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=Complication+rates+following+stand-alone+lateral+interbody+fusion:+a+single+institution+series+after+10+years+of+experience.">Complication rates following stand-alone lateral interbody fusion: a single institution series after 10 years of experience.</a> Eur J Orthop Surg Traumatol. 33 (5), 2121-2127 (2022).</li><li>Walker, C. T., 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=Complications+for+minimally+invasive+lateral+interbody+arthrodesis:+a+systematic+review+and+meta-analysis+comparing+prepsoas+and+transpsoas+approaches.">Complications for minimally invasive lateral interbody arthrodesis: a systematic review and meta-analysis comparing prepsoas and transpsoas approaches.</a> J Neurosurg Spine. 30 (4), 446-460 (2019).</li><li>Amini, D. A., 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=Development+of+a+decision-making+pathway+for+utilizing+standalone+lateral+lumbar+interbody+fusion.">Development of a decision-making pathway for utilizing standalone lateral lumbar interbody fusion.</a> Eur Spine J. 31 (7), 1611-1620 (2022).</li><li>Camino-Willhuber, 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=Lumbar+lateral+interbody+fusion:+step-by-step+surgical+technique+and+clinical+experience.">Lumbar lateral interbody fusion: step-by-step surgical technique and clinical experience.</a> J Spine Surg. 9 (3), 294-305 (2023).</li><li>Kwon, B., Kim, D. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lateral+lumbar+interbody+fusion.">Lateral lumbar interbody fusion.</a> J Am Acad of Orthop Surg. 24 (2), 96-105 (2016).</li><li>Lall, R. R., 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=Intraoperative+neurophysiological+monitoring+in+spine+surgery:+indications,+efficacy,+and+role+of+the+preoperative+checklist.">Intraoperative neurophysiological monitoring in spine surgery: indications, efficacy, and role of the preoperative checklist.</a> Neurosurg Focus. 33 (5), E10 (2012).</li><li>Taba, H. A., Williams, S. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lateral+lumbar+interbody+fusion.">Lateral lumbar interbody fusion.</a> Neurosurg Clin of N Am. 31 (1), 33-42 (2020).</li><li>Rodgers, W. B., Gerber, E. J., Patterson, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intraoperative+and+early+postoperative+complications+in+extreme+lateral+interbody+fusion.">Intraoperative and early postoperative complications in extreme lateral interbody fusion.</a> Spine. 36 (1), 26-32 (2011).</li><li>Moro, T., Kikuchi, S., Konno, S., Yaginuma, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+anatomic+study+of+the+lumbar+plexus+with+respect+to+retroperitoneal+endoscopic+surgery.">An anatomic study of the lumbar plexus with respect to retroperitoneal endoscopic surgery.</a> Spine. 28 (5), 423-427 (2003).</li><li>Ng, J. P. H., Kaliya-Perumal, A. K., Tandon, A. A., Oh, J. Y. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+oblique+corridor+at+L4-L5:+a+radiographic-anatomical+study+into+the+feasibility+for+lateral+interbody+fusion.">The oblique corridor at L4-L5: a radiographic-anatomical study into the feasibility for lateral interbody fusion.</a> Spine. 45 (10), E552-E559 (2020).</li><li>Huang, C., Xu, Z., Li, F., Chen, Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Does+the+access+angle+change+the+risk+of+approach-related+complications+in+minimally+invasive+lateral+lumbar+interbody+fusion?+An+MRI+study.">Does the access angle change the risk of approach-related complications in minimally invasive lateral lumbar interbody fusion? An MRI study.</a> J Korean Neurosurg Soc. 61 (6), 707-715 (2018).</li><li>Kramer, D. E., Woodhouse, C., Kerolus, M. G., Yu, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lumbar+plexus+safe+working+zones+with+lateral+lumbar+interbody+fusion:+a+systematic+review+and+meta-analysis.">Lumbar plexus safe working zones with lateral lumbar interbody fusion: a systematic review and meta-analysis.</a> Eur Spine J. 31 (10), 2527-2535 (2022).</li><li>Godolias, P., 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=Lumbosacral+plexus+3D+printing+with+dissection+validation+-+a+baseline+study+with+regards+to+lateral+spine+surgery.">Lumbosacral plexus 3D printing with dissection validation - a baseline study with regards to lateral spine surgery.</a> Interdiscip Neurosurg. 31, 101666 (2023).</li><li>Agarwal, N., 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=Lateral+lumbar+interbody+fusion+in+the+elderly:+a+10-year+experience.">Lateral lumbar interbody fusion in the elderly: a 10-year experience.</a> J Neurosurg Spine. 29 (5), 525-529 (2018).</li><li>Chen, E., 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=Cage+subsidence+and+fusion+rate+in+extreme+lateral+interbody+fusion+with+and+without+fixation.">Cage subsidence and fusion rate in extreme lateral interbody fusion with and without fixation.</a> World Neurosurg. 122, 969-977 (2019).</li><li>Wang, Y., Beydoun, M. A., Min, J., Xue, H., Kaminsky, L. A., Cheskin, L. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Has+the+prevalence+of+overweight,+obesity+and+central+obesity+levelled+off+in+the+United+States?+Trends,+patterns,+disparities,+and+future+projections+for+the+obesity+epidemic.">Has the prevalence of overweight, obesity and central obesity levelled off in the United States? Trends, patterns, disparities, and future projections for the obesity epidemic.</a> Int J Epidemiol. 49 (3), 810-823 (2020).</li><li>Barrie, U., 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=Impact+of+obesity+on+complications+and+surgical+outcomes+after+adult+degenerative+scoliosis+spine+surgery.">Impact of obesity on complications and surgical outcomes after adult degenerative scoliosis spine surgery.</a> Clin Neurol Neurosurg. 226, 107619 (2023).</li><li>Shasby, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Erratum.+Does+minimally+invasive+spine+surgery+improve+outcomes+in+the+obese+population?+A+retrospective+review+of+1442+degenerative+lumbar+spine+surgeries.">Erratum. Does minimally invasive spine surgery improve outcomes in the obese population? A retrospective review of 1442 degenerative lumbar spine surgeries.</a> J Neurosurg Spine. 36 (6), 1035 (2022).</li><li>Hijji, F. Y., 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=Lateral+lumbar+interbody+fusion:+a+systematic+review+of+complication+rates.">Lateral lumbar interbody fusion: a systematic review of complication rates.</a> Spine J. 17 (10), 1412-1419 (2017).</li><li>Hu, W. -. 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=An+MRI+study+of+psoas+major+and+abdominal+large+vessels+with+respect+to+the+X/DLIF+approach.">An MRI study of psoas major and abdominal large vessels with respect to the X/DLIF approach.</a> Eur Spine J. 20 (4), 557-562 (2011).</li></ol>

Conflict of interest Jens Chapman MD receives consulting fees from Globus Medical Inc. Rod Oskouian MD receives royalties from Stryker and consulting fees from Seaspine, Globus Medical Inc., Stryker, DePuy Synthes, Medtronic and ATEC. All other authors have no relevant financial or non-financial interests to disclose.

Lateral Lumbar Interbody Fusion (LLIF) has become a popular minimally invasive technique for achieving arthrodesis. Since its introduction, indications have expanded for the treatment of various lumbar conditions such as degenerative diseases, deformity, and lumbar spinal pathologies. It allows implantation of larger interbody cages than TLIF or PLIF across the apophysis leading to effective correction of coronal deformities and indirect decompression of the neuroforamina by restoring disc height18</sup...

Lower back pain, an important symptom of degenerative lumbar disease (DLD), is common in patients over 65 years1. Other symptoms of DLD include radiculopathy and claudication. When non-surgical treatment fails, surgical decompression or, if indicated, interbody fusion of the spine may be a viable treatment option2. Several techniques and approaches have been developed to achieve interbody fusion or decompression of the segment. Traditional approaches include posterior lumbar interbody fusion (PLIF), transforaminal lumbar interbody fusion (TLIF), and anterior lumbar interbody fusion (ALIF). Approaches to the lumbar spine are illustrated in Figure 1.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/66878/66878fig01.jpg" /> 
Figure 1: Different approaches to the lumbar spine for interbody fusion12. Overview of the different approaches used for lumbar interbody fusion. LLIF is a trans-psoas approach, and OLIF is a pre-psoas approach. <a href="https://www.jove.com/files/ftp_upload/66878/66878fig01large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
Over the last decades, minimally invasive techniques for interbody fusion of the lumbar spine have been developed to reduce tissue damage and complications, allowing for quicker patient recovery, reducing complications, and surpassing the technical limitations of traditional approaches to the spine. In 2001, Pimenta et al. introduced a minimally invasive retroperitoneal approach to the lumbar spine by splitting the psoas, providing direct disc exposure by expanding the retroperitoneal space. This has been introduced as the lateral trans-psoas approach3,4. This technique was modified with the use of special retractors and popularized by Ozgur et al.5. In recent years, extreme lateral interbody fusion in a prone patient position has been developed. This technique offers efficiency with combined posterior procedures and improved lumbar lordosis6,7.
Lateral interbody fusion (LLIF) can be achieved utilizing various approaches. These include trans-psoas approaches (extreme lateral interbody fusion (XLIF8), direct lateral interbody fusion (DLIF9) using different instruments), and a pre-psoas approach (oblique lateral interbody fusion (OLIF10). The approach used for the procedure depends on the patient and the surgeon&#39;s training, among others. Anatomical studies showed notable benefits for trans-psoas approaches (minimal blood loss, preservation of the posterior musculature and ligamentous chain, the ability to perform an extensive discectomy, and placement of a large intervertebral graft) but also disadvantages (post-operative nerve palsies, visceral abdominal injuries)11. Reported major but rare complications include intestinal perforation, common iliac vein injury, cage subsidence, vertebral body fractures around the interbody device, retroperitoneal hematoma, and pneumoretroperitoneum with an associated pneumoscrotum12. Overall, pre-psoas approaches are associated with a slightly lower complication rate and fewer postoperative neurological deficits13. To allow optimal outcome, the indication for a lateral interbody fusion needs to be done carefully. We advise obtaining a computed tomography (CT) and magnetic resonance (MR)-scan of the lumbar spine. To assess the segment hypermobility or instability, obtain flexion-extension X-ray images besides regular anteroposterior (AP) and lateral. Common indications are patients with segmental instability and concurrent radiculopathy who have failed non-surgical treatment. In the case of segmental instability or deformity surgery, additional internal fixation may be necessary. LLIF may be limited in the lower lumbar spine, depending on the height of the iliac crest. Supplemental posterior fixation may add valuable construct stiffness and deformity reduction for patients with high-grade instability, deformity, or questionable bone stability. Contraindications for this procedure are typically malignancy, high-grade deformities, or bifurcation abnormalities. A history of retroperitoneal infection or disease and previous retroperitoneal surgery or injury are important considerations. Risk factors for poor outcomes include osteoporosis, smoking, long-term steroid use, severe deformities, and segment hypermobility due to facet effusion or previous laminectomy14,15,16. Also, patients with very low body mass index and anterior psoas location are potentially adverse patients for increased complexity of access. In revision surgery, a pre-psoas approach may be favorable to avoid scar tissue.
The aim of this article is to provide step-by-step guidance to surgeons on a stand-alone lateral trans-psoas interbody fusion, including pitfalls and complication rates after 10 years of single-center experience.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>100mm Aluminum Center Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3244100</td>
			<td></td>
		</tr>
		<tr>
			<td>100mm Electrode Center Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3243100</td>
			<td></td>
		</tr>
		<tr>
			<td>100mm Left Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3241100</td>
			<td></td>
		</tr>
		<tr>
			<td>100mm Right Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3242100</td>
			<td></td>
		</tr>
		<tr>
			<td>110mm Aluminum Center Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3244110</td>
			<td></td>
		</tr>
		<tr>
			<td>110mm Electrode Center Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3243110</td>
			<td></td>
		</tr>
		<tr>
			<td>110mm Left Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3241110</td>
			<td></td>
		</tr>
		<tr>
			<td>110mm Right Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3242110</td>
			<td></td>
		</tr>
		<tr>
			<td>120mm Aluminum Center Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3244120</td>
			<td></td>
		</tr>
		<tr>
			<td>120mm Electrode Center Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3243120</td>
			<td></td>
		</tr>
		<tr>
			<td>120mm Left Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3241120</td>
			<td></td>
		</tr>
		<tr>
			<td>120mm Right Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3242120</td>
			<td></td>
		</tr>
		<tr>
			<td>130mm Aluminum Center Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3244130</td>
			<td></td>
		</tr>
		<tr>
			<td>130mm Electrode Center Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3243130</td>
			<td></td>
		</tr>
		<tr>
			<td>130mm Left Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3241130</td>
			<td></td>
		</tr>
		<tr>
			<td>130mm Right Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3242130</td>
			<td></td>
		</tr>
		<tr>
			<td>140mm Aluminum Center Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3244140</td>
			<td></td>
		</tr>
		<tr>
			<td>140mm Electrode Center Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3243140</td>
			<td></td>
		</tr>
		<tr>
			<td>140mm Left Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3241140</td>
			<td></td>
		</tr>
		<tr>
			<td>140mm Right Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3242140</td>
			<td></td>
		</tr>
		<tr>
			<td>150mm Aluminum Center Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3244150</td>
			<td></td>
		</tr>
		<tr>
			<td>150mm Electrode Center Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3243150</td>
			<td></td>
		</tr>
		<tr>
			<td>150mm Left Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3241150</td>
			<td></td>
		</tr>
		<tr>
			<td>150mm Right Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3242150</td>
			<td></td>
		</tr>
		<tr>
			<td>160mm Aluminum Center Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3244160</td>
			<td></td>
		</tr>
		<tr>
			<td>160mm Electrode Center Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3243160</td>
			<td></td>
		</tr>
		<tr>
			<td>160mm Left Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3241160</td>
			<td></td>
		</tr>
		<tr>
			<td>160mm Right Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3242160</td>
			<td></td>
		</tr>
		<tr>
			<td>50mm Aluminum Center Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3244050</td>
			<td></td>
		</tr>
		<tr>
			<td>50mm Left Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3241050</td>
			<td></td>
		</tr>
		<tr>
			<td>50mm Right Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3242050</td>
			<td></td>
		</tr>
		<tr>
			<td>60mm Aluminum Center Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3244060</td>
			<td></td>
		</tr>
		<tr>
			<td>60mm Left Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3241060</td>
			<td></td>
		</tr>
		<tr>
			<td>60mm Right Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3242060</td>
			<td></td>
		</tr>
		<tr>
			<td>70mm Aluminum Center Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3244070</td>
			<td></td>
		</tr>
		<tr>
			<td>70mm Left Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3241070</td>
			<td></td>
		</tr>
		<tr>
			<td>70mm Right Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3242070</td>
			<td></td>
		</tr>
		<tr>
			<td>80mm Aluminum Center Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3244080</td>
			<td></td>
		</tr>
		<tr>
			<td>80mm Left Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3241080</td>
			<td></td>
		</tr>
		<tr>
			<td>80mm Right Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3242080</td>
			<td></td>
		</tr>
		<tr>
			<td>90mm Aluminum Center Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3244090</td>
			<td></td>
		</tr>
		<tr>
			<td>90mm Electrode Center Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3243090</td>
			<td></td>
		</tr>
		<tr>
			<td>90mm Left Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3241090</td>
			<td></td>
		</tr>
		<tr>
			<td>90mm Right Blade&#160;</td>
			<td>Nuvasive</td>
			<td>3242090</td>
			<td></td>
		</tr>
		<tr>
			<td>ALGI Penfield, Long Push&#160;</td>
			<td>Nuvasive</td>
			<td>3300118</td>
			<td></td>
		</tr>
		<tr>
			<td>Anterior Crossbar&#160;</td>
			<td>Nuvasive</td>
			<td>3240003</td>
			<td></td>
		</tr>
		<tr>
			<td>Bayonetted Shim Inserter&#160;</td>
			<td>Nuvasive</td>
			<td>3200215</td>
			<td></td>
		</tr>
		<tr>
			<td>Blade Rotation Driver&#160;</td>
			<td>Nuvasive</td>
			<td>3240005</td>
			<td></td>
		</tr>
		<tr>
			<td>Dilator - 12mm&#160;</td>
			<td>Nuvasive</td>
			<td>1010968</td>
			<td></td>
		</tr>
		<tr>
			<td>Dilator - 6mm&#160;</td>
			<td>Nuvasive</td>
			<td>1010966</td>
			<td></td>
		</tr>
		<tr>
			<td>Dilator - 9mm&#160;</td>
			<td>Nuvasive</td>
			<td>1010967</td>
			<td></td>
		</tr>
		<tr>
			<td>Fixation Shim Screw Driver&#160;</td>
			<td>Nuvasive</td>
			<td>3200052</td>
			<td></td>
		</tr>
		<tr>
			<td>Fluoro Modulator&#160;</td>
			<td>Nuvasive</td>
			<td>3220131</td>
			<td></td>
		</tr>
		<tr>
			<td>Hex Driver (3/32&#8221;)&#160;</td>
			<td>Nuvasive</td>
			<td>1011691</td>
			<td></td>
		</tr>
		<tr>
			<td>Hex Key (3/32&#8221;)&#160;</td>
			<td>Nuvasive</td>
			<td>1011748</td>
			<td></td>
		</tr>
		<tr>
			<td>Initial Dilator Holder&#160;</td>
			<td>Nuvasive</td>
			<td>3230140</td>
			<td></td>
		</tr>
		<tr>
			<td>K-wire (13.5&#8221;)&#160;</td>
			<td>Nuvasive</td>
			<td>3230101</td>
			<td></td>
		</tr>
		<tr>
			<td>Light Cable Adapter, Storz&#160;</td>
			<td>Nuvasive</td>
			<td>1011811</td>
			<td></td>
		</tr>
		<tr>
			<td>Lock Shim Inserter/Repositioning Tool&#160;</td>
			<td>Nuvasive</td>
			<td>3240001</td>
			<td></td>
		</tr>
		<tr>
			<td>Lock Shim Inserter/Repositioning Tool,</td>
			<td>Nuvasive</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Low-Profile Shim</td>
			<td>Nuvasive</td>
			<td>3240002</td>
			<td></td>
		</tr>
		<tr>
			<td>MaXcess 4 4th Blade Attachment&#160;</td>
			<td>Nuvasive</td>
			<td>3240004</td>
			<td></td>
		</tr>
		<tr>
			<td>Maxcess 4 Access System</td>
			<td>Nuvasive</td>
			<td></td>
			<td>Tray with XLIF Dilator and Retractors in different seizes</td>
		</tr>
		<tr>
			<td>MaXcess 4 Articulating Arm&#160;</td>
			<td>Nuvasive</td>
			<td>3240121</td>
			<td></td>
		</tr>
		<tr>
			<td>MaXcess 4 Blade, 180mm Electrode Ctr&#160;</td>
			<td>Nuvasive</td>
			<td>3243180</td>
			<td></td>
		</tr>
		<tr>
			<td>Needle Electrodes&#160;</td>
			<td>Nuvasive</td>
			<td>8050029</td>
			<td>NVM5 System</td>
		</tr>
		<tr>
			<td>Surface Electrodes&#160;</td>
			<td>Nuvasive</td>
			<td>8020029</td>
			<td>NVM5 System</td>
		</tr>
		<tr>
			<td>Targeting Instrument&#160;</td>
			<td>Nuvasive</td>
			<td>3240000</td>
			<td></td>
		</tr>
		<tr>
			<td>XL (18mm wide)</td>
			<td>Nuvasive</td>
			<td>1000-00-0716</td>
			<td>Implant&#160;</td>
		</tr>
		<tr>
			<td>XL-F (18mm wide)&#160;</td>
			<td>Nuvasive</td>
			<td>1000-00-0719</td>
			<td>Implant&#160;</td>
		</tr>
		<tr>
			<td>XL-F Wide (22mm wide)</td>
			<td>Nuvasive</td>
			<td>1000-00-0720</td>
			<td>Implant&#160;</td>
		</tr>
		<tr>
			<td>XLIF Annulus Cutter, 4x14mm&#160;</td>
			<td>Nuvasive</td>
			<td>6942414</td>
			<td></td>
		</tr>
		<tr>
			<td>XLIF Annulus Cutter, 4x16mm&#160;</td>
			<td>Nuvasive</td>
			<td>6942416</td>
			<td></td>
		</tr>
		<tr>
			<td>XLIF Cobb, 12mm Straight&#160;</td>
			<td>Nuvasive</td>
			<td>6940012</td>
			<td></td>
		</tr>
		<tr>
			<td>XLIF Cobb, 18mm Down&#160;</td>
			<td>Nuvasive</td>
			<td>6940118</td>
			<td></td>
		</tr>
		<tr>
			<td>XLIF Cobb, 18mm Straight&#160;</td>
			<td>Nuvasive</td>
			<td>6940018</td>
			<td></td>
		</tr>
		<tr>
			<td>XLIF Cobb, 22mm Straight&#160;</td>
			<td>Nuvasive</td>
			<td>6940022</td>
			<td></td>
		</tr>
		<tr>
			<td>XLIF Cobb, Serrated&#160;</td>
			<td>Nuvasive</td>
			<td>6940001</td>
			<td></td>
		</tr>
		<tr>
			<td>XLIF Cutter, 8mm Disc&#160;</td>
			<td>Nuvasive</td>
			<td>6940151</td>
			<td></td>
		</tr>
		<tr>
			<td>XLIF Forceps, Bipolar Str Extra Long&#160;</td>
			<td>Nuvasive</td>
			<td>3200322</td>
			<td></td>
		</tr>
		<tr>
			<td>XLIF Handle, Slide&#160;</td>
			<td>Nuvasive</td>
			<td>6940004</td>
			<td></td>
		</tr>
		<tr>
			<td>XLIF Inserter, Angled XL&#160;</td>
			<td>Nuvasive</td>
			<td>D6904485</td>
			<td></td>
		</tr>
		<tr>
			<td>XLIF Kerrison, 2mm&#160;</td>
			<td>Nuvasive</td>
			<td>6940132</td>
			<td></td>
		</tr>
		<tr>
			<td>XLIF Kerrison, 5mm&#160;</td>
			<td>Nuvasive</td>
			<td>6940135</td>
			<td></td>
		</tr>
		<tr>
			<td>XLIF Nerve Retractor, Extra Long&#160;</td>
			<td>Nuvasive</td>
			<td>3300319</td>
			<td></td>
		</tr>
		<tr>
			<td>XLIF Paddle Sizer, 4x16mm&#160;</td>
			<td>Nuvasive</td>
			<td>6940416</td>
			<td></td>
		</tr>
		<tr>
			<td>XLIF Paddle Sizer, 6x18mm&#160;</td>
			<td>Nuvasive</td>
			<td>6940618</td>
			<td></td>
		</tr>
		<tr>
			<td>XLIF Paddle Sizer, 6x22mm&#160;</td>
			<td>Nuvasive</td>
			<td>6940622</td>
			<td></td>
		</tr>
		<tr>
			<td>XLIF Penfield, Pull Extra Long&#160;</td>
			<td>Nuvasive</td>
			<td>3300318</td>
			<td></td>
		</tr>
		<tr>
			<td>XLIF Pituitary, Large&#160;</td>
			<td>Nuvasive</td>
			<td>6940431</td>
			<td></td>
		</tr>
		<tr>
			<td>XLIF Pituitary, Medium&#160;</td>
			<td>Nuvasive</td>
			<td>6940430</td>
			<td></td>
		</tr>
		<tr>
			<td>XLIF Pituitary, Small&#160;</td>
			<td>Nuvasive</td>
			<td>6940429</td>
			<td></td>
		</tr>
		<tr>
			<td>XLIF Rasp&#160;</td>
			<td>Nuvasive</td>
			<td>6940340</td>
			<td></td>
		</tr>
		<tr>
			<td>XLIF Scraper, Endplate&#160;</td>
			<td>Nuvasive</td>
			<td>6940020</td>
			<td></td>
		</tr>
		<tr>
			<td>XLIF Slide, Bayonetted&#160;</td>
			<td>Nuvasive</td>
			<td>6940063</td>
			<td></td>
		</tr>
		<tr>
			<td>XLIF Slide, XW Bayonetted&#160;</td>
			<td>Nuvasive</td>
			<td>6940064</td>
			<td></td>
		</tr>
		<tr>
			<td>XLIF Suction, 12FR Extra Long&#160;</td>
			<td>Nuvasive</td>
			<td>3300320</td>
			<td></td>
		</tr>
		<tr>
			<td>XLIF Suction, 15FR Extra Long&#160;</td>
			<td>Nuvasive</td>
			<td>3300321</td>
			<td></td>
		</tr>
		<tr>
			<td>XL-W (22mm wide)</td>
			<td>Nuvasive</td>
			<td>1000-00-0717</td>
			<td>Implant&#160;</td>
		</tr>
		<tr>
			<td>XL-XW (26mm wide)&#160;</td>
			<td>Nuvasive</td>
			<td>1000-00-0718</td>
			<td>Implant&#160;</td>
		</tr>
	</tbody>
</table>

surgical approach and complications of stand-alone lateral trans-psoas interbody fusion

Interbody fusion of the lumbar spine is a standard procedure for symptomatic degenerative lumbar spine disease if conservative treatment fails. Surgical decompression and fusion of the segment can be achieved using several different techniques. Over the last decades, minimally invasive techniques, such as lateral interbody fusion (LLIF), have been developed to reduce tissue damage and complications and allow quicker patient recovery. With growing popularity, indications for LLIF have expanded to treat spinal deformities and foraminal/central stenosis. Mechanically, it allows for an unsurpassed fixation through the left-to-right apophyseal ring placement of the cage. LLIF utilizes a minimally disruptive retroperitoneal corridor and includes both trans-psoas and pre-psoas approaches. For the pre-psoas approach, the risk of damage from manipulation of the intramuscular lumbar plexus is reduced compared to a trans-psoas approach. However, increased risks of major vascular, ureteral, bowel injury and sympathetic plexus damage are reported.
This article aims to provide a detailed and comprehensive guide on stand-alone lateral trans-psoas interbody fusion, including its indications, surgical procedure, potential complications, and outcomes based on a decade of experience from a single center.

In our recent study, we investigated the complication rates following a stand-alone lateral interbody fusion12. We retrospectively investigated 158 patients (145 trans-psoas, 13 pre-psoas) who received an LLIF between 2016 and 2020, with a mean follow-up of 14 months (Table 1).
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Patient characteristics&#160;</td>
			<td>All (n=158)</td>
			<td>Trans-psoas (n=145)</t...

Interbody fusion of the lumbar spine can be achieved surgically using different techniques. Minimally invasive techniques, including lateral interbody fusion, have been developed within recent decades to reduce rates of complications and allow for quicker patient recovery. We provide insight into stand-alone lateral trans-psoas interbody fusion, highlighting potential complications and pitfalls.

Surgical Approach and Complications of Stand-alone Lateral Trans-Psoas Interbody Fusion

Interbody fusion of the lumbar spine is a standard procedure for symptomatic degenerative lumbar spine disease if conservative treatment fails. Surgical ...

surgical-approach-complications-stand-alone-lateral-trans-psoas

Research

JoVE Journal

Medicine

519 Views.  Swedish Medical Center. Interbody fusion of the lumbar spine can be achieved surgically using different techniques. Minimally invasive techniques, including lateral interbody fusion, have been developed within recent decades to reduce rates of complications and allow for quicker patient recovery. We provide insight into stand-alone lateral trans-psoas interbody fusion, highlighting potential complications and pitfalls.

Video: Surgical Approach and Complications of Stand-alone Lateral Trans-Psoas Interbody Fusion

A Novel Surgical Approach for Intratracheal Administration of Bioactive Agents in a Fetal Mouse Model

Prenatal pulmonary delivery of cells, genes or pharmacologic agents could provide the basis for new therapeutic strategies for a variety of genetic and acquired diseases. Apart from congenital or inherited abnormalities with the requirement for long-term expression of the delivered gene, several non-inherited perinatal conditions, where short-term gene expression or pharmacological intervention is sufficient to achieve therapeutic effects, are considered as potential future indications for this kind of approach. Candidate diseases for the application of short-term prenatal therapy could be the transient neonatal deficiency of surfactant protein B causing neonatal respiratory distress syndrome1,2 or hyperoxic injuries of the neonatal lung3. Candidate diseases for permanent therapeutic correction are Cystic Fibrosis (CF)4, genetic variants of surfactant deficiencies5 and &alpha;1-antitrypsin deficiency6.
Generally, an important advantage of prenatal gene therapy is the ability to start therapeutic intervention early in development, at or even prior to clinical manifestations in the patient, thus preventing irreparable damage to the individual. In addition, fetal organs have an increased cell proliferation rate as compared to adult organs, which could allow a more efficient gene or stem cell transfer into the fetus. Furthermore, in utero gene delivery is performed when the individual's immune system is not completely mature. Therefore, transplantation of heterologous cells or supplementation of a non-functional or absent protein with a correct version should not cause immune sensitization to the cell, vector or transgene product, which has recently been proven to be the case with both cellular and genetic therapies7.
In the present study, we investigated the potential to directly target the fetal trachea in a mouse model. This procedure is in use in larger animal models such as rabbits and sheep8, and even in a clinical setting9, but has to date not been performed before in a mouse model. When studying the potential of fetal gene therapy for genetic diseases such as CF, the mouse model is very useful as a first proof-of-concept because of the wide availability of different transgenic mouse strains, the well documented embryogenesis and fetal development, less stringent ethical regulations, short gestation and the large litter size.
Different access routes have been described to target the fetal rodent lung, including intra-amniotic injection10-12, (ultrasound-guided) intrapulmonary injection13,14 and intravenous administration into the yolk sac vessels15,16 or umbilical vein17. Our novel surgical procedure enables researchers to inject the agent of choice directly into the fetal mouse trachea which allows for a more efficient delivery to the airways than existing techniques18.

We developed a novel surgical approach for intratracheal administration of bioactive agents into the mouse fetus. The delivery route is more efficient in targeting the fetal mouse lungs than the commonly used intra-amniotic injection. This procedure has to date not been described in a mouse model.

Prenatal pulmonary delivery of cells, genes or pharmacologic agents could provide the basis for new therapeutic strategies for a variety of genetic and ...

The Mouse Round-window Approach for Ototoxic Agent Delivery: A Rapid and Reliable Technique for Inducing Cochlear Cell Degeneration

Investigators have utilized a wide array of animal models and investigative techniques to study the mammalian auditory system. Much of the basic research involving the cochlea and its associated neural pathways entails exposure of model cochleae to a variety of ototoxic agents. This allows investigators to study the effects of targeted damage to cochlear structures, and in some cases, the self-repair or regeneration of those structures. Various techniques exist for delivery of ototoxic agents to the cochlea. When selecting a particular technique, investigators must consider a number of factors, including the induction of inadvertent systemic toxicity, the amount of cochlear damage produced by the surgical procedure itself, the type of lesion desired, animal survivability, and reproducibility/reliability of results. Currently established techniques include parenteral injection, intra-peritoneal injection, trans-tympanic injection, endolymphatic sac injection, and cochleostomy with perilymphatic perfusion. Each of these methods has been successfully utilized and is well described in the literature; yet, each has various shortcomings. Here, we present a technique for topical application of ototoxic agents directly to the round window niche. This technique is non-invasive to inner ear structures, produces rapid onset of reliably targeted lesions, avoids systemic toxicity, and allows for an intra-animal control (the contra-lateral ear). Results stemming from this approach have helped deeper understanding of auditory pathophysiology, cochlear cell degeneration, and regenerative capacity in response to an acute injury. Future investigations may use this method to conduct interventional studies involving gene therapy and stem cell transplantation to combat hearing loss.

Various methods exist for introducing ototoxic agents to the cochleae of animal models. Presented is a surgical protocol for delivery of ototoxic agents to the round window niche. The procedure is reliable, creates targeted intra-cochlear lesions, and avoids mechanical damage to the microarchitecture. Examination of cochlear self-repair/regeneration is possible.

Investigators have utilized a wide array of animal models and investigative techniques to study the mammalian auditory system. Much of the basic research ...

Surgical Approach for Middle Cerebral Artery Occlusion and Reperfusion Induced Stroke in Mice

Stroke is a leading cause of death worldwide and continues to be one of the major causes of long-term adult disabilities. About 87% of strokes are ischemic in origin and occur in the territory of the middle cerebral artery (MCA). Currently the only Food and Drug Administration (FDA) approved drug for the treatment of this devastating disease is tissue plasminogen activator (tPA). However, tPA has a small therapeutic window for administration (3 - 6 hr), and is only effective in 4% of the patients who actually receive it. Current research focuses on understanding the pathophysiology of stroke in order to find potential therapeutic targets. Thus, reliable models are crucial, and the MCA occlusion (MCAo) model (also termed the intraluminal filament or suture model) is deemed to be the most clinically relevant surgical model of ischemic stroke, and is fairly non-invasive and easily reproducible. Typically the MCAo model is used with rodents, especially with mice due to all the genetic variations available for this species. Here we describe (and present in the video) how to successfully perform the MCAo model (with reperfusion) in mice to generate reliable and reproducible data.

In order to understand the pathophysiology of stroke, it is important to use reliable models. This paper will describe one of the most frequently used stroke models in mice, termed the middle cerebral artery occlusion (MCAo) model (also termed the intraluminal filament or suture model) with reperfusion.

Stroke is a leading cause of death worldwide and continues to be one of the major causes of long-term adult disabilities. About 87% of strokes are ...

Intravital Microscopy of Tumor-associated Vasculature Using Advanced Dorsal Skinfold Window Chambers on Transgenic Fluorescent Mice

Tumor and tumor vessel development, as well as tumor response to therapeutics, are highly dynamic biological processes. Histology provides static information and is often not sufficient for a correct interpretation. Intravital evaluation, in which a process is followed in time, provides extra and often unexpected information. With the creation of transgenic animals expressing cell-specific markers and live cell tracers, improvements to imaging equipment, and the development of several imaging chambers, intravital microscopy has become an important tool to better understand biological processes. This paper describes an experimental design for the investigation of tumor vessel development and of therapeutic effects in a spatial and temporal manner. Using this setup, the stage of vessel development, tip cell and lumen formation, blood flow, extravasation, an established vascular bed, and vascular destruction can be visualized and followed. Furthermore, therapeutic effects, intratumoral fate, and the localization of chemotherapeutic compounds can also be followed.

This protocol describes the intravital imaging of transgenic mice expressing cell-specific fluorescent markers. Intravital imaging provides a non-invasive method for high-resolution observations in living animals using implantable windows through which the microscopic visualization of processes is possible. This method is especially useful to study longitudinal processes.

Tumor and tumor vessel development, as well as tumor response to therapeutics, are highly dynamic biological processes. Histology provides static ...

Cone Beam Intraoperative Computed Tomography-based Image Guidance for Minimally Invasive Transforaminal Interbody Fusion

Transforaminal lumbar interbody fusion (TLIF) is commonly used for the treatment of spinal stenosis, degenerative disc disease, and spondylolisthesis. Minimally invasive surgery (MIS) approaches have been applied to this technique with an associated decrease in estimated blood loss (EBL), length of hospital stay, and infection rates, while preserving outcomes with traditional open surgery. Previous MIS TLIF techniques involve significant fluoroscopy that subjects the patient, surgeon, and operating room staff to non-trivial levels of radiation exposure, particularly for complex multi-level procedures. We present a technique that utilizes an intraoperative computed tomography (CT) scan to aid in placement of pedicle screws, followed by traditional fluoroscopy for confirmation of cage placement. Patients are positioned in the standard fashion and a reference arc is placed in the posterior superior iliac spine (PSIS) followed by intraoperative CT scan. This allows for image-guidance-based placement of pedicle screws through a one-inch skin incision on each side. Unlike traditional MIS-TLIF that requires significant fluoroscopic imaging during this stage, the operation can now be performed without any additional radiation exposure to the patient or operating room staff. After completion of the facetectomy and discectomy, final TLIF cage placement is confirmed with fluoroscopy. This technique has the potential to decrease operative time and minimize total radiation exposure.

The purpose of this article is to provide image-guidance for minimally invasive transforaminal interbody fusion.

Transforaminal lumbar interbody fusion (TLIF) is commonly used for the treatment of spinal stenosis, degenerative disc disease, and spondylolisthesis. ...

Designing CAD/CAM Surgical Guides for Maxillary Reconstruction Using an In-house Approach

Computer-aided design/computer-assisted manufacturing (CAD/CAM) is now being evaluated as a preparative technique for maxillofacial surgery. Because this technique is expensive and available in only limited areas of the world, we developed a novel CAD/CAM surgical guide using an in-house approach. By using the CAD software, the maxillary resection area and cutting planes and the fibular cutting planes and angles are determined. Once the resection area is decided, the necessary faces are extracted using a Boolean modifier. These superficial faces are united to fit the surface of the bones and thickened to stabilize the solids. Not only the cutting guides for the fibula and maxilla but also the location arrangement of the transferred bone segments is defined by thickening the superficial faces. The CAD design is recorded as .stl files and three-dimensionally (3-D) printed as actual surgical guides. To check the accuracy of the guides, model surgery using 3-D-printed facial and fibular models is performed. These methods may be used to assist surgeons where commercial guides are not available.

Methods for designing a computer-aided design/computer-aided manufacturing (CAD/CAM) surgical guide are shown. Cutting planes are separated, united, and thickened to easily visualize the necessary bone transfer. These designs can be three-dimensional printed and checked for accuracy.

Computer-aided design/computer-assisted manufacturing (CAD/CAM) is now being evaluated as a preparative technique for maxillofacial surgery. Because this ...

An Ex Vivo Tissue Culture Model for Fibrovascular Complications in Proliferative Diabetic Retinopathy

Diabetic retinopathy (DR) is the most common microvascular complication of diabetes and one of the leading causes of blindness in working-age adults. No current animal models of diabetes and oxygen-induced retinopathy develop the full-range progressive changes manifested in human proliferative diabetic retinopathy (PDR). Therefore, understanding of the disease pathogenesis and pathophysiology has relied largely on the use of histological sections and vitreous samples in approaches that only provide steady-state information on the involved pathogenic factors. Increasing evidence indicates that dynamic cell-cell and cell-extracellular matrix (ECM) interactions in the context of three-dimensional (3D) microenvironments are essential for the mechanistic and functional studies towards the development of new treatment strategies. Therefore, we hypothesized that the pathological fibrovascular tissue surgically excised from eyes with PDR could be utilized to reliably unravel the cellular and molecular mechanisms of this devastating disease and to test the potential for novel clinical interventions. Towards this end, we developed a novel method for 3D ex vivo culture of surgically-excised patient-derived fibrovascular tissue (FT), which will serve as a relevant model of human PDR pathophysiology. The FTs are dissected into explants and embedded in fibrin matrix for ex vivo culture and 3D characterization. Whole-mount immunofluorescence of the native FTs and end-point cultures allows thorough investigation of tissue composition and multicellular processes, highlighting the importance of 3D tissue-level characterization for uncovering relevant features of PDR pathophysiology. This model will allow the simultaneous assessment of molecular mechanisms, cellular/tissue processes and treatment responses in the complex context of dynamic biochemical and physical interactions within the PDR tissue architecture and microenvironment. Since this model recapitulates PDR pathophysiology, it will also be amenable for testing or developing new treatments.

Here, we present a protocol to study the pathophysiology of proliferative diabetic retinopathy by using patient-derived, surgically-excised, fibrovascular tissues for three-dimensional native tissue characterization and ex vivo culture. This ex vivo culture model is also amenable for testing or developing new treatments.

Diabetic retinopathy (DR) is the most common microvascular complication of diabetes and one of the leading causes of blindness in working-age adults. No ...

Orthotopic Rat Kidney Transplantation: A Novel and Simplified Surgical Approach

Kidney transplantation offers increased survival rates and improved quality of life for patients with end-stage renal disease, as compared to any type of renal replacement therapy. Over the past few decades, the rat kidney transplantation model has been used to study the immunological phenomena of rejection and tolerance. This model has become an indispensable tool to test new immunomodulatory pharmaceuticals and regimens prior to proceeding with expensive preclinical large animal studies.
This protocol provides a detailed overview of how to reliably perform orthotopic kidney transplantation in rats. This protocol includes three distinctive steps that increase the probability of success: perfusion of the donor kidney by flushing through the portal vein and the use of a cuff system to anastomose the renal veins and ureters, thereby decreasing cold and warm ischemia times. Using this technique, we have achieved survival rates beyond 6 months with normal serum creatinine in animals with syngeneic or tolerant kidney transplants. Depending on the aim of the study, this model can be modified by pre- or posttransplant treatments to study the acute, chronic, cellular, or antibody-mediated rejection. It is a reproducible, reliable, and cost-effective animal model to study different aspects of kidney transplantation.

The purpose of this manuscript and protocol is to explain and demonstrate in detail the surgical procedure of orthotopic kidney transplantation in rats. This method is simplified to achieve the correct perfusion of the donor kidney and shorten the reperfusion time by using the venous and ureteral cuff anastomosis technique.

Kidney transplantation offers increased survival rates and improved quality of life for patients with end-stage renal disease, as compared to any type of ...

Robotic Lateral Pancreaticojejunostomy for Chronic Pancreatitis

Lateral pancreaticojejunostomy (LPJ) has shown good postoperative outcomes in patients with painful, morphine dependent, chronic pancreatitis (CP). The recent rise of robotic and laparoscopic pancreatic surgery has found benefits such as reduced time to functional recovery. Few studies have reported on the feasibility, technique and outcome of robotic LPJ, especially including transection of the gastroduodenal artery. The present study describes the main steps for robotic LPJ in a patient with painful chronic pancreatitis with a dilated main pancreatic duct. The patient underwent robotic LPJ. The LPJ anastomosis is performed using a running suture technique in a longitudinal side-to-side manner. Routinely, the gastroduodenal artery is transected to drain the entire length of the main pancreatic duct. The patient is in French position; 7 trocars are placed (4 robotic, 2 laparoscopic assistants, 1 liver-retractor). After docking of the robot system, the omental bursa is opened, and the right gastroepiploic artery and vein are ligated at their base at the lower border of the pancreas. Intraoperative ultrasonography is performed in order to determine trajectory of the dilated main pancreatic duct which is opened for its entire length after the gastroduodenal artery has been suture ligated both cranially and caudally from the main pancreatic duct. A Roux limb is created, and a latero-lateral PJ is fashioned using several 3-0 barbed sutures. A stapled jejuno-jejunostomy is created at sufficient distance from the pancreatic anastomosis, aided by a 50 cm suture. The described technique for robotic LPJ is a complex but feasible operation for patients with treatment refractory CP and a dilated main pancreatic duct. Due to its complexity, implementation in high volume centers with extensive experience with CP surgery may improve outcomes.

Robotic lateral pancreaticojejunostomy (RLPJ) may be used in patients with painful, morphine dependent, chronic pancreatitis and a dilated main pancreatic duct. We describe a standardized and reproducible technique for RLPJ, which includes transection of the gastroduodenal artery.

Lateral pancreaticojejunostomy (LPJ) has shown good postoperative outcomes in patients with painful, morphine dependent, chronic pancreatitis (CP). The ...

Isolation and Profiling of Human Primary Mesenteric Arterial Endothelial Cells at the Transcriptome Level

Endothelial cells (ECs) are crucial for vascular and whole-body function through their dynamic response to environmental cues. Elucidating the transcriptome and epigenome of ECs is paramount to understanding their roles in development, health, and disease, but is limited in the availability of isolated primary cells. Recent technologies have enabled the high-throughput profiling of EC transcriptome and epigenome, leading to the identification of previously unknown EC cell subpopulations and developmental trajectories. While EC cultures are a useful tool in the exploration of EC function and dysfunction, the culture conditions and multiple passages can introduce external variables that alter the properties of native EC, including morphology, epigenetic state, and gene expression program. To overcome this limitation, the present paper demonstrates a method of isolating human primary ECs from donor mesenteric arteries aiming to capture their native state. ECs in the intimal layer are dissociated mechanically and biochemically with the use of particular enzymes. The resultant cells can be directly used for bulk RNA or single-cell RNA-sequencing or plated for culture. In addition, a workflow is described for the preparation of human arterial tissue for spatial transcriptomics, specifically for a commercially available platform, although this method is also suitable for other spatial transcriptome profiling techniques. This methodology can be applied to different vessels collected from a variety of donors in health or disease states to gain insights into EC transcriptional and epigenetic regulation, a pivotal aspect of endothelial cell biology.

The protocol describes the isolation, culture, and profiling of endothelial cells from human mesenteric artery. Additionally, a method is provided to prepare human artery for spatial transcriptomics. Proteomics, transcriptomics, and functional assays can be performed on isolated cells. This protocol can be repurposed for any medium- or large-size artery.