The authors have no acknowledgments.

This study was reviewed and approved by the Hebei Medical University Third Affiliated Hospital ethics committee, and written informed consent was obtained from all the patients. In addition, no images are identifiable to any patients.
1. Preoperative preparation
<ol>
	<li>Select appropriate cases based on the patient history, including symptoms, signs, history of previous lumbar and abdominal surgery, abdominal examination, and imaging, such as lumbar X-ray, computed tomography (CT), and magnetic resonance imaging (MRI).</li>
	<li>Advise the patients to undergo preoperative CT angiography of the abdominal aorta and CT angiography of the inferior vena cava to rule out vascular malformations, as well as fasting and enemas the day before surgery for gastrointestinal preparation.</li>
</ol>
2. Surgical procedures
<ol>
	<li>Figure 1 depicts the surgical procedure for Mini-ALIF. After general anesthesia, place the patient in the supine position with the hands either flat or on the chest to accommodate an intraoperative lateral X-ray. 
	NOTE: If the abdominal wall and psoas major muscles are too tight, padding under the thighs is added, and the patients are maneuvered into the bladder stone position.</li>
	<li>Locate the surgical lumbar segment by abdominal palpation of the iliac crest and the location of the Kirschner needle under X-ray.</li>
	<li>Use a right side incision for the operation of the L5-S1 segment, and use a left approach for the rest of the segments. Use a scalpel to cut the skin and subcutaneous tissue in turn. Make a transverse incision in the lateral rectus abdominis muscle next to the lower abdomen, with a single segment length of ~5 cm. Use oblique or vertical incisions of about 8 cm in double-segment surgery.</li>
	<li>Identify and incise the anterior rectus abdominis sheath with the aid of a microscope (with a working distance of 535 mm). Then, separate the rectus abdominis muscle bluntly to its outer edge, and retract the outer edge of the rectus abdominis toward the midline using a pulling hook to reveal the posterior rectus abdominis sheath.</li>
	<li>Adjust the appropriate distance and magnification from the microscope to the operating area during the operation. Then, separate the anterolateral abdominal wall of the peritoneum with gauze balls under a microscope, and push contralaterally into the retroperitoneal space to reach the anterior aspect of the vertebral space.</li>
	<li>Separate the prevertebral soft tissue bluntly with gauze and vascular forceps. Explore the sacral vascular space microscopically. Use vascular forceps and nerve strippers to separate the iliac arteriovenous vein. Furthermore, ligate the median sacral artery using silk thread depending on its occlusion. 
	NOTE: Take care to avoid having to use electrocoagulation, which can damage the inferior ventral plexus.</li>
	<li>Use the spreader to expose the surgical field in all directions. Fix the pulling hook to the vertebral body using a K-wires positioning tube on either side of the vertical section. Figure 2A shows the pull hook part of the spreader.</li>
	<li>Figure 2B, C shows the second part of the spreader, which is designed as a combination of two draw-off tabs with a puller and a push-rod. Connect the retractor on one side to the straight-grip pull-rod to provide a pulling force on the soft tissue. The other retractor piece has three attachment holes at different depths; have the assistant attach these holes with a T-pusher on the opposite side to assist the surgeon in pushing away the soft tissue.</li>
	<li>Then, use a 3.2 mm diameter positioning tube to secure the spreader to the two adjacent vertebral bodies of the operated segment using K-wires on either side of the retractor.</li>
	<li>Expose the intervertebral space, and incise the disc annulus fibrosus. Remove the diseased disc, and then decompress the spinal canal guided by a microscope.</li>
	<li>Scrape the endplate with an endplate rugine. Select anterior lumbar fusion apparatus of an appropriate size using a trial model. Fill autogenous bone fragments or bone mud and bone particles into the fusion apparatus and implant them into the surgical intervertebral space. Use an appropriate internal fixation according to the bone quality and diagnosis.</li>
</ol>
3. Post-surgery
<ol>
	<li>Use 1 g of cefazolin sodium per 6 h to prevent infection for 24 h after the operation, and restrict the patient from eating until intestinal exsufflation.</li>
	<li>After the patient gets out of bed the next day, advise them to gradually undergo rehabilitation training. Instruct the patient to wear a brace to walk and to use the waistline brace continuously for 3 months.</li>
</ol>

<ol>
	<li>O'Brien, J. P. <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+of+fusion+for+chronic+low+back+pain.">The role of fusion for chronic low back pain.</a> The Orthopedic Clinics of North America. 14 (3), 639-647 (1983).</li><li>Cho, J. Y., Goh, T. S., Son, S. M., Kim, D. S., Lee, J. S. <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+anterior+approach+and+posterior+approach+to+instrumented+interbody+fusion+for+spondylolisthesis:+A+meta-analysis.">Comparison of anterior approach and posterior approach to instrumented interbody fusion for spondylolisthesis: A meta-analysis.</a> World Neurosurgery. 129, e286-e293 (2019).</li><li>Min, J. H., Jang, J. S., Lee, S. H. <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+anterior-+and+posterior-approach+instrumented+lumbar+interbody+fusion+for+spondylolisthesis.">Comparison of anterior- and posterior-approach instrumented lumbar interbody fusion for spondylolisthesis.</a> Journal of Neurosurgery. Spine. 7 (1), 21-26 (2007).</li><li>Choy, W., 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=Risk+factors+for+medical+and+surgical+complications+following+single-level+ALIF.">Risk factors for medical and surgical complications following single-level ALIF.</a> Global Spine Journal. 7 (2), 141-147 (2017).</li><li>Amaral, 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=Stand-alone+anterior+lumbar+interbody+fusion+-+Complications+and+perioperative+results.">Stand-alone anterior lumbar interbody fusion - Complications and perioperative results.</a> Revista Brasileira de Ortopedia. 52 (5), 569-574 (2017).</li><li>H&#228;rtl, R., Joeris, A., McGuire, R. A. <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+the+safety+outcomes+between+two+surgical+approaches+for+anterior+lumbar+fusion+surgery:+anterior+lumbar+interbody+fusion+(ALIF)+and+extreme+lateral+interbody+fusion+(ELIF).">Comparison of the safety outcomes between two surgical approaches for anterior lumbar fusion surgery: anterior lumbar interbody fusion (ALIF) and extreme lateral interbody fusion (ELIF).</a> European Spine Journal. 25 (5), 1484-1521 (2016).</li><li>Richter, M., Weidenfeld, M., Uckmann, F. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anterior+lumbar+interbody+fusion.+Indications,+technique,+advantages+and+disadvantages.">Anterior lumbar interbody fusion. Indications, technique, advantages and disadvantages.</a> Der Orthopde. 44 (2), 154-161 (2015).</li><li>Zdeblick, T. A., David, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+prospective+comparison+of+surgical+approach+for+anterior+L4-L5+fusion:+laparoscopic+versus+mini+anterior+lumbar+interbody+fusion.">A prospective comparison of surgical approach for anterior L4-L5 fusion: laparoscopic versus mini anterior lumbar interbody fusion.</a> Spine. 25 (20), 2682-2687 (2000).</li><li>Wert, W. 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=Identifying+risk+factors+for+complications+during+exposure+for+anterior+lumbar+interbody+fusion.">Identifying risk factors for complications during exposure for anterior lumbar interbody fusion.</a> Cureus. 13 (7), e16792 (2021).</li><li>Michael, M. H., Karsten, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microsurgical+anterior+approaches+to+the+lumbar+spine+for+interbody+fusion+and+total+disc+replacement.">Microsurgical anterior approaches to the lumbar spine for interbody fusion and total disc replacement.</a> Neurosurgery. 51, 159-165 (2002).</li><li>Aebi, M., Steffen, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synframe:+A+preliminary+report.">Synframe: A preliminary report.</a> European Spine Journal. 9 (1), S044-S050 (2000).</li><li>Momin, A. 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=Exploring+perioperative+complications+of+anterior+lumber+interbody+fusion+in+patients+with+a+history+of+prior+abdominal+surgery:+A+retrospective+cohort+study.">Exploring perioperative complications of anterior lumber interbody fusion in patients with a history of prior abdominal surgery: A retrospective cohort study.</a> The Spine Journal. 20 (7), 1037-1043 (2020).</li><li>Brau, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mini-open+approach+to+the+spine+for+anterior+lumbar+interbody+fusion:+description+of+the+procedure,+results+and+complications.">Mini-open approach to the spine for anterior lumbar interbody fusion: description of the procedure, results and complications.</a> The Spine Journal. 2 (3), 216-223 (2002).</li><li>Brau, S. A., Delamarter, R. B., Schiffman, M. L., Williams, L. A., Watkins, R. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vascular+injury+during+anterior+lumbar+surgery.">Vascular injury during anterior lumbar surgery.</a> The Spine Journal. 4 (4), 409-412 (2004).</li><li>Westfall, S. H., 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=Exposure+of+the+anterior+spine.+Technique,+complications,+and+results+in+85+patients.">Exposure of the anterior spine. Technique, complications, and results in 85 patients.</a> American Journal of Surgery. 154 (6), 700-704 (1987).</li><li>Jasani, V., Jaffray, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+anatomy+of+the+iliolumbar+vein.+A+cadaver+study.">The anatomy of the iliolumbar vein. A cadaver study.</a> The Journal of Bone and Joint Surgery. British Volume. 84 (7), 1046-1049 (2002).</li><li>Garg, J., Woo, K., Hirsch, J., Bruffey, J. D., Dilley, R. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vascular+complications+of+exposure+for+anterior+lumbar+interbody+fusion.">Vascular complications of exposure for anterior lumbar interbody fusion.</a> Journal of Vascular Surgery. 51 (4), 946-950 (2010).</li><li>Hrabalek, L., Adamus, M., Gryga, A., Wanek, T., Tucek, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+comparison+of+complication+rate+between+anterior+and+lateral+approaches+to+the+lumbar+spine.">A comparison of complication rate between anterior and lateral approaches to the lumbar spine.</a> Biomedical Papers of the Medical Faculty of the University Palacky. 158 (1), 127-132 (2014).</li><li>Escobar, E., Transfeldt, E., Garvey, T., Ogilvie, J., Schultz, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Video-assisted+versus+open+anterior+lumbar+spine+fusion+surgery.">Video-assisted versus open anterior lumbar spine fusion surgery.</a> Spine. 28 (7), 729-732 (2003).</li><li>Katkhouda, 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=Is+laparoscopic+approach+to+lumbar+spine+fusion+worthwhile.">Is laparoscopic approach to lumbar spine fusion worthwhile.</a> American Journal of Surgery. 178 (6), 458-461 (1999).</li><li>Comer, G. 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=Retrograde+ejaculation+after+anterior+lumbar+interbody+fusion+with+and+without+bone+morphogenetic+protein-2+augmentation:+A+10-year+cohort+controlled+study.">Retrograde ejaculation after anterior lumbar interbody fusion with and without bone morphogenetic protein-2 augmentation: A 10-year cohort controlled study.</a> The Spine Journal. 12 (10), 881-890 (2012).</li><li>Mayer, H. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+ALIF+concept.">The ALIF concept.</a> European Spine Journal. 9 (1), S035-S043 (2000).</li><li>Shin, S. H., 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=Microscopic+anterior+foraminal+decompression+combined+with+anterior+lumbar+interbody+fusion.">Microscopic anterior foraminal decompression combined with anterior lumbar interbody fusion.</a> The Spine Journal. 13 (10), 1190-1199 (2013).</li><li>Ikard, R. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Methods+and+complications+of+anterior+exposure+of+the+thoracic+and+lumbar+spine.">Methods and complications of anterior exposure of the thoracic and lumbar spine.</a> Archives of Surgery. 141 (10), 1025-1034 (2006).</li><li>Derman, P. B., Albert, T. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interbody+fusion+techniques+in+the+surgical+management+of+degenerative+lumbar+spondylolisthesis.">Interbody fusion techniques in the surgical management of degenerative lumbar spondylolisthesis.</a> Current Reviews in Musculoskeletal Medicine. 10 (4), 530-538 (2017).</li><li>Dias Pereira Filho, A. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Technique+for+exposing+lumbar+discs+in+anterior+approach+using+steinmann+wires:+Arthroplasties+or+arthrodesis.">Technique for exposing lumbar discs in anterior approach using steinmann wires: Arthroplasties or arthrodesis.</a> World Neurosurgery. 148, 189-195 (2021).</li><li>Motov, 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=Implementation+of+a+three-dimensional+(3D)+robotic+digital+microscope+(AEOS)+in+spinal+procedures.">Implementation of a three-dimensional (3D) robotic digital microscope (AEOS) in spinal procedures.</a> Scientific Reports. 12 (1), 22553 (2022).</li><li>Siller, 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=A+high-definition+3D+exoscope+as+an+alternative+to+the+operating+microscope+in+spinal+microsurgery.">A high-definition 3D exoscope as an alternative to the operating microscope in spinal microsurgery.</a> Journal of Neurosurgery. Spine. 33 (5), 705-714 (2020).</li></ol>

The authors have no conflicts of interest in this research.

Several turns surrounding the peritoneum during Mini-ALIF surgical exposure and decompression of the spinal canal are critical steps in the surgery. Injury to the anterior peritoneum when opening the anterior rectus abdominis sheath and separating the transverse abdominal fascia can easily lead to failure with this approach5. In addition, patients with lumbar spine infections and a history of abdominal surgery can develop intraoperative complications such as adhesions of the peritoneum and soft ti...

Anterior lumbar interbody fusion (ALIF), a fusion procedure that takes an abdominal approach to the anterior lumbar spine, was first described by O&#39;Brien in 19831. With the advantages of less bleeding, less muscle and nerve damage, and the ability to restore lumbar lordosis and reduce the impact on adjacent segmental degeneration better than posterior lumbar interbody fusion, ALIF is now widely used to treat lumbar spondylolisthesis, spinal deformities, lumbar spine infections, and degenerative lumbar disc disease2,3. However, the procedure can also lead to complications such as vascular, nerve, and ureteral injuries; early vascular injuries are especially common, occurring in 10.4% of cases4,5,6,7,8,9.
The use of a microscope during the procedure allows for a clearer operative field, resulting in greater safety in terms of reducing tissue damage, as well as smaller surgical incisions8,10. However, minimally invasive anterior lumbar interbody fusion (Mini-ALIF) still requires a high degree of visualization and stability and requires the use of appropriate spreaders. Early framed laparoscopic spreaders, such as the Synframe system&#39;s Activ O spreader or the currently used Miaspas-ALIF spreader (Aesculap), are primarily used for conventional open ALIF surgery11, but their poor microscopic stability, complex installation requirements, and high costs have hampered the use of microscopy in anterior lumbar spine surgery.
In this study, we introduce a new spreader system for microscope-assisted Mini-ALIF that involves opening the operative field and accomplishing nerve decompression under a microscope through a block and retractors fixed to the vertebral body. This study aims to investigate the technical aspects of microscope-assisted anterior decompression fusion and to introduce a spreader system suitable for Mini-ALIF. This system can provide good intraoperative disc exposure, good discrimination of important structures, adequate spreading of the intervertebral space, and the restoration of the necessary intervertebral height, which is very helpful for less experienced surgeons.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Anterior Lumbar Cage Instrument</td>
			<td>LDR Medical</td>
			<td>ROI-A</td>
			<td></td>
		</tr>
		<tr>
			<td>Cefazolin Sodium for Injection</td>
			<td>Brilliant Pharmaceuticals</td>
			<td>Chinese Drug Approval Number H20217016</td>
			<td></td>
		</tr>
		<tr>
			<td>Coagulation Forceps</td>
			<td>Zhenjiang Hengsheng Juen Medical Instrument Co., Ltd.</td>
			<td>BZN-Q-A-S</td>
			<td></td>
		</tr>
		<tr>
			<td>Coated, Braided Silk</td>
			<td>Suzhou Jiasheng Medical Treatment Products Co.,Ltd.</td>
			<td>2-0(4#)</td>
			<td></td>
		</tr>
		<tr>
			<td>Endplate Rugine</td>
			<td>LDR Medical</td>
			<td>IGO16R</td>
			<td></td>
		</tr>
		<tr>
			<td>Microscope</td>
			<td>Carl Zeiss AG</td>
			<td>S88</td>
			<td></td>
		</tr>
		<tr>
			<td>SPSS Statistics for Windows</td>
			<td>IBM Corp</td>
			<td>version 26.0</td>
			<td></td>
		</tr>
		<tr>
			<td>Surgical ablation electrodes</td>
			<td>Jiangsu Yibo Leiming Medical Technology Co., Ltd.</td>
			<td>LM-A5</td>
			<td></td>
		</tr>
	</tbody>
</table>

clinical application of microscope-assisted minimally invasive anterior lumbar interbody fusion

This study aims to investigate the technical aspects of microscope-assisted anterior decompression fusion and to introduce a spreader system suitable for minimally invasive anterior lumbar interbody fusion (Mini-ALIF). This article is a technical description of anterior lumbar spine surgery under a microscope. We retrospectively collected information on patients who underwent microscope-assisted Mini-ALIF surgery at our hospital between July 2020 and August 2022. A repeated-measures ANOVA was used to compare imaging indicators between periods. Forty-two patients were included in the study. The mean volume of intraoperative bleeding was 180 mL, and the mean operative time was 143 min. The mean follow-up time was 18 months. Apart from one case of peritoneal rupture, no other serious complications occurred. The postoperative foramen and disc height were both higher on average than before surgery. The spreader-assisted micro-Mini-ALIF is simple and easy to use. It can provide good intraoperative disc exposure, good discrimination of important structures, adequate spreading of the intervertebral space, and the restoration of the necessary intervertebral height, which is very helpful for less experienced surgeons.

Patients who received Mini-ALIF for lumbar degenerative disease at Hebei Medical University Third Affiliated Hospital between July 2020 and August 2022 were enrolled retrospectively, and basic information such as age and gender, as well as medical records and imaging information, were recorded. The inclusion criteria were patients receiving Mini-ALIF for lumbar spinal stenosis, discogenic low back pain, and low-grade (I or II) slippage that had failed to respond to strictly conservative treatment for more than 6 months. ...

Watch this Scientific Journal Video about Clinical Application of Microscope-Assisted Minimally Invasive Anterior Lumbar Interbody Fusion at JoVE.com

Clinical Application of Microscope-Assisted Minimally Invasive Anterior Lumbar Interbody Fusion

The technique described in this article is well-suited to the Mini-ALIF procedure, allows for excellent exposure and decompression, and facilitates microscope-assisted manipulation.

This study aims to investigate the technical aspects of microscope-assisted anterior decompression fusion and to introduce a spreader system suitable for ...

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460 Views.  Hebei Medical University Third Affiliated Hospital. The technique described in this article is well-suited to the Mini-ALIF procedure, allows for excellent exposure and decompression, and facilitates microscope-assisted manipulation.

Video: Clinical Application of Microscope-Assisted Minimally Invasive Anterior Lumbar Interbody Fusion

Minimally Invasive Establishment of Murine Orthotopic Bladder Xenografts

Orthotopic bladder cancer xenografts are the gold standard to study molecular cellular manipulations and new therapeutic agents&#160;in vivo. Suitable cell lines are inoculated either by intravesical instillation (model of nonmuscle invasive growth) or intramural injection into the bladder wall (model of invasive growth). Both procedures are complex and highly time-consuming. Additionally, the superficial model has its shortcomings due to the lack of cell lines that are tumorigenic following instillation. Intramural injection, on the other hand, is marred by the invasiveness of the procedure and the associated morbidity for the host mouse.
With these shortcomings in mind, we modified previous methods to develop a minimally invasive approach for creating orthotopic bladder cancer xenografts. Using ultrasound guidance we have successfully performed percutaneous inoculation of the bladder cancer cell lines UM-UC1, UM-UC3 and UM-UC13 into 50 athymic nude. We have been able to demonstrate that this approach is time efficient, precise and safe. With this technique, initially a space is created under the bladder mucosa with PBS, and tumor cells are then injected into this space in a second step. Tumor growth is monitored at regular intervals with bioluminescence imaging and ultrasound. The average tumor volumes increased steadily in in all but one of our 50 mice over the study period.
In our institution, this novel approach, which allows bladder cancer xenograft inoculation in a minimally-invasive, rapid and highly precise way, has replaced the traditional model.

The established technique to inoculate primary invasive orthotopic bladder cancer xenografts requires laparotomy and mobilization of the bladder. This procedure inflicts significant morbidity on the mice, is technically challenging and time-consuming. We therefore developed a high-precision, percutaneous approach utilizing ultrasound guidance.

Orthotopic bladder cancer xenografts are the gold standard to study molecular cellular manipulations and new therapeutic agents&#160;in vivo. Suitable ...

Minimally Invasive Thumb-sized Pterional Craniotomy for Surgical Clip Ligation of Unruptured Anterior Circulation Aneurysms

Less invasive surgical approaches for intracranial aneurysm clipping may reduce length of hospital stay, surgical morbidity, treatment cost, and improve patient outcomes. We present our experience with a minimally invasive pterional approach for anterior circulation aneurysms performed in a major tertiary cerebrovascular center and compare the results with an aged matched dataset from the Nationwide Inpatient Sample (NIS). From August 2008 to December 2012, 22 elective aneurysm clippings on patients &#8804;55 years of age were performed by the same dual fellowship-trained cerebrovascular/endovascular neurosurgeon. One patient (4.5%) experienced transient post-operative complications. 18 of 22 patients returned for follow-up imaging and there were no recurrences through an average duration of 22 months. A search in the NIS database from 2008 to 2010, also for patients aged &#8804;55 years of age, yielded 1,341 hospitalizations for surgical clip ligation of unruptured cerebral aneurysms. Inpatient length of stay and hospital charges at our institution using the minimally invasive thumb-sized pterional technique were nearly half that of NIS (length of stay: 3.2 vs 5.7 days; hospital charges: $52,779 vs. $101,882). The minimally invasive thumb-sized pterional craniotomy allows good exposure of unruptured small and medium-sized supraclinoid anterior circulation aneurysms. Cerebrospinal fluid drainage from key subarachnoid cisterns and constant bimanual microsurgical techniques avoid the need for retractors which can cause contusions, localized venous infarctions, and post-operative cerebral edema at the retractor sites. Utilizing this set of techniques has afforded our patients with a shorter hospital stay at a lower cost compared to the national average.

Minimally invasive thumb-sized pterional craniotomy for aneurysm clipping has afforded our patients with a shorter hospital stay at a lower cost compared to the national average.

Less invasive surgical approaches for intracranial aneurysm clipping may reduce length of hospital stay, surgical morbidity, treatment cost, and improve ...

Encapsulation Thermogenic Preadipocytes for Transplantation into Adipose Tissue Depots

Cell encapsulation was developed to entrap viable cells within semi-permeable membranes. The engrafted encapsulated cells can exchange low molecular weight metabolites in tissues of the treated host to achieve long-term survival. The semipermeable membrane allows engrafted encapsulated cells to avoid rejection by the immune system. The encapsulation procedure was designed to enable a controlled release of bioactive compounds, such as insulin, other hormones, and cytokines. Here we describe a method for encapsulation of catabolic cells, which consume lipids for heat production and energy dissipation (thermogenesis) in the intra-abdominal adipose tissue of obese mice. Encapsulation of thermogenic catabolic cells may be potentially applicable to the prevention and treatment of obesity and type 2 diabetes. Another potential application of catabolic cells may include detoxification from alcohols or other toxic metabolites and environmental pollutants.

Here, we present a protocol for encapsulation of catabolic cells, which consume lipids for heat production in intra-abdominal adipose tissue and increase energy dissipation in obese mice.

Cell encapsulation was developed to entrap viable cells within semi-permeable membranes. The engrafted encapsulated cells can exchange low molecular ...

Minimally Invasive Transverse Aortic Constriction in Mice

Minimally invasive transverse aortic constriction (MTAC) is a more desirable method for the constriction of the transverse aorta in mice than standard open-chest transverse aortic constriction (TAC). Although transverse aortic constriction is a highly functional method for the induction of high pressure in the left ventricle, it is a more difficult and lengthy procedure due to its use of artificial ventilation with tracheal intubation. TAC is oftentimes also less survivable, as the newer method, MTAC, neither requires the cutting of the ribs and intercostal muscles nor tracheal intubation with a ventilation setup. In MTAC, as opposed to a thoracotomy to access to the chest cavity, the aortic arch is reached through a midline incision in the anterior neck. The thyroid is pulled back to reveal the sternal notch. The sternum is subsequently cut down to the second rib level, and the aortic arch is reached simply by separating the connective tissues and thymus. From there, a suture can be wrapped around the arch and tied with a spacer, and then the sternal cut and skin can be closed. MTAC is a much faster and less invasive way to induce left ventricular hypertension and enables the possibility for high-throughput studies. The success of the constriction can be verified using high-frequency trans-thoracic echocardiography, particularly color Doppler and pulsed-wave Doppler, to determine the flow velocities of the aortic arch and left and right carotid arteries, the dimension of the blood vessels, and the left ventricular function and morphology. A successful constriction will also trigger significant histopathological changes, such as cardiac muscle cell hypertrophy with interstitial and perivascular fibrosis. Here, the procedure of MTAC is described, demonstrating how the resulting flow changes in the carotid arteries can be examined with echocardiography, gross morphology, and histopathological changes in the heart.

Minimally invasive transverse aortic constriction (MTAC) conserves the essentials of regular transverse aortic constriction (TAC) while eliminating the use of a ventilator with tracheal intubation. It proves to be a highly desirable method for high-throughput studies on left ventricular overload, particularly in translational studies.

Minimally invasive transverse aortic constriction (MTAC) is a more desirable method for the constriction of the transverse aorta in mice than standard ...

A Minimally Invasive Model to Analyze Endochondral Fracture Healing in Mice Under Standardized Biomechanical Conditions

Bone healing models are necessary to analyze the complex mechanisms of fracture healing to improve clinical fracture treatment. During the last decade, an increased use of mouse models in orthopedic research was noted, most probably because mouse models offer a large number of genetically-modified strains and special antibodies for the analysis of molecular mechanisms of fracture healing. To control the biomechanical conditions, well-characterized osteosynthesis techniques are mandatory, also in mice. Here, we report on the design and use of a closed bone healing model to stabilize femur fractures in mice. The intramedullary screw, made of medical-grade stainless steel, provides through fracture compression an axial and rotational stability compared to the mostly used simple intramedullary pins, which show a complete lack of axial and rotational stability. The stability achieved by the intramedullary screw allows the analysis of endochondral healing. A large amount of callus tissue, received after stabilization with the screw, offers ideal conditions to harvest tissue for biochemical and molecular analyses. A further advantage of the use of the screw is the fact that the screw can be inserted into the femur with a minimally invasive technique without inducing damage to the soft tissue. In conclusion, the screw is a unique implant that can ideally be used in closed fracture healing models offering standardized biomechanical conditions.

This protocol describes a minimally invasive osteosynthesis technique using an intramedullary screw for standardized stabilization of femur fractures, which can be used to analyze endochondral bone healing in mice.

Bone healing models are necessary to analyze the complex mechanisms of fracture healing to improve clinical fracture treatment. During the last decade, an ...

Endoscopic Septoplasty with Limited Two-line Resection: Minimally Invasive Surgery for Septal Deviation

Endoscopic septoplasty is a surgical procedure in otolaryngology that is commonly performed to treat nasal airway obstruction caused by nasal septal deviation. It has a long history with multiple variations. In this article, a modified endoscopic septoplasty procedure using the limited two-line resection (2LoRs) technique at the posterior and inferior junction of the cartilaginous and bony septum is presented based on embryologic and anatomic knowledge of the nasal septum and the biomechanics of cartilaginous behavior. With this procedure, the quadrangular cartilage can be preserved as much as possible, which is helpful in retaining the supporting framework and rigidness of the septum. 2LoRs has been proven effective and sound for the correction of nasal septal deviation with rare complications. This modified procedure can be applied to correct the deviated nasal septum in the absence of any external nasal deformity to improve nasal patency or to improve access to the middle meatus or to the axillary region of the middle turbinate. It may also be used to expand the indications of septoplasty to children and adolescents because of its minimally invasive approach.

Endoscopic septoplasty is a time-honored surgical procedure with multiple variations. This paper focuses on a step-by-step surgical approach to perform a modified septoplasty procedure known as limited two-line resection. This surgical technique can be applied to correct a deviated nasal septum in the absence of an external nasal deformity.

Endoscopic septoplasty is a surgical procedure in otolaryngology that is commonly performed to treat nasal airway obstruction caused by nasal septal ...

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. ...

Electromagnetic Navigation Transthoracic Nodule Localization for Minimally Invasive Thoracic Surgery

The increased use of chest computed tomography (CT) has led to an increased detection of pulmonary nodules requiring diagnostic evaluation and/or excision. Many of these nodules are identified and excised via minimally invasive thoracic surgery; however, subcentimeter and subsolid nodules are frequently difficult to identify intra-operatively. This can be mitigated by the use of electromagnetic transthoracic needle localization. This protocol delineates the step-by-step process of electromagnetic localization from the pre-operative period to the postoperative period and is an adaptation of the electromagnetically guided percutaneous biopsy previously described by Arias et al. Pre-operative steps include obtaining a same day CT followed by the generation of a three-dimensional virtual map of the lung. From this map, the target lesion(s) and an entry site are chosen. In the operating room, the virtual reconstruction of the lung is then calibrated with the patient and the electromagnetic navigation platform. The patient is then sedated, intubated, and placed in the lateral decubitus position. Using a sterile technique and visualization from multiple views, the needle is inserted into the chest wall at the prechosen skin entry site and driven down to the target lesion. Dye is then injected into the lesion and, then, continuously during needle withdrawal, creating a tract for visualization intra-operatively. This method has many potential benefits when compared to the CT-guided localization, including a decreased radiation exposure and decreased time between the dye injection and the surgery. Dye diffusion from the pathway occurs over time, thereby limiting intra-operative nodule identification. By decreasing the time to surgery, there is a decrease in wait time for the patient, and less time for dye diffusion to occur, resulting in an improvement in nodule localization. When compared to electromagnetic bronchoscopy, airway architecture is no longer a limitation as the target nodule is accessed via a transparenchymal approach. Details of this procedure are described in a step-by-step fashion.

Presented here is a protocol for lung nodule localization using dye marking via electromagnetically navigated transthoracic needle access. The technique described here can be accomplished in the peri-operative period to optimize nodule localization and to successful resection when performing minimally invasive thoracic surgery.

The increased use of chest computed tomography (CT) has led to an increased detection of pulmonary nodules requiring diagnostic evaluation and/or ...

A Pre-clinical Rat Model for the Study of Ischemia-reperfusion Injury in Reconstructive Microsurgery

Ischemia-reperfusion injury is the main cause of flap failure in reconstructive microsurgery. The rat is the preferred preclinical animal model in many areas of biomedical research due to its cost-effectiveness and its translation to humans. This protocol describes a method to create a preclinical free skin flap model in rats with ischemia-reperfusion injury. The described 3 cm x 6 cm rat free skin flap model is easily obtained after the placement of several vascular ligatures and the section of the vascular pedicle. Then, 8 h after the ischemic insult and completion of the microsurgical anastomosis, the free skin flap develops the tissue damage. These ischemia-reperfusion injury-related damages can be studied in this model, making it a suitable model for evaluating therapeutic agents to address this pathophysiological process. Furthermore, two main monitoring techniques are described in the protocol for the assessment of this animal model: transit-time ultrasound technology and laser speckle contrast analysis.

Here, we describe a pre-clinical animal model for studying the pathophysiology of ischemia-reperfusion injury in reconstructive microsurgery. This free skin flap model based on the superficial caudal epigastric vessels in the rat may also allow for the evaluation of different therapies and compounds to counteract ischemia-reperfusion injury-related damage.

Ischemia-reperfusion injury is the main cause of flap failure in reconstructive microsurgery. The rat is the preferred preclinical animal model in many ...

Evaluation of Capnography Sampling Line Compatibility and Accuracy when Used with a Portable Capnography Monitor

Capnography is commonly used to monitor patient&#8217;s ventilatory status. While sidestream capnography has been shown to provide a reliable assessment of end-tidal CO2 (ETCO2), its accuracy is commonly validated using commercial kits composed of a capnography monitor and its matching disposable nasal cannula sampling lines. The purpose of this study was to assess the compatibility and accuracy of cross-paired capnography sampling lines with a single portable bedside capnography monitor. A series of 4 bench tests were performed to evaluate the tensile strength, rise time, ETCO2 accuracy as a function of respiratory rate, and ETCO2 accuracy in the presence of supplemental O2. Each bench test was performed using specialized, validated equipment to allow for a full evaluation of sampling line performance. The 4 bench tests successfully differentiated between sampling lines from different commercial sources and suggested that due to increased rise time and decreased ETCO2 accuracy, not all nasal cannula sampling lines provide reliable clinical data when cross-paired with a commercial capnography monitor. Care should be taken to ensure that any cross-pairing of capnography monitors and disposable sampling lines is fully validated for use across respiratory rates and supplemental O2 flow rates commonly encountered in clinical settings.

The goal of this study was to evaluate the accuracy of capnography sampling lines used in conjunction with a portable bedside capnography monitor. Sampling lines from 7 manufacturers were evaluated for tensile strength, rise time, and ETCO2 accuracy as a function of respiratory rate or supplemental oxygen flow rate.

Capnography is commonly used to monitor patient&#8217;s ventilatory status. While sidestream capnography has been shown to provide a reliable assessment ...