This work is funded by grants from Peking University Third Hospital Scientific Research Foundation for the Returned Overseas Scholars (Grant No: 77434-01, Long Zhang) and Beijing Higher Education Young Elite Teacher Project (Grant No: YETP0072, Wen-Hui Wang).

The protocol has been approved by the local medical and ethics committees. The procedure lasts approximately 15 min per side.
1. Indications
<ol>
	<li>Ensure the patient has the following indications for CLS: thromboangiitis obliterans (Buerger&#39;s disease), ischemic diabetic foot, Raynaud&#39;s disease, parmoplantar hyperhidrosis, erythromelalgia, phantom limb pain, or livedo reticularis of the lower extremities.</li>
</ol>
2. Contraindications
<ol>
	<li>Exclude the patient if any of the following contraindications are fulfilled: spinal deformity, bleeding tendency, any infection in the procedure-involved areas, unstable vital signs, pregnancy, or any conditions that render the ability for compliance with the procedure.</li>
</ol>
3. Preoperative Preparation
<ol>
	<li>Confirm the presence of indications and lack of contraindications based on clinical and laboratory results.</li>
	<li>Obtain written, informed consent from the patient/relative.</li>
</ol>
4. Treatment Procedure
<ol>
	<li>Patient position: ensure that the patient is in lateral decubitus position with the side to be treated facing upwards and the lower limbs flexed to make the back as stretched as possible.</li>
	<li>Disinfection: disinfect the skin at the planned needle puncture site (approximately 30 cm diameter) with 2% entoiodine, twice. Then, cover the patient&#39;s back with surgical towels.</li>
	<li>Anesthetization of the needle tract under lateral fluoroscopy guidance: anesthetize the skin and entire needle tract with 5&#8211;8 mL of 0.5% lidocaine (2% lidocaine diluted in 0.9% saline solution) without vasoconstrictors. Advance the needle under local anesthesia to the vertebral body surface gradually. Position the needle tip in the optimal injection area. 
	NOTE: The puncture point on the skin is approximately 7&#8211;8 cm from the dorsomedial line, depending on body shape. Figure 1A shows the needle tract. Figure 1B shows the optimal injection area, which is at approximately one-third the dividing line of the vertebral body in the lateral view of a lumbar X-ray.</li>
	<li>Confirmation of the accuracy of the needle position with contrast agent: after ensuring that the needle tip is in the optimal area in the lateral view of a lumbar X-ray, inject 0.5 mL of the contrast agent to further evaluate the correct position of the needle tip. 
	NOTE: The goal is to keep the contrast agent mainly confined to the optimal area then spreading along the psoas major muscle. Distribution of the contrast along the psoas muscle fibers is the marker of successful injection behind the anterior fascia (Figure 2).</li>
	<li>Injection of inactivating agent, 5% phenol: after aspiration, to ensure no puncture accidents, inject 2 mL of 5% aqueous solution of phenol into the optimal area (adjust the needle tip direction to ensure 1 mL of phenol spreads to the direction of the head then 1 mL of phenol to the direction of the foot). Then, withdraw the needle from the skin and compress and cover the puncture site with gauze to achieve hemostasis. 
	NOTE: Steps 4.3 to 4.5 were performed at L3 and L4, respectively.</li>
	<li>Evaluation of the efficacy of sympathetic interruption: define satisfactory sympathetic interruption as a rise of at least 2 &#176;C in skin temperature 5 min after the completion of step 4.5. If satisfactory interruption is not achieved, perform supplemental injection to another optimal area or L5, with a total phenol volume no larger than 10 mL for both sides. Perform the other side in the same manner if needed. Measure the skin temperature using an infrared thermometer, and calculate the average among temperature increases in the shin, plantar, and dorsal foot.</li>
</ol>
5. Postoperative Care
<ol>
	<li>Encourage the patient to drink water and ambulate after completion of the procedure. Check the patient on the following day for any discomfort, especially in the loin, groin, and thigh, and for improvement of symptoms and any signs of primary disease. Measure the skin temperature as described in step 4.6. Follow-up with the patient accordingly.</li>
</ol>

<ol>
	<li>Karanth, V. K., Karanth, T. K., Karanth, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lumbar+sympathectomy+techniques+for+critical+lower+limb+ischaemia+due+to+non-reconstructable+peripheral+arterial+disease.">Lumbar sympathectomy techniques for critical lower limb ischaemia due to non-reconstructable peripheral arterial disease.</a> Cochrane Database of Systematic Reviews. 12, 011519 (2016).</li><li>Kothari, R., Maharaj, A., Tomar, T. S., Agarwal, P., Sharma, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Percutaneous+chemical+lumbar+sympathectomy+for+Buerger's+disease:+Results+in+147+patients.">Percutaneous chemical lumbar sympathectomy for Buerger's disease: Results in 147 patients.</a> Indian Journal of Vascular Endovascular Surgery. 4, 185-190 (2017).</li><li>Dong, G. X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemical+lumbar+sympathectomy.">Chemical lumbar sympathectomy.</a> Chinese Journal of Practical Surgery. 4, 245-246 (2004).</li><li>Dong, G. X., Zhao, J., Luan, J. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemical+lumbar+sympathectomy+for+the+treatment+of+lower+limb+ischemia.">Chemical lumbar sympathectomy for the treatment of lower limb ischemia.</a> Chinese Journal of General Surgery. 1, 30-32 (2002).</li><li>Dong, G. X., Zhao, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemical+sympathectomy+for+ischemia+of+lower+extremity.">Chemical sympathectomy for ischemia of lower extremity.</a> Journal of Beijing Medical University. 1, 59-60 (1998).</li><li>Yoshida, W. B., Cataneo, D. C., Bomfim, G. A., Hasimoto, E., Cataneo, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemical+lumbar+sympathectomy+in+plantar+hyperhidrosis.">Chemical lumbar sympathectomy in plantar hyperhidrosis.</a> Clinical Autonomic Research. 20 (2), 113-115 (2010).</li><li>Zhang, L., Wang, W. H., Li, L. 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=Long-term+remission+of+primary+erythermalgia+with+R1150W+polymorphism+in+SCN9A+after+chemical+lumbar+sympathectomy.">Long-term remission of primary erythermalgia with R1150W polymorphism in SCN9A after chemical lumbar sympathectomy.</a> European Journal of Dermatology. 20 (6), 763-767 (2010).</li><li>Cerci, F. B., Kapural, L., Yosipovitch, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intractable+erythromelalgia+of+the+lower+extremities+successfully+treated+with+lumbar+sympathetic+block.">Intractable erythromelalgia of the lower extremities successfully treated with lumbar sympathetic block.</a> Journal of the American Academy of Dermatology. 69 (5), 270-272 (2013).</li><li>Wang, W. H., Zhang, L., Dong, G. 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M., Langdon, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hazard+of+chemical+sympathectomy.">Hazard of chemical sympathectomy.</a> British Medical Journal. 1 (6120), 1143 (1978).</li><li>Wijeyaratne, S. M., Seneviratne, L. N., Umashankar, K., Perera, N. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Minimal+access+is+not+maximal+safety:+pelviureteric+necrosis+following+percutaneous+chemical+lumbar+sympathectomy.">Minimal access is not maximal safety: pelviureteric necrosis following percutaneous chemical lumbar sympathectomy.</a> British Medical Journal Case Reports. , (2010).</li><li>Antao, B., Rowlands, T. E., Singh, N. P., McCleary, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pelviureteric+junction+disruption+as+a+complication+of+chemical+lumbar+sympathectomy.">Pelviureteric junction disruption as a complication of chemical lumbar sympathectomy.</a> Cardiovascular Surgery. 11 (1), 42-44 (2003).</li><li>Ranjan, P., Kumar, J., Chipde, S. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Acute+renal+failure+due+to+bilateral+ureteric+necrosis+following+percutaneous+chemical+lumbar+sympathectomy.">Acute renal failure due to bilateral ureteric necrosis following percutaneous chemical lumbar sympathectomy.</a> Indian Journal of Nephrology. 22 (4), 292-294 (2012).</li><li>Cutts, S., Williams, H. T., Lee, J., Downing, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ureteric+injury+as+a+complication+of+chemical+sympathectomy.">Ureteric injury as a complication of chemical sympathectomy.</a> European Journal of Vascular and Endovascular Surgery. 19 (2), 212-213 (2000).</li><li>Ernst, S., Heindel, W., Fischbach, 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=Complications+of+CT+guided+lumbar+sympathectomy:+our+own+experiences+and+literature+review.">Complications of CT guided lumbar sympathectomy: our own experiences and literature review.</a> Rofo. 168 (1), 77-83 (1998).</li><li>Daschner, H., Allgayer, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ureteral+obstruction+following+CT-guided+lumbar+sympathetic+exclusion.">Ureteral obstruction following CT-guided lumbar sympathetic exclusion.</a> Rofo. 161, 85-87 (1994).</li><li>Ryttov, N., Boe, S., Nielsen, H., Jacobsen, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Necrosis+of+ureter+as+a+complication+to+chemical+lumbar+sympathectomy.+Report+of+a+case.">Necrosis of ureter as a complication to chemical lumbar sympathectomy. Report of a case.</a> Acta Chirurgica Scandinavica. 147 (1), 79-80 (1981).</li><li>Benchekroun, A., Lachkar, A., Soumana, 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=Ureter+injuries.+Apropos+of+42+cases.">Ureter injuries. Apropos of 42 cases.</a> Annals of Urology. 31 (5), 267-272 (1997).</li><li>Coveliers, H., Meyer, M., Gharagozloo, 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=Robotic+selective+postganglionic+thoracic+sympathectomy+for+the+treatment+of+hyperhidrosis.">Robotic selective postganglionic thoracic sympathectomy for the treatment of hyperhidrosis.</a> Annals of Thoracic Surgery. 95 (1), 269-274 (2013).</li><li>Coveliers, H., Meyer, M., Gharagozloo, F., Wisselink, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Selective+sympathectomy+for+hyperhidrosis:+technique+of+robotic+transthoracic+selective+postganglionic+efferent+sympathectomy.">Selective sympathectomy for hyperhidrosis: technique of robotic transthoracic selective postganglionic efferent sympathectomy.</a> European Journal of Cardio-thoracic Surgery. 43 (2), 428-430 (2013).</li><li>Akil, A., Semik, M., Fischer, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficacy+of+Miniuniportal+Video-Assisted+Thoracoscopic+Selective+Sympathectomy+(Ramicotomy)+for+the+Treatment+of+Severe+Palmar+and+Axillar+Hyperhidrosis.">Efficacy of Miniuniportal Video-Assisted Thoracoscopic Selective Sympathectomy (Ramicotomy) for the Treatment of Severe Palmar and Axillar Hyperhidrosis.</a> Thoracic Cardiovascular Surgery. , (2018).</li><li>Sanderson, C. 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G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Phenol+injection+of+the+sympathetic+chain.">Phenol injection of the sympathetic chain.</a> British Journal of Surgery. 57 (1), 45-50 (1970).</li><li>Haynsworth, R. F., Noe, C. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Percutaneous+lumbar+sympathectomy:+a+comparison+of+radiofrequency+denervation+versus+phenol+neurolysis.">Percutaneous lumbar sympathectomy: a comparison of radiofrequency denervation versus phenol neurolysis.</a> Anesthesiology. 74 (3), 459-463 (1991).</li><li>Boas, 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=Sympathetic+blocks+in+clinical+practice.">Sympathetic blocks in clinical practice.</a> International Anesthesiology Clinics. 16 (4), 149-182 (1978).</li><li>Duncan, J. 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The authors have nothing to disclose.

Here we classify CLS as either conventional or selective CLS, with the major difference being the targeting of sympathetic trunk vs. gray rami communicantes (injection of phenol in front of vs. behind the anterior fascia of the psoas major muscle). We have implemented selective CLS in young, female patients with livedo reticularis10, children with erythromelalgia7,9, and senile patients with end-stage arteriosclerosis obliterans a...

Chemical lumbar sympathectomy (CLS) has been shown to be an effective treatment for ischemic diseases1,2,3,4,5 including thromboangiitis obliterans (sometimes called Buerger&#39;s disease), ischemic diabetic foot, Raynaud&#39;s disease, parmoplantar hyperhidrosis6, erythromelalgia7,8,9, and livedo reticularis10. It has replaced open surgery due to a number of advantages. It is minimally invasive and economically attractive, it does not require general anesthesia and hospitalization, and it can be performed repeatedly. However, exquisite precision is critical. For example, paraplegia has been reported in CLS using blind technique11. The precision of the procedure is greatly improved with radiographical guidance to control the exact position of the puncture needle tip and puncture path and depth, through the use of contrast media to visualize treatment areas. However, even with radiographical guidance, damages to adjacent organs, particularly ureteropelvic organs12,13,14,15,16,17,18,19, have still been reported.
It is commonly practiced to position the needle tip beyond the anterior fascia of the psoas major muscle and inject the drug around the sympathetic trunk8,12,13,14,15, which we define as conventional CLS. However, because the location of the sympathetic trunk and ureter are both in front of the anterior fascia, inactivating agents may spread to the ureter and cause damage. In reports of ureteropelvic damage that presented radiographic images12,13,14,15, the drug was injected in front of the anterior fascia, according to contrast spreading.
Based on our prior experience performing CLS procedures, we have found that targeting gray rami communicantes comparably effective and safer compared to targeting the sympathetic trunk. Gray rami communicantes are postganglionic sympathetic fibers located behind the sympathetic trunk and in front of the lumber nerve root, running along the lateral edge of the vertebral body, mostly within the psoas major muscle. Thus, the anterior fascia provides a good barrier for the ureteropelvic area, and the psoas major muscle provides a good barrier for the lumbar nerve root. We define this procedure as selective CLS, and the technical details of selective CLS are described in this protocol.

<table><tbody><tr><td>10 cm 9# puncture needle</td><td>Peking University Third Hospital</td><td>Not Applicable</td><td>7# for children</td></tr><tr><td>5% Phenol diluted in aqueous solution</td><td>Peking University Third Hospital</td><td>Not Applicable</td><td>10 mL</td></tr><tr><td>Aseptic puncture kit</td><td>Peking University Third Hospital</td><td>Not Applicable</td><td>6 pieces of surgical towel, gauze, cotton balls, blood vessel forceps, etc.</td></tr><tr><td>Infrared frontal thermometer&amp;nbsp;</td><td>OMRON health care (China) Co.,Ltd.</td><td>MC-720</td><td></td></tr><tr><td>Iodophors skin disinfectants&amp;nbsp;</td><td>Shanghai Likang Disinfectant Hi-Tech Co., Ltd.</td><td>20180404</td><td></td></tr><tr><td>Sterile surgical gloves</td><td>Beijing Ruijing Latex products Co., Ltd.&amp;nbsp;</td><td>2018070352</td><td></td></tr></tbody></table>

targeting gray rami communicantes in selective chemical lumbar sympathectomy

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

The needle tip should be in the optimal area as shown in Figure 1. In selective CLS, the contrast is injected behind the anterior fascia of the psoas major muscle, targeting gray rami communicantes. A comparison of contrast spreading in selective CLS (A) and conventional CLS (B) is shown in Figure 2.
The expected clinical effects are vasodilation (for treatment of Rayna...

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Targeting Gray Rami Communicantes in Selective Chemical Lumbar Sympathectomy

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

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

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7.0K Views.  Peking University Third Hospital. We present a protocol for selective chemical lumbar sympathectomy (CLS), which inactivates only gray rami communicantes and not the sympathetic trunk. Selective CLS can help achieve therapeutic efficacy in vasodilation, sweat reduction, and pain relief that are comparable to conventional CLS, and serious complications, particularly ureteropelvic damages, can be reduced.

Video: Targeting Gray Rami Communicantes in Selective Chemical Lumbar Sympathectomy

Surgical Technique for Superior Cervical Ganglionectomy in a Murine Model

Growing evidence suggests that the sympathetic nervous system plays an important role in cancer progression. Adrenergic innervation regulates salivary gland secretion, circadian rhythm, macular degeneration, immune function, and cardiac physiology. Murine surgical sympathectomy is a method for studying the effects of adrenergic innervation by allowing for complete, unilateral adrenergic ablation while avoiding the need for repeated pharmacologic intervention and the associated side effects. However, surgical sympathectomy in mice is technically challenging because of the small size of the superior cervical ganglion. This study describes a surgical technique for reliably identifying and resecting the superior cervical ganglion to ablate the sympathetic nervous system. The successful identification and removal of the ganglion are validated by imaging the fluorescent sympathetic ganglia using a transgenic mouse, identifying post-resection Horner's syndrome, staining for adrenergic markers in the resected ganglia, and observing diminished adrenergic immunofluorescence in the target organs following sympathectomy. This model enables future studies of cancer progression as well as other physiological processes regulated by the sympathetic nervous system.

The present protocol describes a mouse model of the ablation of adrenergic innervation by identifying and resecting the superior cervical ganglion.

Growing evidence suggests that the sympathetic nervous system plays an important role in cancer progression. Adrenergic innervation regulates salivary ...

Cancer Research

An Anesthesia, Surgery, and Harvest Method for the Evaluation of Transpedicular Screws Using an In Vivo Porcine Lumbar Spine Model

Pedicle screw fixation is the gold standard for the treatment of spinal diseases. However, many studies have reported the issue of loosening pedicle screws after spinal surgery, which is a serious concern. To address this problem, diverse types of pedicle screws have been examined to identify those with good fixation strength and osseointegration in spine bone. The porcine spine is a good alternative for the human spine in the evaluation of pedicle screws due to the anatomical size, mechanical characteristics, and cost. Although several studies have reported that pedicle screws are efficient in the porcine model, no study has described detailed protocols for the evaluation of a pedicle screw using the porcine model. Here, we describe a detailed method for evaluating transpedicular screws using an in vivo porcine lumbar spine model. The technical details for anesthesia, spine surgery, and harvest provided here will facilitate with the evaluation of the transpedicular screw fixation model.

An Anesthesia, Surgery, and Harvest Method for the Evaluation of Transpedicular Screws Using an In Vivo Porcine Lumbar Spine Model

Here, we introduce a method to evaluate transpedicular screws by using an in vivo porcine lumbar spine model.

Pedicle screw fixation is the gold standard for the treatment of spinal diseases. However, many studies have reported the issue of loosening pedicle ...

Laminotomy for Lumbar Dorsal Root Ganglion Access and Injection in Swine

Dorsal root ganglia (DRG) are anatomically well defined structures that contain all primary sensory neurons below the head. This fact makes DRG attractive targets for injection of novel therapeutics aimed at treating chronic pain. In small animal models, laminectomy has been used to facilitate DRG injection because it involves surgical removal of the vertebral bone surrounding each DRG. We demonstrate a technique for intraganglionic injection of lumbar DRG in a large animal species, namely, swine. Laminotomy is performed to allow direct access to DRG using standard neurosurgical techniques, instruments, and materials. Compared with more extensive bone removal via laminectomy, we implement laminotomy to conserve spinal anatomy while achieving sufficient DRG access. Intraoperative progress of DRG injection is monitored using a non-toxic dye. Following euthanasia on post-operative day 21, the success of injection is determined by histology for intraganglionic distribution of 4&#39;,6-diamidino-2-phenylindole (DAPI). We inject a biologically inactive solution to demonstrate the protocol. This method could be applied in future preclinical studies to target therapeutic solutions to DRG. Our methodology should facilitate testing the translatability of intraganglionic small animal paradigms in a large animal species. Additionally, this protocol may serve as a key resource for those planning preclinical studies of DRG injection in swine.

We describe a method for laminotomy in swine that provides access to lumbar dorsal root ganglia (DRG) for intraganglionic injection. Injection progress is monitored intraoperatively and histologically confirmed up to 21 days after surgery. This protocol could be used for future preclinical studies involving DRG injection.

Dorsal root ganglia (DRG) are anatomically well defined structures that contain all primary sensory neurons below the head. This fact makes DRG attractive ...

Neuroscience

A Novel Method: Super-selective Adrenal Venous Sampling

Primary aldosteronism (PA) and subclinical Cushing&#39;s syndrome (SCS) are conditions in which the adrenal glands autonomously produce excessive amounts of aldosterone and cortisol, respectively. The conventional adrenal venous sampling (cAVS) method collects blood samples from both adrenal central veins and is useful for identifying the laterality of excess hormone production in a unilateral lesion(s), as documented in PA cases. In cAVS, plasma cortisol concentrations (PCCs) are used to normalize plasma aldosterone concentrations (PACs). A novel &#34;super-selective&#34; adrenal venous sampling (ssAVS) method was developed using a micro-catheter, which collects blood samples from adrenal tributary veins (TVs). PACs in ssAVS samples do not require PCC normalization because samples contain a limited amount of systemic venous blood, if any. The ssAVS method enabled segmental lesion(s) to be detected in both adrenal glands, which may be treated by bilateral adrenalectomy, thereby sparing lesion-free segment(s). Right and left adrenals typically have three TVs each, i.e., the superior, lateral, and inferior TVs in the right adrenal as well as the superior-median, superior-lateral, and lateral TVs in the left adrenal. In the ssAVS method, specific parent catheters and a technique to handle them are required, and have been described herein. Furthermore, ssAVS results from three cases of PA are presented: bilateral aldosterone-producing adenoma (APA) (Case #1), left APA and right possible cortisol-producing adenoma causing SCS (Case #2), and idiopathic hyperaldosteronism in which bilateral adrenal segments produced excessive amounts of aldosterone (Case #3). The ssAVS method is not difficult for expert angiographers, and, thus, is recommended worldwide to treat PA cases for which cAVS does not represent a viable surgical treatment option.

&#39;Super-selective&#39; adrenal venous sampling (ssAVS, also called segmental adrenal venous sampling: sAVS)&#160;was performed using a micro-catheter to identify adrenal segment(s) that produce excessive amounts of hormones. The ssAVS technique was described, cases in which adrenal segmental lesion(s) were identified by ssAVS were presented, and the usefulness of ssAVS in future adrenal research was discussed.

Primary aldosteronism (PA) and subclinical Cushing&#39;s syndrome (SCS) are conditions in which the adrenal glands autonomously produce excessive amounts ...

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

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

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

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

Ethanol-Induced Cervical Sympathetic Ganglion Block Applications for Promoting Canine Inferior Alveolar Nerve Regeneration Using an Artificial Nerve

Polyglycolic acid collagen (PGA-C) tubes are bio-absorbable nerve tubes filled with collagen of multi-chamber structure, which consist of thin collagen films. Favorable clinical outcomes have been achieved when using these tubes for the treatment of damaged inferior alveolar nerve (IAN). A critical factor for the successful nerve regeneration using PGA-C tubes is blood supply to the surrounding tissue. Cervical sympathetic ganglion block (CSGB) creates a sympathetic blockade in the head and neck region thus increasing blood flow in the area. To ensure an adequate effect, the blockade must be administered with local anesthetics one to two times a day for several consecutive weeks; this poses a challenge when creating animal models for investigating this technique. To address this limitation, we developed an ethanol-induced CSGB in a canine model of long-term increase in blood flow in the orofacial region. We examined whether IAN regeneration via PGA-C tube implantation can be enhanced by this model. Fourteen Beagles were each implanted with a PGA-C tube across a 10-mm gap in the left IAN. The IAN is located within the mandibular canal surrounded by bone, therefore we chose piezoelectric surgery, consisting of ultrasonic waves, for bone processing, in order to minimize the risk of nerve and vessel injury. A good surgical outcome was obtained with this approach. A week after surgery, seven of these dogs were subjected to left CSGB by injection of ethanol. Ethanol-induced CSGB resulted in improved nerve regeneration, suggesting that the increased blood flow effectively promotes nerve regeneration in IAN defects. This canine model can contribute to further research on the long-term effects of CSGB.

We evaluated the effect of cervical sympathetic ganglion block on nerve repair using artificial nerve conduits. Male beagle dogs were each implanted with an artificial nerve across a 10-mm gap in the left inferior alveolar nerve; left cervical sympathetic ganglion was blocked by injecting 99.5% ethanol via lateral thoracotomy.

Polyglycolic acid collagen (PGA-C) tubes are bio-absorbable nerve tubes filled with collagen of multi-chamber structure, which consist of thin collagen ...

Emergency Undocking in Robotic Surgery: A Simulation Curriculum

The following is a training platform to allow robotic surgeons to develop the skills necessary to lead an interprofessional team in emergency undocking of a robotic system. In traditional robotic training for surgeons, a brief web based overview of performing an emergency undocking is provided during initial introductory training to the robotics system. During such a process, there is no training in delineation of interdisciplinary roles for operating room (OR) personnel. The training presented here uses formative simulation and debriefing followed by a lecture. For the simulation, a modified gynecologic simulator is draped in a steep trendelenburg position consistent with most gynecologic laparoscopic surgery. The training torso is modified using tubing hooked to pressure bags of red food colored IV fluid used to simulate a catastrophic vessel injury on demand. Positioned throughout the operating room setting is an interprofessional team consisting of embedded standardized persons (ESPs) to fulfill the roles of a circulating nurse, scrub nurse, anesthesiologist, and bedside assist surgeon. Robotic surgeons are presented a case scenario necessitating emergency undocking, and given control of the robotic instruments. The scenario is terminated following either successful completion of an emergency undock, or at five minutes due to the emergent nature of the case. A debriefing session with hands on training of the steps to emergency undocking, necessary equipment, troubleshooting techniques, and operating room personnel roles follows the simulation. The learners are presented with a short lecture reemphasizing the material presented in the debriefing for their own self-study. This training results in improved time accessing the patient, improved knowledge, confidence, and completion of critical actions, and can be replicated in most institutions. All robotic surgeons should be able to demonstrate competence in this crucial intervention. A limitation of the curriculum is ability to access the in-situ environment for training purposes.

This training platform is designed to allow robotic surgeons to develop the skills necessary to lead an interprofessional team in emergency undocking of the robotic system. Training includes the utilization of the technology and equipment to perform an emergency undocking, as well as delineation of roles for such a scenario.

The following is a training platform to allow robotic surgeons to develop the skills necessary to lead an interprofessional team in emergency undocking of ...

Advanced Imaging of Dorsal Root Ganglion Neurons for Sensory Modality Research

In Vivo Calcium Imaging of Dorsal Root Ganglia Neurons' Response to Somatic and Visceral Stimuli

A technique is described for surgically exposing the dorsal root ganglion (DRG) of the lumbar-6 in a live, anesthetized laboratory mouse, along with the protocol for in vivo calcium imaging of the exposed DRG in response to various visceral and somatic stimuli. Pirt-GCaMP6s mice or C57BL6 mice intrathecally injected with AAV viruses packaged with GCaMP6s were utilized to capture Ca2+ transients. The amplitude of these transients indicates sensitivity to specific sensory modalities. Afferent fibers originate from internal organs, with primary neuronal cell bodies in spinal or vagal ganglia. Studies on visceral nociception and acupuncture analgesia can potentially be conducted on primary sensory neurons using advanced imaging technologies like in vivo calcium imaging, allowing for the recording of neuronal activity ensembles in the intact animal during stimulation or intervention. The responses of DRG neuron ensembles to somatic and visceral stimuli applied to their corresponding receptive fields were recorded. This technique illustrates how neuronal populations react to various types of somatic and visceral stimuli. It is possible to comprehensively compare neuronal ensemble responses to different stimuli, which is a particularly valuable approach in research on visceral pain and segmental mechanisms of somatic stimulation, such as acupuncture.

The present protocol outlines in vivo calcium imaging for measuring the responses of ensembles of lumbar-6 DRG neurons to somatic and visceral stimuli. Thorough comparisons can be made among neurons responding to different stimuli. This protocol is valuable for investigating mechanisms of visceral pain and somatic stimulation, such as acupuncture.

A technique is described for surgically exposing the dorsal root ganglion (DRG) of the lumbar-6 in a live, anesthetized laboratory mouse, along with the ...

Targeting Mouse Sympathetic Neurons: A Lumbar Sympathectomy Approach

Surgical Lumbar Sympathectomy in Mice

Peripheral nerve injuries are common, and full functional recovery after injury is achieved in only 10% of patients. The sympathetic nervous system plays many critical roles in maintaining bodily homeostasis, but it has rarely been studied in the context of peripheral nerve injury. The extent of postganglionic sympathetic neuronal functions in distal targets in the periphery is currently unclear. To better explore the role of sympathetic innervation of peripheral targets, a surgical &#34;knock-out&#34; model provides an alternative approach. Although this can be achieved chemically, chemical destruction of postganglionic sympathetic neurons can be nonspecific and dose-dependent. The use of a surgical lumbar sympathectomy in mice, once thought to be &#34;virtually not practicable&#34; in small animals, allows for specific targeting of postganglionic sympathetic neurons that innervate the hind limbs. This manuscript describes how to surgically remove the L2-L5 lumbar sympathetic ganglia from a mouse as a survival surgery, which reliably decreases the hind paw sweat response and the number of sympathetic axons in the sciatic nerve.

Author Spotlight: Exploring Plasticity of Sympathetic Neurons

This manuscript presents a protocol for surgically removing the postganglionic lumbar sympathetic neurons from a mouse. This procedure will facilitate a multitude of studies aimed at investigating the role of sympathetic innervation in distal tissue targets.

Peripheral nerve injuries are common, and full functional recovery after injury is achieved in only 10% of patients. The sympathetic nervous system plays ...

Procedure for Targeted Muscle Reinnervation for Treating Postamputation Pain

Targeted Muscle Reinnervation: Surgical Protocol for a Randomized Controlled Trial in Postamputation Pain

Over the past decade, the field of prosthetics has witnessed significant progress, particularly in the development of surgical techniques to enhance the functionality of prosthetic limbs. Notably, novel surgical interventions have had an additional positive outcome, as individuals with amputations have reported neuropathic pain relief after undergoing such procedures. Subsequently, surgical techniques have gained increased prominence in the treatment of postamputation pain, including one such surgical advancement - targeted muscle reinnervation (TMR). TMR involves a surgical approach that reroutes severed nerves as a type of nerve transfer to &#34;target&#34; motor nerves and their accompanying motor end plates within nearby muscles. This technique originally aimed to create new myoelectric sites for amplified electromyography (EMG) signals to enhance prosthetic intuitive control. Subsequent work showed that TMR also could prevent the formation of painful neuromas as well as reduce postamputation neuropathic pain (e.g., Residual and Phantom Limb Pain). Indeed, multiple studies have demonstrated TMR&#39;s effectiveness in mitigating postamputation pain as well as improving prosthetic functional outcomes. However, technical variations in the procedure have been identified as it is adopted by clinics worldwide. The purpose of this article is to provide a detailed step-by-step description of the TMR procedure, serving as the foundation for an international, randomized controlled trial (ClinicalTrials.gov, NCT05009394), including nine clinics in seven countries. In this trial, TMR and two other surgical techniques for managing postamputation pain will be evaluated.

Author Spotlight: Advancements and Challenges in Surgical Treatments for Postamputation Pain

The protocol outlines the surgical procedure&#160;for the treatment of postamputation pain using Targeted Muscle Reinnervation (TMR). TMR will be compared with two other surgical techniques, specifically Regenerative Peripheral Nerve Interface (RPNI) and neuroma excision, followed by immediate burying within muscle under the context of an international, randomized controlled trial.

Over the past decade, the field of prosthetics has witnessed significant progress, particularly in the development of surgical techniques to enhance the ...

Targeting Gray Rami Communicantes in Selective Chemical Lumbar Sympathectomy

Summary

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