This study was supported by the Okayama Spine Group.

This study was approved by the ethics committee of Okayama Rosai Hospital (No. 305).
1. Patient history taking
<ol>
	<li>Ensure that the patient has a herniated disc that causes severe sciatica. Usually, the patient will have a history of some prodromal low back pain. They may correlate their symptoms with an episode of trauma.</li>
	<li>Ask the patient to describe their radiating leg pain, including its location. Also ask them about the activities that make it better or worse when LFS or LLDH is suspected.</li>
</ol>
2. Physical examination
<ol>
	<li>To determine the nerve level, check for the signs of the loss of sensation and weakness in the leg.</li>
	<li>Perform a range of lumbar motion tests by asking the patient to bend forward and backward.
	<ol>
		<li>Check for the induction of low back pain in the patient with a herniated disc when forward bending is done.</li>
		<li>Elevate the patient&#39;s leg in a supine position. If the angle between the bed and the leg is less than 70&#176; due to sciatica, this is a strong suggestion that the patient has a herniated disc, which means the straight leg raise (SLR) test is positive. 
		NOTE: The SLR test is very useful to distinguish between lumbar canal stenosis (SLR-) and lumbar disc herniation (SLR+).</li>
	</ol>
	</li>
	<li>Perform deep tendon reflex, and check muscle weakness in the patient.</li>
	<li>Perform the Kemp test7. Fix the patient&#39;s opposite ilium from the side being tested with one hand in a standing position. Grab the patient&#39;s shoulder with the other hand and lead the patient to extension, ipsilateral side bending, and rotation. 
	NOTE: LFS is characterized by exacerbation with foraminal narrowing caused by lumbar extension (Kemp&#39;s sign)7. If the Kemp test is positive, foraminal nerve compression by disc herniation or stenosis is likely.</li>
</ol>
3. Evaluation of radiograms (XP) and magnetic resonance imaging (MRI)
<ol>
	<li>Perform anteroposterior and lateral radiography in a standing position to check lumbar deformity and spondylolisthesis. If the patient has severe deformity, spinal fusion is indicated.</li>
	<li>Perform functional radiography in a standing position. Check the functional radiograms to confirm lumbar instability by measuring vertebral abnormal movement (Figure 1A, B). 
	NOTE: If there is severe instability that indicates more than 10&#176; or more than 3 mm slip at the L5-S1 level, L5-S1 fusion should be considered.</li>
	<li>Perform MRI to accurately assess the nerve compression site.
	<ol>
		<li>For lateral lumbar disc herniation (LLDH), take a coronal T2 weighted image to identify the location of the herniated disc (Figure 1C-E).</li>
	</ol>
	</li>
</ol>
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/63603/63603fig01.jpg" /> 
Figure 1: Preoperative radiograms and MRI. (A) Lateral extension radiogram, (B) Lateral flexion radiogram, (C) Parasagittal T2 weighted MRI image, (D) Coronal T2 weighted MRI image, (E) Axial T2 weighted MR&#160;imaging at the L5-S1. The arrow indicates FLDH. <a href="https://www.jove.com/files/ftp_upload/63603/63603fig01large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
4. Evaluation of computed tomography (CT) and MRI-CT fusion images
<ol>
	<li>Perform CT to check if there is a calcified disc (Figure 2A, D) or foraminal osteophyte (Figure 2B, C) not by the disc.</li>
	<li>Take an MRI-CT fusion image to understand the exact 3D location of the herniated disc (Figure 3).</li>
</ol>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/63603/63603fig02.jpg" /> 
Figure 2: Preoperative CT. (A,B) Parasagittal reconstruction CT, (C) Coronal reconstruction CT, (D) Axial CT at L5-S1. The white arrows indicate calcified FLDH; a black arrow shows an osteophyte. <a href="https://www.jove.com/files/ftp_upload/63603/63603fig02large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/63603/63603fig03.jpg" /> 
Figure 3: CT MRI fusion images. (A) Posterior view, (B) Posterolateral view. The white arrow indicates FLDH. <a href="https://www.jove.com/files/ftp_upload/63603/63603fig03large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
5. Patient positioning and neuromonitoring (NM)
<ol>
	<li>Provide general&#160;anesthesia to the patient.</li>
	<li>Then, place the patient in a prone position on a carbon table.</li>
	<li>Ensure that the patient&#39;s eyes are not compressed with a special face cover. Pay attention to the bolster position not to compress the abdomen of the patient.</li>
	<li>Perform neuromonitoring using a multi-modality intraoperative monitoring system that assesses spinal cord integrity and provides a warning of potential harm to critical neural pathways (Figure 4A).Transcranial motor evoked potentials (MEPs) generate a stimulus at the motor cortex.
	<ol>
		<li>Use recording electrodes to measure the signals at predetermined peripheral upper and lower extremity muscle group sites. 
		NOTE: If neuromonitoring is used, nerve decompression is also confirmed with this. For a muscle of which the innervated nerve is decompressed adequately, the amplitude of the MCV usually increases.</li>
	</ol>
	</li>
</ol>
6. Intraoperative CT scan and spinal navigation
<ol>
	<li>Place a navigation reference frame (RF) percutaneously into the spinous process or sacroiliac joint. Obtain intraoperative CT scan images with a mobile CT scanner (Figure 4B).</li>
	<li>Transmit the CT 3D images to the navigation system automatically using a cable (Figure 4C).</li>
</ol>
<img alt="Figure 4" class="xfigimg" src="/files/ftp_upload/63603/63603fig04.jpg" /> 
Figure 4: Neuromonitoring, O-arm, and navigation. (A) Neuromonitoring, (B) O-arm, (C) Navigation. <a href="https://www.jove.com/files/ftp_upload/63603/63603fig04large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
7. Navigated instrument registration
<ol>
	<li>Register the navigated pointer, dilater, and high-speed burr by tapping the tip to the RF hole manually. Then, perform the accuracy check by touching the bony surface.</li>
</ol>
8. Incision and muscle dissection
<ol>
	<li>With the help of a navigated pointer, confirm the location of the L5-S1 foraminal level by a 50-60 mm extended image from the pointer tip and mark the entry point for the skin incision (Figure 5A).</li>
	<li>Make an approximately 2 cm longitudinal skin incision, and then dissect the subcutaneous tissue, lumbar iliocostalis, and multifidus muscle along the muscle fibers.</li>
	<li>Dock the navigated first dilator at the base of the L5 transverse process using a navigation system (Figure 5B). Then, insert the sequential dilators (5.3 mm, 9.4 mm).</li>
	<li>Insert the final tube (14 mm) and fix it to the flexible arm assembly firmly (Figure 5C). Confirm the position of the tube with a navigation system and the anatomy through endoscopy.</li>
</ol>
<img alt="Figure 5" class="xfigimg" src="/files/ftp_upload/63603/63603fig05.jpg" /> 
Figure 5: Skin incision and sequential dilation. (A) Navigated pointer, (B) Navigation monitor, (C) Tubular retractor. <a href="https://www.jove.com/files/ftp_upload/63603/63603fig05large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
9. Bone resection with the navigated high-speed burr
<ol>
	<li>Check the level with the navigated probe. Check the L5-S1 level with a navigated pointer in the navigation monitor.</li>
	<li>Remove the bone at the lower base of the transverse process and the lateral part of the facet joint with a navigated high-speed burr or conventional high-speed burr (Figure 6). 
	NOTE: Further surgical steps are planned according to the disc herniation or canal stenosis.</li>
	<li>In the case of canal stenosis, remove the bony element that compresses the nerve root completely. 
	CAUTION: Before using the navigated instruments, the surgeon should check the accuracy of navigation because sometimes the reference frame is moved.</li>
</ol>
<img alt="Figure 6" class="xfigimg" src="/files/ftp_upload/63603/63603fig06.jpg" /> 
Figure 6: Navigated high-speed burr. (A,B): Intraoperative image, (B): Navigated high-speed burr. <a href="https://www.jove.com/files/ftp_upload/63603/63603fig06large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
10. Endoscopic disc resection
<ol>
	<li>For LLDH, identify the L5 nerve root and retract cranially by a nerve retractor. Then, remove the disc fragment using pituitary forceps carefully.</li>
	<li>In the case of LFS, widen the L5 foramen using a navigated high-speed burr under navigation guidance.</li>
	<li>Remove every compressing soft tissue and bony element by pituitary forceps and Kerrison rongeurs. Identify the L5 root by its surrounding perineural fat and vessels (Figure 7).</li>
</ol>
<img alt="Figure 7" class="xfigimg" src="/files/ftp_upload/63603/63603fig07.jpg" /> 
Figure 7: Nerve root decompression. (A) Endoscope image; identifying and decompressing the L5 root (white arrow); the inter-vertebral foramen is widened by burring down the osteophytes with the help of a navigated burr. (B) Navigation monitor; during operation, the surgeons can view the one monitor indicating four pieces of information simultaneously: the surgical field, intraoperative neuromonitoring, intraoperative navigation, and microendoscope view. <a href="https://www.jove.com/files/ftp_upload/63603/63603fig07large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
11. Skin closure
<ol>
	<li>After irrigation with saline water to remove the debris, place a wound suction tube at L5-S1.</li>
	<li>Then, close the skin with an absorbable suture.</li>
	<li>Postoperatively, remove the drain after 48 h. 
	NOTE: Postoperative images are shown in Figure 8.</li>
</ol>
<img alt="Figure 8" class="xfigimg" src="/files/ftp_upload/63603/63603fig08.jpg" /> 
Figure 8: Postoperative images. (A) Axial CT image at L5-S1, (B) Parasagittal reconstruction CT, (C) Axial T2 weighted MR&#160;imaging&#160;at L5-S1. The white arrows indicate the decompression area. <a href="https://www.jove.com/files/ftp_upload/63603/63603fig08large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>

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The authors declare that there are no conflicts of interest.

L5 radicular symptoms are caused mainly by L4-L5 disc herniation or stenosis. These symptoms may also occur due to L5 lumbar foraminal stenosis or L5-S1 lateral lumbar disc herniation (LLDH)9. Of all the symptomatic lumbar disc herniations, L5-S1 FLDH accounts for approximately 3%10. For L5-S1 foraminal lesions, a posterolateral or transforaminal approach is recommended. For this approach, there are three main techniques, such as the microscopic, tube with endoscopic, and f...

Diagnosis and surgeries for lumbar foraminal stenosis (LFS) and lumbar lateral disc herniation (LLDH) at the L5-S1 level are challenging for spine surgeons because of this level&#39;s unique structure1. The iliac crest, broad L5 transverse process (TP), small space between the sacral ala and the L5 TP, and osteophytes make the operating window very narrow2. If the bony resection is not enough, inadequate decompression to the L5 nerve root may lead to residual symptoms. Massive bony removal causes postoperative instability. These issues limit surgeons&#39; competencies with foraminal/extraforaminal L5 root decompression. Several reports have shown good results with minimally invasive spine surgeries, such as microscopic or endoscopic procedures in this area to decompress the L5 nerve root3,4. Recently, the use of navigation for foraminal decompression of the L5 root has been reported with good surgical outcomes5.
Fully endoscopic discectomy is becoming popular for removing lateral lumbar disc herniation6. Furthermore, microendoscopic procedures in combination with navigation can help the surgeon to decompress the L5 root with precision2. Usually, these techniques require intraoperative C-arm usage. The goal of this method is to decompress the L5 root precisely with minimum bony resection without a C-arm.
The indications for this technique are extraforaminal lumbar disc herniation and herniation/stenosis of the lateral half of the foraminal lumbar disc. The contraindications are herniation/stenosis of the medial one-third of the foraminal lumbar disc because the scope cannot reach the targeted area2.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>1488 HD 3-Chip camera system</td>
			<td>Stryker</td>
			<td>1000902487</td>
			<td></td>
		</tr>
		<tr>
			<td>16mm Endoscope Attachment, Sterile</td>
			<td>Medtronic</td>
			<td>9560160</td>
			<td></td>
		</tr>
		<tr>
			<td>18mm Endoscope Attachment, Sterile</td>
			<td>Medtronic</td>
			<td>9560180</td>
			<td></td>
		</tr>
		<tr>
			<td>4K 32&#34; surgical display</td>
			<td>Stryker</td>
			<td>0240-031-050</td>
			<td></td>
		</tr>
		<tr>
			<td>Adjustable hinged operating carbon table</td>
			<td>Mizuho OSI</td>
			<td>6988A-PV-ACP</td>
			<td>OSI Axis Jackson table</td>
		</tr>
		<tr>
			<td>L10 AIM light source</td>
			<td>Stryker</td>
			<td>1000902487</td>
			<td></td>
		</tr>
		<tr>
			<td>METRx MED System Endoscope, Long</td>
			<td>Medtronic</td>
			<td>9560102</td>
			<td></td>
		</tr>
		<tr>
			<td>METRx MED System Reusable Endoscope</td>
			<td>Medtronic</td>
			<td>9560101</td>
			<td>Metrx</td>
		</tr>
		<tr>
			<td>METRx MED System Reusable Endoscope</td>
			<td>Medtronic</td>
			<td>9560101 M</td>
			<td></td>
		</tr>
		<tr>
			<td>METRx MED System Reusable Endoscope, Long</td>
			<td>Medtronic</td>
			<td>9560102</td>
			<td></td>
		</tr>
		<tr>
			<td>Navigated high speed bur</td>
			<td>Medtronic</td>
			<td>EM200N</td>
			<td>Stelth&#160;</td>
		</tr>
		<tr>
			<td>Navigated passive pointer</td>
			<td>Medtronic</td>
			<td>960-559</td>
			<td></td>
		</tr>
		<tr>
			<td>NIM Eclipse system</td>
			<td>Medtronic</td>
			<td>ECLC</td>
			<td>Neuromonitouring</td>
		</tr>
		<tr>
			<td>O-arm</td>
			<td>Medtronic</td>
			<td>224ABBZX00042000</td>
			<td>Intraoperative CT</td>
		</tr>
		<tr>
			<td>Stealth station navigation system Spine 7R</td>
			<td>Medtronic</td>
			<td>9733990</td>
			<td>Navigation</td>
		</tr>
		<tr>
			<td>Surgical Carts</td>
			<td>Stryker</td>
			<td>F-NSK-006-00</td>
			<td></td>
		</tr>
		<tr>
			<td>Tubular Retractor, 16mm</td>
			<td>Medtronic</td>
			<td>955-524</td>
			<td></td>
		</tr>
		<tr>
			<td>Tubular Retractor, 16mm, Long</td>
			<td>Medtronic</td>
			<td>9560216</td>
			<td></td>
		</tr>
		<tr>
			<td>Tubular Retractor, 18mm</td>
			<td>Medtronic</td>
			<td>9560118</td>
			<td></td>
		</tr>
		<tr>
			<td>Tubular Retractor, 18mm, Long</td>
			<td>Medtronic</td>
			<td>9560218</td>
			<td></td>
		</tr>
	</tbody>
</table>

transtubular endoscopic posterolateral decompression for l5-s1 lumbar lateral disc herniation

We report a novel technique for C-arm free transtubular L5 nerve decompression under CT-based navigation to reduce the radiation hazard. This procedure is performed under general anesthesia and neuromonitoring. The patient is placed in a prone position on an operating carbon table. A navigation reference frame is placed percutaneously into the contralateral sacroiliac joint or spinous process. Then, CT scan images are obtained. After instrument registration, the L5-S1 foraminal level is confirmed with a navigated probe, and the entry point is marked. Using an approximately 2 cm skin incision, the subcutaneous tissue and muscles are dissected. The navigated first dilator is aimed at the L5-S1 Kambin&#39;s triangle, and sequential dilation is performed. The 18 mm tube is used and fixed to the frame. The bone around the Kambin&#39;s triangle is removed with a navigated burr. For lateral disc herniation, the L5 nerve root is identified and retracted, and the disc fragment is removed. The navigation-guided tubular endoscopic decompression is an effective procedure. There is no radiation hazard to the surgeon or the operating room staff.

Eight cases (four men, four women) underwent surgery using this new technique. The average age was 72.0 years, and the average follow-up period was 1.5 years. There were five patients with L5/S1 foraminal stenosis, two patients with L5/S foraminal disc herniation, and one patient with L3/4 foraminal disc herniation. We could perform all surgeries without a C-arm. The average surgical time and blood loss were 143 min &#177; 14 min and 134 &#177; 18 mL, respectively.
The average recovery percent...

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Transtubular Endoscopic Posterolateral Decompression for L5-S1 Lumbar Lateral Disc Herniation

Presented here is a novel technique of C-arm free transtubular posterolateral decompression for lumbar foraminal stenosis and lateral disc herniation under O-arm navigation.

We report a novel technique for C-arm free transtubular L5 nerve decompression under CT-based navigation to reduce the radiation hazard. This procedure is ...

transtubular-endoscopic-posterolateral-decompression-for-l5-s1-lumbar

Research

JoVE Journal

Neuroscience

3.6K Views.  Okayama Rosai Hospital. Presented here is a novel technique of C-arm free transtubular posterolateral decompression for lumbar foraminal stenosis and lateral disc herniation under O-arm navigation.

Video: Transtubular Endoscopic Posterolateral Decompression for L5-S1 Lumbar Lateral Disc Herniation

Lateral Diffusion and Exocytosis of Membrane Proteins in Cultured Neurons Assessed using Fluorescence Recovery and Fluorescence-loss Photobleaching

Membrane proteins such as receptors and ion channels undergo active trafficking in neurons, which are highly polarised and morphologically complex. This directed trafficking is of fundamental importance to deliver, maintain or remove synaptic proteins.
Super-ecliptic pHluorin (SEP) is a pH-sensitive derivative of eGFP that has been extensively used for live cell imaging of plasma membrane proteins1-2. At low pH, protonation of SEP decreases photon absorption and eliminates fluorescence emission. As most intracellular trafficking events occur in compartments with low pH, where SEP fluorescence is eclipsed, the fluorescence signal from SEP-tagged proteins is predominantly from the plasma membrane where the SEP is exposed to a neutral pH extracellular environment. When illuminated at high intensity SEP, like every fluorescent dye, is irreversibly photodamaged (photobleached)3-5. Importantly, because low pH quenches photon absorption, only surface expressed SEP can be photobleached whereas intracellular SEP is unaffected by the high intensity illumination6-10. 
FRAP (fluorescence recovery after photobleaching) of SEP-tagged proteins is a convenient and powerful technique for assessing protein dynamics at the plasma membrane. When fluorescently tagged proteins are photobleached in a region of interest (ROI) the recovery in fluorescence occurs due to the movement of unbleached SEP-tagged proteins into the bleached region. This can occur via lateral diffusion and/or from exocytosis of non-photobleached receptors supplied either by de novo synthesis or recycling (see Fig. 1). The fraction of immobile and mobile protein can be determined and the mobility and kinetics of the diffusible fraction can be interrogated under basal and stimulated conditions such as agonist application or neuronal activation stimuli such as NMDA or KCl application8,10. 
We describe photobleaching techniques designed to selectively visualize the recovery of fluorescence attributable to exocytosis. Briefly, an ROI is photobleached once as with standard FRAP protocols, followed, after a brief recovery, by repetitive bleaching of the flanking regions. This 'FRAP-FLIP' protocol, developed in our lab, has been used to characterize AMPA receptor trafficking at dendritic spines10, and is applicable to a wide range of trafficking studies to evaluate the intracellular trafficking and exocytosis.

This report describes the use of live cell imaging and photobleach techniques to determine the surface expression, transport pathways and trafficking kinetics of exogenously expressed, pH-sensitive GFP-tagged proteins at the plasma membrane of neurons.

Membrane proteins such as receptors and ion channels undergo active trafficking in neurons, which are highly polarised and morphologically complex. This ...

A Large Lateral Craniotomy Procedure for Mesoscale Wide-field Optical Imaging of Brain Activity

The craniotomy is a commonly performed procedure to expose the brain for in vivo experiments. In mouse research, most labs utilize a small craniotomy, typically 3 mm x 3 mm. This protocol introduces a method for creating a substantially larger 7 mm x 6 mm cranial window exposing most of a cerebral hemisphere over the mouse temporal and parietal cortices (e.g., bregma 2.5 - 4.5 mm, lateral 0 - 6 mm). To perform this surgery, the head must be tilted approximately 30&#176; and much of the temporal muscle must be retracted. Due to the large amount of bone removal, this procedure is intended only for acute experiments with the animal anesthetized throughout the surgery and experiment.
The main advantage of this innovative large lateral cranial window is to provide simultaneous access to both medial and lateral areas of the cortex. This large unilateral cranial window can be used to study the neural dynamics between cells, as well as between different cortical areas by combining multi-electrode electrophysiological recordings, imaging of neuronal activity (e.g., intrinsic or extrinsic imaging), and optogenetic stimulation. Additionally, this large craniotomy also exposes a large area of cortical blood vessels, allowing for direct manipulation of the lateral cortical vasculature.

This protocol presents a method for creating a large unilateral craniotomy over the temporal and parietal regions of the mouse cerebral cortex. This is especially useful for real time imaging over an expansive area of a cortical hemisphere.

The craniotomy is a commonly performed procedure to expose the brain for in vivo experiments. In mouse research, most labs utilize a small craniotomy, ...

Lateral Chronic Cranial Window Preparation Enables In Vivo Observation Following Distal Middle Cerebral Artery Occlusion in Mice

Focal cerebral ischemia (i.e., ischemic stroke) may cause major brain injury, leading to a severe loss of neuronal function and consequently to a host of motor and cognitive disabilities. Its high prevalence poses a serious health burden, as stroke is among the principal causes of long-term disability and death worldwide1. Recovery of neuronal function is, in most cases, only partial. So far, treatment options are very limited, in particular due to the narrow time window for thrombolysis2,3. Determining methods to accelerate recovery from stroke remains a prime medical goal; however, this has been hampered by insufficient mechanistic insights into the recovery process. Experimental stroke researchers frequently employ rodent models of focal cerebral ischemia. Beyond the acute phase, stroke research is increasingly focused on the sub-acute and chronic phase following cerebral ischemia. Most stroke researchers apply permanent or transient occlusion of the MCA in mice or rats. In patients, occlusions of the MCA are among the most frequent causes of ischemic stroke4. Besides proximal occlusion of the MCA using the filament model, surgical occlusion of the distal MCA is probably the most frequently used model in experimental stroke research5. Occlusion of a distal (to the branching of the lenticulo-striate arteries) MCA branch typically spares the striatum and primarily affects the neocortex. Vessel occlusion can be permanent or transient. High reproducibility of lesion volume and very low mortality rates with respect to the long-term outcome are the main advantages of this model. Here, we demonstrate how to perform a chronic cranial window (CW) preparation lateral to the sagittal sinus, and afterwards how to surgically induce a distal stroke underneath the window using a craniotomy approach. This approach can be applied for sequential imaging of acute and chronic changes following ischemia via epi-illuminating, confocal laser scanning, and two-photon intravital microscopy.

Lateral Chronic Cranial Window Preparation Enables In Vivo Observation Following Distal Middle Cerebral Artery Occlusion in Mice

Surgical occlusion of a distal middle cerebral artery branch (MCAo) is a frequently used model in experimental stroke research. This manuscript describes the basic technique of permanent MCAo, combined with the insertion of a lateral cranial window, which offers the opportunity for longitudinal intravital microscopy in mice.

Focal cerebral ischemia (i.e., ischemic stroke) may cause major brain injury, leading to a severe loss of neuronal function and consequently to a host of ...

Endoscopic Endonasal Trans-sphenoidal Approach: Minimally Invasive Surgery for Pituitary Adenomas

Endoscopic endonasal trans-sphenoidal surgery has become the gold standard for the surgical treatment of pituitary adenomas and many other pituitary lesions. Refinements in surgical techniques, technological advancements, and incorporation of neuronavigation have rendered this surgery minimally invasive. The complication rates of this surgery are very low while excellent results are consistently obtained through this approach.
This paper focuses on the step-by-step surgical approach to pituitary adenomas, which is based on personal experience, and details the results obtained with this minimally invasive surgery.

The aim of this paper is to describe the different steps of the endoscopic endonasal approach to the sella turcica.

Endoscopic endonasal trans-sphenoidal surgery has become the gold standard for the surgical treatment of pituitary adenomas and many other pituitary ...

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 ...

Minimally Invasive Endoscopic Intracerebral Hemorrhage Evacuation

Intracerebral hemorrhage (ICH) is a subtype of stroke with high mortality and poor functional outcomes, largely because there are no evidence-based treatment options for this devastating disease process. In the past decade, a number of minimally invasive surgeries have emerged to address this issue, one of which is endoscopic evacuation. Stereotactic ICH Underwater Blood Aspiration (SCUBA) is a novel endoscopic evacuation technique performed in a fluid-filled cavity using an aspiration system to provide an additional degree of freedom during the procedure. The SCUBA procedure utilizes a suction device, endoscope, and sheath and is divided into two phases. The first phase involves maximal aspiration and minimal irrigation to decrease clot burden. The second phase involves increasing irrigation for visibility, decreasing aspiration strength for targeted aspiration without disturbing the cavity wall, and cauterizing any bleeding vessels. Using the endoscope and aspiration wand, this technique aims to maximize hematoma evacuation while minimizing collateral damage to the surrounding brain. Advantages of the SCUBA technique include the use of a low-profile endoscopic sheath minimizing brain disruption and improved visualization with a fluid-filled cavity rather than an air-filled one.

This paper details the surgical protocol for minimally invasive endoscopic intracerebral hemorrhage evacuation using the SCUBA technique.

Intracerebral hemorrhage (ICH) is a subtype of stroke with high mortality and poor functional outcomes, largely because there are no evidence-based ...

Role of Diffusion MRI Tractography in Endoscopic Endonasal Skull Base Surgery

Endoscopic endonasal surgery has gained a prominent role in the management of complex skull base tumors. It allows the resection of a large group of benign and malignant lesions through a natural anatomical extra-cranial pathway, represented by the nasal cavities, avoiding brain retraction and neurovascular manipulation. This is reflected by the patients' prompt clinical recovery and the low risk of permanent neurological sequelae, representing the main caveat of conventional skull base surgery. This surgery must be tailored to each specific case, considering its features and relationship with surrounding neural structures, mostly based on preoperative neuroimaging. Advanced MRI techniques, such as tractography, have been rarely adopted in skull base surgery due to technical issues: lengthy and complicated processes to generate reliable reconstructions for inclusion in the neuronavigation system. 
This paper aims to present the protocol implemented in the institution and highlights the synergistic collaboration and teamwork between neurosurgeons and the neuroimaging team (neurologists, neuroradiologists, neuropsychologists, physicists, and bioengineers) with the final goal of selecting the optimal treatment for each patient, improving the surgical results and pursuing the advancement of personalized medicine in this field.

We present a protocol to integrate diffusion MRI tractography in patient work-up to endoscopic endonasal surgery for a skull base tumor. The methods for adopting these neuroimaging studies in the pre- and intra-operative phases are described.

Endoscopic endonasal surgery has gained a prominent role in the management of complex skull base tumors. It allows the resection of a large group of ...

Activity of Posterior Lateral Line Afferent Neurons during Swimming in Zebrafish

Sensory systems gather cues essential for directing behavior, but animals must decipher what information is biologically relevant. Locomotion generates reafferent cues that animals must disentangle from relevant sensory cues of the surrounding environment. For example, when a fish swims, flow generated from body undulations is detected by the mechanoreceptive neuromasts, comprising hair cells, that compose the lateral line system. The hair cells then transmit fluid motion information from the sensor to the brain via the sensory afferent neurons. Concurrently, corollary discharge of the motor command is relayed to hair cells to prevent sensory overload. Accounting for the inhibitory effect of predictive motor signals during locomotion is, therefore, critical when evaluating the sensitivity of the lateral line system. We have developed an in vivo electrophysiological approach to simultaneously monitor posterior lateral line afferent neuron and ventral motor root activity in zebrafish larvae (4-7 days post fertilization) that can last for several hours. Extracellular recordings of afferent neurons are achieved using the loose patch clamp technique, which can detect activity from single or multiple neurons. Ventral root recordings are performed through the skin with glass electrodes to detect motor neuron activity. Our experimental protocol provides the potential to monitor endogenous or evoked changes in sensory input across motor behaviors in an intact, behaving vertebrate.

We describe a protocol to monitor changes in the afferent neuron activity during motor commands in a model vertebrate hair cell system.

Sensory systems gather cues essential for directing behavior, but animals must decipher what information is biologically relevant. Locomotion generates ...

Three-dimensional Navigation-guided, Prone, Single-position, Lateral Lumbar Interbody Fusion Technique

Lateral interbody fusion provides a significant biomechanical advantage over the traditional transforaminal lumbar interbody fusion due to the large implant size and optimal implant position. However, current methods for lateral interbody cage placement require either a two-staged procedure or a single lateral decubitus position that precludes surgeons from having either full access to the posterior spine for direct decompression or comfortable pedicle screw placement.
Herein is one institution's experience with 10 cases of a prone single-position approach for simultaneous access to the anterior and posterior lumbar spine. This allows both lateral lumbar interbody cage placement, direct posterior decompression, and pedicle screw placement, all in one position. Three-dimensional (3D) navigation is utilized for increased precision in both approaching the lateral spine and interbody cage placement. The traditional blind psoas muscle tubular dilation was also modified. Tubular retractors and lateral vertebral body retractor pins were used to minimize the risks to the lumbar plexus.

The single-position, prone, lateral approach allows for both lateral lumbar interbody placement and direct posterior decompression with pedicle screw placement in one position.

Lateral interbody fusion provides a significant biomechanical advantage over the traditional transforaminal lumbar interbody fusion due to the large ...

Primary Cultures of Rat Astrocytes and Microglia and Their Use in the Study of Amyotrophic Lateral Sclerosis

This protocol demonstrates how to prepare primary cultures of glial cells, astrocytes, and microglia from the cortices of Sprague Dawley rats and how to use these cells for the purpose of studying the pathophysiology of amyotrophic lateral sclerosis (ALS) in the rat hSOD1G93A model. First, the protocol shows how to isolate and culture astrocytes and microglia from postnatal rat cortices, and then how to characterize and test these cultures for purity by immunocytochemistry using the glial fibrillary acidic protein (GFAP) marker of astrocytes and the ionized calcium-binding adaptor molecule 1 (Iba1) microglial marker. In the next stage, methods are described for dye-loading (calcium-sensitive Fluo 4-AM) of cultured cells and the recordings of Ca2+ changes in video imaging experiments on live cells.
The examples of video recordings consist of: (1) cases of Ca2+ imaging of cultured astrocytes acutely exposed to immunoglobulin G (IgG) isolated from ALS patients, showing a characteristic and specific response compared to the response to ATP as demonstrated in the same experiment. Examples also show a more pronounced transient rise in intracellular calcium concentration evoked by ALS IgG in hSOD1G93A astrocytes compared to non-transgenic controls; (2) Ca2+ imaging of cultured astrocytes during a depletion of calcium stores by thapsigargin (Thg), a non-competitive inhibitor of the endoplasmic reticulum Ca2+ ATPase, followed by store-operated calcium entry elicited by the addition of calcium in the recording solution, which demonstrates the difference between Ca2+ store operation in hSOD1G93A and in non-transgenic astrocytes; (3) Ca2+ imaging of the cultured microglia showing predominantly a lack of response to ALS IgG, whereas ATP application elicited a Ca2+ change. This paper also emphasizes possible caveats and cautions regarding critical cell density and purity of cultures, choosing the correct concentration of the Ca2+ dye and dye-loading techniques.

We present here a protocol on how to prepare primary cultures of glial cells, astrocytes, and microglia from rat cortices for time-lapse video imaging of intracellular Ca2+ for research on pathophysiology of amyotrophic lateral sclerosis in the hSOD1G93A rat model.

This protocol demonstrates how to prepare primary cultures of glial cells, astrocytes, and microglia from the cortices of Sprague Dawley rats and how to ...