This study was supported by a grant from the National R&amp;D Program for Cancer Control, Ministry of Health &amp; Welfare, Republic of Korea (1320270).

Ethics Statement: This procedure involving human subjects has been approved by the Institutional Review Board (IRB) at Ajou University Hospital.
1. Preparation for Surgery
<ol>
	<li>Allow a soft diet one day before surgery, with nothing by mouth after midnight before the surgery. 
	Note: Do not insert a nasogastric tube before and during the surgery. This protocol does not use any tube to deflate the stomach. Instead of that, the intra-gastric gas can be aspirated by laparoscopic puncture needle if the stomach is distended causing limited view for laparoscopic surgery.</li>
	<li>After placing the patient on the operating table, administer the induction agent (Thiopental Sodium, 100 mg).</li>
	<li>After intravenous injection of a muscle relaxant (Rocuronium bromide, 1.0 mg/kg), insert the endotracheal tube through the oral cavity.</li>
	<li>Start the anesthetic gas (Sevoflurane, 2 - 3%) via the endotracheal tube, then monitor the patient for stability during surgery.</li>
</ol>
2. Surgical Procedure before Intraoperative Gastroscopy
<ol>
	<li>Place the patient in reverse Trendelenburg position, and stand at the right side of the patient.</li>
	<li>Make 10 mm incision at the infraumbilical area, and insert the first trocar into the abdominal cavity.</li>
	<li>As soon as the trocar is inserted, connect the gas tube for carbon dioxide with the trocar to create a pneumoperitoneum of 15 - 18 mm Hg.</li>
	<li>Insert a rigid 30&#176; laparoscope through the trocar, and explore the abdominal cavity on a monitor connected with the laparoscopic system.</li>
	<li>Insert 4 additional trocars (one 12 mm and three 5 mm) as working ports. Insert 12 mm trocar at the right upper side of the umbilicus. Insert other three 5 mm trocars at left upper side of the umbilicus and both upper outer quadrants of the abdomen.</li>
	<li>Dissect the gastrocolic ligament along the transverse colon toward the inferior pole of the spleen using ultrasonic endoscopic scissors.</li>
	<li>Ligate the left gastroepiploic artery and vein originating from splenic vessels at the root with a laparoscopic clip and resect them using ultrasonic endoscopic scissors, after exposure of the superior border of the pancreatic tail.</li>
	<li>Using ultrasonic endoscopic scissors, dissect the peripyloric lymph nodes around the pylorus and the head of the pancreas, and resect the right gastroepiploic vessels at their origin.</li>
	<li>Before resection of the first portion of the duodenum, clamp the duodenum with a laparoscopic clamp to prevent migration of gas into the small bowel during the gastroscopic procedure (Figure 1).</li>
</ol>
3. Intraoperative Gastroscopy
<ol>
	<li>Move to the left side of the patient&#39;s head to perform intraoperative gastroscopy.</li>
	<li>Insert a gum shield to protect the teeth and gums during intraoperative gastroscopy.</li>
	<li>Turn the head of the patient to the left side for insertion of the gastroscope.</li>
	<li>Insert the gastroscope into the stomach carefully through the mouth and the esophagus, to avoid injury to the mucosa of the oral cavity, the esophagus, and the stomach.</li>
	<li>Insufflate the stomach by injecting gas through the gastroscope to locate the primary lesion. 
	Note: Most gastroscopes have a specific button to inject gas into the bowel during the procedure.</li>
	<li>Approximate the distance between the proximal margin of the tumor and the esophagogastric junction using the scale marked on the gastroscope (Figure 2), and perform total gastrectomy (as described previously) if the distance is too short to salvage the proximal stomach.10</li>
	<li>If total gastrectomy is not necessary, insert an endoscopic injector through a small hole of the gastroscope, and inject 2 - 3 cc of indigo carmine into the gastric wall using an endoscopic injector at an area 2 - 3 cm proximal from the tumor margin, avoiding intra- or extraluminal leakage (Figure 3A).
	<ol>
		<li>Insert the needle of the injector into the gastric wall obliquely to avoid the perforation of gastric wall by the needle. In addition, inject indigo carmine very slowly to identify intraluminal leakage during injection.</li>
	</ol>
	</li>
	<li>After dye injection, aspirate inflation gas through the gastroscope to make the laparoscopic procedure easier. 
	Note: Most gastroscopes have a specific button to aspirate inflation gas during the procedure.</li>
</ol>
4. Procedure after Intraoperative Gastroscopy
<ol>
	<li>Return to the right side of the patient after the gastroscopic procedure.</li>
	<li>In the laparoscopic view, confirm the proximal portion of the tumor by identifying serosal staining by blue dye (Figure 3B).</li>
	<li>Mark the stained portion to be resected with an endoscopic clip, avoiding involvement of tumor at the resection margin (Figure 4A). 
	Note: We recommend performing this procedure within 5 - 10 min after surgery begins, because the dye can sometimes be washed out during subsequent procedures.</li>
	<li>If the dye cannot be detected in the serosa, immediately re-inject the dye under gastroscopic visualization.</li>
</ol>
5. Procedure after Intraoperative Gastroscopy
<ol>
	<li>Resect the duodenum, and perform other procedures for lymph node dissection according to the Japanese treatment guidelines.11</li>
	<li>After lymph node dissection, resect the stomach at the proper location at least 3 cm proximal from the tumor margin, guided by the marking clip, using 2 endoscopic staplers.</li>
	<li>As soon as the distal stomach is resected, insert the specimen into an endoscopic bag and withdraw it from the abdominal cavity through a 2 - 3 cm extension of the infraumbilical trocar site.</li>
	<li>Send the tissue from the proximal margin to pathology for intraoperative histological evaluation.</li>
	<li>After confirmation of tumor-free tissue in the proximal portion of the resected stomach, perform an anastomosis between the remaining stomach and the proximal jejunum with intracorporeal linear staplers (Figure 4B).</li>
</ol>

<ol>
	<li>Kim, Y. W., Yoon, H. M., Eom, B. W., Park, 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=History+of+minimally+invasive+surgery+for+gastric+cancer+in+Korea.">History of minimally invasive surgery for gastric cancer in Korea.</a> J Gastric Cancer. 12, 13-17 (2012).</li><li>Kim, H. 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=Morbidity+and+mortality+of+laparoscopic+gastrectomy+versus+open+gastrectomy+for+gastric+cancer:+an+interim+report--a+phase+III+multicenter,+prospective,+randomized+Trial+(KLASS+Trial).">Morbidity and mortality of laparoscopic gastrectomy versus open gastrectomy for gastric cancer: an interim report--a phase III multicenter, prospective, randomized Trial (KLASS Trial).</a> Ann Surg. 251, 417-420 (2010).</li><li>Kim, M. C., Kim, K. H., Kim, H. H., Jung, G. J. <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+laparoscopy-assisted+by+conventional+open+distal+gastrectomy+and+extraperigastric+lymph+node+dissection+in+early+gastric+cancer.">Comparison of laparoscopy-assisted by conventional open distal gastrectomy and extraperigastric lymph node dissection in early gastric cancer.</a> J Surg Oncol. 91, 90-94 (2005).</li><li>Kim, Y. 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=Improved+quality+of+life+outcomes+after+laparoscopy-assisted+distal+gastrectomy+for+early+gastric+cancer:+results+of+a+prospective+randomized+clinical+trial.">Improved quality of life outcomes after laparoscopy-assisted distal gastrectomy for early gastric cancer: results of a prospective randomized clinical trial.</a> Ann Surg. 248, 721-727 (2008).</li><li>Kinoshita, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+laparoscopy-assisted+and+total+laparoscopic+Billroth-I+gastrectomy+for+gastric+cancer:+a+report+of+short-term+outcomes.">Comparison of laparoscopy-assisted and total laparoscopic Billroth-I gastrectomy for gastric cancer: a report of short-term outcomes.</a> Surg Endosc. 25, 1395-1401 (2011).</li><li>Song, K. Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Is+totally+laparoscopic+gastrectomy+less+invasive+than+laparoscopy-assisted+gastrectomy?:+prospective,+multicenter+study.">Is totally laparoscopic gastrectomy less invasive than laparoscopy-assisted gastrectomy?: prospective, multicenter study.</a> J Gastrointest Surg. 12, 1015-1021 (2008).</li><li>Hyung, W. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intraoperative+tumor+localization+using+laparoscopic+ultrasonography+in+laparoscopic-assisted+gastrectomy.">Intraoperative tumor localization using laparoscopic ultrasonography in laparoscopic-assisted gastrectomy.</a> Surg Endosc. 19, 1353-1357 (2005).</li><li>Jeong, O., Cho, S. B., Joo, Y. E., Ryu, S. Y., Park, Y. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+technique+for+intraoperative+tumor+localization+during+totally+laparoscopic+distal+gastrectomy:+endoscopic+autologous+blood+tattooing.">Novel technique for intraoperative tumor localization during totally laparoscopic distal gastrectomy: endoscopic autologous blood tattooing.</a> Surg Endosc. 26, 1778-1783 (2012).</li><li>Kim, H. I., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intraoperative+portable+abdominal+radiograph+for+tumor+localization:+a+simple+and+accurate+method+for+laparoscopic+gastrectomy.">Intraoperative portable abdominal radiograph for tumor localization: a simple and accurate method for laparoscopic gastrectomy.</a> Surg Endosc. 25, 958-963 (2011).</li><li>Kim, H. I., Cho, I., Jang, D. S., Hyung, W. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intracorporeal+esophagojejunostomy+using+a+circular+stapler+with+a+new+purse-string+suture+technique+during+laparoscopic+total+gastrectomy.">Intracorporeal esophagojejunostomy using a circular stapler with a new purse-string suture technique during laparoscopic total gastrectomy.</a> J Am Coll Surg. 216, e11-e16 (2013).</li><li>Japanese Gastric Cancer Association. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Japanese+gastric+cancer+treatment+guidelines+2010+(ver.+3).">Japanese gastric cancer treatment guidelines 2010 (ver. 3).</a> Gast Can. 14, 113-123 (2011).</li><li>Lee, H. H., Song, K. Y., Park, C. H., Jeon, 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=Training+of+surgical+endoscopists+in+Korea:+assessment+of+the+learning+curve+using+a+cumulative+sum+model.">Training of surgical endoscopists in Korea: assessment of the learning curve using a cumulative sum model.</a> J Surg Educ. 69, 559-563 (2012).</li><li>Cho, W. Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hybrid+natural+orifice+transluminal+endoscopic+surgery:+endoscopic+full-thickness+resection+of+early+gastric+cancer+and+laparoscopic+regional+lymph+node+dissection--14+human+cases.">Hybrid natural orifice transluminal endoscopic surgery: endoscopic full-thickness resection of early gastric cancer and laparoscopic regional lymph node dissection--14 human cases.</a> Endoscopy. 43, 134-139 (2011).</li><li>Abe, 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=Endoscopic+full-thickness+resection+with+laparoscopic+assistance+as+hybrid+NOTES+for+gastric+submucosal+tumor.">Endoscopic full-thickness resection with laparoscopic assistance as hybrid NOTES for gastric submucosal tumor.</a> Surg Endosc. 23, 1908-1913 (2009).</li><li>Hoetker, M. 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=Molecular+in+vivo+imaging+of+gastric+cancer+in+a+human-murine+xenograft+model:+targeting+epidermal+growth+factor+receptor.">Molecular in vivo imaging of gastric cancer in a human-murine xenograft model: targeting epidermal growth factor receptor.</a> Gastrointest Endosc. 76, 612-620 (2012).</li><li>Ishihara, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Infrared+endoscopy+in+the+diagnosis+and+treatment+of+early+gastric+cancer.">Infrared endoscopy in the diagnosis and treatment of early gastric cancer.</a> Endoscopy. 42, 672-676 (2010).</li></ol>

The authors have no conflicts of interest or financial ties to disclose.

In this protocol, we introduced a procedure for intraoperative gastroscopy to accurately and reliably identify tumor location in the middle third of the stomach. We were able to successfully perform distal subtotal gastrectomy based on the findings of intraoperative gastroscopy.
To date, various methods have been applied to identify the location of early gastric cancer in the laparoscopic view. Most common methods used preoperative gastroscopic clipping, and surgeons could detect the location ...

Laparoscopic surgery has been become the treatment of choice for early gastric cancer in East Asian countries, including Korea and Japan.1 The advantage of this surgery has been well demonstrated in several clinical trials for early gastric cancer (EGC).2-4 Most of the procedures in these trials were accomplished by laparoscopy, but identification of the tumor location, resection of the stomach, including the primary tumor, and reconstruction were performed via minilaparotomy. Therefore, surgery requiring minilaparotomy has been labeled &#34;laparoscopy-assisted gastrectomy.&#34;
Recently, however, surgical procedures have evolved to minimize trauma, improving the postoperative quality of life for patients. Since this concept has also been applied in laparoscopic surgery for gastric cancer, some experienced laparoscopic surgeons have tried to avoid minilaparotomy. Totally laparoscopic gastrectomy (TLG) for gastric cancer requires that all procedures are completed using only laparoscopic devices, without requiring an additional minilaparotomy for specimen resection and anastomosis. Since this type of surgery results in less pain and faster recovery relative to open or laparoscopy-assisted surgery, which require laparotomy, more surgeons prefer it.5,6 However, an obstacle to TLG for gastric cancer is tumor localization without direct visualization or palpation to determine the area of stomach resection.
Tumor absence at the resection margin is very important to achieve success in gastric cancer surgery. If there is tumor involvement at the resection margin during distal gastrectomy for gastric cancer, additional resection is needed to avoid leaving tumor in the remaining stomach. In open and laparoscopy-assisted surgery, the primary tumor can be easily localized by palpation or direct visualization through a temporary gastrostomy. However, because the primary tumor is not easily detected in the laparoscopic view, determining resection margins for EGC in TLG may be difficult.
Several other methods requiring additional preoperative gastroscopy to determine resection margins have been proposed.7-9 However, additional preoperative gastroscopy can be inconvenient for patients. We introduced a procedure for intraoperative gastroscopy to directly mark tumors during TLG for gastric cancer in the middle third of the stomach.
In this protocol, we applied the laparoscopic surgery for patients with early gastric cancers at the preoperative studies, which are not included in absolute indication for endoscopic submucosal dissection.

<table border="0" cellpadding="0" cellspacing="0" width="717">
	<tbody>
		<tr height="20">
			<td height="20" style="height:20px;width:216px;">Pentothal Sodium</td>
			<td style="width:157px;">JW pharmatheutical Co.</td>
			<td style="width:119px;">644912100</td>
			<td style="width:225px;">It was used as induction asgent</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Rocumeron</td>
			<td style="width:157px;">&#160;Ilsung pharmatheutical Co.</td>
			<td style="width:119px;">655402960</td>
			<td style="width:225px;">It was used for general anesthestia as muscle relaxant.</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">SevoFRAN</td>
			<td style="width:157px;">Hana pharmatheutical Co.</td>
			<td style="width:119px;">657801060</td>
			<td style="width:225px;">It was used as general anesthetics</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:216px;">Endoscopy system</td>
			<td style="width:157px;">Olympus Corp.</td>
			<td style="width:119px;">CLV-260</td>
			<td style="width:225px;">It was used for intraoperative GFS</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Laparoscopic surgery system</td>
			<td style="width:157px;">Striker Endoscopy</td>
			<td style="width:119px;">1488 HD 3-CHIP</td>
			<td style="width:225px;">It was a system for laparoscopic surgery</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Ultrasonic scissor</td>
			<td style="width:157px;">Johnson and Johnson Medical Corp.</td>
			<td style="width:119px;">HAR23</td>
			<td style="width:225px;">It was used during tissue dissection</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Laparoscopic clip</td>
			<td style="width:157px;">Johnson and Johnson Medical Corp.</td>
			<td style="width:119px;">ER420</td>
			<td style="width:225px;">It was used for ligation of the vessels.</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Indigo carmine</td>
			<td style="width:157px;">Korea United Pharma</td>
			<td style="width:119px;">Carmine</td>
			<td style="width:225px;">It was injected into the gastric wall</td>
		</tr>
		<tr height="60">
			<td height="60" style="height:60px;width:216px;">Linear stapler</td>
			<td style="width:157px;">Johnson and Johnson Medical Corp.</td>
			<td style="width:119px;">ECHELON FLEX Powered Endopath Stapler</td>
			<td style="width:225px;">It was used for resection the stomach</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Gastroscopic injector</td>
			<td style="width:157px;">TaeWoong Medical</td>
			<td style="width:119px;">Cobra injector</td>
			<td style="width:225px;">I was used for gastroscopic injection of blue dye</td>
		</tr>
	</tbody>
</table>

intraoperative gastroscopy for tumor localization in laparoscopic surgery for gastric adenocarcinoma

Determining resection margins for gastric cancer, which are not exposed to the serosal surface of the stomach, is the most important procedure during totally laparoscopic gastrectomy (TLG). The aim of this protocol is to introduce a procedure for intraoperative gastroscopy, in order to directly mark tumors during TLG for gastric cancer in the middle third of the stomach. Patients who were diagnosed with adenocarcinoma in the middle third of the stomach were enrolled in this case series. Before surgery, additional gastroscopy for tumor localization is not performed. Under general anesthesia, laparoscopic mobilization of the stomach is performed first. After the first portion of the duodenum is mobilized from the pancreas and clamped, the surgeon moves to the other side for the gastroscopic procedure. On the insertion of a gastroscope through the oral cavity into the stomach, 2 - 3 cc of indigo carmine is administered via an endoscopic injector into the gastric muscle layer at the proximal margin of the stomach. The location of stained serosa in the laparoscopic view is used to guide distal subtotal gastrectomy, however, total gastrectomy is performed if the tumor is too close to the esophagogastric junction. A specimen is sampled after distal gastrectomy to confirm sufficient length from resection margin to tumor before reconstruction. In our case series, all patients had tumor-free margins and required no additional resection. There was no morbidity related to the gastroscopic procedure, and the time required for the procedure has gradually decreased to about five minutes. Intraoperative gastroscopy for tumor localization is an accurate and tolerated method for gastric cancer patients undergoing totally laparoscopic distal gastrectomy.

Of 20 patients who underwent intraoperative gastroscopy, 18 underwent distal subtotal gastrectomy, guided by findings at gastroscopy. However, we performed total gastrectomy on two patients, because the proximal tumor margin was too close to the esophagogastric junction, as determined on intraoperative gastroscopy. The distance from the tumor to the proximal resection margin was 3.5 cm and 2.5 cm in these two patients, respectively (Table 1).
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Watch this Scientific Journal Video about Intraoperative Gastroscopy for Tumor Localization in Laparoscopic Surgery for Gastric Adenocarcinoma at JoVE.com

Intraoperative Gastroscopy for Tumor Localization in Laparoscopic Surgery for Gastric Adenocarcinoma

In early gastric cancer, the aim of surgery is to precisely remove the distal stomach including the primary tumor. To do this, accurate localization of the tumor is crucial, especially in totally laparoscopic surgery. This protocol describes a procedure for intraoperative gastroscopy in totally laparoscopic subtotal gastrectomy.

Determining resection margins for gastric cancer, which are not exposed to the serosal surface of the stomach, is the most important procedure during ...

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12.6K Views.  Ajou University, School of Medicine. In early gastric cancer, the aim of surgery is to precisely remove the distal stomach including the primary tumor. To do this, accurate localization of the tumor is crucial, especially in totally laparoscopic surgery. This protocol describes a procedure for intraoperative gastroscopy in totally laparoscopic subtotal gastrectomy.

Video: Intraoperative Gastroscopy for Tumor Localization in Laparoscopic Surgery for Gastric Adenocarcinoma

Roux-en-Y Gastric Bypass Operation in Rats

Currently, the most effective therapy for the treatment of morbid obesity to induce significant and maintained body weight loss with a proven mortality benefit is bariatric surgery1,2. Consequently, there has been a steady rise in the number of bariatric operations done worldwide in recent years with the Roux-en-Y gastric bypass (gastric bypass) being the most commonly performed operation3. Against this background, it is important to understand the physiological mechanisms by which gastric bypass induces and maintains body weight loss. These mechanisms are yet not fully understood, but may include reduced hunger and increased satiation4,5, increased energy expenditure6,7, altered preference for food high in fat and sugar8,9, altered salt and water handling of the kidney10 as well as alterations in gut microbiota11. Such changes seen after gastric bypass may at least partly stem from how the surgery alters the hormonal milieu because gastric bypass increases the postprandial release of peptide-YY (PYY) and glucagon-like-peptide-1 (GLP-1), hormones that are released by the gut in the presence of nutrients and that reduce eating12.
During the last two decades numerous studies using rats have been carried out to further investigate physiological changes after gastric bypass. The gastric bypass rat model has proven to be a valuable experimental tool not least as it closely mimics the time profile and magnitude of human weight loss, but also allows researchers to control and manipulate critical anatomic and physiologic factors including the use of appropriate controls. Consequently, there is a wide array of rat gastric bypass models available in the literature reviewed elsewhere in more detail 13-15. The description of the exact surgical technique of these models varies widely and differs e.g. in terms of pouch size, limb lengths, and the preservation of the vagal nerve. If reported, mortality rates seem to range from 0 to 35%15. Furthermore, surgery has been carried out almost exclusively in male rats of different strains and ages. Pre- and postoperative diets also varied significantly.
Technical and experimental variations in published gastric bypass rat models complicate the comparison and identification of potential physiological mechanisms involved in gastric bypass. There is no clear evidence that any of these models is superior, but there is an emerging need for standardization of the procedure to achieve consistent and comparable data. This article therefore aims to summarize and discuss technical and experimental details of our previously validated and published gastric bypass rat model.

Numerous studies using gastric bypass rat models have been recently conducted to uncover the underlying physiological mechanisms of Roux-en-Y gastric bypass operations. This article aims to demonstrate and discuss the technical and experimental details of our published gastric bypass rat model to understand advantages and limitations of this experimental tool.

Currently, the most effective therapy for the treatment of morbid obesity to induce significant and maintained body weight loss with a proven mortality ...

Screening for Melanoma Modifiers using a Zebrafish Autochthonous Tumor Model

Genomic studies of human cancers have yielded a wealth of information about genes that are altered in tumors1,2,3. A challenge arising from these studies is that many genes are altered, and it can be difficult to distinguish genetic alterations that drove tumorigenesis from that those arose incidentally during transformation. To draw this distinction it is beneficial to have an assay that can quantitatively measure the effect of an altered gene on tumor initiation and other processes that enable tumors to persist and disseminate. Here we present a rapid means to screen large numbers of candidate melanoma modifiers in zebrafish using an autochthonous tumor model4 that encompasses steps required for melanoma initiation and maintenance. A key reagent in this assay is the miniCoopR vector, which couples a wild-type copy of the mitfa melanocyte specification factor to a Gateway recombination cassette into which candidate melanoma genes can be recombined5. The miniCoopR vector has a mitfa rescuing minigene which contains the promoter, open reading frame and 3'-untranslated region of the wild-type mitfa gene. It allows us to make constructs using full-length open reading frames of candidate melanoma modifiers. These individual clones can then be injected into single cell Tg(mitfa:BRAFV600E);p53(lf);mitfa(lf)zebrafish embryos. The miniCoopR vector gets integrated by Tol2-mediated transgenesis6 and rescues melanocytes. Because they are physically coupled to the mitfa rescuing minigene, candidate genes are expressed in rescued melanocytes, some of which will transform and develop into tumors. The effect of a candidate gene on melanoma initiation and melanoma cell properties can be measured using melanoma-free survival curves, invasion assays, antibody staining and transplantation assays.

A rapid way to screen for melanoma modifiers using a zebrafish autochthonous tumor model is presented. It takes advantage of the miniCoopR vector which allows for expression of candidate melanoma genes in melanocytes. A method to obtain melanoma-free survival curves, an invasion assay, a protocol for antibody staining of scale melanocytes and a melanoma transplantation assay are described.

Genomic studies of  human cancers have yielded a wealth of information about genes that are altered  in tumors1,2,3. A challenge arising from these ...

Assessing Specificity of Anticancer Drugs In Vitro

A procedure for assessing specificity of anticancer drugs in vitro using cultures containing both tumor and non-tumor cells is demonstrated. The key element is the quantitative determination of a tumor-specific genetic alteration in relation to a universal sequence using a dual-probe digital PCR assay and the subsequent calculation of the proportion of tumor cells. The assay is carried out on a culture containing tumor cells of an established line and spiked-in non-tumor cells. The mixed culture is treated with a test drug at various concentrations. After the treatment, DNA is prepared directly from the survived adhesive cells in wells of 96-well plates using a simple and inexpensive method, and subjected to a dual-probe digital PCR assay for measuring a tumor-specific genetic alteration and a reference universal sequence. In the present demonstration, a heterozygous deletion of the NF1 gene is used as the tumor-specific genetic alteration and a RPP30 gene as the reference gene. Using the ratio NF1/RPP30, the proportion of tumor cells was calculated. Since the dose-dependent change of the proportion of tumor cells provides an in vitro indication for specificity of the drug, this genetic and cell-based in vitro assay will likely have application potential in drug discovery. Furthermore, for personalized cancer-care, this genetic- and cell-based tool may contribute to optimizing adjuvant chemotherapy by means of testing efficacy and specificity of candidate drugs using primary cultures of individual tumors.

Assessing Specificity of Anticancer Drugs In Vitro

The goal of this protocol is to assess specificity of anticancer drugs in vitro using mixed cultures containing both tumor and non-tumor cells.

A procedure for assessing specificity of anticancer drugs in vitro using cultures containing both tumor and non-tumor cells is demonstrated. The key ...

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. ...

Intraoperative Ultrasound in Spinal Surgery

Since the 1980s, there have been several reports for the use of intraoperative ultrasound as a useful adjunct in spinal surgery. However, with the advent of newer cutting-edge imaging modalities, the use of intraoperative ultrasound in spine surgery has largely fallen out of favor. Despite this, intraoperative ultrasound continues to provide several advantages over other intraoperative techniques such as magnetic resonance imaging and computed tomography including being more cost-effective, efficient, and easy to operate and interpret. Additionally, it remains the only method for the real-time visualization of soft tissue and pathologies. This paper focuses on the advantages of using intraoperative ultrasound, especially in cases of intradural lesions and lesions ventral to the thecal sac when approaching posteriorly.

Here, we present a protocol on the use of intraoperative ultrasound in spinal surgery, particularly in cases of intradural lesions and lesions in the ventral spinal canal when using a posterior approach.

Since the 1980s, there have been several reports for the use of intraoperative ultrasound as a useful adjunct in spinal surgery. However, with the advent ...

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 ...

Laparoscopic Radical Left Pancreatectomy for Pancreatic Cancer: Surgical Strategy and Technique Video

Radical resection margins, resection of Gerota&#8217;s (perirenal) fascia, and adequate lymph node dissection are crucial for an adequate oncological resection of left-sided pancreatic cancer. Several surgical techniques have been described in recent years, but few were specifically designed for minimally invasive approaches. This study describes and demonstrates a standardized and reproducible technique for an adequate oncological resection of pancreatic cancer: laparoscopic radical left pancreatectomy (LRLP).
A 61-year-old woman presented with an incidental finding of a 3 cm mass in the left pancreas suspect for malignancy. Imaging did not reveal distant metastases, central vascular involvement, or morbid obesity, hence the patient was suitable for LRLP. This study describes the main steps of LRLP for pancreatic cancer. First, the lesser sac is opened by transecting the gastrocolic ligament. The splenic flexure of the colon is mobilized and the inferior border of the pancreas including Gerota&#39;s fascia is dissected down to the inferior border of the spleen. The pancreas is tunneled and hung, including Gerota&#8217;s fascia with a vessel loop. At the pancreatic neck, a tunnel is created between the pancreas and the portal vein, likewise a vessel loop is passed. The pancreas is then transected using the graded compression technique with an endostapler. Both the splenic vein and artery are transected before completing the resection. The entire specimen is extracted in a retrieval bag via a small Pfannenstiel incision.
Duration of the surgery was 210 min with 250 mL blood loss. Pathology revealed a R0-resection (&#62;1 mm) of a well-to-moderately differentiated adenocarcinoma originating from an intraductal papillary mucinous neoplasm. A total of 15 tumor-negative lymph nodes were resected. This is a detailed description of LRLP for left-sided pancreatic cancer as is currently being used within the international, multicenter randomized DIPLOMA (Distal Pancreatectomy Minimally Invasive or Open for PDAC) trial.

Oncologically safe left pancreatectomy requires radical resection (R0), Gerota&#8217;s (perirenal) fascia resection, and adequate lymph node dissection. This study describes the technical details of laparoscopic radical left pancreatectomy (LRLP), used in the first international multicenter randomized trial comparing minimally invasive with open left pancreatectomy for pancreatic cancer, the DIPLOMA trial.

Radical resection margins, resection of Gerota&#8217;s (perirenal) fascia, and adequate lymph node dissection are crucial for an adequate oncological ...

A Protocol for Roux-en-Y Gastric Bypass in Rats using Linear Staplers

Roux-en-Y gastric bypass (RYGB) is commonly performed for the treatment of severe obesity and type 2 diabetes. However, the mechanism of weight loss and metabolic changes are not well understood. Multiple factors are thought to play a role, including reduced caloric intake, decreased nutrient absorption, increased satiety, the release of satiety-promoting hormones, shifts in bile acid metabolism, and alterations in the gut microbiota.
The rat RYGB model presents an ideal framework to study these mechanisms. Prior work on mouse models have had high mortality rates, ranging from 17 to 52%, limiting their adoption. Rat models demonstrate more physiologic reserve to surgical stimulus and are technically easier to adopt as they allow for the use of surgical staplers. One challenge with surgical staplers, however, is that they often leave a large gastric pouch which is not representative of RYGB in humans. 
In this protocol, we present a RYGB protocol in rats that result in a small gastric pouch using surgical staplers. Utilizing two stapler fires which remove the forestomach of the rat, we obtain a smaller gastric pouch similar to that following a typical human RYGB. Surgical stapling also results in better hemostasis than sharp division. Additionally, the forestomach of the rat does not contain any glands and its removal should not alter the physiology of RYGB.
Weight loss and metabolic changes in the RYGB cohort were significant compared to the sham cohort, with significantly lower glucose tolerance at 14 weeks. Furthermore, this protocol has an excellent survival of 88.9% after RYGB. The skills described in this protocol can be acquired without previous microsurgical experience. Once mastered, this procedure will provide a reproducible tool for studying the mechanisms and effects of RYGB.

Roux-en-Y gastric bypass (RYGB) is performed to treat obesity and diabetes. However, the mechanisms underlying RYGB's efficacy are not fully understood, and studies are limited by technical difficulty leading to high mortality in animal models. This article provides instructions on how to perform RYGB in rats with high success rates.

Roux-en-Y gastric bypass (RYGB) is commonly performed for the treatment of severe obesity and type 2 diabetes. However, the mechanism of weight loss and ...

Laparoscopy-endoscopy Cooperative Surgery for the Treatment of Gastric Gastrointestinal Stromal Tumors

In view of the shortcomings of endoscopic or laparoscopic surgeries alone in the treatment of gastric gastrointestinal stromal tumors (G-GISTs), this approach makes an innovative improvement in the treatment of G-GISTs that are less than 5 cm in size. Laparoscopy-endoscopy cooperative surgery (LECS) is used to combine endoscopic and laparoscopic surgeries, fully realizing their respective advantages and avoiding their drawbacks. The main steps are as follows. First, gastroscopy and laparoscopy are combined to confirm the location and boundary of the tumor. Tumor resection is carried out laparoscopically, guided by a gastroscope. The specimen is removed orally and the gastric wound closed laparoscopically. Then, gastroscopy and laparoscopy are combined to determine whether there is wound bleeding, if the suture is satisfactory, and if the gastric cavity is deformed.
LECS has natural advantages in the treatment of G-GISTs that are less than 5 cm in size. The accurate estimation of tumor location and boundary greatly improves the complete resection rate of tumors. The risk of tumor rupture is substantially reduced, and the long-term prognosis of patients is significantly improved. The process allows for accurate resection of the tumor, maximum preservation of normal gastric tissue and organ function, and avoids postoperative gastric deformation. The patient's postoperative rehabilitation is greatly accelerated, and oral feeding can resume on the day of the operation. The specimen is taken out through the mouth to avoid the need for an extended abdominal incision. This greatly reduces the patient's postoperative pain and scarring. The method greatly shortens the postoperative hospital stay (i.e., discharge is possible on the day after the operation), increasing the turnover of hospital beds.

Laparoscopy-endoscopy cooperative surgery is appropriate for the treatment of gastric gastrointestinal stromal tumors less than 5 cm in size. It can achieve the respective advantages of endoscopic and laparoscopic surgeries while avoiding their drawbacks.

In view of the shortcomings of endoscopic or laparoscopic surgeries alone in the treatment of gastric gastrointestinal stromal tumors (G-GISTs), this ...

Fluorescent Laparoscopic Central Hepatectomy for Liver Cancer Using Indocyanine Green Negative Staining

Laparoscopic hepatectomy is an important treatment method for liver cancer. In the past, the resection boundary was usually determined by intraoperative ultrasound, important vascular structures, and surgeon experience. With the development of anatomical hepatectomy, visual surgery technology has gradually been applied to this type of surgery, particularly indocyanine green (ICG)-guided anatomical hepatectomy. As ICG can be specifically ingested by hepatocytes and used for fluorescence tracing, negative staining techniques have been applied according to different tumor positions. Under ICG fluorescent guidance, the surface boundary and deep resection plane can be more accurately displayed during liver resection. Thus, the tumor-bearing liver segment can be anatomically removed, which helps to avoid damage to important vessels and reduce ischemia or congestion of the remaining liver tissue. Finally, the incidence of postoperative biliary fistula and liver dysfunction is reduced; therefore, a better prognosis is obtained after the resection of liver cancer. Centrally located liver cancer is usually defined as a tumor located at segments 4, 5, or 8 that requires resection of the middle section of the liver. These are among the most difficult hepatectomies to perform because of the large surgical wounds and multiple vessel transections. Based on the specific tumor location, we formulated the required resection ranges by designing personalized fluorescent staining strategies. By completing anatomical resection based on the portal territory, this work aims to achieve the best therapeutic effect.

The present protocol describes fluorescent negative staining in laparoscopic central hepatectomy. This technique can make hepatectomy more accurate and precise.

Laparoscopic hepatectomy is an important treatment method for liver cancer. In the past, the resection boundary was usually determined by intraoperative ...