Marco Bueter and Florian Seyfried were supported by the Deutsche Forschungsgemeinschaft (DFG). Thomas A Lutz was supported by the Swiss National Research Foundation (SNF). Marco Bueter and Thomas A Lutz further receive funding from the National Institute of Health (NIH) and from the Zurich Center for Integrative Human Physiology (ZIHP). Carel W le Roux was supported by a Department of Health Clinician scientist award. Imperial College London receives support from the NIHR Biomedical Research Centre funding scheme.

1. Preoperative Care
<ol>
	<li>Remove food from rat overnight prior to surgery.</li>
	<li>Induce anaesthesia in chamber with 4-5% isoflurane and O2 flow of 2 l/min.</li>
	<li>Shave abdomen from sternum to pelvis using electric razor.</li>
	<li>Place anaesthetised rat in supine position on isothermal heating pad.</li>
	<li>Apply eye ointment (Vitagel) before placing the rats' snout in nosecone.</li>
	<li>Maintain anaesthesia with isoflurane concentration of 2-3% and O2 flow of 2 l/min.</li>
	<li>Disinfect skin with Betadine-Solution.</li>
	<li>Confirm depth of anaesthesia with forceps pinch between toes of hind leg.</li>
	<li>Administer 5.7 mg/kg Enrofloxacin intraperitoneally as perioperative antibiotic prophylaxis, and 1 mg/kg Flunixin for analgesia.</li>
</ol>
2. Median Laparotomy
<ol>
	<li>Perform midline incision using scalpel starting just below xyphoid process (Blade No. 10).</li>
	<li>Mobilise skin circumferentially from underlying abdominal muscles using Metzenbaum scissors.</li>
	<li>Open abdominal cavity.</li>
	<li>Install retractors to facilitate best possible exposure of the operation field.</li>
</ol>
3. Biliopancreatic and Alimentary Limb
<ol>
	<li>Identify where the duodenum or proximal jejunum passes under the colon.</li>
	<li>Transect small bowel about 10 cm aborally from here and ligate both ends of the gut (PDS 5-0).</li>
	<li>Place proximal stump of the two ends in left upper quadrant of abdomen as it will be later used to form the biliopancreatic limb of Roux-en-Y reconstruction.</li>
	<li>Place distal stump of the two ends in right upper quadrant of abdomen as it will be later used to form the alimentary limb of Roux-en-Y reconstruction.</li>
</ol>
4. Jejuno-Jejunostomy
<ol>
	<li>Identify caecum with ileocoecal valve and ileum.</li>
	<li>Follow ileum orally for approximately 25 cm. The Jejuno-Jejunostomy will be placed here as starting point of the common channel of Roux-en-Y reconstruction.</li>
	<li>Retrieve biliopancreatic limb from left upper quadrant of abdomen and position it next to common channel where you plan to perform Jejuno-Jejunostomy.</li>
	<li>Secure biliopancreatic limb and common channel with retention stitch (PDS 6-0).</li>
	<li>Incise both loops over approximate 10 mm by using micro scissors.</li>
	<li>Create Jejuno-Jejunostomy by performing side-to-side anastomosis using interrupted sutures (PDS 6-0).</li>
	<li>First complete dorsal side and then ventral side of anastomosis.</li>
</ol>
5. Gastric Pouch
<ol>
	<li>Identify gastro-oesophageal junction.</li>
	<li>Mobilise this area by dissecting gastro-hepatic and gastro-splenic ligaments using Metzenbaum scissors.</li>
	<li>Move left gastric artery and vagal fibres of left para-oesophageal bundle laterally to prevent major bleedings and vagal nerve damage when small gastric pouch is created.</li>
	<li>Expose gastro-oesophageal junction by placing cotton swab retro-oesophageally.</li>
	<li>Coagulate small vessels of frontal stomach by using commercially available cautery device - also to prevent bleedings.</li>
	<li>Transect stomach approximately 5 mm below gastro-oesophageal junction creating gastric pouch of a size of no more than 2-3% of original stomach size using delicate, curved scissors.</li>
	<li>Close gastric remnant (PDS 5-0).</li>
</ol>
6. Gastro-Jejunostomy
<ol>
	<li>Retrieve alimentary limb from right upper quadrant of abdomen and position it next to gastric pouch.</li>
	<li>Create Gastro-Jejunostomy by performing end-to-side anastomosis (PDS 7-0).</li>
	<li>First complete back side and then front side of anastomosis.</li>
</ol>
7. Abdominal Closure
<ol>
	<li>Reduce anaesthesia by reducing isoflurane concentration to 1.5%.</li>
	<li>Close muscle layer of abdominal wall using continuous sutures (PDS 4-0).</li>
	<li>Administer 100 &mu;l of 0.3 mg/ml buprenorphine solution subcutaneously for analgesia.</li>
	<li>Further reduce isoflurane concentration down to 1%.</li>
	<li>Close the skin using interrupted sutures (Vicryl 4-0).</li>
</ol>
8. Postoperative Care
<ol>
	<li>Stop isoflurane and continue with O2.</li>
	<li>Administer 5 ml of warm saline for fluid replacement in three subcutaneous depots.</li>
	<li>Position rat under red light until full recovery.</li>
	<li>Return the rat to home cage.</li>
</ol>
9. Representative Results
Animals and housing
Male Wistar rats (Harlan Laboratories Inc., Blackthorn, UK; Elevage Janvier, Le-Genest-St. Isle, France) weighing between 350 and 500 g were individually housed under a 12 h /12 h light-dark cycle at a room temperature of 21&plusmn;2 &deg;C. Water and standard chow were available ad libitum, unless otherwise stated. All experiments were performed under a license issued by the Home Office, UK (PL70-6669) or approved by the Veterinary Office of the Canton Zurich, Switzerland. All rats were given one week of acclimatization before being randomized to gastric bypass or sham-operation. After surgery, rats received liquid diet for 3 days before access to normal chow was reinstalled.
Body weight
Data of our rat gastric bypass model are consistent with previous findings that gastric bypass surgery is effective to reduce body weight and especially to maintain body weight loss (Figure 2). Average pre-surgical body weight of rats used for gastric bypass and sham-operations was similar (sham: 433.4 &plusmn; 8.3 g vs. bypass: 420.7 &plusmn; 8.4 g, p= 0.28). Five days after surgery sham-operated controls weighed significantly more compared to gastric bypass rats (sham: 422.2 &plusmn; 8.3 g vs. bypass: 374.7 &plusmn; 7.6 g, p&lt;0.001). On postoperative day 60, difference in body weight was almost 170 g (sham: 533.2 &plusmn; 8.1 g vs. bypass: 366.2 &plusmn; 10.8 g, p&lt;0.001).
Food intake
Food intake followed similar patterns as body weight and was reduced in gastric bypass rats when compared to sham-operated ad libitum fed rats. Figure 3 shows the average daily food intake for both groups (postoperative day 1-60). Daily food intake was consistently lower after gastric bypass (sham: 29.9 &plusmn; 0.2 g vs. bypass: 25.7 &plusmn; 0.3 g, p&lt;0.001).
Gut hormones
Blood from all rats was collected on the day of study termination 8,16. Animals had ad libitum food access the night before and were decapitated at the beginning of the light cycle on postoperative day 60. Blood was obtained, immediately centrifuged at 3000 rpm for 10 minutes at 4&deg;C, and stored at -20&deg;C until the samples were assayed in duplicate in a single run. PYY-like immunoreactivity was measured with a specific and sensitive radioimmunoassay, which measures, both the full length (PYY1-36) and the fragment (PYY3-36). GLP-1 was measured by established in-house radioimmunoassays17,18. Differences in food intake may be partly explained by increased postprandial plasma levels of peptide YY (PYY) and glucagon-like peptide 1 (GLP-1) as gastric bypass rats showed significantly higher levels for PYY (sham: 26 &plusmn; 2 pmol/L vs. bypass: 141 &plusmn; 14 pmol/L, p&lt;0.001) and GLP-1 (sham: 40 &plusmn; 5 pmol/L vs. bypass: 215 &plusmn; 23 pmol/L, p&lt;0.001; Figure 4).
<img alt="Figure 1" src="/files/ftp_upload/3940/3940fig1.jpg" /> 
Figure 1. Gastric bypass anatomy. Schematic illustration of the small bowel anatomy before (A) and after (B) gastric bypass operation. The different shades of red approximately represent corresponding segments of the small bowel with the medium red representing the foregut (oesophagus, stomach duodenum and proximal jejunum), the light red representing the midgut (proximal and mid jejunum, proximal ileum) and the dark red representing the hindgut (ileum, caecum).
<img alt="Figure 2" src="/files/ftp_upload/3940/3940fig2.jpg" /> 
Figure 2. Body weight loss after gastric bypass surgery in rats. Body weight change for a representative group of rats after gastric bypass (- -) (n=52) and sham-operated rats (- -) (n=52) throughout an observation period of 60 days. Data were pooled from previous publications6,8-10 and are shown as mean values &plusmn; SEM (*** = p&lt;0.001).
<img alt="Figure 3" src="/files/ftp_upload/3940/3940fig3.jpg" /> 
Figure 3. Average food intake after gastric bypass surgery in rats. Average daily food intake of a representative group of rats after gastric bypass (black, n=52) and sham-operated rats (white, n=52) throughout a postoperative period of 60 days. Data were pooled from previous publications6,8-10 and are shown as mean values &plusmn; SEM.
<img alt="Figure 3" src="/files/ftp_upload/3940/3940fig3.jpg" /> 
Figure 4. Postprandial PYY and GLP-1 serum levels after gastric bypass surgery in rats. Postprandial PYY and GLP-1 serum level for gastric bypass rats (black, n=18) and sham-operated rats (white, n=22). Data were pooled from previous publications8,16 and are shown as mean values &plusmn; SEM.

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C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+common+hepatic+branch+of+the+vagus+is+not+required+to+mediate+the+glycemic+and+food+intake+suppressive+effects+of+glucagon-like-peptide-1.">The common hepatic branch of the vagus is not required to mediate the glycemic and food intake suppressive effects of glucagon-like-peptide-1.</a> Am. J. Physiol. Regul. Integr. Comp. Physiol. 301, R1479-R1485 (2011).</li></ol>

No conflicts of interest declared.

The Roux-en-Y gastric bypass procedure in humans was first described by Mason in 1967 and modified to its current form by Torres in 198319. Currently, the procedure consists of a small gastric pouch and the bypass of the proximal small bowel. A schematic illustration of the pre- and postoperative anatomy is given in Figure 1.
Gastric bypass in humans induces and maintains body weight loss of approximately 15-30%2. The majority of body weight is lost durin...

<table border="1">
	<tbody>
		<tr>
			<td>Generic name</td>
			<td>Brand name</td>
			<td>Company</td>
			<td>Catalogue number</td>
		</tr>
		<tr>
			<td>Enrofloxacin</td>
			<td>Baytril 2.5%</td>
			<td>Provet AG</td>
			<td>1036</td>
		</tr>
		<tr>
			<td>Flunixin</td>
			<td>Finadyne</td>
			<td>Graeub</td>
			<td>908040</td>
		</tr>
		<tr>
			<td>Buprenorphin</td>
			<td>Temgesic</td>
			<td>Reckitt Benckiser</td>
			<td>138976</td>
		</tr>
		<tr>
			<td>Isoflurane</td>
			<td>IsoFlo</td>
			<td>Graeub</td>
			<td>902035</td>
		</tr>
		<tr>
			<td>Vitamin A</td>
			<td>Vitagel</td>
			<td>Bausch &amp; Lomb</td>
			<td>690</td>
		</tr>
		<tr>
			<td>Iodine solution</td>
			<td>Betadine</td>
			<td>Mundipharma</td>
			<td>111141</td>
		</tr>
		<tr>
			<td>NaCl 0.9%</td>
			<td>NaCl 0.9%</td>
			<td>B. Braun</td>
			<td>534534</td>
		</tr>
	</tbody>
</table>
Table 1. Drugs.
<table border="1">
	<tbody>
		<tr>
			<td>Name</td>
			<td>Size</td>
			<td>Company</td>
			<td>Catalogue number</td>
		</tr>
		<tr>
			<td>PDS II</td>
			<td>4-0</td>
			<td>Ethicon</td>
			<td>Z924H</td>
		</tr>
		<tr>
			<td>PDS II</td>
			<td>5-0</td>
			<td>Ethicon</td>
			<td>Z925H</td>
		</tr>
		<tr>
			<td>PDS II</td>
			<td>6-0</td>
			<td>Ethicon</td>
			<td>PUU2971E</td>
		</tr>
		<tr>
			<td>PDS II</td>
			<td>7-0</td>
			<td>Ethicon</td>
			<td>Z1370E</td>
		</tr>
		<tr>
			<td>Vicryl</td>
			<td>4-0</td>
			<td>Ethicon</td>
			<td>V451H</td>
		</tr>
	</tbody>
</table>
Table 2. Sutures.
<table border="1">
	<tbody>
		<tr>
			<td>Name</td>
			<td>Company</td>
			<td>Catalogue number</td>
		</tr>
		<tr>
			<td>Scalpel handle No. 3</td>
			<td>Aesculap</td>
			<td>BB073R</td>
		</tr>
		<tr>
			<td>Scalpel blades No. 10</td>
			<td>Swann-Morton</td>
			<td>0301</td>
		</tr>
		<tr>
			<td>Needle holder</td>
			<td>Aesculap</td>
			<td>BM124R</td>
		</tr>
		<tr>
			<td>Tissue forceps</td>
			<td>Aesculap</td>
			<td>BD555R</td>
		</tr>
		<tr>
			<td>Metzenbaum scissors, straight</td>
			<td>Aesculap</td>
			<td>BC022R</td>
		</tr>
		<tr>
			<td>Metzenbaum scissors, curved</td>
			<td>Aesculap</td>
			<td>BC023R</td>
		</tr>
		<tr>
			<td>Delicate scissors, curved</td>
			<td>Aesculap</td>
			<td>BC061R</td>
		</tr>
		<tr>
			<td>Artery forceps, curved</td>
			<td>Aesculap</td>
			<td>BH109R</td>
		</tr>
		<tr>
			<td>Artery forceps, curved, 1x2 teeth</td>
			<td>Aesculap</td>
			<td>BH121R</td>
		</tr>
		<tr>
			<td>Probe, double-ended</td>
			<td>Aesculap</td>
			<td>BN113R</td>
		</tr>
		<tr>
			<td>Micro needle holder</td>
			<td>Aesculap</td>
			<td>FM 541R</td>
		</tr>
		<tr>
			<td>Micro forceps</td>
			<td>Aesculap</td>
			<td>FM571R</td>
		</tr>
		<tr>
			<td>Micro scissors</td>
			<td>Aesculap</td>
			<td>FM470R</td>
		</tr>
		<tr>
			<td>Disposable eye cautery</td>
			<td>John Weiss International</td>
			<td>0111122</td>
		</tr>
		<tr>
			<td>Cotton buds</td>
			<td>Hartmann AG</td>
			<td>9679369</td>
		</tr>
	</tbody>
</table>
Table 3. Surgical equipment.

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.

Watch this Scientific Journal Video about Roux-en-Y Gastric Bypass Operation in Rats at JoVE.com

Roux-en-Y Gastric Bypass Operation in Rats

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 ...

roux-en-y-gastric-bypass-operation-in-rats

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JoVE Journal

Medicine

23.4K Views.  University Hospital Zürich. 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.

Video: Roux-en-Y Gastric Bypass Operation in Rats

Acute Myocardial Infarction in Rats

With heart failure leading the cause of death in the USA (Hunt), biomedical research is fundamental to advance medical treatments for cardiovascular diseases. Animal models that mimic human cardiac disease, such as myocardial infarction (MI) and ischemia-reperfusion (IR) that induces heart failure as well as pressure-overload (transverse aortic constriction) that induces cardiac hypertrophy and heart failure (Goldman and Tarnavski), are useful models to study cardiovascular disease. In particular, myocardial ischemia (MI) is a leading cause for cardiovascular morbidity and mortality despite controlling certain risk factors such as arteriosclerosis and treatments via surgical intervention (Thygesen). Furthermore, an acute loss of the myocardium following myocardial ischemia (MI) results in increased loading conditions that induces ventricular remodeling of the infarcted border zone and the remote non-infarcted myocardium. Myocyte apoptosis, necrosis and the resultant increased hemodynamic load activate multiple biochemical intracellular signaling that initiates LV dilatation, hypertrophy, ventricular shape distortion, and collagen scar formation. This pathological remodeling and failure to normalize the increased wall stresses results in progressive dilatation, recruitment of the border zone myocardium into the scar, and eventually deterioration in myocardial contractile function (i.e. heart failure). The progression of LV dysfunction and heart failure in rats is similar to that observed in patients who sustain a large myocardial infarction, survive and subsequently develops heart failure (Goldman). The acute myocardial infarction (AMI) model in rats has been used to mimic human cardiovascular disease; specifically used to study cardiac signaling mechanisms associated with heart failure as well as to assess the contribution of therapeutic strategies for the treatment of heart failure. The method described in this report is the rat model of acute myocardial infarction (AMI). This model is also referred to as an acute ischemic cardiomyopathy or ischemia followed by reperfusion (IR); which is induced by an acute 30-minute period of ischemia by ligation of the left anterior descending artery (LAD) followed by reperfusion of the tissue by releasing the LAD ligation (Vasilyev and McConnell). This protocol will focus on assessment of the infarct size and the area-at-risk (AAR) by Evan's blue dye and triphenyl tetrazolium chloride (TTC) following 4-hours of reperfusion; additional comments toward the evaluation of cardiac function and remodeling by modifying the duration of reperfusion, is also presented. Overall, this AMI rat animal model is useful for studying the consequence of a myocardial infarction on cardiac pathophysiological and physiological function.

The rat model of acute myocardial infarction (AMI) is useful to study the consequence of a MI on cardiac pathophysiological and physiological function.

With heart failure leading the cause of death in the USA (Hunt), biomedical research is fundamental to advance medical treatments for cardiovascular ...

Orthotopic Liver Transplantation in Rats

Clinical progress in the field of liver transplantation has been largely supported by animal models1,2. Since the publication of the first orthotopic rat liver transplantation in 1979 by Kamada et al.3, this model has remained the gold standard despite various proposed alternative techniques4. Nevertheless, its broader use is limited by its steep learning curve5.
In this video paper, we show a simple and easy-to-establish revision of Kamada's two-cuff technique. The suprahepatic vena cava anastomosis is performed manually with a running suture, and the vena porta and infrahepatic vena cava anastomoses are performed utilizing a quick-linker cuff system6. Manufacturing the quick-linker kit is shown in a separate video paper.

We present an easy-to-establish revision of the classical two-cuff technique for orthotopic liver transplantation in rat.

Clinical progress in the field of liver transplantation has been largely supported by animal models1,2. Since the publication of the first orthotopic rat ...

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.

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 ...

Vein Interposition Model: A Suitable Model to Study Bypass Graft Patency

Bypass grafting is an established treatment method for coronary artery disease. Graft patency continues to be the Achilles heel of saphenous vein grafts. Research models for bypass graft failure are essential for a better understanding of pathobiological and pathophysiological processes during graft patency loss. Large animal models, such as pigs or sheep, resemble human anatomical structures but require special facilities and equipment. This video describes a rat vein interposition model to investigate vein graft patency loss. Rats are inexpensive and easy to handle. Compared to mouse models, the convenient size of rats permits better operability and enables a sufficient amount of material to be obtained for further diverse analysis. In brief, the inferior epigastric vein of a donor rat is harvested and used to replace a segment of the femoral artery. Anastomosis is conducted via single stitches and sealed with fibrin glue. Graft patency can be monitored non-invasively using duplex sonography. Myointimal hyperplasia, which is the main cause for graft patency loss, develops progressively over time and can be calculated from histological cross sections.

This video demonstrates a model to study the development of myointimal hyperplasia after venous interposition surgery in rats.

Bypass grafting is an established treatment method for coronary artery disease. Graft patency continues to be the Achilles heel of saphenous vein grafts. ...

Techniques of Sleeve Gastrectomy and Modified Roux-en-Y Gastric Bypass in Mice

Obesity is a major public health issue, with a prevalence of 4 to 28% for men and 6.2 to 36.5% for women in Europe (from 2003 to 2008). Morbid obesity is frequently associated with metabolic complications, such as type 2 diabetes, hypertension, and dyslipidemia, reducing life expectancy and quality. In the absence of any effective noninvasive treatments, bariatric surgery is a valuable therapeutic option for patients with morbid obesity (body mass index (BMI) &#62;40 kg/m2), leading to long-term, sustained weight loss and improvements in metabolic complications. However, the underlying cellular and molecular mechanisms sustaining the beneficial effects of bariatric surgery are not yet fully understood. Due to the numerous genetically-modified strains available, the mouse model is the most convenient animal model to explore the molecular mechanisms behind the pleiotropic beneficial effects of bariatric surgeries. Here, we detailed the optimized healthcare methods and surgical protocols in mice for the two most widely-used bariatric surgeries: the sleeve gastrectomy and the modified Roux-en-Y gastric bypass. Deciphering the molecular mechanisms underlying the therapeutic effects of bariatric surgeries offers the promise of identifying new therapeutics targets.

Bariatric surgery is the most efficient way to reduce body weight and the deadly metabolic complications (diabetes, obesity, and dyslipidemia) frequently associated with morbid obesity. Mouse models of bariatric surgery represent a unique asset for deciphering molecular mechanisms behind the beneficial effects of these surgeries on diabetes, hypertension, and dyslipidemia.

Obesity is a major public health issue, with a prevalence of 4 to 28% for men and 6.2 to 36.5% for women in Europe (from 2003 to 2008). Morbid obesity is ...

Cardiopulmonary Bypass in a Mouse Model: A Novel Approach

As prolonged cardiopulmonary bypass becomes more essential during cardiac interventions, an increasing clinical demand arises for procedure optimization and for minimizing organ damage resulting from prolonged extracorporal circulation. The goal of this paper was to demonstrate a fully functional and clinically relevant model of cardiopulmonary bypass in a mouse. We report on the device design, perfusion circuit optimization, and microsurgical techniques. This model is an acute model, which is not compatible with survival due to the need for multiple blood drawings. Because of the range of tools available for mice (e.g., markers, knockouts, etc.), this model will facilitate investigation into the molecular mechanisms of organ damage and the effect of cardiopulmonary bypass in relation to other comorbidities.

This paper describes how to perform cardiopulmonary bypass in mice. This novel model will facilitate the investigation of the molecular mechanisms involved in organ damage.

As prolonged cardiopulmonary bypass becomes more essential during cardiac interventions, an increasing clinical demand arises for procedure optimization ...

One-anastomosis Gastric Bypass (OAGB) in Rats

The goal of this protocol is to set up a preclinical model of bariatric surgery and, more specifically, OAGB in obese rats. Based on this preclinical model, longitudinal studies can be carried out to provide an improved understanding of the mechanisms underlying the outcomes seen after bariatric surgery in humans. For this purpose, rats are operated on through a laparotomy under general anesthesia with isoflurane. First, the surgeon creates a long and tubular gastric pouch: after greater curve and hiatal dissection, the nonglandular stomach is stapled and removed. Then, the remaining stomach is also stapled in order to create a gastric tube and exclude the antrum of the stomach. After that, the surgeon performs a single end-to-side gastrojejunostomy 35 cm from the duodenojejunal angle. This limb length has been chosen in order to reproduce the same ratio between the biliopancreatic limb (BPL) and common limb (CL) length as in human bariatric surgery. The operation ends by aponeurotic and cutaneous closure. The early postoperative management consists of subcutaneous hydration, an intramuscular prophylactic antibiotic injection, a parietal injection of xylocaine, the administration of painkillers, and a progressive reintroduction of diet.

One-anastomosis Gastric Bypass OAGB in Rats

This protocol is for the performance of one-anastomosis gastric bypass (OAGB) on rat. The operator performs a long and tubular-stapled gastric pouch followed by hand-sewn anastomosis. For this model, the operator reproduces the same ratio between biliopancreatic and common limb in humans; therefore, the biliopancreatic limb measures 35 cm.

The goal of this protocol is to set up a preclinical model of bariatric surgery and, more specifically, OAGB in obese rats. Based on this preclinical ...

Preparation of Decellularized Kidney Scaffolds in Rats

Tissue engineering is a cutting-edge discipline in biomedicine. Cell culture techniques can be applied for regeneration of functional tissues and organs to replace diseased or damaged organs. Scaffolds are needed to facilitate the generation of three-dimensional organs or tissues using differentiated stem cells in vivo. In this report, we describe a novel method for developing vascularized scaffolds using decellularized rat kidneys. Eight-week-old Sprague-Dawley rats were used in this study, and heparin was injected into the heart to facilitate flow into the renal vessels, allowing heparin to perfuse into the renal vessels. The abdominal cavity was opened, and the left kidney was collected. The collected kidneys were perfused for 9 h using detergents, such as Triton X-100 and sodium dodecyl sulfate, to decellularize the tissue. Decellularized kidney scaffolds were then gently washed with 1% penicillin/streptomycin and heparin to remove cellular debris and chemical residues. Transplantation of stem cells with the decellularized vascular scaffolds is expected to facilitate the generation of new organs. Thus, the vascularized scaffolds may provide a foundation for tissue engineering of organ grafts in the future.

This protocol introduces a method to develop a scaffold using decellularized rat kidneys. The protocol includes decellularization and recellularization processes to confirm bioavailability. Decellularization is performed using Triton X-100 and sodium dodecyl sulfate.

Tissue engineering is a cutting-edge discipline in biomedicine. Cell culture techniques can be applied for regeneration of functional tissues and organs ...

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 ...

Robotic Central Pancreatectomy with Roux-en-Y Pancreaticojejunostomy

Central pancreatectomy is a parenchyma-sparing alternative to distal pancreatectomy in patients with a benign or low-grade malignant tumor in the body of the pancreas. The aim of central pancreatectomy is to prevent postoperative life-long endocrine and exocrine insufficiency. The downside of central pancreatectomy is the high rate of postoperative pancreatic fistula, which is the main reason that many surgeons do not routinely use central pancreatectomy in eligible patients. Most studies report open or laparoscopic central pancreatectomy with a pancreatico-gastrostomy anastomosis in adults. This is the first description of a standardized approach to robotic central pancreatectomy with Roux-en-Y pancreaticojejunostomy reconstruction in an adolescent (16-year-old boy) with a pseudopapillary tumor in the body of the pancreas. The operation time was 248 min with 20 mL of blood loss. The postoperative course was uneventful except for the short-term medical treatment for a grade B pancreatic fistula. Robotic central pancreatectomy can be safely applied in selected patients in experienced centers.

Robotic central pancreatectomy may be used in selected patients in experienced centers. This protocol presents all steps and the feasibility of a robotic central pancreatectomy with Roux-en-Y pancreaticojejunostomy in a 16-year-old adolescent patient.

Central pancreatectomy is a parenchyma-sparing alternative to distal pancreatectomy in patients with a benign or low-grade malignant tumor in the body of ...