The C-seal project is a part of the collaboration between the department of surgery of the University Medical Center Groningen (UMCG) and Polyganics BV. The project was initially supported by a SenterNovem Grant of the Dutch Ministry of Economic Affairs. Intellectual property, commercial interest and patent are held by Polyganics BV. Intellectual interest is held by the UMCG. Polyganics BV has manufactured the devices for this study. The study was performed in the UMCG.

Fabrication of the C-seal
The C-Seal is made of biodegradable polyurethane, composed of hard and soft molecular components. The hard component provides the material the desirable elastic and mechanical properties. The hard component consists of polyurethane bindings (HNCO2) composed of a di-isocyanate (OCN-NCO) and a diol (HO-OH).
The soft segment determines the degradation behavior of the polyurethane. The soft segment is called the prepolymer and consists of polyether-ester chains. The hard segment is incorporated into the soft segment. This incorporation is called 'chain-extension' of the polymerization.
Once these two segments interact, a poly-ether-ester-urethane is synthesized and the polymer is ready to be processed into a C-Seal:
<ol>
<li>	The polymer is diluted to a concentration suitable for spray coating.</li>
<li>	The polyurethane solution is sprayed on a rotating mould to a certain thickness.</li>
<li>	The mould is placed into a water bath in order to release the C-seal safely from the mould without causing damage.</li>
<li>	The C-seal is dried.</li>
<li>	The C-Seal is packaged in a Tyvek pouch and sterilized using EtO gas.</li>
<li>	After sterilization, the C-Seal is ready for use.</li>
</ol>
Surgical Procedure
The patient has given informed consent for participation in the C-seal study.
<ol>
<li>	The patient is positioned in the supine position in stirrups, the abdomen and perineum is disinfected and the patient is covered with sterile drapes.</li>
<li>	Establishment of pneumoperitoneum or laparotomy via midline incision.</li>
<li>	Inspection of the liver and abdominal cavity.</li>
<li>	Mobilization of the sigmoid colon and mobilization of the splenic flexure.</li>
<li>	In open surgery: division of the sigmoid colon at the level of the proximal resection margin.</li>
<li>	Right paramedian incision of the peritoneum, opening of the presacral plane; ligation and division of the superior rectal artery and vein.</li>
<li>	Mobilization of the mesorectum.</li>
<li>	Division of the rectum distally.</li>
<li>	In a laparoscopic setting: a suprapubic incision is performed to extract the specimen. Division of the proximal sigmoid colon.</li>
<li>	The C-seal can be used if the length of the rectal stump is max. 15 centimeters.</li>
<li>	The bowel diameter determines the stapler diameter; we prefer to use a CEA stapler with a diameter of 29 or 33 mm.</li>
<li>	The C-seal and a sterilized 12mm stainless steel marble are unpacked on a clean and sterile surface using clean and sterile surgical gloves.</li>
<li>	Open the C-seal, insert the marble and insert the anvil with the connection pin first. The two flaps in the opening of the C-seal are attached to the anvil using the two strips of adhesive tape.</li>
<li>	The anvil is advanced in the C-seal so that the connection pin 'punctures' the open pointed end of the C-seal. Gently unfold the C-seal completely and make sure the marble ends up inside the C-seal away from the anvil.</li>
<li>	Any type of anastomosis (end-to-end, end-to-side, side-to-end and side-to-side) can be performed when using the C-seal; we prefer to create a side-to-end anastomosis. There are multiple strategies to insert the anvil in the proximal bowel loop. The C-seal does not interfere with any of these strategies (open bowel end with pursestring suture/longitudinal bowel incision) </li>
<li>	Insert the anvil together with the C-seal in de proximal bowel loop by first advancing the C-seal with help of the marble and, if necessary, a blunt forceps. Ensure the tail of the C-seal is placed upwards in the bowel and check that the tail of the C-seal is stretched; check the position of the marble (the marble should be at adequate distance of the anvil). Then penetrate the bowel wall with the anvil's pin and create a pursestring suture around the pin.</li>
<li>	Gently dilate the anus and insert the stapler in the rectal stump. Connect the anvil with the stapler. Check for torsion of the bowel.</li>
<li>	Fire the circular stapler. Now, the bowel ends are connected and the C-seal is attached to the staples </li>
<li>	Gently pull the stapler out of the anus. Do not turn the stapler more than 180 degrees when pulling out (the C-seal may twist). By removing the stapler from the rectum, the C-seal is pulled through the anus. Cut the C-seal at a distance of approximately 4 cm from the anus.</li>
<li> Remove the marble from the rectum. Often the marble comes out together with the C-seal. If not, gently manually remove the marble which is situated between the C-seal and the intestinal wall.</li>
<li>	Verify the anastomosis. Optionally, perform an air-test by filling the pelvis with a saline solution and inject air into the anal canal (within the C-seal and between the C-seal and bowel). The absence of bubbles confirms a complete anastomosis.</li>
<li>	If indicated, create a protective stoma.</li>
<li>	In a laparoscopic setting: exsufflation of the abdominal cavity and trocars extraction.</li>
<li>	Close the incision(s)</li>
<li>	Postoperative phase: 
Postoperative recovery is according to the ERAS (enhanced recovery after surgery) protocol9. The C-seal should be left in situ for at least one week. The patient has no restrictions and can lose stool via the C-seal. When the patient has recovered well and no anastomotic complications are suspected, the C-seal may be cut at the level of the anus. The remaining C-seal will degrade and the patient will lose the C-seal together with the stool via the natural route.</li>
</ol>
Representative Results
When the C-seal is applied correctly (figure 2 and 3), it covers the anastomosis. If a dehiscence is formed at the anastomotic site or distal from the anastomosis in the proximal rectal stump, extravasation of feces is prevented since the C-seal covers the defect and directs the fecal matter through the anus. In the postoperative phase, the C-seal protrudes from the anus (figure 3).
<img src="/files/ftp_upload/2223/2223fig1.jpg" alt="Figure 1" /> 
Figure 1: Schematic drawing of the C-seal. 
<img src="/files/ftp_upload/2223/2223fig2.jpg" alt="Figure 2" /> 
Figure 2: Schematic representation of attaching the C-seal to the stapler head.
<img src="/files/ftp_upload/2223/2223fig3.jpg" alt="Figure 3" /> 
Figure 3: After inserting the stapler-head together with the attached C-seal in the proximal bowel and the stapler in the rectal stump, the stapler is fired and gently pulled through the anus together with the C-seal.

<ol>
	<li>Peeters, K. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Risk+factors+for+anastomotic+failure+after+total+mesorectal+excision+of+rectal+cancer.">Risk factors for anastomotic failure after total mesorectal excision of rectal cancer.</a> Br. J. Surg. 92, 211-216 (2005).</li><li>Dehni, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influence+of+a+defunctioning+stoma+on+leakage+rates+after+low+colorectal+anastomosis+and+colonic+J+pouch-anal+anastomosis.">Influence of a defunctioning stoma on leakage rates after low colorectal anastomosis and colonic J pouch-anal anastomosis.</a> Br. J. Surg. 85, 1114-1117 (1998).</li><li>Matthiessen, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Risk+factors+for+anastomotic+leakage+after+anterior+resection+of+the+rectum.">Risk factors for anastomotic leakage after anterior resection of the rectum.</a> Colorectal Dis. 8, 366-366 (2006).</li><li>Laxamana, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Long-term+results+of+anterior+resection+using+the+double-stapling+technique.">Long-term results of anterior resection using the double-stapling technique.</a> Dis. Colon Rectum. 38, 1246-1250 (1995).</li><li>Jung, S. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Risk+factors+and+oncologic+impact+of+anastomotic+leakage+after+rectal+cancer+surgery.">Risk factors and oncologic impact of anastomotic leakage after rectal cancer surgery.</a> Dis. Colon Rectum. 51, 902-908 (2008).</li><li>Ravo, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+intracolonic+bypass+procedure.">The intracolonic bypass procedure.</a> Int. J. Colorectal Dis. 2, 38-42 (1987).</li><li>Ye, F., Wang, D., Xu, X., Liu, F., Lin, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+intracolonic+bypass+secured+by+a+biodegradable+anastomotic+ring+to+protect+the+low+rectal+anastomosis.">Use of intracolonic bypass secured by a biodegradable anastomotic ring to protect the low rectal anastomosis.</a> Dis. Colon Rectum. 51, 109-115 (2008).</li><li>Hawley, P. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Causes+and+prevention+of+colonic+anastomotic+breakdown.">Causes and prevention of colonic anastomotic breakdown.</a> Dis. Colon Rectum. 16, 272-277 (1973).</li><li>Lassen, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Consensus+review+of+optimal+perioperative+care+in+colorectal+surgery:+Enhanced+Recovery+After+Surgery+(ERAS)+Group+recommendations.">Consensus review of optimal perioperative care in colorectal surgery: Enhanced Recovery After Surgery (ERAS) Group recommendations.</a> Arch. Surg. 144, 961-969 (2009).</li><li>Kolkert, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Protection+of+stapled+colorectal+anastomoses+with+a+biodegradable+device:+the+C-seal+feasibility+study.">Protection of stapled colorectal anastomoses with a biodegradable device: the C-seal feasibility study.</a> Am J of Surg. , .</li></ol>

IRB approval: Procedures involving human subjects have been approved by the Institutional Review Board (IRB) at the University Medical Center Groningen and the Dutch Central Committee of Research inv. Human Subjects (CCMO). No conflicts of interest declared.

The C-seal is a technique aimed at preventing anastomotic leakage in stapled colorectal anastomoses. It can be used in laparoscopic surgery as well as during a laparotomy. The C-seal does not prevent anastomotic dehiscence; however, it prevents leakage of feces outside the bowel lumen.
When applying the C-seal, extra care should be taken at the moment the C-seal is inserted in the proximal bowel loop. Adequate positioning of the C-seal in the proximal bowel loop is important, since it is theoretically possible to double staple the C-seal. Double stapling of the C-seal occurs when the tail of the C-seal is folded and ends up between the stapler and the stapler head. The marble helps in determining the position of the C-seal in the proximal bowel loop. The marble should be positioned at adequate distance of the stapler head, to guarantee that the C-seal tail is stretched and can not become stapled together with the anastomosis.
The C-seal can be positioned in the proximal bowel loop in different ways. If a side-to-end anastomosis is preferred, we advise to perform this according to the following protocol: The C-seal is inserted via the open bowel end, tail first followed by the stapler head. The connection pin is then penetrated through the bowel wall by stabbing it in the direction of the open bowel end. Subsequently, the open bowel end is closed and a pursestring suture is placed around the connection pin for extra support. The pin is connected to the stapler, the position of the marble is checked and the stapler is fired.
If an end-to-end anastomosis is preferred, the C-seal is inserted in the open proximal bowel end, tail first. A pursestring suture encircles the bowel end around the connection pin. The pin is connected to the stapler, the position of the marble is checked and the stapler is fired.
In a pilot study initiated by the University Medical Center Groningen, the C-seal was employed in 15 patients undergoing resection of the rectum followed by a stapled anastomoses10. No clinical or subclinical AL was diagnosed in these patients. Currently, a phase II study testing the C-seal in another 35 patients is recruiting.

<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>Stainless Steel Marble</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
</tr>
<tr>
<td>C-seal</td>
<td>&nbsp;</td>
<td>Polyganics</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
</tr>
		</tbody>
		</table>

the c-seal: a biofragmentable drain protecting the stapled colorectal anastomosis from leakage

Colorectal anastomotic leakage (AL) is a serious complication in colorectal surgery leading to high morbidity and mortality rates1. The incidence of AL varies between 2.5 and 20% 2-5. Over the years, many strategies aimed at lowering the incidence of anastomotic leakage have been examined6, 7. 
The cause of AL is probably multifactorial. Etiological factors include insufficient arterial blood supply, tension on the anastomosis, hematoma and/or infection at the anastomotic site, and co-morbid factors of the patient as diabetes and atherosclerosis8. Furthermore, some anastomoses may be insufficient from the start due to technical failure.
Currently a new device is developed in our institute aimed at protecting the colorectal anastomosis and lowering the incidence of AL. This so called C-seal is a biofragmentable drain, which is stapled to the anastomosis with the circular stapler. It covers the luminal side of the colorectal anastomosis thereby preventing leakage.
The C-seal is a thin-walled tube-like drain, with an approximate diameter of 4 cm and an approximate length of 25 cm (figure 1). It is a tubular device composed of biodegradable polyurethane. Two flaps with adhesive tape are found at one end of the tube. These flaps are used to attach the C-seal to the anvil of the circular stapler, so that after the anastomosis is made the C-seal can be pulled through the anus. The C-seal remains in situ for at least 10 days. Thereafter it will lose strength and will degrade to be secreted from the body together with the gastrointestinal natural contents.
The C-seal does not prevent the formation of dehiscences. However, it prevents extravasation of faeces into the peritoneal cavity. This means that a gap at the anastomotic site does not lead to leakage.
Currently, a phase II study testing the C-seal in 35 patients undergoing (colo-)rectal resection with stapled anastomosis is recruiting. The C-seal can be used in both open procedures as well as laparoscopic procedures. The C-seal is only applied in stapled anastomoses within 15cm from the anal verge. In the video, application of the C-seal is shown in an open extended sigmoid resection in a patient suffering from diverticular disease with a stenotic colon.

Watch this Scientific Journal Video about The C-seal: A Biofragmentable Drain Protecting the Stapled Colorectal Anastomosis from Leakage at JoVE.com

The C-seal: A Biofragmentable Drain Protecting the Stapled Colorectal Anastomosis from Leakage

The C-seal is a biofragmentable drain protecting the stapled colorectal anastomosis. In this video, details of the manufacturing, deployment and use are shown.

Colorectal anastomotic leakage (AL) is a serious complication in colorectal surgery leading to high morbidity and mortality rates1. The incidence of AL ...

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21.8K Views.  University Medical Center Groningen. The C-seal is a biofragmentable drain protecting the stapled colorectal anastomosis. In this video, details of the manufacturing, deployment and use are shown.

Video: The C-seal: A Biofragmentable Drain Protecting the Stapled Colorectal Anastomosis from Leakage

Flexible Colonoscopy in Mice to Evaluate the Severity of Colitis and Colorectal Tumors Using a Validated Endoscopic Scoring System

The use of modern endoscopy for research purposes has greatly facilitated our understanding of gastrointestinal pathologies. In particular, experimental endoscopy has been highly useful for studies that require repeated assessments in a single laboratory animal, such as those evaluating mechanisms of chronic inflammatory bowel disease and the progression of colorectal cancer. However, the methods used across studies are highly variable. At least three endoscopic scoring systems have been published for murine colitis and published protocols for the assessment of colorectal tumors fail to address the presence of concomitant colonic inflammation. This study develops and validates a reproducible endoscopic scoring system that integrates evaluation of both inflammation and tumors simultaneously. This novel scoring system has three major components: 1) assessment of the extent and severity of colorectal inflammation (based on perianal findings, transparency of the wall, mucosal bleeding, and focal lesions), 2) quantitative recording of tumor lesions (grid map and bar graph), and 3) numerical sorting of clinical cases by their pathological and research relevance based on decimal units with assigned categories of observed lesions and endoscopic complications (decimal identifiers). The video and manuscript presented herein were prepared, following IACUC-approved protocols, to allow investigators to score their own experimental mice using a well-validated and highly reproducible endoscopic methodology, with the system option to differentiate distal from proximal endoscopic colitis (D-PECS).

Over the past few years, new generation endoscopes have emerged as important diagnostic research aids for evaluating murine colitis and colorectal tumors. We present herein a detailed protocol for endoscopic assessment of inflammation and colorectal tumors in mice, as well as a novel scoring system that uses decimal identifiers to document the endoscopic severity of colitis and colorectal tumors.

The use of modern endoscopy for research purposes has greatly facilitated our understanding of gastrointestinal pathologies. In particular, experimental ...

Murine Ileocolic Bowel Resection with Primary Anastomosis

Intestinal resections are frequently required for treatment of diseases involving the gastrointestinal tract, with Crohn&#8217;s disease and colon cancer being two common examples. Despite the frequency of these procedures, a significant knowledge gap remains in describing the inherent effects of intestinal resection on host physiology and disease pathophysiology. This article provides detailed instructions for an ileocolic resection with primary end-to-end anastomosis in mice, as well as essential aspects of peri-operative care to maximize post-operative success. When followed closely, this procedure yields a 95% long-term survival rate, no failure to thrive, and minimizes post-operative complications of bowel obstruction and anastomotic leak. The technical challenges of performing the procedure in mice are a barrier to its wide spread use in research. The skills described in this article can be acquired without previous surgical experience. Once mastered, the murine ileocolic resection procedure will provide a reproducible tool for studying the effects of intestinal resection in models of human disease.

Ileocolic resection is commonly performed in several human diseases; however, little is known regarding the impact of intestinal resection on surgical illnesses. This article provides instruction on executing the procedure in mice with high success, providing a means to study the effects of ileocolic resection in models of disease.

Intestinal resections are frequently required for treatment of diseases involving the gastrointestinal tract, with Crohn&#8217;s disease and colon cancer ...

Isolation and Propagation of Circulating Tumor Cells from a Mouse Cancer Model

Cancer metastasis is the foremost cause of cancer-associated deaths. Recent studies have shown that circulating tumor cells (CTCs) are important in cancer metastasis. Indeed, the number of CTCs correlates with tumor size. Here, a detailed description is provided of a methodology for isolation and propagation of CTCs from a syngeneic mouse model of hepatocellular carcinoma (HCC) which allows for downstream analysis of potentially important molecular mechanisms of solid organ tumor metastasis. This method is efficient and reproducible. It is a non-invasive technique and, therefore, has potential to replace the invasive biopsy of tissues from humans which may be associated with complications. Therefore, the method discussed here allows for the isolation and propagation of CTCs from whole blood samples such that they can be examined and characterized. This has potential for future adaptation for clinical applications such as diagnosis, and personalized targeted therapy.

Circulating tumor cells (CTCs) have been shown to play an important role in tumor metastasis. Here, a method for the isolation and propagation of CTCs from the whole blood of a syngeneic mouse tumor model of hepatocellular carcinoma (HCC) metastasis is described.

Cancer metastasis is the foremost cause of cancer-associated deaths. Recent studies have shown that circulating tumor cells (CTCs) are important in cancer ...

Vessel-sparing Excision and Primary Anastomosis

Urethroplasty is considered to be the standard treatment for urethral strictures since it provides excellent long-term success rates. For isolated short bulbar or posterior urethral strictures, urethroplasty by excision and primary anastomosis (EPA) is recommended. As EPA only requires the excision of the narrowed segment and the surrounding spongiofibrosis, a full-thickness transection of the corpus spongiosum, as performed in the traditional transecting EPA (tEPA), is usually unnecessary. Jordan et al. introduced the idea of a vessel-sparing approach in 2007, aiming to reduce surgical trauma, especially to the dual arterial blood supply of the urethra, and, thus, potentially reducing the risk of postoperative erectile dysfunction or glans ischemia. This approach could also be beneficial for subsequent urethral interventions such as redo urethroplasty using a free graft, in which a well-vascularized graft bed is imperative. Nevertheless, these potential benefits are only assumptions as prospective studies comparing the functional outcome of both techniques with validated questionnaires are currently lacking. Moreover, vessel-sparing EPA (vsEPA) should at least be able to provide similar surgical outcomes as tEPA. The aim of this paper is to give an elaborate, step-by-step overview of how to manage patients with isolated short bulbar or posterior urethral strictures with vsEPA. The main objective of this manuscript is to outline the surgical technique and to report the representative surgical outcome. A total of 117 patients were managed according to the described protocol. The analysis was performed on the entire patient cohort and on the bulbar (n = 91) and posterior (n = 26) vsEPA group separately. Success rates were 93.4% and 88.5% for the bulbar and posterior vsEPA, respectively. To conclude, vsEPA, as outlined in the protocol, provides excellent success rates with low complication rates for isolated short bulbar and posterior urethral strictures.

Here, we present an elaborate and efficient protocol to treat isolated short bulbar or posterior urethral strictures with vessel-sparing excision and primary anastomosis.

Urethroplasty is considered to be the standard treatment for urethral strictures since it provides excellent long-term success rates. For isolated short ...

Creation of Colonic Anastomosis in Mice

Intestinal anastomoses are commonly performed in both elective and emergent operations. Even so, anastomotic leaks are a highly feared complications of colonic surgeries and can occur in up to 26% of surgical anastomoses, with mortality being up to 39% for patients with such a leak. Currently, there remains a paucity of data detailing the cellular mechanisms of anastomotic healing. Devising preventative strategies and treatment modalities for anastomotic leak could be greatly potentiated by a better understanding of appropriate anastomotic healing.
A murine model is ideal as previous studies have shown that the murine anastomosis is the most clinically similar to the human case as compared with other animal models. We offer an easily reproducible murine model of colonic anastomosis in mice that will allow for further illustration of anastomotic healing.

Anastomotic leak or breakdown after surgery is a major cause of postoperative morbidity and mortality. Our surgery for creating a colonic anastomosis is a reliable and reproducible method for studying the healing mechanisms of anastomoses.

Intestinal anastomoses are commonly performed in both elective and emergent operations. Even so, anastomotic leaks are a highly feared complications of ...

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 ...

Murine Appendectomy Model of Chronic Colitis Associated Colorectal Cancer by Precise Localization of Caecal Patch

The human appendix has been recently implicated to play important biological roles in the pathogenesis of various complex diseases, such as colorectal cancer, inflammatory bowel disease, and Parkinson&#8217;s disease. To study the function of the appendix, a gut disease-associated murine appendectomy model has been established and its step-by-step protocol is described here. This report introduces a facile protocol for caecal patch removal in mice followed by the chemical induction of chronic colitis-associated colorectal cancer using a combination of dextran sulfate sodium (DSS) and azoxymethane (AOM). IgA specific cells and IgA concentration were significantly reduced upon removal of the caecal patch in male C57BL/6 mice&#160;compared to those in the sham group. Simultaneously administering 2% DSS and AOM resulted in nearly 80% mice survival in both sham and appendectomy groups without significant body weight loss. Histological results confirmed colonic inflammation and different degrees of adenocarcinoma. This model can be used for the study of the functional role of the appendix in maintaining gut microbiota homeostasis and pathogenesis of gut colitis and malignancies, as well as for the potential development of drug targeting therapies.

The presented protocol describes a facile surgical removal of the appendix (caecal patch) in a mouse followed by the induction of inflammatory bowel disease-associated colorectal cancer. This murine appendectomy model enables investigation of the biological role of the appendix in the pathogenesis of human gastrointestinal disease.

The human appendix has been recently implicated to play important biological roles in the pathogenesis of various complex diseases, such as colorectal ...

Establishing In Situ Closed Circuit Perfusion of Lower Abdominal Organs and Hind Limbs in Mice

Ex vivo perfusion is an important physiological tool to study the function of isolated organs (e.g. liver, kidneys). At the same time, due to the small size of mouse organs, ex vivo perfusion of bone, bladder, skin, prostate, and reproductive organs is challenging or not feasible. Here, we report for the first time an in situ lower body perfusion circuit in mice that includes the above tissues, but bypasses the main clearance organs (kidney, liver, and spleen). The circuit is established by cannulating the abdominal aorta and inferior vena cava above the iliac artery and vein and cauterizing peripheral blood vessels. Perfusion is performed via a peristaltic pump with perfusate flow maintained for up to 2 h. In situ staining with fluorescent lectin and Hoechst solution confirmed that the microvasculature was successfully perfused. This mouse model can be a very useful tool for studying pathological processes as well as mechanisms of drug delivery, migration/metastasis of circulating tumor cells into/from the tumor, and interactions of immune system with perfused organs and tissues.

A protocol is described for in situ perfusion of the mouse lower body, including the bladder, the prostate, sex organs, bone, muscle and foot skin.

Ex vivo perfusion is an important physiological tool to study the function of isolated organs (e.g. liver, kidneys). At the same time, due to the small ...

Application of a New Mesh Fixation Method in Laparoscopic Incisional Hernia Repair

Laparoscopic incisional hernia repair using intraperitoneal onlay mesh (IPOM) is one of the most widely used minimally invasive methods for repairing incisional hernias. The laparoscopic IPOM involves implanting the mesh into the abdominal cavity through laparoscopy to repair an abdominal wall hernia. In the IPOM surgery, after the closure of the hernia ring, an anti-adhesion mesh is placed laparoscopically. The correct placement of this mesh is critical to the success of the method, and surgical skills are required to achieve perfect placement. If the mesh placement is not mastered properly, the operation and anesthesia time will be prolonged. In addition, improper placement of the mesh can lead to serious consequences, such as intestinal obstruction and mesh infection. A "contraposition and alignment" mesh fixation method is described in this study, which involves pre-marking the fixation position of the mesh to reduce the difficulty of mesh placement. A properly placed mesh is completely flat on the peritoneum, the edges are not curled or wrapped, and the mesh is adhered firmly such that there is no displacement after removing the pneumoperitoneum pressure. The "contraposition and alignment" mesh fixation technique offers the advantages of reliable placement of the mesh and fewer complications than other techniques, and it is easy to learn and master. It also allows for positioning the nail gun in advance based on the anatomy of the incisional hernia. This enables the use of the minimum number of nails possible while still ensuring good fixation, which can reduce the occurrence of complications and reduce the cost of surgery. Thus, the mesh fixation method described here is highly suitable for clinical applications based on the aforementioned advantages.

Presented here is a method for improving the mesh placement in laparoscopic incisional hernia repair, which can shorten the time required for mesh fixation and reduce the occurrence of postoperative chronic pain.

Laparoscopic incisional hernia repair using intraperitoneal onlay mesh (IPOM) is one of the most widely used minimally invasive methods for repairing ...

Application of Laparoscopic Hepatectomy Combined with Intraoperative Microwave Ablation in Colorectal Cancer Liver Metastasis

Laparoscopic hepatectomy is a common treatment for colorectal cancer liver metastasis. Previously, a sufficient number of functional liver masses had to be maintained during laparoscopic hepatectomy, with a residual liver volume of &gt;40% in cirrhotic patients and &gt;30% in non-cirrhotic patients. The high incidence of complications such as bleeding, bile leakage, or liver failure due to the exposure and difficulty of the resection of specific liver segments such as S2 and S7 reduces the success rate of liver resection. At present, microwave ablation is mainly applied in the treatment of liver metastasis using a percutaneous approach, which makes it difficult to identify hidden parts or small lesions. For some liver segments, the percutaneous puncture of liver segment 7 (S7) is likely to pass through the thoracic cavity, and the percutaneous puncture of liver segment 2 (S2) adjacent to the diaphragm is likely to injure the diaphragm and heart; these issues restrict the application of percutaneous ablation in colorectal cancer liver metastasis. Considering multiple lesions, laparoscopic microwave ablation combined with hepatectomy was performed in this study. The location of the lesions was determined by contrast-enhanced ultrasound under laparoscopy, and small lesions that were difficult to detect before the operation were identified. For the scattered lesions, which had diameters less than 3 cm and were difficult to resect, ablation was adopted to substitute hepatectomy. This technique helped to more explicitly locate the tumors, simplified the operation procedures, reduced the risk of complications such as bleeding and bile leakage, shortened the operation time, accelerated the postoperative recovery, significantly improved the success rate of operation, and enhanced the clinical prognosis of colorectal cancer liver metastasis by surgical resection.

This protocol describes the laparoscopic resection of colorectal cancer liver metastases combined with ultrasound-guided microwave ablation. This technique can safely, effectively, and accurately treat refractory liver metastases &lt;3 cm, reduce postoperative complications, and accelerate the postoperative rehabilitation of patients.

Laparoscopic hepatectomy is a common treatment for colorectal cancer liver metastasis. Previously, a sufficient number of functional liver masses had to ...