Name: minimizing post-infusion portal vein bleeding during intrahepatic islet transplantation in mice
Uploaded: 2021-05-10T15:00:00
Description: Watch this Scientific Journal Video about Minimizing Post-Infusion Portal Vein Bleeding during Intrahepatic Islet Transplantation in Mice at JoVE.com

This study was supported by the Department of Veterans Affairs (VA-ORD BLR&#38;D Merit I01BX004536), and the National Institute of Health grants # 1R01DK105183, DK120394, DK118529, to HW. We would like to thank you Mr. Michael Lee and Ms. Lindsay Swaby for language editing

All procedures were conducted with the approval of the Institutional Animal Care and Use Committees at the Medical University of South Carolina and the Ralph H Johnson Medical Center in Charleston.
1. Diabetes induction using streptozotocin (STZ)
<ol>
	<li>Recipient mice preparation:
	<ol>
		<li>Weigh all mice individually.</li>
		<li>Check blood glucose levels from a tail vein blood sample using a glucometer.</li>
	</ol>
	</li>
	<li>STZ dose determination for three different scenarios:
	<ol...

<ol>
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L., 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=Activated+protein+C+preserves+functional+islet+mass+after+intraportal+transplantation:+A+novel+link+between+endothelial+cell+activation,+thrombosis,+inflammation,+and+islet+cell+death.">Activated protein C preserves functional islet mass after intraportal transplantation: A novel link between endothelial cell activation, thrombosis, inflammation, and islet cell death.</a> Diabetes. 53 (11), 2804-2814 (2004).</li><li>Moberg, L., 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=Production+of+tissue+factor+by+pancreatic+islet+cells+as+a+trigger+of+detrimental+thrombotic+reactions+in+clinical+islet+transplantation.">Production of tissue factor by pancreatic islet cells as a trigger of detrimental thrombotic reactions in clinical islet transplantation.</a> Lancet. 360 (9350), 2039-2045 (2002).</li><li>Melzi, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intrahepatic+islet+transplant+in+the+mouse:+functional+and+morphological+characterization.">Intrahepatic islet transplant in the mouse: functional and morphological characterization.</a> Cell Transplantation. 17 (12), 1361-1370 (2008).</li><li>Wang, 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=Donor+treatment+with+carbon+monoxide+can+yield+islet+allograft+survival+and+tolerance.">Donor treatment with carbon monoxide can yield islet allograft survival and tolerance.</a> Diabetes. 54 (5), 1400-1406 (2005).</li><li>Desai, C. 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=Effect+of+liver+histopathology+on+islet+cell+engraftment+in+the+model+mimicking+autologous+islet+cell+transplantation.">Effect of liver histopathology on islet cell engraftment in the model mimicking autologous islet cell transplantation.</a> Islets. 9 (6), 140-149 (2017).</li><li>Cui, W., Angsana, J., Wen, J., Chaikof, E. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Liposomal+formulations+of+thrombomodulin+increase+engraftment+after+intraportal+islet+transplantation.">Liposomal formulations of thrombomodulin increase engraftment after intraportal islet transplantation.</a> Cell Transplantation. 19 (11), 1359-1367 (2010).</li><li>Cui, 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=Thrombomodulin+improves+early+outcomes+after+intraportal+islet+transplantation.">Thrombomodulin improves early outcomes after intraportal islet transplantation.</a> American Journal of Transplantation. 9 (6), 1308-1316 (2009).</li><li>Proto, C., Grasso, G., Fassio, P. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hepatoparenchymal+clearance+of+indocyanine+green+in+infectious+hepatitis.">Hepatoparenchymal clearance of indocyanine green in infectious hepatitis.</a> Giornale di Malattie Infettive e Parassitarie. 20 (9), 845-851 (1968).</li><li>Cabral, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Purification+of+hepatocytes+and+sinusoidal+endothelial+cells+from+mouse+liver+perfusion.">Purification of hepatocytes and sinusoidal endothelial cells from mouse liver perfusion.</a> Journal of Visualized Experiments. (132), e56993 (2018).</li><li>Khatri, R., Hussmann, B., Rawat, D., Gurol, A. O., Linn, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intraportal+transplantation+of+pancreatic+islets+in+mouse+model.">Intraportal transplantation of pancreatic islets in mouse model.</a> Journal of Visualized Experiments. (135), e57559 (2018).</li><li>Wang, 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=Autologous+mesenchymal+stem+cell+and+islet+cotransplantation:+Safety+and+efficacy.">Autologous mesenchymal stem cell and islet cotransplantation: Safety and efficacy.</a> Stem Cells Translational Medicine. 7 (1), 11-19 (2018).</li></ol>

In this study, two improved procedures that can prevent bleeding and may reduce mouse mortality during mouse IIT have been demonstrated. This study enables researchers to visualize the islet transplantation model that is unique in studying the instant blood mediated inflammatory response after transplantation. The IIT model is a distinctive model for studying islet cell survival and hepatic ischemic injuries in response to islet transplantation19. Here, we refined the procedure based on previous s...

Intraportal islet transplantation (IIT) via the portal vein is the most commonly used method for human islet transplantation in clinical settings. The mouse IIT model offers a great opportunity to study islet transplantation and test promising interventional approaches that can enhance the efficacy of islet transplantation1. IIT was first described in the 1970s and used by several groups1,2,3,4,5. It regained popularity after the breakthrough in human islet transplantation in the year 20006,7. However, most islet transplant studies used the kidney capsule as a preferred site for experimental islet transplantation due to its easy success. On the contrary, IIT is more technically challenging and less frequently used for islet transplantation studies8,9. Unlike IIT, however, islets transplanted under the kidney capsule do not suffer from the immediate blood-mediated inflammatory reaction characterized by thrombosis, inflammation, and hepatic tissue ischemia, and thus have better function than islets transplanted into the liver. The kidney capsule model, therefore, may not fully mimic the stresses encountered by islets in human islet transplantation10,11,12.
One of the major complications of IIT in mice is bleeding from the injection site after transplantation, which could cause 10-30% of mortality among different mouse strains12. In this paper, two refined approaches have been developed to stop bleeding more rapidly and securely and to reduce mouse mortality after an IIT. Visual demonstration of these refined details will help researchers identify the key steps of this technically challenging procedure.&#160;In addition, the location of the islet grafts in the recipient&#8217;s liver was determined by histological examination of the Hematoxylin and Eosin (H&#38;E) stained liver tissue (whole section) bearing transplanted islets.

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			<td>10% Neutral buffered formalin v/v</td>
			<td>Fisher Scientific</td>
			<td>23426796</td>
			<td></td>
		</tr>
		<tr>
			<td>1 mL Syringe with needle</td>
			<td>AHS</td>
			<td>AH01T</td>
			<td></td>
		</tr>
		<tr>
			<td>20 mL Syringe</td>
			<td>BD</td>
			<td>301031</td>
			<td></td>
		</tr>
		<tr>
			<td>25G x 5/8&#34; hypodermic needles</td>
			<td>BD</td>
			<td>305122</td>
			<td></td>
		</tr>
		<tr>
			<td>Alcohol prep pads, sterile</td>
			<td>Fisher Scientific</td>
			<td>22-363-750</td>
			<td></td>
		</tr>
		<tr>
			<td>Animal Anesthesia system</td>
			<td>VetEquip, Inc.</td>
			<td>901806</td>
			<td></td>
		</tr>
		<tr>
			<td>Buprenorphine hydrochloride, injection</td>
			<td>Par Sterile Products, LLC</td>
			<td>NDC 42023-179-05</td>
			<td></td>
		</tr>
		<tr>
			<td>Centrifuge tubes, 15 mL</td>
			<td>Fisher Scientific</td>
			<td>0553859A</td>
			<td></td>
		</tr>
		<tr>
			<td>CMRL-1066</td>
			<td>Corning</td>
			<td>15110CV</td>
			<td></td>
		</tr>
		<tr>
			<td>DMEM</td>
			<td>Corning</td>
			<td>10013CV</td>
			<td></td>
		</tr>
		<tr>
			<td>Ethanol, absolute (200 proof), molecular biology grade</td>
			<td>Fisher Scientific</td>
			<td>BP2818500</td>
			<td></td>
		</tr>
		<tr>
			<td>Extra fine Micro Dissecting scissors 4&#8221; straight sharp</td>
			<td>Roboz Surgical Instrument Co.</td>
			<td>RS-5882</td>
			<td></td>
		</tr>
		<tr>
			<td>Fetal bovine serum (FBS)</td>
			<td>Corning</td>
			<td>35011CV</td>
			<td></td>
		</tr>
		<tr>
			<td>FreeStyle&#160; Glucose meter</td>
			<td>Abbott</td>
			<td>Lite</td>
			<td></td>
		</tr>
		<tr>
			<td>FreeStyle Blood Glucose test strips</td>
			<td>Abbott</td>
			<td>Lite</td>
			<td></td>
		</tr>
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			<td>Gelfoam (absorbable gelatin sponge, USP)</td>
			<td>Pharmacia &#38; Upjohn Company</td>
			<td>34201</td>
			<td></td>
		</tr>
		<tr>
			<td>Graefe forceps 4&#8221; extra delicate tip</td>
			<td>Roboz Surgical Instrument Co.</td>
			<td>RS-5136</td>
			<td></td>
		</tr>
		<tr>
			<td>Heated pad</td>
			<td>Amazon</td>
			<td>B07HMKMBKM</td>
			<td></td>
		</tr>
		<tr>
			<td>Hegar-Baumgartner Needle Holder 5.25&#8221;</td>
			<td>Roboz Surgical Instrument Co.</td>
			<td>RS-7850</td>
			<td></td>
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			<td>Insulin syringe with 27-gauge needle</td>
			<td>BD</td>
			<td>879588</td>
			<td></td>
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		<tr>
			<td>Iodine prep pads</td>
			<td>Fisher Scientific</td>
			<td>19-027048</td>
			<td></td>
		</tr>
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			<td>Isoflurane</td>
			<td>Piramal Critical Care</td>
			<td>NDC 66794-017-25</td>
			<td></td>
		</tr>
		<tr>
			<td>Penicillin/streptomycin (P/S)</td>
			<td>HyClone</td>
			<td>SV30010</td>
			<td></td>
		</tr>
		<tr>
			<td>Polypropylene Suture 4-0</td>
			<td>Med-Vet International</td>
			<td>MV-8683</td>
			<td></td>
		</tr>
		<tr>
			<td>Polypropylene Suture 5-0</td>
			<td>Med-Vet International</td>
			<td>MV-8661</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium chloride, 0.9% intravenous solution</td>
			<td>VWR</td>
			<td>2B1322Q</td>
			<td></td>
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		<tr>
			<td>Streptozocin (STZ)</td>
			<td>Sigma</td>
			<td>S0130</td>
			<td></td>
		</tr>
		<tr>
			<td>Surgical drape, sterile</td>
			<td>Med-Vet International</td>
			<td>DR1826</td>
			<td></td>
		</tr>
		<tr>
			<td>Tissue Cassette</td>
			<td>Fisher Scientific</td>
			<td>22-272416</td>
			<td></td>
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minimizing post-infusion portal vein bleeding during intrahepatic islet transplantation in mice

Although the liver is currently accepted as the primary transplantation site for human islets in clinical settings, islets are transplanted under the kidney capsule in most rodent preclinical islet transplantation studies. This model is commonly used because murine intrahepatic islet transplantation is technically challenging, and a high percentage of mice could die from surgical complications, especially bleeding from the injection site post-transplantation. In this study, two procedures that can minimize the incidence of post-infusion portal vein bleeding are demonstrated. The first method applies an absorbable hemostatic gelatin sponge to the injection site, and the second method involves penetrating the islet injection needle through the fat tissue first and then into the portal vein by using the fat tissue as a physical barrier to stop bleeding. Both methods could effectively prevent bleeding-induced mouse death. The whole liver section showing islet distribution and evidence of islet thrombosis post-transplantation, a typical feature for intrahepatic islet transplantation, were presented. These improved protocols refine the intrahepatic islet transplantation procedures and may help laboratories set up the procedure to study islet survival and function in pre-clinical settings.

We performed syngeneic and xenogeneic islet transplantations via the portal vein. Islet graft function was observed in a dose-dependent manner in both islet transplantation models. In the syngeneic islet transplantation model using C57BL/6 mice, transplantation of 250 islets led to transitory normoglycemia before mice returned to hyperglycemia. Mice receiving 500 islets reached and maintained normoglycemia beyond 30 days after transplantation (Figure 2A). Mice in both groups showed increased...

Watch this Scientific Journal Video about Minimizing Post-Infusion Portal Vein Bleeding during Intrahepatic Islet Transplantation in Mice at JoVE.com

Minimizing Post-Infusion Portal Vein Bleeding during Intrahepatic Islet Transplantation in Mice

Here we present refined surgical procedures on successfully performing intraportal islet transplantation, a clinically relevant but technically challenging surgical procedure, in mice.

Although the liver is currently accepted as the primary transplantation site for human islets in clinical settings, islets are transplanted under the ...

Liver is a primary site for transplantation in the human islet clinical setting. Mouse intrahepatic islet transplantation is technically challenging, and a high percentage of mice could die from surgical complications, especially bleeding. In this study, the two methods we showed both could effectively prevent bleeding-induced mouse death.Our method can be applied to research in liver cancer and other liver diseases by allowing injection of cancer cells, mesenchymal stem cells, and hepatocyte directly to the liver. To begin, detach a human islet culture with gentle scratching. Use a 1 cubic centimeter syringe to pick 300 to 350 islets into sterile 1.5 milliliter microcentrifuge tubes on ice.When all of the islets have been picked, centrifuge the tubes for 10 seconds to sediment the cells. Discard all but a small volume of supernatant to prevent pellet loss and resuspend the islets in 200 microliters HBSS containing 5%BSA. Load the resuspended islets into a 5 milliliter insulin syringe and turn the syringe needle-end up for 1 minute to let the islets settle at the plunger.Depress the plunger to remove any bubbles, keeping approximately 100 to 150 microliters of solution in the syringe and invert the syringe with gentle tapping to evenly distribute the islets. After confirming a lack of response to pedal reflex, apply ointment to the eyes to prevent drying. Shave the abdomen of the anesthetized mouse to remove the fur and disinfect the surgical area with three alternating wipes of 2%iodine and 75%alcohol.Next, make a 1 to 1.5-centimeter incision in the abdomen and open the peritoneal cavity. Place a sterile piece of gauze around the incision and use forceps or cotton tips to gently transfer the intestine onto the gauze. The then cover the intestine with a piece of saline-soaked gauze and expose the portal vein.To stop islet transfer-induced bleeding using gel foam, hold the needle with the bevel facing down and position the needle tip with the opening parallel to the portal vein wall before inserting the needle into the portal vein. Retract the plunger to draw 20 to 50 microliters of blood into the syringe to mix with the islets before infusing the islets into the portal vein while repeatedly depressing and retracting the plunger. When all of the islets have been delivered, place an approximately 5 by 5 centimeter piece of gel foam over the injection site.Use a cotton tip to press the gel foam down while removing the needle from the portal vein. Hold the gel in place for about 2 minutes, rolling the gel foam to make sure it covers the portal vein. Once the bleeding is stopped, gently return the intestine to the peritoneal cavity in the original position and inject 500 microliters of warm saline into the abdominal cavity.Use sutures to close the muscle and skin layers. Then place the mouse in a clean cage on a heating pad with monitoring until complete recovery from anesthesia, administering analgesia every 12 hours and heat for 48 hours. To stop islet transfer-induced bleeding using a fat pad, after exposing the portal vein as demonstrated, use two cotton tips to hold the exposed vein on the left and right sides and locate the fat tissue pad between the duodenum and portal vein.Penetrate the fat pad with the needle tip before insertion into the portal vein. Infuse the islets into the portal vein as demonstrated. When all of the islets have been delivered, press the fat tissue with a cotton tip for about 1 minute while removing the needle from the vein.Then return the intestine to the abdominal cavity and perform the rest of the postsurgical care procedures as demonstrated. The effects of the islet transplantation are dose-dependent, as normal glycemia is observed 30 days after syngeneic islet transplantation when 500 islets are transferred, but only transitory normoglycemia is observed when 250 islets are delivered, with the mice returning to hyperglycemia by 10 days post-transplant. An increased body weight is observed in both groups and identical responses observed when human islets are transplanted into diabetic NOD-SCID mice, with normoglycemia observed when higher numbers of islet equivalents are transplanted but not smaller numbers.The majority of the mice that have bleeding after the transfer die after the surgery, while the mice without bleeding survive. At 28 days post-transplantation, insulin staining reveals an even distribution of the human islet throughout the liver, mostly close to blood vessels. In addition to insulin, fibrin and polymorphonuclear cell filtration are also observed within the transplanted human islets.Intrahepatic islet transplantation will generate a large hole in the portal vein that may cause bleeding. Using our two improved procedures can prevent bleeding and reduce mortality post islet transplantation. The intraportal islet transplantation model can mimic clinical human islet transplantation.Our refined procedures can lead to higher survival rates for recipients, which allow further islet function study after transplantation.

minimizing-post-infusion-portal-vein-bleeding-during-intrahepatic

Research

JoVE Journal

Medicine

A Method for Murine Islet Isolation and Subcapsular Kidney Transplantation

Since the early pioneering work of Ballinger and Reckard demonstrating that transplantation of islets of Langerhans into diabetic rodents could normalize their blood glucose levels, islet transplantation has been proposed to be a potential treatment for type 1 diabetes 1,2. More recently, advances in human islet transplantation have further strengthened this view 1,3. However, two major limitations prevent islet transplantation from being a widespread clinical reality: (a) the requirement for large numbers of islets per patient, which severely reduces the number of potential recipients, and (b) the need for heavy immunosuppression, which significantly affects the pediatric population of patients due to their vulnerability to long-term immunosuppression. Strategies that can overcome these limitations have the potential to enhance the therapeutic utility of islet transplantation.
Islet transplantation under the mouse kidney capsule is a widely accepted model to investigate various strategies to improve islet transplantation. This experiment requires the isolation of high quality islets and implantation of islets to the diabetic recipients. Both procedures require surgical steps that can be better demonstrated by video than by text. Here, we document the detailed steps for these procedures by both video and written protocol. We also briefly discuss different transplantation models: syngeneic, allogeneic, syngeneic autoimmune, and allogeneic autoimmune.

Transplantation of isolated islets has been proposed to be a potential treatment for type 1 diabetes. Here we describe a method to isolate islets from mouse pancreata and transplant them to the subcapsular space of the kidney.

Since the early pioneering work of Ballinger and Reckard demonstrating that transplantation of islets of Langerhans into diabetic rodents could normalize ...

3-Dimensional Resin Casting and Imaging of Mouse Portal Vein or Intrahepatic Bile Duct System

In organs, the correct architecture of vascular and ductal structures is indispensable for proper physiological function, and the formation and maintenance of these structures is a highly regulated process. The analysis of these complex, 3-dimensional structures has greatly depended on either 2-dimensional examination in section or on dye injection studies. These techniques, however, are not able to provide a complete and quantifiable representation of the ductal or vascular structures they are intended to elucidate. Alternatively, the nature of 3-dimensional plastic resin casts generates a permanent snapshot of the system and is a novel and widely useful technique for visualizing and quantifying 3-dimensional structures and networks.
A crucial advantage of the resin casting system is the ability to determine the intact and connected, or communicating, structure of a blood vessel or duct. The structure of vascular and ductal networks are crucial for organ function, and this technique has the potential to aid study of vascular and ductal networks in several ways. Resin casting may be used to analyze normal morphology and functional architecture of a luminal structure, identify developmental morphogenetic changes, and uncover morphological differences in tissue architecture between normal and disease states. Previous work has utilized resin casting to study, for example, architectural and functional defects within the mouse intrahepatic bile duct system that were not reflected in 2-dimensional analysis of the structure1,2, alterations in brain vasculature of a Alzheimer's disease mouse model3, portal vein abnormalities in portal hypertensive and cirrhotic mice4, developmental steps in rat lymphatic maturation between immature and adult lungs5, immediate microvascular changes in the rat liver, pancreas, and kidney in response in to chemical injury6.
Here we present a method of generating a 3-dimensional resin cast of a mouse vascular or ductal network, focusing specifically on the portal vein and intrahepatic bile duct. These casts can be visualized by clearing or macerating the tissue and can then be analyzed. This technique can be applied to virtually any vascular or ductal system and would be directly applicable to any study inquiring into the development, function, maintenance, or injury of a 3-dimensional ductal or vascular structure.

A method of visualizing and quantifying the 3-dimensional structure of mouse hepatic portal vein or intrahepatic bile duct is described. This resin cast technique can also be applied to other ductal or vascular systems and allows for in situ visualization or quantification of a system's intact communicating architecture.

In  organs, the correct architecture of vascular and ductal structures is  indispensable for proper physiological function, and the formation and  ...

Direct Pressure Monitoring Accurately Predicts Pulmonary Vein Occlusion During Cryoballoon Ablation

Cryoballoon ablation (CBA) is an established therapy for atrial fibrillation (AF). Pulmonary vein (PV) occlusion is essential for achieving antral contact and PV isolation and is typically assessed by contrast injection. We present a novel method of direct pressure monitoring for assessment of PV occlusion.
Transcatheter pressure is monitored during balloon advancement to the PV antrum. Pressure is recorded via a single pressure transducer connected to the inner lumen of the cryoballoon. Pressure curve characteristics are used to assess occlusion in conjunction with fluoroscopic or intracardiac echocardiography (ICE) guidance. PV occlusion is confirmed when loss of typical left atrial (LA) pressure waveform is observed with recordings of PA pressure characteristics (no A wave and rapid V wave upstroke). Complete pulmonary vein occlusion as assessed with this technique has been confirmed with concurrent contrast utilization during the initial testing of the technique and has been shown to be highly accurate and readily reproducible.
We evaluated the efficacy of this novel technique in 35 patients. A total of 128 veins were assessed for occlusion with the cryoballoon utilizing the pressure monitoring technique; occlusive pressure was demonstrated in 113 veins with resultant successful pulmonary vein isolation in 111 veins (98.2%). Occlusion was confirmed with subsequent contrast injection during the initial ten procedures, after which contrast utilization was rapidly reduced or eliminated given the highly accurate identification of occlusive pressure waveform with limited initial training.
Verification of PV occlusive pressure during CBA is a novel approach to assessing effective PV occlusion and it accurately predicts electrical isolation. Utilization of this method results in significant decrease in fluoroscopy time and volume of contrast.

Effective pulmonary vein isolation utilizing a cryoballoon depends on complete pulmonary vein occlusion. The point of occlusion can be effectively predicted by direct analysis of pulmonary vein pressure waveform analysis during balloon inflation using a simple and reproducible technique.

Cryoballoon  ablation (CBA) is an established therapy for atrial fibrillation (AF).  Pulmonary vein (PV) occlusion is essential for achieving antral ...

Generation of Subcutaneous and Intrahepatic Human Hepatocellular Carcinoma Xenografts in Immunodeficient Mice

In vivo experimental models of hepatocellular carcinoma (HCC) that recapitulate the human disease provide a valuable platform for research into disease pathophysiology and for the preclinical evaluation of novel therapies. We present a variety of methods to generate subcutaneous or orthotopic human HCC xenografts in immunodeficient mice that could be utilized in a variety of research applications. With a focus on the use of primary tumor tissue from patients undergoing surgical resection as a starting point, we describe the preparation of cell suspensions or tumor fragments for xenografting. We describe specific techniques to xenograft these tissues i) subcutaneously; or ii) intrahepatically, either by direct implantation of tumor cells or fragments into the liver, or indirectly by injection of cells into the mouse spleen. We also describe the use of partial resection of the native mouse liver at the time of xenografting as a strategy to induce a state of active liver regeneration in the recipient mouse that may facilitate the intrahepatic engraftment of primary human tumor cells. The expected results of these techniques are illustrated. The protocols described have been validated using primary human HCC samples and xenografts, which typically perform less robustly than the well-established human HCC cell lines that are widely used and frequently cited in the literature. In comparison with cell lines, we discuss factors which may contribute to the relatively low chance of primary HCC engraftment in xenotransplantation models and comment on technical issues that may influence the kinetics of xenograft growth. We also suggest methods that should be applied to ensure that xenografts obtained accurately resemble parent HCC tissues.

Human tumor xenografts in immunodeficient mice are valuable tools to study cancer biology. Specific protocols to generate subcutaneous and intrahepatic xenografts from human hepatocellular carcinoma cells or tumor fragments are described. Liver regeneration induced by partial hepatectomy in recipient mice is presented as a strategy to facilitate intrahepatic engraftment.

In  vivo experimental models of hepatocellular carcinoma (HCC) that recapitulate  the human disease provide a valuable platform for research into disease  ...

Heterotopic Auxiliary Rat Liver Transplantation With Flow-regulated Portal Vein Arterialization in Acute Hepatic Failure

In acute hepatic failure auxiliary liver transplantation is an interesting alternative approach. The aim is to provide a temporary support until the failing native liver has regenerated.1-3 The APOLT-method, the orthotopic implantation of auxiliary segments- averts most of the technical problems. However this method necessitates extensive resections of both the native liver and the graft.4 In 1998, Erhard developed the heterotopic auxiliary liver transplantation (HALT) utilizing portal vein arterialization (PVA) (Figure 1). This technique showed promising initial clinical results.5-6 We developed a HALT-technique with flow-regulated PVA in the rat to examine the influence of flow-regulated PVA on graft morphology and function (Figure 2).
A liver graft reduced to 30 % of its original size, was heterotopically implanted in the right renal region of the recipient after explantation of the right kidney.&#160; The infra-hepatic caval vein of the graft was anastomosed with the infrahepatic caval vein of the recipient. The arterialization of the donor&#8217;s portal vein was carried out via the recipient&#8217;s right renal artery with the stent technique. The blood-flow regulation of the arterialized portal vein was achieved with the use of a stent with an internal diameter of 0.3 mm. The celiac trunk of the graft was end-to-side anastomosed with the recipient&#8217;s aorta and the bile duct was implanted into the duodenum. A subtotal resection of the native liver was performed to induce acute hepatic failure. 7
In this manner 112 transplantations were performed. The perioperative survival rate was 90% and the 6-week survival rate was 80%. Six weeks after operation, the native liver regenerated, showing an increase in weight from 2.3&#177;0.8 g to 9.8&#177;1 g. At this time, the graft&#8217;s weight decreased from 3.3&#177;0.8 g to 2.3&#177;0.8 g.
We were able to obtain promising long-term results in terms of graft morphology and function. HALT with flow-regulated PVA reliably bridges acute hepatic failure until the native liver regenerates.

Auxiliary liver transplantation provides a temporary support in acute hepatic failure, until regeneration of the failing liver. The heterotopic auxiliary liver transplantation (HALT) with portal vein arterialization (PVA) renders sufficient liver function. We developed an analogous technique in the rat, to examine the influence of the portal vein arterialization on the morphology and function of the graft.

In acute hepatic failure auxiliary liver transplantation is an interesting alternative approach. The aim is to provide a temporary support until the ...

Heterotopic Cervical Heart Transplantation in Mice

The heterotopic cervical heart transplantation in mice is a valuable tool in transplant and cardiovascular research. The cuff technique greatly simplifies this model by avoiding challenging suture anastomoses of small vessels thereby reducing warm ischemia time. In comparison to abdominal graft implantation the cervical model is less invasive and the implanted graft is easily accessible for further follow-up examinations. Anastomoses are performed by pulling the ascending aorta of the graft over the cuff with the recipient&#8217;s common carotid artery and by pulling the main pulmonary artery over the cuff with the external jugular vein. Selection of appropriate cuff size and complete mobilization of the vessels are important for successful revascularization. Ischemia-reperfusion (I/R) injury can be minimized by perfusing the graft with a cardioplegic solution and by hypothermia. In this article, we provide technical details for a simplified and improved cuff technique, which should allow surgeons with basic microsurgical skills to perform the procedure with a high success rate.

The cuff technique shortens and facilitates the model of heterotopic cervical heart transplantation in mice by avoiding technically challenging suture anastomoses of small vessels. The technical details shown in this video paper should allow researches to establish this model in their laboratories.

The heterotopic cervical heart transplantation in mice is a valuable tool in transplant and cardiovascular research. The cuff technique greatly simplifies ...

Using the Sleeve Technique in a Mouse Model of Aortic Transplantation - An Instructional Video

Orthotopic aortic transplantation using the sleeve technique reduces injury to the aorta with failure rate of only 10-20%. The time to anastomose the aorta in mice using the sleeve method was short and easy averaging 20 min, permitting studies of iso/allo grafts. The following article describes the aortic transplantation procedure used in our laboratory. The mice were anesthetized with a mixture of 1.5% volume isoflurane and 100% oxygen through a face mask. At this point, the segment of the aorta between the renal arteries and its bifurcation was separated from the vena cava, freely prepared and clampedat the proximal and distal segments with a single silk suture. Prior to the removal of the aorta, a saline solution containing heparin was injected into the inferior vena cava. Then the aorta was cut between the clamps and a saline heparin solution was used to flush the lumen. The sleeve technique with monofilament sutures was used in order to transplant the abdominal aorta in the orthotopic position.

We present an orthotopic aortic transplantation model using the sleeve technique in mice. It is a very rapid anastomosis method, which can be employed in studies of vascular disease.

Orthotopic aortic transplantation using the sleeve technique reduces injury to the aorta with failure rate of only 10-20%. The time to anastomose the ...

Rat Model of the Associating Liver Partition and Portal Vein Ligation for Staged Hepatectomy (ALPPS) Procedure

Recent clinical data support an aggressive surgical approach to both primary and metastatic liver tumors. For some indications, like colorectal liver metastases, the amount of liver tissue left behind after liver resection has become the main limiting factor of resectability of large or multiple liver tumors. A minimal amount of functional tissue is required to avoid the severe complication of post-hepatectomy liver failure, which has high morbidity and mortality. Inducing liver growth of the prospective remnant prior to resection has become more established in liver surgery, either in the form of portal vein embolization by interventional radiologists or in the form of portal vein ligation several weeks prior to resection. Recently, it was shown that liver regeneration is more extensive and rapid, when the parenchymal transection is added to portal vein ligation in a first stage and then, after only one week of waiting, resection performed in a second stage (Associating Liver Partition and Portal vein ligation for Staged hepatectomy = ALPPS). ALPPS has rapidly become popular across the world, but has been criticized for its high perioperative mortality. The mechanism of accelerated and extensive growth induced by this procedure has not been well understood. Animal models have been developed to explore both the physiological and molecular mechanisms of accelerated liver regeneration in ALPPS. This protocol presents a rat model that allows mechanistic exploration of accelerated regeneration.

Rat Model of the Associating Liver Partition and Portal Vein Ligation for Staged Hepatectomy ALPPS Procedure

Inducing rapid liver hypertrophy using Associating Liver Partition and Portal vein ligation for a Staged hepatectomy (ALPPS) has been proposed for resection of borderline resectable liver tumors. This model may elucidate mechanisms involved in rapid hypertrophy and allows testing of drugs that promote or block the acceleration of regeneration.

Recent clinical data support an aggressive surgical approach to both primary and metastatic liver tumors. For some indications, like colorectal liver ...

Blood Collection Through Subclavian Vein Puncture in Mice

The mouse is the foremost mammalian model for studying human disease and human health. However, blood sample collection from mice is challenging in research work. Tail blood collection is a popular method when a small amount of blood sample is needed. Orbital artery could be considered if a large amount of blood is needed but this blood collection method has ethical issues. Formerly, we demonstrated the feasibility and safety of blood sample collection through subclavian vein puncture in rats, and here we investigate whether this method could be used in mice. We report that this method is safe and practical for blood collection in mice. Blood collection through the subclavian vein puncture in mice can be a convenient method in daily research works.

Here, we present a protocol to take blood samples from the subclavian vein of mice.

The mouse is the foremost mammalian model for studying human disease and human health. However, blood sample collection from mice is challenging in ...

Fat-Covered Islet Transplantation Using Epididymal White Adipose Tissue

Islet transplantation is a cellular replacement therapy for severe diabetes mellitus. The intraperitoneal cavity is typically the transplant site for this procedure. However, intraperitoneal islet transplantation has some limitations, including poor transplant efficacy, difficult graft detection ability, and a lack of graftectomy capability for post-transplant analysis. In this paper, "fat-covered islet transplantation", an intraperitoneal islet transplantation method that utilizes epididymal white adipose tissue, is used to assess the therapeutic effects of bioengineered islets. The simplicity of the method lies in the seeding of islets onto epididymal white adipose tissue and using the tissue to cover the islets. While this method can be categorized as an intraperitoneal islet transplantation technique, it shares characteristics with intra-adipose tissue islet transplantation. The fat-covered islet transplantation method demonstrates more robust therapeutic effects than intra-adipose tissue islet transplantation, however, including the improvement of blood glucose and plasma insulin levels and the potential for graft removal. We recommend the adoption of this method for assessing the mechanisms of islet engraftment into white adipose tissue and the therapeutic effects of bioengineered islets.

This fat-covered islet transplantation method is suitable for the detection of engrafted islets in the intraperitoneal cavity. Notably, it does not require the use of biobinding agents or suturing.

Islet transplantation is a cellular replacement therapy for severe diabetes mellitus. The intraperitoneal cavity is typically the transplant site for this ...