This work was supported in part by the National Institute of Health grant R01-HL095498, as well as with the resources and the use of facilities at the VA Connecticut Healthcare System, West Haven, CT.

1. Anesthesia and Pre-operative Procedures
<ol>
 <li>Induction of general anesthesia 
 Approval by the appropriate Institutional Animal Care and Use Committee is obtained. Male C57/black mice, aged 10 weeks, are anesthetized. Deliver 4% isoflurane with 0.8 L/min oxygen to a Plexiglas box via an isoflurane vaporizer and place the mouse inside. Alternatively, if preferred by the surgeon, intraperitoneal anesthesia can be used.</li>
 <li>Preserving anesthesia 
 After confirmation of anesthesia by lack of reaction to toe pinch, the mouse is put on the operation table in a supine position with a silicone mask. Isoflurane is decreased to 2% to maintain appropriate anesthesia level.</li>
 <li>Hair removal 
 Ventral hair is removed from the neck to lower abdomen using a hair remover. Hair remover is preferred because the hair that is left using a shaver may interfere with the Doppler ultrasound.</li>
</ol>
2. Preoperative Ultrasound
<ol>
 <li>Objectives of the ultrasound 
 Doppler ultrasound examination is performed prior to AVF surgery so as to record the base level findings that can be compared with post-operative findings to see anatomical and physiological changes.</li>
 <li>Points of observation 
 The jugular vein, supra- and infra-renal inferior vena cava (IVC), and abdominal aorta are examined using both pulse Doppler and B-mode.</li>
 <li>Measurements 
 Using the B-mode, diameter of each vasculature is measured. In addition, maximum velocity (peak systolic velocity in arteries) and waveforms are recorded in each of the measuring points described above.</li>
</ol>
3. Operative Procedures
<ol>
 <li>Mouse Preparation 
Prepare the incision site with a topical antiseptic and continue proper aseptic technique during the surgery including using a surgical drape, sterile gloves and instruments, etc.</li>
 <li>Laparotomy 
 Midline abdominal incision is made from lower edge of the liver to just above the pubis.</li>
 <li>Exposure of the aorta and IVC. 
 A retractor is inserted and all of the bowels are pulled out of the abdominal cavity to the right side and kept wrapped in gauze soaked with saline. Dissect the membrane that connects the retroperitoneum and lower colon to get full view of the aorta and IVC. Apply pressure on the bladder if it is dilated and gets in way.</li>
 <li>Exposure of the puncture site 
 Puncture site will be between half to three quarters of the distance from left renal vein to aortic bifurcation. (Figure 1) Dissect the left margin of the aorta so that it can be punctured. Keep in mind that the aorta is positioned about 45 degrees behind the IVC and it must be dissected posteriorly in addition to the left. (Figure 2) The most important point of this surgery is not to dissect between the aorta and IVC. Keep far away from them.</li>
 <li>Exposure of the clamp site of the aorta 
 Dissect the infrarenal aorta from surrounding tissues. Be careful not to injure the IVC on the left and left renal veins with its tributaries on the right.</li>
 <li>Clamping of the aorta 
 Clamp the proximal aorta by applying microsurgery clips.</li>
 <li>Rotation of the aorta 
 By grasping the connective tissue surrounding the aorta, rotate the aorta so that the puncture can be made from slightly dorsal side of the aorta (Figure 2).</li>
 <li>Puncture of the aorta through to IVC 
 Keeping the aorta in a rotated position, puncture the aorta through to IVC using a 25 G needle. (Figure 2) If successful, the needle can be seen through the thin IVC wall.</li>
 <li>Hemostasis 
 By pulling the retroperitoneal tissues, including the muscles, wrap the puncture site of the aorta. Do not compress the aorta against the IVC, as it may clot the AVF (Figure 3).</li>
 <li>De-clamping the aorta 
 After confirmation of the primary hemostasis, de-clamp the aorta. Additional bleeding may occur but it can be stopped with further compression described above. Upon de-clamping, arterial blood can be seen flowing into the IVC instead of dark venous blood flow.</li>
 <li>Closure of the abdomen 
 Return the bowels into its natural position and close the abdomen.</li>
</ol>
4. Post-operative Procedures
<ol>
 <li>Post-operative care 
 After closure of the abdomen, isoflurane is stopped. Post-operative care including analgesia and wound care is applied in accordance with the instructions recommended by Institutional Animal Care and Use Committee. For analgesia we use buprenorphine at 0.1 mg/kg intrasmuscularly every 12 hr for 24 hr following the surgical procedures.</li>
 <li>Post-operative ultrasound 
 On the first day after operation, Doppler ultrasound is performed to confirm the AVF. In addition, other variables are measured to check the changes from pre-operative values.</li>
</ol>

<ol>
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A., Muto, A., 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=Venous+identity+is+lost+but+arterial+identity+is+not+gained+during+vein+graft+adaptation.">Venous identity is lost but arterial identity is not gained during vein graft adaptation.</a> Arteriosclerosis, Thrombosis, and Vascular Biology. 27 (7), 1562-1571 (2007).</li><li>Muto, A., Yi, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Eph-B4+prevents+venous+adaptive+remodeling+in+the+adult+arterial+environment.">Eph-B4 prevents venous adaptive remodeling in the adult arterial environment.</a> The Journal of Experimental Medicine. 208 (3), 561-575 (2011).</li><li>Croatt, A. J., Grande, J. 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A., 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=The+rat+femoral+arteriovenous+fistula+model:+increased+expression+of+matrix+metalloproteinase-2+and+-9+at+the+venous+stenosis.">The rat femoral arteriovenous fistula model: increased expression of matrix metalloproteinase-2 and -9 at the venous stenosis.</a> Journal of Vascular and Interventional Radiology. 19 (4), 587-594 (2008).</li><li>Kojima, T., Miyachi, 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=The+relationship+between+venous+hypertension+and+expression+of+vascular+endothelial+growth+factor:+hemodynamic+and+immunohistochemical+examinations+in+a+rat+venous+hypertension+model.">The relationship between venous hypertension and expression of vascular endothelial growth factor: hemodynamic and immunohistochemical examinations in a rat venous hypertension model.</a> Surgical Neurology. 68 (3), 277-284 (2007).</li><li>Caplice, N. 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J., Mori, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetic+variation+in+angiotensin-converting+enzyme+does+not+prevent+development+of+cardiac+hypertrophy+or+upregulation+of+angiotensin+II+in+response+to+aortocaval+fistula.">Genetic variation in angiotensin-converting enzyme does not prevent development of cardiac hypertrophy or upregulation of angiotensin II in response to aortocaval fistula.</a> Circulation. 103 (7), 1012-1016 (2001).</li><li>Guzman, R. J., Krystkowiak, A., Zarins, C. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Early+and+sustained+medial+cell+activation+after+aortocaval+fistula+creation+in+mice.">Early and sustained medial cell activation after aortocaval fistula creation in mice.</a> The Journal of Surgical Research. 108 (1), 112-121 (2002).</li><li>Castier, Y., Lehoux, 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=Characterization+of+neointima+lesions+associated+with+arteriovenous+fistulas+in+a+mouse+model.">Characterization of neointima lesions associated with arteriovenous fistulas in a mouse model.</a> Kidney International. 70 (2), 315-320 (2006).</li></ol>

There are several reports that have described AVF in rats, including femoral AVF,6, 7 carotid to jugular AVF8 and aorto-caval AVF.9, 10 The rat is several times larger than the mouse, allowing easier surgery in the rat compared to the mouse. Nevertheless, in order to take advantage of mouse genetic strains and variants the procedure must be extended to include mouse models. Several previously published reports introduced the AVF model in mice, but these reports have generally been in the ...

The most common option chosen for renal replacement therapy in patients with end stage renal disease is hemodialysis. Access for hemodialysis is performed by arteriovenous fistula (AVF), arteriovenous graft, or temporary catheter placement. Although AVF are the preferred mode of access, AVF are still far from perfect. One-year primary AVF patency rates are only 60-65%, with many failures due to neointimal hyperplasia. The molecular biology and physiology of normal AVF formation and maladaptive formation remains poorly characterized. As such, much is to be gained in improving AVF outcomes with the accompanying gain in understanding of the regulation of fistula formation.1-3
Exposure of a vein to arterial flow is commonly studied in the context of vein grafts that are direct models of surgical bypass.4, 5 Although vein grafts and AVF similarly expose a vein to an arterial environment, there are several critical differences between them. First, the resistance of the distal runoff bed is much lower in AVF, as the AVF drains to the right atrium whereas the vein graft drains to the often diseased distal small arteries, resulting in increased blood flow and shear stress in the AVF. Second, the blood in the venous limb of the AVF can be a mixture of venous and arterial blood leading to lower oxygenation compared to the purely arterial content in the vein graft. Third, the vein in the AVF is not removed from its bed, leading to preservation of its vaso venorum and nervous innervations, compared to the complete transposition of the vein graft into the arterial bed. Lastly, the number of anastomoses is usually two in vein grafts whereas an AVF typically has only one. In this study, we introduce a mouse model of aortocaval fistula that can be used for the study of AVF.

<table><tbody><tr><td>Vevo 770 ultrasound machine</td><td>Visualsonics</td><td>20-60 Mhz scan head; RMV-704</td><td></td></tr><tr><td>Vascular clamp</td><td>Roboz Surgical Instrument Co.</td><td>RS-5424</td><td></td></tr><tr><td>Clamp applying forceps</td><td>Roboz Surgical Instrument Co.</td><td>RS-5410</td><td></td></tr><tr><td>25 Gauge Needle</td><td>Becton Dickinson</td><td>BD PrecisionGlide Needle 25G x 7/8 #305124</td><td></td></tr></tbody></table>

technical aspects of the mouse aortocaval fistula

Technical aspects of creating an arteriovenous fistula in the mouse are discussed. Under general anesthesia, an abdominal incision is made, and the aorta and inferior vena cava (IVC) are exposed. The proximal infrarenal aorta and the distal aorta are dissected for clamp placement and needle puncture, respectively. Special attention is paid to avoid dissection between the aorta and the IVC. After clamping the aorta, a 25 G needle is used to puncture both walls of the aorta into the IVC. The surrounding connective tissue is used for hemostatic compression. Successful creation of the AVF will show pulsatile arterial blood flow in the IVC. Further confirmation of successful AVF can be achieved by post-operative Doppler ultrasound.

After practice, survival on the first post-operative day is typically over 95%; at post-operative day 7, survival was 91.3%. Figures 1 and 2 show the ideal puncture site in coronal and cross-sectional views; placement of the puncture site is critical to obtaining good survival without excessive hemorrhage. Intra-operative deaths and early post-operative deaths are typically due to hemorrhage. This tends to occur with excessive dissection between the aorta and the IVC, or from inadequate hemostatic pressu...

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Technical Aspects of the Mouse Aortocaval Fistula

The goal is to produce an arteriovenous fistula that is simple and reproducible. This method does not use sutures or glue adhesive. Therefore the samples can be used with the least amount of foreign materials for analysis.

Technical aspects of creating an arteriovenous fistula in the mouse are discussed. Under general anesthesia, an abdominal incision is made, and the aorta ...

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16.4K Views.  Yale University. Het doel is om een ​​arterioveneuze fistel die is eenvoudig en reproduceerbaar te produceren. Deze methode maakt geen gebruik van hechtingen of lijm lijm. Derhalve kunnen de monsters worden met de minste hoeveelheid vreemde materialen voor analyse.

Video: Technical Aspects of the Mouse Aortocaval Fistula

Orthotopic Aortic Transplantation in Mice for the Study of Vascular Disease

Vascular procedures involving anastomoses in the mouse are generally thought to be difficult and highly dependent on the skill of the individual surgeon. This is largely true, but there are a number of important principles that can reduce the difficulty of these procedures and enhance reproducibility. Orthotopic aortic transplantation is an excellent procedure in which to learn these principles because it involves only two end-to-end anastomoses, but requires good suturing technique and handling of the vessels for consistent success. This procedure begins with the procurement of a length of abdominal aorta from a donor animal, followed by division of the native aorta in the recipient. The procured aorta is then placed between the divided ends of the recipient aorta and sutured into place using end-to-end anastomoses. To accomplish this objective successfully requires a high degree of concentration, good tools, a steady hand, and an appreciation of how easily the vasculature of a mouse can be damaged, resulting in thrombosis. Learning these important principles is what occupies most of the beginner's time when learning microsurgery in small rodents. Throughout this protocol, we refer to these important points. This model can be used to study vascular disease in a variety of different experimental systems1-8. In the context shown here, it is most often used for the study of post-transplant vascular disease, a common long-term complication of solid organ transplantation in which intimal hyperplasia occurs within the allograft. The primary advantage of the model is that it facilitates quantitative morphometric analyses and the transplanted vessel lies contiguous to the endogenous vessel, which can serve as an additional control9. The technique shown here is most often used for mice weighing 18-25 grams. We have accumulated most of our experience using the C57BL/6J, BALB/cJ, and C3H/HeJ strains.

We describe a technique in which a section of the abdominal aorta from a mouse is transplanted orthotopically to just below the renal arteries in an allogeneic or syngeneic recipient. This technique can be useful in studies in which transplantation of large arteries of uniform size is deemed advantageous.

Vascular procedures involving anastomoses in the mouse are generally thought to be difficult and highly dependent on the skill of the individual surgeon. ...

Mouse Models for Graft Arteriosclerosis

Graft arteriosclerois (GA), also called allograft vasculopathy, is a pathologic lesion that develops over months to years in transplanted organs characterized by diffuse, circumferential stenosis of the entire graft vascular tree. The most critical component of GA pathogenesis is the proliferation of smooth muscle-like cells within the intima. When a human coronary artery segment is interposed into the infra-renal aortae of immunodeficient mice, the intimas could be expand in response to adoptively transferred human T cells allogeneic to the artery donor or exogenous human IFN-&gamma; in the absence of human T cells. Interposition of a mouse aorta from one strain into another mouse strain recipient is limited as a model for chronic rejection in humans because the acute cell-mediated rejection response in this mouse model completely eliminates all donor-derived vascular cells from the graft within two-three weeks. We have recently developed two new mouse models to circumvent these problems. The first model involves interposition of a vessel segment from a male mouse into a female recipient of the same inbred strain (C57BL/6J). Graft rejection in this case is directed only against minor histocompatibility antigens encoded by the Y chromosome (present in the male but not the female) and the rejection response that ensues is sufficiently indolent to preserve donor-derived smooth muscle cells for several weeks. The second model involves interposing an artery segment from a wild type C57BL/6J mouse donor into a host mouse of the same strain and gender that lacks the receptor for IFN-&gamma; followed by administration of mouse IFN-&gamma; (delivered via infection of the mouse liver with an adenoviral vector. There is no rejection in this case as both donor and recipient mice are of the same strain and gender but donor smooth muscle cells proliferate in response to the cytokine while host-derived cells, lacking receptor for this cytokine, are unresponsive. By backcrossing additional genetic changes into the vessel donor, both models can be used to assess the effect of specific genes on GA progression. Here, we describe detailed protocols for our mouse GA models.

We describe protocols for our mouse graft arteriosclerois (GA) models which involve interposition of a mouse vessel segment into a recipient of the same inbred strain. By backcrossing additional genetic changes into the vessel donor, the model can assess the effect of specific genes on GA.

Graft arteriosclerois (GA),  also called allograft vasculopathy, is a pathologic lesion that develops over  months to years in transplanted organs ...

Adult Mouse Venous Hypertension Model: Common Carotid Artery to External Jugular Vein Anastomosis.

The understanding of the pathophysiology of brain arteriovenous malformations and arteriovenous fistulas has improved thanks to animal models. A rat model creating an artificial fistula between the common carotid artery (CCA) and the external jugular vein (EJV) has been widely described and proved technically feasible. This construct provokes a consistent cerebral venous hypertension (CVH), and therefore has helped studying the contribution of venous hypertension to formation, clinical symptoms, and prognosis of brain AVMs and dural AVFs. Equivalent mice models have been only scarcely described and have shown trouble with stenosis of the fistula. An established murine model would allow the study of not only pathophysiology but also potential genetic therapies for these cerebrovascular diseases.
We present a model of arteriovenous fistula that produces a durable intracranial venous hypertension in the mouse. Microsurgical anastomosis of the murine CCA and EJV can be difficult due to diminutive anatomy and frequently result in a non-patent fistula. In this step-by-step protocol we address all the important challenges encountered during this procedure. Avoiding excessive retraction of the vein during the exposure, using 11-0 sutures instead of 10-0, and making a carefully planned end-to-side anastomosis are some of the critical steps. Although this method requires advanced microsurgical skills and a longer learning curve that the equivalent in the rat, it can be consistently developed.
This novel model has been designed to integrate transgenic mouse techniques with a previously well-established experimental system that has proved useful to study brain AVMs and dural AVFs. By opening the possibility of using transgenic mice, a broader spectrum of valid models can be achieved and genetic treatments can also be tested. The experimental construct could also be further adapted to the study of other cerebrovascular diseases related with venous hypertension such as migraine, transient global amnesia, transient monocular blindness, etc.

We describe a method for creating a reliable model of cerebral venous hypertension in the adult mouse. This model has been widely described and tested in the rat. This new counterpart in the mice opens the possibility of using genetic modified animals and thereby broadens the applications of the model.

The understanding of the pathophysiology of brain arteriovenous malformations and arteriovenous fistulas has improved thanks to animal models. A rat model ...

A Novel Murine Model of Arteriovenous Fistula Failure: The Surgical Procedure in Detail

The arteriovenous fistula (AVF) still suffers from a high number of failures caused by insufficient remodeling and intimal hyperplasia from which the exact pathophysiology remains unknown. In order to unravel the pathophysiology a murine model of AVF-failure was developed in which the configuration of the anastomosis resembles the preferred situation in the clinical setting. A model was described in which an AVF is created by connecting the venous end of the branch of the external jugular vein to the side of the common carotid artery using interrupted sutures. At a histological level, we observed progressive stenotic intimal lesions in the venous outflow tract that is also seen in failed human AVFs. Although this procedure can be technically challenging due to the small dimensions of the animal, we were able to achieve a surgical success rate of 97% after sufficient training. The key advantage of a murine model is the availability of transgenic animals. In view of the different proposed mechanisms that are responsible for AVF failure, disabling genes that might play a role in vascular remodeling can help us to unravel the complex pathophysiology of AVF failure.

Here we present a murine model of arteriovenous fistula (AVF) failure in which a clinically relevant anastomotic configuration is incorporated. This model can be used to study the pathophysiology and to test possible therapeutic interventions.

The arteriovenous fistula (AVF) still suffers from a high number of failures caused by insufficient remodeling and intimal hyperplasia from which the ...

Intraluminal Drug Delivery to the Mouse Arteriovenous Fistula Endothelium

Delivery of therapeutic agents to enhance arteriovenous fistula (AVF) maturation can be administered either via intraluminal or external routes. The simple murine AVF model was combined with intraluminal administration of drug solution to the venous endothelium at the same time as fistula creation. Technical aspects of this model are discussed. Under general anesthesia, an abdominal incision is made and the aorta and inferior vena cava (IVC) are exposed. The infra-renal aorta and IVC are dissected for clamping. After proximal and distal clamping, the puncture site is exposed and a 25 G needle is used to puncture both walls of the aorta and into the IVC. Immediately after the puncture, a reporter gene-expressing viral vector was infused in the IVC via the same needle, followed by 15 min of incubation. The intraluminal administration method enabled more robust viral gene delivery to the venous endothelium compared to administration by the external route. This novel method of delivery will facilitate studies that explore the role of the endothelium in AVF maturation and enable intraluminal drug delivery at the time of surgical operation.

After puncturing the aorta through the inferior vena cava (IVC) to create an aorto-caval fistula in the mouse, solution containing a drug is infused into the IVC via the same needle, followed by incubation. This method enables more robust drug delivery to the venous endothelium compared to the external route.

Delivery of therapeutic agents to enhance arteriovenous fistula (AVF) maturation can be administered either via intraluminal or external routes. The ...

Murine Model of Central Venous Stenosis using Aortocaval Fistula with an Outflow Stenosis

Central venous stenosis is an important entity contributing to arteriovenous fistula (AVF) failure. A murine AVF model was modified to create a partial ligation of the inferior vena cava (IVC) in the outflow of the fistula, mimicking central venous stenosis. Technical aspects of this model are introduced. The aorta and IVC are exposed, following an abdominal incision. The infra-renal aorta and IVC are dissected for proximal clamping, and the distal aorta is exposed for puncture. The IVC at the midpoint between the left renal vein and the aortic bifurcation is carefully dissected to place an 8-0 suture beneath the IVC. After clamping the aorta and IVC, an AVF is created by puncturing the infra-renal aorta through both walls into the IVC with a 25 G needle, followed by ligating a 22 G intra-venous (IV) catheter and IVC together. The catheter is then removed, creating a reproducible venous stenosis without occlusion. The aorta and IVC are unclamped after confirming primary hemostasis. This novel model of central vein stenosis is easy to perform, reproducible, and will facilitate studies on AVF failure.

An aortocaval fistula was created by puncturing the murine infra-renal aorta through both walls into the inferior vena cava and was followed by creation of a stenosis in its outflow via partial ligation of the inferior vena cava. This reproducible model can be used to study central venous stenosis.

Central venous stenosis is an important entity contributing to arteriovenous fistula (AVF) failure. A murine AVF model was modified to create a partial ...

A Murine Model of Hemodialysis Access-Related Hand Dysfunction

Chronic kidney disease is a major public health problem, and the prevalence of end-stage renal disease (ESRD) requiring chronic renal replacement therapies such as hemodialysis continues to increase. Autogenous arteriovenous fistula (AVF) placement remains a primary vascular access option for ESRD patients. Unfortunately, approximately half of the hemodialysis patients experience dialysis access-related hand dysfunction (ARHD), ranging from subtle paresthesia to digital gangrene. Notably, the underlying biologic drivers responsible for ARHD are poorly understood, and no adequate animal model exists to elucidate the mechanisms and/or develop novel therapeutics for the prevention/treatment of ARHD. Herein, we describe a new mouse model in which an AVF is created between the left common iliac artery and vein, thereby facilitating the assessment of limb pathophysiology. The microsurgery includes vessel isolation, longitudinal venotomy, creation of arteriovenous anastomosis, and venous reconstruction. Sham surgeries include all the critical steps except for AVF creation. Iliac AVF placement results in clinically relevant alterations in central hemodynamics, peripheral ischemia, and impairments in hindlimb neuromotor performance. This novel preclinical AVF model provides a useful platform that recapitulates common neuromotor perturbations reported by hemodialysis patients, allowing researchers to investigate the mechanisms of ARHD pathophysiology and test potential therapeutics.

This protocol details the surgical steps of murine common iliac arteriovenous fistula creation. We developed this model to study hemodialysis access-related limb pathophysiology.

Chronic kidney disease is a major public health problem, and the prevalence of end-stage renal disease (ESRD) requiring chronic renal replacement ...

Drug Treatment by Central Venous Catheter in a Mouse Model of Angiotensin II Induced Abdominal Aortic Aneurysm and Monitoring by 3D Ultrasound

Since pharmaceutical treatment options are lacking in the clinical management of abdominal aortic aneurysm (AAA), animal models, in particular mouse models, are applied to advance the understanding of the disease pathogenesis and to identify potential therapeutic targets. Testing novel drug candidates to block AAA growth in these models generally requires repeated drug administration during the time course of the experiment. Here, we describe a compiled protocol for AAA induction, insertion of an intravenous catheter to facilitate prolonged therapy, and serial AAA monitoring by 3D ultrasound. Aneurysms are induced in apolipoprotein E (ApoE) deficient mice by angiotensin II release over 28 days from osmotic mini-pumps implanted subcutaneously into the mouse back. Subsequently, the surgical procedure for external jugular vein catheterization is conducted to allow for daily intravenous drug treatment or repeated blood sampling via a subcutaneous vascular access button. Despite the two dorsal implants, the monitoring of AAA development is readily facilitated by sequential semi-automated 3D ultrasound analysis, which yields comprehensive information on the expansion of aortic diameter and volume and on aneurysm morphology, as illustrated by experimental examples.

This protocol describes the consecutive implantation of an osmotic pump to induce abdominal aortic aneurysm by angiotensin II release in apolipoprotein E (ApoE) deficient mice and of a vascular access port with a jugular vein catheter for repeated drug treatment. Monitoring of aneurysm development by 3D ultrasound is effectively conducted despite dorsal implants.

Since pharmaceutical treatment options are lacking in the clinical management of abdominal aortic aneurysm (AAA), animal models, in particular mouse ...

Modified Arteriovenous Fistula Surgery to Establish the RV Volume Overload Mouse Model

Establishment and Confirmation of a Postnatal Right Ventricular Volume Overload Mouse Model

Right ventricular (RV) volume overload (VO) is common in children with congenital heart disease. In view of distinct developmental stages,the RV myocardium may respond differently to VO in children compared to adults. The present study aims to establish a postnatal RV VO model in mice using a modified abdominal arteriovenous fistula. To confirm the creation of VO and the following morphological and hemodynamic changes of the RV, abdominal ultrasound, echocardiography, and histochemical staining were performed for 3 months. As a result, the procedure in postnatal mice showed an acceptable survival and fistula success rate. In VO mice, the RV cavity was enlarged with a thickened free wall, and the stroke volume was increased by about 30%-40% within 2 months after surgery. Thereafter, the RV systolic pressure increased, corresponding pulmonary valve regurgitation was observed, and small pulmonary artery remodeling appeared. In conclusion, modified arteriovenous fistula (AVF) surgery is feasible to establish the RV VO model in postnatal mice. Considering the probability of fistula closure and elevated pulmonary artery resistance, abdominal ultrasound and echocardiography must be performed to confirm the model status before application.

Author Spotlight: Establishment and Confirmation of a Postnatal Right Ventricular Volume Overload Mouse Model  

This protocol presents the establishment and confirmation of a postnatal right ventricular volume overload (VO) model in mice with abdominal arteriovenous fistula (AVF), which can be applied to investigate how VO contributes to postnatal heart development.

Right ventricular (RV) volume overload (VO) is common in children with congenital heart disease. In view of distinct developmental stages,the RV ...

Surgically Induced Cardiac Volume Overload by Aortic Regurgitation in Mouse

Aortic regurgitation (AR) is a common valvular heart disease that exerts volume overload on the heart and represents a global public health problem. Although mice are widely applied to shed light on the mechanisms of cardiovascular disease, mouse models of AR, especially those induced by surgery, are still paucity. Here, a mouse model of AR was described in detail which is surgically induced by disruption of the aortic valves under high-resolution echocardiography. In accordance with regurgitated blood flow, AR mouse hearts present a distinctive and clinically relevant volume overload phenotype, which is characterized by eccentric hypertrophy and cardiac dysfunction, as evidenced by echocardiographic and invasive hemodynamic evaluation. Our proposal, in a reliable and reproducible manner, provides a practical guide on the establishment and assessment of a mouse model of AR for future studies on molecular mechanisms and therapeutic targets of volume overload cardiomyopathy.

This protocol presents a practical guide on the surgery for creation of aortic regurgitation (AR) in the mouse. Assessment of the AR mouse by echocardiography and invasive hemodynamic measurement recapitulates its clinically relevant characteristics of volume overload-induced eccentric hypertrophy, suggesting its promising application in the study of cardiac hypertrophy.

Aortic regurgitation (AR) is a common valvular heart disease that exerts volume overload on the heart and represents a global public health problem. ...

Technical Aspects of the Mouse Aortocaval Fistula

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