Published: June 29th, 2013
We show here the in vivo insertion of an osmotic pump for constant local drug delivery and the creation of hindlimb ischemia in a mouse model. Moreover, the hindlimb vasculature is perfused with Microfil, a silicone radiopaque agent, to prepare for micro-computed tomography (micro-CT) imaging.
Preclinical research in animal models of peripheral arterial disease plays a vital role in testing the efficacy of therapeutic agents designed to stimulate microcirculation. The choice of delivery method for these agents is important because the route of administration profoundly affects the bioactivity and efficacy of these agents1,2. In this article, we demonstrate how to locally administer a substance in ischemic hindlimbs by using a catheterized osmotic pump. This pump can deliver a fixed volume of aqueous solution continuously for an allotted period of time. We also present our mouse model of unilateral hindlimb ischemia induced by ligation of the common femoral artery proximal to the origin of profunda femoris and epigastrica arteries in the left hindlimb. Lastly, we describe the in vivo cannulation and ligation of the infrarenal abdominal aorta and perfusion of the hindlimb vasculature with Microfil, a silicone radiopaque casting agent. Microfil can perfuse and fill the entire vascular bed (arterial and venous), and because we have ligated the major vascular conduit for exit, the agent can be retained in the vasculature for future ex vivo imaging with the use of small specimen micro-CT3.
Peripheral arterial disease (PAD) is an atherosclerotic disease that causes insufficient blood supply in the legs4. It affects 8 to 12 million Americans, and current medical treatments offer only limited relief5,6. Novel therapeutic agents that improve blood circulation in legs would not only restrain disease progression but also enhance quality of life. The incidence of PAD is higher in people over the age of 50 years, so local pharmacologic therapy is a more desirable treatment modality because the reduced kidney and liver function often seen in older patients can decrease drug metabolism and increase side effects with systemic administration.<....
1. Priming the Osmotic Pump
The animation demonstrates the osmotic pump insertion and hindlimb ischemia surgery detailed in the protocol. Figure 1 shows laser Doppler images of perfusion of the hindlimb, confirming ischemia. After vascular casting with Microfil, a 3D micro-CT image of the vascular network shows that Microfil can fill the vessels effectively (Figure 2A) but that discontinuities can occur (Figure 2B) due to various procedural factors (e.g., air bubbles, lack of pressure, vis.......
Here we present a method for osmotic drug/substance delivery in a mouse model of hindlimb ischemia. In addition, we describe a casting technique in which we have used Microfil to produce a 3D reconstruction for analysis of the vascular network.
The level or severity of ischemia varies according to where the arterial ligation/excision is made. We created a double ligation in the common femoral artery proximal to the origin of the profunda femoris and epigastrica arteries; this approac.......
The authors would like to thank Keith Michel of the MD Anderson Small Animal Imaging Facility for his technical assistance with micro-CT imaging, Edward T.H. Yeh, MD, for surgical assistance, and Rebecca Bartow, PhD, for editorial assistance. This work was supported in part by the American Heart Association.....
|Fine Science Tools
|Puritan sterile cotton swabs
|70% Alcohol pads
|Phosphate buffered saline
|6-0 prolene suture
|8-0 prolene suture
|Type: Tool, 14 day release
|Heparinized saline (0.9%)
|Neutral buffered formalin
|Microfil (silicone rubber contrast agent)
|Type Reagent, Microfil White
|Cal-Ex II (formic acid solution)
|Carl Zeiss Microimaging
|Zeiss Stemi 2000-C
|Laser Doppler perfusion imager
|Micro-CT imaging system
|Explore Locus SP
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