|TECHNIQUES AND INNOVATIONS
|Year : 2015 | Volume
| Issue : 1 | Page : 28-30
A Reformed Corrosion Cast Technique using Commercially Available Polyvinyl Chloride Solution
Sabita Mishra, Madhu Sethi
Department of Anatomy, Maulana Azad Medical College, New Delhi, India
|Date of Web Publication||27-Jan-2015|
Dr. Sabita Mishra
Department of Anatomy, Maulana Azad Medical College, New Delhi - 110 002
Source of Support: None, Conflict of Interest: None
Corrosion cast technique has advanced since its first application using wax by Leonardo da Vinci in 16 th century. Various materials such as metal alloys, celloidin, latex gum, synthetic resins/epoxy resins, polyester resins, and silicone have been used to prepare cast of vasculature and ductal architecture. However, the current reformed technique as described used commercially available polyvinyl chloride (PVC) solution to prepare cast of vascular/ductal anatomy. This technique being cost-effective and rapid can be easily applied in low resource situation. The Department of Anatomy Maulana Azad Medical College, New Delhi standardized this technique to prepare corrosion casts using PVC solution and is regularly training participants in the annual workshop on "body preservation techniques on embalming plastination and musemology" conducted by the Department.
Keywords: Blood vessel, corrosion cast, polyvinyl chloride, resin
|How to cite this article:|
Mishra S, Sethi M. A Reformed Corrosion Cast Technique using Commercially Available Polyvinyl Chloride Solution. MAMC J Med Sci 2015;1:28-30
|How to cite this URL:|
Mishra S, Sethi M. A Reformed Corrosion Cast Technique using Commercially Available Polyvinyl Chloride Solution. MAMC J Med Sci [serial online] 2015 [cited 2020 May 31];1:28-30. Available from: http://www.mamcjms.in/text.asp?2015/1/1/28/150058
| Introduction|| |
Corrosion casts are an established technique to study the three-dimensional structure of blood vessels, ductal system, and cavities of organ and tissue. A well-prepared cast provides an excellent tool to have an in-depth knowledge of the organ and tissue studied; as they replicate the vasculature and ductal system anatomy. 
| Background|| |
In 16 th century, Lenardo Da vinci was the first to prepare a cast by injecting dissolved wax into the bovine ventricles and heart chambers. Later, anatomists tried to improvise the technique of casting in order to produce a replica of the biological structure. The modern corrosion casting methods are based upon the idea of Jan Schwamnerdan of the 17 th century, following the injection of wax into the blood vessels the surrounding parenchyma was dissolved by a corroding agent. Low melting point metal alloys and later celloidin dissolved in organic solvents have also been used to make casts. Hinmann in 1923 formulated the basic principle of injecting low viscosity resins which could enter vessels of small caliber. These techniques were improvised by introducing celluloid solutions, polymerizing resins, latex gum, and subsequently great advance in the corrosion casting technique was made with the introduction of synthetic resins, polyester resins and silicone. Cellulose acetyl butyrate and Epoxy resin with the addition of a hardener can also be used to prepare a corrosion cast. ,
| Advanced Study|| |
Revolutionary advancement of corrosion casting techniques was initiated by Murakami in 1971. He introduced a semipolymerized methyl methacrylate for the purpose of cast making and later observing the casts under the Scanning electron microscope. ,
| Properties of an Ideal Casting Media|| |
An ideal casting media has certain properties which makes it easy to inject into the blood vessels or ductal system of an organ. The media/resin should be of a low viscosity nontoxic liquid, polymerize within a short period following injection with minimal shrinking and should be resistant to corrosion, cleaning, and dissection.
Although there are a number of methods to prepare corrosion cast, there are no studies where commonly used polyvinyl chloride (PVC) solution used in plastic industry has been tried out to prepare a corrosion cast. For the first time as an innovation, we tried to prepare a corrosion cast using PVC a simple thermoplastic polymer with 57% chlorine and 43% carbon widely used in plastic industry. It has the properties of an ideal casting medium, easily available and economical. 
| Procedure of Preparing a Corrosion Cast|| |
Preparation of the polyvinyl chloride
PVC is available as thick colorless viscous liquid which is stored in airtight containers. Colored resins available commercially in the plastic industries are used to make different colored PVC solutions. One can select the colors according to the vessel, duct or cavity to be studied using the routine anatomical color codes; E.g., red-artery, blue-vein, green-ducts, yellow, white or orange for cavities. To prepare an ideal colored casting medium, the thick viscous fluid is diluted with acetone in a proportion of 1:1 and then a few drops of the colored resin is added.
Procurement of a fresh specimen is a prerequisite to prepare an ideal cast. Formalin-fixed specimens cannot be used. To remove blood and debris, the specimen is washed under running water. The vessels (artery/vein) and ducts of specimen into which media is to be injected are exposed by careful dissection. Vessels/ducts are flushed with water/normal saline to clear the lumen. However, it causes water absorption and can make the specimen edematous, which can be resolved by immersion in any dehydrating agent.
| Injection of Casting Media|| |
With the help of disposable syringes attached to plastic cannulas, the casting material is injected into the vessels according to the color code [Figure 1]. The injection is continued until a resistance is felt, avoiding leakage from the injection site as it would polymerize and give a false picture. The procedure should take place within an hour, to avoid early polymerization of the casting media. The vessels are clamped and ligated following the injection [Figure 2]. The specimens are kept at 80°C overnight in an incubator for the solution to polymerize in each vessel uniformly. Next day, the specimens are brought to room temperature and washed with tap water. The specimens are then immersed in a large glass container containing 50% hydrochloric acid. The acid gradually corrodes the surrounding tissue. Time taken for corrosion depends on the size of the specimen. Once the corrosion process is completed, the corroded cast is washed gently and with a fi ne forceps all debris is removed to finally get an intact well-formed cast [Figure 3]. The Department of Anatomy, Maulana Azad Medical College, New Delhi standardized this technique to prepare corrosion casts using PVC solution and is regularly training participants in the annual workshop on "body preservation techniques on embalming plastination and musemology" conducted by the department [Figure 4].
|Figure 1: Injection of casting media into the specimen of placenta with syringes attached to plastic cannula (arrow)|
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|Figure 2: Clamping and ligation of vessels after the injection of casting media in the specimen of placenta. The placental vasculature can be seen clearly with the casting media in their lumen|
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|Figure 3: Displaying the corrosion cast of placenta. Vein is seen in blue and artery is in red color media. The casting media (polyvinyl chloride) can also be seen penetrating the terminal vessels|
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|Figure 4: Demonstration of the corrosion cast technique during a National Workshop on "Preservation techniques of the human body" held by the Department of Anatomy in February 2014|
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This technique using commercially available PVC solution is cost-effective, easily reproducible, and consumes less time. Casts formed by this method are relatively firm and give an ideal three-dimensional picture of the vascular pattern of the specimen. The standard casts have to be handled meticulously and stored in containers as they become dry and brittle while the PVC casts are firm. Thus, they can be displayed in the museum and used effectively for teaching.
| References|| |
Mishra S, Kheya R, Ajmani ML, Murty OP. The segmental anatomy of human liver by special technique of vascular injection. J Med Toxicol 1998;XIV: 6-9.
Giuvarasteanu I. Scanning electron microscopy of vascular corrosion casts - Standard method for studying microvessels. Rom J Morphol Embryol 2007;48:257-61.
Motta PM, Murakami T, Fujita H. Scanning Electron Microscopy of Vascular Casts: Methods and Application. Electron Microscopy in Biology and Medicine. New York: Kluwer Academic Publishers; 1992. p. 416.
Hossler FE, Quillen JH. Vascular corrosion casting can provide quantitative as well as morphological information on the microvasculature of organs and tissues. Micros Today Sept 1998;6: 14-5.
KinPatrick S. Practical Guide to Polyviny Chloride. 1 st
ed., Ch. 1, 4. Shrposhire, UK: Smithers Rapra Publishing; 2005.
[Figure 1], [Figure 2], [Figure 3], [Figure 4]