Resin polymer and corrosion casting of the porcine pelvi-calyceal system: a useful model for investigating new imaging and endoscopic techniques of the upper urinary tract

Abstract

We describe the use of polyester resin casting of the pelvi-calyceal (PC) system as a method of evaluating the accuracy of new three-dimensional imaging technology such as ultrasound and computerised tomography. Thirty-eight kidneys from large white pigs were used for the study. We describe the process of preparation of the kidney and polyester resin for injection into the PC systems. The setting process of the resin is an exothermic reaction with an associated change in consistency. The PC systems of the kidneys were injected with resin in a controlled manner and casts obtained by maceration of the kidneys. Some of these kidneys had been distended previously with 11% glycerol and three-dimensional ultrasound reconstructions of their PC systems were compared to resin casts to assess accuracy of the reconstructions. Thirty-eight casts were created out of which 13 were poor. The quality of the casts improved with practice and pelvi-calyceal morphology could be faithfully recreated. Controlled perfusion and watching for signs such as a "turgid feel" of the kidney help avoid pelvi-calyceal disruption. Anatomically accurate casts of the kidney PC system can be created using polyester resin with the technique described. These casts can be a useful research and training tool with urological and radiological applications.

Casting Materials and their Application in Research and Teaching

“…Creation of free radicals at the unsaturated bonds propagates a chain reaction to other unsaturated bonds in adjacent molecules, linking them in the process. To reduce working temperatures (called cold-setting) and thus hasten the hardening process a catalyst is used (John et al, 2008). Three percent methyl ethyl peroxide (Pereira-Sampaio et al, 2012) or styrene monomer (John et al, 2008) are popular catalysts.…”

“…To reduce working temperatures (called cold-setting) and thus hasten the hardening process a catalyst is used (John et al, 2008). Three percent methyl ethyl peroxide (Pereira-Sampaio et al, 2012) or styrene monomer (John et al, 2008) are popular catalysts. Polyester forms a brittle nonpliable cast, is capillarypassable, can be used for SEM (Ohkuma et al, 1997), and is also used as a plastination resin (Weiglein, 1997).…”

Evaluation of the Accuracy of 3-Dimensional Ultrasonography of the Kidney Using an In Vitro Renal Model

“…The PCS was first modeled out of clay (Air-hardening modeling clay; Calder Colours [Ashby] Ltd, Ashby-de-la-Zouch, England), and latex (latex emulsion; Specialist Crafts, Leicester, England) was then coated over. Previously created casts of a pig kidney PCS 14 and pictures of casts of human kidneys were used as references to model the clay. There were 7 calices and infundibula in total.…”