TissueDB/Simulators/Percutaneous Renal Access Simulator (Ewald)
The Ewald Percutaneous Renal Access Trainer is a low-cost ballistic-gelatin model for fluoroscopy-guided percutaneous renal access training, letting trainees practise needle access to the upper, middle and lower renal calyces under fluoroscopy.[1]
| Field | Details |
|---|---|
| Features and Basic Operation | The model is built in three layers. A radio-opaque renal collecting system is made by pouring ballistic gelatin, iohexol contrast (Omnipaque 300) and water into a nitrile glove shaped like the collecting system, with the fingers tied off to set calyceal length. This is embedded in a plain gelatin block on a clear acrylic base, so the collecting system is visible from below, and covered with opaque polyurethane foam holding chalk sticks that stand in for ribs 10–12. Under fluoroscopy the trainee guides a needle into the upper, middle or lower calyx and confirms the puncture through the acrylic base or the side of the block. Difficulty can be raised by shaping the glove into anatomic variants (horseshoe or malrotated kidney, calyceal diverticula), adding adjacent-organ models, or thickening the foam.[1] |
| Current Development Status | Built and evaluated for content validity at a single institution; durable, but not construct-validated or clinically tested.[1] |
| Estimated Build Time and Cost | US$60[1] |
| Specialized Tools and Equipment | A fluoroscopy (C-arm) unit for image guidance and a percutaneous access needle (for use). For construction: half-inch electrical tape to shape the glove and refrigeration to set the gelatin.[1] |
| Version | 1 |
| Development Team Contact Information | Jonathan M. Ewald, Julie W. Cheng, Shawn M. Engelhart, Michael C. Wilkinson, Mohammad Hajiha, Hillary Wagner and D. Duane Baldwin, of the Loma Linda University School of Medicine and the Department of Urology, Loma Linda University, California, USA. Corresponding author: D. Duane Baldwin (dbaldwin@llu.edu).[1] |
Tissues
| Tissue | Qty | Material | Cost | Notes |
|---|---|---|---|---|
| Kidney | 1 | Ballistic gelatin (iohexol-enhanced) | — | 10% ballistic gelatin + 30% iohexol (Omnipaque 300) + 60% water by weight, poured into a nitrile glove shaped as the collecting system, then embedded in a plain contrast-free 10% ballistic-gelatin block that forms the surrounding tissue the needle passes through. Radio-opaque calyceal anatomy for fluoroscopic needle targeting.[1] |
| Skin | 1 | Polyurethane Foam | — | Premium Poly Foam. Layers of thick, visually opaque foam encase the gelatin block, giving resistance and visual obstruction that simulate overlying skin, fat and muscle.[1] |
| Bone | Not specified in source | Chalk | — | Chalk sticks embedded between foam layers to simulate ribs 10–12; create fluoroscopic needle interference.[1] |
Structural Parts
| Part Name | Qty | Material | Cost | Notes |
|---|---|---|---|---|
| Clear acrylic glass base | 1 | Acrylic | — | Supports the gelatin block and allows direct visualisation of the collecting system from below.[1] |
| Nitrile examination glove | 1 | Nitrile | — | Small glove fashioned into the renal collecting-system shape; fingers tied off to adjust calyceal length.[1] |
| Rectangular casting mould (24 × 13 × 6.5 cm) | 1 | Not specified in source | — | Build-only form; the contrast-enhanced collecting system is embedded and the plain gelatin block is cast in it, then removed once set.[1] |
Build Instructions
Phase 1: Collecting system
The source gives the gelatin as proportions by weight rather than fixed amounts. Mix enough contrast-enhanced gelatin to fill the glove, and enough plain gelatin (Phase 2) to fill the 24 × 13 × 6.5 cm mould — roughly two litres.
- Mix 10% ballistic gelatin with 30% iohexol contrast (Omnipaque 300, GE Healthcare) and 60% water by weight.[1]
- Pour the contrast-enhanced gelatin mixture into a small nitrile examination glove (Halyard Health Inc., Alpharetta GA).
- Tie off the fingers of the glove to adjust calyceal length to a diameter of 1.5–2 cm.
- Wrap tied fingers with half-inch electrical tape to adjust infundibular width.
- Set the contrast-enhanced gelatin at 2 °C for 3 hours to create a radio-dense renal collecting system.
Verification: The collecting system should be firm and radio-opaque when viewed under fluoroscopy.
Phase 2: Block assembly
- Place the collecting system in a 24 × 13 × 6.5 cm rectangular mold.
- Cover the collecting system with 10% ballistic gelatin (no contrast added).
- Set for an additional 12 hours at 2 °C.
- Remove the finished gelatin block from the mold.
- Place the gelatin block on a clear acrylic glass base.
Verification: The collecting system should be visible through the clear acrylic base and through the sides of the gelatin block.
Phase 3: Cover assembly
- Cover the gelatin block with layers of thick, visually opaque polyurethane foam (Premium Poly Foam, American Excelsior Company, Arlington TX).
- Embed chalk sticks measuring 10 × 1.5 × 1.5 cm between foam layers to simulate ribs 10–12.
Verification: Chalk sticks should be visible on fluoroscopy and should create needle interference requiring technique adjustment.
Not Suitable For
- Percutaneous nephrostomy tract dilation — model trains needle access only, not tract dilation or sheath placement[1]
- Nephroscopy or lithotripsy of stones — model does not incorporate these procedures.[1]
- Ultrasound-guided access training — polyurethane foam contains air that obscures ultrasound visualization of calyces (removal of foam layer required for ultrasound use)[1]
- Respiratory excursion simulation — model does not simulate kidney movement during breathing[1]
References
- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 1.14 1.15 1.16 1.17 1.18 Ewald JM, Cheng JW, Engelhart SM, Wilkinson MC, Hajiha M, Wagner H, Baldwin DD. A realistic, durable, and low-cost training model for percutaneous renal access using ballistic gelatin. Turk J Urol 2019;45(1):31–6. DOI: 10.5152/tud.2018.43569. PMID: 30668307.
| Authors | Arturopelayo |
|---|---|
| License | CC-BY-SA-4.0 |
| Cite as | Arturopelayo (2026). "TissueDB/Simulators/Percutaneous Renal Access Simulator (Ewald)". Appropedia. Retrieved July 13, 2026. |