TissueDB/Simulators/Percutaneous Renal Access Simulator (Ewald)
General Information
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 |
|---|---|
| General Information | A low-cost, durable ballistic-gelatin model for fluoroscopy-guided percutaneous renal access. The collecting system can be shaped to represent anatomic variants such as horseshoe kidney, calyceal diverticula and malrotated kidneys; adjacent organ models (diaphragm, colon) can be added and the foam cover thickened to simulate obesity, all to increase difficulty. As described in Ewald et al. 2019 (PMID 30668307).[1] |
| Features and Basic Operation | The model is built in three layers. A radio-opaque renal collecting system is made by pouring a mix of ballistic gelatin, iohexol contrast (Omnipaque 300) and water into a nitrile glove shaped like the collecting system, with the glove fingers tied off to set calyceal length. This is embedded in a plain ballistic-gelatin block on a clear acrylic base, so the collecting system can be seen from below, and covered with opaque polyurethane foam holding chalk sticks that stand in for ribs 10–12. The trainee uses fluoroscopy to guide a needle into the upper, middle or lower calyx; a successful puncture is confirmed by looking through the acrylic base or the side of the block.[1] |
| Current Development Status | Built and content-validated; durable. Ewald et al. 2019.[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: a 24 × 13 × 6.5 cm rectangular mould, half-inch electrical tape and refrigeration to set the gelatin.[1] |
| Version | As described in Ewald et al. 2019 (Turkish Journal of Urology 45(1):31–6).[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 nitrile glove shaped as collecting system. Radio-opaque calyceal anatomy for fluoroscopic needle targeting.[1] |
| Skin and Subcutaneous Tissue | 1 | Polyurethane Foam | — | Premium Poly Foam. Layers of thick, visually opaque foam encase the gelatin block, giving resistance and visual obstruction that simulate overlying tissue.[1] |
| Bone | 3 | 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 (1.5–2 cm diameter).[1] |
Build Instructions
Phase 1: Collecting system
- 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 1.19 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 June 4, 2026. |