TissueDB/Simulators/Abdominal Wall Defect Simulator (Medeiros)
The Abdominal Wall Defect Simulator ("WALL-GO") is a pair of low-cost neonatal mannequins, built from locally available materials, for visually recognising and telling apart two congenital abdominal wall defects — gastroschisis and omphalocele. Each mannequin is built for one defect only, so the two are not interchangeable.[1]
| Field | Details |
|---|---|
| Features and Basic Operation | The finished models are used by visual inspection: the two are compared and the defects told apart by location and by the presence or absence of a covering sac. Gastroschisis shows exposed bowel loops to the right of the umbilicus with no covering; omphalocele shows viscera at the umbilicus covered by a translucent membranous sac. A small incision in the sac can simulate membrane rupture. |
| Current Development Status | Built and validated for face and content validity; transfer validity not fully addressed — a stated limitation. |
| Estimated Build Time and Cost | US$42 |
| Specialized Tools and Equipment | None — only ordinary household items are used (scissors, glue, pens, and white correction fluid). |
| Version | Version one — the first published WALL-GO build; the source does not number versions. Later iterations by other groups would be recorded here and in the development status. |
| Development Team Contact Information | Developed by Gabriel Araújo Medeiros and colleagues, with senior author Lourenço Sbragia (pediatric surgeon), at the University of São Paulo (Bauru and Ribeirão Preto Medical Schools), Brazil. Correspondence: sbragia@fmrp.usp.br. |
Tissues
| Tissue | Qty | Material | Cost | Notes |
|---|---|---|---|---|
| Skin and Subcutaneous Tissue | 2 | Vinyl doll | US$20 | Neonatal doll providing the torso, skin, and umbilical landmark; its abdominal wall is incised to make the defect. Newborn finish (a "spice" on the skin): talcum powder is dusted on as a cosmetic so the mannequin resembles a just-born newborn — applied once at build, not a consumable; its cost is included in the overall build total. ⚑ Open for review: a Talcum Powder material/class page is needed (route to Felipe). |
| Small Intestine | 1 | Sausage | US$0.50 | Herniated bowel loops; perishable, so the gastroschisis model is effectively single-use (the authors suggest a red cotton ball wrapped in cellophane tape as a durable substitute). Viscera colouring (a "spice" on the bowel): fake blood makeup is applied to colour the loops — applied once at build, not a consumable; its cost is included in the overall build total. The source notes the blood can be confused for bowel damage and suggests removing it in future versions. ⚑ Open for review: the colourant's class is a dye/fake-blood material page (missing — route to Felipe). |
| Peritoneum and Serosa | 1 | Yellow cellophane paper | US$0.50 | Omphalocele model only — forms the membranous sac over the viscera; a small incision in it can simulate membrane rupture. |
| Peritoneum and Serosa | n = 3 | Female condom | US$3 | ⚑ Open for review (best-attempt placement): the omphalocele membranous sac. The source lists the female condom among its materials and needed "a material covering these loops to represent the membranous sac"; it names only the cellophane in that role, but the translucent latex condom is the likely sac membrane (the project's earliest build draft classed the OC sac as latex + plastic film). Confirm with the team. No dedicated material/class page exists yet — pending the role decision, route to Felipe. |
| Umbilical cord (gastroschisis model) | 5 mm × 1 m | Latex tourniquet tube | US$4 | The umbilical cord, elaborated and separated from the herniated bowels on the gastroschisis model. Classed as tissue per Dr. Mohr (10 Jun 2026 walkthrough: "this is tissue… elaborating the umbilical cord separated from the bowels"); the source describes "components for elaborating the umbilical cord" without naming the specific material. Linked to the Umbilicus tissue page as the closest existing class. ⚑ Open for review: a dedicated umbilical-cord tissue/class page may be warranted, and the linked Plastic Tubing material page is currently tagged for deletion as a structural part, so the material-link target needs resolution too (route to Felipe). |
Structural Parts
| Part Name | Qty | Material | Cost | Notes |
|---|---|---|---|---|
| Umbilical cord clamp | 1 | Umbilical cord clamp | US$1 | Marks the umbilical cord and is kept clear of the herniated viscera (an expert found it sat too close in the source). The source does not state which model it is used on; this build places it on the gastroschisis model, where the cord is formed. |
| Pink fabric tape | 48 mm × 1 m | Pink fabric tape | US$6 | ⚑ Open for review: the source lists pink fabric tape with no stated use, and the project's prior notes never recorded one (Dr. Mohr recalled on 10 Jun that its use had been worked out, but it is not in the notes; she grouped it with the umbilical-cord elaboration). Placed here as a best-attempt assembly/fastening material — "pink" treated as an incidental, non-functional qualifier (links to the generic Tape class). Confirm the intended use with the team. |
Consumables
None — the trainer is used by visual inspection only; nothing is consumed during use. The build-time finishes (viscera colouring, newborn finish) are "spices" on their tissues, not consumables.
| Consumable | Quantity | Material | Approximate Cost | Notes |
|---|
Build Instructions
Phase 1: Prepare the doll bodies
- Obtain two 40 cm vinyl dolls, one for each defect model.
- Make a 4 cm circular incision to the right of the umbilicus on the first doll (gastroschisis).
- Make a 4 cm circular incision in the umbilical region of the second doll (omphalocele).
Verification: Each doll has a 4 cm opening — to the right of the umbilicus on the gastroschisis model and central on the omphalocele model.
Phase 2: Build and place the viscera
- Cut a 15 cm length of sausage (about 15 mm diameter) for the herniated intestinal loops. The source's Table 2 gives 15 cm while its text says about 25 cm; the 15 cm figure from the priced materials table is used here as the build spec.
- Colour the herniated viscera with about 20 ml of fake blood makeup.
- Place the viscera through the gastroschisis opening so they protrude, uncovered.
- Form the umbilical cord from a length of latex tourniquet tube and position it on the gastroschisis model, separated from the herniated bowel loops.
- Cover the viscera at the omphalocele opening with yellow cellophane paper (0.5 m²) to form the membranous sac; a small incision in it can simulate membrane rupture.
- Place the umbilical cord clamp on the umbilical cord, keeping it clear of the herniated viscera (on the gastroschisis model, where the cord is formed; the source does not state which model it is used on).
Verification: The gastroschisis model shows exposed loops with no covering; the omphalocele model shows viscera under a translucent membranous sac.
Phase 3: Finish
- Dust the models with about 100 g of talcum powder so they resemble newborns.
- Use the two finished models together to practise telling the two defects apart.
Verification: The two models are visually distinct — gastroschisis: paraumbilical defect, exposed viscera, no sac; omphalocele: central defect with a covering sac.
References
- ↑ Medeiros GA, Gualberto IJN, da Silva CHND, Diniz AMB, de Santana JBF, Volpe FP, Gadde R, Mazzo A, de Oliveira RC, Sbragia L. Development of a low-cost congenital abdominal wall defect simulator (wall-go) for undergraduate medical education: a validation study. BMC Medical Education. 2023;23(1):966. Open access (CC BY 4.0). DOI: 10.1186/s12909-023-04929-3. PMID 38102605.
| Authors | Arturopelayo |
|---|---|
| License | CC-BY-SA-4.0 |
| Cite as | Arturopelayo (2026). "TissueDB/Simulators/Abdominal Wall Defect Simulator (Medeiros)". Appropedia. Retrieved June 24, 2026. |