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 Not stated in source. |
| 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. |
| 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. |
Source — every material, build step and cost on this page is drawn from Medeiros et al., BMC Medical Education 2023 unless a cell notes otherwise.
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. Talcum powder is dusted over the finished model so it resembles a just-born newborn. |
| 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). Fake blood makeup is applied to colour the loops. The source notes the blood can be confused for bowel damage and suggests removing it in future versions. |
| 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. |
Structural Parts
| Part Name | Qty | Material | Cost | Notes |
|---|---|---|---|---|
| Umbilical cord clamp | 1 | Umbilical cord clamp | US$1 | Clamps the umbilical cord. One of the paper's expert reviewers judged the clamp to sit too close to the viscera, and the authors list moving it away as a change for the next version of the model. |
| Latex tourniquet tube | 5 mm × 1 m | Latex tourniquet tube | US$4.00 | Listed and costed in the source's materials table (Table 2). The source does not state what this material is used for.[1] |
| Pink fabric tape | 48 mm × 1 m | Pink fabric tape | US$6.00 | Listed and costed in the source's materials table (Table 2). The source does not state what this material is used for.[1] |
| Female condom | 3 | Female condom | US$3.00 | Listed and costed in the source's materials table (Table 2), which gives no measurement for it. The source does not state what this material is used for — in particular it is not the membranous sac, which the source builds from yellow cellophane paper.[1] |
Consumables
| Consumable | Quantity | Material | Approximate Cost | Notes |
|---|---|---|---|---|
| Fake blood makeup | 20 mL | Fake blood makeup | US$4.00 | Applied to colour the herniated bowel loops. The source notes the blood can be confused for bowel damage and suggests removing it in future versions.[1] |
| Talcum powder | 100 g | Talcum powder | US$3.00 | Listed and costed in the source's materials table (Table 2). The source states only that cosmetics were applied to the mannequins so they would resemble newborns; it does not say individually what the talcum powder does.[1] |
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 length of sausage for the herniated intestinal loops. The source's materials table gives 15 mm × 15 cm; its text describes a sausage of about 25 cm.
- 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 and position it on the gastroschisis model, separated from the herniated bowel loops. The source does not name the material used for the cord.
- 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.
- Clamp the umbilical cord with the umbilical cord clamp.
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
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 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 August 4, 2026. |