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 tested; shown validity under certain circumstances.[1] |
| 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. |
| 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 |
|---|---|---|---|---|
| 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 possible durable substitute for a future version. The source lists fake blood makeup among the materials but does not state where it is applied. It notes that blood can be confused with 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 the cellophane can simulate membrane rupture. |
| Umbilical Cord | 1 | - | - | Figures 3 and 4 show a clamped umbilical cord. The source does not identify which listed material forms the cord. |
Structural Parts
| Part Name | Qty | Material | Cost | Notes |
|---|---|---|---|---|
| Mannequin host | 2 | 40 cm vinyl doll | US$20 | Provides the neonatal mannequin body and umbilical landmark. A 4 cm abdominal opening is cut into each doll to construct the corresponding defect. The source does not establish the vinyl doll as a specific tissue surrogate. |
| 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 farther away as a possible improvement for a future version. |
| Latex tourniquet tube | 5 mm × 1 m | Latex tourniquet tube | US$4.00 | Listed and costed in Table 2 of the source. The source does not state what this material is used for. |
| Pink fabric tape | 48 mm × 1 m | Pink fabric tape | US$6.00 | Listed and costed in Table 2 of the source. The source does not state what this material is used for. |
| Female condom | 3 | Female condom | US$3.00 | Listed and costed in Table 2 of the source. The source does not state what this material is used for. It is not assigned as the omphalocele membranous sac; the source explicitly uses yellow cellophane paper for that role. |
Consumables
| Consumable | Quantity | Material | Approximate Cost | Notes |
|---|---|---|---|---|
| Fake blood makeup | 20 mL | Fake blood makeup | US$4.00 | Listed and costed in Table 2 of the source. The source does not state where this material is applied. It notes that blood can be confused with bowel damage and suggests removing it in future versions. |
| Talcum powder | 100 g | Talcum powder | US$3.00 | Listed and costed in Table 2 of the source. The source states only that cosmetics were applied to the mannequins so they would resemble newborns; it does not state an individual function for the talcum powder. |
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 for the gastroschisis model.
- Make a 4 cm circular incision in the umbilical region of the second doll for the omphalocele model.
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.
- The source lists 20 mL of fake blood makeup among the materials but does not state where it is applied. Do not assign a source-specific placement.
- Place the viscera through the gastroschisis opening so that the loops protrude without a covering membrane.
- Form the umbilical cord and position it on the gastroschisis model, separated from the herniated bowel loops. The source does not identify the material used to form the cord.
- Cover the viscera at the omphalocele opening with 0.5 m² of yellow cellophane paper to form the membranous sac. A small incision in the cellophane can simulate membrane rupture.
- Clamp the umbilical cord with the umbilical cord clamp.
Verification: The gastroschisis model shows exposed bowel loops with no covering; the omphalocele model shows viscera beneath a translucent membranous sac.
Phase 3: Finish
Figure 4 — the finished gastroschisis (upper) and omphalocele (lower) mannequins in the frontal plane, with close-up panels. The frontal view shows the location of each defect in relation to the umbilicus. Faces are blurred as published. Image by Medeiros GA, Gualberto IJN, da Silva CHND, Diniz AMB, de Santana JBF, Volpe FP, Gadde R, Mazzo A, de Oliveira RC, Sbragia L, BMC Medical Education 2023;23:966; CC BY 4.0.
- Apply the cosmetics listed by the source — approximately 100 g of talcum powder and 20 mL of fake blood makeup — so that the models resemble newborns. The source does not state the individual function or placement of each cosmetic.
- Use the two finished models together to practise visually differentiating the two abdominal wall defects.
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 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.
| Alternative names | WALL-GO |
|---|
| Authors | Arturopelayo |
|---|---|
| License | CC-BY-SA-4.0 |
| Cite as | Arturopelayo (2026). "TissueDB/Simulators/Abdominal Wall Defect Simulator (Medeiros)". Appropedia. Retrieved September 13, 2026. |