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 | Evaluated by 15 experts and 90 medical students for recognition of congenital abdominal-wall defects. Transfer validity was not fully addressed.[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. Fake blood makeup colours the loops. The authors note that blood can be confused with bowel damage and suggest 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 m | Latex tourniquet tube | US$4.00 | Represents the umbilical cord, separated from the herniated bowel loops in the gastroschisis model. Table 2 lists 1 m of 5 mm tubing stock; the cut length for an individual cord is not specified. |
| Skin (doll body) | 2 | 40 cm vinyl doll | US$20 | Provides the neonatal body and umbilical landmark. A 4 cm abdominal opening is cut into each doll. The source describes cosmetic finishing but does not assess skin-tissue realism. |
| Viscera colouring | 20 mL | Fake blood makeup | US$4.00 | Adds colour to the herniated bowel loops. The authors note that blood can be confused with bowel damage and suggest removing it in future versions. |
| Newborn skin finish | 100 g | Talcum powder | US$3.00 | Listed among the materials in Table 2. The paper gives no application method or evidence of reduced stickiness. |
Structural Parts
| Part Name | Qty | Material | Cost | Notes |
|---|---|---|---|---|
| Umbilical cord clamp | 2 | Umbilical cord clamp | US$1 | Clamps the umbilical cord. Figures 3 and 4 show one clamp on each mannequin; Table 2 does not give a purchase count. One expert reviewer judged the clamp too close to the viscera, and the authors suggest moving it farther away in a future version. |
| Pink fabric tape | 1 m | Pink fabric tape | US$6.00 | 48 mm wide. Listed and costed in Table 2 of the source; its use in the assembly is not specified. |
| 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. |
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.
- Colour the herniated bowel loops with fake blood makeup. Table 2 lists 20 mL of makeup; it does not give a per-model application amount. The authors suggest omitting the blood in future versions because it can be confused with bowel damage.
- Place the viscera through the gastroschisis opening so that the loops protrude without a covering membrane.
- Form the umbilical cord from latex tourniquet tubing and position it on the gastroschisis model, separated from the herniated bowel loops. The paper lists 5 mm × 1 m tubing stock but does not give the cut length or attachment method for the cord.
- Cover the viscera at the omphalocele opening with yellow cellophane paper to form the membranous sac. A small incision in the cellophane can simulate membrane rupture. Table 2 lists 0.5 m² of purchased cellophane; it does not prescribe a cut size for the sac.
- 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
The authors describe cosmetic finishing after construction. Table 2 lists 100 g of talcum powder. The paper gives no application method or per-model amount.
- 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 October 3, 2026. |