Inguinal hernias appear as a bulge in a patient’s groin region and occur when tissues from the abdomen push through weakened abdominal muscles. As these hernias are common throughout childhood, inguinal hernia repair (IHR) is a key pediatric surgical procedure. The success of this surgery is heavily reliant on the knowledge of a patient's groin anatomy, and both open, and laparoscopic approaches require considerable repetition to master. As surgical simulations have shown promise in other surgical fields, the Munich Team and the Digital Lab came together to develop a 3D printed open and laparoscopic pediatric IHR simulator.

To develop a model that was optimal for IHR practice, the team opted to create a virtual 3D model  of a 2-year-old child. The structures that were segmented in the creation of the model were determined based on findings from normal contrast-enhanced computed tomography (CT) scans of both male and female patients aged 3-7. To limit the impacts of small patient size and radiation treatment on anatomical accuracy, a CT scan of a 7-year old patient was scaled to model the 2-year old following validated protocols. After being validated by a radiologist the model was manufactured.

Combinations of silicone, mesh, and thread were utilized to create low-cost skin, the aponeurosis of the external oblique, preperitoneal fat, cremaster muscle, retroperitoneum, and peritoneum. Other anatomical structures such as ligaments and blood vessels were constructed from rubber, rope and thread. A condom was used to replicate the hernia sac.  

Using Computer Aided Design (CAD) software, a physical simulator was designed to encapsulate all 3D printed anatomical structures and to include modular sections for laparoscopic and open inguinal hernia repair cartridges. Through an iterative design process, all additive manufactured components were incorporated into the cartridge designs with detailed instructions on replacing and assembling the cartridges for both surgical techniques.

The validation of our bespoke inguinal hernia surgical simulator has been successfully completed, involving surgical residents, fellows, and experienced surgeons in iterative qualitative user testing. Participants engaged in simulated scenarios, performing both open and laparoscopic surgeries on the simulator while following procedural surgical steps and anatomical landmarks.Following the simulations, participants completed a post-simulation questionnaire assessing anatomy representation, instrument handling, procedural content, perceived realism, confidence, and comfort level. Expert feedback guided refinements throughout the process, leading to an optimized surgical training tool. With this validation, the simulator is now positioned to enhance inguinal hernia repair (IHR) education and improve surgical outcomes.

This study was funded by the Evidence to Innovation seed grant at the BC Children's Hospital.

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Iterative Design and Manufacturing of a 3D-Printed Pediatric Open and Laparoscopic Integrated Simulator for Hernia Repair (POLISHeR) (Link)

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