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Título Del Artículo (Inglés): 3d Printed Supramesocolic Laparoscopic Simulator for the Choledochoduodeno Anastomosis: Proposal for a Model

This study proposes and validates a 3D-printed supramesocolic laparoscopic simulator for choledochoduodenostomy, demonstrating that repeated practice on the model significantly improves surgical skills and reduces procedure time.

Original authors: Miguel Vassallo Palermo, Aquiles Ramón Molero Chacón, José Leonardo Morao Pompilli, Alexis Oliveros Grimán

Published 2026-06-26✓ Author reviewed ⓘ

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CC BY 4.0

Original authors: Miguel Vassallo Palermo, Aquiles Ramón Molero Chacón, José Leonardo Morao Pompilli, Alexis Oliveros Grimán

Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). ✨ This is an AI-generated explanation of the paper below. It is not written by the authors. For technical accuracy, refer to the original paper. Read full disclaimer

Imagine you are trying to learn how to tie a very complex knot inside a tiny, dark box while wearing thick gloves and looking at the knot only through a tiny camera screen. That is essentially what modern laparoscopic (minimally invasive) surgery feels like. It's not just about knowing the steps; it's about developing a "muscle memory" that your brain doesn't naturally have.

This paper presents a clever solution to that problem: a 3D-printed practice box designed specifically to teach surgeons how to perform a difficult procedure called a choledochoduodenostomy (connecting the bile duct to the intestine).

Here is the breakdown of their work, explained simply:

The Problem: The "Video Game" Difficulty

Surgeons today often operate through tiny holes rather than big cuts. This is great for patients (less pain, faster recovery), but it's hard for the surgeon. You lose your sense of touch, your view is flat (2D), and your hands move in weird ways.

The Analogy: Think of it like trying to play a high-speed video game using only a joystick and a 2D screen, but the "game" is real life, and if you make a mistake, a patient gets hurt.
The Gap: There are many rare, complex procedures (like the one in this study) that surgeons don't get to practice often enough in real life. They need a safe place to fail and learn before touching a real patient.

The Solution: A Custom "Flight Simulator" for the Belly

The authors built a specialized training model using 3D printing.

The Build: They didn't just print a plastic block. They created a "hybrid" model. The bones and organs (like the stomach and duodenum) are printed in rigid plastic (PLA), but the soft, squishy parts (like the bile duct and blood vessels) are made from flexible rubber tubes inserted into the plastic.
The Setup: This model fits inside a standard "box trainer" (a plastic box with holes for tools). The surgeons look through a camera (a custom-made, low-cost scope) and use real surgical tools to operate on this fake anatomy.
The Mission: The goal was to practice the Sasse technique, a specific way of connecting the bile duct to the duodenum to let stones pass through.

The Experiment: 25 Rounds of Practice

The researchers had a participant practice this specific surgery 25 times on their 3D model.

The Rules: They didn't just guess if it got better. They used two strict measuring sticks:
1. GOALS Scale: A checklist where experts rated the surgeon's skill (like a video game score for "dexterity" and "safety").
2. Stopwatch: They timed exactly how long the surgery took.

The Results: The Learning Curve

The results were clear and impressive, showing a classic "learning curve":

Speed: On the very first try, the surgery took 120 minutes (2 hours). By the 25th try, it took only 54 minutes.
Skill: The "GOALS" score started low (9 out of 25) and climbed steadily until it hit the maximum score (25 out of 25) by the end.
The Turning Point: Around the 14th practice session, the surgeon hit a "sweet spot." After this point, they were consistently fast and highly skilled.
Satisfaction: The surgeon rated the training experience a perfect 5 out of 5, saying they felt highly satisfied with how the model helped them learn.

Why This Matters (According to the Paper)

The paper argues that this 3D-printed model is a game-changer for a few reasons:

Realism: Unlike simple plastic boxes, this model feels real because of the rubber tubes, giving the surgeon the right "tactile feedback" (the feeling of the tissue).
Safety: It allows surgeons to make mistakes and learn from them without risking a human life.
Accessibility: Traditional training often uses cadavers (which are expensive and hard to get) or basic boxes (which aren't specific enough). This 3D model is cheap to make, repeatable, and specific to the exact surgery needed.

The Bottom Line

The authors conclude that this 3D-printed simulator successfully recreated the complex steps of a rare surgery. It proved that if you give a surgeon a realistic, repeatable "flight simulator" to practice on, they can drastically improve their speed and skill in a short amount of time, making them much safer and more efficient when they eventually perform the real surgery.

Technical Summary: 3D Printed Supramesocolic Laparoscopic Simulator for Choledochoduodenostomy

Problem Statement
Laparoscopic surgery offers significant patient benefits, including reduced recovery times and postoperative pain. However, the transition from open to minimally invasive techniques presents steep learning curves due to altered depth perception, reduced tactile feedback, and hand-eye coordination challenges. While simulation is a recognized tool for acquiring these skills, training for rare and complex procedures like the side-to-side choledochoduodenostomy (CDD) remains difficult. Traditional cadaveric models are limited by high costs and availability, and standard box trainers often lack the specific anatomical fidelity required for advanced supramesocolic procedures. Furthermore, a review of existing literature revealed a lack of 3D-printed training models specifically designed to replicate the sequential steps of a CDD using the Sasse technique.

Methodology
The study proposed and evaluated a novel 3D-printed supramesocolic laparoscopic simulator designed to replicate a side-to-side CDD. The methodology involved three primary components:

The Simulator Model: A hybrid model consisting of 27 modular pieces printed with Polylactic Acid (PLA) and Thermoplastic Polyurethane (TPU). It features a semi-U-shaped base (20 cm x 20 cm) adapted to a standard laparoscopic box trainer. The model integrates rigid 3D-printed structures with elastomeric rubber tubing (10 mm diameter) to simulate the common bile duct, duodenum, and portal venous system, providing realistic tactile feedback.
Instrumentation: The setup included a standard laparoscopic box trainer with three 5-mm trocars and a custom-made, low-cost choledochoscope (3 mm diameter, 1080p HD, 0° view) connected to a monitor.
Training Protocol: A prospective, longitudinal cohort study was conducted involving 25 practical sessions. Participants performed the Sasse technique for CDD, which included steps such as the Kocher maneuver, choledochotomy, choledochoscopy, stone extraction, and the anastomosis itself.
Evaluation Metrics: Performance was assessed by three expert surgeons using the Global Operative Assessment of Laparoscopic Skills (GOALS) scale and by recording the execution time for each session. Participant satisfaction was measured via a structured Likert scale. Statistical analysis utilized Kendall's tau-b and Spearman's rho coefficients to correlate practice sessions with performance metrics.

Key Contributions

Model Design: The paper presents a reproducible, 3D-printed hybrid model that successfully replicates the anatomical conditions of the supramesocolic region, specifically the relationship between the common bile duct and the duodenum required for a CDD.
Procedural Fidelity: The simulator allows for the complete rehearsal of the Sasse technique, including critical steps often omitted in basic trainers, such as intraoperative choledochoscopy, stone extraction, and complex intracorporeal suturing.
Validation Framework: The study integrates the GOALS scale and operative time measurement to objectively quantify the learning curve for this specific procedure, moving beyond subjective assessment.

Results
The study demonstrated a clear learning curve over the 25 sessions:

Skill Acquisition: GOALS scores showed a statistically significant positive correlation with the number of practice sessions, increasing from a low of 9 points in the first session to a maximum of 25 points by the 25th session.
Efficiency: Execution time decreased significantly, dropping from 120 minutes in the initial session to 54 minutes in the final session.
Learning Curve Inflection: A strong inverse correlation was found between session number and execution time ( $p < 0.001$ ). The data indicated an asymptotic crossover point at session 14, suggesting a critical inflection point where technical efficiency and procedural quality substantially improved.
Satisfaction: Participants reported maximum satisfaction (5/5 on all items) regarding the training curriculum, instructor support, and the utility of the simulator in refining technical skills.

Significance and Claims
The authors claim that this 3D-printed simulator serves as a vital educational resource for advanced laparoscopic training, particularly for procedures that are infrequently performed during standard residency. By offering a cost-effective, highly reproducible alternative to cadaveric models, the simulator enables surgeons-in-training to master the neuro-psychomotor skills required for CDD in a safe, controlled environment. The study concludes that the model successfully shortens the learning curve for this complex surgery, thereby potentially enhancing patient safety when these procedures are eventually performed in clinical settings. The integration of specific anatomical fidelity with objective assessment tools (GOALS and time tracking) provides a rigorous framework for evaluating technical proficiency before transitioning to the operating room.