EP404 - High fidelity model for teaching ileoanal pouch procedure (IPAA) using fresh frozen vs preserved cadaver; Educational outcomes compared

Purpose/Background: Surgical intervention for ulcerative colitis (UC) has been decreasing for decades, as has exposure of colorectal surgery trainees to restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA). We previously conducted a study with a fresh frozen cadaver model. Post procedure assessment showed comparable tissue handling and anatomic fidelity to in vivo, with improved anatomic understanding and confidence. The current study uses a conventionally preserved cadaver, which is more accessible and less costly. Outcomes of the two studies are compared.

Methods/Interventions: Both studies include a didactic module on patient selection and assessment, and a practical module of total proctocolectomy, techniques for a tension free IPAA, and ileal pouch construction and anastomosis. Modules were taught by board certified colorectal surgeons; learners included a colorectal fellow and three senior general surgery residents. The previous study used a fresh frozen cadaver; the current study used a conventionally preserved cadaver. Learners were asked to assess anatomic understanding, ease/fidelity of tissue handling, and confidence after each study with results compared.

Results/Outcomes: In the previous study, learners felt tissue handling and anatomic fidelity of the fresh frozen tissues were comparable to in vivo, and anatomic understanding and confidence were improved. The involved board-certified surgeons agreed that the primary outcome of effectively teaching the IPAA procedure with high fidelity in tissue handling and anatomic identification was achieved.

However, preserved tissues were inelastic and fragile compared to fresh frozen tissues. Tissue quality particularly hampered maneuvers to mobilize the small bowel mesentery for gaining length for pouch construction. The preserved tissues held staples and stitches poorly. Learners reported inferior anatomic understanding and a less realistic experience regarding pouch construction and attempts at anastomosis, and did not report increased confidence. The involved board-certified surgeons agreed that the primary outcome of effectively teaching the IPAA procedure with high fidelity in tissue handling and anatomic identification was not achieved in this model.

Conclusion/Discussion: Surgical trainees value high fidelity surgical skills labs for performing advanced/complex procedures in an environment similar to the OR that is safer than operating on humans. Anatomic understanding, skills, and confidence are improved compared to conventional lower fidelity models. The IPAA procedure is a key skill in colorectal surgery, and trainees must be well trained in its performance. Colorectal surgery educators are investigating how the procedure, or its component steps, may be effectively taught outside the operating room, with the goal of augmenting CRS trainees' clinical experience. The current study and our previous study show that a fresh frozen cadaver model can be used to effectively teach performance of the IPAA procedure with improved anatomic understanding and confidence, and that substitution of a preserved cadaver does not produce the same educational outcomes. There are increased costs and logistical needs when using a fresh frozen cadaver, which may hamper the ability of some institutions to employ this model. Additional investigations into educational methods of teaching the IPAA procedure to CRS trainees should continue to be explored.

Figure 1
Preserved Cadaver
Figure 2
Fresh Frozen Cadaver