Alphonsus Chong's Personal Wiki

Learning to perform microvascular anastomosis is difficult. Laboratory practice models using artificial vessels are frequently used for this purpose. However, the efficacy of such practice models has not been objectively assessed for the performance of microvascular anastomosis during live surgical settings. This study was conducted to assess the transfer of learning from practicing microvascular anastomosis on tubes to anastomosing rat abdominal aorta.

Ten surgeons without any experience in microvascular anastomosis were randomly assigned to an experimental or a control group. Both groups received didactic and visual training on end-to-end microvascular anastomosis. The experimental group received 24 sessions of hands-on training on microanastomosis using Silastic tubes. Next, both groups underwent recall tests on weeks 1, 2, and 8 after training. The recall test consisted of completing an end-to-end anastomosis on the rat's abdominal aorta. Anastomosis score, the time to complete the anastomosis, and the average time to place 1 stitch on the vessel perimeter were compared between the 2 groups.

Compared with the control group, the experimental group did significantly better in terms of anastomosis score, total time, and per-stitch time. The measured variables showed stability and did not change significantly between the 3 recall tests.

The skill of microvascular anastomosis is transferred from practicing on Silastic tubes to rat's abdominal aorta. Considering the relative advantages of Silastic tubes to live rodent surgeries, such as lower cost and absence of ethical issues, our results support the widespread use of Silastic tubes in training programs for microvascular anastomosis.

• Small sample size - 5 each arm
• Population - non-novice – trained neurosurgeons, with some microsurgical experience but no microvascular anastomosis experience; stated that groups had between 5-5.2 years of microsurgical experience
• Randomization - not stated
• Blinding - yes, 2 independent assessors (both are authors too)
• Experimental arm - silastic tube repairs:
  • 1 every other day
  • 6 x 2 mm tube then 6 x 1 mm tube
  • Ethilon 10/0
  • Participants given food before the session
• Both arms: didactic teaching about anastomosis and showed a video
• Outcome - transfer test at 1, 2, 8 weeks post training

Anastomosis Score Scale Used to Rate the Anastomosis of Rat Abdominal Aorta

*Patency of anastomosis was considered a more important feature than the amount of leakage. ^{^}Stenosis greater than 50% of the original diameter was scored as “significant.”

• Suggest no decay in 8 weeks; but small sample size

The authors spent a good portion of their discussion contrasting their paper with that of Grober et al. Their comments about the weaknesses of that study are generally fair. Both papers contribute to the literature for transfer of microsurgical skills.

• This is a useful contribution to the literature on skill transfer training in microvascular surgery. The fact that such a small sample size managed to show such an effect, points to the large effect size of the training.
• One major limitation, which the authors acknowledge, is the findings may not be generalizable to the wider population of trainees, because their “trainee” pool consisted of trained neurosurgeons with microsurgical experience
• Their inability to demonstrate lack of skill decay is most likely due to the small sample size rather than the absence of decay.

Mokhtari, P., Tayebi Meybodi, A., Lawton, M. T., Payman, A., & Benet, A. (2017). Transfer of Learning from Practicing Microvascular Anastomosis on Silastic Tubes to Rat Abdominal Aorta. World Neurosurgery, 108, 230–235. https://doi.org/10.1016/j.wneu.2017.08.132