Abstract
Background Extensive studies have been conducted using the rat model to understand the potential
technical errors that lead to anastomotic failure. However, current literature indicates
that the rat model has excellent tolerance to diverse errors committed by microsurgeons.
The error-investigating rat model is often created by one or two experienced surgeons,
and only one isolated technical error is examined. These biases may potentially cause
limitations of the results from previous studies. Meanwhile, venous anastomoses have
rarely been investigated in previous literature. Therefore, it is important to elucidate
this topic with a more comprehensive study design.
Methods Ninety-four arterial and 94 venous anastomoses on Sprague–Dawley rat femoral vessels
that were performed by 47 microsurgeons who participated in the microsurgery course
at the Columbia University and the University of Thessaloniki were evaluated. In total,
10 technical errors were examined: (1) disruption of suture line, (2) back-wall stitch,
(3) oblique stitch, (4) wide bite, (5) partial thickness bite, (6) unequal suture
distance, (7) tear in vessel wall, (8) excessively tight suture, (9) suture threads
in lumen, and (10) large edge overlap. The frequency of each error committed, and
the 30-minute postoperative patency was also recorded. The underlying causal relationship
between these errors, potential interaction, and the short-term anastomosis patency
was analyzed statistically.
Results Only the back-wall stitch was found to have a significant causal effect on arterial
anastomosis failure (p < 0.001). Back-wall stitch, wide bite, and partial thickness bite significantly impact
venous anastomosis patency (p < 0.001). No other statistically significant result was found.
Conclusion Overall, the rat model is highly resilient to various technical errors despite these
mistakes being often considered clinically unacceptable. Therefore, researchers need
to consider the resilience of the rat model when designing and analyzing future studies.
In addition, microsurgery instructors should focus on individual stitch quality rather
than the final patency.
Keywords
microsurgery training - microsurgery errors - rat model in microsurgery
