Research Article: Suture length to wound length ratio for simple continuous abdominal closures in veterinary surgery: An experimental in vitro study

Date Published: April 26, 2019

Publisher: Public Library of Science

Author(s): Moriz E. Klonner, Brigitte Degasperi, Barbara Bockstahler, Gilles Dupré, Vincenzo Miragliotta.


This study aimed to investigate the suture length to wound length ratio (SL:WL) in an in vitro model of abdominal wall closure. Effects of the surgeon’s experience level on the SL:WL ratio were evaluated, hypothesizing that small animal surgeons do not spontaneously apply SL:WL ratios equal to or larger than 4:1.

Three groups of surgeons with varying levels of experience performed 4 simple continuous sutures before (3 sutures) and after (1 suture) being educated on principles of the SL:WL ratio. All sutures were evaluated for their gaping, number of stitches, stitch intervals, tissue bite size and suture length.

No significant differences in suture parameters or SL:WL ratios were found among the 3 groups, and 60.5% of control sutures and 77.0% of test sutures had SL:WL ratios above 4:1. There was a significant improvement in the mean ratio after the information was provided (p = 0.003). Overall, the SL:WL ratios ranged from 1.54:1 to 6.81:1, with 36.3% falling between 4:1 and 5:1 (5.17 mm mean stitch interval, 5.52 mm mean tissue bite size). A significant negative correlation was observed between the SL:WL ratio and the stitch interval to tissue bite ratio (r = -0.886). Forty-nine of 120 sutures fulfilled the current recommendations for abdominal wall closure with a mean SL:WL ratio of 4.1:1.

A SL:WL ratio larger than 4:1 was achieved in 60% of the control sutures and in 77% of test sutures. Additional animal studies are necessary to evaluate the SL/WL ratio in small animal surgery.

Partial Text

Incisional hernias are a frequent and unpredictable complication after midline laparotomy surgeries on humans; depending on the definition, their incidence rate in humans ranges from 4–23%.[1] The most common causes of incisional hernias are improper suturing techniques and wound infection, but suture breakage, knot slippage and untying are also possible causes.[2–4]

Three groups of ten participants each were assembled: group A (European College of Veterinary Surgery and European College of Animal Reproduction diplomates with more than 5 years of experience in small animal soft tissue surgery), group B (junior veterinary staff surgeons and residents in small animal veterinary surgery) and group C (small animal interns of veterinary medicine and surgery).

In total, 120 sutures were analyzed, and 8,747 measurements were taken.

To our knowledge,[25] this is the first study to assess the surgical techniques of small animal surgeons performing abdominal wall closures and evaluating their SL:WL ratios using an in vitro model. We explored how the surgeon’s level of experience affected the suturing technique and how the surgeon’s techniques changed after being educated on the SL:WL ratio.

By following the current textbook recommendations and applying a stitch interval close to the tissue bite size, an SL:WL ratio equal to or larger than 4:1 can be achieved using an in vitro laparotomy closure model.