Analysis of factors influencing wound healing complications following wide excision of feline injection site sarcomas

Copyright of these abstracts is retained by the authors of the abstract unless assigned elsewhere by them. Abstracts are grouped by topic (either Small Animal or Large Animal) and then listed in alphabetical order of the first author's name. Presenters names are underlined. Names with asterisk indicate that the author is an ECVS or ACVS Diplomate. Introduction: Wide surgical resection is the main therapy for injection site sarcomas in cats. The aim of this study was to analyze factors influencing the development of wound healing complications in cats undergoing wide surgical resection of injection site sarcomas. The relationship between clinical dimension and computed tomographic (CT) dimension was also investigated. Materials and methods: Medical records of client owned cats with injection site sarcomas located on the trunk were reviewed. Cats were enrolled in the study if they underwent wide excision planned with contrast‐enhanced computed tomography. Cats receiving neoadjuvant treatment were not included. The relationship between clinical dimensions and CT dimensions was evaluated by linear regression. Wound healing complications were divided into major (when further surgery and/or general anesthesia were required) and minor. The prognostic effect of covariates (sex, age, weight, body condition score, site, clinical dimension, CT dimensions, histological type, duration of surgery, surgical margin status, local anesthesia) on major and minor wound healing complications was evaluated by a Cox model. Bivariate analysis of tumor dimension adjusted for duration of surgery and a multiple regression linear model was used to evaluate the relationship between duration of surgery and clinical variables (site, CT width, excision and reconstruction pattern). Results: Forty‐nine cats were enrolled in the study. The risk of developing major wound healing complications significantly increased with a body condition score of 5/ 5, with increasing weight, duration of surgery and CT dimensions and when non‐ linear reconstruction was adopted. On bivariate analysis the duration of surgery remained associated with the risk of major complication whereas tumor size no longer had a significant impact. In the multiple regression model the duration of surgery influenced by the excision pattern and tumor CT width. The clinical dimensions underestimated CT dimensions, especially in small injection site sarcomas. Conclusion: An increased duration of surgery, caused by a larger tumor and non‐ linear reconstruction, is associated with a significantly increased risk of developing major wound healing complications following injection site sarcoma resection. The clinical dimensions underestimates true tumor size and pre‐surgical CT examination is advisable for both large and small masses.