Peripheral sentinel lymphadenectomy in 163 dogs: Postoperative surgical complications and comparison between intraoperative dissection techniques

Objective: The first aim was to describe the incidence and severity of surgical complications following peripheral lymphadenectomy in dogs. The second was to compare three surgical techniques: unassisted lymphadenectomy, intraoperative guidance by methylene blue dye alone (MB) or by a combination of γ-probe and MB (γ-MB). The third was to assess whether the number, palpability, and site of lymph nodes (LNs) influenced the incidence of complications. Study design: Retrospective multicenter study. Sample population: Lymphadenectomies (n = 201) from 163 client-owned tumor-bearing dogs. Methods: Medical records of dogs undergoing both preoperative sentinel LN (SLN) mapping and excision of peripheral SLNs between December 2020 and April 2023 were reviewed. Signalment, intraoperative assistance technique, number of LNs, surgical time, postoperative treatments, site, and timing of complications observed were collected. Results: Seventy-two (36%) lymphadenectomies were performed without assistance, 24% with MB and 40% with γ-MB. The overall incidence of surgical complications was 7.5%, of which 80% were mild. The most frequent complication was seroma (2.5%). None of the variables considered in the logistic regression model, including intraoperative guidance, influenced the complication rate (p =.255). Using the decision tree statistical model, mandibular and retropharyngeal lymphadenectomy affected the complication rate when surgery lasted more than 21.5 min. Conclusion: Lymphadenectomy of peripheral LNs was associated with a low rate of mild complications, regardless of intraoperative assistance. Mandibular and retropharyngeal lymphadenectomies lasting more than 21.5 min may result in more complications. Clinical significance: Lymphadenectomy of superficial LNs is a safe procedure that is easy to perform in most cases, even without intraoperative assistance.