Laparoscopic extirpation of iliosacral lymph nodes in select dogs is safe and effective with or without intraoperative lymphangiography

Objective: To describe the surgical technique, complications, and outcomes of laparoscopic iliosacral lymph node (ISLN) extirpation in dogs with apocrine gland anal sac adenocarcinoma (AGASACA), with or without intraoperative lymphangiography. Animals: 18 client-owned dogs underwent laparoscopic ISLN extirpation (19 procedures) between March 2012 and May 2024. Dogs were included if medical records were complete, the dogs were diagnosed with AGASACA, and an attempted laparoscopic ISLN extirpation was performed. Clinical Presentation: Dogs were evaluated for staging and/or management of suspected metastasis to ISLNs. The study population included 11 male castrated and 7 female spayed dogs with a mean age of 9.95 ± 1.8 years (range, 7 to 14 years). Pertinent physical examination abnormalities included firm, irregular, or nodular masses involving one or both anal sacs, perianal subcutaneous tissues, or prior anal sacculectomy sites. Results: 16 of 19 procedures (84.2%) were completed totally laparoscopically, while 3 of 19 (15.8%) required reactive conversion to open celiotomy. Intraoperative lymphangiography was attempted in 6 of 19 procedures (31.6%) using indocyanine green, methylene blue, or both. Indocyanine green was successful in 2 of 3 cases (66.7%), whereas methylene blue was unsuccessful in all attempts. Intraoperative surgical complications occurred in 9 of 19 procedures (47.3%), and most were mild and self-limiting. Histopathology confirmed metastatic ISLN(s) in 14 of 19 cases (73.7%). All dogs survived to discharge, and 18 of 19 cases (94.7%) survived beyond 14 days postoperatively. Clinical Relevance: Laparoscopic ISLN extirpation, with or without intraoperative lymphangiography, is a viable diagnostic and treatment approach for dogs with AGASACA, supporting the increasing role of minimally invasive surgery in veterinary surgery including oncologic staging.