Ultrasound-Guided Hook-Wire Localization for Surgical Excision of Non-Palpable Superficial Inguinal Lymph Nodes in Dogs: A Pilot Study

SIMPLE SUMMARY: The evaluation of regional/sentinel lymph nodes (LN) plays an important prognostic role and assists the clinical decision making in canine cancer patients; thus, surgeons are frequently asked to perform regional/sentinel lymphadenectomies together with management of the primary tumor sites, even when these are non-palpable and/or normal size LN. Several techniques have been described to localized regional/sentinel LN in a pre-surgical setting. The wire-guided localization is commonly used to localize non-palpable breast masses in women, with the aim to reduce surgical dissection and excision of unnecessary tissue and to reduce surgical time. This study describes the use of an ultrasound-guided hook-wire localization method to facilitate intraoperative localization of non-palpable superficial inguinal LN. The results of the present study suggest that this method is safe and effective and may allow a high rate of successful superficial inguinal LN excisions in dogs. ABSTRACT: The evaluation of loco-regional lymph nodes (LN) plays an important prognostic role and assists the clinical decision making in canine cancer patients. Excision of non-palpable LN can be challenging. The aim of the study was to evaluate surgical time, successful excision rate and surgical complications associated with the use of an ultrasound-guided hook-wire (UGHW) LN localization method for non-palpable superficial inguinal LN (SILN) in dogs. Dogs that presented for excision of non-palpable SILN, performed with the aid of an UGHW placement, were enrolled. Information including signalment, SILN width, UGHW placement and surgical procedure time, hook-wire position, successful excision and intra- and post-operative complications were reviewed. Seventeen dogs were enrolled. Median LN width was 3 mm (range 2–11). Median time of preoperative UGHW placement and surgical LN excision was 8 min and 15 min, respectively. Successful SILN excision was achieved in all cases. Two minor intra-operative (hook migration and wire fragmentation) and one minor post-operative complications (seroma) were observed. No major intraoperative or post-operative complications occurred. The UGHW LN localization method is safe and effective and may allow a high rate of successful SILN excisions in dogs. This method has the potential to facilitate LN excision for other superficial LN locations.