Ultrasound-Guided Funicular Block: Ropivacaine Injection into the Tissue around the Spermatic Cord to Improve Analgesia during Orchiectomy in Dogs

SIMPLE SUMMARY: Orchiectomy is a common surgical procedure performed on small animals and postoperative analgesia is very important because pain causes various negative effects that prevent patient recovery. Our study aimed to compare the intraoperative ultrasound-guided funicular block with ropivacaine and general anaesthesia using hypnotic and/or analgesic drugs and the postoperative hemodynamic stability and pain scores. This study demonstrated that the use of ultrasound-guided funicular, using ropivacaine, guarantees long-lasting and high-quality analgesic coverage and minimises the post-surgical pain inevitably associated with orchiectomy. This study stemmed from a general trend towards increasing attention on postoperative pain after orchiectomy in dog. Since veterinarians are becoming more focused on relieving surgical pain, anaesthetists are expected to use better protocols that can minimise pain. In fact, acute postsurgical pain is of great interest due to potential risk of becoming chronic if not treated properly. The routine use of the intraoperative ultrasound-guided funicular block with ropivacaine block is considered a useful alternative for pain management for orchiectomy in dogs, which can be performed under sedation or superficial general anaesthesia. In addition, the intraoperative ultrasound-guided funicular block with ropivacaine block ensures satisfactory analgesic coverage that lasts for at least 6 h postoperatively. ABSTRACT: Orchiectomy is a common surgical procedure performed on small animals, and it requires postoperative pain management despite its relative simplicity. This study aimed to evaluate the hemodynamic stability, intraoperative administration of additional hypnotic and/or analgesic drugs, and postoperative pain scores following the combination of ultrasound-guided injection of ropivacaine hydrochloride into the spermatic cord and infiltration by the same anaesthetic of the incisional prescrotal line (ROP) or general anaesthesia. Dogs in the ROP group showed greater intraoperative hemodynamic stability and lower pain scores than the control group. The locoregional approach used in this study proved effective in minimising the responses to the surgical stimulus and ensured adequate analgesia intra- and postoperatively. This method, called ultrasound-guided funicular block, allows orchiectomy to be performed under deep sedation without general anaesthesia.