Electrosurgery tip touching a pair of thumb forceps illustrating coaptive coagulation, where the forceps occlude the vessel and the electrical current is transferred to the tissue via the forceps. This allows for more precise application of monopolar electrosurgery. Photo courtesy Dr. Brandy Willeford Good surgery requires good hemostasis. As we learn in veterinary school, meticulous hemostasis is one of the basic principles of surgery. Controlling bleeding minimizes blood loss, reduces tissue trauma, maintains visibility of the surgical field, and can ultimately make a procedure more efficient. Electrosurgery is one tool that can help surgeons accomplish these goals. Studies in both veterinary and human medicine have demonstrated decreased blood loss with electrosurgical techniques for tissue incision compared with traditional scalpel incisions.1,2 Other studies have demonstrated reductions in surgical time with electrosurgical techniques.3 For practices considering an upgrade to their surgical equipment, electrosurgery can be a valuable addition to the surgical suite. However, not all electrosurgical devices work the same way, and understanding the differences between monopolar, bipolar, and vessel-sealing devices can help surgeons use them more effectively and safely. What is electrosurgery? Electrosurgery uses electrical current to cut tissue or achieve hemostasis. The electrosurgical generator produces an electrical waveform that is delivered to the tissue through an active electrode. Depending on the waveform and the way the current is delivered, the result can be tissue cutting, coagulation, or vessel sealing.4 Electrosurgery should not be confused with electrocautery, which uses electricity to heat an instrument that is then applied to tissue, much like a small branding iron. When using this device, electrical current itself does not pass through the patient. With electrosurgery, current is applied directly to tissue. The two primary electrosurgical circuits are monopolar and bipolar. Vessel-sealing devices are an advanced form of bipolar electrosurgery. Monopolar electrosurgery Monopolar electrosurgery is probably the most familiar form of electrosurgery in veterinary practice. The system uses a pencil-like handpiece with an active electrode at its tip and requires a dispersive or grounding pad. The electrical current travels from the active electrode through the patient’s tissue to the dispersive pad and back to the generator. Monopolar electrosurgery typically has cutting and coagulation functions. Cutting uses a continuous waveform that vaporizes tissue, allowing the electrode to create an incision, while coagulation uses an interrupted waveform that heats tissue in bursts, promoting protein denaturation and hemostasis. Coagulation energy can be applied directly to tissue or to a vessel grasped with a metal instrument when more precise hemostasis is needed. A variety of monopolar handpieces and tips are available, including blade and needle-style electrodes. Reusable handpieces may be appropriate when sterilized according to the manufacturer’s instructions, including any stated limits on autoclave cycles. An electrosurgery tip is applied to the vessel, illustrating the traditional use of monopolar electrosurgery. Photo courtesy Dr. Brandy Willeford Considerations when using monopolar electrosurgery One limitation of monopolar electrosurgery is that it can be less effective in a wet surgical field because fluid may provide an alternative pathway for current. Safety also depends on correct dispersive-pad placement, adequate pad contact, and proper patient positioning. The dispersive pad should be placed according to the manufacturer’s recommendations. Some pads require conductive gel, and others do not, so follow the instructions for the specific pad. The patient should be insulated from a metal surgical table, and metal collars, harnesses, or other conductive materials should be removed because they can create unintended current pathways. Alcohol-based skin preparation deserves particular attention because electrosurgical devices can ignite flammable vapors. Allow alcohol-based preparations to dry completely before activation, and follow appropriate fire-safety precautions. Many modern electrosurgical generators incorporate safety features that monitor the dispersive pad and can prevent activation if the pad is not appropriately connected. These features provide an additional layer of protection but should not replace proper patient preparation and pad placement. The blade monopolar tip is the most common monopolar electrosurgery tip. Photo courtesy Dr. Brandy Willeford A needle-point tip allows for precise application of monopolar electrosurgery. Photo courtesy Dr. Brandy Willeford Bipolar electrosurgery Bipolar electrosurgery uses a handpiece that resembles forceps. One tip acts as the active electrode and the other as the return electrode. Electrical current travels through the tissue between the two tips. Because current is confined primarily to the tissue between the electrodes, a dispersive pad is not required. Bipolar electrosurgery is useful when precise energy delivery is needed and can perform well in wet surgical fields. The trade-off is coagulation time may take longer than with monopolar electrosurgery, depending on the tissue and device. As with monopolar electrosurgery, the surgeon should understand the specific device being used, including recommended tissue types, settings, activation times, and limitations. An example of bipolar electrosurgery tips. Photo courtesy Dr. Brandy Willeford Vessel-sealing devices Vessel-sealing devices are an advanced form of bipolar electrosurgery. These devices combine pressure with bipolar electrical energy to seal tissue. The energy causes denaturation of collagen and elastin, creating a seal across the compressed tissue.4 Many vessel-sealing devices are marketed for sealing vessels up to 7 mm in diameter. However, the maximum vessel size varies by device, and the manufacturer’s recommendations should always be followed. Vessel-sealing devices can replace traditional ligatures in selected procedures, but they should not be assumed to work on every tissue. Seal quality depends on the tissue, structure size, specific device, and published evidence supporting its use. For example, researchers compared a vessel-sealing device with encircling ligature in canine uterine horns and bodies.5 They found no significant difference in burst pressure for structures less than 9 mm in diameter, but vessel-sealed tissue performed worse at 9 mm or greater. Based on these findings, they did not recommend the device for uterine horns or bodies 9 mm or larger. More recently, vessel sealing has also been evaluated for use on the cystic duct during canine cholecystectomy. In a retrospective study of 47 dogs undergoing open cholecystectomy for gallbladder mucocele, authors evaluated perioperative and short-term complications associated with sealing the cystic duct with a vessel-sealing device. They concluded the technique was safe and effective in the population studied.6 How often should vessel-sealing devices be reused? Manufacturers label many vessel-sealing handpieces as single-use devices, but some veterinary practices re-sterilize and reuse them because of cost. If a practice chooses to reuse a single-use device, the potential for device failure must be considered. A team evaluated the repeated sterilization of two commonly used vessel-sealing devices.7 The smaller scissor-like handpiece failed after a mean of 17.2 cycles, with the earliest failure after 10 cycles; While the larger handpieces failed after a mean of 20 cycles, with the earliest failure after 17 cycles. Based on these findings, the authors recommended discarding reused small scissor-like handpieces after nine sterilization cycles and the larger handpieces after 16 cycles, or sooner if there was any indication of intraoperative failure. These findings do not mean every vessel-sealing device will fail at the same cycle number. They do show why practices that reuse these devices should track sterilization cycles, monitor function, and remove devices from service before performance becomes unreliable. Putting it all together Electrosurgery is more than a replacement for the scalpel. When used appropriately, it can provide effective tissue dissection and hemostasis while improving visualization and potentially reducing surgical time. However, the goal should not simply be to use the latest available technology. The goal is to understand the technology well enough to use it appropriately. Monopolar electrosurgery can provide efficient cutting and coagulation but requires appropriate dispersive-pad placement and attention to patient safety. Bipolar electrosurgery provides more localized delivery of electrical energy and can be particularly useful when precision is important. Vessel-sealing devices can further simplify hemostasis in selected procedures, but their limitations need to be understood. Ultimately, electrosurgery is another surgical instrument. Like a scalpel, hemostat, or suture, its value depends on the surgeon knowing when to use it and when not to. Brandy Willeford, DVM, MS, DACVS-SA, is a board-certified veterinary surgeon and the medical director at Advanced Veterinary Care in Salt Lake City, Utah, a Thrive Pet Healthcare partner. In addition to her clinical and hospital leadership roles, Dr. Willeford serves as Thrive Pet Healthcare’s National Specialty Director of Surgery, supporting surgical teams and specialty care across the organization. Willeford is actively involved in the American College of Veterinary Surgeons and currently serves on the Certification Council. Her clinical interests include oncologic and urogenital surgery, wound management, acute and chronic pain management, and mentorship and leadership in veterinary medicine. References Meakin, Lee B, Jo C Murrell, Ivan C P Doran, Toby G Knowles, Michael S Tivers, and Guilllaume P A Chanoit. 2017. "Electrosurgery reduces blood loss and immediate postoperative inflammation compared to cold instruments for midline celiotomy in dogs: A randomized controlled trial." Veterinary Surgery 46 (4): 515-519. Aird, Lisa N.F., and Carl J. Brown. 2012. "Systematic review and meta-analysis of electrocautery versus scalpel for surgical skin incisions." The American Journal of Surgery 204 (2): 216-221. Scott, Jacqueline E, Elizabeth A Swanson, Jim Cooley, Robert W Wills, and Emily C Pearce. 2107. "Healing of canine skin incisions made with monopolar electrocautery versus scalpel blade." Veterinary Surgery 46 (4): 520-529. Benitez, Marian E. 2018. Chapter 15: Principles and Use of Energy Sources in Small Animal Surgery. Vol. 1, in Veterinary Surgery: Small Animal Expert Consult, by Spencer A Johnston and Karen M Tobias. St. Louis, Missouri: El. Barrera, Jessica S, and Eric Monnet. 2012. "Effectiveness of a bipolar vessel sealant device for sealing uterine horns and bodies from dogs." Journal of the American Veterinary Medical Association 73 (2): 302-305. Prychka, Holly A, and Ryan P Fulcher. 2025. "Use of a bipolar vessel-sealing device for cholecystectomy in dogs with gallbladder mucocele has similar complication rates to traditional cystic duct ligation methods (2018-2024)." Journal of the American Veterinary Medical Association 263 (10): 1-8. Kuvaldina, Alexandra, Galina Hayes, Julia Sumner, and Erica Behling-Kelly. 2018. "Incidence of multiple reuse and resterilizaiton cycles on the performance of a bipolar vessel sealing device (LigaSure) intended for single use." Veterinary Surgery 47: 951-957. Nezhat, Camran, Michael Lewis, and Louise P King. n.d. SLS Members Do Amazing Things. Accessed 7 25, 2026. https://sls.org/the-3rd-edition-prevention-management/chapter-11/.
