As with other types of extremity surgery, podiatric surgery is very specialized and very diverse in the different types of procedures performed routinely by surgical specialists. Procedures can range from simple or complex osseous surgery to delicate peripheral nerve surgery — all of which require some type of hemostasis to be performed optimally.
It is universally accepted that damage to tissues can result in a less optimal outcome for the patient. Such damage can occur via poor tissue handling, extensive dissection or collateral damage subsequent to a particular aspect of the overall surgical technique. For example, the injudicious use of electocautery can increase postoperative morbidity. Many times, the patient is subject to costly and painful additional reparative surgery because of nerve damage due to use of monopolar electrocautery.
It is also widely accepted that the use of monopolar cautery is routine in podiatric surgery and that the use of bipolar cautery constitutes only a small percentage of the cases that utilize some form of electrosurgery for hemostasis.
It is our conjecture that the widespread use of monopolar electrocautery is more a function of surgeon training rather than surgeons actually taking into consideration the goals of hemostasis and the physical properties of these different electrosurgical modalities. A review of the history and development and the physical characteristics of electrocautery may cause the surgeon using monopolar cautery to reconsider that modality and switch to the use of bipolar cautery.
Functional results and research from other surgical specialties, such as neurosurgery and hand surgery, can be extrapolated into podiatric surgery to improve technique and outcomes.
A Guide To The History And Principles Of Electrosurgery
Heating tissue to achieve hemostasis is not a recently developed technique. In 1926, William T. Bovie, PhD, a physicist at Harvard, modernized the technique.1 Building on the advances of his predecessors, Bovie constructed an electrosurgical unit that “produced high-frequency current delivered by a ‘cutting loop’ to be used for cutting, coagulation and desiccation.”2
At a staff meeting in which his new device was under discussion, Bovie was approached by Harvey Cushing, MD, a surgeon who was interested in using Bovie’s device to control blood loss in a brain operation.1 A 64-year-old patient of Cushing’s had an enlarging vascular myeloma of the head, a tumor that Cushing had unsuccessfully attempted to remove by more traditional means. The vascularity of the tumor was complicating the removal of the tumor but Bovie’s new electrosurgical device seemed promising.
Accordingly, Cushing used Bovie’s device when he made another attempt at removing the myeloma. The operation was a success and Dr. Cushing thereafter used the Bovie device increasingly with excellent results.2
In electrosurgery, electrical current passes through tissues to create a desired clinical effect.2 A generator produces the current and sends the current along to an active electrode. The active electrode then passes the current on to the tissue to create the desired effect, whether that is cutting, fulguration or desiccation. The current exits the tissue via the return electrode, which completes the electrical circuit by returning the current to the generator.2,3
What You Should Know About The Risks Of Monopolar Electrosurgery
In monopolar electrosurgery, the active electrode has a small tip that concentrates the electrical current before it enters the tissue. This high current density at the tip of the active electrode produces heat and energy, which facilitate the desired clinical effect such as cutting, fulguration or desiccation. In order to prevent this heat and energy from producing the same effect on the tissue where the current leaves the body, the return electrode is large and disperses the exiting current over a broad surface area.3,4
This electrosurgical delivery system has inherent risks and dangers. Burns are one of the most common complications of monopolar electrosurgery.1 Burns are the result of a concentrated current exiting the body, which can happen if the dispersive electrode is not in full contact with the body, if it has dried out or if it becomes disconnected.1,3,5 As Advincula and Wang pointed out, “Excessive hair, adipose, scar tissue and even the presence of fluid lotions can diminish the quality of contact between the return electrode and the patient’s skin.”3 In these situations, current will seek other routes, such as electrocardiogram leads, towel clips, intravenous stands or stirrups, neurosurgical head frames and even the operating table.1,2,5 Although return electrode monitoring systems can usually detect if the dispersive electrode has lost full contact with the patient’s skin, they will not prevent all burns.6
Fires are another problem associated with electrosurgical devices. These devices are the most common cause of operating room fires and explosions with 100 cases reported each year. “Electrosurgical units can ignite nearby sources of fuel that include paper or cloth drapes, flammable liquids or gaseous anesthetics when in proximity with an oxygen-rich environment,” according to Advincula and Wang.3
Electromagnetic interference is another inherent danger of monopolar electrosurgery. The electrical current in a monopolar device can interfere not only with electrocardiogram monitors but also with pacemakers, conductive prosthetic joints and cochlear implants.1,2 In the case of the pacemaker, this interference can result in asystole, syncope, bradycardia, ventricular fibrillation, reprogramming or even destruction of the pacemaker. As for cochlear implants, they can be damaged by the electrical interference or cause “unintended cochlear stimulation and injury through the electrode array.”1
Finally, the current can cause unwanted muscle and nerve stimulation.1 It is not hard to see why monopolar cautery is considered to be so much more dangerous than bipolar cautery.6
A Pertinent Overview Of The Emergence Of Bipolar Electrosurgery
In February 1973, Jacques Emile-Rioux, MD, a gynecologist from Laval University in Quebec, Canada, attended a staff meeting to discuss an intestinal burn during a laparoscopic sterilization.7 Troubled by this puzzling complication, he struggled to find a solution. Then he found one: “All of a sudden, it hit me. Why not bring the current into one prong of the forceps and retrieve it from the other, thus providing the shortest path for the returning current — that is, whatever is between them.”7
He quickly made his idea a reality. From sturdy, malleable coat hanger wires, Emile-Rioux made the prongs by flattening one end of each on an anvil and twisting the other ends with pliers, making finger holds. For insulation, he used a thin piece of wood introduced in a hollow, rigid tubing from a broom.7 Emile-Rioux then showed his creation to someone in the department of electrical engineering, who had a prototype ready for him a week later.
Emile-Rioux brought his bipolar prototype to his next abdominal hysterectomy. He coagulated one tube with a conventional monopolar instrument and coagulated the other tube with his new device.7 The pathologist evaluated the depth of coagulation as “quite sufficient.” As he noted, the only difference was that on the bipolar side, only the tube was coagulated whereas on the unipolar side, coagulation had spread into the mesosalpinx. Thus bipolar electrosurgery was born.
This ingenious contraption became the solution to many of the problems (including burns, fires and electromagnetic interference) created by the monopolar electrosurgical unit. Since the active electrode is on one side of the forceps, the return electrode is on the other side of the forceps. Furthermore, the only tissue involved is the tissue that the forceps grasp (in between the two electrodes).
There is “very little chance for unintended dispersal of current” and therefore little chance of the associated complications.2 This also results in “a more refined area of coagulation with less char formation. Damage to the surrounding tissue is minimized” and so is “unwanted muscle and nerve stimulation.”1,3
Due to the many advantages of bipolar electrosurgery, many surgeons prefer it and many more recommend it. Brill stated that the advantages of bipolar electrosurgery have “quickly catapulted the use of bipolar electrosurgery as the principal method for non-mechanical laparoscopic tubal sterilization” and added further that “most gynecologic surgeons are inherently more comfortable and apt to use bipolar rather than monopolar electrosurgery.”8
Malis commented on the decreased damage to the tissue induced by bipolar electrosurgery and how “the geometry of the current flow permits the use of the bipolar system in the most delicate areas where unipolar currents would be completely unacceptable.”9
In podiatric surgery and especially lower extremity peripheral nerve surgery, there is no advantage to the use of monopolar cautery over bipolar cautery as hemostasis does not diminish with the use of bipolar cautery. We have seen several cases of iatrogenic drop foot in neurolysis of the common peroneal nerve (common fibularis), in which the surgeon used monopolar cautery, which caused thermal injury to the nerve. In specialized lower extremity peripheral nerve surgery workshops, we emphasize that use of monopolar cautery is dangerous and can have disastrous consequences for the patient.
Bipolar cautery is not only recommended in patients with pacemakers or other implanted devices — such as cochlear implants — by the Association of periOperative Registered Nurses (AORN), but also in patients needing arthroscopic shoulder surgery.1,10,11 This shows the versatility and safety of this incredible technology.
There are minimal disadvantages to bipolar electrosurgery, such as “increased time needed for coagulation … and adherence to tissue with incidental tearing of adjacent blood vessels.”1 However, in lower extremity surgery, this is rarely a real consideration and the benefits and safety for the patient so far outweigh this potentially small laparoscopic complication.
Technology is always improving, however, and new bipolar devices are no exception. Surgeons implementing bipolar cautery in podiatric surgery find that there is no real compromise in hemostasis. Decreasing the tissue damage induced by monopolar electrosurgery and the associated postoperative morbidity while concurrently increasing patient safety should be the goal of all surgeons.
Dr. Barrett is an Adjunct Professor with the Arizona Podiatric Medical Program at the Midwestern University College of Health Sciences in Glendale, Ariz. He is a Fellow of the American College of Foot and Ankle Surgeons.
Joseph Vella is a fourth-year podiatry student with the Arizona Podiatric Medicine Program at the Midwestern University College of Health Sciences in Glendale, Ariz.
Dr. Dellon is a Professor of Plastic Surgery and Neurosurgery at Johns Hopkins University in Baltimore.
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10. Recommended practices for electrosurgery. AORN Journal 2005; 81(3):616-42.
11. Diab MA, Fernandez GN, Elsorafy K. Time and cost savings in arthroscopic subacromial decompression: the use of bipolar versus monopolar radiofrequency. Int Orthop 2009; 33(1):175-179.