The original Bovie electrosurgical unit was monopolar, passing current through the patient’s body and back to the generator via a return pad. Today, though, “Bovie” has become a generic term for virtually any electrosurgical device, and Bovie-brand generators can operate in both monopolar and bipolar modes. So when someone in the operating room asks for “the Bovie,” they almost always mean the monopolar pencil, but the generator powering it is capable of both.
Why “Bovie” Usually Means Monopolar
William T. Bovie was a plant physiologist at Harvard who, in 1920, developed an electrosurgical unit that could deliver continuous or interrupted waveforms to cut or coagulate tissue. Neurosurgeon Harvey Cushing brought it into clinical practice, and the name stuck. That original device worked on a monopolar principle: high-frequency alternating current traveled from a handheld electrode into the patient’s tissue, spread through the body, and returned to the generator through a large pad placed on the patient’s skin.
Because that monopolar pencil was the breakthrough tool, surgeons began calling any electrosurgical generator a “Bovie.” The habit persists. In most operating rooms, saying “hand me the Bovie” means the monopolar cautery pencil, not a bipolar instrument.
How Monopolar Current Travels
In monopolar electrosurgery, your body becomes part of the electrical circuit. Current leaves the tip of the active electrode (the pencil), passes through the target tissue, disperses widely through the body, and exits through a return electrode, a sticky pad placed on a large muscle mass like the thigh. The pad’s large surface area spreads the current out so it doesn’t concentrate enough to burn the skin underneath.
Because the current covers a broad path, monopolar mode is effective for cutting through tissue and achieving wide coagulation. It also means more energy travels through the body overall, which matters in certain patient populations.
How Bipolar Current Travels
Bipolar electrosurgery keeps the current contained. The instrument is typically a pair of forceps where one tine delivers the current and the other receives it. Current passes only through the small piece of tissue pinched between the tips, then returns directly to the generator. No return pad is needed, and no current flows through the rest of the body.
This localized path gives bipolar instruments a shallower depth of tissue effect. Less surrounding tissue is heated, which reduces collateral damage. In one comparative study of surgical wound excisions, the bipolar group had no wound infections while the monopolar group did, a difference researchers attributed to less heat spreading into adjacent tissue. The tradeoff is that bipolar mode generally takes longer to achieve the same coagulation and is not as efficient for broad cutting.
When Surgeons Choose One Over the Other
Monopolar electrosurgery dominates in procedures that require fast cutting and broad coagulation. It’s the default for skin incisions, dissection through muscle layers, and most open surgeries where speed matters and the tissue being treated isn’t near delicate structures.
Bipolar is preferred when precision matters more than speed. Neurosurgery, microsurgery, and procedures near nerves or small blood vessels all favor bipolar instruments because the current stays between the forceps tips and won’t stray into nearby structures. It’s also the safer choice for patients with implanted cardiac devices like pacemakers or defibrillators.
Safety Differences Worth Knowing
The biggest safety distinction comes down to how far the current travels. Monopolar electrosurgery is the primary source of electromagnetic interference with implanted cardiac devices. If a monopolar instrument is used above the waistline, the current path can pass near a pacemaker or defibrillator and potentially cause it to malfunction. When the surgical site is below the umbilicus and the return pad is also placed below the umbilicus, the risk drops significantly. Bipolar electrosurgery does not cause electromagnetic interference unless the instrument is applied directly on top of the device itself.
For patients with cardiac implants, guidelines recommend using bipolar electrosurgery whenever possible. When monopolar must be used, keeping bursts to five seconds or less and placing the return electrode on the opposite lower limb from the device both help minimize risk.
Return pad placement also matters for skin safety in any patient. Current clinical guidelines from the Association of periOperative Registered Nurses recommend using dual-foil conductive return electrodes or capacitive electrodes over single-foil pads, and the preferred terminology is now “return electrode” rather than the outdated “grounding pad.” Notably, there is no definitive evidence linking standard electrosurgery with modern generators to burns caused by jewelry, metal implants, or tattoos, though surgical teams still assess those factors on a case-by-case basis.
Modern Bovie Generators Do Both
Any modern electrosurgical generator, whether made by the Bovie brand (now Apyx Medical) or competitors like Covidien or Erbe, includes both monopolar and bipolar output ports. The generator itself is neither exclusively monopolar nor exclusively bipolar. It produces the high-frequency current, and the mode depends on which instrument is plugged in and which port the surgeon activates. Plug in a pencil electrode with a return pad on the patient, and you’re using monopolar. Plug in bipolar forceps, and the same generator delivers bipolar output.
So while the name “Bovie” traces back to a monopolar invention and still informally refers to monopolar cautery in everyday surgical language, the machines themselves have long since evolved to support both modes from a single unit.