Diathermy: Electrosurgery for Tissue Treatment & Bleeding Control

What Is Diathermy and How Does It Work?

Diathermy is a medical procedure that uses high-frequency alternating electric current to generate controlled heat in body tissues. The heat can cut through tissue like a scalpel, coagulate blood vessels to stop bleeding, or destroy unwanted tissue. A small instrument resembling a pen or forceps delivers the electric current precisely to the treatment area.

The word "diathermy" comes from the Greek words dia (through) and therma (heat), literally meaning "heating through." This accurately describes the fundamental principle: electric current passes through body tissue, generating heat that produces the desired therapeutic effect. Modern diathermy equipment can produce temperatures exceeding 200°C at the point of contact, allowing for precise tissue manipulation.

Diathermy has been used in medicine for over a century, with continuous refinements in safety and effectiveness. The technique works because body tissues conduct electricity, and when current flows through tissue with natural resistance, heat is generated according to the laws of physics. By controlling the current's intensity, waveform, and duration, physicians can achieve different effects ranging from gentle tissue coagulation to precise cutting.

The technology behind diathermy involves generating radiofrequency electrical energy, typically in the range of 300 kHz to 3 MHz. At these frequencies, the current does not stimulate nerves or muscles, making it safe for surgical use. Instead, the energy is converted to heat at the point where the electrode contacts tissue, creating highly localized thermal effects without affecting surrounding structures.

Types of Diathermy

There are two main types of diathermy used in medical practice, each with distinct characteristics and applications:

Monopolar diathermy is the most common form used in surgery. In this configuration, current flows from an active electrode (the surgical instrument) through the patient's body to a large dispersive electrode (return pad) placed on the skin, usually on the thigh or back. The current density is very high at the small active electrode, producing intense heat, while the large return pad spreads the current over a wide area, preventing burns. Monopolar diathermy is effective for cutting and coagulation over larger areas but requires careful patient positioning and pad placement.

Bipolar diathermy uses an instrument with two electrodes close together, such as forceps. Current flows only between these two electrodes through the small amount of tissue between them. This provides precise, localized energy delivery with minimal current passing through the rest of the body. Bipolar diathermy is preferred for delicate procedures, especially near sensitive structures like nerves and blood vessels, and is safer for patients with pacemakers.

What Are the Medical Uses of Diathermy?

Diathermy has several medical applications including stopping nosebleeds (epistaxis) by cauterizing bleeding vessels, permanent hair removal (electrolysis), removing skin lesions such as warts and skin tags, controlling bleeding during surgical procedures, and treating certain gynecological conditions. The technique is used across multiple medical specialties including ENT, dermatology, and general surgery.

The versatility of diathermy makes it valuable across many medical disciplines. Its ability to precisely control bleeding while simultaneously cutting tissue has made it indispensable in modern surgery. Beyond the operating room, diathermy finds applications in outpatient clinics and specialized treatment centers for various conditions.

Treatment of Nosebleeds (Epistaxis)

One of the most common outpatient uses of diathermy is treating recurrent nosebleeds. When a specific bleeding vessel can be identified in the nasal cavity, diathermy provides a quick and effective solution. The procedure involves applying a numbing spray to the nose, then using the diathermy instrument to cauterize (seal) the bleeding vessel. The heat causes the blood vessel to constrict and the surrounding tissue proteins to coagulate, creating a seal that stops the bleeding.

This treatment is particularly useful for patients who experience frequent nosebleeds from the same location, often due to a prominent blood vessel in the nasal septum (the wall between the nostrils). The procedure typically takes only a few minutes and provides lasting relief for most patients. While some discomfort is possible, the local anesthetic makes the treatment tolerable.

Permanent Hair Removal (Electrolysis)

Diathermy is the basis for electrolysis, a method of permanent hair removal. During this procedure, a fine probe is inserted into the hair follicle, and electric current destroys the follicle's ability to produce new hair. Because each follicle must be treated individually, the process can be time-consuming, especially for larger areas. Multiple sessions are typically required because hair grows in cycles, and only actively growing hairs can be effectively treated.

Local anesthesia, either as a topical cream or injection, can be provided to manage discomfort during the procedure. While the treatment effectively destroys hair follicles, the skin may be red and slightly swollen for a few days afterward. Proper aftercare, including keeping the area clean, is important to prevent infection.

Removal of Skin Lesions

Dermatologists commonly use diathermy to remove benign skin growths including warts, skin tags (acrochordons), seborrheic keratoses, and small blood vessel lesions. The controlled heat destroys the abnormal tissue while cauterizing blood vessels simultaneously, making it an efficient method for removing multiple small lesions in a single session.

For larger or deeper lesions, diathermy may be combined with surgical excision. The surgeon uses diathermy to cut around the lesion and then to control bleeding from the wound edges. This technique provides both precise tissue removal and excellent hemostasis (bleeding control), often eliminating the need for sutures in superficial procedures.

Surgical Applications

In the operating room, diathermy is used extensively for both cutting tissue and controlling bleeding. Surgeons can adjust the device settings to emphasize cutting (using a continuous waveform) or coagulation (using an intermittent waveform), or use a blend of both. This flexibility allows for efficient tissue dissection while maintaining a clear surgical field.

During operations, diathermy significantly reduces blood loss compared to traditional scalpel techniques. This is particularly valuable in highly vascular areas or when operating on patients with bleeding disorders. The ability to seal small blood vessels as they are encountered speeds up surgical procedures and improves visualization of the operative field.

How Should I Prepare for a Diathermy Procedure?

Before diathermy treatment, inform your doctor if you are pregnant, have a pacemaker or other implanted electronic device, or take blood-thinning medications. These factors may require modifications to the procedure or alternative treatments. Otherwise, no special preparation is needed for most diathermy procedures, and you can eat and drink normally before your appointment.

Proper preparation ensures both safety and optimal outcomes from diathermy treatment. While the procedure itself is generally straightforward, certain medical conditions and devices require special consideration. Your healthcare provider will assess your individual situation during a pre-procedure consultation.

Pacemakers and Implanted Devices

Patients with cardiac pacemakers, implantable cardioverter-defibrillators (ICDs), or other implanted electronic devices face potential risks from monopolar diathermy. The electrical current can interfere with device function, potentially causing inappropriate pacing or shock delivery. If you have any implanted device, your medical team will coordinate with your cardiologist to determine the safest approach.

Options may include reprogramming the device before the procedure, using bipolar diathermy (which has minimal current spread through the body), or choosing alternative treatment methods entirely. The decision depends on the type of device, its settings, and the nature and location of the planned diathermy procedure.

Pregnancy Considerations

If you are pregnant or might be pregnant, inform your doctor before any diathermy procedure. While localized diathermy treatments away from the abdomen are generally considered safe, certain precautions may be necessary. The electric current in monopolar diathermy passes through the body, and while harmful effects on the fetus from properly performed procedures have not been documented, your doctor may prefer to postpone elective treatments or use alternative methods.

For emergency procedures where diathermy is medically necessary, your healthcare team will take appropriate precautions, such as careful placement of the return electrode and using the minimum effective power settings.

Medications

Blood-thinning medications such as warfarin, aspirin, clopidogrel, or direct oral anticoagulants may increase bleeding risk during and after the procedure. Depending on the extent of the planned treatment, your doctor may advise temporarily stopping these medications. However, never stop prescribed blood thinners without specific medical guidance, as this decision involves balancing bleeding risk against the risk of blood clots.

For minor procedures like treating a nosebleed, adjusting anticoagulant medications is usually unnecessary because diathermy itself provides excellent bleeding control. Your doctor will evaluate your specific situation and provide personalized recommendations.

What Happens During the Diathermy Procedure?

During diathermy, local anesthesia is first applied to numb the treatment area. The doctor then uses a small electrode instrument to apply controlled electric current to the target tissue. For nosebleed treatment, this takes only a few minutes. For hair removal, each follicle is treated individually, making sessions longer. You may feel pressure or slight warmth, but pain is minimal due to the anesthesia.

Understanding what to expect during your diathermy procedure can help reduce anxiety and ensure cooperation for the best results. The specific steps vary depending on the condition being treated, but the general approach follows a similar pattern.

Anesthesia Application

Almost all diathermy procedures begin with local anesthesia to ensure patient comfort. The type of anesthesia depends on the treatment location and extent. For nasal procedures, a topical anesthetic spray is applied inside the nose, usually lidocaine or a similar agent. This numbs the area within minutes and makes the procedure comfortable.

For skin procedures, options include topical anesthetic cream (applied 30-60 minutes before treatment), local anesthetic injection around the treatment area, or both. The injection may cause brief stinging, but quickly produces effective numbness. For extensive procedures or anxious patients, mild sedation may also be offered.

The Treatment Process

Once the area is numb, the doctor positions the diathermy electrode at the treatment site. For nosebleed treatment, this involves using a small probe inside the nostril to cauterize the visible bleeding vessel. The probe is held against the vessel for several seconds while the current is applied, causing the vessel to seal. You may hear a slight buzzing sound from the equipment and notice a faint smell from the cauterized tissue.

For hair removal, the process is more meticulous. A fine probe is inserted alongside each hair into the follicle. A brief pulse of current destroys the follicle, after which the hair can be easily removed. This is repeated for each hair in the treatment area, making sessions for larger areas quite lengthy. Multiple sessions spaced weeks apart are typically needed for complete hair removal.

For skin lesion removal, the doctor may use various techniques depending on the lesion type. Some lesions are simply touched with the electrode and desiccated (dried out). Others are shaved off with a cutting current and the base cauterized. Larger lesions may require excision followed by diathermy to the wound edges for hemostasis.

What You May Feel

With adequate anesthesia, pain should be minimal during the procedure. You may feel pressure where the electrode contacts tissue and perceive warmth from the heat generation. Some patients describe a pulling or tugging sensation during skin lesion removal. If you experience significant pain, inform your doctor immediately so additional anesthesia can be provided.

The buzzing or crackling sound from the diathermy unit is normal. The distinctive odor of cauterized tissue, while potentially unpleasant, is also a normal part of the procedure. Some patients find it helpful to breathe through their mouth during treatment to reduce awareness of the smell.

What Should I Expect After Diathermy Treatment?

After diathermy, mild soreness is normal and typically lasts from a few hours (for nosebleed treatment) to several days (for hair removal or skin lesion removal). Keep the treated area clean by washing daily with soap and water. Watch for signs of infection such as increasing redness, swelling, or discharge. Complete healing usually takes 1-2 weeks for skin procedures.

Proper aftercare is essential for optimal healing and preventing complications. The recovery period and care requirements vary based on the type and extent of treatment performed.

Immediate Post-Procedure Period

Immediately after diathermy, the treated area will show effects of the heat treatment. Skin may appear white, gray, or dark where tissue was cauterized. Surrounding areas may be red and slightly swollen. These changes are normal and expected. The anesthesia will wear off over the following hours, and you may then notice some discomfort at the treatment site.

For nasal procedures, avoid blowing your nose forcefully for at least 24 hours to prevent dislodging the cauterized seal. Gentle nose cleaning with saline is acceptable. Some blood-tinged mucus is normal in the first day or two.

Wound Care

Keeping the treated area clean is the most important aspect of aftercare. Wash the area gently with mild soap and water daily. For skin procedures, you may be instructed to apply antibiotic ointment and cover with a bandage. Follow your doctor's specific instructions regarding wound care products and dressing changes.

Avoid picking at any crusts or scabs that form over the treated area. These protect the healing tissue beneath and will fall off naturally when healing is complete. Premature removal can cause scarring or delayed healing.

Managing Discomfort

Over-the-counter pain relievers such as acetaminophen (paracetamol) or ibuprofen are usually sufficient to manage any post-procedure discomfort. Apply them as directed on the package. Cold compresses can also help reduce swelling and provide comfort, especially after extensive treatments.

The duration of discomfort varies by procedure:

• Nosebleed treatment: Mild tenderness inside the nose for several hours to a day
• Hair removal: Treated follicles may be sore for several days; the area may be red and slightly swollen
• Skin lesion removal: Wound tenderness for several days, gradual improvement as healing progresses

Signs of Complications

While complications are uncommon with proper technique and aftercare, infection can occur, particularly after skin procedures. Contact your healthcare provider if you notice:

• Increasing redness spreading from the treatment site
• Worsening swelling or pain after the first few days
• Pus or foul-smelling discharge from the wound
• Fever or feeling generally unwell
• Bleeding that doesn't stop with gentle pressure

What Are the Risks and Potential Complications?

Diathermy is generally safe when performed correctly, but potential risks include infection at the treatment site, scarring (especially with deeper treatments), burns from improper technique or equipment malfunction, and interference with pacemakers or implanted devices. Serious complications are rare when proper safety protocols are followed by trained healthcare providers.

Like any medical procedure, diathermy carries some risks. Understanding these helps you make informed decisions and recognize problems early if they occur. Most complications are minor and manageable, while serious adverse events are rare with modern equipment and proper technique.

Common Minor Effects

Some effects are essentially unavoidable and represent normal healing rather than complications. Temporary redness, swelling, and tenderness at the treatment site are expected. Crusting and scab formation over treated skin is part of the normal healing process. These resolve spontaneously as the tissue heals.

Mild scarring may occur, particularly after removing deeper or larger skin lesions. The extent of scarring depends on the location, depth of treatment, individual healing characteristics, and aftercare. Scars typically improve over several months as they mature and flatten.

Infection

The cauterized tissue initially provides some protection against infection, but the healing wound remains vulnerable until the skin fully closes. Infection risk increases if aftercare instructions are not followed or if the wound is contaminated. Signs of infection include increasing pain, spreading redness, swelling, warmth, and discharge. Infected wounds require evaluation and may need antibiotic treatment.

Thermal Injury

Although heat is intentionally used to achieve therapeutic effects, unintended thermal injury can occur. Burns may result from excessive power settings, prolonged application, or equipment malfunction. Proper training, equipment maintenance, and adherence to safety protocols minimize these risks.

With monopolar diathermy, burns can also occur at the return electrode site if the pad has poor contact with the skin, is placed over bony prominences, or becomes partially detached. Modern return pads include safety features that alert to inadequate contact, reducing this risk.

Pacemaker and Device Interference

As discussed in preparation, implanted electronic devices can be affected by diathermy current. Effects range from temporary device inhibition to permanent damage in extreme cases. When diathermy is necessary in patients with these devices, appropriate precautions significantly reduce risk. Bipolar diathermy, when feasible, eliminates most concerns related to device interference.

What Are the Alternatives to Diathermy?

Alternatives to diathermy include cryotherapy (freezing), laser treatment, chemical cauterization, radiofrequency ablation, and traditional surgical excision. The best option depends on the specific condition, treatment location, available equipment, and patient factors. Your doctor can recommend the most appropriate approach for your situation.

While diathermy is effective for many conditions, alternative treatments exist and may be preferable in certain circumstances. Understanding the options allows for informed discussion with your healthcare provider about the best approach for your specific needs.

Cryotherapy

Cryotherapy uses extreme cold, typically liquid nitrogen, to destroy tissue. It's commonly used for warts, precancerous skin lesions, and some other skin growths. Cryotherapy is generally quick and doesn't require anesthesia, though the freezing sensation can be uncomfortable. It may cause blistering and takes several days to weeks to heal. Scarring is possible, though often less prominent than with some other methods.

Laser Treatment

Various lasers can cut, vaporize, or coagulate tissue depending on their wavelength and settings. Lasers offer precise tissue targeting and can be advantageous for certain conditions, particularly vascular lesions and hair removal. However, laser equipment is expensive, and specific lasers work best for specific applications. Laser hair removal differs from electrolysis diathermy in that it treats multiple hairs simultaneously but works best on dark hair with light skin.

Chemical Cauterization

Silver nitrate sticks or other chemical agents can cauterize bleeding vessels or destroy small amounts of tissue. This method is simple and requires no electrical equipment, making it useful in resource-limited settings. However, chemical cauterization offers less precision than diathermy and limited ability to control depth of effect.

Traditional Surgical Excision

Cutting tissue with a scalpel and controlling bleeding with sutures or ties remains a valid approach, especially for larger lesions requiring pathological examination. While this method doesn't involve electrical current (avoiding device interference concerns), it may result in more bleeding and longer procedures compared to using diathermy for hemostasis.