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Medicinal leeches

Taking a bite out of venous congestion

Ward, Constance RN-BC, CNRN, MSN; Craw, Leticia RN, MBA, MSN; Cherian, Aleyamma RN; Delos-Reyes, Mila RN; Joseph, Sally RN

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doi: 10.1097/01.NURSE.0000341075.68329.55
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Abstract

SUPPOSE YOU'RE caring for Joe Bago, 60, who recently underwent chest wall resection for a desmoid tumor. Twenty-four hours after surgery, his wound flap has developed venous congestion, indicated by a dusky, purple color and edema. The next day, leech therapy is ordered. Here's what you need to know about this what's-old-is-new treatment. First, though, let's quickly review Mr. Bago's case.

Setting the scene

Mr. Bago had a recurrent desmoid tumor at the left thoracic outlet. Multiple desmoid tumors were found during surgery, at the left clavicle and the anterior chest wall and on the ribs. (For more details, see What are desmoid tumors?) Plastic surgeons performed a reconstruction of Mr. Bago's left chest wall using his rectus abdominis and left latissimus dorsi muscles. They applied a myocutaneous pedicle flap with a split thickness skin graft over the desmoid tumors removal site. (A pedicle flap retains part of its original blood supply; the tissue is tunneled under the skin from the donor site to the chest wall.)

Mr. Bago arrived in the surgical ICU endotracheally intubated and mechanically ventilated, with an indwelling urinary catheter, chest tubes and multiple wound drains, and a central venous access device delivering fluids, analgesia, and antibiotics. To promote venous drainage of the flap, he was kept in a lawn chair position (slightly head up with hips and knees partially flexed), and perfusion to his flap was monitored every 2 hours via Doppler ultrasound. Mr. Bago was hemodynamically stable and neurologically intact. But the next day, you noticed the venous congestion in the wound flap. Now let's look at the therapy that's been ordered for your patient.

Buggy about leeches

The FDA approved leeches as a medical device in 2004. Today, medicinal leeches are widely used to relieve venous congestion, particularly following plastic and reconstructive surgery.

Leeches can help restore venous circulation following the reattachment of body parts, such as a finger, toe, ear, nose, or scalp, and in skin flaps. However, the site must have good arterial inflow for leech therapy to work. (Arterial insufficiency also increases the risk of infection from leech bites.) Fortunately, Mr. Bago has brisk capillary refill in 50% of his wound flap.

Reattaching arteries in severed body parts and grafts is easier than reattaching veins, which are thin-walled and difficult to suture, especially if they're damaged. If arterial flow is reestablished but venous outflow at the site is decreased, the reattached part or skin flap becomes congested with stagnant blood. This delays healing and causes a skin graft to fail.1

The leeches help because their anticoagulant saliva and the vasodilation caused by their bite result in prolonged localized bleeding. (Leech saliva also contains a local anesthestic.) Up to 150 mL of blood will ooze from the wound for an average of 48 hours after the leech detaches, greatly reducing venous congestion.2

Mr. Bago has been ordered 4 days of leech therapy with five leeches at each application. Typically, therapy lasts 4 to 10 days, but it may be discontinued after 5 to 7 days if the leeches aren't successful in reducing venous congestion in the affected part.

Now let's look at how leeches can help Mr. Bago.

Your role

The leeches arrive in the surgical ICU from the pharmacy; several dozen are in a container of distilled water and Hirudosalt in the medication room refrigerator.

Reinforce the physician's explanation of the therapy to your patient, assuring him that leech therapy is medically accepted, isn't painful, and carries minimal risk of infection because the leeches are raised under sterile conditions. A patient-teaching handout can help allay your patient's concerns or squeamishness about this therapy.

Obtain baseline hemoglobin and hematocrit levels. Check the order for leech therapy, which should specify the area to be treated, how many leeches to attach, and how often to apply new leeches. Follow standard precautions during therapy. Use soap and water to clean the area to be treated, rinse with sterile water, and dry with a sterile cloth. (Other skin preparations may discourage the leeches from attaching.)

For each leech, you can dampen a 2-inch (5-cm) square of gauze with sterile water and cut a 0.5-inch (1-cm) square hole in the middle. Place this gauze on the patient with the hole over the treatment area. The gauze forms a barrier to prevent the leech from wandering.

Some facilities require the physician to apply the leeches the first time. If facility policy permits you to perform the application, place the container of leeches close to the patient's bed and don gloves. Use long, nontoothed forceps to pick a leech out of the container. Hold a piece of sterile gauze under the leech as you transfer it to the area to be treated.

The pointed narrow end is the leech's head. You may need to hold it in the treatment area for a few seconds until it bites.

When it attaches to the skin, the leech will begin to distend with blood. Don't try to forcibly remove it; this could contaminate the bite wound with regurgitated bacteria from the leech's gut. When it's full of blood, it will release its hold and drop off harmlessly. If the patient is able, ask him to notify you when a leech detaches.

Check the patient hourly while the leeches are feeding. Every 2 hours, assess the perfusion of the graft and assess for signs of local infection.

When a leech detaches, put on gloves and use tweezers or forceps to pick it up and place it in a capped container of 70% alcohol. Apply fresh leeches if ordered. Keep fresh leeches in the covered pharmacy container. Protect them from sunlight, heat, and chlorinated tap water.

Figure
Figure:
The photo at right shows venous congestion in a skin flap; the dusky, ecchymotic area over the clavicle is at risk for necrosis. Leech therapy has just been started. In the photo below, medicinal leeches placed on the skin flap have reduced the venous congestion. Notice the oozing caused by the leech bites.

At the end of the shift, dispose of used leeches according to your facility's infectious waste policy. Never reuse a leech on another patient or return used leeches to the pharmacy.

Several times a day, between leech applications, clean the treatment site with sterile water to remove serosanguineous drainage caused by the leeches. Don't use 0.9% sodium chloride solution; leeches don't like salt.3 Use sterile gauze to gently remove local blood clots and encourage each bite to bleed. Monitor the patient's hemoglobin and hematocrit levels.

By understanding leech therapy and helping your patient feel at ease with it, his graft was saved. After 7 days in the surgical ICU, he was transferred to the surgical unit and continued to recover uneventfully.

What are desmoid tumors?

Desmoid tumors arise from connective tissue. Although considered benign, these tumors are insistent fibromatoses that become locally aggressive and have the capacity to destroy adjacent normal tissues and bones. The painless masses or lumps can develop anywhere on the body. As the tumors grow, they place pressure on body structures, can cause pain, and can destroy adjacent vital structures and organs.

The cause of desmoid tumors is unknown, but they're thought to run in families. Between 2 and 4 million people are affected annually in the United States. These tumors typically affect patients ages 15 to 60 and are slightly more common in women than in men.

Ultrasound can be used to determine the size of the mass; however, if it's solid, a computed tomography or magnetic resonance imaging scan must be used to determine if the tumor is adhering to internal structures and to make sure it can be removed safely. A biopsy is needed to definitively diagnose the tumor. Surgical removal is the treatment of choice, especially if needed for cosmetic purposes.

Unfortunately, tumor recurrence is common. Some patients undergo radiation therapy for 6 to 8 weeks to shrink the tumor if surgery isn't an option.

Source: Agresta S, et al., About desmoid tumors (2007), http://www.dtrf.org/dtrf_aboutdesmoids.htm. Accessed April 15, 2008.

References

1. Connor NP, et al. Augmented blood removal after medicinal leech feeding in congested tissue flaps. J Rehabil Res Dev. 2002;39(4):505–512.
2. Biopharm Leeches . http://www.biopharmleeches.com. Accessed April 24, 2008.
3. Voge C, Lehnherr SM. Get attached to leeches. Nursing. 1999;29(11):46–47.
© 2008 Lippincott Williams & Wilkins, Inc.