Practicing with chicken thighs

A peek into Wei Chen’s office refrigerator might reveal a few bottles of water, some snacks, or maybe his lunch. Open the small freezer and there’s a bag of raw chicken thighs.

The thighs are the best biological model he has found to practice the microsurgery and super-microsurgery for which he’s become one of just a handful of experts across the United States.

Chen, MD, assistant professor of plastic and reconstructive surgery in the University of Iowa Carver College of Medicine, performs two innovative techniques to treat lymphedema, the swelling in an arm or leg caused by a blockage in a person’s lymphatic system. Lymphedema is a common side effect of cancer surgery or radiation treatment, and correcting the condition—using a lymph node transfer or lymphovenus anastomosis (LVA)—involves severing and reattaching tiny lymph vessels.

Chen-chickenvessels-web

Lymph vessels in a chicken thigh are as slim as the letter “I” on a dime.

The larger vessels are about 1.8 millimeters wide—about one-sixteenth of an inch. Others, particularly those involved in LVA, are about 0.3 millimeters—similar in size to a human hair. Some vessels, especially in the lymph node transfer procedure, are short, creating an even greater challenge.

“These procedures are really challenging what human surgery is capable of,” Chen says. “Working on a 1.8-millimeter vessel is very different from working on a 1.0-millimeter vessel, which is very different from working on a 0.3-millimeter vessel.”

For Chen, the chicken thighs have become a super-microsurgery training model for other surgeons and surgical trainees, as well as a tool to help them hone their steadiness when working with such a tiny canvas.

“You think your hands are steady when you look at them with your eye, but when you look at them with a regular microscope, you see a little shake,” he says. “So you steady that shake, and you look at them with a 15x microscope, and you see they’re still shaking. You steady that shake, then you look at them with a 30x microscope and you see they’re still shaking. You don’t want to be shaking when you’re going in for this kind of surgery.”

Wei Chen, MD

Wei Chen, MD, plastic surgeon who treats lymphedema

Chen is the only surgeon at UI Hospitals and Clinics to offer either procedure, and the hospital is one of a small but growing number in the United States to make it available. Although both procedures are beginning to gain some ground in understanding and use, Chen says, there is still a long way to go.

Lymphedema centers around the world traditionally use massage therapy and pain management to treat patients with the condition, which ranges from localized swelling to legs and arms swollen to two or three times their normal size.

“We’ve been trying to educate both physicians and patients that patients have options, that there are treatments to help reduce this swelling and this pain,” Chen says. “It’s time we really start to take this condition seriously because we are causing this condition, in this country, with medical treatments for cancer.”

In developed countries like the United States, the leading cause of lymphedema is cancer survivorship, Chen says.

While the majority of lymphedema patients are breast cancer patients, lymphedema can occur after any cancer or its treatment, according to the National Cancer Institute (NCI). There is no set timeline for lymphedema to occur—it has been reported within days of surgery, or even up to 30 years later—though NCI records show that 80 percent of lymphedema patients experience the onset of symptoms within the first three years after surgery.

The NCI data also shows that lymphedema typically occurs in the upper body after breast cancer, but in the lower body following uterine or prostate cancer, lymphoma, or melanoma.

When surgically treating lymphedema, Chen prefers to use an LVA, which is minimally invasive and “works very well in the majority of patients.” The lymph nodes remain intact and vessels are simply rerouted around the blockage, providing an alternate route for the lymph fluid to flow. For more advanced cases, or for patients whose lymphedema doesn’t respond well to the LVA, Chen recommends a lymph node transfer as another option.

This article first appeared in Medicine Iowa.