Microsurgery: What You Need To Know
BY KATHY KATELLA September 28, 2022
A severed finger. A deeply infected wound without enough skin to cover it. Breast reconstruction after a mastectomy. Accidents—and life—happen to all of us, and sometimes bring great harm to our bodies. Fortunately, surgical techniques have advanced dramatically, to the point where such issues can often be fixed. A technique called “microsurgery” is an intricate procedure that takes a piece of tissue—with its tiny nerves, and blood and lymphatic vessels—from one part of the body, and uses it in the reconstruction of another area damaged by trauma or disease.
And now, in the case of face transplants, microsurgery is the technique that allows patients to successfully receive donor tissue from the body of another.
“Microsurgery allows us to perform operations for patients who would not have survived in the past,” says Bohdan Pomahac, MD, chief of Yale Medicine Plastic & Reconstructive Surgery, who specializes in face transplantation, the newest application of microsurgery. “For those who would have survived, microsurgery can dramatically improve their quality of life. It’s a powerful technique.”
Microsurgery has been around for decades, but it has advanced to the point where it is now used in multiple areas of surgery. Below are some important ways Yale Medicine plastic surgeons are using microsurgery to provide patients with better outcomes.
What is microsurgery?
Microsurgery is a technique that uses instruments (with very fine tips and grasping ends), high-magnification microscopes (that blow up visualization as much as 40 or 50 times), and other tools to carefully disconnect tissue from one part of the body and reconnect it in a different place. “It’s a process called ‘free-tissue transfer.’ You connect arteries and veins to provide proper blood circulation,” Dr. Pomahac says.
These surgeries move nerves and vessels that can be a millimeter or less in size (for comparison, a nickel is about 2 millimeters thick) and can take hours, depending on the parts of the body involved and the goal.
Only a limited number of surgeons are trained in the technique. It falls mostly in the realm of plastic surgery, although not all plastic surgeons perform microsurgery. And those who do often work in collaboration with orthopaedic surgeons, head and neck surgeons, and other specialists.
Microsurgery for reattaching fingers and thumbs
In hand surgery, microsurgical techniques are used routinely to reattach amputated fingers or thumbs. Patients may have had a traumatic accident while operating machinery or a blast injury while setting off fireworks. “Before microsurgery was available to us, amputation was our only option,” says plastic surgeon David Colen, MD. “Now we routinely repair fingers, with arteries that are a fraction of a millimeter in diameter.”
Odds that surgery will be successful are best when the severed digit is retrieved, wrapped in saline-moistened gauze, placed in a bag (on ice)—and the patient gets to the hospital quickly. In the operating room, the missing structures are identified, and then all of the bones and tendons are pieced back together. At that point, the surgeons perform microsurgery, connecting arteries, nerves, and veins where possible, bringing the severed digit back to life.
Reattaching a finger and restoring blood flow is delicate work, since each digital artery is a millimeter in diameter, decreasing in size (as it moves from the top of the finger to the bottom) to fractions of a millimeter before branching into capillaries.
Injuries to the soft tissues of the hand and upper extremities commonly require microsurgical reconstruction. Because of the general lack of skin in the hand and upper extremities, free tissue transfer is commonly required to cover important structures such as nerves, tendons, and bone with soft tissue.
When the small bones of the hand and wrist are damaged, vascularized bone (with blood flow) may be taken from somewhere else, such as from the side of the knee. “We can take a piece of bone from another part of the body, with blood vessels going into and out of that bone, and connect it to blood vessels in the hand or wherever it’s needed,” Dr. Colen says. “That bone has now been transplanted. It has its own blood supply, and it will heal like normal bone.”
Microsurgery for damaged arms and legs
Sometimes, people need reconstructive limb surgery if an arm or leg was seriously damaged in an accident, and they have lost some of the soft tissue that covers the bone. Often, an infected wound also calls for microsurgery. “These are cases where we would otherwise have no way of covering the exposed bone,” says Adnan Prsic, MD, a Yale plastic surgeon who specializes in microsurgery for both the hands and extremities. “Without an experienced microsurgeon, that patient would likely need an amputation.”
If a patient has lost motor function in an arm, for example, a muscle transfer can be done to restore movement, Dr. Prsic says. “We take muscle from another part of the body, such as the inner thigh, and connect it to blood vessels in the damaged area so there is a new muscle that can move the fingers or flex the elbow, depending on the surgery site.” This involves connecting nerves so that a pre-existing nerve in the arm can power the transferred muscle.
In both hand and limb surgeries, plastic surgeons partner with orthopaedic surgeons and perform the procedure together, Dr. Prsic says. Care and support from specialized, certified physical and occupational hand therapists after surgery are also critical, he adds, especially if the surgery has made a drastic change, such as putting a leg muscle into an arm. “The therapists play an enormous role in recovery,” he says.
Microsurgery for breast reconstruction after cancer
One in eight women is diagnosed with breast cancer. Among those who have a mastectomy—the surgical removal of one or both breasts—to remove the cancer, many opt for some kind of breast reconstruction. They will have a choice between getting an artificial implant and an autologous reconstruction, an umbrella term for microsurgeries that take tissue from their body—usually the abdomen—and use it to recreate the breast.
There are pros and cons to each of these approaches, and plastic surgeon Haripriya Ayyala, MD, says it’s important for women to understand all of their options, including the benefits of microsurgery. While microsurgery takes longer and is more complex than implant surgery, if the patient’s own tissue is used, it will last for the rest of their life, compared to 10 to 20 years for a breast implant, she says.
The most common breast microsurgery procedure is called “deep inferior epigastric perforator (DIEP) flap.” It takes abdominal tissue, fat, and blood vessels from the belly, similar to a “tummy tuck,” and uses them to recreate the breast. To help visualize the complexity of this surgery, the blood vessels that are removed and reattached in the breast are 2 to 3 millimeters in diameter.
DIEP flap surgery has improved over time. In the past, surgeons would remove the entire abdominal muscle, which put patients at risk for hernias. “Now, we have developed perforator techniques in which we don't take the muscle at all,” Dr. Ayyala says. “We just gently split the muscle, as needed, to access the blood vessels and remove the necessary tissue, leaving the muscle intact in the belly.”
Newer microscopes have provided increasingly better magnification and resolution, as well as a wider range of view, says plastic surgeon Michael Alperovich, MD. Angiography, a type of imaging that uses contrast dye to visualize blood flow, helps map the location of blood vessels to be detached. “This works in the same way GPS does,” Dr. Alperovich says. “I can say to myself, ‘The blood vessel I want is 2 centimeters to the left.’”
While the sensation in your breast after a DIEP flap won’t be the same as with your original breast, the skin and tissue will feel natural, he says. “You lose that daily reminder that you had cancer.”
Microsurgery for face transplantation
Face transplants are the newest, most innovative use of microsurgery. They are used to treat patients who have extensive facial damage from disease, serious burns, animal attacks, or other traumas such as gunshot wounds. It’s an example of a surgery where taking tissue from other parts of a patient’s body won't work—you can take tissue from the abdomen and use it to rebuild a breast, but that doesn’t work with such areas as the nose or lips, says Dr. Pomahac, a pioneer in the field who created the Face Transplant Program at Yale.
Instead, the procedure recovers anatomically identical tissue from a deceased patient and attaches it to a living patient. “You can then use microsurgical techniques to connect the arteries and veins,” Dr. Pomahac says.
A face transplant is a meticulous and precise procedure, he says, adding that there are 16 paired muscles in the face—so 32 altogether—that need to be considered. “In the face, every millimeter of misalignment will be visible,” he says. “The operation takes between 17 and 24 hours, with multiple microsurgeons either working together or switching off."
Recovery from a face transplant is a lengthy process. For a while, the new face is paralyzed. For instance, it will be several months before the newly connected nerves start growing in and reaching the muscles. “The first movement we see is at around three months, and then it progresses for about two years,” Dr. Pomahac says.
While face transplants don’t yet have a long track record and solid data behind them, many of the ones that have been performed have improved patients’ survival rates and reportedly brought back their quality of life.
Questions to ask if you are going to have microsurgery
“Many people will never need microsurgery,” says Dr. Alperovich. “But patients who do should find a surgeon who has performed a high volume of the surgery they need—as is the case with any surgery.”
According to Dr. Alperovich, it can be helpful to ask your surgeon the following questions:
- How will microsurgery affect my daily life immediately—and years later?
- How will microsurgery affect sensation in both the place where the tissue was removed and where it’s transplanted?
- Will microsurgery limit function in any way?
- What kind of physical therapy will I need to help me return to activities?
While the specifics may depend on the urgency of the situation, conversations between patients and surgeons should happen before the surgery. “I may talk with my patient about their goals in life,” says Dr. Prsic.
For some patients, such as a woman who has abdominal tissue taken for a DIEP flap, function won’t be impacted by the removed muscles, Dr. Prsic says, although these patients may have other questions. “But if you take muscle from somewhere else in the body, there may be a small functional deficit in that location. For example, if they are a rower or somebody who uses their back muscles, taking tissue from that area would impact that activity. So, it’s important that patients have a candid conversation with their surgeon well ahead of the surgery,” he says.