Research Currents - 1999
Pioneering Microsurgery: Offering Hope to Trauma Victims
Harry J. Buncke, MD Gregory M. Buncke, MD
At first glance, the color photograph appears to depict an ordinary human hand lying palm-side up on blue fabric. If you peer closer you might notice a thin diagonal scar running from the base of the index finger to the base of the thumb. Other than that, a normal-looking hand. The photo caption reads: A 24-year-old right-handed woman who caught her thumb in a conveyer belt. She suffered an avulsion injury [the separation by tearing off any part of the body from the whole] that was nonreplantable. The patient underwent a right great toe-to-thumb transplant and required secondary operations to the rest of her hand for scar release. She ultimately returned to work approximately 16 months after injury. Her return to work was delayed by a pregnancy. Now you look even closer . . . at the thumb. Yes, it is a bit broader and fleshier than a normal thumb, but never did you imagine it was a big toe. This and similar remedies for victims of amputation and severe injury is the work of the Buncke Clinic of California Pacific Medical Center's Davies Campus, specialists in reconstructive, replantation, and transplantation microsurgery for fingers, hands, extremities, and facial parts such as scalps, ears, noses, lips, and tongues.
Skin Grafts and Beyond
"The things we see most commonly are amputation injuries in people who have caught their hand in machinery or severed a finger when their ring got caught on something," said Gregory M. Buncke, MD, co-director of the Buncke Clinic and son of pioneering microsurgeon and clinic founder and co-director Harry J. Buncke, MD. "Before the advent of microsurgery," he continued, "if you had a big open wound on your body or an amputated finger, there was little that could be done." A skin graft could be applied to the exposed area, but skin grafts are only very thin sheets of the topmost layer of skin without the underlying subcutaneous tissue layer, which provides support and durability, and handles shear forces. Without the subcutaneous layer, a skin graft is fragile and easily damaged and does little to remedy the injury or restore functionality; it merely covers the wound.
"Skin grafts take immediately," said Dr. Harry Buncke, "but if you want to graft anything thicker than just a few thousandths of an inch, it needs constant and immediate blood supply." So, he learned to graft large and small blocks of tissue using microsurgery techniques to provide an immediate and continual supply of blood.
A New Field in the Making
"It all started in the late 1950s. I was taking an extra fellowship in plastic surgery in Scotland under a surgeon named Thomas Gibson. He was a profound thinker who speculated that there must be an easier way to transplant tissue from one place on the body to another," said Dr. Harry Buncke.
A method for grafting tissue flaps existed at the time (and is still used in some cases), but it was a clumsy process. A surgeon would make a large inverted U-shaped incision in the tissue of the patient's abdomen. The patient's mangled hand, for example, still attached to his or her body would then be inserted under the abdomen tissue flap, sewn in place, and left there for three weeks. "It was practically like creating a Siamese twin," said Dr. Greg Buncke. "Your limb would be attached to your own stomach, which was often very uncomfortable."
During the three weeks of attachment, it was hoped that tissues from the flap and damaged limb would grow together, bringing new blood supply to the wound area. At the end of three weeks, the limb with the newly attached tissue flap would be detached from the abdomen, the abdominal incision would be sewn up, and reconstructive plastic surgery to model the newly attached tissue flap would be done.
But what Thomas Gibson, Harry Buncke, and other pioneering microsurgeons envisioned was first excising a piece of tissue or muscle from the patient's body and then sewing it directly to the damaged area. No intermediate sew-the-limb-to--the-abdomen step was required. To do this meant being able to surgically connect the veins, arteries, and nerves of the damaged area directly to those of the transplanted flap - no mean feat when dealing with blood vessels and nerve fibers of a millimeter or less in diameter (the diameter of a paperclip wire).
Ingenuity Is Key
Operating under a microscope was a logical first step, but finding suitable surgical instruments proved difficult. "When I first started there were no sutures, no needles, and no instruments small enough for surgery of this type," said Dr. Harry Bunke. "I used to make the needles myself under the microscope, and we borrowed or copied jewelers' instruments. A big breakthrough cane from the Silicon Valley and its microassembly techniques. Engineers were able to make needles for me that were thinner than your hair and drill the needle eye with a laser."
Other hurdles involved keeping the tiny blood vessels open (patent) during the procedure, so that two vessels could be joined by sutures, and after the procedure, so that blood would flow naturally in and out of the repaired area. Explained Dr. Greg Buncke: "In the normal process of injury, an artery or vein that has been cut goes into spasms - a protective mechanism to keep you from bleeding to death. We have to modulate and control this normal response to injury in order to keep these little blood vessels open to do flap transplants."
One solution was to experiment with the number and placement of sutures so as not to obstruct blood flow; another was to use blood vessel dilation medications and anticoagulants, like aspirin, dextran, and heparin, both topically during the operation and systemically during and immediately after the procedure.
Practice Pays Off
By the mid-1960s Harry Buncke was a professor of surgery at the University of California, San Francisco and Stanford University Medical Center and was experimenting in his free time on sewing together 1-millimeter blood vessels in rabbit ears. He steadily gained expertise, and in 1972 successfully performed the first toe-to-hand transplant in a human.
Over the next 10 years, while further refining his technique, he established microsurgical laboratories at the University of California, San Francisco; Stanford University; the Oak Knoll Naval Hospital (Oakland, Calif.); the Davies Campus of the California Pacific Medical Center; and the Hospital Jeanne d'Arc (Nancy, France). He also helped perform the first successful microvascular transplants at Davies Medical Center; San Francisco General Hospital; University of California at San Francisco and Irvine; Stanford University; Johns Hopkins University; New York University; Puerto Alegre, Brazil; and the Royal Medical Center in Amman, Jordan.
Since its inception in 1970, the Buncke Clinic has accomplished many firsts in microsurgery. In the United States in 1976, the first scalp replant was performed (the world's first was performed by an Australian surgeon who trained at the Buncke Clinic). Also in 1976, the first four-finger replant from a dominant hand was performed. Worldwide, in 1979, the clinic was the first to transplant the serratus muscle (a back muscle) to the face for facial paralysis; in 1986, the first scalp transplant between identical twins; and in 1997, the first tongue replant. All told, the Buncke Clinic has conducted more than 3,000 replants and 1,200 microvascular transplants, including more than 300 toe-to-hand transplants and 250 multiple microvascular transplants.
High Priorities: Training and Research
The clinic has an active microsurgical training program that has trained over 150 clinical and research fellows and residents. Many have gone on to head microsurgery departments at the nation's top universities and medical centers. Some have even made national news, like the microvascular surgeon and former Buncke Clinic fellow who replanted (reattached) John Wayne Bobbitt's severed penis.
The clinic also churns out research papers at a staggering rate. Since 1970, over 385 articles, books, or chapters have been published by the group, reflecting the extensive, ongoing microsurgery-related research the clinic team pursues. Many of the studies are done in animal models, mainly rats, looking for new and better ways to improve techniques and postsurgical outcomes. The prodigious efforts have paid off. "All surgery has potential complications. Even under the best of circumstances we lose a muscle transplant or a toe now and then, but our yearly success rate is 98 to 99%," said Dr. Harry Buncke.
The field of reconstructive microsurgery is not without controversies. "The biggest for the lay public is the whole concept of homotransplants," said Dr. Greg Buncke. Homotransplantation is like organ transfer; surgical teams in Lyon, France, and Louisville, Kentucky, have transplanted a hand from a recently deceased person to a living person. Because the donor hand comes from another person, the transplant recipient must take antirejection medications for the rest of his or her life.
"These medications (the same ones a kidney transplant or heart transplant patient takes) are potentially lethal. We have to weigh the risk/ benefit of that," said Dr. Greg Buncke. He is in favor of homotransplantation for bilateral amputees who otherwise would be severely incapacitated, but questions the value of subjecting patients with less severe amputation injuries to a lifetime of antirejection drugs.
Generosity of Spirit
In the realm of unusual cases the Bunckes have treated is the teenage boy who two years ago bit off the bulk of his tongue in a car accident. The clinic team did the world's first tongue replant and later presented the case, along with the young man, at a scientific conference in San Francisco. "I brought the patient, who aspires to be a sports announcer, to the podium and he said a few words, thanking us for enabling him to speak once again. He got a standing ovation. I've never seen that before at a scientific meeting," said Dr. Harry Buncke, beaming with pleasure, not at his own accomplishment but at the evident normal life this young man will enjoy.
Clearly, the Hippocratic oath is a driving principle at the Buncke Clinic. And part of that oath, Dr. Buncke said, "is to educate other people to do the same sort of work. We don't have any trade secrets or secret instruments." As a testament to this principle and the quality work it is doing in microsurgery, the Buncke Clinic receives more training applications each year than it can possibly handle.