"The situation was pretty complicated," said Dr. Khosla, who practices at Lucile Packard Children's Hospital in Palo Alto, CA, and is an assistant professor of plastic and reconstructive surgery at the Stanford University School of Medicine, in a news release. "If he tried to open his mouth, part of the jaw would get stuck. We had to come up with a way to remove all the bone that was involved and reconstruct the mandible."
To complicate things further, the boy, whose family asked that he not be identified in the media, wasn't finished growing. If his diseased bone was replaced with a static implant, he would eventually outgrow it, leaving his face lopsided.
So Dr. Khosla decided to try a surgery believed to be the first of its kind in the U.S. He would transplant part of a rib to the patient's face, taking along the rib's blood vessels to feed the bone and encourage its growth. He hoped the transplanted bone would keep growing, allowing the boy's face to reach its natural adult shape.
Before the unusual reconstructive surgery, CT scans showed the 12-year-old patient's jaw bone ballooning with a rare tumor. Images courtesy of Lucile Packard Children's Hospital.
The patient was initially treated by Peter Lorenz, MD, chief of plastic surgery at Packard Children's Hospital. Dr. Lorenz diagnosed a chondromyxoid fibroma, a nonmalignant bone tumor that usually occurs in the limbs and feet. This type of tissue overgrowth, which looks like a patch of bubbly bone in CT scans, can usually be cured simply by cutting it out.
But in this case, after surgery to excise it, the tumor returned, larger than before. Dr. Lorenz and Dr. Khosla could soon see that about a third of the patient's mandible, the section extending forward from the temporomandibular joint near his right ear, would have to be entirely removed.
The Eve procedure
Early in the summer of 2010, the surgeons decided to try an approach that had been reported in the medical literature only once before. In 1996, a team in Belgium described a surgery they nicknamed the "Eve procedure" (Plastic & Reconstructive Surgery, March 1996, Vol. 97:3, pp. 527-535). They planned to transplant a rib to the face along with its blood vessels and attach this circulation to an artery and vein in the neck.
"Technically, it's a very demanding procedure," Dr. Khosla said. Even if the microsurgery that connected the tiny blood vessels succeeded in the operating room, the vessels could clot later, necessitating surgical revision.
On the day of the operation, Packard Children's Hospital otolaryngology surgeons Anna Messner, MD, and Mike Yao, MD, removed the diseased mandible. After the tumor was removed, Dr. Khosla cut a 14-cm portion of the patient's seventh rib cut from his chest. Ribs are often used in reconstructive surgeries because recovery from loss of one rib is fairly straightforward, according to the surgeons. And the rib is ideal for replacing one side of the mandible because it consists of a bony end and a cartilage end.
"This allows us to use the cartilage to sculpt a jaw joint, and use the bone to give foundation and structure to replace the bone that was removed," said Dr. Khosla, adding that, in this case, he also used the rib's envelope of muscle, which contains the bone-feeding blood vessels and helped fill out the face.
After surgery, a CT scan shows the rib segment that plastic surgeon Dr. Rohit Khosla transplanted to the jaw. Dr. Khosla also connected the rib's blood vessels during the surgery to encourage the transplant to grow in its new location.
Once he had crafted a replacement joint, Dr. Khosla trimmed the rib to fit the gap where the tumor-laden mandible had been removed. He used about 10 cm of the rib, measuring precisely so that the patient's upper and lower teeth would line up neatly once the surgery was complete. He fused the rib to the remaining healthy mandible with surgical plates and screws, then attached the blood vessels. He closed the patient's skin, hiding the scar in the natural skin creases in front of his ear and on his neck.
After the surgery came anxious weeks of waiting. Dr. Khosla was relieved that the patient easily cleared the first major hurdle of healing: At discharge from the hospital, his facial circulation to the transplant looked good.
"The other time I felt really good was when he was six to eight weeks out from surgery and was able to chew again," Dr. Khosla said. "I saw that he could eat pretty much whatever he wanted without pain and without restriction in movement of his jaw. It was very reassuring that the reconstructed jaw joint was working well."
Now, six months after the surgery, the patient continues to thrive. It's still too soon to know for sure if the transplanted rib is growing, but signs so far look good, according to hospital officials. And the patient is back to his usual activities: playing soccer, excelling in his 7th-grade math classes, and enjoying being a 12-year-old kid.
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