Hunter's new ear - research summary

BACKGROUND: One out of every 8,000 to 10,000 children is born with the ear deformity called microtia. The deformity appears more commonly in males and on the right side of the head. Each case falls into one of four categories of microtia: Grades 1, 2 or 3, or anotia. Anotia literally means "no ear" and is the most severe form of microtia. In Grade 1 microtia, the ear is smaller than normal, but has most of the features of a normal ear. Grade 2 microtia results in an ear lacking normal features, although there is still an earlobe and parts of the outer folds of the ear. Grade 3 microtia is also called "The Classic Microtia." In this category, the ear consists of a vertical skin appendage with a malformed earlobe on the lower end. There is usually no external auditory canal in this type of microtia.

CAUSES: Causes of microtia are hard to define, but a few theories attempt explanations. One theory links the deformity to decreased blood supply in utero. Another theory blames medications taken during pregnancy like isotretinoin (Accutane), thalidomide (Thalomid) and retinoic acid (Retin-A). Others have questioned environmental factors as a cause of microtia. Some cases of microtia are genetic. Abnormalities in chromosomes occur in six to 16 percent of cases, according to the Texas Department of State Health Services.

Microtia is an isolated condition in only about 65 percent of cases -- for the other 45 percent, the deformity occurs alongside syndromes like Treacher Collins syndrome, Goldenhar syndrome and hemifacial microsomia. Hemifacial microsomia is the most common craniofacial abnormality after cleft lip and cleft palate.

TREATMENT: The main treatment option for microtia is reconstructive surgery. Sometimes hearing loss is also treated, especially in children with microtia of both ears, or bilateral microtia. Children with bilateral microtia usually require bone-conduction hearing aids within the first few months of life.

One microtia treatment that has gained popularity recently is the Nagata Auricular Reconstruction Method. This procedure was first carried out by Dr. Satoru Nagata of Japan, where the abnormality is most common. Although reconstruction of microtia-affected ears is always a two-stage process, not all surgeries fit the stages into two surgeries. Dr. Nagata's technique compresses the process into two procedures about six months apart. The first operation, which can take up to eight hours, involves harvesting cartilage from the child's ribs, forming a framework of the ear from that cartilage, and grafting the frame to its proper location on the side of the head. The second operation involves pulling the reconstructed ear away from the head to match the appearance of the other ear. A recent study found Dr. Nagata's procedure produced satisfactory results in 100 percent of cases. Most doctors recommend patients wait until they are eight to 10 years old for ear reconstruction, although there are some exceptions. The reason for this is to make sure the ear is fully grown at the time of surgery. In addition, most children aren't emotionally prepared for such an involved procedure until they are around eight years old. "That is usually when they are emotionally ready to go through this elaborate, two-stage procedure as well, because it requires a lot of cooperation on the part of the child; and when they are really excited about getting their new ear, then they are also very cooperative," Ann Schwentker, M.D., medical director of the Center for Facial Nerve and Brachial Plexus Reconstruction at Children's Healthcare of Atlanta, told Ivanhoe.

FOR MORE INFORMATION, PLEASE CONTACT:

Children's Healthcare of Atlanta
Brian Katzowitz, Public Relations
Brian.katzowicz@choa.org
choa.org