The disadvantage is that the costal cartilage cut from the body is at the expense of normal tissues of the human body, and the operation increases the pain of the patient, and the trauma is greater. Moreover, the carving technology of the ear bracket of the operator is also very demanding, and there is the possibility of pneumothorax and sternal malformation. If the ear is compressed in the later stage, it will absorb deformation, which will have a certain impact on the appearance, but it has been proved to be the most ideal material at present.
1920, ills began to use the carved costal cartilage as the ear support for total ear reconstruction; 1959, Tanzer began to use the costal cartilage support for ear reconstruction successfully; 1993, Kaneko used 3-D system to carve costal cartilage with three-dimensional structure. Generally speaking, cartilage scaffold is constructed from the 6th to 8th costal cartilage. In ear reconstruction surgery, the cutting range of accessory cartilage is usually the 6th, 7th and 8th costal cartilage or the 6th, 7th, 8th and 9th costal cartilage. In order to prevent abnormal development of thoracic cavity after costal cartilage resection, most scholars advocate using contralateral costal cartilage as donor site.
Park and Nagata advocate the use of ipsilateral costal cartilage, and at the same time cut the perichondrium on the upper surface of costal cartilage, so as to strengthen the contact between ear bracket and mastoid after carving and increase the stability; Brent advocates retaining the costal cartilage at the junction of the upper edge ridge of joint and sternal stalk to prevent the residual costal cartilage from warping. Some scholars believe that removing the perichondrium when cutting costal cartilage can make costal cartilage better adhere to the recipient and promote the survival of cartilage in the ear; However, if the perichondrium of the cut costal cartilage is completely removed, it will cause chest depression deformity, so most scholars believe that part of the perichondrium should be preserved in the donor site of the cut costal cartilage to facilitate cartilage regeneration and prevent chest deformity.
It has been reported that in order to give consideration to both donor and recipient areas, the perichondrium on the upper surface of cartilage should be removed, while Nagata on the lower surface should be retained. Clinically, the degree of thoracic deformity is closely related to the patient's age, the proportion of healthy ears in the body, the preservation degree of perichondrium, and the replantation of residual cartilage. However, the degree and principle of correlation need further discussion. Ohara expounded the mechanism of thoracic deformity and thought that the stability of free ribs after rib amputation was very important.
Roy et al reported that among the 12 pairs of ribs, the 6th and 7th accessory bones have the greatest growth and development potential. The deformity caused by the interference of operation is also the most serious. Due to the lack of uniform standards for the timing of F-shaped auricle reconstruction with costal cartilage as scaffold material, the amount of cartilage tissue in children is insufficient, and thoracic deformation is easy to occur after cutting, and the size of auricle is quite different from that of adults. However, with the increase of age, costal cartilage calcifies, its biological performance declines, and it is prone to complications such as fracture and deformation. Moreover, cutting off the costal cartilage from the body increases the pain and trauma of the patient, which requires a high carving technique for the ear bracket of the operator, and the ear may be absorbed and deformed during the later reconstruction.