Surgical Correction of Cryptotia using Hirose's Rotation Flap

Cryptotia is rare in Caucasians but more common in Orientals, particularly in Japanese people, where incidence has been reported as 1:400. The features of cryptotia are the invagination of the upper part of the auricle under the temporal skin and the deformation of the auricular cartilage itself. The principles of the surgical correction are the coverage of skin deficit and the correction of deformed cartilage if needed. For the correction of cryptotia, several methods have been tried. But, inadequate amounts of local tissue often result in undercorrection of the cephalo-auricular sulcus, with a tendency to recurrence of the buried ear. Incision scars, hair line distortion, poor color match of graft and multi-staged operation of tissue expansion are noted as the their shortcomings. Therefore, We have performed Hirose's rotation flap method in 15 cases of the 12 patients that available skin in the inferior part of the cephalo-auricular sulcus is transferred to the upper part where skin is deficient, and satisfactory results were achieved. This method has many advantages that the design is simple and the procedure easy, the required depth of the cephalo-auricular sulcus is achieved, the correction of the cartilage deformity can be carried out with unrestricted access, the hairline is not disturbed by the operation, the scar behind the auricle is not visible, and there is no need for additional skin grafting.

Various Vein Conduit Modalities for Nerve Regeneration in Rats

Over the years, many surgeons have used various natural and synthetic materials to bridge the nerve defect. However, none of these materials has surpassed the effectiveness of the nerve autograft. Among natural materials, a vein graft has been used as conduit for nerve regeneration in both research protocols and clinical situations. Unfortunately, the comparison of various research reports is difficult, for each research has employed a different experimental model and method of evaluation for the study of the nerve regeneration. This study introduced various modifications of the vein graft technique, and investigated several vein graft models in an attempt to find the most effective formulation . Four vein graft models were employed: 1) the empty vein graft, 2) the inside-out pattern vein graft, 3) the vein graft filled with skeletal muscle strips, 4) the inside-out pattern vein graft filled with skeletal muscle strips. Regeneration was assessed with gross appearance, histologic examination and electromyography(EMG). In the vein graft filled with muscle strips, there was the increased axonal diameter, myelin sheath thickness, ratio of myelinated axon to unmyelinated axon, and conduction velocities. The result showed that any vein graft filled with muscle strips is superior to the empty vein graft and the inside-out pattern vein graft model which are not filled with muscle strips. It is concluded that the nerve repair using a vein graft filled with skeletal muscle strips can be effectively employed in the clinical field. Further study should be aimed at the regeneration of a longer distance nerve gap and its clinical application.