背景：複雑な骨折を伴う顔面外傷や腫瘍切除による広範な骨欠損以外で，手術に3Dモデルを利用することは少ない。定型的な手術方法が困難であった術後性上顎嚢胞による眼窩底欠損に対する骨移植で，新たに二重橋渡し法を考案し，3Dモデルを利用して術前・術中にシミュレーションを行った。
 手術方法：術前に１mmスライスで撮影したCT画像をもとに3Dモデルを作製し，これを用いてチタンプレートや移植する骨の形状を推測した。手術の際に滅菌した3Dモデルを手術室に持ち込み，実際に使用する２本のチタンプレートと移植骨を3Dモデルに設置しながら形状の加工を行い，良好な形態を再現してプレート固定と骨移植を行った。
 結果：術直後から眼球運動障害，眼球陥凹ともに認めず，術後３ヵ月経過しても経過は良好であった。
 結語：二重橋渡し法という非定型的な骨移植を3Dモデルを活用して行い，良好な眼窩形態を得ることができた。

 Various surgical methods have been considered for fixation after split-thickness skin grafting, depending on the size and location of the skin defect. We performed split-thickness skin grafting in the lumen of a thoracic cutaneous fistula. Considering the potential difficulty in fixing the inlay skin graft, we devised a novel surgical procedure using a tissue expander (TE) and obtained good results.
 Our patient was a 67-year-old man who developed a thoracic cutaneous fistula with repeated infections originating from a bronchial segment following respiratory surgery for malignant pleural mesothelioma. When performing surgery for a fistula with a narrow skin opening and a wide sinus-like lumen, applying the skin graft to an appropriate position on the wall so that it effectively adheres and maintains postoperative pressure fixation is difficult. The TE technique allows for efficient skin graft adherence to the wall by injecting distilled water from the port and adjusting to attain appropriate fixation pressure.

 In Japan, there are relatively few reports of reconstructive cases for traumatic chest wall injuries. Shotgun chest wall injuries are often extensive, making it challenging to determine the most appropriate reconstruction method.
 In this report, we describe the case of a 73-year-old man who was admitted to the emergency department after sustaining injuries from a shotgun pellet. The patient had a 12 cm×9 cm defect in the left thoracic region and underwent chest wall reconstruction using a latissimus dorsi musculocutaneous flap.
 In deciding on the reconstruction method, immediate chest closure was necessary. Although rigid reconstruction is necessary for extensive defects, the use of prosthetics or other devices that are potential sources of infection should be avoided.
 The postoperative course was excellent, demonstrating that one-stage reconstruction with a latissimus dorsi musculocutaneous flap is a viable option for such cases.

 We report a case of cutaneous nocardiosis in a 75-year-old man who had previously injured his right lower limb in a bike accident nine years and again six years prior. Over the previous month, the condition of the injury had worsened, causing debilitating pain and prompting the patient to seek medical attention. Cultures and pathological tissues from small cysts and granulation tissue revealed no malignant findings. Consequently, surgical debridement and antibiotic treatment were initiated. Initially, a broad-spectrum antibiotic regimen (TAZ/PIPC and DAP) was administered due to the non-specific nature of the infection. However, subsequent identification of Nocardia species led to modification of the antibiotic regimen to MINO and ST. Following debridement, the patient experienced pain reduction, regained the ability to walk, and was discharged from the hospital. Oral antibiotics were continued post-discharge, and no recurrence of the disease was observed.

 We report a rare case of a first branchial cleft cyst surrounding the auricle. A 15-year-old girl presented with persistent drainage from the right posterior auricle. An elastic, soft mass extending from the posterior of the right auricle to the crus of the helix was observed. A cyst was located on the lower posterior part of the auricle. Magnetic resonance imaging detected a solitary cystic lesion encompassing the external auditory canal and the crus of the helix. Tumor resection was performed on the posterior auricular lesion, including the fistula, with careful consideration of the posterior auricular vessels. An additional incision was made at the anterior auricular lesion to remove the frontal portion of the tumor, which extended across the gap between the external auditory canal and the crus of the helix. Histopathological findings revealed a cystic tumor lined with stratified squamous epithelium and filled with keratinous material. There was no postoperative recurrence or complications such as facial paralysis.