猿渡 万里子¹, 城戸 咲¹, 甲斐 翔太朗¹, 中野 嵩大¹, 蜂須賀 正紘¹, 日高 庸博¹, 柳 佑典², 田口 智章², 加藤 聖子¹

Mariko SARUWATARI¹, Saki KIDO¹, Shotaro KAI¹, Takahiro NAKANO¹, Masahiro HACHISUGA¹, Nobuhiro HIDAKA¹, Yusuke YANAGI², Tomoaki TAGUCHI², Kiyoko KATO¹

¹九州大学病院産科婦人科, ²九州大学病院小児外科

¹Department of Obstetrics and Gynecology, Kyushu University Hospital, ²Department of Pediatric Surgery, Kyushu University Hospital

キーワード : ectopic intrathoracic kidney, congenital diaphragmatic hernia, mesocardia, prenatal diagnosis

胸部異所性腎は稀な先天異常でしばしば先天性横隔膜ヘルニア（Congenital Diaphragmatic hernia: CDH）を合併するが，胎児診断例は少ない．胎児正中心を呈し右胸部異所性腎，右CDHの診断に至った症例を経験した．症例は32歳，1妊0産．妊娠18週の健診時に正中心を指摘した．28週の超音波検査で右胸腔内構造が左肺より低輝度を示し腫瘤性病変を疑った．MRI検査で胎児右胸腔内に右腎と肝右葉の陥入を認め，右CDHと診断した．36週の肺胸郭断面積比0.24，肺断面積児頭周囲長比2.47と肺低形成の程度は強くないことが予測されたが，CDHに準じて管理を行う方針とした．妊娠37週に帝王切開で2,812gの女児を分娩し， Apgarスコアは1分値5点，5分値7点であった．出生直後より人工呼吸管理を行い，軽度の肺高血圧を認めたが循環動態は安定していた．日齢2のCT検査で右CDHと診断し同日根治術を施行した．横隔膜背側で肝後区域が胸腔内に挙上し，腎臓は胸部の高さで後腹膜下に存在した．ヘルニア嚢に裂孔はなく有嚢性右CDHと診断した．腎臓は腹部へ還納できなかった．横隔膜，腹横筋およびGerota筋膜でヘルニア門の縫縮を行い日齢46に退院した．胸部異所性腎の胎児診断は稀だが，本症例は正中心がその契機となった．胸部異所性腎を合併した右CDHでは患側への縦隔偏位が起こりうることを認識した．

Although an ectopic intrathoracic kidney can be complicated by congenital diaphragmatic hernia (CDH), prenatal diagnosis of this condition is rare. We report a rare case of prenatally diagnosed ectopic intrathoracic kidney with CDH presenting as fetal mesocardia. A 32-year-old gravida 1, para 0 showed fetal mesocardia on ultrasonographic screening performed at 18 weeks' gestation. No additional ultrasonographic anomalies were identified at the time. Detailed examination using magnetic resonance imaging at 30 weeks' gestation showed that the fetal right kidney and a part of the liver were intrathoracic in location, and we diagnosed right CDH. She underwent cesarean section at 37 weeks' gestation and delivered a female infant weighing 2,812 g with Apgar scores of 5・7. The infant was intubated immediately after birth, and mechanical ventilation was initiated. Although mild pulmonary hypertension was observed, her cardiorespiratory status stabilized smoothly. Computed tomography confirmed the diagnosis of right CDH, and we performed surgical repair on day 2 of birth. The posterior segment of the hepatic lobe and the right kidney were herniated through a right diaphragmatic defect and were covered by a hernia sac. The right kidney was located retroperitoneally and could not be replaced under the diaphragm. We diagnosed right CDH and concomitant ectopic intrathoracic kidney. We performed plication of the hernia sac with the transversus abdominis and Gerota's fascia. In this case, fetal mesocardia led to the prenatal diagnosis. Our case suggests that CDH can cause an ipsilateral mediastinal shift by complication with ectopic intrathoracic kidney.