方法：2004年7月から2009年1月に当院NICUに入院したPICC留置例を対象にエコーにてCRTの有無を調べ危険因子を解析した。
結果：184名延べ221本のPICCのうち描出成功不良の総腸骨静脈留置を除外し，鎖骨下静脈，腕頭静脈＋上大静脈，下大静脈（IVC）に留置した173名の210本につき解析した。CRT検出率は11.4％で全例無症状であった。合併群は有意に出生体重が小さくIVC留置例に多かった。また，経静脈栄養施行率が高く，挿入期間が長く，24時間以上の前期破水が少ない傾向を認めた。ロジスティック回帰分析では前期破水がないこととIVC留置が独立した危険因子であった。
結論：CRT頻度は11.4％で全例無症候性であった。IVC留置中はCRTの発生に注意が必要と考えられた。
Method：Neonates admitted to Gunma University Hospital NICU from July 2004 to Jan. 2009 and were inserted PICC were eligible for this study. Ultrasonographic examinations were conducted twice a week to detect CRT. Successful detectability rate of PICC tip and incidence of CRT were compared among different PICC tip positions. Risk factors for CRT development was assessed by comparison groups with or without CRT followed by multiple logistic regression analysis.
Results：The study subject was 221 PICCs placed in 184 patients. PICCs placed in common iliac vein were poorly visualized and excluded. Thus final analysis was conducted on 210 PICCs placed in 173 patients. Twenty-four patients were diagnosed as having CRT（11.4%）．All CRT were asymptomatic, although total inferior vena cava（IVC）occlusion was demonstrated in an infant. Infants with CRT had significantly lower birth body weight and higher proportion of IVC placement. Also they are tended to having higher rate of parenteral nutrition, lower rate of preterm rupture of over 24 hours, and longer duration of placement. After multiple logistic regression analysis, IVC placement and lacking for preterm rupture of membrane over 24 hours and were independent contributor to CRT development.
Conclusion：CRT was diagnosed in 11.4% of PICCs placed in NICU patients, All patients were clinically asymptomatic. One must be careful to the development of CRT in cases of IVC placement. Ultrasonography may be a visual modality to detect CRT except for common iliac vein placement.
