Intraoperative endosonography enhances laparoscopy-assisted colon pull-through for high imperforate anus

The authors used ultrasonographic endoprobes during laparoscopy-assisted colon pull-through (LACPT) for the repair of high imperforate anus to confirm the pull-through canal was surrounded symmetrically by pelvic floor muscles.

Six patients with high imperforate anus were treated by LACPT (mean age at LACPT, 8.2 months). An endoscopic (12-MHz, 2.5-mm in diameter) and proctoscopic (7.5-MHz, 12-mm in diameter) probe were inserted into the proposed route of dissection intraoperatively to measure the thickness of the surrounding muscle tissue at at least 3 levels: the external anal sphincter, the levator ani muscle sling, and the intervening muscle complex.

The average thickness of the external anal sphincter was 2.3 +/- 0.4 mm anteriorly, 2.4 +/- 0.4 mm on the left, 2.4 +/- 0.5 mm posteriorly, and 2.6 +/- 0.6 mm on the right. The average thickness of the muscle complex was 2.3 +/- 0.6 mm anteriorly, 2.2 +/- 0.5 mm on the left, 2.1 +/- 0.4 mm posteriorly, and 2.2 +/- 0.5 mm on the right. The average thickness of the left crus of the levator ani muscle was 1.8 +/- 0.3 mm, the right crus was 1.9 +/- 0.4 mm, and the rim located posterior to the rectum was 2.0 +/- 0.3 mm. No statistically significant difference was found between the measurements taken at each level.

Intraoperative endosonography during LACPT can greatly enhance the precision of positioning the pull-through canal.