Visualization of Pelvic Splanchnic Nerve and Pelvic Plexus by Magnetic Resonance Imaging

Kazutaka Koganei

Second Department of Surgery, Yokohama City University, School of Medicine (Director: Prof. Hiroshi Shimada)

Magnetic resonance imaging (MRI) was used to identify the pelvic splanchnic nerve and/or pelvic plexus using the resected surgical specimen in vitro. The distance between splanchnic nerve or pelvic plexus and the rectal wall was then measured preoperatively in patients with rectal cancer. In the resected surgical specimen, the fourth splanchnic nerve (S4) was recognized in 5 of 5 cases (100%) and the pelvic plexus in 4 of 5 cases (80%) as low-intensity fibers in T1-weighted sagittal imaging. Preoperatively, S4 was recognized in 36 of 42 patients (86%) by T1-weighted sagittal imaging, at least on one side. The pelvic plexus was recognized in 33 of 42 (79%). Continuity from the sacral foramen and anatomical location on the axial section confirmed the accuracy of imaging. Projecting nerves on the axial image, we measured the distance between S4 or pelvic plexus and the rectal outer margin (the tumor itself or muscle proper). The distance averaged 8.8 mm when the tumor was on the same level as the pelvic plexus, and 14.0 mm when the tumor was located cephalad or caudal to the pelvic plexus. MRI is thus useful in evaluating the location of the pelvic splanchnic nerve and plexus, and this information aids in conducting nerve-preserving surgery for advanced rectal cancer.

Key words
advanced rectal cancer, nerve preservating operation, magnetic resonance imaging, pelvic splanchnic nerve, pelvic plexus

Reprint requests
Kazutaka Koganei Second Department of Surgery, Yokohama City University School of Medicine 3-8 Fukuura, Kanazawaku, Yokohama, 236-0004 JAPAN

Accepted
March 28, 2001

To read the PDF file you will need Abobe Reader installed on your computer.