Detection of Residual Disc Hernia Material and Confirmation of Nerve Root Decompression at Lumbar Disc Herniation Surgery by Intraoperative Ultrasound

Aoyama, Takeshi; Hida, Kazutoshi; Akino, Minoru; Yano, Shunsuke; Iwasaki, Yoshinobu

doi:10.1016/j.ultrasmedbio.2008.12.014

« Previous Next »Ultrasound in Medicine and Biology
Volume 35, Issue 6 , Pages 920-927, June 2009

Detection of Residual Disc Hernia Material and Confirmation of Nerve Root Decompression at Lumbar Disc Herniation Surgery by Intraoperative Ultrasound

Takeshi Aoyama
- Department of Neurosurgery, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, Japan
- Address correspondence to: Takeshi Aoyama, Department of Neurosurgery, Hokkaido University Graduate School of Medicine, Kita 15 Nishi 7, Kitaku, Sapporo, Hokkaido, 060-8638, Japan.
Kazutoshi Hida
- Department of Neurosurgery, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, Japan
Minoru Akino
- Department of Neurosurgery, Sapporo Azabu Neurosurgical Hospital, Sapporo, Hokkaido, Japan
Shunsuke Yano
- Department of Neurosurgery, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, Japan
Yoshinobu Iwasaki
- Department of Neurosurgery, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, Japan

Received 26 July 2008; received in revised form 12 December 2008; accepted 16 December 2008. published online 20 April 2009.

Abstract

The aim of lumbar disc herniation surgery is the removal of herniated disc material (HDM) and complete decompression of the nerve root. As some patients present with residual HDM, we examined the ability of intraoperative ultrasound (IOUS) to detect this material. Between February 2006 and June 2007, we used IOUS in 30 patients undergoing surgery for lumbar disc herniation. They were 17 men and 13 women; their ages ranged from 22 to 63 y (mean 44.0 y). The level surgically addressed was L3/4 in 1, L4/5 in 14 and L5/S1 in 15 patients; they were operated in the prone position. After placing a 3–4 cm midline skin incision, partial hemi-semilaminotomy was performed. HDM was removed through a bone window; a surgical microscope was used during the operation. After removal was judged as adequate, IOUS was performed; 17 patients also underwent IOUS before removal of the herniated disc. For the acquisition of IOUS images, we used LOGIQ 9 and 8c microconvex probes (GE Healthcare, Wauwatosa, WI, USA). The normal anatomical structures were well visualized. HDM was iso- to hyperechoic compared with normal nerve tissue. In three of 17 patients, the dural sac and nerve root could not be distinguished from HDM before removal, although in all 30, the decompressed dural sac, intradural cauda equina and nerve root were well visualized. We posit that the echogenicity of nerve tissue was raised due to compression, rendering it similar to that of the herniated disc. In two patients, IOUS detected residual disc material; the surgical procedure was resumed and sufficient removal was accomplished. IOUS monitoring is safe, convenient and inexpensive. It is also highly useful for the detection of residual HDM and the confirmation of adequate nerve root decompression. (E-mail: taoya@sirius.ocn.ne.jp)

Key Words: Echography, Intraoperative, Lumbar disc herniation, Ultrasonography, Ultrasound