Oral Posters: Thoraco-lumbar Degenerative

Presented by: Y.J. Jin - View Audio/Video Presentation (Members Only)

Author(s):

Y.J. Jin(1)

(1) Seoul Paik Hospital, College of Medicine, Inje University, Department of Neurosurgery, Seoul, Korea, Republic of

Abstract

On gadolinium-enhanced fat suppression technique, enhancements of dorsal epidural venous plexus (DVCE), periradicular vein (PVCE), and intraradicular vein (IRCE) at the site of stenosis are frequently observed. The purpose of this study was to compare those patterns and specific values of IRCE with clinical situations and discuss whether these values help the symptomatic grading and selection of surgical level. We divided 163 patients who were diagnosed as central stenosis(CS, 181 levels) with or without accompanying lateral recess stenosis(LS) into IRCE(+) Bilateral Sx(+) as group 1 (n=64, 68 levels), IRCE(+) Unilateral Sx(+) as group 2 (n=12, 12 levels), IRCE(-) Bilatreral Sx(+) as group 3 (n=15, 18 levels), IRCE(-) Unilatreral Sx(+) as group 4 (n= 25, 26 levels), IRCE(-) Sx(-) as group 5 (n=47, 57 levels). Data from normal control (14 patients, L3-4 14 levels, L4-5 14 levels) was obtained. A digitizer with MR apparatus measured the area of the dural sac (DCSA) and specific values (whole rootlets vs maximal spot rootlet) associated with white signal intensity of IRCE at the most stenotic level. The values for sedimented and aggregated conglomerate of rootlets on L2-3 disc level in all groups were measured to compare those of normal control group. In addition, DCSA, VAS, treatment modalities, clinical outcomes, and the incidence of DVCE, PVCE, redundant nerve root (RNR), and nerve root sedimentation sign (NRSS) were checked depending on the groups.
DCSA/VAS/whole rootles/spot rootlet/op rate were 30.9±8.8mm2/7.0±1.5/304.3±33/371.8±46/62% in group 1, 27.7±6.0mm2/6.7±1.3/300.5±28/362.3±53/42% in group 2, 38.8±11.2mm2/6.5±2.0/ 242.6±14/285.4±17/22% in group 3, 44.6±14mm2/6.4±2.2/220.7±18/254.4±29/19% in group 4, 45.4±15mm2/0/211.2±21/250.4±26 in group 5. The cut-off values of DSA/whole rootlets/spot rootlet enhancement in terms of the presence of symptom and IRCE were estimated as 42.5mm2 /229/289 and 36.5 mm2 /255/307. Symptom may precede the development of IRCE. The incidence of DVCE were as follows : 91%/100%/94%/88%/39% in group 1/2/3/4/5. Symptom was significantly related to the presence of DVCE (92% vs 30%). However, the degree of IRCE had nothing to do with the increase of VAS. IRCE group had higher operation rate (58%) than that (24%) of non-enhanced group. The laterality of symptom was related to the degree and presence of PVCE. The linear increasing pattern of IRCE and the presence of DVCE/PVCE may show the relations between venous congestion and various clinical situations. Both of redundant nerve roots sign(RNR) and nerve rootlet sedimentation sign(NRSS) were not related with the presence of Sx although incidence of RNR and NRSS in symptomatic group were detected in 46%, 83% comparing to 19%, 81% in asymptomatic stenosis group.
The pathogenesis of IRCE(+) group may be related to polyradiculopathy secondary to venous congestion and edema in intrathecal multiple rootlets. The pathogenesis of IRCE(-) group was considered as unilateral or bilateral monoradiculopathy due to local venous congestion including direct injury from mechanical compression around root sleeve. IRCE(+) and IRCE(-) groups are likely to correspond to typical central stenosis and lateral recess stenosis radiologically and clinically. The degree of intraradicular enhancement and the presence of DVCE and PVCE on Gd-enhanced fat suppression MR may help for level selection and symptomatic grading of lumbar stenosis. Those may enable to do superselected (target-oriented) surgery in patients with multilevel stenosis.