3D reconstructions of spinal segmental arteries using CT angiography: applications in minimally invasive spinal procedures

BACKGROUND AND PURPOSE

Injury to spinal segmental arteries may potentially occur during spinal surgery, particularly during anterior or minimally invasive approaches. Use of a noninvasive radiologic tool to evaluate these arteries before surgery may reduce this risk.

MATERIAL AND METHODS

We performed spinal CT angiography and reconstructed 3D images of segmental arteries in 41 patients. We classified the pathways and locations of the segmental arteries into 4 zones (A, B, C, and D) according to pedicle and vertebral endplates. We designated segmental arteries from T8 to L1 as "high-level segmental arteries" and those from L2 to L4, as "low-level segmental arteries." We compared the distribution of segmental arteries between these 2 groups. We also investigated anatomic variations of segmental arteries and the rate of occurrence of the artery of Adamkiewicz.

RESULTS

In all patients, 3D reconstruction images from spinal CT angiography clearly showed the pathways of segmental arteries on the vertebral bodies. Most of the segmental arteries passed the middle portion of the vertebral body (zones B and C). However, 51 of 738 segmental arteries (6.9%) had uncommon pathways (zones A and D), and segmental arteries from L2 to L4 had a higher incidence of uncommon pathways than higher level vertebrae (P < .05). We also observed 2 types of segmental artery anatomic variation, agenesis and dual supply.

CONCLUSIONS

We suggest that spinal CT angiography can help to precisely visualize the spinal segmental arteries and surrounding bony structures and can aid clinicians in deciding on optimal approaches for spinal surgery.

Recollapse of previous vertebral compression fracture after percutaneous vertebroplasty

This study was undertaken to investigate the incidence rate, characteristics, and predisposing factors associated with recollapse of the same vertebrae after percutaneous vertebroplasty (PVP). Recollapse of the same vertebra after PVP is the one of the complications of the procedure, and the incidence rate in our study was 3.21%. The most important predisposing factor was pre-operative osteonecrosis. Recollapse was not related to trauma.

INTRODUCTION

PVP using polymethylmethacrylate has become a popular treatment for osteoporotic vertebral compression fracture. Recollapse of the same vertebrae after PVP has rarely been reported. This study was undertaken to investigate the incidence, characteristics, and predisposing factors associated with recollapse of the same vertebrae after PVP.

METHODS

Eleven patients (seven females and four males; mean age, 69.91 +/- 5.49 years), out of a total of 343 patients, developed recollapse of the same vertebra after PVP. The 11 patients who developed recollapse comprised the "recollapse group", while the remaining 332 patients comprised the "well-maintained group".

RESULTS

Pre-operative magnetic resonance imaging revealed that the incidence of osteonecrosis was significantly higher in the recollapse group than the well-maintained group (p < 0.05). The degree of re-expansion of the compressed vertebral body after PVP was significantly higher in the recollapse group than in the well-maintained group (p < 0.05).

CONCLUSIONS

The most important predisposing factor for recollapse was pre-operative osteonecrosis. Recollapse was not related to trauma. Osteoporotic vertebral compression fracture with osteonecrosis or pseudoarthrosis has been regarded as a relative indication for PVP; however, the findings of this study suggest that this disease category may be a relative contraindication for PVP.

Rapidly calcified epidural hematoma in a neonate

We report a very rare case of a rapidly calcified chronic epidural hematoma (EDH) in a neonate. A 26-day-old female infant was referred to us from a regional hospital because of drowsy mentality and a seizure attack. She was delivered through caesarian section because normal spontaneous vaginal delivery was prolonged and failed. At birth, mild scalp swelling was found on the right frontal area. Scalp swelling was spontaneously resolved and she was discharged without any problems. On the 25th day after her birth, the baby presented with drowsiness and hypotonia following a generalized tonic-clonic seizure. Magnetic resonance imaging (MRI) and a computed tomography (CT) scan revealed a chronic EDH that had a thick layer of calcification. A small burr-hole trephination was performed and a single silastic drainage catheter was inserted. After the operation, a total of 12 ml of liquefied hematoma was drained, and the patient's mentality improved from drowsiness to alertness. The patient was asymptomatic when discharged.