Vulnerability of great medullary artery

The complications of transforaminal lumbar epidural steroid injections

STUDY DESIGN

A prospective observational study.

OBJECTIVE

In this study, we aimed to investigate the major and minor complications of transforaminal lumbar epidural steroid injections guided by fluoroscopy and the incidence of vascular penetration encountered during this procedure.

SUMMARY OF BACKGROUND DATA

Epidural steroid administration is one of the treatment options for lumbar disc hernia accompanied by radiculopathy. This method, initially applied by blind interlaminar technique, has generally been performed by fluoroscopically guided transforaminal method now. The complications of this method cause to a serious concern. The complications of this intervention have been reported by either mostly retrospective studies or case reports until now. Prospective studies with large patient series are needed to determine the types and incidences of the complications.

METHODS

In this study carried out for more than 5 years, major and minor complications of transforaminal lumbar epidural steroid injections were investigated prospectively. All of the interventions were performed under fluoroscopic guidance by the same physician using a standardized method. A follow-up was made once in the third week. The complications encountered during the procedure and in the third week were prospectively recorded. In addition, the incidence of vascular penetration that is potentially hazardous is included in the study.

RESULTS

A total of 562 patients were performed 1305 times transforaminal lumbar epidural steroid. The overall incidence of vascular penetration encountered was 7.4%. Although major complications were not seen, the total rate of all minor complications was 11.5%. Whereas all of the minor complications were transient, the most frequent minor complication was vasovagal reaction (8.7%).

CONCLUSION

On the basis of the results of this study in which only minor complications were encountered, it can be said that the frequency of major complications is pretty rare in transforaminal lumbar epidural steroid injections in expert hands and in the conditions in which safety precautions are taken.

Paraplegia following image-guided transforaminal lumbar spine epidural steroid injection: two case reports

OBJECTIVE

To present two case reports of a rare but devastating injury after image-guided, lumbar transforaminal injection of steroids, and to explore features in common with previously reported cases.

BACKGROUND

Image (fluoroscopic and computed tomography [CT])-guided, lumbar transforaminal injections of corticosteroids have been adopted as a treatment for radicular pain. Complications associated with these procedures are rare, but can be severe.

CASE REPORTS

An 83-year-old woman underwent a fluoroscopically guided, left L3-L4, transforaminal injection of betamethasone (Celestone Soluspan). A 79-year-old man underwent a CT-guided, right L3-L4, transforaminal injection of methylprednisolone (DepoMedrol). Both patients developed bilateral lower extremity paralysis, with neurogenic bowel and bladder, immediately after the procedures. Magnetic resonance imaging scans were consistent with spinal cord infarction. There was no evidence of intraspinal mass or hematoma.

CONCLUSION

These cases consolidate a pattern emerging in the literature. Distal cord and conus injury can occur following transforaminal injections at lumbar levels, whether injection is on the left or right. This conforms with the probability of radicular-medullary arteries forming an arteria radicularis magna at lumbar levels. All cases used particulate corticosteroids, which promotes embolization in a radicular artery as the likely mechanism of injury. The risk of this complication can be reduced, and potentially eliminated, by the utilization of particulate free steroids, testing for intra-arterial injection with digital subtraction angiography, and a preliminary injection of local anesthetic.

Bilateral drop foot secondary to a primary tumor in the conus medullaris

Intramedullary tumors of the spinal cord are rare neoplasms that can be associated with severe neurological and functional handicaps. To our knowledge, we describe for the first time the case of a male patient who developed bilateral drop foot as an initial manifestation of a primary tumor in the conus medullaris of the spinal cord, probably an astrocytoma.

Spinal cord feeding arteries at MR angiography for thoracoscopic spinal surgery: feasibility study and implications for surgical approach

PURPOSE

To prospectively investigate the feasibility of contrast material-enhanced magnetic resonance (MR) angiography for visualization of the spinal vasculature in patients referred for video-assisted thoracoscopic surgical treatment of a thoracic herniated disk and to prospectively assess the influence of preoperative imaging of the spinal vasculature on the choice of surgical approach.

MATERIALS AND METHODS

Eight patients (three men and five women; mean age, 58 years; range, 42-83 years) with a thoracic herniated disk underwent contrast-enhanced MR angiography of the thoracoabdominal aorta and posterior branches. Imaging was performed with three-dimensional first-pass contrast-enhanced MR angiographic technique and a triple dose of gadolinium-based contrast agent. Images were analyzed by two observers in consensus to localize the Adamkiewicz artery (AKA) and its connections to the aorta and the anterior spinal artery (ASA). This information was used to determine any change in surgical approach.

RESULTS

In all eight patients, the AKA, the ASA, and the connections with the aorta were identified. The AKA originated between T9 and L2 in all patients and derived from the left side of the aorta in 75% (six of eight) of the patients. In three patients in whom the AKA was observed on the left side, the surgical approach was changed to the right side to preserve spinal cord integrity.

CONCLUSION

Preoperative imaging of the AKA is feasible with contrast-enhanced MR angiography. Contrast-enhanced MR angiography can be used to image the main feeding arteries of the spinal cord in patients undergoing thoracoscopic spinal surgery, and results can be used to change the side of surgical approach.

Results of preoperative embolization for metastatic spinal neoplasms

OBJECT

Arterial embolization reduces blood loss in patients undergoing surgery for hypervascular spinal tumors. The objectives of this study were twofold: 1) to evaluate the role of magnetic resonance (MR) imaging in predicting tumor vascularity and 2) to assess the effectiveness of preoperative embolization in devascularizing these tumors.

METHODS

Fifty-one patients with metastatic spinal neoplasms underwent angiography, preoperative embolization, and excision of the lesion between 1995 and 2000. The MR imaging studies were correlated with tumor vascularity on angiograms. Embolization was angiographically graded on a five-point scale ranging from no embolization (Grade A) to total embolization (Grade E). The embolization grade was correlated with intraoperative blood loss. The mean age was 57 years, the male/female ratio was 1.2:1, and back pain was present in all patients. Metastatic renal cell carcinoma (30 cases) and thoracic spine involvement (33 cases) were most frequent. The positive predictive value of MR imaging in determining tumor vascularity was 77%, whereas the negative predictive value was 21%. Total embolization (Grade E) was achieved in 34 patients. A shared vascular pedicle between a radiculomedullary artery (RMA) and a tumor diminished the likelihood of complete embolization (p = 0.02). Small asymptomatic cerebellar infarctions were demonstrated in two cases. The mean intraoperative blood loss was 2,586 ml. Following Grade D or E embolization, intraoperative bleeding was largely related to unembolized epidural veins.

CONCLUSIONS

Tumor histology and MR imaging findings are predictive of hypervascularity, however, hypervascular tumors may not be detected by standard MR imaging sequences. Superselective catheterization permits Grade D or E embolization in 80% of patients. Shared blood supply with an RMA is the most important factor precluding complete embolization.

Thoracic disc herniation presenting with transient anterior spinal artery syndrome. A case report

SUMMARY

This report is a clinical and radiologic correlation of anterior spinal arterial distribution ischemia with a thoracic disc herniation affecting the artery of Adamkiewicz. We could only find one other similar reported case. A 38-year-old woman developed sudden onset of severe back pain and radiculopathy, followed by rapidly evolving paraparesis. The neurological examination was consistent with a deficit caused by anterior spinal artery ischemia. MRI revealed T2 signal change in the thoracolumbar spinal cord and a laterally placed, non-calcified disc herniation. Selective spinal angiography performed 30 hours after onset revealed displacement of the left T9 radicular feeding artery by the disc herniation; at this time the artery was patent. The patient experienced some resolution of symptoms within the first 24 hours and was managed conservatively and made a significant recovery within two weeks. Appropriately located thoracic disc herniations can disturb the blood supply to the thoracolumbar spinal cord.