Dong Hwa Heo

Simple oblique lumbar magnetic resonance imaging technique and its diagnostic value for extraforaminal disc herniation.

Study Design. Prospective study evaluating the oblique lumbar magnetic resonance imaging (MRI). Objective. To present the technique of oblique lumbar MRI and assess the clinical efficacy of this technique for diagnosis of extraforaminal disc herniation. Summary of Background Data. Herniated lumbar discs are traditionally diagnosed using conventional lumbar axial and sagittal MRI. However, conventional lumbar MRI might not reveal nerve root compression in the extraforaminal area. Oblique lumbar MRI can provide clear visualization of the dorsal root ganglion and lumbar nerve root in the foraminal and extraforaminal areas. Methods. Ten patients diagnosed with extraforaminal disc herniations underwent bilateral oblique lumbar MRIs before surgery (turbo spin-echo T2-weighted sequence). We compared the side with symptomatic extraforaminal disc herniation to the asymptomatic contralateral side. Results. Oblique lumbar MRI succeeded in depicting pedicles, dorsal root ganglions, and lumbar nerve roots of the foraminal and extraforaminal areas. In 9 of 10 patients (90.0%), nerve root compression by the herniated disc in the extraforaminal area was clearly demonstrated when compared with the asymptomatic contralateral side (P < 0.05). In 1 patient with scoliosis and spinal stenosis, oblique MRI could not clearly display foraminal or extraforaminal anatomy due to spinal deformity. Conclusion. In light of this data, we suggest that oblique lumbar MRI can precisely demonstrate nerve roots in foraminal and extraforaminal areas. This technique is a simple and useful diagnostic tool for extraforaminal lumbar disc herniations.

Adjacent Segment Degeneration After Lumbar Dynamic Stabilization Using Pedicle Screws and a Nitinol Spring Rod System With 2-year Minimum Follow-up

Study Design: Prospective study evaluating the adjacent segment degeneration after lumbar dynamic stabilization using pedicle screws and a Nitinol spring rod system. Objective: To assess the changes of the adjacent and implantation segments after lumbar dynamic stabilization surgery using magnetic resonance imaging (MRI). Summary of Background Data: Lumbar fusion operations can accelerate the degeneration of adjacent levels. Recently, motion preservation surgery has been attempted for the treatment of lumbar degenerative diseases to prevent degeneration of adjacent levels. However, there is a controversy over whether lumbar dynamic stabilization accelerates degeneration of adjacent levels. Methods: We performed the dynamic stabilization procedure in patients with grade 1 degenerative lumbar spondylolisthesis, lumbar spondylotic stenosis with segmental instability, or a herniated lumbar disc with segmental instability. Postoperative MRI scans were taken for >2 years in all enrolled 25 patients. We compared the findings regarding disc degeneration in the cranial, implantation, and caudal segments between the preoperative period and 2-year-plus postoperative period using T2-weighted sagittal MR images. In addition, we investigated the progression of the central and foraminal stenosis of the adjacent cranial and caudal levels. Results: Three of the 25 cranial adjacent discs (12.0%) and 4 of the 25 (16%) caudal adjacent discs demonstrated progression of degeneration after dynamic stabilization. One of the 13 discs in the implantation segment demonstrated progression of degeneration, and 2 of the 13 discs in the implantation segment showed improvement of their disc degeneration (disc rehydration). A total of 5 (10.0%) of the 50 segments (3 cranial and 2 caudal adjacent) showed increased spinal stenosis postoperatively. Among the 5 cases, 3 patients had symptomatic adjacent stenosis. Conclusion: According to our results, lumbar dynamic stabilization using pedicle screws and a Nitinol spring rod system may not prevent adjacent level degeneration completely.

Intraarterial Tirofiban Thrombolysis for Thromboembolisms During Coil Embolization for Ruptured Intracranial Aneurysms

Objective Thromboembolus can occur during endovascular coil embolization. The aim of our study was to show our experience of intraarterial (IA) tirofiban infusion for thromboembolism during coil embolization for ruptured intracranial aneurysms. Methods This retrospective analysis was conducted in 64 patients with ruptured aneurysms who had emergent endovascular coil embolization from May 2007 to April 2011 at a single institute. Thromboembolic events were found in ten patients (15.6%). Anticoagulation treatment with intravenous heparin was started after the first coil deployment in ruptured aneurysmal sac. When a thrombus or embolus was found during the procedure, we tried to resolve them without delay with an initial dosage of 0.3 mg of tirofiban up to 1.2 mg. Results Three patients of four with total occlusion had recanalizations of thrombolysis in myocardial infarction (TIMI) grade III and five of six with partial occlusion had TIMI grade III recanalizations. Eight patients showed good recovery, with modified Rankin Scale (mRS) score of 0 and one showed poor outcome (mRS 3 and 6). There was no hemorrhagic or hematologic complication. Conclusion IA tirofiban can be feasible when thromboembolic clots are found during coil embolization in order to get prompt recanalization, even in patients with subarachnoid hemorrhage.

Lumbar epidural gas-containing pseudocysts as a cause of severe radicular pain

OBJECTIVES Intradiscal gas can herniate to the epidural space, and herniated epidural gas may produce pseudocysts. We assessed the characteristics of and surgical treatments for lumbar epidural gas-containing pseudocysts as a cause of severe radicular pain. METHODS We surgically treated epidural gas-containing pseudocysts in a total of 22 patients. We reviewed radiological parameters including the concomitant presence of vacuum discs, segmental instability, spinal stenosis, and location of pseudocysts. We retrospectively reviewed preoperative clinical parameters such as age, sex, clinical symptoms, neurologic deficits, and surgical methods. RESULTS We observed 25 levels of gas-containing pseudocysts in 22 patients. Twelve (48.0%) pseudocysts were in the canal, eight (32.0%) were in the foramen, and five (20.0%) were of extraforaminal type. All of the patients had degenerative vacuum discs in the affected levels. The incidence of neurologic deficits in patients with spinal stenosis was significantly higher than in patients without spinal stenosis (P<0.05). We performed pseudocyst removal, neural decompression, and fusion surgery in 12 patients with symptomatic spinal stenosis or instability, and microscopic removal of pseudocysts in 10 patients without symptomatic spinal stenosis or instability. CONCLUSION We propose that lumbar gas-containing pseudocysts can produce radicular pain and/or neurologic symptoms, and that surgical removal of pseudocysts with or without optimal stabilization operations can significantly improve symptoms. The selection of surgical methods may depend on the presence of concomitant spinal stenosis or segmental instability.

Do Postoperative Biomechanical Changes Induce Heterotopic Ossification After Cervical Arthroplasty?: A 5-Year Follow-up Study.

Study Design:Prospective clinical study. Objective:To evaluate the factors that would predispose a patient to heterotopic ossification (HO) formation after cervical arthroplasty. Summary of Background Data:HO after arthroplasty is one of the complications of cervical total disk replacement (TDR). However, the predisposing factors and pathophysiology of HO have not been precisely described. Materials and Methods:We prospectively enrolled and followed up 23 patients, who received single-level arthroplasty with ProDisc-C, for 5 years after the operation. The patients who developed grade 3 or 4 HO were classified into the “high-grade HO group,” whereas the patients with grade 0, 1, or 2 HO were classified into the “low-grade HO group.” We compared the postoperative changes in the range of motion (ROM) and height of the functional segmental unit (FSU) of the implantation segments between the 2 groups. Results:The mean differences in height and ROM of the FSU were 2.59±1.42 mm and 6.7±3.2 degrees in the high-grade HO group, and 0.87±0.72 mm and 3.1±2.8 degrees in the low-grade HO group. The mean differences in height and ROM of the FSU were significantly higher in the high-grade HO group than in the low-grade HO group (P<0.05). After cervical arthroplasty, the height of the FSU and ROM of the implantation segments were significantly increased in the high-grade HO group compared with the low-grade HO group. Conclusions:Overcorrection of the height of the FSU and increase in the ROM of the implantation segment may influence the formation of HOs after cervical arthroplasty.

Intravenous Magnesium Infusion for the Prevention of Symptomatic Cerebral Vasospasm after Aneurysmal Subarachnoid Hemorrhage

Objective The study examined the difference in the incidence of symptomatic cerebral vasospasm with magnesium supplementation in aneurysmal subarachnoid hemorrhage (SAH) in a Korean population. Methods This retrospective analysis was performed in 157 patients diagnosed with aneurysmal SAH from January 2007 to December 2011 at a single center. Seventy patients (44.6%) received a combination treatment of nimodipine with magnesium and 87 patients (55.4%) received only nimodipine. A matched case-control study using propensity scores was conducted and 41 subjects were selected from each group. A dosage of 64 mmol/day of magnesium was administrated. Results The infusion of magnesium did not reduce the incidence of symptomatic cerebral vasospasm (n=7, 17.1%, p=0.29) compared with simple nimodipine injection (n=11, 26.8%). The ratios of good clinical outcome (modified Rankin scale 0-2) at 6 months were similar, being 78% in the combination treatment group and 80.5% in the nimodipine only group (p=0.79). The proportions of delayed cerebral infarction was not significantly lower in patients with combination treatment (n=2, 4.9% vs. n=3, 7.3%; p=0.64). There was no difference in the serum magnesium concentrations between the patients with symptomatic vasospasm and without vasospasm who had magnesium supplementation. No major complications associated with intravenous magnesium infusion were observed. Conclusion Magnesium supplementation (64 mmol/day) may not be beneficial for the reduction of the incidence of symptomatic cerebral vasospasm in patients with aneurysmal SAH.

Spontaneous migration of a polymethylmethacrylate mass after vertebroplasty in osteoporotic lumbar compression fracture with avascular osteonecrosis: A case report

Joint Bone Spine - In Press.Proof corrected by the author Available online since mercredi 13 octobre 2010

Heterotopic ossifications after vertebroplasty using calcium phosphate in osteoporotic vertebral compression fractures: Report of 2 cases

BACKGROUND Recently, calcium phosphate (CaP) cement, instead of polymethylmethacrylate, has been injected into the compressed vertebral body. Calcium phosphate may have the potential for ectopic or heterotopic ossification and, thus, injected CaP cement can induce unwanted heterotopic ossifications in the human body. CASE DESCRIPTION The authors describe 2 cases of heterotopic ossifications after vertebroplasty using CaP in osteoporotic vertebral compression fractures. We performed percutaneous vertebroplasty using CaP cement in a 69-year-old woman with L2 compression fracture and an 80-year-old man with L1 compression fracture. Follow-up radiologic studies for both cases showed that heterotopic ossifications had developed around the CaP-augmented vertebral bodies and that the cemented vertebral bodies had recollapsed. Also, subsequent vertebral compression fractures had occurred. CONCLUSIONS We suggest that heterotopic ossification may be complications of vertebroplasty with CaP. Therefore, we strongly recommended that the patients who undergo a vertebroplasty with CaP need strict observation.

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 patients mentality improved from drowsiness to alertness. The patient was asymptomatic when discharged.

Segmental artery injury following percutaneous vertebroplasty using extrapedicular approach.

We performed a percutaneous vertebroplasty at the compressed L2 vertebral body of a 73-year-old female using a left-sided unilateral extrapedicular approach. She complained severe radiating pain and a tingling sensation in her left leg two hours after the vertebroplasty. Spinal computed tomographic scan showed a large retroperitoneal hematoma, and a subsequent spinal angiography revealed a left L2 segmental artery injury. Bleeding was successfully controlled by endovascular embolization. Recently, extrapedicular approaches have been attempted, allowing for the avoidance of facet and pedicle injury with only a unilateral approach. With this approach, however, the needle punctures the vertebral body directly. Therefore, this procedure carries the potential risk of a spinal segmental artery.