Dysplastic aberrant left subclavian artery originating from a thoracic intersegmental artery associated with a right aortic arch.

PURPOSE: A right aortic arch (RAA) is a rare vascular anomaly that often coexists with an aberrant left subclavian artery (ALSA). Due to the rarity of RAA, the development of an ALSA is not well understood. METHOD: We describe a case in which a 58-year-old man who was scheduled to undergo posterior decompression and fusion surgery for thoracic ossification of the posterior longitudinal ligament from Th1 to Th3 was found to have a RAA and an ALSA. RESULTS: Preoperative computed tomography angiography demonstrated a RAA and an ALSA. The ALSA was extremely tortuous and ran in the paraspinal muscles behind the thoracic laminae, which meant it was in the surgical field. The ALSA arose from the descending aorta and bifurcated into the left segmental arteries of Th1 and Th2, and also bifurcated into the left vertebral artery, which had a normal subsequent course. The dysplastic ALSA was considered to have developed from the thoracic intersegmental artery. Based on preoperative examination findings, we performed spinal surgery without vessel injury. CONCLUSION: We report a rare case of a dysplastic ALSA that developed from the thoracic intersegmental artery with a RAA. The knowledge of this anomaly provides safety in spinal surgery of the cervicothoracic junction.

[What are the Indications and Points of Anterior Cervical Decompression Surgery?]

Anterior cervical foraminotomy is a motion-preserving and precise decompressing surgery with minimal bone removal. As preserving the motion segment and maximizing decompression are contradictory concepts, proficiency is needed to balance these requirements. Anatomical knowledge and good intraoperative orientation are essential to reach the nerve roots accurately in a narrow surgical field.

[Investigation of Repeatability of Residual Urine Volume Measurement for Lower Urinary Tract Disorder in Patients with Lumbar Degenerative Disorders].

STUDY DESIGN: prospective study OBJECTIVE:To evaluate repeatability of residual urine(RU)volume measurement(RUM)in patients with lumbar degenerative disorders. SUMMARY OF BACKGROUND DATA: RUM by abdominal echo is a non-invasive modality to evaluate lower urinary tract disorder(LUTD), repeatability of which is not found in urological disorders. Additionally, its repeatability has not been confirmed in spinal disorders. The authors examined repeatability of RUM for evaluation of LUTD in patients with lumbar degenerative disorders. METHODS: Thirty-four patients with lumbar degenerative disorders and 7 normal adult volunteers entered our study. RUM was performed at least twice(two to seven times; average 3.6 times). According to urological guidelines, RU over 50 cc is defined as abnormal. Thirty-four patients were divided into two groups:the U+group with lower urinary tract lesion(16 patients)and the U-group without such a lesion(18 patients). RESULTS: In normal adult volunteers:In all volunteers, there was no abnormal RU. Repeatability of RUM was 100%. Average RU volume was 1.6 cc. In patients with lumbar degenerative disorders:Repeatability of RUM was 94.4% in the U-group(average RU volume was 35.2 cc)and 50% in the U+group(average RU volume was 50.1 cc). In all patients with lumbar degenerative disorders, repeatability of RUM was 73.5%(average RU volume was 43.0 cc). CONCLUSIONS: Repeatability of RUM in patients with lumbar degenerative disorders was 73.5%. Especially, in patients without lower urinary tract lesion, high repeatability of RUM was confirmed. According to the present study, RUM seemed to be a dependable modality to evaluate LUTD in patients with lumbar degenerative disorders.

Spontaneous Intracranial Hypotension Discovered Following Cerebral Venous Thrombosis: A Case Report and Review of the Literature.

Cerebral venous thrombosis (CVT) is a rare complication of spontaneous intracranial hypotension (SIH). We encountered a case where SIH was discovered after the diagnosis of CVT, suggesting the occurrence of CVT during the acute phase of SIH. We report this rare case of isolated cortical vein thrombosis in the acute phase of SIH. A 48-year-old woman taking low-dose oral contraceptives presented with neck pain, headache, and right-sided weakness. Magnetic resonance imaging and digital subtraction angiography confirmed isolated cortical vein thrombosis. No other specific imaging abnormalities were noted. The patient was initially treated with anticoagulation. Subsequent worsening of her orthostatic headache led to the diagnosis of SIH, with diffuse dural enhancement on gadolinium-enhanced T1-weighted imaging. An epidural blood patch was performed, resulting in a favorable outcome with no neurological deficits. Although CVT can occur in the acute phase of SIH, particularly in patients with thrombophilia, the lack of characteristic imaging findings associated with SIH often complicates the diagnosis.

Thoracic spinal cord injury after surgical removal of a ruptured cerebellar arteriovenous malformation in a patient in the Concorde position: illustrative case.

BACKGROUND: Thoracic spinal cord injury after posterior cranial fossa surgery in younger patients is a rare complication. There have been reports of this complication in tumor and spine fields but not in vascular surgery. OBSERVATIONS: A 22-year-old-man experienced cerebellar arteriovenous malformation rupture, and the malformation was surgically removed with the man in the Concorde position. After surgery, the man had severe paraplegia, and a thoracic spinal cord injury was diagnosed. LESSONS: In younger patients, cervical hyperflexion in the Concorde position can cause thoracic spinal cord injury even in surgery for cerebrovascular disease.

Symptomatic interdural cerebrospinal fluid collections after surgery for idiopathic spinal cord herniation: illustrative case.

BACKGROUND: Idiopathic spinal cord herniation (ISCH) is very rare. Some reports have described postoperative ventral cerebrospinal fluid (CSF) collections in patients with ISCH; however, such collections are asymptomatic in most patients, and there is no consensus regarding whether they are part of the natural history or a complication. OBSERVATIONS: A 30-year-old man with ISCH underwent direct closure of a duplicated dura mater. Eight months postoperatively, he developed reworsening of right lower limb paresis and new severe right arm pain and paresis. Three-dimensional magnetic resonance imaging revealed ventral CSF collections, which the authors judged as the responsible lesions. The authors initially considered these collections to be present in the epidural space, extradurally compressing the dural sac and resulting in myelopathy. An epidural blood patch failed; however, a CSF drainage test resulted in dramatic improvement. The authors therefore determined that the CSF collections were located in the interdural space, not the epidural space. A lumboperitoneal (LP) shunt was performed to reduce the CSF pressure. The patient's symptoms improved immediately postoperatively. He had developed no recurrence of symptoms 6 months after surgery. LESSONS: Ventral interdural CSF collections after ISCH surgery can cause reworsening of myelopathy and may be cured by a LP shunt to control CSF pressure.

Long-term Radiological Evidence of Affected and Adjacent Segment Disease after Anterior Cervical Foraminotomy.

Anterior cervical foraminotomy (ACF) is a surgical procedure for cervical radiculopathy to avoid fusion and adjacent segment disease (ASD), but its long-term outcome has yet to be investigated. It is also unclear whether ACF enables preservation of range of motion (ROM) and decreases ASD compared with anterior cervical discectomy and fusion (ACDF). This study included nine patients who underwent ACF, and 12 who underwent ACDF and with follow-up period of at least 5 years (average follow-up: 8.7 years). Preoperative and postoperative radiological findings were investigated, comparing the changes in ACF versus ACDF. All disc height (DH) levels (C2/3-C7/Th1) were measured preoperatively and postoperatively in all 21 patients to compare with the change due to the natural history. The ACF group experienced significant loss of DH (0.6 mm, 13.5%, p <0.01) and ROM (p <0.01) at the operated level postoperatively. However, loss of DH was not significantly different from natural changes at unaffected levels, and ROM was maintained. The ACDF group experienced a significant increase in the ROM of the cranial adjacent segment from 6.46 mm to 7.45 mm (p <0.01), and the dislocation in dynamic X-ray was also significantly increased from 1.61 mm to 2.89 mm (p <0.01), indicating radiological ASD. The ACF group had no significant increase in ROM and dislocation. ACF causes significant loss of DH and ROM, but this change is not significantly different compared with natural changes at unaffected levels. Furthermore, ACF causes less ASD than ACDF in the long term.

Investigation of Radiologic Landmarks Used to Decide the Appropriate Surgical Approach for Upper Thoracic Ventral Degenerative Disorders.

BACKGROUND: Ventral lesions of upper thoracic spinal cord due to degenerative diseases are rare and often have poor operative outcomes. Anterior decompression of the lesion is difficult because of the local anatomy. This retrospective study aimed to evaluate reproducible anatomic measurements for selecting the best surgical approach for anterior decompression of ventral lesions of upper thoracic spinal cord. METHODS: Cases of anterior decompression of ventral lesions of upper thoracic spinal cord due to degenerative diseases at our institution from 2004 to 2015 were assessed. Several lines were drawn on magnetic resonance imaging and computed tomography scans of midsagittal sections of the upper thoracic spine to evaluate the most optimal approach for treating upper thoracic lesions. A line from the suprasternal notch to the vertebral body (suprasternal notch to vertebral body [SV] line) was accepted as baseline. RESULTS: The caudal edge of the lesion was above the SV line in 10 cases, each of which was treated via an anterior approach without sternotomy. The caudal edge was below the SV line in 7 cases, 5 of which underwent surgery with the sternum-splitting or transthoracic approach. The other 2 lesions were approached via an obliquely deviated route without sternotomy. The SV line sometimes changed with patients' posture alterations. CONCLUSIONS: The SV line, a useful landmark for upper thoracic lesions, is not sufficiently reliable because it changes according to the patient's posture. By leaning in the direction of the surgical microscope, more caudal upper thoracic lesions can be reached than when using the SV line as a surgical landmark.

Morphological Patterns of the Anterior Median Fissure in the Cervical Spinal Cord Evaluated by Computed Tomography After Myelography.

OBJECTIVE: Computed tomography following myelography (CTM) revealed an unusual flow of contrast dye into the anterior median fissure (AMF) in a patient with cervical spondylotic myelopathy. Since then, several AMF configurations have been observed on CTM. Therefore, we evaluated morphological patterns of the AMF on CTM and investigated the significance and mechanisms of contrast dye flow into the AMF. METHODS: Morphological patterns of the AMF on CTM were examined in 79 patients. Group A (24 patients) underwent surgery because of symptomatic cervical myelopathy. Group B (43 patients) had no clinical symptoms but showed spinal cord compression on CTM. Group C (12 patients), who showed neither clinical symptoms nor cord changes, underwent CTM for lumbar lesion evaluation. AMF patterns were classified into 4 types according to their configurations on CTM (reversed T, Y, V, and O types). RESULTS: In group B, the reversed T type and Y type appeared significantly more often near the compressed portion (p<0.001). A similar tendency was seen in group A. The V and O types were most frequently observed in group C (p<0.001). CONCLUSION: On CTM, contrast dye tends to flow into the AMF of the cervical cord when the spinal cord is compressed. We speculate that there may be 3 possible mechanisms for this phenomenon: deformation of the epipial layer of the AMF due to cervical cord compression, AMF dilatation due to atrophy of the anterior funiculus or anterior horn, and temporary AMF dilatation when it becomes an alternative route for cerebrospinal fluid circulation.

Precocious Solitary Cervical Metastasis from Endometrial Cancer Presenting as Cervical Radicular Pain.

BACKGROUND: Bone metastases from endometrial cancer are rare. To our knowledge, only 2 cases of solitary vertebral metastases from endometrial cancer presenting with osseous and/or neurologic symptoms before the diagnosis of the primary endometrial cancer have been reported; however, in both cases, the metastases were thoracic. Thus, cervical vertebral metastases are extremely rare. CASE DESCRIPTION: We describe the case of a 55-year-old woman who presented with right C6 radicular and neck pain. Neurologic imaging showed destruction of the C6 vertebral body by an extradural mass with kyphotic changes in the cervical spine. Fluorodeoxyglucose positron emission tomography showed increased uptake in the enlarged body of the uterus as well as the C6 vertebral body. Additional pelvic magnetic resonance images and endometrial biopsy confirmed endometrial cancer. The patient underwent excision of the cervical tumor with anterior reconstruction and posterior fixation followed 1 month later by semiradical hysterectomy and bilateral salpingo-oophorectomy with pelvic and para-aortic lymph node dissection. The cervical and endometrial histopathologic findings were similar, and the final diagnosis made was cervical metastatic adenocarcinoma originating from an endometrial cancer. CONCLUSIONS: We describe an extremely rare case of a precocious solitary cervical metastasis from an endometrial cancer presenting as cervical radicular pain. In our review of published reports, we found that solitary spinal metastases are significantly associated with longer overall survival than are multiple lesions. Resection of the spinal lesion with rigid spinal reconstruction followed by radical hysterectomy may be beneficial in such patients.

Indication for Partial Vertebral Osteotomy and Realignment in Posterior Spinal Fixation for Osteoporotic Thoracolumbar Vertebral Collapse with Neurological Deficits.

Instrumented spinal fixation is ordinarily required in patients who present with myelopathy or cauda equina syndrome secondary to vertebral collapse following osteoporotic thoracolumbar fracture. Posterior spinal fixation is a major surgical option, and partial vertebral osteotomy (PVO) through a posterior approach is occasionally reasonable for achievement of complete neural decompression and improvement of excessive local kyphosis. However, the indications and need for PVO remain unclear. The objectives of this retrospective study were to determine the efficacy and safety of posterior spinal fixation with or without PVO for osteoporotic thoracolumbar vertebral collapse and identify patients who require neural decompression and alignment correction by PVO. We retrospectively reviewed the clinical records of 20 patients (13 females, 7 males; mean age, 67.1 years) who underwent instrumented posterior fixation for osteoporotic thoracolumbar vertebral fracture. Clinical outcomes were assessed by the Japanese Orthopedic Association score and visual analog scale scores in the lumbar and leg areas. PVO was added with posterior spinal fixation in eight patients because neural decompression was incomplete after laminectomy as indicated by intraoperative echo imaging. Neurological and functional recovery significantly improved during follow-up. Clinical outcomes in patients who underwent PVO were similar to those in patients who did not undergo PVO. However, correction of the local kyphotic angle and improvement of spinal canal compromise after surgery was significant in patients who underwent PVO. The patients who required PVO had a less local kyphotic angle in the supine position and higher occupation rate of the fractured fragment in the spinal canal in the preoperative examination.

Current Status of Lumbar Interbody Fusion for Degenerative Spondylolisthesis.

Instrumented lumbar fusion can provide immediate stability and assist in satisfactory arthrodesis in patients who have pain or instability of the lumbar spine. Lumbar adjunctive fusion with decompression is often a good procedure for surgical management of degenerative spondylolisthesis (DS). Among various lumbar fusion techniques, lumbar interbody fusion (LIF) has an advantage in that it maintains favorable lumbar alignment and provides successful fusion with the added effect of indirect decompression. This technique has been widely used and represents an advancement in spinal instrumentation, although the rationale and optimal type of LIF for DS remains controversial. We evaluated the current status and role of LIF in DS treatment, mainly as a means to augment instrumentation. We addressed the basic concept of LIF, its indications, and various types including minimally invasive techniques. It also has acceptable biomechanical features, and offers reconstruction with ideal lumbar alignment. Postsurgical adverse events related to each LIF technique are also addressed.