Wei Pan, Jia-li Zhao, Jin Xu, Ming Zhang, Tao Fang, Jing Yan, Xin-hong Wang, and Quan Zhou
The purpose of this study was to compare the preoperative radiographic features of degenerative lumbar spondylolisthesis (DLS) with and without local coronal imbalance (LCI) and to investigate the surgical outcomes of transforaminal lumbar interbody fusion (TLIF) in the treatment of DLS with LCI at the spondylolisthesis level. DLS with scoliotic disc wedging and/or lateral listhesis at the same involved segment, as well as LCI, constitutes a distinct subgroup. However, previous studies concerning surgical outcomes focused mainly on sagittal profiles. There is a paucity of valid data regarding lumbar coronal alignment and patient-reported outcomes (PROs) after surgery in DLS with LCI.
The authors reviewed consecutive patients who received TLIF for L4/5 DLS between 2009 and 2018. Patients were assigned to the LCI and non-LCI groups based on preoperative radiographs. Demographics, radiographic parameters related to both sagittal and coronal alignment, and PROs were compared between the 2 groups.
There were 21 patients in the LCI and 80 in the non-LCI group. Compared with the non-LCI group, the LCI group was characterized by lower preoperative lumbar lordosis on sagittal alignment (38.3° vs 43.7°, p < 0.05), higher lumbar Cobb angle on coronal alignment (12.4° vs 5.1°, p < 0.05), and worse lumbar coronal balance (18.5 mm vs 6.8 mm, p < 0.05). After surgery, lumbar alignment in the sagittal and coronal planes was significantly improved in the LCI group, whereas no significant changes occurred in the non-LCI group. Scores on the preoperative Oswestry Disability Index and the visual analog scale for back pain and leg pain scores were significantly higher in the LCI group, whereas no differences were found between the 2 groups in the postoperative evaluation (p > 0.05).
DLS with LCI constitutes a distinct subgroup characterized by coronal malalignment and loss of whole lumbar lordosis, which may result in worse PROs. The TLIF procedure allows the reconstruction of the coronal and sagittal lumbar profile and achievement of satisfactory PROs.
Song-tao Qi, Yi Liu, Jun Pan, Silky Chotai, and Lu-xiong Fang
The completeness of meningioma resection depends on the resection of dura mater invaded by the tumor. The pathological changes of the dura around the tumor can be interpreted by evaluating the dural tail sign (DTS) on MRI studies. The goal of this study was to clarify the pathological characteristics of the DTSs, propose a classification based on the histopathological and radiological correlation, and identify the invasive range of tumor cells in different types of DTS.
The authors retrospectively reviewed 179 patients with convexity meningiomas who underwent Simpson Grade I resection. All patients underwent an enhanced MRI examination preoperatively. The convexity meningiomas were dichotomized into various subtypes in accordance with the 2007 WHO classification of tumors of the CNS, and the DTS was identified based on the Goldsher criteria. The range of resection of the involved dura was 3 cm from the base of the tumor, which corresponded with the length of DTS on MRI studies. Histopathological examination of dura at 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 cm from the base of the tumor was conducted, and the findings were correlated with the preoperative MRI appearance of the DTS.
A total of 154 (86%) of 179 convexity meningiomas were classified into WHO Grade I subtype, including transitional (44 [28.6%] of 154), meningothelial (36 [23.4%] of 154), fibrous (23 [14.9%] of 154), psammomatous (22 [14.3%] of 154), secretory (10 [6.5%] of 154), and angiomatous (19 [12.3%] of 154). The other 25 (14%) were non–Grade I (WHO) tumors, including atypical (12 [48%] of 25), anaplastic (5 [20%] of 25), and papillary (8 [32%] of 25). The DTS was classified into 5 types: smooth (16 [8.9%] of 179), nodular (36 [20.1%] of 179), mixed (57 [31.8%] of 179), symmetrical multipolar (15 [8.4%] of 179), and asymmetrical multipolar (55 [30.7%] of 179). There was a significant difference in distribution of DTS type between Grade I and non–Grade I tumors (p = 0.004), whereas the difference was not significant among Grade I tumors (0.841) or among non–Grade I tumors (p = 0.818). All smooth-type DTSs were encountered in Grade I tumors, and the mixed DTS (52 [33.8%] of 154) was the most common type in these tumors. Nodular-type DTS was more commonly seen in non–Grade I tumors (12 [48%] of 25). Tumor invasion was found in 88.3% (158 of 179) of convexity meningiomas, of which the range of invasion in 82.3% (130 of 158) was within 2 cm and that in 94.9% (150 of 158) was within 2.5 cm. The incidence of invasion and the range invaded by tumor cells varied in different types of DTS, and differences were statistically significant (p < 0.001).
Nodular-type DTS on MRI studies might be associated with non–Grade I tumors. The range of dural resection for convexity meningiomas should be 2.5 cm from the tumor base, and if this extent of resection is not feasible, the type of DTS should be considered. However, for skull base meningiomas, in which mostly Simpson Grade II resection is achieved, the use of this classification should be further validated. The classification of DTS enables the surgeon to predict preoperatively and then to achieve the optimal range of dural resection that might significantly reduce the recurrence rate of meningiomas.
Tao Yang, Liang Wu, Jingyi Fang, Chenlong Yang, Xiaofeng Deng, and Yulun Xu
Intramedullary neurenteric cysts (NECs) are exceedingly rare lesions and have been previously reported in case reports. The aim of this study was to determine the clinical manifestations, radiological features, and long-term prognosis of patients with such lesions.
The authors retrospectively reviewed the records of 13 patients with an intramedullary NEC. Each patient underwent MRI, laminotomy, and microsurgery. The accurate diagnosis was based on imaging and pathology findings. Each patient's follow-up status was determined through individual office visits and a structured telephone interview.
The series included 7 male and 6 female patients. Progressive or intermittent motor deficit was the main symptom associated with or without pain or sensory disturbance. Five cysts were located in the cervical cord, 1 in the cervicothoracic cord, 3 in the thoracic cord, and 4 in the conus medullaris. Concurrent malformations included scoliosis (3 cases), fusion of rib (1 case), enlarged spinal canal (1 case), tethered spinal cord (1 case), and ectocardia (1 case). Gross-total resection of the cyst was achieved in 8 cases, and subtotal resection (STR) was achieved in 5 cases. All patients were followed up, with a mean duration of 66.5 months. Cyst recurrence was observed in 4 cases after STR. In 2 cases the patients underwent reoperation; the other 2 patients remained clinically stable and did not undergo reoperation. At the last evaluation, neurological function was improved in 11 patients and remained stable in 2 patients.
Intramedullary NECs should be considered in the differential diagnosis of a middle-aged patient with intermittent neurological symptoms and concurrent malformations. Early surgery is advocated to prevent permanent neurological deficits. When gross-total resection cannot be achieved, maximally safe removal under the protection of intraoperative neuromonitoring is advised. Because of the high risk of cyst recurrence, routine follow-up MRI is needed. If a residual cyst shows obvious regrowth and results in neurological deficits, timely reoperation with a goal of STR should be performed.
Liang Wu, Tao Yang, Xiaofeng Deng, Chenlong Yang, Lei Zhao, Ning Yao, Jingyi Fang, Guihuai Wang, Jun Yang, and Yulun Xu
Extradural en plaque meningiomas are very rare tumors in the spinal canal. Most studies on these lesions have been case reports with literature reviews. In this paper, the authors review their experience in a surgical series of 12 patients with histologically proven, purely extradural en plaque meningiomas and discuss their clinical features, radiological findings, and long-term outcomes.
Clinical and imaging data of 12 patients with spinal extradural en plaque meningiomas treated at a single institution were retrospectively analyzed.
There were 5 male and 7 female patients, with a mean age of 39.9 years. The mean follow-up period was 74.8 months. Nine tumors were located in the cervical spine, 1 in the cervicothoracic spine, and 2 in the thoracic spine. All the tumors were confirmed as extradural en plaque meningiomas with sheetlike growth along the dura mater. Gross-total resection of the tumor with a well-demarcated dissection plane was achieved in 4 cases. Subtotal resection was achieved in 8 cases, 2 of whom underwent postoperative low-dose radiation therapy. The symptoms present before the surgery were improved in all cases at the last follow-up evaluation. The postoperative follow-up MRI showed no recurrence or regrowth in 4 cases with gross-total removal and 7 cases with subtotal removal during the mean follow-up periods of 58.0 months and 71.1 months, respectively. One patient experienced recurrence at 88 months after his initial subtotal removal and improved following a revision operation.
Spinal extradural en plaque meningiomas are amenable to surgery if complete removal can be achieved. Because of the encirclement of the dura that is characteristic of the tumors, complete resection is usually difficult, subtotal removal for spinal cord decompression is advised, and follow-up imaging is needed. The risk of long-term recurrence/regrowth of the lesions is low, and a good clinical outcome after total or subtotal removal can be expected.
Xiaofeng Deng, Kai Wang, Liang Wu, Chenlong Yang, Tao Yang, Lei Zhao, Jun Yang, Guihuai Wang, Jingyi Fang, and Yulun Xu
Intraspinal hemangioblastomas are relatively uncommon benign tumors. The surgical strategies remain controversial, and the risk factors with regard to clinical outcome are unclear. The purpose of this study was to analyze the clinical characteristics, imaging findings, surgical strategies, and functional outcomes associated with intraspinal hemangioblastomas.
A series of 92 patients who underwent 102 operations for resection of 116 intraspinal hemangioblastomas at a single institution during 2007–2011 were consecutively enrolled in this study. Of these, 60 patients (65.2%) had sporadic hemangioblastomas and 32 (34.8%) had von Hippel-Lindau disease. Preoperatively, 13 patients underwent digital subtraction angiography (DSA), 15 patients underwent 3D CT angiography (3D CTA), and none underwent preoperative embolization. Clinical characteristics, imaging findings, and operative records were analyzed. The advantages and disadvantages of DSA and 3D CTA were compared. For identification of risk factors that affect prognosis, logistic analysis was performed.
The male/female patient ratio was 1.8:1.0 (59 male and 33 female patients). Of the tumors, 41% were intramedullary, 37% were intramedullary-extramedullary, and 22% were primarily extramedullary. Three-dimensional CTA and DSA did not differ significantly in the ability to identify the feeding arteries (p = 1.000) and image qualities (p = 0.367). However, compared with 3D CTA, the effective x-ray dose of spinal DSA was 2.73 times higher and the mean amount of contrast media injected was 1.88 times higher. Spinal DSA was more time consuming (mean 120 minutes) than 3D CTA (scanning time < 1 minute). No complications were observed after 3D CTA; acute paraparesis developed in 1 patient after DSA.
Gross-total resection was achieved for 109 tumors (94.0%), and resection was subtotal for 7 tumors. Mean duration of follow-up was 50 months (range 24–78 months). At the most recent follow-up visit, the functional outcome was improved for 38 patients (41.3%), remained stable for 40 (43.5%), and deteriorated for 14 (15.2%). Logistic analysis showed that subtotal resection was a risk factor affecting prognosis (p = 0.003, OR 12.833, 95% CI 2.429–67.806).
The authors' study suggests that safe and effective treatment of intraspinal hemangioblastomas can be achieved for most patients, even without preoperative embolization. Gross-total resection, when safe to perform, leads to better outcomes. Compared with spinal DSA, 3D CTA is a promising technique because it is noninvasive, takes less time to perform, requires lower x-ray doses and less contrast media, results in fewer complications, and offers high accuracy for delineating the feeding arteries.