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The role of sacral laminoplasty in the management of spina bifida and sacral cystic lesions: case series

Yu-Ning Chen, Shih-Hung Yang, Sheng-Che Chou, and Meng-Fai Kuo

OBJECTIVE

Although laminae are not viewed as essential structures for spinal integrity, in the sacrum the anatomical weakness and gravity makes it a vulnerable area for CSF accumulation and expansion. The congenital or postoperative defects of sacral laminae, such as in patients with spina bifida, make this area more susceptible to forming progressive dural ectasia, pseudomeningocele, or expansile arachnoid cyst (Tarlov cyst). In addition, adhesions between the dura and surrounding soft tissue after laminectomy can cause some local symptoms, which are difficult to relieve. The authors propose that sacral laminoplasty with titanium mesh can provide a rigid support and barrier to resolve these sacral lesions and local symptoms.

METHODS

From January 2016 to December 2017, patients with progressive CSF-containing lesions in the sacral area and defective sacral laminae were included in the study. After repair of the lesion, the authors performed sacral laminoplasty with titanium mesh in each patient. Subsequently, the soft tissue and skin were closed primarily.

RESULTS

A total of 6 patients were included. Four patients with repaired myelomeningocele had progressive dural ectasia. One patient with lipomyelomeningocele previously underwent detethering surgery and developed postoperative pseudomeningocele. One patient had a symptomatic Tarlov cyst. Four of these 6 cases presented with low-back pain and local tenderness. During follow-up, ranging from 13 to 37 months, all 6 patients experienced no recurrence of dural ectasia or pseudomeningocele and were free from local symptoms.

CONCLUSIONS

Sacral laminoplasty with titanium mesh is a safe and effective procedure for treating progressive sacral dural ectasia and refractory pseudomeningocele, preventing CSF leakage as well as relieving local symptoms that may occur years after previous surgery for spina bifida.

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Using a burr hole valve prevents proximal shunt failure in infants and toddlers

Chiu-Hao Hsu, Sheng-Che Chou, Shih-Hung Yang, Ming-Chieh Shih, and Meng-Fai Kuo

OBJECTIVE

Proximal malfunction is the most common cause of ventriculoperitoneal (VP) shunt failure in young children. In this study, the authors sought to determine factors that affect the migration rate of ventricular catheters in hydrocephalic children who undergo shunt implantation in the first 3 years of life.

METHODS

The authors reviewed the medical records and imaging studies of newly diagnosed and treated hydrocephalic children who were younger than 3 years. Patients who received VP shunt insertion through the parieto-occipital route were not included. In total, 78 patients were found who underwent VP shunt insertion between December 2006 and April 2017. Eighteen patients were excluded due to mortality, short follow-up period (< 1 year), and lack of imaging follow-up. The age, sex, etiology of hydrocephalus, initial length of ventricular catheter, valve type (burr hole vs non–burr hole), time to ventricular catheter migration, subsequent revision surgery, and follow-up period were analyzed. The diagnosis of a migrated ventricular catheter was made when serial imaging follow-up showed progressive withdrawal of the catheter tip from the ventricle, with the catheter shorter than 4 mm inside the ventricle, or progressive deviation of the ventricular catheter toward the midline or anterior ventricular wall.

RESULTS

Sixty patients were enrolled. The mean age was 5.1 months (range 1–30 months). The mean follow-up period was 50.9 months (range 13–91 months). Eight patients had ventricular catheter migration, and in 7 of these 8 patients a non–burr hole valve was used. In the nonmigration group, a non–burr hole valve was used in only 6 of the 52 patients. Six of the 8 patients with catheter migration needed second surgeries, which included removal of the shunt due to disconnection in 1 patient. The remaining 2 patients with shunt migration were followed for 91 and 46 months, respectively, without clinical and imaging changes. The authors found that patient age at catheter insertion, ventricular catheter length, and the use of a burr hole valve were protective factors against migration. After ventricular catheter length and patient age at catheter insertion were treated as confounding variables and adjusted with multivariable Weibull proportional hazards regression, the use of a burr hole valve shunt remained a protective factor.

CONCLUSIONS

The use of burr hole valves is a protective factor against ventricular catheter migration when the shunt is inserted via a frontal route. The authors suggest the use of a burr hole valve along with a frontal entry point in hydrocephalic children younger than 3 years to maintain long-term shunt function.

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Tethered spinal cord and VACTERL association

Meng-Fai Kuo, Yihsin Tsai, Wen-Ming Hsu, Ruei-Sheng Chen, Yong-Kwang Tu, and Huei-Shyong Wang

Object

Vertebral defects, anal atresia, cardiovascular anomalies, tracheoesophageal fistulas (TEFs), renal anomalies, and limb defects (most often of the radius) are commonly associated and known collectively by the acronym VACTERL. The authors studied these nonrandomly associated birth defects to determine if a further relationship exists between VACTERL association and the presence of a tethered spinal cord (TSC).

Methods

From 2001 to 2004, 12 patients with VACTERL association who were treated operatively by a single pediatric surgeon underwent magnetic resonance (MR) imaging to evaluate the intraspinal abnormalities that may cause tethering. Three patients were excluded from the study due to complications after surgery for TEF. Coincidentally, these three patients did not have imperforate ani. In the remaining nine patients, seven had associated urogenital anomalies, and six of these also had high-type imperforate ani. Five of the six patients and the one patient with low-type imperforate anus and a urogenital anomaly were found to have TSCs. In the remaining two patients without urogenital anomalies there was a high-type imperforate anus without a TSC in one patient and a low-type imperforate anus with a TSC in the other. All seven patients with TSCs underwent successful untethering. The lesions contributing to TSC included terminal filum lipomas (TFLs) in five patients, an intramedullary ependymal cyst in one patient, and a lipomeningomyelocele in another patient.

Conclusions

The authors found that in patients with VACTERL association there was a high incidence of TSC (seven of nine patients) if an imperforate anus was present as one of the anomalies. In patients with VACTERL association and urogenital anomalies, the incidence of TSC was even higher (86%). Five of the seven cases of TSC in the present study were caused by a TFL, a lesion that can be easily and safely managed surgically. The authors conclude that MR imaging is essential for ruling out the possibility of a TSC in patients with VACTERL association combined with urogenital anomalies or an imperforate anus.

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High expression of stathmin protein predicts a fulminant course in medulloblastoma

Clinical article

Meng-Fai Kuo, Huei-Shyong Wang, Quang-Ting Kuo, Chia-Tung Shun, Hey-Chi Hsu, Shih-Hong Yang, and Ray-Hwang Yuan

Object

Stathmin, an important cytosolic phosphoprotein, is involved in cell proliferation and motility. This study was performed to elucidate the role of stathmin in the progression of medulloblastoma.

Methods

The expression of stathmin protein was examined by immunohistochemical staining of tumor sections obtained in 17 consecutive patients with medulloblastoma who underwent resection between 1995 and 2005. Four patients were excluded because they were either lost to follow-up or underwent biopsy sampling only, leaving a total of 13 patients in the study. The stathmin expression was scored according to the immunoreactive fraction of tumor cells, and the level was correlated with various clinicopathological factors.

Results

The expression level of stathmin protein was ≤ 10% in 9 patients, 11–50% in 1, and > 50% in 3. No staining was seen in the tissues adjacent to the tumors. For comparison, the authors grouped the expression level of stathmin into high (> 50%) and low (≤ 50%). It was found that patients with high expression of stathmin had more frequent tumor dissemination at the time of resection or soon after total excision of the tumor (p = 0.0035), and hence experienced a fulminant course with lower patient survival (p < 0.0001), with an average survival period of 6.7 months (range 2–10 months). The expression level of stathmin did not correlate with patient age, sex, CSF cytological findings, use of adjuvant therapies, Ki 67 index, or risk classification of the tumors according to previously described categories in the literature.

Conclusions

High stathmin expression correlates with tumor dissemination, is an important prognostic factor of medulloblastoma, and may serve as a useful marker for more intensive adjuvant therapies.

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The state of neurosurgical training and education in East Asia: analysis and strategy development for this frontier of the world

Kevin Paul Ferraris, Hideaki Matsumura, Dewa Putu Wisnu Wardhana, Theodor Vesagas, Kenny Seng, Mohd Raffiz Mohd Ali, Eiichi Ishikawa, Akira Matsumura, Rohadi Muhammad Rosyidi, Tjokorda Mahadewa, and Meng-Fai Kuo

OBJECTIVE

The authors, who are from Indonesia, Japan, Malaysia, the Philippines, and Taiwan, sought to illustrate the processes of training neurosurgeons in their respective settings by presenting data and analyses of the current state of neurosurgical education across the East Asian region.

METHODS

The authors obtained quantitative data as key indicators of the neurosurgical workforce from each country. Qualitative data analysis was also done to provide a description of the current state of neurosurgical training and education in the region. A strengths, weaknesses, opportunities, and threats (SWOT) analysis was also done to identify strategies for improvement.

RESULTS

The number of neurosurgeons in each country is as follows: 370 in Indonesia, 10,014 in Japan, 152 in Malaysia, 134 in the Philippines, and 639 in Taiwan. With a large neurosurgical workforce, the high-income countries Japan and Taiwan have relatively high neurosurgeon to population ratios of 1 per 13,000 and 1 per 37,000, respectively. In contrast, the low- to middle-income countries Indonesia, Malaysia, and the Philippines have low neurosurgeon to population ratios of 1 per 731,000, 1 per 210,000, and 1 per 807,000, respectively. In terms of the number of training centers, Japan has 857, Taiwan 30, Indonesia 7, Malaysia 5, and the Philippines 10. In terms of the number of neurosurgical residents, Japan has 1000, Taiwan 170, Indonesia 199, Malaysia 53, and the Philippines 51. The average number of yearly additions to the neurosurgical workforce is as follows: Japan 180, Taiwan 27, Indonesia 10, Malaysia 4, and the Philippines 3. The different countries included in this report have many similarities and differences in their models and systems of neurosurgical education. Certain important strategies have been formulated in order for the system to be responsive to the needs of the catchment population: 1) establishment of a robust network of international collaboration for reciprocal certification, skills sharing, and subspecialty training; 2) incorporation of in-service residency and fellowship training within the framework of improving access to neurosurgical care; and 3) strengthening health systems, increasing funding, and developing related policies for infrastructure development.

CONCLUSIONS

The varied situations of neurosurgical education in the East Asian region require strategies that take into account the different contexts in which programs are structured. Improving the education of current and future neurosurgeons becomes an important consideration in addressing the health inequalities in terms of access and quality of care afflicting the growing population in this region of the world.

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Greater ultrasonographic changes in pediatric moyamoya patients compared with adults after indirect revascularization surgeries

Shin-Joe Yeh, Sung-Chun Tang, Li-Kai Tsai, Chung-Wei Lee, Ya-Fang Chen, Hon-Man Liu, Shih-Hung Yang, Yu-Lin Hsieh, Meng-Fai Kuo, and Jiann-Shing Jeng

OBJECTIVE

Pediatric and adult patients with moyamoya disease experience similar clinical benefits from indirect revascularization surgeries, but there are still debates about age-related angiographic differences of the collaterals established after surgery. The goal of this study was to assess age-related differences on ultrasonography before and after indirect revascularization surgeries in moyamoya patients, focusing on some ultrasonographic parameters known to be correlated with the collaterals supplied by the external carotid artery (ECA).

METHODS

The authors prospectively included moyamoya patients (50 and 26 hemispheres in pediatric and adult patients, respectively) who would undergo indirect revascularization surgery. Before surgery and at 1, 3, and 6 months after surgery, the patients underwent ultrasonographic examinations. The ultrasonographic parameters included peak-systolic velocity (PSV), end-diastolic velocity (EDV), resistance index (RI), and flow volume (FV) measured in the ECA, superficial temporal artery (STA), and internal carotid artery on the operated side. The mean values, absolute changes, and percentage changes of these parameters were compared between the pediatric and adult patients. Logistic regression analysis was used to clarify the determinants affecting postoperative EDV changes in the STA.

RESULTS

Before surgery, the adult patients had mean higher EDV and lower RI in the STA and ECA than the pediatric group (all p < 0.05). After surgery, the pediatric patients had greater changes (absolute and percentage changes) in the PSV, EDV, RI, and FV in the STA and ECA (all p < 0.05). The factors affecting postoperative EDV changes in the STA at 6 months were age (p = 0.006) and size of the revascularization area (i.e., revascularization in more than the temporal region vs within the temporal region; p = 0.009). Pediatric patients who received revascularization procedures in more than the temporal region had higher velocities (PSV and EDV) in the STA than those who received revascularization within the temporal region (p < 0.05 at 1–6 months), but such differences were not observed in the adult group.

CONCLUSIONS

The greater changes of these parameters in the STA and ECA in pediatric patients than in adults after indirect revascularization surgeries indicated that pediatric patients might have a greater increase of collaterals postoperatively than adults. Pediatric patients who undergo revascularization in more than the temporal region might have more collaterals than those who undergo revascularization within the temporal region.