Clinical features and surgical outcomes of intramedullary schwannomas

Object

Intramedullary schwannomas are exceedingly rare. Most previous studies are case reports with an associated literature review. The aim of this study was to discuss the clinical features and the outcomes of microsurgery for these rare lesions.

Methods

The authors retrospectively reviewed the data of twenty patients with intramedullary schwannomas. All patients had performed preoperative and postoperative magnetic resonance imaging (MRI) and underwent microsurgery. The diagnosis of intramedullary schwannomas was based on radiological and pathological criteria. Modified McCormick classification was applied to assess neurological function.

Results

There were 15 males and five females with a mean age of 44.7 years. Ten tumors were located in the cervical cord, five in the thoracic cord, two in the cervicothoracic cord, two in the thoracolumbar cord and one in the conus medullaris. Patients presented with nonspecific symptoms and the mean duration of symptoms was 37.4 months. Intraoperatively, the tumor was connected to the dorsal rootlet in four cases. Gross total resection (GTR) of the tumor with a well-demarcated dissection plane was achieved in 16 cases, and subtotal resection (STR) was achieved in four cases. No patients received postoperative radiotherapy. During a mean follow-up period of 67.9 months, no recurrence or regrowth of the residual tumors was observed on MRI. Ninety percent of patients experienced an improvement in the McCormick grade and 10 % of patients maintained their preoperative status.

Conclusions

Intramedullary schwannomas are benign but clinically progressive lesions. The accurate diagnosis depends on pathology. For symptomatic patients, early surgery should be performed before neurological deficits deteriorate. When GTR cannot be achieved, STR of the tumor for decompression is advised. Postoperative radiotherapy is not recommended for these benign tumors. A good clinical outcome after GTR or STR can be expected.     

升温速度对多孔生物陶瓷特性的影响

目的:观察升温速度对多孔生物陶瓷孔结构、显气孔率与容重、水渗透率、收缩率以及压缩强度的影响.方法:实验于2005-09/2007-09在武汉理工大学生物中心和重庆邮电大学生物实验中心完成.①在保温时间为2 h,烧成温度为850 ℃条件下,有机泡沫微球与骨料质量配比为0.25时,粘结剂的添加量为20%,升温速度分别为30,60,90,120,150和200 ℃/h条件下,采用有机泡沫微球作为成孔剂的热压铸多孔陶瓷的制备方法制得不同样品.②用电子扫描显微镜观察孔道和表面形貌;根据GB/T1964-1967.1996和GB/T1969～1970-1996测量显气孔率、容重;用自制水渗透率测定仪测定水渗透率;用体积法测定收缩率;用ASTM材料强度测试机测定压缩强度.结果:①升温速度变化对孔径＞100 μm大孔的影响明显,对孔径＜50 μm小孔的影响不明显,对晶体的长大影响也明显.②随着升温速度从30 ℃/h提高到150 ℃/h,显气孔率从72%增加到82%,容重从0.89×103 kg/m3下降0.52×103 kg/m3,水渗透率从12×10-3 cm2增加到25×10-3 cm2,收缩率27%从减少到23%,抗压强度从17.3 MPa降低到1.59 MPa.结论:升温速度对孔结构、显气孔率与容重、水渗透率、收缩率以及抗压强度有着重要的影响,为了保证成品有较好的孔结构、较高的显气孔率的同时具有一定的机械强度,升温速度选择在120 ℃/h左右较佳.     

Microwave coagulation therapy and drug injection to treat splenic injury

Background

The present study compares the efficacy of 915- and 2450-MHz contrast-enhanced ultrasound (CEUS)–guided percutaneous microwave coagulation with that of CEUS-guided thrombin injection for the treatment of trauma-induced spleen hemorrhage.

Materials and methods

In a canine splenic artery hemorrhage model with two levels of arterial diameter (A, <1 mm and B, between 1 and 2 mm), hemostatic therapy was performed using 915- and 2450-MHz microwaves and drug injection. Therapy efficacy was measured by comparing bleeding rate, hemostatic time, bleeding index, bleeding volume, and pathology.

Results

The most efficient technique was CEUS-guided 915-MHz percutaneous microwave coagulation therapy in terms of action time and total blood loss. The success rate of the 915-MHz microwave group was higher than that of the 2450-MHz microwave and the drug injection groups (except A level, P < 0.05). Hemostatic time, bleeding index, and bleeding volume were significantly less in the 915-MHz microwave group than those in the 2450-MHz microwave and drug injection groups (P < 0.05). Obvious degeneration and necrosis of parenchyma and large intravascular thrombosis were observed in the cavity of larger vessels in the 915-MHz microwave group, but pathologic changes of light injury could be seen in the other groups.

Conclusions

The present study provides evidence that microwave coagulation therapy is more efficient than thrombin injection for the treatment of splenic hemorrhage. Furthermore, treatment with 915-MHz microwaves stops bleeding more rapidly and generates a wider cauterization zone than does treatment with 2450-MHz microwaves.     

Review of stoma site and midline incisional hernias after stoma reversal

Background

The incidence of incisional hernias after stoma reversal is not well reported. The aim of this study was to systematically review the literature reporting data on incisional hernias after stoma reversal. We evaluated both the incidence of stoma site and midline incisional hernias.

Methods

A systematic review identified studies published between January 1, 1980, and December 31, 2012, reporting the incidence of incisional hernia after stoma reversal at either the stoma site or at the midline incision (in cases requiring laparotomy). Pediatric studies were excluded. Assessment of risk of bias, detection method, and essential study-specific characteristics (follow-up duration, stoma type, age, body mass index, and so forth) was done.

Results

Sixteen studies were included in the analysis; 1613 patients had 1613 stomas formed. Fifteen studies assessed stoma site hernias and five studies assessed midline incisional hernias. The median (range) incidence of stoma site incisional hernias was 8.3% (range 0%–33.9%) and for midline incisional hernias was 44.1% (range 8.7%–58.1%). When evaluating only studies with a low risk of bias, the incidence for stoma site incisional hernias is closer to one in three and for midline incisional hernias is closer to one in two.

Conclusion

Stoma site and midline incisional hernias are significant clinical complications of stoma reversals. The quality of studies available is poor and heterogeneous. Future prospective randomized controlled trials or observational studies with standardized follow-up and outcome definitions/measurements are needed.     

Interaction between auditory and motor systems in speech perception

Based on the Motor Theory of speech perception, the interaction between the auditory and motor systems plays an essential role in speech perception. Since the Motor Theory was proposed, it has received remarkable attention in the field. However, each of the three hypotheses of the theory still needs further verification. In this review, we focus on how the auditory-motor anatomical and functional associations play a role in speech perception and discuss why previous studies could not reach an agreement and particularly whether the motor system involvement in speech perception is task-load dependent. Finally, we suggest that the function of the auditory-motor link is particularly useful for speech perception under adverse listening conditions and the further revised Motor Theory is a potential solution to the “cocktail-party” problem.     

Urinary stone analysis on 12,846 patients: a report from a single center in China

We reported a retrospective review of the urinary stone compositions in 12,846 patients. Data on urinary stone compositions analyzed between January 2003 and December 2012 in our center were collected. Infrared spectroscopy was used for stone analysis. Predominant stone component was recorded. Patients were divided into four age groups: 0–18, 19–40, 41–60, and 61–92, and five categories by components. In order to determine the change of stone characteristics with respect to time, data were also divided into two periods, 2003–2007 and 2008–2012. A total of 12,846 stones were included in this study. The age of the patients ranged from 1 to 92 years with 7,736 males and 5,110 females. Stone made of single component was rare, 2.61 %. Calcium oxalate stone was the most common component at 82.56 %. Calcium oxalate and uric acid stones were more common in male than in female. The incidence of calcium phosphate stones and uric acid stones had increased during the past 5 years, while calcium oxalate stones decreased. We found the highest incidence of stone disease in the 41–60 years old group and the lowest in the 1–18 years old for both genders. Calcium oxalate was the dominant component in every group but was more prevalent in 19–40 years group. The percentage of magnesium ammonium phosphate stone and uric acid stone increased with age.