Nai-Feng Tian, Ai-Min Wu, Li-Jun Wu, Xin-Lei Wu, Yao-Sen Wu, Xiao-Lei Zhang, Hua-Zi Xu and Yong-Long Chi
This study aimed to investigate the incidence rate of heterotopic ossification (HO) after implantation of Coflex interspinous devices. Possible risk factors associated with HO were evaluated.
The authors retrospectively analyzed patients who had undergone single-level (L4–5) implantation of a Coflex device for the treatment of lumbar spinal stenosis. Patient data recorded were age, sex, height, weight, body mass index, smoking habits, and surgical time. Heterotopic ossification was identified through lumbar anteroposterior and lateral view radiographs. The authors developed a simple classification for defining HO and compared HO-positive and HO-negative cases to identify possible risk factors.
Among 32 patients with follow-up times of 24–57 months, HO was detectable in 26 (81.2%). Among these 26 patients, HO was in the lateral space of the spinous process but not in the interspinous space in 8, HO was in the interspinous space but did not bridge the adjacent spinous process in 16, and interspinous fusion occurred at the level of the device in 2. Occurrence of HO was not associated with patient age, sex, height, weight, body mass index, smoking habits, or surgical time.
A high incidence of HO has been detected after implantation of Coflex devices. Clinicians should be aware of this possible outcome, and more studies should be conducted to clarify the clinical effects of HO.
Ya-Bin Ji, Yong-Ming Wu, Zhong Ji, Wei Song, Sui-Yi Xu, Yao Wang and Su-Yue Pan
Intracarotid artery cold saline infusion (ICSI) is an effective method for protecting brain tissue, but its use is limited because of undesirable secondary effects, such as severe decreases in hematocrit levels, as well as its relatively brief duration. In this study, the authors describe and investigate the effects of a novel ICSI pattern (interrupted ICSI) relative to the traditional method (uninterrupted ICSI).
Ischemic strokes were induced in 85 male Sprague-Dawley rats by occluding the middle cerebral artery for 3 hours using an intraluminal filament. Uninterrupted infusion groups received an infusion at 15 ml/hour for 30 minutes continuously. The same infusion speed was used in the interrupted infusion groups, but the whole duration was divided into trisections, and there was a 20-minute interval without infusion between sections. Forty-eight hours after reperfusion, H & E and silver nitrate staining were utilized for morphological assessment. Infarct sizes and brain water contents were determined using H & E staining and the dry-wet weight method, respectively. Levels of neuron-specific enolase (NSE), S100β protein, and matrix metalloproteinase 9 (MMP-9) in the serum were determined using enzyme-linked immunosorbent assay. Neurological deficits were also evaluated.
Histology showed that interrupted ICSI did not affect neurons or fibers in rat brains, which suggests that this method is safe for brain tissues with ischemia. The duration of hypothermia induced by interrupted ICSI was longer than that induced via the traditional method, and the decrease in hematocrit levels was less pronounced. There were no differences in infarct size or brain water content between uninterrupted and interrupted ICSI groups, but neuron-specific enolase and matrix metalloproteinase 9 serum levels were more reduced after interrupted ICSI than after the traditional method.
Interrupted ICSI is a safe method. Compared with traditional ICSI, the interrupted method has a longer duration of hypothermia and less effect on hematocrit and offers more potentially improved neuroprotection, thereby making it more attractive as an infusion technique in the clinic.
Jie Zhang, Dong-Xiao Zhuang, Cheng-Jun Yao, Ching-Po Lin, Tian-Liang Wang, Zhi-Yong Qin and Jin-Song Wu
The extent of resection is one of the most essential factors that influence the outcomes of glioma resection. However, conventional structural imaging has failed to accurately delineate glioma margins because of tumor cell infiltration. Three-dimensional proton MR spectroscopy (1H-MRS) can provide metabolic information and has been used in preoperative tumor differentiation, grading, and radiotherapy planning. Resection based on glioma metabolism information may provide for a more extensive resection and yield better outcomes for glioma patients. In this study, the authors attempt to integrate 3D 1H-MRS into neuronavigation and assess the feasibility and validity of metabolically based glioma resection.
Choline (Cho)–N-acetylaspartate (NAA) index (CNI) maps were calculated and integrated into neuronavigation. The CNI thresholds were quantitatively analyzed and compared with structural MRI studies. Glioma resections were performed under 3D 1H-MRS guidance. Volumetric analyses were performed for metabolic and structural images from a low-grade glioma (LGG) group and high-grade glioma (HGG) group. Magnetic resonance imaging and neurological assessments were performed immediately after surgery and 1 year after tumor resection.
Fifteen eligible patients with primary cerebral gliomas were included in this study. Three-dimensional 1H-MRS maps were successfully coregistered with structural images and integrated into navigational system. Volumetric analyses showed that the differences between the metabolic volumes with different CNI thresholds were statistically significant (p < 0.05). For the LGG group, the differences between the structural and the metabolic volumes with CNI thresholds of 0.5 and 1.5 were statistically significant (p = 0.0005 and 0.0129, respectively). For the HGG group, the differences between the structural and metabolic volumes with CNI thresholds of 0.5 and 1.0 were statistically significant (p = 0.0027 and 0.0497, respectively). All patients showed no tumor progression at the 1-year follow-up.
This study integrated 3D MRS maps and intraoperative navigation for glioma margin delineation. Optimum CNI thresholds were applied for both LGGs and HGGs to achieve resection. The results indicated that 3D 1H-MRS can be integrated with structural imaging to provide better outcomes for glioma resection.
Bing Zhao, Yu-Kui Wei, Gui-Lin Li, Yong-Ning Li, Yong Yao, Jun Kang, Wen-Bin Ma, Yi Yang and Ren-Zhi Wang
The standard transsphenoidal approach has been successfully used to resect most pituitary adenomas. However, as a result of the limited exposure provided by this procedure, complete surgical removal of pituitary adenomas with parasellar or retrosellar extension remains problematic. By additional bone removal of the cranial base, the extended transsphenoidal approach provides better exposure to the parasellar and clival region compared with the standard approach. The authors describe their surgical experience with the extended transsphenoidal approach to remove pituitary adenomas invading the anterior cranial base, cavernous sinus (CS), and clivus.
Retrospective analysis was performed in 126 patients with pituitary adenomas that were surgically treated via the extended transsphenoidal approach between September 1999 and March 2008. There were 55 male and 71 female patients with a mean age of 43.4 years (range 12–75 years). There were 82 cases of macroadenoma and 44 cases of giant adenoma.
Gross-total resection was achieved in 78 patients (61.9%), subtotal resection in 43 (34.1%), and partial resection in 5 (4%). Postoperative complications included transient cerebrospinal rhinorrhea (7 cases), incomplete cranial nerve palsy (5), panhypopituitarism (5), internal carotid artery injury (2), monocular blindness (2), permanent diabetes insipidus (1), and perforation of the nasal septum (2). No intraoperative or postoperative death was observed.
The extended transsphenoidal approach provides excellent exposure to pituitary adenomas invading the anterior cranial base, CS, and clivus. This approach enhances the degree of tumor resection and keeps postoperative complications relatively low. However, radical resection of tumors that are firm, highly invasive to the CS, or invading multidirectionally remains a big challenge. This procedure not only allows better visualization of the tumor and the neurovascular structures but also provides significant working space under the microscope, which facilitates intraoperative manipulation. Preoperative imaging studies and new techniques such as the neuronavigation system and the endoscope improve the efficacy and safety of tumor resection.
Yong-Jian Zhu, Guang-Yu Ying, Ai-Qin Chen, Lin-Lin Wang, Dan-Feng Yu, Liang-Liang Zhu, Yu-Cheng Ren, Chen Wang, Peng-Cheng Wu, Ying Yao, Fang Shen and Jian-Min Zhang
Posterior midline laminectomy or hemilaminectomy has been successfully applied as the standard microsurgical technique for the treatment of spinal intradural pathologies. However, the associated risks of postoperative spinal instability increase the need for subsequent fusion surgery to prevent potential long-term spinal deformity. Continuous efforts have been made to minimize injuries to the surrounding tissue resulting from surgical manipulations. The authors report here their experiences with a novel minimally invasive surgical approach, namely the interlaminar approach, for the treatment of lumbar intraspinal tumors.
A retrospective review was conducted of patients at the Second Affiliated Hospital of Zhejiang University School of Medicine who underwent minimally invasive resection of lumbar intradural-extramedullary tumors. By using an operative microscope, in addition to an endoscope when necessary, the authors were able to treat all patients with a unilateral, paramedian, bone-sparing interlaminar technique. Data including preoperative neurological status, tumor location, size, pathological diagnosis, extension of resections, intraoperative blood loss, length of hospital stay, and clinical outcomes were obtained through clinical and radiological examinations.
Eighteen patients diagnosed with lumbar intradural-extramedullary tumors were treated from October 2013 to March 2015 by this interlaminar technique. A microscope was used in 15 cases, and the remaining 3 cases were treated using a microscope as well as an endoscope. There were 14 schwannomas, 2 ependymomas, 1 epidermoid cyst, and 1 enterogenous cyst. Postoperative radiological follow-up revealed complete removal of all the lesions and no signs of bone defects in the lamina. At clinical follow-up, 14 of the 18 patients had less pain, and patients' motor/sensory functions improved or remained normal in all cases except 1.
When meeting certain selection criteria, intradural-extramedullary lumbar tumors, especially schwannomas, can be completely and safely resected through a less-invasive interlaminar approach using a microscope, or a microscope in addition to an endoscope when necessary. This approach was advantageous because it caused even less bone destruction, resulting in better postoperative spinal stability, no need for facetectomy and fusion, and quicker functional recovery for the patients. Individualized surgical planning according to preoperative radiological findings is key to a successful microsurgical resection of these lesions through the interlaminar space.