Yongning Li

Extended transsphenoidal approach for pituitary adenomas invading the anterior cranial base, cavernous sinus, and clivus: a single-center experience with 126 consecutive cases

OBJECT 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. METHODS 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. RESULTS 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. CONCLUSIONS 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.

Diagnosis and management of pituitary abscess: experiences from 33 cases

Objective  Pituitary abscess is a rare disorder with nonspecific presenting manifestations, often making a correct preoperative diagnosis difficult. To better determine the salient signs and symptoms of pituitary abscess and to evaluate the effectiveness of surgical and antibiotic therapies, we conducted a review of patients treated for pituitary abscess at the Peking Union Medical College Hospital (PUMCH).

Postacute ischemia vascular endothelial growth factor transfer by transferrin-targeted liposomes attenuates ischemic brain injury after experimental stroke in rats.

Our objective was to achieve the enhanced delivery of vascular endothelial growth factor (VEGF) to ischemically disordered brain through transferrin-coupled liposomes (Tf-PLs) via intravenous administration, and to observe the effect of Tf-VEGF-PLs on ischemic brain neuroprotection and angiogenesis. Cerebral VEGF overexpression was achieved with Tf-PLs by intravenous injection 48 hr after an acute stroke. β-Galactosidase expression was monitored; saline was injected as a control. The success of postischemic gene transduction was confirmed by β-galactosidase staining and by increased VEGF mRNA and protein in ischemic brain. Vascular density, neurological recovery, and ischemic area calculation were performed to evaluate the effect of Tf-VEGF-PLs. The positive expression of β-galactosidase indirectly indicated that VEGF was successfully delivered into brain by Tf-VEGF-PLs. VEGF mRNA in the Tf-VEGF-PL group 24 hr after injection was significantly higher than in the control group (p < 0.05). Western blot analysis showed that postischemic Tf-VEGF-PLs resulted in increased VEGF protein levels compared with VEGF-PLs and saline-administered rats (p < 0.05) 48 hr after administration. At 21 days after drug injection, we observed a significant decrease in infarct volume and better neurological function in the Tf-VEGF-PL-treated group, compared with the VEGF-PL group. FITC-dextran marking showed increased vascular density in the penumbra of Tf-VEGF-PL-treated hemispheres (245,873.9, number of microvessels per field) compared with that in VEGF-PL-treated hemispheres (139,801.3) or saline-treated hemispheres (102,175.5) (p < 0.05). The remainder of the cerebral blood flow after ischemia in the Tf-VEGF-PL group was significantly more than in the control groups (0.35 vs. 0.29, 0.21; p < 0.05). We conclude that the VEGF gene can be delivered noninvasively into the brain by Tf-VEGF-PLs. Postischemic treatment with Tf-VEGF-PLs effectively promoted neuroprotection and vascular regeneration in the chronic stage of cerebral infarction.

Transplantation of neural stem cells modified by human neurotrophin-3 promotes functional recovery after transient focal cerebral ischemia in rats.

The study tested the hypothesis that transplantation of human neurotrophin-3 (hNT-3) over-expressing neural stem cells (NSCs) into rat striatum after a severe focal ischemia would promote functional recovery. Rat NSCs, transduced by Flag-tagged hNT-3 gene mediated by lentiviral vector (LV), were transplanted into the striatum ipsilateral to the injury of adult rats 7 days after 2-h occlusion of the middle cerebral artery (MCAO). From 3 days to 2 weeks after transplantation, the modified cells (NSCs-hNT3, as defined by Flag immunofluorencence staining) that survived the transplantation procedures could secrete significantly higher levels of neurotrophin-3 protein in the graft sites than controls (P<0.001). Furthermore, the rats that accepted NSCs-hNT3 exhibited enhanced functional recovery on neurological and behavioral tests, compared with controlled animals transplanted with saline or untransduced NSCs. This study suggests: (1) LV is an ideal vector to transduce foreign gene into the NSCs; (2) modified NSCs could carry therapeutic genes to disease tissues and express effectively; (3) modified cells could survive in the ischemic brains and continue to secrete neurotrophin-3 abundantly for over 2 weeks, which might have values for enhancing functional recovery after stroke.

Overview of the health care system in Hong Kong and its referential significance to mainland China

Abstract Hong Kongs health system was established within the framework of a perfect market‐oriented economic matrix, where there are wide‐ranging social security and medical service systems. There are many differences in the economic foundations, social systems, and ideologies between Hong Kong and mainland China, therefore, it would probably be entirely impossible to copy Hong Kongs health care system mode. However, under the framework of one country, two systems, the referential significance of relevant concepts of Hong Kongs medical service system to mainland China cannot be ignored, and merits further study.

A meta-analysis: Do prophylactic antiepileptic drugs in patients with brain tumors decrease the incidence of seizures?

BACKGROUND Seizures are a potentially devastating complication of brain tumors. Several studies in the past have attempted to demonstrate that prophylactic antiepileptic drugs (AEDs) in patients with brain tumors can decrease the incidence of seizures. However, it is currently unclear whether AEDs should be routinely administered to patients with brain tumors who have never had a seizure. OBJECTIVE A meta-analysis of randomized trials was conducted to estimate the effectiveness of seizure prophylaxis in people with brain tumors. METHODS A range of electronic databases were searched (1966-2014): MEDLINE, the Cochrane Library Database, EMBASE, CINAHL, Web of Science and the Chinese Biomedical Database (CBM) without language restrictions. Two independent reviewers assessed trials for eligibility and quality, and meta-analysis was performed using the STATA 12.0 software. Integrated Odd Ratio (OR) with its corresponding 95% confidence interval (95%CI) was calculated. RESULTS Six RCTs were included with a total of 547 patients with brain tumors. The meta-analysis results revealed that patients with brain tumors who received prophylactic antiepileptic interventions did not have significantly lower epilepsy incidence than those in controlled groups (OR=0.939, 95%CI=0.609-1.448, z=0.29, P=0.775). Sensitivity analysis suggested the statistical results were robust. No publication bias was detected in this meta-analysis (P>0.05). CONCLUSION Although some past studies indicated AEDs can be used in patients with brain tumors to relieve epilepsy, present integrated evidences cannot show in unequivocal terms that brain tumor patients can benefit from seizure prophylaxis.

A Comparative Study of Transfection Efficiency between Liposomes, Immunoliposomes and Brain-specific Immunoliposomes

This study investigated the transfection ability and efficiency of liposomes and immunoliposomes for exogenous gene delivery into the brain via the venous system. Four groups of rats underwent tail vein injection with one of the following: liposomes encapsulating pCMV (human cytomegalovirus promoter)-LacZ plasmid 80 μg (low dose) or 300 μg (high dose); general immunoliposomes encapsulating 80 μg transferrin receptor antibodies (OX26)-pCMV-LacZ plasmid; or brain-specific immunoliposomes encapsulating 80 μg OX26-pGFAP (glial fibrillary acidic protein promoter)-LacZ plasmid. A control group received no injected agent. The LacZ mRNA levels (1 h post-injection) and β-galactosidase activity (48 h post-injection) in the brain and peripheral organs were assayed using real-time reverse transcription–polymerase chain reaction and histochemical staining, respectively. Both immunoliposomes delivered exogenous DNA containing the LacZ gene into the brain after venous injection, resulting in extensive LacZ expression in the brain. Furthermore, the brain-specific OX26-pGFAP-LacZ immunoliposome decreased the non-specific expression of LacZ in peripheral organs without affecting transfection efficiency in the brain. Thus, brain-specific immunoliposomes are an efficient and brain-specific targeting vector.

Primary malignant peripheral nerve sheath tumor of the cauda equina with metastasis to the brain in a child: case report and literature review

BACKGROUND CONTEXT Primary intradural malignant peripheral nerve sheath tumors (MPNSTs) are extremely rare; only 23 cases have been reported in the English-language literature till now. No gold standard for treating primary intradural MPNSTs has yet been established. PURPOSE To report a rare case of primary intradural MPNSTs in a child and review the literature pertaining to this rare disease. STUDY DESIGN/SETTING Case report and literature review. METHODS We report our experience with one new case. An 8-year-old boy diagnosed with primary intradural MPNSTs underwent three surgical excisions and two rounds of radiotherapy; however, metastasis to the brain was found, and the boy died 16 months after the first surgery. We also review the literature pertaining to both MPNSTs in general and primary intradural MPNSTs. RESULTS Surgery is currently the mainstay of MPNST treatment. Radiotherapy and chemotherapy are of limited value in these tumors. Based on the review of the 24 cases described in the literature, including the present case, primary intradural MPNST is a very aggressive tumor with a very high recurrence rate even after gross total resection and with significant potential for leptomeningeal and systemic metastasis. The overall prognosis is very poor and seems to be worse than that of MPNSTs in general. CONCLUSIONS Primary intradural MPNST is a very rare entity with a poor prognosis. Surgical tumor removal combined with postoperative high-dose radiation may be recommended. Chemotherapy is usually reserved for patients with disseminated metastases or tumors that are unresectable at the time of diagnosis.

Primary Intraosseous Cavernous Hemangioma in the Skull

AbstractPrimary intraosseous cavernous hemangiomas (PICHs) are benign vascular tumors that may involve any part of the body. PICH occurs more frequently in the spine and less commonly in skull. The earliest description in the English literature was in 1845 by Toynbee, who reported a vascular tumor arising in the confines of the parietal bone. Skull PICHs do not always have typical radiologic features and should always be considered in the differential diagnosis of malignant skull lesions. We now reviewed and analyzed related literatures in detail with reporting a rare case of PICH in the left front bone that was surgically resected.

Comparison of posterior fossa decompression with and without duraplasty for the surgical treatment of Chiari malformation type I in adult patients: A retrospective analysis of 103 patients.

Abstract Chiari malformation type I (CM-I) is a congenital neurosurgical disease about the herniation of cerebellar tonsil through the foramen magnum. A variety of surgical techniques for CM-I have been used, and there is a controversy whether to use posterior fossa decompression with duraplasty (PFDD) or posterior fossa decompression without duraplasty (PFD) in CM-I patients. Here, we compared the clinical results and effectiveness of PFDD and PFD in adult patients with CM-I. The cases of 103 adult CM-I patients who underwent posterior fossa decompression with or without duraplasty from 2008 to 2014 were reviewed retrospectively. Patients were divided into 2 groups according to the surgical techniques: PFDD group (n = 70) and PFD group (n = 33). We compared the demographics, preoperative symptoms, radiographic characteristics, postoperative complications, and clinical outcomes between the PFD and PFDD patients. No statistically significant differences were found between the PFDD and PFD groups with regard to demographics, preoperative symptoms, radiographic characteristics, and clinical outcomes(P > 0.05); however, the postoperative complication aseptic meningitis occurred more frequently in the PFDD group than in the PFD group (P = 0.027). We also performed a literature review about the PFDD and PFD and made a summary of these preview studies. Our study suggests that both PFDD and PFD could achieve similar clinical outcomes for adult CM-I patients. The choice of surgical procedure should be based on the patients condition. PFDD may lead to a higher complication rate and autologous grafts seemed to perform better than nonautologous grafts for duraplasty.