Minimally Invasive Neurosurgery最新文献

Objective: The learning curve for endonasal endoscopic and neuroendoscopic port surgery is long and often associated with an increase in complication rates as surgeons gain experience. We present an animal model for laboratory training aiming to encourage the young generation of neurosurgeons to pursue proficiency in endoscopic neurosurgical techniques.

Methods: 20 Wistar rats were used as models. The animals were introduced into a physical trainer with multiple ports to carry out fully endoscopic microsurgical procedures. The vertical and horizontal dimensions of the paired ports (simulated nostrils) were: 35×20 mm, 35×15 mm, 25×15 mm, and 25×10 mm. 2 additional single 11.5 mm endoscopic ports were added. Surgical depth varied as desired between 8 and 15 cm. The cervical and abdominal regions were the focus of the endoscopic microsurgical exercises.

Results: The different endoscopic neurosurgical techniques were effectively trained at the millimetric dimension. Levels of progressive surgical difficulty depending upon the endoneurosurgical skills set needed for a particular surgical exercise were distinguished. LEVEL 1 is soft-tissue microdissection (exposure of cervical muscular plane and retroperitoneal space); LEVEL 2 is soft-tissue-vascular and vascular-capsule microdissection (aorto-cava exposure, carotid sheath opening, external jugular vein isolation); LEVEL 3 is artery-nerve microdissection (carotid-vagal separation); LEVEL 4 is artery-vein microdissection (aorto-cava separation); LEVEL 5 is vascular repair and microsuturing (aortic rupture), which verified the lack of current proper instrumentation.

Conclusion: The animal training model presented here has the potential to shorten the length of the learning curve in endonasal endoscopic and neuroendoscopic port surgery and reduce the incidence of training-related surgical complications.

Background: The adequate repair of intraoperative CSF leaks during transsphenoidal surgery remains a challenge. The authors describe the application of N-butyl 2-cyanoacrylate (cyanoacrylate) tissue glue for repair of CSF fistulas during transsphenoidal surgery.

Methods: The authors retrospectively reviewed the records of 221 consecutive patients who underwent transsphenoidal surgery during 1998-2007. Among these patients, 52 (24%) experienced detectable intraoperative CSF leakage. The CSF fistulas were graded on a scale of 1-3, according to the amount of CSF loss and extent of diaphragmatic disruption. 39 patients who had an average leak scale of 1.28 received cyanoacrylate glue to seal the floor. The remaining 13 patients who were not part of this report received other dura sealant substitutes, including Tisseel and Dura Seal, or fat/cartilage grafts without any additional glue material.

Results: 4 of 221 patients (2%) who underwent surgery had postoperative CSF fistula. Of the 39 patients who underwent repair of their fistula using fat graft, cartilage/bone buttress and cyanoacrylate reconstruction, 2 (5.13%) developed postoperative CSF fistulas without any other side effects. The average intraoperative leak grade in these 2 patients was 2.00.

Conclusions: The authors used cyanoacrylate glue for intraoperative repair of higher grade CSF fistulas. As an adjunct to careful sellar reconstruction, cyanoacrylate glue appears to be effective and safe in preventing postoperative CSF leakage after transsphenoidal surgery.

Background: A vein of Galen aneurysmal malformation (VGAM) is a relatively rare vascular malformation, often resulting in high morbidity and mortality. While surgical arterial clipping has been reported for decades, results in the literature have recently favored endovascular treatment.

Methods: During a 10-year period, all children who were diagnosed with VGAM were included in our follow-up study. Clinical and radiological records of 5 consecutive patients were reviewed.

Results: 5 children (4 infants and 1 child) who suffered from symptoms caused by VGAM were treated by means of transarterial embolization with N-butyl cyanoacrylate (NBCA) alone. Their age at the time of diagnosis ranged from 4 months to 3 years. 4 of the 5 patients presented with macrocranium, and 3 of those 4 patients were infants. The fifth patient presented with seizures. None of the patients presented with hemorrhage. 2 of the 5 VGAM patients were classified as the mural type, while the others 3 were of the choroidal type. Both mural type patients achieved total obliteration of lesions with good outcomes. One of the remaining 3 patients exhibited autistic behavior during late follow-up, whereas the other 2 had good outcomes. 2 patients suffered from asymptomatic ruptured arterial feeders during embolization, which were treated immediately with glue embolization.

Conclusion: Our purpose in treating a patient with VGAM is to achieve normal brain development using minimally invasive interventions. Our treatment strategies were influenced by each patient's clinical status, their ages, and varying radiographic features. We achieved considerable successful in treating our patients by means of transarterial embolization alone.

Background: Endoscopic lumbar decompression is useful for the treatment of various spinal conditions and is being performed in an increasing number of patients worldwide. We reviewed the surgery-related complications in patients who underwent endoscopic surgery and discuss the learning curve for this procedure.

Methods: Since the first case in August 2000, a total of 138 patients have undergone endoscopic posterior decompression surgery. Of these, there were 74 patients with Herniated Nucleus Pulposus (HNP), 57 with Lumbar Canal Stenosis (LCS), and 7 with other conditions. From 2003 to 2005, the senior surgeon took a sabbatical, and no endoscopic surgery was conducted. We divided the cases based on the date of surgery: there were 62 patients in the early (E) group (before September 2003), and 76 in the late (L) group (from January 2006 to April 2008). We compared the incidence of surgery-related complications between 2 disease types as well as between the E and L groups.

Results: We encountered 11 complications, which included 6 dural tears, 2 post-surgical hematomas, 2 neural complications and 1 fracture of the inferior articular process. The incidence of surgery-related complications was 8.6%. The incidences of complications were 8.1% and 9.3% for HNP and LCS, respectively, and 11.3%, and 5.3% in the E and L groups, respectively. The incidence was particularly high (16.7%) in the E group with LCS.

Conclusion: There is a steep learning curve for endoscopic surgery. Based on the data, surgeons should start performing endoscopic techniques for LCS after gaining enough experience of endoscopic surgery for HNP.

Background: Minimally invasive spinal surgery (MISS) has evolved over the past years due to the combination of microsurgery, minimal access strategies and neuronavigation. Percutaneous or mini-open pedicle screw placement is a challenge, especially for surgeons not experienced in the use of biplanar fluoroscopy or stereotactic imaging techniques. The aim of the study was to compare the precision of pedicle screw fixation for lumbar fusion procedures using Iso-C/stereotactic 3D neuronavigation (3D NAV) vs. standard AP/lateral fluoroscopy (2D NAV).

Methods: Our first 42 patients undergoing MISS for one- or 2-level lumbar or lumbosacral fusion procedures for degenerative lumbar pathology were included in this study. Either 3D NAV (n=29) or standard fluoroscopy (n=13) was used to aid screw placement. Demographics, operative time, blood loss, and screw placement accuracy were evaluated. Screw placement was evaluated postoperatively using lumbar CT scanning. Accuracy of 3D NAV was evaluated by comparing intraoperative planning screenshots to postoperative CT placement of screws.

Results: There were no significant differences between groups for mean age, gender or intraoperative blood loss. 90.9% of 3D NAV screws and 73.7% of fluoroscopy screws had no pedicle perforation (p=0.04). Intraoperative navigation screenshots accurately predicted pedicle screw placement in 90.9% of cases. There was a positive correlation between 3D NAV accuracy and better screw grade (rs 0.45, p=0.036).

Conclusions: Utilization of 3D NAV for percutaneous or mini-open lumbar screw placement during the early learning curve for MISS was associated with higher screw accuracy. This study demonstrates that the use of 3D navigation can facilitate the learning curve for MISS.

Case 1, a 61-year-old female presented with paresthesia of her right upper lip. Computed tomography (CT) and magnetic resonance (MR) imaging with contrast material revealed an enhanced mass in the right Meckel's cave, which included the lateral and posterior parts of the cavernous sinus and surrounded the right internal carotid artery. To establish the best surgical strategy, a percutaneous biopsy through the foramen ovale was performed, and the histological examination indicated that the tumor was a transitional meningioma. We performed combined treatment with microsurgery and radiosurgery. Case 2,a 66-year-old female presented with paresthesia of the right side of her face. MR images with gadolinium revealed an abnormal enhanced mass at the right Meckel's cave, and a CT scan with a bone window showed a large foramen ovale in the right side. We performed a percutaneous biopsy using the same method, but this tumor was too hard to sample through the needle. Although this manipulation has the major advantage of establishing the best therapeutic strategy and avoiding unnecessary surgery, special care should be taken for hard tumors, especially for those aspirated by needle biopsy.

Background: The purpose of this study is to demonstrate the added value of intraoperative MRI in treating secondary empty sella syndrome.

Case report: We describe the case of a 66-year-old woman who was diagnosed with a prolactinoma stage IIIb. During treatment with cabergoline she presented with a secondary empty sella syndrome resulting in visual symptoms. We performed intraoperative MRI-guided packing of the secondary empty sella. We explain why this is useful in surgical treatment of secondary empty sella syndrome.

Conclusion: Intraoperative MRI helps to achieve adequate sellar packing while avoiding insufficient packing as well as overpacking.

Background: Anastomosis of the superficial temporal artery (STA) to the middle cerebral artery (MCA) is useful for treating certain patients with internal carotid artery occlusion or MCA occlusion. However, in the case of common carotid artery (CCA) occlusion, since the blood flow in the STA is insufficient, another artery should be used as the donor artery. The cortical branches of the MCA are usually selected as recipients in the STA-MCA bypass. However, the intracranial vascular filling gradually increases over a few months after conventional cortical MCA bypass grafting, while early or even immediate vascular filling is observed after proximal MCA bypass grafting. This study aims to develop an elongation technique of the contralateral STA to reach the proximal segment of the ipsilateral MCA.

Methods: Anastomosis of the contralateral STA to the secondary trunk of the ipsilateral MCA was performed in 2 patients with occlusion of the CCA and ipsilateral vertebral artery (VA). The contralateral STA was extended with a radial artery (RA) graft in order to supply blood to the ischemic area. Elongation of the STA by using an RA interposition graft sufficiently lengthens the graft to enable its anastomosis with the contralateral M2 segment. Postoperative imaging revealed good bypass patency even at 1 year after the surgery.

Conclusion: This novel technique of performing the "bonnet" bypass was effective in treating both CCA and ipsilateral VA occlusion; moreover, this procedure of elongation of the STA can increase candidates of the recipient, and enables one to perform a double bypass to the anterior cerebral artery (ACA) or posterior cerebral artery (PCA).

Background: Endoscopic third ventriculostomy (ETV) is a procedure of choice in the treatment of obstructive hydrocephalus. Neurovascular injury while perforating the ventricular floor can occur when using a conventional probe, especially in patients with a thick and opaque third ventricle floor. The water jet dissection technique can be useful in such cases to perform an initial perforation.

Patients/material and methods: The water jet dissection technique was used to perform ETV in 36 patients with obstructive hydrocephalus with a thick and opaque third ventricle floor over a 3-year period. A water jet was generated using a syringe connected to a 2-mm catheter.

Results: The water jet dissection technique successfully created a patent ETV stoma in 31 patients. 5 patients needed a re-operation due to a blocked stoma. There were no complications related to the procedure. An improvement in clinical function was seen in 28 (83.3%) patients at a median follow-up of 29 months.

Conclusion: The water jet dissection is a useful technique while performing ETV to prevent neurovascular injury. Our improvised technique of creating a water jet is safe, inexpensive, readily available and can be practiced at any centre performing ETV.

Background: The aim of this study was to illustrate the anatomy of the medial compartment of the orbit by comparing the endoscopic transnasal perspective with the external ones.

Methods: 8 orbits from 5 double-injected heads were carefully dissected. An endoscopic anterior transconjunctival dissection was performed in one orbit while an endoscopic transnasal intraconal dissection was conducted in 3 orbits. External dissections (from medial, superior and anterior perspective) were also performed.

Results: The role of the medial rectus muscle is emphasised. It represents the first important landmark encountered, covering all the other structures during transnasal approaches. By displacing it, the medial intraconal space with its contents becomes visible: the ophthalmic artery and related branches, the superior ophthalmic vein, the nasociliary nerve and, in the deepest part of the medial compartment, the optic nerve.

Conclusion: The medial compartment of the orbit can be addressed transnasally. By displacing the medial rectus muscle, it is possible to gain adequate space for the instruments and to control all of the medial compartment, including the medial aspect of the optic nerve.