Since its revival in the early 1990s, neuroendoscopy has become an integral component of modern neurosurgery.
Advantages of endoscopic surgery include better visualization, panoramic vision, and the ability to work around corners. Limitations with endoscopic procedures include proximal blind areas, obstruction in instrument handling due to a narrow corridor, disorientation, frequent lens fogging, loss of depth perception, and difficulty in achieving hemostasis, leading to complications and longer operative time during the learning curve.
Surgeons need to learn endoscopic skills in addition to microsurgical ones to perform microendoscopic procedures properly. Attending live workshops, watching operative videos, visiting various departments, watching an experienced and accomplished endoscopic surgeon, proper case selection, a multidisciplinary team approach, practicing on models, hands-on cadaveric workshops, laboratory training, and simulators can improve results and shorten the learning curve 1)
see also Microendoscopic Spine Surgery.
Neuroendoscopy is now considered to be a minimally invasive surgical approach for expanding lesions bulging into the ventricle, and it is also considered to be a relevant tool for performing biopsy procedures, fenestration of cystic walls, or for performing tumor removal in selected cases. Furthermore, the use of neuroimaging and the accurate follow-up of brain tumor patients have allowed the documentation of tumoral and pseudotumoral cystic areas that cause the obstruction of cerebrospinal fluid (CSF) pathways. Neuroendoscopic procedures enable the fenestration of cystic lesions, in addition to enabling third ventriculostomy or septostomy to restore CSF pathways.
The result of using neuroendoscopy is the reconstruction of CSF pathways that bypass the tumor occlusion. This surgical procedure is not only limited to the relief of noncommunicating hydrocephalus, but it is also useful for tumor removal or biopsies and the evacuation of cystic lesions. In patients affected by malignant tumors, neuroendoscopy can be performed to control intracranial hypertension before the patients start adjuvant chemotherapy or radiotherapy 2).
Endoscope-controlled microneurosurgery means that the endoscope is the only visualization tool and microsurgical instruments are used along the endoscope. Major applications are endonasal endoscopic skull base surgery, endoport surgery, and endoscopic transcranial surgery.
Endoscope-assisted microneurosurgery means that the microscope and the endoscope are used in the same surgery. The endoscopes are applied when hidden structures to be inspected are not visible in straight line with the microscope.
Endoscopic techniques are a valuable addition to the neurosurgeon's armamentarium. Endoscopes are especially beneficial in deep and narrow surgical approaches and when “looking around a corner” is required 4).
It is increasingly being used in the management of intraventricular tumors. The role of endoscopy for diagnostic biopsy is well established. Expansion of these techniques may allow for definitive resection of intraventricular tumors.
Endoscopic surgery for any type of skull base defect is the gold standard. The size of the defects does not seem to play a significant role in the success rate. Fascia lata and mucoperiosteum of the turbinate allow a two-layer reconstruction of small and midsized defects. For larger skull base defects, a combination of fat, fascia lata, and nasoseptal pedicled flaps provides a successful reconstruction 5).
Endoscopic procedures may be performed purely endoscopic, for example for the treatment of occlusive hydrocephalus and cystic lesions or in combination with the operating microscope for example for the treatment of large tumors of the skull base or vascular lesions. The latter technique is named endoscope-assisted microsurgery (EAM). If endoscopes are used as the only optical tool but manipulations performed along the scope, it is referred to as endoscope-controlled microsurgery (ECM). This technique is recently more and more applied for transnasal skull base surgery.
Improvements in endoscopic techniques in neurosurgery have led to their being utilized not only for endonasal approaches to the skull base but also as an adjuvant in open cranial surgery. 6) 7) 8) 9) 10) 11) 12) 13) 14) 15).
The development and refinement of neuroendoscopy has been driven by the persistent desire of neurosurgeons to advance the field and offer less invasive, more efficacious options to patients. This remarkable multimedia book reflects the technological advances achieved in the last two decades in optical fibers, cold light, cameras, and endoscopic instrumentation. Written by an impressive Who’s Who of international neurosurgeons, the outstanding text and videos reflect global contributions to neuroendoscopy.
Current indications for intracranial and intraventricular endoscopy are described in depth, through detailed chapters, stellar videos, professional animations, and exquisite illustrations. The authors share their clinical expertise on procedures ranging from endoscopic third ventriculostomy to transventricular approach of the fourth ventricle. Cover to cover, this book details the differences, alternatives, advantages, and limitations of the flexible neuroendoscope.
This hands-on learning tool will enable neurosurgeons to perform endoscopy of the ventricles and basal cisterns for exploratory purposes and conditions such as hydrocephalus, congenital aqueductal stenosis, tumors, hypothalamic hamartoma, arachnoid cysts, and neurocysticercosis. Additional topics include endoscopic-assisted microvascular decompression and aneurysm surgery, fluorescence, complications, anesthesia, utilization in developing countries, and future trends.
Comprehensive multimedia reference with online access to 50 videos More than 300 meticulously drawn illustrations Beautifully illustrated anatomical chapters that facilitate in-depth understanding of endoscopic anatomy An entire chapter devoted to flexible neuroendoscopy Indications, preoperative preparation, procedure description, intraoperative complications and their management (““risk and rescue”” techniques), expert pearls, postoperative management, and outcomes This volume is a must-have resource for neurosurgery and neurology residents, neurosurgeons, pediatric neurosurgeons, and all physicians involved in the care of patients with intracranial and intraventricular disease.
Cerebrospinal fluid diversion
Brain parenchymal surgery
Skull base surgery.
The majority of endoscopic intraventricular surgery is performed for cerebrospinal fluid (CSF) diversion, but is also frequently used for colloid cyst resection, tumor biopsy, and arachnoid cyst treatment. Improved technology has given the neuroendoscopist an additional margin of confidence by means of improved visualization: preoperative 1.5-T and 3-T magnetic resonance imaging with constructive interference in steady state/fast imaging using steady-state acquisition sequences, high-definition cameras (2 million pixels), and coupling of navigation to the endoscope system.
During the development of these technologies over the past 20 years, multiple large series have reported on complications associated with endoscopic neurosurgery.
Neuroendoscopy is a minimally invasive technique whose related complications have been focused on cortical function and surface vessels injury. However, white matter disruption has been insufficiently acknowledged.
A method using tractography and oriented models of surgical instruments allows assessing white matter transgression, both qualitatively and quantitatively, for a deep brain trajectory. Thus, this method permits to optimize safety and avoid transgression of eloquent tracts during surgical planning. Nevertheless more studies are needed 16).