Paolo Pacca

Endoscopic Endonasal Approach to the Odontoid Pathologies.

BACKGROUND Surgical anterior decompression represents the treatment of choice for symptomatic irreducible ventral craniovertebral junction (CVJ) compression. With the refinement of the endoscopic techniques, the endonasal route has been proposed as alternative to the classic transoral approach to CVJ. Some reports assess the effectiveness and safety of endoscopic endonasal approaches to CVJ pathologies. MATERIALS AND METHODS From July 2011 to February 2014, 12 patients with symptomatic nonreducible ventral spinal cord compression underwent purely 3-dimensional endoscopic endonasal odontoidectomy in our department. The surgical technique is described. RESULTS A good brainstem-medullary decompression was achieved in all patients. In 10 of 12 patients the endotracheal tube was removed just after the procedure with good recovery of the respiratory function. We report no cases of velopharyngeal insufficiency. In 5 of 12 patients the preservation of C1 anterior was achieved, without the need for posterior cervical fixation. DISCUSSION AND CONCLUSIONS Endoscopic endonasal odontoidectomy has proven to be safe and effective in selected patients. Soft and hard palate preservation dramatically reduces the risk of postoperative velopharyngeal insufficiency. Moreover, the endonasal endoscopic approach provides a direct access to the dens. Three-dimensional high-definition endoscope, laser, and ultrasound bony curettes revealed to be useful tools for this approach that, however, remains a demanding one.

Three-dimensional endoscopy in transnasal transsphenoidal approach to clival chordomas

The purpose of this prospective, observational study was to evaluate the management of skull base chordomas surgically resected via a 3D‐endoscopic transnasal approach.

C1 anterior arch preservation in transnasal odontoidectomy using three‑dimensional endoscope: A case report

Background: The transoral ventral corridor is the most common approach used to reach the craniovertebral junction (CVJ). Over the last decade, many case reports have demonstrated the transnasal corridor to the odontoid peg represents a practicable route to remove the tip of the odontoid process. The biomechanical consequences of the traditional odontoidectomy led to the necessity of a cervical spine stabilization. Preserving the inferior portion of the C1 anterior arch should prevent instability. Case Description: This is the first report in which the technique to remove the tip of the odontoid while preserving the C1 anterior arch is described by means of a three-dimensional (3D) endoscope. A 53-year-old man underwent a transnasal 3D endoscopic approach because of a complex CVJ malformation. The upper-medial portion of the C1 anterior arch was removed preserving its continuity, and the odontoidectomy was performed. After surgery, a dynamic X-ray scan showed no difference in CVJ motility in comparison with the preoperative one. Conclusions: The stereoscopic perception augmented the precision of the surgical gesture in the deep field. The importance of a 3D view relates to the depth of field, which a two-dimensional endoscopy cannot provide. This affects the preservation of the C1 anterior arch because of the presence of critical structures that are exposed to potential damage if not displayed.

Intraoperative neurophysiological monitoring during spinal surgery: technical review in open and minimally invasive approaches

Neurophysiological monitoring is of undoubted value for the intraoperative safety of neurosurgical procedures. Widely developed and used for cranial surgery, it is equally as effective, though perhaps less commonly employed, for spinal pathology. The most frequently used techniques for intraoperative monitoring during spinal surgery include somatosensory evoked potentials (SSEPs), motor evoked potentials (MEPs) and electromyography, which can either be spontaneous free-running (sEMG) or triggered (tEMG). The knowledge of the benefits and limitations of each modality is essential in optimising the value of intraoperative monitoring during spinal procedures. This review will analyse the single techniques, their anatomical and physiological basis, their use in spinal surgery as reliable indicators of functional injury, their limits and their application to specific procedures in minimally invasive surgery, such as the lateral transpsoas access for interbody fusion and the divergent trajectory for cortico-pedicular screws. In these particular techniques, because of reduced visual exposure, neuromonitoring is indeed essential to exploit the full potential of minimally invasive surgery, while avoiding damage to nervous structures.

Nanofibrous Synthetic Dural Patch for Skull Base Defects: Preliminary Experience for Reconstruction after Extended Endonasal Approaches.

Setting One of the consequences of the widespread use of endoscopic endonasal approaches (EEA) to skull base pathologies is the management of complex skull base defects. Nowadays, the gold standard is a multilayer closure that reproduces the physiological tissue barriers. Several techniques have been described in the literature; however, skull base reconstruction after EEA still represents a matter of debate, especially after extended EEA. A watertight closure is paramount to prevent cerebrospinal fluid leak and meningitis. Design Regarding this issue, we present our experience with a new synthetic dural patch, ReDura (Medprin Biotech, La Mirada, California, United States), as a subdural inlay in three patients who underwent endoscopic endonasal removal of sellar and suprasellar lesions. Conclusions ReDura patch showed the same versatility of autologous iliotibial tract. A dural patch that easily adapts to all defects, revealed to be a useful tool for performing watertight closure, possibly in a short operative time, after endoscopic approaches.

Detailed anatomy knowledge: first step to approach petroclival meningiomas through the petrous apex. Anatomy lab experience and surgical series

Petroclival meningiomas are a challenge for neurosurgeons due to the complex anatomy of the region that is rich of vessels and nerves. A perfect and detailed knowledge of the anatomy is very demanding in neurosurgery, especially in skull base surgery. The authors describe the microsurgical anatomy to perform an anterior petrosectomy based on their anatomical and surgical experience and perform a literature review. The temporal bone is the most complex and fascinating bone of skull base. The apex is located in the angle between the greater wing of the sphenoid and the occipital bone. Removing the petrous apex exposes the clivus. The approach directed through the temporal bone in this anatomical area is referred to as an anterior petrosectomy. The area that must be drilled is the rhomboid fossa that is defined by the Kawase, premeatal, and postmeatal triangles. In Division of Neurosurgery - University of Turin, 130 patients, from August 2013 to September 2015, underwent surgical resection of intracranial meningiomas. In this group, we have operated 7 PCMs and 5 of these were approached performing an anterior petrosectomy with good results. In our conclusions, we feel that this surgery require an advanced knowledge of human anatomy and a specialized training in interpretation of radiological and microsurgical anatomy both in the dissection lab and in the operating room.

3D Endoscopic Endonasal Approach in Skull Base Surgery: Experience on 87 Consecutive Patients

Objectives: Assess advantages and disadvantages of 3-dimensional endoscopy in the transnasal approach to sellar region, posterior skull base, and cervical junction. Methods: Between January 2012 and December 2013, 87 patients were consecutively treated at the Neurosurgery Division of the University of Turin for sellar, skull base, and cervical junction pathologies. All procedures were performed by the same team (2 ENT surgeons and 2 neurosurgeons) using a 3-dimensional (3D) stereoendoscope (VSII system, Visionsense Ltd, Petach Tikva, Israel). After each procedure each surgeon was asked to fill out a questionnaire (based on visual analogue scales) designed to assess comfort and learning curve. Results: Seventy patients were treated for pituitary macroadenomas, 10 for chordomas, 6 for a malformation of the cervical junction, and 1 for a chondrosarcoma of the odontoid process of C2. A cerebrospinal fluid (CSF) leak was observed in 6 out of 70 patients, 1 out of 10 patients, and 0 out of 7 patients, respectively; 5 out of 7 CSF leaks were intraoperatively solved and 2 out of 7 required revision surgery. No vascular complications were recorded. Median global comfort score (sensation of strain + dizziness + system ergonomics scores), recorded at the end of the first and second procedure, was 9.1 and 9.6, respectively; after the third procedure it reached 10. The learning curve score reached the maximum level of 9.5 after the eighth procedure. Conclusions: 3D stereoscopic vision system is comfortable for the surgeons allowing them to have a better visualization of anatomic structures and landmarks; it is easy to use and after only a few procedures surgeon skills reach high levels.