360 Degrees Endoscopic Access to and Through the Orbit

The treatment of pathologies located within and surrounding the orbit poses considerable surgical challenges, due to the intricate presence of critical neurovascular structures in such deep, confined spaces. Historically, transcranial and craniofacial approaches have been widely employed to deal with orbital pathologies. However, recent decades have witnessed the emergence of minimally invasive techniques aimed at reducing morbidity. Among these techniques are the endoscopic endonasal approach and the subsequently developed endoscopic transorbital approach (ETOA), encompassing both endonasal and transpalpebral approaches. These innovative methods not only facilitate the management of intraorbital lesions but also offer access to deep-seated lesions within the anterior, middle, and posterior cranial fossa via specific transorbital and endonasal corridors. Contemporary research indicates that ETOAs have demonstrated exceptional outcomes in terms of morbidity rates, cosmetic results, and complication rates. This study aims to provide a comprehensive description of endoscopic-assisted techniques that enable a 360° access to the orbit and its surrounding regions. The investigation will delve into indications, advantages, and limitations associated with different approaches, while also drawing comparisons between endoscopic approaches and traditional microsurgical transcranial approaches.

Purely endoscopic and endoscope-assisted approaches to lesions of the third ventricle in pediatric age-a technical collection

BACKGROUND

One of the main difficulties in third ventricle surgery is its deep and central location within the brain, surrounded by many eloquent neurovascular structures. Such anatomical environment obviously makes it very hard to safely approach and excise lesions in there.

METHODS

The introduction of the surgical microscope into the neurosurgical field undoubtedly played an important and pivotal role in improving the surgical results and increasing the safety of operations in and around the third ventricle. Although the surgical microscope remained the gold standard of intraoperative visualization for many decades, the advent of endoscopes revolutionized surgery of the third ventricle. Neuroendoscopic procedures for lesions of the third ventricle encompass a greatly variable array of endochannel, endoscope-assisted and endoscope-controlled techniques.

CONCLUSION

In this collection on purely endoscopic and endoscope-assisted approaches to lesions of the third ventricle in pediatric age, the readership is presented with a selected group of these operations performed by experts in the field, shedding light mainly on their technical aspects and surgical pearls. The text description in each article is supplemented by a surgical video.

Endoscope-assisted microsurgical resection of a third ventricular immature teratoma

BACKGROUND

Reaching a tumor within the third ventricle is challenging, and planning an accessible trajectory is crucial without injuring the surrounding structures. We report a 5-year-old boy presented with headache and a seizure where sequential MRI brain studies in a short time period revealed a rapid growing immature teratoma within the third ventricle with hydrocephalic changes. Several management procedures were performed for CSF diversion and medical treatment of the tumor with chemotherapy and stem cell therapy. The tumor was rapidly growing, and surgical excision was decided. Total resection was achieved via endoscope-assisted microsurgical transcallosal approach. Seven years after surgery, the patient experienced no recurrence of the tumor with a favorable clinical condition.

CONCLUSION

We report a rare case of posterior third ventricular immature teratoma where the endoscope-assisted microsurgical technique was implemented with favorable long-term postoperative outcome.

Endoscopic-assisted microvascular decompression for trigeminal neuralgia secondary to vertebrobasilar dolichoectasia: A case report

INTRODUCTION AND IMPORTANCE

Trigeminal neuralgia (TN) secondary to vertebrobasilar dolichoectasia (VBD) was a rare condition. This paper reported a successful endoscopic-assisted microvascular decompression (MVD) for TN secondary to VBD.

CASE PRESENTATION

A 53-year-old male with a history of myocardial infarction and heart failure complained of left refractory facial pain three years prior to admission. His pain was intermittent, electrical-like, severe, sharp, and radiated along the maxillary and mandibular branches. He used carbamazepine 600 mg daily. Brain magnetic resonance imaging revealed a neurovascular conflict between VBD and the left trigeminal nerve. The endoscopic-assisted MVD was indicated. The shredded neurosurgical sponges were interposed between VBD and trigeminal nerve. The 0° and 30° rigid rod-lens endoscope was used to explore and confirm the complete decompression. Postoperatively, TN was disappeared entirely. At a three-month postoperative, no facial pain and paraesthesia were found. The patient discontinued carbamazepine permanently.

CLINICAL DISCUSSION

MVD was still the most effective treatment. An inspection of root entry zone (REZ) and complete MVD with a solely operating microscope were challenging due to the massive diameter of VBD and multiple offending arteries behind the VBD. However, the wide viewing field and high-quality resolution of endoscopes allowed better visualization of REZ and neurovascular conflicts behind neural structures and least cerebellar retraction. This is essential in case of less potential space created by VBD.

CONCLUSION

Endoscope-assisted MVD allowed better visualization of REZ and neurovascular conflicts behind neural structures and least cerebellar retraction in management of trigeminal neuralgia secondary to VBD.

3D Printer Application for Endoscope-Assisted Spine Surgery Instrument Development: From Prototype Instruments to Patient-Specific 3D Models

Developing new surgical instruments is challenging. While making surgical instruments could be a good field of application for 3D printers, attempts to do so have proven limited. We designed a new endoscope-assisted spine surgery system, and using a 3D printer, attempted to create a complex surgical instrument and to evaluate the feasibility thereof. Developing the new surgical instruments using a 3D printer consisted of two parts: one part was the creation of a prototype instrument, and the other was the production of a patient model. We designed a new endoscope-assisted spine surgery system with a cannula for the endoscope and working instruments and extra cannula that could be easily added. Using custom-made patient-specific 3D models, we conducted discectomies for paramedian and foraminal discs with both the newly designed spine surgery system and conventional tubular surgery. The new spine surgery system had an extra portal that can be well bonded in by a magnetic connector and greatly expanded the range of access for instruments without unnecessary bone destruction. In foraminal discectomy, the newly designed spine surgery system showed less facet resection, compared to conventional surgery. We were able to develop and demonstrate the usefulness of a new endoscope-assisted spine surgery system relying on 3D printing technology. Using the extra portal, the usability of endoscope-assisted surgery could be greatly increased. We suggest that 3D printing technology can be very useful for the realization and evaluation of complex surgical instrument systems.

Supraorbital keyhole approach: Pure endoscopic and endoscope-assisted perspective

OBJECTIVE

To assess the assumed advantages of pure endoscopic and endoscope-assisted methods for the supraorbital keyhole approach. The aim is to demonstrate visibility and accessibility of the pure endoscope approach as a possible standard approach for the supraorbital keyhole approach.

PATIENTS AND METHODS

We performed eight dissections on four cadaver heads using an operating microscope, an endoscope, and neuronavigation. The visibility and accessibility of the anterior and middle cranial fossae regions were compared for each. Special structures were defined to assess their preservation in both approaches. We used pure endoscopy on the eight sides and with a microscope on those same eight sides. Accessibility was quantified for key structures using linear measurements taken with the navigation system. In addition, we present clinical cases in which an endoscope-assisted supraorbital approach was employed.

RESULTS

Our measurements have been reported for each side in the formalin-fixed heads as the mean ± SD (in mm) from the bone margin to selected regions. Moreover, image analysis was performed using ImageJ software to compare selected surface area measurements between the endoscope and microscope images on each side for all cadaveric available specimens. There were no significant statistical differences between visualization of the selected areas. This means that by visual analysis both endoscopic and microscopic images can provide the surgeon nearly the same visibility and accessibility of a selected region.

CONCLUSION

A pure endoscopic method can be used to conduct the supraorbital keyhole approach when the endoscope is used as a primary tool. Our recommendation is to use the measurements described in this study for preoperative planning of the keyhole approach. We believe that with advances in neuro-endoscope technology, and instrumentations, the endoscopic approach may replace the microscopic approach in the near future.

Development of a virtual reality training system for endoscope-assisted submandibular gland removal

PURPOSE

Endoscope-assisted surgery has widely been adopted as a basic surgical procedure, with various training systems using virtual reality developed for this procedure. In the present study, a basic training system comprising virtual reality for the removal of submandibular glands under endoscope assistance was developed. The efficacy of the training system was verified in novice oral surgeons.

MATERIAL AND METHODS

A virtual reality training system was developed using existing haptic devices. Virtual reality models were constructed from computed tomography data to ensure anatomical accuracy. Novice oral surgeons were trained using the developed virtual reality training system.

RESULTS

The developed virtual reality training system included models of the submandibular gland and surrounding connective tissues and blood vessels entering the submandibular gland. Cutting or abrasion of the connective tissue and manipulations, such as elevation of blood vessels, were reproduced by the virtual reality system. A training program using the developed system was devised. Novice oral surgeons were trained in accordance with the devised training program.

CONCLUSIONS

Our virtual reality training system for endoscope-assisted removal of the submandibular gland is effective in the training of novice oral surgeons in endoscope-assisted surgery.

The value of lateral spread response monitoring in predicting the clinical outcome after microvascular decompression in hemifacial spasm: a prospective study on 100 patients

Microvascular decompression represents an effective treatment for hemifacial spasm. The use of lateral spread response (LSR) monitoring remains a useful intraoperative tool to ensure adequate decompression of the facial nerve. The aim of this study was to assess the value of LSRs intraoperative monitoring as a prognostic indicator for the outcome of microvascular decompression in hemifacial spasm. Our study included 100 patients prospectively. The patients were classified into four groups whether LSRs were totally, partially, not relieved, or not detected from the start. According to clinical outcome, the patients were classified into four groups depending on the clinical course after surgery and the residual symptoms if any. Then, correlations were made between LSR events and treatment outcome to detect its reliability as a prognostic indicator. LSRs were relieved totally in 56 % of the patients, partially relieved in 14 %, not relieved in 10 %, and were not detected in 20 % of the patients from the start. HFS was relieved directly after operation in 62 % with clinical improvement of 90-100 %. Thirty-one percent described 50-90 % improvement over the next 3 months after surgery. Almost all of these 31 % (28 out of 31 patients) reported further clinical improvement of 90-100 % within 1 year after surgery. Three percent suffered from a relapse after a HFS-free period, and 4 % reported minimal or no improvement describing 0-50 % of the preoperative state. The percentage of the satisfied patients with the clinical outcome who reported after 1 year a clinical improvement of 90-100 % was 90 %. Statistical analysis did not find a significant correlation between the relief of LSRs and clinical outcome. LSRs may only represent an intraoperative tool to guide for an adequate decompression but failed to represent a reliable prognostic indicator for treatment outcome.