Application of Technology for Minimally Invasive Neurosurgery

Use of an Endoscope Reduces the Size of Craniotomy Without Increasing Operative Time Compared With Conventional Microscopic Corpus Callosotomy

BACKGROUND AND OBJECTIVES

Corpus callosotomy (CC) is an epilepsy surgery that disconnects the commissural fibers at the corpus callosum, a structure that often plays a key role in propagating seizure activity. CC is particularly beneficial in patients with drop attacks. Less invasive endoscopic surgeries have recently been introduced to some fields of neurosurgery but have not yet become common in epilepsy surgery. Endoscopic surgeries offer better visualization and require a smaller corridor than conventional microscopic surgeries. Here, we presented a case series comparing endoscopic CC with microscopic CC.

METHODS

This 2-center retrospective study involved patients who underwent all types of CC (anterior, total, or posterior CC [pCC]) between January 2014 and May 2022. We excluded patients who underwent additional craniotomy for electrocorticography rather than CC, prior craniotomy, or CC without craniotomy. The primary outcomes were comparing size of craniotomy, operative time, and surgical complications between endoscopic CC and microscopic CC.

RESULTS

We included 14 CCs in 11 patients in the endoscopic group and 58 CCs in 55 patients in the microscopic group. No significant difference in age was seen between groups. Craniotomies were significantly smaller in the endoscopic group for anterior (13.36 ± 1.31 cm 2 vs 27.55 ± 3.78 cm 2 ; P = .001), total (14.07 ± 2.54 cm 2 vs 26.63 ± 6.97 cm 2 ; P = .001), and pCC (9.44 ± 1.18 cm 2 vs 30.23 ± 10.76 cm 2 ; P = .002). Moreover, no significant differences in operative time (anterior CC [261 ± 53.11 min vs 298.73 ± 81.08 min, P = .226], total CC [339.5 ± 48.2 min vs 321.39 ± 65.98 min, P = .452], pCC [198 ± 24.73 min vs 242.5 ± 59.12 min, P = .240]), or complication rate were seen.

CONCLUSION

Endoscopic CC is a promising technique requiring a smaller craniotomy than microscopic CC, without significantly increasing operative time or complication rate compared with microscopic CC.

Specialised Surgical Instruments for Endoscopic and Endoscope-Assisted Neurosurgery: A Systematic Review of Safety, Efficacy and Usability

While there have been great strides in endoscopic and endoscope-assisted neurosurgical approaches, particularly in the treatment of deep-sited brain and skull base tumours, the greatest technical barrier to their adoption has been the availability of suitable surgical instruments. This systematic review seeks to identify specialised instruments for these approaches and evaluate their safety, efficacy and usability. Conducted in accordance with the PRISMA guidelines, Medline, Embase, CENTRAL, SCOPUS and Web of Science were searched. Original research studies that reported the use of specialised mechanical instruments that manipulate tissue in human patients, cadavers or surgical models were included. The results identified 50 specialised instruments over 62 studies. Objective measures of safety were reported in 32 out of 62 studies, and 20 reported objective measures of efficacy. Instruments were broadly safe and effective with one instrument malfunction noted. Measures of usability were reported in 15 studies, with seven reporting on ergonomics and eight on the instruments learning curve. Instruments with reports on usability were generally considered to be ergonomic, though learning curve was often considered a disadvantage. Comparisons to standard instruments were made in eight studies and were generally favourable. While there are many specialised instruments for endoscopic and endoscope-assisted neurosurgery available, the evidence for their safety, efficacy and usability is limited with non-standardised reporting and few comparative studies to standard instruments. Future innovation should be tailored to unmet clinical needs, and evaluation guided by structured development processes.

2D versus 3D Endoscopy: Head-to-Head Comparison in a Simulated Model of Endoscopic Endonasal Dural Suturing

Objective Endonasal dural suturing (EDS) has been reported to decrease the incidence of cerebrospinal fluid fistula. This technique requires handling of single-shaft instrumentation in the narrow endonasal corridor. It has been proposed that three-dimensional (3D) endoscopes were associated with improved depth perception. In this study, we sought to perform a comparison of two-dimensional (2D) versus 3D endoscopy by assessing surgical proficiency in a simulated model of EDS.

Materials and Methods Twenty-six participants subdivided into groups based on previous endoscopic experience were asked to pass barbed sutures through preset targets with either 2D (Storz Hopkins II) or 3D (Storz TIPCAM) endoscopes on 3D-printed simulation model. Surgical precision and procedural time were measured. All participants completed a Likert scale questionnaire.

Results Novice, intermediate, and expert groups took 11.0, 8.7, and 5.7 minutes with 2D endoscopy and 10.9, 9.0, and 7.6 minutes with 3D endoscopy, respectively. The average deviation for novice, intermediate, and expert groups (mm) was 5.5, 4.4, and 4.3 with 2D and 6.6, 4.6, and 3.0 with 3D, respectively. No significant difference in procedural time or accuracy was found in 2D versus 3D endoscopy. 2D endoscopic visualization was preferred by the majority of expert/intermediate participants, while 3D endoscopic visualization by the novice group.

Conclusion In this pilot study, there was no statistical difference in procedural time or accuracy when utilizing 2D versus 3D endoscopes. While it is possible that widespread familiarity with 2D endoscopic equipment has biased this study, preliminary analysis suggests that 3D endoscopy offers no definitive advantage over 2D endoscopy in this simulated model of EDS.

Extended endonasal endoscopic approach for anterior midline skull base lesions

AIM

In recent years, extended endoscopic endonasal approach (EEEA) has been used as an alternative to transcranial approaches in the treatment of anterior midline skull base lesions. We retrospectively reviewed our cases operated using this technique and compared the results with current literature.

METHOD

The data of 24 patients who were operated using EEEA in our department between 2010-2018 were retrospectively analyzed. The lesions were located in the midline between the posterior wall of the frontal sinus and tuberculum sella. Tumor locations, histopathological diagnoses, surgical techniques, outcomes and complications were documented.

RESULTS

Eleven patients were female and 13 were male. Their ages ranged between 18-75 years (mean 40.5 years). Considering their locations; 12 were in the anterior fossa (50 %), 7 were in the tuberculum sella (29.1 %), and 5 were in both anatomic sites (20.8 %). Histopathologically, our series consisted of 15 meningiomas, 6 osteomas, 2 dermoid tumors and 1 metastatic carcinoma. We achieved gross total resection in 75 % of our patients. Ten patients presented with visual complaints and 7 of them improved postoperatively. Postoperative cerebrospinal fluid leakage (CSF) was observed in 3 patients and one of them developed meningitis and subsequently died of sepsis.

CONCLUSION

Although the number of cases is low, EEEA seems like a safe, effective and well-tolerated treatment modality for anterior midline skull base lesions. But strict preventive measures should be taken for a possible CSF leak.

Smartphone-assisted minimally invasive neurosurgery

OBJECTIVE

Advances in video and fiber optics since the 1990s have led to the development of several commercially available high-definition neuroendoscopes. This technological improvement, however, has been surpassed by the smartphone revolution. With the increasing integration of smartphone technology into medical care, the introduction of these high-quality computerized communication devices with built-in digital cameras offers new possibilities in neuroendoscopy. The aim of this study was to investigate the usefulness of smartphone-endoscope integration in performing different types of minimally invasive neurosurgery.

METHODS

The authors present a new surgical tool that integrates a smartphone with an endoscope by use of a specially designed adapter, thus eliminating the need for the video system customarily used for endoscopy. The authors used this novel combined system to perform minimally invasive surgery on patients with various neuropathological disorders, including cavernomas, cerebral aneurysms, hydrocephalus, subdural hematomas, contusional hematomas, and spontaneous intracerebral hematomas.

RESULTS

The new endoscopic system featuring smartphone-endoscope integration was used by the authors in the minimally invasive surgical treatment of 42 patients. All procedures were successfully performed, and no complications related to the use of the new method were observed. The quality of the images obtained with the smartphone was high enough to provide adequate information to the neurosurgeons, as smartphone cameras can record images in high definition or 4K resolution. Moreover, because the smartphone screen moves along with the endoscope, surgical mobility was enhanced with the use of this method, facilitating more intuitive use. In fact, this increased mobility was identified as the greatest benefit of the use of the smartphone-endoscope system compared with the use of the neuroendoscope with the standard video set.

CONCLUSIONS

Minimally invasive approaches are the new frontier in neurosurgery, and technological innovation and integration are crucial to ongoing progress in the application of these techniques. The use of smartphones with endoscopes is a safe and efficient new method of performing endoscope-assisted neurosurgery that may increase surgeon mobility and reduce equipment costs.

Techniques for Interventional MRI Guidance in Closed-Bore Systems

Efficient image guidance is the basis for minimally invasive interventions. In comparison with X-ray, computed tomography (CT), or ultrasound imaging, magnetic resonance imaging (MRI) provides the best soft tissue contrast without ionizing radiation and is therefore predestined for procedural control. But MRI is also characterized by spatial constraints, electromagnetic interactions, long imaging times, and resulting workflow issues. Although many technical requirements have been met over the years-most notably magnetic resonance (MR) compatibility of tools, interventional pulse sequences, and powerful processing hardware and software-there is still a large variety of stand-alone devices and systems for specific procedures only.Stereotactic guidance with the table outside the magnet is common and relies on proper registration of the guiding grids or manipulators to the MR images. Instrument tracking, often by optical sensing, can be added to provide the physicians with proper eye-hand coordination during their navigated approach. Only in very short wide-bore systems, needles can be advanced at the extended arm under near real-time imaging. In standard magnets, control and workflow may be improved by remote operation using robotic or manual driving elements.This work highlights a number of devices and techniques for different interventional settings with a focus on percutaneous, interstitial procedures in different organ regions. The goal is to identify technical and procedural elements that might be relevant for interventional guidance in a broader context, independent of the clinical application given here. Key challenges remain the seamless integration into the interventional workflow, safe clinical translation, and proper cost effectiveness.

Neuronavigation in small animals: development, techniques, and applications

A persistent obstacle to accurate diagnosis and treatment of brain disease has been the difficulties in safely obtaining representative biopsy material in a live patient. Major problems are the variability in the anatomy between individuals and the inability to reliably locate deep structures through reliance on surface anatomic features. Although stereotaxic devices have been available for many years, they have now been supplanted by frameless systems, which are more accurate and less cumbersome and allow good surgical access and provision of intraoperative feedback of instrument location.