Surgical Microscope Research Articles

Fibroepithelial polyp as an unexpected pathology in the external auditory canal: a case report

Introduction and importanceFibroepithelial polyps are rare benign lesions with uncertain origins. They are commonly found in the skin and genitourinary system. Fibroepithelial polyps in the external auditory canal are infrequent.Case presentationWe report a 60-year-old Persian woman with an incidentally discovered painless fibroepithelial polyp in the right external auditory canal. Microscopic transcanal surgery confirmed the diagnosis after temporal computed tomography imaging showed a soft tissue mass.Clinical discussionFibroepithelial polyps have an uncertain etiology and are typically asymptomatic. Surgical resection is the preferred treatment, and the prognosis following resection is generally favorable, with low recurrence rates.ConclusionThis case highlights the rarity of fibroepithelial polyps in the external auditory canal and underscores the importance of considering them in the differential diagnosis of external auditory canal lesions.

Augmented Reality in Extratemporal Lobe Epilepsy Surgery.

Background: Epilepsy surgery for extratemporal lobe epilepsy (ETLE) is challenging, particularly when MRI findings are non-lesional and seizure patterns are complex. Invasive diagnostic techniques are crucial for accurately identifying the epileptogenic zone and its relationship with surrounding functional tissue. Microscope-based augmented reality (AR) support, combined with navigation, may enhance intraoperative orientation, particularly in cases involving subtle or indistinct lesions, thereby improving patient outcomes and safety (e.g., seizure freedom and preservation of neuronal integrity). Therefore, this study was conducted to prove the clinical advantages of microscope-based AR support in ETLE surgery. Methods: We retrospectively analyzed data from ten patients with pharmacoresistant ETLE who underwent invasive diagnostics with depth and/or subdural grid electrodes, followed by resective surgery. AR support was provided via the head-up displays of the operative microscope, with navigation based on automatic intraoperative computed tomography (iCT)-based registration. The surgical plan included the suspected epileptogenic lesion, electrode positions, and relevant surrounding functional structures, all of which were visualized intraoperatively. Results: Six patients reported complete seizure freedom following surgery (ILAE 1), one patient was seizure-free at the 2-year follow-up, and one patient experienced only auras (ILAE 2). Two patients developed transient neurological deficits that resolved shortly after surgery. Conclusions: Microscope-based AR support enhanced intraoperative orientation in all cases, contributing to improved patient outcomes and safety. It was highly valued by experienced surgeons and as a training tool for less experienced practitioners.

Microscope integrated MHz optical coherence tomography system for neurosurgery: development and clinical in-vivo imaging.

Neurosurgical interventions on the brain are impeded by the requirement to keep damages to healthy tissue at a minimum. A new contrast channel enhancing the visual separation of malign tissue should be created. A commercially available surgical microscope was modified with adaptation optics adapting the MHz speed optical coherence tomography (OCT) imaging system developed in our group. This required the design of a scanner optics and beam delivery system overcoming constraints posed by the mechanical and optical parameters of the microscope. High quality volumetric OCT C-scans with dense sample spacing can be acquired in-vivo as part of surgical procedures within seconds and are immediately available for post-processing.

Surgical microscope in periodontics – Journeying towards precision

Surgical microscope in periodontics – Journeying towards precision

Minimally Invasive Surgery: A Paradigm Shift in Surgical Procedures

Minimally Invasive Surgery (MIS) and microsurgery have significantly transformed periodontal treatment by reducing tissue trauma and improving patient outcomes. MIS focuses on minimizing flap reflection and tissue manipulation, preserving blood supply, and ensuring the stability of blood clots at the wound site, which collectively reduce postoperative complications such as shrinkage and discomfort. Microsurgery, enabled by advancements in surgical microscopes, enhances visual acuity and allows for precise surgical interventions. In periodontology, the integration of MIS and microsurgery has led to refined surgical techniques that prioritize minimal tissue disruption, passive wound closure, and the use of specialized microsurgical instruments. These approaches offer significant advantages over conventional flap surgeries, which were often associated with extensive tissue damage, prolonged healing times, and aesthetic compromises. The evolution of MIS in periodontology represents a shift from resection-based procedures to those focused on regeneration, emphasizing the importance of skill enhancement and the adoption of advanced technologies. As MIS techniques continue to develop, they hold the potential to become the standard of care, providing patients with effective, less invasive treatment options that result in better clinical and aesthetic outcomes. The current article's goal was to gather and record different minimally invasive periodontology techniques. Peer-reviewed materials from journals, Medline/PubMed, Google Scholar, and other reviews served as the foundation for the research.

Intraoperative Electromyogram Analysis of Postural Musculature With Three-dimensional Screen Display Versus Operating Microscope in Ophthalmic Surgery: A Clinical Methods Study.

To objectively analyze the effect of three-dimensional screen-based surgery (3D SBS) versus traditional operating microscope (TOM) on operating surgeon posterior chain postural musculature during ophthalmic surgery. We hypothesized an increase in median amplitude of electromyography (EMG) signals when using a TOM compared to 3D SBS. The goal was to assess surgical ergonomics that may contribute to cervical and lumbar spine pathology. EMG analysis was conducted at the University of Cincinnati Medical Center Epilepsy Monitoring Unit. Data were collected in the private practice setting at Cincinnati Eye Institute. This was an institutional review board exempt, nonrandomized, prospective, single center, n = 1 clinical methods study. EMG surface electrodes were affixed to the bilateral splenius capitis, sternocleidomastoid, upper trapezius, anterior deltoid, and quadratus lumborum musculature. EMG data were collected across four sessions consisting of one day each using 3D SBS or a TOM, and two cross-over days. A survey regarding surgeon comfort was administered before, during, and after each surgery, and at the end of each day. EMG cross-over data demonstrated an increase in muscle activation in all measured muscles except the anterior deltoids and right quadratus lumborum with use of a TOM. Survey data showed increased fatigue when using a TOM relative to 3D SBS. EMG demonstrated increased postural muscle activation when utilizing TOM relative to 3D SBS. Similar to previous studies, our survey data suggest inferior ergonomics of TOM relative to 3D SBS. [Ophthalmic Surg Lasers Imaging Retina 2024;55:628-636.].

Intraoperative confocal laser endomicroscopy during 5-aminolevulinic acid-guided glioma surgery: significant considerations for resection at the tumor margin.

Because gliomas have poorly defined tumor margins, the ability to achieve maximal resection is limited. To better discern these margins, fluorescence-guided surgery has been used to aid maximal safe resection. The authors describe their experience with the simultaneous use of intraoperative fluorescein sodium (FNa) confocal laser endomicroscopy (CLE) and operating microscope 5-aminolevulinic acid (5-ALA) fluorescence imaging for glioma resection to improve CLE use for better margin discrimination. FNa CLE and 5-ALA wide-field imaging were used in 33 patients with gliomas. CLE imaging was enhanced with the use of a telesurgical pathology software platform that enables real-time conversation between the operating neurosurgeons and the pathologists located remotely. CLE was used for imaging tumor regions that were subjectively regarded as tumor margins under normal visualization with the operative microscope. After FNa CLE imaging, 5-ALA wide-field imaging was performed in the same regions. Tissue was biopsied at imaging locations, and interpretations of FNa CLE and 5-ALA wide-field imaging were compared to those of permanent histological sections. Eighty-eight deep- and superficial-margin regions of interest (ROIs) were imaged with FNa CLE and 5-ALA imaging. Most of the ROIs interpreted by the neuropathologist as infiltrative glioma based on FNa CLE imaging lacked 5-ALA-induced fluorescence. Permanent histological sections from the corresponding regions were concordant with the interpretation of FNa CLE images in 57 of 88 (65%) ROIs and with the interpretation of 5-ALA imaging in 43 of 88 (49%) ROIs. The sensitivity and specificity of FNa CLE for the interpretation of tumor margins were 73% and 41%, respectively, and those of 5-ALA were 38% and 82%, respectively. Positive and negative predictive values for CLE were 79% and 33%, respectively, and those for 5-ALA were 86% and 31%, respectively. Conventional intraoperative evaluation of tumor margins, based on MRI and wide-field fluorescence imaging, can underestimate the invasiveness of gliomas. FNa CLE showed higher accuracy in detecting regions with infiltrating tumors than intraoperative 5-ALA imaging. Future considerations should include more rigorous comparisons of FNa CLE imaging and 5-ALA-guided resections on a larger cohort of patients.

Vertebral artery pseudoaneurysm: a rare cause of posterior circulation infarction in a middle-aged man.

Pseudoaneurysm of the vertebral artery is a rare cause of posterior circulation stroke. Treatment for this condition can be achieved through microscopic surgery or endovascular therapy. We report a case of a 36-year-old middle-aged male patient who presented with left limb numbness as the sole complaint. On a magnetic resonance imaging examination, multiple infarcts were observed in the left cerebellar tonsil. A subsequent head and neck computed tomography angiography examination led to the diagnosis of a pseudoaneurysm in the left vertebral artery. Following standard antiplatelet therapy, the patient underwent endovascular intervention. The patient's left limb numbness gradually subsided after surgery. A follow-up angiography performed 1 week after discharge showed no recurrence. These findings suggest that covered stent placement is an effective method of treating pseudoaneurysm of the vertebral artery.

Comparative Evaluation of Dentinal Microcrack Formation During Root Canal Preparation Using Different Rotary Files: An In Vitro Study

Background:The success of endodontic treatment depends on completely removing all vital and necrotic pulp tissue, microorganisms, and microbial toxins from the root canal. During the cleaning and shaping process, the canal is shaped through the interaction between instruments and the dentin walls. These interactions can create several temporary stress points within the dentin, which may lead to the development of dentinal defects, craze lines, or microcracks. As a result, the techniques employed for shaping root canals carry the risk of starting crack formation, which, under functional pressure, could progress into complete fractures. This study was aimed to compare and evaluate the incidence of dentinal microcrack formation during root canal preparation using ProTaper Universal, ProTaper Gold, NeoEndo Flex and Hyflex EDM files. Materials and Methods: A total of 95 freshly extracted single rooted premolars with single straight canal were selected and stored in normal saline. Each specimen was examined using dental operating microscope to exclude cracked samples. Specimens then decoronated using a diamond disc and water as a coolant to a standardized length of 14 mm. Canal patency was determined by passing 10 K file passively and the working length was established 1 mm short of the file length at which the file become visible at the apical foramen. Canal was then enlarged upto15 k size file. Teeth samples were then divided into 5 groups having 19 teeth each. Group 1: Control Group (Uninstrumented teeth), Group 2 : Protaper Universal, Group 3 : Protaper Gold, Group 4 : NeoEndo Flex ,Group 5 : Hyflex EDM. After completion of cleaning and shaping procedure (to a standard apical diameter of 25), canal was rinsed with distilled water. Root was then horizontally sectioned at 3 mm, 6 mm and 9 mm from the apex with diamond disc at low speed under water cooling. All the sections were evaluated under stereomicroscope for presence of cracks and images were recorded. Cracks were observed as lines extending from the root canal lumen to the dentin or from the outer surface into the dentin. Results: All the file systems used in this study showed dentinal microcracks. ProTaper Universal exhibited the highest percentage of dentinal defects, while Hyflex EDM displayed the lowest among the file systems used (ProTaper Universal, ProTaper Gold, NeoEndo Flex and Hyflex EDM). The defects were present more in the apical third (3 mm) as compared to 6 mm (middle third) and 9 mm (coronal third) sections

EVALUATION OF WOUND HEALING AND EPITHELIALIZATION USING TOLUIDINE BLUE DYE INDICATOR IN DIODE LASER FRENECTOMY WITH AND WITHOUT SURGICAL MICROSCOPE

Objective: The study aimed to evaluate the wound healing and epithelialization in diode laser frenectomy using toluidine blue dye as an indicator, comparing outcomes between procedures performed with and without the use of a surgical microscope at 1- and 2-weeks post-operatIvely. Materials and Methods: This controlled clinical trial involved patients undergoing diode laser frenectomy, divided into two groups: one group underwent the procedure with the aid of a surgical microscope, while the other group did not use a microscope. Wound healing and epithelialization were assessed using toluidine blue dye at 1 and 2 weeks following the procedure. Results: The group that received diode laser frenectomy with the use of a surgical microscope demonstrated significantly faster and more complete wound healing and epithelialization at both 1 and 2 weeks compared to the group that did not use the surgical microscope. The toluidine blue stain uptake showed similar results. Conclusion: The use of a surgical microscope in diode laser frenectomy appears to enhance wound healing and epithelialization, as evidenced by the results at both 1 and 2 weeks. This suggests that incorporating a surgical microscope into the procedure may improve clinical outcomes and reduce recovery time. Further research is needed to confirm these findings across larger and more diverse patient populations.

Comparison of Endoscopic and Microscopic Surgery for the Treatment of Acquired Cholesteatoma by EAONO/JOS Staging.

Cholesteatoma is a benign tumor of the middle ear. Tympanoplasty is performed to remove cholesteatoma, prevent recurrence, and avoid complications. Previously, microscopy was used for tympanoplasty; however, endoscopy has become increasingly popular for this procedure. The effectiveness of endoscopy and the appropriate candidacy for endoscopic ear surgery remain controversial. In this retrospective chart review study, we enrolled 107 patients with cholesteatoma who underwent tympanoplasty and compared the microscopic approach (71 patients) and the endoscopic approach (36 patients) at different stages to clarify the benefits of using endoscopy and to determine candidacy for endoscopic ear surgery. Approach selection, complication rate, recurrence rate, and postoperative hearing threshold were compared between microscopic and endoscopic approaches in stages I, II, and III. Endoscopy was used more often than microscopy for early-stage (stage I) cholesteatoma (p = 0.005) and less frequently for advanced-stage (stage II) cholesteatoma (p = 0.02). Endoscopy surgery resulted in chorda tympani injury less often than microscopic surgery (p = 0.049); however, there were no significant differences between these two groups in terms of recurrence rate or postoperative hearing outcome. Endoscopy is particularly useful for early-stage cholesteatoma, and both approaches show no difference in hearing outcome in stage I and II; nevertheless, further research is required to determine an appropriate approach for more advanced stages (stage III).

Open-type cholesteatoma is the predictive factor for residual disease in congenital cholesteatoma treated with TEES

ObjectiveTo determine the predictive factors for residual disease occurring after surgical removal of congenital cholesteatomas and whether these predictive factors differ between microscopic ear surgery (MES) using data from the literature and transcanal endoscopic ear surgery (TEES) using data from our own institution. MethodsTwenty-three patients with a congenital cholesteatoma who underwent surgical treatment at Yamagata University Hospital between December 2011 and December 2017 were retrospectively investigated. We divide TEES into three different approaches: non-powered TEES, powered TEES and dual MES/TEES. Main outcome measures were Potsic stage, closed or open congenital cholesteatoma type, TEES surgical approach, appearance of residual disease, tympanoplasty type and hearing outcome. ResultsA logistic regression analysis was conducted on the Potsic stage, closed or open type, TEES surgical approach and age to obtain the odds ratio for residual disease. The chance of residual disease significantly increased in the presence of an open-type congenital cholesteatoma (odds ratio: 30.82; 95 % confidence interval: 1.456–652.3; p = 0.0277), but not for any of the other factors including Potsic stage. The timing of the confirmation of residual disease after ossicular chain reconstruction was analyzed using a Kaplan-Meier analysis. The residual disease rate was significantly higher with an open-type congenital cholesteatoma (log-rank test, p < 0.05). In addition, all residual disease occurred within three years after surgery. ConclusionsOur results showed that an open-type congenital cholesteatoma is the strongest predictive factor for residual disease when removing a congenital cholesteatoma by TEES.

Efficacy of Otoendoscopy for Residual Cholesteatoma Detection During Microscopic Chronic Ear Surgery.

The aim of this article is to determine the efficacy of otoendoscopy during microscopic cholesteatoma surgery on residual cholesteatoma rates postoperatively. The medical records of patients (aged 4-90) with primary acquired cholesteatoma who underwent microscopic cholesteatoma surgery (exclusively transcanal approach or canal wall-up tympano-mastoidectomy) with subsequent otoendoscopic examination (80 ears) for intraoperative cholesteatoma residues were retrospectively reviewed. All cases with mixed microscopic/endoscopic, fully endoscopic, or fully microscopic dissection were excluded, as well as cases where a canal wall-down technique was used. After microscopic cholesteatoma removal, the otoendoscope was used to inspect the middle ear recesses for intraoperative cholesteatoma residues. The intra- and postoperative cholesteatoma residue rate were evaluated. On endoscopic examination, intraoperative cholesteatoma residues were encountered in 24 patients (30%). A total of 30 foci were detected. Most of them were found in the superior retrotympanum (15 foci). In 9 cases an antral remnant guided the surgeon to convert to a canal wall up tympanomastoidectomy. During the postoperative follow-up period, residual cholesteatoma was detected on postoperative magnetic resonance imaging in 6 patients (7.5%). Adding an otoendoscopic examination to microscopic cholesteatoma surgery reduced the postoperative cholesteatoma residues rate (odds ratio=0.16). A negative otoendoscopic examination led to a cholesteatoma residue-free follow-up period in 95% of cases(NPV=0.95). Otoendoscopy is effective in identifying intraoperative cholesteatoma residues after microscopic cholesteatoma surgery. It reduces the postoperative cholesteatoma residue rate, and a negative otoendoscopic examination increases the likelihood of a cholesteatoma residue-free follow-up.

A Novel Way for Efficient and Safe Posterior Fossa Relaxation: The Extradural Opening of the Cisterna Magna in Retrosigmoid Craniotomy.

Cerebrospinal fluid drainage is a common practice to provide brain relaxation during intradural surgery. In retrosigmoid approaches, cerebrospinal fluid can be drained from the cisterna magna to provide brain relaxation in the posterior fossa. To our knowledge, most techniques to achieve cerebrospinal fluid release concern intradural opening of the cisterns. We describe a novel way for the extradural opening of the cisterna magna in retrosigmoid surgery that avoids direct cerebellar contact. Patients elected for surgical treatment of cerebellopontine angle tumors are positioned supine with a roll under the ipsilateral shoulder and the head turned to the contralateral side. After performing a retrosigmoid craniotomy, the surgical microscope is tilted, and the foramen magnum is approached extradurally. A horizontal dural slit is made at the level of the cisterna magna, and cerebrospinal fluid is drained without having direct cerebellar contact. After brain relaxation, the intradural surgery can proceed as usual. This slight adaptation for a very common practice avoids the need for direct cerebellar retraction when approaching the cisterna magna to drain cerebrospinal fluid. It is a clean and easy step to perform, that we believe improves surgical efficacy and could potentially diminish cerebellar harm because it obviates the need for intradural opening of the cisterna magna.

Advanced Visualization in Minimally Invasive Spine Surgery: The Ergonomics, Economics, and Evolution of Camera-Based Tubes and Retractors.

Tubular spine surgery has emerged as a hallmark of minimally invasive spine (MIS) procedures. In recent years, thanks to technological advances, tubular dilators and retractors have been integrated with digital cameras to allow for ergonomic, high-definition visualization of the surgical field. To detail the evolution, ergonomics, economics, and outcomes of camera-based tubular spine surgery, spanning the origins of MIS tubular techniques to the current use of operative microscopes and tube-mounted digital cameras (TMDCs). This is a narrative review of studies examining the evolution of tubular spine surgery as well as its most recent advances, with a particular emphasis on advances in visualization of the surgical field. Despite early resistance to tubular techniques due to a steep learning curve, minimally invasive tubular approaches are being increasingly adopted by the mainstream spine surgical community, which has resulted in an expansion of both indications and procedural modalities. This can largely be attributed to the increased quality of visualization, as evidenced by improvements in microscopes as well as emerging technologies like exoscopes and TMDCs. Tubular MIS procedures have also achieved superior efficacy compared with open surgical approaches for the treatment of several spinal pathologies while allowing for improved ergonomics, which may have lasting consequences on surgeon longevity. Advances in visualization technologies have allowed tubular surgery to become an effective, ergonomic, and muscle-sparing alternative to open spine surgery. Further research is necessary to quantify the true costs and outcomes associated with nascent TMDC technology. This work elucidates developments in visualization for tubular spine surgery.

Not Every Size Fits All: Surgical Corridors for Clival and Cervical Chordomas-A Systematic Review of the Literature and Illustrative Cases.

Introduction. Clival chordomas represent a rare but clinically significant subset of skull base tumors, characterized by a locally aggressive nature and a location in proximity to vital neurovascular structures. Surgical resection, often combined with adjuvant therapies, remains the cornerstone of clival chordoma treatment, and various approaches and techniques have evolved to maximize tumor removal while preserving neurological function. Recent advancements in skull base surgery, imaging, and adjuvant therapies have improved outcomes by reducing morbidity and thus enhancing long-term survival. Methods and Results. We have conducted a systematic review on PubMed/Medline following PRISMA guidelines regarding indications, the extent of resection (EOR), and complication rates. Then, we present three illustrative cases from our personal experience, which started 25 years ago with CVJ instrumentation procedures and 15 years ago with anterior decompressive transmucosal procedures performed with the aid of an operative microscope, an endoscope, and neuroradiological monitoring. Conclusions. Traditionally, the transoral approach (TOA) is the most frequently used corridor for accessing the lower clivus and the anterior craniovertebral junction (CVJ), without the need to mobilize or retract neural structures; however, it is associated with a high rate of complications. The endonasal approach (EEA) provides access to the anterior CVJ as well as to the lower, middle, and superior clivus, decreasing airway and swallowing morbidity, preserving palatal function, decreasing postoperative pain, and reducing the incidence of tracheostomy. The submandibular retropharyngeal approach (SRA) allows unique access to certain cervical chordomas, which is better suited when the lesion is located below the clivus and in the midline.

Exoscope and Supermicrosurgery: Pros and Cons of 3D Innovation in Lymphatic Surgery.

Background: The surgical treatment of lymphedema has seen advancements in recent years, with supramicrosurgical lymphaticovenular anastomosis (sLVA) gaining global acceptance. The integration of 3D exoscopes into microsurgery offers potential ergonomic and educational benefits. However, systematic evaluation of their efficacy in sLVA remains limited. Methods: A retrospective cross-sectional study was conducted comparing the use of 3D exoscopes to conventional operating microscopes (OM) in sLVA surgeries. Patient data from January 2019 to January 2024 were reviewed, with demographic, clinical, and surgical outcome variables analyzed. Ergonomic assessments were performed using Rapid Entire Body Assessment (REBA) and Rapid Upper Limb Assessment (RULA), while surgeon satisfaction was evaluated through the Microsurgical Intraoperative Satisfaction and Comfort questionnaire (MISCq). Results: An analysis of 25 patients (OM group: n = 14; exoscope group: n = 11) revealed no significant differences in age, sex, etiology, or surgical site between the two groups. Surgical time, number of incisions, and number of anastomoses showed nonsignificant variations between the OM and exoscope groups. Ergonomic assessments indicated potential benefits with exoscope use, particularly for the assistant surgeon. Survey results demonstrated comparable levels of surgeon satisfaction with both instruments, with no significant differences in image quality, contrast, illumination, magnification, visual field, ergonomic maintenance, or stereoscopic orientation. Conclusions: The study suggests that 3D exoscopes are a valuable tool for sLVA supermicrosurgery, offering comparable outcomes to traditional microscopes with potential ergonomic advantages. Their integration into microsurgical practice may contribute to improved surgical comfort and team performance. Further research is warranted to confirm these findings and explore additional factors such as cost-effectiveness and long-term patient outcomes.

Use of intraoperative microvascular Doppler during subinguinal microsurgical varicocelectomy in children reduces complications.

This study assessed the impact of intraoperative microvascular Doppler ultrasonography (MDU) during microsurgical subinguinal varicocele correction in children. Nineteen patients who underwent intraoperative MDU during subinguinal microsurgical varicocelectomy between 2021 and 2023 were included in this study. Each patient's age, varicocele side, clinical examination findings, preoperative ultrasonography results, intraoperative findings, spermatic artery counts and findings in terms of MDU use, postoperative complications, and results were evaluated. All varicoceles were on the left side and the average age of the patients was 15.2 years. The indications for varicocelectomy were testicular hypotrophy (n = 10) and scrotal pain or fullness (n = 9). When a surgical microscope was used, testicular artery pulsation was detected in only five patients, whereas it was detected in all cases when MDU was used. In 16 cases, a single testicular artery was identified, and two arteries were identified in three cases. Additionally, in a case where a spermatic vein was suspected, it was not ligated due to the detection of pulsation with an arterial pattern using MDU. Two to three lymphatic channels were isolated and preserved, an average of 7.5 vessels were ligated, and five external spermatic veins were identified and ligated. There were no complications, and six of the patients with testicular hypotrophy showed signs of the catch-up growth phenomenon. The use of MDU during subinguinal microsurgical varicocelectomy in children not only increases the success rate but also minimizes complications such as hydrocele and recurrence.

From microscope to head-mounted display: integrating hand tracking into microsurgical augmented reality.

The operating microscope plays a central role in middle and inner ear procedures that involve working within tightly confined spaces under limited exposure. Augmented reality (AR) may improve surgical guidance by combining preoperative computed tomography (CT) imaging that can provide precise anatomical information, with intraoperative microscope video feed. With current technology, the operator must manually interact with the AR interface using a computer. The latter poses a disruption in the surgical flow and is suboptimal for maintaining the sterility of the operating environment. The purpose of this study was to implement and evaluate free-hand interaction concepts leveraging hand tracking and gesture recognition as an attempt to reduce the disruption during surgery and improve human-computer interaction. An electromagnetically tracked surgical microscope was calibrated using a custom 3D printed calibration board. This allowed the augmentation of the microscope feed with segmented preoperative CT-derived virtual models. Ultraleap's Leap Motion Controller 2 was coupled to the microscope and used to implement hand-tracking capabilities. End-user feedback was gathered from a surgeon during development. Finally, users were asked to complete tasks that involved interacting with the virtual models, aligning them to physical targets, and adjusting the AR visualization. Following observations and user feedback, we upgraded the functionalities of the hand interaction system. User feedback showed the users' preference for the new interaction concepts that provided minimal disruption of the surgical workflow and more intuitive interaction with the virtual content. We integrated hand interaction concepts, typically used with head-mounted displays (HMDs), into a surgical stereo microscope system intended for AR in otologic microsurgery. The concepts presented in this study demonstrated a more favorable approach to human-computer interaction in a surgical context. They hold potential for a more efficient execution of surgical tasks under microscopic AR guidance.

Exoscope as a financially viable solution for micro neurosurgery in low-middle-income countries

Operating microscope is a backbone for the development of micro neurosurgery. In resource-limited setups and low-income countries, the volume of annual microsurgical procedures is low due to lack of the required equipment, one of which is the operating microscope. The price of currently available operating microscopes makes it difficult to address this issue in resource-constrained areas and low-income countries. Exoscope with a relatively lower price and the same even better imaging qualities can be used as an option for this problem.