Two-Dimensional High Definition Versus Three-Dimensional Endoscopy in Endonasal Skull Base Surgery: A Comparative Preclinical Study

Safety and efficacy of three-dimensional versus two-dimensional endoscopy in otolaryngology surgery and training: A systematic review

OBJECTIVE

Three-dimensional (3D) endoscopy has been developed to provide depth perception to allow for improved visualisation during otolaryngology surgery. We conducted a systematic review to determine the surgical safety and efficacy of 3D endoscopy in comparison to two-dimensional (2D) endoscopy in performing otolaryngology procedures, and the role of 3D endoscopy as a training tool for novice otolaryngology surgeons.

METHODS

Primary studies were identified through MEDLINE, Embase and Web of Science databases, which were searched for articles published through June 2022 that compared the outcomes of 2D and 3D endoscopy in otolaryngology surgical procedures or otolaryngology-relevant simulations. Candidate articles were independently reviewed by two authors.

RESULTS

A total of 18 full-text articles met inclusion criteria for this study. In clinical trials (n = 8 studies, 362 subjects), there were no significant differences in performance time, intraoperative or postoperative complications with 3D endoscopes when compared to 2D. In simulation studies (n = 10 studies, 336 participants), 3D endoscopes demonstrated a decreased error rate (n = 5 studies) and shorter performance time (n = 3 studies). Studies also reported improved depth perception (n = 14 studies) and visualisation preference (n = 5 studies) with 3D over 2D systems. The 3D systems were found to have a shorter learning curve and better manoeuvrability among novice surgeons.

CONCLUSION

3D endoscopy showed equivalent safety and efficacy compared to 2D endoscopy in otolaryngology surgery. The improved depth perception and performance for novices using 3D endoscopes suggests the technology may be superior to 2D endoscopes as a training tool for otolaryngology surgeons.

Two- and three-dimensional endoscopic endonasal surgery of large and giant pituitary adenomas-outcome analysis of a series of 62 patients from a single pituitary center

To analyze the perioperative course and clinical outcome of patients with large (lPA) and giant (gPA) pituitary adenoma who underwent endoscopic endonasal transsphenoidal surgery (EETS) using either two-dimensional (2D-E) or three-dimensional (3D-E) endoscopic systems. Single-center retrospective study of consecutive patients with lPA and gPA who underwent EETS between November 2008 and January 2023. LPA were defined as ≥ 3 cm and < 4 cm in diameter in at least one dimension and a volume of ≥ 10ccm; gPA were defined as larger than 4 cm in diameter and with a greater volume than 10ccm. Patient data (age, sex, endocrinological and ophthalmological status) and tumor data (histology, tumor volume, size, shape, cavernous sinus invasion according to the Knosp classification) were analyzed. 62 patients underwent EETS. 43 patients were treated for lPA (69.4%) and 19 patients for gPA (30.6%). 46 patients (74.2%) underwent surgical resection using 3D-E and 16 patients 2D endoscopy (25.8%). Statistical results are referred to the comparison between 3D-E and 2D-E. Patients' age ranged from 23-88 years (median 57), 16 patients were female (25.8%), 46 male (74.2%). Complete tumor resection was possible in 43.5% (27/62), partial resection in 56.5% (35/62). Resection rates did not differ between 3D-E (27 patients [43.5%]) and 2D-E (7 patients [43.8%], (p = 0.985). Visual acuity improved in 30 of 46 patients with preoperative deficit (65.2%). In the 3D-E group 21 of 32 patients (65.7%) improved, compared to 9 of 14 patients in the 2D-E group (64.3%). Improvement of visual field was achieved in 31 of 50 patients (62.0%; 22 of 37 patients in the 3D-E group [59.4%] and 9 of 13 patients in the 2D-E group [69.2%]). CSF leak was the most frequent complication and occurred in 9 patients (14.5%, [8 patients 17.4% 3D-E]) without statistical significance. Other surgical complications like postoperative bleeding, infection (meningitis) and deterioration of visual acuity and field were detected without statistical difference. New pituitary anterior lobe dysfunction was observed in 30 of 62 patients (48.4%, 8 patients [50.0%] in the 2D-E group and 22 patients [47.8%] in the 3D-E group). A transient deficit of posterior lobe was detected in 22.6% (14/62). No patient died within 30 days of surgery. Although 3D-E may improve surgical dexterity, in this series of lPA and gPA it was not associated with higher resection rates compared to 2D-E. However, 3D-E visualization during resection of large and giant PA is safe and feasible and patient's clinical outcome is not different compared to 2D-E.

Three-dimensional versus two-dimensional endoscopes in anatomical orientation of the middle ear and in simulated surgical tasks

Background

Three-dimensional endoscopes provide a stereoscopic view of the operating field, facilitating depth perception compared to two-dimensional systems, but are not yet widely accepted. Existing research addresses performance and preference, but there are no studies that quantify anatomical orientation in endoscopic ear surgery.

Methods

Participants (n = 70) were randomised in starting with either the two-dimensional or three-dimensional endoscope system to perform one of two tasks: anatomical orientation using a labelled three-dimensional printed silicone model of the middle ear, or simulated endoscopic skills. Scores and time to task completion were recorded, as well as self-reported difficulty, confidence and preference.

Results

Novice surgeons scored significantly higher in a test of anatomical orientation using three-dimensional compared to two-dimensional endoscopy (p < 0.001), with no significant difference in the speed of simulated endoscopic skills task completion. For both tasks, there was lower self-reported difficulty and increased confidence when using the three-dimensional endoscope. Participants preferred three-dimensional over two-dimensional endoscopy for both tasks.

Conclusion

The findings demonstrate the superiority of three-dimensional endoscopy in anatomical orientation, specific to endoscopic ear surgery, with statistically indistinguishable performance in a skills task using a simulated trainer.

Three-Dimensional Endoscopic Endonasal Surgery: A Systematic Review

OBJECTIVES

To compare participant performance and preference in the use of three-dimensional (3D) endoscopy compared to traditional two-dimensional (2D) endoscopy.

METHODS

PubMed, Embase, Medline, ClinicalKey, BMJ Case Reports, and the Cochrane library were systematically searched for English-language articles published between 2005 and 2020. Studies reporting comparisons of outcomes between 3D and 2D endoscopes were identified. Data relating to performance-related outcomes, as well as the participants' preferred endoscope were extracted, and pooled using meta-analysis models.

RESULTS

Ten studies were included in the qualitative synthesis. Six studies reported results of participants completing simulated tasks with endoscopes, while four reported full procedures. Peg transfer tasks (n = 4 cohorts) were found to be completed significantly faster with the 3D versus 2D endoscope (pooled mean difference 6.8 seconds, 95% confidence interval [CI]: 2.3-11.3), while no significant difference in times taken was observed for touch tasks (n = 4; pooled mean difference 3.7 seconds, 95% CI: -1.9 to 9.2). The secondary outcome of participant preference was reported by five studies, in which a significant preference for the 3D endoscope was observed (P = .010), with a pooled total of 72% (95% CI: 59-83) of participants preferring this to the 2D endoscope.

CONCLUSIONS

There is a growing body of evidence in support of 3D visualization in endoscopy. We have demonstrated 3D endoscopy to be associated with a significantly shorter time to performing simulated, reproducible and controlled tasks, and to be the preference of participants. This study provides grounds for further evaluation of the technology, and the potential for a greater widespread use. Laryngoscope, 2021.

Integration of Comprehensive Metrics into the PsT1 Neuroendoscopic Training System

OBJECTIVE

Metric-based surgical training can be used to quantify the level and progression of neurosurgical performance to optimize and monitor training progress. Here we applied innovative metrics to a physical neurosurgery trainer to explore whether these metrics differentiate between different levels of experience across different tasks.

METHODS

Twenty-four participants (9 experts, 15 novices) performed 4 tasks (dissection, spatial adaptation, depth adaptation, and the A-B-A task) using the PsT1 training system. Four performance metrics (collision, precision, dissected area, and time) and 6 kinematic metrics (dispersion, path length, depth perception, velocity, acceleration, and motion smoothness) were collected.

RESULTS

For all tasks, the execution time (t) of the experts was significantly lower than that of novices (P < 0.05). The experts performed significantly better in all but 2 of the other metrics, dispersion and sectional area, corresponding to the A-B-A task and dissection task, respectively, for which they showed a nonsignificant trend towards better performance (P = 0.052 and P = 0.076, respectively).

CONCLUSIONS

It is possible to differentiate between the skill levels of novices and experts according to parameters derived from the PsT1 platform, paving the way for the quantitative assessment of training progress using this system. During the current coronavirus disease 2019 pandemic, neurosurgical simulators that gather surgical performance metrics offer a solution to the educational needs of residents.

Comparison of two- and three-dimensional endoscopic visualization for fetal myelomeningocele repair: a pilot study using a fetoscopic surgical simulator

INTRODUCTION

The objective of this study was to evaluate the utility of three-dimensional (3D) versus conventional two-dimensional (2D) endoscopy for fetal myelomeningocele repair using a low-fidelity fetoscopic surgical simulator.

METHODS

A low-fidelity fetoscopic box trainer was developed for surgical simulation of myelomeningocele repair. Participants with varying surgical experience were recruited and completed three essential tasks (cutting skin, dural patch placement, and suturing skin) using both 2D and 3D endoscopic visualization. Participants were randomized to begin all tasks in either 2D or 3D. Time to completion was measured for each task, and each participant subsequently completed the NASA Load Index test and a questionnaire evaluating their experience.

RESULTS

Sixteen participants completed the study tasks using both 2D and 3D endoscopes in the simulator. While the mean performance time across all tasks was shorter with 3D versus 2D endoscopy (cutting skin, 47 vs. 54 seconds; dural patch placement, 38 vs. 52 seconds; and suturing skin, 424 vs. 499 seconds), the results did not reach statistical significance. When comparing times to completion of each of the three tasks between levels of expertise, participants in the expert category were faster when suturing skin on the 2D modality (P = 0.047). Under 3D visualization, experts were faster at cutting the skin (P = 0.008). When comparing experiences using the NASA-TLX test, participants felt that their performance was better using 3D over the 2D system (P = 0.045). Overall, 13 of 16 (81.3%) participants preferred 3D over 2D visualization.

CONCLUSIONS

Three-dimensional endoscopes could potentially be used in the near future for relative improvement in visualization and possibly performance during complex fetoscopic procedures such as prenatal repair of myelomeningocele defects. Further studies utilizing 3D scopes for other related procedures may potentially support clinical implementation of this technology in fetal surgery and also prove to be a useful tool in surgical training.

Updates in techniques for improved visualization in sinus surgery

PURPOSE OF REVIEW

Adequate visualization during endoscopic sinus surgery (ESS) is one of the most critical aspects of performing well tolerated and successful surgery. The topic of visualization encompasses a broad spectrum of preoperative and intraoperative manoeuvres the surgeon can perform that aid in the understanding of the patient's anatomy and in the delivery of efficient surgical care.

RECENT FINDINGS

Preoperative considerations to improve visualization include optimization of haemostasis through management of comorbidities (e.g. hypertension, coagulopathies), medication management (e.g. blood thinners) and systemic versus topical corticosteroids. New technologies allow preoperative visual mapping of surgical plans. Advances in knowledge of intraoperative anaesthesia have encouraged a move toward noninhaled anaesthetics to reduce bleeding. High definition cameras, angled endoscopes, 3D endoscopes and more recently augmented reality, image-guided surgery, and robotic surgery, represent the state of the art for high-quality visualization. Topical interventions, such as epinephrine, tranexamic acid and warm isotonic saline, can help to reduce bleeding and improve the operative field. Surgical manoeuvres, such as polyp debulking, septoplasty, carefully controlled tissue manipulation and a consistent repeatable approach remain fundamental to appropriate intraoperative surgical visualization.

SUMMARY

This chapter delineates medical, technical and technological means - preoperatively and intraoperatively - to achieve optimized visualization of the surgical field in ESS.

Three-Dimensional versus 2-Dimensional Endoscopic Third Ventriculostomy: Surgical Results of a Preliminary Comparative Study

BACKGROUND

Three-dimensional (3-D) endoscopes have been widely used for a large variety of approaches in neurosurgical practice. However, in the last decade, 3-D scopes were barely used for ventricular surgery. In this study, we illustrated our preliminary experience with a 3-D endoscope for third ventriculostomy using new dedicated endoscopic equipment.

METHODS

Over a 12-month period, a high-definition 3-D endoscopic third ventriculostomy (ETV) was performed in 14 patients with obstructive hydrocephalus. Patients were followed prospectively and compared retrospectively with a matched group of 16 similar patients who underwent ETV with a standard 2-dimensional (2-D) endoscope. Surgical outcome and intra- and postoperative course were retrospectively reviewed.

RESULTS

3-D ETV provided excellent surgical results, and no significant difference was shown in terms of outcome, complication, and length of hospitalization between the 2 groups. Moreover, operative time (minutes) was significantly shorter in the 3-D group than the 2-D ETV group (19.9 ± 4.8 vs. 22.9 ± 1.4, respectively; P < 0.05), and the use of the 3-D endoscope provided subjective improvements of depth perception, hand-eye coordination, and surgeon comfort.

CONCLUSIONS

Our preliminary study clearly demonstrated the effectiveness of 3-D ETV and provided a significant reduction of operative time. Depth information from the 3-D scope appears to facilitate rapid and stable ETV maneuvers, representing a critical development that may become a valuable tool for neuroendoscopy.

A Review of Physical Simulators for Neuroendoscopy Skills Training

BACKGROUND

Minimally invasive neurosurgical approaches reduce patient morbidity by providing the surgeon with better visualization and access to complex lesions, with minimal disruption to normal anatomy. The use of rigid or flexible neuroendoscopes, supplemented with a conventional stereoscopic operating microscope, has been integral to the adoption of these techniques. Neurosurgeons commonly use neuroendoscopes to perform the ventricular and endonasal approaches. It is challenging to learn neuroendoscopy skills from the existing apprenticeship model of surgical education. The training methods, which use simulation-based systems, have achieved wide acceptance. Physical simulators provide anatomic orientation and hands-on experience with repeatability. Our aim is to review the existing physical simulators on the basis of the skills training of neuroendoscopic procedures.

METHODS

We searched Scopus, Google Scholar, PubMed, IEEE Xplore, and dblp. We used the following keywords "neuroendoscopy," "training," "simulators," "physical," and "skills evaluation." A total of 351 articles were screened based on development methods, evaluation criteria, and validation studies on physical simulators for skills training in neuroendoscopy.

RESULTS

The screening of the articles resulted in classifying the physical training methods developed for neuroendoscopy surgical skills into synthetic simulators and box trainers. The existing simulators were compared based on their design, fidelity, trainee evaluation methods, and validation studies.

CONCLUSIONS

The state of simulation systems demands collaborative initiatives among translational research institutes. They need improved fidelity and validation studies for inclusion in the surgical educational curriculum. Learning should be imparted in stages with standardization of performance metrics for skills evaluation.

The effect of three-dimensional visualisation on performance in endoscopic sinus surgery: A clinical training study using surgical navigation for movement analysis in a randomised crossover design

OBJECTIVES

Endoscopic imaging techniques and endoscopic endonasal surgery (EES) expertise have evolved rapidly. Only few studies have assessed the effect of three-dimensional (3D) endoscopy on endoscopic sinus surgery (ESS). The present study aimed to objectively and subjectively assess the additional value of 3D high-definition (HD) endoscopy in ESS.

DESIGN

A randomized crossover study of endoscopic surgery performance, using five ESS tasks of varying complexity, performed on Thiel embalmed human specimens.

SETTING

Simulated surgical environment.

PARTICIPANTS

Thirty participants, inexperienced in ESS.

MAIN OUTCOME MEASURES

Performance was assessed using video imaging, surgical navigation and questionnaires. Main outcome measures were as follows: efficiency (defined by time to task completion), distance covered inside the nose, average velocity towards target, accuracy (measured by error rate), and subjective assessment of endoscope characteristics.

RESULTS

During ESS tasks, both efficiency and accuracy did not differ significantly between 2D HD and 3D HD endoscopy. Subjectively, imaging characteristics of the 3D HD endoscope were rated significantly better.

CONCLUSIONS

ESS performance of inexperienced participants was not significantly improved by the use of 3D HD endoscopy during ESS tasks, although imaging characteristics of the 3D HD endoscope were rated significantly better. Surgical field characteristics and surgical techniques are likely to influence any additional value of 3D HD endoscopy.

Hybrid Robotics for Endoscopic Skull Base Surgery: Preclinical Evaluation and Surgeon First Impression

BACKGROUND

A robotic endoscope holder should theoretically provide various advantages in transnasal endoscopic skull base surgery, but only recently has a robotic system become commercially available. The objective of this study was to provide a preclinical evaluation of potential advantages and surgeon first impression of this robotic hybrid solution.

METHODS

Thirty skull base surgeons, attending the Joint European Diploma of Endoscopic Skull Base Surgery 2018-2019 in Paris, France, were enrolled. A questionnaire, mainly concerning personal surgical experience and habits, was administered. The test phase consisted of 2 different dry-lab tasks, performed with and without EndoscopeRobot, according to randomization and on 2 different days. A modified NASA Task Load Index test was subsequently administered via e-mail to all participants. Completion times and modified Global Evaluative Assessment of Robotic Skills in Endoscopy scores of the videotaped tasks were recorded.

RESULTS

Nineteen otorhinolaryngologic surgeons and 11 neurosurgeons, with different surgical habits and endoscopic experience, were enrolled. No one appeared unfavorable a priori to robotic endoscopic surgery. Although the robot did not provide an advantage in the simple grasping task 1, a trend toward better completion times and efficacy was evident in the bimanual task 2, when performed with the robot and bimanually. According to the modified NASA Task Load Index test, surgeons felt more successful with the robot in task 2, finding it less stressful and mentally demanding.

CONCLUSIONS

Endoscopic skull base surgeons seem to view a hybrid robotic solution positively. EndoscopeRobot seems to provide a benefit to the single surgeon with experience in bimanual endoscopic surgery. Further preclinical and clinical evaluation of this technology is necessary.

Comparison of 3- vs 2-Dimensional Endoscopy Using Eye Tracking and Assessment of Cognitive Load Among Surgeons Performing Endoscopic Ear Surgery

Importance

Endoscopic ear surgery (EES) is an emerging technique to treat middle ear diseases; however, the interventions are performed in 2-dimensional (2D) endoscopic views, which do not provide depth perception. Recent technical developments now allow the application of 3-dimensional (3D) endoscopy in EES.

Objective

To investigate the usability, advantages, and disadvantages of 3D vs 2D endoscopy in EES under standardized conditions.

Design, Setting, and Participants

This cohort study conducted at a tertiary academic medical center in Bern, Switzerland, included 16 residents and consultants of the Department of Otorhinolaryngology, Head & Neck Surgery, Inselspital, Bern.

Interventions

Each participant performed selected steps of a type I tympanoplasty and stapedotomy in 3D and 2D views in a cadaveric model using a randomized, Latin-square crossover design.

Main Outcomes and Measures

Time taken to perform the EES, number of attempts, and accidental damage during the dissections were compared between 3D and 2D endoscopy. Eye tracking was performed throughout the interventions. Cognitive load and subjective feedback were measured by standardized questionnaires.

Results

Of the 16 surgeons included in the study (11 inexperienced residents; 5 experienced consultants), 8 were women (50%); mean age was 36 years (range, 27-57 years). Assessment of surgical time revealed similar operating times for both techniques (181 seconds in 2D vs 174 seconds in 3D). A total of 64 surgical interventions were performed. Most surgeons preferred the 3D technique (10 for 3D vs 6 for 2D), even though a higher incidence of eye strain, measured on a 7-point Likert scale, was observed (3D, 2.19 points vs 2D, 1.44 points; mean difference , 0.74; 95% CI, 0.29-1.20; r = 0.67). Eye movement assessment revealed a higher duration of fixation for consultants in 2D (0.79 seconds) compared with 3D endoscopy (0.54 seconds), indicating a less-efficient application of previously acquired experiences using the new technique. Residents (mean [SD], 49.02 [16.4]) had a significantly higher workload than consultants (mean [SD], 27.21 [12.20]), independent of the used technique or task.

Conclusions and Relevance

Three-dimensional endoscopy is suitable for EES, especially for inexperienced surgeons whose mental model of the intervention has yet to be consolidated. The application of 3D endoscopy in clinical routines and for educational purposes may be feasible and beneficial.

Assessment of Middle Ear Anatomy Teaching Methodologies Using Microscopy versus Endoscopy: A Randomized Comparative Study

Teaching methodologies for the anatomy of the middle ear have not been investigated greatly due to the middle ear's highly complex structure and hidden location inside of the temporal bone. The aim of this randomized study was to quantitatively compare the suitability of using microscope- and endoscope-based methods for teaching the anatomy of the middle ear. We hypothesize that the endoscopic approach will be more efficient compared to the microscopic approach. To answer the study questions, 33 sixth-year medical students, residents and otorhinolaryngology specialists were randomized either into the endoscopy or the microscopy group. Their anatomical knowledge was assessed using a structured anatomical knowledge test before and after each session. Each participant received tutoring on a human cadaveric specimen using one of the two methods. They then performed a hands-on dissection. After 2-4 weeks, the same educational curriculum was repeated using the other technique. The mean gains in anatomical knowledge for the specialists, residents, and medical students were +19.0%, +34.6%, and +23.4%, respectively. Multivariate analyses identified a statistically significant increase in performance for the endoscopic method compared to the microscopic technique (P < 0.001). For the recall of anatomical structures during dissection, the endoscopic method outperformed the microscopic technique independently of the randomization or the prior training level of the attendees (P < 0.001). In conclusion, the endoscopic approach to middle ear anatomy education is associated to an improved gain in knowledge as compared to the microscopic approach. The participants subjectively preferred the endoscope for educational purposes.

Breadth and Depth: Three-Dimensional Endoscopic Field of View: Two-Dimensional Versus Three-Dimensional Endoscopic Field of View

BACKGROUND

Three-dimensional (3D) endoscopy is an emerging tool in ear-nose-throat (ENT) and skull base surgery with the benefit of providing real-time depth perception. Several investigators have reported that the field of view (FOV) is reduced in 3D endoscopes compared with regular 2-dimensional (2D) endoscopes. Thus, we objectively compared the FOV of 2D and 3D endoscopes.

METHODS

Using a standard 2D and 2 different 3D ENT endoscopes, images were captured of 1-mm graph paper from a set distance of 6 cm. The FOV was calculated from these images and compared among the endoscopes.

RESULTS

The VisionSense 3D endoscope had a slightly smaller FOV (9.1 cm vs. 10.1 cm; -9.9%), and the Karl Storz 3D endoscope showed a slightly larger FOV (10.4 cm vs. 10.1 cm; +3.0%). However, the results were complicated by the different-shaped images produced by the 3D endoscopes.

CONCLUSION

The differences in the FOV between the 2D and 3D endoscopes used in ENT surgery were not clinically significant. Thus, the FOV should not be considered a limitation of 3D technology.

The Superior Hypophyseal Arteries: Anatomical Study with an Endoscopic Endonasal Perspective

BACKGROUND

The use of high-definition endoscopes in extended transsphenoidal approaches to the suprasellar area has significantly improved visualization of its vascularization.

OBJECTIVE

To systematically examine the superior hypophyseal arteries (SHAs) anatomy from an endonasal endoscopic perspective.

METHODS

The endoscopic endonasal transsphenoidal trans-tuberculum approach was performed in 19 adult, fresh and latex injected specimens. Dissections recordings were reviewed to analyze SHAs type, number, and branches, as well as internal carotid arteries (ICA) branches that vascularized optic nerves and chiasm.

RESULTS

Identification of SHAs was possible in all specimens (37/38 sides). The number of SHAs varied from 1 to 3 per side (mean: 1.7). The anterior superior hypophyseal artery was visible in almost all cases (35/37 sides) and originated at the level of the carotid cave in 18/35 specimens; number of branches ranged from 1 to 6 (mean: 3.5), directed to the optic nerve (86%), chiasm (57%), infundibulum (86%), and/or parallel to the pituitary stalk (74%). The 4 main branches and patterns, originally described by McConnell in 1953, were confirmed. The posterior superior hypophyseal artery was evident in 28/37 sides with number of branches ranging from 0 to 4 (mean: 2.1), directed to the optic chiasm (50%), optic tract (32%), infundibulum (79%), and/or pituitary stalk (36%). The surgical implications of this study, together with anatomical and clinical videos, are also briefly discussed.

CONCLUSION

SHAs constitute a complex of anterior and posterior branches that stem from the medial ICA with different patterns, vascularizing the optic apparatus and pituitary stalk.

Three-dimensional endoscopy: The future of nasoendoscopic training

OBJECTIVES/HYPOTHESIS

Three-dimensional (3D) endoscopy is an emerging tool in surgery that provides real-time depth perception. Its benefits have been investigated in surgical training, but the current literature lacks significant objective outcome data. We aimed to objectively compare the efficacy of two-dimensional (2D) versus 3D high-definition endoscopes in novice users.

STUDY DESIGN

Prospective, randomized crossover study.

METHODS

Ninety-two novice medical students who used both 2D and 3D endoscopes to complete two validated tasks in a box trainer participated in the study. Time taken and error rates were measured, and subjective data were collected.

RESULTS

Wilcoxon tests showed 3D technology was significantly faster than 2D (78 vs. 95 seconds, P = .004), and errors per task were significantly lower (3 vs. 5, P < .001). Sixty-nine percent of participants preferred the 3D endoscope.

CONCLUSIONS

3D high-definition endoscopy could be instrumental in training the next generation of endoscopic surgeons. Further research is required in a clinical setting.

LEVEL OF EVIDENCE

2b Laryngoscope, 129:1280-1285, 2019.

Outcome of endoscopic vs microsurgical transsphenoidal resection for Cushing's disease

INTRODUCTION

It is unclear whether the proportions of remission and the recurrence rates differ between endoscopic transsphenoidal surgery (TS) and microscopic TS in Cushing's disease (CD); thus, we conducted a systematic review and meta-analysis to evaluate studies of endoscopic TS and microscopic TS.

METHODS

We conducted a comprehensive search of PubMed to identify relevant studies. Remission and recurrence were used as outcome measures following surgical treatment of CD.

RESULTS

A total of 24 cohort studies involving 1670 adult patients were included in the comparison. Among these studies, 702 patients across 9 studies underwent endoscopic TS, and 968 patients across 15 studies underwent microscopic TS. Similar baseline characteristics were observed in both groups. There was no significant difference in remission between the two groups: 79.7% (95% CI: 73.1-85.0%) in the endoscopic group and 76.9% (95% CI: 71.3-81.6%) in the microscopic group (P = 0.485). It appears that patients who underwent endoscopic surgery experience recurrence less often than patients who underwent microscopic surgery, with recurrence proportions of 11.0% and 15.9%, respectively (P = 0.134). However, if follow-up time is taken into account, both groups had a recurrence rate of approximately 4% per person per year (95% CI: 3.1-5.4% and 3.6-5.1%, P = 0.651).

CONCLUSIONS

We found that remission proportion and recurrence rate were the same in patients who underwent endoscopic TS as in patients who underwent microscopic TS. The definition of diagnosis, remission and recurrence should always be considered in the studies assessing therapeutic efficacy in CD.