Field of view comparison between two-dimensional and three-dimensional endoscopy

Trends in Endoscopic and Microscopic Approaches to Transsphenoidal Pituitary Surgery in the US

OBJECTIVES

Among the transsphenoidal (TSS) approaches to pituitary tumors, the microscopic approach (MA) has historically been the predominant technique with the increasing adoption of the endoscopic approach (EA). This study investigates national trends in TSS approaches and postoperative outcomes for MA and EA through 2021.

METHODS

The TriNetX database was queried for patients undergoing TSS (MA and EA) between 2010 and 2021. Data were collected on demographics, geographic distribution of surgical centers, postoperative complications, stereotactic radiosurgery (SRT), repeat surgery, and postoperative emergency department (ED) visits.

RESULTS

8644 TSS cases were queried between 2010 and 2021. MA rates were highest until 2013 when rates of EA (52%) surpassed MA (48%) and continued to increase through 2021 (81%). From 2010 to 2015 EA had higher odds of a postoperative CSF leak (OR 3.40) and diabetes insipidus (DI (OR 2.30)) versus MA (p < 0.05); from 2016 to 2021 differences were not significant. Although there was no significant difference among approaches from 2010 to 2015 for syndrome of inappropriate antidiuretic hormone (SIADH), hyponatremia, or bacterial meningitis, from 2016 to 2021 EA had lower odds of SIADH (OR 0.54) and hyponatremia (OR 0.71), and higher odds of meningitis (OR 1.79) versus MA (p < 0.05). EA had higher odds of additional surgery (either EA or MA) after initial surgery from 2010 to 2021. From 2010 to 2015 EA had lower odds of postoperative SRT compared to MA, whereas in 2016-2021 there was no statistical difference among approaches.

CONCLUSION

This study demonstrates increasing EA adoption for TSS in the United States since 2013. Complication rates have overall improved for EA compared to MA, potentially as a result of improving surgeon familiarity and experience.

LEVEL OF EVIDENCE

4 Laryngoscope, 133:2135-2140, 2023.

Does High-Definition 3-Dimensional Imaging Improve Orientation During Endoscopic Transsphenoidal Surgery? A Prospective Trial

BACKGROUND

Endoscopy has evolved as the standard visualization tool for endonasal transsphenoidal resection of sellar lesions. The most widely used 2-dimensional (2D) endoscopes harbor the problem of limited depth perception. Therefore, 3-dimensional (3D) endoscopes have been developed to enable depth perception through a stereoscopic view.

OBJECTIVE

To evaluate the impact of high-definition (HD) 2D vs 3D HD endoscopes on spatial orientation within the sphenoid sinus.

METHODS

In this prospective single-center study, 21 patients have been investigated (2021-2022). Eleven standardized anatomic landmarks, which were preoperatively defined on neuronavigation imaging, were intraoperatively targeted with a navigation probe using either 2D HD or 3D HD endoscopes for visualization.

RESULTS

Overall, 3D HD endoscopes provided a statistically significant higher accuracy of identification of sphenoid sinus landmarks (median deviation: 5.2 mm vs 4.2 mm, P < .001). In detail: tuberculum sellae (3.0 mm vs 4.3 mm, P = .047), most anterior point of sella (3.3 mm vs 4.8 mm, P = .049), and clivus indentation (3.8 mm vs 5.3 mm, P = .035). Anatomic variations such as a complex sphenoid sinus configuration had no influence on identifying sphenoid sinus landmarks.

CONCLUSION

According to our data, stereoscopic 3D HD endoscopy enhances intraoperative orientation by improved depth perception within the sphenoid sinus. This may add to the safety of endoscopic skull base procedures, especially in extended approaches and cases with distorted anatomy.

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.

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.

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.

Development of three-dimensional laryngostroboscopy for office-based laryngeal diagnostics and phonosurgical therapy

OBJECTIVE

To develop a three-dimensional (3D) laryngostroboscopic examination unit, compare the optic playback quality in relation to established 2D procedures, and report the first case series using 3D rigid laryngostroboscopy for diagnosis and management of laryngotracheal diseases.

STUDY DESIGN

Laboratory study, prospective case series.

METHODS

The optical efficacy of newly developed rigid 3D endoscopes was examined in a laboratory setting. Diagnostic suitability was investigated in 100 subjects (50 male, 50 female) receiving 2D high-definition (HD) and 3D laryngostroboscopy. Two of the subjects subsequently underwent 3D-assisted office-based transoral phonosurgery under local anesthesia. Main outcome measures were comparative visualization of laryngotracheal pathologies, influence on preoperative planning, and evaluation of prognostic factors for the outcome of phonosurgical interventions.

RESULTS

Three-dimensional endostroboscopic procedures were effectively optimized to establish an examination protocol for all-day clinical use. Office-based 3D laryngostroboscopy was successfully applied in subjects with normal anatomy (n = 10) and various laryngotracheal findings (n = 90). In comparison to 2D HD videolaryngostroboscopy, the 3D view offered enhanced visualization of laryngotracheal anatomy, with qualitatively improved depth perception and spatial representation. In organic pathologies, this resulted in a more precise indication of phonosurgical procedures, increased accuracy in surgical planning, facilitated office-based endoscopic surgery, and better evaluation of prognostic factors for the outcome of phonosurgical interventions.

CONCLUSION

Three-dimensional laryngostroboscopy proved to increase the understanding of functional and surgical anatomy. Its application has enormous potential for improving the diagnostic value of laryngoscopy, surgical precision in laryngotracheal interventions, tissue preservation, and methods of teaching.

LEVEL OF EVIDENCE

NA Laryngoscope, 128:2823-2831, 2018.

Endoscopic training-is the future three-dimensional?

Background/Objectives

Endoscopic surgery has a distinct disadvantage compared to direct vision: loss of binocular vision. Three-dimensional endoscopy has been welcomed due to the promise of improving stereopsis.

Methods

Prospective randomized study of junior doctors with minimal endoscopic experience, using both two-dimensional and three-dimensional, zero-degree, 4-mm Storz endoscopes. Data was collected using validated, standardized training models, both objectively and subjectively. Paired comparisons between variables relating to the endoscopes were performed using Wilcoxon's tests. Operators were then split into groups based on their endoscope preference, with comparisons made using Mann-Whitney tests for Likert scale responses, Kendall's tau for ordinal variables, and Fisher's exact tests for nominal variables.

Results

Reduction of field of vision of three-dimensional endoscopy by 2%. Significant findings included decreased past-pointing, improved depth and perception and image quality.

Conclusion

The use of an endoscopic endonasal approach with three-dimensional technology has measurable advantages for novice users, and highlights potential tailoring of future surgical training.

Level of Evidence

1b.

Enhanced visualization of the surgical field in pediatric direct laryngoscopy using a three-dimensional endoscopic system

BACKGROUND

Direct laryngoscopy and rigid bronchoscopy are currently performed using 2-dimensional endoscopic systems. Our objective was to determine whether a 3-dimensional endoscopic system can enhance visualization of the surgical field in pediatric direct laryngoscopy and rigid bronchoscopy.

METHODS

A prospective cohort study was conducted. Thirty three children who underwent direct laryngoscopies in a tertiary referral children's hospital were enrolled. Direct laryngoscopy was performed using both 2- and 3-dimensional endoscopic systems, after which the surgeons scored the quality of the images obtained with each system on a scale from 1 (low) to 5 (high). Comparison of the scores obtained with the 2 endoscopic systems was performed.

RESULTS

The 33 study children (mean age 2.3 years, M:F ratio 1:1.6) underwent 47 direct laryngoscopies. The mean score for visualization of the glottis was 4.8 for the three-dimensional system compared to 4.0 for the two-dimensional system (P = .025), 4.7 vs. 3.8, respectively, (P = .019) for the subglottis, and 4.6 vs. 3.9, respectively (P = .031) for visualization of the proximal trachea. The mean score for visualization of the distal trachea was 3.0 vs. 3.7, respectively (P = .020). In a child with recurrent type 3 laryngotracheal cleft a residual tracheo-esophageal fistula could not be detected using the 2D system, but was immediately detected using the 3D system.

CONCLUSIONS

Visualization of the glottis, subglottis and proximal trachea during direct laryngoscopy using a 3-dimensional endoscopic system was rated by the surgeons as being superior to the conventional 2-dimensional technique. Further outcome studies that will demonstrate the clinical advantage of the 3D technology are highly required.

LEVEL OF EVIDENCE

2b.

Endoscopic Endonasal Surgery for Removal of Pituitary Adenomas: A Surgical Case Series of Treatment Results Using Different 2- and 3-Dimensional Visualization Systems

BACKGROUND

Endoscopic endonasal transsphenoidal surgery (EETS) is a common treatment for patients with pituitary adenomas (PAs). A disadvantage of endoscopic surgery has been the lack of stereoscopic vision and depth perception. Recent developments offer high-definition 3-dimensional (3D-HD) visualization with a higher resolution and better image quality compared with 3D standard endoscopy (3D-SD). In this study, we compared treatment results of surgically treated patients with PAs using 3 different visualization systems: 2-dimensional (2D)-HD, 3D-SD, and 3D-HD.

METHODS

Data from patients with primary PAs that were surgically treated between December 2008 and December 2017 were analyzed. Preoperative and postoperative tumor size and location, perioperative complications, and ophthalmologic, endocrine, and clinical outcomes were compared.

RESULTS

A total of 170 patients underwent endoscopic resection of a primary PA (54 patients with 2D-HD, 75 with 3D-SD, and 41 with 3D-HD). Preoperatively, no statistical differences were found for tumor size, extension, and endocrine and ophthalmologic status. Tumor resection was not statistically different among the 3 groups. Complete resection was performed in 33 patients (80%) in the 3D-HD group, 54 patients (72%) in the 3D-SD group, and 39 patients (72%) in the 2D-HD group. The number of complications was not different across the groups (P = 0.436). Ophthalmologic outcomes did not differ based on EETS technique. The rate of new pituitary insufficiency was slightly lower in the 3D-HD group compared with 2D-HD and 3D-SD groups (4.8%, 16.6%, and 12%, respectively; P = 0.290).

CONCLUSIONS

Although the resection rate was higher in the 3D-HD group, and subjective advantages of the 3D-HD endoscopes were noted, there were no significant differences in terms of gross total resection or new hormonal deficits among the 3 groups.

Endoscope field of view measurement

The current International Organization for Standardization (ISO) standard (ISO 8600-3: 1997 including Amendment 1: 2003) for determining endoscope field of view (FOV) does not accurately characterize some novel endoscopic technologies such as endoscopes with a close focus distance and capsule endoscopes. We evaluated the endoscope FOV measurement method (the FOV_WS method) in the current ISO 8600-3 standard and proposed a new method (the FOV_EP method). We compared the two methods by measuring the FOV of 18 models of endoscopes (one device for each model) from seven key international manufacturers. We also estimated the device to device variation of two models of colonoscopes by measuring several hundreds of devices. Our results showed that the FOV_EP method was more accurate than the FOV_WS method, and could be used for all endoscopes. We also found that the labelled FOV values of many commercial endoscopes are significantly overstated. Our study can help endoscope users understand endoscope FOV and identify a proper method for FOV measurement. This paper can be used as a reference to revise the current endoscope FOV measurement standard.

Comprehensive review on endonasal endoscopic sinus surgery

Endonasal endoscopic sinus surgery is the standard procedure for surgery of most paranasal sinus diseases. Appropriate frame conditions provided, the respective procedures are safe and successful. These prerequisites encompass appropriate technical equipment, anatomical oriented surgical technique, proper patient selection, and individually adapted extent of surgery. The range of endonasal sinus operations has dramatically increased during the last 20 years and reaches from partial uncinectomy to pansinus surgery with extended surgery of the frontal (Draf type III), maxillary (grade 3-4, medial maxillectomy, prelacrimal approach) and sphenoid sinus. In addition there are operations outside and beyond the paranasal sinuses. The development of surgical technique is still constantly evolving. This article gives a comprehensive review on the most recent state of the art in endoscopic sinus surgery according to the literature with the following aspects: principles and fundamentals, surgical techniques, indications, outcome, postoperative care, nasal packing and stents, technical equipment.