Comparison of learning curves and skill transfer between classical and robotic laparoscopy according to the viewing conditions: implications for training

Augmented-reality-assisted intraoral scanning: A proof-of-concept study

PURPOSE

The aims of the present study were (a) to compare the scanning time and image count to complete optical scans of a typodont between augmented-reality-assisted intraoral scanning (ARIOS) and intraoral scanning (IOS); (b) to compare the accuracy of the digital casts derived from ARIOS and IOS; (c) to compare participant-related outcomes between ARIOS and IOS.

MATERIALS AND METHODS

A multi-session within-subject experiment was conducted to compare ARIOS and IOS. Thirty-one dental students participated in the study. Following a trial session, each participant obtained optical scans under ARIOS and IOS conditions. The time required to complete the scan, and the number of images taken were recorded. Participant feedback was collected using entry, exit, and NASA-Task Load Index (TLX) surveys. The accuracy of the digital casts derived from the optical scans was measured in root mean square error (RMSE).

RESULTS

The present study found a 6.8% increase in preference for ARIOS from entry to exit survey. Slightly more participants favored the ARIOS setup compared to IOS; 54.8% of participants favored ARIOS, 9.7% were indifferent, and 35.5% favored IOS. NASA-TLX subscale ratings were higher for IOS in general apart from mental demand. The accuracy of the digital casts between ARIOS and IOS was comparable in RMSE.

CONCLUSION

ARIOS was advantageous compared to IOS in ergonomics, improved scanner tracking, and ease of scanner orientation. However additional trials, increased field of view, and better superimposition of scanning status to the target site were improvements desired by the study participants.

The first robotic-assisted hysterectomy below the bikini line with the Dexter robotic system™

Background

Robotic-assisted hysterectomy (RAH) is a widely accepted minimally invasive approach for uterus removal. However, as RAH is typically performed in the umbilical region, it usually results in scars in cosmetically suboptimal locations. This is the first case of RAH with cervicosacropexy performed below the bikini line, using the new Dexter robotic system™.

Objectives

The aim of this article is to show the surgical steps of the first RAH with cervicosacropexy performed below the bikini line with the new Dexter robotic system™ (Distalmotion), and furthermore assess the feasibility of this approach using this robotic platform.

Materials and Methods

A 43-year-old woman with uterine adenomyosis and recurrent uterine prolapse underwent a robotic-assisted subtotal hysterectomy with cervicosacropexy, performed below the bikini line, using the Dexter robotic system™, at the Clinic of Gynecology and Obstetrics at Universitätsklinikum Schleswig-Holstein (UKHS) in Kiel, Germany.

Main outcome measures

Perioperative data, surgical approach specifics, objective, and subjective outcomes of this new approach.

Results

The procedure was performed without intra-operative complications; estimated blood loss was 10 ml. Operative time was 150 minutes, console time 120 minutes, total docking time 6 minutes. Dexter performed as expected; no device-related issues or robotic arm collisions occurred. The patient did not require pain medication and was released on the second postoperative day.

Conclusion

RAH performed below the bikini line using the Dexter robotic system™ is a feasible, safe, and adequate procedure. These initial results should be confirmed and further extensively refurbished with larger patient cohorts, and functional and psychological outcomes need further investigation.

Laparoscopic but not open surgical skills can be transferred to robot-assisted surgery: A systematic review and meta-analysis

BACKGROUND

With an increase in robot-assisted surgery across all specialties, adequate training and credentialing strategies need to be identified to ensure patients safety. The meta-analysis assesses the transferability of technical surgical skills between laparoscopic surgery, open surgery, and robot-assisted surgery.

DESIGN

A systematic search was conducted in Medline, Cochrane Central Register of Controlled Trials, and Web of Science. Outcomes were categorized into time, process, product, and composite outcome measures and pooled separately using Hedges'g (standardized mean difference [SMD]). Subgroup analyses were performed to assess the effect of study design, virtual reality platforms and task difficulty.

RESULTS

Out of 14,120 screened studies, 30 were included in the qualitative synthesis and 26 in the quantitative synthesis. Technical surgical skill transfer was demonstrated from laparoscopic to robot-assisted surgery (composite: SMD 0.40, 95%-confidence interval [CI] [0.19; 0.62], time: SMD 0.62, CI [0.33; 0.91]) and vice versa (composite: SMD 0.66, CI [0.33; 0.99], time [basic skills]: SMD 0.36, CI [0.01; 0.72]). No skill transfer was seen from open to robot-assisted surgery with limited available data.

CONCLUSION

Technical surgical skills can be transferred from laparoscopic to robot-assisted surgery and vice versa. Robot-assisted and laparoscopic surgical skills training and credentialing should not be regarded separately, but a reasonable combination could shorten overall training times and increase efficiency. Previous experience in open surgery should not be considered as an imperative prerequisite for training in robot-assisted surgery. Recommendations for studies assessing skill transfer are proposed to increase comparability and significance of future studies.

PROSPERO REGISTRATION NUMBER

PROSPERO CRD42018104507.

Expanding Robotic-Assisted Surgery in Gynecology Using the Potential of an Advanced Robotic System

Minimally invasive surgery (MIS) in gynecology was introduced to achieve the same surgical objectives as traditional open surgery while minimizing trauma to surrounding tissues, reducing pain, accelerating recovery, and improving overall patient outcomes. Minimally invasive approaches, such as laparoscopic and robotic-assisted surgeries, have become the standard for many gynecological procedures. In this review, we aim to summarize the advantages and main limitations to a broader adoption of robotic-assisted surgery compared to laparoscopic surgeries in gynecology. We present a new surgical system, the Dexter Robotic System™ (Distalmotion, Switzerland), that facilitates the transition from laparoscopy expertise to robotic-assisted surgery.

Enhanced U-Net with GridMask (EUGNet): A Novel Approach for Robotic Surgical Tool Segmentation

This study proposed enhanced U-Net with GridMask (EUGNet) image augmentation techniques focused on pixel manipulation, emphasizing GridMask augmentation. This study introduces EUGNet, which incorporates GridMask augmentation to address U-Net's limitations. EUGNet features a deep contextual encoder, residual connections, class-balancing loss, adaptive feature fusion, GridMask augmentation module, efficient implementation, and multi-modal fusion. These innovations enhance segmentation accuracy and robustness, making it well-suited for medical image analysis. The GridMask algorithm is detailed, demonstrating its distinct approach to pixel elimination, enhancing model adaptability to occlusions and local features. A comprehensive dataset of robotic surgical scenarios and instruments is used for evaluation, showcasing the framework's robustness. Specifically, there are improvements of 1.6 percentage points in balanced accuracy for the foreground, 1.7 points in intersection over union (IoU), and 1.7 points in mean Dice similarity coefficient (DSC). These improvements are highly significant and have a substantial impact on inference speed. The inference speed, which is a critical factor in real-time applications, has seen a noteworthy reduction. It decreased from 0.163 milliseconds for the U-Net without GridMask to 0.097 milliseconds for the U-Net with GridMask.

Transfer of skills between laparoscopic and robot-assisted surgery: a systematic review

BACKGROUND

Robot-assisted surgery is today well-implemented in many surgical specialties, but requires another skill set than laparoscopy. Most often, robot-assisted surgery is considered add-on to laparoscopic skills but very little is known about the transfer of skills. The aim of the study was to examine to what extent surgical skills are transferable between laparoscopic and robot-assisted surgery.

METHODS

A systematic search was conducted in three databases (Ovid Medline, Embase, and Web of Science). Studies investigating transfer of skills between laparoscopy and robot-assisted surgery in either a phantom-based, simulation-based, animal model, or clinical setting were eligible for inclusion. Quality assessment was done using the Medical education research study quality instrument and educational New Ottawa Scale.

RESULTS

Of 15,610 studies identified, 89 studies continued to full-text reading, and 37 studies were included. Four studies were found non-comparable and were left out of the results for the primary outcome. All 33 studies explored transfer from laparoscopy to robot-assisted surgery and 17 found a positive transfer whereas 15 did not. Only 11 studies explored transfer from robot-assisted surgery to laparoscopy, of which only three found a positive transfer.

CONCLUSION

An almost equal number of publications found a positive transfer and no transfer from laparoscopic to robot-assisted surgery. Fewer studies explored the transfer from robot-assisted surgery to laparoscopy. Very little evidence supports that surgeons trained solely in robot-assisted surgery can perform laparoscopy. This must be considered in future training programs as robot-assisted surgery is expected to become the first-in-line modality for many future surgeons.

The Future of Neuroendoscopy: Looking Ahead Through a Lens

Neuroendoscopy has progressed remarkably in the past few decades. Ventriculoscopy, skull base endoscopy, and spinal endoscopy are now part of routine practice in the neurosurgical treatment of numerous pathologies. Like other developing fields, however, it faces numerous challenges and obstacles that must be overcome for the field to continue to evolve and expand. This brief review of new and exciting developments in neuroendoscopy describes some of the most interesting directions the field is starting to steer towards.

Learning curve for robotic-assisted total mesorectal excision: a multicentre, prospective study

AIM

Robotic-assisted surgery (RAS) is becoming increasingly important in colorectal surgery. Recognition of the short, safe learning curve (LC) could potentially improve implementation. We evaluated the extent and safety of the LC in robotic resection for rectal cancer.

METHOD

Consecutive rectal cancer resections (January 2018 to February 2021) were prospectively included from three French centres, involving nine surgeons. LC analyses only included surgeons who had performed more than 25 robotic rectal cancer surgeries. The primary endpoint was operating time LC and the secondary endpoint conversion rate LC. Interphase comparisons included demographic and intraoperative data, operating time, conversion rate, pathological specimen features and postoperative morbidity.

RESULTS

In 174 patients (69% men; mean age 62.6 years) the mean operating time was 334.5 ± 92.1 min. Operative procedures included low anterior resection (n = 143) and intersphincteric resection (n = 31). For operating time, there were two or three (centre-dependent) LC phases. After 12-21 cases (learning phase), there was a significant decrease in total operating time (all centres) and an increase in the number of harvested lymph nodes (two centres). For conversion rate, there were two or four LC phases. After 9-14 cases (learning phase), the conversion rate decreased significantly in two centres; in one centre, there was a nonsignificant decrease despite the treatment of significantly more obese patients and patients with previous abdominal surgery. There were no significant differences in interphase comparisons.

CONCLUSION

The LC for RAS in rectal cancer was achieved after 12-21 cases for the operating time and 9-14 cases for the conversion rate. RAS for rectal cancer was safe during this time, with no interphase differences in postoperative complications and circumferential resection margin.

Comparison of 2D and autostereoscopic 3D visualization during mixed reality simulation

PURPOSE

In general minimally invasive surgical procedures, surgeons are tied to 2D visualization, leading to the loss of depth perception. This can lead to large mental load for the surgeons and may be responsible for the long learning curve. To restore the sense of depth, this study investigated the use and benefits of an autostereoscopic (3D) display during a simulated laparoscopic task.

METHODS

A mixed reality simulator was developed for comparing the performance of participants while using 2D and autostereoscopic 3D visualization. An electromagnetic sensor was mounted on a physical instrument, and its pose was mapped to the virtual instrument. The virtual scene was developed using Simulation Open Framework Architecture (SOFA). Finite element modeling was used to calculate interaction forces, which were then mapped to visual soft tissue deformation.

RESULTS

Ten non-expert participants completed a virtual laparoscopic task, where the subjects were asked to contact eighteen target areas distributed on the surface of the vagina, both in 2D and 3D. Results showed an improvement with 3D vision in task completion time (-16%), total traveled distance (-25%) and errors made (-14%). There was no difference in the average contact forces between the vagina and the instrument. Only the difference in time and forces were shown to be statistically significant.

CONCLUSION

Overall, autostereoscopic 3D showed superiority over conventional 2D visualization. The traveled trajectory increased in 2D as the instrument was retracted more between the targets to avoid contact. The 2D and 3D deformation upon contact seems not to contribute differently to force perception. However, the participants only had visual feedback, but no haptic feedback. Therefore, it could be interesting to include haptic feedback in a future study.

Uretero-neocystostomy: a retrospective comparison of open, laparoscopic and robotic techniques

BACKGROUND

Uretero-neocystostomy (UNC) is the gold-standard for distal-ureter repair. Whether the surgery should be conducted minimally invasive (laparoscopic (LAP), robotic RAL)) or open remains unanswered by the literature.

METHODS

Retrospective analysis of surgical outcome of patients treated with UNC for distal ureteral stenosis (January 2012 - October 2021). Patient demographics, estimated blood loss (EBL), surgical technique, operative time, complications and length of hospital stay (LOS) were recorded. During the follow-up period, patient underwent renal ultrasound and kidney function tests. Success was defined as relieve of symptoms or no findings of obstruction needing urine drainage.

RESULTS

60 patients were included (9 RAL, 25 LAP, 26 open). The different cohorts were similar of age, gender, American Society of Anesthesiologists (ASA) score, body-mass index and history of prior treatment of the ureter. No intraoperative complications were detected in all groups. There was no conversion to open surgery in the RAL group, whereas one was found in the LAP arm. Six patients had a recurrent stricture, but with no significant difference between the cohorts. EBL was not different between the groups. LOS was significantly lower in the RAL + LAP group compared to open (7 vs. 13 days, p = 0.005) despite significantly longer operating times (186 vs. 125.5 min, p = 0.005).

CONCLUSION

Minimal invasive UNC, especially RAL, is a feasible and safe surgical method and provides similar results in terms of success rates in comparison to open approach. A shorter LOS could be detected. Further prospective studies need to be done.

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.

Transfer of open and laparoscopic skills to robotic surgery: a systematic review

Due to its advantages over open surgery and conventional laparoscopy, uptake of robot-assisted surgery has rapidly increased. It is important to know whether the existing open or laparoscopic skills of robotic novices shorten the robotic surgery learning curve, potentially reducing the amount of training required. This systematic review aims to assess psychomotor skill transfer to the robot in clinical and simulated settings. PubMed, EMBASE, Cochrane Library and Scopus databases were systematically searched in accordance with PRISMA guidelines from inception to August 2021 alongside website searching and citation chaining. Article screening, data extraction and quality assessment were undertaken by two independent reviewers. Outcomes included simulator performance metrics or in the case of clinical studies, peri- and post-operative metrics. Twenty-nine studies met the eligibility criteria. All studies were judged to be at high or moderate overall risk of bias. Results were narratively synthesised due to heterogeneity in study designs and outcome measures. Two of the three studies assessing open surgical skill transfer found evidence of successful skill transfer while nine of twenty-seven studies evaluating laparoscopic skill transfer found no evidence. Skill transfer from both modalities is most apparent when advanced robotic tasks are performed in the initial phase of the learning curve but quality and methodological limitations of the existing literature prevent definitive conclusions. The impact of incorporating laparoscopic simulation into robotic training curricula and on the cost effectiveness of training should be investigated.

Patient-Related Functional Outcomes After Robotic-Assisted Rectal Surgery Compared With a Laparoscopic Approach: A Systematic Review and Meta-analysis

BACKGROUND

Robotic surgery has gained significant momentum in rectal cancer surgery. Most studies focus on short-term and oncological outcomes, showing similar outcomes to laparoscopic surgery. Increasing survivorship mandates greater emphasis on quality of life and long-term function.

OBJECTIVE

This study aimed to compare quality of life and urinary, sexual, and lower GI functions between robotic and laparoscopic rectal surgeries.

DATA SOURCES

A systematic search of Medline, PubMed, Embase, Clinical Trials Register, and Cochrane Library-identified articles comparing robotic with laparoscopic rectal resections was performed.

MAIN OUTCOME MEASURES

The outcome measures were quality of life and urinary, sexual, and GI functions between robotic and laparoscopic rectal resection patient groups. Where comparable data were available, results were pooled for analysis.

RESULTS

The initial search revealed 1777 papers; 101 were reviewed in full, and 14 studies were included for review. Eleven assessed male sexual function; 7 favored robotic surgery, and the remaining studies showed no significant difference. Pooled analysis of 5 studies reporting rates of male sexual dysfunction at 12 months showed significantly lower rates after robotic surgery (OR, 0.51; p = 0.043). Twelve studies compared urinary function. Six favored robotic surgery, but in 2 studies, a difference was seen at 6 months but not sustained at 12 months. Pooled analysis of 4 studies demonstrated significantly better urinary function scores at 12 months after robotic surgery (OR, 0.26; p = 0.016). Quality of life and GI function were equivalent, but very little data exist for these parameters.

LIMITATIONS

A small number of studies compare outcomes between these groups; only 2 are randomized. Different scoring systems limit comparisons and pooling of data.

CONCLUSIONS

The limited available data suggest that robotic rectal cancer resection improves male sexual and urinary functions when compared with laparoscopy, but there is no difference in quality of life or GI function. Future studies should report all facets of functional outcomes using standardized scoring systems.

Measuring the Quality of Learning in a Human–Robot Collaboration: A Study of Laparoscopic Surgery

Robot-Assisted Laparoscopic Surgery (RALS) is now prevalent in operating rooms. This situation requires future surgeons to learn Classic Laparoscopic Surgery (CLS) and RALS simultaneously. Therefore, along with the investigation of the differences in performance between the two techniques, it is essential to study the impact of training in RALS on the skills mastered in CLS. In this article, we study comanipulated RALS (Co-RALS), one of the two designs for RALS, where the human and the robot share the execution of the task. We use a rarely used in Human–Robot Interaction measuring tool: gaze tracking and time recording to measure for the acquisition of skills in CLS when training in Co-RALS or in CLS and time recording to compare the learning curves between Co-RALS and CLS. These metrics allow us to observe differences in Co-RALS and CLS. Training in Co-RALS develops slightly better but not significantly better hand–eye coordination skills and significantly better timewise performance compared with training in CLS alone. Co-RALS enhances timewise performance in laparoscopic surgery on specific types of tasks that require precision rather than depth perception skills compared with CLS. The results obtained enable us to further define the Human–Robot Interaction quality in Co-RALS.

The learning curve in robotic colorectal surgery compared with laparoscopic colorectal surgery: a systematic review

AIM

The learning curve has implications for efficient surgical training. Robotic surgery is perceived to have a shorter learning curve than laparoscopy; however, detailed analysis is lacking. The aim of this work was to analyse studies comparing robotic and laparoscopic colorectal learning curves. Simulation studies comparing novices' learning curves were analysed in order to surmise applicability to colorectal surgery.

METHOD

A systematic search of Medline, PubMed, Embase and the Cochrane Library identified colorectal papers (from 1 January 2000 to 3 March 2021) comparing robotic and laparoscopic learning curves where surgeons lacked laparoscopic colorectal experience. Simulation studies comparing learning curves were also included. The learning curve was defined as the period of ongoing improvement in speed and/or accuracy.

RESULTS

From 576 abstracts reviewed, three operative and 16 simulation studies were included. The robotic learning curve for right colectomy was significantly faster in one study (16 vs. 25 cases) and equal for anterior resection in two studies (44 vs. 41 cases and 55 vs. 55). One study showed fewer complications for robotic patients (14.6% vs. 0%, p = 0.013). Ten simulation studies reported faster times and eight recorded error rates favouring robotic surgery. Seven studies measured the learning curve. Four favoured laparoscopic surgery, but operating times were faster using the robotic platform.

CONCLUSION

Operating times for robotic surgery may be faster than laparoscopy when surgeons are inexperienced with both platforms. This may be related to a superior baseline performance rather than a shorter learning curve. Whether a shorter learning curve on the laparoscopic platform will persist for long enough to enable skills to overtake robotic ability needs further investigation.

Laparoscopic skills training: the effects of viewing mode (2D vs. 3D) on skill acquisition and transfer

BACKGROUND

Three-dimensional (3D) visual displays have been suggested to aid laparoscopic skills training by providing the depth cues not present in traditional two-dimensional (2D) displays. However, few studies have robustly investigated the impact of viewing mode (2D vs. 3D) on learning outcomes.

PURPOSE

To examine how viewing mode (2D vs. 3D) impacts the acquisition and transferability of basic laparoscopic skills by comparing performance between transfer and control groups on a complete proficiency-based training program.

METHOD

A counterbalanced between-subjects design was employed. Each participant was randomly allocated to one of four groups, comprising two transfer groups (trained in one viewing mode and tested in the alternate mode: the 2D → 3D and 3D → 2D groups) and two control groups (trained and tested in one viewing mode: the 2D → 2D and 3D → 3D groups). Participants completed proficiency-based training in six laparoscopic training tasks. Testing included two further repetitions of all tasks under test conditions. Objective performance measures included the total number of repetitions to reach proficiency, and total performance scores (i.e. time + error penalties across all repetitions) in training and testing.

RESULTS

The groups trained in 3D demonstrated superior training performance (i.e. less time + errors) and took fewer repetitions to reach proficiency than the groups trained in 2D. The groups tested in 3D also demonstrated superior test performance compared to those tested in 2D. However, training mode did not yield significant test differences between the groups tested in 2D (i.e. 2D → 2D vs. 3D → 2D), or between the groups tested in 3D (i.e. 3D → 3D vs. 2D → 3D).

CONCLUSION

Novices demonstrate superior performance in laparoscopic skills training using a 3D viewing mode compared to 2D. However, this does not necessarily translate to superior performance in subsequent testing or enhanced learning overall. Rather, test performance appears to be dictated by the viewing mode used during testing, not that of prior training.

Short-term comparative study of three-dimensional and two-dimensional laparoscopic surgery for total extraperitoneal primary inguinal hernia repair

Purpose

The aim of this study was to compare the short-term outcomes of two-dimensional (2D) and three-dimensional (3D) laparoscopic surgery for total extraperitoneal (TEP) primary inguinal hernia repair.

Methods

This was a single-center, retrospective, observational database study of 38 patients who underwent laparoscopic TEP inguinal hernia repair from March 1, 2019 to August 30, 2019 at Kyung Hee University Hospital at Gangdong in Seoul, Korea.

Results

There was no significant difference in sex ratio, age, or body mass index between the two groups. The 2D group had two patients with direct hernia and 18 patients with indirect hernia. The 3D group had five patients with direct hernia, 11 patients with indirect hernia, and two patients with femoral hernia. The mean operation time was 38.2 minutes in the 2D group compared with 37.2 minutes in the 3D group. There was no severe intraoperative bleeding in either group. During the operation, peritoneal tearing occurred in 12 out of 20 patients in the 2D group compared with five out of 18 patients in the 3D group (p = 0.02). The average length of hospital stay was 1.3 days in both groups. The numeric rating scale score was 3.3 and 3 in the 2D group and the 3D group, respectively. In the 2D group, two patients revisited the outpatient clinic because of the postoperative occurrence of seroma and varicocele.

Conclusion

A 3D laparoscopic surgery is feasible and safe for inguinal hernia repair and showed less peritoneal tearing compared with 2D laparoscopic surgery for primary inguinal hernia repair.

Fellowship training in robotic colorectal surgery within the current hospital setting: an achievable goal?

BACKGROUND

Although currently limited, the requirement for colorectal trainees to attain skills in robotic surgery is likely to increase due to further utilization of robotic platforms globally. The aim of the study is to describe the training programme utilized and assess outcomes of fellowship training in robotic colorectal surgery.

METHODS

A structured robotic training programme was generated across a tertiary hospital setting. Review of four prospectively maintained fellow operative logbooks was performed to assess caseload and skill acquisition. Operative and patient-related outcomes were compared with consultant trainer performed cases. Data were analysed using R with a P < 0.05 considered significant.

RESULTS

The structured robotic training scheme is a two-tiered system over a 12-month period. The trainer-directed pathway comprised of a robotic console safety course followed by cart-side assisting, a wet lab animal course, dual-console accreditation training course and onsite proctoring, prior to becoming an independent console surgeon. Over 2 years, 265 robotic (n = 143 primary/component surgeon) cases were undertaken with fellows A, B, C and D involved in 63, 77, 75 and 50 robotic colorectal cases, respectively. Individual learning curves revealed independent procedure competency at cases 11, 14, 15 and 12, respectively, for robotic anterior resection. There was no significant difference observed in operative time (P = 0.39), blood loss (P = 0.41), lymph node harvest (P = 0.35), conversion rates (2% versus 4%), anastomotic leaks (1% versus 3%) and R0 resection rates (100% versus 98% colonic, 96% versus 96% rectal, P = 0.48) between surgical fellows and consultant trainers. Clavien-Dindo(III-IV) complications were similar (10% versus 6%,P = 0.25) with no mortalities encountered.

CONCLUSION

It is feasible and safe to train fellows in robotic colorectal surgery without compromise of operative- and patient-related outcomes.

Robotic-assisted cholecystectomy is superior to laparoscopic cholecystectomy in the initial training for surgical novices in an ex vivo porcine model: a randomized crossover study

Background

Robotic-assisted surgery (RAS) potentially reduces workload and shortens the surgical learning curve compared to conventional laparoscopy (CL). The present study aimed to compare robotic-assisted cholecystectomy (RAC) to laparoscopic cholecystectomy (LC) in the initial learning phase for novices.

Methods

In a randomized crossover study, medical students (n = 40) in their clinical years performed both LC and RAC on a cadaveric porcine model. After standardized instructions and basic skill training, group 1 started with RAC and then performed LC, while group 2 started with LC and then performed RAC. The primary endpoint was surgical performance measured with Objective Structured Assessment of Technical Skills (OSATS) score, secondary endpoints included operating time, complications (liver damage, gallbladder perforations, vessel damage), force applied to tissue, and subjective workload assessment.

Results

Surgical performance was better for RAC than for LC for total OSATS (RAC = 77.4 ± 7.9 vs. LC = 73.8 ± 9.4; p = 0.025, global OSATS (RAC = 27.2 ± 1.0 vs. LC = 26.5 ± 1.6; p = 0.012, and task specific OSATS score (RAC = 50.5 ± 7.5 vs. LC = 47.1 ± 8.5; p = 0.037). There were less complications with RAC than with LC (10 (25.6%) vs. 26 (65.0%), p = 0.006) but no difference in operating times (RAC = 77.0 ± 15.3 vs. LC = 75.5 ± 15.3 min; p = 0.517). Force applied to tissue was similar. Students found RAC less physical demanding and less frustrating than LC.

Conclusions

Novices performed their first cholecystectomies with better performance and less complications with RAS than with CL, while operating time showed no differences. Students perceived less subjective workload for RAS than for CL. Unlike our expectations, the lack of haptic feedback on the robotic system did not lead to higher force application during RAC than LC and did not increase tissue damage. These results show potential advantages for RAS over CL for surgical novices while performing their first RAC and LC using an ex vivo cadaveric porcine model.

Registration number

researchregistry6029

Graphic abstract

The influence of learning curve of robot-assisted laparoscopy on oncological outcomes in early-stage cervical cancer: an observational cohort study

OBJECTIVE

To investigate the learning curve of robot-assisted laparoscopy in early-stage cervical cancer and quantify impact on oncological outcomes.

DESIGN

Observational cohort study.

SETTING

Tertiary referral centre with one surgical team.

POPULATION

All women with early-stage cervical cancer treated consecutively with robot-assisted laparoscopy between 2007 and 2017.

METHODS

With multivariate risk-adjusted cumulative sum analysis (RA-CUSUM), we assessed the learning curve of robot-assisted laparoscopy of a single surgical team based on cervical cancer recurrence. Subsequently, a survival analysis was conducted comparing oncological outcomes of women treated during different phases of the learning curve.

MAIN OUTCOME MEASURES

Surgical proficiency based on recurrence, survival rates in the different learning phases.

RESULTS

One hundred and sixty-five women with cervical cancer underwent robot-assisted laparoscopy, with a median follow up of 57 months (range 3-132 months). The RA-CUSUM analysis demonstrated two phases of the learning curve: a learning phase of 61 procedures (group 1) and an experienced phase representing the 104 procedures thereafter (group 2). The 5-year disease-free survival was 80.2% in group 1 and 91.1% in group 2 (P = 0.040). Both the 5-year disease-specific survival and overall survival significantly increased after the learning phase.

CONCLUSION

The learning phase of robot-assisted laparoscopy in early-stage cervical cancer in this institutional cohort is at least 61 procedures, with higher survival rates in the women treated thereafter. The learning curve of robot-assisted laparoscopy affects oncological outcomes and warrants more attention in the design of future studies.

TWEETABLE ABSTRACT

The learning curve of robot-assisted laparoscopy in early-stage cervical cancer affects oncological outcomes and warrants more attention.

Skill-Oriented and Performance-Driven Adaptive Curricula for Training in Robot-Assisted Surgery Using Simulators: A Feasibility Study

OBJECTIVE

Virtual Reality (VR) simulators represent a remarkable educational opportunity in order to acquire and refine surgical practical skills. Nevertheless, there exists no consensus regarding a standard curriculum of simulation-based training. This study introduces an automatic, adaptive curriculum where the training session is real-time scheduled on the basis of the trainee's performances.

METHODS

An experimental study using the master console of the da Vinci Research Kit (Intuitive Surgical Inc., Sunnyvale, US) was carried out to test this approach. Tasks involving fundamental skills of robotic surgery were designed and simulated in VR. Twelve participants without medical background along with twelve medical residents were randomly and equally divided into two groups: a control group, self-managing the training session, and an experimental group, undergoing the proposed adaptive training.

RESULTS

The performances of the experimental users were significantly better with respect to the ones of the control group after training (non-medical: p < 0.01; medical: p = 0.02). This trend was analogous in the non-medical and medical populations and no significant difference was identified between these two classes (even in the baseline assessment).

CONCLUSION

The analysis of the learning of the involved surgical skills highlighted how the proposed adaptive training managed to better identify and compensate for the trainee's gaps. The absence of initial difference between the non-medical and medical users underlines that robotic surgical devices require specific training before clinical practice.

SIGNIFICANCE

This feasibility study could pave the way towards the improvement of simulation-based training curricula.

Learning curve of digital intraoral scanning - an in vivo study

Background

The spread of digital technology in dentistry poses new challenges and sets new goals for dentists. The aim of the present in vivo study was to determine the learning curve of intraoral scanning described by (1) scanning time and (2) image number (count of images created by intraoral scanner during the scanning process).

Methods

Ten dental students of Semmelweis University took part in the study. Dental students took digital study impressions using a 3Shape Trios 3® (3Shape, Copenhagen, Denmark) intraoral scanning device. Each student took 10 digital impressions on volunteers. Volunteer inclusion criteria included full dentition (except for missing third molars) and no prosthetic/restorative treatment. Digital impression taking was preceded by tuition consisting of both theoretical education and practical training. Digital impressions were taken of the upper and lower arches, and the bite was recorded according to the manufacturer's instructions. Total scanning times and image numbers were recorded.

Results

The difference in scanning time between the first and the tenth digital impressions was significant (p = 0.007). The average scanning time for the first impressions was 23 min 9 s; for the tenth impressions, it was 15 min 28 s. The difference between the scanning times of the first and the tenth procedures was 7 min 41 s. The average image count for the first impressions was 1964.5; for the tenth impressions, it was 1468.6. The image count difference between the first and the tenth procedures was 495.9. The image count versus sequential number of measurement curve shows an initial decreasing tendency followed by a trough around the sixth measurement and a final increasing phase.

Conclusion

Our results indicate an association between the sequential number of measurements and the outcome variables. The drop in scanning time is probably explained by a practice effect of repeated use, i.e. the students learned to move the scanning tip faster. The image count first showed a decreasing tendency, and after the sixth measurement, it increased; there was no consistent decline in mean scan count. Shorter scanning times are associated with poorer coverage quality, with the operator needing to make corrections by adding extra images; this manifests as the time function of image counts taking an increase after the sixth measurement.

Preliminary Clinical Microneurosurgical Experience With the 4K3-Dimensional Microvideoscope (ORBEYE) System for Microneurological Surgery: Observation Study

BACKGROUND

The exoscope has been reported as a novel neurosurgical instrumentation in clinical practice.

OBJECTIVE

To investigate the possibility that ORBEYE (OE), a novel instrument that excludes eyepiece lenses and allows for microsurgery by observation of the 4K3D monitor, could replace microscopes.

METHODS

We report 22 clinical cases by 5 experienced neurosurgeons and the comparative results of training 10 residents. An observation study with questionnaire survey was conducted on usability. Twelve items including image quality, eyestrain, and function of the arm were evaluated.

RESULTS

The following 22 clinical procedures were conducted: surgery for intracranial hemorrhage (n = 2) and brain tumor (n = 8), laminectomy (n = 3), aneurysm clipping (n = 3), vascular anastomosis (n = 2), carotid endarterectomy (n = 2), and nerve decompression (n = 1). No complications were observed. The fluorescent study, including indocyanine-green and 5-aminolevunic acid, allowed for clear depiction on the 4K monitor. The surgeon could operate in a comfortable posture. Similar to the microscope, it was possible to change the optical and viewing axes with the OE, but the OE was switched to the microscope or endoscope in hematoma removal and pituitary surgery. Residents judged that eyestrain was strong (P = .0096). Experienced neurosurgeons acting as assistants judged that the scope arm's range of movement was narrow (P = .0204). Sixty percent of residents judged that the OE was superior to the microscope.

CONCLUSION

Although based on limited experience, it was not possible to substitute the microscope with the OE in all operations; however, the OE surpasses the microscope in terms of ergonomic features.

Learning curves, potential and speed in training of laparoscopic skills: a randomised comparative study in a box trainer

Background

The effectiveness of practical surgical training is characterised by an inherent learning curve. Decisive are individual initial starting capabilities, learning speed, ideal learning plateaus, and resulting learning potentials. The quantification of learning curves requires reproducible tasks with varied levels of difficulty. The hypothesis of this study is that the use of three-dimensional (3D) vision is more advantageous than two-dimensional vision (2D) for the learning curve in laparoscopic training.

Methods

Forty laparoscopy novices were recruited and randomised to a 2D Group and a 3D Group. A laparoscopy box trainer with two standardised tasks was used for training of surgical tasks. Task 1 was a positioning task, while Task 2 called for laparoscopic knotting as a more complex process. Each task was repeated at least ten times. Performance time and the number of predefined errors were recorded. 2D performance after 3D training was assessed in an additional final 2D cycle undertaken by the 3D Group.

Results

The calculated learning plateaus of both performance times and errors were lower for 3D. Independent of the vision mode the learning curves were smoother (exponential decay) and efficiency was learned faster than precision. The learning potentials varied widely depending on the corresponding initial values and learning plateaus. The final 2D performance time of the 3D-trained group was not significantly better than that of the 2D Group. The final 2D error numbers were similar for all groups.

Conclusions

Stereoscopic vision can speed up laparoscopic training. The 3D learning curves resulted in better precision and efficiency. The 3D-trained group did not show inferior performance in the final 2D cycle. Consequently, we encourage the training of surgical competences like suturing and knotting under 3D vision, even if it is not available in clinical routine.

Three-Dimensional Flexible Endoscopy Can Facilitate Efficient and Reliable Endoscopic Hand Suturing: An ex-vivo Study

BACKGROUND/AIMS

Three-dimensional (3D) flexible endoscopy, a new imaging modality that provides a stereoscopic view, can facilitate endoscopic hand suturing (EHS), a novel intraluminal suturing technique. This ex-vivo pilot study evaluated the usefulness of 3D endoscopy in EHS.

METHODS

Four endoscopists (two certified, two non-certified) performed EHS in six sessions on a soft resin pad. Each session involved five stitches, under alternating 3D and two-dimensional (2D) conditions. Suturing time (sec/session), changes in suturing time, and accuracy of suturing were compared between 2D and 3D conditions.

RESULTS

The mean suturing time was shorter in 3D than in 2D (9.8±3.4 min/session vs. 11.2±5.1 min/session) conditions and EHS was completed faster in 3D conditions, particularly by non-certified endoscopists. The suturing speed increased as the 3D sessions progressed. Error rates (failure to grasp the needle, failure to thread the needle, and puncture retrial) in the 3D condition were lower than those in the 2D condition, whereas there was no apparent difference in deviation distance.

CONCLUSION

3D endoscopy may contribute to increasing the speed and accuracy of EHS in a short time period. Stereoscopic viewing during 3D endoscopy may help in efficient skill acquisition for EHS, particularly among novice endoscopists.

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.

Does three-dimensional surgery affect recurrence patterns in patients with gastric cancer after laparoscopic R0 gastrectomy? Results from a 3-year follow-up phase III trial

BACKGROUND

Numerous studies have shown that the short-term efficacy of three-dimensional (3D) laparoscopic radical gastrectomy (LG) is comparable to that of two-dimensional (2D)-LG. Whether 3D-LG affects the recurrence patterns of gastric cancer (GC) patients has not been investigated.

METHODS

From January 2015 to April 2016, a total of 419 patients were recruited for a phase III clinical trial (NCT02327481), which compared the short-term outcomes between the 2D and 3D groups. The long-term efficacy including recurrence patterns was compared between the 2D and 3D groups in this retrospective study. Multivariate analyses were performed to determine whether 3D-LG affects the recurrence patterns.

RESULTS

Ultimately, 401 patients were analyzed (197 in the 2D-LG group and 204 in the 3D-LG group), and no differences were observed in the clinicopathological data between the two groups. There were no significant differences between the two groups in the recurrence types, first recurrence time or recurrence-free survival (RFS) (all p > 0.05). According to the 7th American Joint Committee on Cancer tumor-node-metastasis (TNM) staging system, both groups were stratified into pathological stages I, II, and III. The stratified analysis showed no significant differences in RFS or overall survival (OS) among patients in each subgroup (all p > 0.05). The multivariate analysis of RFS showed that tumor diameter, pTNM stage, lymphovascular invasion, and adjuvant chemotherapy were independent factors (all p < 0.05). The multivariate analysis of post-recurrence survival (PRS) showed that adjuvant chemotherapy was an independent protective factor (p = 0.043).

CONCLUSIONS

3D-LG for GC did not differ significantly from 2D-LG in the effects on 3-year recurrence patterns, RFS and OS, which provides more tumor-related evidence for 3D technology. And due to the technological similarity, it may have certain reference value for robotic-assisted gastrectomy. Further multicenter, large-scale clinical trials are warranted.

Laparoscopy for living donor left nephrectomy: Comparison of three-dimensional and two-dimensional vision

The main objective of this preliminary study was to evaluate the feasibility and safety of 3-D laparoscopic living donor left nephrectomy (LDLN). The secondary objective was to compare intraoperative and postoperative outcomes between 3-D and 2-D laparoscopic LDLN. All patients who underwent a laparoscopic LDLN from January 2015 to April 2018 in a university center were included. All surgeries were performed by three experienced surgeons. Seventy three patients were included the following: 16 underwent a 3-D laparoscopic LDLN (3-D group), and 57 underwent a 2-D laparoscopic LDLN (2-D group). Operative time and warm ischemia time (WIT) were significantly lower in the 3-D group (operative time: 80.9 ± 10.2 vs 114.1 ± 32.3 minutes in the 3-D and 2-D groups, P = .0002) (WIT: 1.7 ± 0.6 vs 2.3 ± 0.9 minutes in the 3-D and 2-D groups, P = .02). No conversion to open surgery occurred in both groups. Length of hospital stay was significantly shorter in the 3-D group. No major postoperative complications (Clavien ≥ III) occurred. One-year postoperative GFR was similar to 3-D and 2-D groups. Our preliminary study demonstrates that 3-D laparoscopic LDLN is a feasible and safe surgical procedure. Intraoperative and postoperative outcomes were similar in both 2-D and 3-D vision systems, but 3-D vision systems allow reduction in WIT and operative time.

Learning curve of intraoral scanning by prosthodontic residents

STATEMENT OF PROBLEM

The use of intraoral scanning (IOS) to replace conventional impressions has become popular. However, the learning time required to use these devices effectively is unknown.

PURPOSE

The purpose of this in vitro study was to investigate the learning rate, plateau, and difficulty level over repetitive IOS among prosthodontic residents.

MATERIAL AND METHODS

Twenty participants with no experience of IOS were recruited. Maxillary and mandibular typodont casts were attached to a manikin head. Participants received training on the IOS device (Omnicam; Dentsply Sirona) and performed maxillary, mandibular, and buccal IOS for 9 trials. The time required for scanning (ST) and the perception of difficulty were recorded. The percentage ratio of time for each trial to the best performance was calculated. A nonlinear regression model was used to estimate the learning plateau and rate.

RESULTS

The findings for maxillary, mandibular, buccal, and total IOS were as follows: ST: 106 ±40 seconds (69 ±24%), 96 ±34 seconds (68 ±22%), 74 ±31 seconds (65 ±22%), and 276 ±88 seconds (72 ±20%); learning plateau: 83.40%, 80.60%, 74.30%, and 85.10%; learning rate: 5.37, 5.01, 3.81, and 4.98. With repetition of the trials, the difficulty level decreased from 6 to 4.

CONCLUSIONS

The repetitive use of IOS showed a learning phase of 5 trials to achieve competence of 80% of their best performance. The scanning time and difficulty level decreased with the repetitive use of IOS.

Implementation of Robotic Surgery in a Pediatric Hospital: Lessons Learned

BACKGROUND

Since the late 1980s, minimally invasive surgery (MIS) has been one of the fastest growing approaches for surgical procedures. However, its development has reached a plateau. One of the reasons is the difficulty to operate on more complex cases, such as neonatal procedures. Some experts report outstanding outcomes for complex operations, but not all surgeons may be able to achieve the same results. Is robotic surgery (RS) a solution?

METHODS

To answer this question, we reviewed the current indications of RS for the pediatric population and the steps needed to incorporate the robotic surgical system in a children's hospital. We reported our experience and presented our first results and the encountered problems.

RESULTS

After a year and a half of experience with RS, several lessons were learned: (1) the current robotic surgical system cannot yet be considered a replacement to conventional MIS, (2) docking is less time consuming than expected, (3) postoperative pain is significantly decreased, (4) the absence of haptic feedback is still a matter of concern, and (5) costs can be afforded by sharing the RS with adult surgeons.

CONCLUSIONS

Based on our experience, the advantages seem to outweigh the drawbacks as it encourages team building and increases overall comfort for the surgeon. However, the current literature fails to prove that RS gives better results for pediatric patients. New advances in technology will probably help to overcome the encountered difficulties and the high costs.

The effect on surgical skills of expert surgeons using 3D/HD and 2D/4K resolution monitors in laparoscopic phantom tasks

BACKGROUND

Recently, several new imaging technologies, such as three-dimensional (3D)/high-definition (HD) stereovision and high-resolution two-dimensional (2D)/4K monitors, have been introduced in laparoscopic surgery. However, it is still unclear whether these technologies actually improve surgical performance.

METHODS

Participants were 11 expert laparoscopic surgeons. We designed three laparoscopic suturing tasks (task 1: simple suturing, task 2: knotting thread in a small box, and task 3: suturing in a narrow space) in training boxes. Performances were recorded by an optical position tracker. All participants first performed each task five times consecutively using a conventional 2D/HD monitor. Then they were randomly divided into two groups: six participants performed the tasks using 3D/HD before using 2D/4K; the other five participants performed the tasks using a 2D/4K monitor before the 3D/HD monitor. After the trials, we evaluated the performance scores (operative time, path length of forceps, and technical errors) and compared performance scores across all monitors.

RESULTS

Surgical performances of participants were ranked in decreasing order: 3D/HD, 2D/4K, and 2D/HD using the total scores for each task. In task 1 (simple suturing), some surgical performances using 3D/HD were significantly better than those using 2D/4K (P = 0.017, P = 0.033, P = 0.492 for operative time, path length, and technical errors, respectively). On the other hand, with operation in narrow spaces such as in tasks 2 and 3, performances using 2D/4K were not inferior to 3D/HD performances. The high-resolution images from the 2D/4K monitor may enhance depth perception in narrow spaces and may complement stereoscopic vision almost as well as using 3D/HD.

CONCLUSIONS

Compared to a 2D/HD monitor, a 3D/HD monitor improved the laparoscopic surgical technique of expert surgeons more than a 2D/4K monitor. However, the advantage of 2D/4K high-resolution images may be comparable to a 3D/HD monitor especially in narrow spaces.

Getting ready for the first robotic prostatectomy, from basics to real practice

PURPOSE OF REVIEW

Robot-assisted radical prostatectomy (RARP) has been embraced by urologists and has become a treatment standard in many countries already. Learning how to perform a RARP is challenging and has not yet been standardized. The current review summarizes the latest concepts regarding the most effective way of training for RARP.

RECENT FINDINGS

The strategy to learn RARP should comprise didactic activities, skills lab training, participating in surgeries and mentorship. Skills lab and virtual simulators are valuable tools to develop manual abilities and to overcome the initial technical learning curve. Participating in surgeries is crucial for familiarization with the robot installation, steps of the surgical procedure and is essential for troubleshooting. Mentorship improves learning and is the safest way to initiate real practice. Innate and individual background variances were suggested to influence the learning process; however, there is paucity of robust evidence correlating previous surgical experience and, for example videogame playing with faster learning of RARP. Structured curricula were proposed to orient the training for robotic surgery; currently, only one is focused exclusively on urology.

SUMMARY

Systematic training is the most effective way to learn and surpass the possibly intense learning curve of RARP. Training activities should focus on developing cognitive and manual abilities. The existing curricula for robotic surgery training still require constant refinement; however, they offer good and structured guidance to train for RARP.

Three-Dimensional Endoscopic Magnification for Treatment of Thoracic Spinal Dural Arteriovenous Fistulas: Technical Note

BACKGROUND

Treatment of thoracic spinal dural arteriovenous fistulas (DAVFs) by microsurgery has recently been approached using minimally invasive spine surgery (MISS). The advantages of such an approach are offset by difficult maneuverability within the tubular retractor and by the creation of "tunnel vision" with reduced luminosity to a remote surgical target.

OBJECTIVE

To demonstrate how the pitfalls of MISS can be addressed by applying 3-D endoscopy to the minimally invasive approach of spinal DAVFs.

METHODS

We present 2 cases of symptomatic thoracic DAVFs that were not amenable to endovascular treatment. The DAVFs were excluded solely via a minimally invasive approach using a 3-D endoscope.

RESULTS

Two patients underwent exclusion of a DAVF following laminotomy, one through a midline 5-cm incision and the other through a paramedian 3-cm incision using minimally invasive nonexpandable tubular retractors. The dura opening, intradural exploration, fistula exclusion, and closure were performed solely under endoscopic 3-D magnification. No incidents were recorded and the postoperative course was marked by clinical improvement. Postoperative imaging confirmed the exclusion of the DAVFs. Anatomical details are exposed using intraoperative videos.

CONCLUSION

When approaching DAVFs via MISS, replacing the microscope with the endoscope remedies the limitations related to the "tunnel vision" created by the tubular retractor, but at the expense of losing binocular vision. We show that the 3-D endoscope resolves this latter limitation and provides an interesting option for the exclusion of spinal DAVFs.

Comparison of 3D laparoscopic gastrectomy with a 2D procedure for gastric cancer: A phase 3 randomized controlled trial

OBJECTIVE

To determine the relative safety and efficacy of 3D laparoscopic gastrectomy and 2D laparoscopic surgery in patients with gastric cancer.

BACKGROUND

There is still a lack of randomized controlled trials regarding the safety and efficacy of 3D versus 2D laparoscopic surgery for gastric cancer.

METHODS

A large-scale, phase 3, prospective, randomized controlled trial was conducted. (ClinicalTrials.gov number NCT02327481).

RESULTS

A total of 438 patients were randomized (3D group: 219 cases; 2D group: 219 cases) between January 1, 2015, and April 1, 2016; 19 patients were excluded. Finally, data from 419 patients were analyzed (3D group: 211 cases; 2D group: 208 cases). There were no differences between the 2 groups regarding the operation time (3D versus 2D, 176 ± 35 min vs. 174 ± 33 min, P = .562). The intraoperative blood loss in the 3D group was somewhat less than in the 2D group (61 ± 83 mL vs. 82 ± 119 mL, P = .045). Further analysis suggested that the use of 3D laparoscopic surgery was a protective factor against excessive blood loss (≥200 mL).

CONCLUSION

3D laparoscopic gastrectomy did not shorten the operation time compared with 2D laparoscopic gastrectomy, but provided the benefit of less intraoperative blood loss and a lesser occurrence of excessive bleeding than the conventional 2D laparoscopic gastrectomy; the clinical value of the difference is limited.

Evolution of stereoscopic imaging in surgery and recent advances

In the late 1980s the first laparoscopic cholecystectomies were performed prompting a sudden rise in technological innovations as the benefits and feasibility of minimal access surgery became recognised. Monocular laparoscopes provided only two-dimensional (2D) viewing with reduced depth perception and contributed to an extended learning curve. Attention turned to producing a usable three-dimensional (3D) endoscopic view for surgeons; utilising different technologies for image capture and image projection. These evolving visual systems have been assessed in various research environments with conflicting outcomes of success and usability, and no overall consensus to their benefit. This review article aims to provide an explanation of the different types of technologies, summarise the published literature evaluating 3D vs 2D laparoscopy, to explain the conflicting outcomes, and discuss the current consensus view.

The learning effect of using stereoscopic vision in the early phase of laparoscopic surgical training for novices

Background

Recently to improve depth perception, the performance of three-dimensional (3D) laparoscopic surgeries has increased. However, the effects of laparoscopic training using 3D are still unclear. This study aimed to clarify the effects of using a 3D monitor among novices in the early phase of training.

Methods

Participants were 40 novices who had never performed laparoscopic surgery (20 medical students and 20 junior residents). Three laparoscopic phantom tasks (task 1: touching markers on a flat disk with a rod; task 2: straight rod transfer through a single loop; and task 3: curved rod transfer through two loops) in the training box were performed ten times, respectively. Performances were recorded by an optical position tracker. The participants were randomly divided into two groups: one group performed each task five times initially under a 2D system (2D start group), and the other group performed each task five times under a 3D system (3D start group). Both groups then performed the same task five times. After the trial, we evaluated the performance scores (operative time, path length of forceps, and technical errors) and the learning curves for both groups.

Results

Scores for all tasks performed under the 3D system were significantly better than scores for tasks using the 2D system. Scores for each task in the 2D start group improved after switching to the 3D system. However, scores for each task in the 3D start group were worse after switching to the 2D system, especially scores related to technical errors.

Conclusions

The stereoscopic vision improved laparoscopic surgical techniques of novices from the early phase of training. However, the performance of novices trained only by 3D worsened by changing to the 2D environment.

Algorithm-Based Motion Magnification for Video Processing in Urological Laparoscopy

PURPOSE

Minimally invasive surgery is in constant further development and has replaced many conventional operative procedures. If vascular structure movement could be detected during these procedures, it could reduce the risk of vascular injury and conversion to open surgery. The recently proposed motion-amplifying algorithm, Eulerian Video Magnification (EVM), has been shown to substantially enhance minimal object changes in digitally recorded video that is barely perceptible to the human eye. We adapted and examined this technology for use in urological laparoscopy.

MATERIALS AND METHODS

Video sequences of routine urological laparoscopic interventions were recorded and further processed using spatial decomposition and filtering algorithms. The freely available EVM algorithm was investigated for its usability in real-time processing. In addition, a new image processing technology, the CRS iimotion Motion Magnification (CRSMM) algorithm, was specifically adjusted for endoscopic requirements, applied, and validated by our working group.

RESULTS

Using EVM, no significant motion enhancement could be detected without severe impairment of the image resolution, motion, and color presentation. The CRSMM algorithm significantly improved image quality in terms of motion enhancement. In particular, the pulsation of vascular structures could be displayed more accurately than in EVM.

CONCLUSIONS

Motion magnification image processing technology has the potential for clinical importance as a video optimizing modality in endoscopic and laparoscopic surgery. Barely detectable (micro)movements can be visualized using this noninvasive marker-free method. Despite these optimistic results, the technology requires considerable further technical development and clinical tests.

Retention of laparoscopic and robotic skills among medical students: a randomized controlled trial

BACKGROUND

Although simulation training beneficially contributes to traditional surgical training, there are less objective data on simulation skills retention.

OBJECTIVE

To investigate the retention of laparoscopic and robotic skills after simulation training.

METHODS

We present the second stage of a randomized single-blinded controlled trial in which 40 simulation-naïve medical students were randomly assigned to practice peg transfer tasks on either laparoscopic (N = 20, Fundamentals of Laparoscopic Surgery, Venture Technologies Inc., Waltham, MA) or robotic (N = 20, dV-Trainer, Mimic, Seattle, WA) platforms. In the first stage, two expert surgeons evaluated participants on both tasks before (Stage 1: Baseline) and immediately after training (Stage 1: Post-training) using a modified validated global rating scale of laparoscopic and robotic operative performance. In Stage 2, participants were evaluated on both tasks 11-20 weeks after training.

RESULTS

Of the 40 students who participated in Stage 1, 23 (11 laparoscopic and 12 robotic) underwent repeat evaluation. During Stage 2, there were no significant differences between groups in objective or subjective measures for the laparoscopic task. Laparoscopic-trained participants' performances on the laparoscopic task were improved during Stage 2 compared to baseline measured by time to task completion, but not by the modified global rating scale. During the robotic task, the robotic-trained group demonstrated superior economy of motion (p = .017), Tissue Handling (p = .020), and fewer errors (p = .018) compared to the laparoscopic-trained group. Robotic skills acquisition from baseline with no significant deterioration as measured by modified global rating scale scores was observed among robotic-trained participants during Stage 2.

CONCLUSION

Robotic skills acquired through simulation appear to be better maintained than laparoscopic simulation skills.

CLINICAL TRIAL

This study is registered on ClinicalTrials.gov (NCT02370407).

Randomized, controlled trial comparing clinical outcomes of 3D and 2D laparoscopic surgery for gastric cancer: an interim report

OBJECTIVE

In this study, we evaluated the short-term outcomes following three-dimensional (3D) or two-dimensional (2D) laparoscopic surgery for patients with gastric cancer.

BACKGROUND

There is a lack of prospective evidence regarding the safety and efficacy of 3D versus 2D laparoscopic surgery for patients with gastric cancer. Therefore, we conducted a phase III single-center, prospective, randomized, controlled trial to compare 3D and 2D laparoscopic surgery for patients with gastric cancer.

METHODS

We compared operation time, intraoperative blood loss, number of lymph node dissections, morbidity, and mortality between the 3D and 2D groups following laparoscopic surgery for gastric cancer. The study is registered at ClinicalTrials.gov with ID number NCT02327481.

RESULTS

A total of 228 patients were randomized (3D group 115 cases; 2D group 113 cases) between January 1, 2015 and September 1, 2015. Seven patients who underwent exploratory operations were excluded. Finally, a total of 221 patients were analyzed (3D group 109 cases, 2D group 112 cases). There were no significant differences between the two groups regarding the clinical pathological characteristics, operating time (3D vs. 2D, 184 ± 36 vs. 178 ± 37 min, P = 0.288), number of lymph node dissections (36 ± 14 vs. 37 ± 13, P = 0.698), time to first ambulation (2.27 ± 1.60 vs. 2.04 ± 0.84, P = 0.18), flatus (3.89 ± 1.49 vs. 3.69 ± 1.12, P = 0.255), liquid diet (4.88 ± 1.88 vs. 4.79 ± 1.57, P = 0.684), or duration of postoperative hospital stay (12.52 ± 4.83 vs. 12.63 ± 7.32, P = 0.903). The postoperative complication rates of the 3D and 2D groups were 18.3 and 16.1%, respectively, P = 0.723. No patients died during the postoperative hospital stay. However, the intraoperative blood loss in the 3D group was significantly lower than the 2D group (58 ± 75 vs. 78 ± 72 ml, P = 0.047).

CONCLUSION

There was no significant difference in operation time and number of lymph node harvested between the 3D and 2D groups; however, 3D laparoscopic surgery may reduce the intraoperative blood loss compared to 2D procedure. Therefore, we conclude that this trial is safe and is thus ongoing.

Comparison of experience curves between two 3-dimensional intraoral scanners

STATEMENT OF PROBLEM

Conventional impression-making methods are being replaced by intraoral digital scanning. How long dental professionals take to master the new technologies is unknown.

PURPOSE

The purpose of this human subject study was to compare the experience curves of 2 intraoral scanners among dental hygienists and determine whether repeated scanning experience could change the scan time (ST).

MATERIAL AND METHODS

A total of 29 dental hygienists with more than 3 years of working experience were recruited (group 1: 3-5 years; group 2: >6 years of clinical experience) to learn the iTero and Trios systems. All learners scanned the oral cavities of 4 human participants (participants A, B, C, and D) 10 times (T1-T10) throughout the learning sessions and the experimental dentoform model twice at the beginning and end of the 10 sessions. ST was measured, and changes in ST were compared between the 2 devices.

RESULTS

The average ST for 10 sessions was greater with iTero than with Trios, but the decrease in the measured ST was greater for iTero than for Trios. Baseline and postexperience STs with iTero showed statistically significant differences, with a decrease in time related to the clinical experience levels of the dental hygienists (group 1: T2 and T4, P<.01; group 2: T2 and T5, P<.01). The experience curve with iTero was not influenced by the human participant's intraoral characteristics, and greater ST was shown for participants B and C than for participants A and D with Trios.

CONCLUSIONS

Although the learning rate of iTero was rapid, the average ST for iTero was longer than Trios, and clinical experience levels influenced the operator's ability to manipulate the device. In contrast, the learning rate of Trios was slow, and measured ST was shorter than iTero, and was not influenced by clinical experience.

Beyond 2D telestration: an evaluation of novel proctoring tools for robot-assisted minimally invasive surgery

Experienced surgeons commonly mentor trainees as they move through their initial learning curves. During robot-assisted minimally invasive surgery, several tools exist to facilitate proctored cases, such as two-dimensional telestration and a dual surgeon console. The purpose of this study was to evaluate the utility and efficiency of three, novel proctoring tools for robot-assisted minimally invasive surgery, and to compare them to existing proctoring tools. Twenty-six proctor-trainee pairs completed validated, dry-lab training exercises using standard two-dimensional telestration and three, new three-dimensional proctoring tools called ghost tools. During each exercise, proctors mentored trainees by correcting trainee technical errors. Proctors and trainees completed post-study questionnaires to compare the effectiveness of the proctoring tools. Proctors and trainees consistently rated the ghost tools as effective proctoring tools. Both proctors and trainees preferred 3DInstruments and 3DHands over standard two-dimensional telestration (proctors p < 0.001 and p = 0.03, respectively, and trainees p < 0.001 and p = 0.002, respectively). In addition, proctors preferred three-dimensional vision of the operative field (used with ghost tools) over two-dimensional vision (p < 0.001). Total mentoring time and number of instructions provided by the proctor were comparable between all proctoring tools (p > 0.05). In summary, ghost tools and three-dimensional vision were preferred over standard two-dimensional telestration and two-dimensional vision, respectively, by both proctors and trainees. Proctoring tools—such as ghost tools—have the potential to improve surgeon training by enabling new interactions between a proctor and trainee.