Clinical Application and Further Development of Augmented Reality Guidance for the Surgical Localization of Pediatric Chest Wall Tumors.

BACKGROUND: Surgical treatment of pediatric chest wall tumors requires accurate surgical planning and tumor localization to achieve radical resections while sparing as much healthy tissue as possible. Augmented Reality (AR) could facilitate surgical decision making by improving anatomical understanding and intraoperative tumor localization. We present our clinical experience with the use of an AR system for intraoperative tumor localization during chest wall resections. Furthermore, we present the pre-clinical results of a new registration method to improve our conventional AR system. METHODS: From January 2021, we used the HoloLens 2 for pre-incisional tumor localization during all chest wall resections inside our center. A patient-specific 3D model was projected onto the patient by use of a five-point registration method based on anatomical landmarks. Furthermore, we developed and pre-clinically tested a surface matching method to allow post-incisional AR guidance by performing registration on the exposed surface of the ribs. RESULTS: Successful registration and holographic overlay were achieved in eight patients. The projection seemed most accurate when landmarks were positioned in a non-symmetric configuration in proximity to the tumor. Disagreements between the overlay and expected tumor location were mainly due to user-dependent registration errors. The pre-clinical tests of the surface matching method proved the feasibility of registration on the exposed ribs. CONCLUSIONS: Our results prove the applicability of AR guidance for the pre- and post-incisional localization of pediatric chest wall tumors during surgery. The system has the potential to enable intraoperative 3D visualization, hereby facilitating surgical planning and management of chest wall resections. LEVEL OF EVIDENCE: IV TYPE OF STUDY: Treatment Study.

The feasibility and benefit of unsupervised at-home training of minimally invasive surgical skills.

BACKGROUND: Simulation-based training may be used to acquire MIS skills. While mostly done in a simulation center, it is proposed that this training can be undertaken at-home as well. The aim of this study is to evaluate whether unsupervised at-home training and assessment of MIS skills is feasible and results in increased MIS skills. METHODS: Medical doctors and senior medical students were tested on their innate abilities by performing a pre-test on a take-home simulator. Henceforth, they followed a two-week interval training practicing two advanced MIS skills (an interrupted suture with knot tying task and a precise peg transfer task) and subsequently performed a post-test. Both tests and all training moments were performed at home. Performance was measured using motion analysis software (SurgTrac) and by expert-assessment and self-assessment using a competency assessment tool for MIS suturing (LS-CAT). RESULTS: A total of 38 participants enrolled in the study. Participants improved significantly between the pre-test and the post-test for both tasks. They were faster (632 s vs. 213 s, p < 0.001) and more efficient (distance of instrument tips: 9.8 m vs. 3.4 m, p = 0.001) in the suturing task. Total LS-CAT scores, rated by an expert, improved significantly with a decrease from 36 at the pre-test to 20 at the post-test (p < 0.001) and showed a strong correlation with self-assessment scores (R 0.771, p < 0.001). The precise peg transfer task was completed faster (300 s vs. 163 s, p < 0.001) and more efficient as well (14.8 m vs. 5.7 m, p = 0.005). Additionally, they placed more rings correctly (7 vs. 12, p = 0.010). CONCLUSION: Unsupervised at-home training and assessment of MIS skills is feasible and resulted in an evident increase in skills. Especially in times of less exposure in the clinical setting and less education on training locations this can aid in improving MIS skills.

Evaluating the Use of a Take-Home Minimally Invasive Surgery Box Training for At-Home Training Sessions Before and During the COVID Pandemic.

Introduction: Acquiring and retaining minimally invasive surgery (MIS) skills may be aided by using MIS take-home box simulators. This study aims to evaluate the use of a take-home MIS box trainer for training sessions at-home. Methods: Trainees who previously bought the LaparoscopyBoxx (between 2016 and 2020) were asked to complete an online questionnaire. The first part was on their demographic data, and the second part was on their use and opinion on the box trainer (on a 5-point Likert scale). Results: A total of 39 participants (9 surgeons and 30 trainees) completed the questionnaire (response rate 40%). Overall, participants had a positive opinion on the use of the box trainer and would recommend it to others for training (mean 4.2). Basic tasks, such as needle trail and ring transfer, were practiced most often and were regarded most relevant (mean 4.1-4.3). They regarded practicing on the stimulator of added value to practicing in the clinic (mean 4.2), were more confident during clinical procedures (mean 3.9), and felt that their skills had improved (mean 4.1). Of quarter of the participants who bought the MIS box trainer during the COVID-19 pandemic reported an increased use during times of less clinical exposure. Conclusion: Surgeons and trainees have a positive opinion on using a take-home MIS box trainer for at-home training for general as well as for pediatric MIS skills. Especially during periods of less exposure in the clinical setting and less hands-on courses, such as during the COVID-19 pandemic, at-home training may be a valuable addition.

The effect of continuous at-home training of minimally invasive surgical skills on skill retention.

BACKGROUND: Skill deterioration of minimally invasive surgical (MIS) skills may be prevented by continuous training. The aim of this study is to evaluate whether unsupervised continuous at-home training of MIS skills results in better skill retention compared to no training. METHODS: Medical doctors followed a two-week interval training for two MIS tasks (precise peg transfer and interrupted suture with knot tying), ending with a baseline test. They were randomly assigned to the no-practice group or continuous-practice group. The latter practiced unsupervised at home every two weeks during the study period. Skill retention was measured after three and six months on both tasks by the total time needed, distance traveled by instruments and LS-CAT score (8 best possible score and > 40 worst score). RESULTS: A total of 38 participants were included. No significant differences in performance were found at pre-test or baseline. At six months the no-practice group needed more time for the suturing task (309 s vs. 196 s at baseline, p = 0.010) and the LS-CAT score was significantly worse (30 vs. 20 at baseline, p < 0.0001). The continuous-practice group performed the suturing task significantly better than the no-practice group at both three and six months (17 vs. 25, p < 0.001 and 17 vs. 30, p < 0.001) and faster as well (p = 0.034 and p = 0.001). CONCLUSION: This study shows a skill decay after only a few months of non-use and shows better skill retention after continuous unsupervised at-home practice of MIS skills. This indicates an added value of regular at-home practice of surgical skills.

Validation of a Newly Developed Competency Assessment Tool for the Posterior Sagittal Anorectoplasty.

INTRODUCTION: The correction of an anorectal malformation (ARM) is complex and relatively infrequent. Simulation training and subsequent assessment may result in better clinical outcomes. Assessment can be done using a competency assessment tool (CAT). This study aims to develop and validate a CAT for the posterior sagittal anorectoplasty (PSARP) on a simulation model. MATERIALS AND METHODS: The CAT-PSARP was developed after consultation with experts in the field. The PSARP was divided into five steps, while tissue and instrument handling were scored separately. Participants of pediatric colorectal hands-on courses in 2019 and 2020 were asked to participate. They performed one PSARP procedure on an ARM simulation model, while being assessed by two objective observers using the CAT-PSARP. RESULTS: A total of 82 participants were enrolled. A fair interobserver agreement was found for general skills (intraclass correlation coefficient [ICC] = 0.524, p < 0.001), a good agreement for specific skills (ICC = 0.646, p < 0.001), and overall performance (ICC = 0.669, p < 0.001). The experienced group scored higher on all steps (p < 0.001), except for "anoplasty (p = 0.540)," compared with an inexperienced group. CONCLUSION: The CAT-PSARP is a suitable objective assessment tool for the overall performance of the included steps of the PSARP for repair of an ARM on a simulation model.

The Use of an Inanimate Simulation Model for the Correction of an Anorectal Malformation in the Training of Colorectal Pediatric Surgery.

INTRODUCTION: An anorectal malformation (ARM) is a congenital malformation that requires surgical correction. To acquire the skills needed to perform this complex procedure, an affordable simulation model has previously been developed and validated. The aim of this study is to evaluate the suitability of this ARM model (with perineal fistula) for training in hands-on workshops. MATERIALS AND METHODS: The ARM model consists of a wooden casing with disposable perineal body. Participants in several international pediatric colorectal hands-on workshops in 2019 and 2020 were asked to participate. They were divided in a target group and an experienced group based on experience. All practiced the posterior sagittal anorectoplasty procedure on the model with multimodality guidance. Subsequently, statements on the suitability of the model for use during hands-on workshops were scored on a 5-point Likert scale. RESULTS: A total of 80 participants were included (43 surgical specialists, 13 pediatric surgery fellows, and 25 residents). Nearly, all statements scored at least a mean of >4.0, all scored significantly better than a neutral opinion. The target group (n = 58) scored higher compared with the experienced group (n = 22) on "transferability of the skills to the clinical setting" (means 4.4 vs. 4.0, p = 0.038); however, the "suitability as a replacement for an animal model" scored significantly lower (means 3.6 vs. 3.9, p = 0.049). No other differences were found. CONCLUSION: This affordable ARM model was regarded a suitable model for training during preclinical hands-on workshops and could be used for the specified steps of the procedure.

The Effect of an Interval Training on Skill Retention of High-Complex Low-Volume Minimal Invasive Pediatric Surgery Skills: A Pilot Study.

Background: Current training programs for complex pediatric minimal invasive surgery (MIS) are usually bulk training, consisting of 1- or 2-day courses. The aim of this study was to examine the effects of bulk training versus interval training on the preservation of high-complex, low-volume MIS skills. Materials and Methods: Medical students, without prior surgical experience, were randomly assigned to either a bulk or interval training program for complex MIS (congenital diaphragmatic hernia [CDH] and esophageal atresia [EA] repair). Both groups trained for 5 hours; the bulk group twice within 3 days and the interval groups five times in 3 weeks. Skills retention was assessed at 2 weeks, 6 weeks, and 6 months posttraining, using a composite score (0%-100%) based on the objective parameters tracked by SurgTrac. Results: Seventeen students completed the training sessions (bulk n = 9, interval n = 8) and were assessed accordingly. Retention of the skills for EA repair was significantly better for the interval training group than for the bulk group at 6 weeks (P = .004). However, at 6 months, both groups scored significantly worse than after the training sessions for EA repair (bulk 60 versus 67, P = .176; interval 63 versus 74, P = .028) and CDH repair (bulk 32 versus 67, P = .018; interval 47 versus 62, P = .176). Conclusion: This pilot study suggests superior retention of complex pediatric MIS skills after interval training, during a longer period of time, than bulk training. However, after 6 months, both groups scored significantly worse than after their training, indicating the need for continuous training.

Are Self-Assessment and Peer Assessment of Added Value in Training Complex Pediatric Surgical Skills?

INTRODUCTION: Self-assessment aids "reflection-before-practice," which is expected to result in a better understanding of one's strengths and weaknesses and consequently a better overall performance. This is, however, rarely used in surgical training. This study aims to evaluate the correlation between self-, peer-, and expert assessment on surgical skills of pediatric surgical trainees. MATERIALS AND METHODS: A competency assessment tool for the posterior sagittal anorectoplasty (CAT-PSARP) was previously developed and validated. During international hands-on pediatric colorectal workshops in 2019 and 2020, participants practiced the PSARP on an inanimate anorectal malformation model. They were assisted by a peer and assessed by two independent expert observers, using the CAT-PSARP. After the training session, both self- and peer assessment were completed, using the same CAT-PSARP. RESULTS: A total of 79 participants were included. No correlation was found between the overall CAT-PSARP scores of the expert observers and the self-assessment (r = 0.179, p = 0.116), while a weak correlation was found between experts and peer assessment (r = 0.317, p = 0.006). When comparing the self-assessment scores with peer assessment, a moderate correlation was found for the overall performance score (r = 0.495, p < 0.001). Additionally, the participants who were first to perform the procedure scored significantly better than those who trained second on the overall performance (mean 27.2 vs. 24.4, p < 0.001). CONCLUSION: Participants, peers, and experts seemed to have a unique view on the performance during training because there was little correlation between outcomes of the trainees and the experts. Self-assessment may be useful for reflection during training; however, expert assessment seems to be essential for assessment of surgical skills.

Take-Home Laparoscopy Simulators in Pediatric Surgery: Is More Expensive Better?

Background: To increase complex minimally invasive skills (MIS), frequent training outside the clinical setting is of uttermost importance. This study compares two low-cost pediatric MIS simulators, which can easily be used preclinically. Materials and Methods: The LaparoscopyBoxx is a portable simulator without a tracking system, with costs ranging from €90 to €315. The EoSim simulator has a built-in camera and tracking system and costs range from €780 to €1800. During several pediatric surgical conferences and workshops (January 2017-December 2018), participants were asked to use both simulators. Afterward, they completed a questionnaire regarding their opinion on realism and didactic value, scored on a five-point Likert scale. Results: A total of 50 participants (24 experts and 25 target group, one unknown) evaluated one or both simulators. Both simulators scored well on the questionnaire. The LaparoscopyBoxx scored significantly better regarding the "on screen representation of the instrument actions" (mean 4.2 versus 3.5, P = .001), "training tool for pediatric surgery" (mean 4.4 versus 3.9, P = .005), and "appealing take-home simulator" (mean 4.6 versus 4.0, P = .002). Conclusion: The simulators tested in this study were both regarded an appealing take-home simulator. The LaparoscopyBoxx scored significantly better than the EoSim, even though this is a low budget simulator without tracking capabilities.

Value of macrobiopsies and transanal endoscopic microsurgery in the histological work-up of rectal neoplasms: A retrospective study.

AIM: To evaluate a step up approach: Taking macrobiopsies and performing excision biopsies in patients with suspected rectal cancer in which biopsies taken though the flexible endoscope showed benign histology. METHODS: Patients with a rectal neoplasm who underwent flexible endoscopy and biopsies were included. In case of benign biopsies rigid rectoscopy and macrobiopsies were employed. If this failed to prove malignancy, transanal endoscopic microsurgery (TEM) was used in a final effort to establish a certain preoperative diagnosis. The preoperative results were compared with the findings after surgical excision and follow up to calculate the reliability of this algorithm. RESULTS: One hundred and thirty-two patients were included. One hundred and ten patients with a carcinoma and 22 with an adenoma. Seventy-five of 110 carcinomas were proven malignant after flexible endoscopy. With the addition of rigid endoscopy and taking of macrobiopsies, this number increased to 89. Performing TEM excision biopsies further enlarged the number of proven malignancies to 100. CONCLUSION: The step-up approach includes taking macrobiopsies through the rigid rectoscope and performing excision biopsies using transanal endoscopic microsurgery in addition to flexible endoscopy. This approach, reduced the number of missed preoperative malignant diagnoses from 32% to 9%.

Acute toxicity and surgical complications after preoperative (chemo)radiation therapy for rectal cancer in patients with inflammatory bowel disease.

PURPOSE: Preoperative therapy reduces local recurrences and may facilitate surgery in rectal cancer patients. However, in patients with inflammatory bowel disease (IBD) this treatment is often withheld due to the perceived risk of excessive side-effects, even though evidence is limited. The purpose of this study is to investigate the effects of preoperative therapy on acute toxicity and post-operative complications in IBD patients with rectal cancer. METHODS: The Dutch pathology registry (PALGA) was searched for patients with IBD and rectal cancer treated between January 1991 and May 2010. Histopathology and clinical charts were reviewed to confirm IBD diagnosis and evaluate clinical and pathological characteristics. RESULTS: Out of 161 patients, 66 received preoperative therapy (41%), including short-course radiation therapy (SC-RT), long course radiation therapy (LC-RT), and chemoradiation therapy (CRT) in 32, 13, and 21 patients respectively. Grade≥3 acute toxicity occurred in 0 patients (0.0%), 1 patient (7.7%), and 6 patients (28.6%) respectively (p=0.004). Systemic corticosteroids were used by 10.5% of patients at time of treatment. Grade≥3 post-operative 30-day complication rate (28.1% overall) was not associated with type of preoperative therapy. CONCLUSION: Results did not show excessive rates of toxicity or post-operative complications and support the use of standard preoperative therapies for rectal cancer (especially SC-RT) in IBD patients with relatively indolent disease. Caution is warranted in patients with active IBD, since the exact impact of active bowel inflammation could not be determined retrospectively. Prospective studies should investigate the influence of active IBD on acute and late toxicity in patients receiving pelvic irradiation.

The CARTS study: Chemoradiation therapy for rectal cancer in the distal rectum followed by organ-sparing transanal endoscopic microsurgery.

BACKGROUND: The CARTS study is a multicenter feasibility study, investigating the role of rectum saving surgery for distal rectal cancer. METHODS/DESIGN: Patients with a clinical T1-3 N0 M0 rectal adenocarcinoma below 10 cm from the anal verge will receive neoadjuvant chemoradiation therapy (25 fractions of 2 Gy with concurrent capecitabine). Transanal Endoscopic Microsurgery (TEM) will be performed 8 - 10 weeks after the end of the preoperative treatment depending on the clinical response.Primary objective is to determine the number of patients with a (near) complete pathological response after chemoradiation therapy and TEM. Secondary objectives are the local recurrence rate and quality of life after this combined therapeutic modality. A three-step analysis will be performed after 20, 33 and 55 patients to ensure the feasibility of this treatment protocol. DISCUSSION: The CARTS-study is one of the first prospective multicentre trials to investigate the role of a rectum saving treatment modality using chemoradiation therapy and local excision. The CARTS study is registered at clinicaltrials.gov (NCT01273051).