Soft Urinary Bladder Phantom for Endoscopic Training

Virtual reality vs. physical models in surgical skills training. An update of the evidence

PURPOSE OF REVIEW

Simulation is a key component of surgical training, enabling trainees to develop their skills in a safe environment. With simulators broadly grouped into physical models and virtual-reality (VR) simulators, it is important to evaluate the comparative effectiveness of the simulator types in terms of validity as well as cost. The review aims to compare the benefits and drawbacks of novel VR and physical simulators within the broader themes of endourology, laparoscopic and robotic operations, and other urological procedures.

RECENT FINDINGS

Key benefits of bench models include their comparatively lower cost, easy access and provision of haptic feedback, whereas VR simulators are generally self-sufficient, reusable and enable skills of haemostasis to be practised. The advent of perfused 3D printed simulators across a range of urological procedures may replace cadavers as the traditional gold-standard simulation modality.

SUMMARY

Although possessing differing strengths and downsides, VR and physical simulators when used together can have an additive effect due to skill transferability across the platforms. Further comparative studies are required to directly quantify the differences between physical models and VR simulators in terms of performance metrics and cost-effectiveness. There is lack of validated VR simulators for open and reconstructive procedures.

[Impact of simulation-based training in endourology: A systematic review of the literature]

INTRODUCTION

The impact of simulation on the acquisition of surgical skills as well as their transfer to the operating room is still debated. The objective was to assess these two specific points, focusing on the field of endourology.

METHODS

A systematic review of the literature, following the PRIMA statement, was performed using Medline database through September 2021 without time limit. Studies focusing on the impact of simulators on the acquisition of surgical technical skills as well as their transfer to the operating room in the field of endourology were included. The endourological procedures were: cystoscopy, ureteroscopy, percutaneous nephrolithotomy, endoscopic treatment of benign prostatic hyperplasia, endoscopic bladder resection.

RESULTS

Among the 11,442 publications identified, fifty-two studies were included in the analysis. The majority reported an improvement in procedure time of the requested tasks and dexterity of participants, regardless of the type of simulator and procedure. The level of evidence of included studies was often low. Few studies evaluated the transfer of acquired skills from the simulator to the operating room.

CONCLUSION

This review showed the positive impact of simulation on the acquisition of technical skills in endourology. However, in order to include proficiency-based progression in the curriculum of trainees, some parameters such as the choice of reference simulators, choice of tasks, and method of validation of acquired skills must be validated in a consensual manner to offer a quality training.

A Hybrid Surgical Simulator for Interactive Endoscopic Training

Endoscopy serves as an indispensable minimally-invasive surgical procedure. Due to the limited view and non-intuitive operation of the instrument, the mastery of endoscopic manipulation requires deep medical knowledge as well as complex perception and motor skills of the surgeon. Intensive surgical training is required, and simulation-based training is of more and more importance over traditional animal- or cadaver-based approaches. Here, we developed a hybrid surgical simulator that consists of a realistic physical organ model and an artificial intelligence (AI)-driven cyber model. We built a physical model of the full urinary tract with soft materials and detailed blood vessel structures. Endourological procedures were performed to localize and treat renal calculi by a flexible endoscope. An AI algorithm detects the lesions automatically with high accuracy and provides quantitative feedback about an operator's endoscopic skills. The hybrid simulator system shows great potential as an interactive and personalized learning environment for endoscopic skills. Clinical Relevance- This work establishes a preliminary approach for realistic endoscopic training. The developed hybrid surgical simulator - with high-fidelity physical organ models and quantitative feedback - can deliver effective hands-on learning to surgeons to improve their endoscopic skills.

Panoramic Imaging Assessment of Different Bladder Phantoms - An Evaluation Study

OBJECTIVE

To evaluate "panoramic image stitching" for cystoscopy, a novel technique to augment a urologist's field of view transoperatively in real-time during a cystoscopic "keyhole" procedure, 3-D bladder phantoms provide a suitable setting. Thus, the objective is the evaluation of different 3-D printed bladder phantoms with respect to their ability to be used for extended experiments of panoramic cystoscopy.

MATERIALS AND METHODS

Five bladder phantoms with different geometries, surface textures, stiffness and materials were assessed with rigid 0- and 30-degree lenses and a video-cystoscope regarding suitability for image stitching. For panoramic image generation, we use an established real-time stitching approach successfully applied to retrospective cystoscopy image sequences from real clinical cases. For evaluation of the experiments two quality criteria were defined, namely 'completeness' (describing the internal area of the phantom that can be stitched), and 'extension' (how far does an acquired panorama extend beyond the assumed 'equator' of the phantom).

RESULTS

Panoramas of all phantom and endoscope combinations were computed. Using landmarks (south pole, north pole, equator) in the phantoms, maximum extension of the panoramas was assessed. The computed panoramas yield maximum extensions between 270^o (0-degree cystoscope) and 330^o (video cystoscope). Deformable phantoms yield larger panoramas than the rigid models.

CONCLUSION

In can be concluded that the stitching process works quite well with all evaluated phantoms. Nevertheless, a novel phantom would be needed, combing a deformable, elliptical geometry and real-type vascular texture in the inside, that can be filled with water.