A pilot ex vivo evaluation of a telerobotic system for transurethral intervention and surveillance.

INTRODUCTION: Transurethral resection of bladder tumor (TURBT) and pathological staging are both standard surgical therapies for nonmuscle-invasive bladder cancer and integral parts of the diagnostic evaluation and progression monitoring of all bladder tumors. We developed and tested a dexterous robot that can fit through a standard resectoscope for evaluation for possible en bloc resection of bladder tumors, especially tumors along the dome and anterior wall of the bladder. MATERIALS AND METHODS: Our dexterous robot uses a continuum (snake-like) mechanical architecture with three working channels through which a fiberscope, biopsy graspers, and a holmium laser were placed. The continuum robot has two segments. Using indigo carmine, injections were performed through the detrusor muscle into the mucosa of the ex vivo bovine bladders at a total of 11 positions throughout all quadrants of the bladder. The snake robot was used in conjunction with the holmium laser to ablate nine of the lesions; two additional lesions were resected en bloc using the grasper and the laser down through the muscle layer. RESULTS: Both experiments showed that the robotic system was able to directly visualize all 11 targets. In both the bladders, we were able to resect en bloc two tumors using the grasper and 200 µm holmium laser fiber down to the muscle layer indicating a good resection. All of the other targets were completely ablated using the holmium laser. CONCLUSION: The dexterous robot allowed for visualization as well as provided adequate ablation and en bloc resection of bladder lesions throughout the entire bladder.

Evaluation of a Telerobotic System for Transnasal Surgery of the Larynx and Airways in Cadavers.

OBJECTIVES: Minimally invasive, transnasal endoscopic approaches to the larynx have been utilized but are limited by the precision and accuracy afforded to the surgeon. The objective of this study is to analyze the feasibility of a rapidly deployable telerobotic system for enabling transnasal microsurgery of the larynx and upper airways, specifically injection laryngoplasty. STUDY DESIGN: This is a feasibility study. SETTING: This study was conducted at a laboratory in the Department of Mechanical Engineering at Vanderbilt University. SUBJECTS AND METHODS: A feasibility study was conducted in which a telerobotic system was transnasally inserted in both a human intubation trainer mannequin and a cadaver. A flexible needle was passed through an instrumentation port and targeted specific areas of the vocal folds of our models to simulate injection laryngoplasty. The experiments were recorded with both still and video photography. Average forces exerted on surrounding tissue and times of deployment were measured. RESULTS: Our robot was able to expeditiously gain access to the glottis with an average manual insertion time of 5.87 seconds while exerting minimal forces on the surrounding tissues with an average force of 4.45 Newtons. The onboard fiberoptic endoscope conveyed images of adequate quality for the completion of a simulated injection medialization laryngoplasty. The experiment was successfully completed in both mannequin and cadaveric models. CONCLUSION: This telerobotic system proved to be capable of being rapidly deployed to the upper airways while exerting minimal forces to the surrounding structures and successfully simulated injection medialization laryngoplasty.

Design and performance evaluation of a minimally invasive telerobotic platform for transurethral surveillance and intervention.

Bladder cancer, a significant cause of morbidity and mortality worldwide, presents a unique opportunity for aggressive treatment due to the ease of transurethral accessibility. While the location affords advantages, transurethral resection of bladder tumors can pose a difficult challenge for surgeons encumbered by current instrumentation or difficult anatomic tumor locations. This paper presents the design and evaluation of a telerobotic system for transurethral surveillance and surgical intervention. The implementation seeks to improve current procedures and enable development of new surgical techniques by providing a platform for intravesicular dexterity and integration of novel imaging and interventional instrumentation. The system includes a dexterous continuum robot with access channels for the parallel deployment of multiple visualization and surgical instruments. This paper first presents the clinical conditions imposed by transurethral access and the limitations of the current state-of-the-art instrumentation. Motivated by the clinical requirements, the design considerations for this system are discussed and the prototype system is presented. Telemanipulation evaluation demonstrates submillimetric RMS positioning accuracy and intravesicular dexterity suitable for improving transurethral surveillance and intervention.