Trapped Flexible Ureteroscope in Ureteral Access Sheath During Retrograde Intrarenal Surgery: An Unexpected Problem

Abstract

Background: Instrument-related complications occur occasionally with the use of flexible ureteroscopes. In this study, we present a unique problem related to instrument malfunction of flexible ureteroscope during retrograde intrarenal surgery. Case Presentation: A 60-year-old male patient with a 1.2 cm left upper ureteral stone initially underwent semirigid ureteroscopic laser lithotripsy and during the procedure the stone got retropulsed into middle calix of the kidney. Subsequently, a 9.5F (internal diameter) ureteral access sheath was placed and using URF P6R flexible ureteroscope (Olympus) the stone was completely dusted with holmium laser. At the end of the procedure, the operating surgeon was unable to remove the ureteroscope out of the ureteral access sheath as it was getting stuck inside. On careful inspection under fluoroscopy, it was noticed that there was a partial break in the outer surface of the flexible ureteroscope at the level of the junction of the distal flexible part of the ureteroscope with the shaft. Since multiple attempts to retrieve the ureteroscope into the access sheath failed, a decision was made to pull the ureteroscope and ureteral access sheath as a whole over a 0.035 † terumo guidewire. Gentle traction was applied on the entire assembly and the instrument was withdrawn out of ureter over the guidewire under fluoroscopic guidance. A lateral angulation of the distal flexible portion with the shaft of the flexible ureteroscope caused by breakage of the fiber-optic cables led to this problem intraoperatively. Conclusion: Breakage of fiber-optic cables caused by excessive manipulation of flexible ureteroscope during retrograde intrarenal surgery can lead to entrapment of the ureteroscope within the ureteral access sheath. This problem might be solved by gently withdrawing the whole assembly out of the ureter over a guidewire.

Safety enhanced surgical robot for flexible ureteroscopy based on force feedback

“…The flexible ureteroscope may be stuck in the urinary system during FURS. Urologists need to be aware of it and take action in time, [14][15][16] or severe complications will be caused. Moreover, the flexible shaft is inside the patient's urinary system, and the urologist can only see the endoscopic view in front of the scope.…”

“…As stated in the introduction section, three interactive forces exist between the flexible ureteroscope and the environment during manipulation, including axial force, axial torque, and bending knob's torque. If the flexible ureteroscope is trapped in the urinary tract for unexpected reasons, 14–16 the axial force and torque will help urologists to notice this dangerous event and avoid worse complications. The torque exerted on the flexible ureteroscope's bending knob is also important, which helps protect the flexible ureteroscope because excessive torque will damage it 18 .…”

“…It will challenge the urologist's operation, surgical safety, and the instrument's efficacy as well. For example, the flexible ureteroscope may be stuck in the urinary system for various reasons 14–16 . If the feeling of force doesn't exist, it will be hard for urologists to perceive this dangerous event.…”

“…For example, the flexible ureteroscope may be stuck in the urinary system for various reasons. [14][15][16] If the feeling of force doesn't exist, it will be hard for urologists to perceive this dangerous event. Moreover, withdrawing the bending flexible ureteroscope from the renal calyx without awareness may also lead to severe intraoperative complications.…”

Will the advances in retrograde intrarenal surgery extinguish percutaneous nephrolithotomy for stones larger than 2 cm?

“…Furthermore, a recent publication showed that UAS increased the odds of a post-operative emergency department visit and re-hospitalization, without better SFR ( 18 ). Unusual but dramatic complications related to the UAS have been described, such as the entrapment of a flexible ureteroscope (fURS) inside the sheath due to a breakage of the outer surface of the scope caused by excessive manipulation ( 20 ).…”