Tips and tricks of ureteroscopy: consensus statement Part I. Basic ureteroscopy

Abstract

Ureteroscopy is fast becoming the first line treatment option for the majority of urinary tract stones. Ureteroscopy training can be performed in a variety of ways including simulation, hands on ureteroscopy courses and supervised operative experience. We report an "expert consensus view" from experienced endourological surgeons, on all aspects of basic ureteroscopic techniques, with a particular focus on avoiding and getting out of trouble while performing ureteroscopy. In this paper we provide a summary of treatment planning, positioning, cannulation of ureteric orifice, guidewire placement, rigid ureteroscopy and stone fragmentation.

Keywords: stent; ureterorenoscopy; ureteroscopy; urolithiasis.

Figure 1

Ureteric catheter as a pointer. 1a. A 6Fr open-ended ureteric catheter is aimed at the Left ureteric orifice. 1b. A pre-loaded hydrophilic tipped “stone wire” is advanced towards the UO – the direction of the wire is determined by the direction of the ureteric catheter; there is no risk that the wire will twist in the scope and exit in the wrong direction. 1c. The wire can be advanced under vision and fluoroscopic control as normal. If necessary, the ureteric catheter can be advanced over the wire, either for additional support of the wire, or for a retrograde contrast study.

Figure 2

A “Navigating” wire. A pre-placed safety wire can be seen heading up the ureter towards the kidney. The green wire, just a few mm beyond the tip of the ureteroscope (i.e. in its flexible segment) can be used like a proboscis for “feeling” the path ahead, and allow the scope to pass smoothly over the contour of the ureter, such as narrow segments, the middle third of the ureter, or to bypass a ureteric stone.

Figure 3

Ureteric catheter to negotiate difficult stone. 3a and 3b. Axial and Coronal CT images showing a distal ureteric stone. 3c. An initial attempt to pass a wire beyond the stone failed with buckling at the site of the stone on flouroscopy 3d. A ureteric catheter over the wire, without contrast, allowed the wire to be directed towards the edge, rather than the middle of the stone 3e. The wire was passed under fluoroscopic control beyond the stone, and could then be advanced straightforwardly to the level of the kidney, and be secured as a safety guide wire.

Figure 4

Ureteric catheter for tortuous upper ureter. 4a and 4b. Axial and Coronal CT images showing a substantially dilated, tortuous proximal ureter (red arrows). 4c. The ureteric catheter is advanced as far as the beginning of the “Z” loop. 4d. A hydrophilic-tipped wire is advanced via the ureteric catheter, and onwards around the “Z” loop. 4e. The ureteric catheter and wire are negotiated upwards towards the kidney in combination. 4f. After removal of the wire, a retrograde study can be performed via the ureteric catheter to define the pelvicalyceal system anatomy (and ensure that the subsequent JJ stent is placed in the correct position). 4g. The wire is replaced via the ureteric catheter – in cases with a particularly tortuous ureter such as this, a “super-stiff” wire is often useful to aid stent placement without buckling or misplacement. 4h. The ureteric catheter is removed over the wire (and replaced with a stent – not shown).

Figure 5

The curve of the ureter. 5a, b and c. The ureter (highlighted with red arrows) is shown at the PUJ (a), in its middle third (b) and with a stone at the VUJ (c). In this series, the arrows show the movement needed from medial (at the VUJ) to lateral (at the PUJ) required for ureteroscope advancement. 5d. This full-length coronal reconstruction shows the initial course of the lower third of the ureter passes laterally, before moving medially in the middle and into the proximal ureter, before curving laterally towards the renal pelvis. 5e. The purple line on this sagittal reconstruction demonstrates the initial posterolateral direction of the ureter, and the substantial anterior displacement needed to traverse the middle third, particularly in patients with a well-developed psoas muscle (highlighted with a white arrow).

Figure 6

A stone being lasered and then basketed. 6a. A stone being fragmented by laser energy. The stone is being “carved into two” to allow the pieces to be retrieved with a basket. 6b. A stone fragment in a tip-less nitinol basket for extraction and biochemical analysis. The stone is close enough to be seen, whilst allowing the ureteric mucosa to be observed at all times that the ureteroscope is being withdrawn.