Dilation of the ureteral orifice is very rarely necessary. If there is difficulty in entering the orifice with the semirigid scope, insert two stiff guide wires through orifice. They will open up the orifice and one of them can be used as a guide for the scope. The other remains as a safety wire.

Rotation of the scope’s tip may be necessary in order to enter the ureteral orifice. Rotation to a medial direction is done, orifice is entered and then re-rotated to original position

Irrigation with a pump significantly improves clarity of visual field and provides dilation of orifice and ureter. However, fragments may be dislocated to upper ureter or pelvis if one is not careful.

Ureteral sheaths are of great value especially when multiple passes of the scope are anticipated. Sheath may be placed in close contact to the stone and aid in the removal of larger fragments. Furthermore, a sheath ensures that pressures in the collecting system will never be high, as it serves as a passive drain. A first pass through the ureter (without the sheath) to identify the stones is recommended, as sometimes the sheath may pass over a small stone and embed it into the ureteral wall.

Ureteral sheaths may be moved caudally without the introducer tip, but NEVER cranially. The edges of the sheath will «catch» the ureteral wall and cause significant damage

When using a basket for retrieval of a stone, it is seldom necessary to close the wire mechanism. Removing a stone with an open basket minimizes the risk of enclosing a portion of the ureteral wall along with the stone

When a fragment is too large to be removed through the sheath, it may be carefully removed together with the sheath and scope. The sheath provides dilation of the caudal ureteral section to ease the passage of the stone. However, If tension is encountered, the stone should be left in place and further diminished using the laser or US lithotripter. To regain access to the ureter, the dual lumen catheter should be inserted over the safety wire and a second working stiff wire should be inserted. Then the dual lumen catheter is removed and the ureteral sheath is placed over the working wire.

Occasionally, a stone in the pelvis, superior or even middle calyces may be found and removed using the semirigid ureteroscope. Stones in the lower calyces are impossible to treat with the semirigid scope.

If a stone obstructs the ureter to the extent that a stiff wire cannot pass through, try to pass a hydrophilic wire. If this passes, (hydrophilic wires almost always pass any obstruction), place a hydrophilic 4 Fr angiography catheter over the hydrophilic wire. It should now be possible to insert a stiff wire to straighten the ureter and provide passage to the ureteroscope

When using the laser fiber to disintegrate a stone, make sure to keep the plastic sheath in the scope’s view. This will ensure a proper distance between the laser and the scope’s lens, minimizing the risk of damage to the optics.

«Blind» activation of the laser could easily result in ureteral wall perforation. The laser fiber should always be kept in view, and on stand-by until ready to fire at stone.

Stones should be disintegrated from the periphery to the center.

The flexible ureteroscope is a very delicate device. Careful handling is mandatory.

Movements of the flexible scope are accomplished using three types of motion. Insertion and withdrawal of the scope, upwards and downwards flexion of the tip using the thumb mechanism and rotation of the wrist medially and laterally. It is not useful to bend the scope using elbow or shoulder rotation. Although the flexible scope may be inserted without a ureteral sheath, our experience has been that it is much easier and quicker to use a sheath.

In order to orient oneself in the pelvis, a combination of fluoroscopy and direct vision may be used. First inject contrast solution to visualize the collecting system. The scope may be advanced to the upper calyces, then the tip should be flexed and rotated to the side of the calyces. By withdrawing the scope, it should sequentially «pop» into the middle and then lower calyces. Then, direct vision may be used to navigate through the calyces.

Laser fibers and baskets should not be inserted into a flexed ureteroscope. This will damage the ureteroscopes’ tip. It should be straightened in the pelvis, the fiber or basket inserted to the tip of the scope, then the scope and fiber are flexed together to enter a calyx. When inside the calyx, the fiber or basket should be further pushed forward.

As with rigid URS, flexible ureteroscopy is greatly facilitated by using a pump to inject irrigation fluid. Repositioning of stones from the lower or middle calyx to pelvis facilitates easier disintegration and removal of stones.