D

Diverticular stones

It refers to the stones in a cystic cavity of the kidney lined by the urothelium, connected to the pelvicalyceal system via a narrow neck.

Dusting

A technique that uses low pulse energy and high frequency during laser lithotripsy to dust the stone. This technique utilizes a Holmium:YAG laser to ablate stones into dust. Recommended settings for dusting are: 0.2 J and 20 Hz.

F

Fragmentation

It is a technique that uses high pulse energy and low frequency during laser lithotripsy to break the stone into fragments.

I

Intrarenal pressure

It refers to the pressure in the pelvicalyceal system during ureteroscopy. While the normal physiological pressure is 10mmHg, this can rise during ureteroscopy causing pyelovenous, pyelosinus and pyelolymphatic backflow. Forced irrigation pressures also increase the risk of infective complications.

Irrigation

It is used to maintain the vision while performing ureteroscopy. Saline is the standard irrigation, which is usually pressurized to get adequate flow.

L

Laser fiber

It is the energy source used to break the stone and varies in its diameter, shape of the tip, affect on ablation of calculi and its degradation.

Laser settings

Laser lithotripters allow the regulating of total power output by controlling the pulse energy and pulse frequency.

By adjusting these parameters for dusting, the energy can range from 0.2–0.6 J with a frequency of 20–50 Hz, and for fragmentation the energy can range from 0.6–1.2 J with a frequency of 5–12 Hz.

Lower pole stones

It refers to the stones in the lower part of the pelvicalyceal system (lower calyx). The stones can either be treated in-situ or relocated to the upper pole calyx or renal pelvis for fragmentation.

P

Port seal

It is placed on the working channel of the ureteroscope, consisting of an O-ring, which allows using the instrument channel without causing any leaks whilst preserving the irrigation flow.

Pre-stenting

It is the insertion of a ureteric stent either electively or in an emergency situation prior to ureteroscopy, which is performed at a later date. It is usually done in difficult retrograde access for ureteroscopy either due to anatomic abnormalities, narrow ureteric lumen, tortuous ureter or previous instrumentation. Elective or planned ureteroscopy is subsequently done after a few weeks.

R

Retropulsion

It refers to proximal migration of the stone during laser lithotripsy, thereby reducing the efficacy and increasing the operating time duration. High pulse energy and short-pulse mode increases retropulsion.

S

Safety wire

It is the guidewire left in place before doing the ureteroscopy and often helps to keep the ureteric orifice open aiding passage of the ureteroscope.

Stone extraction devices

It refers to the stone graspers, baskets and forceps used to extract stone fragments.

U

Ureteral access sheath

A two-piece hydrophilic device consisting of a sheath and the internal dilator. It is inserted over the working wire under fluoroscopic control; the inner dilator can be removed once the sheath is in place to facilitate easy access to the collecting system and multiple passages of the ureteroscope. It comes in various diameters (9.5 Fr – 14 Fr internal diameter; 11.5 Fr – 17.5 Fr external diameter) and lengths (20–55 cm).

Ureteral catheter

It is used for retrograde pyelogram (RPG) or for positioning of guidewire in the ureter or to obtain urine sample from pelvicalyceal system for cytology/culture.

Ureteroscopy

 It is an endoscopic procedure to examine the ureter and/or kidney using a ureteroscope.

W

Working/navigating guidewire

 It is the second guidewire inserted via the ureteroscope and used for navigating, enabling the passage of ureteroscope.