In the last decade, single-use flexible ureteroscopes (su-fURS) have emerged to address the challenges associated with reusable fURS, including high costs of acquisition, sterilization and maintenance, limited durability due to deflection loss, and contamination risks. Since the launch of LithoVue™, the first fully disposable digital fURS in 2016 by Boston Scientific (MA, USA), numerous manufacturers have introduced various models of su-fURS in India. There are around 17 su-fURS currently available in the commercial market globally with both Food and Drug Administration (FDA) and European Conformity (CE) certifications.(1,2) However, most of them are not available in India. The Uscope UE3022/3022A, su-fURS developed by Pusen (Zhuhai, China), was the next model to be launched in the market. The next additions to the range were the Indoscope SLEEK (Biorad Medisys, Pune, India) and the HU30 (HugeMed, Shenzhen, China). The Flex-XC1 by Karl Storz, Tuttlingen, Germany, has been developed recently and launched in 2024. This article brings together the various physical and technical characteristics of su-fURS currently offered in the Indian market.
The design of fURS is heavily influenced by size, particularly the tip and outer shaft diameter, as these factors ensure smooth access to the ureteral orifice and minimize the risk of ureteral injury. The working channel size is also critical, as it supports the use of accessory devices like guide wires, baskets and laser fibers while facilitating effective irrigation to displace blood, stone fragments and dust, improving visibility. Deflection capability, which refers to the range of motion at the distal tip of the scope, is crucial for treating lower-pole stones and accessing difficult calyces. Modern devices offer bidirectional deflection of 270-285°, and self-locking mechanisms to reduce muscle fatigue during long procedures. Digital sensors, particularly complementary metal-oxide semiconductors (CMOS), have enhanced imaging by offering faster image processing and cost efficiency compared to charge-coupled devices (CCDs). Most su-fURS models provide a 160K pixel resolution and a field of view between 85° and 120°. The inclusion of buttons on ureteroscope handpieces for image capture and video recording enhances their functionality. Several in-vivo and in-vitro comparisons of su-fURS have been performed to compare their functionality.(3,4) Castellani et al, assessed complications and stone-free rate of flexible ureteroscopy reusing disposable scopes after repeated sterilization, and concluded that it can be used as a cost-conscious approach with a low rate of serious infections but with a high rate of residual fragments.(5)
Table 1: Physical and technical features of available scopes in India
FOV (degree) | Shaft Length (mm) | Tip Diameter (Ch) | Outer Shaft Diameter (Ch) | Working Channel Diameter (Ch) | Working Channel Position (O’clock) | Deflection | Resolution (pixels) | Depth of Field (mm) | |
Flex-XC1, Karl Storz | 105 | 700 | 9 | 9 | 3.5 | 3 | 270 | 400x400 | 5-50 |
LithoVue, Boston Scientific | 85 | 680 | 7.7 | 9.5 | 3.6 | 3 | 270 | 400x400 | 2-50 |
Indoscope SLEEK, Biorad MediSys | 110 | 670 | 7.5 | 7.5 | 3.3 | 2-11 | 270 | 400x400 | 2-50 |
Uscope 3033/3033A, Pusen | 120 | 650 | 7.5 | 7.5 | 3.6 | 3 | 270 | 400x400 | 3-50 |
Uscope 3022/3022A, Pusen | 90 | 650 | 9.2 | 9.2 | 3.6 | 3 | 270 | 250x250 | 3-50 |
HU30M, HugeMed | 120 | 650 | 6.3 | 6.3 | 3.6 | 3-9 | 285 | 400x400 | 3-100 |
HU30S, HugeMed | 120 | 650 | 7.5 | 7.5 | 3.6 | 3-9 | 285 | 400x400 | 3-100 |
HU30, HugeMed | 120 | 650 | 9.0 | 9.0 | 3.6 | 3-9 | 285 | 400x400 | 3-100 |
Figure 2: A. Flex-XC1 (Karl Storz) B. LithoVue™ (Boston Scientific) C. Indoscope Sleek (Biorad MediSys) D. Uscope (Pusen) E. HU30 (Shenzhen HugeMed)
Authored by Dr Swapnil Singh Kushwaha, Max, Vaishali