Life Cycle Assessment of Flexible Ureteroscopy: Analysis of Four Centers and Recommendations for an Eco-Designed Approach

Abstract

Objective:

This study aims, for the first time, to assess and quantify the environmental impact of ureteroscopy. We conducted a life cycle assessment of flexible ureteroscopy for lithiasis in four different centers, with objective of comparing their respective impacts, determining the most environmentally unsustainable steps of the procedure, and comparing the toll of different medical devices, such as single-use and reusable flexible ureteroscopes (SUFU and RFU). In order to identify eco-designed approaches and to suggest recommendations for sustainable and eco-responsible strategies.

Methods:

For each step of the procedure, we collected the reference of every medical device, their quantities, composition, transport, and disposal methods. Reusable devices’ impacts were divided by their lifespans, with sterilization processes included. Data analysis was carried out by Agence Primum non nocere—an independent company specialized in sustainable development—using SimaPro 9.5 with the Ecoinvent 3.9 database and assessing 18 environmental impacts.

Results:

The steps with the highest environmental cost were equipment installation, surgical staff attire, calculi exploration, and patient setup. There was no clear overall difference between SUFU and RFU regarding global warming, though differences were more significant in certain specific impact categories. Reusable laser fibers exhibit significantly lower environmental impacts compared with single-use fibers. The absence of transparency regarding production data from manufacturers constitutes a significant limitation to our study. We recommend designing optimized ureteroscopy packs, promoting the use of reusable fabric attire, using RFU sterilized with the low-temperature hydrogen peroxide method, prioritizing SUFU with a recycling program, revising disinfection protocols, and increasing waste valorization in operative rooms. We further recommend a hybrid approach to increase the lifespan of reusable ureteroscopes.

Keywords

environmental impact flexible ureteroscopy life cycle assessment reusable single use ureteroscope

Introduction

The health care sector makes up 8% of total greenhouse gas emissions in France.¹ Medical devices (MD) account for 21% of these,² highlighting the environmental impact of surgeries, particularly those using single-use devices. Flexible ureteroscopy, with approximately 45,000 procedures conducted annually in France,^3,4 contributes to this carbon footprint. Surgeons’ preferences for specific tools and techniques, while not affecting treatment outcomes, can vary widely and impact the environment. This study evaluates the environmental impact of flexible ureteroscopy using life cycle assessment (LCA) across four centers, aiming to determine eco-designed practices.

Materials and Methods

LCA is a standardized evaluation method⁵ used to conduct a multi-criteria and multistage environmental assessment of a system throughout its entire life cycle. This encompasses everything from the extraction of necessary raw materials for its production to its disposal.

LCA enables the environmental comparison of two systems with the same function at an equal amount of performance. An LCA study consists of four stages: goal and scope definition, inventory analysis, impact assessment, and interpretation.

Goal and scope definition

The primary objective is to perform an LCA of ureteroscopy for each center to compare their respective environmental impacts. The secondary objectives aim to determine the most environmentally unsustainable steps of the procedure and to compare the toll of different MD, such as single-use and reusable flexible ureteroscopes (SUFU and RFU). This data analysis aims to define eco-designed ureteroscopy, which involves achieving the lowest possible carbon footprint while maintaining the quality of care.

The entire procedure’s steps have been defined in a flowchart Figure 1. We decided to begin from patient preparation and entry into the operating room (OR) until the departure from the OR.

FIG. 1.

Flowchart of ureteroscopy procedure. OR = operating room.

We excluded some data: –

Transportations (pre- and postoperative stages): this would be a difficult criterion to quantify and potential source of errors.

–

Anesthesia: A standardized value was assigned, based on the assumption that the duration of general anesthesia is 2 hours.

–

Manufacturing of MD: The production processes and infrastructure associated (excluding sterilization) have been omitted from this analysis due to limited transparency in data provided by manufacturers. Regarding transportation, the analysis considers only the transportation of MD from the distribution site to the health care facility, excluding the transport of raw materials to the manufacturing site and from the manufacturing site to the distribution site.

We excluded diagnostic ureteroscopy and ureteroscopy for conservative treatment of upper urinary tract lesions. We collected data in 2022 from four French centers of different sizes and statuses: one university hospital center (Center A), one nonprofit private hospital (Center B), and two private hospitals (Centers C and D).

Life cycle inventory analysis

MD used at each stage are listed in Supplementary Table S1. For each of these, the following data were collected: product reference, manufacturer, quantity used, number of uses, material composition, weight of each material, sterilization method, place of manufacture, method of transportation, disposal process within the hospital structure, and final disposal location. Furthermore, we collected data regarding packaging: number of items per, details of primary and secondary packaging materials, their weight, disposal process within the hospital structure, and final disposal location.

We chose to take into account an average presence of seven people in the OR: one surgeon, two scrub nurses, one anesthesiologist, one nurse anesthetist, one nursing assistant, and one cleaning technician. We added three people to Center A due to its status as a university center.

For reusable devices, the impact is divided by the number of intended uses, with the addition of a disinfection or sterilization cycle per use. For surgical instruments, according to recommendations from suppliers and data used in the literature,⁶ the lifespan has been estimated at 500 cycles of use.

Regarding ureteroscopes, we specified the types and brands in Table 1. The environmental impact of SUFU was estimated based on the components outlined in the manufacturer’s data sheets. In the absence of data, the impact of assembly was estimated to be 30% of the total impact.

Table 1.

Models and Use of Ureteroscopes, Lasers, and Laser Fibers for Each Center in 2022

Center	Reusable ureteroscopes		Single use ureteroscopes		Laser : model, technology, brand	Laser fibers : model, brand, utilization	Total of interventions per year
Center	Model, brand	Interventions per year (%)	Model, brand	Interven-tions per year (%)	Laser : model, technology, brand	Laser fibers : model, brand, utilization	Total of interventions per year
A	URF V3, Olympus	50 (53%)	Neoscope, Aseptinmed	44 (47%)	Lumenis Pulse 120H Holmium, Boston Scientific	SlimLine SIS EZ 200, Boston Scientific, single use	94
B	FLEX-X2S, Storz	113 (97%)	LithoVue, Boston Scientific	3 (3%)	Lumenis Pulse 100H, Holmium, Boston Scientific Rhapsody® H-30, Holmium, Cook medical	SlimLine SIS 200, Boston Scientific Multi-Use Holmium Laser Fibers 273 µm, Cook medical Reusable 10 times	116
C	FLEX-XC, Storz	199 (74%)	LithoVue, Boston Scientific	70 (26%)	Laser SIRIUS 60W, Thulium, Rocamed	Laser fiber 200 microns, Rocamed Reusable 5 times	269
D		0 (0%)	Neoscope, Aseptinmed	122 (100%)	Lumenis Pulse 100H, Holmium, Boston Scientific	SlimLine SIS 200 or 500, Boston ScientificReusable 10 times	122

For RFU, we listed all products, materials, and techniques used for the disinfection protocols (Supplementary Table S2); they all include washes with sterile and non-sterile water (between 50 and 100 L per ureteroscope) and peracetic acid baths. Center A uses a flexible endoscope washer-disinfector and storage cabinets for thermosensitive endoscopes. Center B uses a hydrogen peroxide low-temperature plasma sterilizer (STERRAD® system), allowing for storage in sterile containers. Center C does not use any specific machine; the endoscope can be used immediately or stored in sterile containers.

Based on literature, we have established a lifespan of 180 uses with a maintenance interval of every 20 uses.⁷ The repair process was modeled through the replacement of the outer sheath, identified as the most commonly occurring event.

Regarding laser fibers, Center A uses single-use fibers, while Centers B, C, and D use reusable fibers that are re-sterilized in an autoclave, see Table 1.

The electricity and water consumption of the various devices used during the procedure, such as lasers, endoscopy devices, or water recovery devices, have also been reviewed using technical specifications provided by the manufacturers.

As a quality improvement project, Human Investigations Committee review was not required.

Life cycle impact assessment

Data analysis was conducted by Agence Primum Non Nocere,⁸ an independent firm specializing in sustainable development, environmental health, and safety, with a 20% margin of error. The aim of the LCA is to adopt a multi-criteria approach to ensure a comprehensive view, avoiding the risk of focusing solely on one impact, which could inadvertently increase others and aggravate the overall environmental footprint. Based on the comprehensive method “ReCipe 2016 Midpoint (H),” Eighteen environmental impacts have been studied, see Table 2 (more details in Supplementary Table S3).

Table 2.

Environmental Impacts Analyzed and Units

Environmental impacts analyzed and units
Climate change (kg eq CO₂)
Stratospheric ozone depletion (kg eq CFC-11)
Ionizing radiation (kBq Co-60 eq)
Ozone formation, human health (kg eq NOx)
Ozone formation, terrestrial ecosystems (kg eq NOx)
Fine particle formation (kg eq PM2.5)
Terrestrial acidification (kg eq SO₂)
Freshwater eutrophication (kg eq P or kg eq N)
Marine eutrophication (kg eq P or kg eq N)
Terrestrial ecotoxicity (kg eq 1,4-DCB)
Freshwater ecotoxicity (kg eq 1,4-DCB)
Marine ecotoxicity (kg eq 1,4-DCB)
Human carcinogenic toxicity (kg eq 1,4-DCB)
Human non-carcinogenic toxicity (kg eq 1,4-DCB)
Land occupation (m². year eq Crop)
Depletion of mineral resources (kg eq Cu)
Depletion of fossil resources (kg eq oil)
Water resource consumption (m³)

This study used the “SimaPro 9.5” software and the “Ecoivent 3.9” database.

Results

The overall impact of a procedure is assessed for each center by detailing the environmental impact of each step and accounting for the use of either SUFU or RFU. These results are subsequently compared across the centers; Figure 2 presents the results for relative global warming, with the additional criteria detailed in Supplementary Figure S1.

FIG. 2.

Stage-by-stage relative global warming impact of ureteroscopy using (a) single use flexible ureteroscope (SUFU) and (b) reusable flexible ureteroscope (RFU). OR = operating room.

Impactful stages

We observe in all four models that the most impactful stages (in descending order) are equipment installation, surgical staff attire, calculi exploration, and patient setup. For example, in center A, within the context of SUFU, these four steps represent 76% of the total global warming impact, with 37%, 26%, 11%, and 2% for each of them, respectively.

Regarding the equipment installation, surgical drape packs, gauzes, and other textile products have the highest impact in several categories.

Regarding surgical staff attire, it consists of disposable apparel in Centers B and C, and reusable fabric attire in Centers A and D. According to the results, wearing reusable attire appears to have a lesser impact. Surgical gowns are the most environmentally detrimental component of the attire.

The significant impact of the calculi exploration step is exclusively linked to the ureteroscope itself.

Finally, regarding patient setup, the use of single-use attire, sheets, and absorbent bed pads largely contributes to the environmental impact of this stage.

Ureteroscopes

Figure 3 shows the relative global warming impact of ureteroscopes for a single use. There is no clear difference between SUFU and RFU (impact ranging from 2.13 to 2.94 kg CO₂ eq). However, in some categories (see Supplementary Fig. S2), the difference is significant; SUFU have a greater impact in the following categories: fine particulate matter formation, terrestrial acidification; terrestrial and marine ecotoxicity; and mineral resource scarcity. In contrast, RFU have a greater impact on marine eutrophication and water consumption.

FIG. 3.

Relative global warming impact of ureteroscopes for one use. SUFU = single use flexible ureteroscope; RFU = reusable flexible ureteroscope.

Components such as polycarbonate, electric connector, and wire clamp are very impactful, as well as their incineration.

Among the methods of disinfecting RFU, Center A’s method had the most negative environmental impact due to its high water and electricity consumption, while Center B had the least detrimental impact. The data collected suggest that the use of sterile water and protective drapes has higher environmental repercussions than the use of disinfectant products. Figure 4 shows the relative global warming impact of the various protocols, the relative impact in each category is detailed in Supplementary Figure S3.

FIG. 4.

Relative global warming impact for the methods of disinfection reusable flexible ureteroscope.

Other devices

–

Reusable laser fibers (Centers B, C, and D) exhibit significantly lower environmental impacts compared with single-use fibers (Center A) across all analyzed categories, see Supplementary Figure S4. Also, the energy consumption of a laser is directly dependent on its power and the duration of its use.

–

We observed that cardboard sorting occurs outside the OR (upon receipt of packages), but not within the rooms themselves: papers, cardboard, and plastics are disposed of in black bins.

Discussion

Our study showed the environmental impact of flexible ureteroscopy for lithiasis across four centers, identifying the most impactful steps.

Therefore, we recommend the following measures to define eco-designed ureteroscopy: –

Designing optimized ureteroscopy packs with the minimum necessary content for all ureteroscopies to avoid wastage.

–

Promoting the use of reusable fabric attire for both staff and patients whenever possible and choosing a laundry service that uses the latest technologies to reduce water, energy, and detergent consumption.

–

Using reusable ureteroscopes sterilized using the STERRAD® system seemed to be the preferred option.

–

Prioritizing single-use ureteroscopes that are integrated into a recycling program.

–

Revising disinfection protocols to minimize the consumption of chemicals, water, and energy.

–

Increasing waste valorization rates by implementing new channels within hospital centers and OR.

The environmental impact of health care is an active area of study with designs that remain unstandardized and varying analysis criteria, posing challenges for cross-study comparability. For instance, Hogan et al.⁹ compared single-use cystoscopes vs reusable ones, focusing on waste production per use and the CO₂ emissions associated with these wastes. Single-use cystoscopes were shown to have a lower impact based on this criterion alone.

Davis et al.¹⁰ specifically compared the environmental impact of a RFU vs a SUFU. The production of CO₂ per procedure was the sole criterion. A common model, evaluating SUFU and RFU, determined the CO₂ production per kg of ureteroscope manufactured, estimating the carbon impact of each component. The lifespan of an RFU was estimated at 180 uses with a repair cycle every 16 uses. 82.5 L of water were required for the disinfection of one ureteroscope. Detergents were not taken into account. They showed that the total carbon footprint of the lifecycle of the RFU was 4.47 kg of CO₂ per case and 4.43 kg of CO₂ for the SUFU, with no statistically significant difference observed between the two.

Lastly, Kemble et al.¹¹ adopted a comprehensive approach comparing the CO₂ production from production to disposal, including transportation, disinfection, and solid waste disposal, of reusable and single-use cystoscopes. The total estimated carbon footprint per use of single-use and reusable devices was, respectively, 2.40 and 0.53 kg of CO₂, thus highlighting the advantage of reusable devices.

There is evident value in studies employing the same analysis criteria and the role of multi-criteria analyses. For example, according to our study, the impact on global warming of a sterile gown is equivalent to that of a single-use flexible ureteroscope. However, the latter exhibits a significantly higher impact in almost all other categories examined, see Supplementary Figure S5. Given the current challenge in identifying which category is the most harmful, a cautious approach to the data provided by the industry is essential.

Our study is the first LCA covering the entire procedure of ureteroscopy. Baboudjian et al.¹² conducted an LCA of reusable and single-use cystoscopes, demonstrating a larger impact of reusable cystoscopes. Although the end-of-life of reusable cystoscopes was not taken into account.

Limitations of this study

For the allocation of usage count per instrument, we set a cutoff, but in practice, the equipment is only replaced when it becomes unusable.

Regarding the decision to account for the production of SUFU by adding 30% to the overall results, this was done to avoid underestimating the impact of assembly for which no data could be obtained. We based our decision on the study by Baboudjian et al.,¹² which indicated that LCA of a cystoscope attributed 30% of its total environmental impact to the assembly process.

We collected data from only four centers with relatively similar techniques. Even if recommendations for best practices exist, other techniques are likely used with different MD. Multicenter international studies are therefore required. LCA allows for a comprehensive analysis of the environmental impact of a procedure but is not designed to compare the use of one device with another.

About ureteroscopes, studies focused on comparing these devices would be necessary to avoid an underestimation of the impact of production and transportation due to the lack of transparency from some laboratories.

Recommendations

We recommend the use of the STERRAD® system and modifications to protocols, provided that infectious safety and effectiveness remain unchanged. Regarding the medico-economic aspect, the cost of a procedure has been thoroughly studied for over 10 years.¹³ Martin et al.¹⁴ demonstrated that the choice is influenced by the center’s activity volume. Ventimiglia et al.¹⁵ showed that introduction of SUFU could increase the longevity of RFU at a high-volume center. A hybrid approach, combining disposable and reusable options mindfully, could be a suitable compromise. By extending the lifespan of reusable items and optimizing their use, this could reduce the environmental impact associated with their production and transportation.

The RFU repair process should also be considered, as some companies offer replacements and send broken ureteroscopes outside the European market. Similarly, the recycling pathway for SUFU is not always implemented in practice by hospitals.

We recommended minimizing the use of MD as much as possible; extracorporeal shock wave lithotripsy (ESWL), alongside flexible ureteroscopy, is a first-line treatment for upper urinary tract stones <15 mm.¹⁶ Considering its potentially lower equipment demands, conducting a LCA of ESWL appears warranted. According to Mehmi et al.,¹⁷ this assessment should ideally take into account patient preferences, which can be evaluated using PROMs.

Conclusion

Based on our LCA of flexible ureteroscopy, we suggested recommendations to guide the development of eco-designed ureteroscopy. We further recommend a hybrid approach to increase the lifespan of reusable ureteroscopes by choosing single use when the reusable one is at risk of breaking. It appears imperative to undertake multiple studies on the environmental impact of health care practices, striving for multiple and standardized criteria to facilitate comparability. Furthermore, it is paramount to prioritize the preservation of health care quality throughout these sustainability initiatives.

Authors’ Contributions

Conceptualization: N.A., R.M., C.A., and E.D.; Data curation: P.M.; Methodology: S.G., N.A., R.M., C.A., E.D., P.M., and L.R.; Formal analysis: S.G., L.R., and P.M.; Writing: P.M.; Review and editing: P.M., N.A., R.M., C.A., E.D., S.G., and L.R.

Footnotes

Acknowledgments

The authors thank all the hospital staff who contributed to the data collection.

Author Disclosure Statement

C.A. participated to symposiums and boards for Storz, Aseptinmed and Int’air. The remaining authors have nothing to disclose.

Funding Information

“Association Nationale pour la Formation permanente du personnel Hospitalier” funded the study without role in study design, data collection, analysis, interpretation, or writing of the report.

Supplemental Material

Abbreviations

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Supplementary Material

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