Table 3.

Selected studies, results and main conclusions

Study ID		Results			Main Conclusions
Author	Year	Type of surgery/Speciality	Environmental impact metric	Outcome	Conclusion
Gilliam et al [16]	2008	All specialties	CO2 used on MIS*: Carbon Footprint CO2e	Each CO2 cylinder produces 0.9 kgCO2e	‘Despite increasing frequency of the laparoscopic approach in general surgery, its impact on global warming is negligible.’
Power et al [17]	2012	All specialties	CO2 used for MIS*	CO2 emissions from MIS*: 355.924 tones/year (estimated)	‘The CO2 emissions of MIS in the United States have a significant environmental impact. This should be considered in larger strategies to reduce healthcare’s carbon footprint while maximizing healthcare quality.’
Cassandra et al	2014	Gynaecology-Hysterectomy	Life Cycle Assessment (Waste & Process)	Minimally invasive surgery presents higher footprint	‘Across the whole healthcare industry, there is a profound opportunity to make healthcare services more efficient environmentally and economically without compromising safety or efficacy’
Woods et al [18]	2015	Gynaecology-Hysterectomy	Waste and energy converted to CO2e	Robotics: 40.3 kgCO2e Laparoscopic: 29.2 kgCO2e Open: 22.7 kgCO2e	‘Our results provide clinicians, administrators and policymakers with knowledge of the environmental impact of their decisions to facilitate adoption of sustainable practices.’
Cassandra et al [14]	2018	Gynaecology-Hysterectomy	Hybrid environmental life cycle assessment CO2e	Laparoscopic hysterectomy 562 kgCO2e (per procedure)	‘To reduce the environmental emissions of surgeries, health care providers need to implement a combination of approaches, including minimizing materials, moving away from certain heat-trapping anesthetic gases, maximizing instrument reuse or single-use device reprocessing and reducing off-hour energy use in the operating room These strategies can reduce the carbon footprint of an average laparoscopic hysterectomy by up to 80%.’
Rizan et al [12]	2021	General SurgeryCholecystectomy	Life Cycle Assessment of the single-use and non-single-use (Hybrid) CO2e	Hybrid: 1.756 kgCO2e Single use: 7.194 kgCO2e	‘The carbon footprint of using hybrid instruments for laparoscopic cholecystectomy is around a quarter of that for single use equivalents and the financial cost around half… adoption of hybrid instruments could play an important role in meeting carbon reduction targets in healthcare…’
Pastore et al [19]	2022	Urology–Prostatectomy	Life Cycle Assessment of surgical devices, Energy consumption & Hospital Stay CO2e	Laparoscopic: 59.7 kgCO2e Robotic: 47.3 kgCO2e	“robot-assisted radical prostatectomy generates substantially less CO2 per procedure than laparoscopic prostatectomy because of the use of more reusable surgical supplies and shorter operative time and hospital stays, resulting in a lower environmental impact.”
Ramani et al	2023	Gynaecology—Hysterectomy	Waste converted to CO2e	Vaginal: 4.2 kgCO2e Laparotomy: 7.1 kgCO2e Laparoscopic: 10.7 kgCO2e Open: 12.0 kgCO2e	“ Robotic hysterectomies generated a statistically significant majority of CO2 emissions. Therefore, robotic surgery, as currently practiced, may offer a good initial opportunity for decreasing the carbon footprint of surgery”

^*MIS Minimally invasive surgery