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The coming decades are poised to usher in an era of commercial spaceflight and extended duration missions beyond low-earth orbit. Urologic challenges and conditions have been central to the history of human spaceflight, and their effective management will continue to play a key role in future endeavors. Voiding equipment, such as the Universal Waste Management System aboard the International Space Station, is emblematic of the significant technical strides that have been made to improve the usability and functionality of non-terrestrial waste elimination and containment devices. Detailed investigations over the past few decades have demonstrated that crew members are at an increased risk of developing nephrolithiasis due, in large part, to the effects of microgravity. Renal calculi and their potentially debilitating effects represent one of the most significant urologic complications that could impact the success of future long duration missions. Other urologic conditions, such as urinary tract infections, urinary retention, and urinary incontinence have been well documented during flight and pose their own challenges. While preventive measures remain central to all mitigation strategies, imaging and treatment modalities such as a S-Mode ultrasound, burst wave lithotripsy, and ultrasonic propulsion are being developed and evaluated as in-flight countermeasures for urologic pathology. Parabolic flights have been conducted to develop and evaluate the feasibility of using surgical and endoscopic techniques to treat urologic conditions in microgravity. Although less often discussed, occupation-related delayed conception and the risk of radiation-induced gamete damage suggests that there may be a need for NASA to adopt a policy for Assisted Reproductive Technology for both male and female astronauts. The last 60 years of human spaceflight have provided a unique opportunity for discovery and medical technology innovation. This paper serves to highlight the advancements that will help pave the way for the next 60 years of human spaceflight.

Introduction. Prophylactic surgery before spaceflight may eliminate the risk of appendicitis and cholecystitis in astronauts on deep space missions. However, even minimally invasive surgery increases the risk of small bowel obstruction (SBO). Probabilistic risk assessment (PRA) is a method that can be used to estimate the benefits and risks of prophylactic surgery. Methods. Risks of appendicitis and cholecystitis during a 2.5-year Mars mission are compared to the risk of SBO after laparoscopic removal of the appendix, gallbladder, or both. A PRA model using Monte Carlo methodology was used to forecast the risks. Results. Prophylactic appendectomy and cholecystectomy combined, conferred an increased probability of medical evacuation (pEVAC) due to SBO as compared to the no surgery group. A slightly higher probability for the loss of crew life (pLOCL) was found in the no surgery group when compared to the cases in which either prophylactic appendectomy alone, or appendectomy plus cholecystectomy are performed. Discussion. The need for medical evacuation can be viewed as a potential risk for death in the context of a space mission where evacuation is not possible. Because of the higher pEVAC due to SBO and relatively small benefit in the reduction of pLOCL in the prophylactic surgery groups, this analysis does not support the prophylactic removal of appendix and/or gallbladder for spaceflight. Future advances in surgical or medical technique or mission medical capabilities may change these results. This work demonstrates the utility of PRA in providing quantitative answers to “what if” questions where limited information is available.