Background Minimally invasive surgery (MIS) has profoundly changed standards of care and lowered perioperative morbidity, but its temporal implementation and factors favoring MIS access remain elusive. We aimed to comprehensibly investigate MIS adoption across different surgical procedures over 20 years, identify predictors for MIS amenability and compare propensity score-matched outcomes among MIS and open surgery. Methods Nationwide retrospective analysis of all hospitalizations in Switzerland between 1998 and 2017. Appendectomies (n = 186,929), cholecystectomies (n = 57,788), oncological right (n = 9138) and left hemicolectomies (n = 21,580), rectal resections (n = 13,989) and gastrectomies for carcinoma (n = 6606) were included. Endpoints were assessment of temporal MIS implementation, identification of predictors for MIS access and comparison of propensity score-matched outcomes among MIS and open surgery. Results The rates of MIS increased for all procedures during the study period (p ≤ 0.001). While half of all appendectomies were performed laparoscopically by 2005, minimally invasive oncological colorectal resections reached 50% only by 2016. Multivariate analyses identified older age (p ≤ 0.02, except gastrectomy), higher comorbidities (p ≤ 0.001, except rectal resections), lack of private insurance (p ≤ 0.01) as well as rural residence (p ≤ 0.01) with impaired access to MIS. Rural residence correlated with low income regions (p ≤ 0.001), which themselves were associated with decreased MIS access. Geographical mapping confirmed strong disparities for rural and low-income areas in MIS access. Matched outcome analyses revealed benefits of MIS for length of stay, decreased surgical site infection rates for MIS appendectomies and cholecystectomies and higher mortality for open cholecystectomies. No consistent morbidity or mortality benefit for MIS compared to open colorectal resections was observed. Conclusion Unequal access to MIS exists in disfavor of older and more comorbid patients and those lacking private insurance, living in rural areas, and having lower income. Efforts should be made to ensure equal MIS access regardless of socioeconomic or geographical factors.

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Objective: To develop a protocol for the defatting of steatotic liver grafts during long-term ex situ normothermic machine perfusion. Background: Despite the alarming increase in donor organ shortage, the highly prevalent fatty liver grafts are often discarded due to the risk of primary non-function. Effective strategies preventing such outcome are currently lacking. An exciting new avenue is the introduction of ex situ normothermic machine perfusion (NMP), enabling a liver to remain fully functional for up to two weeks and providing a unique window of opportunity for defatting prior to transplantation. Methods: Over a 5-year period, 23 discarded liver grafts and 28 partial livers from our resection program were tested during ex situ NMP. The steatosis degree was determined on serial biopsies by expert pathologists, and triglyceride contents measured simultaneously. Results: Of 51 liver grafts, 20 were steatotic, with up to 85% macrovesicular steatosis, and were perfused for up to 12 days. 10 livers displayed marked (5 of which almost complete) loss of fat, while the other 10 did not respond to long-term perfusion. Successful defatting was related to prolonged perfusion, automated glucose control, circadian nutrition, and L-carnitine/fenofibrate supplementation. Pseudopeliotic steatosis and the associated activation of Kupffer/stellate cells were unexpected processes that might contribute to defatting. Synthetic and metabolic function remained preserved for most grafts until perfusion end. Conclusion: Ex situ long-term perfusion effectively reduces steatosis while preserving organ viability and may in the future allow transplantation of primarily unusable high-risk grafts, significantly increasing the number of organs available for transplantation.