What is the evidence for oxygenation during kidney preservation for transplantation in 2021? A scoping review.

PURPOSE: The main objective of static cold storage is to reduce cellular metabolic demands to extend the period of ischaemia prior to transplantation. Hypothermia does not halt metabolism and the absence of oxygen causes a cellular shift toward anaerobic respiratory pathways. There is emerging evidence that the introduction of oxygenation during organ preservation may help ameliorate the degree of ischaemia reperfusion injury and improve post-transplantation outcomes. This review aims to appraise and summarise all published literature that utilises oxygenation to improve kidney preservation for purposes of transplantation. METHODS: We performed a scoping review of the literature using the bibliographic databases Embase and MEDLINE. The final date for searches was 20 March 2021. All research studies included were those that reported oxygen delivery during kidney preservation as well as providing a description of the oxygenation technique. RESULTS: 17 human and 48 animal studies met the inclusion criteria. The oxygen delivery methods investigated included hypothermic oxygenated machine perfusion (HOPE), oxygen carriers, two-layer method, venous systemic persufflation, hyperbaric oxygenation, normothermic machine perfusion and sub-normothermic machine perfusion. The COMPARE trial was the only study carried out with the most methodological robustness being a randomised, double blind, controlled, phase III trial that investigated the efficacy of HOPE versus HMP. CONCLUSION: A variety of studies reflect the evolution of oxygenation with useful lessons and encouraging outcomes. The first in human studies investigating HOPE and oxygen carriers are most robustly investigated strategies for oxygenation during kidney preservation and are, therefore, the best clinical references.

Residents and patients benefit from surgical simulation on a live porcine model, could we consider it as ethical?

INTRODUCTION: The objective was to evaluate, by self-questionnaire, the feeling of participants in surgical training sessions on a live porcine model. METHODS: A computerized questionnaire (GoogleForm ©) was sent to the members of the French Association of Urologists-in-Training (AFUF) (fellows and residents). Only questionnaires from Urologists-in-training who had participated in surgical training sessions were included. The sessions consisted of performing surgeries such as laparoscopic nephrectomies or laparoscopic cystectomies. RESULTS: Overall, 198 met the inclusion criteria. A total of 36.4% (72/198) of the participants were fellows and 63.6% (126/198) were residents. According to the participants, the main interest of sessions was to be able to train for emergency situations. A total of 79.8% (158/198) of the participants wanted surgical simulation to become compulsory. To their opinion, the main advantage of surgical simulation on a live porcine model was: technical progress in 87.4% (173/198) of cases. A total of 13.1% (26/198) of the participants found it was unethical to perform the first technical procedures on live animal models. A total of 65.7% (130/198) of the participants considered that there is currently no system of substitution. CONCLUSION: For the participants, surgical training on a live porcine model allows technical progress while training for serious emergency situations. Surgeons and patients could benefit from this risk-free mock surgical scenario. LEVEL OF EVIDENCE: 3.

Recognition of mental incapacity when consenting patients with intracranial tumours for surgery: how well are we doing?

INTRODUCTION: Many patients with intracranial tumours have cognitive deficits that might affect their mental capacity to give valid consent to neurosurgical treatment. The aim of this study was to determine the incidence of mental incapacity, as assessed by neurosurgeons, in patients with intracranial tumours undergoing neurosurgery. METHODS: The case notes of successive patients undergoing brain tumour surgery between 16 October 2008 and 16 October 2010 were reviewed. The frequency of use of standard consent forms and Certificates of Incapacity was recorded. In addition, the frequency and scores of pre-operative cognitive assessments were recorded. RESULTS: Case notes of 247 of 262 patients undergoing surgery for intracranial tumours were reviewed since there was no record of either a standard consent form or a Certificate of Incapacity in the case notes for 15 patients. Nine of 247 brain tumour patients were issued with a Certificate of Incapacity (3.6%, 95% CI 1.6-6.8%), while 238 (96.4%) signed a standard consent form. Seven of these nine had high-grade gliomas, for an incidence of incapacity of 5.9% (95% CI 2.8-11.8%), while the remaining two Certificates of Incapacity were issued for patients with meningiomas (incidence 3%; 95% CI 0.04-10.4%). Fifty of the 262 patients (19%) had some form of pre-operative cognitive assessment documented, but only three of these were issued with a Certificate of Incapacity. All three patients issued with a Certificate of Incapacity had Mini-Mental State Examination scores suggestive of cognitive impairment. CONCLUSIONS: Incapacity to consent to brain tumour surgery, as assessed by neurosurgeons, is uncommon. The incidence of incapacity is less than might be expected given the level of cognitive impairment known in this population. Decisions about capacity by neurosurgeons are often made in the absence of any documented assessment of cognition or other objective evidence that could support their decision in the event of dispute.