Nefrolitotomía Endoscópica ex vivo del injerto renal de donante vivo con instrumento flexible

Introduction: The finding of an asymptomatic stone in the study of a living kidney donor does not necessarily contraindicate donation, however, there is no consensus on the management of these cases. The use of a graft with lithiasis may represent a risk of recurrence in the remaining kidney in the donor and eventual obstructive complications in the transplanted kidney. The objective of this work is to present the usefulness of ureteroscopy (URS) to resolve lithiasis ex vivo before transplantation. Material and Methods: Donors with a small, asymptomatic kidney stone and with an analysis of lithogenic factors without relevant findings were considered to continue in the donation process. The kidney unit with stone was selected for nephrectomy. Results: Four donor kidneys underwent flexible URS after nephrectomy under hypothermic preservation conditions during bench preparation. The average time of the procedure was 35 minutes and the stone was extracted in all cases without incident. The transplant was carried out in the usual way and the evolution of the recipients was without complications and with excellent renal function. During follow-up, no recurrence of lithiasis was observed in donors or recipients. Conclusions: In this experience, the URS of the donor kidney was a feasible procedure and was not associated with adverse consequences for the graft. The main advantage of this procedure is to avoid the potential risk to the recipient of an obstructive graft complication.

[Living-donor kidney graft ex vivo endoscopic nephrolithotomy with flexible instrument]. / Nefrolitotomía Endoscópica ex vivo del injerto renal de donante vivo con instrumento flexible.

INTRODUCTION: The finding of an asymptomatic stone in the study of a living kidney donor does not necessarily contraindicate donation, however, there is no consensus on the management of these cases. The use of a graft with lithiasis may represent a risk of recurrence in the remaining kidney in the donor and eventual obstructive complications in the transplanted kidney. The objective of this work is to present the usefulness of ureteroscopy (URS) to resolve lithiasis ex vivo before transplantation. MATERIAL AND METHODS: Donors with a small, asymptomatic kidney stone and with an analysis of lithogenic factors without relevant findings were considered to continue in the donation process. The kidney unit with stone was selected for nephrectomy. RESULTS: Four donor kidneys underwent flexible URS after nephrectomy under hypothermic preservation conditions during bench preparation. The average time of the procedure was 35 minutes and the stone was extracted in all cases without incident. The transplant was carried out in the usual way and the evolution of the recipients was without complications and with excellent renal function. During follow-up, no recurrence of lithiasis was observed in donors or recipients. CONCLUSIONS: In this experience, the URS of the donor kidney was a feasible procedure and was not associated with adverse consequences for the graft. The main advantage of this procedure is to avoid the potential risk to the recipient of an obstructive graft complication.

SARS-CoV-2 vaccine booster in solid organ transplant recipients previously immunised with inactivated versus mRNA vaccines: A prospective cohort study.

Background: Solid-organ transplant (SOT) recipients have worse COVID-19 outcomes than general population and effective immunisation in these patients is essential but more difficult to reach. We aimed to determine the immunogenicity of an mRNA SARS-CoV-2 vaccine booster in SOT recipients previously immunised with either inactivated or homologous SARS-CoV-2 mRNA vaccine. Methods: Prospective cohort study of SOT recipients under medical care at Red de Salud UC-CHRISTUS, Chile, previously vaccinated with either CoronaVac or BNT162b2. All participants received a BNT162b2 vaccine booster. The primary study end point was anti-SARS-CoV-2 total IgG antibodies (TAb) seropositivity at 8-12 weeks (56-84 days) post booster. Secondary end points included neutralising antibodies (NAb) and specific T-cell responses. Findings: A total of 140 (50% kidney, 38% liver, 6% heart) SOT recipients (mean age 54 [13.6] years; 64 [46%] women) were included. Of them, 62 had homologous (three doses of BNT162b2) and 78 heterologous vaccine schedules (two doses of CoronaVac followed by BNT162b2 booster). Boosters were received at a median of 21.3 weeks after primary vaccination. The proportion achieving TAb seropositivity (82.3% vs 65.4%, P = 0.035) and NAb positivity (77.4% vs 55.1%, P = 0.007) were higher for the homologous versus the heterologous group. On the other hand, the number of IFN-γ and IL-2 secreting SARS-CoV-2-specific T-cells did not differ significantly between groups. Interpretation: This cohort study shows that homologous mRNA vaccine priming plus boosting in SOT recipients, reaches a significantly higher humoral immune response than inactivated SARS-CoV-2 vaccine priming followed by heterologous mRNA booster. Funding: School of Medicine, UC-Chile and ANID.ClinicalTrials.gov ID: NCT05124509.