The excess mortality of COVID-19 solid organ transplant recipients (SOTRs) throughout the pandemic remains unclear. This prospective cohort study based on the Japanese nationwide registry included 1,632 SOTRs diagnosed with COVID-19 between February 1, 2020, and July 31, 2022, categorized based on dominant phases of variants of concern (VOC): Waves 1-3 (Beta), 4 (Alpha), 5 (Delta), 6 (Omicron BA.1/BA.2), and 7 (Omicron BA.5). Excess mortality of COVID-19-affected SOTRs was analyzed by calculating standardized mortality ratios (SMRs). Overall, 1,632 COVID-19-confirmed SOTRs included 1,170 kidney, 408 liver, 25 lung, 20 heart, 1 small-intestine, and 8 multiorgan recipients. Although disease severity and all-cause mortality decreased as VOC transitioned, SMRs of SOTRs were consistently higher than those of the general population throughout the pandemic, showing a U-shaped gap that peaked toward the Omicron BA.5 phase; SMR (95% CI): 6.2 (3.1-12.5), 4.0 (1.5-10.6), 3.0 (1.3-6.7), 8.8 (5.3-14.5), and 21.9 (5.5-87.6) for Waves 1-3 (Beta), Wave 4 (Alpha), Wave 5 (Delta), Wave 6 (Omicron BA.1/2), and Wave 7 (Omicron BA.5), respectively. In conclusion, COVID-19 SOTRs had greater SMRs than the general population across the pandemic. Vaccine boosters, immunosuppression optimization, and other protective measures, particularly for older SOTRs, are paramount.

Compensation of contralateral kidney function after living-donor kidney donation is well known, and many predictive factors have been proposed. However, no prediction model has been proposed. This study was performed to establish a tool with which to estimate the degree of compensation of the contralateral kidney after living-donor kidney donation. We retrospectively analyzed 133 living donors for renal transplantation in our institution. We defined a favorable compensation as a post-donation estimated glomerular filtration rate (eGFR) at 1 year (calculated by the Chronic Kidney Disease Epidemiology Collaboration equation) of > 60% of the pre-donation eGFR. We analyzed the living donors’ clinical characteristics and outcomes. The median (range) donor age was 59 (24–79) years, median (range) body mass index was 22.9 (16.8–32.7) kg/m2, and median (range) body surface area was 1.6 (1.3–2.0) m2. All donors were Japanese, and 73% of the donors were biologically related. The median (range) donor pre-donation eGFR was 108.7 (82–144) ml/min/1.73 m2, and the median (range) post-donation eGFR at 1 year was 86.9 (43–143) ml/min/1.73 m2. Eighty-six percent of donors had compensatory hypertrophy. In the univariate analysis, age, female sex, history of hypertension, body surface area, and pre-donation eGFR were significantly associated with hypertrophy (p < 0.05). In the multivariate analysis, age, female sex, history of hypertension, and ratio of the remnant kidney volume to body weight were significantly associated with hypertrophy (p < 0.05). Based on these results, we created a compensation prediction score (CPS). The median (range) CPS was 8.7 (1.1–17.4). Receiver operating characteristic analysis showed strong diagnostic accuracy for predicting favorable compensation (area under the curve, 0.958; 95% confidence interval, 0.925–0.991, p < 0.001). The optimal cut-off value of the CPS was 5.0 (sensitivity, 92.0%; specificity, 89.5%). The CPS had a strong positive correlation with the post-donation eGFR (R = 0.797, p < 0.001). The CPS might be useful tool with which to predict a favorable compensation of the contralateral kidney and remnant kidney function. If the CPS is low, careful management and follow-up might be necessary. Further investigations are needed to validate these findings in larger populations.

Adequate renal perfusion at the time of unclamping is important because it has been known to affect outcomes in renal transplantation. Nevertheless, the ideal intraoperative systolic arterial pressure (SAP) has not been well defined. We performed a retrospective analysis of 106 living donor renal transplants performed at our center from June 2010 to May 2019. We divided the cohort into 2 groups according to our center's goal SAP of ≥150 mm Hg: 57 patients had SAP ≥150 mm Hg and 49 patients had SAP <150 mm Hg. We analyzed pretransplant characteristics, intraoperative measurements, and postoperative laboratory values to validate our center's target SAP at the time of reperfusion. This study strictly complied with the Helsinki Congress and the Istanbul Declaration regarding donor sources. Patients with SAP ≥150 mm Hg had been on dialysis for a significantly shorter duration before transplant compared with those who had SAP <150 mm Hg. In the SAP ≥150 mm Hg group, urinary sodium excretion normalized earlier, and they had a significantly smaller stroke volume variation, higher cardiac output and cardiac index, earlier initial urination, and higher intraoperative urine output. There were no differences in intraoperative volume repletion, central venous pressure, or postoperative estimated glomerular filtration rate. Achieving SAP ≥150 mm Hg at the time of reperfusion may be associated with early stabilization of graft function. Nevertheless, our data suggested that recipients with a prolonged dialysis history are less likely to achieve SAP ≥150 mm Hg at the time of unclamping in living donor renal transplantation.

Background. A single dose of perioperative dexamethasone (8–10 mg) reportedly decreases postoperative nausea, vomiting, and pain but has not been widely used in laparoscopic donor nephrectomy (LDN). Methods. We performed a retrospective cohort study of living donors who underwent LDN between 2013 and 2015. Donors who received a lower dose (4–6 mg) (n=70) or a higher dose (8–14 mg) of dexamethasone (n=100) were compared with 111 donors who did not receive dexamethasone (control). Outcomes and incidence of postoperative nausea, vomiting, and pain within 24 h after LDN were compared before and after propensity-score matching. Results. The higher dose of dexamethasone reduced postoperative nausea and vomiting incidences by 28% (P=0.010) compared to control, but the lower dose did not. Total opioid use was 29% lower in donors who received the higher dose than in control (P=0.004). The higher dose was identified as an independent factor for preventing postoperative nausea and vomiting. Postoperative complication rates and hospital stays did not differ between the groups. After propensity-score matching, the results were the same as for the unmatched analysis. Conclusion. A single perioperative injection of 8–14 mg dexamethasone decreases antiemetic and narcotic requirements in the first 24 h, with no increase in surgical complications.