Living donor postnephrectomy kidney function and recipient graft loss: A dose-response relationship

Exploiting the Potential of Photon-Counting CT in Abdominal Imaging

ABSTRACT

Photon-counting computed tomography (PCCT) imaging uses a new detector technology to provide added information beyond what can already be obtained with current CT and MR technologies. This review provides an overview of PCCT of the abdomen and focuses specifically on applications that benefit the most from this new imaging technique. We describe the requirements for a successful abdominal PCCT acquisition and the challenges for clinical translation. The review highlights work done within the last year with an emphasis on new protocols that have been tested in clinical practice. Applications of PCCT include imaging of cystic lesions, sources of bleeding, and cancers. Photon-counting CT is positioned to move beyond detection of disease to better quantitative staging of disease and measurement of treatment response.

Liver Transplant Center Size and The Impact on the Clinical Outcomes and Resource Utilization

BACKGROUND

Prior studies suggest that transplant center volume is associated with liver transplantation (LT) outcomes. We compared patient characteristics and waitlist outcomes among transplant centers in the U.S. with different volumes.

METHODS

Data for adult waitlisted candidates and LT recipients in the U.S. between 2008 and 2017 were extracted from the Scientific Registry of Transplant Recipients database. Transplant centers were categorized by transplants/year into tertiles:low-volume centers (LVCs; <20 transplantations per year)medium-volume centers (MVCs; 20-55 transplantations per year)high-volume centers (HVCs; >55 transplantations per year)Patient characteristics, waitlist outcomes, and factors associated with post-transplantation mortality were compared.

RESULTS

From 141 centers, 112,110 patients were waitlisted for LT: 6% at LVCs, 26% at MVCs, and 68% at HVCs. Patients listed in LVCs were less likely to have private insurance but had higher Medicaid and Veterans Affairs healthcare rates. Patients at LVCs were less likely to receive LT (47% vs. 53% in MVC vs. 61% in HVC), had higher transfer rates to other centers, and were more likely to be removed from the waitlist. In competing risk survival analysis, adjusted for center location, MELD score, and clinico-demographic factors, patients listed at an HVC were more likely to receive LT (aHR:1.30; 95%CI= 1.27-1.33; P<0.001). Among LT-recipients (n=62,131), receiving a transplant at an LVC was associated with higher post-LT mortality (aHR:1.16; 95%CI=1.05-1.28; P=0.003).

CONCLUSION

Patients in LVCs were less likely to receive a LT and a higher risk of post-LT death.Supplemental Visual Abstract; http://links.lww.com/TP/C274.

Impact of the Mayo Adhesive Probability Score on Donor and Recipient Outcomes After Living-donor Kidney Transplantation: A Retrospective, Single-center Study of 782 Transplants

Supplemental Digital Content is available in the text.

Background.

This study was performed to assess the impact of the Mayo Adhesive Probability (MAP) score on donor and recipient outcomes after living-donor kidney transplantation (LDKT).

Methods.

We retrospectively analyzed 782 transplants involving LDKT between February 2008 and October 2019 to assess the correlation between the MAP score and outcome after LDKT. We divided the transplants into 2 groups according to the donor MAP score: 0 (MAP₀) and 1–5 (MAP_1–5).

Results.

Compared with the MAP₀ group, donors in the MAP_1–5 group were significantly older, had higher body mass index, and were more likely to be men. The prevalences of hypertension, hyperlipidemia, and diabetes were also higher among donors in the MAP_1–5 group than among donors in the MAP₀ group. Operative time, estimated blood loss during donor nephrectomy, and percentage of glomerular sclerosis were significantly greater in the MAP_1–5 group than in the MAP₀ group. Donor and recipient perioperative complications were comparable between the 2 groups; death-censored graft survival rates also did not significantly differ between groups. Although the recipient mean estimated glomerular filtration rate (eGFR) from postoperative d 1 to 7 was significantly higher in the MAP₀ group than in the MAP_1–5 group (P = 0.007), eGFR reductions within 5 y after transplantation were similar between groups. There were no significant differences between groups in recipient mortality and biopsy-proven acute rejection episodes within 1 y after transplantation. Additionally, multivariate analysis showed that the only factors affecting recipient eGFR at postoperative d 7 were donor age, recipient age, and female sex (P < 0.001, <0.001, and =0.004, respectively).

Conclusions.

The MAP score did not influence surgical complications or graft survival; therefore, it should not affect donor selection.

Correlation of preoperative imaging characteristics with donor outcomes and operative difficulty in laparoscopic donor nephrectomy

This study aimed to understand the relationship of preoperative measurements and risk factors on operative time and outcomes of laparoscopic donor nephrectomy. Two hundred forty-two kidney donors between 2010 and 2017 were identified. Patients' demographic, anthropomorphic, and operative characteristics were abstracted from the electronic medical record. Glomerular filtration rates (GFR) were documented before surgery, within 24 hours, 6, 12, and 24 months after surgery. Standard radiological measures and kidney volumes, and subcutaneous and perinephric fat thicknesses were assessed by three radiologists. Data were analyzed using standard statistical measures. There was significant correlation between cranio-caudal and latero-lateral diameters (P < .0001) and kidney volume. The left kidney was transplanted in 92.6% of cases and the larger kidney in 69.2%. Kidney choice (smaller vs. larger) had no statistically significant impact on the rate of change of donor kidney function over time adjusting for age, sex and race (P = .61). Perinephric fat thickness (+4.08 minutes) and surgery after 2011 were significantly correlated with operative time (P ≤ .01). In conclusion, cranio-caudal diameters can be used as a surrogate measure for volume in the majority of donors. Size may not be a decisive factor for long-term donor kidney function. Perinephric fat around the donor kidney should be reported to facilitate operative planning.

Bariatric surgery for prospective living kidney donors with obesity?

The obesity epidemic has gripped the transplant community. With nearly 40% of adults in the United States being obese (BMI ≥30 kg/m² ) and 20% being morbidly obese (BMI ≥35 kg/m² ), the implications for both donors and recipients of solid organs continue to grow.¹ Nowhere is this more impactful than the candidacy of living kidney donors (LKDs). As increasing numbers of obese adults present for LKD consideration and evidence of inferior outcomes among obese LKDs grows, transplant surgeons will become progressively challenged by how to manage these patients in the clinic. Therefore, we offer this Personal Viewpoint to the transplant surgery community in order to review the current impact of obesity on living kidney donation, highlight what weight-loss interventions have already been attempted, and discuss the role that referral for weight-loss interventions including bariatric surgery might have going forward.