Citations

The 2024 Annual Congress of the International Liver Transplantation Society (ILTS) was from May 1–4 in Houston, Texas, USA, under the theme “Liver Disease and Transplantation: Breaking Barriers and Exploring New Frontiers.” In addition to a robust scientific program, the congress also hosted a hands-on cadaveric robotic liver surgery course, a machine perfusion workshop, and a transesophageal echocardiography course. In this report, the ILTS Vanguard and Basic Sciences Committees present a summary of the congress proceedings.

BACKGROUND: Although most transplant centers preferentially offer minimally invasive approaches to donor nephrectomies, there remains less standardization specific to the kidney extraction site. This study aimed to evaluate incisional hernia occurrence in living kidney donors based on kidney extraction site location. STUDY DESIGN: This was a retrospective study of all donors who underwent minimally invasive living donor nephrectomies at the Mayo Clinic Arizona between 2011 and 2023 with a 2-year external validation cohort from Mayo Clinic Florida and Mayo Clinic Minnesota. The cohort was divided into 2 groups based on the kidney extraction site type: midline infraumbilical and Pfannenstiel. RESULTS: In the primary cohort, incisional hernia occurrence was observed in 1.2% of donors with an infraumbilical midline kidney extraction site compared with 0.1% with a Pfannenstiel extraction site (p = 0.04). Donors with an infraumbilical midline kidney extraction site were more likely to be men (50.8% vs 23.3%, p < 0.0001), have a higher BMI (mean 27.2 vs 26 kg/m2, p < 0.0001), and have current or former tobacco use (p = 0.002). There were no differences in incisional hernia occurrence when comparing minimally invasive surgical techniques (p = 0.52). In the external validation cohort, hernia occurrence was observed in 4.5% of donors with a midline incision compared with 0.0% with a Pfannenstiel incision (p = 0.09). Using combined data from the 3 sites, the use of a Pfannenstiel incision as the extraction site was associated with significantly lower odds of developing a hernia compared with the infraumbilical midline incision (odds ratio 0.06, 95% CI 0.008 to 0.456). CONCLUSIONS: Although the risk of hernia in living kidney donors is generally low, the use of a Pfannenstiel incision for kidney extraction appears to offer an additional incremental reduction in risk.

Objectives To evaluate the feasibility for use of electronic health record (EHR) data in conducting adverse event surveillance among women who received mid-urethral slings (MUS) to treat stress urinary incontinence (SUI) in five health systems. Design Retrospective observational study using EHR data from 2010 through 2021. Women with a history of MUS were identified using common data models; a common analytic code was executed at each site. A manual chart review was conducted in a per-site random patient subset to establish a reference standard. Automated text processing (Text Processed Integrated (TPI)) was developed and evaluated at each site to determine the surgical approach and synthetic mesh implantation. Patients were characterized and surgical outcomes were ascertained over 730 subsequent days. Setting Five large tertiary care academic medical centers. Participants Across five health systems, 9,906 eligible patients (mean age 57–60 per site) were identified. Main outcome measures Determination of surgical approach, synthetic mesh implantation, and assessment of the duration of surveillance for mortality and reoperation rates following MUS implantation. Results In the TPI cohort analysis, 3,331 patients were identified. Surgical approach per site was retropubic (42% to 77%), transobturator (6% to 44%), single incision (0% to 24%), and adjustable sling (0% to <4%). Concordance rates for TPI using chart review were 71%–90% at each site for the surgical approach and 28%–85% for synthetic mesh implantation. Patient follow-up observation rates for mortality and reoperation ranged from 22% to 36% at 90 days, 15% to 30% at 365 days, and 8% to 19% at 730 days. Conclusion Using EHR data alone, identification of medical devices and surgical approaches was feasible among women with MUS surgery for SUI, but long-term follow-up ascertainment rates were low. Medical device surveillance using EHR data should be evaluated in the context of the clinical use case, as applicability may vary.

Abstract Durable T cell immunity against cancer depends on the continual replenishment of effector CD8+ T cells. Thymic output has been correlated with favorable prognosis in cancer patients across a range of ages, suggesting that the thymus is an important source for replenishing T cells capable of controlling cancer progression. However, the effector potential of thymic mature CD8+ T cells and their regulation have not been clearly defined. In this study, we identified the ability of thymic single positive CD8+ T cells to gain effector potential after thymic selection, but they are subject to the regulation of PD-1. We found a previously undisclosed role of PD-1 in limiting both the cytotoxic and exhaustion potential of thymic and peripheral CD8+ T cells. Our results show that although PD-1 inhibition facilitates the expansion of effector CD8+ T cells, effector CD8+ cells gradually lose their antitumor activity within tumor tissues due to advanced exhaustion in the absence of PD-1. Thus, although the preset effector potential in thymic mature CD8+ T cells allows them to rapidly respond to malignant cells in the periphery, PD-1, as a checkpoint, is embedded in the thymic mature CD8+ T cells after positive selection to balance their effector function from exaggeration and exhaustion. Therefore, we propose that a strategy capable of upholding the cytotoxic capacity and avoiding exhaustion of CD8+ T cells during the early stages of PD-1 inhibition therapy is needed to achieve durable antitumor immunity.

Background. The availability of in situ normothermic regional perfusion (NRP) or ex situ normothermic machine perfusion (NMP) has revolutionized donation after circulatory death (DCD) liver transplant (LT). While some have suggested that NRP and NMP may represent competing technologies for DCD LT, there are many scenarios where these technologies can function in a complementary manner. Methods. Between January 2022 and March 2024, 83 DCD LTs were performed using NRP (62 NRP alone and 21 NRP + NMP) and were compared with 297 static cold storage (SCS) DCD LTs. NRP + NMP was used in scenarios with (1) long travel distances, (2) complicated transplant recipients, or (c) the need for additional liver graft recovery in “marginal” cases. Results. Ischemic cholangiopathy was lower in the NRP alone group (0%) and the NRP + NMP group (0%) compared with the SCS group (16.8; P < 0.001 and P = 0.04, respectively). In addition, early allograft dysfunction, number of packed red blood cells transfused, and acute kidney injury were lower in the NRP alone and NRP + NMP groups compared with the SCS group. Graft survival was higher in cases where NRP was used than in cases where SCS was used ( P = 0.016). In all the cases where lactate remained elevated at the end of NRP (mean 8.2 ± 2.0), it ultimately normalized at the end of NMP (0.92 ± 0.56). Conclusions. The present study demonstrates lower rates of ischemic cholangiopathy and improved graft survival with NRP alone or NRP + NMP compared with SCS when using liver grafts from DCD donors. It also demonstrates that excellent outcomes can be achieved with sequential NRP + NMP in cases with prolonged travel distances, complicated recipients, or when there is a need for additional liver recovery in “marginal” cases.

There is a paucity of data on the impact of cold ischemia time before the initiation of normothermic machine perfusion (NMP), particularly in more susceptible organs such as livers from donation after circulatory death (DCD) donors. The present analysis aimed to investigate the impact of prolonged time from cross-clamp until NMP start on early allograft dysfunction and other peri–liver transplant (LT) outcomes. All DCD LT performed and placed on NMP at Mayo Clinic Arizona, Florida, and Rochester from January 2022 to March 2024 were included. The decision was made a priori to divide the population into 2 groups based on terciles: typical cross-clamp to on-pump time (lower 2 terciles) versus prolonged cross-clamp to on-pump time (upper tercile; >2 h 45.6 min). Three hundred eighty-four DCD LT undergoing NMP met the inclusion criteria. The rate of early allograft dysfunction was significantly higher in the prolonged cross-clamp to on-pump group (51.2%) compared to the typical cross-clamp to on-pump group (37.6%) (p = 0.01). The prolonged cross-clamp to on-pump group also had higher rates of acute kidney injury and the number of packed red blood cells transfused during LT. No significant difference in ischemic cholangiopathy (2.4% vs. 3.1%; p = 0.68) or graft survival at 12 months was seen between the prolonged cross-clamp to on-pump and typical cross-clamp to on-pump group, respectively. Following cross-clamp, DCD liver grafts should be placed on the NMP pump as quickly as is safely and logistically possible. In cases where delays are unavoidable, such as waiting for biopsy results or liver reallocation with another center, acceptable results can still be achieved, and therefore, livers with prolonged times should still be used.