Donor-recipient race-ethnicity concordance and patient survival after liver transplantation.

INTRODUCTION: We assessed the association between patient survival after liver transplantation (LT) and donor-recipient race-ethnicity (R/E) concordance. METHODS: The Scientific Registry of Transplant Recipients (SRTR) was retrospectively analyzed using data collected between 2002 and 2019. Only adults without history of prior organ transplant and recipients of LT alone were included. The primary outcome was patient survival. Donors and recipients were categorized into five R/E groups: White/Caucasian, African American/Black, Hispanic/Latino, Asian, and Others. Statistical analyses were performed using Kaplan-Meier survival curves and Cox Proportional Hazards models, adjusting for donor and recipient covariates. RESULTS: 85,427 patients were included. Among all the R/E groups, Asian patients had the highest 5-year survival (81.3%; 95% CI = 79.9-82.7), while African American/Black patients had the lowest (71.4%; 95% CI = 70.3-72.6) (P < 0.001). Lower survival rates were observed in recipients who received discordant R/E grafts irrespective of their R/E group. The fully adjusted hazard ratio for death was statistically significant in African American/Black (aHR 1.07-1.18-1.31; P < 0.01) and in White∕Caucasian patients (aHR 1.00-1.04-1.07; P = 0.03) in the presence of donor-recipient R/E discordance. CONCLUSION: Disparities in post-LT outcomes might be influenced by biological factors in addition to well-known social determinants of health.

Interaction between cold ischemia time and Kidney Donor Profile Index on postrenal transplant outcomes.

We analyzed whether there is an interaction between the Kidney Donor Profile Index (KDPI) and cold ischemia time (CIT) in recipients of deceased donor kidney transplant (KTs). Adults who underwent KTs in the United States between 2014 and 2020 were included and divided into 3 KDPI groups (≤20%, 21%-85%, >85%) and 4 CIT strata (<12, 12-17.9, 18-23.9, ≥24 hours). Multivariate analyses were used to test the interaction between KDPI and CIT for the following outcomes: primary graft nonfunction (PGNF), delayed graft function (DGF), estimated glomerular filtration rate (eGFR) at 6 and 12 months, patient survival, graft survival, and death-censored graft survival (DCGS). A total of 69,490 recipients were analyzed: 18,241 (26.3%) received a graft with KDPI ≤20%, 46,953 (67.6%) with KDPI 21%-85%, and 4,296 (6.2%) with KDPI >85%. Increasing KDPI and CIT were associated with worse post-KT outcomes. Contrary to our hypothesis, howerver, the interaction between KDPI and CIT was statistically significant only for PGNF and DGF and eGFR at 6 months. Paradoxically, the negative coefficient of the interaction suggested that increasing duration of CIT was more detrimental for low and intermediate-KDPI organs relative to high-KDPI grafts. Conversely, for mortality, graft survival, and DCGS, we found that the interaction between CIT and KDPI was not statistically significant. We conclude that, high KDPI and prolonged CIT are independent risk factors for inferior outcomes after KT. Their interaction, however, is statistically significant only for the short-term outcomes and more pronounced on low and intermediate-KDPI grafts than high-KDPI kidneys.

Multiple infusions of ex vivo-expanded regulatory T cells promote CD163+ myeloid cells and kidney allograft survival in non-lymphodepleted non-human primates.

Clinical verification of adoptively transferred regulatory T cell (Treg) efficacy in transplantation remains challenging. Here, we examined the influence of autologous ex vivo-expanded polyclonal Tregs on kidney graft survival in a clinically relevant non-human primate model. Peripheral blood Tregs were isolated and expanded using artificial antigen presenting cells. Immunosuppression was comprised of tapered tacrolimus and CTLA4 immunoglobulin, in five animals each without or with Treg infusions. Escalating Treg doses were administered 6, 10, 13, 16, 20, 23, 27 and 30 days after transplant. Infused Tregs were monitored for Treg signature, anti-apoptotic (Bcl-2) and proliferation (Ki67) marker expression. Treg infusions prolonged median graft survival time significantly from 35 to 70 days. Treg marker (Ki67 and Bcl-2) expression by infused Tregs diminished after their infusion but remained comparable to that of circulating native Tregs. No major changes in circulating donor-reactive T cell responses or total Treg percentages, or in graft-infiltrating T cell subsets were observed with Treg infusion. However, Treg infusion was associated with significant increases in CD163 expression by circulating HLA-DR+ myeloid cells and elevated levels of circulating soluble CD163. Further, graft-infiltrating CD163+ cells were increased with Treg infusion. Thus, multiple Treg infusions were associated with M2-like myeloid cell enhancement that may mediate immunomodulatory, anti-inflammatory and graft reparative effects.

Virtual crossmatch for deceased donor kidney transplantation in the United States: A survey of histocompatibility lab directors and transplant surgeons.

Virtual crossmatch (VXM) is used as an alternative to or in conjunction with a cell-based physical crossmatch (PXM) for assessing HLA (human leukocyte antigen) compatibility prior to deceased donor kidney transplantation (DDKT). Data on practice patterns and perceptions regarding VXM use in the US are limited. We performed a survey of US HLA directors and transplant surgeons regarding HLA testing and crossmatch strategies. 53 (56 %) HLA directors and 68 surgeons (representing âˆ¼ 23 % of US transplant centers) completed the survey. Both groups agreed that VXM could reduce cold ischemia time (CIT), costs and improve allocation efficiency. VXM use increased following the 2021 kidney allocation change. Reducing CIT was the primary reason for favoring VXM over PXM. Preference for VXM reduced as candidates' panel reactive antibodies increased. Regulations, program policies and limitations of HLA technology were cited as important reasons for preferring PXM over VXM. Surgeons reported similar perceptions, but findings are limited by the low response rate. Finally, half the labs reported lacking specific protocols for VXM use. In conclusion, improved HLA technology and protocols along with changes to institutional procedures and policy regulations are needed for safer expansion of VXM in DDKT.

Early Effect of the Circular Model of Kidney Allocation in the United States.

BACKGROUND: In March 2021, the United States implemented a new kidney allocation system (KAS250) for deceased donor kidney transplantation (DDKT), which eliminated the donation service area-based allocation and replaced it with a system on the basis of distance from donor hospital to transplant center within/outside a radius of 250 nautical miles. The effect of this policy on kidney discards and logistics is unknown. METHODS: We examined discards, donor-recipient characteristics, cold ischemia time (CIT), and delayed graft function (DGF) during the first 9 months of KAS250 compared with a pre-KAS250 cohort from the preceding 2 years. Changes in discards and CIT after the onset of COVID-19 and the implementation of KAS250 were evaluated using an interrupted time-series model. Changes in allocation practices (biopsy, machine perfusion, and virtual cross-match) were also evaluated. RESULTS: Post-KAS250 saw a two-fold increase in kidneys imported from nonlocal organ procurement organizations (OPO) and a higher proportion of recipients with calculated panel reactive antibody (cPRA) 81%-98% (12% versus 8%; P <0.001) and those with >5 years of pretransplant dialysis (35% versus 33%; P <0.001). CIT increased (mean 2 hours), including among local OPO kidneys. DGF was similar on adjusted analysis. Discards after KAS250 did not immediately change, but we observed a statistically significant increase over time that was independent of donor quality. Machine perfusion use decreased, whereas reliance on virtual cross-match increased, which was associated with shorter CIT. CONCLUSIONS: Early trends after KAS250 show an increase in transplant access to patients with cPRA>80% and those with longer dialysis duration, but this was accompanied by an increase in CIT and a suggestion of worsening kidney discards.

Back Table Preparation of the Right Lobe Live Donor Liver Allograft: A Crucial Part of the Adult Live Donor Liver Transplant Procedure.

INTRODUCTION: We aimed to describe our procedure for vascular reconstruction and back table bench preparation for the right lobe live donor allograft. Live donor liver transplantation (LDLT) remains an important option for the expansion of the donor pool. The procedure has been widely used, and its success is dependent on a technically perfect operation with appropriate inflow and outflow of the allograft. Adequate preparation of the right lobe (RL) allograft prior to implantation remains a vital part of the procedure. METHODS: Our technique of back table vascular reconstruction of the RL allograft has been performed using a hepatic vein patch venoplasty, inferior hepatic vein inclusion, portal vein reconstruction, and segment V and VIII reconstruction for all of our LDLTs. RESULTS: Between March 2009 and January 2020, 321 consecutive adult LDLTs were performed and underwent back table reconstruction with the techniques described. During that time period, no patients had hepatic insufficiency. There was a single thrombosis of a superior mesenteric vein (SMV) to PV jump conduit. CONCLUSIONS: Our technique of back table reconstruction of the LDLT right lobe graft remains a crucial part of the operative procedure. Our experience with RL grafts without middle hepatic vein (MHV) and our systematic approach for inflow and outflow reconstruction has yielded excellent results with no technical outflow issues and minimal inflow complications.

Treatment modalities and long-term outcomes of hepatic hemangioendothelioma in the United States.

BACKGROUND: We analyzed the outcomes of patients with hepatic epithelioid hemangioendothelioma (HEHE) in the United States after stratification by their most definitive treatment. METHODS: The National Cancer Data Base was used to identify patients with HEHE between 2004 and 2018. Patients were divided in four treatment groups: no surgical therapy, ablation, liver resection or liver transplantation. Demographics and clinical characteristics were compared, and Kaplan Meier functions and Cox-regression were used for unadjusted and adjusted survival analyses. RESULTS: Among a total of 334 patients, 218 (65.2%) were managed non-surgically, 74 (22.1%) underwent hepatic resections, 35 (10.4%) underwent liver transplantation and 7 (2.1%) underwent ablations. The overall median survival was 111 months (95%CI 73-149) after liver transplantation, 69 months (95%CI 45-92) after hepatic resection, 38 months (95%CI 0-78) after ablation and 80 months (95%CI 70-90) for patients managed by watchful waiting (P < 0.001). After adjustment, patients who underwent liver transplantation were found to have a better survival when compared to other therapies (Hazard Ratio: 0.61, 95% Confidence Interval: 0.38-0.97, p = 0.035). CONCLUSIONS: This study reports the outcomes of the largest cohort of patients with HEHE. The longest survival was observed after liver transplantation, followed by non-surgical management and hepatic resection. Because of selection bias, future studies to better characterize what criteria should be used for the selection of treatment modalities for HEHE are urgently needed.

Increasing Living Donor Liver Transplantation Using Liver Paired Exchange.

BACKGROUND: Living donor liver transplantation (LDLT) continues to be the primary modality of liver transplantation in Asia, but it accounts for about 5% of all liver transplantations in the US. ABO incompatibility is the primary reason motivated donors are declined. Although kidney paired exchanges are common, liver paired exchange (LPE) is still evolving in the US. STUDY DESIGN: This is a retrospective review (between January 1, 2019, and July 31, 2021) of our initial experience with LPE. RESULTS: A total of 10 LPEs (20 LDLTs) were performed during the study period. Seven LPEs were initiated by a nondirected O donor. The other 3 pair sets involved 1 ABO compatible and 1 ABO incompatible pair. Transplantations in a pair set were completed within a mean of 4.8 (range 1-14) days of each other. All 20 donors are doing well with no major complications at 12.7 (range 1-20) months. Seventeen of 20 recipients are alive and have good allograft function. One recipient died in the early postoperative period. Two late deaths of patients with functioning allografts were due to COVID-19 (at 8 months) and peritoneal carcinomatosis and gram-negative sepsis (at 9 months). CONCLUSIONS: LPE is feasible in a high-volume LDLT center and is a useful option to increase LDLT by overcoming ABO incompatibility. Nondirected donors can be utilized to initiate an LPE.

Scedosporiosis in a Combined Kidney and Liver Transplant Recipient: A Case Report of Possible Transmission from a Near-Drowning Donor.

Scedosporium spp. are saprobic fungi that cause serious infections in immunocompromised hosts and in near-drowning victims. Solid organ transplant recipients are at increased risk of scedosporiosis as they require aggressive immunosuppression to prevent allograft rejection. We present a case of disseminated Scedosporium apiospermum infection occurring in the recipient of a combined kidney and liver transplantation whose organs were donated by a near-drowning victim and review the literature of scedosporiosis in solid organ transplantation.

Life-threatening postoperative hemorrhage from hepatic artery pseudoaneurysm successfully treated by transcatheter embolization in a 5-year-old.

Upper gastrointestinal bleeding caused by a pseudoaneurysm after hepatobiliary operation is well described in adults. This can be successfully treated with transcatheter embolization under angiographic guidance. We report a case of massive upper gastrointestinal bleeding in a 5-year-old boy secondary to a pseudoaneurysm of the right hepatic artery after choledochal cyst excision. A coil embolization successfully treated this life-threatening event and spared the child, the morbidity of a challenging gastrointestinal and vascular reconstruction. Use of percutaneous interventional technique to treat this rare complication of choledochal cyst excision has not been previously described in the pediatric surgical literature. Transcatheter embolization of a pseudoaneurysm may be a safe and less morbid treatment alternative for this surgical complication even in the pediatric population.

Robotic vs. laparoscopic colorectal surgery: an institutional experience.

BACKGROUND: Robotic colorectal surgery is gaining interest in general and colorectal surgery. The use of the da Vinci(®) Robotic system has been postulated to improve outcomes, primarily by increasing the dexterity and facility with which complex dissections can be performed. We report a large, single institution, comparative study of laparoscopic and robotic colectomies, attempting to better elucidate the benefits of robotic surgery in patients with colorectal disease. METHODS: We conducted a retrospective review of 171 patients who underwent robotic and laparoscopic colectomies (79 and 92, respectively) at our institution between November 2004 and November 2009. Patients in both groups had well-matched preoperative parameters. All cases were further subdivided by their anatomical location into right-sided and left-sided colectomy, and analysis was performed within these two subgroups. Perioperative outcomes reported include operative time, operative blood loss, time to return of bowel function, time to discontinuation of patient controlled analgesia, length of stay, and intraoperative or postoperative complications. RESULTS: Our results indicate that there is no statistical difference in length of stay, time to return of bowel function, and time to discontinuation of patient-controlled analgesia between robotic and laparoscopic left and right colectomies. Interestingly, the total procedure time difference between the laparoscopic and robotic colectomies was much smaller than previously published accounts (mean 140 min vs. 135 min for right colectomy; mean 168 min vs. 203 min for left colectomy). CONCLUSIONS: Our study is one of the largest reviews of robotic colorectal surgery to date. We believe that our results further demonstrate the equivalence of robotic surgery to laparoscopic surgery in colorectal procedures. Future research should focus on surgeon-specific variables, such as comfort, ergonomics, distractibility, and ease of use, as other ways to potentially distinguish robotic from laparoscopic colorectal surgery.

The effect of low body mass index on outcome in critically ill surgical patients.

BACKGROUND: Body mass index (BMI) has been correlated with complications and outcome in surgical patients at the two extremes of the nutrition spectrum. OBJECTIVE: To study the relationship between BMI, outcome, hospital length of stay, and complications in patients admitted to the surgical intensive care unit (SICU). DESIGN: Review of prospectively acquired data in SICU patients. Data acquired included weight, height, age, gender, Acute Physiology and Chronic Health Evaluation (APACHE) II-III scores, Simplified Acute Physiology II (SAPS II) scores, and morbidity and mortality. Patients who stayed in the unit <24 hours were excluded. RESULTS: Of 793 patients, 706 had a normal BMI (NBMI; mean 22.12 kg/m²) and 87 were underweight (UBMI; mean 16.81 kg/m²). There was no statistically significant difference in APACHE II-III and SAPS scores. The NBMI group had more infections, and the UBMI group had more pulmonary complications (χ(2), P < .0087). There was no significant difference in acute respiratory distress syndrome, atrial fibrillation, myocardial infarction, septicemia, or ventilator- associated pneumonia (Fisher exact test, P = 0.38; χ(2), P = .41). The ICU length of stay between the 2 groups was not significantly different (6.7 vs 5.8 days; P = .64). Overall, there was 11.1% (88/793) SICU mortality; 74 of 706 (10.5%) patients expired in the NBMI group, and 14 of 87 (16.1%) patients expired in the UBMI group. CONCLUSIONS: Low BMI is associated with increased mortality in SICU patients. A BMI <18.5 kg/m² is an independent factor affecting outcome in surgical critical care patients.

Endovascular stenting of blunt thoracic aortic injury in an 11-year-old.

Blunt traumatic thoracic aortic injury in children is very rare. Open surgical repair is the definitive treatment. Thoracic endovascular aortic repair (TEVAR) for trauma has been performed in adults with good outcomes. Its use has been adopted in pediatric population, and its role is evolving. We report a successful TEVAR in a critically injured 11-year-old boy. To our knowledge, this is the youngest patient to be successfully treated with TEVAR.