Three-dimensional Liver Model Application for Liver Transplantation.

BACKGROUND: Children are removed from the liver transplant waitlist because of death or progressive illness. Size mismatch accounts for 30% of organ refusal. This study aimed to demonstrate that 3-dimensional (3D) technology is a feasible and accurate adjunct to organ allocation and living donor selection process. METHODS: This prospective multicenter study included pediatric liver transplant candidates and living donors from January 2020 to February 2023. Patient-specific, 3D-printed liver models were used for anatomic planning, real-time evaluation during organ procurement, and surgical navigation. The primary outcome was to determine model accuracy. The secondary outcome was to determine the impact of outcomes in living donor hepatectomy. Study groups were analyzed using propensity score matching with a retrospective cohort. RESULTS: Twenty-eight recipients were included. The median percentage error was -0.6% for 3D models and had the highest correlation to the actual liver explant (Pearson's R = 0.96, P < 0.001) compared with other volume calculation methods. Patient and graft survival were comparable. From 41 living donors, the median percentage error of the allograft was 12.4%. The donor-matched study group had lower central line utilization (21.4% versus 75%, P = 0.045), shorter length of stay (4 versus 7 d, P = 0.003), and lower mean comprehensive complication index (3 versus 21, P = 0.014). CONCLUSIONS: Three-dimensional volume is highly correlated with actual liver explant volume and may vary across different allografts for living donation. The addition of 3D-printed liver models during the transplant evaluation and organ procurement process is a feasible and safe adjunct to the perioperative decision-making process.

Portable hypothermic oxygenated machine perfusion for organ preservation in liver transplantation: A randomized, open-label, clinical trial.

BACKGROUND AND AIMS: In liver transplantation, cold preservation induces ischemia, resulting in significant reperfusion injury. Hypothermic oxygenated machine perfusion (HMP-O 2 ) has shown benefits compared to static cold storage (SCS) by limiting ischemia-reperfusion injury. This study reports outcomes using a novel portable HMP-O 2 device in the first US randomized control trial. APPROACH AND RESULTS: The PILOT trial (NCT03484455) was a multicenter, randomized, open-label, noninferiority trial, with participants randomized to HMP-O 2 or SCS. HMP-O 2 livers were preserved using the Lifeport Liver Transporter and Vasosol perfusion solution. The primary outcome was early allograft dysfunction. Noninferiority margin was 7.5%. From April 3, 2019, to July 12, 2022, 179 patients were randomized to HMP-O 2 (n=90) or SCS (n=89). The per-protocol cohort included 63 HMP-O 2 and 73 SCS. Early allograft dysfunction occurred in 11.1% HMP-O 2 (N=7) and 16.4% SCS (N=12). The risk difference between HMP-O 2 and SCS was -5.33% (one-sided 95% upper confidence limit of 5.81%), establishing noninferiority. The risk of graft failure as predicted by Liver Graft Assessment Following Transplant score at seven days (L-GrAFT 7 ) was lower with HMP-O 2 [median (IQR) 3.4% (2.4-6.5) vs. 4.5% (2.9-9.4), p =0.024]. Primary nonfunction occurred in 2.2% of all SCS (n=3, p =0.10). Biliary strictures occurred in 16.4% SCS (n=12) and 6.3% (n=4) HMP-O 2 ( p =0.18). Nonanastomotic biliary strictures occurred only in SCS (n=4). CONCLUSIONS: HMP-O 2 demonstrates safety and noninferior efficacy for liver graft preservation in comparison to SCS. Early allograft failure by L-GrAFT 7 was lower in HMP-O 2 , suggesting improved early clinical function. Recipients of HMP-O 2 livers also demonstrated a lower incidence of primary nonfunction and biliary strictures, although this difference did not reach significance.

Utilization of Segmental Grafts Is Associated With Higher Transplant Rates in Pediatric Patients.

INTRODUCTION: In July 2017, a policy to increase the use of segmental grafts (SGs) was implemented at our institution. The aim was to compare changes in waitlist activity after implementation of this policy. METHODS: A single-center, retrospective study. Pediatric patients on the liver waiting list between January 2015 and December 2019 were screened. Patients were classified as receiving a liver transplant (LT) before (Period 1) or after (Period 2) policy changes. Primary end points were transplant rates and time to transplant. RESULTS: Sixty five first LT performed on 65 patients were included. Twenty nine LT were performed during Period 1 and 36 during Period 2. More than half (55%) of LT in Period 2 were SG, compared to 10.3% in Period 1 (P < 0.001). Forty nine and 56 pediatric candidates on the waiting list accounted for 38.78 and 24.48 person-years during Period 1 and Period 2, respectively. Transplant rates per 100 person-years on the waiting list increased from 85.09 during Period 1 to 187.87 in Period 2 (Rate ratio: 2.20; P < 0.001). Median time to receive a LT decreased from 229 d in Period 1 to 75 d during Period 2 (P = 0.013). One-year patient survival rates were 96.6% in Period 1 and 95.7% in Period 2. One-year graft survival rates were 89.7% and 88% in Period 1 and Period 2, respectively. CONCLUSIONS: A policy to increase the use of SG was associated with significantly higher transplant rates and lower waiting times. Implementation of this policy can be done successfully with no observed negative impact on patient and graft survival.

Performance of a Prospective Anticoagulation Stratification Algorithm After Liver Transplantation.

Venous thromboembolism (VTE) occurs in 0.4% to 15.5% and bleeding occurs in 20% to 35% of patients after liver transplantation (LT). Balancing the risk of bleeding from therapeutic anticoagulation and risk of thrombosis in the postoperative period is challenging. Little evidence exists regarding the best treatment strategy for these patients. We hypothesized that a subset of LT patients who develop postoperative deep vein thromboses (DVTs) could be managed without therapeutic anticoagulation. We implemented a quality improvement (QI) initiative using a standardized Doppler ultrasound-based VTE risk stratification algorithm to guide parsimonious implementation of therapeutic anticoagulation with heparin drip. Methods: In a prospective management QI initiative for DVT management, we compared 87 LT historical patients (control group; January 2016-December 2017) to 182 LT patients (study group; January 2018-March 2021). We analyzed the rates of immediate therapeutic anticoagulation after DVT diagnosis within 14 d of LT, clinically significant bleeding, return to the operating room, readmission, pulmonary embolism, and death within 30 d of LT before and after the QI initiative. Results: Ten patients (11.5%) in the control group and 23 patients (12.6%; P = 0.9) in the study group developed DVTs after LT. Immediate therapeutic anticoagulation was used in 7 of 10 and 5 of 23 patients in the control and study groups, respectively (P = 0.024). The study group had lower odds of receiving immediate therapeutic anticoagulation after VTE (21.7% versus 70%; odds ratio = 0.12; 95% confidence interval, 0.019-0.587; P = 0.013) and a lower rate of postoperative bleeding (8.7% versus 40%; odds ratio = 0.14, 95% confidence interval, 0.02-0.91; P = 0.048). All other outcomes were similar. Conclusions: Implementing a risk-stratified VTE treatment algorithm for immediate post-LT patients appears to be safe and feasible. We observed a decrease in the use of therapeutic anticoagulation and a lower rate of postoperative bleeding without adverse impacts on early outcomes.

Implementation of Incidental Liver Lesion Clinically Integrated Workflow Increases Compliance With ACR Follow-Up Guidelines, Closing Care Gaps.

OBJECTIVE: Follow established management guidelines from the ACR and improve adherence to follow-up recommendations for incidental liver lesions (ILLs) for all patients undergoing CT abdomen and pelvis with contrast (CTAPw) examinations, with advocacy from a multidisciplinary care team. METHODS: A mandatory structured radiology reporting module was developed for use in CTAPw reports for ILL recommendations. Data from the electronic medical record describing patients with radiology-reported ILLs and their clinical risk diagnosis categories were tabulated in a queryable electronic database. A nurse co-ordinator initiated workflow to communicate the need for ILL follow-up MRI to ordering physicians and primary care providers. MRIs were ordered by the ILL team. An interactive process was undertaken with continuous review to improve identification of eligible patients and adherence to recommendations. RESULTS: During the initial launch phase from December 2020 to March 2021, 1,577 ILLs were detected on 20,667 CTAPw examinations, and for those with the characterize now recommendation, 36 of 114 (31.6%) received follow-up in 30 days. Between January 2021 and June 2022, 117,520 CTAPws were performed and 4,371 ILLs were detected. Using the ILL workflow, in the MRI now cohort, follow-up occurred within 30 days in 202 of 542 (36.2%) patients, and a total of 368 of 542 (67.9%) patients have completed their follow-up to date. DISCUSSION: Using a focused effort to close a gap in ILL care, adherence to follow-up recommendations improved over the long term, although there remains a gap in adherence to short-term interventions. A multidisciplinary approach, radiology reporting, and software solutions were leveraged to improve a complex process.

Hepatitis C-positive liver transplantation: outcomes and current practice.

PURPOSE OF REVIEW: The coincidence of the opioid epidemic and the approval of direct-acting antivirals for the treatment of hepatitis C virus (HCV) has resulted in an imbalance in HCV viraemic donors relative to HCV viraemic patients awaiting liver transplantation. Although ethical concerns exist about knowingly infecting patients with HCV in the absence of prospective, protocolized studies, transplantation of HCV-positive liver allografts into HCV-negative recipients has increased exponentially in recent years. For this reason, we sought to review outcomes, cost-effectiveness and ethical concerns associated with this practice. RECENT FINDINGS: Short-term outcomes in terms of patient and graft survival are equivalent to those who received HCV-negative allografts without an increase in acute rejection, biliary or vascular complications. Few cases of treatment failure have been reported and complications related to the virus itself such as fibrosing cholestatic hepatitis and membranous glomerulonephritis are rare and reversible with prompt direct-acting antiretroviral treatment. The practice appears cost-effective and modelling suggests a survival benefit for patients willing to accept HCV-positive organs compared with those who do not. SUMMARY: In light of the preponderance of current data, one could argue it is unethical to withhold HCV-positive grafts from HCV-negative recipients who have undergone thorough informed consent.

Revision of meso-Rex bypass utilizing a collateral vein in a patient with portal steal phenomenon after liver transplant: A case report.

INTRODUCTION: In children with extrahepatic portal vein obstruction or those who develop portal vein thrombosis after liver transplant, the use of Meso-Rex Bypass (MRB) creates a more physiological state by redirecting mesenteric blood flow back into the intrahepatic portal system via a venous conduit. PRESENTATION OF CASE: A 3-year-old female with biliary atresia associated with polysplenia syndrome and a surgical history of Kasai portoenterostomy procedure, and an ABO incompatible whole liver transplant. Within a year after transplant she presented with prehepatic portal hypertension, that was treated with MRB using a deceased donor ABO compatible iliac vein as conduit. Six months later, she was taken to the operating room for bypass revision, during the procedure the MRB showed no flow and no thrombus, and a large splenorenal collateral vein that was causing a portal perfusion steal phenomenon was observed. After dissecting the collateral vein, an 8 cm x8 mm segment of this vessel was used as an autologous conduit to re-do the Rex. DISCUSSION: Failed of MRB can be attributed to portal steal phenomenon, hypercoagulable disorders, bypass contraction or kinking. In this case we believe the culprit to be the former. When there is a history of longstanding portal hypertension, large collaterals develop; thus, intraoperative portal vein flow measurement is critical and ligation of large collaterals during liver transplantation and MRB should be performed to avoid portal steal phenomenon postprocedure. CONCLUSION: Using a collateral vein as an alternative autologous venous conduit is a feasible option that can have durable success.

Impact of Pretransplant Donor BK Viruria in Kidney Transplant Recipients.

BACKGROUND: BK virus (BKV) is a significant cause of nephropathy in kidney transplantation. The goal of this study was to characterize the course and source of BKV in kidney transplant recipients. METHODS: We prospectively collected pretransplant plasma and urine samples from living and deceased kidney donors and performed BKV polymerase chain reaction (PCR) and immunoglobulin G (IgG) testing on pretransplant and serially collected posttransplant samples in kidney transplant recipients. RESULTS: Among deceased donors, 8.1% (17/208) had detectable BKV DNA in urine prior to organ procurement. BK viruria was observed in 15.4% (6/39) of living donors and 8.5% (4/47) of deceased donors of recipients at our institution (P = .50). BKV VP1 sequencing revealed identical virus between donor-recipient pairs to suggest donor transmission of virus. Recipients of BK viruric donors were more likely to develop BK viruria (66.6% vs 7.8%; P < .001) and viremia (66.6% vs 8.9%; P < .001) with a shorter time to onset (log-rank test, P < .001). Though donor BKV IgG titers were higher in recipients who developed BK viremia, pretransplant donor, recipient, and combined donor/recipient serology status was not associated with BK viremia (P = .31, P = .75, and P = .51, respectively). CONCLUSIONS: Donor BK viruria is associated with early BK viruria and viremia in kidney transplant recipients. BKV PCR testing of donor urine may be useful in identifying recipients at risk for BKV complications.