Objective: Assess cost and complication outcomes after liver transplantation (LT) using normothermic machine perfusion (NMP). Background: End-ischemic NMP is often used to aid logistics, yet its impact on outcomes after LT remains unclear, as does its true impact on costs associated with transplantation. Methods: Deceased donor liver recipients at 2 centers (January 1, 2019, to June 30, 2023) were included. Retransplants, splits, and combined grafts were excluded. End-ischemic NMP (OrganOx-Metra) was implemented in October 2022 for extended-criteria donation after brain death (DBDs), all donations after circulatory deaths (DCDs), and logistics. NMP cases were matched 1:2 with static cold storage controls (SCS) using the Balance-of-Risk [donation after brain death (DBD)-grafts] and UK-DCD Score (DCD-grafts). Results: Overall, 803 transplantations were included, 174 (21.7%) receiving NMP. Matching was achieved between 118 NMP-DBDs with 236 SCS; and 37 NMP-DCD with 74 corresponding SCS. For both graft types, median inpatient comprehensive complications index values were comparable between groups. DCD-NMP grafts experienced reduced cumulative 90-day comprehensive complications index (27.6 vs 41.9, P=0.028). NMP also reduced the need for early relaparotomy and renal replacement therapy, with subsequently less frequent major complications (Clavien-Dindo ≥IVa). This effect was more pronounced in DCD transplants. NMP had no protective effect on early biliary complications. Organ acquisition/preservation costs were higher with NMP, yet NMP-treated grafts had lower 90-day pretransplant costs in the context of shorter waiting list times. Overall costs were comparable for both cohorts. Conclusions: This is the first risk-adjusted outcome and cost analysis comparing NMP and SCS. In addition to logistical benefits, NMP was associated with a reduction in relaparotomy and bleeding in DBD grafts, and overall complications and post-LT renal replacement for DCDs. While organ acquisition/preservation was more costly with NMP, overall 90-day health care costs-per-transplantation were comparable.

Histotripsy is a novel, noninvasive, nonionizing, and nonthermal approach that uses focused ultrasound waves to treat liver tumors. This technology received a de novo Food and Drug Administration grant in late 2023. This study aimed to provide the first report on post-trial real-world clinical safety data. Safety outcomes within 30 days of histotripsy were collected after obtaining Food and Drug Administration clearance (December 22, 2023 to July 26, 2024). All centers that performed histotripsy were invited to participate in this study. Complications requiring treatment were graded using the Clavien-Dindo classification and Comprehensive Complication Index (CCI). A total of 295 patients underwent histotripsy for 510 tumors at 18 centers. The treated liver tumor types included colorectal metastases (n = 140), neuroendocrine tumors (n = 46), hepatocellular carcinomas (n = 31), pancreatic tumors (n = 30), and breast metastases (n = 26). The most common numbers of tumors treated per procedure were 1 (n = 170), 2 (n = 69), and 3 (n = 37). All 8 liver segments were treated for tumors. Safety data were available for 230 patients from 9 centers. Of note, 12 of 230 patients (5.2%) experienced complications of any grade. Most patients (9 [75%]) had minor cases (Clavien-Dindo grade ≤ II). The median and mean CCIs were 0.00 (IQR, 0.00-0.00) and 0.00 (95% CI, 0.00-0.75). All 3 major complications (Clavien-Dindo grade > II [1.3%]) were death due to disease progression. All 3 patients underwent histotripsy with palliative intent for known advanced intra- and extrahepatic diseases. To the best of our knowledge, this is the first study to report on the real-world therapeutic use of histotripsy for liver tumors. Histotripsy was well tolerated, with few overall complications and rare serious complications, indicating a safety profile that compares favorably with that of other liver-directed and surgical therapies for the treatment of liver tumors. Long-term follow-up data, including oncologic outcomes, were collected.

Ex situ normothermic machine perfusion (NMP) helps increase the use of extended criteria donor livers. However, the impact of an NMP program on waitlist times and mortality has not been evaluated. Adult patients listed for liver transplant (LT) at 2 academic centers from January 1, 2015, to September 1, 2023, were included (n=2773) to allow all patients ≥6 months follow-up from listing. Routine NMP was implemented on October 14, 2022. Waitlist outcomes were compared from pre-NMP pre-acuity circles (n=1460), pre-NMP with acuity circles (n=842), and with NMP (n=381). Median waitlist time was 79 days (IQR: 20–232 d) at baseline, 49 days (7–182) with acuity circles, and 14 days (5–56) with NMP (p<0.001). The rate of transplant-per-100-person-years improved from 61-per-100-person-years to 99-per-100-person-years with acuity circles and 194-per-100-person-years with NMP (p<0.001). Crude mortality without transplant decreased from 18.3% (n=268/1460) to 13.3% (n=112/843), to 6.3% (n=24/381) (p<0.001) with NMP. The incidence of mortality without LT was 15-per-100-person-years before acuity circles, 19-per-100 with acuity circles, and 9-per-100-person-years after NMP (p<0.001). Median Model for End-Stage Liver Disease at LT was lowest with NMP, but Model for End-Stage Liver Disease at listing was highest in this era (p<0.0001). The median donor risk index of transplanted livers at baseline was 1.54 (1.27–1.82), 1.66 (1.42–2.16) with acuity circles, and 2.06 (1.63–2.46) with NMP (p<0.001). Six-month post-LT survival was not different between eras (p=0.322). The total cost of health care while waitlisted was lowest in the NMP era ($53,683 vs. $32,687 vs. $23,688, p<0.001); cost-per-day did not differ between eras (p=0.152). The implementation of a routine NMP program was associated with reduced waitlist time and mortality without compromising short-term survival after liver transplant despite increased use of riskier grafts. Routine NMP use enables better waitlist management with reduced health care costs.

Objective: Describe the utility of circulating tumor DNA in the postoperative surveillance of hepatocellular carcinoma (HCC). Background: Current biomarkers for HCC like alpha-fetoprotein (AFP) are lacking. Circulating tumor DNA (ctDNA) has shown promise in colorectal and lung cancers, but its utility in HCC remains relatively unknown. Methods: Patients with HCC undergoing curative-intent resection from November 1, 2020, to July 1, 2023, received ctDNA testing using the Guardant360 platform. Tumor mutational burden (TMB) is calculated as the number of somatic mutations-per-megabase of genomic material identified. Results: Forty-seven patients had postoperative ctDNA testing. The mean follow-up was 27 months, and the maximum was 43.2 months. Twelve patients (26%) experienced recurrence. Most (n=41/47, 87.2%) had identifiable ctDNA postoperatively; 55.3% (n=26) were TMB-not detected versus 45.7% (n=21) TMB-detectable. Postoperative identifiable ctDNA was not associated with RFS (P=0.518). Detectable TMB was associated with reduced RFS (6.9 vs 14.7 mo, P=0.049). There was a higher rate of recurrence in patients with TMB (n=9/21, 42.9%, vs n=3/26, 11.5%, P=0.02). Area under the curve for TMB-prediction of recurrence was 0.752 versus 0.550 for AFP. ROC analysis established a TMB cutoff of 4.8mut/mB for predicting post-operative recurrence (P=0.002) and RFS (P=0.025). AFP was not correlated with RFS using the lab-normal cutoff (<11 ng/mL, P=0.682) or the cutoff established by ROC analysis (≥4.6 ng/mL, P=0.494). TMB-high was associated with poorer RFS on cox-regression analysis (hazard ratio=5.386, 95% CI: 1.109–26.160, P=0.037), while microvascular invasion (P=0.853) and AFP (P=0.439) were not. Conclusions: Identifiable TMB on postoperative ctDNA predicts HCC recurrence and outperformed AFP in this cohort. Perioperative ctDNA may be a useful surveillance tool following curative-intent hepatectomy. Larger-scale studies are needed to confirm this utility and investigate additional applications in HCC patients, including the potential for prophylactic treatment in patients with residual TMB after resection.

Introduction: Minimally invasive Pancreatoduodenectomy (MIPD), or the Whipple procedure, is increasingly utilized. No study has compared laparoscopic (LPD) and robotic (RPD) approaches, and the impact of the learning curve on oncologic, technical, and post-operative outcomes remains relatively understudied. Methods: The National Cancer Database was queried for patients undergoing LPD or RPD from 2010 to 2020 with a diagnosis of pancreatic cancer. Outcomes were compared between approaches using propensity-score matching (PSM); the impact of annual center-level volume of MIPD was also assessed by dividing volume into quartiles. Results: A total of 3,342 patients were included. Most (n = 2,716, 81.3%) underwent LPD versus RPD (n = 626, 18.7%). There was a high rate (20.2%, n = 719) of positive margins. Mean length-of-stay (LOS) was 10.4 ± 8.9 days. Thirty-day mortality was 2.8% (n = 92) and ninety-day mortality was 5.7% (n = 189). PSM matched 625 pairs of patients receiving LPD or RPD. After PSM, there was no differences between groups based on age, sex, race, CCI, T-stage, neoadjuvant chemo/radiotherapy, or type of PD. After PSM, there was a higher rate of conversion to open (HR = 0.68, 95%CI = 0.50–0.92)., but there was no difference in LOS (HR = 1.00, 95%CI = 0.92–1.11), 30-day readmission (HR = 1.08, 95% CI = 0.68–1.71), 30-day (HR = 0.78, 95% CI = 0.39–1.56) or 90-day mortality (HR = 0.70, 95% CI = 0.42–1.16), ability to receive adjuvant therapy (HR = 1.15, 95% CI = 0.92–1.44), nodal harvest (HR = 1.01, 95%CI = 0.94–1.09) or positive margins (HR = 1.19, 95% CI = 0.89–1.59). Centers in lower quartiles of annual volume of MIPD demonstrated reduced nodal harvest (p = 0.005) and a higher rate of conversion to open (p = 0.038). Higher-volume centers had a shorter LOS (p = 0.012), higher rate of initiation of adjuvant therapy (p = 0.042), and, most strikingly, a reduction in 90-day mortality (p = 0.033). Conclusion: LPD and RPD have similar surgical and oncologic outcomes, with a lower rate of conversion to open in the robotic cohort. The robotic technique does not appear to eliminate the “learning curve”, with higher volume centers demonstrating improved outcomes, especially seen at minimum annual volume of 5 cases.

Introduction: Circulating tumor DNA (ctDNA) is emerging as a promising, non-invasive diagnostic and surveillance biomarker in solid organ malignancy. However, its utility before and after liver transplant (LT) for patients with primary and secondary liver cancers is still underexplored. Methods: Patients undergoing LT for hepatocellular carcinoma (HCC), cholangiocarcinoma (CCA), and colorectal liver metastases (CRLM) with ctDNA testing were included. CtDNA testing was conducted pre-transplant, post-transplant, or both (sequential) from 11/2019 to 09/2023 using Guardant360, Guardant Reveal, and Guardant360 CDx. Results: 21 patients with HCC (n = 9, 43%), CRLM (n = 8, 38%), CCA (n = 3, 14%), and mixed HCC/CCA (n = 1, 5%) were included in the study. The median follow-up time was 15 months (range: 1–124). The median time from pre-operative testing to surgery was 3 months (IQR: 1–4; range: 0–5), and from surgery to post-operative testing, it was 9 months (IQR: 2–22; range: 0.4–112). A total of 13 (62%) patients had pre-transplant testing, with 8 (62%) having ctDNA detected (ctDNA+) and 5 (32%) not having ctDNA detected (ctDNA-). A total of 18 (86%) patients had post-transplant testing, 11 (61%) of whom were ctDNA+ and 7 (33%) of whom were ctDNA-. The absolute recurrence rates were 50% (n = 5) in those who were ctDNA+ vs. 25% (n = 1) in those who were ctDNA- in the post-transplant setting, though this difference was not statistically significant (p = 0.367). Six (29%) patients (HCC = 3, CCA = 1, CRLM = 2) experienced recurrence with a median recurrence-free survival of 14 (IQR: 6–40) months. Four of these patients had positive post-transplant ctDNA collected following diagnosis of recurrence, while one patient had positive post-transplant ctDNA collected preceding recurrence. A total of 10 (48%) patients had sequential ctDNA testing, of whom n = 5 (50%) achieved ctDNA clearance (+/−). The remainder were ctDNA+/+ (n = 3, 30%), ctDNA−/− (n = 1, 10%), and ctDNA−/+ (n = 1, 11%). Three (30%) patients showed the acquisition of new genomic alterations following transplant, all without recurrence. Overall, the median tumor mutation burden (TMB) decreased from 1.23 mut/Mb pre-transplant to 0.00 mut/Mb post-transplant. Conclusions: Patients with ctDNA positivity experienced recurrence at a higher rate than the ctDNA- patients, indicating the potential role of ctDNA in predicting recurrence after curative-intent transplant. Based on sequential testing, LT has the potential to clear ctDNA, demonstrating the capability of LT in the treatment of systemic disease. Transplant providers should be aware of the potential of donor-derived cell-free DNA and improved approaches are necessary to address such concerns.