Fates of retained hepatic segment IV and its prognostic impact in adult split liver transplantation using an extended right liver graft

Purpose@#When splitting a liver for adult and pediatric graft recipients, the retained left medial section (S4) will undergo ischemic necrosis and the right trisection graft becomes an extended right liver (ERL) graft. We investigated the fates of the retained S4 and its prognostic impact in adult split liver transplantation (SLT) using an ERL graft. @*Methods@#This was a retrospective analysis of 25 adult SLT recipients who received split ERL grafts. @*Results@#The mean model for end-stage liver disease (MELD) score was 27.3 ± 10.9 and graft-recipient weight ratio (GRWR) was 1.98 ± 0.44. The mean donor age was 26.5 ± 7.7 years. The split ERL graft weight was 1,181.5 ± 252.8 g, which resulted in a mean GRWR of 1.98 ± 0.44. Computed tomography of the retained S4 parenchyma revealed small ischemic necrosis in 16 patients (64.0%) and large ischemic necrosis in the remaining 9 patients (36.0%). No S4-associated biliary complications were developed. The mean GRWR was 1.87 ± 0.43 in the 9 patients with large ischemic necrosis and 2.10 ± 0.44 in the 15 cases with small ischemic necrosis (P = 0.283). The retained S4 parenchyma showed gradual atrophy on follow-up imaging studies. The amount of S4 ischemic necrosis was not associated with graft (P = 0.592) or patient (P = 0.243) survival. A MELD score of >30 and pretransplant ventilator support were associated with inferior outcomes. @*Conclusion@#The amount of S4 ischemic necrosis is not a prognostic factor in adult SLT recipients, probably due to a sufficiently large GRWR.

Fates of retained hepatic segment IV and its prognostic impact in adult split liver transplantation using an extended right liver graft

Purpose@#When splitting a liver for adult and pediatric graft recipients, the retained left medial section (S4) will undergo ischemic necrosis and the right trisection graft becomes an extended right liver (ERL) graft. We investigated the fates of the retained S4 and its prognostic impact in adult split liver transplantation (SLT) using an ERL graft. @*Methods@#This was a retrospective analysis of 25 adult SLT recipients who received split ERL grafts. @*Results@#The mean model for end-stage liver disease (MELD) score was 27.3 ± 10.9 and graft-recipient weight ratio (GRWR) was 1.98 ± 0.44. The mean donor age was 26.5 ± 7.7 years. The split ERL graft weight was 1,181.5 ± 252.8 g, which resulted in a mean GRWR of 1.98 ± 0.44. Computed tomography of the retained S4 parenchyma revealed small ischemic necrosis in 16 patients (64.0%) and large ischemic necrosis in the remaining 9 patients (36.0%). No S4-associated biliary complications were developed. The mean GRWR was 1.87 ± 0.43 in the 9 patients with large ischemic necrosis and 2.10 ± 0.44 in the 15 cases with small ischemic necrosis (P = 0.283). The retained S4 parenchyma showed gradual atrophy on follow-up imaging studies. The amount of S4 ischemic necrosis was not associated with graft (P = 0.592) or patient (P = 0.243) survival. A MELD score of >30 and pretransplant ventilator support were associated with inferior outcomes. @*Conclusion@#The amount of S4 ischemic necrosis is not a prognostic factor in adult SLT recipients, probably due to a sufficiently large GRWR.

Prognosis of Split Liver Transplantation Compared with Whole Liver Transplantation in Adult Patients:Single-center Results under the Korean MELD Score-based Allocation Policy

Background@#Split liver transplantation (SLT) has been occasionally performed in Korea. This study compared the incidence and prognosis of SLT with whole liver transplantation (WLT) in adult patients. @*Methods@#Between June 2016 and November 2019, 242 adult patients underwent a total of 256 deceased donor liver transplantation operations. SLT was performed in 7 patients (2.9%). @*Results@#The mean age of SLT donors was 29.7 ± 7.4 years, and the mean age of recipients was 55.7 ± 10.6 years, with the latter having a mean model for end-stage liver disease score of 34.6 ± 3.1. Mean split right liver graft weight was 1,228.6 ± 149.7 g and mean graft-recipient weight ratio was 1.97 ± 0.39. Of the seven SLT recipients, Korean Network for Organ Sharing (KONOS) status was one in status 1, one in status 2 and five in status 3. The graft (p = 0.72) and patient (p = 0.84) survival rates were comparable in the SLT and WLT groups. Following propensity score matching, graft (p = 0.61) and patient (p = 0.91) survival rates remained comparable in the two groups. Univariate analysis showed that pretransplant ventilator support and renal replacement therapy were significantly associated with patient survival, whereas KONOS status category and primary liver diseases were not. Multivariate analysis showed that pretransplant ventilator support was an independent risk factor for patient survival. @*Conclusion@#Survival outcomes were similar in adult SLT and WLT recipients, probably due to selection of high-quality grafts and low-risk recipients. Prudent selection of donors and adult recipients for SLT may expand the liver graft pool for pediatric patients without affecting outcomes in adults undergoing SLT.

Refined surgical techniques to improve the patency of cryopreserved iliac artery homografts for middle hepatic vein reconstruction during living donor liver transplantation

Purpose@#A cryopreserved iliac artery homograft (IAH) has not been considered suitable for middle hepatic vein (MHV) reconstruction during living donor liver transplantation (LDLT), primarily due to the low patency from its small diameter. We revised our surgical techniques for MHV reconstruction using an IAH to improve its patency. @*Methods@#This study analyzed the causes of early conduit occlusion and developed revised techniques to address this that had clinical application. @*Results@#The potential risk factors for early conduit occlusion were the small IAH size, small graft in the segment V vein (V5) and segment VIII vein (V8) opening, and small recipient MHV-left hepatic vein stump. These factors were reflected to our revised surgical methods which included endarterectomy of the atherosclerotic plaque, unification of the internal and external iliac artery branches for large V5, and branch-patch arterioplasty for large V8. IAH endarterectomy, branch unification technique, and branch-patch arterioplasty were applied to 8, 5, and 5 patients, respectively and resulted in 1-month occlusion rates of 37.5%, 20.0%, and 40.0%, respectively. The overall patency rates of the IAH-MHV conduits in our 18 patients were 66.7% at 1 month, 38.9% at 3 months, and 33.3% at 1 year. @*Conclusion@#Our refined MHV reconstruction using an IAH improved short-term MHV conduit patency, but did not effectively prevent early conduit occlusion, particularly with a small- or medium-sized IAH. Individualized reconstruction designs during LDLT operation are needed when an IAH is used for a modified right liver graft.

Determination of Hepatitis B Immunoglobulin Infusion Interval Using Pharmacokinetic Half-life Simulation for Posttransplant Hepatitis B Prophylaxis

BACKGROUND: Prophylaxis for hepatitis B virus (HBV) recurrence is essential after liver transplantation (LT) in HBV-associated recipients. This study established an individualized HBV prophylaxis protocol, through optimization of hepatitis B immunoglobulin (HBIG) administration, with application of simulative half-life (SHL). METHODS: This study involved five parts: Part 1 developed the SHL estimation method with 20 patients; Parts 2 and 3 assessed the SHL variability and developed a simulation model to apply SHL in 100 patients; Part 4 validated the simulation model in 114 patients, and Part 5 was a cross-sectional study on the current status of HBIG infusion intervals in 660 patients. RESULTS: In Part 1, infusion of 10,000 IU HBIG induced add-on rise hepatitis B surface antibody (anti-HBs) titer of 5,252.5 ± 873.7 IU/L, which was 4.4% lower than actual measurement. Mean SHL of 20.0 ± 3.7 days was 2.2% longer than actual measurement. In Part 2, the medians of the intra- and inter-individual coefficient of variation in SHL were 13.5% and 18.5%, respectively. Pretransplant HBV DNA load and posttransplant antiviral therapy did not affect SHL. In Part 3, a simulation model was developed to determine the interval of HBIG infusion, by using SHL. In Part 4, all 114 patients were successfully managed with regular HBIG infusion intervals of ≥ 8 weeks, and the interval was prolonged to ≥ 12 weeks in 89.4%, with a target trough anti-HBs titer ≥ 200 IU/L. In Part 5, 47.4% of our patients received HBIG excessively, at a target trough titer of 500 IU/L. CONCLUSION: SHL estimation using only clinically available parameters seems to be reliably accurate when compared with actual measurements. We believe that SHL estimation is helpful to establish a personalized HBV prophylaxis protocol for optimizing HBIG administration.

Changes in the types of liver diseases requiring hepatic resection: a single-institution experience of 9016 cases over a 10-year period

BACKGROUNDS/AIMS: To understand the changing demands for hepatic resection (HR), we collected data regarding HR performed in a tertiary centre over a period of 10 years. METHODS: We carried out extensive search of institutional databases to identify HR cases performed between January 2005 and December 2014. A study cohort of 9,016 patients were divided into 5 disease categories, namely hepatocellular carcinoma (HCC), intrahepatic cholangiocarcinoma (ICC), intrahepatic duct stone disease (IHDS), colorectal cancer liver metastasis (CRLM), and uncommon/rare diseases (URD). RESULTS: There were 5,661 (62.8%) HCC cases, followed by 1441 (16.0%) CRLM, 942 (10.5%) ICC, 638 (7.1%) IHDS and 334 (3.7%) URD. The number of annual HR cases gradually increased from 443 in 2005 to 1,260 in 2015. Annual HCC cases also gradually increased, but the annual proportion of HCC cases fluctuated narrowly between 58.3% and 70.2%. Annual CRLM cases increased rapidly, and their proportion increased progressively from 4.7% to 20.5%. Annual ICC cases increased slowly, and their annual proportion fluctuated between 7.2% and 15.6%. Annual IHDS cases decreased slowly, and their annual proportion decreased progressively from 17.2% to 3.4%, while annual URD cases fluctuated, with annual proportions varying between 2.3% and 5.6%. CONCLUSIONS: Annual cases of HR increased over the last 10 years in a tertiary center probably due to a center-specific centralization effect. The number of CRLM cases increased rapidly; those of HCC and ICC increased gradually, and those of IHDS declined gradually. We believe that these results reflect real changes in the types of liver disease requiring HR.

Clinical Experience of H-type Tracheoesophageal Fistula

Tracheoesophageal fistula without esophageal atresia (H-type TEF) is a congenital anomaly that is characterized by a fistula between the posterior wall of the trachea and the anterior wall of the esophagus, not accompanied by esophageal atresia. The purpose of this study is to investigate the clinical characteristics, diagnostic time, the side of cervical approach and short term result after surgery by searching medical records of patients treated for H-type TEF. The search was done at University of Ulsan, Department of Pediatric Surgery of Asan Medical Center, and the total number of patients from May 1989 to December 2010 was 9 with M:F ratio of 1:2. The median gestational age was 39(+6) (32(+6)~41(+0)) wks. Seven out of nine patients were born at term and the other two were born premature. The clinical presentation was aspiration pneumonia, difficulty in feeding, chronic cough, vomiting, abdominal distension and growth retardation. The symptoms presented right after birth. The diagnosis was made with esophagography and the median time of diagnosis was 52 days of life. The majority of surgical corrections were performed within two weeks of diagnosis (median; 15d, range; 1d - 6m). Six patients had associated anomalies, and cardiac anomalies were most common. The cervical approach was utilized in all cases (right 2, left 7). Transient vocal cord palsy and minor esophageal leakage complicated two cases. Although the diagnosis of H-type TEF was difficult and often delayed, we had a good short term result. The left cervical approach was preferred.