Are transmembrane 6 superfamily member 2 gene polymorphisms associated with steatohepatitis after pancreaticoduodenectomy?

Aim: After pancreaticoduodenectomy, 20-40% of patients develop steatotic liver disease (SLD), and steatohepatitis can be a problem. Although patatin-like phospholipase domain-containing 3 protein (PNPLA3) and transmembrane 6 superfamily member 2 (TM6SF2) polymorphisms are involved in SLD and steatohepatitis development, whether this is the case after pancreaticoduodenectomy is unclear. Methods and Results: Forty-three patients with pancreatic cancer who underwent pancreaticoduodenectomy at our hospital between April 1, 2018, and March 31, 2021, were included. We extracted DNA from noncancerous areas of residual specimens after pancreaticoduodenectomy and determined PNPLA3 and TM6SF2 gene polymorphisms using real-time polymerase chain reaction. SLD was defined as a liver with an attenuation value of ≤40 HU or a liver-to-spleen ratio of ≤0.9 on computed tomography. We defined high hepatic fibrosis indexes (HFI) instead of steatohepatitis as a Fibrosis-4 index of ≥2.67 or nonalcoholic fatty liver disease fibrosis score of ≥0.675 in patients with SLD. The cumulative incidence of SLD (P = 0.299) and high HFI (P = 0.987) after pancreaticoduodenectomy were not significantly different between the PNPLA3 homozygous and minor allele groups. The incidences of high HFI at 1 year after pancreaticoduodenectomy were 16.8% and 27.0% in the TM6SF2 major homozygous and minor allele groups, respectively, with a significant difference in the cumulative incidence (P = 0.046). Conclusion: The TM6SF2 minor allele may contribute to steatohepatitis development after pancreaticoduodenectomy.

A Multicenter Phase 2 Trial Evaluating the Efficacy and Safety of Preoperative Lenvatinib Therapy for Patients with Advanced Hepatocellular Carcinoma (LENS-HCC Trial).

Introduction: The phase III REFLECT trial demonstrated that lenvatinib was superior to sorafenib in terms of progression-free survival (PFS), time to progression, and objective response rate (ORR) for patients with unresectable hepatocellular carcinoma (HCC). This study assessed the efficacy and safety of preoperative lenvatinib therapy for patients with oncologically or technically unresectable HCC. Methods: In this multicenter single-arm phase II trial, patients with advanced HCC and factors suggestive of a poor prognosis (macroscopic vascular invasion, extrahepatic metastasis, or multinodular tumors) were enrolled. Patients with these factors, even with technically resectable HCC, were defined as oncologically unresectable because of the expected poor prognosis after surgery. After 8 weeks of lenvatinib therapy, the patients were assessed for resectability, and tumor resection was performed if the tumor was considered technically resectable. The primary endpoint was the surgical resection rate. The secondary endpoints were the macroscopic curative resection rate, overall survival (OS), ORR, PFS, and the change in the indocyanine green retention rate at 15 min as measured before and after lenvatinib therapy. The trial was registered with the Japan Registry of Clinical Trials (s031190057). Results: Between July 2019 and January 2021, 49 patients (42 oncologically unresectable patients and 7 technically unresectable patients) from 11 centers were enrolled. The ORR was 37.5% based on mRECIST and 12.5% based on RECIST version 1.1. Thirty-three patients underwent surgery (surgical resection rate: 67.3%) without perioperative mortality. The surgical resection rate was 76.2% for oncologically unresectable patients and 14.3% for technically unresectable patients. The 1-year OS rate and median PFS were 75.9% and 7.2 months, respectively, with a median follow-up period of 9.3 months. Conclusions: The relatively high surgical resection rate seen in this study suggests the safety and feasibility of lenvatinib therapy followed by surgical resection for patients with oncologically or technically unresectable HCC.

Current status and future perspectives of robotic liver surgery.

Robotic liver resection has been reported in case series since the early 2000s. The surgical robot is capable of precise operation using articulated forceps with seven degrees of freedom. The robot also eliminates tremors and provides a good surgical field with highly detailed 3D high-definition images. The clinical results demonstrating their usefulness have been increasing year by year. Initially, a shorter hospital stay was observed in comparison with open hepatectomy. Recent reports have also shown lower conversion and complication rates in comparison with laparoscopic hepatectomy. The clamp and crush method with bipolar forceps, sealing devices, ultrasonic shears, and the combined procedure of Cavitron ultrasonic surgical aspirator and robotic forceps as hybrid procedures have been reported as effective methods of parenchymal transection in robotic surgery. Theoretically, the advantages of the robotic platform allow for more complex liver resection around hilar structures and major blood vessels, as well as for vascular reconstruction or biliary reconstruction. The application of robotic liver surgery for hilar cholangiocarcinoma, living donor hepatectomy, and living donor liver transplantation has been reported. Robotic liver surgery is becoming more popular for certain indications; however, it is important to further evaluate its long-term surgical and oncological outcomes and costs in comparison with conventional laparoscopic and open liver surgery, based on accumulated experience.

DCLK1 Expression and its Functional Significance in Intrahepatic Cholangiocarcinoma and Bil-IN Stage.

BACKGROUND/AIM: Although several studies in some neoplasms have reported correlation between the expression levels of Doublecortin-like kinase1(DCLK1) and carcinogenesis, its role in cholangiocarcinoma remains unknown. MATERIALS AND METHODS: DCLK1 expression in normal epithelium (NE), biliary intraepithelial neoplasia (BilIN)1∼3, and intrahepatic cholangiocarcinoma (ICC) were investigated immuno-histochemically. The molecular effects of DCLK1 were investigated by gene silencing using RNAi [DCLK1-tagrgeting (siDCLK1)]. The human ICC cell lines HuCCT1 and HuH28 were transfected with these siRNAs, and used for assays in the presence or absence of DCLK1 inhibitors. RESULTS: The positive ratio of DCLK1 expression in ICC was higher than that in NE, and equally distributed among BilIN1∼3 (NE: BilIN1: BilIN2: BilIN3: ICC=62%: 91%: 97%: 100%: 95%, p<0.05). In the wound healing assay, the migration of the siDCLK1-treated cells was significantly inhibited compared to the NT-treated cells (p<0.05). In the cell invasion assay, the invasion of the siDCLK1-treated cells was significantly inhibited compared to the NT-treated cells (p<0.05). In the presence of the DCLK1 inhibitor, cell proliferative capacity at 24 hours was decreased in a concentration-dependent manner. CONCLUSION: DCLK1 was highly expressed in the early stage of ICC carcinogenesis. Human ICC cell growth was suppressed in vitro by siRNA silencing of DCLK1 or after treatment with the DCLK1 inhibitor, indicating DCLK1 may be molecular target for ICC therapy.

Investigation of the impact of COVID-19 on postoperative outcomes using a nationwide Japanese database of patients undergoing laparoscopic distal gastrectomy and low anterior resection for gastric cancer and rectal cancer.

Background: The COVID-19 outbreak made conventional medical care impossible, forcing changes in both healthcare providers and patients. In Japan, COVID-19 infection began spreading in earnest in 2020 and exploded in 2021. There was concern that the medical impact of COVID-19 in 2021 would differ from that in 2020. We aimed to clarify the impact of COVID-19 on mortality and anastomotic leakage in laparoscopic surgery for gastric cancer and rectal cancer in Japan using the National Clinical Database (NCD). Methods: We collected data from patients who underwent laparoscopic distal gastrectomy (LDG) and laparoscopic low anterior resection (LLAR) from January 2018 to December 2021 from the NCD, a web-based surgical registration system in Japan. The number of surgical cases, monthly incidence of mortality and morbidity (anastomotic leakage), standardized mortality ratio (SMR), and standardized morbidity-leakage ratio (SMLR [ratio of observed patients to expected patients calculated using the risk calculator established in the NCD]) were evaluated. Results: The numbers of LDG and LLAR cases continued to decline in the first year of the pandemic in 2020 and were as low in 2021 as in 2020. Although the numbers of robot-assisted LDG and LLAR cases increased, the growth rate was lower than the rate of increase prior to the pandemic. Mortality and anastomotic leakage, two of the most important complications, as assessed by SMR and SMLR, did not worsen during the pandemic in comparison to the pre-pandemic period. Conclusions: Laparoscopic surgeries were performed safely in Japan and were not affected by the COVID-19 pandemic.

A first-in-human clinical study of laparoscopic autologous myoblast sheet transplantation to prevent delayed perforation after duodenal endoscopic mucosal dissection.

BACKGROUND: The detection rate of superficial non-ampullary duodenal epithelial tumors (SNADETs) has recently been increasing. Large tumors may contain malignant lesions and early therapeutic intervention is recommended. Endoscopic mucosal dissection (ESD) is considered a feasible treatment modality, however, the anatomical and physiological characteristics of the duodenum create a risk of postoperative perforation after ESD. METHODS: To explore whether myoblast sheet transplantation could prevent delayed perforation after ESD, a first-in-human (FIH) clinical trial of laparoscopic autologous myoblast sheet transplantation after duodenal ESD was launched. Autologous myoblast sheets fabricated from muscle tissue obtained seven weeks before ESD were transplanted laparoscopically onto the serous side of the ESD. The primary endpoints were the onset of peritonitis due to delayed perforation within three days after surgery and all adverse events during the follow-up period. RESULTS: Three patients with SNADETs ≥ 20 mm in size underwent transplantation of a myoblast sheet onto the serous side of the duodenum after ESD. In case 1, The patient's postoperative course was uneventful. Endoscopy and abdominal computed tomography revealed no signs of delayed perforation. Despite incomplete mucosal closure in case 2, and multiple micro perforations during ESD in case 3, cell sheet transplantation could prevent the postoperative massive perforation after ESD, and endoscopy on day 49 after transplantation revealed no stenosis. CONCLUSIONS: This clinical trial showed the safety, efficacy, and procedural operability of this novel regenerative medicine approach involving transplanting an autologous myoblast sheet laparoscopically onto the serosa after ESD in cases with a high risk of delayed perforation. This result indicates the potential application of cell sheet medicine in treating various abdominal organs and conditions with minimal invasiveness in the future. TRIAL REGISTRATION: jRCT, jRCT2073210094. Registered November 8 2021, https://jrct.niph.go.jp/latest-detail/jRCT2073210094 .

Short-term outcomes after liver resection with vascular reconstruction: Results from a study with the National Clinical Database of Japan.

BACKGROUND: Although curative resection with vascular reconstruction improves the prognosis of blood-invading locally advanced hepatobiliary tumors, the mortality and morbidity of the procedure remains unclear. This study aimed to clarify the risk factors associated with mortality and morbidity in patients undergoing liver resection with vascular reconstruction. METHODS: This retrospective observational study included 1215 patients undergoing hepatectomy of more than one section with vascular reconstruction, except for left lateral sectionectomy registered in the National Clinical Database (NCD) between 2015 and 2019. The rates of surgical mortality and relevant clinical factors were evaluated. RESULTS: Among the four types of vascular reconstruction, portal venous reconstruction was frequently performed in 724 patients (59.6% of the enrolled patients). Surgical mortality was 8.1%. Patients with hepatic artery reconstruction had the highest surgical mortality rate of 15.8%. In other types of reconstruction, surgical mortality was 9.1% in the portal vein, 5.2% in inferior vena cava, and 4.9% in hepatic vein. Factors significantly associated with surgical mortality include age, sex (male), preoperative comorbidity (American Society of Anesthesiologists grade >3, respiratory distress, diabetes, preoperative pneumonia, weight loss, and obstructive jaundice), poorer liver functional reserve (indocyanine green retention rate at 15 min and prothrombin time/international normalized ratio >1.1) and accompanying biliary reconstruction. CONCLUSIONS: The NCD revealed the detailed status of liver resection combined with vascular reconstruction in Japan. Based on the results of this analysis, understanding the factors that influence the outcome and postoperative course of each procedure will provide patients with accurate information and opportunities to improve future outcomes.

Ectopic Liver Tissue on the Gallbladder Wall Encountered During Laparoscopic Cholecystectomy.

Ectopic liver tissue is a rare developmental anomaly that is not directly connected to the liver. We encountered ectopic liver tissue on the surface of the gallbladder wall during laparoscopic cholecystectomy. It has vasculature arising from the liver parenchyma and is classified according to its branching pattern. Ectopic liver tissue has been reported to occur in a variety of locations, and when encountered in surgery, it is clinically important to identify ectopic liver tissue with vascular supply to prevent unexpected bleeding. Ectopic liver tissue should be resected and examined histologically for the potential for malignancy when detected during surgical intervention.

Improvement in aged liver regeneration using cell transplantation with chemically induced liver progenitors.

BACKGROUND: A decrease in the regenerative capacity of age-damaged liver tissue has been reported. Liver progenitor cells may play an important role in the regeneration of injured livers. In the present study we aimed to investigate improvements in the regenerative capacity of age-damaged livers using chemically induced liver progenitors (CLiPs) derived from mature hepatocytes. METHODS: Old (>90 weeks) and young (<20 weeks) mice underwent 70% hepatectomy, with or without trans-splenic CLiP administration. The residual liver/bodyweight (LW/BW) ratio was measured on postoperative days 1 and 7, and changes in liver regeneration and histology were evaluated. RESULTS: At 7 days post-hepatectomy, LW/BW ratios were significantly better in CLiP-treated old mice than in untreated old mice (p = .02). By contrast, no effect of CLiP transplantation was observed in young mice (p = .62). Immunofluorescence staining of liver tissue after CLiP administration showed an increase in Ki67-positive cells (p < .01). Flow cytometry analysis of green fluorescent protein-labeled CLiPs indicated that transplanted CLiPs differentiated into mature hepatocytes and were present in the recipient liver. CONCLUSIONS: CLiP transplantation appears to ameliorate the age-related decline in liver regeneration in mice.

Tele-proctoring for minimally invasive surgery across Japan: An initial step toward a new approach to improving the disparity of surgical care and supporting surgical education.

Aim: The aim of this study was to verify the clinical feasibility of tele-proctoring using our ultra-low latency communication system with shared internet access. Methods: Connections between two multiple remote locations at various distances were established through the TELEPRO® tele-proctoring system. The server records the latency between the two locations for tele-proctoring using the annotations. Questionnaires were administered to the surgeons, assistants, and medical staff. Respondents rated the quickness and quality of communication in terms of latency and disturbances in the audio, video, and usefulness of the live telestrations with annotation. Results: Seven hospitals tele-proctored with Sapporo Medical University between January 2021 and September 2022. The median latency of annotation between the two locations ranged from 24.5 to 48.5 ms. No major technological problems occurred, such as streaming interruption, loss of video or audio, poor resolution. The video encoding time was 10 ms, and its decoding time was 0.8 ms. The total latency positively correlated with the distance between two locations (R = 0.55, p < 0.01). The quality of communication regarding latency, disturbance, and surgical education with intraoperative annotative instructions showed similar trends, with perfectly fine being the most common response. No significant differences in surgical quality, educational effect, or social impact were observed between the latency ≥30 and <30 ms groups for whether the size of latency affects surgical education. Conclusion: The feasibility of the tele-proctoring system is expected to be a sustainable approach to help education for young surgeons and surgical supports in rural areas, thereby reducing disparities in health care.

Analysis of the Clinical Course in a Population of Patients with Biliary Tract Cancer Diagnosed as Unresectable After Portal Vein Embolization: A Case Series.

Portal vein embolization (PVE) is recommended as a preoperative procedure for patients with biliary tract cancer scheduled to undergo hepatic resection of more than 50%-60% of the liver. However, details and/or information regarding the follow-up of unresectable cases are often lacking, and the clinical course of unresectable cases is not well analyzed and reported. This study aimed to clarify the clinical prognosis of patients with unresectable biliary tract cancer after PVE. We retrospectively analyzed the clinical backgrounds of patients with biliary tract cancer who underwent PVE without subsequent resection between January 2011 and October 2022. Of the 21 patients with biliary tract cancer who underwent PVE during the study period, eight (38%) cases were unsuitable for resection after PVE for the following reasons: intraoperatively detected dissemination (n=2), para-aortic lymph node metastasis (n=1), liver metastasis (n=1), decreased liver function (n=2), development of liver metastasis while waiting (n=1), and insufficient residual liver volume (n=1). All patients received subsequent chemotherapy, including gemcitabine plus S-1 therapy in three cases, gemcitabine plus cisplatin plus S-1 in three cases, and gemcitabine plus cisplatin or S-1+cisplatin in one case each. As there is currently no curative treatment for biliary tract cancer other than surgery, multidisciplinary management and treatment of patient factors, including tumor factors and liver function, are essential to reducing the number of unresectable cases after PVE.

High serum alpha-fetoprotein and positive immunohistochemistry of alpha-fetoprotein are related to poor prognosis of gastric cancer with liver metastasis.

Liver metastasis in gastric cancer is incurable. Alpha-fetoprotein-producing gastric cancer has a poor prognosis and is prone to liver metastasis. We investigated the association between preoperative serum alpha-fetoprotein levels, liver metastasis, and expression of primitive enterocyte phenotype markers. We reviewed the medical records of 401 patients with gastric cancer who underwent curative surgical resection and immunohistochemically evaluated the primitive phenotype markers. The preoperative serum alpha-fetoprotein levels were elevated and normal in 8 and 393 patients, respectively. Liver metastasis was more frequent in patients with higher preoperative alpha-fetoprotein levels. The 5-year postoperative recurrence-free survival and overall survival rates were significantly worse in patients with higher preoperative serum alpha-fetoprotein levels. Although alpha-fetoprotein and Glypican3 and Spalt-like transcription factor 4 tended to be stained with high preoperative serum alpha-fetoprotein levels, these markers were also positive in some patients with normal alpha-fetoprotein levels. In summary, patients with gastric cancer and high preoperative serum alpha-fetoprotein levels have a poor prognosis and high incidence of liver metastasis. Alpha-fetoprotein can help detect liver metastasis relating to the primitive enterocyte phenotype.

[Air embolism after biliary stent removal during endoscopic retrograde cholangiopancreatography for cholangitis after biliary reconstruction: a case report].

A 62-year-old male patient underwent pancreaticoduodenectomy with modified Child reconstruction for distal cholangiocarcinoma. After eight years, a contrast-enhanced computed tomography (CT) revealed a recurrent lesion at the biliojejunal anastomosis, and a biliary stent was placed for obstructive cholangitis in the right posterior segment of the liver. A right hepatectomy was planned for a local recurrent lesion;thus, percutaneous transhepatic portal embolization was performed on the portal vein's right branch to enlarge the left liver. However, he was referred to our department for endoscopic retrograde biliary drainage for the subsequent cholangitis and liver abscess appearance. A double-balloon enteroscope under CO2 insufflation was used to reach the bile duct-jejunal anastomosis. After removing the bile duct stent with grasping forceps, his general condition suddenly deteriorated, causing cardiopulmonary arrest. He was diagnosed with air embolism based on the findings of air in the heart, aorta, and brain on CT after the return of spontaneous circulation. Treatment for the air embolism and subsequent complications continued in the intensive care unit, but he eventually died 114 days after the onset of the air embolism due to his deteriorating general condition. Pathological autopsy revealed cholangiocarcinoma that extends from the porta hepatis to the posterior segment. Additionally, the proximity between the bile duct and vein extended by the adenocarcinoma and the fibrous obstruction of the vein were revealed, indicating the possibility of a bile duct-vein shunt.

Clinical Validation of Computer-Aided Diagnosis Software for Preventing Retained Surgical Sponges.

BACKGROUND: We previously reported the successful development of a computer-aided diagnosis (CAD) system for preventing retained surgical sponges with deep learning using training data, including composite and simulated radiographs. In this study, we evaluated the efficacy of the CAD system in a clinical setting. STUDY DESIGN: A total of 1,053 postoperative radiographs obtained from patients 20 years of age or older who underwent surgery were evaluated. We implemented a foreign object detection application software on the portable radiographic device used in the operating room to detect retained surgical sponges. The results of the CAD system diagnosis were prospectively collected. RESULTS: Among the 1,053 images, the CAD system detected possible retained surgical items in 150 images. Specificity was 85.8%, which is similar to the data obtained during the development of the software. CONCLUSIONS: The validation of a CAD system using deep learning in a clinical setting showed similar efficacy as during the development of the system. These results suggest that the CAD system can contribute to the establishment of a more effective protocol than the current standard practice for preventing the retention of surgical items.

Outcomes of living donor liver transplant recipients receiving grafts with the graft-to-recipient weight ratio less than 0.6%: A matched pair analysis.

We sometimes experience living donor liver transplantation (LDLT) involving very small grafts with graft-to-recipient weight ratio (GRWR) < 0.6% when the actual graft size is smaller than predicted. The outcomes in this situation have not been fully investigated. The present study aimed to determine the graft outcomes of LDLT with GRWR < 0.6%. We retrospectively reviewed 280 cases of adult LDLT performed at our institution between January 2000 and March 2021. In our institution, the lower limit for graft volume/standard liver volume ratio was 30%. The patients were divided into 2 groups according to the cutoff value of 0.6% for actual GRWR. Graft survival and surgical outcomes, including small-for-size syndrome (SFSS), were compared between the groups using propensity score matching analysis. Risk factors associated with SFSS in recipients with GRWR < 0.6% were also evaluated. Fifty-nine patients received grafts with GRWR < 0.6%. After propensity score matching, similar graft survival rates were observed for GRWR < 0.6% (n = 53) and GRWR ≥ 0.6% (n = 53) ( p = 0.98). However, patients with GRWR < 0.6% had a significantly worse 3-month graft survival rate (86.8% vs. 98.1%, p = 0.03) and higher incidence of SFSS ( p < 0.001) than patients with GRWR ≥0.6%. On multivariate analysis, Model for End-Stage Liver Disease score and donor age were associated with SFSS in patients with GRWR < 0.6%. The same factors were also associated with graft survival. In conclusion, although similar overall graft survival rates were observed for LDLT with GRWR < 0.6% and GRWR ≥ 0.6%, GRWR < 0.6% was associated with an increased risk of SFSS. Appropriate donor and recipient selection is important for successful LDLT with very small grafts.

The impact of colonic allograft inclusion on intestinal transplantation outcomes: Results from UNOS/OPTN database analysis.

BACKGROUND: Outcomes of intestinal transplantation with colon allograft (ICTx) remain controversial. We aimed to assess the outcomes of ICTx in comparison to intestinal transplantation without colon (ITx) using the UNOS/OPTN registry database. METHODS: We retrospectively reviewed 2612 patients who received primary intestinal transplants from 1998 to 2020. The rates of acute rejection (AR) within 6 months after transplant were compared between ICTx and ITx. Risk factors of 6-month AR were examined using logistic regression model by era. Furthermore, conditional graft survival was analyzed to determine long-term outcomes of ICTx. RESULTS: Of 2612 recipients, 506 (19.4%) received ICTx. Graft and patient survival in ICTx recipients were comparable to those in ITx recipients. White ICTx recipients had a higher incidence of AR within 6 months compared to ITx during the entire study period (p = .002), colonic inclusion did not increase the risk of 6-month AR in the past decade. ICTx recipients who experienced 6-month AR had worse graft and patient survival compared to those who did not (p <.001 and p = .004, respectively). Among patients who did not develop 6-month AR, Cox proportional hazard model analysis revealed that colonic inclusion was independently associated with improved conditional graft survival. CONCLUSIONS: In the recent transplant era, colonic inclusion is no longer associated with a heightened risk of 6-month AR and may provide better long-term survival compared to ITx when AR is absent. Risk adjustment for rejection and proper immunosuppressive therapy are crucial to maximize the benefits of colonic inclusion.

Questionnaire survey of Japanese board-certified expert hepatobiliary and pancreatic surgeons and instructors on the surgical indications for hepatocellular carcinoma.

BACKGROUND: Recent advancements in systemic therapy for hepatocellular carcinoma (HCC) necessitate the establishment of resectability criteria for advanced HCC. METHODS: A questionnaire survey sought to clarify the perspectives of Japanese expert hepatobiliary surgeons regarding surgical indications for HCC. Thirty-one questions were used to determine when surgery is strongly recommended (resectable: R) or not recommended (unresectable: UR). RESULTS: A total of 351 responses were obtained. While 64.7% of the respondents considered solitary tumors as being R, irrespective of size, opinions diverged on the upper limit of the number of tumors/tumor size for R: (1) up to three nodules with no size limit (27.9%), (2) up to three nodules ≤5 cm in diameter each (21.4%) and (3) up to three nodules ≤3 cm in diameter each (19.4%). Vp1, Vp2, Vp3, and Vp4 were considered as being R by 90.9%, 70.7%, 39.0%, and 8.0% of respondents, respectively. Half of the respondents indicated they would consider resection even for cases with extrahepatic spread under limited conditions. CONCLUSIONS: The current views of Japanese expert surgeons on the resectability criteria for HCC were clarified for the first time. The findings could serve as a basis for preparing expert consensus statements on the resectability criteria for HCC.

An Analysis of 10,000 Cases of Living Donor Liver Transplantation in Japan: Special Reference to the Graft-Versus-Recipient Weight Ratio and Donor Age.

OBJECTIVE: To analyze 10,000 cases of living donor liver transplantation (LDLT) recipient data to elucidate outcomes with special reference to the graft-versus-recipient weight ratio (GRWR), based on the Japanese Liver Transplantation Society (JLTS) registry. BACKGROUND: The JLTS registry has been accurate and complete in characterizing and following trends in patient characteristics and survival of all patients with LDLT. METHODS: Between November 1989 and August 2021, 10,000 patients underwent LDLT in Japan. The procedures performed during the study period included pediatric liver transplantation (age <18 years, n = 3572) and adult liver transplantation (age ≥18 years, n=6428). Factors related to patient survival (PS) and graft survival (GS) were also analyzed. RESULTS: The GRWR was <0.7, 0.7 to <0.8, 0.8 to <3, 3 to <5, and ≥5 in 0.2%, 2.0%, 61.8%, 31.8%, and 2.6% of pediatric patients and <0.6, 0.6 to <0.7, 0.7 to <0.8, and ≥0.8 in 8.0%, 12.7%, 17.7%, and 61.5% of adult patients, respectively. Among pediatric recipients, the PS rate up to 5 years was significantly better in cases with a GRWR ≤5 than in those with a GRWR >5. When the GRWR and donor age were combined, among adult recipients 50 to 60 years old, the early PS and GS up to 5 years were significantly better in cases with a GRWR ≥0.7, than in those with a GRWR <0.7. (P = 0.02). In adults, a multivariate analysis showed that GRWR <0.6, transplant era (<2011), donor age (>60 years), recipient age (>60 years), model for end-stage liver disease score (≥20), and center volume (<10) were significant prognostic factors for long-term PS. CONCLUSION: Although a satisfactory long-term PS and GS, especially in the recent era (2011-2021), was achieved in the JLTS series, a GRWR ≥5 in pediatric cases and relatively old donors with a GRWR <0.7 in adult cases should be managed with caution.