The RAPID Concept-Novel Idea or a Bridge Too Far?

International consensus recommendations for the RAPID procedure in liver transplantation: The RAPID Consensus ISLS 2023 Zurich Collaborative

INTRODUCTION

Since its beginning in 1963, liver transplantation has significantly advanced, now including transplant oncology. As indications broaden, donor supply reduces. The two-stage RAPID procedure (initially abbreviated as "Resection And Partial Liver Segment 2/3 Transplantation With Delayed Total Hepatectomy") has emerged to address the use of small-for-size grafts. However, a comprehensive evaluation of RAPID is essential given its novelty, scarcity, and diverse outcomes reported.

METHODS

The RAPID Consensus International Society of Liver Surgeons 2023 Zurich initiative established evidence around the RAPID procedure using the Danish Model of Consensus. Engaging an international community of specialists, the initiative ensured multidisciplinary involvement and used the GRADE framework to evaluate the quality of evidence and grade the recommendations.

RESULTS

Comprehensive discussions and debates led to internationally recognized recommendations addressing perioperative measures for RAPID. Key recommendations highlighted the significance of standardized nomenclature, specific indications, graft criteria, surgical techniques, optimal interstage timings, and measures to manage potential complications.

CONCLUSION

The consensus provides recommendations for the RAPID procedure, emphasizing transparency and outcome reporting. Establishing dedicated registries can improve care standards, which may ensure the benefits of RAPID by maximizing patient safety and improving outcomes.

The Potential Role of Liver Transplantation as a Treatment Option in Colorectal Liver Metastases

Liver resection is the only potentially curative treatment option in patients with liver metastases from colorectal cancer, but only about 20% of the patients are resectable. Liver transplantation of patients with unresectable liver metastases was attempted in the early era but it was abandoned due to poor survival. During the last decade, several case reports, a controlled pilot study, and a retrospective cohort study indicated that prolonged disease-free survival and overall survival can be obtained in a proportion of these patients. Strict selection criteria have not yet been well defined, but tumor load, response to chemotherapy, pretransplant carcinoembryonic antigen level, and time interval from resection of the primary tumor to transplant are all factors related to outcome. Carefully selected patients may obtain 5-year overall survival that approaches conventional indications for liver transplant. The scarcity of liver grafts is a significant problem, but this can possibly to some extent be addressed by use of extended criteria grafts and novel surgical techniques. There is an increasing interest in liver transplantation in these patients in the transplant community, and currently 4 clinical trials are active and are recruiting.

Liver transplantation for hepatobiliary malignancies: a new era of "Transplant Oncology" has begun

The indications of liver transplantation for hepatobiliary malignancies have been carefully expanded in a stepwise fashion, despite the fundamental limitations in oncological, immunological, and technical aspects. A new era of "Transplant Oncology," the fusion of transplant surgery and surgical oncology, has begun, and we stand at the dawn of a paradigm shift in multidisciplinary cancer treatment. For hepatocellular carcinoma, new strategies have been undertaken to select recipients based on biological and dynamic markers instead of conventional morphological and static parameters, opening the doors for a more deliberate expansion of the Milan criteria and locoregional therapies before liver transplantation. Neoadjuvant chemoradiation therapy followed by liver transplantation for unresectable perihilar cholangiocarcinoma developed by the Mayo Clinic provided excellent outcomes in a US multicenter study; however, the surgical indications are not necessarily universal and await international validation. Similarly, an aggressive multidisciplinary approach has been applied for other tumors, including intrahepatic cholangiocarcinoma, hepatoblastoma, liver metastases from colorectal and neuroendocrine primary and gastrointestinal stromal tumors as well as rare tumors, such as hepatic undifferentiated embryonal sarcoma and infantile choriocarcinoma. In conclusion, liver transplantation is an important option for hepatobiliary malignancies; however, prospective studies are urgently needed to ensure the appropriate patient selection, organ allocation and living donation policies, and administration of antineoplastic immunosuppression.