Postchemotherapy histological analysis of major intrahepatic vessels for reversal of attachment or invasion by colorectal liver metastases

Optimal treatment strategies for borderline resectable liver metastases from colorectal cancer

BACKGROUND

Traditionally, colorectal liver metastases (CRLMs) are divided into "initially resectable" and "initially unresectable." The terminology "borderline resectable" continues to be elusive without any common consensus or definition. This narrative review aims to decode the conundrum of "borderline resectable CRLM (BR-CRLM)" and to discuss optimal treatment strategies.

METHODS

A comprehensive review was performed using Medline/PubMed and Web of Science databases with a search period ending on January 1, 2024. Using PubMed, the terms "CRLM," "BR-CRLM," and "management of BR-CRLM" were searched.

RESULTS

The 2016 European Society for Medical Oncology guidelines defined the term "resectability" in CRLM using the "technical (surgical) criteria" and the "oncologically criteria." These 2 criteria form the basis of defining BR-CRLM. Thus, BR-CRLM can be either technically easy but with unfavorable oncologically criteria or technically difficult with favorable oncologically criteria. Although defining BR-CRLM by incorporating both these criteria seems to be the most logical way forward, there is currently a lot of heterogeneity in the literature. It is generally agreed upon that some form of chemotherapy needs to be administered in BR-CRLM before embarking on surgery. Conversion chemotherapy is used in patients with BR-CRLM in which there is a possibility of resection after effective downsizing. Along with improved effective chemotherapy, great strides have been made in pushing the limits of surgery to achieve resectability in this subset of patients.

CONCLUSION

Advanced surgical techniques and locoregional liver-directed therapies coupled with perioperative chemotherapy with or without targeted therapy have made long-term survival benefit, a reality in patients with BR-CRLM. Thus, the time has come to recognize "BR-CRLM" as a distinct entity.

A contemporary view on vascular resections and reconstruction during hepatectomies

Oncological hepatic surgery carries the possibility to perform vascular reconstructions for advanced tumours with vessel invasion since surgery often represents the only potentially curative approach for these tumours. An extended review was conducted in an attempt to understand and clarify the latest trends in hepatectomies with vascular resections. We searched bibliographic databases including PubMed, Scopus, references from bibliographies and Cochrane Library. Information and outcomes from worldwide clinical trials were collected from qualified institutions performing hepatectomies with vascular resection and reconstruction. Careful patient selection and thorough preoperative imaging remain crucial for correct and safe surgical planning. A literature analysis shows that vascular resections carry different indications in different diseases. Despite significant advances made in imaging techniques and technical skills, reports of hepatectomies with vascular resections are still associated with high postoperative morbidity and mortality. The trend of complex liver resection with vascular resection is constantly on the increase, but more profound knowledge as well as further trials are required. Recent technological developments in multiple fields could surely provide novel approaches and enhance a new era of digital imaging and intelligent hepatic surgery.

Full-Circumference Prosthetic Grafts for Replacing a Retrohepatic Inferior Vena Cava Segment During Hepatectomy for Tumor

BACKGROUND

Although hepatectomy including inferior vena cava (IVC) resection is becoming more common, some details remain uncertain such as use of artificial materials to replace a tumor-involved, damaged, or narrowed retrohepatic IVC segment.

METHODS

Surgical outcomes of 12 patients who underwent hepatectomy with IVC resection including reconstruction using synthetic tubular grafts were investigated to clarify safety and feasibility.

RESULTS

Operative time (median, 573 min; range, 268 to 774) and the blood loss (1076 mL; 155 to 2960) were acceptable. In-hospital mortality was 8% (1/12), and morbidity was 42% (5/12). Among the 12 patients, 2 were planned to undergo IVC reconstruction without an artificial graft. In one patient, prosthetic repair was adopted because of massive bleeding from the IVC wall during dissection of tumor from the IVC. In the other, severe stricture became evident during attempted direct closure of the partially resected IVC wall.

DISCUSSION

Ongoing experience has increased our acceptance of combined liver and IVC resection. We believe that segmental IVC resection and reconstruction with a prosthetic tubular graft could be chosen more frequently in managing liver tumors suspected to involve the IVC.

Tumor attachment to Major intrahepatic vascular for Colorectal liver metastases

BACKGROUND

Colorectal liver metastases attached major intrahepatic vessels has been considered to be a risk factor for survival outcome after liver resection. The present study aimed to clarify the outcomes of R1 surgery (margin < 1 mm) in CRLM patients, distinguishing parenchymal margin R1 and attached to major intrahepatic vessels R1.

METHODS

In present study, 283 CRLM patients who were evaluated to be attached to major intrahepatic vessels initially and underwent liver resection following preoperative chemotherapy. They were assigned to two following groups: R0 (n = 167), R1 parenchymal (n = 58) and R1 vascular (n = 58). The survival outcomes and local recurrence rates were analyzed in each group.

RESULTS

Overall, 3- and 5-year overall survival rates after liver resection were 53.0% and 38.2% (median overall survival 37 months). Five-year overall survival was higher in patients with R0 than parenchymal R1 (44.9%% vs. 26.3%, p = 0.009), whereas there was no significant difference from patients with vascular R1 (34.3%, p = 0.752). In the multivariable analysis, preoperative chemotherapy > 4 cycles, clinical risk score 3-5, RAS mutation, parenchymal R1 and CA199 > 100 IU/ml were identified as independent predictive factors of overall survival (p < 0.05). There was no significant difference for local recurrence among three groups.

CONCLUSION

Parenchymal R1 resection was independent risk factor for CRLM. Vascular R1 surgery achieved survival outcomes equivalent to R0 resection. Non-anatomic liver resection for CRLM attached to intrahepatic vessels might be pursued to increase patient resectability by preoperative chemotherapy.

Reversal of attachment to or invasion of major intrahepatic vessels by colorectal liver metastases according to prehepatectomy chemotherapy regimen

BACKGROUND

Tumor reduction by present-day prehepatectomy chemotherapy can render initially unresectable disease resectable. However, little is known about whether effects on liver metastases with radiologically defined "attachment to or invasion of" major intrahepatic vessels differ between chemotherapy regimens with or without monoclonal antibodies. We compared histologically the relationships between liver tumors and major intrahepatic vessels after chemotherapy according to regimens used to treat colorectal liver metastasis.

METHODS

In 38 patients who underwent chemotherapy and hepatectomy with pretreatment images showing metastases attached to or invading major intrahepatic vessels, 62 metastases showed attachment to or invasion of 88 vessels. After resection, attachment, invasion, and separation were determined histopathologically in resected specimens.

RESULTS

Thirteen patients received cytotoxic drug combinations alone, whereas 25 were treated with regimens including a monoclonal antibody (bevacizumab in 15 and cetuximab in 10). By imaging, 16% (5/32) of vessels in patients receiving cytotoxic drugs alone, 23% (8/35) of vessels in those also receiving bevacizumab, and 48% (10/21) of vessels in those also receiving cetuximab showed detachment after chemotherapy (P = .015 for cetuximab versus cytotoxic and P = .039 for cetuximab versus bevacizumab). Excluding 8 vessels not evaluated histologically, 23 of 31 vessels in the cytotoxic group remained attached or invaded, as did 16 of 29 in the bevacizumab group and 8 of 20 vessels in the cetuximab group (P = .05 versus cytotoxic).

CONCLUSION

Prehepatectomy chemotherapy regimens including monoclonal antibodies, particularly anti-epidermal growth factor receptor antibodies, eradicated attachment or invasion between vessels and metastases more frequently. Individualized strategies for prehepatectomy chemotherapy based on intrahepatic location of metastases may offer advantages according to proximity of the metastases to the major intrahepatic vessels.