Combined Resection of Liver and Hilar Bifurcation for Colorectal Liver Metastasis: A Single-Center Experience and Review of the Literature.

Introduction: Colorectal liver metastases (CRLM) infiltrating the hilar bifurcation is rarely described. We investigated the outcome of partial hepatectomy combined with resection of the hilar bifurcation. Methods: Data collection for patients who underwent resection for CRLM at our institution was performed prospectively from January 2008 to August 2021. Follow-up ended in August 2023. Patients with and without bile duct infiltration of CRLM were analyzed retrospectively. The primary endpoints were overall (OS) and recurrence-free survival (RFS). Results: A total of 1,156 liver resections were screened. Out of those, 18 were combined resections of the liver and the hilar bifurcation. Bile duct infiltration of CRLM was histologically proven in 5 of 18 cases. Preoperative mild obstructive jaundice occurred in 6 of 18 patients and was treated by drainage. Out of those, only 2 had a confirmed infiltration of the hilar bifurcation by CRLM. The median recurrence-free survival (RFS) was 10 months in those patients with bile duct infiltration compared to 9 months in those with no infiltration (p = 0.503). Conclusion: While CRLM is common, infiltration into the central biliary tract is rare. Tumor invasion of the biliary tree can cause jaundice, but jaundice does not necessarily mean tumor invasion. We have shown that combined resection of the liver and hilar bifurcation for CRLM is safe and infiltration of the bile duct by CRLM did not seem to have a significant effect on RFS or OS.

ß-Nicotinamide Adenine Dinucleotide (ß-NAD) Inhibits ATP-Dependent IL-1ß Release from Human Monocytic Cells.

While interleukin-1ß (IL-1ß) is a potent pro-inflammatory cytokine essential for host defense, high systemic levels cause life-threatening inflammatory syndromes. ATP, a stimulus of IL-1ß maturation, is released from damaged cells along with ß-nicotinamide adenine dinucleotide (ß-NAD). Here, we tested the hypothesis that ß-NAD controls ATP-signaling and, hence, IL-1ß release. Lipopolysaccharide-primed monocytic U937 cells and primary human mononuclear leukocytes were stimulated with 2'(3')-O-(4-benzoyl-benzoyl)ATP trieethylammonium salt (BzATP), a P2X7 receptor agonist, in the presence or absence of ß-NAD. IL-1ß was measured in cell culture supernatants. The roles of P2Y receptors, nicotinic acetylcholine receptors (nAChRs), and Ca2+-independent phospholipase A2 (iPLA2ß, PLA2G6) were investigated using specific inhibitors and gene-silencing. Exogenous ß-NAD signaled via P2Y receptors and dose-dependently (IC50 = 15 µM) suppressed the BzATP-induced IL-1ß release. Signaling involved iPLA2ß, release of a soluble mediator, and nAChR subunit α9. Patch-clamp experiments revealed that ß-NAD inhibited BzATP-induced ion currents. In conclusion, we describe a novel triple membrane-passing signaling cascade triggered by extracellular ß-NAD that suppresses ATP-induced release of IL-1ß by monocytic cells. This cascade links activation of P2Y receptors to non-canonical metabotropic functions of nAChRs that inhibit P2X7 receptor function. The biomedical relevance of this mechanism might be the control of trauma-associated systemic inflammation.