A current update on the evolution of robotic liver surgery.

Laparoscopic liver surgery has evolved significantly over the past decade. Increasing understanding of hepatic anatomy and advancements in technology have extended the scope of the minimally invasive approach. Robotic-assisted technology offers solutions to the fundamental limitations of conventional laparoscopic liver resection. Several centers have begun to utilize robotic technology to perform complex liver surgeries. The purpose of this review is to provide a comprehensive analysis of published literature about the role of robotic-assisted laparoscopic technology in liver surgery. A literature search of Pubmed was used to identify all English publications about robotic liver surgery. Publications were selected to examine all unique patient series. Outcomes analyzed included operative time, estimated blood loss, length of stay, complication rate, conversion rate to open, cost, and oncologic outcomes. A total of eight series containing 134 unique patients were selected for review. Sixty-nine percent of patients had malignant lesions resected, while 31% had benign lesions. Segmentectomy/wedge (36%) was the most common resection performed, followed by left lateral sectionectomy (28%) right hepatectomy (16%) and left hepatectomy (9%). A meta-analysis of the remaining data was not possible due to heterogeneity in methods for reporting. Outcomes varied widely between studies. Based on analysis of early published series, robotic liver surgery is a feasible and safe tool for the minimally invasive resection of hepatic lesions. Further evaluation is required to assess for improvement in outcomes, and long-term oncologic outcomes are still pending.

Hepatocellular stem cells.

The liver has enormous regenerative capacity. Restitution of the liver in response to different injuries involves proliferation of cells at different levels of liver lineage. Mature hepatocytes, which are normally dormant, could undergo rapid replication with a near infinite capacity to proliferate. When the replication of mature hepatocytes is inhibited, a reserve compartment of bipotential hepatic progenitor/stem cells is activated. The degree of activation appears to correlate with the degree of inflammation and stage of chronic liver disease. Deregulation of key regulatory signaling pathways such as transforming growth factor-beta, Wnt, hepatocyte growth factor, insulin-like growth factor, transforming growth factor-alpha and epidermal growth factor in this progenitor/stem cell population could give rise to HCC. Further understanding of these key signaling pathways and the molecular and genetic alterations associated with HCC could provide major advances in new therapeutic and diagnostic modalities.

Disruption of transforming growth factor-beta signaling through beta-spectrin ELF leads to hepatocellular cancer through cyclin D1 activation.

Transforming growth factor-beta (TGF-beta) signaling members, TGF-beta receptor type II (TBRII), Smad2, Smad4 and Smad adaptor, embryonic liver fodrin (ELF), are prominent tumor suppressors in gastrointestinal cancers. Here, we show that 40% of elf(+/-) mice spontaneously develop hepatocellular cancer (HCC) with markedly increased cyclin D1, cyclin-dependent kinase 4 (Cdk4), c-Myc and MDM2 expression. Reduced ELF but not TBRII, or Smad4 was observed in 8 of 9 human HCCs (P<0.017). ELF and TBRII are also markedly decreased in human HCC cell lines SNU-398 and SNU-475. Restoration of ELF and TBRII in SNU-398 cells markedly decreases cyclin D1 as well as hyperphosphorylated-retinoblastoma (hyperphosphorylated-pRb). Thus, we show that TGF-beta signaling and Smad adaptor ELF suppress human hepatocarcinogenesis, potentially through cyclin D1 deregulation. Loss of ELF could serve as a primary event in progression toward a fully transformed phenotype and could hold promise for new therapeutic approaches in human HCCs.

Intra-operative acute isovolemic hemodilution is safe and effective in eliminating allogeneic blood transfusions during right hepatic lobectomy: comparison of living donor versus non-donors.

BACKGROUND: Multiple studies have shown acute isovolemic hemodilution (AIH) to be safe and effective during liver resection to limit the use of banked blood. However, no studies to date have studied AIH in living donor right hepatectomy. Conventional right hepatectomies for living donors is not identical to non-donor right hepatectomies. Since division of the parenchyma is often performed without devascularization of the right lobe, blood loss may be significantly higher. METHODS: Ten consecutive patients undergoing living donor right hepatectomies (LDRH) and ten consecutive patients undergoing non-donor right hepatectomies (NDRH) were compared using AIH. RESULTS: There was no mortality or morbidity related to the use of AIH. No allogeneic blood transfusions were required in either group, intra-operatively or post-operatively. There was no significant difference in post-operative hematocrit, average estimated blood loss, and average fluid replacement. Average hospital length of stay and operating room time were longer for the LDRH. CONCLUSION: AIH can be performed safely and effectively in both LDRH and NDRH without subjecting patients to unnecessary risks of allogeneic blood transfusions.