In situ hypothermic perfusion with retrograde outflow during right hemihepatectomy: first experiences with a new technique

Complex Hepatectomy Under Total Vascular Exclusion of the Liver Preserving the Caval Flow with Portal Hypothermic Perfusion and Temporary Portacaval Shunt: A Proof of Concept

BACKGROUND

Hypothermic liver perfusion decreases ischemia/reperfusion injury during hepatectomy under standard total vascular exclusion (TVE) of the liver. This surgery needs venovenous bypass and is hampered by high morbi-mortality. TVE preserving the inferior vena cava (IVC) flow is hemodynamically well tolerated but remains limited in duration when performed under liver normothermia. The objective of this study was to report the results of TVE preserving the caval flow, modified to allow hypothermic liver perfusion and obviate splanchnic congestion.

PATIENTS AND METHODS

The technique, indicated for tumors abutting large tributaries of the hepatic veins but sparing their roots in IVC and the latter, was applied when TVE was anticipated to last for ≥ 60 min. It combines continuous TVE preserving the IVC flow with hypothermic liver perfusion and temporary portacaval shunt (PCS). Results are given as median (range).

RESULTS

Vascular control was achieved in 13 patients with excellent hemodynamical tolerance. PCS was direct or via an interposed synthetic graft (five and eight cases, respectively). Liver temperature dropped to 16.5 (6-24) °C under perfusion of 2 (2-4) L of cold perfusate. TVE lasted 67 (54-125) min and 4.5 (0-8) blood units were transfused. Resection was major in nine cases and was complete in all cases. Five complications occurred in four patients, and the 90-day mortality rate was zero.

CONCLUSIONS

This technique maintains stable hemodynamics and combines the advantages of in situ or ex situ standard TVE with hypothermic liver perfusion, without their inherent prolongation of ischemia time and need for venovenous bypass.

The damage-associated molecular pattern HMGB1 is released early after clinical hepatic ischemia/reperfusion

OBJECTIVE AND BACKGROUND

Activation of sterile inflammation after hepatic ischemia/reperfusion (I/R) culminates in liver injury. The route to liver damage starts with mitochondrial oxidative stress and cell death during early reperfusion. The link between mitochondrial oxidative stress, damage-associate molecular pattern (DAMP) release, and sterile immune signaling is incompletely understood and lacks clinical validation. The aim of the study was to validate this relation in a clinical liver I/R cohort and to limit DAMP release using a mitochondria-targeted antioxidant in I/R-subjected mice.

METHODS

Plasma levels of the DAMPs high-mobility group box 1 (HMGB1), mitochondrial DNA, and nucleosomes were measured in 39 patients enrolled in an observational study who underwent a major liver resection with (N = 29) or without (N = 13) intraoperative liver ischemia. Circulating cytokine and neutrophil activation markers were also determined. In mice, the mitochondria-targeted antioxidant MitoQ was intravenously infused in an attempt to limit DAMP release, reduce sterile inflammation, and suppress I/R injury.

RESULTS

In patients, HMGB1 was elevated following liver resection with I/R compared to liver resection without I/R. HMGB1 levels correlated positively with ischemia duration and peak post-operative transaminase (ALT) levels. There were no differences in mitochondrial DNA, nucleosome, or cytokine levels between the two groups. In mice, MitoQ neutralized hepatic oxidative stress and decreased HMGB1 release by ±50%. MitoQ suppressed transaminase release, hepatocellular necrosis, and cytokine production. Reconstituting disulfide HMGB1 during reperfusion reversed these protective effects.

CONCLUSION

HMGB1 seems the most pertinent DAMP in clinical hepatic I/R injury. Neutralizing mitochondrial oxidative stress may limit DAMP release after hepatic I/R and reduce liver damage.

The Safety and Feasibility of Three-Dimensional Visualization Technology Assisted Right Posterior Lobe Allied with Part of V and VIII Sectionectomy for Right Hepatic Malignancy Therapy

BACKGROUND

Hepatectomy is the optimal method for liver cancer; the virtual liver resection based on three-dimensional visualization technology (3-DVT) could provide better preoperative strategy for surgeon. We aim to introduce right posterior lobe allied with part of V and VIII sectionectomy assisted by 3-DVT as a promising treatment for massive or multiple right hepatic malignancies to retain maximum residual liver volume on the basis of R0 resection.

METHODS

Among 126 consecutive patients who underwent hepatectomy, 9 (7%) underwent right posterior lobe allied with part of V and VIII sectionectomy. 21 (17%) underwent right hemihepatectomy (RH). The virtual RH was performed with 3-DVT, which provided better observation of spatial position relationship between tumor and vessels, and the more accurate estimation of the remnant liver volume. If remnant liver volume was <40%, right posterior lobe allied with part of V and VIII sectionectomy should be undergone. Then, the precut line ought to be planned on the basis of protecting the portal branch of subsegment 5 and 8. The postoperative outcome of patients was compared before and after propensity score matching.

RESULTS

Nine patients meeting the eligibility criteria received right posterior lobe allied with part of V and VIII sectionectomy. The variables, including the overall mean operation time, blood transfusion, operation length, liver function, and postoperative complications, were similar between two groups before and after propensity matching. The postoperative first, third, fifth, and seventh days mean value of aspartate aminotransferase (AST), alanine aminotransferase (ALT), albumin (ALB), and total bilirubin had no significant difference compared with preoperative value. One patient in each group had recurrence six months after surgery.

CONCLUSION

Right posterior lobe allied with part of V and VIII sectionectomy based on 3-DVT is safe and feasible surgery way, and can be a very promising method in massive or multiple right hepatic malignancy therapy.

Warm ischemia time-dependent variation in liver damage, inflammation, and function in hepatic ischemia/reperfusion injury

BACKGROUND

Hepatic ischemia/reperfusion (I/R) injury is characterized by hepatocellular damage, sterile inflammation, and compromised postoperative liver function. Generally used mouse I/R models are too severe and poorly reflect the clinical injury profile. The aim was to establish a mouse I/R model with better translatability using hepatocellular injury, liver function, and innate immune parameters as endpoints.

METHODS

Mice (C57Bl/6J) were subjected to sham surgery, 30min, or 60min of partial hepatic ischemia. Liver function was measured after 24h using intravital microscopy and spectroscopy. Innate immune activity was assessed at 6 and 24h of reperfusion using mRNA and cytokine arrays. Liver inflammation and function were profiled in two patient cohorts subjected to I/R during liver resection to validate the preclinical results.

RESULTS

In mice, plasma ALT levels and the degree of hepatic necrosis were strongly correlated. Liver function was bound by a narrow damage threshold and was severely impaired following 60min of ischemia. Severe ischemia (60min) evoked a neutrophil-dominant immune response, whereas mild ischemia (30min) triggered a monocyte-driven response. Clinical liver I/R did not compromise liver function and displayed a cytokine profile similar to the mild I/R injury model.

CONCLUSIONS

Mouse models using ≤30min of ischemia best reflect the clinical liver I/R injury profile in terms of liver function dynamics and type of immune response.

GENERAL SIGNIFICANCE

This short duration of ischemia therefore has most translational value and should be used to increase the prospects of developing effective interventions for hepatic I/R.

Hepatocellular carcinoma on cirrhosis complicated with tumoral thrombi extended to the right atrium: results in three cases treated with major hepatectomy and thrombectomy under hypothermic cardiocirculatory arrest and literature review

Background

Hepatocellular carcinoma (HCC) with the presence of tumor thrombus in hepatic veins and vena cava, until the atrium (RATT), is correlated with poor prognosis and with risk of tricuspid valve occlusion, congestive heart failure, and pulmonary embolism.

Methods

Three patients with HCC on cirrhotic liver with RATT were studied. Operative technique, pre-operative and post-operative liver function tests, blood loss and transfusions, post-operative morbidity and mortality, and the overall survival and the disease free survival were analyzed.

Results

Mean operative time was 336 ± 66 min. Intra-operative blood loss was 926.6 ± 325.9 ml. No major complications occurred. The times of hospital stay were 10, 21, and 19 days, respectively. The survival times were 90, 161, and 40 days, and the disease-free survival times were 30, 141, and 30 days, respectively.

Conclusions

The complete removal of HCC with RATT may be achieved with cardiopulmonary by-pass (CPB) and total hepatic vascular exclusion (THVE). Adding the hypothermic cardiocirculatory arrest (HCCA) to the use of CPB allowed us to have minimal blood loss and hemostasis of the resectional plane. So the use of CPB and HCCA should be considered a good therapeutic alternative to the normothermic CPB with THVE.

Protective Mechanisms of Hypothermia in Liver Surgery and Transplantation

Hepatic ischemia/reperfusion (I/R) injury is a side effect of major liver surgery that often cannot be avoided. Prolonged periods of ischemia put a metabolic strain on hepatocytes and limit the tolerable ischemia and preservation times during liver resection and transplantation, respectively. In both surgical settings, temporarily lowering the metabolic demand of the organ by reducing organ temperature effectively counteracts the negative consequences of an ischemic insult. Despite its routine use, the application of liver cooling is predicated on an incomplete understanding of the underlying protective mechanisms, which has limited a uniform and widespread implementation of liver-cooling techniques. This review therefore addresses how hypothermia-induced hypometabolism modulates hepatocyte metabolism during ischemia and thereby reduces hepatic I/R injury. The mechanisms underlying hypothermia-mediated reduction in energy expenditure during ischemia and the attenuation of mitochondrial production of reactive oxygen species during early reperfusion are described. It is further addressed how hypothermia suppresses the sterile hepatic I/R immune response and preserves the metabolic functionality of hepatocytes. Lastly, a summary of the clinical status quo of the use of liver cooling for liver resection and transplantation is provided.

Liver resection using total vascular exclusion of the liver preserving the caval flow, in situ hypothermic portal perfusion and temporary porta-caval shunt: a new technique for central tumors

Standard total vascular exclusion (TVE) of the liver is indicated for resection of tumors involving or adjacent to the vena cava and/or the confluence of the hepatic veins. The duration of liver ischemia can be prolonged by combined portal hypothermic perfusion of the liver (in or ex situ). The use of a venovenous bypass (VVB) during standard TVE maintains stable hemodynamics as well as optimal renal and splanchnic venous drainage. When the hepatic veins can be controlled, TVE preserving the caval flow negates the need for VVB. However this technique remains limited in duration as it is performed under warm ischemia (so-called normothermia) of the liver. To prolong the ischemia time, we have designed a modification of TVE with preservation of the caval flow including the use of temporary porta-caval shunt (PCS) and hypothermic perfusion of the liver. We describe here the first two cases of this new technique. Two patients underwent left hepatectomy extended to segments 5 and 8 (also called extended left hepatectomy) for large centrally located tumors. TVE lasted seventy-two and seventy-nine minutes, respectively. The postoperative course was uneventful and both patients were discharged on day ten and day twenty-five respectively. Both are alive without recurrence at ten and seven months following surgery. Provided the roots of the hepatic veins can be controlled, this technique combines the advantages of standard TVE with in situ hypothermic perfusion and VVB and obviates the need and the subsequent risks of the latter.