Ischemic preconditioning-induced hyperperfusion correlates with hepatoprotection after liver resection

Post-hepatectomy liver failure: A timeline centered review

BACKGROUND

Post-hepatectomy liver failure (PHLF) is a leading cause of postoperative mortality after liver surgery. Due to its significant impact, it is imperative to understand the risk stratification and preventative strategies for PHLF. The main objective of this review is to highlight the role of these strategies in a timeline centered way around curative resection.

DATA SOURCES

This review includes studies on both humans and animals, where they addressed PHLF. A literature search was conducted across the Cochrane Library, Embase, MEDLINE/PubMed, and Web of Knowledge electronic databases for English language studies published between July 1997 and June 2020. Studies presented in other languages were equally considered. The quality of included publications was assessed using Downs and Black's checklist. The results were presented in qualitative summaries owing to the lack of studies qualifying for quantitative analysis.

RESULTS

This systematic review with 245 studies, provides insight into the current prediction, prevention, diagnosis, and management options for PHLF. This review highlighted that liver volume manipulation is the most frequently studied preventive measure against PHLF in clinical practice, with modest improvement in the treatment strategies over the past decade.

CONCLUSIONS

Remnant liver volume manipulation is the most consistent preventive measure against PHLF.

Impacts of ischemic preconditioning in liver resection: systematic review with meta-analysis

OBJECTIVE

To assess the beneficial effects of ischemic preconditioning (IPC) in liver resection and evaluate its applicability in clinical practice.

SUMMARY BACKGROUND DATA

Liver surgeries are usually associated with intentional transient ischemia for hemostatic control. IPC is a surgical step that intends to reduce the effects of ischemia-reperfusion; however, there is no strong evidence about the real impact of the IPC, and it is necessary to effectively clarify what its effects are.

METHODS

Randomized clinical trials were selected, comparing IPC with no preconditioning in patients undergoing liver resection. Data were extracted by three independent researchers according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, Supplemental Digital Content 1, http://links.lww.com/JS9/A79 . Several outcomes were evaluated, including postoperative peaks of transaminases and bilirubin, mortality, length of hospital stay, length of stay in the ICU, bleeding, and transfusion of blood products, among others. Bias risks were assessed using the Cochrane collaboration tool.

RESULTS

Seventeen articles were selected, with a total of 1052 patients. IPC did not change the surgical time of the liver resections while these patients bled less (Mean Difference: -49.97 ml; 95% CI: -86.32 to -13.6; I2 : 64%), needed less blood products [relative risk (RR): 0.71; 95% CI: 0.53-0.96; I2 =0%], and had a lower risk of postoperative ascites (RR: 0.40; 95% CI: 0.17-0.93; I2 =0%). The other outcomes had no statistical differences or could not have their meta-analyses conducted due to high heterogeneity.

CONCLUSIONS

IPC is applicable in clinical practice, and it has some beneficial effects. However, there is not enough evidence to encourage its routine use.

Hepatic cytoprotective effect of ischemic and anesthetic preconditioning before liver resection when using intermittent vascular inflow occlusion: a randomized clinical trial

BACKGROUND

Ischemic preconditioning (IPC) and anesthetic preconditioning (APC) have been reported to attenuate ischemia-reperfusion (IR) injury after liver resection under continuous inflow occlusion. This study evaluates whether these strategies enhance hepatic protection of remnant liver against IR after liver resection with intermittent clamping (INT).

METHODS

A total of 106 patients without underlying liver disease and submitted to liver resection using INT were randomized into 3 groups: IPC (10 minutes of inflow occlusion followed by 10 minutes of reperfusion before liver transection), APC (sevoflurane administration for 20 minutes before liver transection), and INT (no preconditioning). Patients were also stratified according to the extent of the hepatectomy. Cytoprotection was evaluated by comparing hepatocyte and endothelial dysfunction markers, apoptosis, histologic lesions, and postoperative outcome.

RESULTS

No differences were observed in preoperative chemotherapy and steatosis, total warm ischemia time, operative time, or blood loss. Kinetics of transaminases (aspartate aminotransferase, P = .137; alanine aminotransferase, P = .616), bilirubin (P = .980), and hyaluronic acid increase (P = .514) revealed no differences. Significant apoptosis was present in 40% of patients, mild-to-moderate leukocyte infiltration and steatosis in 45% and 55%, respectively, and mild sinusoidal congestion in 65%, with a similar distribution in the 3 groups. When patients were stratified by major versus minor resections, no differences were observed in any of the variables studied. Postoperative clinical outcomes were also similar.

CONCLUSION

These results suggest that these protocols of IPC and APC used in this study do not provide better cytoprotection from IR when INT is used.

Systematic review of pathophysiological changes following hepatic resection

OBJECTIVES

Major hepatic resection is now performed frequently and with relative safety, but is accompanied by significant pathophysiological changes. The aim of this review is to describe these changes along with interventions that may help reduce the risk for adverse outcomes after major hepatic resection.

METHODS

The MEDLINE, EMBASE and CENTRAL databases were searched for relevant literature published from January 2000 to December 2011. Broad subject headings were 'hepatectomy/', 'liver function/', 'liver failure/' and 'physiology/'.

RESULTS

Predictable changes in blood biochemistry and coagulation occur following major hepatic resection and alterations from the expected path indicate a complicated course. Susceptibility to sepsis, functional renal impairment, and altered energy metabolism are important sequelae of post-resection liver failure.

CONCLUSIONS

The pathophysiology of post-resection liver failure is difficult to reverse and thus strategies aimed at prevention are key to reducing morbidity and mortality after liver surgery.

The Delay Phenomenon: A Compilation of Knowledge across Specialties

Objective The purpose of this article is to review and integrate the available literature in different fields to gain a better understanding of the basic physiology and optimize vascular delay as a reconstructive surgery technique. Methods A broad search of the literature was performed using the Medline database. Two queries were performed using "vascular delay," a search expected to yield perspectives from the field of plastic and reconstructive surgery, and "ischemic preconditioning," (IPC) which was expected to yield research on the same topic in other fields. Results The combined searches yielded a total of 1824 abstracts. The "vascular delay" query yielded 76 articles from 1984 to 2011. The "ischemic preconditioning" query yielded 6534 articles, ranging from 1980 to 2012. The abstracts were screened for those from other specialties in addition to reconstructive surgery, analyzed potential or current uses of vascular delay in practice, or provided developments in understanding the pathophysiology of vascular delay. 70 articles were identified that met inclusion criteria and were applicable to vascular delay or ischemic preconditioning. Conclusion An understanding of IPC's implementation and mechanisms in other fields has beneficial implications for the field of reconstructive surgery in the context of the delay phenomenon. Despite an incomplete model of IPC's pathways, the anti-oxidative, anti-apoptotic and anti-inflammatory benefits of IPC are well recognized. The activation of angiogenic genes through IPC could allow for complex flap design, even in poorly vascularized regions. IPC's promotion of angiogenesis and reduction of endothelial dysfunction remain most applicable to reconstructive surgery in reducing graft-related complications and flap failure.

Hepatic ischemic preconditioning increases portal vein flow in experimental liver ischemia reperfusion injury

BACKGROUND

Ischemic preconditioning (IPC) has been shown to decrease liver injury and to increase hepatic microvascular perfusion after liver ischemia reperfusion. This study aimed to evaluate the effects of IPC on hemodynamics of the portal venous system.

METHODS

Thirty-two rats were randomized into two groups: IPC group and control group. The rats of the IPC group underwent IPC by 10 minutes of liver ischemia followed by 10 minutes of reperfusion before liver ischemia, and the rats of the control group were subjected to 60 minutes of partial liver ischemia. Non-ischemic lobes were resected immediately after reperfusion. The animals were studied at 4 hours and 12 hours after reperfusion. Mean arterial pressure, heart rate, portal vein flow and pressure were analyzed. Blood was collected for the determination of the levels of aspartate aminotransferase, alanine aminotransferase, calcium, lactate, pH, bicarbonate, and base excess.

RESULTS

IPC increased the mean portal vein flow at 4 hours and 12 hours after reperfusion. IPC recovered 78% of the mean portal vein flow at 12 hours after reperfusion. IPC decreased the levels of aspartate aminotransferase, alanine aminotransferase and lactate, and increased the levels of ionized calcium, bicarbonate and base excess at 12 hours after reperfusion.

CONCLUSIONS

This study demonstrated that IPC increases portal vein flow and enhances hepatoprotective effects in liver ischemia reperfusion. The better recovery of portal vein flow after IPC may be correlated with the lower levels of transaminases and with the better metabolic profile.

Meta-analysis of ischaemic preconditioning for liver resections

BACKGROUND

Vascular clamping reduces blood loss during liver resection but leads to ischaemia-reperfusion injury. Ischaemic preconditioning (IP) may reduce this. This study aimed to evaluate IP in liver resection under clamping.

METHODS

This was a systematic review and meta-analysis of randomized clinical trials (RCTs) evaluating IP in adults undergoing liver resection under either continuous clamping (CC) or intermittent clamping (IC). Primary outcomes were mortality, liver failure and morbidity. Secondary outcomes included duration of operation, blood loss, length of hospital stay, length of intensive therapy unit stay, transfusion requirements, prothrombin time, and bilirubin and aminotransferase levels. Weighted mean differences were calculated for continuous data, and pooled odds ratios (ORs) for dichotomous data. Results were produced with a random-effects model with 95 per cent confidence intervals (c.i.).

RESULTS

A total of 2960 records were identified and 11 RCTs included 669 patients (IP 331, control 338). No significant difference in mortality (6 RCTs; IP 186, control 190; OR 1·36, 95 per cent c.i. 0·13 to 13·68; P = 0·80) or morbidity (6 RCTs; IP 186, control 190; OR 0·58, 0·31 to 1·07; P = 0·08) was found for IP plus CC versus CC. Nor was there a significant difference in mortality (4 RCTs; IP 122, control 121; OR 1·33, 0·24 to 7·32; P = 0·74) or morbidity (4 RCTs; IP 122, control 121; OR 0·87, 0·52 to 1·47; P = 0·61) for IP plus (CC or IC) versus IC. No significant differences were found for secondary outcome measures.

CONCLUSION

This meta-analysis failed to find a significant benefit of IP in liver resection.

Hepatic ischemia and reperfusion injury and trauma: current concepts

Context

Ischemia-reperfusion injury is a fascinating topic which has drawn a lot of interest in the last several years. Hepatic ischemia reperfusion injury may occur in a variety of clinical situations. These include transplantation, liver resection, trauma, and vascular surgery.

Evidence Acquisition

The purpose of this review was to outline the molecular mechanisms underlying hepatic I/R injury and present the latest approaches, both surgical and pharmacological, regarding the prevention of it. A comprehensive electronic literature search in MEDLINE/PubMed was performed to identify relative articles published within the last 2 years.

Results

The basic mechanism of hepatic ischemia – reperfusion injury is one of blood deprivation during ischemia, followed by the return of flow during reperfusion. It involves a complex series of events, such as mitochondrial deenergization, adenosine-5'-triphosphate depletion, alterations of electrolyte homeostasis, as well as Kupffer cell activation, oxidative stress changes and upregulation of proinflammatory cytokine signaling. The great number of variable pathways, with several mediators interacting with each other, leads to a high number of candidates for potential therapeutic intervention. As far as surgical approaches are concerned, the modification of existing clamping techniques and the ischemic preconditioning are the most promising techniques till recently. In the search for novel techniques of protecting against hepatic ischemia reperfusion injury, many different strategies have been used in experimental models. The biggest part of this research lies around antioxidant therapy, but other potential solutions have been explored as well.

Conclusions

The management of hepatic trauma, in spite of the fact that it has become increasingly nonoperative, there still remains the possibility of hepatic resection in the hepatic trauma setting, especially in severe injuries. Hence, clinicians should be familiar with the concept of hepatic ischemia-reperfusion injury and respond appropriately and timely.

A prospective randomized controlled trial to compare pringle manoeuvre with hemi-hepatic vascular inflow occlusion in liver resection for hepatocellular carcinoma with cirrhosis

BACKGROUND

The duration of hepatic vascular inflow occlusion and the amount of intraoperative blood loss have significant negative impacts on postoperative morbidity, mortality and long-term survival outcomes of patients who receive partial hepatectomy for hepatocellular carcinoma (HCC) with cirrhosis.

AIM

This study aimed to compare the perioperative outcomes of partial hepatectomy for HCC superimposed on hepatitis B-related cirrhosis using two different occlusion techniques.

METHODS

A randomized controlled trial was carried out to evaluate the impact of two different vascular inflow occlusion techniques. The postoperative short-term results were compared.

RESULTS

During the study period, 252 patients received partial hepatectomy for HCC with cirrhosis. Of these patients, 120 were randomized equally into two groups: the Pringle manoeuvre group (n = 60) and the hemi-hepatic vascular inflow occlusion group (n = 60). The number of patients who had poor liver function on postoperative day 5 with ISLGS grade B or worse was 24 and 13, respectively (P = 0.030). The postoperative complication rate was significantly higher in the Pringle manoeuvre group (40 versus 22 %, P = 0.030). However, the Pringle manoeuvre group had significantly shorter operating time (116 versus 136 min, P = 0.012) although there was no significant difference in intraoperative blood loss between the two groups [200 ml (range 10-5,000 ml) versus 300 ml (range 100-1,000 ml); P = 0.511]. There was no perioperative mortality.

CONCLUSIONS

The results indicated that for patients with HCC with cirrhosis, hemi-hepatic vascular inflow occlusion was a better inflow occlusion method than Pringle manoeuvre.