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Malignancy of the liver has historically meant a poor prognosis and remains the second most common cause of cancer-related deaths globally. Traditionally, hepatectomy has utilized the clamp-crush technique; however, this is associated with high incidence of postoperative complications. Many novel techniques have been developed—radiofrequency ablation and transarterial chemoembolization; however, these are not applicable to numerous cases. Clamp-crush liver resection (CCLR) remains the gold standard. Radiofrequency-assisted liver resection (RFLR) is a technique that aims to reduce mortality through bloodless liver resection. A systematic review was previously performed on RFLR but the results neither recommended nor refuted the use of RFLR owing to the lack of sufficient evidence from well-designed randomized controlled trials (RCTs) at the time.
The aim of the study is the meta-analysis and systematic review of recent studies comparing RFLR against CCLR.
Articles comparing RFLR and CCLR that were published from 2014 until 2019 will be reviewed and relevant data will be extracted and statistically analyzed through Review Manager 5 (by the Cochrane Collaboration) together with the results of the previous meta-analysis.
Data collection is currently underway, with papers being screened. We hope to publish the results by the end of 2019.
Given the high mortality rates currently associated with liver resection, it is imperative that novel surgical techniques are undertaken and investigated so we can improve best practice guidance and outcomes.
DERR1-10.2196/13437
Malignancy of the liver has historically meant a poor prognosis for patients and remains the second most common cause of cancer-related deaths globally [
Incidence of hepatocellular carcinoma (HCC) is predicted to rise to 22 million over the next few decades owing to rises in cirrhotic liver disease related to alcohol and viral hepatitis and Noncirrhotic Liver Disease related to Fatty Liver Disease [
Recent advances in surgical technology have led to the development of devices utilizing radiofrequency. These devices do not require hilar dissection or blood flow occlusion, mitigating risks associated with blood loss and reperfusion injury. The devices coagulate viable tissue around the resection margin, allowing for subsequent excision with minimal blood loss. A meta-analysis in 2014 by Xiao et al [
A systematic review will be undertaken assessing the recent studies from 2014 until 2019 that compare RFLR with CCLR for all various types of devices that utilize radiofrequency energy for liver resection. The search strategy will therefore include any individual device that has evidence published comparing its efficacy to CCLR, such as Habib 4X System, Cool-tip System, Tissue Link, and Radionics. Relevant data from these studies and the meta-analysis by Xiao et al [
Population: patients requiring liver resection for benign or malignant liver disease in both normal and cirrhosed liver.
Intervention: RFLR.
Comparison: CCLR.
Primary outcome: intraoperative blood loss.
Secondary outcomes: (1) operation time; (2) number of patients developing postoperative bile leak; (3) number of patients requiring blood transfusion; (4) number of patients developing intra-abdominal abscess; and (5) mortality at 30 days.
Study design: all human study types (randomized and nonrandomized) comparing RFLR and CCLRs.
The source databases were as follows: (1) PubMed (2) Ovid (3) EMBASE and (4) Cochrane.
Mirroring the search strategy employed by Xiao et al [
(((radiofrequency[All Fields] AND “hepatectomy/mortality”[Mesh Terms]) OR (radiofrequency[All Fields] AND liver resection[Title/Abstract])) OR (radiofrequency[All Fields] AND liver transection[Title/Abstract])) OR (radiofrequency[All Fields] AND liver surgery[Title/Abstract]) AND (“2012/12/01”[PDAT]: “3000/12/31”[PDAT]) AND “humans”[MeSH Terms]
The inclusion criteria were as follows: all studies published as full-text articles from peer-review journals comparing RFLR and CCLR in which at least data from one of the quantitative outcomes mentioned are reported. These studies had to have more than 20 patients included in them.
Nonhuman studies.
No control group.
Publication not available in English.
Review articles.
Letters and editorial comments.
Case reports.
We will use the Systematic Review Facility Web-based screening tool to screen the title and abstract of each paper that is identified in our literature search. This will be done by 2 independent reviewers (EO and MM) assessing each paper’s eligibility against our inclusion and exclusion criteria. A third reviewer (CD) will then confirm the appropriateness of extracted papers.
Quality assessment will mirror similar methodologies to Xiao et al [
The quality of all RCTs will be assessed using a modified Jadad score, comprising the following 5 variables [
Randomization.
Generation of random numbers.
Details of the double-blinding procedure.
Information on withdrawals.
Concealment of allocation.
One point is allocation for each variable from the criteria that a study includes, totaling a maximum score of 5.
The quality of all non-RCTs will be assessed using the modified Newcastle-Ottawa scale that is recommended by the Cochrane Collaboration [
Patient selection—comprising 4 items, worth one point each.
Comparability of study groups—comprising 1 item, worth up to 2 points.
Assessment of outcomes—comprising 3 items, worth one point each.
Therefore, the maximum score is 9, and the score is represented by stars. Studies labeled with 6 or more stars will be considered to be of high quality.
Analysis of the data will be done through Review Manager 5, provided by the Cochrane Collaboration. All included studies for each outcome measure will be presented graphically and plotted on a forest plot. The comparison of dichotomous outcomes will be through their odds ratios with 95% Cis. Continuous variables will be compared through their weighted mean differences with 95% CI. Any
Data collection is currently underway, with the screening process being undertaken. We will then begin data analysis, with the expectation to publish results and a full manuscript by the end of 2019.
Given the growing complexity of patients, a procedure that reduces the known risks associated with high morbidity and mortality is desirable. Although intraoperative blood loss and subsequent blood transfusions are traditionally expected within surgery, in relation to liver resection, it is associated with poor outcomes. The crucial period in minimizing blood loss is during division of the liver parenchyma. Surgical techniques such as radiofrequency can theoretically eradicate bleeding during this period, leading to bloodless liver resections, thus improving outcomes for patients. However, if new surgical techniques such as RFLR cause a rise in postoperative complication rates, for example, bile leak and infection, they will not be favorable alternatives to traditional CCLR. Given the poor outcomes currently associated with liver resection, it is imperative that new best practice surgical techniques are undertaken.
clamp-crush liver resection
hepatocellular carcinoma
randomized controlled trials
radiofrequency-assisted liver resection
None declared.