Thirty-day mortality leads to underestimation of postoperative death after liver resection: A novel method to define the acute postoperative period

Predictive factors of 90-day mortality after curative hepatic resection for hepatocellular carcinoma: a western single-center observational study

PURPOSE

The aim of this study was to identify predictive risk factors associated with 90-day mortality after hepatic resection (HR) in hepatocellular carcinoma (HCC).

METHODS

All patients undergoing elective resection for HCC from a single- institutional and prospectively maintained database were included. Multivariate regression analysis was conducted to identify pre- and intraoperative as well as histopathological predictive factors of 90-day mortality after elective HR.

RESULTS

Between August 2004 and October 2021, 196 patients were enrolled (148 male /48 female). The median age of the study cohort was 68.5 years (range19-84 years). The rate of major hepatectomy (≥ 3 segments) was 43.88%. Multivariate analysis revealed patient age ≥ 70 years [HR 2.798; (95% CI 1.263-6.198); p = 0.011], preoperative chronic renal insufficiency [HR 3.673; (95% CI 1.598-8.443); p = 0.002], Child-Pugh Score [HR 2.240; (95% CI 1.188-4.224); p = 0.013], V-Stage [HR 2.420; (95% CI 1.187-4.936); p = 0.015], and resected segments ≥ 3 [HR 4.700; (95% 1.926-11.467); p = 0.001] as the major significant determinants of the 90-day mortality.

CONCLUSION

Advanced patient age, pre-existing chronic renal insufficiency, Child-Pugh Score, extended hepatic resection, and vascular tumor involvement were identified as significant predictive factors of 90-day mortality. Proper patient selection and adjustment of treatment strategies could potentially reduce short-term mortality.

Association Between Frailty and Time Alive and At Home After Cancer Surgery Among Older Adults: A Population-Based Analysis

BACKGROUND

Although frailty is known to impact short-term postoperative outcomes, its long-term impact is unknown. This study examined the association between frailty and remaining alive and at home after cancer surgery among older adults.

METHODS

Adults aged ≥70 years undergoing cancer resection were included in this population-based retrospective cohort study using linked administrative datasets in Ontario, Canada. The probability of remaining alive and at home in the 5 years after cancer resection was evaluated using Kaplan-Meier methods. Extended Cox regression with time-varying effects examined the association between frailty and remaining alive and at home.

RESULTS

Of 82,037 patients, 6,443 (7.9%) had preoperative frailty. With median follow-up of 47 months (interquartile range, 23-81 months), patients with frailty had a significantly lower probability of remaining alive and at home 5 years after cancer surgery compared with those without frailty (39.1% [95% CI, 37.8%-40.4%] vs 62.5% [95% CI, 62.1%-63.9%]). After adjusting for age, sex, rural living, material deprivation, immigration status, cancer type, surgical procedure intensity, year of surgery, and receipt of perioperative therapy, frailty remained associated with increased hazards of not remaining alive and at home. This increase was highest 31 to 90 days after surgery (hazard ratio [HR], 2.00 [95% CI, 1.78-2.24]) and remained significantly elevated beyond 1 year after surgery (HR, 1.56 [95% CI, 1.48-1.64]). This pattern was observed across cancer sites, including those requiring low-intensity surgery (breast and melanoma).

CONCLUSIONS

Preoperative frailty was independently associated with a decreased probability of remaining alive and at home after cancer surgery among older adults. This relationship persisted over time for all cancer types beyond short-term mortality and the initial postoperative period. Frailty assessment may be useful for all candidates for cancer surgery, and these data can be used when counseling, selecting, and preparing patients for surgery.

Factors associated with failure to rescue after liver resection and impact on hospital variation: a nationwide population-based study

BACKGROUND

Failure to rescue (FTR) is defined as postoperative complications leading to mortality. This nationwide study aimed to assess factors associated with FTR and hospital variation in FTR after liver surgery.

METHODS

All patients who underwent liver resection between 2014 and 2017 in the Netherlands were included. FTR was defined as in-hospital or 30-day mortality after complications Dindo grade ≥3a. Variables associated with FTR and nationwide hospital variation were assessed using multivariable logistic regression.

RESULTS

Of 4961 patients included, 3707 (74.4%) underwent liver resection for colorectal liver metastases, 379 (7.6%) for other metastases, 526 (10.6%) for hepatocellular carcinoma and 349 (7.0%) for biliary cancer. Thirty-day major morbidity was 11.5%. Overall mortality was 2.3%. FTR was 19.1%. Age 65-80 (aOR: 2.86, CI:1.01-12.0, p = 0.049), ASA 3+ (aOR:2.59, CI: 1.66-4.02, p < 0.001), liver cirrhosis (aOR:4.15, CI:1.81-9.22, p < 0.001), biliary cancer (aOR:3.47, CI: 1.73-6.96, p < 0.001), and major resection (aOR:6.46, CI: 3.91-10.9, p < 0.001) were associated with FTR. Postoperative liver failure (aOR: 26.9, CI: 14.6-51.2, p < 0.001), cardiac (aOR: 2.62, CI: 1.27-5.29, p = 0.008) and thromboembolic complications (aOR: 2.49, CI: 1.16-5.22, p = 0.017) were associated with FTR. After case-mix correction, no hospital variation in FTR was observed.

CONCLUSION

FTR is influenced by patient demographics, disease and procedural burden. Prevention of postoperative liver failure, cardiac and thromboembolic complications could decrease FTR.

Nationwide oncological networks for resection of colorectal liver metastases in the Netherlands: Differences and postoperative outcomes

INTRODUCTION

Widespread differences in patient demographics and disease burden between hospitals for resection of colorectal liver metastases (CRLM) have been described. In the Netherlands, networks consisting of at least one tertiary referral centre and several regional hospitals have been established to optimize treatment and outcomes. The aim of this study was to assess variation in case-mix, and outcomes between these networks.

METHODS

This was a population-based study including all patients who underwent CRLM resection in the Netherlands between 2014 and 2019. Variation in case-mix and outcomes between seven networks covering the whole country was evaluated. Differences in case-mix, expected 30-day major morbidity (Clavien-Dindo ≥3a) and 30-day mortality between networks were assessed.

RESULTS

In total 5383 patients were included. Thirty-day major morbidity was 5.7% and 30-day mortality was 1.5%. Significant differences between networks were observed for Charlson Comorbidity Index, ASA 3+, previous liver resection, liver disease, preoperative MRI, preoperative chemotherapy, ≥3 CRLM, diameter of largest CRLM ≥55 mm, major resection, combined resection and ablation, rectal primary tumour, bilobar and extrahepatic disease. Uncorrected 30-day major morbidity ranged between 3.3% and 13.1% for hospitals, 30-day mortality ranged between 0.0% and 4.5%. Uncorrected 30-day major morbidity ranged between 4.4% and 6.0% for networks, 30-day mortality ranged between 0.0% and 2.5%. No negative outliers were observed after case-mix correction.

CONCLUSION

Variation in case-mix and outcomes are considerably smaller on a network level as compared to a hospital level. Therefore, auditing is more meaningful at a network level and collaboration of hospitals within networks should be pursued.

Morbidity and mortality after liver surgery for colorectal liver metastases: a cohort study in a high-volume fast-track programme

BACKGROUND

For colorectal liver metastases, surgery is a high-risk procedure due to perioperative morbidity. The objective was to assess severity of complications after fast-track liver surgery for colorectal liver metastases and their impact on morbidity and mortality.

METHODS

All patients were treated according to the same fast-track programme. Complications were graded according to the Clavien-Dindo classification for patients undergoing surgery from 2013 to 2015. Correlation between complications and length of stay was analysed by multivariate linear regression.

RESULTS

564 patient cases were included of which three patients died within 3 months (0.53%, 95% CI: 0.17-1.64%). Complications were common with Grade ≤ 2 in 167 patients (30%) and ≥ Grade 3a in 93 (16%). Patients without complications had a mean length of stay of 4.1 days, which increased with complications: 1.4 days (95% CI: 1.3-1.5) for Grade 2, 1.7 days (1.5-2.0) for Grade 3a, 2.3 days (1.7-3.0) for Grade 3b, 2.6 days (1.6-4.2) for Grade 4a, and 2.9 days (2.8-3.1) for Grade 4b. Following were associated with increased length of stay: complication severity grade, liver insufficiency, ascites, biliary, cardiopulmonary, and infectious complications.

CONCLUSIONS

Complications after liver surgery for colorectal liver metastases, in a fast track setting, were associated with low mortality, and even severe complications only prolonged length of stay to a minor degree.

Implementation of the Management of Anticoagulation in the Periprocedural Period App Into an Electronic Health Record: A Prospective Cohort Study

Appropriate perioperative management of patients on chronic oral anticoagulation (OAC)—including warfarin and the direct oral anticoagulants—is a poorly defined yet important clinical issue with potentially severe consequences in the postoperative period. We sought to prospectively evaluate the effect of the Management of Anticoagulation in the Periprocedural Period (MAPPP) mobile app as a clinical decision tool in the management of patients on chronic OAC undergoing elective procedures or surgeries. Between January 1, 2018, and January 31, 2019, 642 patients treated in our health system were included. Eligible patients met the following criteria: age >18 years old, creatinine clearance ≥15 mL/min, and on chronic OAC with adequate information regarding baseline characteristics. Our study outcome was patient’s emergency department (ED) visits within 30 days postprocedure. The MAPPP app was integrated into the electronic health record (EHR), and the end user was free to accept or decline recommended evidence-based perioperative anticoagulation management guidance. Analysis revealed that acceptance was more common in younger patients (P = .0137), patients on oral anticoagulants other than warfarin (P < .0001), and patients undergoing increased bleeding risk procedures (P = .0068). Acceptance of the MAPPP app recommendation was significantly associated with fewer ED visits (acceptance group: 4.0% vs rejection group: 8.3%, P = .0205). Logistic regression showed that intervention acceptance and female gender were significantly associated with fewer—while age ≥80 with more—30-day ED visits. Our findings indicate that newer technologies, such as the MAPPP app, integrated into clinical EHR workflow, can significantly augment evidence-based perioperative anticoagulation management and potentially result in a reduction of adverse outcomes.

Ninety-day mortality after total gastrectomy for gastric cancer

BACKGROUND

Total gastrectomy for gastric cancer is associated with significant 30-day mortality, but this endpoint may underestimate the short-term mortality of the procedure.

METHODS

Retrospective analysis was performed using the National Cancer Database (2004-2015). Patients who underwent total gastrectomy for stage I to III gastric adenocarcinoma were identified and divided into cohorts based on 90-day mortality. Predictors of mortality were analyzed using multivariable logistic regression, and annual trends in mortality rates were calculated by Joinpoint Regression.

RESULTS

Of the 5,484 patients who underwent total gastrectomy, 90-day and 30-day mortality rates were 9.1% and 4.7%, respectively. Factors associated with 90-day mortality included increasing age (odds ratio 1.0, P < .001), income below the median (odds ratio 1.2, P = .039), Charlson-Deyo score ≥2 (odds ratio 1.4, P = .039), treatment at low-volume facilities (odds ratio 1.5, P < .001), N1 (odds ratio 2.0, P < .001), N2 (odds ratio 2.0, P < .001), or N3 (odds ratio 2.7, P < .001) stage disease, having <16 lymph nodes harvested (odds ratio 1.5, P < .001), and lack of treatment with chemotherapy (3.7, P < .001). Lack of health insurance (odds ratio 4.1, P = .080), and positive microscopic margins (odds ratio 1.3, P = .080) were correlated, but not significantly associated, with 90-day mortality. The 90-day mortality rate significantly declined from 14.3% in 2004 to 7.9% in 2015 (P = .006), and the 30-day mortality rate significantly declined from 7.7% in 2004 to 4.8% in 2015 (P = .009).

CONCLUSION

Nearly half of the deaths within 90 days after total gastrectomy for cancer occur beyond 30 days postoperative. Ninety-day mortality has improved over time, but rates remain high, suggesting the need for improved out-of-hospital postoperative care beyond 30 days.

Liver resection safety in a developing country: Analysis of a collective learning curve

AIM OF THE STUDY

To analyze the collective learning curve in the performance of safe liver resections, using the decrease of severe postoperative complications (SPC) as a proxy for overall safety competency.

MATERIAL AND METHODS

This was a retrospective analysis of a prospective database in the setting of a liver surgery program implementation in a tertiary center in Morocco. The 100 first consecutive cases of elective liver resections starting from January 1st, 2018 were included in the analysis. SPC were defined as CD>IIIa during the first 90 postoperative days. We used a cumulative sum (CUSUM) technique to determine the number of cases required to achieve safety competency. We then compared case characteristics before and after the learning curve completion.

RESULTS

SPC occurred in 15 cases (15%), including 5 deaths (5%). The CUSUM chart revealed a learning curve completion at the 49th case, marked by an inflection point towards the decrease in SPC (24.5% vs 5.9%; P=0.009). In period 2 (after), cases were associated with less diabetes, less synchronous digestive resection, more cirrhosis, and more prolonged preoperative chemotherapy. The rates of major resection (30.6% vs 29.9%; P=0.89) and biliary reconstruction were comparable, as were the operating time, and estimated blood loss.

CONCLUSION

Approximately 50 cases were required to complete the learning curve and improve the overall safety of liver resection. In our setting, the learning curve chronology was consistent with collective measures, including team stabilization and protocol development.

Contributing factors to severe complications after liver resection: an aggregate root cause analysis in 105 consecutive patients

Background

The aggregate root cause analysis (AggRCA) was designed to improve the understanding of system vulnerabilities contributing to patient harm, including surgical complications. It remains poorly used due to methodological complexity and resource limitations. This study aimed to identify the main patterns contributing to severe complications after liver resection using an AggRCA.

Methods

This was a retrospective qualitative study aimed to identify the main patterns contributing to severe complications, defined as strictly higher than grade IIIa according to the Clavien-Dindo classification within the first 90 days after liver resection. All consecutive severe complications that occurred between January 1st, 2018 and December 31st, 2019 were identified from an electronic database and included in an AggRCA. This included a structured morbidity and mortality review (MMR) reporting tool based on 50 contributory factors adapted from 6 ALARM categories: "Patient", "Tasks", "Individual staff", "Team", "Work environment", and "Management and Institutional context". Data resulting from individual-participant root cause analysis (RCA) of single-cases were validated collectively then aggregated. The main patterns were suggested from the contributory factors reported in more than half of the cases.

Results

In 105 consecutive liver resection cases, 15 patients (14.3%) developed severe postoperative complications, including 5 (4.8%) who died. AggRCA resulted in the identification of 36 contributory factors. Eight contributory factors were reported in more than half of the cases and were compiled in three entangled patterns: (1) Disrupted perioperative process, (2) Unplanned intraoperative change, (3) Ineffective communication.

Conclusion

A pragmatic aggregated RCA process improved our understanding of system vulnerabilities based on the analysis of a limited number of events and a reasonable resource intensity. The identification of patterns contributing to severe complications lay the rationale of future contextualized safety interventions beyond the scope of liver resections.

Development of an Integer-based Risk Score to Predict 90-Day Mortality After Hepatectomy in Patients With Hepatocellular Carcinoma

BACKGROUND

The incidence of liver cancer has more than tripled since 1980. Hepatectomy represents the major curative treatment for liver cancer. The risk factors associated with 90-day mortality after hepatectomy are not well understood and there are currently no good prediction models for this outcome. The objectives of the current study were to identify risk factors of 90-day mortality after hepatectomy in patients with hepatocellular carcinoma and to develop an integer-based risk score using the National Cancer Database.

METHODS

Hepatectomies recorded in the National Cancer Database during 2004-2012 were reviewed for 90-day mortality. Risk factors were identified by multivariate logistic regression models. An integer-based risk score was developed using the β coefficients derived from the logistic regression model and tested for discriminatory ability. According to the total risk score, patients were grouped into 4 risk groups.

RESULTS

The overall 90-day mortality was 10.2%. Ten risk factors were identified, which included sex, age, race/ethnicity, insurance status, education, annual hospital volume, stage, tumor grade, Charlson-Deyo Score, and surgical procedure. The risk of 90-day mortality was stratified into 4 groups. The calculated 90-day mortality rates were 2.47%, 5.88%, 12.58%, and 24.67% for low-risk, medium-risk, high-risk, and excessive-risk groups, respectively. An area under the receiver operating characteristic curve of 0.69 was obtained for model discrimination.

CONCLUSIONS

The integer-based risk score we developed could easily quantify each patient's risk level and predict 90-day mortality after hepatectomy. The stratified risk score could be a useful addition to perioperative risk management and a tool to improve 90-day mortality after hepatectomy.

Safety and feasibility of robotic major hepatectomy for novice surgeons in robotic liver surgery: A prospective multicenter pilot study

BACKGROUND

Robotic liver resection has not yet been widely implemented. We aimed to evaluate the feasibility and safety of robotic major liver resection by performing a prospective multicenter study.

METHODS

From July 2017 to December 2018, five surgeons from five tertiary hospitals who were novices in robotic liver resection but experienced in open and laparoscopic liver resection performed 46 cases of robotic major anatomical liver resections. Perioperative clinical data and surgical data, including detailed procedure times were prospectively collected. All operations were performed according to a protocol for unify surgical techniques and instruments.

RESULTS

Twenty-two cases of left hemihepatectomy, one case of extended left hemihepatectomy, 14 cases of right hemihepatectomy, two cases of right anterior sectionectomy, six cases of right posterior sectionectomy, and one case of central bisectionectomy were performed. The most common indications were hepatocellular carcinoma (21 cases) followed by intrahepatic duct stones (10 cases), intrahepatic cholangiocellular carcinoma (7 cases), liver metastases (3 cases), intraductal papillary neoplasms (2 cases), sarcoma (1 case), mucinous cystic neoplasm (1 case), and hemangioma (1 case). Surgical resection margins for all tumor cases were negative. The mean operation time was 378.58 ± 124.31 (190-696) minutes and the estimated intraoperative blood loss was 276.67 ± 397.41 mL (range, 10-2600 mL). Overall complications developed in 16 cases (34.8%). There were three cases of severe surgical complications (Clavien-Dindo classification of III or more). Only one of 46 cases was converted to conventional open left hemihepatectomy because of bleeding. The mean hospital stay was 7.3 ± 2.5 (4-18) days.

CONCLUSIONS

The results of this study indicate that robotic anatomic major liver resection can be safely performed by robotic beginners who are advanced open and laparoscopic liver surgeons.

Laparoscopic versus open hemihepatectomy: comprehensive comparison of complications and costs at 90 days using a propensity method

Laparoscopic hemihepatectomy (LHH) may offer advantages over open hemihepatectomy (OHH) in blood loss, recovery, and hospital stay. The aim of this study is to evaluate our recent experience performing hemihepatectomy and compare complications and costs up to 90 days following laparoscopic versus open procedures. Retrospective evaluation of patients undergoing hemihepatectomy at our center 01/2010–12/2018 was performed. Patient, tumor, and surgical characteristics; 90-day complications; and costs were analyzed. Inverse probability of treatment weighting (IPTW) was used to balance covariates. A total of 141 hemihepatectomies were included: 96 OHH and 45 LHH. While operative times were longer for LHH, blood loss and transfusions were less. At 90 days, there were similar rates of liver-specific and surgical complications but fewer medical complications following LHH. Medical complications that arose with greater frequency following OHH were primarily pulmonary complications and urinary and central venous catheter infections. Complications at 90 days were lower following LHH (Clavien–Dindo grade ≥ III OHH 23%, LHH 11%, p = 0.130; Comprehensive Complication Index OHH 20.0 ± 16.1, LHH 10.9 ± 14.2, p = 0.001). While operating costs were higher, costs for hospital stay and readmissions were lower with LHH. Patients undergoing LHH experience a significant reduction in postoperative medical complications and costs, resulting in 90-day cost equity compared with OHH.

Natural Orifice Transluminal Endoscopic Surgery: Long-Term Experience with Hybrid Transvaginal Cholecystectomies

Objective. To assess outcome and safety of 571 hybrid natural orifice transluminal endoscopic surgery (NOTES) cholecystectomies. Methods. We retrospectively analyzed all consecutive NOTES cholecystectomies performed at our center between June 2009 and January 2018. All procedures were performed using a hybrid transvaginal technique, including an umbilical small-size trocar. End points, calculated at discharge, 30 and up to 90 days postoperatively, included intra- and postoperative morbidity assessed by the validated Clavien-Dindo classification and the Comprehensive Complication Index (CCI). Special focus was held on outcome and necessity of pre- and postoperative gynecological examinations. Results. We performed 571 hybrid NOTES cholecystectomies within 9 years. The vast majority were elective, 9.6% were emergency cholecystectomies. 6.7% of patients developed at least one complication until discharge, most of them minor (≤grade II). 30- and 90-day complication rates were 10.7% and 11%, respectively. Mean CCI at discharge and postoperative days 30 and 90 was 1.45 (±6.4), 2.3 (±7.7), and 2.4 (±7.8), respectively. Major complications (≥grade IIIa) occurred in 1.6% of patients, and 4 patients required emergency reoperation. No mortality was observed. In 9.8%, an additional abdominal trocar was placed. All patients underwent routine gynecological examination, whereof only 5 were rejected for transvaginal access preoperatively. In no case transvaginal access was discontinued intraoperatively due to gynecological disease. Conclusion. Hybrid NOTES transvaginal cholecystectomy represents a safe and feasible alternative to standard laparoscopic cholecystectomy. Preoperative gynecological examination is no longer routinely necessary, as intraoperative assessment is adequate.

A novel machine learning algorithm to predict disease free survival after resection of hepatocellular carcinoma

Background

Due to organ shortage, liver transplantation (LT) in hepatocellular carcinoma (HCC) patients can only be offered subsidiary to other curative treatments, including liver resection (LR). We aimed at developing and validating a machine-learning algorithm (ML) to predict which patients are sufficiently treated by LR.

Methods

Twenty-six preoperatively available routine laboratory values along with standard clinical-pathological parameters [including the modified Glascow Prognostic Score (mGPS), the Kings Score (KS) and the Model of Endstage Liver Disease (MELD)] were retrieved from 181 patients who underwent partial LR due to HCC in non-cirrhosis or compensated cirrhosis from January 2007 through March 2018 at our institution. These data were processed using a Random Forest (RF)-based workflow, which included preprocessing, recursive feature elimination (RFE), resampling, training and cross-validation of the RF model. A subset of untouched patient data was used as a test cohort. Basing on the RF prediction, test data could be stratified according to high (HR) or low risk (LR) profile characteristics.

Results

RFE analysis provided 6 relevant outcome predictors: mGPS, aPTT, CRP, largest tumor size, number of lesions and age at time of operation. After down-sampling, the predictive value of our model was 0.788 (0.658-0.919) for early DFS. 16.7% of HR and 74.2% of LR patients survived 2 years of follow-up (P<0.001).

Conclusions

Our RF model, based solely on clinical parameters, proved to be a powerful predictor of DFS. These results warrant a prospective study to improve the model for selection of suitable candidates for LR as alternative to transplantation. The predictive model is available online: tiny.cc/hcc_model.

Impact of concomitant ablation on the perioperative outcomes of patients with colorectal liver metastases undergoing hepatectomy: a propensity score matched nationwide analysis

BACKGROUND

Intraoperative ablation (IA) is often performed at the time of liver resection (LR) for colorectal liver metastases (CRLMs) but its impact on postoperative outcomes remains poorly understood.

METHODS

The ACS-NSQIP targeted hepatectomy database was used to identify patients who underwent LR vs LR + IA for CRLMs during 2014-2016. Perioperative outcomes were compared following propensity score match based on age, receipt of neoadjuvant therapy, operative approach, liver resection type, tumor diameter and number of metastases.

RESULTS

Among 1,384 patients, 692 (50%) underwent LR alone and 692 (50%) underwent LR + IA. After propensity score matching, overall morbidity (22% vs 13%, P < 0.0001) was increased among patients undergoing LR alone compared to LR + IA, whereas mortality did not differ (1.1% vs 0.8%, P=0.5911). On multivariable analysis, ASA class ≥3 (OR: 1.5, 95% CI: 1.06-2.3), preoperative biliary stent (OR: 3.5, 95% CI: 0.9-13.01), biliary reconstruction (OR: 5.02, 95% CI: 1.3-18.6), operative time > 245 minutes (OR: 1.8, 95% CI:1.3-2.4) and IA (OR:0.5, 95% CI:0.3-0.7) were associated with overall morbidity.

CONCLUSIONS

In this propensity matched nationwide analysis of patients undergoing LR for CRLM, the use of concomitant IA was associated with decreased postoperative morbidity compared to LR alone. These findings suggest that IA combined with LR is a safe approach that may expand the number of patients who are candidates for curative-intent surgical strategies.

Predicting Postoperative Liver Dysfunction Based on Blood-Derived MicroRNA Signatures

There is an urgent need for an easily assessable preoperative test to predict postoperative liver function recovery and thereby determine the optimal time point of liver resection, specifically as current markers are often expensive, time consuming, and invasive. Emerging evidence suggests that microRNA (miRNA) signatures represent potent diagnostic, prognostic, and treatment-response biomarkers for several diseases. Using next-generation sequencing as an unbiased systematic approach, 554 miRNAs were detected in preoperative plasma of 21 patients suffering from postoperative liver dysfunction (LD) after liver resection and 27 matched controls. Subsequently, we identified a miRNA signature-consisting of miRNAs 151a-5p, 192-5p, and 122-5p-that highly correlated with patients developing postoperative LD after liver resection. The predictive potential for postoperative LD was subsequently confirmed using real-time PCR in an independent validation cohort of 98 patients. Ultimately, a regression model of the two miRNA ratios 151a-5p to 192-5p and 122-5p to 151a-5p was found to reliably predict postoperative LD, severe morbidity, prolonged intensive care unit and hospital stays, and even mortality before an operation with a remarkable accuracy, thereby outperforming established markers of postoperative LD. Ultimately, we documented that miRNA ratios closely followed liver function recovery after partial hepatectomy. Conclusion: Our data demonstrate the clinical utility of an miRNA-based biomarker to support the selection of patients undergoing partial hepatectomy. The dynamical changes during liver function recovery indicate a possible role in individualized patient treatment. Thereby, our data might help to tailor surgical strategies to the specific risk profile of patients.

The 3-60 criteria challenge established predictors of postoperative mortality and enable timely therapeutic intervention after liver resection

Background

To date, definitions of liver dysfunction (LD) after hepatic resection rely on late postoperative time points. Further, the used parameters are markedly influenced by perioperative management. Thus, we aimed to establish a very early postoperative score to predict postoperative mortality.

Methods

Liver related parameters were evaluated after liver resection in a retrospective evaluation cohort of 228 colorectal cancer patients with liver metastasis (mCRC) and subsequent validation in a prospective set of 482 consecutive patients from 4 independent institutions undergoing hepatic resection was performed.

Results

C-reactive protein (CRP, AUC =0.739, P<0.001) and antithrombinIII-activity (ATIII, AUC =0.844, P<0.001) on the first postoperative day (POD) were found to be elevated in patients with LD. Cut-off values for CRP at 3 mg/dL and for ATIII at 60% significantly identified high-risk patients for postoperative LD and mortality (P<0.001) and thus defined the 3-60 criteria on POD1. The 3-60 criteria showed superior sensitivity and specificity compared to established criteria for LD [3-60 criteria: total positive patients: 26 patients (70% mortality detected), odds ratio (OR): 48.8; International Study Group for Liver Surgery: total positive patients: 43 (70% mortality detected), OR: 23.3; Peak7: total positive patients: 9 (30% mortality detected), OR: 27.8; 50-50: total positive patients: 9 (30% mortality detected), OR: 27.8]. These results could be validated in a multi-center analysis and ultimately the 3-60 criteria remained an independent predictor of postoperative mortality upon multivariable analysis.

Conclusions

The 3-60 criteria on POD1 predict postoperative LD and mortality early after liver resection with a comparable or better accuracy than established criteria, allowing for immediate identification of high-risk patients.

Nonparametric change point estimation for survival distributions with a partially constant hazard rate

We present a new method for estimating a change point in the hazard function of a survival distribution assuming a constant hazard rate after the change point and a decreasing hazard rate before the change point. Our method is based on fitting a stump regression to p values for testing hazard rates in small time intervals. We present three real data examples describing survival patterns of severely ill patients, whose excess mortality rates are known to persist far beyond hospital discharge. For designing survival studies in these patients and for the definition of hospital performance metrics (e.g. mortality), it is essential to define adequate and objective end points. The reliable estimation of a change point will help researchers to identify such end points. By precisely knowing this change point, clinicians can distinguish between the acute phase with high hazard (time elapsed after admission and before the change point was reached), and the chronic phase (time elapsed after the change point) in which hazard is fairly constant. We show in an extensive simulation study that maximum likelihood estimation is not robust in this setting, and we evaluate our new estimation strategy including bootstrap confidence intervals and finite sample bias correction.

Impact of Neoadjuvant Chemotherapy on the Postoperative Outcomes of Patients Undergoing Liver Resection for Colorectal Liver Metastases: A Population-Based Propensity-Matched Analysis

BACKGROUND

The role of neoadjuvant chemotherapy in the management of colorectal liver metastases remains controversial. We sought to investigate whether neoadjuvant systemic chemotherapy contributes to clinically significant increases in postoperative morbidity and mortality using a population-based cohort.

STUDY DESIGN

The American College of Surgeons NSQIP Targeted Hepatectomy Participant Use Files were queried from 2014 to 2016 to identify patients with colorectal liver metastases who underwent liver resection. Patients were stratified by receipt of neoadjuvant chemotherapy using propensity score matching. Univariate and multivariable analyses were used to characterize the effect of neoadjuvant chemotherapy on perioperative morbidity and mortality.

RESULTS

After propensity score matching, 1,416 (50%) patients received neoadjuvant chemotherapy before hepatectomy and 1,416 (50%) underwent liver resection without neoadjuvant chemotherapy. There were no differences in age (60 vs 61 years), maximum tumor size (≤5 cm: 79% vs 80%, >5 cm: 21% vs 20%), resection type (partial hepatectomy: 69% vs 70%), simultaneous colectomy (9% vs 9%), or use of preoperative portal vein embolization (5% vs 5%) in those undergoing neoadjuvant chemotherapy compared with those who did not (all, p > 0.05). Overall 30-day postoperative morbidity (34% vs 33%), including rates of biliary fistula (6% vs 5%), post-hepatectomy liver failure (5% vs 5%), and mortality rates (0.8% vs 0.7%), were similar among patients who received neoadjuvant chemotherapy vs those who did not (all, p > 0.05). On multivariable analysis, receipt of neoadjuvant chemotherapy was not associated with increased morbidity (odds ratio 1.07; 95% CI 0.90 to 1.27; p = 0.43) or mortality (odds ratio 1.09; 95% CI 0.44 to 2.72; p = 0.85).

CONCLUSIONS

In this propensity-matched population-based cohort study, the use of neoadjuvant systemic chemotherapy was not associated with higher rates of complications, biliary fistula, post-hepatectomy liver failure, or mortality among patients with colorectal liver metastases undergoing liver resection.

Intrahepatic fibrin(ogen) deposition drives liver regeneration after partial hepatectomy in mice and humans

Platelets play a pivotal role in stimulating liver regeneration after partial hepatectomy in rodents and humans. Liver regeneration in rodents is delayed when platelets are inhibited. However, the exact mechanisms whereby platelets accumulate and promote liver regeneration remain uncertain. Thrombin-dependent intrahepatic fibrin(ogen) deposition was recently reported after partial hepatectomy (PHx) in mice, but the role of fibrin(ogen) deposits in liver regeneration has not been investigated. We tested the hypothesis that fibrin(ogen) contributes to liver regeneration by promoting intrahepatic platelet accumulation and identified the trigger of rapid intrahepatic coagulation after PHx. PHx in wild-type mice triggered rapid intrahepatic coagulation, evidenced by intrahepatic fibrin(ogen) deposition. Intrahepatic fibrin(ogen) deposition was abolished in mice with liver-specific tissue factor deficiency, pinpointing the trigger of coagulation after PHx. Direct thrombin activation of platelets through protease-activated receptor-4 did not contribute to hepatocyte proliferation after PHx, indicating that thrombin contributes to liver regeneration primarily by driving intrahepatic fibrin(ogen) deposition. Fibrinogen depletion with ancrod reduced both intrahepatic platelet accumulation and hepatocyte proliferation after PHx, indicating that fibrin(ogen) contributes to liver regeneration after PHx by promoting intrahepatic platelet accumulation. Consistent with the protective function of fibrin(ogen) in mice, low postoperative plasma fibrinogen levels were associated with liver dysfunction and mortality in patients undergoing liver resection. Moreover, increased intrahepatic fibrin(ogen) deposition was evident in livers of patients after liver resection but was remarkably absent in patients displaying hepatic dysfunction postresection. The results suggest a novel mechanism whereby coagulation-dependent intrahepatic fibrin(ogen) deposition drives platelet accumulation and liver regeneration after PHx.

Validation of clinical risk score for colorectal liver metastases resected in a contemporary multicenter cohort

BACKGROUND

Recent advances in care for colorectal liver metastases (CRLM) have lengthened 5-year survival. In this new era, prognostic tools such as the clinical risk score (CRS) for colorectal liver metastases require reevaluation.

METHODS

Patients undergoing resection for CRLM between 2008 and 2012 at 4 specialty hepatobiliary centers in Canada (N = 740) were stratified by CRS and analyzed in Kaplan-Meier survival curves. Primary outcome of overall survival (OS) and secondary outcome of recurrence-free survival (RFS). Multivariate Cox regression compared CRS to patient factors.

RESULTS

Median OS not reached (>60 months), median RFS 16 months. Original CRS strata was a significant (p < 0.001) predictor of both OS (5-year OS: 0; 75%, 1; 71%, 2; 57%, 3; 57%, 4; 46%) and RFS (5-year RFS: 0; 39%, 1; 33%, 2; 21%, 3; 21%, 4; 8%). The presence of extrahepatic colorectal metastatic disease increased recurrence risk (RFS hazard ratio of 1.32 (1.06-1.65)), and the use of intraoperative portal pedicle clamping reduced recurrence risk (RFS hazard ratio of 0.78 (0.61-0.99)).

CONCLUSIONS

The CRS remains a relevant tool for predicting long-term outcomes for patients undergoing resection of CRLM. Additional factors such as the presence of extrahepatic colorectal metastatic disease and the use of intraoperative portal pedicle clamping may improve the prognostic power of the CRS.

Defining Benchmarks for Major Liver Surgery: A multicenter Analysis of 5202 Living Liver Donors

OBJECTIVE

To measure and define the best achievable outcome after major hepatectomy.

BACKGROUND

No reference values are available on outcomes after major hepatectomies. Analysis in living liver donors, with safety as the highest priority, offers the opportunity to define outcome benchmarks as the best possible results.

METHODS

Outcome analyses of 5202 hemi-hepatectomies from living donors (LDs) from 12 high-volume centers worldwide were performed for a 10-year period. Endpoints, calculated at discharge, 3 and 6 months postoperatively, included postoperative morbidity measured by the Clavien-Dindo classification, the Comprehensive Complication Index (CCI), and liver failure according to different definitions. Benchmark values were defined as the 75th percentile of median morbidity values to represent the best achievable results at 3 month postoperatively.

RESULTS

Patients were young (34 ± [9] years), predominantly male (65%) and healthy. Surgery lasted 7 ± [2] hours; 2% needed blood transfusions. Mean hospital stay was 11.7± [5] days. 12% of patients developed at least 1 complication, of which 3.8% were major events (≥grade III, including 1 death), mostly related to biliary/bleeding events, and were twice higher after right hepatectomy. The incidence of postoperative liver failure was low. Within 3-month follow-up, benchmark values for overall complication were ≤31 %, for minor/major complications ≤23% and ≤9%, respectively, and a CCI ≤33 in LDs with complications. Centers having performed ≥100 hepatectomies had significantly lower rates for overall (10.2% vs 35.9%, P < 0.001) and major (3% vs 12.1%, P < 0.001) complications and overall CCI (2.1 vs 8.5, P < 0.001).

CONCLUSIONS

The thorough outcome analysis of healthy LDs may serve as a reference for evaluating surgical performance in patients undergoing major liver resection across centers and different patient populations. Further benchmark studies are needed to develop risk-adjusted comparisons of surgical outcomes.

Early prediction of postoperative liver dysfunction and clinical outcome using antithrombin III-activity

BACKGROUND AND AIMS

Antithrombin III (ATIII) has been reported to be associated with liver pathologies and was shown to predict outcome in patients undergoing liver resection for hepatocellular carcinoma. We now aimed to assess whether perioperative ATIII-activity could predict postoperative outcome in patients without underlying liver disease, as well as in a routine clinical setting of patients undergoing hepatic resection.

METHODS

ATIII-activity was evaluated preoperatively and on the first (POD1) and fifth day after liver resection in a retrospective evaluation cohort of 228 colorectal cancer patients with liver metastasis (mCRC). We further aimed to prospectively validate our results in a set of 177 consecutive patients undergoing hepatic resection.

RESULTS

Patients developing postoperative liver dysfunction (LD) had a more pronounced postoperative decrease in ATIII-activity (P<0.001). ATIII-activity on POD1 significantly predicted postoperative LD (P<0.001, AUC = 84.4%) and remained independent upon multivariable analysis. A cut-off value of 61.5% ATIII-activity was determined using ROC analysis. This cut-off was vital to identify high-risk patients for postoperative LD, morbidity, severe morbidity and mortality (P<0.001, respectively) with a highly accurate negative predictive value of 97%, which could be confirmed for LD (P<0.001) and mortality (P = 0.014) in our independent validation cohort. Further, mCRC patients below our cut-off suffered from a significantly decreased overall survival (OS) at 1 and 3 years after surgery (P = 0.011, P = 0.025).

CONCLUSIONS

The routine laboratory parameter ATIII-activity on POD1 independently predicted postoperative LD and was associated with clinical outcome. Patients with a postoperative ATIII-activity <61.5% might benefit from close monitoring and timely initiation of supportive therapy.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01700231.

Time-dependent impact of age and comorbidities on long-term overall survival after liver resection

BACKGROUND & AIMS

Advanced age and comorbidities are known to be associated with increased perioperative risks after liver resection. However, the precise impact of these variables on long-term overall survival (OS) remains unclear. Thus, the aim of this study was to evaluate the confounder-adjusted, time-dependent effect of age and comorbidities on OS following hepatectomy for primary and secondary malignancies.

METHODS

From a prospective database of 1.143 liver resections, 763 patients treated for primary and secondary malignancies were included. For time-varying OS calculations, a Cox-Aalen model was fitted. The confounder-adjusted hazard was compared with mortality tables of the German population.

RESULTS

Overall, age (P = 0.003) and comorbidities (P = 0.001) were associated with shortened OS. However, time-dependent analysis indicated that age and comorbidities had no impact on OS within 39 and 55 months after resection respectively. From this time on, a significant decline in OS was shown. Subgroup analysis indicated an earlier increase of the effect of age in patients with hepatocellular carcinoma (17 months) than in those with colorectal metastases (70 months). The confounder-adjusted hazard of 70-year-old patients was increased post-operatively but dropped 66 months after surgery, and the risk of death was comparable to the general population 78 months after resection. At this time, one-third of patients aged 70 years and older were still alive.

CONCLUSIONS

With regard to long-term outcome, liver resection for both primary and secondary malignancies should not be categorically denied due to age and comorbidities. This information should be considered for the patient selection process and informed consent.