Cardiopulmonary exercise testing before liver surgery

Clinical Tools to Assess Functional Capacity During Risk Assessment Before Elective Noncardiac Surgery : A Scoping Review

BACKGROUND

Functional capacity is critical to preoperative risk assessment, yet guidance on its measurement in clinical practice remains lacking.

PURPOSE

To identify functional capacity assessment tools studied before surgery and characterize the extent of evidence regarding performance, including in populations where assessment is confounded by noncardiopulmonary reasons.

DATA SOURCES

MEDLINE, EMBASE, and EBM Reviews (until July 2024).

STUDY SELECTION

Studies evaluating performance of functional capacity assessment tools administered before elective noncardiac surgery to stratify risk for postoperative outcomes.

DATA EXTRACTION

Study details, measurement properties, pragmatic qualities, and/or clinical utility metrics.

DATA SYNTHESIS

6 categories of performance-based tests and 5 approaches using patient-reported exercise tolerance were identified. Cardiopulmonary exercise testing (CPET) was the most studied tool (132 studies, 32 662 patients) followed by field walking tests (58 studies, 9393 patients) among performance-based tests. Among patient-reported assessments, the Duke Activity Status Index (14 studies, 3303 patients) and unstructured assessments (19 studies, 28 520 patients) were most researched. Most evidence focused on predictive validity (92% of studies), specifically accuracy in predicting cardiorespiratory complications. Several tools lacked evidence on reliability (test consistency across similar measurements), pragmatic qualities (feasibility of implementation), or concurrent criterion validity (correlation to gold standard). Only CPET had evidence on clinical utility (whether administration improved postoperative outcomes). Older adults (≥65 years) were well represented across studies, whereas there were minimal data in patients with obesity, lower-limb arthritis, and disability.

LIMITATION

Synthesis focused on reported data without requesting missing information.

CONCLUSION

Though several tools for preoperative functional capacity assessment have been studied, research has overwhelmingly focused on CPET and only 1 aspect of validity (predictive validity). Important evidence gaps remain among vulnerable populations with obesity, arthritis, and physical disability.

PRIMARY FUNDING SOURCE

None. (Open Science Framework: https://osf.io/ah7u5).

Ventilatory efficiency as a prognostic factor for postoperative complications in patients undergoing elective major surgery: a systematic review

BACKGROUND

Major surgery is associated with high complication rates. Several risk scores exist to assess individual patient risk before surgery but have limited precision. Novel prognostic factors can be included as additional building blocks in existing prediction models. A candidate prognostic factor, measured by cardiopulmonary exercise testing, is ventilatory efficiency (VE/VCO2). The aim of this systematic review was to summarise evidence regarding VE/VCO2 as a prognostic factor for postoperative complications in patients undergoing major surgery.

METHODS

A medical library specialist developed the search strategy. No database-provided limits, considering study types, languages, publication years, or any other formal criteria were applied to any of the sources. Two reviewers assessed eligibility of each record and rated risk of bias in included studies.

RESULTS

From 10,082 screened records, 65 studies were identified as eligible. We extracted adjusted associations from 32 studies and unadjusted from 33 studies. Risk of bias was a concern in the domains 'study confounding' and 'statistical analysis'. VE/VCO2 was reported as a prognostic factor for short-term complications after thoracic and abdominal surgery. VE/VCO2 was also reported as a prognostic factor for mid- to long-term mortality. Data-driven covariable selection was applied in 31 studies. Eighteen studies excluded VE/VCO2 from the final multivariable regression owing to data-driven model-building approaches.

CONCLUSIONS

This systematic review identifies VE/VCO2 as a predictor for short-term complications after thoracic and abdominal surgery. However, the available data do not allow conclusions about clinical decision-making. Future studies should select covariables for adjustment a priori based on external knowledge.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO (CRD42022369944).

Feasibility of a prehabilitation program before major abdominal surgery: a pilot prospective study

OBJECTIVE

To assess the feasibility of a prehabilitation program and its effects on physical performance and outcomes after major abdominal surgery.

METHODS

In this prospective pilot study, patients underwent prehabilitation involving three training sessions per week for 3 weeks preoperatively. The feasibility of delivering the intervention was assessed based on recruitment and adherence to the program. Its impacts on fitness (oxygen uptake (VO₂)) and physical performance (Timed Up and Go Test, 6-Minute Walk Test) were evaluated.

RESULTS

From May 2017 to January 2020, 980 patients were identified and 44 (4.5%) were invited to participate. The main obstacles to patient recruitment were insufficient time (<3 weeks) prior to scheduled surgery (n = 276, 28%) and screening failure (n = 312, 32%). Of the 44 patients, 24 (55%) declined to participate, and 20 (23%) were included. Of these, six (30%) were not adherent to the program. Among the remaining 14 patients, VO₂ at ventilatory threshold significantly increased from 9.7 to 10.9 mL/min/kg. No significant difference in physical performance was observed before and after prehabilitation.

CONCLUSION

Although prehabilitation seemed to have positive effects on exercise capacity, logistic and patient-related difficulties were encountered. The program is not feasible in its current form for all-comers.

Preoperative physical performance as predictor of postoperative outcomes in patients aged 65 and older scheduled for major abdominal cancer surgery: A systematic review

BACKGROUND

Abdominal cancer surgery is associated with considerable morbidity in older patients. Assessment of preoperative physical status is therefore essential. The aim of this review was to describe and compare the objective physical tests that are currently used in abdominal cancer surgery in the older patient population with regard to postoperative outcomes.

METHODS

Medline, Embase, CINAHL and Web of Science were searched until 31 December 2020. Non-interventional cohort studies were eligible if they included patients ≥65 years undergoing abdominal cancer surgery, reported results on objective preoperative physical assessment such as Cardiopulmonary Exercise Testing (CPET), field walk tests or muscle strength, and on postoperative outcomes.

RESULTS

23 publications were included (10 CPET, 13 non-CPET including Timed Up & Go, grip strength, 6-minute walking test (6MWT) and incremental shuttle walk test (ISWT)). Meta-analysis was precluded due to heterogeneity between study cohorts, different cut-off points, and inconsistent reporting of outcomes. In CPET studies, ventilatory anaerobic threshold and minute ventilation/carbon dioxide production gradient were associated with adverse outcomes. ISWT and 6MWT predicted outcomes in two studies. Tests addressing muscle strength and function were of limited value. No study compared different physical tests.

DISCUSSION

CPET has the ability to predict adverse postoperative outcomes, but it is time-consuming and requires expert assessment. ISWT or 6MWT might be a feasible alternative to estimate aerobic capacity. Muscle strength and function tests currently have limited value in risk prediction. Future research should compare the predictive value of different physical instruments with regard to postoperative outcomes in older surgical patients.

Preoperative Cardiopulmonary Exercise Test Associated with Postoperative Outcomes in Patients Undergoing Cancer Surgery: A Systematic Review and Meta-Analyses

BACKGROUNDS

There is mixed evidence on the value of preoperative cardiorespiratory exercise test (CPET) to predict postoperative outcomes in patients undergoing a cancer surgical procedure. The purpose of this review was to investigate the association between preoperative CPET variables and postoperative complications, length of hospital stay, and quality of life in patients undergoing cancer surgery.

METHODS

A search was conducted on MEDLINE, Embase, AMED, and Web of science from inception to April 2020. Cohort studies investigating the association between preoperative CPET variables, including peak oxygen uptake (peak VO₂), anaerobic threshold (AT), or ventilatory equivalent for carbon dioxide (V_E/V_CO2), and postoperative outcomes (complications, length of stay, and quality of life) were included. Risk of bias was assessed using the QUIPS tool. A random-effect model meta-analysis was performed whenever possible.

RESULTS

Fifty-two unique studies, including 10,030 patients were included. Overall, most studies were rated as having low risk of bias. Higher preoperative peak VO₂ was associated with absence of postoperative complications (mean difference [MD]: 2.28; 95% confidence interval [CI]: 1.26-3.29) and no pulmonary complication (MD: 1.47; 95% CI: 0.49-2.45). Preoperative AT and V_E/V_CO2 also demonstrated some positive trends. None of the included studies reported a negative trend.

CONCLUSIONS

This systematic review and meta-analysis demonstrated a significant association between superior preoperative CPET values, especially peak VO₂, and better postoperative outcomes. The assessment of preoperative functional capacity in patients undergoing cancer surgery has the potential to facilitate treatment decision making.

Systematic Review of Treatments for Colorectal Metastases in Elderly Patients to Guide Surveillance Cessation Following Hepatic Resection for Colorectal Liver Metastases

BACKGROUND

Although included in surveillance programmes for colorectal cancer (CRC) metastases, elderly patients are susceptible to declines in health and quality of life that may render them unsuitable for further surveillance. Deciding when to cease surveillance is challenging.

METHODS

There are no publications focused on surveillance of elderly patients for CRC metastases. A systematic review of studies reporting treatment outcomes for CRC metastases in elderly patients was performed to assess the risk-benefit balance of the key objectives of surveillance; detecting and treating CRC metastases.

RESULTS

Sixty-eight eligible studies reported outcomes for surgery and chemotherapy in the elderly. Liver resections and use of chemotherapy, including biologics, are more conservative and have poorer outcomes in the elderly compared with younger patients. Selected studies demonstrated poorer quality-of-life (QoL) following surgery and chemotherapy. Studies of ablation in elderly patients are limited.

DISCUSSION

The survival benefit of treating CRC metastases with surgery or chemotherapy decreases with advancing age and QoL may decline in the elderly. The relatively lower efficacy and detrimental QoL impact of multimodal therapy options for detected CRC metastases in the elderly questions the benefit of surveillance in some elderly patients. Care of elderly patients should thus be customized based on their preference, formal geriatric assessment, natural life-expectancy, and the perceived risk-benefit balance of treating recurrent CRC metastases. Clinicians may consider surveillance cessation in patients aged 75 years and above if geriatric assessment is unsatisfactory, patients decline surveillance, or patient fitness deteriorates catastrophically.

The accuracy of pre-operative (P)-POSSUM scoring and cardiopulmonary exercise testing in predicting morbidity and mortality after pancreatic and liver surgery: A systematic review

Background

Cardiopulmonary exercise-testing (CPET) and the (Portsmouth) Physiological and Operative Severity Score for the enUmeration of Mortality and Morbidity ((P)-POSSUM) are used as pre-operative risk stratification and audit tools in general surgery, however, both have been demonstrated to have limitations in major hepatopancreatobiliary (HPB) surgery.

Materials and methods

The aim of this review is to determine if CPET and (P)-POSSUM scoring systems accurately predict morbidity and mortality. Eligible articles were identified with an electronic database search. Analysis according to surgery type and tool used was performed.

Results

Twenty-five studies were included in the final review. POSSUM predicted morbidity demonstrated weighted O/E ratios of 0.75(95%CI0.57–0.97) in hepatic surgery and 0.85(95%CI0.8–0.9) in pancreatic surgery. P-POSSUM predicted mortality in pancreatic surgery demonstrated an O/E ratio of 0.75(95%CI0.27–2.13) and 0.94(95%CI0.57–1.55) in hepatic surgery. In both pancreatic and hepatic surgery an anaerobic threshold(AT) of between 9 0.5–11.5 ml/kg/min was predictive of post-operative complications, and in pancreatic surgery ventilatory equivalence of carbon dioxide(˙VE/˙VCO2) was predictive of 30-day mortality.

Conclusion

POSSUM demonstrates an overall lack of predictive fit for morbidity, whilst CPET variables provide some predictive power for post-operative outcomes. Development of a new HPB specific risk prediction tool would be beneficial; the combination of parameters from POSSUM and CPET, alongside HPB specific markers could overcome current limitations.

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Current pre-operative scoring for pancreatic and liver surgery is inaccurate.

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In pancreatic and liver surgery anaerobic threshold scores were predictive of complications.

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In pancreatic surgery ventilatory equivalence of carbon dioxide was predictive of mortality.

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P-POSSUM is inaccurate for predicting mortality and morbidity in pancreatic surgery.

Performance of cardiopulmonary exercise testing for the prediction of post-operative complications in non cardiopulmonary surgery: A systematic review

INTRODUCTION

Cardiopulmonary exercise testing (CPET) is widely used within the United Kingdom for preoperative risk stratification. Despite this, CPET's performance in predicting adverse events has not been systematically evaluated within the framework of classifier performance.

METHODS

After prospective registration on PROSPERO (CRD42018095508) we systematically identified studies where CPET was used to aid in the prognostication of mortality, cardiorespiratory complications, and unplanned intensive care unit (ICU) admission in individuals undergoing non-cardiopulmonary surgery. For all included studies we extracted or calculated measures of predictive performance whilst identifying and critiquing predictive models encompassing CPET derived variables.

RESULTS

We identified 36 studies for qualitative review, from 27 of which measures of classifier performance could be calculated. We found studies to be highly heterogeneous in methodology and quality with high potential for bias and confounding. We found seven studies that presented risk prediction models for outcomes of interest. Of these, only four studies outlined a clear process of model development; assessment of discrimination and calibration were performed in only two and only one study undertook internal validation. No scores were externally validated. Systematically identified and calculated measures of test performance for CPET demonstrated mixed performance. Data was most complete for anaerobic threshold (AT) based predictions: calculated sensitivities ranged from 20-100% when used for predicting risk of mortality with high negative predictive values (96-100%). In contrast, positive predictive value (PPV) was poor (2.9-42.1%). PPV appeared to be generally higher for cardiorespiratory complications, with similar sensitivities. Similar patterns were seen for the association of Peak VO2 (sensitivity 85.7-100%, PPV 2.7-5.9%) and VE/VCO2 (Sensitivity 27.8%-100%, PPV 3.4-7.1%) with mortality.

CONCLUSIONS

In general CPET's 'rule-out' capability appears better than its ability to 'rule-in' complications. Poor PPV may reflect the frequency of complications in studied populations. Our calculated estimates of classifier performance suggest the need for a balanced interpretation of the pros and cons of CPET guided pre-operative risk stratification.

Cardiopulmonary Exercise Testing for Preoperative Evaluation: What Does the Future Hold?

Purpose of Review

Cardiopulmonary exercise testing (CPET) informs the preoperative evaluation process by providing individualised risk profiles; guiding shared decision-making, comorbidity optimisation and preoperative exercise training; and informing perioperative patient management. This review summarises evidence on the role of CPET in preoperative evaluation and explores the role of novel and emerging CPET variables and alternative testing protocols that may improve the precision of preoperative evaluation in the future.

Recent Findings

CPET provides a wealth of physiological data, and to date, much of this is underutilised clinically. For example, impaired chronotropic responses during and after CPET are simple to measure and in recent studies are predictive of both cardiac and noncardiac morbidity following surgery but are rarely reported. Exercise interventions are increasingly being used preoperatively, and endurance time derived from a high intensity constant work rate test should be considered as the most sensitive method of evaluating the response to training. Further research is required to identify the clinically meaningful difference in endurance time. Measuring efficiency may have utility, but this requires exploration in prospective studies.

Summary

Further work is needed to define contemporaneous risk thresholds, to explore the role of other CPET variables in risk prediction, to better characterise CPET’s role in combination with other tools in multifactorial risk stratification and increasingly to evaluate CPET’s utility for preoperative exercise prescription in prehabilitation.

Perioperative exercise capacity in chronic liver injury patients with hepatocellular carcinoma undergoing hepatectomy

Dynamic assessment of preoperative exercise capacity may be a useful predictor of postoperative prognosis. We aimed to clarify whether perioperative exercise capacity was related to long-term survival in hepatocellular carcinoma patients with chronic liver injury undergoing hepatectomy. One hundred-six patients with hepatocellular carcinoma underwent pre- and postoperative cardiopulmonary exercise testing to determine their anaerobic threshold, defined as the point between carbon dioxide production and oxygen consumption per unit of time. Testing involved 35 items including blood biochemistry analysis, in-vivo component analysis, dual-energy X-ray absorptiometry, and cardiopulmonary exercise testing preoperatively and 6 months postoperatively. We classified patients with anaerobic threshold ≥ 90% 6 months postoperatively compared with the preoperative level as the maintenance group (n = 78) and patients with anaerobic threshold < 90% as the decrease group (n = 28). Five-year recurrence-free survival rates were 39.9% vs. 9.9% (maintenance vs. decrease group) (hazard ratio: 1.87 [95% confidence interval: 1.12–3.13]; P = 0.018). Five-year overall survival rates were maintenance: 81.9%, and decrease: 61.7% (hazard ratio: 2.95 [95% confidence interval: 1.37–6.33]; P = 0.006). Multivariable Cox proportional hazards models showed that perioperative maintenance of anaerobic threshold was an independent prognostic indicator for both recurrence-free- and overall survival. Although the mean anaerobic threshold from preoperative to postoperative month 6 decreased in the exercise-not-implemented group, the exercise-implemented group experienced increased anaerobic threshold, on average, at postoperative month 6. The significant prognostic factor affecting postoperative survival for chronic liver injury patients with HCC undergoing hepatectomy was maintenance of anaerobic threshold up to 6 months postoperatively.

Myosteatosis is associated with poor physical fitness in patients undergoing hepatopancreatobiliary surgery

BACKGROUND

Body composition assessment, measured using single-slice computed tomography (CT) image at L3 level, and aerobic physical fitness, objectively measured using cardiopulmonary exercise testing (CPET), are each independently used for perioperative risk assessment. Sarcopenia (i.e. low skeletal muscle mass), myosteatosis [i.e. low skeletal muscle radiation attenuation (SM-RA)], and impaired objectively measured aerobic fitness (reduced oxygen uptake) have been associated with poor post-operative outcomes and survival in various cancer types. However, the association between CT body composition and physical fitness has not been explored. In this study, we assessed the association of CT body composition with selected CPET variables in patients undergoing hepatobiliary and pancreatic surgery.

METHODS

A pragmatic prospective cohort of 123 patients undergoing hepatobiliary and pancreatic surgery were recruited. All patients underwent preoperative CPET. Preoperative CT scans were analysed using a single-slice CT image at L3 level to assess skeletal muscle mass, adipose tissue mass, and muscle radiation attenuation. Multivariate linear regression was used to test the association between CPET variables and body composition. Main outcomes were oxygen uptake at anaerobic threshold ( V̇ O₂ at AT), oxygen uptake at peak exercise ( V̇ O₂ peak), skeletal muscle mass, and SM-RA.

RESULTS

Of 123 patients recruited [77 men (63%), median age 66.9 ± 11.7, median body mass index 27.3 ± 5.2], 113 patients had good-quality abdominal CT scans available and were included. Of the CT body composition variables, SM-RA had the strongest correlation with V̇ O₂ peak (r = 0.57, P < 0.001) and V̇ O₂ at AT (r = 0.45, P < 0.001) while skeletal muscle mass was only weakly associated with V̇ O₂ peak (r = 0.24, P < 0.010). In the multivariate analysis, only SM-RA was associated with V̇ O₂ peak (B = 0.25, 95% CI 0.15-0.34, P < 0.001, R²  = 0.42) and V̇ O₂ at AT (B = 0.13, 95% CI 0.06-0.18, P < 0.001, R²  = 0.26).

CONCLUSIONS

There is a positive association between preoperative CT SM-RA and preoperative physical fitness ( V̇ O₂ at AT and at peak). This study demonstrates that myosteatosis, and not sarcopenia, is associated with reduced aerobic physical fitness. Combining both myosteatosis and physical fitness variables may provide additive risk stratification accuracy and guide interventions during the perioperative period.

Cardiopulmonary Exercise Testing and Surgery

The surgical patient population is increasingly elderly and comorbid and poses challenges to perioperative physicians. Accurate preoperative risk stratification is important to direct perioperative care. Reduced aerobic fitness is associated with increased postoperative morbidity and mortality. Cardiopulmonary exercise testing is an integrated and dynamic test that gives an objective measure of aerobic fitness or functional capacity and identifies the cause of exercise intolerance. Cardiopulmonary exercise testing provides an individualized estimate of patient risk that can be used to predict postoperative morbidity and mortality. This technology can therefore be used to inform collaborative decision-making and patient consent, to triage the patient to an appropriate perioperative care environment, to diagnose unexpected comorbidity, to optimize medical comorbidities preoperatively, and to direct individualized preoperative exercise programs. Functional capacity, evaluated as the anaerobic threshold and peak oxygen uptake ([Formula: see text]o₂peak) predicts postoperative morbidity and mortality in the majority of surgical cohort studies. The ventilatory equivalents for carbon dioxide (an index of gas exchange efficiency), is predictive of surgical outcome in some cohorts. Prospective cohort studies are needed to improve the precision of risk estimates for different patient groups and to clarify the best combination of variables to predict outcome. Early data suggest that preoperative exercise training improves fitness, reduces the debilitating effects of neoadjuvant chemotherapy, and may improve clinical outcomes. Further research is required to identify the most effective type of training and the minimum duration required for a positive effect.

Optimal perioperative care in peri-hilar cholangiocarcinoma resection

Surgical resection remains the only proven curative treatment for peri-hilar cholangiocarcinoma. Despite recent advances in liver surgery techniques and perioperative care, resection for peri-hilar cholangiocarcinoma remains associated with significant morbidity and mortality. Considerable variation in the perioperative management of these patients exists. Optimal perioperative management has the potential to deliver improved outcomes. This article seeks to summarize the evidence underpinning best practice in the perioperative care of patients undergoing resection of peri-hilar cholangiocarcinoma. The authors also seek to identify areas where research efforts and future clinical trials should be targeted.

Hepatectomy for octogenarians with colorectal liver metastasis in the era of enhanced recovery

BACKGROUND

Concern exists regarding the use of hepatectomy to treat colorectal liver metastasis (CRLM) in octogenarians due to prior studies suggesting elevated morbidity and mortality. Cardiopulmonary exercise testing (CPET) within pre-operative assessment and enhanced recovery after surgery (ERAS) have both been shown to be associated with low morbidity and mortality in patients undergoing hepatectomy. This study sought to compare the outcomes of octogenarians with patients aged 70-79 undergoing hepatectomy for CRLM, within a center utilizing both CPET and ERAS.

METHODS

Consecutive patients age 70 or older who underwent hepatectomy for CRLM at Aintree University Hospital (Liverpool,UK), between May 2008 and May 2015 were identified from a prospectively maintained cancer database. Data were extracted and comparisons drawn.

RESULTS

127 patients aged 70-79 years and 34 octogenarians underwent respectively 137 and 35 hepatectomy for CRLM. There was no difference in hospital stay (6 days), morbidity and mortality between the groups. OS at 1, 3 and 5 years were 86.7%, 55% and 35.8% for those aged 70-79 compared to 79.4%, 37.3% and 20.4% for the octogenarians (p=0.127). DFS at 1,3 and 5 years was 52.5%, 31.7% and 31.7% for 70-79 group compared to 46.2%, 31.5% and 16.8% for the octogenarians (p=0.838). On multivariate analysis major hepatectomy was associated with an increased risk of post-operative complications, inferior OS and DFS. Chronological age was not a predictor of postoperative complications, poorer OS or DFS.

CONCLUSIONS

Appropriately selected octogenarians can have similar postoperative outcomes to patients aged 70-79 when undergoing hepatectomy for CRLM using ERAS combined with CPET. This study advocates using CPET and ERAS in the selection and management of octogenarian patients with CRLM undergoing hepatectomy.

Comparison of risk-scoring systems in the prediction of outcome after liver resection

Background

Risk prediction techniques commonly used in liver surgery include the American Society of Anesthesiologists (ASA) grading, Charlson Comorbidity Index (CCI) and cardiopulmonary exercise tests (CPET). This study compares the utility of these techniques along with the number of segments resected as predictive tools in liver surgery.

Methods

A review of a unit database of patients undergoing liver resection between February 2008 and January 2015 was undertaken. Patient demographics, ASA, CCI and CPET variables were recorded along with resection size. Clavien-Dindo grade III–V complications were used as a composite outcome in analyses. Association between predictive variables and outcome was assessed by univariate and multivariate techniques.

Results

One hundred and seventy-two resections in 168 patients were identified. Grade III–V complications occurred after 42 (24.4%) liver resections. In univariate analysis of CPET variables, ventilatory equivalents for CO₂ (VEqCO₂) was associated with outcome. CCI score, but not ASA grade, was also associated with outcome. In multivariate analysis, the odds ratio of developing grade III–V complications for incremental increases in VEqCO₂, CCI and number of liver segments resected were 1.09, 1.49 and 2.94, respectively.

Conclusions

Of the techniques evaluated, resection size provides the simplest and most discriminating predictor of significant complications following liver surgery.

Colorectal Liver Metastases: A Critical Review of State of the Art

BACKGROUND

Over 50% of patients with colorectal cancer will develop liver metastases. Only a minority of patients present with technically resectable disease. Around 40% of those undergoing surgical resection are alive five years after their diagnosis compared with less than 1% for those with disseminated disease treated with systemic chemotherapy. Surgical resection remains the only possibility for long-term survival for these patients and great efforts have been made to increase the rates of resection whilst improving long-term outcomes.

SUMMARY

This review considers current technical and oncological criteria for resection, as well as targeted approaches to stratify underlying tumor biology in order to better predict long-term benefit. The role of neoadjuvant and perioperative systemic chemotherapy is critically reviewed, with suggestions for patient stratification in order to identify those who are likely to derive the greatest benefit. The key role of multidisciplinary assessment and decision making for these complex patients is also discussed.

KEY MESSAGES

Surgery remains the optimal treatment for colorectal liver metastases (CRLM). Despite the curative intent of surgical resection, the majority of patients develop recurrence. Surgical strategies should therefore be adopted to maximize the potential for repeat resections in the event of recurrence. Although a number of preoperative prognostic markers have been identified, none are absolute contraindications to resection. In order to reduce postoperative recurrence, neo-adjuvant chemotherapy is now the standard of care in a number of countries. The evidence base for this approach is contentious, and the potential benefit of such a strategy is likely to be greatest in patients with high oncological risk disease. Multidisciplinary care is essential to ensure the optimal management of these complex patients. In addition, all patients with CRLM should be discussed with specialist hepatobiliary surgeons.

Adherence to early mobilisation: Key for successful enhanced recovery after liver resection

BACKGROUND

Enhanced Recovery After Surgery (ERAS) has been proven effective in liver surgery. Adherence to the ERAS pathway is variable. This study seeks to evaluate adherence to key components of an ERAS protocol in liver resection, and identify the components associated with successful clinical outcomes.

METHOD

All patients undergoing liver resections for two consecutive years were included in our ERAS pathway. Six key components of ERAS included preoperative assessment, nutrition and gastrointestinal function, postoperative analgesia, mobilisation and discharges. Successful accomplishment of ERAS was defined as hospital discharge by postop day (POD) 6. Adherences of these elements were compared between the successful and un-successful groups.

RESULTS

During the studied period, 223 patients underwent liver resections, among which 103 had major hepatectomies. N = 147 patients (66%) were discharged within our ERAS protocol target (6 days). On multivariable analysis, sitting out of bed by POD 1 (p < 0.03), walking by POD 3 (p = 0.03), removal of urinary catheter by POD 3 (p < 0.01), and avoiding major complications (p < 0.01) were factors associated with successful completion to our ERAS protocol; whereas advanced age (p = 0.34) and discontinuation of PCA/epidural by POD 3 (p = 0.50) were not significant parameters. There was a significant difference in the length of stay (p < 0.01) following major and minor liver resection, of which the indications for surgery also varied significantly. There was no difference in hospital re-admission rate, and morbidity and mortality between major and minor liver resection.

CONCLUSIONS

Facilitating early mobilisation and reducing postoperative complications are keys to successful outcomes of ERAS in liver resection.

The impact of cardiopulmonary exercise testing on patients over the age of 80 undergoing elective colorectal cancer surgery

AIM

Advanced age and occult cardiorespiratory disease are associated with increased morbidity and mortality following surgery. Cardiopulmonary exercise testing (CPET) may allow the identification of high-risk patients and facilitate planned postoperative critical care support. The aim of this study was to determine whether preoperative CPET in patients aged over 80 undergoing elective colorectal cancer resection was associated with improved outcome.

METHOD

All patients aged 80 years and above undergoing elective colorectal cancer resection between 1 March 2011 and 1 September 2013 were retrospectively analysed. Referral for CPET testing was at the discretion of the operating surgeon. Postoperative critical care unit (CCU) admission was based upon the CPET results.

RESULTS

Ninety-four patients were identified, of whom 48 underwent CPET testing. The CPET group were significantly older than the non-CPET group (85 vs 83 years, P = 0.04) and were more likely to have a planned admission to CCU postoperatively (P < 0.0001). Despite the increased use of CCU resources, the overall CCU length of stay (LOS) in the CPET group did not differ from the non-CPET group, but the non-CPET group had a higher proportion of Level-3 care. There were no differences in the incidence of unplanned CCU admission between the CPET and the non-CPET group (P = 0.23). There were no differences in overall LOS between the two groups (P = 0.42). There was no difference in mortality (P = 0.11), overall complications (P = 0.53) or severe complications (P = 0.3).

CONCLUSION

Preoperative CPET testing in patients aged over 80 undergoing elective colorectal cancer resection allows identification of higher-risk patients and mitigation of risk by preemptive admission to a CCU. This stratification allows equivalent results to be achieved in high- and low-risk elderly patients undergoing colorectal surgery.

Randomized clinical trial of prehabilitation before planned liver resection

BACKGROUND

Patients with low fitness as assessed by cardiopulmonary exercise testing (CPET) have higher mortality and morbidity after surgery. Preoperative exercise intervention, or prehabilitation, has been suggested as a method to improve CPET values and outcomes. This trial sought to assess the capacity of a 4-week supervised exercise programme to improve fitness before liver resection for colorectal liver metastasis.

METHODS

This was a randomized clinical trial assessing the effect of a 4-week (12 sessions) high-intensity cycle, interval training programme in patients undergoing elective liver resection for colorectal liver metastases. The primary endpoint was oxygen uptake at the anaerobic threshold. Secondary endpoints included other CPET values and preoperative quality of life (QoL) assessed using the SF-36®.

RESULTS

Thirty-eight patients were randomized (20 to prehabilitation, 18 to standard care), and 35 (25 men and 10 women) completed both preoperative assessments and were analysed. The median age was 62 (i.q.r. 54-69) years, and there were no differences in baseline characteristics between the two groups. Prehabilitation led to improvements in preoperative oxygen uptake at anaerobic threshold (+1·5 (95 per cent c.i. 0·2 to 2·9) ml per kg per min) and peak exercise (+2·0 (0·0 to 4·0) ml per kg per min). The oxygen pulse (oxygen uptake per heart beat) at the anaerobic threshold improved (+0·9 (0·0 to 1·8) ml/beat), and a higher peak work rate (+13 (4 to 22) W) was achieved. This was associated with improved preoperative QoL, with the overall SF-36® score increasing by 11 (95 per cent c.i. 1 to 21) (P = 0·028) and the overall SF-36® mental health score by 11 (1 to 22) (P = 0·037).

CONCLUSION

A 4-week prehabilitation programme can deliver improvements in CPET scores and QoL before liver resection. This may impact on perioperative outcome.

REGISTRATION NUMBER

NCT01523353 (https://clinicaltrials.gov).

Cardiopulmonary exercise testing for predicting postoperative morbidity in patients undergoing hepatic resection surgery

OBJECTIVES

Cardiopulmonary exercise testing (CPET) may predict which patients are at risk for adverse outcomes after major abdominal surgery. The primary aim of this study was to determine whether CPET variables are predicative of morbidity.

METHODS

High-risk patients undergoing elective, one-stage, open hepatic resection were preoperatively assessed using CPET. Morbidity, as defined by the Postoperative Morbidity Survey (POMS), was assessed on postoperative day 3.

RESULTS

A total of 104 patients underwent preoperative CPET and were included in the analysis. Of these, 73 patients (70.2%) experienced postoperative morbidity. Oxygen consumption at anaerobic threshold (V˙O2 at AT, ml/kg/min) was the only CPET predictor of postoperative morbidity on multivariable analysis, with an area under the curve (AUC) of 0.66 [95% confidence interval (CI) 0.55-0.76]. In patients requiring a major hepatic resection (three or more segments), a V˙O2 at AT of <10.2 ml/kg/min gave an AUC of 0.79 (95% CI 0.68-0.86) with 83.9% sensitivity and 52.0% specificity, 80.6% positive predictive value and 62.5% negative predictive value.

CONCLUSIONS

The application of a cut-off value for V˙O2 at AT of <10.2 ml/kg/min in patients undergoing major hepatic resection may be useful for predicting which patients will experience morbidity.

Clinical assessment before hepatectomy identifies high-risk patients

BACKGROUND

Liver resection is associated with significant morbidity, and assessment of risk is an important part of preoperative consultations. Objective methods exist to assess operative risk, including cardiopulmonary exercise testing (CPX). Subjective assessment is also made in clinic, and patients perceived to be high-risk are referred for CPX at our institution. This article addresses clinicians' ability to identify patients with a higher risk of surgical complications after hepatectomy, using selection for CPX as a surrogate marker for increased operative risk.

MATERIALS AND METHODS

Prospectively collected data on patients undergoing hepatectomy between February 2008 and November 2013 were retrieved and the cohort divided according to CPX referral. Complications were classified using the Clavien-Dindo system.

RESULTS

CPX testing was carried out before 101 of 405 liver resections during the study period. The median age was 72 and 64 in CPX and non-CPX groups, respectively (P < 0.001). The resection size was similar between the groups. No difference was noted for grade III complications between CPX and non-CPX tested-groups; however, 19 (18.8%) and 28 (9.2%) patients suffered grade IV-V complications, respectively (P = 0.009). There was no difference in long-term survival between groups (P = 0.63).

CONCLUSIONS

This study attempts to assess clinicians' ability to identify patients at greater risk of complications after hepatectomy. The confirmation that patients identified in this way are at greater risk of grade IV-V complications demonstrates the value of preoperative counseling. High-risk patients do not have worse long-term outcomes suggesting survival is determined by other factors, particularly disease recurrence.