Cardiopulmonary exercise testing for preoperative risk assessment before hepatic resection

Pre-operative subjective functional capacity and postoperative outcomes in adult non-cardiac surgery: a systematic review and meta-analysis

INTRODUCTION

Assessment of functional capacity is an essential part of peri-operative risk stratification. Subjective functional capacity is easier to examine than objective tests of patient fitness. However, the association between subjective functional capacity and postoperative outcomes has not been established.

METHODS

Four databases were searched for studies describing the associations between subjective functional capacity and postoperative outcomes in adults undergoing non-cardiac surgery. Meta-analysis was conducted among studies where functional capacity was expressed in metabolic equivalents. The primary outcome was postoperative major adverse cardiovascular events. Secondary outcomes were mortality and postoperative overall complications. We estimated the ORs of the outcomes in patients with poor functional capacity (< 4 metabolic equivalents) as compared with those with good functional capacity (≥ 4 metabolic equivalents). Random-effects models were used for the meta-analysis.

RESULTS

We identified 7835 abstracts. After screening and a full-text review, 23 studies were selected. Evaluation methods of functional capacity included: questionnaires (n = 7); specific questions (n = 6); and subjective assessment by anaesthetists (n = 5). The probability of major postoperative adverse cardiovascular events was significantly higher in patients with poor functional capacity (OR 1.84, 95%CI 1.62-2.08) than in those with good functional capacity. Patients with poor functional capacity also had higher odds of mortality (OR 2.48, 95%CI 1.45-4.25) and postoperative complications (OR 1.85, 95%CI 1.34-2.55).

DISCUSSION

Subjective functional capacity of < 4 metabolic equivalents was associated with postoperative complications including cardiovascular events and other serious outcomes. The results need to be interpreted with caution due to the diverse measures used to assess functional capacity.

Advanced Liver Fibrosis Impairs Cardiorespiratory Fitness in Patients with Metabolic Dysfunction-Associated Steatotic Liver Disease

BACKGROUND

MASLD is a leading reason for liver transplant waitlisting. The relationship between cardiorespiratory fitness (CRF) and liver fibrosis in patients with MASLD remains unclear. This study aims to provide further evidence supporting the relationship between liver fibrosis and CRF.

METHODS

Participants with MASLD across various fibrosis stages, including those with cirrhosis awaiting liver transplantation from three U.S. transplant centers, underwent cardiopulmonary exercise testing (CPX). We compared participants based on fibrosis stage (F0-F1, F2-F3, and F4) and CPX parameters such as VO2peak, respiratory exchange ratio (RER), ventilatory efficiency (VE/VCO2), double product (DP) and chronotropic incompetence (CI). Multivariable models were then built to evaluate factors associated with these parameters.

RESULTS

Sixty-one participants underwent CPX testing across three centers. Participants with F4 had lower VO2peak (11.8 mL/kg/min) compared to F0-F1 (22.2 mL/kg/min) and F2-F3 (22.9 mL/kg/min), p < 0.001. Participants with F4 had higher RER (median 1.25) compared to F0-F1 (1.08) and F2-F3 (1.05), p = 0.001. Similarly, F4 participants exhibited higher VE/VCO2 (median 36.5) compared to F0-F1 (31) and F2-F3 (30), p < 0.001. Additionally, F4 participants had lower DP values (median 17,696) compared to F0-F1 (25,460) and F2-F3 (25,372), and higher prevalence of CI (90%) compared to F0-F1 (39%) and F2-F3 (25%), both p =  < 0.001. Multivariable modeling confirmed advanced fibrosis (F > 3) as an independent predictor of low CRF.

CONCLUSIONS

In MASLD patients, advanced liver fibrosis, particularly cirrhosis, is associated with reduced CRF and poorer hemodynamic performance during CPX. Prioritizing exercise training for those in earlier stages (F3) may prevent fitness decline, which could hinder physical training and liver transplantation candidacy.

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).

Risk factors for failure to rescue after hepatectomy in a high-volume UK tertiary referral center

BACKGROUND

Mortality after severe complications after hepatectomy (failure to rescue) is strongly linked to center volume. The aim of this study was to evaluate the risk factors for failure to rescue after hepatectomy in a high-volume center.

METHODS

Retrospective study of 1,826 consecutive patients who underwent hepatectomy from 2011 to 2018. The primary outcome was a 90-day failure to rescue, defined as death within 90 days posthepatectomy after a severe (Clavien-Dindo grade 3+) complication. Risk factors for 90-day failure to rescue were evaluated using a multivariable binary logistic regression model.

RESULTS

The cohort had a median age of 65.3 years, and 56.6% of patients were male. The commonest indication for hepatectomy was colorectal metastasis (58.9%), and 46.9% of patients underwent major or extra-major hepatectomy. Severe complications developed in 209 patients (11.4%), for whom the 30- and 90-day failure to rescue rates were 17.0% and 35.4%, respectively. On multivariable analysis, increasing age (P = .006) and modified Frailty Index (P = .044), complication type (medical or combined medical/surgical versus surgical; P < .001), and body mass index (P = .018) were found to be significant independent predictors of 90-day failure to rescue.

CONCLUSION

Older and frail patients who experience medical complications are particularly at risk of failure to rescue after hepatectomy. These results may inform preoperative counseling and may help to identify candidates for prehabilitation. Further study is needed to assess whether failure to rescue rates could be reduced by perioperative interventions.

Recovery of surgery in the elderly (ROSE) program: The efficacy of a multi-modal prehabilitation program implemented in frail and pre-frail elderly undergoing major abdominal surgery

BACKGROUND

Major abdominal surgery is associated with a high rate of post-operative complications with increased risk of adverse surgical outcomes due to the presence of frailty. This study aims to evaluate the effectiveness of the multimodal Recovery of Surgery in the Elderly (ROSE) prehabilitation program with supervised exercise in mitigating postoperative functional decline when compared to standard care.

METHOD

The ROSE program enrolled ambulant patients who were 65 years and above, had a Clinical Frailty Scale score of 4 or more and were planned for major abdominal surgery. Participation in supervised exercise sessions before surgery were compared with standard physiotherapy advice. The primary outcome was 6-min walk test (6MWT) distance assessed at baseline, after prehabilitation and 30 days follow-up after surgery. Secondary outcomes included physical performance, length of hospital stay and postoperative morbidity.

RESULTS

Data from 74 eligible patients, 37 in each group, were included. Median age was 78 years old. Forty-two patients (22 in Prehab group and 20 in control group) with complete 6MWT follow-up data at 30 days follow-up were analysed for outcomes. Most patients underwent laparoscopic surgery (63.5%) and almost all of the surgeries were for abdominal malignancies (97.3%). The Prehab group had an increase in 6MWT distance at the 30-day follow up, from a baseline mean (SD) of 277.4 (125) m to 287.6 (143.5) m (p = 0.415). The 6MWT distance in the control group decreased from a baseline mean (SD) of 281.7 (100.5) m to 260.1 (78.6) m at the 30-day follow up (p = 0.086). After adjusting for baseline 6MWT distance and frailty score, the Prehab group had significantly higher 6MWT distance at 30-day follow-up than control (difference in adjusted means 41.7 m, 95% confidence interval 8.7-74.8 m, p = 0.015). There were no significant between-group differences in the secondary outcomes.

CONCLUSION

A multimodal prehabilitation program with supervised exercise within a short time frame can improve preoperative functional capacity and maintain baseline functional capacity in frail older adults undergoing major abdominal surgery.

Sex-related differences in functional capacity and its implications in risk stratification before major non-cardiac surgery: a post hoc analysis of the international METS study

Background

Poor functional capacity has been identified as an important modifiable risk factor for postoperative complications. Cardiopulmonary exercise testing (CPET) provides objective parameters of functional capacity (e.g., oxygen consumption at peak exercise, peak VO2), with significant prognostication for postoperative complications. However, sex-specific thresholds for functional capacity to predict surgical risk are yet to be established. Therefore, we performed a post hoc analysis of the international, multicentre, prospective observational METS (Measurement of Exercise Tolerance before Surgery) study to evaluate if sex-specific thresholds of peak VO2 improve risk prediction of postoperative complications.

Methods

We undertook a post hoc analysis (HREC/71824/PMCC) of the METS study, which was performed between March 2013 and March 2016. We investigated whether sex-specific differences exist for CPET-derived parameters and associated thresholds for predicting postoperative complications in this large cohort of patients that had major non-cardiac surgery (n = 1266). Logistic regression models were analyzed for the association of low peak VO2 with moderate-to-severe in-hospital postoperative complications. Optimal sex-specific peak VO2 thresholds were obtained by maximizing the Youden index of receiver operating characteristic (ROC) curves. Finally, multivariable logistic regression models tested the resulting sex-specific thresholds against the established non-sex-specific peak VO2 threshold (14 mL kg-1 min-1) adjusted for clinically relevant features such as comorbidities and surgical complexity. Models were evaluated by bootstrapping optimism-corrected area under the ROC curve and the net reclassification improvement index (NRI).

Findings

Female patients (n = 480) had a lower mean (SD) peak VO2 than males (16.7 (4.9) mL kg-1 min-1 versus 21.2 (6.5) mL kg-1 min-1, p < 0.001) and a lower postoperative complication rate (10.4% versus 15.3%; p = 0.018) than males (n = 786). The optimal peak VO2 threshold for predicting postoperative complications was 12.4 mL kg-1 min-1 for females and 22.3 mL kg-1 min-1 for males, respectively. In the multivariable regression model, low non-sex-specific peak VO2 did not independently predict postoperative complications. In contrast, low sex-specific peak VO2 was an independent predictor of postoperative complications (OR 2.29; 95% CI: 1.60, 3.30; p < 0.001). The optimism-corrected AUC-ROC of the sex-specific model was higher compared with the non-sex-specific model (0.73 versus 0.7; DeLong's test: p = 0.021). The sex-specific model classified 39% of the patients more correctly than the baseline model (NRI = 0.39; 95% CI: 0.24, 0.55). In contrast, the non-sex-specific model only classified 9% of the patients more correctly when compared against the baseline model (NRI = 0.09; 95% CI: -0.04, 0.22).

Interpretation

Our data report sex-specific differences in preoperative CPET-derived functional capacity parameters. Sex-specific peak VO2 thresholds identify patients at increased risk for postoperative complications with a higher discriminatory ability than a sex-unspecific threshold. As such, sex-specific threshold values should be considered in preoperative CPET to potentially improve risk stratification and to guide surgical decision-making, including eligibility for surgery, preoperative optimization strategies (prehabilitation) or seeking non-surgical options.

Funding

There was no funding for the present study. The original METS study was funded by Canadian Institutes of Health Research, Heart and Stroke Foundation of Canada, Ontario Ministry of Health and Long-Term Care, Ontario Ministry of Research, Innovation and Science, UK National Institute of Academic Anaesthesia, UK Clinical Research Collaboration, Australian and New Zealand College of Anaesthetists, and Monash University.

Multisocietal European consensus on the terminology, diagnosis, and management of patients with synchronous colorectal cancer and liver metastases: an E-AHPBA consensus in partnership with ESSO, ESCP, ESGAR, and CIRSE

BACKGROUND

Contemporary management of patients with synchronous colorectal cancer and liver metastases is complex. The aim of this project was to provide a practical framework for care of patients with synchronous colorectal cancer and liver metastases, with a focus on terminology, diagnosis, and management.

METHODS

This project was a multiorganizational, multidisciplinary consensus. The consensus group produced statements which focused on terminology, diagnosis, and management. Statements were refined during an online Delphi process, and those with 70 per cent agreement or above were reviewed at a final meeting. Iterations of the report were shared by electronic mail to arrive at a final agreed document comprising 12 key statements.

RESULTS

Synchronous liver metastases are those detected at the time of presentation of the primary tumour. The term 'early metachronous metastases' applies to those absent at presentation but detected within 12 months of diagnosis of the primary tumour, the term 'late metachronous metastases' applies to those detected after 12 months. 'Disappearing metastases' applies to lesions that are no longer detectable on MRI after systemic chemotherapy. Guidance was provided on the recommended composition of tumour boards, and clinical assessment in emergency and elective settings. The consensus focused on treatment pathways, including systemic chemotherapy, synchronous surgery, and the staged approach with either colorectal or liver-directed surgery as first step. Management of pulmonary metastases and the role of minimally invasive surgery was discussed.

CONCLUSION

The recommendations of this contemporary consensus provide information of practical value to clinicians managing patients with synchronous colorectal cancer and liver metastases.

Facility Volume Thresholds for Optimization of Short- and Long-Term Outcomes in Patients Undergoing Hepatectomy for Primary Liver Tumors

BACKGROUND

Volume-outcome relationships have been described for a variety of surgical procedures. We aimed to define the facility volume threshold at which postoperative mortality after hepatectomy was optimal.

METHODS

We determined volume percentiles for institutions performing hepatectomy for any primary liver tumor within the National Cancer Database (2004-2017). Marginal structural logistic regression defined the volume percentile (Vmin) at which the odds of 90-day mortality were optimally reduced in patients with hepatocellular carcinoma (HCC) or intrahepatic cholangiocarcinoma (ICC). Short-term postoperative and survival outcomes were compared between patients treated at facilities above and below Vmin.

RESULTS

Thresholds for the 10^th/25^th/50^th/75^th/90^th percentiles were 2/7/26/46/59 hepatectomies/year. A total of 17,833 patients underwent resection of HCC or ICC. The 90-day postoperative mortality was optimized at the 75^th percentile for all hepatectomies (IP-weighted OR = 0.67, 95% CI = 0.52-0.87) and major hepatectomy (IP-weighted OR = 0.62, 95% CI = 0.49-0.80). Seven of 446 facilities met the Vmin threshold. The odds of 30-day mortality were also reduced for all hepatectomies (IP-weighted OR = 0.55, 95% CI = 0.42-0.73) and major hepatectomy (IP-weighted OR = 0.58, 95% CI = 0.41-0.75). There were no differences in length of stay or 30-day readmission rate. Patients with HCC or ICC treated at facilities ≥ 10^th percentile had an associated improvement in overall survival.

CONCLUSIONS

Resection of HCC and ICC is performed at a large number of facilities. Postoperative mortality is optimally reduced at facilities performing at least 46 liver operations annually. Regionalization of surgical care among patients with primary liver malignancies to high-volume centers may result in improved outcomes.

The Marsden Morbidity Index: the derivation and validation of a simple risk index scoring system using cardiopulmonary exercise testing variables to predict morbidity in high-risk patients having major cancer surgery

Background

Morbidity and mortality risk prediction tools are increasingly being used as part of preoperative assessment of patients presenting for major abdominal surgery. Cardiopulmonary exercise testing (CPET) can predict which patients undergoing major abdominal surgery are at risk of complications. The primary objective of this study was to identify preoperative variables including those derived from CPET, which were associated with inpatient morbidity in high-risk patients following major abdominal cancer surgery. The secondary objective was to use these variables to derive and validate a morbidity risk prediction tool.

Methods

We conducted a retrospective cohort analysis of consecutive adult patients who had CPET as part of their preoperative work-up for major abdominal cancer surgery. Morbidity was a composite outcome, defined by the Clavien-Dindo score and/or the postoperative morbidity survey (POMS) score which was assessed on postoperative day 7. A risk prediction tool was devised using variables from the first analysis which was then applied prospectively to a matched cohort of patients.

Results

A total of 1398 patients were included in the first phase of the analysis between June 2010 and May 2017. Of these, 540 patients (38.6%) experienced postoperative morbidity. CPET variables deemed significant (p < 0.01) were anaerobic threshold (AT), maximal oxygen consumption at maximal exercise capacity (VO2 max), and ventilatory equivalent for carbon dioxide at anaerobic threshold (AT VE/VCO2). In addition to the CPET findings and the type of surgery the patient underwent, eight preoperative variables that were associated with postoperative morbidity were identified. These include age, WHO category, body mass index (BMI), prior transient ischaemic attack (TIA) or stroke, chronic renal impairment, diabetes mellitus, chronic obstructive pulmonary disease (COPD), and cancer stage. Both sets of variables were then combined to produce a validated morbidity risk prediction scoring tool called the Marsden Morbidity Index. In the second phase of the analysis, this tool was applied prospectively to 424 patients between June 2017 and December 2018. With an area under the curve (AUC) of 0.79, this new model had a sensitivity of 74.2%, specificity of 78.1%, a positive predictive value (PPV) of 79.7%, and a negative predictive value of (NPV) of 79%.

Conclusion

Our study showed that of the CPET variables, AT, VO2 max, and AT VE/VCO2 were shown to be associated with postoperative surgical morbidity following major abdominal oncological surgery. When combined with a number of preoperative comorbidities commonly associated with increased risk of postoperative morbidity, we created a useful institutional scoring system for predicting which patients will experience adverse events. However, this system needs further validation in other centres performing oncological surgery.

Work-Up and Outcome of Hepatic Resection for Peri-Hilar Cholangiocarcinoma (PH-CCA) without Staging Laparoscopy

Simple Summary

This is a single centre cohort of patients undergoing surgery for PH-CCA suggests that routine staging laparoscopy may not be necessary in the pre-operative work-up.

Abstract

Background: This study reports the outcome of a work-up programme for resection of peri-hilar cholangiocarcinoma (PH-CCA) without the use of staging laparoscopy. Methods: This is a clinical case cohort series of patients undergoing surgical resection of PH-CCA without the use of staging laparoscopy in the work-up algorithm. During the 13 years from 1 January 2009 to 1 January 2022, 32 patients underwent laparotomy for planned surgical resection of PH-CCA. Data were collected on demographic profile, admission biochemistry, radiology, pre-operative intervention, operation and outcome, together with post-operative complications and disease-free and overall survival. Results: All patients underwent pre-operative contrast-enhanced CT. Twenty-four (75%) underwent pre-operative MR. Twenty-three (72%) underwent pre-operative biliary drainage. Twenty-nine patients (91%) had either type III or IV peri-hilar cholangiocarcinoma. One patient (3%) in this series underwent a non-resectional laparotomy. Twenty-nine (91%) had a final histopathological diagnosis of PH-CCA. One further patient had a final diagnosis of an intraductal papillary neoplasm of the biliary tree (IPNB) with high-grade dysplasia but no invasive cancer. Eleven patients (36%) received chemotherapy after surgery. The median (95% CI) time to recurrence was 14 (7–31) months. The median survival was 25 (18-upper limit not reached) months. Conclusion: This cohort of 32 patients undergoing attempted resection for PH-CCA without the use of staging laparoscopy in the work-up algorithm indicates that with careful attention to patient fitness and cross-sectional and interventional radiologic/endoscopic imaging, a very low non-therapeutic laparotomy rate of 3% can be achieved and sustained.

Anaesthesia for Hepatic Resection Surgery

This article will focus on the perioperative management of hepatic resection for colorectal cancer (CRC) liver metastases (CLRMs) (the liver is the dominant metastatic site for CRC) within the context of the Enhanced Recovery After Surgery (ERAS) paradigm. It discusses the epidemiology and outcomes along with the history of hepatic resection surgery and pertinent anatomy. The discussion of the preoperative phase includes patient selection, assessment of liver functional status, and new developments in prehabilitation. The intraoperative phase details developments in surgical and anesthetic techniques to minimize liver hemorrhage and reduce the risk of postoperative hepatic failure. Newer analgesic options are included. Management of potential complications is outlined in the postoperative section followed by a description of current evidence for ERAS and future directions.

Cardiopulmonary Exercise Testing and Other Tests of Functional Capacity

Purpose of Review

Assessment of functional capacity is a cornerstone of preoperative risk assessment. While subjective clinician assessment of functional capacity is poorly predictive of postoperative outcomes, other objective functional assessment measures may provide more useful information.

Recent Findings

Cardiopulmonary exercise testing (CPET) is generally accepted as the gold standard for functional capacity assessment. However, CPET is resource-intensive and not universally available. Simpler objective tests of functional capacity such as the Duke Activity Status Index (DASI) and the 6-min walk test (6MWT) are cheap and efficient. In addition, they predict important postoperative outcomes including death, disability, and myocardial infarction.

Summary

Simple preoperative tests such as the DASI may be useful for routine preoperative assessment. CPET may be helpful to investigate further patients with functional status limitation, and to guide prehabilitation and perioperative shared decision-making in high-risk patients.

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.

The effect of prehabilitation on postoperative complications and postoperative hospital stay in hepatopancreatobiliary surgery a systematic review

BACKGROUND

Increasing numbers of high-risk (older and/or frail) patients are undergoing hepatopancreatobiliary (HPB) surgery. Therefore, optimization of the patient's psychophysiological capacity by prehabilitation is rapidly gaining importance. The aim of this study was to collect all available evidence on prehabilitation in HPB surgery and determine its effects on postoperative complications and length of hospital stay.

METHODS

A systematic review was performed according to PRISMA guidelines. The electronic databases MEDLINE, Web of Science, Embase, CENTRAL, clinicaltrials.gov, and the international clinical trials registry platform (ICTRP) were searched from inception to April 2020. Methodological quality of included studies was assessed using the Cochrane Collaboration's tool for assessing risk of bias and the ROBINS-I tool.

RESULTS

Seven articles including a total of 1377 patients were included in the quality analysis. A trend towards less complications and a shorter hospital stay was seen in the prehabilitation group, but current evidence fails to demonstrate a statistically significant difference between groups. Risk of bias in included studies was variable, and was generally scored as moderate.

CONCLUSION

Strong evidence for the beneficial effect of prehabilitation on clinical outcomes in HPB surgery is lacking. A trend towards less complications and shorter hospital stay was seen in the prehabilitation group.

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.

Wearables, Physical Activity, and Exercise Testing in Liver Disease

Physical inactivity is a major cause of deterioration in all forms of advanced liver disease. It is especially important as a driver of the components of the metabolic syndrome, with nonalcoholic fatty liver disease rapidly becoming the dominant cause of liver-related death worldwide. Growing realization of the health benefits of moderate-to-vigorous physical activity has captured the interest of persons who desire to improve their health, including those at risk for chronic liver injury. They are increasingly adopting wearable activity trackers to measure the activity that they seek to improve. Improved physical activity is the key lifestyle behavior that can improve cardiorespiratory fitness, which is most accurately measured with cardiopulmonary exercise testing (CPET). CPET is showing promise to identify risk and predict outcomes in transplant hepatology. Team effort among engaged patients, social support networks, and clinicians supported by web-based connectivity is needed to fully exploit the benefits of physical activity tracking.

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.

Enhanced recovery after surgery programmes in older patients undergoing hepatopancreatobiliary surgery: what benefits might prehabilitation have?

Due to an aging population and the related growing number of less physically fit patients with multiple comorbidities, adequate perioperative care is a new and rapidly developing clinical science that is becoming increasingly important. This narrative review focuses on enhanced recovery after surgery (ERAS®) programmes and the growing interest in prehabilitation programmes to improve patient- and treatment-related outcomes in older patients undergoing hepatopancreatobiliary (HPB) surgery. Future steps required in the further development of optimal perioperative care in HPB surgery are also discussed. Multidisciplinary preoperative risk assessment in multiple domains should be performed to identify, discuss, and reduce risks for optimal outcomes, or to consider alternative treatment options. Prehabilitation should focus on high-risk patients based on evidence-based cut-off values and should aim for (partly) supervised multimodal prehabilitation tailored to the individual patient's risk factors. The program should be executed in the living context of these high-risk patients to improve the participation rate and adherence, as well as to involve the patient's informal support system. Developing tailored (multimodal) prehabilitation programmes for the right patients, in the right context, and using the right outcome measures is important to demonstrate its potential to further improve patient- and treatment-related outcomes following HPB 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.

Prehabilitation: how to prepare our patients for elective major abdominal surgeries?

Surgical approach is the main form of treatment for several diseases of the abdominal cavity. However, surgical procedure itself is a stressor that may lead to adverse effects unrelated to the treatment goal. Prehabilitation has emerged as a multifactorial preoperative health conditioning program, which promotes improvement in functional capacity and postoperative evolution. The present study reviews literature using MEDLINE, Ovid, Google Scholar, and Cochrane databases in order to determine the concept of prehabilitation program and the indications and means of patient selection for it, as well as to suggest ways to implement this program in cases of major abdominal surgeries.

The association between preoperative physical functioning and short-term postoperative outcomes: a cohort study of patients undergoing elective hepatic resection

BACKGROUND

This study evaluated the association between practical performance-based indices of preoperative physical functioning and short-term postoperative outcomes in patients undergoing hepatic resection.

METHOD

Preoperative characteristics and results of practical performance-based tests of physical functioning were analyzed concerning the effect on postoperative outcomes (recovery of physical functioning, non-surgical complications, and length of hospital stay) using univariable and multivariable logistic regression.

RESULTS

Perioperative data of 96 patients showed that besides the conventional risk-factors (American Society of Anesthesiologists grade III and BMI), lower absolute steep ramp test performance (in watts; OR 0.992), and lower perceived level of functional capacity to perform activities of daily living (ADL) on Duke activity status index (in metabolic equivalent of task (MET); OR 0.806) and lower score on the veterans-specific activity questionnaire (in MET, OR 0.875) were associated with delayed recovery of physical functioning. Furthermore, more comorbidities, worse functional mobility, and lower levels of perceived functional capacity to perform ADL were associated with non-surgical complications and length of hospital stay.

CONCLUSION

Adequate preoperative performance and perceived level of functional capacity to perform ADL appear to be of importance to identify individual patients that are at risk of a complicated postoperative course.

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.

CPET and cardioesophagectomy: A single centre 10-year experience

INTRODUCTION

CPET is a routine investigation prior to cardioesophagectomy. Over a 10-year period 200 patients had CPET before elective cardioesophagectomy. We examine the relationship between CPET and outcomes in these patients.

MATERIALS AND METHODS

Complication data were prospectively collected using the Clavien-Dindo system. Logistic regression analysis was used to determine whether 90-day mortality and morbidity were significantly different between fitter and less fit patients.

RESULTS

90-day mortality was 5.5%. In univariate analysis the following factors were associated with a significantly increased risk of death at 90 days: anaerobic threshold <11 ml kg^-1 min^-1 OR (95% CI) = 4.38 (1.23,15.6), p = 0.023; V̇O2 peak <15 ml kg^-1 min^-1 O₂ OR (95% CI) = 5.0 (1.42,15.55), p = 0.012; V̇E/V̇CO₂ > 34 OR (95% CI) = 4.07 (1.19,14.0), p = 0.026; diabetes mellitus OR (95% CI) = 5.76 (1.55,21.35) p = 0.009. In multivariate logistic regression analysis both diabetes (OR = 5.76 [1.55,21.4] p = 0.009) and presence of ≥ 1 subthreshold CPET value (OR = 6.72 [1.32,29.8] p = 0.021) were significantly associated with increased risk of death at 90 days. Median (95% CI) survival for patients who had a CPET with 'normal' parameters was 1176 (565, 1787) days, compared with 642 (336, 948) days for patients with ≥ one subthreshold parameter. 15.5% of patients had ECG ischaemia; there were no deaths in this group.

CONCLUSION

Presence of at least one sub-threshold CPET value at pre-operative testing is associated with increased risk of 90-day mortality and shorter long term survival. These results allow us to better define risks during shared decision-making with patients.

[Preconditioning prior to visceral oncological surgery : A paradigm shift in visceral surgery?]

BACKGROUND

Postoperative complications after complex visceral oncological surgery can lead to substantial impairment of patients. In addition, preoperative physical performance and the severity of postoperative complications determine the long-term recovery process of physical function. Therefore, preconditioning in the preoperative period should be an important part of the preoperative/neoadjuvant treatment.

OBJECTIVE

The aim of this article is a critical appraisal of current concepts of prehabilitation as well as their development potential and applicability in visceral surgery.

MATERIAL AND METHODS

Based on a selective literature review, current studies and implemented concepts are presented and therapy algorithms are provided.

RESULTS

This study differs in primary outcome, design and temporal framework of the intervention. The study results showed positive effects of an active increase in physical fitness in the preoperative period with respect to the quality of life, convalescence and postoperative pulmonary complication rate.

DISCUSSION

In addition to the assessment of the individual risk of complications by means of spiroergometry, a targeted nutrition and exercise program can increase the individual performance level prior to visceral surgery and, thus, influence the postoperative risk of complications. The performance should be understood as a modifiable risk factor, which can also be positively influenced in the preoperative phase, even in a short time period. Individual preoperative care optimizes the physical and psychological situation of patients. To ensure the required individual care, approaches must be created and pursued, which can be implemented in a decentralized way.

Interobserver variability of ventilatory anaerobic threshold in asymptomatic volunteers

Background

The ventilatory anaerobic threshold (VO₂@AT) has been used in preoperative risk assessment and rehabilitation for many years. Our aim was to determine the interobserver variability of AT using cardiopulmonary exercise (CPET) data from a large epidemiological study (SHIP, Study of Health in Pomerania).

Methods

VO₂@AT was determined from CPET of 1,079 cross-sectional volunteers, according to American Heart Association guidelines. VO₂@AT determinations were compared between two experienced physicians, between physicians and qualified medical assistants, and between physicians or medical assistants and software-based algorithms. For the first 522 data sets, the two physicians discussed discrepant readings to reach consensus; the remaining data sets were analyzed without consensus discussion.

Results

VO₂@AT was detectable in 1,056 data sets. The physicians recorded identical VO₂@AT values in 319 out of 522 cases before consensus discussion (61.1%; intraclass correlation coefficient [ICC]: 0.90; 95% confidence interval [CI]: 0.88-0.92) and in 700 out of 1,056 cases overall (66.3%; ICC: 0.95; 95% CI: 0.95-0.96), with an interobserver difference of 0 ± 8% (95% limits of agreement [LOA]: ±161 mL/min). The interobserver difference was - 2 ± 18% (95% LOA: ±418 mL/min) between a physician and medical assistants, and - 19 ± 24% to - 22 ± 26% (95% LOAs: ±719-806 mL/min) between physicians or medical assistants and software-based algorithms.

Conclusions

Experienced physicians show high agreement when determining AT in asymptomatic volunteers. However, agreement between physicians and qualified medical assistants is lower, and there is substantial deviation in AT determination between physicians or medical assistants and software-based algorithms. This must be considered when using AT as a decision tool.

A Comparison of the Learning Curves of Laparoscopic Liver Surgeons in Differing Stages of the IDEAL Paradigm of Surgical Innovation: Standing on the Shoulders of Pioneers

OBJECTIVE

To compare the learning curves of the self-taught "pioneers" of laparoscopic liver surgery (LLS) with those of the trained "early adopters" in terms of short- and medium-term patient outcomes to establish if the learning curve can be reduced with specific training.

SUMMARY OF BACKGROUND DATA

It is expected that a wider adoption of a laparoscopic approach to liver surgery will be seen in the next few years. Current guidelines stress the need for an incremental, stepwise progression through the learning curve in order to minimize harm to patients. Previous studies have examined the learning curve in Stage 2 of the IDEAL paradigm of surgical innovation; however, LLS is now in stage 3 with specific training being provided to surgeons.

METHODS

Using risk-adjusted cumulative sum analysis, the learning curves and short- and medium-term outcomes of 4 "pioneering" surgeons from stage 2 were compared with 4 "early adapting" surgeons from stage 3 who had received specific training for LLS.

RESULTS

After 46 procedures, the short- and medium-term outcomes of the "early adopters" were comparable to those achieved by the "pioneers" following 150 procedures in similar cases.

CONCLUSIONS

With specific training, "early adapting" laparoscopic liver surgeons are able to overcome the learning curve for minor and major liver resections faster than the "pioneers" who were self-taught in LLS. The findings of this study are applicable to all surgical specialties and highlight the importance of specific training in the safe expansion of novel surgical practice.

The association of preoperative cardiac stress testing with 30-day death and myocardial infarction among patients undergoing kidney transplantation

BACKGROUND

Although periodic cardiac stress testing is commonly used to screen patients on the waiting list for kidney transplantation for ischemic heart disease, there is little evidence to support this practice. We hypothesized that cardiac stress testing in the 18 months prior to kidney transplantation would not reduce postoperative death, total myocardial infarction (MI) or fatal MI.

METHODS

Using the United States Renal Data System, we identified ESRD patients ≥40 years old with primary Medicare insurance who received their first kidney transplant between 7/1/2006 and 11/31/2013. Propensity matching created a 1:1 matched sample of patients with and without stress testing in the 18 months prior to kidney transplantation. The outcomes of interest were death, total (fatal and nonfatal) MI or fatal MI within 30 days of kidney transplantation.

RESULTS

In the propensity-matched cohort of 17,304 patients, death within 30 days occurred in 72 of 8,652 (0.83%) patients who underwent stress testing and in 65 of 8,652 (0.75%) patients who did not (OR 1.07; 95% CI: 0.79-1.45; P = 0.66). MI within 30 days occurred in 339 (3.9%) patients who had a stress test and in 333 (3.8%) patients who did not (OR 1.03; 95% CI: 0.89-1.21; P = 0.68). Fatal MI occurred in 17 (0.20%) patients who underwent stress testing and 15 (0.17%) patients who did not (OR 0.97; 95% CI: 0.71-1.32; P = 0.84).

CONCLUSION

Stress testing in the 18 months prior to kidney transplantation is not associated with a reduction in death, total MI or fatal MI within 30 days of kidney transplantation.

Preoperative Preparations for Enhanced Recovery After Surgery Programs: A Role for Prehabilitation

Preoperative risk assessment is valuable only if subsequent targeted optimization of patient care is allowed. Early assessment of high-risk surgical patients is essential to facilitate appropriate optimization. Preoperative assessment and optimization should not be exclusively focused on patients' comorbidities, but also include nutritional assessment, functional capacity, and promote healthy life style habits that affect surgical outcomes (eg, smoking cessation); it requires a multidisciplinary approach.

The cardiopulmonary exercise test grey zone; optimising fitness stratification by application of critical difference

BACKGROUND

Cardiorespiratory fitness can inform patient care, although to what extent natural variation in CRF influences clinical practice remains to be established. We calculated natural variation for cardiopulmonary exercise test (CPET) metrics, which may have implications for fitness stratification.

METHODS

In a two-armed experiment, critical difference comprising analytical imprecision and biological variation was calculated for cardiorespiratory fitness and thus defined the magnitude of change required to claim a clinically meaningful change. This metric was retrospectively applied to 213 patients scheduled for colorectal surgery. These patients underwent CPET and the potential for misclassification of fitness was calculated. We created a model with boundaries inclusive of natural variation [critical difference applied to oxygen uptake at anaerobic threshold (V˙O2-AT): 11 ml O2 kg-1 min-1, peak oxygen uptake (V˙O2 peak): 16 ml O2 kg-1 min-1, and ventilatory equivalent for carbon dioxide at AT (V̇E/V̇CO2-AT): 36].

RESULTS

The critical difference for V˙O2-AT, V˙O2 peak, and V˙E/V˙CO2-AT was 19%, 13%, and 10%, respectively, resulting in false negative and false positive rates of up to 28% and 32% for unfit patients. Our model identified boundaries for unfit and fit patients: AT <9.2 and ≥13.6 ml O2 kg-1 min-1, V˙O2 peak <14.2 and ≥18.3 ml kg-1 min-1, V˙E/V˙CO2-AT ≥40.1 and <32.7, between which an area of indeterminate-fitness was established. With natural variation considered, up to 60% of patients presented with indeterminate-fitness.

CONCLUSIONS

These findings support a reappraisal of current clinical interpretation of cardiorespiratory fitness highlighting the potential for incorrect fitness stratification when natural variation is not accounted for.

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.

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.

Risk Assessment

Purpose of Review

The central question of preoperative assessment is not “What can be done?” but “What should be done and how?” Predicting a patient’s risk of unwanted outcomes is vital to answering this question. This review discusses risk prediction tools currently available and anticipates future developments.

Recent Findings

Simple, parsimonious risk scales and scores are being replaced by complex risk prediction models as high-capacity information systems become ubiquitous. The accuracy of risk estimation will be further increased by improved assessment of physical fitness, frailty, and incorporation of existing and novel biomarkers. However, the limitations of risk prediction for individual patient care must be recognized.

Summary

Risk prediction is transforming from clinical estimation to statistical science. Predictions should be used within the context of a patient’s baseline risk (life expectancy independent of surgery), personal circumstances, quality of life, their expectations and values, and consideration of outcomes that are meaningful for the patient.

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.

An evaluation of the validity of the pre-operative oxygen uptake efficiency slope as an indicator of cardiorespiratory fitness in elderly patients scheduled for major colorectal surgery

This study aimed to investigate the validity of the oxygen uptake efficiency slope as an objective and submaximal indicator of cardiorespiratory fitness in elderly patients scheduled for major colorectal surgery. Patients ≥ 60 years of age, with a metabolic equivalent score using the Veterans Activity Questionnaire ≤ 7 and scheduled for major colorectal surgery participated in a pre-operative cardiopulmonary exercise test. The oxygen uptake efficiency slope was calculated up to different exercise intensities, using 100%, 90% and 80% of the exercise data. Data from 71 patients (47 men, mean (SD) age 75.2 (6.7) years) were analysed. The efficiency slope obtained from all the data was statistically significantly different from the values when 90% (p = 0.027) and 80% (p = 0.023) of the data were used. The 90% and 80% values did not differ significantly from each other (p = 0.152). Correlations between the oxygen uptake efficiency slope and the peak oxygen uptake ranged from 0.816 to 0.825 (all p < 0.001), and correlations between oxygen uptake efficiency slope and the ventilatory anaerobic threshold ranged from 0.793 to 0.805 (all p < 0.001). Receiver operating characteristic curves showed that the oxygen uptake efficiency slope is a sensitive and specific predictor of a peak oxygen uptake ≤ 18.2 ml.kg^-1 .min^-1 , with an area under the curve (95%CI) of 0.876 (0.780-0.972, p < 0.001) and a ventilatory anaerobic threshold ≤ 11.1 ml.kg^-1 .min^-1 , with an area under the curve (95%CI) of 0.828 (0.726-0.929, p < 0.001). These correlations suggest that the oxygen uptake efficiency slope provides a valid (sub)maximal measure of cardiorespiratory fitness in these patients, and the predictive ability described indicates that it might help discriminate patients at higher risk of postoperative morbidity. However, future research should investigate the prognostic value of the oxygen uptake efficiency slope for postoperative outcomes.

Complications of liver resection in geriatric patients

Introduction and aims. Liver resection is the treatment of choice for many primary and secondary liver diseases. Most studies in the elderly have reported resection of primary and secondary liver tumors, especially hepatocellular carcinoma and colorectal metastatic cancer. However, over the last two decades, hepatectomy has become safe and is now performed in the older population, implying a paradigm shift in the approach to these patients.

MATERIAL AND METHODS

We retrospectively evaluated the risk factors for postoperative complications in patients over 65 years of age in comparison with those under 65 years of age after liver resection (n = 360). The set comprised 127 patients older than 65 years (35%) and 233 patients younger than 65 years (65%).

RESULTS

In patients younger than 65 years, there was a significantly higher incidence of benign liver tumors (P = 0.0073); in those older than 65 years, there was a significantly higher incidence of metastasis of colorectal carcinoma to the liver (0.0058). In patients older than 65 years, there were significantly more postoperative cardiovascular complications (P = 0.0028). Applying multivariate analysis, we did not identify any independent risk factors for postoperative complications. The 12-month survival was not significantly different (younger versus older patients), and the 5-year survival was significantly worse in older patients (P = 0.0454).

CONCLUSION

In the case of liver resection, age should not be a contraindication. An individualized approach to the patient and multidisciplinary postoperative care are the important issues.

Cardiac Evaluation and Monitoring of Patients Undergoing Noncardiac Surgery

Surgical management of disease has a tremendous impact on our health system. Millions of people worldwide undergo surgeries every year. Cardiovascular complications in the perioperative period are one of the most common events leading to increased morbidity and mortality. Although such events are very small in number, they are associated with a high mortality rate making it essential for physicians to understand the importance of perioperative cardiovascular risk assessment and evaluation. Its involves a detailed process of history taking, patient's medical profile, medications being used, functional status of the patient, and knowledge about the surgical procedure and its inherent risks. Different risk assessment tools and calculators have also been developed to aid in this process, each with their own advantages and limitations. After such a comprehensive evaluation, a physician will be able to provide a risk assessment or it may all lead to further testing if it is believed that a change in management after such testing will help to reduce perioperative morbidity and mortality. There is extensive literature on the significance of multiple perioperative testing modalities and how they can change management. The purpose of our review is to provide a concise but comprehensive analysis on all such aspects of perioperative cardiovascular risk assessment for noncardiac surgeries and provide a basic methodology toward such assessment and decision making.

Preoperative 6-minute walk distance accurately predicts postoperative complications after operations for hepato-pancreato-biliary cancer

BACKGROUND

Operation for hepato-pancreato-biliary cancer is among the most invasive open abdominal operations, with a high postoperative morbidity and mortality rate. The purpose of the present study is to investigate whether a preoperative 6-minute walk distance can predict major postoperative complications after operation for hepato-pancreato-biliary diseases.

METHODS

A total of 81 participants who underwent pancreaticoduodenectomy, major hepatectomy with extrahepatic bile duct resection, or hepatopancreatoduodenectomy were included. The 6-minute walk distance was performed within 1 week before operation. Patients were categorized into 2 groups based on surgical complications: Clavien-Dindo grade <3 and Clavien-Dindo grade ≥3. Clinical differences between the 2 groups were analyzed. Multivariate logistic regression analysis was performed to identify risk factors for postoperative complications that were categorized as Clavien-Dindo grade ≥3.

RESULTS

The multiple logistic regression model revealed a significant correlation between major postoperative complications and preoperative low 6-minute walk distance, low body mass index, and major blood loss. In patients with 6-minute walk distance <400 m (1,312 feet), the Clavien-Dindo grade was considerably greater than patients with ≥400 m.

CONCLUSION

The 6-minute walk distance is useful in identifying patients with a greater chance of developing major postoperative complications after surgery for hepato-pancreato-biliary cancer.