Evaluation of the ACS NSQIP Surgical Risk Calculator in Elderly Patients Undergoing Hepatectomy for Hepatocellular Carcinoma

Predictive value of the American college of surgeons "surgical risk calculator" (ACS-NSQIP SRC) for plastic and reconstructive surgery: a validation study from an academic tertiary referral center in Germany

AIMS

The American College of Surgeons Surgical Risk Calculator (ACS-NSQIP SRC) was designed to predict morbidity and mortality in order to help providing informed consent. This study evaluated its performance in the field of plastic and reconstructive surgery for patients undergoing body contouring and breast reconstruction procedures.

METHODS

A retrospective analysis of patients undergoing body contouring and breast reconstruction procedures from January 1, 2022 to November 1, 2024 was performed.

RESULTS

The ACS-NSQIP SRC showed good prediction only for severe complications in patients undergoing breast reconstruction with DIEP flap (AUC = 0.727); overall prediction and calibration for the remaining 15 subgroups was poor. The incidence of overall and general complications, as well as length of hospital stay was underestimated.

CONCLUSIONS

The overall performance of the ACS-NSQIP SRC was poor, a finding that underlines the importance of individual decision-making, also considering the surgeon's expertise and patient-specific characteristics.

Perioperative inflammatory index differences between pulmonary squamous cell carcinoma and adenocarcinoma and their prognostic implications

Background

Perioperative inflammatory indices reflect systemic inflammatory responses and have been linked to cancer progression and prognosis. This study aims to explore the differences in perioperative inflammatory indices between lung squamous cell carcinoma (LSCC) and adenocarcinoma (LUAD) and their association with long-term outcomes.

Methods

This study included 287 lung cancer patients who underwent curative resection between June 2016 and December 2017, comprising 61 cases of LSCC and 226 cases of LUAD. Perioperative baseline information and inflammatory cell counts were collected. Patients were followed up for a median duration of 76 months, during which disease-free survival (DFS) and overall survival (OS) were recorded. Cox regression analysis was used to evaluate the prognostic significance of inflammatory factor levels.

Results

Significant differences were observed in white blood cell count and systemic inflammation response index (SIRI) between LSCC and LUAD (P < 0.05). Regression analysis identified age (OR=2.096, P=0.004), postoperative day 1 D-dimer level (OR=1.550, P<0.001), and Platelet-to-lymphocyte ratio (PLR) (OR=1.901, P=0.031) as independent risk factors for perioperative venous thromboembolism (VTE). Furthermore, open surgical approach (HR=2.437, P=0.016), tumor type (LSCC; HR=2.437, P=0.016), and PLR (HR=1.534, P=0.019) were independent risk factors for DFS.

Conclusion

Inflammatory index is key predictors of perioperative VTE and DFS in lung cancer, emphasizing their critical role in prognosis.

Development and validation of an EHR-based risk prediction model for geriatric patients undergoing urgent and emergency surgery

BACKGROUND

Clinical determination of patients at high risk of poor surgical outcomes is complex and may be supported by clinical tools to summarize the patient's own personalized electronic health record (EHR) history and vitals data through predictive risk models. Since prior models were not readily available for EHR-integration, our objective was to develop and validate a risk stratification tool, named the Assessment of Geriatric Emergency Surgery (AGES) score, predicting risk of 30-day major postoperative complications in geriatric patients under consideration for urgent and emergency surgery using pre-surgical existing electronic health record (EHR) data.

METHODS

Patients 65-years and older undergoing urgent or emergency non-cardiac surgery within 21 hospitals 2017-2021 were used to develop the model (randomly split: 80% training, 20% test). The primary outcome was a 30-day composite outcome including several postoperative major complications and mortality; secondary outcomes included common individual complications included in the primary composite outcome (sepsis, progressive renal insufficiency or renal failure, and mortality). Patients' EHR-based clinical history, vital signs, labs, and demographics were included in logistic regression, LASSO, decision tree, Random Forest, and XGBoost models. Area under the receiver operating characteristics curve (AUCROC) was used to compare model performance.

RESULTS

Overall, 66,262 patients (median [IQR] age 78 [(70.9-84.0], female 53.9%, White race 68.5%) received urgent or emergency non-cardiac surgery (25.7% orthopedic cases, 21.9% general surgery cases). AUCROC ranged from 0.655 (Decision Tree) - 0.804 (XGBoost) for the primary composite outcome. XGBoost AUCROC was 0.823, 0.781, and 0.839 in predicting outcomes of sepsis, progressive renal insufficiency or renal failure, and mortality, respectively.

CONCLUSIONS

We developed a model to accurately predict major postoperative complications in geriatric patients undergoing urgent or emergency surgery using the patient's own existing EHR data. EHR implementation of this model could efficiently support clinicians' surgical risk assessment and perioperative decision-making discussions in this vulnerable patient population.

Extent of resection and underlying liver disease influence the accuracy of the preoperative risk assessment with the American College of Surgeons Risk Calculator

BACKGROUND

Liver surgery is associated with a significant risk of postoperative complications, depending on the extent of liver resection and the underlying liver disease. Therefore, adequate patient selection is crucial. This study aimed to assess the accuracy of the American College of Surgeons Risk Calculator (ACS-RC) by considering liver parenchyma quality and the type of liver resection.

METHODS

Patients who underwent open or minimally invasive liver resection for benign or malignant indications between January 2019 and March 2023 at the University Hospital Basel were included. Brier score and feature importance analysis were performed to investigate the accuracy of the ACS-RC.

RESULTS

A total of 376 patients were included in the study, 214 (57%) who underwent partial hepatectomy, 89 (24%) who underwent hemihepatectomy, and 73 (19%) who underwent trisegmentectomy. Most patients had underlying liver diseases, with 143 (38%) patients having fibrosis, 75 patients (20%) having steatosis, and 61 patients (16%) having cirrhosis. The ACS-RC adequately predicted surgical site infection (Brier score of 0.035), urinary tract infection (Brier score of 0.038), and death (Brier score of 0.046), and moderate accuracy was achieved for serious complications (Brier score of 0.216) and overall complications (Brier score of 0.180). Compared with the overall cohort, the prediction was limited in patients with cirrhosis, fibrosis, and steatosis and in those who underwent hemihepatectomy and trisegmentectomy. The inclusion of liver parenchyma quality improved the prediction accuracy.

CONCLUSION

The ACS-RC is a reliable tool for estimating 30-day postoperative morbidity, particularly for patients with healthy liver parenchyma undergoing partial liver resection. However, accurate perioperative risk prediction should be adjusted for underlying liver disease and extended liver resections.

Effect of Frailty on Postoperative Outcomes Following Major Abdominal Surgeries: A Prospective Observational Study

BACKGROUND

Frailty poses unique challenges for patients undergoing major cancer surgeries due to their extreme vulnerability to physiological stressors and can be an important factor in determining postoperative outcomes.

AIMS AND OBJECTIVE

The objective of the study was to determine the incidence of frailty in patients undergoing major abdominal cancer surgeries and identify the risk factors predicting poor outcomes.

MATERIALS AND METHODS

This was a prospective observational study conducted following institutional ethics approval and CTRI registration. We included 308 adult patients who underwent major abdominal cancer surgeries over two years. The preoperative frailty score was calculated using the 11-point modified frailty index score (mFI scale). Patients with a mFI score ≥ 3 points were considered frail. Clinical outcomes such as postoperative complications (Clavien-Dindo grades III and IV), surgical site infections, need for vasopressors, mechanical ventilation, acute kidney injury (AKI), length of ICU and hospital stay, and mortality at 30 days were recorded.

RESULTS

The overall incidence of frailty according to the mFI scale was 8.1%. Age and higher American Society of Anesthesiology (ASA) status were significantly associated with frailty (OR -1.073, p < 0.001, and OR -10.220, p < 0.001) respectively. Frailty was an independent predictor of major postoperative complications (OR -8.147, 95%; CI -2.524-26.292, p < 0.001). Frailty was also significantly associated with an increased duration of mechanical ventilation and length of stay (p < 0.001).

CONCLUSION

The modified frailty index (mFI) score remains a strong predictor of postoperative complications in patients undergoing major abdominal cancer surgeries and can help optimize risk factors to minimize complications.

HOW TO CITE THIS ARTICLE

Joshi M, Bhoslae SJ, Pandhare J, Rathod R, Solanki SL, Kulkarni AP. Effect of Frailty on Postoperative Outcomes Following Major Abdominal Surgeries: A Prospective Observational Study. Indian J Crit Care Med 2024;28(11):1038-1043.

Evaluation of the American College of Surgeons risk calculator in hepatectomy for metastatic colorectal cancer in a Southeast Asian population

PURPOSE

This study evaluated the accuracy of the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) calculator in predicting outcomes after hepatectomy for colorectal cancer (CRC) liver metastasis in a Southeast Asian population.

METHODS

Predicted and actual outcomes were compared for 166 patients undergoing hepatectomy for CRC liver metastasis identified between 2017 and 2022, using receiver operating characteristic curves with area under the curve (AUC) and Brier score.

RESULTS

The ACS-NSQIP calculator accurately predicted most postoperative complications (AUC > 0.70), except for surgical site infection (AUC = 0.678, Brier score = 0.045). It also exhibited satisfactory performance for readmission (AUC = 0.818, Brier score = 0.011), reoperation (AUC = 0.945, Brier score = 0.002), and length of stay (LOS, AUC = 0.909). The predicted LOS was close to the actual LOS (5.9 vs. 5.0 days, P = 0.985).

CONCLUSION

The ACS-NSQIP calculator demonstrated generally accurate predictions for 30-day postoperative outcomes after hepatectomy for CRC liver metastasis in our patient population.

Risk factors of venous thromboembolism for liver tumors: a systematic review and meta-analysis

BACKGROUND

Venous thromboembolism (VTE) is a significant complication in liver tumors patients, and understanding the associated risk factors is essential for effective risk assessment, prevention, and management strategies. This systematic review and meta-analysis aimed to identify key risk factors and their clinical implications for VTE in liver tumors patients.

METHODS

A comprehensive search of multiple databases was conducted to identify relevant studies. Eligible studies were selected, and odds ratios (ORs) and 95% confidence intervals (CIs) were extracted and synthesized for meta-analysis.

RESULTS

A total of 11 studies involving 73,652 liver tumors patients and 2049 VTE cases were included. The analysis identified several significant risk factors for VTE in liver tumors patients. Age (≥65 years), male gender, high BMI, diabetes, hepatitis B and C infections, elevated D-dimer and AST levels, reduced albumin levels, and MELD score were all associated with increased VTE risk.

CONCLUSION

This systematic review and meta-analysis revealed several key risk factors for VTE in liver tumors patients, these findings highlight the importance of risk assessment, prevention, and management strategies in this high-risk population. Further research with larger sample sizes and standardized methods is needed to strengthen the existing evidence and validate these findings.

Evaluation of the ACS NSQIP surgical risk calculator in patients undergoing common bile duct exploration

PURPOSE

The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) surgical risk calculator is a risk stratification tool to help predict risks of postoperative complications, which is important for informed decision-making. The purpose of this study was to evaluate the accuracy of the calculator in predicting postoperative complications in patients undergoing common bile duct (CBD) exploration.

METHODS

A retrospective chart review was completed for 305 patients that underwent open and laparoscopic CBD exploration at a single institution from 2010 to 2018. Patient demographics and preoperative risk factors were entered into the calculator, and the predicted complication risks were compared with observed complication rates. Brier score, C-statistic, and Hosmer-Lemeshow regression analysis were used to assess discrimination and calibration.

RESULTS

The observed rate exceeded the predicted rate for any complication (35.1% vs. 21%), return to operating room (5.9% vs. 3.6%), death (3.3% vs. 1%), and sepsis (3% vs. 2.4%). The model performed best in predicting serious complication (Brier 0.087, C-statistic 0.818, Hosmer-Lemeshow 0.695), surgical site infection (Brier 0.068, C-statistic 0.670, Hosmer-Lemeshow 0.292), discharge to rehabilitation facility (Brier 0.041, C-statistic 0.907, Hosmer-Lemeshow 0.638), and death (Brier 0.028, C-statistic 0.898, Hosmer-Lemeshow 0.004). In multivariable analysis, there was no statistically significant predicted complication type that affected the type of surgery.

CONCLUSION

The calculator was accurate in predicting serious complication, surgical site infection, discharge to rehabilitation facility, and death. However, the model displayed poor predictive ability in all other complications that were analyzed.

Tumor cell-induced platelet aggregation accelerates hematogenous metastasis of malignant melanoma by triggering macrophage recruitment

BACKGROUND

Tumor cell-induced platelet aggregation (TCIPA) is not only a recognized mechanism for paraneoplastic thrombocytosis but also a potential breakthrough alternative for a low response to immune checkpoint inhibitors (ICIs) in hematogenous metastasis of malignant melanoma (MM). However, there is no TCIPA-specific model for further investigation of the relationship among TCIPA, the tumor immune microenvironment (TIME), and metastasis.

METHODS

We developed a TCIPA metastatic melanoma model with advanced hematogenous metastasis and enhanced TCIPA characteristics. We also investigated the pathway for TCIPA in the TIME.

RESULTS

We found that TCIPA triggers the recruitment of tumor-associated macrophages (TAMs) to lung metastases by secreting B16 cell-educated platelet-derived chemokines such as CCL2, SDF-1, and IL-1β. Larger quantities of TAMs in the TCIPA model were polarized to the M2 type by B16 cell reprocessing, and their surface programmed cell death 1 ligand 1 (PD-L1) expression was upregulated, ultimately assisting B16 cells in escaping host immunity and accelerating MM hematogenous metastasis.

CONCLUSIONS

TCIPA accelerates MM lung metastasis via tumor-educated platelets (TEPs), triggering TAM recruitment, promoting TAM polarization (M2), and remodeling the suppressive TIME in lung metastases.

Evaluation of the ACS-NSQIP Surgical Risk Calculator in Patients with Hepatic Metastases from Colorectal Cancer Undergoing Liver Resection

BACKGROUND

The American College of Surgeons National Surgical Quality Improvement Program surgical risk calculator (ACS-NSQIP SRC) has been designed to predict morbidity and mortality and help stratify surgical patients. This study evaluates the performance of the SRC for patients undergoing surgery for colorectal liver metastases (CRLM).

METHODS

SRC was retrospectively computed for patients undergoing liver or simultaneous colon and liver surgery for colorectal cancer (CRC) in two high tertiary referral centres from 2011 to 2020. C-statistics and Brier score were calculated as a mean of discrimination and calibration respectively, for both group and for every level of surgeon adjustment score (SAS) for liver resections in case of simultaneous liver-colon surgery. An AUC ≥ 0.7 shows acceptable discrimination; a Brier score next to 0 means the prediction tool has good calibration.

RESULTS

Four hundred ten patients were included, 153 underwent simultaneous resection, and 257 underwent liver-only resections. For simultaneous surgery, the ACS-NSQIP SRC showed good calibration and discrimination only for cardiac complication (AUC = 0.720, 0.740, and 0.702 for liver resection unadjusted, SAS-2, and SAS-3 respectively; 0.714 for colon resection; and Brier score = 0.04 in every case). For liver-only surgery, it only showed good calibration for cardiac complications (Brier score = 0.03). The SRC underestimated the incidence of overall complications, pneumonia, cardiac complications, and the length of hospital stay.

CONCLUSIONS

ACS-NSQIP SRC showed good predicting capabilities only for 1 out of 5 evaluated outcomes; therefore, it is not a reliable tool for patients undergoing liver surgery for CRLM, both in the simultaneous and staged resections.

Can the American College of Surgeons NSQIP Surgical Risk Calculator Accurately Predict Adverse Postoperative Outcomes in Emergency Abdominal Surgery? An Italian Multicenter Analysis

BACKGROUND

The American College of Surgeons NSQIP surgical risk calculator provides an estimation of 30-day postoperative adverse outcomes. It is useful in the identification of high-risk patients needing clinical optimization and supports the informed consent process. The purpose of this study is to validate its predictive value in the Italian emergency setting.

STUDY DESIGN

Six Italian institutions were included. Inclusion diagnoses were acute cholecystitis, appendicitis, gastrointestinal perforation or obstruction. Areas under the receiving operating characteristic curves, Brier score, Hosmer-Lemeshow index, and observed-to-expected event ratio were measured to assess both discrimination and calibration. Effect of the Surgeon Adjustment Score on calibration was then tested. A patient's personal risk ratio was obtained, and a cutoff was chosen to predict mortality with a high negative predicted value.

RESULTS

A total of 2,749 emergency procedures were considered for the analysis. The areas under the receiving operating characteristic curve were 0.932 for death (0.921 to 0.941, p < 0.0001; Brier 0.041) and 0.918 for discharge to nursing or rehabilitation facility (0.907 to 0.929, p < 0.0001; 0.070). Discrimination was also strong (area under the receiving operating characteristic curve >0.8) for renal failure, cardiac complication, pneumonia, venous thromboembolism, serious complication, and any complication. Brier score was informative (<0.25) for all the presented variables. The observed-to-expected event ratios were 1.0 for death and 0.8 for discharge to facility. For almost all other variables, there was a general risk underestimation, but the use of the Surgeon Adjustment Score permitted a better calibration of the model. A risk ratio >3.00 predicted the onset of death with sensitivity = 86%, specificity = 77%, and negative predicted value = 99%.

CONCLUSIONS

The American College of Surgeons NSQIP surgical risk calculator has proved to be a reliable predictor of adverse postoperative outcomes also in Italian emergency settings, with particular regard to mortality. We therefore recommend the use of the surgical risk calculator in the multidisciplinary care of patients undergoing emergency abdominal surgery.

Preparing for participation in the centers for Medicare and Medicaid Services' bundle care payment initiative-advanced for major bowel surgery

BACKGROUND

As healthcare costs rise, there is an increasing emphasis on alternative payment models to improve care efficiency. The bundled payment represents an alternative reimbursement model gaining popularity within the surgical sphere. We aimed to assess where the largest opportunities for care improvement lay and how best to identify patients at high risk of suffering costly complications.

METHODS

We utilized itemized CMS claims data for a retrospective cohort of patients between 2014 and 2016 who met inclusion criteria for the Major Bowel Bundled Payment Program and performed a cost analysis to identify opportunities for improved care efficiency. Based on the results of this cost analysis, we identified readmissions as a target for improvement. We then assessed whether the American College of Surgeons' National Surgical Quality Improvement Program surgical risk calculator (ACS NSQIP SRC) could accurately identify patients within our bundled payment population who were at high risk of readmission using a logistic regression model.

RESULTS

Our study cohort included 252 patients. Readmissions accounted for 12.8% of the average total care episode cost with a coefficient of variation of 2.72, thereby representing the most substantial, non-fixed cost for our bundled payment patients. Patients readmitted within their 90-day care episode were 2.53 times more likely to be high-cost (>$60,000) than patients not readmitted. However, the ACS NSQIP SRC did not accurately predict patients at high risk of readmission within the first 30 days with an AUROC of 0.58.

CONCLUSIONS

Our study highlights the importance of reducing readmissions as a central component of improving care for bowel surgery bundled payment patients. Preventing such readmissions requires accurate identification of patients at high risk of readmission; however, current risk prediction models lack the adaptability necessary for this task.

The efficacy of the American College of Surgeons Surgical Risk Calculator in the prediction of postoperative complications in oncogeriatric patients after curative surgery for abdominal tumors

BACKGROUND

The American College of Surgeons (ACS) has developed a Surgical Risk Calculator (SRC) to predict postoperative surgical complications. No studies have reported the performance of the ACS-SRC in oncogeriatric patients. Our objective was to evaluate the predictive performance of the ACS-SRC in these patients, treated with curative surgery for an abdominal malignancy.

METHODS

This is a retrospective study including 136 patients who underwent elective abdominal oncological surgery, between 2017 and 2019, at our institution. Postoperative complications were classified according to the ACS-SRC, and its predictive performance was analyzed by assessing discrimination and calibration and using receiver operating characteristics and area under the curve (AUC).

RESULTS

Discrimination was adequate with AUC of 0.7113 (95% confidence interval [CI]: 1.062-1.202, p = 0.0001; Brier 0.198) for serious complications and 0.7230 (95% CI: 1.101-1.756, p = 0.0057; Brier 0.099) for pneumonia; and poor for sepsis, surgical site infection (SSI), and urinary tract infection (UTI) with AUCs of 0.6636 (95% CI: 1.016-1.353, p = 0.0299; Brier 0.142), 0.6167 (95% CI: 1.003-1.266, p = 0.0450; Brier 0.175), and 0.6598 (95% CI: 1.069-2.145, p = 0.0195; Brier 0.082), respectively.

CONCLUSION

The ACS-SRC is an adequate predictor for serious complications and pneumonia in oncogeriatric patients treated surgically for abdominal cancer. However, the predictive power of the calculator appears to be low for sepsis, UTI, and SSI.

Development and validation of risk stratification tool for prediction of increased dependence using preoperative frailty after hepatopancreatic surgery

BACKGROUND

Despite the known association between frailty and postoperative morbidity, the use of preoperative frailty in surgical practice remains limited. We sought to develop a risk tool to predict postoperative increase in functional dependence.

METHODS

Patients of ≥65 years in the National Surgical Quality Improvement Project database who had a primary hepatopancreatic surgery between 2015 and 2019 were used to identify predictors of increased dependence and development of a simplified tool to calculate the risk stratification score for increased discharge care level (https://ktsahara.shinyapps.io/care_discharge/).

RESULTS

Among 31,338 patients who underwent primary hepatopancreatic surgery, 4,259 (13.6%) had an increased level of care at discharge compared to their preadmission care. Patients with increased discharge care had a higher proportion of patients with a modified frailty index of at least 2 (n = 1496; 35.1%) compared with individuals with unchanged care (n = 6,760; 25.0%). In addition, 12.3% (n = 3,858) were discharged to a skilled nursing or rehabilitation facility. Of note, the odds of increased care at discharge were increased by 1.41 (95% confidence interval: 1.32-1.50), 1.11 (95% confidence interval :1.11-1.12), and 1.95 (95% confidence interval:1.86-2.04) times with every unit increase in modified frailty index, age beyond 65 years, and the number of in-hospital complications, respectively. Area under receiver operative curve for the parsimonious model used to develop the risk calculator was 0.7486 (95% confidence interval: 0.7405-0.7566) (all P < .001).

CONCLUSION

Approximately, 1 in 7 patients required an increased level of care at the time of discharge compared with their preadmission status. A simplified web-based risk tool can be used in clinical practice as a surgical decision aid in post-discharge planning after complex elective surgery.

Timing and Severity of Postoperative Complications and Associated 30-Day Mortality Following Hepatic Resection: a National Surgical Quality Improvement Project Study

BACKGROUND

The effect of varying severity and timing of complications after hepatic resection on 30-day mortality has not been thoroughly examined.

METHODS

National Surgical Quality Improvement Program Patient User Files (NSQIP-PUF) were used to identify patients who underwent elective hepatic resection between 2014 and 2019. The impact of number, timing, and severity of complications on 30-day mortality was examined.

RESULTS

Among 25,084 patients who underwent hepatic resection, 7436 (29.9%) patients developed at least one NSQIP complication, while 2688 (10.7%) had multiple (≥2) complications. Overall, 30-day mortality was 1.7% (n=424), among whom 81.4% (n=345) patients had ≥2 complications. The 30-day mortality was highest among patients with three consecutive severe complications (47.8%), as well as patients with one non-severe and two subsequent severe complications (47.6%). The adjusted probability of 30-day mortality was 35.5% (95%CI: 29.5-41.4%) when multiple severe complications occurred within the first postoperative week and 16.2% (95%CI: 7.2-25.1%) when the second severe complication occurred at least one week apart. The adjusted risk of 30-day mortality after even two non-severe complications was as high as 5.3% (95%CI: 3.7-6.9%) when the second complication occurred within a week postoperatively.

CONCLUSION

Approximately 1 in 10 patients developed multiple complications following hepatectomy. Timing and severity of complications were independently associated with 30-day mortality.

Impact of Perioperative Thromboembolic Complications on Future Long-term Risk of Venous Thromboembolism among Medicare Beneficiaries Undergoing Complex Gastrointestinal Surgery

BACKGROUND

Venous thromboembolism (VTE), including deep venous thrombosis (DVT) and pulmonary embolism (PE), represents a common cause of morbidity and mortality following complex gastrointestinal surgery. Whether perioperative VTE also exposes patients to a higher long-term risk of VTE events remains poorly defined.

METHODS

The Medicare 100% Standard Analytic Files were used to identify patients undergoing esophageal, hepatic, pancreatic, and colorectal resection between 2013 and 2017. The impact of perioperative VTE, defined as a VTE episode occurring during the index hospitalization or within 30 days of discharge, on the risk of developing subsequent long-term VTE episodes (i.e., more than 30 days following discharge) was examined.

RESULTS

Among 253,212 patients who underwent complex gastrointestinal surgery, 1.9% (n=4763) developed a VTE episode perioperatively. With a median follow-up period of 553 days (IQR 194-1052), a total of 11,052 patients (4.4%) developed a long-term VTE episode. Of note, patients who developed a DVT perioperatively had a higher risk of experiencing a long-term VTE episode than patients who had no perioperative thromboembolic complications (HR 6.50, 95%CI 6.04-6.98). The increase in risk was more pronounced among patients who had a PE (HR 27.97, 95%CI 25.39-30.80) at the time of surgery. Risk factors for long-term thromboembolic events following complex GI surgery included Black patients (HR 1.20, 95%CI 1.11-1.30), receipt of surgery at a teaching hospital (HR 1.09, 95%CI 1.04-1.13), nonelective surgery (HR 1.19, 95%CI 1.14-1.24), as well as a diagnosis of cancer (HR 1.10, 95%CI 1.05-1.16). The development of a perioperative DVT was associated with an increased long-term risk of VTE in both cancer (HR 5.59, 95%CI 5.29-6.61) and non-cancer patients (HR 6.98, 95%CI 6.37-7.64). Similarly, experiencing a PE at the time of surgery led to a higher long-term risk of VTE in cancer (HR 24.30, 95%CI 21.08-28.02), as well as non-cancer (HR 30.81, 95%CI 27.01-35.15) patients.

CONCLUSIONS

Patients with a history of perioperative VTE had a higher risk of developing subsequent VTE events within 1-2 years following complex GI surgery. The risk was more pronounced among patients who had perioperative PE rather than DVT. These findings were consistent among both cancer and non-cancer patients.

What is the Accuracy of the ACS-NSQIP Surgical Risk Calculator in Emergency Abdominal Surgery? A Meta-Analysis

BACKGROUND

The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) surgical risk calculator provides an estimation of 30-d post-operative complications including mortality. This tool has the potential to both aid in decision-making for patients and their families and also in optimizing the clinical management of high-risk patients. However, it's utility in patients requiring emergency abdominal surgery has shown to be inconsistent outside of NSQIP participating institutions. This study undertook a meta-analysis to assess the calculator's accuracy in predicting mortality in these patients.

METHODS

A literature search of PubMed, Medline and Cochrane databases was conducted between October 2019 to April 2020. The PubMed, Medline and Cochrane Databases were searched for relevant studies. The search strategy included studies from January 2013 to April 2020. Studies including elective surgery were excluded. A random effects model was used and fitted using restricted maximum likelihood estimation. The O:E ratio was used to validate the calculator's accuracy in predicting mortality.

RESULTS

Six studies were included in the meta-analysis, with a total of 1835 patients undergoing emergency intra-abdominal surgery. The summary estimate of the O:E ratio of the ACS-NSQIP surgical risk calculator in predicting 30-d post-operative mortality was 1.06 (95% CI 0.74-1.51). There was significant heterogeneity between studies with a Cochrane Q of 11.96 (P = 0.04) and I² = 57.5%.

CONCLUSIONS

The ACS-NSQIP surgical risk calculator is a reliable predictor of mortality in this external cohort and has potential to be utilised in the multi-disciplinary care of patients undergoing emergency abdominal surgery.

Survival Benefit of Primary Tumor Resection Among Elderly Patients with Pancreatic Neuroendocrine Tumors

BACKGROUND

Pancreatectomy is the main curative therapeutic option for pancreatic neuroendocrine tumors (pNETs). Given the indolent behavior of pNETs and the relatively limited lifetime of elderly patients, the impact of primary site surgery (PSS) of pNETs on long-term outcomes among older patients has been a topic of debate.

METHODS

Patients aged 70 or older with pNETs were identified in the Surveillance, Epidemiology and the End Results (SEER) database from 1998 to 2016. Propensity score matching was used to compare overall (OS) and cancer-specific survival (CSS) of patients who did versus did not undergo PSS.

RESULTS

Among 2,319 elderly patients with pNETs, 942 patients (40.6%) underwent PSS, while 1,377 (59.4%) did not undergo PSS (non-PSS: NPSS). After propensity score matching (n = 433 in each group), PSS group had improved survival compared with the NPSS group (5-year OS: 53.4% vs. 37.3%; 5-year CSS: 77.2% vs. 58.1%, both p < 0.001). In contrast, subgroup analysis of individuals aged ≥ 80 revealed no difference in 5-year CSS (PSS: 69.2% vs. NPSS: 67.4%, p = 0.27). A subgroup analysis among patients who had small (≤ 2 cm) non-functional (NF) pNETs noted comparable long-term outcomes among patients who underwent PSS versus NPSS patients (5-year OS: 73.1% vs. 66.5%, p = 0.19; 5-year CSS: 98.5% vs. 95.2%, p = 0.14).

CONCLUSIONS

Approximately 2 in 5 elderly patients with pNETs underwent PSS. While PSS was generally associated with prolonged OS and CSS among older patients, PSS was not associated with improved CSS among a subset of patients aged 80 or older, as well as among patients age ≥ 70 years with NF-pNET less than 2 cm.

A simple scoring system to estimate perioperative mortality following liver resection for primary liver malignancy-the Hepatectomy Risk Score (HeRS)

Background

Selection of the optimal treatment modality for primary liver cancers remains complex, balancing patient condition, liver function, and extent of disease. In individuals with preserved liver function, liver resection remains the primary approach for treatment with curative intent but may be associated with significant mortality. The purpose of this study was to establish a simple scoring system based on Model for End-stage Liver Disease (MELD) and extent of resection to guide risk assessment for liver resections.

Methods

The 2005-2015 NSQIP database was queried for patients undergoing liver resection for primary liver malignancy. We first developed a model that incorporated the extent of resection (1 point for major hepatectomy) and a MELD-Na score category of low (MELD-Na =6, 1 point), medium (MELD-Na =7-10, 2 points) or high (MELD-Na >10, 3 points) with a score range of 1-4, called the Hepatic Resection Risk Score (HeRS). We tested the predictive value of this model on the dataset using logistic regression. We next developed an optimal multivariable model using backwards sequential selection of variables under logistic regression. We performed K-fold cross validation on both models. Receiver operating characteristics were plotted and the optimal sensitivity and specificity for each model were calculated to obtain positive and negative predictive values.

Results

A total of 4,510 patients were included. HeRS was associated with increased odds of 30-day mortality [HeRS =2: OR =3.23 (1.16-8.99), P=0.025; HeRS =3: OR =6.54 (2.39-17.90), P<0.001; HeRS =4: OR =13.69 (4.90-38.22), P<0.001]. The AUC for this model was 0.66. The AUC for the optimal multivariable model was higher at 0.76. Under K-fold cross validation, the positive predictive value (PPV) and negative predictive value (NPV) of these two models were similar at PPV =6.4% and NPV =97.7% for the HeRS only model and PPV =8.4% and NPV =98.1% for the optimal multivariable model.

Conclusions

The HeRS offers a simple heuristic for estimating 30-day mortality after resection of primary liver malignancy. More complicated models offer better performance but at the expense of being more difficult to integrate into clinical practice.

Development and validation of a risk calculator for post-discharge venous thromboembolism following hepatectomy for malignancy

BACKGROUND

Post-discharge venous thromboembolism (VTE) chemoprophylaxis decreases VTEs following cancer surgery, however identifying high-risk patients remains difficult. Our objectives were to (1) identify factors available at hospital discharge associated with post-discharge VTE following hepatectomy for malignancy and (2) develop and validate a post-discharge VTE risk calculator to evaluate patient-specific risk.

METHODS

Patients who underwent hepatectomy for malignancy from 2014 to 2017 were identified from the ACS NSQIP hepatectomy procedure targeted module. Multivariable logistic regression identified factors associated with post-discharge VTE. A post-discharge VTE risk calculator was constructed, and predicted probabilities of post-discharge VTE were calculated.

RESULTS

Among 11 172 patients, 95 (0.9%) developed post-discharge VTE. Post-discharge VTE was associated with obese BMI (OR 2.29 vs. normal BMI [95%CI 1.31-3.99]), right hepatectomy/trisegmentectomy (OR 1.63 vs. partial/wedge [95%CI 1.04-2.57]), and several inpatient postoperative complications: renal insufficiency (OR 5.29 [95%CI 1.99-14.07]), transfusion (OR 1.77 [95%CI 1.12-2.80]), non-operative procedural intervention (OR 2.97 [95%CI 1.81-4.86]), and post-hepatectomy liver failure (OR 2.22 [95%CI 1.21-4.08]). Post-discharge VTE risk ranged from 0.3% to 30.2%. Twenty iterations of 10-fold cross validation identified internal validity.

CONCLUSIONS

Risk factors from all phases of care, including inpatient complications, are associated with post-discharge VTE following hepatectomy. Identifying high-risk patients may allow for personalized risk-based post-discharge chemoprophylaxis prescribing.

Machine learning predicts unpredicted deaths with high accuracy following hepatopancreatic surgery

Background

Machine learning to predict morbidity and mortality-especially in a population traditionally considered low risk-has not been previously examined. We sought to characterize the incidence of death among patients with a low estimated morbidity and mortality risk based on the National Surgical Quality Improvement Program (NSQIP) estimated probability (EP), as well as develop a machine learning model to identify individuals at risk for "unpredicted death" (UD) among patients undergoing hepatopancreatic (HP) procedures.

Methods

The NSQIP database was used to identify patients who underwent elective HP surgery between 2012-2017. The risk of morbidity and mortality was stratified into three tiers (low, intermediate, or high estimated) using a k-means clustering method with bin sorting. A machine learning classification tree and multivariable regression analyses were used to predict 30-day mortality with a 10-fold cross validation. C statistics were used to compare model performance.

Results

Among 63,507 patients who underwent an HP procedure, median patient age was 63 (IQR: 54-71) years. Patients underwent either pancreatectomy (n=38,209, 60.2%) or hepatic resection (n=25,298, 39.8%). Patients were stratified into three tiers of predicted morbidity and mortality risk based on the NSQIP EP: low (n=36,923, 58.1%), intermediate (n=23,609, 37.2%) and high risk (n=2,975, 4.7%). Among 36,923 patients with low estimated risk of morbidity and mortality, 237 patients (0.6%) experienced a UD. According to the classification tree analysis, age was the most important factor to predict UD (importance 16.9) followed by preoperative albumin level (importance: 10.8), disseminated cancer (importance: 6.5), preoperative platelet count (importance: 6.5), and sex (importance 5.9). Among patients deemed to be low risk, the c-statistic for the machine learning derived prediction model was 0.807 compared with an AUC of only 0.662 for the NSQIP EP.

Conclusions

A prognostic model derived using machine learning methodology performed better than the NSQIP EP in predicting 30-day UD among low risk patients undergoing HP surgery.

The American College of Surgeons Surgical Risk Calculator performs well for pulmonary resection: A validation study

OBJECTIVE

The American College of Surgeons National Surgical Quality Improvement Program Surgical Risk Calculator (NSQIP SRC) was developed to estimate the risk of postoperative morbidity and mortality within 30 days of an operation. We sought to externally evaluate the performance of the NSQIP SRC for patients undergoing pulmonary resection.

METHODS

Patients undergoing pulmonary resection at our center between January 2016 and December 2018 were included. Using data from our institution's prospectively maintained Society of Thoracic Surgeons General Thoracic Database, we identified 2514 patients. We entered requisite patient demographic information, preoperative risk factors, and procedural details into the online calculator. Predicted performance of the calculator versus observed outcomes was assessed by discrimination (concordance index [C-index]) and calibration.

RESULTS

The observed and predicted probabilities of any complication were 8.3% and 9.9%, respectively, and of serious complications were 7.4% and 9.2%, respectively. Observed and predicted 30-day mortality were 0.5% and 0.9%, respectively. The C-index for readmission was 0.644; the C-indices corresponding to all other outcomes in the NSQIP SRC ranged from 0.703 to 0.821. Calibration curves indicated excellent calibration for all binary end points, with the exception of renal failure (predicted underestimated observed probabilities), discharge to a nursing or rehabilitation facility (overestimated), and sepsis (overestimated). Correlation between predicted and observed length of stay was moderate (Spearman coefficient, 0.562), and calibration was good.

CONCLUSIONS

Except for readmission, renal failure, discharge to a location other than home, and sepsis, the NSQIP SRC can be used to reasonably predict postoperative complications in patients undergoing pulmonary resection.

Platelets in aging and cancer-"double-edged sword"

Platelets control hemostasis and play a key role in inflammation and immunity. However, platelet function may change during aging, and a role for these versatile cells in many age-related pathological processes is emerging. In addition to a well-known role in cardiovascular disease, platelet activity is now thought to contribute to cancer cell metastasis and tumor-associated venous thromboembolism (VTE) development. Worldwide, the great majority of all patients with cardiovascular disease and some with cancer receive anti-platelet therapy to reduce the risk of thrombosis. However, not only do thrombotic diseases remain a leading cause of morbidity and mortality, cancer, especially metastasis, is still the second cause of death worldwide. Understanding how platelets change during aging and how they may contribute to aging-related diseases such as cancer may contribute to steps taken along the road towards a "healthy aging" strategy. Here, we review the changes that occur in platelets during aging, and investigate how these versatile blood components contribute to cancer progression.

Impact of Preoperative Cholangitis on Short-term Outcomes Among Patients Undergoing Liver Resection

BACKGROUND

The impact of preoperative cholangitis (PC) on perioperative outcomes among patients undergoing liver resection remains poorly defined. We sought to characterize the prevalence of PC among patients undergoing hepatectomy and define the impact of PC on postoperative outcomes.

METHODS

Patients who underwent liver resection between 2013 and 2015 were identified using the Center for Medicare Services (CMS) 100% Limited Data Set (LDS) Standard Analytic Files (SAFs). Short-term outcomes after liver resection, stratified by the presence of PC, were examined. Subgroup analyses were performed to evaluate the relationship between the timing of liver resection relative to PC.

RESULTS

Among 7392 patients undergoing liver resection, 251 patients (3.4%) experienced PC. Patients with PC were more likely to be male (59.0% vs. 50.6%) and to have a benign diagnosis (34.3% vs. 19.8%) compared with patients without PC (both p<0.05). On multivariable analysis, PC was associated with increased odds of experiencing a complication (OR 1.54, 95%CI 1.17-2.03), extended LOS (OR 2.60, 95%CI 1.99-3.39), 90-day mortality (OR 2.31, 95%CI 1.64-3.26), and higher Medicare expenditures (OR 3.32, 95%CI 2.55-4.32). Among patients with PC, requirement of both endoscopic and percutaneous biliary drainage (OR 5.16, 95%CI 1.36-9.61), as well as liver resection < 2 weeks after PC (OR 2.92, 95%CI 1.13-7.57) were associated with higher odds of 90-day mortality.

CONCLUSION

Approximately 1 in 30 Medicare beneficiaries undergoing liver resection had a history of PC. PC was associated with an increased risk of adverse short-term outcomes and higher healthcare expenditures among patients undergoing hepatectomy.

Assessment of the American College of Surgeons surgical risk calculator of outcomes after hepatectomy for liver tumors: Results from a cohort of 950 patients

BACKGROUND

The American College of Surgeons National Surgical Quality Improvement Program's (ACS-NSQIP) calculator has been endorsed to counsel patients regarding complications. The aim of this study was to assess its ability to predict outcomes after hepatectomy.

METHODS

Outcomes generated by the ACS-NSQIP were recorded in a consecutive cohort of patients. By using established classifications of complications, post-hepatectomy insufficiency and bile leak, the calculator was tested by the comparison of expected versus observed rates of events. The performance of the calculator was tested by using c-statistic and Brier score.

RESULTS

950 patients who underwent hepatectomy between January 2014 and June 2019 were included. Predicted rates were significantly lower than actual rates: the mean ACS-NSQIP morbidity was 17.97% ± 8.4 vs. actual 37.01% ± 0.56 (P < 0.001); the mean ACS-NSQIP mortality was 0.91% ± 1.48 vs. actual 1.76% ± 0.11 (P < 0.001). Predicted length of stay (LOS) was significantly shorter: mean ACS-NSQIP was 5.81 ± 1.66 days vs. actual 10.91 ± 4.6 days (P < 0.001). Post-hepatectomy liver insufficiency and bile leak were recorded in 6.8% and 11.9% of patients, respectively. These events were not expressed by the calculator. C-statistic and Brier scores showed low performance of the calculator.

CONCLUSION

The calculator underestimates the risks of complications, mortality and LOS after hepatectomy. Refinements of the ACS-NSQIP model that account for organ-specific risks should be considered.

Retroperitoneal sarcoma perioperative risk stratification: A United States Sarcoma Collaborative evaluation of the ACS-NSQIP risk calculator

BACKGROUND

The ACS-NSQIP risk calculator predicts perioperative risk. This study tested the calculator's ability to predict risk for outcomes following retroperitoneal sarcoma (RPS) resection.

METHODS

The United States Sarcoma Collaborative database was queried for adults who underwent RPS resection. Estimated risk for outcomes was calculated twice in the risk calculator, once using sarcoma-specific CPT codes and once using codes indicative of most comorbid organ resection (eg nephrectomy). ROC curves were generated, with area under the curve (AUC) and Brier scores reported to assess discrimination and calibration. An AUC < 0.6 was considered ineffective discrimination. A negative ▲ Brier indicated improved performance relative to baseline outcome rates.

RESULTS

In total, 482 patients were identified with a 42.3% 90-day complication rate. Discrimination was poor for all outcomes except "all complications" and "renal failure." Baseline outcome rates were better predictors than calculator estimates except for "discharge to nursing or rehab facility" and "renal failure." Replacing sarcoma-specific CPT codes with resection-specific codes did not improve performance.

CONCLUSION

The ACS-NSQIP risk calculator poorly predicted outcomes following RPS resection. Changing sarcoma-specific CPT to resection-specific codes did not improve performance. Comorbidities in the calculator may not effectively capture perioperative risk. Future work should evaluate a sarcoma-specific calculator.

Comparison of laparoscopic cholecystectomy and delayed laparoscopic cholecystectomy in aged acute calculous cholecystitis: a cohort study

BACKGROUND

In elderly patients with calculous acute cholecystitis, the risk of emergency surgery is high, and percutaneous cholecystostomy tube drainage (PC) combined with delayed laparoscopic cholecystectomy (DLC) may be a good choice. We retrospectively compared laparoscopic cholecystectomy (LC) to DLC after PC to determine which is the better treatment strategy.

METHOD

We performed a retrospective cohort analysis of 752 patients with acute calculous cholecystitis. Patients with the following conditions were included: (1) age > 65 years old; (2) patients with a grade 2 or 3 severity of cholecystitis according to the 2013 Tokyo Guidelines (TG13); (3) the surgeons who performed the LC were professors or associate professors and (4) the DLC was performed in our hospital after PC. Patients who missed their 30-day follow-up; were diagnosed with bile duct stones, cholangitis or gallstone pancreatitis or were pregnant were excluded from the study. A total of 51 of 314 patients who underwent LC and 73 of 438 patients who underwent PC + DLC were assessed. PC + DLC and LC patients were matched by cholecystitis severity grade according to the TG13, and the National Surgical Quality Improvement Program (NSQIP) calculator was used to predict mortality (n = 21/group). Preoperative characteristics and postoperative outcomes were analysed.

RESULTS

Compared to the matched LC group, the DLC group had less intraoperative bleeding (42.2 vs 75.3 mL, p = 0.014), shorter hospital stays (4.9 vs 7.4 days, p = 0.010) and lower rates of type A bile duct injury (4.8% vs 14.3%, p = 0.035) and type D (0 vs 9.5%, p = 0.002) according to Strasberg classification, residual stones (4.8 vs 14.3%, p = 0.035) and gastrointestinal organ injury (0 vs 3.6%, p < 0.001). Patients in the DLC group had lower incidences of ICU admission and death and a significantly lower incidence of repeat surgery.

CONCLUSION

In elderly patients treated for acute calculous cholecystitis, the 30-day mortality and complication rates were lower for PC + DLC than for LC. However, the total hospitalisation time was significantly prolonged and the costs were significantly higher for PC + DLC.

Potential disease burden of patients with substance abuse undergoing major abdominal surgery: A propensity score-matched analysis

BACKGROUND

Over 19 million Americans have a substance abuse disorder. The current study sought to characterize the relationship between substance abuse with in-hospital outcomes following major, elective abdominal surgery.

METHODS

The Nationwide Inpatient Sample was used to identify patients who underwent major abdominal surgery between 2007 to 2014. Patients with preoperative substance abuse, including alcohol, opioids, and non-opioid drugs, were identified. Propensity score matching was used to examine the association of substance abuse with perioperative outcomes.

RESULTS

Among 301,659 patients, 7,925 patients (2.6%) had a history of substance abuse. Pancreatectomy was the surgical procedure with the highest proportion of patients with substance abuse history (n = 844, 4.7%). Compared with patients without a substance abuse history, patients with a substance abuse history were more likely to be younger (median age, 60 years [interquartile range (IQR) 52-69] vs 63 years [IQR 52-72]), male (n = 5,438, 67.5% vs n = 132,961, 54.7%), and be in the lowest income category (n = 2,062, 26% vs n = 64,345, 21.9%) (all P < .001). On propensity score matching, substance abuse was associated with increased odds ratio of experiencing a complication (odds ratio [OR] 1.68, 95% confidence interval [CI] 1.55-1.82), non-home discharge (OR 1.95, 95% CI 1.76-2.16), extended length of stay (OR 1.88, 95% CI 1.76-2.02), and higher expenditure (OR 1.62, 95% CI 1.49-1.77). Stratified by the type of substance abuse, patients with history of alcohol (OR 1.57, 95% CI 1.44-1.71) and drug abuse (OR 1.26, 95% CI 1.14-1.39) were more likely to experience a complication, whereas only history of alcohol abuse was associated with higher odds ratio of in-hospital mortality (OR 1.38, 95% CI 1.07-1.79) (all P < .05).

CONCLUSION

Up to 1 in 50 patients undergoing complex abdominal surgery had a substance abuse history. History of substance abuse was associated with an increased risk of adverse perioperative outcomes and higher healthcare expenditures.