Reducing the risk of vascular surgery

Risk Prediction Models for Peri-Operative Mortality in Patients Undergoing Major Vascular Surgery with Particular Focus on Ruptured Abdominal Aortic Aneurysms: A Scoping Review

PURPOSE

The present scoping review aims to describe and analyze available clinical data on the most commonly reported risk prediction indices in vascular surgery for perioperative mortality, with a particular focus on ruptured abdominal aortic aneurysm (rAAA).

MATERIALS AND METHODS

A scoping review following the PRISMA Protocols Extension for Scoping Reviews was performed. Available full-text studies published in English in PubMed, Cochrane and EMBASE databases (last queried, 30 March 2023) were systematically reviewed and analyzed. The Population, Intervention, Comparison, Outcome (PICO) framework used to construct the search strings was the following: in patients with aortic pathologies, in particular rAAA (population), undergoing open or endovascular surgery (intervention), what different risk prediction models exist (comparison), and how well do they predict post-operative mortality (outcomes)?

RESULTS

The literature search and screening of all relevant abstracts revealed a total of 56 studies in the final qualitative synthesis. The main findings of the scoping review, grouped by the risk score that was investigated in the original studies, were synthetized without performing any formal meta-analysis. A total of nine risk scores for major vascular surgery or elective AAA, and 10 scores focusing on rAAA, were identified. Whilst there were several validation studies suggesting that most risk scores performed adequately in the setting of rAAA, none reached 100% accuracy. The Glasgow aneurysm score, ERAS and Vancouver score risk scores were more frequently included in validation studies and were more often used in secondary studies. Unfortunately, the published literature presents a heterogenicity of results in the validation studies comparing the different risk scores. To date, no risk score has been endorsed by any of the vascular surgery societies.

CONCLUSIONS

The use of risk scores in any complex surgery can have multiple advantages, especially when dealing with emergent cases, since they can inform perioperative decision making, patient and family discussions, and post hoc case-mix adjustments. Although a variety of different rAAA risk prediction tools have been published to date, none are superior to others based on this review. The heterogeneity of the variables used in the different scores impairs comparative analysis which represents a major limitation to understanding which risk score may be the "best" in contemporary practice. Future developments in artificial intelligence may further assist surgical decision making in predicting post-operative adverse events.

The Comorbidity-Polypharmacy Score is an Objective and Practical Predictor of Outcomes and Mortality after Vascular Surgery

BACKGROUND

The comorbidity-polypharmacy score (CPPS) was developed to quantify the severity of comorbidities of patients with geriatric trauma. CPPS is the sum of the number of medications and comorbidities, and is thus objective, user-friendly, and potentially adaptable to many clinical situations. We sought to understand if CPPS associates with outcomes and mortality after common vascular surgery procedures.

METHODS

This is a retrospective single-center study. A total of 466 patients who underwent carotid endarterectomy, infrainguinal bypass, percutaneous lower extremity revascularization, or endovascular abdominal aortic aneurysm repair at a single medical center were included. CPPS were classified as mild, moderate, severe, and morbid based on scores of 0-7, 8-15, 15-21, and ≥21, respectively. End points were reinterventions, 30-day readmission, and mortality. We used chi-squared tests to analyze differences in categorical variables; Kruskal-Wallis tests to analyze differences in continuous variables; Kaplan-Meier estimation and Cox proportional hazard modeling to examine survival data; and receiver operator characteristic (ROC) curve analyses to assess sensitivity and specificity.

RESULTS

The mean preoperative CPPS was 14.1 ± 6.1. Higher CPPS were associated with longer hospital and postoperative length of stay (P < 0.001). Severe and morbid CPPS categories had higher rates of ICU admission, reintervention, and 30-day readmission which did not reach statistical significance after correction for multiple comparisons. CPPS was independently associated with 1- and 5-year mortality in a multivariable Cox model (hazard ratio = 2.2, 95% confidence interval: 1.3-3.3). ROC analysis revealed C-statistics of 0.81 and 0.72 for 1-year and 5-year all-cause mortality, respectively (P < 0.001).

CONCLUSIONS

CPPS is a simple and pragmatic clinical tool for quantifying risk of postoperative outcomes and mortality after common vascular surgery procedures. Further investigation is needed to validate the use of CPPS in enhancing existing predictors of patient outcomes and in serving as an adjunctive tool for determining resource allocation and discharge planning in patients who underwent vascular surgery.

Inter-relationship of procedural mortality rates in vascular surgery in England: retrospective analysis of hospital episode statistics from 2005 to 2010

BACKGROUND

Wide variations in vascular surgical outcomes have been demonstrated in England. The objective of this study was to determine whether risk-adjusted postoperative mortality rates for elective and emergency vascular surgical procedures were inter-related.

METHODS AND RESULTS

A retrospective observational study using National Health Service administrative data on adult patients undergoing elective or emergency vascular surgery from 2005 to 2010. The 10 procedures covered the broad spectrum of workload for a vascular surgical service. The primary outcome measure was in-hospital mortality, and secondary outcomes were 30-day and 1-year mortality. Data were risk-adjusted using multilevel modeling. Analyses comprised a 2-level basket designed to evaluate variations in outcome and whether the outcome of each procedure could be predicted by the composite outcome of all other procedures. A total of 116,596 vascular surgical procedures were performed across 166 providers. For 9 of 10 procedures, there were hospitals lying outside 95% control limits for ≥1 mortality outcome. The key finding was that ≥1 risk-adjusted mortality outcome for any 1 of the 9 vascular surgical procedures could be predicted by the aggregated within provider performance of the other vascular surgical procedures combined.

CONCLUSIONS

Hospital-level risk-adjusted mortality for both elective and emergency vascular procedures in England varies considerably, and providers were globally high or low performers. The data should be made available to patients, relatives, and the purchasers of services to drive improvements in the provision of vascular surgical services.