Editor's Choice - Prolonged ICU Length of Stay after AAA Repair: Analysis of Time Trends and Long-term Outcome

Editor's Choice -- European Society for Vascular Surgery (ESVS) 2024 Clinical Practice Guidelines on the Management of Abdominal Aorto-Iliac Artery Aneurysms

OBJECTIVE

The European Society for Vascular Surgery (ESVS) has developed clinical practice guidelines for the care of patients with aneurysms of the abdominal aorta and iliac arteries in succession to the 2011 and 2019 versions, with the aim of assisting physicians and patients in selecting the best management strategy.

METHODS

The guideline is based on scientific evidence completed with expert opinion on the matter. By summarising and evaluating the best available evidence, recommendations for the evaluation and treatment of patients have been formulated. The recommendations are graded according to a modified European Society of Cardiology grading system, where the strength (class) of each recommendation is graded from I to III and the letters A to C mark the level of evidence.

RESULTS

A total of 160 recommendations have been issued on the following topics: Service standards, including surgical volume and training; Epidemiology, diagnosis, and screening; Management of patients with small abdominal aortic aneurysm (AAA), including surveillance, cardiovascular risk reduction, and indication for repair; Elective AAA repair, including operative risk assessment, open and endovascular repair, and early complications; Ruptured and symptomatic AAA, including peri-operative management, such as permissive hypotension and use of aortic occlusion balloon, open and endovascular repair, and early complications, such as abdominal compartment syndrome and colonic ischaemia; Long term outcome and follow up after AAA repair, including graft infection, endoleaks and follow up routines; Management of complex AAA, including open and endovascular repair; Management of iliac artery aneurysm, including indication for repair and open and endovascular repair; and Miscellaneous aortic problems, including mycotic, inflammatory, and saccular aortic aneurysm. In addition, Shared decision making is being addressed, with supporting information for patients, and Unresolved issues are discussed.

CONCLUSION

The ESVS Clinical Practice Guidelines provide the most comprehensive, up to date, and unbiased advice to clinicians and patients on the management of abdominal aorto-iliac artery aneurysms.

Identification of Clinical Heterogeneity and Construction of Prediction Models for Novel Subtypes in Patients with Abdominal Aortic Aneurysm: An Unsupervised Machine Learning Study

BACKGROUND

Abdominal aortic aneurysm (AAA) is one of the most common diseases in vascular surgery. Endovascular aneurysm repair (EVAR) can effectively treat AAA. It is essential to accurately classify patients with AAA who need EVAR.

METHODS

We enrolled 266 patients with AAA who underwent EVAR. Unsupervised machine learning algorithms (UMLAs) were used to cluster subjects according to similar clinical characteristics. To verify UMLA's accuracy, the operative and postoperative results of the 2 clusters were analyzed. Finally, a prediction model was developed using binary logistic regression analysis.

RESULTS

UMLAs could correctly classify patients based on their clinical characteristics. Patients in Cluster 1 were older, had a higher BMI, and were more likely than patients in Cluster 2 to develop pneumonia, chronic obstructive pulmonary disease, and cerebrovascular disease. The aneurysm diameter, neck angulation, diameter and angulation of bilateral common iliac arteries, and incidence of iliac artery aneurysm were significantly higher in cluster 1 patients than in cluster 2. Cluster 1 had a longer operative time, a longer length of stay in the intensive care unit and hospital, a higher medical expense, and a higher incidence of reintervention. A nomogram was established based on the BMI, neck angulation, left common iliac artery (LCIA) diameter and angulation, and right common iliac artery (RCIA) diameter and angulation. The nomogram was evaluated using receiver operating characteristic curve analysis, with an area under the curve of 0.933 (95% confidence interval, 0.902-0.963) and a C-index of 0.927.

CONCLUSIONS

Our findings demonstrate that UMLAs can be used to rationally classify a heterogeneous cohort of patients with AAA effectively, and the analysis of postoperative variables also verified the accuracy of UMLAs. We established a prediction model for new subtypes of AAA, which can improve the quality of management of patients with AAA.

Exploiting endovascular aortic repair as a minimally invasive method - Nine years of experience in a non-university hospital

Background

At the introduction of endovascular aortic repair (EVAR) in 2013 in our non-university hospital, we established a quality registry to monitor our EVAR activity.

Purpose

To observe if we over time were able to exploit EVAR as a minimally invasive method in an elective as well as emergency setting, and to monitor our treatment quality in terms of complications, secondary interventions and mortality.

Material and methods

From November 2013 to March 2022, we treated 207 patients with EVAR, including six patients with rupture. Follow-up regimen was partly based on contrast-enhanced computer tomography, and partly on contrast-enhanced ultrasound in combination with plain radiography.

Results

During the observation period, the method of anesthesia changed from general, via spinal, to local anesthesia. The groin access changed from surgical cut down to percutaneous and the median length of postoperative stay decreased from 3 days to 1 day. EVAR on ruptured aneurysm was done for the first time in 2019. Endoleak was detected in 85 patients (42%) and 37 patients (18%) had one or more secondary interventions, of which 85% were endovascular. Estimated five-year survival was 72% in patients below 80 years of age and 45% in patients 80 years or older.

Conclusion

Nine years of experience enabled us to exploit EVAR's advantages as a minimally invasive method in an elective as well as emergency setting. Complications, secondary interventions and survival rates in our low volume non-university hospital matches results from larger vascular centers.

Evaluando la experiencia local: primeros 50 casos de reparo endovascular de aneurismas aórticos en Manizales, Colombia

Introducción. En las últimas décadas, la terapia endovascular en aneurismas aórticos abdominales ha ganado un papel representativo en los escenarios quirúrgicos, lo que nos motivó a conocer los resultados de este procedimiento en nuestra población. Métodos. Estudio analítico retrospectivo en el cual se incluyeron los primeros 50 casos de aneurismas aórticos abdominales con terapia endovascular, en la ciudad de Manizales, Colombia, entre los años 2015 y 2021. Se describió la población estudiada, la relación de los antecedentes prequirúrgicos con las complicaciones posoperatorias, la estancia hospitalaria y la mortalidad. Resultados. La edad promedio fue de 73 años, el sexo predominante fue el femenino (72 %), el aneurisma fusiforme fue el tipo más frecuente (63,3 %), con un diámetro promedio de 70 mm (+/- 17,3 mm). En relación con los antecedentes, el más frecuente fue hipertensión arterial (86 %), encontrándose una asociación entre la presencia de enfermedad pulmonar obstructiva crónica e hipertensión arterial con las complicaciones. Se encontró también relación entre el valor de creatinina con las complicaciones. Las complicaciones tempranas fueron de carácter leve en la mayoría de los casos (30,6 %), a diferencia de las tardías, que fueron principalmente graves (12,5 %), asociadas a una mortalidad del 10,2 % y una estancia hospitalaria promedio de 10,8 días (mediana de 5 días). Conclusiones. La población analizada tiene una alta carga de morbilidad, en la cual factores como los antecedentes médicos prequirúrgicos y la función renal, se asocian con una mayor morbilidad postquirúrgica y mortalidad.

EVAR Conversion is an Increasingly Common Indication for Open AAA Repair

OBJECTIVE

Although EVAR re-intervention is common, conversion to open repair(EVAR-c) occurs less frequently but can be associated with significant technical complexity and perioperative risk. There is a paucity of data highlighting the evolution of peri-procedural results surrounding EVAR-c and change in practice patterns, especially for referral centers that increasingly manage EVAR failures. The purpose of this analysis was to perform a temporal analysis of our EVAR-c experience and describe changes in patient selection, operative details and outcomes.

METHODS

A retrospective single center review of all open AAA repairs was performed(2002-2019) and EVAR-c procedures were subsequently analyzed. EVAR-c patients(n=184) were categorized into two different eras(2002-2009, n=21; 2010-2019, n=163) for comparison. Logistic regression and Cox proportional hazards modeling were used for risk-adjusted comparisons.

RESULTS

A significant increase in EVAR-c as an indication for any type of open aneurysm repair was detected(9%→27%;p<.001). Among EVAR-c patients, no change in age or individual comorbidities was evident[mean age: 71±9 years]; however, the proportion of female subjects(p=.01) and ASA classification >3 declined(p=.05). There was no difference in prevalence[50% vs. 43%;p=.6] or number[median-1.5(0, 5)] of pre-admission EVAR re-interventions; however, time to re-intervention decreased(median: 23[6,34] vs. 0[0,22] months;p=.005). In contrast, time to EVAR-c significantly increased(median: 16[9,39]vs. 48[20,83]-months;p=.008). No difference in frequency of non-elective presentation[mean-52%;p=.9] or indication was identified but a trend toward increasing mycotic EVAR-c was observed(5% vs. 15%;p=.09). Use of retroperitoneal exposure(14% vs. 77%;p<.0001), suprarenal cross-clamp application[6286%;p=.04] and visceral-ischemia time(median: 0[0,11] vs. 5[0,20]min;p=.05) all increased. In contrast, estimated blood loss(P-trend=.03) and procedure-time(p=.008) decreased. The unadjusted elective 30-day mortality rate improved but did not reach statistical significance[elective: 10% vs. 5%;p=.5] with no change for non-elective operations[18% vs. 16%;p=.9]. However, a significantly decreased risk of complications was evident(OR 0.88, 95%CI .8-.9;p=.01). One and 3-year survival was similar over time.

CONCLUSION

EVAR-c is now a common indication for open AAA repair. Patients frequently present non-electively and at increasingly later intervals after their index EVAR. Despite increasing technical complexity, decreased complication risk and comparable survival can be anticipated when patients are managed at a high-volume aortic referral center.

Extended intensive care correlates with worsening of surgical outcome after elective abdominal aortic reconstruction

BACKGROUND

The aim of this study was to evaluate the impact of extended postoperative intensive care on short- and long-term patient outcome after elective abdominal aortic surgery and to assess the risk factors for patient survival after extended intensive care unit (ICU) treatment.

METHODS

The data of 231 patients that underwent open or endovascular abdominal aortic surgery were retrospectively analysed with regard to extended postoperative intensive care, defined as ICU treatment for more than 24 consecutive hours. Pre- and intraoperative factors were evaluated. The endpoints of the study were postoperative complications, mortality, and long-term follow-up. Univariate and multivariate Cox proportional regression analyses were performed to identify risk factors of worse overall survival.

RESULTS

Extended postoperative intensive care was needed in 84 patients (63 after open and 21 after endovascular surgery). The period of ICU treatment was similar in both groups. Only the wound complications (31.8% vs. 9.5%, p=.0498; OR 4.42 (0.94-20.84)) and the rate of acute kidney injury (82.5% vs. 57.1%, p=.0352; OR 3.55 (1.20-0.46)) were more frequent after open surgery, whereas brief reactive psychosis (38.1% vs. 14.3%, p=.0281; OR 0.27 (0.09- 0.84)) was more frequent after endovascular surgery. ICU stay of ≥8 days correlated with significantly lower survival rates compared to a shorter ICU stay (p=.0034), independent of open or endovascular techniques. Other multivariate risk factors for worse survival were the absence of preoperative aspirin medication, a body mass index (BMI) of <25, chronic renal insufficiency (CRI), and coronary artery disease (CAD). Endovascular therapy was a positive predictive factor of short ICU stay of ≤3 days.

CONCLUSIONS

The outcome after extended intensive care following elective aortic surgery is strongly dependent on the length of ICU stay.

Characteristics and Prognosis of Abdominal or Thoracic Aortic Aneurysm Patients Admitted to Intensive Care Units After Surgical Treatment: A Multicenter Retrospective Observational Study

Objective

To investigate the characteristics and prognosis of abdominal or thoracic aortic aneurysm (AAA or TAA) patients admitted to intensive care unit (ICU) postoperatively.

Methods

Patients admitted to ICU postoperatively with a primary diagnosis of AAA or TAA were screened in the eICU Collaborative Research Database, which contained data from multiple ICUs throughout the continental United States in 2014 and 2015. Baseline characteristics and comorbidities and were investigated and factors associated with ICU mortality were explored using univariable logistic regression. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the prognosis predictive performance of the widely used severity scoring system APACHE IVa.

Results

A total of 974 patients including 677 AAA and 297 TAA patients admitted to ICU postoperatively were included. Compared with TAA, AAA patients had a significantly higher median age (72 versus 64 years, P<0.001). 89.07% AAA and 84.51% TAA patients underwent elective surgery (P=0.046), 8.71% AAA and 31.99% TAA patients were with aortic dissection (P<0.001), and 10.19% AAA and 2.36% TAA patients suffered from rupture of aortic aneurysm (P<0.001). Hypertension requiring treatment was the most common comorbidity (57.31% for AAA and 61.95% for TAA). TAA patients had significantly higher ICU mortality (9.43% versus 2.36%, P<0.001) than AAA. Several factors were found to be significantly associated with ICU mortality, including urgent surgery, with aortic dissection, rupture of aortic aneurysm, TAA, and a higher APACHE IVa score on ICU admission. APACHE IVa showed a good predictive performance for ICU mortality with an area under the ROC curve of 0.9176 (95% CI 0.8789–0.9390).

Conclusion

The prognosis of aortic aneurysm patients admitted to ICU postoperatively is yet to improve, and factors associated with prognosis are mainly related to the condition itself. APACHE IVa can be used for prognosis prediction.

Hospital resource use and costs among abdominal aortic aneurysm repair patients admitted to the intensive care unit

BACKGROUND

Abdominal aortic aneurysm (AAA) repair is associated with significant morbidity and mortality. As a result, many of these patients are monitored postoperatively in the intensive care unit (ICU). However, little is known about resource utilization and costs associated with ICU admission in this population. We sought to evaluate predictors of total costs among patients admitted to the ICU after repair of nonruptured or ruptured AAA.

METHODS

We retrospectively analyzed prospectively collected data (2011-2016) of ICU patients admitted after AAA repair. The primary outcome was total hospital costs. We used elastic net regression to identify pre-ICU admission predictors of hospitalization costs separately for nonruptured and ruptured AAA patients.

RESULTS

We included 552 patients in the analysis. Of these, 440 (79.7%) were admitted after repair of nonruptured AAA, and 112 (20.3%) were admitted after repair of ruptured AAA. The mean age of patients with nonruptured AAA was 74 (standard deviation, 9) years, and the mean age of patients with ruptured AAA was 70 (standard deviation, 8) years. Median total hospital cost (in Canadian dollars) was $21,555 (interquartile range, $17,798-$27,294) for patients with nonruptured AAA and $33,709 (interquartile range, $23,173-$53,913) for patients with ruptured AAA. Among both nonruptured and ruptured AAA patients, increasing age, illness severity, use of endovascular repair, history of chronic obstructive pulmonary disease, and excessive blood loss (≥4000 mL) were associated with increased costs, whereas having an anesthesiologist with vascular subspecialty training was associated with lower costs.

CONCLUSIONS

Patient-, procedure-, and clinician-specific variables are associated with costs in patients admitted to the ICU after repair of AAA. These factors may be considered future targets in initiatives to improve cost-effectiveness in this population.

Sex differences in repair rates and outcomes of patients with ruptured abdominal aortic aneurysm

BACKGROUND

Data are conflicting on sex differences in ruptured abdominal aortic aneurysm (rAAA) repair rates and outcomes have rarely been addressed. The aim of this study was to investigate differences in the management and outcome of rAAA in men and women, and to describe time trends over a 15-year interval.

METHODS

Data on patients with rAAA were extracted from the Swedish National Patient Registry and the Cause of Death Registry for the interval 2001-2015. The study included patients with rAAA whether or not they were admitted to any hospital in Sweden. A propensity score-matched model was used to determine sex differences in repair type and outcome after rupture. Time trends for rAAA events and mortality were investigated.

RESULTS

Some 10 724 patients were identified. A higher percentage of men were admitted to hospital (79·8 versus 77·5 per cent; P = 0·011). Of those admitted, a higher percentage of men than women were treated (56·6 versus 40·4 per cent, P < 0·001). Women were less likely to be treated when diagnosed with rAAA (average treatment effect (ATE) in the model -0·080, 95 per cent c.i. -0·106 to -0·055; P < 0·001). Thirty-day mortality was also higher in women (ATE 0·094, 0·053 to 0·135; P < 0·001); this effect persisted to 1 year (ATE 0·095, 0·052 to 0·137; P < 0·001). Time trends indicated a decrease in rAAA incidence, mostly owing to a decrease among men.

CONCLUSION

In this study, fewer women with rAAA received surgery and 30-day mortality was higher than in men. There was an overall decrease in rAAA incidence, principally in men.