Factors predicting acute kidney injury in patients after abdominal aortic aneurysm repair

Introduction

Postoperative acute kidney injury (AKI) is one of the most frequent complications in abdominal aortic aneurysm (AAA) patients after open and endovascular aortic aneurysm repair. AKI decreases the efficiency of kidney function, allowing accumulation of waste products in the body, and an imbalance of water, acid and electrolytes in the body. As a result, the functioning of various organs throughout the body is affected. These effects may raise the cost of treatment, length of stay, and mortality rate.

Objective

This study aims to examine the predictive factors of AKI – preoperative of estimated glomerular filtration rate (eGFR), preoperative of hemoglobin level, types of abdominal aortic aneurysms repair, and intraoperative of cardiac arrhythmias – after open and endovascular aortic repair among AAA patients within 72 h.

Methods

This is a retrospective study of 196 patients with AAA after elective open and endovascular aortic aneurysm repair within the first 72 h who met the inclusion criteria recruited from a tertiary care hospital in Bangkok, Thailand. Postoperative AKI after elective open and endovascular aortic repair among AAA patients is defined by the 2012 Kidney Disease Improving Global Outcomes (KDIGO) Clinical Practice Guidelines.

Results

A total of 196 AAA patients, 75.5% were male with an average age of 75.12 years (SD = 8.45). Endovascular aortic aneurysm repair was used more frequently than open aortic aneurysm repair (64.8% vs 35.2%) and 37.2% of the AAA patients had intraoperative cardiac arrhythmias. The occurrence of AKI among the AAA patients after abdominal aortic aneurysm repair within 72 h was 54.1%. The AKI rate of EVAR patients was 69.8% while the AKI rate for OAR patients was 30.2%. The preoperative estimated glomerular filtration rate (eGFR) and hemoglobin level were found to jointly predict AKI and explain 32.2% of the variance (Nagelkerke R² = 0.322, p < .05). However, the type of abdominal aortic aneurysms repair and intraoperative cardiac arrhythmias did not correlate with the incidence of AKI in AAA repair patients. The predictive factors for AKI among AAA patients after aortic aneurysm repair were preoperative eGFR < 60 mL/min/1.73 m² (OR = 4.436, 95% CI: 2.202–8.928, p < .001) and preoperative hemoglobin level between 8.1–10.0 g/dL (OR = 4.496, 95% CI: 1.831–11.040, p = .001).

Conclusion

Preoperative eGFR < 60 mL/min/1.73 m² and preoperative hemoglobin level between 8.1–10.0 g/dL were the predictive factors for AKI among AAA patients after both open and endovascular AAA repair. Therefore, healthcare providers should be aware of and monitor signs of AKI after surgery in AAA patients, especially those undergoing EVAR with lower eGFR and hemoglobin levels.