الفهرس 
Incidence of Acute Kidney Injury (AKI) after Endovascular Abdominal Aortic Aneurysm Repair (EVAR) and its Effect on Patients’ Outcome
ContentsOnly 14 pages are availabe for public view
 |  | from | 103 |  |  |
| | | from | 103 | | |
Abstract
: Abdominal aortic aneurysms (AAA) constitute a serious health problem with a current prevalence for men above the age of 65 ranging from 2% to 7%. Advantages in perioperative survival rates have led endovascular abdominal aortic aneurysm repair (EVAR) to become the first line of treatment for anatomically suitable aneurysms in many centers, as early and medium-term outcomes have proven similar or superior to open repair. However, those undergoing EVAR are at risk of developing acute kidney injury (AKI). AKI after any type of surgical or radiological intervention is independently associated with higher morbidity, prolonged length of hospital stays, cost, and short-term mortality. Stage 1 AKI is defined as an absolute increase in serum creatinine (SCr) of more than or equal to 0.3 mg/dL, or a percentage increase in SCr of more than or equal to 50 % or a reduction in urine output to less than 0.5 mL/kg per hour for more than 6 hours. (1) Despite being a relatively common complication, there is no clear consensus regarding the incidence of AKI after elective EVAR and the available data is heterogenous.
Methods: This interventional prospective case series study included 30 patients and was designed to determine the incidence of AKI in AAA patients indicated for and undergoing EVAR in Kasr Al Ainy, Cairo University Hospitals. It aimed to assess the impact of AKI on patients’ outcome in terms of morbidity and mortality over a period of 20 months from January 2020 to September 2021. We also aimed to ascertain whether any specific medical or technical risk factors were involved. Pre- and post-operative evaluation followed the same standard protocol and included a thorough personal, medical and surgical history, complete laboratory tests and a computed tomography angiogram (CTA). Blood samples (complete blood count, urea, SCr and electrolytes) were repeated at 24 and 48 hours after the EVAR procedure for every patient in addition to monitoring the urine output for 48 hours post-operatively. Patients who developed AKI over the initial 48 hours after EVAR were subsequently reviewed by a nephrologist and further treatment was decided based on that consultation. If the patient developed any cardiorespiratory complications, postoperatively, he was managed in the ICU. A standard follow-up protocol, including laboratory checks at 30 days and 3 months after the operation, was employed for all patients. Imaging during follow up included a repeat surveillance CTA at 3 months.
Results: In this case series study, the incidence of AKI was 16.7%. AKIN, KDIGO and NICE criteria were used in this study for diagnosing AKI post EVAR. (1) One of the main preoperative predictors of AKI development in this study was the presence of T2DM, despite its relatively low prevalence among patients with AAA. Four out of five patients who developed AKI were diabetic. (p value: 0.047) In terms of intraoperative risk factors, there was a correlation between AKI and the volume of contrast administered intraoperatively. There was a statistically significant increase in the incidence of AKI in patients who received higher volume of contrast; a mean volume of 144 ml of Ultravist 300, Bayer, Berlin, Germany. (p value: 0.001). The risk of morbidity and mortality was 20% in the group who developed AKI. This was statistically significant compared to the group who did not develop AKI (p value of 0.018). Determining whether supra-renal fixation was associated with higher incidence of AKI could not be ascertained from this study as supra-renal fixation stent grafts were used in all patients. No statistically significant correlation was identified between AKI and age, angiotensin receptor blockers and aortic neck diameter. In addition, no statistical significance was found between accessory renal artery coverage and AKI.
Conclusion: AKI post EVAR is relatively common compared to previous studies and is associated with increased mortality and morbidity. Further studies are needed to assess the impact of AKI on longer term results and examine possible perioperative preventative strategies including using CO2 angiography and 3D registration method of image fusion guidance as an alternative to significantly reduce the volume of contrast administered.