Effect of mannitol administration on outcomes of open abdominal aortic aneurysm repair

Mannitol, a hyperosmolar solution widely administered for renal protection, may also have cardioprotective effects. Although its benefits in chronic kidney disease patients undergoing vascular surgery are documented, the impact of mannitol on all patients undergoing open abdominal aortic aneurysm (AAA) repair, including patients without chronic kidney disease, remains unclear. This study aimed to evaluate the effect of intraoperative mannitol on mortality, renal protection, and other postoperative outcomes in patients undergoing open AAA repair.

We conducted a retrospective analysis using data from the Society for Vascular Surgery Vascular Quality Initiative database, covering patients who underwent open AAA repair from 2003 to 2021. The study population was divided into two groups based on intraoperative mannitol use, stratified by proximal clamp location (suprarenal vs infrarenal). Baseline characteristics, comorbidities, and perioperative details were compared between the groups. Postoperative outcomes, including 30-day mortality, renal complications, prolonged length of stay, and 1-year survival, were analyzed using univariable and multivariable logistic regression, Kaplan-Meier survival curves, and Cox regression, adjusting for potential confounders. The multivariable models were adjusted for variables including age, sex, urgency of the procedure, preoperative smoking status, American Society of Anesthesiologists class, clamp duration, estimated blood loss, preoperative creatinine, prior history of congestive heart failure, total procedure time, statin use, and P2Y receptor inhibitor use.

Among the 15,961 patients, 8963 (56.2%) received intraoperative mannitol. Mannitol use was associated with lower 30-day mortality rates in both infrarenal (5.4% vs 9.6%; P < .001) and suprarenal clamping (7.3% vs 18.2%; P < .001). In adjusted analyses, mannitol was associated with a significant reduction in 30-day mortality in the suprarenal group (hazard ratio, 0.63; P < .001). Mannitol use did not significantly affect renal complications in either group. However, mannitol use in patients undergoing suprarenal clamping experienced a significant survival benefit regardless of glomerular filtration rate status.

Intraoperative mannitol use during open AAA repair is associated with improved postoperative survival, particularly in patients undergoing suprarenal clamping. Although mannitol does not reduce renal complications significantly, its cardioprotective effects may provide substantial benefits in specific patient subgroups. These findings support the selective use of mannitol in open AAA repair, particularly in high-risk patients.