TAAA, when meeting surgical criteria, has a poor prognosis with a 5-year survival rate of 10-20% if untreated. Open surgery is effective and alters the disease’s natural progression, though it remains technically challenging and carries a higher surgical risk. This results in perioperative complications more frequent than in other cardiovascular surgeries, with high morbidity and mortality rates.
Acute kidney injury (AKI) following cardiac surgery increases the risk of cardiovascular events and mortality. Additionally, TAAA surgery is linked to worse outcomes in terms of postoperative mortality and long-term survival.
This randomized, double-blind, prospective, single-center study (CURITIBA) involved 90 patients with TAAA who underwent elective repair surgery. Each group comprised 45 patients, with no differences observed between groups in terms of key demographic variables, comorbidities, preoperative risk factors, and aneurysm per Crawford classification. The primary goal was to assess postoperative AKI, defined by the KDIGO scale, categorizing patients based on whether renal perfusion was performed with Custodiol solution or Lactated Ringer’s solution enriched with methylprednisolone and mannitol. Mortality, survival, and renal function at one year were analyzed. Univariate and multivariate analyses were conducted to identify associations between key variables and the occurrence of AKI. AKI was observed in 62% of patients, with stage 1 (32.9%) prevailing in both groups. In the Custodiol group, 40% of patients developed AKI compared to 60% in the RL group (p = 0.001). Any AKI stage was more frequent in the RL group (75% vs. 48.9% with Custodiol, p = 0.02), with severe AKI in 35.6% of RL cases versus 24.4% in the Custodiol group, p=0.36. The need for renal replacement therapy, either with continuous veno-venous hemofiltration or hemodialysis, was higher in the RL group (13.3% vs. 2.2% with Custodiol), though not statistically significant. No differences were observed in postoperative complications, ICU or hospital stay, or mortality (6 patients in the RL group vs. 4 in the Custodiol group). Univariate analysis indicated that RL solution (p = 0.01) and Crawford type II TAAA (p = 0.05) were associated with AKI development. Conversely, multivariate analysis identified independent predictors of severe AKI as smoking, COPD, chronic kidney disease, and Crawford type II and III aneurysms, while Custodiol use emerged as an independent protective factor against AKI (p = 0.003).
The authors conclude that Custodiol use for intraoperative renal perfusion in open TAAA surgery is safe and significantly reduces AKI incidence compared to perfusion with Lactated Ringer’s solution.
COMMENTARY:
Custodiol is a cardioplegic preservation solution, an extracellular crystalloid with low sodium and calcium content, administered in a single dose to induce asystole with a high volume of 1500-2000 mL. It is also used as a preservation solution for cardiac, renal, hepatic, and pancreatic transplants with favorable outcomes. The RL perfusion solution includes 125 mg/L of methylprednisolone and 12.5 g/L of mannitol.
In this study, the renal arteries were cannulated with 9F occlusion-perfusion catheters directly through the ostia intraluminally. Cold solutions at 4°C were administered via a drip perfusion system, averaging 1.5 mL per gram of estimated renal weight, with a mean total of 500 mL for Custodiol and 400 mL for RL (p = 0.54), and renal ischemia times of 41 minutes with Custodiol and 36 minutes with RL (p = 0.46). Initially, a rapid infusion was applied, followed by drip-controlled dosing based on estimated renal weight. Renal perfusion strategy could be improved, as a drip system does not strictly control parameters like temperature, continuous flow, or perfusion pressure, which could be achieved with auxiliary roller pumps from the extracorporeal circulation machine.
The study has limitations due to its small sample size and single-center nature. Future studies should include larger sample sizes and be multicentric to obtain more consistent evidence. Despite these limitations, this well-designed, randomized study provides robust initial data supporting further investigation into Custodiol as a renal protective solution in this surgery, as it shows no adverse events and better AKI outcomes compared to RL. Nonetheless, despite renal protection strategies, AKI remains high at 62%, indicating room for improvement.
REFERENCE:
Kahlberg A, Tshomba Y, Baccellieri D, Bertoglio L, Rinaldi E, Ardita V, et al. Renal perfusion with histidine-tryptophan-ketoglutarate compared with Ringer’s solution in patients undergoing thoracoabdominal aortic open repair. J. Thorac Cardiovasc Surg. 2023;165:569-79.e5. doi: 10.1016/j.jtcvs.2021.02.090.
