Ulinastatin

Type A aortic dissection (TAAD) is a life-threatening disease with high mortality and poor prognosis, usually treated by surgery. There are many complications in its perioperative period, one of which is oxygenation impairment (OI). As a common complication of TAAD, OI usually occurs throughout the perioperative period of TAAD and requires prolonged mechanical ventilation (MV) and other supportive measures. The purpose of this article is to review the risk factors, mechanisms, and treatments of type A aortic dissection-related oxygenation impairment (TAAD-OI) so as to improve clinicians’ knowledge about it. Among risk factors, elevated body mass index (BMI), prolonged extracorporeal circulation (ECC) duration, higher inflammatory cells and stored blood transfusion stand out. A reduced occurrence of TAAD-OI can be achieved by controlling these risk factors such as suppressing inflammatory response by drugs. As for its mechanism, it is currently believed that inflammatory signaling pathways play a major role in this process, including the HMGB1/RAGE signaling pathway, gut-lung axis and macrophage, which have been gradually explored and are expected to provide evidences revealing the specific mechanism of TAAD-OI. Numerous treatments have been investigated for TAAD-OI, such as nitric oxide (NO), continuous pulmonary perfusion/inflation, ulinastatin and sivelestat sodium, immunomodulation intervention and mechanical support. However, these measures are all aimed at postoperative TAAD-OI, and not all of the therapies have shown satisfactory effects. Treatments for preoperative TAAD-OI are not currently available because it is difficult to correct OI without correcting the dissection. Therefore, the best solution for preoperative TAAD-OI is to operate as soon as possible. At present, there is no specific method for clinical application, and it relies more on the experience of clinicians or learns from treatments of other diseases related to oxygenation disorders. More efforts should be made to understand its pathogenesis to better improve its treatments in the future.

Ulinastatin is a protease-inhibiting drug with anti-inflammatory and other pharmacological properties. Little is known regarding its role following acute type A aortic dissection (ATAAD) surgery. We perform a randomized controlled trial to investigate the protective effect of ulinastatin against negative inflammatory response and organ dysfunction in ATAAD surgery (PANDA). The primary outcome of mean daily Sequential Organ Failure Assessment (SOFA) score from baseline to 7 days of surgery is 8.80 (SD, 4.11) in the ulinastatin group and 8.61 (SD, 4.47) in the control group (mean difference between groups was 0.04; 95% confidence interval [CI], -0.24 to 0.33; p = 0.765). Systemic inflammatory response syndrome (SIRS) within 7 days of surgery is lower in the ulinastatin group than in the control group (p < 0.001). Additional ulinastatin to standard treatment is likely to reduce SIRS rates instead of preventing organ dysfunction, highlighting the potential importance of the benefits of anti-inflammatory pharmacotherapeutics. The trial is registered on clinicaltrials.org (NCT04711889).