Background To determine whether venous congestion is an important predictor of postoperative kidney injury and other adverse events after type A aortic dissection (TAAD).

Methods Authors collected data of adults who underwent surgery for TAAD between January 2016 and July 2023. Primary exposures were venous congestion defined by central venous pressure (CVP) and mean arterial pressure (MAP). The primary outcomes were acute kidney injury (AKI) and acute injury disease (AKD). The secondary outcomes encompassed death and stroke. Restricted cubic spline regression model was used to adjust for confounding factors and multiple comparisons.

Type A aortic dissection (TAAD) is a catastrophic cardiac macrovascular disease with a striking in-hospital mortality rate of 22%-31%. Among the myriad of complications following TAAD surgeries, acute kidney injury (AKI) is one of the most prevalent, boasting an incidence of 40-55%. Notably, this incidence surpasses that observed in other cardiovascular procedures, such as coronary artery bypass grafting (CABG), which ranges from 10-20%, and aortic valve replacement (AVR) at 17-23%. Furthermore, the occurrence of AKI post-TAAD surgeries has been linked with escalated in-hospital, short-term, and long-term mortalities, as well as significant complications.

Preoperatively, patients with TAAD usually have poorly controlled blood pressure, long-term hypertension can cause chronic kidney damage. In some cases, involving renal artery origins, renal perfusion insufficiency may exist preoperatively. Intraoperatively, the kidneys need to undergo a complete ischemic phase of deep hypothermic circulatory arrest (DHCA), inflammatory reactions associated with cardiopulmonary bypass (CPB), and a large number of blood and fluid transfusions could potentially cause renal dysfunction. Patients are at high risk for postoperative surgical site infection following TAAD procedure, further exacerbating acute kidney injury. The myriad factors mentioned above collectively exacerbate the elevated occurrence of kidney injury following Type A Aortic Dissection (TAAD) surgeries when juxtaposed with other cardiac surgical procedures. Pathological anatomy and surgical procedure intricacies pose formidable challenges in mitigation. Consequently, the pursuit of precise intraoperative hemodynamic management objectives aimed at maximizing organ perfusion has emerged as a focal point in contemporary research endeavours. A study encompassing 5,127 patients undergoing CABG and cardiac valvular surgery underscored the role of venous congestion duration and severity as independent postoperative AKI/AKD risk determinants. However, the relationship between intraoperative hemodynamic in TAAD surgeries and ensuing AKI/AKD remains elusive. There's a paucity of comprehensive evaluations, primarily due to a dearth of long-term data from expansive TAAD cohorts. The investigators' primary objective was to discern the correlation between intraoperative hypotension and venous congestion durations and magnitudes at varied thresholds during TAAD surgeries and the subsequent risks of postoperative AKI/AKD. As a secondary objective, the investigators sought to elucidate the association between intraoperative hemodynamic and major adverse events, including stroke and mortality. The investigators hypothesize that both intraoperative hypotension and venous congestion are paramount predictors for postoperative AKI and AKD following TAAD surgeries.

Inclusion Criteria:

1) Eligible patients were adults, aged 18 or older.

Exclusion Criteria:

1. Lacking preoperative serum creatinine (Scr) values
2. Insufficient hemodynamic or laboratory data
3. Exhibiting a preoperative Scr level ≥133 μmol/L
4. Patients with renal insufficiency before surgery
5. Patients on preoperative dialysis

Eligible patients underwent surgery for TAAD.