JVS: Reliable new risk scoring tool can guide operative decisions for rAAA patients

PREOPERATIVE RISK SCORE TO PREDICT MORTALITY AFTER REPAIR OF RUPTURED ABDOMINAL AORTIC ANEURYSMS, Journal of Vascular Surgery, October 2018.

CHICAGO, Illinois, Sept. 25, 2018 –An accurate new scoring tool using only pre-operative metrics can predict whether patients with a ruptured abdominal aortic aneurysm are likely to survive surgery. The condition is often a quick killer, and many patients don’t make it to the operating room, while others die after surgery.

“In cases where mortality is expected to be 100%, initiating comfort care allows the family to spend time with the patient as opposed to risking the patient dying during transport while the family desperately drives to the hospital,” explained vascular surgeon and lead researcher Brandon Garland, MD, of the University of Washington, Seattle.

Other risk scoring tools are available, but most are based on older information collected before the advent of endovascular therapy for ruptured AAA, or rely on intra-operative information only.

As reported in the October 2018 edition of the Journal of Vascular Surgery, researchers aimed to develop a practical, preoperative risk score to predict mortality after repair of rAAA in the modern era. They retrospectively studied the outcomes of 303 patients presenting with rAAA between 2002 and 2013 who underwent either open or endovascular repair.

Despite significant effort to screen appropriately selected patients for AAA, rupture remains the most frequent and lethal complication of AAAs world-wide, particularly in elderly men. Fortunately, recent advances, including endovascular therapies, multi-disciplinary protocols and regionalization of aortic care, have improved the survival of patients presenting rAAA.

Several previous risk scores have been suggested to help guide decision-making between the practitioner, the patient and the family. The utility of such guides becomes progressively important as the potential for mortality increases.

In certain circumstances, it might be most appropriate to offer supportive care rather than a futile operation with an unavoidable bad outcome and associated excessive cost. Unfortunately, most of the previous risk scores were proposed before the advent of endovascular therapy for rAAA or relied on intra-operative information only.

In the UW study, 70% of patients underwent open repair; however, after 2007 when an “EVAR first” policy was adopted, this percent dropped to 53% for open repair. Four risk factors found to be most predictive of mortality were:
• Age > 76 years (Odds Ratio 2.11, Confidence Interval 1.47-4.97)
• Creatinine > 2.0 mg/dL (OR 3.66, CI 1.85-7.24)
• pH < 7.2 (OR 2.58, CI 1.27-5.24)
• systolic blood pressure ever < 70 mmHg (OR 2.70, CI 1.46-4.97)

Assigning each of these risk factors one point, the researchers found a significant correlation between number of points and 30-day mortality:
• 0 points = 27% (18 of 62 patients)
• 1 point = 22% (18 of 83 patients)
• 2 points = 70% (48 of 70 patients)
• 3 points = 80% (25 of 32 patients)
• 4 points = 100% (5 of 5 patients)

“In presenting referring providers with this information about our mortality rates under varying conditions, it is usually well received.” Dr. Garland said. “The physicians now have data to tell the patient and their families that transfer may be futile.”

In addition to the social implications, he added, “the cost of transport from these hospitals may be avoided as well as the operating room costs that occur when the family is presented with the bill after their loved one has died.”

Dr. Garland noted that limitations of the study include: it was conducted during a period of changing paradigms for care; it may not be applicable to institutions with low volume AAA care; it studied only patients who had already survived transport.

This article is open source at vsweb.org/JVS-RiskScore from the Journal for Vascular Surgery until Nov. 30, 2018.