Risk of postoperative visual loss is highest after heart surgery

The new research confirms that this "rare but potentially devastating" complication is most frequent after cardiac surgery or spinal fusion procedures. It also reports a higher-than-expected rate of postoperative visual loss after other common surgeries, as well as in children.

Postoperative visual loss occurs in about 2 of 10 000 surgeries

Using a large nationwide database, Yang Shen, M.A., M.S., and colleagues of The University of Chicago analyzed more than 5.6 million patients undergoing common surgical procedures between 1996 and 2005. The overall rate of postoperative visual loss was low and decreased significantly during the 10-year period studied: from approximately 3 to 2 cases per 10 000 surgeries.

The risk of postoperative visual loss was highest after heart surgery, nearly 9 out of 10 000 procedures; followed by spinal fusion surgery, 3 out of 10 000 procedures. The researchers were surprised to find lower but still significant rates of postoperative visual loss after other common procedures as well: about 1 to 2 out of 10 000 patients undergoing hip replacement, knee replacement, or colorectal surgery. At the other end of the scale, for patients undergoing appendectomy, the risk was only 1 out of every 100 000.

In another surprise, the researchers found that patients under 18 years old were one of the highest-risk groups. "Postoperative visual loss has typically been considered a disease with a higher risk in elderly patients, presumably because of diseased arteries," comments Dr. Steven L. Shafer of Columbia University, editor-in-chief of Anaesthesia & Analgesia. "Clearly more studies are needed in children to understand their risk." Risk was also higher in men, patients with multiple medical problems, and patients with anaemia or blood transfusions.

One of the most-feared complications

Postoperative visual loss is one of the most-feared complications of surgery and anaesthesia. However, it is so rare that it is often not mentioned to patients undergoing surgery, except for those undergoing known high-risk procedures—especially heart and spinal surgery.

The new research confirms that the risk of postoperative visual loss is highest after cardiac surgery and spinal fusion procedures. "This is well known to surgeons and anaesthesiologists, who typically present this as a rare but devastating complication when discussing the risks of surgery and anaesthesia with patients," according to Dr. Shafer.

The study also demonstrates an "appreciable" risk of postoperative visual loss with several other common procedures, including hip replacement, knee replacement, and major abdominal surgery. Dr. Shafer adds, "Although the risk is small, patients and surgeons need to consider this when assessing the overall risks and benefits of these procedures."

Source: International Anaesthesia Research Society