Rare But Important Risk After Spine Surgery

If you have ever had surgery of any kind or even known someone else getting ready for surgery, one thing is always discussed preoperatively. And that’s the possible complications. Though most post-op problems are uncommon or even rare, it is still the responsibility of the health care provider to review all possibilities with patients. Infection, blood clots, heart attacks, stroke and even death are all listed for major spine surgery.

In this study from Taiwan, the risk of stroke following spinal fusion surgery is investigated. Taiwan has a unique study situation in that the entire one million population is covered by a government-run health insurance. Everyone has free and unlimited access to health care even if they are traveling or out of their own country and receive treatment overseas.

This type of system makes follow-up easier and more predictable. Even if a patient in a study like this goes somewhere else within the system, the records are still available for follow-up. Therefore, incidence rates calculated tend to be more accurate and estimates of stroke risk more reliable.

Out of one million people, there were 2,249 who had spinal fusion. This group was matched with a very similar group of 2,203 adults who did not have spinal fusion. When we say the groups were “matched” closely, it means they were the same ages, gender (male versus female), education level, income level, and living location (rural versus urban). They were also very similar in terms of general health and the presence of other health problems such as diabetes, high blood pressure, heart or lung disease, and so on.

The rates of stroke during a three-year follow-up were compared. They found no differences between the two groups (those who had spinal fusion surgery and those who did not). In fact, the spinal fusion group had slightly (though not significantly) lower rates of stroke.

The authors suggest some possible reasons for these results. Stabilizing the spine reduces pain and improves function. Patients who were previously inactive or sedentary because of back pain can increase their activity and exercise after spinal fusion. This effect could reduce the risk of stroke. Patients with health problems like diabetes or heart arrhythmias are treated for these problems before surgery. Controlling conditions like these that can contribute to stroke may be another preventive factor.

People who smoke or use tobacco products are asked to stop prior to surgery. Some may not go back to this habit, thus improving their chances of better health afterwards. And surgeons do screen patients before surgery in order to select those who are more likely to have a positive result. Anyone with significant health problems may not be accepted for surgery. The healthier and more active someone is before surgery, the more likely they will have fewer complications and better results after surgery.

In summary, this was the first study to evaluate the risk of stroke after spinal fusion surgery. They did not find an increased risk of stroke. In fact, they report that stroke as a postoperative complication is rare following spinal fusion. It is possible to conclude that patients at increased risk for stroke should not be kept from having spinal fusion surgery if they need it. The positive results from the procedure (including increased activity and exercise) could improve their overall health and reduce risk for many other health conditions.

The authors point out several areas for future study related to this topic. First, there are many different ways to perform spinal fusion. There are different spinal levels and number of levels fused. These factors may affect how long someone is in surgery, how much blood is lost, and postoperative recovery. Any of these variables may influence the risk of stroke or other complications and should be investigated.

Likewise, as improved surgical techniques are developed, it has become safer for a larger number of older adults to have spinal fusion surgery. The increased age of patients having spinal fusion surgery may change the incidence of stroke following this procedure. Future studies are needed to keep an eye on this possibility as well.