Even as the frequency of decompression surgeries has fallen, the rate of complex fusion procedures for the treatment of spinal stenosis has jumped 15-fold, a new study shows.

Furthermore, that increase may be leading to higher complication rates. Life-threatening complications rose with increasing surgical invasiveness, from 2.3% in patients with decompressions alone to 5.6% in those who received complex fusions, according to the report, published in the Journal of the American Medical Association (2010;303:1259-1265).

“I would argue that a lot of patients are getting a more complex surgery than they need,” said the study’s lead author, Richard A. Deyo, MD, Kaiser Permanente Professor of Evidence-Based Family Medicine at the Oregon Health & Science University, in Portland. “While improvements in technique have made these complex procedures more feasible, there has also been a lot of aggressive marketing. Other factors that may be at play are the financial incentives to both the hospitals and the doctors, and the drive for surgeons to be perceived as being on the cutting edge.”

For the new study, Dr. Deyo and his colleagues examined all spinal surgery claims filed between 2002 and 2007 (but focused on the 32,152 claims from 2007) in order to determine the number of complications associated with each procedure type. The procedures were rated 1 to 3, depending on their level of invasiveness: decompression alone, simple fusion (one or two disc levels, single surgical approach), or complex fusion (more than two disc levels or combined anterior and posterior approach).

During the five-year study period, surgeries for lumbar stenosis decreased slightly from 137.4 per 100,000 Medicare beneficiaries in 2002 to 135.5 per 100,000 in 2007. The rates of spinal decompression and simple fusions also declined. In contrast, the rate of complex fusions increased from 1.3 to 19.9 per 100,000. Although patients with scoliosis had the highest percentage of complex fusion procedures, patients without spondylolisthesis or scoliosis accounted for 50%, Dr. Deyo pointed out.

The researchers looked at three categories of complications: major medical complications, such as cardiopulmonary resuscitation, acute myocardial infarction and respiratory failure; wound complications, such as hemorrhage, hematoma and postoperative infection; and 30-day mortality.

Patients who had a complex fusion procedure were nearly three times as likely as those with decompression alone to have a life-threatening complication. Complex procedures also increased the likelihood that a patient would need to be readmitted to hospital: 7.8% of those who underwent decompression returned to the hospital within 30 days compared with 13% of those who received a complex fusion procedure. The researchers also found that complex fusion led to a much higher hospital charge: $80,888 on average compared with $23,724 for decompression.

Long-term Outlook

Spine surgeons aren’t convinced that the findings signal a problem with overuse of complex procedures. There are a lot of factors that could explain the increase, said William Welch, MD, professor and vice chair of clinical affairs in the Department of Neurosurgery at the University of Pennsylvania School of Medicine, in Philadelphia.

These days, patients are healthier overall, Dr. Welch explained. They live longer and that means if they have a degenerative condition like scoliosis, the surgeon may choose a procedure that will keep the spine stable for many years. “While decompression alone might work in the short term, it may not be a good choice for the long term,” he said. Another reason for the increase in complex procedures is that more surgeons have become comfortable using them, Dr. Welch said.

Even when patients do not have an unstable spine, fusion may make sense, said Arya Nick Shamie, MD, associate professor of orthopedic surgery and neurosurgery at the University of California, Los Angeles. That’s because decompression itself can lead to instability. “We want to get our patients better by decompressing their nerves completely and not to have them come back with a spine that has slipped sideways because we didn’t fuse it,” Dr. Shamie said.

Dr. Shamie also points to the changing expectations of patients and their surgeons. These days, both want a surgery that will allow maximal function, he explained.

Although it is possible that there are some cases in which surgeons choose the more invasive approach because they are worried about spinal instability and lawsuits, Dr. Shamie believed that physicians are ultimately picking the procedure they believe will do the most good for their patients.