Single-stage I&D for SSI After Spine Surgery May Not Be Enough

What’s the Claim?

In a large, single-center study (11,023 elective spine surgeries), 27% of patients who developed surgical site infection (SSI) after spine surgery and were treated with I&D and primary closure over a drain (“one-stage irrigation and debridement”) had persistent symptoms and signs of infection and underwent further surgery. Patients who presented with bacteremia did especially poorly with this approach — 80% of them had persistent infection following one-stage treatment.

How’s It Stack Up?

These findings are in line with what has been published elsewhere, generally speaking, in terms of the odds of a patient undergoing multiple debridements when the surgeon’s intention was just a single procedure. The best comparator, of course, was a somewhat larger study on the same topic that set out to develop a risk calculator to identify which patients would wind up undergoing multiple debridements. That study also identified bacteremia as a bad actor in this context, found diabetes and MRSA were associated with more-frequent repeat debridements (factors not identified by the current study), and had a somewhat lower proportion of patients who underwent repeat debridement (18% vs. 27%). It’s impossible to know whether that was a function of a different patient population or loss to follow-up, and neither study reported what percentage of patients were missing — a key factor that journal editors need to pay more attention to. For that reason, we need to compare both of those percentages as low-end estimates. Interestingly, the current study applied the risk calculator reported in that other study and found it did not perform very well — the sensitivity of that risk calculator (which is the parameter a patient would be interested in when making this decision) was only 12.5%. That is, the calculator correctly “predicted” only 12.5% of the patients who ultimately underwent a second debridement. Another study found late infection to be a bad actor in that single-stage debridement generally didn’t do the job adequately, and this is consistent with findings in other specialties (such as arthroplasty).

What’s Our Take?

The most important message here is that a single-stage I&D is the wrong approach for patients with bacteremia — at least two studies came to the same conclusion on that, and it makes sense. Another is the more-general caution that with a risk of reoperation in the ballpark of one in four patients (here, as well as in other studies), if one is to use this approach, one needs to tell one’s patients that it does not have a great (or even good) batting average. Finally, a sensible approach is to focus on the risk factors identified in any of the available studies, and surmise that if a factor appears in one study, that's enough — the fact that another study might miss it could be a function of insufficient power. That list includes bacteremia, late or chronic infection, MRSA or C. acnes infection, diabetes, and the presence of spinal instrumentation. Consider avoiding single-stage I&D in patients who present with with one or more of those factors.

Source

Dhodapkar MM, Galivanche AR, Halperin SJ, Elaydi A, Rubio DR, Grauer JN. Postoperative Spine Surgical Site Infections: High Rate of Failure of One-stage Irrigation and Debridement. Spine J. 2023;23:484-491.