In the Canadian study you mentioned, data from a large university hospital was reported. From this report, we get an idea just what kinds of morbidity (problems) and amount of mortality (deaths) occur in adults undergoing spinal surgery. This particular university setting serves 4.5 million people. In a year’s time, there were 942 patients who had emergency or elective (planned) spinal surgeries.
The researchers conducting the study used a spine specific system called the Spine AdVerse Events Severity System (SAVES V2) to collect the data. This tool is designed to collect complete and accurate information about all complications from minor to major. Data was collected before, during, and after spinal surgery.
The SAVES V2 form includes a place to record the severity of each problem. The grade given each problem ranged from the number one (event does not require treatment and has no adverse effect) to six (adverse event resulting in death). Some examples of these intraoperative “adverse events” include allergic reactions, heart attack, blood loss, pressure sores, nerve root injury, or other organ injury. Intraoperative refers to complications and problems that developed during the operation.
Pre- or post-operative adverse events ranged from heart failure, blood clot, and wound infection to delirium, pneumonia, urinary tract infection, and cerebrospinal leak. In both categories (intraoperative and pre- or post-operative), surgeons could report and record “other” complications and provide a description of what that was.
Besides collecting data about specific adverse events, the authors also took this opportunity to compare their results using this tool against the more traditional (and previously used method) of reviewing patient charts some time after treatment to assess results.
They found that the old method significantly under-recorded postoperative events. The SAVES system was much more accurate and thorough. Deaths were more likely to occur in patients requiring emergency surgery for gunshot wounds, cancer, traumatic neck injuries, and spinal infections. Older adults with traumatic injuries were at the greatest risk of death during spinal surgery.
Four per cent of the total group had to have a second surgery. There was a variety of reasons for this including infection, nerve pain, problems with hardware, and the need for additional decompression of disc herniations. Infection was the number one reason why patients were readmitted to the hospital during the first year following the primary (first or initial) surgery.
Not surprisingly, the types of adverse events were different during surgery compared with after surgery. Blood loss, dural tears, and anesthetic-related problems were the most common intraoperative complications. After surgery, electrolyte imbalances, problems caused by medications, heart complications, urinary tract infections, and spinal deformities were among the most problems reported.
The SAVES tool used by this Canadian group brought to light the significant underreporting of complications associated with complex spinal surgeries. How those statistics compare to U.S. surgeries will only be known if a similar American study is done and results can be contrasted between the two groups.