Surgeons don’t perform spinal surgery on just anyone without a strong chance that the procedure will help the patient. Possible complications are always considered ahead of time. And if a patient has too many risks, surgery may not be advised. In this study, surgeons from the University of Washington in Seattle explore various risks for medical complications after spine surgery.
Relying on surgeons and even patients to remember what happened for each person after surgery is not the most accurate way to identify common risk factors after spinal surgery. Even chart reviews are not always as complete as needed. That’s why this study used national databases of information (e.g., Medicare, Worker’s Compensation, National Inpatient Sample) collected on thousands of patients.
There are some disadvantages in using a national database to conduct research. Although the number of patients included tends to be large, not all the pertinent information is gathered. For example, details of the surgery are not collected (e.g., number of spinal levels affected, whether the procedure was a fusion or nonfusion, if hardware was used such as metal plates, pins, or screws).
Even so, the amount of data that is collected can be very helpful. Demographic factors such as age; gender; use of tobacco, alcohol, or other drugs; and diagnosis can be factored in. Body mass index (an indication of obesity), presence of other health problems (e.g., diabetes, high blood pressure, heart disease, history of cancer) can also be considered.
In this study, they also looked at area of the spine operated on (cervical, thoracic, lumbar, sacral) and the underlying pathology (degenerative, trauma, tumor, infection, fracture). The surgical approach (anterior, posterior, combined) was also recorded and compared with the number and type of complications after surgery. All patients were followed for at least two years after the first spinal surgery.
The most common problem after spinal surgery was pulmonary complications (e.g., acute respiratory distress syndrome, pneumonia). This was followed by hematologic complications (e.g., blood loss requiring transfusion, blood clots), urologic problems (e.g., urinary tract infections), and cardiac complications (heart attack, arrhythmias, heart failure).
Other problems involving the gastrointestinal (GI) system or neurologic complications though less common were also reported. GI bleeding, colitis, or ascites (fluid in the abdomen) were the most common adverse events. Neurologic problems stemmed most commonly from strokes, delirium, electrolyte imbalances, and seizures.
After gathering and analyzing all the data, they found the two strongest risk factors for complications after spinal surgery were age (older than 65) and extent of surgery (invasiveness). Surgical invasiveness refers to the number of spinal levels involved, the amount of hardware used, and the approach (anterior, posterior, both). A special scoring system was used to calculate level of invasiveness for each procedure.
Two other risk factors affecting almost all the body systems were hypertension (high blood pressure) and anemia. History of diabetes, heart disease, and thoracic surgery were major risk factors affecting four of the six major organ systems included in this study. Patients who had cardiac or pulmonary complications were four to 10 times more likely to die during the first two years after surgery.
Surgeons involved in spinal surgery may find the charts and tables provided in this article useful. Significant risk factors for medical complications are listed for each system (cardiac, pulmonary, GI, neurological, hematological, urological). Likewise, the risk of death based on individual patient risk factors is also provided. A complete breakdown of each system, type of complications, and incidence is presented in detailed tables.
What’s the take home message from this study? First, complications after spinal surgery are more serious than previously believed AND they happen more often than remembered or reported. Second, patient selection based on risks for complications should be an important part of the pre-operative work up. The decision to have surgery, the type of surgery, and the invasiveness of the procedure can be influenced in part by considering potential complications.