In the study, “Does muscle biopsy change the treatment of pediatric muscular disease?” published in the journal Pediatric Surgery International, researchers found that results from muscle biopsies could help physicians reach a definitive diagnosis and choose the most appropriate treatments.
They also looked at which patients were more likely to benefit from the exam and the types of health complications that could occur as a result of the procedure.
To do this, they conducted a retrospective analysis, reviewing data from 90 young patients with neuromuscular symptoms, who underwent a muscle biopsy between 2010 and 2016 at The Children’s Mercy Hospital in Kansas City, Missouri.
Demographic data, patient symptoms prior to biopsy, diagnosis, treatment, hospital course, and a median of three years of follow-up were evaluated.
Most patients had a muscle biopsy early in life, at a median age of 5 years. The exam was able to provide a definitive diagnosis for 37% of them. For the remaining patients, 27% tested normal, and 35% did not get a final diagnosis from the biopsy.
A key finding showed that the muscle biopsy led to a change in the diagnosis for 39% and a change in treatment course for 37% of all patients.
In terms of treatment change, the biopsy seemed to mostly benefit patients diagnosed with inflammatory muscle disease or muscular dystrophy, with 44% of muscular dystrophy patients and 23% of inflammatory muscle disease patients seeing a change in treatment.
Prior to biopsy, rehabilitation therapy was the most prescribed treatment, while nonsteroidal anti-inflammatory drugs (NSAIDs), steroids, and immunosuppressive therapies were the least used.
However, after obtaining biopsy results, physicians often opted for increasing the number of prescriptions for steroids and immunosuppressive therapies and maintaining rehabilitation. On the other hand, there was a decrease in the use of NSAIDs.
In total, there was a significant increase in the use of steroids — from 14% to 27% — and immunosuppressants —from 8% to 33% — following biopsy.
In general, the biopsy procedure was safe, leading to complications in only one patient out of 90. The patient developed malignant hypothermia — an inherited condition that triggers a severe reaction to certain medications used as part of anesthesia for surgery.
“None of the patients in our population required return to the operating room for a complication. There was no findings of post-operative hematoma, new found weakness, or nerve injury,” the researchers wrote. This suggests that muscle biopsy may have a lower complication rate than they had previously thought.
“Muscle biopsy should be considered to diagnose patients with symptoms consistent with inflammatory or dystrophic muscular disease,” they said. “The likelihood of this altering the patient’s treatment course is around 40%.”