N. Le1, J. Sujka1, J. Sobrino1, L. A. Benedict1, R. Rentea1, H. Alemayehu1, T. Oyetunji1, S. St. Peter1 1Children’s Mercy Hospital- University Of Missouri Kansas City,Kansas City, MO, USA
Introduction:
Muscle disease presentation is highly variable. Tissue biopsy is performed to confirm diagnosis and to guide therapy however it is unclear if this changes management. The purpose of our study was to determine if muscle biopsy changed patient diagnosis or treatment, which patients were most likely to benefit from muscle biopsy, and the complications resulting from muscle biopsy.
Methods:
With IRB approval a retrospective chart review of all patients less than 18 years old undergoing muscle biopsy between Jan 2010 and Aug 2016 was performed. Demographics, patient presentation, change in treatment and diagnosis, hospital course, and follow up were evaluated. T-test and descriptive statistical analysis was performed; all means reported with standard deviation.
Results:
A total of 90 patients underwent a muscle biopsy at our institution during the study period. Mean age at time of biopsy was 6.5 years (±5) with the most common site of biopsy was the vastus lateralis. Of these patients only 37% (n=34) had a definitive diagnosis by muscle biopsy, in the remaining patients 27% (n=25) were normal and 35% (n=31) were non diagnostic. Of all patients biopsied, 39% (n=35) had a change in their diagnosis with only 37% (n=34) having a change in their treatment course from the pathology result.
Among the 34 patients who had a change in their treatment, the most common diagnosis was Inflammatory muscle disease at 44% (n=15) followed by those with muscular dystrophy, 23% (n=8). In the 56 patients who did not have a change in treatment, the most common diagnosis was hypotonia at 30% (n=17) followed by those patients whose diagnosis remained undetermined at 25% (n=14). However, the third most common diagnosis that did not change treatment was inflammatory with 21% (n=12). Two of these patients had definitive diagnosis from their biopsy but the remaining 10 were previously suspected of, and being treated for, myositis.
Using the T-test we compared those who did or did not have a change in treatment based on their pathology. There was no statistically significant difference in the patient’s weight, age, operative duration, or length of follow up post operatively. One patient was found to have a complication from surgery, malignant hypothermia. No patients returned to the operating room secondary to operative complications. Mean length of follow up for all patients was 2.75 years (±2).
Conclusion:
Muscle biopsy could be considered to diagnose patients with symptoms consistent with inflammatory or dystrophic muscular disease though the likelihood of this altering the patient’s treatment course is less than 50%.