Post-biopsy, patients were reviewed on an outpatient basis, determined by clinical need.
Histology reports for the ultrasound-guided procedures were reviewed to confirm if this technique had allowed adequate diagnosis. Samples for genetic analysis
In addition, each patient undergoing the procedure was retrospectively surveyed and asked to comment on any scar, complication and if they would favour the procedure in the future.
Results
Over a two year period, a cohort of 10 patients met criteria to undergo the ultrasound-guided muscle biopsy using a modified Bergström needle and suction technique. These patient's underwent a total of 11 biopsies during this time. Table 1. summarises the outcome of these.
A retrospective review demonstrated that ten of the eleven samples were of satisfactory diagnostic quality and permitted histological analysis. The one that was non-diagnostic was inappropriately transported in formaldehyde following the biopsy. The biopsy for this patient was successfully repeated. One patient had vastus lateralis and a paraspinal muscle biopsied. For this patient, the vastus lateralis was diagnostic, but the paraspinal was not. Furthermore, all ten of the successful ultrasound-guided biopsies aided a diagnosis, either by confirming non-specific muscle pathology, directly supporting a specific diagnosis or by excluding a specific diagnosis.
Patient feedback from the procedure was encouraging and no significant complications were reported. Four patients had undergone a surgical biopsy previously. Two of these preferred the ultrasound-guided biopsy to the surgical approach, while the remaining two did not specify. No complications were reported from the eleven biopsies. When asked to rate their experience between 0-5, with 0 being extremely poor and 5 being excellent, six patients rated 4 or 5, one rated 3. The others did not fill this part of the questionnaire.
Furthermore, of the four patient's who had had a previous surgical biopsy that had been unsuccessful in establishing a diagnosis, an ultrasound guided biopsy was successful in aiding a diagnosis in all. This is particularly well demonstrated in a case of a 55 year old patient with a history of myopathic weakness since his teenage years affecting all limbs and extra-ocular muscles. The MRI of his muscles had shown marked atrophy and fatty infiltration (Figure 1) , making a viable muscle biopsy target difficult to select. This was discussed with the neurosurgical team who did not feel they could reliably biopsy muscle. He had already undergone two surgical muscle biopsies over the preceding decade which had been non-diagnostic. Therefore, after discussion in muscle MDT, he underwent a successful ultrasound guided muscle biopsy using the aforementioned technique. This high quality biopsy has aided us in diagnosing an autophagic vacuolar myopathy that is suspected to be a new case of X-linked myopathy with excessive autophagy (XMEA).