Hi Sarah,
There is no issue with needling him and based on our research there is benefit to DN for spasticity ( more to come). I would not of course needle directly near the pump or any of its components and I would not use ENS near it. Remember in the IDN model you can needle the nerve distributions and get an effect both proximally and distally so you can avoid direct areas of concern. Don't forget the paravertebral segments those are of high value for hamstring symptoms.
Hope that helps

Thank you so much for the quick response. Very helpful.