A.P.
Im so sorry about the pending surgery. A quick search of "pediatric nephrostomy" led me to the Childrens Hospital in Boston.
http://www.childrenshospital.org/az/Site1428/mainpageS142...
I would demand a meeting with the surgeon as soon as possible to discuss the entire procedure and plan for post-op treatment. Also any advice she or he may have for community support. You may qualify for a visiting nurse. This is major reconstructive surgery which obviously needs to be done but I would get some face time with the Dr. preferable without your children there to minimize distractions. Bring paper and pen and at the end ask when and how would be the best time to follow up if there are any further questions after you and your husband have had time to digest the info.
Good luck!