[Avodah] Mi shberekh for the sick at a brit

[Arie Folger]

If have read/heard about a new (revived) practice of having a mohel pray for 
the sick at a milah. The practice is reportedly ideally done by having 
thirteen mohalim recite it on the same day.

I am interested in investigating this practice. Can anyone provide some 
pointers and/or the nussa'h of the special mi sheberakh (or is it the garden 
variety MsB recited, for example, at qeriat haTorah?).

So far, google did not help.
-- 
Arie Folger
http://www.ariefolger.googlepages.com