Node.js domains in Express app middleware

Question

I believe the following code might be useful to handle exceptions that occur to certain requests:

var domain = require('domain');

app.use(function(req,res,next){

    var d = domain.create();

    d.on('error',function(err){
      res.json({error: err.stack});
    });

    d.run(function(){
       next();
    });

});

however, I read that this type of code can leak memory. I am not sure I understand why. Is there a way to avoid leaking memory? Perhaps I should manually remove all the event handling and listeners for the domain after the response stream is closed? How do I allow the domain object to be garbage collected?