BALTIMORE - Cardinal William Keeler, head of the Roman Catholic archdiocese of Baltimore, had a shunt inserted in his brain during surgery Monday.

Keeler spent about more than two hours in surgery, The Baltimore Sun reported.

While the cardinal was on the operating table, members of his flock gathered at the Basilica of the Assumption to pray for him. His red chair stood empty as Bishop Francis Malooly celebrated mass.

The shunt is to drain excess fluid from Keeler's brain. His doctors believe that the hydrocephalus was caused by a car crash in Italy last October.

Keeler, at 76 a year past the usual retirement age for bishops, has submitted his resignation to the Vatican. No successor has been appointed yet.

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