Yes, but not many. Semi-closed rebreathers only exhaust a small percentage of each breath and the bubbles that are released are often mechanically diffused. Fully closed rebreathers release no bubbles as the result of breathing. Both types will release some bubbles as the diver ascends and the gases in his breathing loop expand. Rebreathers cover a range of prices.
Maintenance is perhaps a little more intensive than open circuit gear on most units.
There are, of course, other maintenance issues that vary from unit to unit. Generally speaking, the fully-closed units require more maintenance and are more costly to maintain. All rebreathers have some consumables which you need to replace on a regular basis. The primary consumable is the scrubber material. As the scrubber material absorbs CO 2 it becomes non-reactive and must be replaced.