When the Norwood procedure is complete, oxygen-poor blood can move directly from the veins to the lungs without having to be pumped by a defective ventricle, and oxygen-poor and oxygen-rich blood are no longer mixed. 

Similarly, oxygen-rich blood will be pumped to the body by the healthy ventricle. In the case of total cavopulmonary connection (TCPC), the creation of this tunnel lessens the amount of turbulence and inefficient blood flow that occurs.

The recovery from the Norwood procedure can be complicated due to the complexity of the surgery. Most children remain in the hospital for three to four weeks. A smaller percentage may continue to experience problems in the first few months of life.

This procedure has a number of side effects. For example, there is increased pressure in the veins because only one ventricle is pumping in the heart. As a result, the body may retain fluid (edema), and there may be some facial puffiness. Fluid may also build up in the stomach or chest. To relieve the extra pressure, a hole is sometimes left in the lateral tunnel to the right atrium.

The Norwood operation is considered a complex procedure but survival after each of the three stages of surgery is 80 percent or higher. Long-term survival at five years of age is 70 percent. Once they have gone through all three stages, most children go on to live fairly normal lives, although they must continue with close medical management.

However, there are problems that may cause trouble for some patients in both the short and long terms. Up to 40 percent of patients who have had the Fontan operation experience significant arrhythmias over the long term. Those patients require careful follow-up therapy and medical management for this potentially dangerous problem. Another 13 percent develop a syndrome called protein-losing enteropathy in which excessive protein is lost through the gastrointestinal tract, along with symptoms of heart failure. These patients require close medical management throughout their lives.

Since the Norwood operation and the Fontan procedure have only been successfully performed widely for slightly over twenty years, most of the oldest patients are only in their early twenties.