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HLHS (Hypoplastic Left Heart Syndrome)

HLHS stands for hypoplastic left heart syndrome. It is a very serious congenital heart condition in which the left side of the heart (the side that pumps blood though the aorta and out into the entire body) does not completely form and is thus too small to function. Most often, the mitral valve, left ventricle, aortic valve and aorta are all small, and there is coarctation or hypoplastic or interrupted aortic arch. Until the mid-late 1980s, all infants with this condition died in the first six to eight weeks of life.


Surgical treatment for HLHS remains difficult and requires at least three separate operations in the first few years of life; it is the most challenging series of heart surgery ever performed in human beings. Gradually over the last 30 years, programs such as ours have been developing experience and seen increasingly successful results with surgery such that many children are now living into their teenage years and beyond.

At Rady Children’s Hospital-San Diego, our surgeons have been specifically trained in surgery for HLHS at the centers that actually developed the modern operations, including Boston Children’s and the University of Michigan. We are now able to offer surgery to almost all newborns with this condition. Different babies have different sub-types of HLHS and different risk factors. There are several different operations and surgical options and these are best tailored to the individual patient’s needs to achieve the best results. When you consult with our surgeons and cardiologists, we will review the options and our current results with them as it pertains to your individual baby.

The traditional first-stage operation (known as the “Norwood,” named after Dr. William Norwood from his work at Boston Children’s) is most difficult and carries the highest risk. It always requires an incision and the use of cardiopulmonary bypass. We utilize several different types of patch material in the repair, including donor human heart tissue to reconstruct the aortic arch. According to recent Society of Thoracic Surgeons national data, the average survival to discharge for the Norwood operation is 81 percent in North America. Since 2007, our program has maintained a 90 percent survival for all Norwood operations performed.

For patients with more risk factors who are thus at higher risk, a Norwood operation may not be the most appropriate initial step. In these cases, we can offer all the newest hybrid options, which as we apply them are techniques to minimize the effects of surgery on these highest risk patients. We have been able to obtain success with higher-risk cases using the hybrid approach, but each case is different, and upon consultation, we can provide more specific information based on your individual child’s case.

For the >90 percent of babies who now survive the classic first-stage Norwood operation, our preferred surgical strategy is to perform the second stage (called Bidirectional Glenn or BDG for short) at age 4-6 months. The hospital discharge survival for BDG in the setting of HLHS is 100 percent since 2004. Once the patient reaches age 3-4, we complete the final stage III operation, known as the Fontan operation; our hospital discharge survival for the Fontan operation in the setting of HLHS is also 100 percent since 2004.

Our pediatric heart surgeons have now performed hundreds of operations in patients with HLHS alone, and thus the entire team has accumulated tremendous experience managing these patients. Our most recent analysis demonstrated that using the latest surgical innovations and techniques since 2004, an overall 10-year survival of over 80 percent is expected, which is among the highest long-term survival rates ever reported for HLHS and is as good as any of the largest centers in the United States. Our experience with high-risk cases is also growing and one form of the hybrid procedure in particular has been able to achieve very encouraging five-year results.