A 6-year-old female came to clinic for a preoperative evaluation for a multiple caries dental procedure. She was in her normal state of health. The past medical history revealed hypoplastic left heart syndrome (HLHS) treated with tricuspid valvoplasty, coarctation of the aorta repair, a bi-directional Glenn procedure and later a Fontan procedure. She had received her well-child care and despite multiple surgical complications of the procedures she was attending kindergarten and making good academic progress.
The pertinent physical exam showed an alert patient with growth parameters in the 40-75% for age. Blood pressure and pulse were also normal. HEENT revealed multiple caries and pressure-equalizing tubes in both ears. The chest showed multiple well-healed scars mainly centrally but also previous chest tube scars laterally. Heart showed a Grade III almost continuous murmur over the anterior upper part of the chest without a thrill. The murmur could be heard laterally and in the back but not to the axilla nor radiating to the neck. The rest of the examination was normal.
The diagnosis of multiple caries and HLHS status post multiple procedures was made. The patient had an appointment scheduled with her cardiologist and the anesthesiologist for that afternoon. The dental resident also seeing the patient was not sure what HLHS and a Norwood procedure were. The pediatrician described the general idea of using the right ventricle as the main pump for the systemic circulation, and needing to balance the pressures and flows to the pulmonary and systemic circulations preferably without mixing of the circulations. She also described how over the course of her practice the treatment of patients with HLHS had moved from being almost universally fatal, to using heart transplantation and then having more success with palliative surgical procedures. She noted that despite the improvements in potential treatment, many patients still die in infancy and in early life, because of the disease itself or the numerous complications.
Some main surgical procedures for congenital heart disease include:
- Atrial Septostomy
- Used to increase mixing of blood at the atrial level such as transposition of the great arteries, tricuspid atresia and mitral atresia
- Shunt: Balloon-tipped catheter creates a larger hole in the atria
- Blalock-Taussig Shunt
- Used for low pulmonary flow states such as Tetrology of Fallot, HLHS, tricuspid atresia
- Uses systemic arterial flow to increase pulmonary flow
- Regular Shunt: Subclavian artery to pulmonary artery by direct anastomosis or by graft
- Glenn Shunt
- Used often as intermediate step to a Fontan procedure, especially in infancy and toddlerhood
- Uses some systemic venous return to increase pulmonary flow
- Shunt: Superior vena cava to right pulmonary artery by graft
- Used for separating the systemic and pulmonary systems in patients with functional single ventricles such as HLHS and tricuspid atresia
- Shunt: two parts – Glenn shunt plus placement of a conduit between the right atria and/or inferior vena cava and the pulmonary arteries
Other procedures include an atrial inversion (aka Mustard or Senning) which is not used much anymore, and a Jatene arterial switch procedure. Both of these are for transposition of the great arteries.
The Ross procedure is an autologous pulmonary valve replacement for a stenosed aortic valve, with an allograph replacement of the pulmonary valve.
HLHS is a congenital heart disease where the left-sided heart structures are underdeveloped and unable to support the systemic circulation. It occurs in about 2:10,000 live births and is universally fatal without treatment. Because HLHS is a cyanotic, duct-dependent lesion, most of the mortality occurs in the first several days. Even with treatment, patients have a survival rate of 65% at 5 years and 55% at 10 years. Families should be counseled so they can make appropriate informed decisions regarding care which also includes the option of comfort care (no intervention), because of the very high mortality and morbidity that accompany HLHS treatment. A review of the complications of cardiovascular surgery can be found here.
Each patient has a slightly different morphological presentation but all components of the left heart are inter-related and individual components cannot be isolated for treatment. The bottom line with any variation of HLHS is that the left-side of the heart cannot support the system circulation, therefore the right side of the heart must support the systemic circulation. Therefore there must be mixing of the pulmonary and systemic circulations at birth which is accomplished by keeping the ductus arteriosus open (usually using Prostaglandin E1 and/or atrial septostomy). A more permanent solution is then necessary so heart transplantation or staged surgical procedures are done.
Heart transplantation theoretically should fix the congenital heart disease as a properly formed and functioning heart is transplanted. However, neonatal hearts are difficult to obtain and mortality while waiting is high. Immunosuppressive therapy is needed for a lifetime, and constant worries include acute rejection, malignancies and additional transplants over time.
A staged Norwood procedure is another option. The goal is to have an “unobstructed systemic circulation while providing a secure but balanced flow to the pulmonary circulation.” The Norwood procedure is named after William Norwood who first performed it in 1980. It has 3 stages:
- Stage 1 – Performed in first days of life. The aortic arch is reconstructed with the main pulmonary artery plumbed into this reconstruction to form a new aorta. The atrial septum is removed to shunt pulmonary bloodflow into the right side of the heart thereby bypassing the left ventricle. This leaves the right ventricle as the pump for the systemic circulation. The pulmonary blood supply is then controlled (usually) by a modified Blalock-Taussig shunt.
Early survival of Stage 1 has increased to 85-90% at 30 days of life.
- Stage 2 – Performed around 5-6 months of life. Bidirectional Glenn shunt used to decrease volume overload. Survival of this procedure is 96-99%.
- Stage 3 – performed around 4 years of age. Fontan procedure. This separates the pulmonary and systemic circulations but only the right ventricle provides the pump for both circulations. Again survival is 96-99%.
Questions for Further Discussion
1. How common is congenital heart disease overall?
2. What is the role of a primary care provider in the management of a child with congenital heart disease?
3. Who are Blalock, Taussig, Fontan and Glenn that cardiovascular palliative shunt procedures are named after?
4. What would be the American Society of Anesthesiologists (ASA) anesthesia risk classification for the patient presented above? Click here for a review
- Symptom/Presentation: Dental Problems
- Age: School Ager
To Learn More
To view pediatric review articles on this topic from the past year check PubMed.
Information prescriptions for patients can be found at MedlinePlus for this topic: Congential Heart Defects
To view current news articles on this topic check Google News.
To view images related to this topic check Google Images.
Barron DJ, Kilby MD, Davies B, Wright JG, Jones TJ, Brawn WJ. Hypoplastic left heart syndrome.
Lancet. 2009 Aug 15;374(9689):551-64.
Yuan SM, Jing H.
Palliative procedures for congenital heart defects. Arch Cardiovasc Dis. 2009 Jun-Jul;102(6-7):549-57.
ACGME Competencies Highlighted by Case
1. When interacting with patients and their families, the health care professional communicates effectively and demonstrates caring and respectful behaviors.
2. Essential and accurate information about the patients’ is gathered.
4. Patient management plans are developed and carried out.
7. All medical and invasive procedures considered essential for the area of practice are competently performed.
8. Health care services aimed at preventing health problems or maintaining health are provided.
9. Patient-focused care is provided by working with health care professionals, including those from other disciplines.
10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.
13. Information about other populations of patients, especially the larger population from which this patient is drawn, is obtained and used.
16. Learning of students and other health care professionals is facilitated.
19. The health professional works effectively with others as a member or leader of a health care team or other professional group.
Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa Children’s Hospital