A Childhood Deformity Corrected

Minimally Invasive Procedure for Pectus Excavatum Offers Improved Results

By Tamir Keshen, MD

 

The modified Ravitch technique was the most common procedure for both pectus excavatum and pectus carinatum before the minimally invasive Nuss procedure was developed in the late 1980s. Dr. Keshen has performed the Nuss procedure for 12 years – including five years at Cottage Children’s Hospital – with excellent results.

 

Congenital chest wall defects are common problems for children and adolescents, both physiologically and psychologically/emotionally.  This is exacerbated by the family’s frustration and confusion since many primary care providers are uncertain how to care for pectus excavatum or which specialist has expertise in treating it.

 

Cause

The deformity is believed to arise from excessive growth of the cartilage in the costochondral region, leading to a symmetrical or asymmetrical intrusion of the sternum on the thoracic cavity (commonly called “sunken chest” or “funnel chest”). It is often present at birth and can be mild or severe.  Pectus excavatum is highly unlikely to become symptomatic prior to early adolescence, and, regardless of physiologic impairment, is not life-threatening.

 

While most pectus excavatum is not associated with any other condition, some children have concomitant disorders, requiring a full workup: Marfan syndrome, Rickets, Scoliosis (15 percent), Homocystinuria, Ehlers-Danlos syndrome.

 

The Nuss minimally-invasive technique entails placing a bent stainless steel bar across the chest to push the sternum anteriorly to a normal location After being placed inside the chest so that both ends of the bar emanate through the right and left rib spaces, the bar is then flipped into position, pushing the sternum anteriorly.  Illustration by Joshua Emerson.

Symptoms

Many patients are asymptomatic; however, a significant number experience fatigue, shortness of breath (commonly during activities they previously had no difficulty performing), chest pain and palpitations.

 

The disease process is indolent and many children acclimate to the slowly increasing physiologic restrictions, often unaware of how significantly it is affecting them until they reach a critical point.  The symptoms typically worsen as the defect becomes more prominent.  Besides its obvious appearance, which creates much consternation in the affected child (regardless of overt denials), the defect can lead to cardiac shift and lung compression that mimic restrictive lung disease with decreased lung capacity and cardiac function.

 

Incidence

Pectus excavatum is more prevalent in males than females (1:3), occurring in approximately 1 in 500-1,000 Caucasian births.

 

It accounts for 90 percent of all congenital chest wall defects and 40 percent of affected patients have one or more family members with the same defect (in varying degrees of severity).

 

Diagnostic Studies

Diagnostic studies for pectus excavatum include pulmonary function test, chest X-ray, chest CT (to evaluate Haller index), echocardiogram and EKG. Haller index (determined from the CT scan) is a ratio of the transverse diameter of the thorax in relation to the distance from sternum to anterior vertebral body at maximal indentation. An index greater than 3.25 connotes significant cardiopulmonary compromise; less than 2.5 is considered normal. Pulmonary function tests may demonstrate restrictive lung disease.

 

The echocardiogram may show anatomic or physiologic impairment consistent with Marfan syndrome, which, if suspected, would require additional testing for diagnosis.

 

Most insurance companies require these objective data prior to authorizing the procedure.

 

Treatment / follow-up

Mild deformities, first encountered in children, may or may not improve without surgery, hence advice that “they will grow out of it” should be tempered with caution.  Children with moderate to severe defects will either remain constant throughout development or worsen, especially during adolescent growth spurts.  The correction of pectus excavatum is surgical, with several techniques being utilized. 

 

We typically operate on children 10 years and older.  Occasionally, children younger than 10 will undergo repair when physiologic impairment is significant.

 

Although the chest wall is less malleable in early adulthood, we have had excellent results (without recurrence) in patients up to 29.

 

Modified Ravitch Technique

The modified Ravitch technique entails a horizontal incision in the inframammary crease with wide mobilization of the pectoralis major and rectus abdominis from the underlying ribs.  The intervening involved cartilage is removed, the sternum repositioned and supported by a bar, and the muscle flaps reattached. The cartilage reforms in the normal position over the ensuing year.

 

Dr. Keshen uses a contoured passing instrument to pull a bent stainless steel bar across the chest of a pectus excavatum patient.

The procedure is quite painful and most patients opt for a peri-operative thoracic epidural.  The procedure usually takes about four hours to complete and the average hospital stay is approximately four days, during which the patient is transitioned to oral analgesics.

 

The Nuss Procedure

The Nuss minimally invasive technique entails placing a stainless steel bar across the chest to push the sternum anteriorly to a normal location.   A 3-4cm incision is made on the lateral aspect of both sides of the chest wall at the point of maximal sternal depression and subcutaneous pockets are created.  A malleable template bar is bent over the anterior contour of the chest to determine the appropriate length bar for that patient and the specific bend necessary for optimal result.  The corresponding stainless steel bar is bent at the bedside.

 

A 5mm trocar is placed in the right anterior midaxillary line (rib space chosen below or above the intended rib space for the bar) and the hemithorax insufflated to 5mm Hg CO2.  A 5mm, 30 degree scope is placed and a contoured passing instrument is passed from the right hemithorax, between the sternum and pericardium, across to the opposite rib space in the left hemithorax (under direct vision).  An umbilical tape is attached to the passer and brought back across the chest. This is then attached to the bent bar which is pulled across the chest, under direct vision, so that either end of the bar emanates through the right and left rib spaces.  The bar is then flipped into position, pushing the sternum anteriorly.   If the bar seats well, a stabilizer is placed over one end and anchored to the bar and adjacent fascia.  Stabilizing sutures are also placed around the bar and rib on both sides of the chest to further prevent rotation of the bar.

 

The operation typically lasts about one hour.  A thoracic epidural is usually placed as the procedure can be as painful as the open technique.  The hospital stay is three to five days.

 

Results

Postoperative pain requiring narcotics may last a few weeks for both procedures.  The child may return to limited activity after a month with less stringent activity precautions at three months and return to full activity in six months (most contact sports).  We recommend avoiding tackle football while the bar is in place. The postop recovery incorporates daily breathing and posture exercises to promote improved chest wall expansion and to correct the typical “pectus posture.”

 

For the open technique, the bar is removed after one year; for the Nuss procedure, the bar is removed in two to four years (both outpatient). This additional time is needed to allow for remodeling of the chest wall and to minimize potential recurrence.

 

Historically, the recurrence rate for the modified Ravitch technique has been documented at 5 percent and at 1-5 percent for the Nuss. Cosmetic and physiologic results are good to excellent in 95 percent of the modified Ravitch patients.  In our experience over the last 12 years performing the Nuss procedure, there has been no recurrence, the cosmetic results are superior to the open technique, and physiologic improvement has been equally excellent for both the Nuss and open technique.

 

The children commonly say they feel better than they ever have before and did not realize how limited they had been before the procedure.  Many also admit that they now allow themselves to be seen in public without a shirt, which for them is a huge deal!

 

Complications

 

Possible complications include pneumothorax, pleural effusion, cardiac perforation, pericarditis, bar displacement, bar infection or wound infection, and recurrence.  Historically, and in our experience, the risks are nominal.

 


 

References

  • Ravitch MM: The operative treatment of pectus excavatum.  Ann Surg 129: 429-444, 1949
  • Nuss D, Kelly RE Jr., et al:  A 10-year review of a minimally invasive technique for the correction of pectus excavatum.  J Pediatr 33:545-552, 1998
  • Nuss D, Kelly RE Jr., et al: Repair of pectus excavatum. Pediatr Endosurg Innovat Techn 2; 205-221, 1998
  • Haller JA Jr, Loughlin GM: Cardiorespiratory function is significantly improved following corrective surgery for severe pectus excavatum:  Proposed treatment guidelines. J Cardiovasc  Surg 41: 125-130, 2000
  • Roberts J, Hayashi A, Anderson JO, et al: Quality of life of patients who have undergone the Nuss procedure for pectus excavatum:  Preliminary findings.  J Pediatr Surg 38: 779-783, 2003

<< Return to Cottage Children's Hospital Magazine