Pectus Excavatum and Carinatum

Pediatric Surgery
Dr Robert Kelly discuses chest wall deformities with Dr Todd Ponsky
Edited by Ian C Glenn, MD and Nicholas Bruns, MD

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Pectus excavatum


History
  • Approximately 2/3 of patients presenting with symptoms, which include dyspnea on exertion, easy fatigability, and/or chest pain (typically localized to the area of the pectus depression). Symptoms typically do not occur at rest.
  • Patients who are asymptomatic but have a significant anatomical defect should be questioned thoroughly, particularly with regard to physical activity (is the patient actually exercising, or is the patient avoiding it?).
  • Inquire about personal or family history of metal allergy
Physical exam
  • Obvious depression in the chest wall is noted
  • Examine the patient while he/she is standing. Have the patient inspire/expire deeply in order to observe the chest during respiration. Normal chest wall motion is like the handles of a bucket. In pectus excavatum, the sternum may not move at all, or may move paradoxically in younger patients. Patients may compensate with abdominal breathing.
  • Examine for chest wall symmetry, costal flaring, displacement of the cardiac point of maximal impulse, striae of the lower back, scoliosis.
  • Particular attention paid to any syndromic disorders. Both Marfan and Ehlers-Danlos syndrome are associated with pectus excavatum.
Scoliosis and pectus excavatum
  • Approximately 25% of pectus excavatum also have scoliosis.
  • Coordination with orthopedic surgery is paramount
  • The problem which is more clinically significant should be repaired first.

Imaging

  • CT
    • Shows the depth of the depression and the anatomic impact on the heart and lungs. In patients who will need surgery, the CT shows cephalo-caudal extension and allows determination of the need for one or two Nuss bars.
    • Haller index is the ratio of the inner transverse diameter of the thorax to the distance between the posterior surface of the sternum and the anterior surface of the vertebrae.
    • Using the Haller index, severe disease is defined as a value of 3.25 or greater.
    • Subsequent studies have demonstrated that in patients with a barrel chest, the severity of disease may be underestimated by the Haller index.
  • MRI
    • MRI has been used, but does not define cartilaginous and bony structures as well as CT.
    • Cardiac MRI has been evaluated, but it is a lengthy test, in addition to the difficulty with identifying bony/cartilaginous structures.

Echocardiogram

  • Mitral valve prolapse is the most common finding, seen in approximately 14% of patients. In the general pediatric population, MVP is present in around 1%.
  • Right ventricular compression may be seen, but this is sometimes only noted on CT.

Pulmonary Function Testing

  • Typically, PFT results are depressed from the expected results by one standard deviation (thus, they will have values 85-90% of the predicted result).
  • Concordantly, patient’s PFT results are expected to improveby one standard deviation following surgery.
  • A restrictive pattern on PFT is not uncommon (FVC < 80% predicted with normal FEV1/FVC ratio), particularly in patients with more severe disease.

Indications for operation (six factors are evaluated, and the presence of three or more is indication or surgery)

  • Haller index > 3.2
  • PFT below 80% predicted
  • Cardiac compression, MVP, or other abnormalities on TTE
  • Symptomatic disease
  • Progression of disease (which may occur to a significant degree during puberty)
  • Major psychosocial issues related to body image, secondary to their pectus excavatum

Timing of surgical repair

  • Ideal age for repair is prior to the onset of puberty or during early puberty. For females, this is typically age 11-13 years, and for males, typically 12-14 years. The advantage of this timing is that the Nuss bar is in place during puberty, when the pectus deformity is most likely to deepen without intervention. The likelihood of recurrence following puberty is very low, thus the bar is ideally able to be left in place through puberty.
  • However, publications from Korea have demonstrated excellent results operating on patients younger than 10 years of age.

Pre-operative counseling of patients and families

  • Movement of the chest wall is painful and pain management must be the top priority in the post-op period. However, the family should understand that pain can be managed well through a variety of measures.
  • PCA pump with a basal rate is used post-operatively. Communication is critical in order to obtain the correct dose.
  • Epidural is not used for any patients.
  • Early ambulation and incentive spirometry are very important.
  • Adequate nutrition is emphasized
  • Patient’s must allow themselves adequate time for recovery (both in the hospital and at home)
Return to activity
  • Nothing but walking for the first month
  • By 3-6 months, any activity is allowed except for contact sports when there may be a blow to the chest.

Pre-operative lab work

  • Screening for metal allergies (using the allergEAZE test, SmartPractice Canada, Calgary, AB, Canada). This specific test includes all of the components of the stainless steel Nuss bar.
    • Most common allergy is nickel. If any allergy is present, then a titanium bar may be used. The disadvantage of titanium bars is that they must be bent at the factory (and thus ordered in advance). Titanium is also much more expensive than stainless steel.
  • Type and screen is performed, but the likelihood of requiring a transfusion is extremely low.

Placement of incisions

  • In the cephalo-caudal plane, the incision is made at the level of the deepest portion of the pectus defect. The incision should be 2-3 cm in length and made between the anterior and mid-axillary lines.
  • n female patients with developed breasts, a curved incision is placed at the lateral aspect of the breast where it meets the chest wall, ideally posterior to the pectoralis major.

Bar placement

  • The incision is made and the bar is tunneled subcutaneously for a distance prior to the thorax being entered. It is critical that the pleural space is entered medial to the anteriormost portion of the rib, yet lateral to the sternum. This is done to ensure that there is adequate support for the bar provided by the underlying ribs.
  • The thoracoscope is typically only inserted on one side, but it may be inserted bilaterally to minimize injury to the patient.
  • Bending the bar in order to avoid overcorrection is important.

One bar or two?

  • Typically, the bar stabilizers are placed on just one side of the bar (to avoid a wasp waist effect).
  • Taller patients are more likely to require a second bar (patients over 6 feet 2 inches are almost guaranteed to required a second bar).
  • Most of the time, this will be an intraoperative decision.

Surgical pearls for the Nuss procedure

  • Patient positioning is key
    • Precautions should be taken to avoid brachial plexus injury
  • Proper measurement/sizing of the bar
    • A common method is to measure the distance between mid-axillary lines and subtract one inch.
  • Infection prophylaxis
    • Chlorhexidine gluconates shower the night before surgery
    • Chlorhexidine wipes the morning of surgery
    • Chlorhexidine scrub used in the OR
    • Pre-incision parenteral antibiotics completed within 1 hour of incision
  •  Skin marking
    • Intercostal spaces and rib margins
    • Deepest portion of pectus
    • Thoracoscopy to avoid cardiac and/or pulmonary injury
  • The most important aspect of the case is seeing the tip of the introducer at all portions of the case. This minimizes the risk of injury to the heart.
  • Once the bar is in position, it must be kept there. A tongue and groove type stabilizer is preferred.
  • Alternatively, the bar and adjacent rib can be wrapped with heavy, absorbable suture (e.g. #1 PDS).

Sternal elevation/retraction

  • Vacuum bell
  • Subxiphoid incision and retraction
  • Rultract Skyhook retractor (Rultract, Cleveland, OH) is the preferred retractor. A stab incision is made ¾ of an inch from the sternum and the retractor is inserted.     

Complications

  • The short-term complication rate is very low
  • The major long-term complication is bar displacement. This requires revision in approximately 2.7% of cases.
    • Bar displacement has been avoided by using bar stabilizers and wrapping sutures around the bar and rib.
    • Bar displacement is typically secondary to a traumatic insult.
  • Bar/metal allergy occurs in 0.9% of cases. This has been dramatically reduced due to allergy testing.
  • Wound infection is in 2.3% of cases and 2/3 of these have been superficial skin infections or cellulitis.
    • Bundled ordered sets for antibiotics prophylaxis have helped to reduce the infection rate.
  • Recurrence occurs in 1.2% of cases. The pathophysiology of recurrence is poorly understood. It may be caused by removing the bar too early, but it may occur even after the bar has been left in for years.

Post-operative management

  • Wean PCA, stop basal rate on POD #2 and stop PSA on POD #3
  • Mobilize patient on POD #1, stairs added on POD #2

Follow up and bar removal

  • Follow up in clinic 6 months after surgery.
  • Bar typically removed around 3 years. The bar should be left in place a minimum of 2 years.
  • Patient should be seen at least annually.

Non-operative management

  • Vacuum bell treatment has been developed for minor degree of pectus excavatum.
  • One recent study showed the therapy was effective in 23 of 73 patients. It is best used in patients younger than 10 years of age.

Role of the Ravitch procedure

  • The Ravitch is never used as the primary means to repair pectus excavatum. It is, however, used in patients with recurrent disease following a prior Ravitch.
  • The Nuss procedure may be performed in patients who have recurred following a Ravitch procedure, but the Nuss will not improve the movement of the chest wall and thus a Ravitch may be preferred.

 

Pectus carinatum


Brace therapy 

  • Brace therapy has been demonstrated to be successful in 2/3 to ¾ of cases. Due to the low morbidity and mortality of the brace compared with any surgery, a trial of non-operative management is warranted.
  • Choice of brace
    • The preferred brace is the FMF Dynamic Compressor System (Pampamed, Buenos Aires, Argentina) developed by Marcello Martinez-Ferro.
    • A previous brace was used, but had poor patient compliance. The previous brace was less comfortable and much more difficult to conceal under clothing.

Surgical treatment 

  • Surgical candidates
    • Failure of non-operative management
    • Symptomatic (pain or exercise limitation, although this is very rare)
  • The reverse Nuss procedure consists of placing a Nuss bar superficial to the sternum.
  • The Ravitch operation is an effective treatment

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