Pectus Excavatum Causes, Symptoms, Diagnosis, Treatment and Surgery
Pectus Excavatum is a congenital chest wall deformity in which several ribs and the sternum grow abnormally, producing a concave, or caved-in, appearance in the anterior chest wall; it is often referred to as sunken or funnel chest. The image below illustrates the typical appearance of this deformity in a 16-year-old boy.
Pectus Excavatum is the most common type of congenital chest wall abnormality (accounting for 90% of chest deformity’s), followed by Pectus Carinatum (5-7% of chest deformity’s), cleft sternum, pentalogy of Cantrell, asphyxiating thoracic dystrophy, and spondylothoracic dysplasia. Pectus Excavatum occurs in approximately 1 in 300-400 child births, with a male predominance (a male-to-female ratio of 3:1). The condition is typically noticed at birth, and more than 90% of cases are diagnosed within the child’s first year. However, the worsening of the chest?s appearance and the onset of symptoms are typically only reported during the rapid bone growth which occurs in the patients early adolescent years. Many patients are not brought to the attention of a pediatric surgeon until the patient and the family notice such changes.
Nevertheless, the appearance of the chest can be very disturbing to many young teenagers. It is often associated with low self-esteem problems and body image perception issues, which are frequently reported in teenaged patients. Similarly, Psychologic disturbances also common in older patients. In girls, the deformity is of particular concern because of the medial displacement of the breast, resulting in significant asymmetry of the breasts and nipples (cross-eyed appearance of the nipples).
In Pectus Excavatum, the growth of bone and cartilage in the anterior chest wall is abnormal, typically affecting 4-5 ribs on each side of the sternum. The appearance of the defect widely varies, from mild to very severe cases, and some patients present with significant asymmetry between the right and left sides. The exact mechanism involved in this abnormal bone and cartilage overgrowth is unknown, and, to date, no known genetic defect is directly responsible for the development of Pectus Excavatum. Despite the lack of an identifiable genetic marker, the familial occurrence of Pectus deformity’s is reported in roughly 35% of cases. Moreover, the condition is partially associated with Marfan syndrome and Poland syndrome.
As previously alluded to, Pectus Excavatum occurs in an estimated 1 in 300-400 births, with male predominance (male-to-female ratio of 3:1). Pectus Excavatum comprises approximately 90% of all chest wall deformities. However, in certain countries (eg, Argentina), Pectus Carinatum is more common than Pectus Excavatum.
Many patients with Pectus Excavatum are asymptomatic from a functional standpoint. The degree of cardiopulmonary impairment caused by lung compression and the level of cardiac displacement that results from the caved-in chest are subjects of controversy. Exercise tolerance is frequently reported as abnormal, and a restrictive pattern in pulmonary function test can be identified in severe cases. Cardiac function is usually normal, but mitral valve prolapse has been reported in 20-60% of cases. Echocardiography typically reveals some degree of atrial compression and cardiac displacement. Rarely, it may reveal mitral or tricuspid regurgitation. Echocardiographic analysis has demonstrated improved cardiac index upon exertion after operative repair of the deformity. The long-term health risks of patients who are managed without surgery are however not known.
Pectus Excavatum appears to be most prevalent in Caucasians. However, unfortunately, no specific data are available regarding racial distribution; however, clinical observation indicates that treating Pectus Excavatum in African Americans is unusual.
As previously alluded to, the male-to-female ratio is 3:1. Despite such observation, no known genetic factor linked to the X or Y chromosome has been reported.
Most cases of severe Pectus Excavatum are noticed at birth, with progressive worsening of the child’s growth and development. More than 80% of all cases are identified within the first 1-2 years. The condition typically becomes much more pronounced at puberty, during the time of rapid bone and cartilage growth. Most patients are brought to medical attention during their teenage years because of the significant change in the appearance of their chest.
Some patients with Pectus Excavatum experience chest and back pain that is typically musculoskeletal in origin. The exact cause of the pain is not really understood. Pectus Excavatum and Pectus Carinatum are frequently associated with Scoliosis. Although such association is probably coincidental, the poor posture noted in many patients with pectus deformities may be a key factor in the development of pain.
Many physicians attribute the symptomatic impairment in Pectus Excavatum to a decrease in intrathoracic volume secondary to the sunken chest. However, this relationship is difficult to prove due to the wide range of pulmonary function among healthy individuals and the correlation of pulmonary function with physical training and body habitus. There has been scientific evidence reported that demonstrates shortness of breath upon exertion in patients with pectus excavatum, primarily due to the decrease in pulmonary reserve.
Clinicians have observed that many patients with Pectus Excavatum tend to become symptomatic during their teenage years or early in adult life. Patients younger than 10 years who have Pectus Excavatum do not typically experience symptoms associated with shortness of breath. Studies of pulmonary function in patients with Pectus Excavatum have provided the following information:
- A prospective study of preoperative and postoperative pulmonary function following corrective surgery for Pectus Excavatum is currently underway.
In 1984, Cahill et al reported that, after operative repair, lung capacity improved little, and maximal voluntary ventilation significantly improved in patients with Pectus Excavatum who had low-to-normal vital capacities prior to surgery.Exercise tolerance was also improved, as measured by total exercise time and maximal oxygen uptake. The heart rate at a given level of work or exercise consistently decreased postoperatively, but oxygen consumption to support an improved efficiency of work was not changed. The observed decrease in heart rate at each workload capacity was a result of increased cardiac stroke volume.
- In 1967, Weg et al evaluated 25 US Air Force recruits with pectus excavatum and compared them with healthy trainees.3 Although the lung compartments and mean vital capacities of both groups were equal, the maximum voluntary ventilation significantly deviated from predicted reference range values (P = 0.005).
- In 1996, Quigley et al studied 36 adolescents (mean age 16 y) with pectus excavatum. Quigley et al reported a significantly lower forced vital capacity in the study group than in an age-matched control group. Moreover, an inverse relationship was observed between the vital capacity and the degree of sternal compression, suggesting that such patients would benefit from operative correction of the pectus deformity.
Posterior displacement of the sternum in Pectus Excavatum can produce a heart deformity, with anterior indentation of the right ventricle. Early pathologic studies demonstrated this finding, and a series of early case reports included cardiac evaluations for patients with severe symptoms. Angiographic studies have demonstrated the sternal imprint on the anterior wall of the right ventricle.
Several studies have demonstrated limitation of cardiac stroke volume in patients with Pectus Excavatum, particularly in the sitting, or upright, position. When patients with pectus remain in the supine position (lying flat), no significant impairment to cardiac function is apparent. Further evidence has suggested that operative repair of pectus results in normalization of the cardiac function. One study assessed cardiac workload in 13 patients with Pectus Excavatum. The patients were assessed in an upright position on a bicycle ergometer. Findings suggested that, following surgery, most patients could more easily reach the target heart rate during exercise without becoming symptomatic. Many use this observation as substantial evidence that operative repair for Pectus Excavatum results in improved cardiac function. However, the role of conditioning and subjective response to surgery is very difficult to assess.
The hallmark of Pectus Excavatum is the caved-in appearance of the anterior chest. As mentioned above, the severity of the defect and the asymmetry of the chest widely vary. Patients may present with a very mild form of Pectus Excavatum or their sternum may be almost touching the spine. Typically, the lower third of the sternum is more involved, and the upper third may appear fairly normal. A compensatory anterior flaring of the lower ribs at each costal margin is also common. Many patients have associated scoliosis, but this is not directly related to the presence of Pectus Excavatum.
- Auscultation of the chest: Heart sounds are typically displaced to the left side because of displacement and rotation of the heart. A click sound of mitral valve prolapse may be present. Lung sounds are clear, but the lung sounds may appear diminished at both bases because of decreased pulmonary volumes.
- Pectus posture: The term pectus posture refers to the position assumed by most patients with significant Pectus Excavatum. They appear to create an anterior curvature of the thoracic spine with the shoulders slumped forward. Whether this is a subconscious maneuver to hide the chest wall deformity or a postural defect directly related to Pectus Excavatum is unclear. Such positioning of the spine appears to accentuate the Pectus Excavatum and can generate spine problems related to poor posture and inadequate spinal support. Correcting this posture is quite difficult, even after successful repair of the Pectus Excavatum.
The precise causes of Pectus Excavatum are not known. It probably originates from a genetic defect that results in abnormal musculoskeletal growth. The cartilaginous portion of the rib is very likely the main source of this abnormal growth pattern. Abnormalities of rib morphogenesis and growth are the most likely causes of Pectus Excavatum and Pectus Carinatum. In Pectus Excavatum, the sternum is thought to be pushed in by abnormal growth at the articulation with the ribs and cartilage. Again, the exact mechanism that results in this abnormal growth pattern is not known. Increased work of breathing, as is observed in young patients during exercise or play activity, may contribute to the progression of the pectus deformity, particularly during early the teenage years. However, no scientific evidence supports such a theory.
Other Problems to Be Considered
Conditions associated with Pectus Excavatum include Marfan syndrome, Poland syndrome, and Pouter pigeon breast.
No specific laboratory study is necessary in the workup of patients with Pectus Excavatum. Most children with this condition are otherwise healthy.
Imaging studies are important in the initial assessment of any patient with Pectus Excavatum.
- Radiography: Perform baseline 2-view chest radiography (anteroposterior and lateral views) in all patients. This provides information about any possible associated intrathoracic pathology, severity of the lung compression, and mediastinal displacement. Plain chest radiography also shows the degree of posterior displacement of the sternum, particularly in relation to the spine. However, it does not provide any information about the appearance of the affected ribs because the cartilaginous part is the involved part and is not visible on standard radiographs. In addition, plain chest radiography allows for assessment of the spine and possible associated scoliosis, a common finding in many patients with Pectus Excavatum.
- Chest CT scanning: This is useful in determining the Haller index, which is derived by dividing the transverse chest diameter by the anteroposterior diameter. An index of more than 3.2 has been correlated with a severe deformity that requires surgery. The author’s experience has demonstrated that the chest index can also be obtained with plain anteroposterior and lateral chest radiography. However, this is not as precise as the measurements obtained from CT scanning. CT scanning can provide helpful information related to the commonly seen asymmetry of the chest in patients with Pectus Excavatum. It also clearly reveals the displacement and rotation of the heart. In cases with significant asymmetry, CT scanning can provide valuable information for planning the operative intervention and can also provide helpful information regarding the asymmetric volume difference between the right and left hemithorax. Many patients with Pectus Excavatum have some degree of rib hypoplasia, which may cause one hemithorax to be much smaller than the other. This typically cannot be corrected by surgery. The image below is a CT scan of a young patient with severe Pectus Excavatum. Note the severe Pectus Excavatum with compression of the lung fields and complete displacement of the heart and mediastinal structures to the left hemi-thorax.
- Echocardiography: Cardiac function and morphology can be easily assessed with noninvasive methods such as echocardiography. Unless the patient is symptomatic, echocardiography is not mandatory in the workup of patients with pectus excavatum. However, if Marfan syndrome is suspected, echocardiography should be performed to evaluate for possible aortic root dilation. In such cases, consultation with a pediatric cardiologist should be considered.
- Pulmonary volumes, ventilation, and exercise tolerance can be easily evaluated in a pulmonary laboratory with a standard pulmonary function test (PFT). Findings in patients with Pectus Excavatum are described in the History section. A progressive (stress) exercise test may help detect abnormalities in exercise response. Most patients have abnormal stress PFT findings.
- Echocardiography, ECG, PFTs, and CBC count are not mandatory and are obtained only if indicated based on the medical history and physical examination findings. Mitral valve prolapse is not unusual in patients with Pectus Excavatum. The PFT results may show a slight decrease in pulmonary volumes and reserve. For more details about cardiopulmonary assessment, see the History section.
The operative procedure for correction of Pectus Excavatum is discussed within this article in the Surgical Care section and in the surgical treatment page. Additionally, non surgical medical procedures are discussed on the non-surgical treatment page
Histologic assessment of the affected ribs, cartilage, and sternum typically does not reveal any abnormal findings other than the unusual shape of the deformed ribs.
No effective nonoperative management strategies can correct of severe Pectus Excavatum, but they can be used in minor cases of the disorder. Several exercise programs have been suggested. However, they are only effective in achieving anatomical correction in minor severity cases.
External braces have also been used in the nonoperative management of Pectus Excavatum, but no experience with this approach in the treatment of chest wall deformities in North America has been reported. Pectus Carinatum is more likely to improve with the consistent use of an external brace because the exogenous compression of the sternum and anterior ribs by the brace may, over time, result in some degree of correction of the deformity. Good results are unlikely to be achieved with external bracing techniques in the correction of severe Pectus Excavatum. For more information on this subject, please consult this website for the Orthopaedic Conservative Method and Information on Pectus Deformities.
Until the mid 1990s, the operative treatment of Pectus Excavatum had been fairly well standardized and was based on the open operation originally described by Ravitch in 1949.6 Few variations to his original description have been added, and the operation became almost universally accepted by pediatric surgeons as the standard for treatment of this condition.
Several published series demonstrated excellent results with low complication rates despite the fairly radical nature of the Ravitch operation, which required anterior chest wall exposure, creation of muscle and skin flaps, extensive cartilage resection, and sternal osteotomy. The procedure involves the surgical exposure of the anterior chest wall, creation of skin and muscle flaps, and resection of the affected cartilages and sternal osteotomy are visible.
In 1987, during the early stages of laparoscopic and minimally invasive surgery, the creative mind of a pediatric surgeon from Virginia, Donald Nuss, MD, challenged the surgical dogma.7 Nuss performed the first minimally invasive operation for the correction of Pectus Excavatum. Not until May of 1997 was this new and innovative technique introduced to the American Pediatric Surgical Association and, subsequently, published in the Journal of Pediatric Surgery. Because of the excellent results obtained with this new technique and because of the less radical nature of the operation, the popularity of this technique has grown dramatically.
Indications for surgical repair
Operative correction should be considered in patients who present with Pectus Excavatum and cardiopulmonary impairment. The most common goal in operative repair of pectus excavatum is to correct the chest deformity. This is particularly important in teenagers, in whom the appearance of the chest can result in significant problems related to body image and self-esteem. Thus, the desire to improve the appearance of the chest is considered an appropriate medical indication for surgery.
Other indications include exercise and physical activity limitations, evidence of cardiac or pulmonary dysfunction, chest pain, psychological distress, and potential future need for sternotomy (open-heart surgery). Adult patients with Pectus Excavatum who undergo open-heart surgery typically have significant displacement and rotation of the heart to the left chest. This can make the operative approach to the heart at the time of open-heart surgery difficult and challenging. With this in mind, elective repair of the pectus deformity prior to open-heart surgery may be indicated in selected cases.
Minimally invasive surgery for repair of Pectus Excavatum
The clinical observations that provided the rationale for developing a less invasive operation that would allow for the anatomical correction of Pectus Excavatum deformity are written below.
First, children have a very soft and malleable chest. Second, the phenomenon of chest remodeling is well known in adult patients with emphysema who develop a barrel-shaped chest. If the chest wall in older adults can be reconfigured, the same should be possible in children and teenagers because of the increased malleability of their anterior chest wall. Third, the use of braces and internal fixating devices has allowed orthopedic surgeons and orthodontists to correct skeletal anomalies such as scoliosis, club foot, and maxillomandibular malocclusion. The anterior chest wall, which is quite malleable, is ideal for this type of correction. Such observations resulted in a technique in which a convex stainless-steel bar is placed under the sternum through a small lateral thoracic incision to correct the condition known as funnel chest. Thus, the minimally invasive repair of pectus excavatum (MIRPE), also known as the Nuss technique, was born.9
Prior to surgery, the chest is measured from the midaxillary line to midaxillary line to determine the approximate length of the bar required, and the correct length is typically obtained by subtracting 1 cm from that initial measurement. A mild bowel preparation 1 day before surgery may be helpful in decreasing problems related to postoperative constipation. Administer a first-generation cephalosporin antibiotic (cefazolin) approximately 1 hour prior to surgery and continue for at least 48 hours or until the patient is afebrile. As a rule, patients can be admitted on the same day of surgery.
The combination of general endotracheal anesthesia and a thoracic epidural is considered ideal. The epidural catheter is left in place for up to 3 days following the operation, providing excellent adjuvant therapy to pain management techniques. Patients and families must understand that, although the technique is considered minimally invasive, postoperative pain and discomfort can be significant because of the forceful bending of the sternum and cartilages. An indwelling Foley catheter is placed because urinary retention is common with thoracic epidurals. Orogastric tube decompression of the stomach is recommended only during the operation. Hemodynamic monitoring by the anesthesiologist does not necessitate central venous or arterial lines.
The surgical technique is as follows:
- The patient is placed in the supine position with both arms abducted at the shoulders to allow access to the lateral chest walls.
- The patient is prepared for surgery and draped such that the entire anterior chest is exposed, including the lateral chest wall (broad exposure).
- The chest is marked with a sterile marking pen in the deepest portion of the pectus (making sure that it is not inferior to the sternum), on the corresponding intercostal spaces on the right and left sides where the bar is to be inserted, and on the points on the pectus ridge that correspond to the horizontal plane from the deepest point of the pectus to the lateral chest wall incisions.
- At this time, the measurement of the Lorenz pectus bar is reconfirmed using the marks made on the chest. The length of the Lorenz bar should be measured from the mid-axillary line in one side to the opposite mid-axillary line. The length of the bar is measured in inches. A typical measurement for a teenage patient may range from 13-inches.
- The bar is bent from the center out to either end, making small gradual bends with a Zimmer bar bender. The curvature (convexity) of the bar is shaped to fit each individual patient’s chest. Occasionally, slightly exaggerating the curvature to allow for the anterior chest wall pressure that may alter the original configuration of the bar may be necessary. The bar must fit snugly over the chest.
- A transverse 2-cm skin incision is made on the midaxillary line at the level of the skin marks in line with the deepest point of the depression on the right and left sides.
- A skin tunnel is raised anteriorly from both incisions to the top of the pectus ridge at the previously selected intercostal space; the skin pocket is extended posteriorly to allow for the distal end of the pectus bar to hug the chest wall posterior to the midaxillary line.
- A thoracoscope is inserted at this point. The authors recommend placement of a 5-mm trocar 1-2 intercostal spaces below the space that has been chosen for the pectus bar on the patient’s right side. The image below illustrates the placement of the thoracoscope. A 30? thoracoscope provides excellent visualization of the pleural cavity, lung, and mediastinal structures.
- If necessary, the scope can be used bilaterally. Insufflating the pleural cavity with carbon dioxide is rarely necessary; in most cases, controlled ventilation by the anesthesiologist with small tidal volumes results in limited lung expansion and good thoracoscopic visualization of vital structures.
- Using a thin but deep retractor, the skin incisions are elevated and the intercostal space previously marked is identified. A long instrument, such as a 15-in Crawford vascular clamp or a Lorenz pectus introducer (S-shaped device), is inserted through the appropriate right intercostal space at the top of the pectus ridge, in line with the point that corresponds to the deepest depression of the sternum (previously marked).
- The clamp or introducer is slowly advanced across the anterior mediastinal space immediately under the sternum with careful videoscopic guidance. Always face the point of the instrument anteriorly (away from the heart) and maintain contact with the sternum to avoid injury to mediastinal structures.
- The sternum is forcefully lifted as the instrument is passed to the contralateral side. Monitoring for cardiac ectopy is important to ensure that the instrument is not near the heart or pericardial sac.
- Once the instrument is passed behind the sternum, the tip is pushed through the intercostal space at the top of the pectus ridge on the left side (also previously marked) and brought out through the left skin incision. Thoracoscopy on the left side is not usually necessary unless the position of the instrument in the left chest is uncertain.
- The Crawford clamp, if used, is advanced such that the tunnel space created is enlarged; if the Lorenz pectus introducer is used, further dilating the space is not necessary. Note that the Lorenz pectus introducer comes in 2 sizes: short, for younger patients aged 4-12 years who have a small chest, and long, for older and larger patients aged 13-20 years.
- Using the clamp or the introducer, 2 strands of umbilical tape are pulled through the tunnel; one tape is used as a spare.
- One of the tapes is used to guide the previously prepared pectus bar through the tunnel and anterior mediastinal space using traction on the tape and concomitant thoracoscopic visualization. The bar is inserted with the convexity facing posteriorly. The image below is an illustration of the bar in place before it is turned over.
- Using a Lorenz pectus bar rotational instrument (also known as a “bar flipper”), the bar is turned over so that the concave part now faces posteriorly (to the mediastinum) and the convex part faces anteriorly. The ends of the bars are placed in the subcutaneous tissue, anterior to the muscle fascia (not under it and not within the muscle tissue). Again, the bar must hug the chest so that the ends do not protrude under the skin pocket. The “flipping maneuver” is also performed under careful thoracoscopic visualization.
- If, after the bar is flipped, the correction of the pectus excavatum is not ideal (either undercorrected or overcorrected), the bar is flipped back, pulled back out, and bent again to fit the patient’s chest in order to achieve the best possible correction of the deformity. If pressure has caused the bar to straighten, it is turned over and, using small hand held benders, the curvature is increased as appropriate. This can be repeated as many times as necessary. Typically, only one bar is necessary to correct the deformity, but, occasionally, a second bar may be necessary. The second bar can be placed above or below the first one. The thoracoscope and trocar are removed at this point.
- Once the bar is in place, determining its stability is imperative. Such assessment dictates the need for placement of a stabilizing bar. The stabilizer serves to limit rotation of the pectus bar, and it is sutured around the bar and to the muscle only after being properly fitted. Teenagers usually require one stabilizer bar that can be placed on either side of the pectus bar.
- With the bar properly placed and stabilized, figure-of-eight sutures are placed to the lateral chest wall musculature. Number 0 nonabsorbable sutures (Prolene) are placed on one side, and absorbable (Vicryl or PDS) sutures are placed on the opposite side.
- Additionally, a third point-of-fixation suture can be placed on the anterior chest to the side of the sternum, around one rib and around the pectus bar, in order to provide another point of fixation for the bar, minimizing the chance of bar displacement.
- At this point, the anesthesiologist places the patient in the Trendelenburg position, and large tidal volumes are used in combination with positive-end expiratory pressure (PEEP) so that any residual pneumothorax is eliminated. A chest tube is rarely needed. The subcutaneous tissue and skin are reapproximated with absorbable sutures. Chest radiography is performed as soon as possible to confirm good lung expansion and to reveal the final positioning of the bar.
- The patient is extubated deeply to minimize any movement and/or agitation because this may result in bar displacement as the patient thrashes about.
Pain management typically requires keeping the patient well sedated for the first 1-3 days to prevent bar displacement. Medications and therapies depend on the patient’s response to pain and may include an epidural catheter, intravenous narcotics for breakthrough pain, patient-controlled analgesia (PCA), and nonsteroidal anti-inflammatory drugs (NSAIDs). In the first postoperative day, the patient is kept flat, with a straight thoracic spine, and is allowed only a small pillow. Mobilization is permitted on the second postoperative day by flexing the bed at the hip level and keeping the back straight. Do not permit waist bending, twisting, and log rolling. Avoid allowing the patient to sit in bed with the thoracic spine flexed. The patient needs assistance when getting out of bed the first few times.
The epidural catheter is generally removed on the third postoperative day, and the patient should be fully ambulatory after that point. The patient is discharged home when able to walk unassisted. The average length of stay is 4-7 days. Good posture with a straight back is very important, even after discharge. Again, bending at the hip and slouching are not allowed in the first month. Regular activity is permitted as pain reduces and mobility increases. Heavy lifting is not permitted for one month following surgery, and contact sports are to be avoided for at least 3 months. The bar generally remains implanted for 2 years and is removed in an outpatient procedure under anesthesia.
To date, only 2 large series that examine complications and outcomes of this new technique have been reported.10,11 In those reports, patient and family satisfaction were found to be very good, with excellent and good results reported at 93% and 96%, respectively. However, the only multi-institutional study, which reviewed 251 cases of MIRPE, demonstrated a significant rate of complications (the overall incidence rate of complications was almost 20%).11 By far, the most common complication requiring reoperation was displacement of the retrosternal stainless steel support bar (initially reported to occur in 9.5% of all patients). Such displacement can include a 90? rotation, a 180? rotation, or a lateral migration. Teenaged patients are at higher risk for complications, particularly pectus bar displacement, probably because of the increased pressure on the bar generated by a larger chest and more rigid chest cage.
Since the introduction of thoracoscopy and lateral stabilizers, as well as the third point of fixation technique, bar displacement has become quite unlikely, with an estimated incidence of less than 2.5% (prospective studies are currently underway to analyze outcomes of surgery).
The acceptance and popularity of MIRPE developed quickly since its introduction in 1997. The principal advantages of this new technique are based on the fact that incising the anterior chest wall, raising the pectoralis muscle flaps, resecting the rib cartilages, and performing a sternal osteotomy are not needed. This leads to a much shorter operating time, minimal blood loss, and early return to full activity because the stability and strength of the chest wall is not compromised. The apparent simplicity of the technique, combined with the early good results reported, contributed to the enthusiastic widespread use of this operation by many pediatric surgeons.
Unfortunately, a relatively high rate of complications was reported when many different surgeons performed the operation, probably reflecting the learning curve associated with the introduction of this new technique. Since the first MIRPE was performed, the bar has been modified 4 times and is now strong enough to withstand the pressure of even the most severe deformity. The poor results likely occurred early in the reported series because the bar was too soft, was removed too soon, or was not stabilized adequately. Experience has shown that stabilization of the bar is absolutely essential for success, and the use of a lateral stabilizing bar and the third point of fixation (when appropriate) minimizes the occurrence of bar displacement.
Fortunately, most factors that may lead to complications and poor results were related to early inexperience, and these factors have been corrected. Moreover, the introduction of thoracoscopy when performing MIRPE has significantly enhanced the surgeon’s ability to pass the bar precisely behind the sternum, avoiding the risk of cardiac or vascular injury. Reassuringly, one reported case of cardiac perforation occurred prior to the routine use of thoracoscopy.
Another significant advantage of MIRPE over the open surgical procedure is that the dreaded complication of “thoracic constriction” (Jeune syndrome) does not seem to occur with this new technique. Chest wall constriction has been described in a few patients following extensive open pectus excavatum operations. Apparently, the bone growth center can be affected, which results in restriction of chest wall growth with marked limitation of ventilatory function. Such patients are very symptomatic and cannot compete in running games. The forced vital capacity and forced expiratory volume in one second is typically decreased by more than 50% of predicted reference range levels. With the MIRPE, because no resection or incision is made on ribs or cartilages, such a complication does not appear to be a problem. Once the cartilage and bony structures are remodeled, normal or improved pulmonary function is established and the flexibility and malleability of the chest remains unaffected.
Critics of the MIRPE claim that the Nuss procedure is too invasive, risky, and not pain free. Proponents argue that this new approach, compared with the open surgery (modified Ravitch operation), eliminates the need for a large anterior chest wall incision with creation of pectoralis muscle flaps, resection of several ribs and cartilages, and sternal osteotomies. The MIRPE allows for a much shorter operating time, minimal blood loss, and minimal anterior chest wall scar. Moreover, the stability and strength of the chest wall is not compromised as it is with the open repair. For a more detailed review of the pros and cons of both approaches, please refer to the article “To Nuss or Not to Nuss? Two Opposing Views” in the Spring 2009 edition of Seminars of Thoracic and Cardiovascular Surgery.12
The current recommendations support the use of MIRPE in patients aged 5-20 years. The ideal age for undergoing this operation is 8-12 years because the chest wall is still very malleable, stabilization of the bar is easily achieved, thoracic epidural can be safely placed, and the child is mature enough to understand the operation and postoperative instructions, particularly incentive spirometry, which is essential for minimizing pulmonary problems after surgery.
Of note, one should not view operative correction of pectus excavatum as an operation limited exclusively to pediatric patients. Indeed, the open technique has been used in adult patients with excellent results. However, experience with the MIRPE in adult patients has been limited to a few cases, reported in anecdotes. Early results seem to indicate that similar principles apply and that operative correction using MIRPE can be achieved in adult patients. Limiting factors include a larger chest wall and poor malleability of the ribs, cartilage, and sternum. A surgeon experienced in the field of chest wall malformations must carefully evaluate adult patients to determine which operation would best correct the anatomical deformity.
An interesting observation has been that complications, mainly bar displacement, have appeared to be more common in teenaged patients. Initially, the MIRPE was limited to the younger prepubertal patients (aged 3-12 y), which probably accounted for the rare occurrence of bar displacement in the first report by Nuss.7 Older patients were offered the procedure because of the success of the procedure in young patients. Only later was the importance of proper stabilization of the bar identified and the lateral stabilizing bar was introduced (in 1998), followed by the addition of the third point of fixation technique (in 2000) to provide additional support and stability for the bar. The results seemed to have improved so much that the operation is now considered in adult patients with pectus excavatum.
A consultation with a cardiologist and pulmonologist are not mandatory and are obtained only if indicated based on the medical history and physical examination findings. However, many physicians and insurance companies believe that such an assessment is important prior to surgery. Experience has shown that, unless medically indicated by the presence of cardiopulmonary symptoms or abnormal physical findings, routine preoperative consultation with such specialists is of little benefit in the clinical evaluation and outcome of patients with pectus excavatum. However, their input can be helpful in cases in which insurance companies deny coverage of the procedure.
A consultation with a physical therapist before or after operative repair of pectus excavatum is considered an important factor in good recovery from surgery. The physical therapist assists and instructs patients on appropriate stretching techniques and exercises that aid the patient in the recovery phase. Continue such therapy for at least one month after surgery, when most patients are free of any significant discomfort with routine activities of daily life. Moreover, the physical therapist can assist patients in establishing proper posture, an important factor for a good functional and cosmetic outcome after surgery.
Dietary restrictions are not indicated. Note that constipation is common after operative repair of pectus excavatum, probably because of the use of narcotics for postoperative pain management. Thus, a high-fiber diet and use of laxatives is recommended early after surgical repair. Normal bowel function should resume after discontinuation of all pain medications.
Good posture with a straight back (ie, the military posture) is very important following surgery. Patients are also instructed to avoid any bending at the hip and to not slouch for the first month. Regular activity is permitted as pain reduces and mobility increases. Heavy lifting is not permitted for one month following surgery (patients are not allowed to carry heavy book bags for at least 4 wk), and contact sports are to be avoided for at least 3 months. After 3 months, most patients return to normal activities, including sports (eg, baseball, basketball, running, swimming, tennis, jumping). Following bar removal (typically performed in the outpatient setting at 2-3 years after the repair of pectus excavatum), patients are not to be restricted from any activities, except for 5-7 days after this minor procedure.
As previously mentioned, no effective drug therapy is available for the treatment of pectus excavatum. See Surgical Care.
Further Inpatient Care
During the patient’s hospital stay following corrective surgery for pectus excavatum, the author strongly recommends consultation with the anesthesia pain team. With intravenous narcotics and epidural analgesia, the pain that follows surgery can be controlled fairly well.
Typically, the thoracic epidural is removed 3-4 days after surgery, and most patients are discharged after 5-7 days. At the time of discharge, pain should be controlled with oral narcotics. NSAIDs, such as ibuprofen or ketorolac tromethamine (Toradol), are frequently added to the postoperative drug regimen. When using NSAIDs, consider adding histamine 2 (H2) blockers to prevent ulcer-related complications.
Further Outpatient Care
The typical follow-up postoperative repair of pectus excavatum involves outpatient visits with the pediatric surgeon 2-3 weeks after surgery and at regular intervals after that for the next 2 years. Monitoring patients at least every 3-6 months is recommended to ensure that they are not developing an anterior protrusion of the chest due to too much pressure from the pectus bar. Pectus carinatum as a sequela of MIRPE has been reported.
Refer patients with pectus excavatum to a pediatric surgeon experienced in the field of congenital chest wall deformities.
Physical fitness and development of strong anterior chest musculature may improve the appearance of pectus excavatum. However, clinical experience has demonstrated that only mild cases of pectus may benefit from this technique. The deformity worsens in most patients with moderate or severe pectus excavatum, particularly during the physiologic rapid growth of puberty.
The prognosis of Pectus Excavatum, with treatment, is excellent. Patients with mild pectus excavatum who do not undergo operative correction also have an excellent prognosis. Patients with moderate-to-severe pectus excavatum may experience problems related to cardiopulmonary impairment, decreased exercise tolerance, decreased stamina, and adjustment disorders related to the impact of this deformity on body image and coping mechanisms. Mortality is not associated with the condition.
Because of the recent advances in the operative repair of pectus excavatum, education of medical professionals and the public is important. Again, patients with pectus excavatum should be referred to a surgeon experienced in the field of congenital chest wall malformations. Early assessment and follow-up is essential to maximize good outcomes.
After operative repair of the pectus excavatum, instruct patients on correct posture to eliminate musculoskeletal pain and to prevent worsening of the spinal deformity. Emphasize that repair of the pectus in itself does not result in correction of any associated spinal deformity or problems related to poor posture.
Miscellaneous Special Concerns
Scoliosis and Pectus Excavatum
An association between anterior chest wall deformities and scoliosis is described in the literature but is poorly defined. Apparently, only 4-5% of patients with severe anterior chest wall deformities have scoliosis of sufficient magnitude to warrant evaluation and observation by a spinal deformity physician. The relationship between anterior chest wall deformity and scoliosis is most clear in patients with Marfan syndrome. Patients with Marfan syndrome who have scoliosis are at high risk for progression of the deformity to unacceptable levels and have not historically responded well to brace therapy. Because of the association between pectus deformities and scoliosis, carefully examine patients with anterior chest wall deformities for signs of scoliosis and perform radiography if indicated. Patients younger than 5 years who present with spinal deformity are at risk for adverse cardiopulmonary sequelae related to the scoliosis. The management of scoliosis in patients with anterior chest wall deformities follows the treatment principles outlined for patients with idiopathic scoliosis.
Pouter pigeon breast and Pectus Excavatum
This condition represents a rare congenital deformity of the chest characterized by a protrusion of the manubriosternal junction and adjacent costal cartilages, as well as premature sternal ossification. One third of patients with Pouter pigeon breast have concomitant depression of the lower sternum (pectus excavatum). Several cardiovascular abnormalities have been associated with premature sternal ossification, the most common being ventricular septal defect. Surgical correction includes the wide wedge transverse sternotomy at the angle of Louis and subperichondrial resection of the adjacent costal cartilages. Long-term outcomes are encouraging.
Poland syndrome and Pectus Excavatum
This syndrome is characterized by pectus excavatum, hypoplasia or absence of the breast or nipple, hypoplasia of subcutaneous tissue, absence of the costosternal portion of the pectoralis major muscle, absence of the pectoralis minor muscle, syndactyly or bony abnormalities of the forearm, and absence of costal cartilages or ribs (typically ribs 2-4 or 3-5). Clinical manifestations of Poland syndrome widely vary, and all features rarely affect a single individual.
Adult patients with Pectus Excavatum
During the era of open surgery to repair pectus excavatum, adult patients rarely underwent corrective surgery. However, with the introduction of MIRPE, surgeons have noticed a significant change in the trend for corrective surgery in patients older than 18 years. Although MIRPE can be successfully performed in adult patients, the risk of bar displacement and other complications is increased in that group of patients. In addition, the degree of postoperative pain is more significant and more prolonged.