Chest wall development begins on day 35 postfertilization with the formation of ribs, which form from costal processes of the developing thoracic vertebrae. The ribs first develop as cartilaginous precursors that eventually ossify by a process called endochondral ossification (1). Like other regions, the bony skeleton is formed first followed by the skeletal musculature and its corresponding nerves. The sternum forms by the end of the sixth week postfertilization from paired condensations of two mesenchymal structures of the ventral body wall. These bars eventually fuse and chondrify to form a single sternal plate in a craniocaudal direction. Ossification occurs by 60 days postfertilization. The xiphoid process ossifies at birth.

The etiology of pectus excavatum is unknown. It occurs in approximately 1:400 live births. There is nearly a 10% incidence in children with elastic tissue abnormalities (e.g., Marfan syndrome and Ehlers Danlos syndrome (9,10). A familial incidence is seen, and male predominance approaches a ratio of 5:1 (11). The excavatum deformity is a result of abnormal growth, lengthening, and rotation of the costal cartilages, all leading to a depression of the sternum. Differential cartilaginous growth can result in significant asymmetry of the chest wall with a classic rotation of the sternum down to the right and the appearance of the left side of the sternum elevated compared with the right. Analysis of the cartilage from children with pectus excavatum shows differences in biomechanical and histochemical properties, but not in morphology compared with children with a normal postmortem exam. The cartilage derived from pectus excavatum exhibits decreased tension, compression, and flexure. Moreover, type II collagen patterns in the deep zones of
cartilage is disturbed, yet proteoglycan, the other component of cartilage matrix, is unaffected (12). The literature is replete with descriptive analyses of pectus excavatum, but molecular observations may eventually point to a mechanism.

Perhaps the most controversial area for this anomaly centers around the magnitude and significance of its physiologic sequelae. The notion that pectus excavatum creates cardiopulmonary compromise and demands reconstruction has eluded proof from prospective randomized trials. Thus, the indications for repair and for what reason are still subject to opinion based on primarily nonrandomized class II (retrospective) data. Historically, physiologic testing for children with pectus excavatum has included pulmonary function studies and heart function by evaluation of electrocardiogram (ECG), Holter monitor, and echocardiography. Static pulmonary function tests are not helpful for making any recommendations. In children and teenagers, these “at rest” studies usually show little to no abnormalities (13). Exercise pulmonary function studies have shown a restrictive pattern in the 10- to 12-year-old and teenager characterized by statistically significant lower lung volumes (14,15). Reduced maximal exercise capacity secondary to reduced cardiovascular performance (threshold for lactate accumulation) rather than ventilatory limitations (total lung capacity and residual volume) has been reported in a cohort of patients ages 13 to 50 years (16). Evaluation of cardiac function points to diminished right ventricular filling, but this seemingly important observation has eluded class I randomized evaluation (17). Moreover, overall cardiac function during exercise seems to not be affected (18). The psychological and psychosomatic aspects associated with pectus excavatum influence every aspect of life for children and teenagers. Embarrassment reactions, social anxiety, feelings of stigma, limited capacity for work, orientation toward failure, reduced tolerance to frustration, and marked depressive reactions are characteristic of children older than age 11 (19). These are important issues when dealing with the indications for repair and collectively demand that all health care providers be advocates for treatment of this congenital anomaly.

The principal concept of the Ravitch operation involves resection of all abnormal costal cartilages (29). The sternum is anatomically normal, but displaced by the overgrowth in length of the cartilages; therefore, it only needs to be fractured on its anterior table to restore a normal position, once it has been freed from the costal cartilages. A

transverse inframammary skin incision through the deepest portion of the sternal defect is the most appealing from a cosmetic perspective. Superiorly and inferiorly based subcutaneous skin flaps, followed by pectoralis muscles flaps are created exposing the costal cartilages in their entire length bilaterally. Typically, this exposure involves cartilages 4 to 7 or, in more severe cases, can involve the second or third cartilage bilaterally. A minimum of four cartilages should be excised bilaterally. A normal cartilage is always exposed cranial to the uppermost abnormal cartilage. The deformed costal cartilages are resected in a subperichondrial fashion from their union with rib to their junction with the sternum. The perichondrium is incised anteriorly along each cartilage and cephalad and caudad flaps created to expose the defective cartilage. Meticulous care is needed during the posterior portion of the dissection to avoid entering the pleural space. The perichondrium must be preserved in its entirety because it is from this tissue that new cartilage and subsequent bone is generated. Moreover, devascularization of the perichondrium may be a major cause for an acquired thoracic chondrodystrophy years later, following pectus reconstruction. A substernal plane is created by exposing and elevating the xiphoid and sweeping the pleura off the underside of the sternum. Meticulous care is taken to preserve both the pleura and the pericardium. The perichondrial bundles are then detached from the sternum to the uppermost resected cartilage. The internal mammary artery is swept laterally and should remain with the detached perichondrial bundles. An anterior triangular-shaped sternal osteotomy is made just above the resected cartilages (usually between cartilages 2 and 3). An oblique osteotomy will resolve the rotation of the sternum to a more anterior and neutral midline. A second, more caudal, anterior osteotomy is sometimes indicated. To further support the sternum, tripod supports can be created using the lowest of the intact costal cartilages (usually the third). Oblique division of this cartilage from medial to lateral facilitates positioning the medial portion atop the lateral, thereby supporting the sternum in its anterior position. The periosteum of the sternum is sutured to further secure the sternum in its neutral position. For children older than the age of 10 or those with elastic cartilage abnormalities (Marfan syndrome, Ehlers-Danlos syndrome), additional sternal support is recommended with a substernal stainless steel bar beneath the distal third of the sternum and secured to ribs (Fig. 57-5). Lateral support for the strut is achieved by securing it to the medial ends of an appropriate rib. The bar is anchored to the ribs using interrupted sutures. Detached intercostal bundles do not need to be sutured to the sternum. However, if the distance between the sternum and resected bundle is no more than 2 to 3 cm, the defect may be closed with approximation of these tissues. We typically reapproximate the last detached intercostal bundle to the lateral sternal border to ensure proper alignment. A chest tube is placed in the retrosternal space and a subcutaneous drain is placed over the muscle to prevent fluid collections; these are typically removed on postop days 2 and 3. Postoperative pain is moderate and adequately managed with intravenous patient-controlled analgesia. Once oral analgesia is established and drains removed, discharge is feasible. Children are usually discharged on hospital day 3 or 4. Early complications include pneumothorax, hemothorax, subcutaneous fluid collections, wound infections, urinary retention, and atelectasis. Urinary retention is common in the teenager and older patient. Therefore, a bladder catheter is recommended, but not mandatory for postop days 1 and 2. Use of postop incentive spirometer is suggested to avoid atelectasis. Taken together, these are all rare complications
and occur in less than 5% of patients. Their incidence is slightly higher in the adult population because of the magnitude of the dissection and the fact that the cartilage is now bone. The requirement for transfusion is extremely rare. Patients are released to home with limited activities. Contact sports are avoided for 6 to 8 weeks. This is typically enough time for regrowth of the cartilages and fixation of the sternum into its new neutral position, regardless of the patient’s age. The retrosternal strut remains in place for at least 6 months and can then be removed in the outpatient setting. Long-term complications include migration of the bar and recurrence, which may occur in up to 5% to 12% of patients in some series (30,31,32,33,34). The recurrence is slightly higher for the younger, school-age child probably because of the number of subsequent growth spurts. Recurrent pectus excavatum following the modified Ravitch technique can be successfully repaired using the same technique. Alternatively, use of other techniques such as autologous bone graft, cartilage grafts, muscular reconstructions, or the Nuss procedure have been used with success (35). Recurrence seems to be more prevalent if the operation was done at a very early age (less than 5 to 7 years old) and in older teenagers (15 to 17 years old).