By Donald Nuss, MD, ChB

Early Documentation

Pectus excavatum, also known as sunken chest, is a congenital chest wall deformity in which several ribs and the sternum grow abnormally, appearing concave or caved-in.  

It is known that pectus excavatum was recognized in antiquity and that and as early as the 16th century Johan Schenck (1531-1590) collected literature on the subject1. A classic paper by Bauhinus in 1594, described the clinical features of pectus excavatum in a patient who suffered from pulmonary compression with dyspnea (shortness of breath) and paroxysmal cough as a result of a severe pectus excavatum.2  

The genetic predisposition of the deformity was first noted by Coulson3 in 1820, who cited a family of three brothers with pectus excavatum, and later by Williams4 in 1872, who described a 17-year-old patient born with a pectus excavatum whose father and brother also suffered from the condition.

Numerous other case reports appeared in the 19th century including a five case report by W. Ebstein in 18825, which covered the clinical spectrum of the condition. Treatment at that time was limited to "fresh air, breathing exercises, aerobic activities and lateral pressure."6,7 Surgeons had yet to learn how to prevent the lungs from collapsing when the chest was opened.

Advent of Thoracic Surgery

Thoracic surgery remained forbidden territory until the early years of the 20th century. It is not surprising that the first attempt at surgical correction of pectus excavatum was a tentative approach by Meyer in 1911.8 Meyer removed the 2nd and 3rd costal cartilage on the right side of the patient with no improvement of the deformity.

In 1913, Sauerbruch7, a pioneer of thoracic surgery who developed a negative pressure chamber for chest surgery, used a more aggressive approach and achieved some measure of success. Sauerbruch excised a section of the anterior chest wall, which included the left 5th to 9th costal cartilages as well as a segment of the adjacent sternum. Before the procedure, the patient had been incapacitated by severe dyspnea and palpitations (even at rest) and was unable to work in his father’s watch factory. After the surgery, though the heart was seen to pulsate under the muscle flap, the patient was able to work without dyspnea and even married three years later.

The Ravitch Procedure for Pectus Repair

In the 1920’s, Sauerbruch performed the first pectus repair using the bilateral costal cartilage resection and sternal osteotomy technique9 later popularized by Ravitch. Sauerbruch advocated external traction to hold the sternum in its corrected position for six weeks postoperatively to prevent recurrence. This technique was soon used by others surgeons in Europe and rapidly gained popularity in the United States as well.

In 1939, Ochsner and DeBakey10 published their experience with the procedure and reviewed the entire surgical literature on the subject.

Also in 1939, Lincoln Brown11 published his experience with the procedure in two patients and reviewed the literature with particular reference to the etiology. He was impressed with the theory that short diaphragmatic ligaments and the pull of the diaphragm were the causative factors.

Ravitch12, having read Brown’s article, believed this theory and as a result advocated even more radical mobilization of the sternum, with transection of all sternal attachments, including the intercostal bundles, rectus muscles, diaphragmatic attachments, and excision of the xiphisternum. He published his experience in 1947 with eight patients using this radically extended modification of Sauerbruch’s technique of bilateral cartilage resection and sternal osteotomy. Since the sternum was cut loose from all its attachments, Ravitch believed the sternum would no longer sink back into the chest and eliminated the use of external traction.

The modified procedure, without external traction, had an increased recurrence rate. As a result, in 1956 Wallgren and Sulamaa13,14 introduced the concept of internal support by use of a slightly curved stainless steel bar. This steel bar was pushed through the caudal end of the sternum from side to side, bridging the newly created gap between the sternum and ribs.

In 1961, Adkins and Blades15 took this concept of internal bracing one step further by passing a straigh, stainless steel bar behind the sternum rather than through the sternum. This form of pectus repair became the established technique for patients of all ages for the next 40 years.

Pectus Repair in Youths

As early as 1958, Welch16 already advocated a less radical approach than Ravitch. He produced excellent results in 75 cases without cutting through all the intercostal bundles and did not cut through the rectus muscle attachments. However, he still advocated doing the procedure in young patients.

Pena17 on the other hand, was very disturbed by the idea of resecting the rib cartilages of very young patients and attributed the development of asphyxiating chondrodystrophy in young patients to this early surgery. He was able to demonstrate experimentally that baby rabbits developed the condition after cartilage resection during their growth phase. He stated, "It appears necessary to develop alternative techniques that avoid the removal of costal cartilage and, to re-evaluate the optimal age for repair of these malformations."

Another surgeon, Haller18 also drew attention to the risk of "Acquired Asphyxiating Chondrodystrophy" in his paper entitled "Chest Wall Constriction After Too Extensive and Too Early Operations for Pectus Excavatum." As a result of these two papers, most surgeons stopped performing open pectus repair in young children, preferring to wait until after puberty. They also decreased the amount of cartilage resected and spoke about a "modified Ravitch procedure." Pediatricians became loath to refer patients for surgical corrections.

The Advent of the Nuss Procedure

In 1986, while operating on a patient with pectus excavatum, I was struck by the flexibility of the rib cartilages and thought "If these cartilages are so flexible and malleable why am I removing them?"

The real question, however, was "What can one do differently?"

The next time I operated on a patient with pectus excavatum and made the standard skin incision across the chest, I chose NOT to remove the skin and muscles off the chest - a necessary requirement in order to gain access to the rib cartilages and sternum - nor did I attempt to remove the rib cartilages and sternum. Instead, a small hole was created between the ribs, in line with the deepest point of the depression. A long, curved clamp was then inserted into the chest and a tunnel under the sternum was slowly created. The tip of the clamp was then advanced out of the chest on the other side of the sternum. Surgical tape was attached to the clamp, and pulled through the substernal tunnel. The tape was then used to guide a convex titanium bar through the tunnel with the convexity facing posteriorly. Once the bar was in position, it was turned over 180 degrees. Much to my delight, the pectus excavatum was corrected completely with no rib resection, no sternal wedge resection and essentially no blood loss.

Modifications to the Nuss Procedure

Unfortunately the titanium bar, used in the old procedure, proved too soft for the new procedure. The initial excellent result lessened after six months. The bar, therefore, was the first instrument modified.

The second modification was to change the long anterior chest incision to two small incisions on each side of the chest. New instruments were developed to make the procedure easier and safer. Most importantly, thoracoscopy was added to allow one to see inside the chest, greatly decreasing the risk of the procedure.

Protocols were developed for selecting patients who were severe enough to warrant surgery. Other protocols were developed for non-operative treatment, pain management and postoperative management.

Widespread Adoption of the Nuss Procedure

The procedure has gained rapid acceptance by the surgical community worldwide. To many, this less invasive procedure is analogous to applying braces to the teeth to straighten them out, rather than removing them.

In 1997, Nuss, Croitoru & Kelly et al 19,20 published their 10-year experience with the Nuss procedure. The minimally invasive technique requires no cartilage incision, no resection and no sternal osteotomy. It relies instead on internal bracing made possible by the flexibility and malleability of the costal cartilages.

The rationale for the technique was based on the three factors:

Children have soft and malleable chests. In young children, the chest is so soft that even minor respiratory obstruction can cause severe sternal retraction. Trauma rarely causes rib fractures; flail chest, etc., because "the chest is so soft and malleable."21-23 The American Heart Association recommends "using only two fingers" when performing cardiac resuscitation in young children and "only one hand in older children" for fear of crushing the heart.

Even middle-aged and older adults develop a barrel-shaped chest configuration in response to chronic obstructive respiratory diseases such as emphysema. If older adults are able to reconfigure the chest wall, children and teenagers should be able to do the same, given the increased malleability of their anterior chest wall.

The role of braces and serial casting in successfully correcting skeletal anomalies such as scoliosis, clubfoot, and maxillomandibular malocclusion by orthopedic and orthodontic surgeons is well established. The anterior chest wall, being even more malleable than the previously mentioned skeletal structures, is therefore ideal for this type of correction.

The popularity of the Nuss procedure is evidenced by the number of papers presented at national and international meetings and the over 100 surgeons who have sought out Dr. Nuss to see and learn the operative technique. As a result, Dr. Nuss and his colleagues have developed an annual international workshop at Children's Hospital of The King's Daughters in Norfolk, Virginia to teach even more surgeons.

Bibliography

Ebstein E: Die Trichterbrust in ihren Beziehungen zur Konstitution. Zeitschr. F. Konstitutionslehre 8:103, 1921.

Bauhinus J: Observationum Medicariam. Liber II, Observ. 264, Francfurti 1600, p507.

Coulson W: Deformities of the chest. London Med Gaz 4:69-73, 1820.

Williams CT: Congenital malformation of the thorax: Great depression of the sternum. Tr Path Soc London 24:50, 1872.

Ebstein W: Ueber die Trichterbrust. Deutsches Arch. 30: 411,1882.

Meade RH: A history of thoracic surgery. Springfield, IL, Thomas, 1961.

Sauerbruch F: Die Chirurgie der Brustorgane. Vol 1:437, Berlin, Springer, 1920.

Meyer L: Zurchirurqishen Behandlung der augeborenen Trichterbrust. Verh Bel Med Gest 42:364, 1911.

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Ochsner A, DeBakey M: Chone-Chondrosternon. J Thorac Surg 8: 469-511, 1939.

Brown AL: Pectus excavatum. J Thorac Surg 9:164-184, 1939.

Ravitch MM: The operative treatment of pectus excavatum. Ann Surg 129: 429- 444, 1949.

Wallgren GR, Sulamaa M: Surgical treatment of funnel chest. Exhib. VIII, Internat. Cong. Paediat. 1956, p32.

Paltia V, Parkkulainen KV, Sulamaa M, et al: Operative technique in funnel chest. Acta Chir Scandinav 116:90-98, 1958/1959.

Adkins PC, Blades BA: Stainless steel strut for correction of pectus excavatum. Surg Gynecol Obstet :111-113, 1961.

Welch KJ: Satisfactory surgical correction of pectus excavatum deformity in childhood. J Thorac Surg 36:697-713, 1958.

Martinez D, Juame J, Stein T, Pena A: The effect of costal cartilage resection on chest wall development. Ped Surg Int 5:170-173, 1990.

Haller JA, Colombani PM, Humphries CT, et al: Chest wall constriction after too extensive and too early operations for pectus excavatum. Ann Thorac Surg 61:1618-1625. 1996.

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. Ped Endosurg & Innovat Techn 2:205-221, 1998.

Kelley SW: Surgical Diseases of Children. Dislocations, Congenital and Acquired. Vol 1, 3 rd ed. St. Louis: C.V. Mosby Co., 1929, p.537.

Haller JA Jr: Thoracic injuries. In Welch KJ, Randolph JG, Ravitch MM, et al (eds): Pediatric Surgery. Vol 1, 4 th ed. Chicago: Year Book Medical Publishers, 1986, p. 147.

Wesson DE: Thoracic Injuries. In O’Neill JA Jr, Rowe MI, Grosfeld JL, Fonkalsrud EW, Coran AG (eds). Pediatric Surgery. Vol 1, 5 th ed. St Louis, MO: Mosby Grosfeld, 1998, p245