Indications and Technique of Nuss Procedure for Pectus Excavatum Donald Nuss, MB, ChB, Robert E. Kelly Jr, MD* KEYWORDS Pectus excavatum Thoracoscopy Nickel allergy Nuss procedure Many modifications have been made to the mini- placement.6,8,9,12,14e19 In addition, complications mally invasive pectus repair since it was first per- have been more clearly defined and are divided formed in 1987 and the 10-year experience into early and late groupings.20e22 The effects of published in the Journal of Pediatric Surgery in the early learning experience have been separated 1998.1 The experience can be divided into the first from those of the later experiences.2,4,13,20e26 decade with 42 patients treated at one institution More studies comparing cardiopulmonary and the second decade with several thousand function18,27e33 and quality of life34e37 before and patients treated worldwide at multiple in- after surgery are now available. Long-term results stitutions.2e9 In the first decade, the modifications after bar removal have confirmed that the excellent included changing the incision from an anterior results achieved at the time of repair are main- chest incision to bilateral thoracic incisions and re- tained after bar removal.7e9,11,12,38 designing the pectus bar from a short, soft, square-ended strut to a much longer and stronger CLINICAL FEATURES steel bar with rounded ends.1 In the second decade, many new features were Pectus excavatum (PE) may be present at birth, added to make the procedure safer and more but in the authors’ series of more than 2000 patients, most presented during the pubertal successful. These features included the routine 38 use of thoracoscopy; the development of growth spurt, of which 80% were boys (Table 1). completely new instruments specifically designed Associated scoliosis occurs in 20% to 30% of the 38,39 for tunneling, bar rotation, and bar bending; the patients, and connective tissue disorders development of a stabilizer; and the placement of such as Marfan syndrome, Marfanoid features pericostal sutures around the bar and underlying and Ehlers-Danlos syndrome occur in up to 38 ribs to prevent bar displacement.9e12 The increase 20%. in the number of patients presenting for surgical Morphology correction was not only because of an increase in referral by primary care physicians but also The deformity most frequently involves the lower because of self-referral by patients who obtained sternum and chest wall. Focal or cup-shaped their information from the Internet.12e14 This depressions are the most common type; broad, increase in numbers worldwide, combined with shallow, saucer-shaped deformities are the longer follow-up, allowed clarification of age limits, second most frequent; a long furrow or trench, indications for surgery, and duration of bar which is usually asymmetrical (Grand Canyon Department of Surgery, Eastern Virginia Medical School, Children’s Hospital of The King’s Daughters, 601 Children’s Lane, Suite 5B, Norfolk, VA 23507, USA * Corresponding author. E-mail address: [email protected] Thorac Surg Clin 20 (2010) 583–597 doi:10.1016/j.thorsurg.2010.07.002 1547-4127/10/$ e see front matter Ó 2010 Elsevier Inc. All rights reserved. thoracic.theclinics.com 584 Nuss & Kelly A computed tomographic (CT) scan of the chest Table 1 Medical history of 327 patients studied without contrast gives a clearer picture of the deformity and the bony and cartilaginous skeleton Condition Number Percentage in 3 dimensions and allows calculation of the CT index. The 3-dimensional reconstruction is useful Exercise intolerance 211 64.5 in determining the number of bars that may be Lack of endurance 205 62.7 necessary, especially in diffuse deformities, which Shortness of breath 203 62.1 extend up toward the clavicles. Cartilaginous Chest pain 167 51.1 deformity is poorly seen on a chest radiograph with exercise but well visualized on a CT scan. Likewise, cardiac Family history of PE 140 42.8 and pulmonary compressions as well as the rela- Chest pain without 104 31.8 tionship of the sternum to the compressed heart exercise are much better visualized on the CT scan than Asthma 70 21.4 on a chest radiograph. CT also helps better to Scoliosis 69 21.1 see abnormal calcification of cartilages in a recur- rent previous open (Ravitch) operation.42 Review Cardiac abnormalities 65 19.9 of the CT scan with the patient and parents before Frequent or 44 13.5 surgery helps to communicate the extent of defor- prolonged URI mity and to form expectations for the hospital Palpitations 37 11.3 course and final outcome. A method for measuring Pneumonia 28 8.6 asymmetry and cephalad extension of the depres- Fainting/dizziness 27 8.3 sion by CT scan has been published.43 Marfan syndrome 15 4.6 Magnetic resonance imaging (MRI) may be used Family history of PC 13 4.0 instead of CT to reduce radiation exposure, espe- Ehlers-Danlos 9 2.8 cially in children who are old enough to cooperate syndrome and do not require sedation or general anesthesia Family history of 8 2.4 for MRI. 44 Marfan syndrome Daunt and colleagues examined normal chil- e Patient adopted 4 1.2 dren to obtain values for the pectus index (2 2.3 in normal individuals). In 557 patients, it was found Patient has 3 0.9 that the 0- to 2-year age group had a significantly identical twin smaller mean Haller (pectus) index than older chil- Family history of 2 0.6 dren. In addition, girls had significantly greater Ehlers-Danlos syndrome pectus index values than boys in the 0- to 6-year and 12- to 18-year age groups. Following surgical Sprengel deformity 2 0.6 correction, Kilda and colleagues45 observed that Æ Abbreviations: PC, pectus carinatum; URI, upper respira- the pectus index increased by 0.45 0.49. Statis- tory infection. tically significant index differences before and From Kelly RE Jr. Pectus excavatum: historical back- after surgery were not detected in 88 children ground, clinical picture, preoperative evaluation and when the preoperation pectus index was less criteria for operation. Semin Pediatr Surg 2008; than 3.12 (P 5 .098). The investigators recommen- 17(3):210; with permission. ded indications for surgical treatment based on improvement in values for several radiographic type), is the third most common; and mixed carina- indices after operation. Kilda and colleagues state tum and excavatum deformities occur in 5%.40 that the commonly used pectus index should be greater than 3.1. Radiographic Evaluation Exercise Limitation Because the morphology varies, preoperative imaging for anatomic assessment and documen- Many patients with PE have a perceived limitation tation of dimensions of the chest are important. of exercise ability.30,37 Investigations of exercise A routine chest radiograph is used in some ability have yielded mixed results. Over more centers41 because it is inexpensive, readily avail- than 50 years, there have been dozens of studies able, and allows measurement of the indices of of cardiac or pulmonary function in PE. In 2006, severity. The radiograph is also helpful in recurrent Malek and associates30 reported a meta-analysis PE because it shows the extent of abnormal calci- based on a computer-assisted search of the liter- fication of cartilages. ature. The investigators concluded that surgical Indications and Technique of Nuss Procedure 585 repair improved cardiovascular function. Sigalet Fig. 1).12,28,33 In a study of patients with recurrent and colleagues32 studied patients pre-and postre- PE, the predicted values showed significant restric- pair and reported significant improvement in tive disease in more than half of the patients.49 cardiac stroke volume, cardiac output, forced expiratory volume in the first second of expiration Cardiology Evaluation (FEV1), total lung capacity (TLC), TLC (percentage expected), diffusing lung capacity, maximum Cardiological evaluation is important because a significant number of patients have findings of oxygen consumption (VO2max), respiratory right atrial and ventricular compression, mitral quotient, and O2 pulse (percentage predicted). valve prolapse, and rhythm abnormalities. Also, because many patients with PE have exercise- Pulmonary Function Studies related symptoms, including chest pain, it is useful Efforts to elicit the cause of exercise intolerance to assure normal heart functioning when planning have led to studies of pulmonary function at rest, a major thoracic operation. Mitral valve prolapse including spirometry and plethysmography. Results was present in 17% of the patients in the authors’ of spirometry in patients with PE are usually 10% to series and in up to 65% of those in other series, 20% less than the expected average for the popula- as opposed to only 1% in the normal pediatric pop- tion. Plethysmography shows that lung volumes are ulation.50e52 Mitral valve prolapse as a direct similarly decreased (Fig. 1).46e48 At the authors’ consequence of compression is suggested by CT institution, in 855 patients with PE presenting for scan53 and confirmed by its resolution in half of surgical treatment, the mean forced vital capacity the surgically treated cases. Dysrhythmias, (FVC) was only 77% instead of the 100% predicted including first-degree heart block, right bundle value, the mean FEV1 was 83%, and the forced expi- branch block, or Wolff-Parkinson-White syndrome, 54 ratory flow, midexpiratory phase (FEF25%e75%)was were present in 16% of the authors’ patients. 73%. In the same group, 26% of the patients had an The hemodynamic effects of PE have been the FVC in the abnormal category, less than the 80% subject of numerous reports and much contro- predicted value, and for FEV1 and FEF25%e75%, versy. The amount of right atrial and ventricular the number in the abnormal range was even higher, compressions varies with the overall shape of the with 32% and 45%, respectively, whereas in the chest.55 These effects were reported first several normal distribution, only 16% of the patients should years ago, but more recent imaging and exer- have less than the 80% predicted value (P<.001).