CHAPTER 11 Surgical Treatment of Chest Wall Deformities
Nuss Procedure
Step 1: Surgical Anatomy
♦ Pectus excavatum is the most common chest wall deformity in children. Its incidence is estimated at approximately 1 in 100 children, and it has a male-to-female ratio of 3-4:1.
Step 2: Preoperative Considerations
♦ A complete history and physical examination are performed on all patients. All patients are encouraged to perform exercises designed to strengthen the chest and back muscles and improve exercise tolerance, along with maintaining proper posture.
♦ Determination of a severe pectus excavatum and the need for repair includes two or more of the following criteria:
♦ Our experience has shown that the optimal age for repair is 10 to 14 years because patients’ chests are still soft and malleable. At this age, they show quick recovery, a rapid return to normal activities, and excellent results. After puberty, the flexibility of the chest wall is decreased and often requires the insertion of two bars. It also takes the patients longer to recover at this age. However, we have performed the procedure in patients up to age 31 years with good results.
Step 3: Operative Steps
Anesthetic Induction
Before Incision
♦ The length of the pectus bar is determined by measuring the distance from the right midaxillary line to the left midaxillary line and subtracting 2 cm or 1 inch. The measurement is done over the area of the deepest depression that is still part of the sternum.
Surgical Procedure
♦ A thoracoscope is inserted into the right side of the chest two intercostal spaces below the planned bar placement to check that the internal anatomy corresponds with the external markings and to look for unexpected pathology.
♦ Lateral thoracic incisions are made in the region of the midaxillary line, and subcutaneous tunnels are created to the greatest apex of the pectus deformity (X) (Fig. 11-2). These “X’s” represent the entrance and exit sites of the bar from the chest. They are in the intercostal space that is in the same level as the deepest depression, and care should be taken that they are placed medial to the greatest apex of the chest.
♦ Skin tunnels are created above the muscle, starting from each of the lateral thoracic incisions to the top of the pectus ridge on each side. To minimize superficial skin retraction, the tunnel can be created between the pectoralis major and minor muscles. The tunnels should be created so that the entry and exit sites of the bar from inside the chest are medial to the top of the pectus ridge on each side.
♦ With the thoracoscope in place, a tonsil clamp is inserted into the subcutaneous tunnel on the right, and a blunt thoracostomy is created at the site marked “X” while taking care not to injure the intercostal vessels, mammary vessels, lung, or pericardium (Fig. 11-3).
♦ Under continued thoracoscopic visualization, a Lorenz introducer (W. Lorenz Surgical, Jacksonville, FL) is inserted into the chest through the right tunnel and thoracostomy site at the top of the pectus ridge. With great care and thoracoscopic guidance, the pleura and pericardium are dissected off the under surface of the sternum, creating a substernal tunnel. The introducer is slowly advanced across the mediastinum and brought out through the corresponding intercostal space on the left and advanced out of the incision on the contralateral side. Again, this exit site is medial to the top of the pectus ridge (see Fig. 11-3)
♦ A 30-degree scope facilitates visualization during the substernal dissection, and care is taken to keep the point of the dissector underneath the sternum at all times to push the heart out of the way of the dissection plane. During the dissection, the ECG monitor should be turned to maximum volume to listen for any ectopy or arrhythmias.
♦ When the introducer is fully in place, the sternum is elevated by lifting the introducer on each side, thus correcting the pectus excavatum. The sternum is brought out of its depressed position by lifting the introducer several times. This is facilitated by pressing down on the lower chest wall while lifting the introducer. This maneuver flexes the cartilage, and in our experience it helps to minimize intercostal muscle stripping when the bar is placed and facilitates correction of sternal torsion, if it is present.
♦ Once the sternal depression has been corrected, umbilical tape is attached to the introducer, and the introducer is slowly withdrawn from the chest cavity with the umbilical tape attached.
♦ The pectus bar that was previously bent into a convex shape is then attached to the umbilical tape. It is then slowly pulled through the right subcutaneous tunnel under thoracoscopic visualization and guided through the substernal tunnel with its convexity facing posteriorly until it merges on the contralateral side.
♦ The pectus bar is positioned inside the chest with its convexity facing posteriorly and an equal amount of bar protruding on each side. Using the specially designed bar flippers, the bar is rotated 180 degrees, giving instant correction to the pectus deformity. The sides of the bar should be resting comfortably against the musculature and should not be too tight or too loose. If the bar does not fit snugly on each side because of pressure on the middle, the bar can be reflipped and molded as necessary while still in place in the chest.
Stabilization of the Bar
♦ The bar is stabilized by attaching a stabilizer to the left end of the bar and wiring the bar and stabilizer together with no. 3 surgical steel wire. The stabilizer and bar are also secured by placing numerous interrupted absorbable sutures through the holes in the bar and adjacent fascia. An additional stabilizing technique uses a laparoscopic “auto-suture” needle to place multiple “0” absorbable sutures around the bar and underlying ribs with thoracoscopic guidance (Fig. 11-4).
Closure
♦ Meticulous hemostasis is obtained, and then the pockets are closed in three layers with absorbable suture.
♦ The chest is evacuated of CO2 by placing the patient in Trendelenburg position with the left side down and the anesthesiologist giving positive ventilatory pressure. By cutting the tubing of the trocar and placing it in water below the level of the patient, one can confirm near-complete evacuation when the bubbles stop. Rarely is a chest tube required.
Step 4: Postoperative Care
♦ Perioperative antibiotics are continued until discharge on the 4th or 5th day. An epidural catheter is used for 3 or 4 days and then transitioned to intravenous and oral pain medications. Patients are discharged receiving a combination of narcotic, anti-inflammatory, and muscle-relaxant medications.
♦ For the first 6 weeks, patients are prohibited from playing sports but are encouraged to do deep-breathing exercises and to ambulate. At 6 weeks after the repair, they are encouraged to resume normal activities, and at 3 months they may resume competitive sports. Heavy contact sports such as football, boxing, and ice hockey are prohibited for a minimum of 6 months. Our preference is that they avoid heavy contact sports while the bar(s) is in place, but other aerobic sports are encouraged.
Step 5: Pearls and Pitfalls
♦ The entry and exit sites must be medial to the greatest apex of the chest; otherwise, the bar is unstable and can flip and strip the intercostal muscles.
♦ In older patients or those with a stiff chest or major torsion, two bars are helpful to distribute the pressure and get a more stable repair. One bar has to be under the bony sternum, and although it is desirable, the second bar need not be.
♦ Any patient with a history of potential allergies should be tested for metal allergy and, if positive, should have titanium bars made. In any postoperative patient with atypical symptoms, including skin reactions, pleural or pericardial fluid, or culture-negative wound collections, one should consider a metal allergy as the cause.
Croitoru DP, Kelly REJr, Nuss D, et al. Experience and modifications update for the minimally invasive Nuss technique for pectus excavatum repair in 303 patients. J Pediatr Surg. 2002;37:437-445.
Kelly RE, Shamberger RC, Mellins RB, et al. Prospective multicenter study of surgical correction of pectus excavatum: design, perioperative complications, pain, and baseline pulmonary function facilitated by Internet-based data collection. J Am Coll Surg. 2007;205(2):205-216.
Lawson ML, Cash TF, Akers RA, et al. A pilot study of the impact of surgical repair on disease—specific quality of life among patients with pectus excavatum. J Pediatr Surg. 2003;38:916-918.
Nuss D, Kuhn MA, Obermeyer RJ. Our approach: MIS repair of pectus excavatum. Contemp Surg. 2007;63:444-451.
