A Simple Technique for Removing the Nuss Bar with One Stabilizer: The Lateral Approach

Introduction

Mini-invasive repair of pectus excavatum (MIRPE), described by Nuss in 1998 et al., ¹ has become the preferred technique for the repair of this anomaly in most centers. The Nuss technique is advantageous because it avoids cartilage excision, sternotomy, and anterior thoracic scars. The procedure is performed by introducing retrosternally a curved metallic bar under thoracoscopic vision. The bar, secured usually by a stabilizer and different absorbable and/or nonabsorbable sutures, is maintained for approximately 3 years and then removed by a second procedure. In the classic technique for the bar removal, described by Nuss et al., ¹ the patient is lying on the dorsal decubitus at the beginning of the procedure and has to be rotated to the lateral position during the operation. The bar is pulled out along the thoracic lateral wall.

A new technique, proposed in 2005 by Noguchi and Fujita, ² avoids the rotation of the patient, who stays on the backside for all the procedure. Through two lateral incisions, the bar is bent on both extremities and easily removed, once straightened. Recently, another technique has been proposed by St. Peter et al., ³ avoiding the necessity of straightening the bar. However, this solution requires two mobile operatory beds and two incisions. In this article, we propose another approach aiming to make the bar removal easier in those patients with only one stabilizer, which are the majority of our cases.

Materials and Methods

Since 2001, we have adopted MIRPE for the treatment of pectus excavatum (PE) patients. We have operated on 230 cases with PE, ranging from 4 to 36 years of age (average, 13.5). In the vast majority (226 cases), we put one bar, and in 4 cases, two bars. The bar was secured by one stabilizer in 212 patients and two stabilizers in 18 cases (mostly at the beginning of our experience). In the last 75 patients, we have used absorbable stabilizers (Lactosorb^®; Biomet, Jacksonville, MS) made of a polylactic and polyglicolic acid combination. ⁴ In previous patients, we have used metallic stabilizers. The metallic stabilizer is tight to the bar with a steel wire and sutured to the muscles with multiple running Vicryl 0 sutures. The absorbable stabilizer is tight only by absorbable sutures. We have stabilized the bar always with polydioxanone stitches passed on both sides around the bar and a rib, using an Endoclose™ device (Autosuture; Covidien Ltd., Hamilton HM, Bermuda), under right thoracoscopy. ⁵ We keep the bar at least 3 years, and, if possible, we do not remove it before the age of 14 years, to reduce the risk of recurrence.

We describe below the lateral approach that we use for the removal of the bar when only one metallic stabilizer has been placed. The patient is lying on right lateral decubitus, with the arm lifted up. Only one thoracic scar, on the side where the stabilizer is positioned, is opened. The dissection is performed by electrocautery, feeling the stabilizer and the bar, and opening the surrounding scar tissue, often ossified around the metal. The steel wire is cut and removed together with the stabilizer, once this has been freed from all the attachments. The tip of the bar is grafted with a forceps, and the bar is pulled out of the thorax, without changing its original concave shape. We ask the anesthesiologist to put the patient in positive end-expiration pressure for a couple of seconds. The patient does not have to be rotated. The wound is then closed after subcutaneous infiltration with bupivacaine. No special instruments are required. A radiograph of the thorax is done in the recovery room.

Results

We adopted the lateral approach in the last 21 cases. The bar was successfully removed in all of these patients. The average operative time has been 34 minutes (range, 20–75). Only in 1 patient, who kept the bar inside for 4 years, could we not remove the bar from the left side. The patient was then rotated on the back, and the right scar was opened. The right tip of the bar was found completely ossified, with bone tissue inside the tip hole of the bar. After dissection, we could straighten the bar and remove it.

In the other 20 patients, once the stabilizer was removed and the left tip of the bar isolated and grafted, the maneuver of pulling the bar out of the thorax required only a few seconds in all cases. We did not observe complications. The radiograph of the thorax was negative in all patients. Pain was very easily managed by paracetamol. The postoperative intrahospital stay was less than 24 hours in all cases.

Discussion

The removal of the bar in PE patients after MIRPE is a procedure not technically complicated, but requiring sometimes meticulous, time-consuming dissection. Life-threatening complications during this procedure have been described. ⁶ Leaving the bar for at least 2–3 years reduces the risk of recurrence, but it makes the bar and the stabilizer often completely covered by new bone tissue. The lateral position has the advantage, common also to the Noguchi and Fujita ² and St. Peter et al. ³ techniques, of avoiding the rotation of the patient on the operative bed, which is a maneuver never easy to be done in a sterile way. Moreover, it is a very simple, fast approach and does not require straightening of the bar. In the St. Peter et al. technique, ³ the patient is lying on two operative beds (the one at the patient's head, right angled) that are moved away one from the other, leaving the thorax unsupported posteriorly. With respect to this, our approach offers the specific advantage of requiring less operating room space.

Regarding the ossification of the bar, in our experience (i.e., personal observation), it is more represented in those cases in whom the bar has been more curved. This could be explained by a mechanical stimulus by the tip of the bar pushing onto the ribs. Although this remains to be confirmed, we now avoid giving an excessive curvature to the bar in order to prevent this possible complication. Our technique is feasible in those patients in which only one metallic stabilizer is in place. If two metallic stabilizers have been positioned, two incisions are required. In these cases, we think the procedure described by Noguchi and Fujita ² or the St. Peter et al. approach, ³ if the operating room allows it, can be considered. Actually, based on our experience, we think that two stabilizers are required only exceptionally, particularly if the bar is tight with stitches passed by Endoclose on both sides. ⁵ Two stabilizers were positioned only at the beginning of our experience. In the very rare cases in which two stabilizers are required, the use of the absorbable ones ⁴ could allow the surgeon to adopt our technique for the removal, because the contralateral incision is not required. We have no experience in removing bars stabilized by absorbable devices, but we can imagine that the dissection required will be much less and the removal easier than in patients with a metallic stabilizer. An important point to be underlined is that our technique is not feasible if nonabsorbable sutures have been used on the contralateral side to the incision. Based on this fact, and on the absence in the literature of advantages in terms of bar dislocations using nonabsorbable sutures, we believe that only absorbable sutures have to be used for the stabilization of the bar.

Conclusion

In conclusion, our initial experience shows that the lateral approach is a simple, safe way to remove a pectus bar after Nuss procedure.