The first operation to correct pectus excavatum was conducted in 1911 by Meyer. The intention of the surgical intercession was to remove rib cartilage. This reinforced the earlier hypothesis of rib overgrowth, being the ascendant predisposing factor, laid out by Hagmann. Meyer removed the second to third costal cartilages on the right side of the chest wall. There was no significant improvement and the operation was deemed unsuccessful [2]. Sauerbruch pioneered twentieth century treatments by incising and excoriating the left 5th to 9th costal cartilages and a section of the adjacent sternum. The surgery was proven to alleviate symptoms of dyspnea and allowed the patient to return to normal life relatively quickly [6]. A few years later, Sauerbruch begun the first consummate pectus correction through subperichondrial resection of all deformed cartilage and sternal stabilization using bar implantation. This operation required excessively invasive retrosternal dissection and transversal osteotomies [2]. Ravitch elucidated and presented the following steps for the surgical correction of pectus excavatum. He described the initial step of a bilateral parasternal and subperichondrial resection of affected costal cartilages, followed by the detachment of the xiphoid process. Further, he outlined the use of transverse wedge osteotomy at the upper edge of the sternal depression and the re-placement of the sternum anteriorly- in order to secure its place. Numerous methods of repair followed Ravitch’s outlines [7].

Sauerbruch’s technique was universalized by Ravitch and preceded revolutionary interventions uncovered by Nuss in 1998. Nuss’ technique was contrastive to others developed earlier in the fact that it was minimally invasive. The procedure operates through the insertion of a steel bar through bilateral anterior-axillary thoracic incisions under thoracoscopic guidance- to highlight the pathway taken by the metal bar [8]. The bar advances to the contralateral side prior to it being pulled through the anterior incisions. At the second procedure (after 2 years), the lateral incisions made to insert the bar are entered and the stabilisers attached to the bar are removed [9]. The steel bar is inserted with convexity facing posteriorly and it is flipped over when in correct positioning. The bar is usually kept in for 2 years to allow for permanent correction and cartilaginous remodeling [10]. The bar is attached to the lateral muscles of the chest wall and is positioned through the use of a stabiliser on either the right side or both sides. In addition, the bar is future cemented to the ribs with subperiosteally-placed cable wires [2]. Other surgical strategies place an external brace, instead of bar, behind the sternum; the Leonard modification is an example of this. This approach incorporates the resection of up to five cartilages and a wedge osteotomy is effectuated, where a wire is positioned behind the sternum and attached to an external brace. Prior to this, the operation requires a curvilinear incision to be made on top of the sternum. To expose the thorax, skin flaps and pectoral muscle flaps are elevated and periosteal elevators are used to dissect the periochondrium from the cartilage. The brace remains in situ for 3 months before removal [9].

Although complications for the Nuss procedure are rare, cardiac perforations from direct cardiac injury have been documented. In addition, pericardial tears are reported in 4.2 % of cases and pericardial effusion in 0.5–2.4 % of cases. Techniques implemented into conventional operations to reduce the risk of cardiac injuries include thoracoscopic guidance and viewing of the mediastinum. Better visualisation of the tip of the dissector or the bar during its passageway through the bilateral incisions and mediastinum has been proven to decrease the rate of direct cardiac injury [11]. Kabbag R et al. carried out a retrospective review of 70 children undergoing the Nuss procedure for correction of pectus excavatum. The data recorded minor complications in 65 % of patients and major complications in 8.5 % of patients. However, no patients experienced major cardiopulmonary or fatal complications. The study concludes the major limitations to thoracoscopic-assisted PE repair to be history of cardio-thoracic surgery and SVD (sternum-to-vertebra distance) sternum rotation angle lower than 5 cm or an SRA greater than 35°, identified through a CT scan. The SVD was measured as the distance from the posterior aspect of the sternum to the anterior aspect of the vertebral body (at the site of greatest deformity depth); the SRA is the angle formed by the horizontal plane and the transverse axis of the sternum, also at the site of greatest deformity depth [12].

The Nuss procedure relies on two interventions: the first, to insert the steel bar through bilateral anterior-axillary thoracic incisions and the second, to remove the bar after 2 years. Future prospects in the field of correctional intervention involve the use of a different bar material. Metal devices were found to migrate into neighbouring tissue and therefore increase postoperative chronic pain. The Strasbourg Thorax Osteosynthesis System (STRATOS®) uses titanium implants to reduce the shift into tissues [2]. STRATOS forms part of numerous novel strategies that erase the requirement for a second intervention. Long-term absorbable stabilisers have recently become available. They are made of poly-L-lactic and polyglycolic acid and aim to reduce postoperative pain and discomfort, by making the removal of the bar easier [13]. Gurkok et al. presented a new technique. Following osteotomy, the sternum is repositioned and a copolymer plaque is placed on top of the sternum. The fixation of the plaque is achieved with re-absorbable polymer screws and a chest tube is inserted if the parietal pleura have been opened. Additionally, a hemovac drain is inserted across the sternum. Gurkok’s approach requires a single intervention as none of the factors used in sternal stabilisation are non-absorbable. Studies on the technique report excellent sternal stability. No severe complications in any of the patients studied, after 1-year follow-up, were observed [14].