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Plast Reconstr Surg Glob Open
Plast Reconstr Surg Glob Open
GOX
Plastic and Reconstructive Surgery Global Open
2169-7574
Lippincott Williams & Wilkins Hagerstown, MD

GOX-D-24-00335
00071
10.1097/GOX.0000000000006186
3
Reconstructive
Ideas and Innovations
Correction of the Manubriosternal Angle: The Missing Link in the Diagnosis and Management of Anterior Chest Wall “Pectus” Deformities
El Oakley Reida FRCS, MD *†
From the * Department of Cardiothoracic Surgery, Venicia Hospital, Benghazi, Libya
† The Libyan International University, Benghazi, Libya.
Reida El Oakley, FRCS, MD, Venicia Hospital and The Libyan International University, Benghazi, Libya, E-mail: eloakley@limu.edu.ly
9 2024
20 9 2024
12 9 e618625 3 2024
24 7 2024
Copyright © 2024 The Author. Published by Wolters Kluwer Health, Inc. on behalf of The American Society of Plastic Surgeons.
2024
https://creativecommons.org/licenses/by-nc-nd/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.

Summary:

A normal manubriosternal angle (MSA) varies between 157 and 161 degrees, and it is either increased (in pectus carinatum) or decreased (in pectus excavatum). Measurements of the MSA can accurately define the severity of both deformities and gauge the degree of response to therapeutic intervention(s). Correction of the MSA during repair of pectus deformity by complete upper transverse sternotomy seems necessary. We found no report of complete upper transverse sternotomy in repairing pectus deformities. Similarly, the MSA was never used in defining the severity of pectus deformity. We describe a novel technique in repairing anterior chest wall deformity (pectus carinatum, MSA = 172) in a young man. Under general anesthesia and complete aseptic precautions, through a midline presternal incision, bilateral pectoral flaps were mobilized, and complete transverse sternotomy at the level of the second intercostal space and bilateral intrapericondrium excision of the costal cartilages (3–7) were performed. The wound was closed in layers after insertion of two, 9-mm subpectoral Redivac drains. The patient had an uneventful recovery with satisfactory cosmetic appearance. Magnetic resonance imaging of the chest 4 months postoperatively showed reduction of the MSA by 8 degrees, which is 78% (8 of 11) progress toward reaching the upper limit of normal MSA values. In correcting pectus deformity, complete transaction of the sternum at the level of the second intercostal space enhances recovery and allows for normalization of the MSA. Using the MSA in assessing the severity and response to treatment of pectus deformity is recommended.

OPEN-ACCESSTRUE
COUNTRYLIBYA
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pmcTakeaways

Question: Can the diagnosis and management of anterior chest wall deformity (pectus) be improved?

Findings: The manubriosternal angle (MSA) can be used as a clinical tool to assess the severity of pectus deformities. Complete transaction of the sternum at the level of the second intercostal space facilitate recovery and pave the way for normalization of the MSA postsurgical correction of pectus deformities.

Meaning: Measure MSA in patients with pectus deformities and consider complete transaction of the sternum at the level of the second intercostal space during surgical repair.

INTRODUCTION

Anterior chest wall deformity (mainly pectus excavatum and pectus carinatum) is associated with cardiorespiratory dysfunction and severe social awkwardness in most of its affected patients.1 The diagnosis is determined by measuring the “Haller” and/or the “correction” indices.2,3 In 3475 participants at the Adult Dallas Heart Study,1 significant variability of both indices was observed; using the threshold of Haller index greater than 3.25, a correction index greater than 10%, or both measured at the level of xiphoid process, the prevalence of pectus excavatum in this population was 0.5%, 5%, and 0.4%, respectively. Furthermore, considerable overlap of theses indices was observed in this multiethnic normal population when compared with the 279 cases referred for evaluation of pectus deformity in the same group regardless of the level of measurement.1

The manubriosternal angle (MSA) is formed at the junction of the manubrium and the body of the sternum.1 In a sagittal radiological view of the sternum, the angle can be measured at the cross point of a straight line parallel to the vertical axis of the manubrium and another parallel to the vertical axis of the body of the sternum (Fig. 1). Utilization of the MSA for the diagnosis, and response to treatment, of pectus deformity (excavatum and carinatum alike), may prove to be more consistent with less interobservers’ variations in measurements. Bolati et al2 measured 700 MSA using sagittal computed tomography (CT) images that were reconstituted from CT images obtained in an axial plane at a thickness of 1 mm. The mean value of this angle was 159 degrees (range 157–161 in individuals aged between 10 and 65 years). With this narrow normal range, anteroposterior displacement of the body of the sternum inherits an easy-to-measure MSA that is increased (in case of pectus carinatum) or decreased (in case of pectus excavatum). These findings1,2 suggest that measurements of the MSA may be a more consistent diagnostic tool in assessing the severity of pectus deformity and its response to treatment.

Fig. 1. Measurements of the manubriosternal junction. A, Preoperative sagittal view of a three-dimensional reconstruction of a CT image of the thoracic cage with superimposed red lines parallel to the vertical axis of the manubrium and that of the body of the sternum to define the MSA, which is 172 degrees in this case. B, Postoperative sagittal view of a three-dimensional reconstruction of an MRI image of the thoracic cage with superimposed red lines parallel to the vertical axis of the manubrium and that of the body of the sternum to define the MSA, which is now 164 degrees.

Furthermore, previous reports of pectus correction4–6 did not pay adequate attention to the potential of correcting the MSA through complete transverse upper sternotomy with total liberation of the body of the sternum from its rigid attachments to the manubrium and the costal cartilages on both sides. We propose that liberating the body of the sternum from its rigid attachments offers a solution to the challenge of correcting chest wall deformity in harmony with principles of both the Ravitch and Nuss procedures.4,5,7

METHODS

We describe surgical correction of pectus carinatum in which normalization of the MSA was achieved within a few weeks by complete transverse sternotomy and excision of costal cartilages 3–7 on both sides of the chest in a 19-year-old man. The patient presented with anxiety regarding the appearance of the chest wall deformity associated with back pain due to increasing compensatory kyphoscoliosis in an attempt to hide the deformity. The MSA was 172 as calculated on a preoperative chest CT (Fig. 1A).

After informed consent of the patient and his father, and under complete aseptic precautions and general anesthesia using single-lumen endotracheal tube, a midline presternal skin incision was made starting at the level of the second intercostal space and ending at the tip of the xiphoid process. The skin and the subcutaneous fat were undermined laterally not exceeding the mid clavicular line. The medial edges of the pectoralis facia and muscles were also mobilized from midline up to the midclavicular line level on both sides. Intraperichondrium excision of costal cartilages 3–7 was performed on both sides. A transverse sternotomy at the level of the second intercostal space was performed using a Stryker sternotomy saw, taking extra care to avoid injury to the internal mammary arteries, aortic root, pulmonary artery, and other mediastinal structures at that level. Pinpoint hemostasis of the periosteal arteries on both edges of the transected sternum were secured, and no attempts were made to rewire the sternum. The bed of the perichondrium was reconstructed to allow reduction of its original length. A 9-mm Redivac surgical drain was inserted under the pectoralis flaps before approximating both flaps at the midline using 2-0 Vicryl sutures, and skin and subcutaneous fat were closed in layers. Please note that the distinguishing features of this technique are:

Complete upper transverse sternotomy allowing correction of the MSA.

The use of bipectoral flaps to support the anterior chest wall.

Potential complete intraperiosteal enucleation of the body, or part, of the sternum in extreme cases of pectus deformity.

The patient had an uneventful recovery and was discharged home on day 2 after surgery, following removal of the drain. He was advised to use the same thoracic brace he had used preoperatively for a minimum of 6 hours a day, starting 4–6 weeks after surgery. The patient stopped using the brace altogether 8 weeks postoperatively. He remained content with the cosmetic results and started active exercise of the shoulder, back, pectoral, and upper abdominal muscles 12 weeks after the operation. Magnetic resonance imaging (MRI) of the chest was performed 16 weeks after the operation, which showed reduction of the MSA to 164 (Fig. 1B). The MSA was reduced by 8 degrees, which is 78% (8 of 11) progress toward reaching the upper limit of normal MSA values.

DISCUSSION

This is the first report in which complete transverse sternotomy was performed to normalize the MSA and facilitate repair of a pectus deformity. Current subconscious attempts to normalize the MSA include (1) forcing anterior displacement of the sternum for pectus excavatum using arched metal bars (in the Nuss procedure5) or (2) forcing posterior disablement of the sternum for pectus carinatum surgically or using customized circumferential metal braces.7 These maneuvers are performed without or with intraperichondrium excision of the second to the seventh costal cartilages as described by Ravitch in 1949. The initial description of the Ravitch procedure4 included:

Excision of the abnormal costal cartilages 3–7 on both sides.

Disarticulation of the xiphosternal joint.

Cuneiform curetting of the “anterior cortex” of the sternum only using an osteotome and a gouge followed by “bending the sternum anteriorly in an attempt to fracture the posterior cortex of the sternum forward” in some cases.

In multiple reports on repair of pectus excavatum and carinatum, including Ravitch, Nuss, and others,4–6 we found no mention of complete transverse sternotomy to free the sternum and pave the way toward normalizing the MSA. In cases with severe pectus excavatum, we go as far as recommending multiple transverse sternotomies or even endoperiosteal enucleation of the deformed part of the sternum; this may be combined with insertion of pectus bar(s) and/or using the vacuum bell device.8

Current surgical techniques for correction of pectus deformity are associated with severe persistent pain in nearly all patients,7,9 justifying routine radiofrequency ablation of the second to the seventh intercostal nerves bilaterally as a first step of the operation. It is also associated with significant perioperative complications in up to 20% of the cases and 5% failure rate necessitating redo surgery within the first 3 years postoperatively.9 We suggest that the severity of pain postoperatively and the rate of postoperative complications may be reduced significantly if a transverse sternotomy at the level of the second intercostal space is performed in patients undergoing surgery for correction of pectus deformity, as described above. Moreover, measurement of the MSA clinically or on thoracic imaging (plain x-ray, CT, or MRI) is a more reliable tool to define the severity of pectus deformity and a more consistent measure in defining the degree of response to any therapeutic intervention whether invasive or noninvasive.

DISCLOSURE

The author has no financial interest to declare in relation to the content of this article.

Published online 20 September 2024.

Disclosure statements are at the end of this article, following the correspondence information.
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