| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Ann Thorac Surg 1998;66:1151-1154
© 1998 The Society of Thoracic Surgeons
a Thoracic Division, Hospital das Clínicas, University of São Paulo Medical Center, São Paulo, Brazil
Accepted for publication April 23, 1998.
Address reprint requests to Dr de Campos, Rua Almirante Soares Dutra n. 520, São Paulo 05654.000, Brazil
e-mail: (jribas{at}usp.br)
Abstract
Background. Clinical and surgical aspects of sternal cleft repair are presented. Primary repair in the neonatal period is the best management for this rare condition, but none of the patients in this report were referred to us during that period. Autologous repair is suitable for older patients because it avoids problems related to the implant of prosthetic materials.
Methods. This article reviews 8 cases of sternal cleft not associated with ectopia cordis in patients presenting between October 1979 and November 1997. Surgical repair consisted of three sliding chondrotomies, three posterior sternal wall repairs, one combination with the Ravitch technique for pectus excavatum repair, and one posterior sternal wall repair associated with total repair of Cantrell’s pentalogy.
Results. All patients who submitted to surgical correction had good aesthetic and structural results. The postoperative period was uneventful except that a subcutaneous fluid collection developed in 1 patient. The mean hospital stay was 5.8 days. The patients were followed up from 4 months to 18 years.
Conclusions. Whether dealing with older children or young adults, the technique of reconstructing a new sternum with a posterior periosteal flap from sternal bars and chondral grafts is a simple, quick, inexpensive, and effective option.
Since the 1850s, fascination with cleft of the manubrium has been evident because the heart and great vessels visibly beat under the skin. This produces an alternate protrusion and retraction movement upon respiration, specifically during coughing or the Valsalva maneuver. In this challenging anomaly, the underlying mediastinal structures (heart and great vessels) may easily be injured by external trauma. In addition, it is an unpleasant cosmetic deformity and quite alarming to the young patient’s family.
Congenital sternal cleft is rare, and hence it is usually reported as an isolated case presentation. The first surgical correction was reported by Lannelongue in 1888, as cited by Ravitch [1], but the first successful repair was published by Burton in 1947 [2]. It is postulated that the sternum has a common origin with the pectoral musculature, which develops from lateral plate mesoderm, and that isolated sternal clefts arise from a failure in either development or fusion of the mesenchymal elements as should normally occur by the eighth week of fetal life [3].
At one time this anomaly was erroneously known as "sternal agenesia," a complete misnomer because the two sternal bars exist in these patients but they are unfused. Little is known about its incidence and pathogenesis. No familial, teratogenic, or nutritional factors have been implicated. As mentioned, most cases are sporadic [4] and there is only one report of 2 cases in the same family [5]. Experimentally, Ramirez-Solis and colleagues [6] in 1993 reported that disruption of the Hoxb-4 gene in the mouse led to alterations in their paraxial mesoderm and that one of the animals presented a total sternal cleft.
This report describes our experience with sternal cleft repair in 8 patients, stressing the different surgical techniques required for each case and presenting another option for selected patients.
Patients and methods
Between May 1979 and September 1997, 8 patients (6 girls and women and 2 boys), ages ranging from 1.5 to 19 years (mean, 7.2 years), were treated. Five were asymptomatic and underwent the operation for cosmetic reasons as well as to shield the unprotected mediastinal structures. Although asymptomatic, the defect in an 11-year-old boy was associated with pectus excavatum. In another asymptomatic patient, the defect corresponded to Cantrell’s pentalogy. The eighth patient presented with congenital muscular subaortic stenosis; both cardiac and sternal defects were corrected at the same operation. The peculiar midline scar was present in 5 patients (Table 1).
|
|
In 1 patient with associated pectus excavatum, this deformity was corrected by the Ravitch [1] procedure; because of the extensive resection of deformed cartilage, the two sternal bars could be easily approximated. For the patient with Cantrell’s pentalogy, a PSW was also used to reinforce the distal end of the cleft sternum.
Results
All patients who underwent surgical correction had good aesthetic and structural results. The follow-up period from 4 months to 18 years (average, 7.1 years) was uneventful except that a subcutaneous fluid collection developed in 1 patient. The mean in-hospital stay was 5.8 days.
Comment
A congenital sternal cleft not associated with cardiac defects or ectopia cordis is a rare and relatively benign malformation of the chest wall. It must be differentiated from thoracic or thoracoabdominal ectopic cordis, in which the heart is situated outside the chest cavity. The latter two conditions are associated with a high mortality rate because complex or uncorrectable cardiac anomalies are also present.
Congenital sternal cleft can be classified as complete or incomplete [8]. A complete cleft is the rarest form and fewer than 10 cases have been reported in the medical literature [3, 5]. Incomplete clefts are subdivided into superior or inferior ones. The latter may occur as an isolated entity, although it is usually associated with other developmental defects of the anterior chest wall such as ectopia cordis, or a combination of defects involving the abdominal wall, sternum, diaphragm, pericardium, and heart in Cantrell’s pentalogy. In the incomplete superior type, a bridge of bony tissue exists at the lower ends of the sternal bars, joining the two edges of the cleft in a U shape (proximal to the fourth cartilage) or V shape (reaching the xiphoid process). This is frequently an isolated entity [9].
There is no explanation for the marked female predilection in our series (2 boys and 6 girls) (see Table 1). However, it is similar to that of Gorlin and colleagues [10] and Heron and colleagues [11], who found the number of female patients was significantly greater when a sternal defect was accompanied by a supraumbilical raphe but not by a facial hemangioma. The unexplained association between cleft sternum and cervicofacial hemangiomas or vascular dysplasias, which has been reported by some authors in the literature [9, 12], was not confirmed in any of our patients. According to Firmin and coworkers [3], major defects of the sternum make the chest wall unstable, allowing the thoracic viscera to move paradoxically during respiration. Therefore, some infants could suffer attacks of cyanosis and develop recurrent chest infections. None of our patients suffered such attacks.
A considerable variety of procedures for sternal cleft repair have been reported in the literature [1, 2, 7, 13–15], but it is an undisputed concept that sternal clefts should be corrected in the neonatal period within the first month of life [3, 8, 16]. At this stage, the sternal bars can be easily approximated by simple sutures, owing to the chest’s flexibility. This also permits approximation of the sternal bars with less danger of cardiac compression.
Nevertheless, patients who have not undergone repair during this period may require reconstruction later on. The increasing rigidity of the chest wall and the physiologic accommodation of the thoracic organs to a certain circumference of the chest determine that simple approximation is impossible without seriously compromising the heart and lungs. This distinguishes these patients from newborns. One of the earliest successful procedures for correction was devised by Sabiston in 1958 [7]. By using multiple bilateral sliding chondrotomies he was able to bring the sternal halves together while simultaneously increasing chest wall dimensions and flexibility. After that, miscellaneous techniques were developed, eg, split ribs, costal cartilage grafts, and segments of costal margin; stainless steel wire mesh [1]; segments of cartilage divided laterally and swung medially to cover the defect [17]; autogenous periosteal graft raised from the tibia in the lower limb [13]; and perichondral flap elevation and pectoralis muscle transposition [14]. In previous reports of repair in older patients, the use of prosthetic materials such as Marlex mesh, Teflon, silicone elastomer, or perforated acrylic plate has also been adapted by different authors [18, 19].
In addition to being effective, our procedure of building a PSW with periosteal flaps raised from the sternal bars, together with the chondral grafts, prepares a natural bed for new bone formation which, despite the reabsorption of the grafts, will provide a genuine bone sternum to protect the mediastinal structures. Our proposal lies between two techniques recently published in The Annals of Thoracic Surgery. Suri and colleagues [20] reported a case of complete sternal cleft in a 25-year-old man. Successful repair was accomplished using autogenous tissue (iliac bone and a V-Y myoplasty of the pectoralis major muscle) with "good cosmetic results and preservation of the already existing anatomic and mechanical sanctity of the thoracic cage, without using any synthetic material." Santini and associates [21], in a letter to the Editor regarding this technique, reported a 52-year-old man with a congenital total cleft sternum associated with an atrial septal defect, a large conoventricular septal defect, and pulmonary stenosis. This patient was successfully treated by direct approximation of the sternal bars. We agree with Santini and associates that repair should be accomplished by the simplest and least invasive procedure. However, direct closure in some cases seems impossible and even dangerous owing to the hemodynamic consequences as already well documented since 1983 [22]. In the same report, Santini and associates mentioned that surgical management of mediastinitis complicating cardiac surgical procedures offers "a model of the repair of a complete sternal cleft in adults." From our point of view, there is no comparison.
Whether dealing with older children or young adults, the rigidity of the chest wall and the lack of new space for accommodation of the intrathoracic organs must be considered, especially when the defect is too large to be closed directly. The heart is the least tolerant organ to reduced space inside the thoracic cage. Enlargement of the thoracic cage diameter is the main reason for our decision to use the PSW, apart from the fact that in older groups approximation of the sternal bars is almost physically and anatomically impossible. We also concur with Knox and colleagues [16], who in 1994 stated that "autologous repair with rib grafts can be accomplished safely without the use of prosthetic material which reduces the risk of infectious complications while allowing normal growth of the chest wall and providing sufficient strength and rigidity in the neosternum, with excellent cosmetic results." In 2 patients, however, small strips of Marlex mesh (2 x 3 and 2 x 4 cm) were used, not as a substitute for the chest wall, but as a bridge for the major pectoralis muscles that could not be sutured despite wide mobilization.
It was unnecessary in any of our patients to suture the sternohyoid and sternothyroid muscles or to slide the origins of the sternocleidomastoid medially to "stabilize the thorax aperture and avoid the tendency toward herniation of the lungs and pulsation in the neck," as proposed by Asp and Sulamaa in 1961, modified by Daum and Hecker in 1964 [1], and used by Greenberg and colleagues in 1991 [14]. On the other hand, we agree with the Greenberg and colleagues and with Salley and Stewart [23] regarding the advantages of contact between the cartilaginous tissue of the two sternal bars, as occurs when the periosteal flaps are raised to facilitate primary union. We also concur that mobilization of the pectoralis muscles may further protect the repair site, reducing site, reducing lateral tension of the advanced rib segments due to approximation of the sternal bars.
According to the literature [14, 16, 20] and our opinion, it is always better to avoid the use of prosthetic materials, considering the risks of infection and the inability of these inert materials to grow with the patient. Those techniques are described to emphasize the feasibility of the repair without resorting to the use of a prosthetic material, regardless of the patient’s age. Included in this report is a computed tomographic scan of patient 6 (see Table 1) taken 5 years after primary repair of an incomplete superior cleft sternum. The new sternum is shown protecting the mediastinal structures (Fig 2).
|
This article has been cited by other articles:
|
|
 |
|
  M. A. Padalino, G. F. Zanon, F. Migneco, M. G. Rubino, F. Fusaro, and G. Stellin Surgical Repair of Incomplete Cleft Sternum and Cardiac Anomalies in Early Infancy Ann. Thorac. Surg., June 1, 2006; 81(6): 2291 - 2294. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. D. St. Louis Pentalogy of Cantrell associated with hypoplastic left heart syndrome and herniation of the ventricular mass into the abdominal cavity Interactive CardioVascular and Thoracic Surgery, June 1, 2006; 5(3): 200 - 201. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| ANN THORAC SURG | ASIAN CARDIOVASC THORAC ANN | EUR J CARDIOTHORAC SURG |
| J THORAC CARDIOVASC SURG | ICVTS | ALL CTSNet JOURNALS |
