Refining silicone implant correction of pectus excavatum through computed tomography

[Contribution of computer-aided design for the conception of custom-made implants in Pectus Excavatum surgical treatment. Experience of the Nantes plastic surgery unit]

INTRODUCTION

Pectus excavatum is the most common congenital chest malformation and is a common reason for consultation in plastic surgery. Our attitude is most often a filling of the depression with a custom-made silicone prosthesis. The objective of this work was to evaluate the interest of computer-aided design (CAD) of implants compared to the conventional plaster molds method.

PATIENTS AND METHODS

We have collected all the cases of custom-made silicone implants to treat funnel chests in our plastic surgery department. The quality of the results was evaluated by the patient, and in a blind manner by the surgical team using photographs and standardized surveys. The pre-operative delays, the operating time and length of hospital stays, the number of surgical recoveries, and the post-operative surgical outcomes were recorded.

RESULTS

Between 1990 and 2016, we designed 29 silicone thoracic implants in our department. Before 2012, implants were made from plaster chest molds (n=13). After this date, implants were designed by CAD (n=16). Patients rated their results as "good" or "excellent" in 77% and 86% of cases respectively in the plaster and CAD groups. The surgical team's ratings for CAD implant reconstructions were better than in the plaster group: 8.17 versus 6.96 (P=0.001). CAD implants were significantly less detectable than the plaster group implants. The operating time was reduced in the CAO group: 60.2 compared to 74.7minutes in the plaster group (P=0.04), as was the length of hospitalization: 3.5 versus 5.3 days (P=0.01). There were no significant differences between the two groups in terms of post-operative complications.

CONCLUSION

The management of pectus excavatum by a custom-made silicone implant is a minimally invasive method that provides good cosmetic results. The design of these implants is facilitated and qualitatively improved by CAD.

Pectus excavatum repair from a plastic surgeon's perspective

Minimally invasive repair of pectus excavatum (MIRPE) or similar procedures for pectus excavatum (PE) repair, nowadays no longer performed by one single speciality, may not always achieve sufficient aesthetic results, particularly in the infrapectoral or infraxiphoidal region. Reasons for this include the diaphragm inhibiting correct positioning of the bars, as well as asymmetric deformities which may still be present after remodelling attempts. Furthermore, some cases develop a mild recurrence or partial concavity once the correction bar is removed. However, any secondary re-do MIRPE procedure remains risky because of adhesions between the pleura, lung, pericardium, thoracic wall as residuals from the primary intervention. Treatment options as secondary correction for these deformities may include open access surgery, resection or reshaping of deformed costal cartilage. Moreover, augmentation of a residual concave area can be achieved by autologous transplantation of resected over-abundant cartilage, as well as by liposhifting or implantation of customized alloplastics. A physician dealing with PE corrections should be familiar with various shaping and complementary reconstructive techniques in order to provide the best options for a variety of expressions of anterior wall deformities. Among treating surgeons, there is an awareness that no single method can be applied for every kind of funnel chest deformity. An appropriate technique, either as a single approach for the ordinary deformities or in conjunction with ancillary procedures for the intricate cases, should be selected carefully based on the heterogeneity of symptoms, severity, expectations and surgical skill in addition to the available equipment. Out of a variety of such ancillary procedures available and based on experience within general plastic reconstructive surgery, some techniques for PE repair are explained and illustrated here with their advantages and disadvantages.

Customized silicone implant for the correction of acquired and congenital chest wall deformities: A valuable option with pectus excavatum

BACKGROUND

Surgical remodeling and correction of congenital and acquired chest wall deformities (CWD) is undertaken many times for cosmesis. Although reportedly minimally invasive, commonly used Nuss procedure for correction of pectus excavatum (PE) is not without complications. Nuss procedure is also not suitable for complex deformities and Poland syndrome cases. Insertion of custom-made silicone implants for the reconstruction of defects has been adopted from adult plastic reconstructive surgery as primary repair of CWD or rescue procedure for recurrence of PE after recurrence or residual deformity.

METHODS

We present our experience with CWD reconstruction in children with customized silicone prosthesis made from a surgically implantable liquid silicone rubber (NuSil MED-4805, Ca).

RESULTS

Since 2006 we treated 26 patients with CWD: six were children (age <17years, median 14.6) with PE. Implants were custom made for each patient's chest. The implants were inserted under general anesthesia. Postoperatively all patients were fully satisfied with the cosmetic result and subjective patient satisfaction remained excellent at follow-up in all the children. Only one child developed postoperative complications (seroma).

CONCLUSIONS

Customized silicone implant for PE in the pediatric age is an alternative therapeutic method, as primary or rescue treatment, with equally good cosmetic outcome, fewer significant complications, less postoperative pain and a faster recovery.

Correction of asymmetric pectus excavatum using a virtually designed silicone implant

BACKGROUND

An extended asymmetric funnel chest deformity with the breast gland located in the thoracic mold can lead to a fictitious aplasia of the breast. The authors termed this condition "pseudo-Amazon syndrome" because the breast tissue and the pectoralis muscle are fully developed.

METHODS

This report presents a detailed technical approach to the fabrication of a precise-fitting custom-made silicone implant. The design of the implant was achieved using a computed tomography (CT) data set and rapid prototyping. The volumes of the "hidden" and the normal breasts measured preoperatively by processing the CT data were similar. These volumes were compared with the breast volumes measured by three-dimensional photography 4 years postoperatively to assess the predictability of the volume congruency. The silicone implant was surgically placed in the epicostal plane and extended almost over the right hemithorax.

RESULTS

The implantation was performed without the necessity of further trimming. Both the surgeon and the patient rated the aesthetic and functional long-term result as good in terms of symmetry and the possibility of exercise without restrictions. The final breast volume of the surgically treated side was 95 % of the volume of the normal contralateral breast.

CONCLUSION

The described method reduces the operation time and the operative trauma by primary implant fit. However, the method is rather elaborate and the production process is expensive. This in turn reduces the generation of proceeds to a minimum.

LEVEL OF EVIDENCE V

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How to perform breast augmentation safely for a pectus excavatum patient

BACKGROUND

Pectus excavatum is the most common chest wall deformity. Women with pectus excavatum may have associated hypoplastic breasts and often desire breast augmentation. This report describes how to perform breast augmentation safely for a pectus excavatum patient.

METHODS

In the past 5 years, the authors have treated 11 women with hypoplastic breasts and pectus excavatum. Their ages have varied from 21 to 39 years. The women generally were healthy without cardiovascular function impairment. Four of the women had breast asymmetry, with a smaller right breast. It was decided to use wide silicone implants to augment the breast and to camouflage the chest wall deformity. The implants were placed under the pectoralis major muscle in all cases.

RESULTS

The follow-up period varied from 10 months to 4.5 years. No acute or late complications related to the breast augmentation were encountered. All the patients were satisfied with the result, and none desired further surgical treatment for pectus excavatum. For two patients, a small depression in the upper part of the breast was persistent after surgery due to insufficient implant coverage.

CONCLUSION

Most women with pectus excavatum desire to have the deformity corrected with minimal or no scarring. The chest is known to be an area prone to hypertrophic or keloid scars. The reported approach is simple and safe, easily camouflaging the deformity. It is a short procedure that results in high satisfaction.

Aesthetic treatment of pectus excavatum: a new endoscopic technique using a porous polyethylene implant

BACKGROUND

Pectus excavatum is the most frequent malformation of the rib cage. Functional aspects associated with this malformation often are absent even in adults not involved in competitive sports activities. Overall, these patients often live with extreme psychological discomfort when the malformations are minor. Traditionally, the correction of these malformations has been geared toward interventions that modify the architecture of the rib cage. However, all these interventions, even the most recent, involve considerably invasive major surgery. In fact, optimal results are not always achieved with corrective surgery using the insertion of silicone prosthesis, and patients often experience complications.

METHODS

To correct intermediate and modest pectus excavatum in a stable manner and with the least amount of invasiveness, the authors developed a camouflage technique that uses porous prostheses made from high-density linear polyethylene. This material is generally used for reconstruction of the brain case. Between February 2001 and March 2006, in the I Unit of Plastic Surgery of the authors' Institute, 11 adult pectus excavatum patients with no previous cardiorespiratory symptoms underwent the authors' surgical technique. The average patient age was 29 years.

RESULTS

Surgical repair was successful in all cases, and the average hospital stay was short. There were no complications during the follow-up period. The described approach repairs nonfunctional pectus excavatum in the adult with satisfying aesthetic and stable results, short hospital stay, and high patient popularity ratings.

CONCLUSIONS

The best therapeutic option for pectus excavatum, especially with intermediate or moderate severity, is still controversial: thoracic surgery or camouflage surgery with implant? Trying to address those issues we propose a new technique by a multidisciplinary, not aggressive approach using a high density linear polyethylene implant and Omentus flap and the early analysis of our data.

Customised silicone prostheses for the reconstruction of chest wall defects: technique of manufacture and final outcome

Chest wall reconstruction with a customised silicone prosthesis in 13 patients (five patients with pectus excavatum, six Poland's syndrome and two with post-surgical chest wall deformity) is presented. An alginate impression or CT scan with three-dimensional reconstruction was used to produce the final mould from which the silicone prosthesis was fabricated. The surface of the silicone implant was roughened to reduce capsular contracture and holes were incorporated to allow for tissue integration. Twelve patients had aesthetically acceptable results after a mean of 5 years follow up. This series indicates that accurate assessment of the defect, modifications on manufacture and proper placement of the implant result in a more satisfactory final outcome.

Pectus excavatum breast and chest deformity: indications for aesthetic plastic surgery versus thoracic surgery in a multicenter experience

BACKGROUND

Breast and chest wall disfiguration attributable to a funnel chest is an aesthetically and sometimes functionally debilitating deformity requiring surgical correction. Whereas extensive and combined deformities of the ventral chest wall are classically corrected using a so-called minimally invasive repair of the pectus excavatum, a modified Ravitch repair, or the minimized Erlangen repair, plastic surgeons are mostly challenged with alloplastic implant corrections of mild funnel chests. The authors have introduced an endoscopic method for placement of customized implants to restore the visible and nonfunctionally disturbing deformation of mild funnel chests when only the sternal plate is involved. This study compared these different plastic surgical and thoracic surgical approaches in a multicenter experience to develop a clinical algorithm and to identify those patients not requiring bony correction but rather alloplastic endoscopic implant correction alone.

METHODS

Patients with deformed rib cages and sternal plates were treated with the Erlangen minimally invasive procedure or a modified Ravitch procedure. For deformities involving the sternal bones only, endoscopically assisted minimally invasive implantation of silastic implants was performed.

RESULTS

Between 1987 and 2003, 599 patients with a pectus excavatum deformity were treated surgically by the authors' group. Between 1999 and 2003, 515 patients underwent surgery using the Erlangen minimally invasive repair technique at Friedrich-Alexander University-Erlangen. In addition, 84 patients underwent surgery at the Freiburg University Medical Center. In the current series, 79 patients underwent surgery using the modified Ravitch method. The mean patient age was 20.5 years (range, 3-54 years), and the rate of postoperative relapses was 5%. The findings showed that 73% of the patients judged the aesthetic result as excellent to good, and 20% were satisfied. In contrast, only five patients were suitable for soft tissue augmentation only. Two of these patients in the initial period received custom implants presternally via classical transverse skin incisions, whereas three patients were treated with endoscopic customized implant tissue augmentation.

CONCLUSION

Whereas with combined deformity of the sternal plate and the rib cage, a modified Ravitch repair yields good results, the endoscopic soft tissue correction with customized implants helps to avoid unsightly scars, allows for safe hemostasis in the dissection pocket, and leads to enhanced patient satisfaction. In the case of major chest wall deformity with orthopedic and functional relevance, a combination of the minimally invasive procedures (e.g., endoscopic correction and Erlangen repair) seems to show both optimized cosmetic results and maximized functionality.

Pectus deformities of the anterior chest wall

Pectus deformities affect about 1% of the population. Despite a subjective reduction in exercise tolerance, objective physiological disturbance is very uncommon. However, there is no doubt that cultural changes have significantly altered perception and tolerance of these deformities and increasing numbers of children are actively seeking surgery. Pectus excavatum is readily amenable to correction using minimally invasive techniques and pectus carinatum can be corrected using safe established conventional techniques. Good or excellent results can be expected in over 90% of cases, and children should no longer be denied treatment.

Silastic implant for reconstruction of pectus excavatum: an update

Twenty-seven patients were operated on for pectus excavatum between 1985 and 1996 and had a custom-made subcutaneous Silastic implant inserted. We have reviewed their medical records to evaluate the clinical course, and used a questionnaire to assess the subjective outcome. There were no major surgical complications. Sixteen of the 27 patients reported improved appearance, and 11 would definitely recommend the operation to other patients under similar circumstances. Increased familiarity with the technique has led to implants with better size and shape, shorter hospital stay, and also to patients being more confident with the outcome. Augmentation with a custom-made Silastic implant is still a simple and straightforward way of concealing the deformity and alleviating the subjective discomfort in patients with pectus excavatum, whose cardiopulmonary function is within the normal range.

Long-term observation in 68 patients operated on for pectus excavatum: surgical repair of funnel chest

BACKGROUND

Recurrence after correction of pectus excavatum may sometimes occur, but its origin is not clear. The type of deformity, surgical technique, and patient lifestyle after operation can all affect the final shape of the thorax. The purpose of the present study was to compare the short-, medium-, and long-term cosmetic results of funnel chest repair.

METHODS

Sixty-eight patients (mean age, 12.1+/-5.4 years; 48 male) were operated on for pectus excavatum using the same surgical technique: subperichondrial resection of the abnormal costal cartilages and stabilization of the elevated anterior chest wall with Kirschner's wires. The patients were followed up every year (1 to 10 years) after operation, and the anterior chest wall contour was checked by physical examination and x-ray film.

RESULTS

Excellent to good cosmetic results 1 year after operation were achieved in 66 patients (97.1%). During the later follow-up period, a mild or moderate degree of recurrent sternal depression was noted in 6 patients (8.8%), teenagers only, 3 to 9 years after primary repair.

CONCLUSIONS

Our technique for correction of pectus excavatum yields good short-term cosmetic results. Late recurrence of the deformity occurs during pubertal growth and does not appear to depend on surgical technique or length of follow-up.