Pectus excavatum and carinatum

Postoperative Pain Management After Minimally Invasive Repair of Pectus Excavatum: A Systematic Review and Network Meta-analysis

BACKGROUND

Minimally invasive repair of pectus excavatum is the accepted standard approach for correction of pectus excavatum. This procedure is associated with significant postoperative pain, which is the dominant factor determining the duration of hospitalization. To date, a multitude of analgesic modalities are used, however, the most effective is to be corroborated. The aim of this study is to systematically evaluate and compare all available analgesic modalities for pain management after minimally invasive repair of pectus excavatum through a network meta-analysis.

METHODS

Electronic scientific databases were systematically searched. Articles were eligible for inclusion when designed as a comparative study evaluating perioperative pain management techniques for patients undergoing minimally invasive repair of pectus excavatum and where length of hospitalization was reported as an outcome. Data concerning length of hospitalization were extracted and submitted for network meta-analysis.

RESULTS

Thirty-nine studies were included, enrolling 4241 patients. Through a network meta-analysis intercostal nerve cryoablation with an adjunct analgesic intervention (e.g., intercostal nerve block or patient controlled analgesia) showed a statistically significant reduction in the length of hospitalization ranging from 0.9 days (95 % confidence interval (CI): -1.7 to -0.1) when compared to locoregional blocks with an adjunct analgesic intervention to 2.5 days (95 % CI: -3.7 to -1.3) when compared to thoracic epidural analgesia.

CONCLUSION

Regarding postoperative pain management after minimally invasive repair of pectus excavatum, intercostal nerve cryoablation with adjunct analgesic intervention is more effective in terms of length of hospitalization compared to other forms of analgesia.

TYPE OF STUDY

Systemic review and meta analysis.

Safety enhancement in Nuss procedure: sternal elevation and thoracoscopic dissection

<b>Introduction:</b> <i>Pectus excavatum</i> (PE) is the most common chest wall deformity. Minimally invasive repair techniques based on the Nuss procedure are a mainstay of treatment. However, intraoperative cardiac injury, though rare, can be a devastating complication.<b>Aim:</b> This study aimed to evaluate a modification of the Nuss procedure designed to minimize the risk of serious complications.<b>Material and methods:</b> A retrospective analysis of medical records for 38 patients treated with a modified Nuss procedure forPE was conducted. The specific modifications to the surgical technique were described.<b>Results:</b> No intraoperative complications were observed in the analyzed patients. In 3 patients (7.9%), early complicationsafter surgery occurred, with none relating to the modification of the surgical technique.<b>Discussion:</b> Minimally invasive PE repair carries a risk of serious complications, prompting the development of variousmodifications. These modifications often involve techniques of sternal elevation and retrosternal dissection to achieve clearview throughout the procedure.<b>Conclusions:</b> The Nuss procedure with sternal elevation and thoracoscopic retrosternal dissection offers a simple andpotentially safer approach to PE repair.

Sternal elevation in pectus excavatum repair: comparison of a unilateral versus bilateral frame crane system

OBJECTIVES

Instability in the conventional, unilateral frame crane system occurs when greater sternal elevation forces are required, which potentially limits optimal sternal elevation during Nuss repair of the pectus excavatum. A bilateral frame setup was subsequently developed. We hypothesized that increasing the retractor's stability with the bilateral frame crane system would yield superior sternal elevation, as reflected by a greater lift of the anterior chest wall.

METHODS

Pectus excavatum patients who underwent the Nuss procedure utilizing sternal elevation between November 2022 and October 2023 were included in this crossover study. Three-dimensional surface imaging was used to evaluate differences in established maximum and average combined chest wall elevation, comparing unilateral to bilateral frame crane systems. The results were also compared to the effect of bar implantation on the deepest point of the deformity.

RESULTS

The 30 patients included in the final analysis were predominantly male (83%) with a median age of 16.0 years (interquartile range 14.3-17.0) and median Haller index of 3.3 (interquartile range 2.9-3.8). The bilateral frame crane system achieved maximum combined chest wall elevation comparable to the effect of definitive bar placement (33 mm vs 38 mm, P = 0.06) and provided significantly greater elevation than the unilateral frame crane system (33 mm vs 24 mm, P < 0.001). Both systems, however, showed similar results for average combined chest wall elevation (4 mm vs 5 mm, P = 0.16).

CONCLUSIONS

The bilateral frame crane system demonstrates superiority in achieving sternal elevation at the deepest point of the deformity, which may theoretically facilitate safer and more optimal bar placement.

Are Adolescents With Chest Wall Deformity Potential Primary Spontaneous Pneumothorax Patients?

INTRODUCTION

Chest wall deformities often become apparent with growth spurts during adolescence. Alterations in the structure of the chest wall can result in the development of pulmonary bullae and blebs, which may lead to spontaneous pneumothorax. There are limited data on this subject in the literature. In this study, it is aimed to investigate the presence of bullae and bleb in patients with anterior and posterior chest wall deformities.

METHODS

Computed tomography scans of adolescent idiopathic scoliosis, pectus carinatum, and pectus excavatum patients were analyzed. The presence of bullae and/or bleb (BB) was recorded as "present" or "absent."

RESULTS

One hundred fifty patients with chest wall deformity have been included in the study. BB has been detected in 55 (36.7%) of the patients. Surgical procedures were performed in 45 (30%) of the patients due to chest wall deformity. BB was present in 12 (26.7%) of these patients. A statistically significant difference has been found between the presence of complications and the presence of BB in surgical patients (P < 0.001). In patients who developed complications, there was a statistically significant difference between the presence of BB and the duration of chest tube follow-up (P = 0.031), as well as between the presence of BB and the length of hospitalization (P = 0.006).

CONCLUSIONS

A significant proportion (36.7%) of patients with chest wall deformity had BB. Chest wall deformities and primary spontaneous pneumothorax (PSP) may have common etiologic factors. It should be kept in mind that patients with chest wall deformities may be potential PSP patients. Medical counseling about PSP should be considered for these patients.

Chest Wall Dermatitis Patterns Following Thoracoscopic Intercostal Nerve Cryoablation for Surgical Correction of Pectus Excavatum

BACKGROUND

Intercostal nerve cryoablation (INC) has been shown to reduce postoperative pain and length of stay following surgical correction of pectus excavatum (SCOPE). Some patients have developed chest wall dermatological symptoms after INC that can be mistaken for metal allergy or infection. The purpose of this study is to report the symptoms, severity, incidence, and treatment of post-cryoablation dermatitis.

METHODS

A retrospective single institution review was performed for patients who underwent SCOPE with and without INC between June 2016 and March 2023 to assess for incidence of postoperative dermatological findings. Characteristics associated with these findings were evaluated.

RESULTS

During study period, 383 patients underwent SCOPE, 165 (43.1%) without INC and 218 (56.9%) with. Twenty-three (10.6%) patients who received INC developed exanthems characteristic of post-cryoablation dermatitis with two distinct phenotypes identified. No patients who underwent SCOPE without INC developed similar manifestations. Early dermatitis, characterized by a painless, erythematous, and blanching rash across the anterior thorax, was observed in 16 patients, presenting on median postoperative day 6.0 [IQR 6.0-8.5], with median time to resolution of 23.0 [IQR 12-71.0] days after symptom onset. Late dermatitis, characterized by hyperpigmentation spanning the anterior thorax, was observed in 7 patients, presenting on median postoperative day 129.0 [IQR 84.5-240.0], with median time to resolution of 114.0 [IQR 48.0-314.3] days.

CONCLUSION

This is the first report of dermatological manifestations following SCOPE with INC, a phenomenon of unknown etiology and no known long-term sequela. In our experience, it is self-resolving and lacks systemic symptoms suggesting observation alone is sufficient for resolution.

LEVEL OF EVIDENCE

IV.

Pectus Disorders: Excavatum, Carinatum and Arcuatum

This article reviews pectus excavatum, carinatum, and arcuatum. Topics covered include etiology, epidemiology, associated syndromes, physiologic impact, workup, indications for treatment, surgical and nonsurgical therapy, results, complications, and emerging therapies. Pectus excavatum is an inward deformation of the sternum and/or anterior chest wall. Pectus carinatum is ether an outward protrusion or tilt of the sternum with potential psychological impact, but no demonstrated physiologic impact. Nonoperative compression bracing is successful in carinatum patients with chest wall flexibility who are compliant with a bracing program. Pectus arcuatum is an abnormally short, fully fused sternum with a high anterior protrusion.

Early-Onset Pectus Excavatum Is More Likely to Be Part of a Genetic Variation

BACKGROUND

 Potential underlying genetic variations of pectus excavatum (PE) are quite rare. Only one-fifth of PE cases are identified in the first decade of life and thus are of congenital origin. The objective of this study is to test if early-onset PE is more likely to be part of genetic variations than PE that becomes apparent during puberty or adolescence.

MATERIALS AND METHODS

 Children younger than 11 years who presented with PE to the outpatient clinic of the Department of Pediatric Surgery at our center between 2014 and 2020 were screened by two clinical geneticists separately. Molecular analysis was performed based on the differential diagnosis. Data of all young PE patients who already had been referred for genetic counseling were analyzed retrospectively.

RESULTS

 Pathogenic genetic variations were found in 8 of the 18 participants (44%): 3 syndromic disorders (Catel-Manzke syndrome and two Noonan syndromes), 3 chromosomal disorders (16p13.11 microduplication syndrome, 22q11.21 microduplication syndrome, and genetic gain at 1q44), 1 connective tissue disease (Loeys-Dietz syndrome), and 1 neuromuscular disorder (pathogenic variation in BICD2 gene).

CONCLUSION

 Early-onset PE is more likely to be part of genetic variations than PE that becomes apparent during puberty or adolescence. Referral for genetic counseling should therefore be considered.

TRIAL REGISTRATION

 NCT05443113.

The effect of surgical repair of the chest on postural stability among patients with pectus excavatum

Pectus excavatum is the most encountered of chest wall deformities. It may produce respiratory and cardiovascular symptoms, hence surgical repair of this defect is performed. The procedure involving the insertion of metal bars under the sternum (the Nuss procedure) usually brings significant improvement to patients. However, the effect of the repair on the postural stability of patients has not been studied so far. To investigate the problem of patients' stability in the postoperative period male patients with pectus excavatum (n = 21) and healthy controls (n = 22) were included in the study. Using posturography methods, we showed a negative impact of the pectus excavatum repair surgery on patients' postural stability in the first postoperative phase. The centre of pressure displacement parameters used to measure postural stability were lower after the repair for both, the frontal and sagittal plane as well as for the velocity of displacements in the sagittal plane in the double stance with eyes open. Poorer postural stability was also found in patients with pectus excavatum when compared to healthy controls. Our findings may be useful for functional monitoring in the evaluation and surgical management of pectus excavatum patients and also when designing the rehabilitation of patients undergoing the Nuss procedure.

Demographics of Anterior Chest Wall Deformity Patients: A Tertiary Children's Hospital Experience

INTRODUCTION

Anterior chest wall deformities consist of abnormal development of the chest, with the most common congenital deformities being pectus excavatum (PE) and pectus carinatum (PC). Surgical series are common, but less research is present assessing the demographics of all who present for initial evaluation. The purpose of this study is to describe the patient characteristics of those who present for ambulatory surgical evaluation.

METHODS

Data were collected from initial patient visits to an established multispecialty chest wall deformities program at a large Children's Hospital from 2017 to 2021. Variables assessed included primary diagnosis, age, sex, race/ethnicity, and whether surgical correction was performed.

RESULTS

A total of 1510 children were evaluated: 50.0% (n = 755) with PE, 43.3% (n = 653) with PC, 2.7% (n = 41) with mixed chest wall deformities, 0.7% (n = 10) with Poland syndrome, 1.1% (n = 17) with Currarino-Silverman syndrome, and 2.3% (n = 34) with other anterior chest wall deformities. Males and females presented at mean age of 12.8 (4.2) and 10.9 (5.5) years, respectively (P = 0.001). White children represented 61.1% of the overall population while Hispanic children represented 26.3%. White, non-Hispanic children represented 61.9% and 71.5% and Hispanic children represented 26.0% and 26.3% of the PE and PC populations, respectively.

CONCLUSIONS

Most patients seen in an urban chest wall deformities clinic were White, non-Hispanic; however, the proportion of other groups such as Hispanic and Asian is greater in this cohort than previously described. Further research is ongoing to ascertain the extent to which disease predisposition versus access to care play roles in this population.

Modified Nuss procedure for the treatment of pectus excavatum: Experience of 259 patients

BACKGROUND

Pectus excavatum is not rare in China. Many treatments for this disease have proved to have many shortcomings. Nuss procedure has been a ground-breaking technology, but it also has some disadvantages. Hence, this study was conducted to review our experience in the use of modified Nuss procedure in our hospital.

METHODS

Data from 259 patients suffered from pectus excavatum between August 2020 and August 2021 who were treated with modified Nuss procedure was analyzed retrospectively.

RESULT

Age was from 3 to 37 years. The average was 15.54 years. The male was 213 cases and the female was 46 cases. The time patients or their family members found pectus excavatum varied. 10 cases had been repaired previously when patients were admitted in our hospital. The clinical symptoms also varied. Each case had an improvement in Haller index. The average of the postoperative hospitalization was 3.97 days. Most cases were inserted 1 bar. Complication rate was also very low. All patients or their parents or their guardians were satisfied with the appearance of the chest wall after operation. There was no death in the whole observation period.

CONCLUSION

From our experience, this modified Nuss procedure have obtained optimistic outcomes with more minimal invasion and low complication rate. This surgical method may be applied to many other hospitals in the future.

Development of a five point enhanced recovery protocol for pectus excavatum surgery

PURPOSE

We implemented and evaluated an Enhanced Recovery after Surgery (ERAS) protocol for Nuss procedures consisting of patient education, bowel management, pre/post-operative transitional pain service involvement, serratus anterior plane blocks and intercostal nerve cryoablation.

METHODS

A 5-point ERAS protocol was implemented using multiple plan-do-study-act (PDSA) cycles. Data was collected prospectively for patients in the full ERAS protocol and retrospectively for previous patients. The primary outcome was length of stay (LOS). Secondary outcomes were opioid consumption, pain scores, protocol compliance and patient satisfaction. The impact of PDSA cycles and the ERAS protocol was quantified using statistical process control charts and Mann Whitney U test.

RESULTS

A total of 53 patients were identified, 13 within the ERAS protocol and 40 prior to introduction. There was no difference in age, sex, or Haller index between the two cohorts. The median LOS was decreased by 3 days in the ERAS cohort (P = 0.00001). There was decreased opioid consumption on post-operative day 1 (1.47 vs 1.96 MME/kg, p = 0.009) and overall (3.12 vs 6.35 MME/kg, p = 0.0042) in the ERAS cohort. Median pain scores did not differ between cohorts. ERAS bundle element compliance was: education 92%, bowel management 100%, transitional pain involvement 100%, serratus block 100% and cryoablation 100%. The 1-month survey revealed that 92% of patients were satisfied with their experience.

CONCLUSION

Our results demonstrate significant reduction in LOS and a trend to decreasing opioid consumption in hospital following ERAS protocol implementation and support the further application of ERAS protocols in pediatrics.

LEVEL OF EVIDENCE

III - Retrospective comparative study.

A Case of Congenital Pulmonary Vein Stenosis with Secondary Post-Capillary Pulmonary Hypertension and Left Sided Congestive Heart Failure in a Cat

A five-month-old, 3.8 kg intact male Maine coon cat presented for dyspnea characterized by increased respiratory effort in addition to open-mouth breathing. Thoracic radiographs showed pectus excavatum, enlarged cardiac silhouette, and generalized interstitial patterns. Echocardiography revealed normal left atrial (LA) and left ventricular dimensions. A large tubular structure, suspected to be a distended pulmonary vein (PV), was identified as draining into the LA. Severe eccentric and concentric right ventricular hypertrophy and paradoxical septal motion were noted. Based on Doppler echocardiography, both pulmonary venous and pulmonary artery pressure was severely elevated. Clinical, radiographic, and echocardiographic abnormalities were hypothesized to result from pulmonary vein stenosis (PVS), causing severely elevated pulmonary venous pressures and resulting in clinical signs of left-sided congestive heart failure (L-CHF) and severe post-capillary pulmonary hypertension (Pc-PH). The prognosis for good quality of life was assessed as poor, and the owner elected euthanasia. Necropsy confirmed the presence of PVS with severe dilation of the PVs draining all but the left cranial lung lobe. All lung lobes except the left cranial lobe had increased tissue density and a mottled cut surface. This case report shows that, in rare cases, both L-CHF and Pc-PH may be present without LA enlargement. To the authors' knowledge, this is the first report on PVS in veterinary medicine.

Abordagem de pectus carinatum na Atenção Primária e seu impacto na saúde emocional do paciente

Introdução: O pectus carinatum (PC) é uma deformidade incomum da parede torácica, que geralmente surge na infância e se acentua na adolescência. Essa malformação pode levar a distúrbios estéticos e de autoestima, além de problemas respiratórios, que se devem à restrição da parede torácica. Existem poucos estudos brasileiros dedicados exclusivamente ao PC, e a maioria desses trabalhos direciona-se ao estudo do pectus excavatum (PE) ou de ambas as condições de forma conjunta. Apresentação do caso: Apresenta-se o caso de um paciente de 13 anos, masculino, que procura atendimento na Atenção Primária à Saúde (APS) por surgimento de tumefação em região paraesternal. Nega sintomas físicos, porém relata constrangimento e desconforto estético com a presença da proeminência. Conclusões: A abordagem multidisciplinar da deformidade torácica é fundamental na aceitação e no tratamento, tendo a APS um papel essencial Toda a equipe deve auxiliar e proporcionar, por meio do tratamento, melhor qualidade de vida estética, física e emocional ao paciente, fatores estes que nos impulsionaram a documentar este caso.

Palpable pediatric chest wall masses

Pediatric chest wall lesions are varied in etiology ranging from normal and benign to aggressive and malignant. When palpable, these lesions can alarm parents and clinicians alike. However, most palpable pediatric chest lesions are benign. Familiarity with the various entities, their incidences, and how to evaluate them with imaging is important for clinicians and radiologists. Here we review the most relevant palpable pediatric chest entities, their expected appearance and the specific clinical issues to aid in diagnosis and appropriate treatment.

Predicting Aesthetic Outcome of the Nuss Procedure in Patients with Pectus Excavatum

Patients suffering from pectus excavatum often experience psychosocial distress due to perceived anomalies in their physical appearance. The ability to visually inform patients about their expected aesthetic outcome after surgical correction is still lacking. This study aims to develop an automatic, patient-specific model to predict aesthetic outcome after the Nuss procedure. Patients prospectively received preoperative and postoperative 3-dimensional optical surface scanning of their chest during the Nuss procedure. A prediction model was composed based on nonlinear least squares data-fitting, regression methods and a 2-dimensional Gaussian function with adjustable amplitude, variance, rotation, skewness, and kurtosis components. Morphological features of pectus excavatum were extracted from preoperative images using a previously developed surface analysis tool to generate a patient-specific model. Prediction accuracy was evaluated through cross-validation, utilizing the mean root squared deviation and maximum positive and negative deviations as performance measures. The prediction model was evaluated on 30 (90% male) prospectively imaged patients. The model achieved an average root mean squared deviation of 6.3 ± 2.0 mm, with average maximum positive and negative deviations of 12.7 ± 6.1 and -10.2 ± 5.7 mm, respectively, between the predicted and actual postoperative aesthetic result. Our developed 2-dimensional Gaussian model based on 3-dimensional optical surface images is a clinically promising tool to predict postsurgical aesthetic outcome in patients with pectus excavatum. Prediction of the aesthetic outcome after the Nuss procedure potentially improves information provision and expectation management among patients. Further research should assess whether increasing the sample size may reduce deviations and improve performance.

Mini thoracic CT adequately determines Haller index and decreases radiation exposure in children with pectus excavatum

INTRODUCTION

The preoperative assessment of Pectus Excavatum (PE) is resource intensive. CT chest for the purpose of calculating a Haller index (HI) remains a central component and is necessary for third-party reimbursment for surgical correction. With the goal of minimizing radiation exposure, a strategy was introduced to perform a mini-Thoracic CT (mini-CT) for the calculation of HI.

OPERATIVE TECHNIQUE

The mini-CT was performed as follows: a radio-opaque marker (ROM) was placed at the clinical deepest point of the deformity. The CT was then columnated to scan 3 cm above and 3 cm below the ROM. HI was calculated according to previously described technique. Seven children with PE who underwent mini-CT were age and weight matched to 7 children with PE who underwent standard low dose CT chest during the same time period. Radiation doses were evaluated using dose length product (DLP) and effective dose (mSv) between the two groups. Significance of differences was determined using the students t-test. The DLP of mini-CT compared to chest-CT was 17.9 vs 48.9,mGycm respectively. (p< 0.001) The mSv of the mini-CT compared to chest-CT was 0.32 vs 0.88, sMV respectively. (p<0.001) Both DLP and mSv were reduced by 63% in children who received a mini-CT. All children obtained insurance authorization and underwent uncomplicated Nuss repair.

CONCLUSION

For children with pectus excavatum deformities the mini-Thoracic CT is an effective method to calculate the HI. Compard to the conventional low dose chest CT, the mini-CT strategy significantly reduces radiation exposure to the child by 63% with no impact on third-party authorizations or Nuss repair.

Musculoskeletal diseases in Marfan syndrome: a nationwide registry study

Background

Marfan syndrome is associated with abnormalities in the musculoskeletal system including scoliosis, pectus deformities, protrusio acetabuli, and foot deformities. Over a life span, many patients with Marfan syndrome will need treatment; however, the musculoskeletal morbidity over a life span is not well described. The aim of the present study was to assess the overall burden of musculoskeletal disease in patients with Marfan syndrome.

Materials and methods

A registry-based, nationwide epidemiological study of patients with a Ghent II verified Marfan syndrome diagnosis from 1977 to 2014. Each patient was matched on age, and sex with up to 100 controls from the background population.

Results

We identified 407 patients with Marfan syndrome and 40,700 controls and compared their musculoskeletal diagnoses and surgical treatments using Cox proportional hazards ratio (HR). The risk of a registration of a musculoskeletal diagnosis in patients with Marfan syndrome was significantly increased compared to controls (HR: 1.94 (1.69–2.24). One out of six with Marfan syndrome was registered with scoliosis (HR: 36.7 (27.5–48.9). Scoliosis was more common in women with Marfan syndrome compared to men (HR: 4.30 (1.73–1.08)). One out of 11 were registered with a pectus deformity HR: 40.8 (28.1–59.3), and one out of six with a deformity of the foot. Primarily pes planus (HR: 26.0 (15.2–44.3). The proportion of patients with Marfan syndrome (94/407) that underwent musculoskeletal surgery was also significantly higher (HR: 1.76 (1.43–2.16)). The major areas of surgery were the spine, pectups correction, and surgery of the foot/ankle. Ten patients with Marfan syndrome had elective orthopedic surgery without being recognized and diagnosed with Marfan syndrome until later in life. None of these had scoliosis, pectus deformity or a foot deformity. Among patients with an aortic dissection, the age at dissection was 34.3 years in those with at least one major musculoskeletal abnormality. In patients without a major abnormality the age at dissection was 45.1 years (p < 0.01).

Conclusions

The extent of musculoskeletal disease is quite significant in Marfan syndrome, and many will need corrective surgery during their life span. Surgeons should be aware of undiagnosed patients with Marfan syndrome when treating patients with a Marfan syndrome like-phenotype.

[Chest Wall Deformities in Children and Adolescents]

Chest wall deformities as a whole are relatively common in children and adolescents, although they comprise a wide spectrum of entities, some of them rare. Pectus excavatum has the highest prevalence. While some patients are asymptomatic, others suffer from substantial limitations. All symptomatic patients should be offered treatment. Minimally invasive surgical correction is the more effective option of treatment, besides the alternative application of a suction bell. Pectus carinatum and combined manifestations of chest wall deformities can also lead to physiological and psychosocial impairment and require treatment tailored to the individual patient in such cases. Syndromal chest wall deformities, such as Jeune syndrome, comprise a separate group of rare diseases that are associated with considerable, occasionally life-threatening comorbidities. These patients should be cared for in centres with appropriate expertise in an interdisciplinary and multimodal manner. This review discusses the different chest wall deformities encountered in paediatric surgical practice, along with their significance and possible therapeutic approaches.

Association between pectus excavatum and congenital genetic disorders: A systematic review and practical guide for the treating physician

BACKGROUND

Pectus excavatum (PE) could be part of a genetic disorder, which then has implications regarding comorbidity, the surgical correction of PE, and reproductive choices. However, referral of a patient presenting with PE for genetic analysis is often delayed because additional crucial clinical signs may be subtle or even missed in syndromic patients. We reviewed the literature to inventory known genetic disorders associated with PE and create a standardized protocol for clinical evaluation.

METHODS

A systematic literature search was performed in electronic databases. Genetic disorders were considered associated with PE if studies reported at least five cases with PE. Characteristics of each genetic disorder were extracted from the literature and the OMIM database in order to create a practical guide for the clinician.

RESULTS

After removal of duplicates from the initial search, 1632 citations remained. Eventually, we included 119 full text articles, representing 20 different genetic disorders. Relevant characteristics and important clinical signs of each genetic disorder were summarized providing a standardized protocol in the form of a scoring list. The most important clinical sign was a positive family history for PE and/or congenital heart defect.

CONCLUSIONS

Twenty unique genetic disorders have been found associated with PE. We have created a scoring list for the clinician that systematically evaluates crucial clinical signs, thereby facilitating decision making for referral to a clinical geneticist.

Minimally Invasive Modified Nuss Procedure for Repair of Pectus Excavatum in Pediatric Patients: Single-Centre Retrospective Observational Study

Background: The treatment of pectus excavatum can be conservative or surgical. The aim of this study was to determine the factors influencing the outcomes of treatment after a minimally invasive Nuss corrective surgery procedure in pediatric patients. Methods: A total of 30 patient who underwent a minimally invasive Nuss corrective procedure for pectus excavatum from 1 January 2014 to 31 December 2020 were included in thisretrospective study. The collected data included thepatient’s demographic characteristics (age, sex, height, weight, body mass index—BMI, Haller index), treatment outcomes (duration of surgery, length of hospital stay, intraoperative complications, early and late complications, postoperative analgesia), and overall patient and legal guardian satisfaction two years after the procedure. Results: A total of 22 male and 8 female patients were included in the study. The median age was 15 years (interquartile range—IQR 14, 16), and the median BMI was 18.5 kg/m2 (IQR 17.7, 20.4) and 18.2 kg/m2 (IQR 16.9, 18.6) for males and females, respectively. The median CT Haller index was 3.67 (IQR 3.48, 4.09) for male and 3.69 (IQR 3.45, 3.9) for female patients. The median surgery duration was 120 min (IQR 100, 130), and the median hospital stay length was 8.5 days (IQR 8, 9.75). Indications for surgery were psychological (47%), followed by respiratory (30%) and combined respiratory-cardiac (20%) and respiratory-psychological disorders (3%). Early complications were observed in 18 patients (60%), and late complications were observed in 7 patients (23.3%). Intraoperative complications were not recorded. The most common early complications were pneumothorax and subcutaneous emphysema (30%), while late complications included bar displacement (10%) and deformity recurrence (6.6%). Overall, the procedure was successful in 93.1% of patients. Upon arrival home, 22 patients (81.5%) used analgesics for at least one day, up to a maximum of six months. A total of 23 (76.7%) operated patients determined that the surgical procedure had excellent results (grade 5), 4 (13.3%) patients report a good result (grade 4), 1(3.3%) patient reported a mediocre result, and one patient (3.3%) reported a bad result (grades 3 and 2, respectively). Conclusion: The Nuss procedure is a safe and effective method for treating funnel chest in children and adolescents. It also providesexcellent cosmetic and aesthetic results as well as subjective satisfaction with the outcome of surgical treatment.

Trends in the Treatment of Pectus Excavatum in the Netherlands

INTRODUCTION

 Pectus excavatum (PE) is the most common deformity of the anterior chest wall and can be corrected surgically with different techniques. In the past years, medical literature suggests that the minimal invasive surgical correction of PE (MIRPE) has currently become the operation technique of choice in Europe, and the number of PE patients undergoing surgery has increased. The aim of this study was to evaluate trends in the number of patients operated on and the surgical techniques generally used in patients with PE in the Netherlands.

MATERIALS AND METHODS

 From the registration by Statistics Netherlands, the numbers of live births and gender were obtained for the period 1980 to 2017. Furthermore, from the Dutch hospital registration performed by Kiwa Prismant systems, the number of total surgical procedures of PE patients from the period 1998 to 2017, and the numbers of open and MIRPE surgery were obtained over the period 2005 to 2013.

RESULTS

 The birth rate in Netherlands has stayed more or less stable in the last two decades. The number of PE patients asking for correction, however, has increased. In addition, the percentage of thoracoscopic assisted correction has increased.

CONCLUSION

 The increase in correction of PE is not due to an increased incidence but to an increase of patient wishes. The use of MIRPE is gaining popularity over time.

Validating 3D indexes in the non-surgical pectus excavatum patient

BACKGROUND/PURPOSE

In recent years there has been an increased interest in three-dimensional (3D) imaging for the assessment of chest wall deformities. Some studies have proven a correlation between 3D and traditional cross-sectional images but only for patients who already had an indication for a computed tomography (CT) scan prior to surgery; mainly due to their severity. Our aim is to determine the accuracy and reliability of the measures obtained by a portable 3D scanner in a cohort of pectus excavatum (PE) patients with different severity grades, as well as in controls.

METHODS

We conducted a study comparing radiological and optical indexes on magnetic resonance imaging (MRI) and 3D surface images. We used a hand-held 3D scanner to obtain the optical Haller Index (3DHI) and Correction Index (3DCI) and a limited MRI scan to obtain the traditional indexes. A statistical analysis was carried out to determine the correlation between optical and radiological measures, plus a subjective severity evaluation.

RESULTS

Twenty-eight patients and controls were enrolled in the study. In both the control and PE groups, there was a significant positive correlation between the indexes, especially for the CI. There were no differences in correlation regarding gender, age or severity. CI appears to better discriminate amongst the different severity groups and controls.

CONCLUSION

3D surface imaging is feasible and appropriate to use to assess PE, regardless of the severity or characteristics of the individual patient. Even with a small hand-held device, we can obtain accurate images and measures which are especially useful for the assessment of the nonsurgical pectus patient.

Amianthoid transformation of costal cartilage matrix in children with pectus excavatum and pectus carinatum

Background

It is unclear if amianthoid transformation (AT) of costal cartilage extracellular matrix (ECM) has an impact on the development of pectus excavatum (PE) and pectus carinatum (PC).

Methods

AT foci were examined in intrasurgical biopsy specimens of costal cartilages of children (8–17 years old) with PE (n = 12) and PC (n = 12) and in age-matching autopsy control samples (n = 10) using histological and immunohistochemical staining, atomic force and nonlinear optical microscopy, transmission and scanning electron microscopy, morphometry and statistics.

Results

AT areas were identified in the costal cartilage ECM in children with normal chest, PE and PC. Each type of the AT areas (“canonical”, “intertwined”, “fine-fibred” and “intralacunary”) had a unique morphological pattern of thickness and alignment of amianthoid fibers (AFs). AFs were formed via lateral aggregation of collagen type II fibrils in the intact ECM. Foci of the AT were observed significantly more frequently in the PE and PC groups. The AT areas had unique quantitative features in each study group.

Conclusion

AT is a structurally diverse form of ECM alteration present in healthy and pathological costal cartilage. PE and PC are associated with specific AT disorders.

Impact of pectus excavatum on cardiac morphology and function according to the site of maximum compression: effect of physical exertion and respiratory cycle

Aims

Previous studies have demonstrated diverse cardiac manifestations in patients with pectus excavatum (PEX), although mostly addressing morphological or physiological impact as separate findings. Using multimodality imaging, we evaluated the impact of PEX on cardiac morphology and function according to the site of maximum compression, and the effect of exertion and breathing.

Methods and results

All patients underwent chest computed tomography, cardiac magnetic resonance (CMR), and stress echocardiography (echo) in order to establish surgical candidacy. We evaluated diastolic function and trans-tricuspid gradient during stress (echo); and systolic function and respiratory-related septal wall motion abnormalities (CMR). Patients were classified according to the site of cardiac compression as type 0 (without cardiac compression); type 1 (right ventricle); and type 2 [right ventricle and atrioventricular (AV) groove]. Fifty-nine patients underwent multimodality imaging, with a mean age of 19.5 ± 5.9 years. Compared with a sex and age matched control group, peak exercise capacity was lower in patients with PEX (8.4 ± 2.0 METs vs. 15.1 ± 4.6 METs, P &lt; 0.0001). At stress, significant differences were found between groups regarding left ventricular E/A (P = 0.004) and e/a ratio (P = 0.005), right ventricular E/A ratio (P = 0.03), and trans-tricuspid gradient (P = 0.001). At CMR, only 9 (15%) patients with PEX had normal septal motion, whereas 17 (29%) had septal flattening during inspiration. Septal motion abnormalities were significantly related to the cardiac compression classification (P &lt; 0.0001).

Conclusions

The present study demonstrated that patients with PEX, particularly those with compression affecting the right ventricle and AV groove, manifest diverse cardiac abnormalities that are mostly related to exertion, inspiration, and diastolic function.

Pectus carinatum: When less is more

Awareness of pectus carinatum has increased among the medical community over the last several decades, as innovative options for nonsurgical treatments have become more widely known. Management alternatives have shifted from open resective to minimally invasive strategies, and finally, to reshaping the chest using both surgical and non-surgical modalities. We aim to review the evolution of the diagnosis and treatment of pectus carinatum up to its current management.

The incidence of Marfan syndrome and cardiac anomalies in patients presenting with pectus deformities

PURPOSE

The incidence of Marfan syndrome in the general population is 0.3%. Two-thirds of patients with Marfan syndrome have concurrent pectus deformity. However, incidence of Marfan syndrome and cardiac abnormalities in patients presenting with an isolated pectus deformity remains unknown. We sought to establish the degree of association between pectus deformities and these abnormalities, and whether referral of these patients for cardiac and genetic workup is warranted.

METHODS

Our pediatric surgery group refers patients with pectus deformities for genetic and cardiac evaluation. We examined 415 records from 2009 to 2016, and identified 241 patients with a chief complaint of a pectus deformity. Patient characteristics, echocardiogram results, Haller indices, and genetic results were analyzed.

RESULTS

The frequency of Marfan syndrome in our study was 5.3%. The incidence of Marfan was highest among patients with combined type pectus deformity (20%). Cardiac anomalies showed an overall incidence of 35%. Of those diagnosed with Marfan, 84% had cardiac abnormalities.

CONCLUSION

More than 5% of patients presenting with a chief complaint of pectus deformity will have a diagnosis of Marfan syndrome, compared to 0.3% in the general population. Approximately a third of this population will have cardiac abnormalities. Referral of patients with pectus deformities for evaluation for Marfan syndrome and cardiac abnormalities is appropriate.

LEVEL OF EVIDENCE

Level IV.

[Costal cartilage changes in children with pectus excavatum and pectus carinatum]

Pectus excavatum (PE) and pectus carinatum (PC) in children are the most common congenital deformities that cause complications in the thoracic organs; however, the role of chondrocytes and cartilage canals in the pathogenesis of these conditions remains unexplored.

OBJECTIVE

To investigate qualitative and quantitative changes of cartilage lacunae and canals in the costal cartilages in children with PE and PC compared to those with normal chests.

SUBJECT AND METHODS

Costal cartilages were investigated in 10 children with normal chests (a control group), in 12 children with PE, and in 12 children with PC. Tissue fragments were fixed in 10% neutral formalin and embedded in compacted paraffin. Sections were stained with hematoxylin and eosin. Slides were examined by light microscopy. Cartilage lacunae, hyper- and hypolacunar zones, and cartilage canals were morphometrically examined, followed by statistical data analysis.

RESULTS

There was a significant decrease in the number of cartilage lacunae and in the frequency of hyperlacunar zones and an increase in that of hypolacunar zones in the PE and PC groups. There were no significant differences in these parameters between the PE and PC groups; however, there was a tendency to the smallest number of cartilage lacunae and canals in the PC group and that to the preponderance of empty lacunae in the PE group. Only the PC group showed also negative correlations between the proportions of empty lacunae and the age of children.

CONCLUSION

The pathogenesis of PE and PC in children is related to the impaired trophism of costal cartilages due to the smaller number of cartilage channels containing vessels and lacunae with chondrocytes. The development of PE and PC is associated with specific costal cartilage morphological changes that suggest that PE and PC are different manifestations of the same disease, namely connective tissue dysplasia.

Constrictive pericarditis with a life-threatening giant pericardial cyst and pectus excavatum as unusual cause for malign cardiac arrhythmias

Pericardial cysts are rare, abnormal, benign and usually congenital anomalies with an estimated incidence of 1:100.000 and are caused by an incomplete coalescence of foetal lacunae of pericardium development. The size of pericardial cysts varies from 1 to 5 cm and generally do not cause any symptoms. Pectus excavatum is one of the most frequent chest wall abnormalities with a caved-in appearance of the chest and mostly of unknown pathogenesis. We present a rare case of constrictive pericarditis with a huge pericardial cyst (11.6 × 8.7 × 7.1 cm) and pectus excavatum which led to compression of the heart and life-threatening cardiac arrhythmias.

Bracing of pectus carinatum: A quantitative analysis

BACKGROUND/PURPOSE

Primary treatment of pectus carinatum (PC) is performed with an external brace that compresses the protrusion. Patients are 'prescribed' a brace tightening force. However, no visual guides exist to display this force magnitude. The purpose of this study was to determine the repeatability of patients in applying their prescribed force over time and to determine whether the protrusion stiffness influences the patient-applied forces and the protrusion correction rate.

METHODS

Twenty-one male participants (12-17years) with chondrogladiolar PC were recruited at the time of brace fitting. Participants were evaluated on three visits: fitting, one month postfitting, and two months postfitting. Differences between prescribed force and patient-applied force were evaluated. Relationships of patient-applied force and correction rate with protrusion stiffness were assessed.

RESULTS

Majority of individuals followed for two months (75%) had a significantly different patient-applied force (p<0.05) from their prescribed force. Protrusion stiffness had a positive relationship with patient-applied force, but no relationship with correction rate.

CONCLUSION

Patients did not follow their prescribed force. Magnitudes of these differences require further investigation to determine clinical significance. Patient-applied forces were influenced by protrusion stiffness, but correction rate was not. Other factors may influence these variables, such as patient compliance.

LEVEL OF EVIDENCE

Treatment Study - Level IV.

[Costal cartilage structural and functional changes in children with a funnel or keeled chest]

Congenital chest wall deformities (CCWDs) in children are severe diseases leading to cosmetic defects and diseases of the respiratory and cardiovascular systems. The most common of these deformities are funnel-shaped (pectus excavatum, FD) and keeled (pectus carinatum, KD) ones. The pathogenesis of CCWDs and the role of costal cartilage structural and functional changes in their pathogenesis have now been not well studied, which makes it difficult to elaborate pathogenetic approaches to correcting these diseases. Analysis of the literature has shown that structural and functional changes occur in the matrix and chondrocytes from the costal cartilage in FD. Similar costal cartilage changes are observed in KD. It is still unknown exactly which pathological processes are present in the costal cartilage and how they result in the development of one or other type of CCWDs. The role of amianthoid transformation (AT) of costal cartilages in these processes is also unknown. It is not improbable that it is AT drastically changing the native cartilage matrix, which is one of the key mechanisms leading to changes in its properties and to the subsequent development of FD or KD.

Surgical Correction of Pectus Excavatum by the Nuss Procedure: A 15-Year Experience Study

Pectus excavatum is the most common congenital deformity of the chest. The Nuss procedure is minimally invasive surgical correction of this defect, using retrosternal metal bars. The purpose of the present study was to describe a 15-year experience with the Nuss surgery, and to evaluate the long-term clinical results of the procedure. We retrospectively evaluated 239 patients, aged 14-34, who underwent the Nuss surgery in the years 2002-2016. Postoperative complications were observed in 40/236 (16.9%) patients. The most common complication was pneumothorax in 14/239 patients. Less common were the following: wound infection in 4, pleural effusion in 3, allergy to nickel in 1, lung atelectasis in 1, and ventricular failure in 1 patient. Three patients were treated because of severe postoperative pain, and in one case the implant had to be removed. Postoperative complications associated with the number of bars inserted, but not with the patient age or gender. A satisfactory and long lasting corrective effect of surgery was observed in 231/239 (96.7%) of patients. There was no perioperative mortality. We conclude that the Nuss surgery is a safe surgery that demonstrates excellent and long-lasting esthetic results, with a low risk of severe complications.

Outcomes in adult pectus excavatum patients undergoing Nuss repair

Pectus excavatum (PEx) is one of the most common congenital chest wall deformities. Depending on the severity, presentation of PEx may range from minor cosmetic issues to disabling cardiopulmonary symptoms. The effect of PEx on adult patients has not been extensively studied. Symptoms may not occur until the patient ages, and they may worsen over the years. More recent publications have implied that PEx may have significant cardiopulmonary implications and repair is of medical benefit. Adults presenting for PEx repair can undergo a successful repair with a minimally invasive "Nuss" approach. Resolution of symptoms, improved quality of life, and satisfying results are reported.

[The morphological and morphometric study of amianthoid transformation of the costal cartilage in health and in keeled chest deformity in children]

Amianthoid transformation (AT) is the accumulations of abnormal collagen structures (amianthoid fibers) in the hyaline cartilages, tumors, and tendons. Neither functional value of costal cartilage matrix AT, nor its role in the pathogenesis of congenital chest deformities is known now.

AIM

to examine the morphological features of AT in the costal cartilage of children with the normal and keeled chest.

SUBJECTS AND METHODS

Costal cartilages were studied in 6 children with the normal chest (autopsy material) and in 5 ones with keeled chest (surgical material). Tissue fragments were fixed in 10% neutral formalin and embedded in compacted paraffin. The sections were stained with hematoxylin and eosin, picrofuchsin by van Gieson, with picrosirius, toluidine blue and by the Malaurie method modified by Gallego. The specimens were examined by light, phase-contrast, dark-field, fluorescence, and polarization microscopy. The frequency of AT sites and their area were morphometrically studied and the findings were then statistically processed.

RESULTS

Various types of AT in the costal cartilages were described as both the normal and keeled chest. According to their morphological features, classic, fine-fiber, twisted, and intralacunar types were identified. There were statistically significant increases in the incidence of all types (except the intralacunar one) and in the area of the fine-fiber AT type in keeled chest deformity as compared to health. There were positive correlations between the area of classic, intralacunar, and twisted types in both groups and between the area of a classic type and age in the controls.

CONCLUSION

A classification of AT areas varying in structures in health and disease has been given for the first time; their relation to each other and to the presence of keeled deformity shown, which, in our opinion, suggests that AT is implicated in the pathogenesis of the disease.

Is the Abramson technique effective in pectus carinatum repair?

BACKGROUND

The minimally invasive pectus carinatum (PC) surgery described by Abramson has been performed in many centers. We have been using this technique since 2011. This article describes our experience with PC correction.

METHODS

Between 2011 and 2016, 32 patients at our institution underwent minimally invasive repair of a PC deformity. All patients presented with cosmetic complaints. The deformity involved the lower sternum (all had chondrogladiolar type PC), and three patients had asymmetrical deformities. All operations followed the principles defined by Abramson.

RESULTS

Satisfactory esthetic results were achieved in our patients. The hospital stay averaged 5.3 days (range 4-7 days). The most common early complication was pneumothorax, and the most common late complication was wire suture breakage.

CONCLUSION

The Abramson technique is an effective, minimally invasive procedure for PC with shorter operating and hospitalization times and low morbidity rates.

Single centre experience on short bar technique for pectus excavatum

BACKGROUND

Pectus excavatum (PE) is the most frequent anomaly of the anterior chest wall. Before 2001, all patients in Denmark were referred to the plastic and reconstructive surgeon for implantation of a subcutaneous silicone prosthesis, because the modified Ravitch procedure was not used. Since 2001, all patients have been treated with a modified Nuss procedure, which today has become the gold standard for correction of PE.

METHODS

From September 2001 to March 2016, 1,713 patients have been operated by a modified Nuss procedure using the short bar at Aarhus University Hospital with a male-female ratio 6:1. The median age was 16 years (range 7-58 years). All operations were done in general anesthesia with epidural analgesia and all patients were operated by the same surgeon. All patients were seen routinely 6 weeks after surgery and the bars were removed after 3 years.

RESULTS

Patients were younger than 18 years in 1,109 cases (65%). The number of bars needed for optimal correction was one in 1,209 patients, two in 486 patients and three in 18 patients. The median length of bar changed from 11 inches to 10 inches during the study period. The annual number of procedures continued to rise during the study period [833 patients during the first 10 years and 880 patients in the last 6 years, though more patients received two bars in the later period, (34%) versus (24%)] and the proportion of patients older than 30 years increased from 7.7% to 10%. The average duration of the operation was 36 minutes (range 12-270 minutes) and did not change significantly during the study period, change in operation time which was around half an hour. The median postoperative hospital stay decreased over time from 6 to 2 days. There was no mortality.

CONCLUSIONS

The modified Nuss procedure with the short bar technique is effective for the correction of PE. The results are stable with a low rate of bar malrotations, and in may most cases can be done in less than an hour in experienced hands.

Minimally invasive repair of pectus excavatum

Pectus excavatum, an acquired or congenital depression of the anterior chest wall, is the most commonly occurring chest wall deformity. Patients with pectus excavatum experience psychosocial and physiologic consequences such as impaired social development and pulmonary and/or cardiac dysfunction as a result of the deformity. Traditionally, repair of the defect was performed with a major open operation, the most common being based on modifications of the Ravitch procedure. In the late 1990's, the operative approach was challenged with a new minimally invasive technique described by Dr. Donald Nuss. This approach utilizes thoracoscopic visualization with small incisions and placement of a temporary metal bar positioned behind the sternum for support it while the costal cartilages remodel. Since introduction, the minimally invasive repair of pectus excavatum (MIRPE) has become accepted in many centers as the procedure of choice for repair of pectus excavatum. In experienced hands, the procedure has excellent outcomes, shorter procedural length, and outstanding cosmetic results. However, proper patient selection and attention to technical details are essential to achieve optimal outcomes and prevent significant complications. In the following, we describe our perspective on pectus excavatum deformities, operative planning, and technical details of the MIRPE procedure.

Minimally Invasive Repair of Pectus Carinatum in Patients Unsuited to Bracing Therapy

Background

We used an Abramson technique for minimally invasive repair of pectus carinatum in patients who preferred surgery to brace therapy, had been unsuccessfully treated via brace therapy, or were unsuitable for brace therapy because of a rigid chest wall.

Methods

Between July 2011 and May 2015, 16 patients with pectus carinatum underwent minimally invasive surgery.

Results

The mean age of the patients was 24.35±13.20 years (range, 14–57 years), and all patients were male. The percentage of excellent aesthetic results, as rated by the patients, was 37.5%, and the percentage of good results was 56.25%. The preoperative and postoperative Haller Index values were 2.01±0.19 (range, 1.60–2.31), and 2.22±0.19 (range, 1.87–2.50), respectively (p-value=0.01), and the median hospital stay was 7.09±2.91 days (range, 5–15 days). Only one patient experienced postoperative complications.

Conclusion

Minimally invasive repair is effective for the treatment of pectus carinatum, even in adult patients.

Open repair of pectus carinatum

Pectus carinatum is a chest deformity characterized by a protrusion of the sternum and ribs (usually 3-7 ribs). The treatment of these patients varies in relation to age. In younger patients we prefer to use a custom-made brace, surgery is the elective treatment for older patients. The minimally-invasive technique (Abramson procedure) is used rarely and for mild defects, whereas open surgery is still preferred by many surgeons to repair major deformities. In our institution we use a modified Ravitch approach trough a vertical incision, which is performed on top of the most prominent part of the defect. The first step is the mobilisation of the pectoralis muscle to allow the exposure of the skeletal structure of the sternum and of the deformed costal cartilages. The second step is to perform multiple parasternal rib cartilage resections to shorten the overabundant length that causes the deformity, avoiding damaging the perichondrium. The third step consists of a wedge osteotomy at the level of the most prominent point of the sternum. The last step is the remodelling and the stabilization of the chest wall. The sternum stabilization is obtained through the placement of one titanium bar and with the filling of the space created at the osteotomy line with fragments of cartilages or with demineralized bone tissue. The perichondrial sheats of the ribs are sutured to the sternum with absorbable sutures. The postoperative pain management should be a priority in order to avoid further complications. In our institution we use a patient-controlled analgesia (PCA) with morphine on the day of the surgery. On the first postoperative day we remove the PCA and start an oral therapy with the combination of opioids and non-steroidal anti-inflammatory drugs. Early mobilisation is also a milestone in the postoperative management of these patients.

Pectus deformities and their impact on pulmonary physiology

Pectus excavatum (PE) and pectus carinatum (PC) are the most common anomalies of the thoracic cage and they have been recognized since ancient times [1-3]. The two conditions differ in their appearance, and their effect on lung function. There is no direct correlation between the appearance of the deformities and the clinical symptoms. Whether, and when these deformities should be corrected as well as with which method (surgical or conservative) remain controversial. The following article reviews the current concepts regarding the pathophysiology of both conditions as well as the advances in their evaluation and management.

Genetics of common malformations

Advanced technology has recently allowed us to study rare Mendelian disorders in an unprecedented manner. The same technology should allow us also to study more common malformations. Many of these are not caused by a variant in a single Mendelian gene but by interplay between series of genetic variants and exogenous influences. Likely the site from which the DNA is derived is of great importance in studying malformations as mosaicism may be much more common than earlier anticipated. Factors other than simple variants in our genomic DNA should be considered in the studies as well. Not only is recognition of someone's liability to disease important, but also determining exogenous factors involved in malformations should receive more attention as it may allow us decrease the burden of malformations in humans.