Pycnodysostosis with extreme sleep apnea: a possible alternative to tracheotomy

A multi-step approach to overcome challenges in the management of head and neck lymphatic malformations, and response to treatment

BACKGROUND

Lymphatic malformations are vascular developmental anomalies varying from local superficial masses to diffuse infiltrating lesions, resulting in disfigurement. Patients' outcomes range from spontaneous regression to severe sequelae notwithstanding appropriate treatment. The current classification guides, in part, clinicians through the decision-making process, prognosis prediction and choice of therapeutic strategies. Even though the understanding of molecular basis of the disease has been recently improved, a standardized management algorithm has not been reached yet.

RESULTS

Here, we report our experience on five children with different lymphatic anomalies of the head and neck region treated by applying a multidisciplinary approach reaching a consensus among specialists on problem-solving and setting priorities.

CONCLUSIONS

Although restitutio ad integrum was rarely achieved and the burden of care is challenging for patients, caregivers and healthcare providers, this study demonstrates how the referral to expert centres can significantly improve outcomes by alleviating parental stress and ameliorating patients' quality of life. A flow-chart is proposed to guide the multidisciplinary care of children with LMs and to encourage multidisciplinary collaborative initiatives to implement dedicated patients' pathways.

A review of uvulopalatopharyngoplasty for pediatric obstructive sleep apnea

OBJECTIVES

To evaluate existing literature to understand the utility and safety of uvulopalatopharyngoplasty (UPPP) for treatment of pediatric obstructive sleep apnea (OSA).

METHODS

A literature review was conducted by two authors to search for studies from the inception of two databases until March 1, 2023. Studies in which participants were under 18 years of age and underwent UPPP for OSA or upper airway obstruction were selected. Data on variables such as pre- and postoperative severity, efficacy, complications, and follow-up were collected from all studies.

RESULTS

After applying inclusion criteria to the initial 91 abstracts that were screened, 26 studies remained that included 224 patients who underwent UPPP. Most children who underwent UPPP had neurologic impairment, developmental delay, craniofacial abnormalities, or were obese, and underwent several procedures for OSA treatment. Of the studies that reported outcomes, 85.6 % of patients had subjective improvement, and 25.6 % of patients had a reported complication.

CONCLUSIONS

Most children who underwent UPPP had serious medical comorbidities with moderate or severe OSA and a multi-procedural treatment plan. Although most patients had subjective improvement and there were low complication rates, the heterogeneity of existing literature makes it difficult to draw conclusions. Future multi-center, prospective studies should be conducted to analyze the true safety and efficacy of UPPP in pediatric patients.

Sleep-disordered breathing in children with pycnodysostosis

Upper airway obstruction is a common feature in pycnodysostosis and may cause obstructive sleep apnea (OSA). The aim of our study was to analyze sleep-disordered breathing and respiratory management in children with pycnodysostosis. A retrospective review of the clinical charts and sleep studies of 10 consecutive children (three girls and seven boys) with pycnodysostosis seen over a time period of 10 years was performed. Six patients had severe OSA and/or nocturnal hypoventilation and were started on continuous positive airway pressure (CPAP) as a first treatment at a median age of 3.4 ± 2.6 years, because of the lack of indication of any surgical treatment. Three patients could be weaned after several years from CPAP after spontaneous improvement (two patients) or multiple upper airway surgeries (one patient). Three patients had upper airway surgery prior to their first sleep study with two patients still needing CPAP during their follow-up. Only one patient never developed OSA. Patients with pycnodysostosis are at a high risk of severe OSA, underlying the importance of a systematic screening for sleep-disordered breathing. Multidisciplinary care is mandatory because of the multilevel airway obstruction. CPAP is very effective and well accepted for treating OSA.

Outpatient initiation of long-term continuous positive airway pressure in children

INTRODUCTION

Current guidelines recommend initiating continuous positive airway pressure (CPAP) in children during an overnight in-hospital titration study. Due to a shortage of hospital beds and economic constraints, we started a program for outpatient initiation of CPAP in selected children with obstructive sleep apnea (OSA).

METHODS

Objective CPAP compliance and efficacy were evaluated in consecutive children enrolled in an outpatient CPAP program when they fulfilled the following criteria: persistent OSA, age >6 months, stable condition, family living in the Parisian area and agreeing with a regular follow-up.

RESULTS

Thirty-one children, median (range) age 8.9 years (0.8-17.5), were included in the program. The most common diagnosis were Down syndrome (n = 7), achondroplasia (n = 3), and obesity (n = 3). Median baseline obstructive apnea-hypopnea index (OAHI) was 12.5 events/h (5-100). Median duration of follow-up was 12.3 months (2.2-25.2). Four subjects (three adolescents with Down syndrome) were not compliant at 2-month follow-up with a compliance <4 h/night. In the other 27 subjects, median compliance was 08:21 h:min/night (05:45-12:20), with a median number of night use per month of 25 (18-30). CPAP efficacy at the end of follow-up was excellent in the compliant subjects with a median AHI of two events/h (0-4) and normal gas exchange with CPAP therapy. Three subjects were successfully weaned from CPAP treatment during the study period.

CONCLUSION

Initiating CPAP in an outpatient setting in children is feasible and effective in selected subjects. A high rate of compliance can be achieved as well as a correction of OSA.

Pycnodysostosis at otorhinolaryngology

AIM

Pycnodysostosis is a rare autosomal, recessive, skeletal dysplasia caused by a mutation in the cathepsin k gene. Pycnodysostosis is characterized by short stature, characteristic facial appearance (delayed closure of fontanelles and cranial sutures, mandibular hypoplasia and angle disorder, blue sclera), and acroosteolysis of the distal phalanges. Our aim was to describe the otorhinolaryngologic findings, differential diagnoses, various treatment options, and followup in eight cases of pycnodysostosis.

METHOD

This retrospective clinical study used data from eight patients diagnosed with pycnodysostosis by a single pediatric endocrinologist primarily based on clinical and radiographic findings. All patients were referred to the otorhinolaryngology outpatient clinic by the pediatric endocrinology unit of the Marmara University between February 2013 and March 2015. Detailed medical histories were obtained in all cases and otorhinolaryngologic physical examination, blood assays, electrocardiogram, lateral skull X-rays, chest radiograph, cephalometric investigations, tympanograms, and audiograms were also carried out. Sleep videos of patients were recorded and those with upper airway problems were evaluated for sleep apnea by polysomnography. Informed consent form was obtained from the parents of all patients.

RESULTS

Eight patients (7 females and 1 male) displaying proportionate dwarfism were included in the study. They had a mean age of 14.7 years (range: 13-16 y), the mean height of 141.3 cm (range 132-155 cm), and mean weight of 44.4 kg (range: 39.6-49.3 kg). All patients had facial dysmorphism with frontal bossing and the hands and feet had short digits with overlying cutaneous wrinkles that tapered off with large overriding nails. Midfacial hypoplasia and malocclusion were observed in seven of the eight patients (87.5%), four (50%) had micrognathia, and five (62.5%) had proptosis. Tympanograms and audiograms of all patients were type A and normal, and the mean of the pure tone audiogram was 13.3 dB (range: 10-16 dB). All patients had a narrow and grooved palate with disturbed dentition; two of them (25%) had mild markedness of the tongue base, five (62.5%) had grade 3 and three (37.5%) had grade 2 tonsillar hypertrophy, and five (62.5%) had adenoid hypertrophy. One patient (12.5%) had grade 3 Mallampati, four (50%) showed grade 2 Mallampati while three (37.5%) patients displayed grade 1 Mallampati score. Further, while six (75%) patients had no uvular pathology, one (12.5%) patient presented with uvular elongation and another patient had a bifid uvula. Cephalometric measurements such as PAS-UP (mean 5.67 mm; range: 5.0-7.6 mm) and PAS-TP (mean 9.61 mm; range: 8.5-12.2 mm) were lower than that of normal subjects. Video recordings showed that six of the eight patients (75%) had respiratory distress and four (50%) had sleep apnea. Polysomnography in these patients with sleep apnea showed that two had mild OSA (AHI: 18.2 and 20.1 events/hour) and two had severe OSA (AHI: 53.4 and 62.8 events/hour). For upper airway problems, an adenotonsillectomy was performed in two (25%) patients while two others required an adenoidectomy. Positive pressure ventilation was recommended in two patients with persistent sleep apnea after adeno/adenotonsillectomy. However, because of the parental objections, the follow-up polysomnographs could not be obtained.

CONCLUSION

Pycnodysostosis is a very rare form of bone dysplasia. Otorhinolaryngologically, proper follow-up of these patients and appropriate treatment of upper airway problems are important to achieve an acceptable quality of life. Adeno/adenotonsillectomy and positive pressure ventilation, used as conservative approaches in treating upper airway problems, are effective and could be used instead of an aggressive surgery such as tracheotomy or maxillomandibular advancement. This study, to the best of our knowledge, is the largest ENT case series on pycnodysostosis.

Long term continuous positive airway pressure (CPAP) and noninvasive ventilation (NIV) in children: Initiation criteria in real life

INTRODUCTION

Long term noninvasive continuous positive airway pressure (CPAP) and noninvasive ventilation (NIV) are increasingly used in children but limited information is available on the criteria and conditions leading to the initiation of these treatments. The aim of the study is to describe the objective overnight respiratory parameters and clinical situations that led to the initiation of CPAP/NIV in a pediatric NIV unit.

MATERIAL AND METHODS

Retrospective analysis of the data of all the children discharged on home CPAP/NIV over a 1 year period.

RESULTS

Seventy-six patients were started on CPAP (n = 64) or NIV (n = 12). CPAP/NIV was initiated because of CPAP/NIV weaning failure (Acute group) in 15 patients. None of these patients had an overnight gas exchange or sleep study before CPAP/NIV initiation. In 18 patients, CPAP/NIV was initiated on abnormal nocturnal gas exchange alone (Subacute group). These patients had a median of three of the following five overnight gas exchange abnormalities: minimal pulse oximetry (SpO2 ) <90%, maximal transcutaneous carbon dioxide (PtcCO2 ) >50 mmHg, time spent with SpO2 <90% or PtcCO2 >50 mmHg ≥2% of recording time, oxygen desaturation index >1.4/hr. In the last 43 patients, CPAP/NIV was initiated after an abnormal sleep study (Chronic group) on a mean of four of the aforementioned criteria and an apnea-hypopnea index >10/hr.

CONCLUSION

In clinical practice, CPAP/NIV was initiated in an acute, subacute and chronic setting with most patients having an association of several abnormal gas exchange or sleep study parameters. Future studies should evaluate the effectiveness and benefits of CPAP/NIV according to the clinical situation and initiation criteria. Pediatr Pulmonol. 2016; 51:968-974. © 2016 Wiley Periodicals, Inc.

Pycnodysostosis presenting as atypical stridor

OBJECTIVES

Pycnodysostosis is a rare genetic disorder caused by a mutation of the cathepsin K gene involved in bone turnover. It is responsible, in particular, for a combination of dwarfism and bone fragility. Upper airway obstruction may be observed, but associated stridor has never been previously described.

MATERIALS AND METHODS

Single-centre retrospective study over a period of 15 years with review of the literature.

RESULTS

Three children (aged 2-18 months) were managed for stridor and obstructive sleep apnoea syndrome confirmed by polysomnography. Physical examination of these children revealed stridor with laryngomalacia, characteristic dysmorphic features and failure to thrive. Patient 1 presented typical laryngomalacia treated by surgical section of the aryepiglottic folds. Patient 2 presented upper airway obstruction with a narrow nasopharynx and long soft palate, treated by surgery and noninvasive ventilation. Patient 3 presented moderate laryngomalacia and nasal obstruction, treated by surgery and noninvasive ventilation.

CONCLUSION

The diagnosis of pycnodysostosis must be considered in the presence of atypical laryngomalacia associated with multifactorial upper airway obstruction, failure to thrive and dysmorphic syndrome. A genetics consultation is essential in these patients.

The role of cathepsin K in oral and maxillofacial disorders

Cathepsin K (CTSK) was thought to be a collagenase, specifically expressed by osteoclasts, and played an important role in bone resorption. However, more and more research found that CTSK was expressed in more extensive cells, tissues, and organs. It may not only participate in regulating human physiological activity, but also be closely related to a variety of disease. In this review, we highlight the relationship between CTSK and oral and maxillofacial disorders on the following three aspects: oral and maxillofacial abnormities in patients with pycnodysostosis caused by CTSK mutations, oral and maxillofacial abnormities in Ctsk(-/-) mice, and the role of CTSK in oral and maxillofacial diseases, including periodontitis, peri-implantitis, tooth movement, oral and maxillofacial tumor, root resorption, and periapical disease.

A subcranial Le Fort III advancement with distraction osteogenesis as a clinical strategy to approach pycnodysostosis with midface retrusion and exorbitism

Pycnodysostosis is a rare autosomal recessive skeletal disorder involving a constellation of craniofacial manifestations including midface retrusion. We report the case of a 13-year-old girl with pycnodysostosis who presented with exorbitism, midface retrusion, malocclusion, and obstructive sleep apnea. Here, we describe the successful use of subcranial Le Fort III advancement using distraction osteogenesis with internal Kawamoto distracters. After a latency of 5 days, distraction for 10 days, and consolidation for 12 weeks, her midface was advanced by 10 mm with slight overcorrection at the occlusion level. At 2 years postoperatively, the patient had complete remission of her sleep apnea, resolution of her exorbitism, and amelioration of her class III malocclusion to class I. To the best of our knowledge, this is the first report of a successful subcranial Le Fort III midface advancement with distraction osteogenesis for craniofacial reconstruction of a pycnodysostosis. Our report highlights the surgical options that have been described for this craniofacial deformity and presents a novel and expedient approach for patients with pycnodysostosis presenting with exorbitism, midface retrusion, and/or sleep apnea.

A Mutation in CTSK Gene in an Autosomal Recessive Pycnodysostosis Family of Chinese Origin

Pycnodysostosis is a rare autosomal recessive skeletal dysplasia characterized by short stature, osteosclerosis, acro-osteolysis, frequent fractures, and skull deformities. Mutation in the gene encoding cathepsin K (CTSK), which is a lysosomal cysteine protease, has been found to be responsible for this disease. Here we reported a consanguineous Chinese family with 1 affected individual demonstrating autosomal recessive pycnodysostosis with recurrent kidney stone, a new clinical manifestation which has not been reported in patients of pycnodysostosis before. To identify the pathogenic mutation, we evaluated the patient clinically, biochemically, and radiographically. To screen for mutations in the CTSK gene of the patient and his family members, all of its exons and exon-intron junctions were PCR amplified from genomic DNA and sequenced. Sequence analysis of the patient's CTSK gene revealed homozygosity for a missense mutation (c.746T>C) in exon 6, which leads to amino change (p.Ile249Thr) in the mature CTSK protein. This mutation was firstly reported by Michela Donnarumma and his colleagues in 2007 in a Spanish family. Our study strengthens the role of this particular mutation in the pathogenesis of pycnodysostosis.

Upper airway surgery of obstructive sleep apnea in pycnodysostosis: case report and literature review

Pycnodysostosis is an autosomal recessive disorder due to a mutation in the cathepsin K gene, which causes a decrease of the bone turnover; a review of the literature suggests that pycnodysostosis is frequently associated with severe respiratory obstruction, which needs surgical treatment. The aim of this paper is to describe the surgical treatment of a 3½-year-old girl affected by Pycnodysostosis complicated by a severe sleep-related respiratory disorder. The surgical treatment, consisting of adenotonsillectomy and palatoplasty, resulted in a striking amelioration of respiratory parameters and increased posterior airway space, and allowed the patient to avoid tracheotomy while awaiting for maxillo-mandibular surgery.

Pycnodysostosis with novel gene mutation and severe obstructive sleep apnoea: management of a complex case

Pycnodysostosis is a rare genetic disease. Impaired osteoclastic function is the basis for typical phenotypic features and bone fragility. The main differential diagnosis is osteopetrosis, also associated with altered bone remodelling, but with a more severe prognosis. We describe the case of an 8-year-old boy who presented life-threatening obstructive sleep apnoea successfully managed with non-invasive ventilation. Haematological overlap phenotype included anaemia and altered bone marrow, more common in osteopetrosis. Molecular analysis of the CTSK gene revealed a mutation not previously described in the literature.

A child with bone fractures and dysmorphic features: remember of pycnodysostosis and craniosynostosis

Accidental bony injuries are common in children. Children may also present with bony injuries following non-accidental injuries. Pathological fractures, though extremely rare, are an important entity and constitute fractures that occur in abnormal bones, usually after minor trauma. Pycnodysostosis is a rare skeletal dysplasia characterised by a clinical phenotype that includes short stature, skull deformities, osteosclerosis, acroosteolysis and bone fragility. Often the disease is diagnosed at an early age as a result of the investigation of short stature. However, the diagnosis is sometimes delayed and must be considered in any child with a history of recurrent or multiple bone fractures and dysmorphic features. The purpose of this report is to describe the clinical, radiological and genetic issues of a 9-year-old girl with a long history of multiple bone fractures. She had been subjected to safeguarding investigations previously and was identified to have dysmorphic features diagnosed as pycnodysostosis associated with craniosynostosis.