Anaesthesia and airway management in mucopolysaccharidosis

Mucopolysaccharidosis (MPS IIIA) mice have increased lung compliance and airway resistance, decreased diaphragm strength, and no change in alveolar structure

Mucopolysaccharidosis type IIIA (MPS IIIA) is characterized by neurological and skeletal pathologies caused by reduced activity of the lysosomal hydrolase, sulfamidase, and the subsequent primary accumulation of undegraded heparan sulfate (HS). Respiratory pathology is considered secondary in MPS IIIA and the mechanisms are not well understood. Changes in the amount, metabolism, and function of pulmonary surfactant, the substance that regulates alveolar interfacial surface tension and modulates lung compliance and elastance, have been reported in MPS IIIA mice. Here we investigated changes in lung function in 20-wk-old control and MPS IIIA mice with a closed and open thoracic cage, diaphragm contractile properties, and potential parenchymal remodeling. MPS IIIA mice had increased compliance and airway resistance and reduced tissue damping and elastance compared with control mice. The chest wall impacted lung function as observed by an increase in airway resistance and a decrease in peripheral energy dissipation in the open compared with the closed thoracic cage state in MPS IIIA mice. Diaphragm contractile forces showed a decrease in peak twitch force, maximum specific force, and the force-frequency relationship but no change in muscle fiber cross-sectional area in MPS IIIA mice compared with control mice. Design-based stereology did not reveal any parenchymal remodeling or destruction of alveolar septa in the MPS IIIA mouse lung. In conclusion, the increased storage of HS which leads to biochemical and biophysical changes in pulmonary surfactant also affects lung and diaphragm function, but has no impact on lung or diaphragm structure at this stage of the disease.NEW & NOTEWORTHY Heparan sulfate storage in the lungs of mucopolysaccharidosis type IIIA (MPS IIIA) mice leads to changes in lung function consistent with those of an obstructive lung disease and includes an increase in lung compliance and airway resistance and a decrease in tissue elastance. In addition, diaphragm muscle contractile strength is reduced, potentially further contributing to lung function impairment. However, no changes in parenchymal lung structure were observed in mice at 20 wk of age.

Causes of death in mucopolysaccharidoses

Mucopolysaccharidoses are inherited metabolic diseases caused by mutations in genes encoding enzymes required for degradation of glycosaminoglycans. A lack or severe impairment of activity of these enzymes cause accumulation of GAGs which is the primary biochemical defect. Depending on the kind of the deficient enzyme, there are 12 types and subtypes of MPS distinguished. Despite the common primary metabolic deficit (inefficient GAG degradation), the course and symptoms of various MPS types can be different, though majority of the diseases from the group are characterized by severe symptoms and significantly shortened live span. Here, we analysed the frequency of specific, direct causes of death of patients with different MPS types, the subject which was not investigated comprehensively to date. We examined a total of 1317 cases of death among MPS patients, including 393 cases of MPS I, 418 cases of MPS II, 232 cases of MPS III, 45 cases of MPS IV, 208 cases of MPS VI, and 22 cases of MPS VII. Our analyses indicated that the most frequent causes of death differ significantly between MPS types, with cardiovascular and respiratory failures being predominant in MPS I, MPS II, and MPS VI, neurological deficits in MPS III, respiratory issues in MPS IV, and hydrops fetalis in MPS VII. Results of such studies suggest what specific clinical problems should be considered with the highest priority in specific MPS types, apart from attempts to correct the primary causes of the diseases, to improve the quality of life of patients and to prolong their lives.

Adenotonsillectomy for the treatment of OSA in children with mucopolysaccharidosis: A systematic review

OBJECTIVE

To study the role of adenotonsillectomy (ADT) for obstructive sleep apnea (OSA) in children with mucopolysaccharidosis (MPS).

METHODS

A systematic review were performed following the PRISMA guideline. PubMed and Embase were searched for studies regarding adenotonsillectomy for OSA in children with MPS. The MINOR Score were applied for quality assessment of the included studies.

RESULTS

Nineteen studies were eligible for inclusion: fifteen were retrospective and four prospective. A total of 1406 subjects were included. The samples size varied from 2 to 336, the male to female ratio is 1.2 and mean age varied from 2.4 to 11 years. Overall, 56.2 % (IC 95%: 53.6-58.8) of the included subjects underwent ADT. MPS I and II are the two most operated types. Three studies, including 50 children, reported improvement in polysomnographic parameters after surgery. Two authors described the duration of follow-up: 8.4 and 9.8 years, respectively.

CONCLUSIONS

More than half of children with MPS underwent ADT for the treatment of OSA, although few evidence demonstrated improvement in term of polysomnographic parameters. The two types of MPS most involved are type I and II. Considering the disease progression and anesthetic risks, multidisciplinary management may help identify the subgroup of children with MPS who benefit from ADT for the treatment of OSA.

Airway and Anaesthetic Management of Adult Patients with Mucopolysaccharidoses Undergoing Cardiac Surgery

Background: Mucopolysaccharidoses (MPSs) are rare congenital lysosomal storage disorders due to a deficiency of enzymes metabolising glycosaminoglycans, leading to their accumulation in tissues. This multisystem disease often requires surgical intervention, including valvular cardiac surgery. Adult MPSs have complex airways making anaesthesia risky. Methods: We report novel three-dimensional (3D) modelling airway assessments and multidisciplinary peri-operative airway management. Results: Five MPS adults underwent cardiac surgery at the national MPS cardiac centre (type I = 4, type II = 1; ages 20, 24, 33, 35, 37 years; two males, three females). All had complex airway abnormalities. Assessments involved examination, nasendoscopy, imaging, functional studies, 3D reconstruction, virtual endoscopy, virtual reality and simulation using computerised, physical modelling. Awake oral fibre-optic intubation was achieved via airway conduit. Staged extubation was performed on the first post-operative day under laryngo-tracheoscopic guidance. The post-operative period involved chest physiotherapy and occupational therapy. All patients had safe intubation, ventilation and extubation. Four had good cardiac surgical outcomes, one (MPS type I; age 35 years) was inoperable due to endocarditis. None had post-operative airway complications. Conclusions: Expertise from cardiovascular-heart team, multidisciplinary airway management, use of novel techniques is vital. Traditional airway assessments are insufficient, so ENT input, radiology and computerised methods to assess and simulate the airway in 3D by collaboration with clinical engineering is essential.

Tracheal Narrowing and Its Impact on Anesthesia Care in Patients With Morquio A (Mucopolysaccharidosis Type IVA): An Observational Study

BACKGROUND

Recently, tracheal narrowing has been recognized as a significant comorbid condition in patients with Morquio A, also known as mucopolysaccharidosis IVA. We studied a large cohort of patients with Morquio A to describe the extent of their tracheal narrowing and its relationship to airway management during anesthesia care.

METHODS

This is an observational study, collecting data retrospectively, of a cohort of patients with Morquio A. Ninety-two patients with Morquio A syndrome were enrolled, among whom 44 patients had their airway evaluated by computed tomography angiography and had undergone an anesthetic within a year of the evaluation. Our hypothesis was that the tracheal narrowing as evaluated by computed tomography angiography increases with age in patients with Morquio A. The primary aim of the study was to examine the degree of tracheal narrowing in patients with Morquio A and describe the difficulties encountered during airway management, thus increasing awareness of both the tracheal narrowing and airway management difficulties in this patient population. In addition, the degree of tracheal narrowing was evaluated for its association with age or spirometry parameters using Spearman's rank correlation. Analysis of variance followed by the Bonferroni test was used to further examine the age-based differences in tracheal narrowing for the 3 age groups: 1 to 10 years, 11 to 20 years, and >21 years.

RESULTS

Patient age showed a positive correlation with tracheal narrowing ( rs= 0.415; 95% confidence interval [95% CI], 0.138-0.691; P = .005) with older patients having greater narrowing of the trachea. Among spirometry parameters, FEF25%-75% showed an inverse correlation with tracheal narrowing as follows: FEF25%-75% versus tracheal narrowing: ( rs = -0.467; 95% CI, -0.877 to -0.057; P = .007). During anesthetic care, significant airway management difficulties were encountered, including cancelation of surgical procedures, awake intubation using flexible bronchoscope, and failed video laryngoscopy attempts.

CONCLUSIONS

Clinically significant tracheal narrowing was present in patients with Morquio A, and the degree of such narrowing likely contributed to the difficulty with airway management during their anesthetic care. Tracheal narrowing worsens with age, but the progression appears to slow down after 20 years of age. In addition to tracheal narrowing, spirometry values of FEF25%-75% may be helpful in the overall evaluation of the airway in patients with Morquio A.

Medium-term outcome of transcatheter aortic valve replacement in mucopolysaccharidosis type I-HS (Hurler-Scheie syndrome)

Mucopolysaccharidoses (MPSs) are inherited metabolic diseases characterized by the deficiency of lysosomal enzymes and the accumulation of glycosaminoglycans in various organs, including the heart. In particular, aortic valve disease causes high morbidity and mortality rates, and sometimes requires surgical aortic valve replacement (SAVR) at a young age. Although transcatheter aortic valve replacement (TAVR) for severe aortic stenosis (AS) in surgical high-risk patients is a well-established treatment, there are few reports of TAVR in MPS and medium- and long-term outcomes are not known. We present a case of severe AS in a MPS patient with high risk for SAVR who was successfully treated with TAVR and has shown a fine medium-term result. A 40-year-old woman with MPS type I-HS (Hurler-Scheie syndrome) receiving enzyme replacement therapy as a systemic treatment had complained of syncope and worsening dyspnea, and she was diagnosed with severe AS. The patient had a history of temporary tracheotomy because of the difficulty of endotracheal intubation. Considering risk for general anesthesia, TAVR was performed under local anesthesia. She has improved symptoms for one-and-a-half years. TAVR for severe AS in MPS would be an alternative option for surgical high-risk patients and can demonstrate preferable medium-term outcomes combined with systemic therapies.

Learning objective

Mucopolysaccharidoses (MPSs) are metabolic diseases affecting various organs. The MPS patients requiring surgical aortic valve replacement (SAVR) for severe aortic stenosis (AS) often have a high surgical risk. However, in MPS, transcatheter aortic valve replacement (TAVR) could be an alternative procedure to SAVR. We report a MPS patient treated with TAVR showing a preferable medium-term outcome. We suggest that TAVR for severe AS in MPS is an acceptable treatment option.

Surgical Management of Valvular Heart Disease in Mucopolysaccharidoses: A Review of Literature

Mucopolysaccharidoses are extremely rare diseases that are frequently presenting with structural heart problems of the aortic and mitral valve in combination with myocardial dysfunction. In a substantial proportion, this leads to heart failure and is a leading cause of death in these patients. As this glycosaminoglycan degradation defect is associated with other conditions strongly influencing the perioperative risk and choice of surgical technique, multidisciplinary planning is crucial to improve short- and long-term outcomes. The extensive variance in clinical presentation between different impaired enzymes, and further within subgroups, calls for personalised treatment plans. Enzyme replacement therapies and bone marrow transplantation carry great potential as they may significantly abrogate the progress of the disease and as such reduce the clinical burden and improve life expectancy. Nevertheless, structural heart interventions may be required. We reviewed the existing literature of the less than 50 published cases regarding surgical management, technique, and choice of prostheses. Although improvement in therapy has shown promising results in protecting valvar tissue when initiated in infancy, concerns regarding stability of this effect and durability of biological prostheses remain.

Transcatheter aortic valve implantation for severe aortic stenosis in a patient with mucopolysaccharidosis type II (Hunter syndrome) accompanied by severe airway obstruction

Mucopolysaccharidosis type II, known as Hunter syndrome, is a rare inherited metabolic disorder with glycosaminoglycan accumulation leading to progressive multisystem involvement, such as heart, respiratory, and central nervous systems. In particular, concurrence of major heart and respiratory problems in this syndrome often causes difficulty in performing curative and invasive treatments. Transcatheter aortic valve implantation (TAVI) has been an established therapy for severe aortic stenosis (AS). In patients who cannot undergo surgical aortic valve replacement because of high risk for general anesthesia, TAVI with local anesthesia has become an alternative therapy for severe AS. We report herein a case of 50-year-old man with Hunter syndrome accompanied by severe airway obstruction who underwent TAVI with local anesthesia for severe AS. <Learning objective: Mucopolysaccharidosis is characterized by glycosaminoglycan accumulation leading to progressive multisystem involvement. Heart disease and respiratory problems are often concomitant in patients with mucopolysaccharidosis. When surgical treatment is required, consideration about treatment strategy and perioperative management are important because of its high surgical risk or inoperable status. We describe a case with mucopolysaccharidosis accompanied by severe airway obstruction who underwent transcatheter aortic valve implantation with local anesthesia for severe aortic stenosis.>.

Anesthetic Concerns of Children With Skeletal Dysplasia

Children with skeletal dysplasia present unique challenges for safe anesthetic care including differences in the anatomy of the respiratory system, possibility of cervical spine instability or spinal stenosis, and a unique body habitus. Even seemly routine anesthesia can result in respiratory arrest or spinal cord injury. These complications can largely be avoided by proper planning such as appropriate techniques for the intubation of difficult airways, recognition of cervical instability, neuromonitoring for any anesthesia over an hour in patients with severe spinal stenosis, and preoperative assessment of the trachea and avoidance of neuraxial anesthesia in children with Morquio syndrome.

Disease Manifestations in Mucopolysaccharidoses and Their Impact on Anaesthesia-Related Complications-A Retrospective Analysis of 99 Patients

Patients with mucopolysaccharidoses (MPS) frequently require anaesthesia for diagnostic or surgical interventions and thereby experience high morbidity. This study aimed to develop a multivariable prediction model for anaesthesia-related complications in MPS. This two-centred study was performed by retrospective chart review of children and adults with MPS undergoing anaesthesia from 2002 until 2018. We retrieved the patients’ demographics, medical history, clinical manifestations, and indication by each anaesthesia. Multivariable mixed-effects logistic regression was calculated for a clinical model based on preoperative predictors preselected by lasso regression and another model based on disease subtypes only. Of the 484 anaesthesia cases in 99 patients, 22.7% experienced at least one adverse event. The clinical model resulted in a better forecast performance than the subtype-model (AICc 460.4 vs. 467.7). The most relevant predictors were hepatosplenomegaly (OR 3.10, CI 1.54–6.26), immobility (OR 3.80, CI 0.98–14.73), and planned major surgery (OR 6.64, CI 2.25–19.55), while disease-specific therapies, i.e., haematopoietic stem cell transplantation (OR 0.45, CI 0.20–1.03), produced a protective effect. Anaesthetic complications can best be predicted by surrogates for advanced disease stages and protective therapeutic factors. Further model validation in different cohorts is needed.

Awake airway endoscopy in mucopolysaccharidosis: a case report

Mucopolysaccharidosis (MPS) are a group of rare genetic inherited diseases with a progressive course due to the accumulation of glycosaminoglycans resulting in anatomic abnormalities and organ dysfunction, including the respiratory, cardiovascular, skeletal, and neurological systems that can increase the risk of anesthesia complications. Clinical manifestations are variable, multisystemic, and include severe morphological changes. The anesthetic management of these patients is complex, particularly airway management, which can be planned to include a fiberoptic airway investigation prior to surgery. We present two cases of patients with MPS type VI and VII who underwent fiberoptic airway mapping under conscious sedation, with no complications. Since MPS is a rare but challenging disease concerning the airway management, we propose a safe and effective anesthetic technique that could be used for fiberoptic bronchoscopy and allow fiberoptic-assisted tracheal intubation at the time of surgery.

Perioperative management of patients with Mucolipidosis II and III: Lessons from a case series

Mucolipidosis (ML) II and III are complex lysosomal storage disorders characterized by progressive multisystem pathology which can pose challenges to the anesthetist and increase the risks associated with general anesthesia. We sought to review the management of patients with ML II and III undergoing anesthesia in our institution in order to better define recommendations for the preoperative assessment and optimization of these children. We further elected to analyze the conduct of anesthesia, intraoperative management, and perioperative complications that our patients had experienced in order to allow improved informed consent and anesthetic planning. We performed a retrospective examination of the medical notes of those patients who had undergone anesthesia in our institution to identify their clinical features, anesthetic technique, airway management, and perioperative complications. Five children underwent 11 episodes of anesthesia. Fiber-optic or videolaryngoscopy was utilized in six out of seven intubations, with four out of seven requiring a change from the method initially chosen to enable intubation. Four of the five patients had an abnormal echocardiogram. Three patients had radiological evaluation of their cervical spine, with two demonstrating abnormalities. One patient had changes suggesting instability at the atlantoaxial junction. Children and babies with ML II and III present multisystem challenges to the anesthetist. Multidisciplinary planning and assessment, followed by a discussion of risk, should proceed any elective surgery. These complex children should undergo elective anesthesia delivered by an experienced (pediatric) anesthetist in an appropriate tertiary center with on-site pediatric ENT and critical care support.

Pulmonary Manifestations of Endocrine and Metabolic Diseases in Children

Advances in technology, methodology, and deep phenotyping are increasingly driving the understanding of the pathologic basis of disease. Improvements in patient identification and treatment are impacting survival. This is true in endocrinology and inborn errors of metabolism, where disease-modifying therapies are developing. Inherent to this evolution is the increasing awareness of the respiratory manifestations of these rare diseases. This review updates clinicians, stratifying diseases spirometerically; pulmonary hypertension and diseases with a predisposition to recurrent pulmonary infection are discussed. This division is artificial; many diseases have multiple pathologic effects on respiration. This review does not cover the impact of obesity.

Hearing Loss in Mucopolysaccharidoses: Current Knowledge and Future Directions

Mucopolysaccharidoses (MPS) are a group of lysosomal storage disorders caused by a deficiency of one of the enzymes involved in the degradation of glycosaminoglycans. Hearing loss is a common clinical presentation in MPS. This paper reviews the literature on hearing loss for each of the seven recognized subtypes of MPS. Hearing loss was found to be common in MPS I, II, III, IVA, VI, and VII, and absent from MPS IVB and MPS IX. MPS VI presents primarily with conductive hearing loss, while the other subtypes (MPS I, MPS II, MPS III, MPS IVA, and MPS VII) can present with any type of hearing loss (conductive, sensorineural, or mixed hearing loss). The sensorineural component develops as the disease progresses, but there is no consensus on the etiology of the sensorineural component. Enzyme replacement therapy (ERT) is the most common therapy utilized for MPS, but the effects of ERT on hearing function have been inconclusive. This review highlights a need for more comprehensive and multidisciplinary research on hearing function that includes behavioral testing, objective testing, and temporal bone imaging. This information would allow for better understanding of the progression and etiology of hearing loss. Owing to the prevalence of hearing loss in MPS, early diagnosis of hearing loss and annual comprehensive audiological evaluations are recommended.

Otorhinolaryngological manifestations in 61 patients with mucopolysaccharidosis

OBJECTIVES

The mucopolysaccharidoses (MPS) are inherited lysosomal storage disorders with multisystemic and highly variable clinical manifestation. ENT symptoms are common and early signs of MPS. The most common ENT diagnoses are chronic/recurrent rhinosinusitis, acute otitis media, otitis media with effusion, hearing loss and airway obstruction.

METHODS

A single-centre retrospective chart review of 61 patients (36 M/25F) with different MPS subtypes (MPS I (n = 15), MPS II (n = 10), MPS III (n = 17), MPS IV (n = 15) and MPS VI (n = 4)) was conducted. The age of ENT presentation and frequency of ENT symptoms, surgeries and their distribution among MPS subtypes was studied. The relationship between ENT presentation, first ENT surgery and the age of diagnosis was also evaluated.

RESULTS

Median age at the first ENT manifestation was 2.8 years, median age at MPS diagnosis 4.1 years. The great majority of patients (90%) manifested at least one ENT diagnosis; often before the diagnosis of MPS (75%). Chronic/recurrent rhinosinusitis was the most prevalent ENT diagnosis (77%), followed by upper airway obstruction (65%) and hearing loss (53%). Chronic/recurrent rhinosinusitis was the first ENT symptom to appear (median age 2.2 years), followed by otitis media with effusion (3.7 years) and hearing loss (4.5 years). At least one ENT surgery was performed in 57% of patients; in 69% before MPS diagnosis was established. Median age of the first ENT surgery was 4.1 years. ENT symptoms and surgical procedures were earliest present in MPS II.

CONCLUSIONS

Our study documents high and early occurrence of various otolaryngologic symptoms in MPS and thus highlights the role of ENT specialist in prompt diagnosis of these rare diseases and their long-term management.

Improvement in functional gait parameters following corrective thoracolumbar surgery in children affected by Mucopolysaccharidosis 1 (Hurler syndrome)

OBJECTIVE

Thoracolumbar kyphosis is a common indication for spinal surgery in children with Mucopolysaccharidosis. Functional outcome of spinal surgical intervention has never been published in patients with this rare disease. We present a cohort of patients with Mucopolysaccharidosis 1(Hurler syndrome) who underwent thoraco-lumbar spinal deformity correction and functional outcome assessed by pre-operative and post-operative gait analysis. This study represents the first attempt at presenting a functional assessment of surgical outcome in any Mucopolysaccharidosis subtype.

METHODS

A retrospective analysis of prospectively collected data was carried out from 11 children diagnosed with this subtype of Mucopolysaccharidosis. All patients underwent thoracolumbar kyphosis correction between the years 2013 to 2016. Gait assessment was performed using GAITRite™ electronic walkway pre-operatively and post-operatively within 9 to 24 months from the index surgery. Walking distance, cadence and gait velocity were the three spatio-temporal parameters analysed. Wilcoxon signed rank test was used to analyse the data and P-Value ≤0.05 was deemed significant.

RESULTS

There was a statistically significant improvement in walking distance in 9 out of 11 patient post-operatively with a mean increase of 232.06 cms (P = 0.05). There was marginal improvement in cadence by 6.33 steps/min post-operatively (P-value 0.79). Gait velocity also showed a marginal increase by 8.73 cms/sec post-operatively (P-value 0.32).

CONCLUSION

The results of our study suggest that correction of thoracolumbar kyphosis in children with Mucopolysaccharidosis 1 resulted in a significant improvement of walking distance with a trend towards improved gait in the other parameters. Post-operative change in cadence was not statistically significant suggesting that physiological maturation of gait had minimal effect in the specified post-operative assessment timeframe. This study emphasizes that outcomes of spinal surgery in children with Mucopolysaccharidosis 1 should be determined by functional measures aiming to maintain or improve quality of life.

Critical clinical situations in adult patients with Mucopolysaccharidoses (MPS)

Background

Mucopolysaccharidoses (MPS) are rare, inherited disorders associated with enzyme deficiencies that result in glycosaminoglycan (GAG) accumulation in multiple organ systems. Management of MPS is evolving as patients increasingly survive to adulthood and undergo multiple surgeries throughout their lives. As surgeries in these patients are considered to be high risk, this can result in a range of critical clinical situations in adult patients.

Results

We discuss strategies to prepare for and manage critical clinical situations in adult patients with MPS, including supporting the multidisciplinary team, preoperative and airway assessments, surgical preparations, and postoperative care. We also present eight critical clinical cases (age range: 21–38 years) from four leading inherited metabolic disease centres in Europe to highlight challenges and practical solutions to optimise the care of adult patients with MPS. Critical clinical situations included surgical procedures, pregnancy and a thrombus in a port-a-cath.

Conclusions

Individualised strategies to manage critical clinical situations need to be developed for each patient to compensate for the heterogeneous symptoms that may be present and the potential complications that may occur. These strategies should include input from the wider MDT, and be coordinated by metabolic specialists with expertise in the management of MPS disorders and surgery in adult patients with MPS.

Case report of endoprosthesis -Y implantation in severe respiratory failure in the MPSII patient; comparison with literature data

Background

The tracheobronchomalacia is a life-threatening complication of mucopolysaccharidosis (MPS) without known effective, optimal treatment. The severe expiratory collapse of the trachea and bronchi is one of causes of the high rate of deaths in the course of airway impairment in MPSII patients.

Case presentation

Due to the adynamic tracheobronchomalacia despite of enzymatic treatment (ERT) in our MPSII patient, a life-saving tracheal bifurcated type-Y endoprosthesis (a self-expanding, metal stent for the prosthesis of tracheal and bronchial stenosis) was implanted. In the followed months, the breathing efficiency improved, but then gradual worsening, progression of bronchi occlusion at the stent border resulted in patient’s death.

Conclusion

The Y-stent implantation appears to be a short-term, life-saving solution without satisfactory long-term effects due to the progress of peripheral bronchomalacia and increased tissue proliferation and granulation, that arises during the illness’ course.

Airway management and perioperative adverse events in children with mucopolysaccharidoses and mucolipidoses: A retrospective cohort study

BACKGROUND

Children suffering from mucopolysaccharidoses (subtypes I, II, III, IV, VI, and VII) or mucolipidoses often require anesthesia, but are at high risk for perioperative adverse events. However, the impact of the disease subtype and the standard of care for airway management are still unclear.

AIMS

This study aimed to assess independent risk factors for perioperative adverse events in individuals with mucopolysaccharidoses/mucolipidoses and to analyze the interaction with the primary airway technique implemented.

METHODS

This retrospective study included individuals with mucopolysaccharidoses/mucolipidoses who underwent anesthesia at two high-volume centers from 2002 to 2016. The data were analyzed in a multivariate hierarchical model, accounting for repeated anesthesia procedures within the same patient and for multiple events within a single anesthesia.

RESULTS

Of 141 identified inpatients, 67 (63 mucopolysaccharidoses and 4 mucolipidoses) underwent 269 anesthesia procedures (study cases) for 353 surgical or diagnostic interventions. At least one perioperative adverse event occurred in 25.6% of the cases. The risk for perioperative adverse events was higher in mucopolysaccharidoses type I (OR 8.0 [1.5-42.7]; P = .014) or type II (OR 8.8 [1.3-58.6]; P = .025) than in type III. Fiberoptic intubation through a supraglottic airway was associated with the lowest risk for perioperative adverse events and lowest conversion rate. Direct laryngoscopy was associated with a significantly higher risk for airway management problems than indirect techniques (estimated event rates 47.8% vs 10.1%, OR 24.05 [5.20-111.24]; P < .001). The risk for respiratory adverse events was significantly higher for supraglottic airway (22.6%; OR 31.53 [2.79-355.88]; P = .001) and direct laryngoscopy (14.8%; OR 14.70 [1.32-163.44]; P = .029) than for fiberoptic intubation through a supraglottic airway (2.1%).

CONCLUSIONS

The disease subtype and primary airway technique were the most important independent risk factors for perioperative adverse events. Our findings indicate that in MPS/ML children with predicted difficult airway indirect techniques should be favored for the first tracheal intubation attempt.

Laryngeal, Tracheal, and Bronchial Disease in the Mucopolysaccharidoses: Endoscopic Study

Mucopolysaccharidoses (MPS) are genetically determined diseases, leading to a deficiency of enzymes in the glycosaminoglycan (GAG) degradation pathway. The accumulation of GAG occurs in connective tissue in various organs and systems of the body, including the larynx, trachea, and bronchi. Respiratory symptoms are common and severe in these patients, and respiratory disease is a frequent cause of death. A cross-sectional study with flexible bronchoscopy was conducted in 30 MPS patients (6 MPS I, 8 MPS II, 2 MPS III, 3 MPS IV-A, and 11 MPS VI). Only four patients (13.33%) had a normal airway; nine (30%) had mild to moderate disease, 12 (40%) moderate to severe, and five patients (16.67%) had severe disease. Of particular interest, neuronopathic MPS II had the largest proportion of tracheostomized patients who died due to respiratory complications; in MPS IV-A, all patients had significant tracheobronchial deformity with associated tracheomalacia, despite lacking laryngeal involvement. Laryngotracheobronchial disease (LTBD) was associated to longer disease history and was significantly more severe in older patients. Longer use of enzyme replacement therapy did not prevent the progression of LTBD, although the age of therapy introduction may be a crucial factor in lower airway involvement.

Successful anaesthesia management of a child with hunter syndrome for adenotonsillectomy

Airway management in a child with hunter syndrome is a challenge to the anesthetists. Various methods to achieve this are reported in literature. Here we describe another method in a three year old male child posted for adenotonsillectomy and myringotomy. After check videolaryngoscopy with C Mac blade size 2, vocal cords were not visible even with various monoevres. Thus a larger blade size 3 was used to place it under the epiglottis after which posterior part of vocal cords became visible and bougie guided endotracheal intubation was successful. Thus we recommend that in a child with hunter syndrome if vocal cords are not visible, a larger blade can be utilized to place under the epiglottis to visualize the vocal cords for successful endotracheal intubation.

Respiratory complications of metabolic disease in the paediatric population: A review of presentation, diagnosis and therapeutic options

Inborn errors of metabolism (IEMs) whilst individually rare, as a group constitute a field which is increasingly demands on pulmonologists. With the advent of new therapies such as enzyme replacement and gene therapy, early diagnosis and treatment of these conditions can impact on long term outcome, making their timely recognition and appropriate investigation increasingly important. Conversely, with improved treatment, survival of these patients is increasing, with the emergence of previously unknown respiratory phenotypes. It is thus important that pulmonologists are aware of and appropriately monitor and manage these complications. This review aims to highlight the respiratory manifestations which can occur. It isdivided into conditions resulting primarily in obstructive airway and lung disease, restrictive lung disease such as interstitial lung disease or pulmonary alveolar proteinosis and pulmonary hypertension, whilst acknowledging that some diseases have the potential to cause all three. The review focuses on general phenotypes of IEMs, their known respiratory complications and the basic metabolic investigations which should be performed where an IEM is suspected.

Transition of patients with mucopolysaccharidosis from paediatric to adult care

Mucopolysaccharidoses (MPS) are rare disorders associated with enzyme deficiencies, resulting in glycosaminoglycan (GAG) accumulation in multiple organ systems. As patients increasingly survive to adulthood, the need for a smooth transition into adult care is essential. Using case studies, we outline strategies and highlight the challenges of transition, illustrating practical solutions that may be used to optimise the transition process for patients with MPS disorders.

Seven MPS case studies were provided by four European inherited metabolic disease centres; six of these patients transferred to an adult care setting and the final patient remained under paediatric care. Of the patients who transferred, age at the start of transition ranged between 14 and 18 years (age at transfer ranged from 16 to 19 years).

While there were some shared features of transition strategies, they varied in duration, the healthcare professionals involved and the management of adult patients with MPS. Challenges included complex symptoms, patients' unwillingness to attend appointments with unfamiliar team members and attachment to paediatricians. Challenges were resolved by starting transition at an early age, educating patients and families, and providing regular communication with and reassurance to the patient and family. Sufficient time should be provided to allow patients to understand their responsibilities in the adult care setting while feeling assured of continued support from healthcare professionals. The involvement of a coordinated multidisciplinary team with expertise in MPS is also key. Overall, transition strategies must be comprehensive and individualised to patients' needs.

Intranasal dexmedetomidine and intravenous ketamine for procedural sedation in a child with alpha-mannosidosis: a magic bullet?

Background

Procedural sedation is increasingly needed in pediatrics. Although different drugs or drugs association are available, which is the safest and most efficient has yet to be defined, especially in syndromic children with increased sedation-related risk factors.

Case report

we report the case of a five-year-old child affected by alpha-mannosidosis who required procedural sedation for an MRI scan and a lumbar puncture. We administered intranasal dexmedetomidine (4 μg/kg) 45 min before intravenous cannulation, followed by one bolus of ketamine (1 mg/kg) for each procedure. The patient maintained spontaneous breathing and no desaturation or any complication occurred.

Conclusion

intranasal dexmedetomidine and intravenous ketamine could be a feasible option for MRI and lumbar puncture in children with alpha-mannosidosis needing sedation.

Recommendations for the management of MPS IVA: systematic evidence- and consensus-based guidance

INTRODUCTION

Mucopolysaccharidosis (MPS) IVA or Morquio A syndrome is an autosomal recessive lysosomal storage disorder (LSD) caused by deficiency of the N-acetylgalactosamine-6-sulfatase (GALNS) enzyme, which impairs lysosomal degradation of keratan sulphate and chondroitin-6-sulphate. The multiple clinical manifestations of MPS IVA present numerous challenges for management and necessitate the need for individualised treatment. Although treatment guidelines are available, the methodology used to develop this guidance has come under increased scrutiny. This programme was conducted to provide evidence-based, expert-agreed recommendations to optimise management of MPS IVA.

METHODS

Twenty six international healthcare professionals across multiple disciplines, with expertise in managing MPS IVA, and three patient advocates formed the Steering Committee (SC) and contributed to the development of this guidance. Representatives from six Patient Advocacy Groups (PAGs) were interviewed to gain insights on patient perspectives. A modified-Delphi methodology was used to demonstrate consensus among a wider group of healthcare professionals with experience managing patients with MPS IVA and the manuscript was evaluated against the validated Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument by three independent reviewers.

RESULTS

A total of 87 guidance statements were developed covering five domains: (1) general management principles; (2) recommended routine monitoring and assessments; (3) disease-modifying interventions (enzyme replacement therapy [ERT] and haematopoietic stem cell transplantation [HSCT]); (4) interventions to support respiratory and sleep disorders; (5) anaesthetics and surgical interventions (including spinal, limb, ophthalmic, cardio-thoracic and ear-nose-throat [ENT] surgeries). Consensus was reached on all statements after two rounds of voting. The overall guideline AGREE II assessment score obtained for the development of the guidance was 5.3/7 (where 1 represents the lowest quality and 7 represents the highest quality of guidance).

CONCLUSION

This manuscript provides evidence- and consensus-based recommendations for the management of patients with MPS IVA and is for use by healthcare professionals that manage the holistic care of patients with the intention to improve clinical- and patient-reported outcomes and enhance patient quality of life. It is recognised that the guidance provided represents a point in time and further research is required to address current knowledge and evidence gaps.

Airway management in patients with mucopolysaccharidoses: The progression toward difficult intubation

BACKGROUND

Patients with mucopolysaccharidoses (MPS) have physical changes to their airways over time. Due to the natural progression of their disease, these patients become more difficult to intubate as they get older.

AIMS

The aims of this study were to evaluate the difficulty of airway management in MPS patients over time, and to evaluate the effect of bone marrow transplant and/or enzyme replacement therapy on airway difficulty.

METHODS

A retrospective review of MPS patients presenting for surgery from January 2012 to May 2018 was performed. Patients were assigned to groups based on their ages at the time of surgery, number of intubation attempts, equipment used for intubation, difficulty of mask ventilation, and difficulty of laryngeal mask airway placement. The same designations were applied to patients with a history of a bone marrow transplant (BMT) and/or enzyme replacement therapy, and they were compared to patients of similar ages who had received no treatment. Logistic regression was used to determine the odds of difficult intubation.

RESULTS

One hundred and twenty-eight anesthetic records were reviewed. In 27 cases, the patient had a BMT and in 54 cases, the patient had received enzyme replacement therapy. Adults (18 years and older) had the highest likelihood of difficult intubation (OR 13.44, CI 1.45-124.86, P = 0.022). Mask ventilation and laryngeal mask airway placement were not significantly more difficult in any age groups. Bone marrow transplant did not improve airway management. A history of enzyme replacement therapy was associated with an increased risk of difficult intubation in patients under the age of 12.

CONCLUSIONS

As patients with MPS get older, there is a progression toward difficult intubation. Mask ventilation and laryngeal mask airway placement does not become more difficult with age. Bone marrow transplantation did not affect airway difficulty in our population, while enzyme replacement therapy was associated with difficult intubations in younger patients.

Recommendations for the management of MPS VI: systematic evidence- and consensus-based guidance

Introduction

Mucopolysaccharidosis (MPS) VI or Maroteaux-Lamy syndrome (253200) is an autosomal recessive lysosomal storage disorder caused by deficiency in N-acetylgalactosamine-4-sulfatase (arylsulfatase B). The heterogeneity and progressive nature of MPS VI necessitates a multidisciplinary team approach and there is a need for robust guidance to achieve optimal management. This programme was convened to develop evidence-based, expert-agreed recommendations for the general principles of management, routine monitoring requirements and the use of medical and surgical interventions in patients with MPS VI.

Methods

26 international healthcare professionals from various disciplines, all with expertise in managing MPS VI, and three patient advocates formed the Steering Committee group (SC) and contributed to the development of this guidance. Members from six Patient Advocacy Groups (PAGs) acted as advisors and attended interviews to ensure representation of the patient perspective. A modified-Delphi methodology was used to demonstrate consensus among a wider group of healthcare professionals with expertise and experience managing patients with MPS VI and the manuscript has been evaluated against the validated Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument by three independent reviewers.

Results

A total of 93 guidance statements were developed covering five domains: (1) general management principles; (2) recommended routine monitoring and assessments; (3) enzyme replacement therapy (ERT) and hematopoietic stem cell transplantation (HSCT); (4) interventions to support respiratory and sleep disorders; (5) anaesthetics and surgical interventions. Consensus was reached on all statements after two rounds of voting. The greatest challenges faced by patients as relayed by consultation with PAGs were deficits in endurance, dexterity, hearing, vision and respiratory function. The overall guideline AGREE II assessment score obtained for the development of the guidance was 5.3/7 (where 1 represents the lowest quality and 7 represents the highest quality of guidance).

Conclusion

This manuscript provides evidence- and consensus-based recommendations for the management of patients with MPS VI and is for use by healthcare professionals that manage the holistic care of patients with the intention to improve clinical- and patient-reported outcomes and enhance patient quality of life. It is recognised that the guidance provided represents a point in time and further research is required to address current knowledge and evidence gaps.

Electronic supplementary material

The online version of this article (10.1186/s13023-019-1080-y) contains supplementary material, which is available to authorized users.

Treatment of thoracolumbar kyphosis in patients with mucopolysaccharidosis type I: results of an international consensus procedure

Background

In all patients with mucopolysaccharidosis type I (MPS I), skeletal disease (dysostosis multiplex) is a prominent, debilitating, condition related complication that may impact strongly on activities of daily living. Unfortunately, it is not alleviated by treatment with hematopoietic cell transplantation (HCT) or enzyme replacement therapy (ERT). Although early kyphosis is one of the key features of dysostosis multiplex, there is no international consensus on the optimal management. Therefore, an international consensus procedure was organized with the aim to develop the first clinical practice guideline for the management of thoracolumbar kyphosis in MPS I patients.

Methods

A literature review was conducted to identify all available information about kyphosis and related surgery in MPS I patients. Subsequently, a modified Delphi procedure was used to develop consensus statements. The expert panel included 10 spinal orthopedic surgeons, 6 pediatricians and 3 physiotherapists, all experienced in MPS I. The procedure consisted of 2 written rounds, a face-to-face meeting and a final written round. The first 2 rounds contained case histories, general questions and draft statements. During the face-to-face meeting consensus statements were developed. In the final round, the panel had the opportunity to anonymously express their opinion about the proposed statements.

Results

Eighteen case series and case reports were retrieved from literature reporting on different surgical approaches and timing of thoracolumbar kyphosis surgery in MPS I. During the face-to-face meeting 16 statements were discussed and revised. Consensus was reached on all statements.

Conclusion

This international consensus procedure resulted in the first clinical practice guideline for the management of thoracolumbar kyphosis in MPS I patients, focusing on the goals and timing of surgery, as well as the optimal surgical approach, the utility of bracing and required additional assessments (e.g. radiographs). Most importantly, it was concluded that the decision for surgery depends not only on the kyphotic angle, but also on additional factors such as the progression of the deformity and its flexibility, the presence of symptoms, growth potential and comorbidities. The eventual goal of treatment is the maintenance or improvement of quality of life. Further international collaborative research related to long-term outcome of kyphosis surgery in MPS I is essential as prognostic information is lacking.

Electronic supplementary material

The online version of this article (10.1186/s13023-019-0997-5) contains supplementary material, which is available to authorized users.

[Rhinosinusitis in Hurler syndrome patients requiring hematopoietic stem cells transplantation]

INTRODUCTION

Allogenic transplantation of hemopoetic stem cells (allo-THSC) is one of the most effective treatment methods for Hurler syndrome, aimed at maximal correction of complications related to the genetic disorder. Presence of infection in the recipient is an adverse risk factor, affecting the possibility of starting the conditioning regimen and THSC peforming in general.

AIM

To assess the condition of the nasal cavity and paranasal sinuses in Hurler syndrome patients before the allo-THSC, dynamics of these changes after the transplantation taking into account the correction of alpha-L-iduronidase enzyme level with donor blood cells.

MATERIAL AND METHODS

From February 2012 to December 2017, In the Raisa Gorbacheva Research Institute of Child Oncology, Hematology and Transplantology of the Pavlov First Saint Petersburg State Medical University, eighteen Hurler syndrome patients (10 girls and 8 boys) received an allo-THSC. Median age at the time of the procedure was 23,5 months (min - 3,4; max - 24,8). Each patient with the shadowing of paranasal sinuses, rhinitis or nasal breathing difficulty received a standard rhinosinusitis treatment before the transplantation, effect of which was insignificant. Symptoms of rhinitis, condition of pharyngeal tonsil and paranasal sinuses were assessed before and auto the allo-THSC.

RESULTS

In the post-allo-THSC, with the correction of alpha-L-iduronidase level each evaluated parameter has improved reliably (p-value < 0,05). Comparative analysis of the condition of the nasal cavity and pharyngeal tonsil before and after THSC was conducted on 14 patients out of 18. Rhinitis symptoms decreased in 9 (64,2%) patients; in 11 patients (78,5%) adenoids size reduced. Comparative analysis of the condition of paranasal sinuses was possible in 12 patients out of 18. Sinuses aeration improved in eight (66,6%) if patients.

CONCLUSION

Nasal cavity and paranasal sinuses changes in Hurler syndrome patients before and after allo-THSC is poorly studied. Our experience demonstrates the normalization of nasal cavity, pharyngeal tonsila and paranasal sinuses symptoms in the majority of the patients receiving allo-THSC. These symptoms are, it seems a consequence of the underlying disease.

ENT and mucopolysaccharidoses

The mucopolysaccharidoses (MPS) are a heterogeneous group of inherited metabolic disorders, each associated with a deficiency in one of the enzymes involved in glycosaminoglycan (GAG) catabolism. Over time, GAGs accumulate in cells and tissues causing progressive damage, a variety of multi-organ clinical manifestations, and premature death. Ear, nose, and throat (ENT) disorders affect more than 90% of MPS patients and appear in the early stage of MPS; also reported are recurrent otitis media and persistent otitis media with effusion, macroglossia, adenotonsillar hypertrophy, nasal obstruction, obstructive sleep apnoea syndrome (OSAS), hearing loss, and progressive respiratory disorders. Undiagnosed MPS patients are frequently referred to otolaryngologists before the diagnosis of MPS is confirmed. Otolaryngologists thus have an early opportunity to recognize MPS and they can play an increasingly integral role in the multidisciplinary approach to the diagnosis and management of many children with MPS. The ENT commitment is therefore to suspect MPS when non-specific ENT pathologies are associated with repeated surgical treatments, unexplainable worsening of diseases despite correct treatment, and with signs, symptoms, and pathological conditions such as hepatomegaly, inguinal hernia, macrocephaly, macroglossia, coarse facial features, hydrocephalous, joint stiffness, bone deformities, valvular cardiomyopathy, carpal tunnel syndrome, and posture and visual disorders.

Anesthesiological risks in mucopolysaccharidoses

Background

Patients suffering from mucopolysaccharidosis are among the most complex from the anesthesiological point of view, especially regarding the management of the airway. The evidence base for anesthesia management is often limited to case reports and small case series.

Aims

To identify useful information about experience with each subtype of mucopolysaccharidosis reported in the literature and propose a guide on the best options for airway management to the anesthesiologists who take care of these patients.

Methods

A query of the PubMed database specific for “anesthesia” and “mucopolysaccharidosis” and a further query specific for “mucopolysaccharidosis and difficult airway management” was conducted. We looked for those items that offered practical guidance to anesthesiological management. We did not exclude case reports, especially those that reported a specific technique, because of their practical suggestions.

Results

We identified 15 reviews, 17 retrospective case series, 5 prospective studies, and 28 case reports that focused on airway managements in anesthesia or had practical suggestions for preoperative evaluation and risk assessment. An accurate preoperative evaluation and the need for an experienced team are emphasized in all the reviewed articles and for each type of mucopolysaccharidosis. Many suggestions on how to plan the perioperative period have been highlighted. Insertion of a laryngeal mask airway generally improves ventilation and facilitates intubation with a fiberoptic bronchoscope. Furthermore, the videolaryngoscope is very useful in making intubation easier and facilitating bronchoscope passage.

Conclusions

Patients with mucopolysaccharidosis are at high risk for anesthesia-related complications and require a high level of attention. However, a multidisciplinary approach, combined with expertise in the use of new techniques and new devices for airway management, makes anesthesiological management safer. Further research with prospective studies would be useful.

Electronic supplementary material

The online version of this article (10.1186/s13052-018-0554-1) contains supplementary material, which is available to authorized users.

Spinal cord issues in adult patients with MPS: transition of care survey

PURPOSE

This study aims to raise awareness of the need for research and appropriate guidelines for managing spinal cord issues in adult patients with mucopolysaccharidosis (MPS) and transition of these patients from pediatric to adult care.

METHODS

Pediatric/adult neurosurgeons, orthopedic spine surgeons, and treating physicians with expertise in metabolic disorders and spinal cord issues were invited to complete a survey to assess their experience with spinal cord problems in MPS and their opinion on transitioning routes from pediatric to adult care.

RESULTS

Twenty specialists completed the survey; 16 had treated spinal cord issues in patients with MPS. Foramen magnum and cervical stenosis (87%), atlanto-axial instability (67%), and lumbar spine instability (33%) were the main spinal cord issues encountered; 28% had treated adult patients for one or more spinal cord issues. In 40% of cases, this concerned an intervention or procedures performed during childhood. The main specialist responsible for the care of adult patients with MPS differed considerably between institutions and included both pediatric and adult specialists (30% pediatric neurosurgeons, 10% pediatric spine orthopedic surgeons, 30% adult spine neurosurgeons, 20% general adult surgeons). The preferred option (> 50%) for the transition of care was an interdisciplinary team of pediatric and adult specialists.

CONCLUSIONS

Further work needs to be done to address problems of managing spinal cord issues in adult patients with MPS. Currently, the responsibility for the care of patients with MPS with spinal cord issues is inconsistent. The best strategy for transitioning these patients from pediatric to adult care is likely an interdisciplinary approach.

Outcomes from 18 years of cervical spine surgery in MPS IVA: a single centre's experience

PURPOSE

This study examines the long-term outcomes of paediatric Morquio (MPS IVA) patients undergoing cervical spine surgery and evaluates the factors that impacting this.

METHODS

A retrospective review was performed on all MPS IVA patients undergoing cervical spine surgery, since the introduction of standardised neuroradiological screening. The impact of preoperative neurological status, growth, genotype and radiological status on outcome is assessed, whilst long-term surgical, radiological and neurological outcomes are documented.

RESULTS

Twenty-six of the eighty-two MPS IVA patients (31%) reviewed underwent cervical spine surgery at a median age of 6.1 years (range, 1.45 to 15.24). Preoperatively, cord signal change was seen in 11 patients with 5 being myelopathic; however, 6 clinically manifesting patients had no overt cord signal change. Postoperatively, none of the 14 preoperatively clinically asymptomatic patients followed long term progressed neurologically during a median follow-up of 77.5 months (range = 18-161). Of the ten preoperatively clinically symptomatic patients who were followed up for the same duration, seven continued to deteriorate, two initially improved and one remained stable. Radiological follow-up performed for a median duration of 7 years (range = 0.5-16) has shown a degree of stenosis at the level immediately caudal to the termination of the graft in 76% of patients, though only one has become clinically symptomatic and required revision.

CONCLUSIONS

Once clinically elicitable neurological signs become evident in patients with MPS IVA, they tend to progress despite surgical intervention. Referring clinicians should also not be falsely reassured by the lack of T2 spinal cord signal change but should consider surgical intervention in the face of new clinical symptomology or radiological signs of progressive canal stenosis or instability.

Posttransplant Cyclophosphamide for HLA-haploidentical Transplantation in Patients With Mucopolysaccharidosis

We successfully used a haploidentical transplantation protocol with posttransplant cyclophosphamide (CY) (50 mg/kg/d on days +3 and +4) for in vivo T-cell depletion in patients with mucopolysaccharidosis using reduced-intensive conditioning regimens, followed by a busulfan-based conditioning regimen, which included busulfan (12 to 16 mg/kg) and fludarabine(150 to 200 mg/m)+rabbit antihuman thymocyte globulin (7.5 to 10 mg/kg) as a conditioning regimen. Cyclosporine or tacrolimus, methotrexate, mycophenolate mofetil, and methylprednisolone were administered to prevent graft-versus-host disease (GVHD). After follow-up for a median period of 1.5 years, all 8 patients without preexisting severe comorbidities and early transplant referrals are alive, with 100% donor chimerism and excellent performance status. Only 1 patient developed chronic GVHD(II). We conclude that posttransplant CY is effective in vivo for T-cell depletion to promote full donor engraftment in patients with mucopolysaccharidosis. In addition, with posttransplant CY, the procedure reduced the rate of GVHD and the cost of transplant and improved the patients' quality of life.

Transnasal adenoidectomy in mucopolysaccharidosis

BACKGROUND

Mucopolysaccharide (MPS) diseases are a heterogeneous group of inherited, metabolic disorders characterized by accumulation of partially degraded glycosaminoglycans (GAG) in multiple organ systems. Due to accumulation in the airway, patients often present with multilevel airway obstruction and obstructive sleep apnoea (OSA). Adenotonsillar surgery leads to a significant improvement in the severity of OSA in MPS patients. However, access to secure the airway and for conventional surgery can be challenging, due to limited neck extension, macroglossia and reduced mouth opening. This study was undertaken to evaluate the role of transnasal microdebridement and radiofrequent plasma ablation (Coblation) in adenoidectomy to treat OSA in patients with MPS and restricted airway access.

METHODS

A retrospective case review was performed including patients with MPS undergoing adenoidectomy for OSA in the period between June 2015 and March 2017. In all cases, either a microdebrider (Gyrus Diablo) or a Coblation wand (EVAC70, Smith&Nephew) was used via a transnasal approach guided by nasendoscopy. The primary outcome was effect upon OSA, measured by sleep oximetry and parental report of benefit. The secondary outcomes were surgical complications and risk factors for persistent OSA after surgery.

RESULTS

A total of nine patients were identified with a mean age of 9 years (range 3-14 years) at surgery. Post-operative sleep study data was available for eight patients (8/9). Six patients (6/8) had improvement in 4% oxygen desaturation index (ODI-4) with a mean of 8.11 pre-operatively (range 2.69-14.0) and 4.99 postoperatively (range 0.68-8.48). ODI-4 did not improve in two (2/8) patients. Irrespective of sleep oximetry results, improvement in OSA-related symptoms was noted by all parents postoperatively. No risk factors for persistent OSA were identified. Furthermore, no complications were noted in this cohort.

CONCLUSION

Transnasal Coblation and Microdebrider adenoidectomy is a safe and effective surgical treatment for OSA in patients with Mucopolysaccharidosis and adenoidal hypertrophy. As lifespan increases for patients with the Mucopolysaccharidoses, greater emphasis is being given to optimising airway management over the longer-term. This technical note describes the novel application of endoscopic techniques for the management of primary adenoidal hypertrophy when transoral access is restricted, or to debulk recurrent disease that would be challenging to remove via the standard transoral route.

Unexpected Exacerbation of Tracheal Stenosis in a Patient with Hunter Syndrome Undergoing Cardiac Surgery

We report unexpected exacerbation of tracheal stenosis during general anesthesia in a 50-year-old patient with Hunter syndrome undergoing cardiac surgery for valvular disease. He had undergone cervical laminoplasty 3 months previously; at that time, his airway had been uneventfully managed. Preoperative flexible fiberoptic laryngoscopy showed a normal upper respiratory tract, but chest computed tomography showed tracheal stenosis that had flattened the lumen. The narrowest part above the tracheal bifurcation was 2 cm long and the anteroposterior diameter was ≤6 mm. Cardiac surgery was uneventfully performed. After weaning from cardiopulmonary bypass, the tidal volume suddenly decreased from 450 to 120 ml at sternal closure. The end-expiratory carbon dioxide pressure increased from 39 to 71 mmHg. Bronchoscopic examination showed that the part of tracheal bifurcation was almost occluded. A tidal volume of 400 ml was obtained after the transesophageal echocardiography probe was removed and the peak inspiratory pressure increased. Although extubation was performed on the second postoperative day, procaterol inhalation and noninvasive positive-pressure ventilation were needed for 3 days because of wheezing and dyspnea. In conclusion, the risk of lower respiratory tract obstruction should be considered during general anesthesia in patients with Hunter syndrome with collapsible tracheal stenosis undergoing cardiac surgery.

Safety of anesthesia for children with mucopolysaccharidoses: A retrospective analysis of 54 patients

BACKGROUND

Complications are common during anesthesia for patients with mucopolysaccharidoses. San Gerardo Hospital (Italy) is a reference center for mucopolysaccharidoses with a dedicated pediatric anesthesia service.

AIMS

This study aims to evaluate the safety of anesthesia for mucopolysaccharidoses patients, describe their anesthetic management at our institution, and assess risk factors for complications.

METHODS

The anesthetic charts of mucopolysaccharidoses patients admitted from January 1999 to December 2014 were retrospectively analyzed. We retrieved patients' demographics; location and type of the procedure; anesthetic approach airway management and occurrence of difficult intubation and complications and outcome at hospital discharge. A generalized linear mixed model was performed to assess risk factors for complications and difficult intubation.

RESULTS

Fifty-four consecutive children were included. The anesthetic charts of 232 procedures (52% radio-diagnostics, 15% orthopedics, 15% ear-nose-throat surgery, 10% neurosurgery, and 8% general surgery) were analyzed. Each patient underwent a median of 4 (1-6) procedures. The median age at the first procedure was 2 (1-5), and overall age was 5 (2-8) years old. One hundred and twenty-five (54%) procedures were performed in remote locations. General anesthesia was utilized for 100 (43%) procedures. No death was recorded. Twenty-one (9%) procedures had respiratory complications. Remote location anesthesia was associated with increased risk for complications (odds ratio 5.405 [1.355-28.571], P = .016). All planned intubations (n = 65) were successful. Nineteen (29%) of those were defined difficult. All emergency intubations (n = 3) failed and were rescued by laryngeal mask airways. Older age was associated with an increased risk of difficult intubation (OR 1.200 [1.019-1.436], P = .028).

CONCLUSION

Patients with mucopolysaccharidoses are at high risk for anesthesia-related complications. Remote location anesthesia is associated with increased risk for complications, and older age is associated with increased risk for difficult intubation.

Perioperative airway management for aortic valve replacement in an adult with mucopolysaccharidosis type II (Hunter syndrome)

We herein report anesthetic management during aortic valve replacement for aortic valve regurgitation in a patient with adult mucopolysaccharidosis type II (MPS type 2) (Hunter syndrome). This disorder is rare and related to the accumulation of a mucopolysaccharide in lysosomes. It affects various organs, including the airways, heart, and central nerves. In children with MPS type 2, the risk of airway obstruction during anesthesia/sedation is high, and the degree of difficulty increases with aging. The patient described herein was a 33-year-old male without mental retardation. Before surgery, trismus, megaloglossia, and the disturbance of cervical vertebral excursion were noted, suggesting difficulties with ventilation/intubation. Anesthesia was induced under sedation/spontaneous respiration. A laryngeal deployment was conducted using a video laryngoscope; however, the Cormack grade was III. Nasotracheal fiber intubation was performed, and airway obstruction occurred. A muscle relaxant was administered, facilitating ventilation. However, subglottic stenosis, which was not detected before the surgery, made the tracheal tube insertion difficult. Aortic valve replacement was performed without complications. A detailed postoperative examination of the airways revealed oropharyngeal soft tissue outgrowth, narrowing of the upper airway, subglottic stenosis, and displacement/circumflex of the airway axis. Either awake intubation or rapid induction can be selected for this patient; however, either way have risks of airway obstruction. It is important that strategies under light anesthesia or incomplete neuromuscular blockade should be avoided for such our patient as suggested in the JSA airway management guidelines. A preoperative multidisciplinary airway assessment and simulation are important.

Anesthesia for patients with mucopolysaccharidoses: Comprehensive review of the literature with emphasis on airway management

Mucopolysaccharidoses (MPS) are rare, inherited, lysosomal storage diseases that cause accumulation of glycosaminoglycans, resulting in anatomic abnormalities and organ dysfunction that can increase the risk of anesthesia complications. We conducted a systematic review of the literature in order to describe the anesthetic management and perioperative outcomes in patients with MPS. We reviewed English-language literature search using an OVID-based search strategy of the following databases: 1) PubMed (1946-present), 2) Medline (1946-present), 3) EMBASE (1946-present), and 4) Web of Science (1946-present), using the following search terms: mucopolysaccharidosis, Hurler, Scheie, Sanfilippo, Morquio, Maroteaux, anesthesia, perioperative, intubation, respiratory insufficiency, and airway. The review of the literature revealed nine case series and 27 case reports. A substantial number of patients have facial and oral abnormalities posing various challenges for airway management, however, evolving new technologies that include videolaryngoscopy appears to substantially facilitate airway management in these patients. The only type of MPS that appears to have less difficulty with airway management are MPS III patients, as the primary site of glycosaminoglycan deposition is in the central nervous system. All other MPS types have facial and oral characteristics that increase the risk of airway management. To mitigate these risks, anesthesia should be conducted by experienced anesthesiologists with expertise in using of advanced airway intubating devices.

Quantitative neuroimaging in mucopolysaccharidoses clinical trials

The mucopolysaccharidosis (MPS) disorders are rare lysosomal storage disorders caused by mutations in lysosomal enzymes involved in glycosaminoglycan (GAG) degradation. The resulting intracellular accumulation of GAGs leads to widespread tissue and organ dysfunction. In addition to somatic signs and symptoms, patients with MPS can present with neurological manifestations such as cognitive decline, behavioral problems (e.g. hyperactivity and aggressiveness), sleep disturbances, and/or epilepsy. These are associated with significant abnormalities of the central nervous system (CNS), including white and gray matter lesions, brain atrophy, ventriculomegaly, and spinal cord compression. In order to effectively manage and develop therapies for MPS that target neurological disease, it is important to visualize and quantify these CNS abnormalities. This review describes optimal approaches for conducting magnetic resonance imaging assessments in multi-center clinical studies, and summarizes current knowledge from neuroimaging studies in MPS disorders. The content of the review is based on presentations and discussions on these topics that were held during a meeting of an international group of experts.

Surgical management of neurological manifestations of mucopolysaccharidosis disorders

The mucopolysaccharidosis (MPS) disorders are ultra-rare lysosomal storage disorders associated with progressive accumulation of glycosaminoglycans (GAGs) in cells and tissues throughout the body. Clinical manifestations and progression rates vary widely across and within the different types of MPS. Neurological symptoms occur frequently, and may result directly from brain damage caused by infiltration of GAGs, or develop secondary to somatic manifestations such as spinal cord compression, hydrocephalus, and peripheral nerve entrapment. Management of secondary neurological manifestations often requires surgical correction of the underlying somatic cause. The present review discusses the surgical management of neurological disease in patients with MPS, including diagnostic imaging. Background information is derived from presentations and discussions during a meeting on the brain in MPS, attended by an international group of experts (April 28-30, 2016, Stockholm, Sweden), and additional literature searches.

Outcome of Combined Mitral and Aortic Valve Replacement in Adults With Mucopolysaccharidosis (the Hurler Syndrome)

We describe 2 adult sisters with type I mucopolysaccharidosis (MPS) who underwent combined mitral and aortic valve replacement for mitral and aortic valve stenosis. One died early postoperatively and the other survived but had a repeat double-valve replacement 1 month after the first. We analyzed previously reported patients with MPS and valve replacement to learn of their outcomes. The study of our 2 patients and those previously reported suggests that valve replacement in patients with MPS should be viewed with extreme caution.

Differences in maxillomandibular morphology among patients with mucopolysaccharidoses I, II, III, IV and VI: a retrospective MRI study

OBJECTIVE

The aims of this study were to analyze the maxillomandibular morphology of patients with mucopolysaccharidosis (MPS) type I, II, III, IVa and VI and to evaluate the craniofacial effect of hematopoietic stem cell transplantation (HCST) in MPS I.

MATERIALS AND METHODS

One hundred head magnetic resonance images were retrospectively analyzed from 41 MPS and 27 control individuals. The width, height and length of the maxilla and mandible were plotted against age and the means of controls, MPS I, MPS II and MPS III were statistically compared. To determine the effect of HSCT in MPS I, jaw morphology was compared between MPS I patients with full donor chimerism versus patients with mixed/no donor chimerism.

RESULTS

Maxillary dimensions were not statistically different between the MPS types. The height and length of the mandible were clearly smaller in MPS I as compared to those in controls, MPS II and MPS III. This was associated with progressive resorption of the mandibular condyles in MPS I, which was also observed in MPS II and VI, but not in MPS III or IVa. Whereas the success of HCST did not affect these changes, mandibular width was significantly smaller in MPS I individuals with full donor chimerism.

CONCLUSION

MPS I individuals have a smaller mandible as compared to control, MPS II and MPS III individuals due to progressive condylar degeneration. These abnormalities are also evident following successful HSCT.

CLINICAL RELEVANCE

Clinicians should be aware of specific differences in mandibular morphology and condylar involvement among the MPS subtypes.

Does orthopaedic surgery improve quality of life and function in patients with mucopolysaccharidoses?

PURPOSE

Mucopolysaccharidoses (MPS) are a group of rare lysosomal storage disorders associated with involvement of multiple organs along with a generalised skeletal dysplasia. Both haematopoetic stem cell transplant and enzyme replacement therapy have improved the outlook for patients while surgery remains high-risk and there is little information on clinical or functional outcome to justify many of the surgical procedures performed. This paper aims to summarise the orthopaedic surgical procedures in MPS patients for which quality of life (QoL) and functional data are available and to describe additional QoL and functional measurement tools of relevance to the assessment of orthopaedic outcomes in MPS.

METHODS

We reviewed the available literature to look for reported outcomes of orthopaedic surgery to lower and upper limbs and the spine. In addition, we describe the general and MPS-specific health measures that might be of relevance to the orthopaedic surgeon.

RESULTS

There is some evidence in the literature that orthopaedic surgery may improve QoL and function in some specific aspects of the MPS condition (in relation to genu valgum, carpal tunnel syndrome and trigger digits); however, the literature is sparse and consists of level 4/5 studies only. Further studies of these conditions should include QoL and functional assessment in order to confirm or refute these reports. In other areas (spine and hip), outcomes are judged largely on radiographic appearances with little clinical correlation and short follow-up; however, one long-term study of function following hip dysplasia surgery suggests poor outcomes. Anaesthetic morbidity/mortality is not insignificant in these complex patients with multi-organ involvement. Careful assessment is required, particularly when there is neurological involvement.

CONCLUSIONS

Orthopaedic surgeons involved with MPS patients should be encouraged to use and report measures of QoL and function with respect to musculoskeletal manifestations and response to surgery, recognising that such assessments in these complex and challenging patients may require a multidisciplinary approach.

Open issues in Mucopolysaccharidosis type I-Hurler

Mucopolysaccharidosis I-Hurler (MPS I-H) is the most severe form of a metabolic genetic disease caused by mutations of IDUA gene encoding the lysosomal α-L-iduronidase enzyme. MPS I-H is a rare, life-threatening disease, evolving in multisystem morbidity including progressive neurological disease, upper airway obstruction, skeletal deformity and cardiomyopathy. Allogeneic hematopoietic stem cell transplantation (HSCT) is currently the gold standard for the treatment of MPS I-H in patients diagnosed and treated before 2–2.5 years of age, having a high rate of success. Beyond the child’s age, other factors influence the probability of treatment success, including the selection of patients, of graft source and the donor type employed. Enzyme replacement therapy (ERT) with human recombinant laronidase has also been demonstrated to be effective in ameliorating the clinical conditions of pre-transplant MPS I-H patients and in improving HSCT outcome, by peri-transplant co-administration. Nevertheless the long-term clinical outcome even after successful HSCT varies considerably, with a persisting residual disease burden. Other strategies must then be considered to improve the outcome of these patients: one is to pursue early pre-symptomatic diagnosis through newborn screening and another one is the identification of novel treatments. In this perspective, even though newborn screening can be envisaged as a future attractive perspective, presently the best path to be pursued embraces an improved awareness of signs and symptoms of the disorder by primary care providers and pediatricians, in order for the patients’ timely referral to a qualified reference center. Furthermore, sensitive new biochemical markers must be identified to better define the clinical severity of the disease at birth, to support clinical judgement during the follow-up and to compare the effects of the different therapies. A prolonged neuropsychological follow-up of post-transplant cognitive development of children and residual disease burden is needed. In this perspective, the reference center must guarantee a multidisciplinary follow-up with an expert team. Diagnostic and interventional protocols of reference centers should be standardized whenever possible to allow comparison of clinical data and evaluation of results. This review will focus on all these critical issues related to the management of MPS I-H.