We report the anaesthetic management of a patient with Proteus syndrome, a rare disease, recently found to be caused by a mosaic somatic mutation of the serine-threonine protein kinase AKT1.1 Proteus disease is characterised by progressive, asymmetric, patchy overgrowth of diverse tissues of all germ layers. Commonly, the clinical signs are not obvious at birth, but appear gradually during the first few months of life and rapidly progress through childhood.2
Thus far, a handful of cases have reported difficult airway management in patients with Proteus disease.3–5 In this case report, we attempt to describe the peculiar upper airway anatomy of a patient with Proteus disease, the anaesthetic airway management and a review of the existing literature. We confirm that written informed consent for publication of the clinical details and pictures has been given by the mother.
Our patient was a 31-year-old man scheduled for surgical removal of a nasal mass that was obstructing breathing. During maxillofacial examination, multiple deformities were found, including macrocephaly, significant right hemimandibular hyperplasia, bossing of the skull in the right frontal area, right facial hemihypertrophy (bigger right ear, nostril, bones and soft tissues) and mandibular prognathism. In the oral cavity, gingival hyperplasia, hypoplastic, haphazardly arranged teeth, reduced tongue mobility and an open mouth at rest were seen.
Physical and clinical examination of the spine revealed severe thoracic and cervical kyphoscoliosis (Fig. 1a). More specifically, the cervical spine was immobile and displayed scoliosis to the left, fixed hyperflexion of its lower part and fixed hyperextension of its upper part. Additionally, there was lipoatrophy of the extremities and the right leg had been amputated because of extreme hypertrophy. Other Proteus syndrome characteristic features were enlarged hands with cerebriform connective tissue nevi and macrodactyly of the fingers. The patient had some degree of intellectual disability and was receiving antiepileptic treatment. Prior to the age of 16, he had received general anaesthesia several times without any record of difficult airway. He had had multiple operations on the right leg, removal of a right enlarged tonsil, removal of an epithelioma of the left testicle, right mastoidectomy for mastoiditis and surgical removal of brain temporal abscess.
The operation of nasal mass removal was attempted 2 weeks earlier in a different hospital, but did not occur because of failed intubation. After induction of general anaesthesia, the Macintosh, the McCoy and a video laryngoscope (GlideScope video laryngoscope, Verathon Medical, Burnaby, British Columbia, Canada) were used in succession, but visualisation of the epiglottis or the glottis, was not feasible. The patient was manually ventilated, allowed to wake up and the surgical procedure was rescheduled.
In our institution, a preoperative fibre-optic evaluation of the upper airway was performed in the Otorhinolaryngology department. The endoscope was inserted through the patient's oral cavity, with the patient awake and tolerating the procedure. The epiglottis had unusual characteristics (Fig. 1b). It was elongated, tubular, ‘ω’ shaped, was retroflexed, projecting into the oropharynx, leaning on the posterior pharyngeal wall and had a right to left deviation.
A fibre-optic orotracheal intubation with sedation and spontaneous breathing was planned. After bypassing the uvula with the fibre-optic bronchoscope, the tip of the epiglottis was eventually recognised at the left pharyngeal area. The fibre-optic bronchoscope was guided with difficulty under the tubular retroflexed epiglottis and was advanced with a left to right direction until the glottis was visualised. The shape of the vocal cords and arytenoids was normal. It was advanced through the vocal cords in the trachea and a size 6.0 endotracheal tube was inserted over it. The surgical removal of the nasal mass was performed successfully and the patient was extubated uneventfully.
There are a handful of case reports of patients with Proteus syndrome undergoing surgery, where difficulty was encountered with airway management. Sinha and colleagues,3 report a 22 year old female with an elongated hanging epiglottis which necessitated the use of the McCoy laryngoscope for intubation. Pennant and Harris4 report a 14-year-old boy with fibre-optic endotracheal intubation, which revealed an enlarged and thickened epiglottis (direct laryngoscopy was performed after intubation, but it was not possible to visualise either the epiglottis or any structure distal to the uvula). Pradhan and colleagues,5 report a 7-year-old boy with an enlarged epiglottis that blocked laryngeal view and endotracheal intubation was accomplished using the McCoy laryngoscope.
However, there are several publications about patients with Proteus syndrome undergoing surgical procedures without reporting any difficulties with endotracheal intubation. Proteus disease is extremely rare; affected patients often need orthopaedic, reconstructive plastic surgery, genitourinary, gastrointestinal, otolaryngological or tumor excision procedures.6 Most of these surgical procedures though, are performed in toddlers and children. Thereafter, we could presume that the alterations of the airway anatomy in patients with Proteus disease are mild or nonexistent in toddlers and become more prominent with ageing.
The factors contributing to a difficult airway in patients with Proteus disease include the asymmetry of facial bones and soft tissues, facial hemihypertophy, gingival hyperplasia, cervical vertebral anomalies (scoliosis and fixed torticollis) and suboptimal positioning of the patient because of severe thoracic kyphoscoliosis.
As mentioned by Tosi and colleagues,7 cervical curves are rare in idiopathic scoliosis, but they are common in Proteus disease. The diagnosis of cervical scoliosis in Proteus disease is typically accompanied by elongation and vertebral body distortion and severe impairment of neck mobility. This deformity can anatomically distort both the spinal canal and the trachea. The combination of cervical scoliosis and right facial hemihypertrophy could be responsible for the right to left deviation of the epiglottis.
In conclusion, patients with Proteus disease could present progressively, increasing difficulty with airway management. The disproportionate overgrowth and disfigurement characterising the disease could be combined with progressive alterations of the patients’ airway. The patients’ previous record of multiple general anaesthetics without any difficulties could mislead the anaesthetist. Preoperative fibre-optic evaluation of the upper airway, helps planning a safe intubation strategy. Malformation of the epiglottis should be expected.
Acknowledgements relating to this article
Assistance with the case report: we would like to thank Dr Nikolaos Papadimitriou Consultant Otolaryngologist, for the provision of the preoperative fibre-optic upper airway video.
Financial support and sponsorship: None
Conflicts of interest: none.
1. Lindhurst MJ, Sapp JC, Teer JK, et al. A mosaic activating mutation in AKT1 associated with the Proteus syndrome. N Engl J Med
2. Cohen MM Jr. Proteus syndrome review: molecular, clinical, and pathologic features. Clin Genet
3. Sinha C, Gupta B, Kaur M, et al. Proteus syndrome: a medical rarity. Saudi J Anaesth
4. Pennant JH, Harris MF. Anaesthesia for Proteus syndrome. Anaesthesia
5. Pradhan A, Sen I, Batra YK, et al. Proteus ayndrome: a concern for the anesthesiologist. Anesth Analg
6. Sethi D. Proteus syndrome: what the anesthetist should know. J Clin Anesth
7. Tosi LL, Sapp JC, Allen ES, et al. Assessment and management of the orthopedic and other complications of Proteus syndrome. J Child Orthop