Neurofibromatosis is an autosomal dominant disorder characterized by the formation of ectodermal and mesodermal tumors which can be divided into two groups with different clinical manifestations:

• Neurofibromatosis 1

• Neurofibromatosis 2 

Neurofibromatosis 1 was first described in 1882 by Frederich von Recklinghausen and became known as von Recklinghausen’s disease. It presents no correlation with gender or ethnicity and has an incidence of 1 in 2500-3000 people per year throughout the world. The genetic mutation on chromosome 17 expresses the gene NF-1, which produces the defective neurofibromin protein in lower quantities. Neurofibromin plays a role in the control of cell division and tumor suppression. Seven characteristics have been identified for diagnosing Neurofibromatosis 1:

• Six or more café-ou-lait spots > 5 mm in children or > 15 mm in post-puberty

• Two or more neurofibroma of some type, or a plexiform neurofibroma

• Axillary or inguinal freckles

• Optical gliomas

• Two or more Lisch nodules

• Distinct bone lesions

• First degree relative with Neurofibromatosis 1

The diagnosis is established with the presence of 2 or more of these characteristics. 

Neurofibromatosis 2 occurs less frequently than type 1, with an incidence of 1 in 33000 - 40000 cases. It is an  autosomal dominant disease, with genetic mutations on chromosome 22. Neurofibromatosis 2 affects both ectodermal and mesodermal tissues, and all systems of the body may be involved, similar to Neurofibromatosis 1. Neurofibromatosis has fundamental implications for anesthesiologist due to its broad clinical spectrum and multisystem involvement. Bulky neurofibromas in and around airway makes anesthetic management more difficult.

Figure 1: Cervical Neurofibromas Causing Restricted Neck Mobility in A Patient with Neurofibromatosis

Case Report

37-year-old-male, weight 54 kg, K/C/O Neurofibromatosis diagnosed with symptomatic cholelithiasis was posted for elective open cholecystectomy. Pre anesthetic and physical examination revealed bulky neurofibromas in cervical region along with axillary and inguinal freckling. Patient had H/O removal of neurofibromas in 1998 under local anesthesia after     which     there   was    gradual    increase in size of  neurofibromas. There was no H/O similar complaints in the family. All laboratory parameters and concerned investigations were within normal limits. On airway assessment MPS was grade III, edentulous, decreased buccal fat with large cervical neurofibromas causing restricted neck mobility with no H/O dysponea, dysphagia, voice change and symptoms suggesting spinal cord compression.

Difficult airway implications were discussed with patient and attendents and endocrionologist opinion was also taken preoperatively. Difficult airway cart was kept ready on day of surgery and patient was taken in OT with all standard monitoring (SpO2, NIBP, ECG, TEMPERATURE) attached. 

Pre-induction vitals were WNL. I/V/O anticipated difficult airway leading anesthetist decided to do video laryngoscope guided check laryngoscopy under local anesthesia (10% lignocaine spray) and sedation (Inj. glycopyrolate 0.2mg iv, Inj. midazolam 1mg iv, Inj. Fentanyl 50 mcg iv). Vocal cords were visible on check laryngoscopy and post induction airway was secured with stylet guided CETT of 8mm ID under video laryngoscopy. Patient was maintained with nitrous oxide in oxygen with isoflurane.

Intra operative course was uneventful. Anesthesia was reversed with Inj. Neostigmine, inj. gylcopyrolate and patient was extubated fully awake. Patient shifted to PACU without any postoperative complications.

Approximately 5% of patients of NF-1 present manifestations of the disease in oral cavity which may provide hindrance to conventional orotracheal intubation making awake fiberoptic as a gold standard approach. Vertebral deformities and spinal neurofibromas make spinal and epidural techniques extremely difficult. Multisystemic involvement in Neurofibromatosis-1 requires special attention to I/O findings such as HTN related pheochromocytoma or renal artery stenosis along with identification of difficult airway predictors, therefore need arises for complete systemic assessment before selecting any anesthetic technique.

Although difficult airway remains a major challenge for anesthesiologist, a detailed pathological and clinical knowledge of neurofibromatosis is needed so that a systemic approach to perioperative assessment of these patients can result in rationale perioperative management. 

Conflict of Interest

Nil.

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