Greater superficial petrosal nerve and its surgical importance: a review

The greater superficial petrosal nerve (GSPN) is an important but often underappreciated branch of the facial nerve. The GSPN is a mixed nerve which contains both sensory and parasympathetic fibers. It serves as the motor root of the pterygopalatine (sphenopalatine) ganglion. GSPN has a long course which passes across the middle skull base between the petrous bone and dura mater and running through the foramen lacerum. It then incorporates to the deep petrosal nerve and crosses along the pterygoid canal to the pterygopalatine ganglion. The postganglionic nerve fibers innervates the lacrimal glands, nasal mucosa and palatal mucosal glands via branches of the zygomatic nerve/zygomaticotemporal branch, sphenopalatine, greater palatine, lesser palatine nerves and pharyngeal nerve. Surgical anatomy of the GSPN nerve is often unfamiliar to many clinicians. As this nerve is usually unrecognized without use of high resolution microscope or endoscope, its anatomical knowledge is essential for surgeons basically otologists and other head and neck surgeon to minimize the risk of injury during surgical intervention. This review article surely increases the precise knowledge of the GSPN including its embryology, surgical anatomy, blood supply, relations with other structures and imaging.

Juvenile Nasopharyngeal Angiofibroma

Juvenile nasopharyngeal angiofibroma (JNA) is a rare benign tumour affecting mostly adolescent and can be malignant because it’s aggressive, destructive, spread locally and often extends to the skull. The exact cause of JNA is unknown. JNA originates from the pterygopalatine fossa at the aperture of the pterygoid canal. Clinical symptoms include nasal obtruction, epistaxis and headaches. The diagnosis is based on anamnesia, physical and radiological examination. CT scan and MRI are the main modalities in detecting and determining tumour stage.

Dissection and Exposure of the Whole Course of Deep Nerves in Human Head Specimens after Decalcification

The whole course of the chorda tympani nerve, nerve of pterygoid canal, and facial nerves and their relationships with surrounding structures are complex. After reviewing the literature, it was found that details of the whole course of these deep nerves are rarely reported and specimens displaying these nerves are rarely seen in the dissecting room, anatomical museum, or atlases. Dissections were performed on 16 decalcified human head specimens, exposing the chorda tympani and the nerve connection between the geniculate and pterygopalatine ganglia. Measurements of nerve lengths, branching distances, and ganglia size were taken. The chorda tympani is a very fine nerve (0.44 mm in diameter within the tympanic cavity) and approximately 54 mm in length. The mean length of the facial nerve from opening of internal acoustic meatus to stylomastoid foramen was 52.5 mm. The mean length of the greater petrosal nerve was 26.1 mm and nerve of the pterygoid canal was 15.1 mm.

Transnasal endoscopic management of angiofibroma extending to pterygopalatine and infratemporal fossae

Introduction:Surgical approaches to the pterygopalatine and infratemporal fossae are complex and cause significant morbidity. The commonest benign tumour to extend to the pterygopalatine and infratemporal fossae is angiofibroma.Patients and methods:This prospective study included 15 male patients aged 12–27 years with recurrent, severe epistaxis. After computed tomography and magnetic resonance imaging, a modified Wormald and Robinson's two-surgeon approach was used. Follow up, with endoscopy and magnetic resonance imaging, ranged from two to five years.Results:Twelve patients were cured (endoscopically and radiologically). Three patients suffered recurrence, one each in the lateral sphenoid wall, pterygoid canal and infratemporal fossa. Revision surgery was performed, but one patient suffered another recurrence (lateral sphenoid wall with cavernous sinus infiltration) and was referred for gamma knife surgery.Conclusion:This endoscopic two-surgeon technique is an excellent approach for managing angiofibroma extending to the pterygopalatine and infratemporal fossae. Our modification markedly decreased morbidity by avoiding septum opening and sublabial incision, and by enabling better haemostasis (via maxillary artery control). Recurrence may be minimised by careful examination of the lateral sphenoid wall, pterygoid canal and infratemporal fossa pterygoid muscles.