For patients with moderate to severe sensorineural hearing loss a new implantable device became available in Britain last year.^1,2 The Vibrant P (programmable) and HF (high frequency) Soundbridges (Symphonix)work by increasing the amplitude of natural ossicular vibration.³ They achieve this through a floating mass transducer attached to the long process of the incus (fig (fig2).2). The transducer, a hermetically sealed titanium bobbin wrapped in gold wire, contains a magnet (the floating mass) that moves back and forth according to the frequency and amplitude of the sound signal. It is driven by an electronic processor unit, which is connected to it by a fine wire. The processor unit modulates an electrical signal delivered by a receiver implanted in the skull just behind the ear. The external component of the system is held on the side of the patient's head by a magnet and concealed behind the hairline. It contains a microphone, battery, and the electronics to convert sound energy into a signal that can be transmitted to the internal receiver. Because this device directly drives the ossicular chain, auditory feedback is eliminated. Furthermore, the ear canal is not occluded by a mould.

Some patients are inherently unsuitable for such a device—for example, those with chronic middle ear disease. Early results with this new technology are encouraging but, like any other implanted device, several years must pass before a final verdict can be made on its robustness and long term effects on the middle and inner ear. Nevertheless, it is an exciting development for patients who are fit for surgery, conform to audiometric criteria, have realistic expectations of possible gain, and cannot use conventional aids. Totally implanted devices are being developed with microphones beneath the skin and transcutaneously rechargeable power sources.

New technology is also helping patients with neurofibromatosis type 2. This disease causes bilateral acoustic neuromas, which over time destroy hearing completely. Some neuromas remain small for many years; others grow inexorably and need to be removed. It is not uncommon for the only hearing ear to be the one with the larger tumour. Resection usually destroys hearing in that ear. Until recently, people deafened by neurofibromatosis type 2 had to rely on signing and vibrotactile aids for communication. However, a multichannel auditory brainstem implant has now been developed. The device is fitted at the time of tumour resection into the lateral recess of the fourth ventricle, where it stimulates the cochlear nucleus. The electrode array is connected to a receiver and stimulator unit, which is sited like a conventional cochlear implant in the temporoparietal region of the skull. A microphone, speech processor, and transmitter coil are worn externally.

Modifications to stapling guns have led to renewed interest in Dohlman's procedure. In this endoscopic technique, the bridge of tissue between the pouch and oesophagus was divided by diathermy or, more recently, a carbon dioxide laser. Despite encouraging results in published series,⁹ the technique has not gained popularity in the United Kingdom because of unacceptable rates of recurrence and postoperative neck infections. The introduction of linear cutting stapling guns that divide the partition between pouch and oesophagus while sealing the edges has overcome these problems.¹⁰

Enthusiasm for functional endoscopic sinus surgery, engendered by a plethora of reports of short term success, has been justified more recently by the publication of long term postoperative results which show a continued trend towards subjective improvement of symptoms in most patients.¹³ Although complications have been reported, they are no worse than with traditional techniques of sinus surgery.¹⁴ Detailed analysis of postoperative results has shown that scarring and adhesions in the region of the maxillary and frontal sinus ostia and middle turbinate are the main cause of symptomatic obstruction of the sinus outflow tract.^14–16 Strategies to minimise scarring and the formation of synechiae have been devised. These include meticulous surgical technique; partial resection of the middle turbinate; use of tissue glues, spacers, and stents for dressings; and regular postoperative endoscopic toilet. Without doubt, minimising trauma to tissues and preserving normal mucosa are of paramount importance. New instrumentation has been developed to achieve this. The microdebrider is an electrically powered endonasal suction tool which contains a small rotating blade capable of excising polyps, mucosa, and even bone. It has been shown to aid preservation of the mucosa and middle turbinate and decrease the incidence of synechiae.¹⁷

Two other complications experienced with functional endoscopic sinus surgery have spawned new management techniques. Firstly, cerebrospinal fluid leaks from defects in the anterior skull base have long been recognised as a possible complication of sinus surgery. They also complicate fractures of the cranial base and sometimes develop spontaneously. Leaks which failed to close spontaneously were managed by a craniotomy with intradural repair. Nowadays endonasal approaches are preferred.^18,19 The defect in the cranial base is often identified by computed tomography. Exact localisation can be facilitated by injecting a small amount of fluorescein into the lumbar theca. This stains the cerebrospinal fluid a yellowish green, which can then be seen flowing from the site of the leak during surgical exploration. Pedicled or free mucosal grafts derived from the nasal cavity have been used to seal these defects, and closure is achieved in about 95%. More importantly, these results have been accomplished with minimal morbidity. Secondly, an endonasal approach has been developed using the holmium yttrium-aluminium-garnet laser as an alternative to dacryocystorhinostomy for the management of epiphora, mucocoeles, and acute dacryocystitis. The procedure can be performed under local anaesthesia as a day case.²⁰ It avoids a facial scar, any disruption of the medial canthal ligament, and also hospital admission for general anaesthesia.