Decompression of the endolymphatic sac for Ménière's disease gives unpredictable results. This may be because the sac is difficult to identify and decompress accurately without causing surgical trauma.

In order to test this idea, transmastoid decompression was simulated in 5 cadaver half heads and the anatomy of the endolymphatic sac was reviewed in a further 14 specimens.

The endolymphatic sac was found and confirmed by histology in all five simulated decompressions. A newly described feature, a trapezoid thickening of dura, was a useful guide. The review showed that the sac was constant proximally, but variable distally. The posterior semicircular canal, posterior fossa dura and sigmoid sinus are at risk during dissection.

The endolymphatic sac may be identified on inspection by an overlying patch of dura, thereby reducing exploratory dissection. It is best to decompress the sac as far proximally as possible, whilst protecting the posterior semicircular canal.

Tranexamic acid is a synthetic antifibrinolytic drug. It has been widely available for over 40 years, but only recently has it started to be used routinely in many surgical disciplines. For ENT surgeons, epistaxis and post-tonsillectomy bleeding contribute a significant proportion of the morbidity and emergency workload in a general ENT department. Published evidence indicates a potentially helpful role for tranexamic acid in managing epistaxis.

To date, the benefits of tranexamic acid as a prophylactic treatment to reduce the rate and severity of post-tonsillectomy bleeding are less certain. Two recently published pilot studies looking at primary haemorrhage in children and secondary haemorrhage in adults following tonsillectomy suggest that further large, randomised trials should explore the efficacy of tranexamic acid in routine ENT surgery. There are potential reductions in patient morbidity and cost savings if tranexamic acid is found to be efficacious in larger trials.

The adoption of evidence-based practice is fundamental to good medical care; it ensures that intervention is clinically effective and safe. In a world of limited healthcare resources, consideration of cost-effectiveness must, unfortunately, restrict clinicians' choice. The National Institute for Health and Clinical Excellence has, for over 10 years, developed guidance to achieve a national consensus on best practice.

This review describes the Institute's methodology, examines guidance relevant to otolaryngology and presents more recent research to update the evidence.

This second segment of the two-part review summarises several modern high-throughput methods in genomics, epigenetics and molecular biology. Many principles from nucleotide sequencing and transcriptomics can be applied to other high-throughput molecular biology techniques. Specifically, this manuscript reviews: array comparative genome hybridisation; single nucleotide polymorphism arrays; microarray technology, used to study epigenetics; and methodology applied in proteomics. Finally, the review describes current methods for the integration of multiple molecular biology platforms.

Progress in treating human disease in general will require close collaboration with experts in bioinformatics. Improved understanding, by clinicians and physician-scientists in our field, of the concepts presented in both parts of this review will advance diagnosis and therapy for diseases of the head and neck.

Sleep disordered breathing in children causes disturbance in behaviour and also in cardiorespiratory and neurocognitive function. Subtotal tonsillectomy (‘tonsillotomy’) has been performed to treat sleep disordered breathing, with outcomes comparable to established therapies such as total tonsillectomy or adenoidectomy. This review critically assesses the role of subtotal tonsillectomy in a paediatric setting.

The Medline database (1966 to October 2012) was electronically searched using key terms including subtotal or intracapsular tonsillectomy, tonsillotomy, tonsillectomy, paediatrics, and sleep disordered breathing.

Eighteen papers were identified and reviewed. Subtotal tonsillectomy would appear to have an efficacy equal to that of total tonsillectomy for the treatment of sleep disordered breathing, and has significant benefits in reducing post-operative pain and analgesia use. Subtotal tonsillectomy patients appear to have less frequent post-operative haemorrhage compared with total tonsillectomy patients.

In children, subtotal tonsillectomy is associated with fewer post-operative complications whilst having a comparable effect in improving sleep disordered breathing, compared with total tonsillectomy.