Tonsillectomy, with or without adenoidectomy, in both children and adults is worldwide one of the most commonly performed surgical procedures in otorhinolaryngology, and the number is increasing. Alone in Denmark, approximately 8.000 tonsillectomies are performed annually. Although, tonsillectomy on benign indication is considered to be a minor and frequently performed surgical procedure, the operation is associated with significant morbidity. Postoperative pain and post tonsillectomy haemorrhage (PTH) are the most frequent, and PTH is potentially life threatening. In cold steel tonsillectomy, the peritonsillar space is dissected with metal instruments, and bleeding is typically controlled by ligation or electrocautery. This method has been used for the past 50 years, and is considered the "Gold Standard". However, new so-called "hot techniques have been developed. One of these is an impedance-dependent tissue sealer device (BiZactTM). The equipment used for BiZactTM tonsillectomy is EC certificated (CE nr. 00500). The equipment is commonly used for tonsillectomy both internationally and in Denmark, and preliminary results in both adults and children are promising. However, when a gold standard technique is replaced by a new technique, it is recommended that the decision is based on evidence obtained in randomized controlled designs, and preferably as a multicenter study.

Within the scope of the CE marking of the equipment, the purpose of the present study is to conduct a randomized controlled trial (RCT) in order to investigate whether tonsillectomy performed with BiZactTM "hot" technique is beneficial or at least non-inferior compared to the gold standard cold steel technique in terms of affecting the incidence of post-tonsillectomy morbidity, interoperative factors, patient satisfaction, and health related quality of life.

Tonsillectomy, with or without adenoidectomy, conducted in both children and adults is worldwide one of the most commonly performed surgical procedures in otorhinolaryngology, and the number of tonsillectomies has increased over the recent decades. In Denmark, approximately 8.000 tonsillectomies are performed annually. The main indications for surgery are recurrent episodes of acute tonsillitis or upper airway obstruction due to adenotonsillar hypertrophy.

Although commonly performed, tonsillectomy is associated with significant morbidity of which postoperative pain and post tonsillectomy haemorrhage (PTH) are the most frequent. PTH is a major and potentially life-threatening complication of tonsil surgery. Postoperative pain lasts for approximately two weeks, and may in severe cases result in delayed discharge, a visit at the emergency department or readmission for pain control, re-hydration, and treatment of possible underlaying infection. The incidences of PTH vary between 0.3 and more than 10%. This variation may be caused by different definitions of PTH, but also differences in populations and indications. Cold steel tonsillectomy is considered to be the gold standard surgical technique, but several hot techniques including bipolar techniques, diathermy, and coblation have been developed and used for tonsillectomy. Until now these hot instruments have not proven better than the gold standard technique in reducing PTH, and it is recommended, that these hot techniques should be used with caution. Recently, a new Impedance-dependent tissue sealer device (BiZactTM) has been manufactured and approved for tonsil operations (19). Preliminary results are promising in terms of a PTH rate of 4.5%, a shortened operative time in the hands of both experienced and training surgeons with a median time of 5.1 minutes (range 1.5-26.5 minutes), and a reduced intraoperative blood loss between 1-10 milliliters.

Ideally, when a gold standard technique is replaced by a new technique, it is recommended that the decision should be based on evidence provided by RCTs involving several centers.

The aim of the present is to conduct a RCT to investigate whether tonsillectomy performed with a new hot technique (BiZactTM) is beneficial or at least non-inferior to the gold standard cold steel technique in terms of incidence of post-tonsillectomy morbidity, interoperative factors, patient satisfaction, and health related quality of life.

The study design is a double blind, multi-centre randomised controlled trial (RCT).

Patients, assessors, and investigators will be blinded to randomisation outcome.

Patients will be recruited at five Dept. Otorhinolaryngology: Region Hospital West, Holstebro, DK, Southwest Regional Hospital, Esbjerg, DK, Lillebaelt Regional Hospital, Vejle, DK, Southern Regional Hospital, Soenderborg, DK, and Aalborg University Hospital, Aalborg, DK.

A total of 1250 eligible patients referred to tonsillectomy on benign indication, who fulfil inclusion criteria and have signed declaration of consent, will be enrolled and randomised in the study; 625 patients are randomized to surgery performed by steel devices (Cold steel group), and 625 patients to surgery by an electrosurgical device (BiZactTM) (Hot group)

In the "cold steel group" the peritonsillar space is dissected with metal instruments, and bleeding is typically controlled by ligation or electrocautery. In the "hot group" the peritonsillar space is dissected and sealed in one step by a bipolar instrument (BiZactTM). The instrument uses Valley Lab adjustable bipolar energy. Energy is automatically adjusted and delivered to the tissue in order minimize thermal tissue damage and seal blood vessels less than 3mm in diameter while dividing the soft tissue.

An Inter-Rim analysis will be conducted after 650 included patients have fulfilled the study protocol.

In order to strengthen study homogeneity, a pilot-study will initially be carried out with the first ten patients at each of the involved otorhinolaryngology departments.

Randomization is computer generated. Random sequences of 5000 numbers with equal numbers of group assignments will be obtained and concealed at the Tonsil database website (www.tonsil.dk).

Randomisation will be performed automatically by ticking a box on a page of the Tonsil database website.

At the preoperative consultation or at the emergency department, a doctor not involved in the study, will establish registration of the patient in the database and carry out the randomisation.

After the randomisation procedure has been carried out, the outcome will be registered on a hidden page of the Tonsil database website, and it will not be possible to change the outcome. The randomization outcome will only be visible on the web-page from the day of surgery to the day after surgery. Hereafter, it will not be possible to see the randomisation outcome. The operating surgeon will not be able to influence the randomisation outcome.

The investigators hypothesise, that tonsillectomy performed with a bipolar electrosurgical device (BiZactTM) is noninferior to tonsillectomy performed with cold steel technique in terms of affecting postoperative morbidity defined as PTH demanding reoperation with haemostasis and pain.

The present study will elucidate whether tonsillectomy performed with a bipolar electrosurgical instrument BiZactTM induces alleged beneficial effects or at least is noninferior to tonsillectomy performed with cold steel instruments. Moreover, should the study uncover that tonsillectomy performed with a bipolar electrosurgical instrument BiZactTM can reduce postoperative morbidity, frequency of reoperations, as well as surgical time, it may potentially optimise future treatment for patients and reduce socio-economic costs. Thus, the present RCT will be followed with an alongside economic evaluation.

Inclusion Criteria:

• Obstruction/ tonsillar hypertrophy.
• Recurrent tonsillitis, including previous peritonsillar abscess
• Chronic tonsillitis
• Systemic complications to tonsillitis (glomerulonephritis)
• Other (Mononucleosis), PFAPA (Periodic Fever, Aphtous stomatitis, pharyngitis, cervical adenitis)
• Foetor ex ore (tonsillar plugs)
• Peritonsillar abscess (Tonsillectomy a chaud)
• Ability to understand the written patient information and to give informed consent

Exclusion Criteria:

• Diseases in the hematopoietic system
• Antithrombotic or anticoagulant drugs in the recovery period
• Suspicion of/known tonsillar malignancies or other malignancy
• Patients or caregivers unable to read or speak Danish
• Patients or caregivers unable to use online application for self-evaluation