Suction diathermy adenoidectomy

2.1 Indications and current treatments

2.1.1 Adenoidectomy is usually carried out in children, for conditions including nasal obstruction, recurrent otitis media with effusion and obstructive sleep apnoea. Depending on the indication, it is often combined with tonsillectomy and/or grommet insertion.

2.1.2 Traditional adenoidectomy is carried out by 'cold' curettage. A potential problem with this technique is persistent bleeding, which may require control by electrocautery or packing of the nasopharynx.

2.2 Outline of the procedure

2.2.1 Suction diathermy adenoidectomy (also known as suction electrocautery or suction coagulation) aims to remove the adenoids while minimising intraoperative blood loss and risk of secondary haemorrhage. It involves the use of heat generated by an electric current to ablate or liquefy adenoid tissue, which is then removed using suction.

2.2.2 The procedure is performed with the patient under general anaesthesia. Direct (using a mirror) or endoscopic visualisation is used. A suction diathermy probe (coagulator) is passed into the mouth and applied to the adenoid tissue in the nasopharynx, to liquefy and remove it. The procedure is considered to be complete when the choanae are clearly visible and the nasopharynx has a smooth contour.

2.2.3 Several different devices are available for this procedure, which may require different diathermy settings to minimise the risk of heat damage.

2.3 Efficacy

2.3.1 A meta-analysis of 2252 patients reported a subjective success rate (definition varied for each study) for 1812 patients treated by suction diathermy across 6 studies of 95% (1721/1812; 95% confidence interval [CI] 92.7 to 97.3; p < 0.001).

2.3.2 A randomised controlled trial of 100 patients treated by suction diathermy or by curettage reported that suction diathermy-treated patients had significantly fewer Wormald and Prescott grade 3 remnant adenoids than patients treated by curettage at 6-month follow-up (p = 0.0184) (scale ranges from grade 1 [less than one third of the posterior choanae are obstructed] to grade 3 [more than two thirds of the posterior choanae are obstructed]).

2.3.3 A prospective audit of 126 patients treated by suction diathermy or by curettage used a scale from 0 (best) to 6 (worst) to measure nasal obstruction, loudness and frequency of snoring, duration of coloured rhinorrhoea and presence of irregular sleep patterns. It reported significantly lower mean postoperative symptom scores after both treatments (0.4 and 0.7, respectively) compared with mean preoperative scores (3.3 and 3.0, respectively) (p < 0.001 for both groups). No significant difference in mean symptom score change from baseline was reported between the 2 treatment groups (absolute figures not stated) (p = 0.07).

2.3.4 The Specialist Advisers listed key efficacy outcomes as reduced blood loss (especially important in small children), completeness of adenoidectomy and relief of symptoms (for example, infection and obstructive sleep apnoea).

2.4 Safety

2.4.1 In the meta-analysis of 2522 patients treated by suction diathermy or curettage, mean intraoperative blood loss was 4.31 ml (95% CI 0.4 to 8.2; p = 0.03; 5 studies, n = 359) and 24.00 ml (95% CI 0 to 48.3; p = 0.052; 3 studies, n = 139), respectively.

2.4.2 A non-randomised controlled trial of 149 patients reported no (0/77) postoperative bleeding episodes in patients treated by suction diathermy compared with 10% (7/72) in those treated by curettage (p < 0.001). In the prospective audit of 126 patients, secondary bleeds (defined in the paper as pink-stained nasal discharge) were reported in 4% (3/68) of patients treated by suction diathermy and in 2% (1/58) of those treated by curettage (no intervention required).

2.4.3 Postoperative neck stiffness was reported in a non-randomised controlled trial of 276 patients treated by suction diathermy, curettage, or microdebrider adenoidectomy to have occurred in 9% (8/93), 10% (8/84) and 17% (17/99) of patients, respectively (p = 0.08, not stated if 'overall' or pair-wise comparison).

2.4.4 Grisel's syndrome was reported in 1 patient in the retrospective study of 1206 patients and 1 patient in a case report. One of these patients had torticollis and type I atlantoaxial subluxation which resolved in 3 weeks and the other patient had a reduced range of neck movement at 9-month follow-up. Retropharyngeal fluid collection resulting in neck stiffness and low-grade fever was reported in 1 patient in the retrospective study of 1206 patients.

2.4.5 Cervical osteomyelitis was reported in 1 patient after suction electrocautery, in a case report: this resolved completely after 4 weeks of medical therapy.

2.4.6 Velopharyngeal insufficiency (improper closing of the soft palate against the posterior pharyngeal wall during speech and swallowing) was reported in 16 patients in the case series of 1206 patients: this resolved within 6 months in all but 1 patient, in whom it persisted for more than 2 years. The prospective audit reported that 4% (3/68) of patients treated by suction diathermy had transient velopharyngeal insufficiency compared with 7% (4/58) of patients treated by curettage: it resolved in all 7 patients within 2–4 weeks.

2.4.7 The Specialist Advisers considered theoretical adverse events to include Grisel's syndrome, thermal damage or burns to the nasopharynx and surrounding structures from diathermy, scarring and infection.