Curettage versus other methods of adenoidectomy in children

  • Major change
  • Protocol
  • Intervention

Authors


Abstract

This is the protocol for a review and there is no abstract. The objectives are as follows:

To assess the effectiveness of alternative methods of adenoidectomy with, for example, suction diathermy or power-assisted debridement compared to the standard method of curettage in children (under the age of 16).

Background

Description of the condition

The adenoids are found at the back of the nose in an area known as the nasopharynx, which is above the level of the soft palate and is therefore not visible via oral inspection. They sit in the midline between the Eustachian tubes which connect with and ventilate the right and left middle ears (the area of the ear behind the ear drum). The composition of the adenoids is very similar to that of the tonsils and is known as lymphoid tissue, a part of the body's immune system that helps protect it from bacterial infection and other foreign entities. Together with both palatine tonsils and a tonsil on the back surface of the tongue (the lingual tonsil), they form what is known as Waldeyer's Ring, which is a circle of lymphoid tissue at the top of the upper aerodigestive tract. The main function of this lymphoid tissue is to produce antibodies and the adenoid therefore appears to be important in the development of acquired immunity in young children (Wysocka 2003).

Indications for adenoidectomy 

Adenoids are often removed as a component of another operation such as ventilation tube (grommet) insertion or tonsillectomy. They can also be removed on their own. Currently, indications for adenoidectomy are:

  • enlargement causing nasal airway obstruction, which can result in obstructive breathing, obstructive sleep apnoea symptoms and chronic mouth breathing (Potsic 1986);

  • otitis media with effusion in children aged three to four years and older (MRC Study Group 2003; MRC Study Group 2012); and

  • recurrent and/or chronic rhinosinusitis (Ungkanont 2004).

Description of the intervention

Adenoidectomy is traditionally performed under general anaesthetic, via the mouth, with a specially designed curette which scrapes the pad of tissue away from the back wall of the nasopharynx. The inevitable bleeding is then stopped by packing the nasopharynx for five minutes. Historically, the adenoidectomy curette was designed for quick adenoid removal in awake children in the days before general anaesthesia was in routine use. Traditional curettage adenoidectomy, however, remains in widespread use in the United Kingdom and worldwide. According to Hospital Episode Statistics, in the UK over 6000 adenoidectomies were performed in the financial year 2011-2012 (HES 2011-12). In the USA the proportion per head of population is even greater, with 22 adenoidectomies performed per 10,000 children, equating to 132,000 in 2006 (NSA 2006).

Complications of adenoidectomy include bleeding, velopharyngeal insufficiency, Eustachian tube injury, torticollis and atlanto-axial subluxation from infection. Significant volumes of blood can be lost during surgery (perioperative) and afterwards (postoperative), especially when it is considered that a child has only 80 ml blood per kilogram of body weight. Another disadvantage of curettage adenoidectomy is that the adenoid pad is not routinely seen directly (although some surgeons will use mirror visualisation). This can lead to incomplete removal of the adenoid pad and subsequent potential for regrowth or hypertrophy of the remnant (Buchinsky 2000). This in itself can render the child symptomatic again and even warrant further surgical intervention.

Why it is important to do this review

The theoretical advantages of newer methods of adenoidectomy, such as suction diathermy or power-assisted techniques (Hartley 1998; Heras 1998), are principally a reduction in the risk of perioperative and possibly postoperative haemorrhage (Skilbeck 2007) and secondly that, as the adenoid pad is viewed directly, it can be removed more precisely (Havas 2002). Whether these theoretical advantages lead to an improvement in clinical effectiveness remains uncertain. Moreover, given the increased costs of the newer techniques, in particular with respect to disposable instruments, cost-effectiveness may also be a potential issue.

Objectives

To assess the effectiveness of alternative methods of adenoidectomy with, for example, suction diathermy or power-assisted debridement compared to the standard method of curettage in children (under the age of 16).

Methods

Criteria for considering studies for this review

Types of studies

Randomised controlled trials in which newer methods of adenoidectomy are compared with traditional curettage, regardless of indication. We may consider retrospective reviews to be of benefit in order to define rare adverse events.

Types of participants

Children up to the age of 16 years who have undergone routine adenoidectomy, in a day case or inpatient setting, by any of the methods under investigation, irrespective of indication.

Types of interventions

The main intervention is curettage adenoidectomy with appropriate haemostasis (swabs with or without adrenaline, diathermy). Inappropriate haemostasis would be the placement of a postnasal pack and we would class this as an adverse event.

Comparison interventions are alternative methods (most notably suction diathermy and power-assisted adenoidectomy with appropriate haemostasis as mentioned above).

Types of outcome measures

Primary outcomes
  • Bleeding

    • Perioperative (including volume lost)

    • Primary (during first 24 hours)

    • Secondary (after 24 hours)

  • Adverse effects (examples include nasal discharge or incompetence of soft palate closure - velopharyngeal insufficiency)

Secondary outcomes
  • Duration of surgery

  • Other postoperative complications

  • Effectiveness of adenoid removal (examples include overall success of surgery, such as resolution of nasal obstruction or hypertrophy of residual adenoid tissue causing symptom recurrence or requiring repeat surgery)

  • Parental satisfaction

  • Control of instruments (surgeon satisfaction)

  • Cost-effectiveness

Search methods for identification of studies

We will conduct systematic searches for randomised controlled trials. There will be no language, publication year or publication status restrictions. We may contact original authors for clarification and further data if trial reports are unclear and we will arrange translations of papers where necessary.

Electronic searches

We will identify published, unpublished and ongoing studies by searching the following databases from their inception: the Cochrane Ear, Nose and Throat Disorders Group Trials Register; the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, current issue); PubMed; EMBASE; CINAHL; LILACS; KoreaMed; IndMed; PakMediNet; CAB Abstracts; Web of Science; ISRCTN; ClinicalTrials.gov; ICTRP; Google Scholar and Google.

We will model subject strategies for databases on the search strategy designed for CENTRAL (Appendix 1). Where appropriate, we will combine subject strategies with adaptations of the highly sensitive search strategy designed by The Cochrane Collaboration for identifying randomised controlled trials and controlled clinical trials (as described in theCochrane Handbook for Systematic Reviews of Interventions Version 5.1.0, Box 6.4.b. (Handbook 2011)).

Searching other resources

We will scan the reference lists of identified publications for additional trials and contact trial authors if necessary. In addition, we will search PubMed, TRIPdatabase, The Cochrane Library and Google to retrieve existing systematic reviews relevant to this systematic review, so that we can scan their reference lists for additional trials. We will search for conference abstracts using the Cochrane Ear, Nose and Throat Disorders Group Trials Register and EMBASE.

Data collection and analysis

Selection of studies

We will obtain the full text of studies which appear to meet the inclusion criteria from the initial literature search. Two authors (JFP and JS) will independently apply the inclusion criteria to the studies found and resolve any difference in opinion as to which studies to include by discussion or, failing that, referral to the third author (MH).

Data extraction and management

Two authors (JFP and JS) will independently extract data from the studies using standardised data forms and then enter data into the Review Manager software for statistical analysis (RevMan 2012). We will extract data so as to allow an intention-to-treat analysis. Where data are missing, we will contact the authors of the specific study requesting the missing data.

Assessment of risk of bias in included studies

JFP and JS will assess the risk of bias of all trials independently and resolve differences in opinion by discussion or referral to the third author (MH).

We will assess selected studies for risk of bias using a domain-based evaluation. We will address the following domains:

  • selection bias (random sequence generation and allocation concealment);

  • performance bias (blinding of participants and personnel);

  • detection bias (blinding of outcome assessment);

  • attrition bias (incomplete outcome data);

  • reporting bias (selective outcome reporting);

  • other sources of bias not covered in the other domains.

We will categorise each domain as 'low' risk, 'high' risk or 'unclear' risk of bias. We will take the criteria for making the judgements from the Cochrane Handbook for Systematic Reviews of Interventions (Handbook 2011).

Data synthesis

For this comparative effectiveness review, we are aiming to use intention-to-treat analysis as both arms of the studies will be having an active intervention and hence the potential for adverse events. Studies are likely to compare one single alternative technique with curettage adenoidectomy. If data from different studies are comparable and of sufficient quality then we will combine the data to give a summary measure of effect; if not, however, we will not combine data.

We will perform meta-analysis using the Review Manager software (RevMan 2012) if data are deemed to be of sufficient clinical and statistical homogeneity. We aim to assess for statistical heterogeneity using the Chi2 test and I2 statistic. The Cochrane Handbook for Systematic Reviews of Interventions provides a rough guide to the interpretation of the I2 statistic (Handbook 2011):

  • 0% to 40%: might not be important;

  • 30% to 60%: may represent moderate heterogeneity;

  • 50% to 90%: may represent substantial heterogeneity;

  • 75% to 100%: considerable heterogeneity.

If meta-analysis of included studies is performed, we will use a random-effects model in the presence of statistical heterogeneity (I2 > 50%), if differences in the results are deemed to be of practical importance. Where heterogeneity is felt to be not significant we will use a fixed-effect model.

Our outcome measures are likely to produce both dichotomous (or binary) and continuous data. For dichotomous data (such as the presence or not of postoperative bleeding) we will present our data both in relative terms (risk ratio (RR)) and in more absolute terms (number needed to treat to benefit (NNTB)). For continuous data (such as duration of surgery for each procedure) we will present the data as the mean difference (MD) if the outcome is represented the same way in all included studies. When included studies present outcome data in a variety of ways we will use standardised mean differences (SMD). We will seek statistical advice to establish the best way of presenting and summarising the data.

Subgroup analysis and investigation of heterogeneity

If the data permit then we will carry out analysis separately for different types of surgical intervention. If data are available we will perform subgroup analysis for adult and paediatric cohorts. If there are sufficient data we will carry out a subgroup analysis of any antibiotic regimes at anaesthetic induction, used in conjunction with the surgical interventions.

Acknowledgements

We are grateful to Gemma Sandberg for the design and running of the search strategy.

Appendices

Appendix 1. CENTRAL search strategy

#1 MeSH descriptor: [Adenoidectomy] explode all trees
#2 MeSH descriptor: [Adenoids] explode all trees
#3 adenoid* or adenoidectom* or adenotom* or adenotonsil* or pharyngeal next tonsil
#4 #1 or #2 or #3
#5 MeSH descriptor: [Curettage] explode all trees
#6 curet* or scrape* or scraping
#7 #5 or #6
#8 #4 and #7
#9 MeSH descriptor: [Adenoidectomy] explode all trees and with qualifiers: [Methods - MT]
#10 #8 or #9

What's new

DateEventDescription
8 July 2013New citation required and major changesProtocol revised, updated and republished, with a new contact author (Jean-François Poirier).

Contributions of authors

Co-author tasks will include searching, selection of studies, data extraction, drafting and co-drafting of the protocol/review, assistance with statistics, data analysis and data presentation.

Declarations of interest

None known.

Sources of support

Internal sources

  • None, Not specified.

External sources

  • None, Not specified.

Notes

The original protocol was withdrawn from Issue 11, 2011. In 2013, it was revised, updated and republished, with a new contact author.

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