Functional endoscopic sinus surgery for chronic rhinosinusitis
Abstract
This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:
The aim of this review is to assess the effectiveness of functional endoscopic sinus surgery as a treatment for patients with chronic rhinosinusitis.
Background
The normal physiologic functioning of the sinuses depends on patency of the osteomeatal unit, normal mucociliary transport and normal quantity and quality of secretions. A popular hypothesis for the development of chronic rhinosinusitis is that environmental factors, such as allergens, viruses or air pollutants, stimulate the epithelium to induce local inflammation of the sinus mucosa. The resulting mucosal oedema leads to ostial obstruction, retention of secretions followed by bacterial proliferation. In response to inflammation, the lining epithelium may become metaplastic and ciliary dysfunction ensues, perpetuating the condition. Various local factors such as nasal polyps, adenoid vegetations, dental infections and sinonasal tumours can predispose to sinusitis. A wide variety of systemic factors may contribute to the pathogenesis of chronic rhinosinusitis including allergy, cystic fibrosis, primary ciliary dyskinesia, and immune deficiency (Naclerio 2001).
Rhinosinusitis is a well‐recognised clinical syndrome affecting patients of all ages and gender. Sinusitis is defined as a condition manifested by inflammation of the mucous membranes of the nasal cavity and paranasal sinuses, fluids within these cavities and/or the underlying bone. Chronic rhinosinusitis is sinusitis lasting more than 12 weeks. Chronic rhinosinusitis is diagnosed by the presence of two or more of the following major factors: facial congestion/fullness, nasal obstruction, nasal discharge (purulent) or discoloured postnasal drainage, hyposmia/anosmia, or one major and two of the following minor factors: headache, halitosis, fatigue, dental pain, cough, or ear pressure/fullness. The diagnosis is also made in the presence of purulent nasal drainage on clinical examination (Lanza 1997).
Rhinosinusitis is a very common disorder. It is estimated that it affects more than 30 million Americans of all ages (NIH data book 1990). A survey of 1200 households in Nottingham, UK revealed that 13.7% had rhinosinusitis in the previous year (Jones 1998).
Bacteria can be recovered in most cases of chronic rhinosinusitis, most commonly consisting of Staphylococcus species, anaerobes, and in some cases, gram‐negative bacteria. Increasing trends toward bacterial resistance have been identified in chronic rhinosinusitis (Bhattacharyya 2002). Fungal rhinosinusitis is thought to be a spectrum of pathologic conditions associated with sinonasal inflammation that is related to the presence of fungi. It is broadly classified into extramucosal (noninvasive) and invasive forms (Dhong and Lanza 2001). Naylor suggests a role for fungi in the pathogenesis of all cases of chronic rhinosinusitis (Naylor 2000).
There are various staging systems for rhinosinusitis. The Lund and Mackay staging is one example and includes a score for symptoms on a visual analogue scale, endoscopic and CT scores as well as a score for each individual step of the endoscopic surgical technique (Lund and Mackay 1993).
Medical therapy is the primary treatment modality for patients with chronic rhinosinusitis in the form of antibiotics and topical nasal steroids. Conventional sinus surgical techniques used to treat chronic sinusitis included antral lavage, external, intranasal and transantral ethmoidectomy, external frontal sinus surgery and the Caldwell‐Luc procedure (Kennedy 2001).
Over the past two decades the surgical management of rhinosinusitis has completely changed. This is due to technical advances in endoscopic systems and the recognition of the importance for normal sinus function of mucociliary flow and ventilation through the anatomical ostia. Functional endoscopic sinus surgery (FESS) is a minimally invasive technique in which sinus air cells and ostia are opened under direct visualisation. The goal of this procedure is to restore sinus ventilation and normal function (Stammberger 1991).
The relative risks of sinus surgery have been a subject of controversy for many years. In 1912, Mosher stated that intranasal ethmoidectomy is one of the most dangerous of all surgical operations (Mosher 1912). In the modern endoscopic era, major and devastating complications continue to occur from time to time. Complications related to FESS include bleeding, orbital haematoma, damage to intraorbital structures, epiphora, loss of vision, cerebrospinal fluid leak, damage to intracranial structures and death. Several large series quote a very low complication rate suggesting that this procedure can be done safely (Jones 1995). Stankiewicz has shown the importance of surgical experience in reducing the risk of complications from endoscopic sinus surgery (Stankiewicz 1989; Stankiewicz 1991).
FESS has now become a well‐established technique for the treatment of chronic rhinosinusitis refractory to medical treatment. Enthusiasm for FESS, 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 (Richards 1999). There is however a conspicuous lack of good scientific evidence of the comparative efficacy of this intervention
Objectives
The aim of this review is to assess the effectiveness of functional endoscopic sinus surgery as a treatment for patients with chronic rhinosinusitis.
Methods
Criteria for considering studies for this review
Types of studies
Randomised controlled and controlled clinical trials.
Types of participants
Inclusion criteria
Any of the below singly or in combination:
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Patients with chronic rhinosinusitis diagnosed by a health professional
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Patients with sinusitis symptoms more than 12 weeks
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Endoscopic evidence of sinusitis
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Radiological evidence of sinusitis
Exclusion criteria
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Immune suppression
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Cystic fibrosis
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Wegner's disease
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Previous sinus surgery
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Sinonasal malignancy
Types of interventions
Functional endoscopic sinus surgery solely or as an adjunct treatment will be compared with medical treatment alone or alternative types of sinus surgery (e.g. antral washout, intranasal antrostomy, intranasal and transantral ethmoidectomy, external ethmoidectomy, frontal sinus procedures, Caldwell‐Luc procedure etc.) with or without medical treatment.
Types of outcome measures
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The primary measure of clinical outcome will be a global change in clinical status (e.g. cured, much improved, worse etc.) or a reduction in symptoms score.
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Secondary outcome measures will include a change in nasal endoscopic findings, documented radiological change in the appearance of the paranasal sinuses, a change in the microbiological flora of the nasal/paranasal sinus secretions (bacteriological cure and relapse rates), and use of postoperative medical treatment.
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Adverse effects/complications. Complication rates will be calculated where applicable to facilitate comparison of treatments.
Search methods for identification of studies
The reviewers will adopt the following detailed search strategies:
1. The Cochrane ENT Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (1966 ‐ ) and EMBASE (1974 ‐ ) will be searched using a topic search strategy to identify the relevant randomised controlled and controlled trials using a combination of controlled vocabulary and free text terms based on the following:
CENTRAL (CCTR)
(MeSH terms appear in upper case and are exploded. Free text terms appear in lower case).
#1 SINUSITIS
#2 rhinosinusitis
#3 nasosinusitis
#4 sinusitis
#5 pansinusitis
#6 ethmoiditis
#7 antritis
#8 sphenoiditis
#9 (kartagener* near syndrome)
#10 (inflamm* near sinus*)
#11 (#1 or #2 or #3 or #4 or #5 or #6 or #7 or #8 or #9 or #10)
#12 CHRONIC DISEASE
#13 chronic*
#14 persist*
#15 (#12 or #13 or #14)
#16 (#11 and #15)
#17 ENDOSCOPY
#18 endoscop*
#19 uncinectomy
#20 antrostomy
#21 antrotomy
#22 ethmoidectomy
#23 sphenoidotomy
#24 SURGERY
#25 (sinus* next surg*)
#26 fess
#27 (#17 or #18 or #19 or #20 or #21 or #22 or #23 or #24 or #25 or #26)
#28 (#16 and #27)
#29 SINUSITIS [su]
#30 (#15 and #29)
#31 (#28 or #30)
(Strategies are suitable for OVID implementations of Medline/Embase)
MEDLINE
1.exp sinusitis/
2.rhinosinusitis.tw.
3.nasosinusitis.tw.
4.sinusitis.tw.
5.pansinusitis.tw.
6.ethmoiditis.tw.
7.antritis.tw.
8.sphenoiditis.tw.
9.(kartagener$ adj1 syndrome$).tw.
10.(inflamm$ adj2 sinus$).tw.
11.or/1‐10
12.exp chronic disease/
13.chronic.tw.
14.persist$.tw.
15.or/12‐14
16.11 and 15
17.exp endoscopy/
18.endoscop$.tw.
19.uncinectmy.tw.
20.antrostomy.tw.
21.antrotomy.tw.
22.ethmoidectomy.tw.
23.sphenoidotomy
24.exp surgery/
25.(sinus adj surg$).tw.
26.fess.tw.
27.or/17‐26
28.16 and 27
29.exp sinusitis/su
30.15 and 29
31.28 or 30
EMBASE
1.exp sinusitis/
2.rhinosinusitis.tw.
3.nasosinusitis.tw.
4.sinusitis.tw.
5.pansinusitis.tw.
6.ethmoiditis.tw.
7.antritis.tw.
8.sphenoiditis.tw.
9.(kartagener$ adj1 syndrome).tw.
10.(inflamm$ adj2 sinus$).tw.
11.or/1‐10
12.exp Chronic Disease/
13.chronic$.tw.
14.persist$.tw.
15.or/12‐14
16.11 and 15
17.exp chronic sinusitis/
18.16 or 17
19.exp endoscopic surgery/
20.endoscop$.tw.
21.uncinectomy.tw.
22.antrostomy.tw.
23.antrotomy.tw.
24.exp ethmoidectomy/
25.ethmoidectomy.tw.
26.sphenoidotomy
27.exp surgery.tw.
28.(sinus$ adj surg$).tw.
29.fess.tw.
30.or/19‐29
31.18 and 30
32.exp chronic sinusitis/su
33.31 or 32
2. The review authors will manually search the reference lists of journal articles and proceedings of meetings. This will include the bibliographies of identified randomised controlled and controlled trials as well as review articles.
3. Two experts in the field will be contacted to review the bibliography.
Language
Non‐English papers will be included.
Unpublished Studies
Personal contacts will be used to identify ongoing or unpublished randomised controlled and controlled trials.
Data collection and analysis
STUDY SELECTION
Verification of the eligibility of the studies identified by the search will be performed prior to data extraction. The titles and abstracts (when available) of all trials identified will be scanned independently by the two reviewers. Articles that clearly do not meet the inclusion criteria will be excluded. The full articles will be obtained for studies that appear to meet the inclusion criteria or where there is insufficient data in the title or abstract to make a decision. In case of disagreement regarding eligibility of a study, the opinion of a third reviewer will be sought
Studies excluded at the outset as well as at subsequent stages will be recorded in the table of excluded studies, and the reason for exclusion recorded.
DATA COLLECTION
All studies meeting the inclusion criteria will undergo validity assessment and the data will be extracted. Data will be extracted independently by the two reviewers and synthesised descriptively using an electronic data collection form based on a Microsoft Excel spreadsheet.
For each trial the following data will be recorded:
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Source of trial (published article, proceeding, unpublished data)
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Year of publication, country of origin, setting, source of funding
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Demographic patient details
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Rhinosinusitis severity based on pre‐operative endoscopy, CT‐scan or surgical findings
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Type of intervention with details
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Surgery: component surgical elements, surgical extent scores
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Antibiotics: generic details, dose and treatment duration
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Steroids: route/s, generic details, dose and treatment duration
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Type of outcome reported with details of method of assessment and time intervals
QUALITY ASSESSMENT
The methodological quality of the included studies will be independently assessed by the two reviewers using the scheme described in the Cochrane Handbook.
Studies included in the review will have four components of quality assessed:
1. Randomisation and allocation concealment
This will be recorded in the data collection form as:
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Adequate
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Unclear
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Inadequate
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Not used
2. Blinding
This will be recorded as present or absent.
3. Reporting of participants by allocated group (intention to treat)
This will be assessed as: A) Yes B) No.
4. Follow up of participants (Is there a clear explanation of withdrawals and drop outs in each treatment group?)
This will be assessed as: A) Yes B) No.
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DATA ANALYSIS
The following primary comparisons will be made:
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FESS versus medical treatment
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FESS versus conventional sinus surgery
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FESS + medical treatment versus medical treatment
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FESS + medical treatment versus conventional sinus surgery + medical treatment
Subgroup analyses will be performed if data allow:
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Surgical treatment (surgical sub‐site/s operated on, surgical endoscopic findings or another index of rhinosinusitis severity)
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Medical treatment (antibiotics, topical steroids or systemic steroids either alone or in combination)
Studies will be summarised as a 'weighted treatment effects' as follows:
1. Binary outcomes will be expressed as a relative risk/odds ratio with 95% confidence intervals;
2. For continuous data the mean differences (with 95% confidence intervals) will be given.
Heterogeneity among the studies will be explored by looking into types of participants, interventions, outcome measures used and time intervals. Sensitivity analyses will be performed in order to investigate the influence of concealed randomisation, and outcome assessor being blind on the assessment of the overall estimates of effects. In addition, the effects of any subgroups and the effect of including unpublished literature on the review's finding will be examined.
