Functional endoscopic balloon dilation of sinus ostia for chronic rhinosinusitis (Review) pdf

Studies compared either balloon sinus ostial dilation or a hybrid procedure balloon dilation in conjunction with functional endoscopic sinus surgery FESS versus conventional surgery e.g.

Functional endoscopic balloon dilation of sinus ostia for

chronic rhinosinusitis (Review)

Ahmed J, Pal S, Hopkins C, Jayaraj S

This is a reprint of a Cochrane review, prepared and maintained by The Cochrane Collaboration and published inThe Cochrane Library

2011, Issue 7

http://www.thecochranelibrary.com

T A B L E O F C O N T E N T S

1 HEADER

1

2

2

4

5 METHODS

6 RESULTS

8

8

9

9 REFERENCES

11

14 DATA AND ANALYSES

14 ADDITIONAL TABLES

14

15 HISTORY

15

15 DECLARATIONS OF INTEREST

16 SOURCES OF SUPPORT

16

i Functional endoscopic balloon dilation of sinus ostia for chronic rhinosinusitis (Review)

[Intervention Review]

Functional endoscopic balloon dilation of sinus ostia for

chronic rhinosinusitis

Jahangir Ahmed1, Surojit Pal1, Claire Hopkins2, Samuel Jayaraj1

1ENT Department, Whipps Cross University Hospital, London, UK.2ENT Department, Guy’s Hospital, London, UK

Contact address: Jahangir Ahmed, ENT Department, Whipps Cross University Hospital, London, UK.Jayahmed11@hotmail.com

Editorial group: Cochrane Ear, Nose and Throat Disorders Group.

Publication status and date: New, published in Issue 7, 2011.

Review content assessed as up-to-date: 19 December 2010.

Citation: Ahmed J, Pal S, Hopkins C, Jayaraj S Functional endoscopic balloon dilation of sinus ostia for chronic rhinosinusitis.

Cochrane Database of Systematic Reviews 2011, Issue 7 Art No.: CD008515 DOI: 10.1002/14651858.CD008515.pub2.

Copyright © 2011 The Cochrane Collaboration Published by John Wiley & Sons, Ltd

A B S T R A C T Background

Dilation of sinus ostia using a high-pressure balloon has been introduced as a treatment for chronic rhinosinusitis (CRS) refractory to medical treatment The efficacy of this technology, however, has not been systematically reviewed

Objectives

To assess the effectiveness of balloon sinus ostial dilation as a treatment for patients suffering with CRS refractory to medical treatment

Search methods

We searched the Cochrane Ear, Nose and Throat Disorders Group Trials Register; CENTRAL; PubMed; EMBASE; CINAHL; Web

of Science; BIOSIS Previews; Cambridge Scientific Abstracts; ISRCTN and additional sources for published and unpublished trials The date of the most recent search was 20 December 2010

Selection criteria

Randomised controlled trials in patients of any age with rhinosinusitis lasting longer than 12 weeks who have failed a prolonged course

of medical treatment Studies compared either balloon sinus ostial dilation or a hybrid procedure (balloon dilation in conjunction with functional endoscopic sinus surgery (FESS)) versus conventional surgery (e.g FESS) or a waiting list control

Data collection and analysis

Two authors independently selected studies for inclusion, extracted data and assessed risk of bias

Main results

One study (34 patients) met our inclusion criteria although it was not yet a peer reviewed publication The study randomised patients with chronic frontal sinusitis who had failed a prolonged course of medical treatment into two groups: balloon dilatation of the frontal recess (plus conventional FESS of other involved sinuses) versus conventional FESS (Draf type 1/2a procedures on the frontal sinuses)

At 12 months follow up there was no statistically significant difference in radiological resolution of frontal sinuses between the two groups The percentages of directly observed patent frontal recesses at 12 months were 75% in the balloon dilation group versus 63%

in the FESS-only group The authors state that this was statistically significant but details of the analysis were not presented Indeed the study as a whole suffers from a bias in the way its outcome measures were reported

No major complications were reported Three patients in the FESS-only group required further revision frontal sinus surgery compared

to one in the balloon dilation group, although synechiae were more common in the latter

Authors’ conclusions

At present there is no convincing evidence supporting the use of endoscopic balloon sinus ostial dilation compared to conventional surgical modalities in the management of CRS refractory to medical treatment With the escalating use of balloon sinuplasty, there is

an urgent need for more randomised controlled trials to determine its efficacy over conventional surgical treatment modalities

P L A I N L A N G U A G E S U M M A R Y

Balloon dilation of sinus openings for chronic rhinosinusitis

Chronic rhinosinusitis is one of the most common ailments in the world, affecting all age groups and causing significant suffering First-line management of this condition is medical, usually comprising a nasally applied steroid, supplemented with a combination of antihistamines, antibiotics and/or oral steroids Surgical intervention usually becomes necessary if there is failure of a prolonged course

of medical treatment In adults, functional endoscopic sinus surgery (FESS) has become established as the main surgical strategy in these circumstances Recently a new technology, balloon dilation of sinus ostia (sinus opening), has been introduced This is designed

to open up the drainage pathways of the sinuses by the inflation of a high-pressure balloon in the sinus opening We sought evidence in the literature evaluating the effectiveness of balloon dilation of sinus ostia compared to conventional surgical methods in the surgical management of patients of all ages suffering with chronic rhinosinusitis

One unpublished trial met our inclusion criteria This randomised 34 patients with chronic frontal sinusitis into two groups: in one group balloon dilation was used to open up the drainage pathways of the frontal sinuses; in the other group conventional endoscopic sinus surgery was used to do the same For both groups all other sinuses were treated using conventional functional endoscopic sinus surgery Balloon dilation did not show an improvement in the resolution of frontal sinusitis as demonstrated by imaging studies, however the technique was associated with an increased likelihood that someone observing a frontal sinus opening would find this open However, it is not clear whether this was a statistically significant result The study report appeared to be biased in the way it reported its outcome measures At present, therefore, we cannot recommend the use of balloon dilation of sinus ostia over conventional surgical treatment modalities in this setting

B A C K G R O U N D

Description of the condition

Rhinosinusitis is defined as inflammation of the nose and paranasal

sinuses Chronic rhinosinusitis (CRS) is one of the most prevalent

chronic ailments in the Western world, affecting up to 16% of

the adult population (Adams 1999;Blackwell 2002) Although

benign it poses significant personal and societal pressures;

impact-ing on quality of life, schoolimpact-ing and work and leadimpact-ing to immense

economic costs Indeed in the USA, CRS has been estimated to

generate annual health-related costs of more than $5 billion (Gross

2001)

The pseudostratified, ciliated, columnar epithelial mucosa of the

nasal cavities and paranasal sinuses are contiguous through the

si-nus ostia Cilia beat the overlying mucus, which traps foreign

ma-terial and microbes, carrying them out of the sinuses through these

narrow openings onto the lateral nasal wall and from there into the

nasopharynx Mucociliary clearance follows well-defined pathways

in healthy individuals A key anatomical area in this mechanism

is the ’osteomeatal complex’, a common confluent drainage out-flow tract for the frontal, maxillary and anterior ethmoid sinuses Anatomically it comprises the uncinate process which guards the laterally placed three-dimensional ethmoid infundibulum, into which the majority of these sinuses drain

According to the European Position Paper on Rhinosinusitis and Nasal Polyposis (EPOS) (Fokkens 2007), rhinosinusitis is clini-cally defined by two or more symptoms, one of which must be nasal blockage/obstruction/congestion or nasal discharge (anterior/pos-terior nasal drip) Accompanying cardinal symptoms may include facial pressure/pain and alteration in smell Chronicity is differen-tiated by the duration of symptoms Acute symptoms last less than

12 weeks with complete resolution; chronic symptoms persist for more than 12 weeks Symptoms should be supplemented by either endoscopic or computed tomographic (CT) evidence of sinusitis The pathogenesis of CRS remains unclear, but is likely to be the result of an interplay of multiple factors that may be broadly

cate-2 Functional endoscopic balloon dilation of sinus ostia for chronic rhinosinusitis (Review)

gorised into infection (e.g bacterial, including biofilms; viral and

fungal), intrinsic mucosal inflammation (e.g allergy, a

predisposi-tion to an eosinophilic inflammatory response) and impaired

mu-cociliary clearance (Sturgess 1979;Zacharek 2003) In an attempt

to rationalise the plethora of data on aetiology, Timperley et al

pro-posed an “educational” model of CRS whereby this triad of factors

interact with and, importantly, propagate each other, culminating

in a positive feedback spiral of mucosal inflammation (Timperley

2010) Contrary to traditional concepts, it is now widely

acknowl-edged that the underlying anatomy of the sinus drainage

path-ways at best only plays an exacerbating role in CRS and that

long-term reduction in mucosal inflammation is the key to

success-ful resolution (Timperley 2010) Thus, first-line management of

CRS is medical and usually involves a prolonged course of

topi-cal nasal steroids Other meditopi-cal options could include a

combi-nation of antibiotics, antihistamines and systemic steroids There

is evidence of benefit from prolonged courses of macrolide

an-tibiotics (Ragab 2004) and saline nasal irrigation (Harvey 2007)

In addition, leukotriene receptor antagonists may have a role in

the management of patients with an allergic aetiology (Grainger

2006) Indeed for the majority of patients with CRS, first-line

optimal medical therapy appears to be as effective as endoscopic

sinus surgery (Fokkens 2007;Khalil 2006) The latter is therefore

usually reserved for failed medical treatment

Functional endoscopic sinus surgery (FESS) opens up the

si-nus drainage pathways, enhancing mucosal clearance The word

’functional’ emphasises the preservation of normal mucosal

clear-ance via the natural anatomic drainage pathways (Kennedy 1985;

Stammberger 1986) Nowhere is this principle more

impor-tant than in the frontal recess Here, preservation of mucosa is

paramount to prevent restenosis (recurrence of narrowing) and

consequent complex and potentially hazardous revision

proce-dures

The outcome of sinus surgery will be affected by multiple

fac-tors These may broadly be divided into patient factors (including

age, anatomy and comorbidity), factors related to disease

(pres-ence of polyposis, extent of inflammation, previous surgery) and

surgeon experience (Fokkens 2007;Hopkins 2006;Stankiewicz

1989) The Royal College of Surgeons of England conducted a

prospective national audit of sinus surgery performed in the UK

in 2000 (Hopkins 2006) This included 3128 patients from 87

National Health Service (NHS) hospitals in England and Wales

undergoing FESS Major complications, such as orbital

penetra-tion and cerebrospinal fluid leak, occurred in 0.4% whereas minor

ones, mostly excessive perioperative bleeding (but also

postoper-ative infection, stenosis and adhesions), occurred in 6.6%

Com-plication risk was related to disease and patient characteristics as

opposed to techniques used or surgeon experience

Description of the intervention

The concept of dilating an ostium via a high-pressure balloon was originally developed and promoted in the fields of cardiology, vascular surgery and urology It has recently been applied to sinus surgery and termed “balloon sinuplasty”T M (Acclarent Inc., CA, USA) As in these specialties, the Seldinger technique (whereby a catheter is advanced and positioned over a guidewire) is used for balloon placement (Brown 2006) Basic equipment requirements include a sinus guidewire (a stainless steel coated wire with a ’soft’ non-penetrating tip), a sinus delivery catheter; a sinus balloon and an inflation device The delivery catheter, which is specifically designed with regard to its length and angulation for each sinus, is endoscopically positioned at the entrance of the relevant ostium The guidewire is passed through the catheter into the sinus and the balloon advanced over it, positioned to straddle the ostium It is then transiently inflated to a high pressure (up to 12 atmospheres) Rather than excising inflamed tissue and adjacent bone, the bal-loon compresses the mucosa and causes microfracture of the un-derlying circumferential bone The aim of this technology is there-fore to restore the natural sinus drainage pathways in a minimally invasive way; with the hope of preventing the scarring associated with mucosal stripping

Early devices required fluoroscopic confirmation of correct place-ment in the sinus, exposing the patient and surgeon to ionising radiation To avoid this, a guidewire, which houses an optical fibre allowing a high power light to be emitted from the tip has been recently developed The guidewire position is confirmed by trans-sinus illumination when correctly positioned in the frontal and maxillary sinuses

Why it is important to do this review

The published literature on efficacy has to date predominantly been limited to feasibility and safety profiling (Bolger 2007;Kuhn

2008;Levine 2008; Weiss 2008) The ’CLinical Evaluation to confirm sAfety and efficacy of sinuplasty in the paRanasal sinuses’ (CLEAR) study, a multi-centred prospective cohort, included 115 patients (358 sinuses) with CRS that were treated either by balloon sinus ostial dilation alone or a hybrid procedure (Bolger 2007) Ninety-seven percent of the sinuses were successfully cannulated Endoscopic patency at six months was reported at 80.5%, with

a similar figure (85.1%) in those followed up to one year (Kuhn

2008) In the latter study the figure rose to 91.6% if patency was implied by radiological improvement Parallel sustained improve-ments in SNOT(sinonasal outcome test)-20 scores over the same time period were also reported

In Levine et al’s retrospective review of 1036 patients treated at different centres (Levine 2008), 95.5% of patients reported an improvement at initial follow up that was maintained in 73.8%

at a mean follow-up period of 40.2 weeks Impressively for such a large cohort, there were no major complications

Friedman et al performed a retrospective chart review of a co-hort of patients who were given a choice of having either

func-tional endoscopic dilation of sinus ostia (FEDS) or convenfunc-tional

FESS (Friedman 2008) They compared pre and postintervention

SNOT-20 scores in two groups There were 35 patients in each

arm Preoperatively, the SNOT-20 scores were similar (2.8 versus

2.7 respectively), but at three months postoperatively the FEDS

group had a significantly lower score (0.78 versus 1.29, P = 0.006)

Ramadan and Terrell reported a non-randomised study

compar-ing balloon sinus ostial dilation and sinus irrigation (with

ade-noidectomy if enlarged) versus adeade-noidectomy alone for the

sur-gical management of children aged below 12 with CRS who had

failed a prolonged course of medical treatment (Ramadan 2010)

Thirty out of 49 children had a balloon sinus dilation procedure

At an average of one-year follow up, 80% of the balloon dilation

group, in comparison to 52.6% of the adenoidectomy-only group,

reported an improvement in symptoms using the SN-5 scale (Kay

2003) Interestingly 87% (48 of the 55) dilated sinus ostia in the

balloon dilation group were maxillary The author in a different

study with a similar patient cohort had reported an 87.5%

im-provement in patient outcome scores if adenoidectomy was

per-formed in conjunction with maxillary sinus washout mediated by

endoscopic insertion of a needle through the natural ostium This

compared favourably to a 60.7% improvement in the

adenoidec-tomy-alone group (Ramadan 2008) It is therefore unclear whether

in addition to adenoidectomy, balloon sinus ostial dilation adds

any advantage over draining the maxillary sinuses by more simpler

means in children with CRS

The United States Food and Drug Administration (FDA) provided

clearance for the use of “balloon sinuplasty”T Min 2005 (US FDA

2005) The UK followed suit in 2008, when the National Institute

of Clinical Excellence (NICE) approved use of balloon dilation of

paranasal sinus ostia based on the above and other short-term

effi-cacy and safety profiles (NICE 2008) Specific mention was made,

however, of the possibility of a revision to their recommendation

in the light of longer-term follow-up studies

Despite these encouraging preliminary data, the use of balloon

sinus ostial dilation has generated much debate First, there is

doubt about the theoretical premise of its action, i.e opening the

ostia by mucosal and bony compression, as opposed to removing

these diseased entities Indeed in addition to inflamed mucosa,

underlying osteitis may occur in up to 53% of surgical candidates

(Lee 2006) Concern has thus been expressed that foci of retained

pathological mucosa and bone may restimulate inflammation (

Lanza 2006) Proponents of the procedure, however, would argue

that to achieve a positive clinical response, it is not necessary nor

indeed practical to remove every piece of osteitic bone, which

conventional FESS does not do either (Melroy 2008)

The high-pressure compression injury inflicted on the respiratory

mucosal epithelium should recover due to the brief nature of the

application, nevertheless there is a lack of published basic scientific

research confirming this or indeed whether the mucociliary action

of the draining sinus is functionally restored Little is also known

about the consequences of crushing the underlying bone, especially

that surrounding the frontal sinus Kieff et al report a case series where repneumatisation and bony regrowth of concha bollosae (an enlarged air-filled middle turbinate) occurred following a crushing procedure to alleviate middle meatal obstruction; in some cases up

to 15 years after the original procedure (Kieff 2009) The authors relate this observation to balloon dilation of the frontal recess area where the agger nasi and other air cells in the vicinity will inevitably

be crushed It is postulated that there may be similar regrowth and thus restenosis perhaps many years later in this region (Kieff 2009)

In the context of recent insights into the underlying, complex ae-tiology of CRS, the traditional idea that surgery for CRS works by relieving ostial obstruction and thus enhancing ventilation may only be a part of the story Indeed up to 24% to 28% of patients may still be symptomatic in terms of quality of life outcome mea-sures following FESS (Smith 2010) Where successful, FESS may

be so for different reasons Thus an overall reduction of the total inflammatory mucosal surface area and removal of osteitic bone may create new cavities that are more efficient in mass-transport-ing the mucous blanket (Timperley 2010) Furthermore, access of topical agents to the sinus mucosa post-surgery may be the key fac-tor in breaking the positive feedback of inflammation Harvey et

al have demonstrated that conventional FESS certainly improves nasal sinus irrigation in a cadaveric model (Harvey 2008) A sim-ilar effect has yet to be demonstrated in ostial balloon dilation as

a sole procedure

Prominent rhinologists also argue that indications for this technol-ogy at present are relatively sparse (Jones 2006) Clearly it cannot

be used as a sole procedure in nasal polyposis or indeed in fungal sinusitis and neoplasm where pathological clearance is vital Pos-sible other indications for this procedure may include recurrent acute sinusitis, patient preference or in ’at-risk’ surgical candidates (e.g from comorbidities or a bleeding predisposition)

Most studies have used balloon dilation of sinus ostia as an adjunct

to FESS; its use being pertinent to anatomical areas deemed at relatively high risk of iatrogenic stenosis or major complications, the frontal recess for example It will therefore be difficult, using standardised outcome tools, to separate the additional benefits of balloon dilation (and justify its relatively high additional monetary cost) in comparison studies of FESS versus hybrid procedures Directly visualising the patency of individual sinuses will help in this regard, but may not necessarily reflect patient well-being

As balloon dilation of sinus ostia is a relatively novel technology, there are likely to be few, high-level comparative studies in the literature This fact needs to be highlighted with the aim of stim-ulating research of high methodological quality

O B J E C T I V E S

To assess the effectiveness of balloon sinuplasty in the treatment

of chronic rhinosinusitis

4 Functional endoscopic balloon dilation of sinus ostia for chronic rhinosinusitis (Review)

M E T H O D S

Criteria for considering studies for this review

Types of studies

Prospective randomised controlled trials

Types of participants

We applied no age restriction

Inclusion criteria

Patients with a diagnosis of chronic rhinosinusitis as defined by

the EPOS 2007 criteria, i.e two or more symptoms one of which

must be blocked nose or nasal discharge, lasting for longer than 12

weeks with accompanying endoscopic signs and/or CT changes

Patients should have failed a prolonged course of medical

treat-ment and thus be eligible for surgical intervention

Exclusion criteria

We excluded patients with granulomatous disease, sinonasal

ma-lignancy or who have undergone revision surgery

Types of interventions

Studies that include patients who have received balloon sinus

os-tial dilation either solely or as part of a hybrid (balloon dilation/

FESS) procedure after failure of an appropriate course of medical

treatment, versus a control group The latter could be a waiting

list control group or a conventional FESS group

Types of outcome measures

Primary outcomes

• A nasal-specific or quality of life symptom scoring system

Secondary outcomes

• Changes in nasal endoscopic view and/or CT images (these

will be a primary outcome measures in studies comparing hybrid

procedures)

• Documented adverse effects and complications

• A reduction in subsequent maintenance/rescue medication

• The need for subsequent revision procedures

Search methods for identification of studies

We conducted systematic searches for randomised controlled tri-als There were no language, publication year or publication status restrictions The date of the last search was 20 December 2010

Electronic searches

We searched the following databases from their inception for pub-lished, unpublished and ongoing trials: the Cochrane Ear, Nose and Throat Disorders Group Trials Register; the Cochrane Cen-tral Register of Controlled Trials (CENTRAL) (The Cochrane Li-brary 2010, Issue 4); PubMed; EMBASE; CINAHL; LILACS;

KoreaMed; IndMed; PakMediNet; CAB Abstracts; Web of Sci-ence; BIOSIS Previews; CNKI; ISRCTN; ClinicalTrials.gov; IC-TRP (International Clinical Trials Registry Platform) and Google

We modelled subject strategies for databases on the search strategy designed for CENTRAL Where appropriate, we combined sub-ject strategies with adaptations of the highly sensitive search strat-egy designed by the Cochrane Collaboration for identifying ran-domised controlled trials and controlled clinical trials (as described

in theCochrane Handbook for Systematic Reviews of Interventions

Version 5.0.2, Box 6.4.b (Handbook 2011)) Search strategies for major databases including CENTRAL are provided inAppendix

1

Searching other resources

We scanned the reference lists of identified publications for tional trials and contacted trial authors where necessary In addi-tion, we searched PubMed, TRIPdatabase, NHS Evidence - ENT

& Audiology, and Google to retrieve existing systematic reviews relevant to this systematic review, so that we could scan their ref-erence lists for additional trials

Data collection and analysis

Selection of studies

Two authors (JA and SP) independently assessed all potential stud-ies as identified by the search strategy for eligibility, defined above

We obtained full-text articles if the relevant information to enable inclusion/exclusion was not apparent from the title or abstract Disagreements were settled by discussion with all authors

Data extraction and management

JA and SP independently extracted data onto a standardised pro-forma We attempted contact with the corresponding author in trials where data were missing or ambiguous

Assessment of risk of bias in included studies

JA and SP individually assessed the risk of bias for each

poten-tially suitable study We utilised the tool recommended by The

Cochrane Collaboration (Handbook 2011) In summary this

in-volved assessing each study with respect to six domains, namely:

se-quence generation, allocation concealment, blinding, incomplete

data, selective outcome reporting and ’other’ issues For each of

these domains we documented a) a description (verbatim if

possi-ble) of the relevant event and b) an overall judgement of the risk

of bias (low, high or unclear risk of bias) Thus, we obtained a six

by two table for each study As more studies emerge in future, we

may use RevMan 5.1 to generate an overall ’Risk of bias’ graph

and summary figure (Higgins 2011;RevMan 2011)

Data synthesis

We aimed to calculate risk ratio (RR) for studies reporting binary

outcomes and standardised mean difference (SMD) for those

re-porting continuous outcomes The latter takes into account the

use of different outcome scales between studies

Subgroup analysis and investigation of heterogeneity

In subsequent updates we will assess the impact of

heterogene-ity on any meta-analyses we perform using the I2statistic As

de-scribed in the currentCochrane Handbook for Systematic Reviews of

Interventions (Handbook 2011), we will use a fixed-effect model

in the absence of significant heterogeneity Should there be

sig-nificant heterogeneity, this will be explored and if necessary we

will reconsider pooling the data and simply report individual trial

outcomes

Where possible, we will perform subgroup analysis, in the first

instance based on the following patient characteristics: chronic

rhinosinusitis with or without nasal polyposis

R E S U L T S

Description of studies

See:Characteristics of included studies;Characteristics of excluded

studies

See Characteristics of included studies and Characteristics of

excluded studies

Results of the search

We retrieved a total of 75 references from the electronic searches:

40 of these were removed at first-level screening (i.e duplicates

and clearly irrelevant items), leaving 35 references for further con-sideration Eleven published references were deemed to be rele-vant and we retrieved full-text versions of these Following exam-ination of the full text, we excluded all 11 studies (seeExcluded studies) We also identified one as yet unpublished trial which was presented as a poster at the American Academy of Otolaryngology, Head and Neck Surgery annual meeting, Boston, September 2010 (Plaza 2010) The corresponding author kindly provided us with

a manuscript detailing the study, but not the raw data This study met the inclusion criteria for the review

Included studies

The study by Plaza et al was a prospective randomised controlled trial that aimed to evaluate the effectiveness and safety of balloon dilation of the frontal recess in the management of CRS of the frontal sinuses Patients were aged over 18, had CRS including nasal polyposis as dictated by EPOS criteria (Fokkens 2007) with radiological involvement of their frontal sinuses and had failed an eight-week course of medical therapy They were randomly allo-cated to the following surgical treatment arms: 1) balloon dilation

of the frontal recess with conventional FESS for the remaining paranasal sinuses as required (i.e a hybrid procedure); or 2) con-ventional FESS for frontal and other paranasal sinuses as required

In the latter arm, dissection was performed until the surgeon was able to completely visualise the frontal sinus ostium, which in all cases was achieved with Draf type 1 or 2a procedures (seeTable

1for the Draf classification) Postoperative care was the same for both groups and patients were followed up for 12 months Pa-tients were excluded if pregnant or lactating, if they had concur-rent asthma, severe systemic illness (e.g diabetes) or had previous nasal surgery Smokers who smoked more than 20 cigarettes per day were also excluded

The primary outcome measures were radiological grading of the frontal sinuses using the Lund-Mackay staging system and office endoscopic assessment of the patency of the frontal recesses They also recorded a pre and postoperative score on non-validated visual analogue scales of common rhinosinusitis symptoms as well as corresponding scores on a Spanish adaptation of the Rhinosinusitis Disability Index (RSDI) Thirty-four patients were randomised, resulting in 17 in each group

Excluded studies

All 11 of the retrieved published studies were excluded (see sections

Characteristics of excluded studiestable andWhy it is important

to do this reviewfor further details)

In adults, all published studies that collected clinical or radiological outcome data prospectively were limited to uncontrolled, non-randomised case series (Bolger 2007;Brown 2006;Catalano 2009;

Friedman 2008; Levine 2008;Luong 2008;Weiss 2008) The CLEAR study, reported over the course of three papers is the most

6 Functional endoscopic balloon dilation of sinus ostia for chronic rhinosinusitis (Review)

cited of these It followed a cohort of 115 patients from multiple

centres In the face of a 43% loss to follow up (50 of 115 patients),

stable improvements in ostial patency and SNOT 20 scores were

maintained at two years of follow up (Weiss 2008; see also section:

Why it is important to do this review) Catalano et al (Catalano

2009) focused on specifically treating different severities of frontal

sinus disease with balloon dilation of the frontal recess, using CT

changes as the primary outcome measure This study was also

excluded for not having a control group but, in addition, 13 of 20

patients had previously had prior endoscopic sinus surgery

We excluded Levine et al’s multicentre review of 1036 patients as

it was a retrospective uncontrolled review (Levine 2008)

The only published comparative study in adults was that of

Fried-man et al (Friedman 2008) We excluded this study because it was

a retrospective chart review, in which selected patients were given

a choice of interventions and were thus not randomised

Simi-larly in children, the comparative study by Ramadan and Terrell

(Ramadan 2010), although carried out prospectively, lacked

ran-domisation and was thus also excluded

Risk of bias in included studies

See the ’Risk of bias’ table inCharacteristics of included studies

The included study (Plaza 2010) was a prospective, randomised

controlled trial Randomisation was by a computer-generated

se-quence of numbers However, from the manuscript provided, it

was unclear whether patient allocation was adequately concealed,

i.e whether the allocator used a pre-drawn list of random

num-bers The patient and the outcome assessor were blinded to the

intervention arm

No formal calculation was made to determine the sample size to

adequately power the study, although the authors state: “sample

size was estimated considering previous papers on sinuplasty” A

type II statistical error therefore remains a possibility One patient

from each group was lost to follow up Statistical analysis was based

on intention-to-treat

In the poster and manuscript provided, the authors state an

im-provement in visual analogue scale (VAS) and Rhinosinusitis

Dis-ability Index (RSDI) scores at 12 months follow up compared

to preoperatively, although no confirmatory statistics were

docu-mented Furthermore, a comparison between the two treatment

groups in this regard was not made Despite these being secondary

outcome measures, the poster (and manuscript in its current

un-published form) therefore suffers from a ’selective reporting’ bias

Indeed, although there was mention of significance or

non-sig-nificance at P < 0.05 with reference to comparison of the main

outcome variables, the exact figures including confidence intervals

were not disclosed (see Effects of interventions) Unfortunately

the authors did not provide us with the raw data to enable us to

perform further analysis We appreciate that these documents may

not reflect the final version and any changes will be highlighted in

the next update of this review

Effects of interventions

On the basis of the only included study (Plaza 2010), we may only comment in this regard on balloon dilation of the frontal recess Thirty-four patients were randomised to the treatment groups: hybrid versus functional endoscopic sinus surgery (FESS)-only (Draf I/2a), resulting in 17 patients in each group The overall median age of enrolled patients was 41.25 (range 20 to 65) The corresponding age figures were not available per group

Primary outcome measures

Nasal-specific or quality of life symptom scoring system

The authors state that there were no significant differences in vi-sual analogue scale (VAS)/Rhinosinusitis Disability Index (RSDI) scores, measured olfactory thresholds or severity of nasal polyposis between the groups but no figures were provided Sixteen patients

in each group were available for follow up at 12 months

Changes in nasal endoscopic view and/or computed tomography (CT) images in studies comparing hybrid procedures

As this study effectively compared a hybrid procedure with con-ventional FESS, Plaza et al’s main outcome measures were radi-ological and endoscopic appearance of sinus ostia in the

follow-up clinic To this effect, Lund-Mackay scores of the frontal si-nuses fell from a preoperative mean of 1.9 to 0.5 at 12 months

in the hybrid group, with similar figures in the FESS-only group (2 to 0.4) These falls in scores were statistically significant, with

P quoted as < 0.05, but exact figures or confidence intervals were not documented A between-group frontal Lund-Mackay score analysis was not performed, although the authors state that the percentage CT resolution of frontal sinus disease at 12 months (80.95% in the hybrid procedure versus 75% in the FESS-only group) was not statistically significant Endoscopic patency at 12 months was quoted as “statistically more frequent after balloon treatment (75% versus 63%; P < 0.05)” Unfortunately no other data or analysis were provided Due to lack of raw data, no sub-group analysis was possible

Secondary outcome measures

Documented adverse effects and complications

No major complications were reported Synechiae were reportedly more common in the hybrid group but “not statistically” No further details of complications were available

A reduction in subsequent maintenance/rescue medication

The study made no reference to this outcome

The need for subsequent revision procedures

Three patients in the FESS-only group required further revision

frontal sinus surgery compared to one in the hybrid group

D I S C U S S I O N

Summary of main results

We felt that although the study by Plaza et al (Plaza 2010) is

yet to be peer reviewed and published and despite the lack of

available raw data it was important to include it in this review

This is the first prospective, double-blind, randomised controlled

trial assessing the efficacy of balloon sinus ostial dilation, in this

case for the management of chronic frontal sinusitis refractory to

medical therapy

With regard to the FESS-only treatment arm, the philosophy of

their approach in dealing with this difficult anatomical area is a

widely accepted one, i.e to perform the least invasive procedure

that enables restoration of physiological drainage (Kuhn 2006),

with more complex procedures reserved for failure of simpler ones

(Kuhn 2006;Lee 2010) In some large case series over 80% of

patients have been successfully managed by endoscopic frontal

si-nusotomy (equivalent to Draf type 1/2 procedures) as the primary

surgical intervention, although they were performed in tertiary

re-ferral centres with a high level of expertise (Chan 2009;Chandra

2004;Philpott 2010) Indeed in one series of 717 frontal sinus

procedures, 92% of patients were effectively managed by a Draf

2a procedure (Hahn 2009) By comparison, in the CLEAR study

(Kuhn 2008) the patency of frontal sinuses treated by balloon

di-lation was 85% (63/74) at a follow-up period of one year

The strengths of the current study are independence from

cor-porate sponsorship, a high-quality methodology, a relatively long

follow up and a low attrition rate In terms of radiological

reso-lution of frontal sinusitis at 12 months postoperatively, there was

no significant difference between a hybrid procedure as compared

to conventional FESS There was a stated significant difference in

endoscopic patency at this time interval, but the treatment effect

appears to be relatively small (75% versus 63%)

However, the overall quality of the trial does suffer, mainly due to

a ’selective reporting’ bias, with a conspicuous absence of

compar-isons of symptom scores between the groups and a lack of much of

the numerical data and statistical analysis Furthermore, the group

sizes were possibly not large enough to detect a true difference in

frontal sinus radiological scores (i.e the trial was not adequately

powered) Pre-trial sample size calculations should always be per-formed where relevant statistical data are available from the litera-ture A minimum effect size or ’minimum clinically important dif-ference (MCID)’ will need to be defined and the study adequately powered (usually at 80%) to detect this minimum difference With regards to quality of life outcome scores, validation across many quality of life instruments consistently appears to place the MCID

at 0.5 times the standard deviation (SD); assuming normality of the distribution of the measured outcome parameter (Norman

2003) As an example, in one multicentred cohort of patients with chronic rhinosinusitis (CRS), the standard deviation (SD) of the RSDI scores in untreated patients was 20.7, giving a MCID of 10.35 (0.5 x 20.7) (Smith 2010;Soler 2010) A total of 128 pa-tients (64 in each arm) will be required in a study with a power

of 80% to detect an MCID of 0.5 times the SD of the measured outcome parameter (calculated using one of the many statistical packages freely available on the internet (Dupont 1990)) This number is relatively large and may require co-operation between multiple centres to achieve

The distribution of the ’total’ Lund-Mackay scores of patients with CRS is also normally distributed and can thus be described with

a mean and SD score In the UK National Comparative Audit of Surgery for Nasal Polyposis and Chronic Rhinosinusitis (Hopkins

2007) the mean and SD of pre-operative Lund-Mackay scores of

1840 patients were 11 and 6.5 The MCID for radiological scoring has not been validated and quality of life symptom scores only weakly correlate with radiology (Hopkins 2007), nevertheless 0.5

x SD is a statistically acknowledged ’moderate’ size effect that is a useful guide in designing an adequately powered study

All other prospective studies in adults lacked a control arm and thus by their very nature can only confirm safety and feasibility The only other comparative study in adults was retrospective and non-randomised Likewise in the paediatric population, a study comparing adenoidectomy with or without balloon sinuplasty suf-fered from being non-randomised

A U T H O R S ’ C O N C L U S I O N S Implications for practice

The only completed randomised controlled trial to date which has assessed the efficacy of balloon dilation of sinus ostia was the study by Plaza et al (Plaza 2010) The study revealed no significant difference in radiological resolution of a balloon dilation/hybrid (with FESS) procedure compared to conventional functional en-doscopic sinus surgery (FESS-only) in the management of chronic frontal sinusitis refractory to medical treatment The authors do report a statistically significant improvement in endoscopic pa-tency, but as mentioned the study in its currently presented form suffers from a significant risk of bias, particularly in the reporting

of outcome measures and statistical analyses Bearing in mind that

8 Functional endoscopic balloon dilation of sinus ostia for chronic rhinosinusitis (Review)