Advice
Clinical and technical evidence
Clinical and technical evidence
A literature search was carried out for this briefing in accordance with the interim process and methods statement. This briefing includes the most relevant or best available published evidence relating to the clinical effectiveness of the technology. Further information about how the evidence for this briefing was selected is available on request by contacting mibs@nice.org.uk.
Published evidence
Three studies are summarised in this briefing.
All of the studies use an intraoperative study design, meaning that the patient acted as their own control, with the study intervention in one sinus and the control intervention in the other. In 2 studies (Murr et al. 2011 and Han et al. 2012) the control was a PROPEL stent alone in the contralateral and in 1 (Smith et al. 2016) it was surgery alone. These studies suggest that the gradual release of mometasone furoate into the sinus cavity through its impregnation in a stent provides better clinical outcomes than a stent alone.
Overall assessment of the evidence
The evidence seen was of a good standard. However, a number of limitations were identified for which further research and evidence would be useful for decision makers. No evidence from a UK perspective was identified, with all the studies taking place in the US. There is little evidence comparing PROPEL to alternative stents, nasal packaging, and corticosteroids. Follow-up periods were relatively short and would benefit from research with longer follow up looking at the need for repeat surgery, stents and other interventions, and longer-term quality of life.
Murr et al. (2011)
Study size, design and location
Intraoperative double-blind randomised trial of 43 adults (86 sinuses) with chronic rhinosinusitis. Patients received the intervention in one nostril and the comparator in the other. Patients were scheduled to have primary or revision endoscopic sinus surgery (ESS) and sinus stents were deemed feasible and appropriate for them. They were recruited prospectively in 4 otolaryngology–head and neck surgery centres in the US.
All interventions were in the ethmoid sinus.
Intervention and comparator(s)
Intervention: PROPEL.
Comparator: non-drug-eluting spacer, a further small subset (non-randomised, n=5) received bilateral drug-eluting stents to assess systemic safety.
Key outcomes
Compared with the control, PROPEL produced a statistically significant reduction in inflammation at days 21 to 45 (p<0.003), frequency of polyp formation (p=0.0391), and frequency of significant adhesion (p=0.0313). Inflammation scores were higher in the PROPEL group at 7 days, and lower (but not by a statistically significant amount: p>0.05) at days 14 and 60. There was also a reduced frequency of middle turbinate lateralisation, but this was not statistically significant. All stents were successfully deployed. There were no device-related adverse events.
Strengths and limitations
The comparator was the PROPEL stent, so it is possible to see the additional benefits from the addition of mometasone furoate. A non-randomised cohort of 5 people was also included to assess the systemic safety of the stent and mometasone furoate. The size of this population was not based on any power calculations but on clinical judgement and previous animal studies.
Han et al. (2012)
Study size, design and location
Meta-analysis of 143 adults having endoscopic sinus surgery refractory to medical management. They were enrolled onto 2 trials: a pilot study (Murr et al. 2011) and the ADVANCE II study (Marple et al. 2012) involving 7 and 11 centres respectively in the US.
The trials were intraoperative (patients received intervention in 1 nostril and comparator in the other) double-blind randomised trials.
Key outcomes
Significant adhesions, defined as dense or severe by clinical investigators, which are a measure of need for surgical lysis, were present in 4.2% of patients treated with PROPEL and 14.1% of patients treated with the control (p=0.0013). Middle turbinate lateralisation occurred in 2.1% of the sides treated with PROPEL and 8.4% in the control (p=0.0225). Need for postoperative intervention was 32.8% for PROPEL and 50.8% for the control (p=0.0008). PROPEL was similarly effective on this measure when compared by polyp and non-polyp. The rate of surgical interventions for adhesion was 14.2% for PROPEL and 29.1% for the control (p=0.0016). The need for steroid intervention for recurrent inflammation was 22.1% for PROPEL and 37.2% for control (p=0.0023). The rate of frank polyposis was 19.8% for PROPEL and 36.9% for control (p<0.0001).
Strengths and limitations
Most outcomes were based on the judgements of an independent panel. Because both nostrils received a stent it is possible to see the impact of mometasone furoate. However, it is not possible to compare the effects against no treatment or topical application of anti-inflammatories. A number of the authors in the original trials were employees of the company.
Smith et al. (2016)
Study size, design and location
Prospective, randomised, blinded trial using an intrapatient control design of 80 adults. Participants were scheduled to have primary or revision bilateral ESS and had evidence of bilateral frontal sinus disease based on computed tomography in 11 investigation centres in the US.
Intervention and comparator(s)
Intervention: PROPEL.
Control: surgery alone (in contralateral side).
Key outcomes
The primary outcome of the study was the need for postoperative intervention in the frontal sinus opening (including debridement and steroid intervention) at 30 days assessed by an independent blinded reviewer. This was 38.8% for PROPEL and 62.7% for the control (p=0.007). When this result was adjusted for a potential confounding effect of 3 people who received oral steroids before the 30-day follow up the differences remained statistically significant (p=0.0107). Need for postoperative interventions at 30 days on the treatment side based on clinical investigator assessment was 16.5% for PROPEL and 41.8% for the control (p<0.0001). The differences remained significant at 90 days (p=0.0129). The need for oral steroid interventions and surgical intervention (based on clinical observation) were also significantly lower for the PROPEL side (p=0.0015 and p=0.0225 respectively).
Strengths and limitations
This was a reasonably large study that provides a useful comparison to sinus surgery alone. The design makes it difficult to determine to what extent the improvement in outcomes were due to the stent, or to slow release of corticosteroids. However, intranasal steroid sprays were allowed from 14 days post surgery. The company provided funding for the study and a number of the authors were consultants for the company.