Abstract
Objectives
The aim of the present prospective, randomized, double-blind, and placebo-controlled investigation (approved by the Ethical Committee of Padova University Hospital [Italy]) was to assess the effect of a nasal gel containing a combination of silver sucrose octasulfate and potassium sucrose octasulfate (Silsos gel® [SG]) in wound healing after endoscopic sinus surgery (ESS) for chronic rhinosinusitis in terms of: nasal symptoms (SNOT22), endoscopic appearance of the sinonasal mucosa (Lund–Kennedy score), nasal air flow (anterior active rhinomanometry), evidence of mucosal inflammatory processes (nasal cytology and histology), and microbiological growth.
Methods
Thirty-four patients with chronic rhinosinusitis were randomized on a 1:1 ratio to receive after ESS either SG or placebo (contained only the excipients [carbopol and propylene glycol] in the same concentrations as in SG).
Results/conclusions
Judging from the present prospective investigation on patients who underwent ESS for chronic rhinosinusitis, treatment with SG seems to enable a significantly faster improvement in specific symptoms (assessed on the validated SNOT22 scale) than placebo. Patients treated with SG also had a quicker improvement in the endoscopic appearance of their nasal mucosa after ESS than patients treated with placebo. These endoscopic improvements in the SG group were also confirmed at the long-term follow-up, while the same did not apply to the placebo-treated group.
1
Introduction
Chronic rhinosinusitis (CRS) is a common disorder that affects more than 31 million people in the United States every year . It is characterized by inflammation of the nasal and paranasal sinus mucosa leading to symptoms such as nasal blockage and nasal discharge lasting more than 12 weeks. The precise definition of CRS was recently revised by Epos 2012 . The condition encompasses two clinically distinguishable phenotypes: CRS without nasal polyposis (CRSsNP), and CRS with nasal polyposis (CRSwNP). Its etiology and pathogenesis are still under debate . Bacteria, viruses, fungi, various cells and proteins, superantigens and biofilms are all believed to have important and often converging roles in this disorder . Treatment for CRS targets infection and inflammation . Medical treatment is necessarily the first approach . If this fails, then surgery – including endoscopic sinus surgery (ESS) – should be considered .
Wound healing after sinonasal surgery is a highly organized process involving inflammation, cell proliferation, matrix deposition or remodeling, and it is regulated by a variety of growth factors . Although some aspects of the nasal mucosa repair mechanisms occurring after sinonasal surgery remain unclear , several medical approaches have been proposed for managing sinonasal inflammatory reactions after ESS .
Silsos gel® (SG) (Interalia S.r.l., Padova, Italy) is a medical device containing silver sucrose octasulfate (IASOS; US7183315, EP1458733) in association with potassium sucrose octasulfate (KSOS), sodium hyaluronate, propylene glycol, carbomer, and water. Silver is quite well known for its antimicrobial properties against a broad spectrum of pathogens, including Gram-positive bacteria, fungi, and viruses . IASOS can inhibit microbial biofilm formation and destabilize the polymeric matrix once the biofilm has formed . KSOS has a carbohydrate-based microbial anti-adhesion effect. Given the combined properties of IASOS and KSOS, SG is believed to restore the nasal mucosae, reinforce tropism by activating fibroblast growth factor pathways, and facilitate mucosal decongestion and hydration . In addition, sodium hyaluronate reportedly has a physical capability for moisturizing and promoting healing.
As very little clinical information is available in the literature on the role of nasal medications in wound healing after ESS, the aim of the present prospective, randomized, double-blind, placebo-controlled investigation was to assess the effect of a combination of IASOS and KSOS after ESS in terms of: (i) nasal symptoms as measured by means of the Sino-Nasal Outcome Test 22 (SNOT22) ; (ii) endoscopic appearance of the sinonasal mucosa (using the Lund–Kennedy score ); (iii) nasal air flow resistance measured by Anterior Active Rhinomanometry (AAR); (iv) evidence of inflammatory processes investigated by means of nasal cytology and histological examination of nasal mucosa specimens; (v) microbiological growth.
2
Methods
2.1
Ethical considerations
The present investigation was a prospective, randomized, double-blind, placebo-controlled study conducted in accordance with the 1996 Helsinki Declaration. The study protocol was approved by the Ethical Committee of Padova University Hospital (Italy) (protocol 2429P, 12/01/12). Written informed consent was obtained from each patient before starting any study-related procedures.
2.2
Study design
The main inclusion criteria were as follows: age ranging from 18 to 65 years; diagnosis of CRS with or without nasal polyps not responding to medical therapy; no contraindications to general anesthesia and ESS. Exclusion criteria were prior sinonasal surgery, autoimmune disease, cystic fibrosis, pregnancy, women of fertile age not taking contraceptives, diabetes, sinonasal malignancy, and hypersensitivity to any ingredient in the device under consideration or the placebo. Before surgery (T0) all patients underwent SNOT 22, nasal endoscopy, computed tomography (CT) scan, basal AAR, nasal cytology, and nasal swab with microbiological culture. An anterior ethmoid mucosa biopsy was taken during ESS. After discharge, all CRSsNP and CRSwNP patients, regardless of disease severity, were randomly assigned to use either SG or placebo, 2 sprays in each nostril twice a day for 1 month after surgery. The placebo contained only the excipients (carbopol and propylene glycol) in the same concentrations as in SG. The containers were identical and indistinguishable for both patients and investigators. All patients were scheduled to be assessed 15 days (T15), 30 days (T30), and 90 days after surgery (T90). The investigation protocol is summarized in Table 1 .
| SNOT 22 | AAR | CYTOLOGY | ENDOSCOPY | MICROBIOLOGICAL SWABS | BIOPSY | |
|---|---|---|---|---|---|---|
| T0 | X | X | X | X | X | X |
| T15 | X | X | X | X | ||
| T30 | X | X | X | X | X | |
| T90 | X | X | X | X | X | X |
2.3
Study population
Thirty-four consecutive adult patients (27 males, 11 of them with CRSsNP; 7 females, 3 of them with CRSsNP) were eligible and enrolled in the investigation.
2.4
Nasal symptoms
SNOT 22 is a validated, disease-specific tool for measuring health-related quality of life in patients suffering from CRS. It was used to underscore the impact of CRS on patients’ quality of life, and to measure the outcomes of nasal therapy in the two groups before and after surgery.
2.5
Endoscopy
Nasal endoscopies were performed using rigid, 0° or 30° endoscopes. Findings were classified using the Lund–Kennedy endoscopic appearance score .
2.6
Preoperative radiological findings
The Lund–Mackay radiological grading system was used to score CRS severity before surgery.
2.7
Rhinomanometry
Nasal patency was assessed by AAR (Rhinolab, Rendsburg, Germany), as described elsewhere . AAR values were recorded in Pascal (Pa).
2.8
Nasal cytology
All specimens were fixed in 100% alcohol and stained with May–Grunwald–Giemsa stain, as explained elsewhere , then examined under the light microscope by the same operator (GO), who was blinded to the postoperative nasal treatments administered. The cytological parameters considered in each specimen were: total number of ciliated cells with or without hyperchromatic supranuclear stria (HSS + or HSS −); and total number of inflammatory cells (neutrophil granulocytes and eosinophil granulocytes) counted in 5 separate high-power fields (HPFs; original magnification 100 ×) ( Fig. 1 ).
2.9
Histology
Biopsy specimens of the anterior ethmoid mucosa were obtained during ESS and at the T90 follow-up. The specimens were fixed in 10% neutral-buffered formalin at room temperature. After embedding in paraffin wax, 4-μm serial sections were placed on silane-coated glass slides. Hematoxylin and eosin (H&E) staining was performed, then all specimens were examined by the pathologist under the light microscope (SB) ( Fig. 2 ). Lymphocytes, neutrophils, eosinophils, plasma cells and macrophages were counted, and the level of fibrosclerosis and vascularization was ascertained in HPFs (original magnification 400 ×) ( Fig. 3 ). Cell counts were performed in 10 separate HPFs per specimen and the results were averaged to obtain the mean number of the various different cell types per HPF.
2.10
Nasal microbiological culture
Nasal swabs were plated onto sheep blood agar (COS; bioMérieux, Marcy l’Etoile, France) and chocolate agar with PolyVitex (bioMérieux). Plates were incubated for 24 and 48 h at 37 °C in aerobic and anaerobic conditions. Gram staining was performed. Isolated bacteria were identified by Maldi-Tof mass spectrometry.
2.11
Statistical analysis
Patients were grouped by positivity/negativity for nasal polyps, then randomized on a 1:1 ratio to receive either SG or placebo, so that about half of the patients treated with SG were cases of CRSwNP, and the other half had CRSsNP, and the same applied to the patients treated with placebo. Patient randomization was done by means of a website: patients were registered at the time of their enrollment, when a code was generated (and written on the box containing the medical device) following a computer-generated randomization schedule under the supervision of a Contract Research Organization’s biostatistics service.
The following statistical tests were applied as appropriate: the Wilcoxon test, Fisher’s exact test, and the Mann–Whitney U test. A p-value of less than 0.05 was considered statistically significant. The STATA 8 (StataCorp, College Station, TX) statistical package was used for all analyses.
2
Methods
2.1
Ethical considerations
The present investigation was a prospective, randomized, double-blind, placebo-controlled study conducted in accordance with the 1996 Helsinki Declaration. The study protocol was approved by the Ethical Committee of Padova University Hospital (Italy) (protocol 2429P, 12/01/12). Written informed consent was obtained from each patient before starting any study-related procedures.
2.2
Study design
The main inclusion criteria were as follows: age ranging from 18 to 65 years; diagnosis of CRS with or without nasal polyps not responding to medical therapy; no contraindications to general anesthesia and ESS. Exclusion criteria were prior sinonasal surgery, autoimmune disease, cystic fibrosis, pregnancy, women of fertile age not taking contraceptives, diabetes, sinonasal malignancy, and hypersensitivity to any ingredient in the device under consideration or the placebo. Before surgery (T0) all patients underwent SNOT 22, nasal endoscopy, computed tomography (CT) scan, basal AAR, nasal cytology, and nasal swab with microbiological culture. An anterior ethmoid mucosa biopsy was taken during ESS. After discharge, all CRSsNP and CRSwNP patients, regardless of disease severity, were randomly assigned to use either SG or placebo, 2 sprays in each nostril twice a day for 1 month after surgery. The placebo contained only the excipients (carbopol and propylene glycol) in the same concentrations as in SG. The containers were identical and indistinguishable for both patients and investigators. All patients were scheduled to be assessed 15 days (T15), 30 days (T30), and 90 days after surgery (T90). The investigation protocol is summarized in Table 1 .
| SNOT 22 | AAR | CYTOLOGY | ENDOSCOPY | MICROBIOLOGICAL SWABS | BIOPSY | |
|---|---|---|---|---|---|---|
| T0 | X | X | X | X | X | X |
| T15 | X | X | X | X | ||
| T30 | X | X | X | X | X | |
| T90 | X | X | X | X | X | X |
2.3
Study population
Thirty-four consecutive adult patients (27 males, 11 of them with CRSsNP; 7 females, 3 of them with CRSsNP) were eligible and enrolled in the investigation.
2.4
Nasal symptoms
SNOT 22 is a validated, disease-specific tool for measuring health-related quality of life in patients suffering from CRS. It was used to underscore the impact of CRS on patients’ quality of life, and to measure the outcomes of nasal therapy in the two groups before and after surgery.
2.5
Endoscopy
Nasal endoscopies were performed using rigid, 0° or 30° endoscopes. Findings were classified using the Lund–Kennedy endoscopic appearance score .
2.6
Preoperative radiological findings
The Lund–Mackay radiological grading system was used to score CRS severity before surgery.
2.7
Rhinomanometry
Nasal patency was assessed by AAR (Rhinolab, Rendsburg, Germany), as described elsewhere . AAR values were recorded in Pascal (Pa).
2.8
Nasal cytology
All specimens were fixed in 100% alcohol and stained with May–Grunwald–Giemsa stain, as explained elsewhere , then examined under the light microscope by the same operator (GO), who was blinded to the postoperative nasal treatments administered. The cytological parameters considered in each specimen were: total number of ciliated cells with or without hyperchromatic supranuclear stria (HSS + or HSS −); and total number of inflammatory cells (neutrophil granulocytes and eosinophil granulocytes) counted in 5 separate high-power fields (HPFs; original magnification 100 ×) ( Fig. 1 ).
2.9
Histology
Biopsy specimens of the anterior ethmoid mucosa were obtained during ESS and at the T90 follow-up. The specimens were fixed in 10% neutral-buffered formalin at room temperature. After embedding in paraffin wax, 4-μm serial sections were placed on silane-coated glass slides. Hematoxylin and eosin (H&E) staining was performed, then all specimens were examined by the pathologist under the light microscope (SB) ( Fig. 2 ). Lymphocytes, neutrophils, eosinophils, plasma cells and macrophages were counted, and the level of fibrosclerosis and vascularization was ascertained in HPFs (original magnification 400 ×) ( Fig. 3 ). Cell counts were performed in 10 separate HPFs per specimen and the results were averaged to obtain the mean number of the various different cell types per HPF.
