Regeneration of maxillary sinus mucosa following surgical removal. Experimental study in rabbits

Outcome of Open Surgery in Disease Progression of Post-COVID Rhinomaxillary Mucormycosis Treated by Functional Endoscopic Sinus Surgery and Proposed Evaluation Scale for Maxillary Sinus Disease and Osteomyelitis

Introduction

Material and Methods

Conclusion

Supplementary Information

A follow-up study of mucociliary clearance and trace element and mineral status in children with chronic rhinosinusitis before and three months after endoscopic sinus surgery

BACKGROUND

The existing data demonstrate the potential role of trace elements in nasal mucociliary clearance, although the association between trace element and mineral status and ciliary function in children with chronic rhinosinusitis is insufficiently studied. Therefore, the objective of the present study is evaluation of trace element and mineral status and mucociliary function in pediatric CRS patients before and after functional endoscopic sinus surgery.

METHODS

The present study involved 30 children with chronic rhinosinusitis without nasal polyps. During this follow-up the patients were examined preoperatively (point 0), underwent functional endoscopic sinus surgery, and were repeatedly examined at three months postoperatively (point 1). At both points the patients were subjected to quality-of-life assessment using SNOT-20 questionnaire; endoscopic and computer tomography examination of the nasal sinuses; evaluation of ciliary function and mucosal cytology using high-speed videomicroscopy; assessment of blood count and inflammatory markers; as well as analysis of trace element and mineral levels in whole blood, serum, and hair using inductively-coupled plasma mass-spectrometry.

RESULTS

The obtained data demonstrate that endoscopic sinus surgery significantly improved sinonasal pathology in children with chronic rhinosinusitis, as evidenced by significantly reduced Lund-Mackay, Lund-Kennedy, and SNOT-20 scores. At the same time, no significant improvement of ciliary functions or mucosal cytology was observed postoperatively. Trace element status assessment demonstrated that postoperative serum Zn, whole blood Mg and Cu were significantly lower as compared to preoperative values. In contrast, serum Mn and Cr, as well as whole blood Cr and hair Se were characterized by a significant increase at three months postoperatively. Multiple linear regression analysis demonstrated that serum Zn is significantly associated with the number of ciliated cells and cell viability, whereas serum Mn and whole blood Cu concentrations are inversely associated with cell viability and ciliary length, respectively. Hair Se was found to be associated with the number of neutrophils in the mucosa biopsy.

CONCLUSION

Redistribution of trace elements and minerals may at least partially mediate prolonged recovery of mucosal ciliary function in children with chronic rhinosinusitis in three months after functional sinus surgery, although the particular mechanisms of these alterations in trace element levels are to be discovered.

Effect of Schneiderian membrane integrity on bone formation in sinus augmentation: An experimental study in rabbits

AIM

To assess the effect of Schneiderian membrane (SM) perforation on bone formation by applying a particulate deproteinized bovine bone mineral (PBBM).

MATERIALS AND METHODS

Bilateral sinus augmentation was performed in eight rabbits. The same amount of PBBM was placed at a sinus where the SM was intentionally perforated for the perforation group (standardized to 3 mm diameter) and the other sinus with an intact SM that served as the intact group. At 12 weeks, all animals were euthanized for radiographic and histomorphometric analyses.

RESULTS

The area of the newly formed bone in the perforation group was significantly less than that in the intact group (18.7% and 25.5%, respectively, p = .028). The newly formed bone in the area close to the perforated SM was significantly less than that in the intact group (18.7% and 26.1%, respectively, p < .05). However, there was no significant difference in the total augmented area (p = .234) and the total augmented volume (p = .382) between the two groups.

CONCLUSION

SM perforation had an adverse effect on new bone formation, predominantly close to the area of membrane perforation. However, no significant difference was found in the total augmented volume between the SM perforation and the intact groups.

A comparative evaluation of bone regeneration using mesenchymal stem cells versus blood coagulum in sinus augmentation procedures

Objective:

The present study evaluated the quality and quantity of new bone formation in the maxillary sinus lift procedures and stability of implants in posterior atrophic maxilla.

Materials and Methods:

This prospective randomized controlled split-mouth study included 20 patients (16 males and 4 females having a mean age of 36.7 years) having atrophic maxilla. They were divided randomly into two groups: Group A using mesenchymal stem cells and Group B into blood coagulum. They were radiographically evaluated using cone-beam computed tomography (CBCT) for residual bone height preoperatively and availability of new bone formation around implants, density, and stability of implants 6 months postoperatively.

Results:

The placement of dental implants in posterior maxilla is challenging due to rapid resorption of alveolar bone after extraction of teeth due to pneumatization of maxillary sinuses. In both the groups, more pain and swelling were observed in the 2^nd postoperative day which gradually decreased over a period of 7 days. Membrane perforation occurs in only four cases (20%). A significant gain in alveolar bone height was observed in Group A (7.69 mm ± 2.5 mm) and Group B (9.32 mm ± 2 mm) after 6 months. On comparing both the groups, there is a similar significant increase in bone density in Hounsfield units postoperatively at various levels buccally and palatally. Total 40 sinuses were lifted and 42 implants were placed, respectively. All implants showed primary stability.

Conclusions:

Such findings provide a significant contribution in future perspective studies that the use of stem cells had the same success rate as blood coagulum.

Ciliary function and sinonasal mucosal cytology in pediatric patients with chronic rhinosinusitis during a year after functional endoscopic sinus surgery

BACKGROUND

The objective of the study is evaluation of ciliary function and mucosal cytology after endoscopic sinus surgery in children with chronic rhinosinusitis (CRS).

METHODOLOGY

A total of 132 children with CRS who underwent endoscopic sinus surgery, as well as 15 healthy controls were involved in the study. In this follow-up study patients were examined preoperatively, as well as 3, 6, 9, and 12 months after endoscopic sinus surgery. Assessment of ciliary function and sinonasal mucosal cytology was performed using high-speed videomicroscopy. Lund-Kennedy, Lund-Mackay, and sinonasal outcome test 20 (SNOT20) scores were also evaluated.

RESULTS

Total SNOT-20, Lund-Mackay, and Lund-Kennedy values significantly decreased after sinus surgery. In contrast, ciliary function and mucosal cytology only tended to improve after 6 months. 9 months after surgery the number of ciliated cells, ciliary beat frequency, cell viability, and ciliary length were significantly higher than preoperatively. The most significant improvement of ciliary function and cell height was observed 12 months after operation, whereas epithelial dystrophy and neutrophil infiltration were significantly reduced.

CONCLUSIONS

Substantial improvement was observed only in a year after surgery, whereas 0 to 3 months after the surgery ciliary function was severely impaired thus predisposing to recurrent sinusitis or other complications.

[Postoperative treatment following paranasal sinus surgery]

Postoperative care is a crucial aspect for the success of paranasal sinus interventions. Basic procedures include saline nasal wash, which should be started on the first postoperative day, topical steroids, and antibiotics in cases of infection. Medical treatment involves aspiration of secretion in the inferior meatus during the first week. Removal of scabs in the surgical field should be carried out under endoscopic control beginning at the second week. Intervals are scheduled individually. Occlusion of the nose for the time of epithelium regeneration provides a moist space in the ethmoid, which improves wound healing.

Collagenated Synthetic Bone Substitute Material for Sinus Floor Elevation at Sites with a Perforated Schneiderian Membrane

Schneiderian membrane perforation (SMP) is the most common complication during sinus floor elevation (SFE). Conventional methods to repair SMP, such as using a collagen barrier, may be clinically demanding. The aim of the present study was to compare the effects of collagenated bone substitute materials with and without a collagen barrier to repair SMP during SFE in terms of new bone formation and dimensional stability. In 12 rabbits, intentional SMP was made during bilateral SFE. The rabbits were randomly assigned under two groups: the control group, in which the sinus was repaired with a collagen barrier, and the test group, in which the sinus was repaired without a collagen barrier. Collagenated bone substitute material was grafted in both groups. Healing periods of 2 weeks and 4 weeks were provided in both groups. There were no adverse clinical events. Histology revealed that the Schneiderian membrane had atrophied with loss of cilia and serous glands in both groups at 4 weeks. Histomorphometry revealed that the newly formed bone (test: 0.42 ± 0.17 mm², control: 0.36 ± 0.18 mm² at 2 weeks; test: 1.21 ± 0.36 mm², control: 1.23 ± 0.55 mm² at 4 weeks) or total augmented area did not significantly differ between the two groups at either time points (p > 0.05). In conclusion, collagenated bone substitute material without a collagen barrier demonstrated similar new bone formation and dimensional stability as that with a collagen barrier in repairing SMP.

Volume stability of the augmented sinus using a collagenated bovine bone mineral grafted in case of a perforated Schneiderian membrane: An experimental study in rabbits

OBJECTIVES

To determine the volume stability of a sinus augmented with a collagenated bovine bone mineral (CBBM) in case of an intact or perforated Schneiderian membrane (SM).

MATERIALS AND METHODS

A bilateral sinus augmentation procedure was performed in eight rabbits. The SM was intentionally perforated in one side (SMP group), while it remained intact in contra-lateral side (control group) and the same amount of CBBM was then grafted. At 12 weeks, the animals were euthanized for radiographic and histomorphometric analyses.

RESULTS

The augmented volume did not differ significantly between the two groups: 262.2 ± 32.1 mm³ in SMP group and 261.9 ± 48.5 mm³ in the control group (p = .959). There was no significant difference in the total augmented area: 24.7 ± 5.2 mm² in SMP group and 23.2 ± 2.9 mm² in the control group (p = .773). The areas of newly formed bone also did not differ significantly between the two groups, but was significantly lower at the centre of the augmented region than in the region of the surgical window in both groups (p < .05).

CONCLUSION

A perforation of the SM in a rabbit model does neither impact the augmented volume nor new bone formation following grafting of the sinus with a CBBM.

Comparative Analysis of the Healing Effects of the Transplanted Cell Sheets to the Experimentally Injured Maxillary Sinuses

BACKGROUND

In our study, the authors aimed to obtain a live and functional sinus epithelium with mesenchymal stem cells and nasal mucosa epithelial cells from rabbits which are cultured in temperature-responsive culture plates to get a single-layer.

METHODOLOGY/PRINCIPAL

Twenty-two female New Zealand rabbits were included in the study. Two of them were used to obtain mesenchymal stem cells. A total of 40 maxillary sinuses were randomly divided into 5 groups: 1) control group which is used to investigate normal rabbit maxillary mucosa, 2) secondary healing group, 3) mesenchymal stem cell graft group, 4) differentiated mesenchymal stem cell group, and 5) nasal mucosal graft group. The animals were sacrificed at the 28th day after the surgery.Scanning electron microscopy, transmission electron microscopy, and immunohistochemical investigations were performed.

RESULTS

With these investigations, it was shown that; all graft groups were histologically better than secondary healing group and when the authors compared the graft groups, differentiated mesenchymal stem cell group were the best.

CONCLUSION

Our study results showed that endoscopic sinus surgery and treatment with cell sheets, which were generated in temperature-responsive culture dishes, had more functional respiratory epithelium.

Comparative preclinical assessment of the use of dehydrated human amnion/chorion membrane to repair perforated sinus membranes

Purpose

The aim of this study was to evaluate the use of dehydrated human amnion/chorion membrane (dHACM) to repair perforated sinus membranes in rabbits.

Methods

Bilateral surgical windows (7.5-mm diameter) were prepared on the nasal bones of 14 rabbits. Standardized circular perforations (5-mm diameter) were made in the sinus membrane by manipulating implant twist drills. The perforated sinus membranes were repaired using dHACM or a resorbable collagen membrane (CM). The negative control (NC) group did not undergo perforated sinus membrane repair, while the positive control (PC) group underwent sinus augmentation without perforations. The same amount of deproteinized porcine bone mineral was grafted in all 4 groups. After 6 weeks, micro-computed tomography (micro-CT) and histomorphometric evaluations were conducted.

Results

The micro-CT analysis revealed that the total augmented volume was not significantly different among the groups. In the dHACM group, newly formed bone filled the augmented area with remaining biomaterials; however, non-ciliated flat epithelium and inflammatory cells were observed on the healed sinus membrane. Histometric analysis showed that the percentage of newly formed bone area in the dHACM group did not differ significantly from that in the CM group. The dHACM group showed a significantly higher percentage of newly formed bone area than the NC group, but there was no significant difference between the dHACM and PC groups.

Conclusions

dHACM could be a feasible solution for repairing sinus membrane perforations that occur during sinus floor augmentation.

Effects of Oral Propolis on Mucosal Wound Healing after Endoscopic Nasal Surgery in a Rabbit Model

Objective

If the respiratory nasal mucosa is damaged and the mucosa does not heal properly during nasal or paranasal sinus surgery, a revision surgery may be required. The aim of this study is to investigate the effects of oral propolis application on mucosal wound healing following endoscopic nasal surgery in a rabbit model.

Methods

Twenty four New Zealand rabbits were randomly divided into three groups, namely the experimental group (EG), the control group (CG), and the negative control group (NCG). Mucosal resection was applied with 3-mm punch forceps in the bilateral ventral nasal concha in the experimental and control groups. 75 mg/kg/day propolis was added to the diet of the rabbits in the EG for 14 days. The CG continued with the standard diet postoperatively. In the NCG, no surgical intervention was made, and no dietary support was given. On postoperative day 14 all rabbits were sacrificed and left nasal specimens were examined histopathologically, hydroxyproline levels were measured in right nasal specimens.

Results

There were no statistically significant differences in hydroxyproline level, epithelial and subepithelial thickness, ciliary and goblet cell count, subepithelial fibrosis and collagen density between EG and CG. Neutrophil count was statistically significantly lower in EG, compared to CG (p=0.019, Tamhane test).

Conclusion

Although there are many studies that show the positive effects of propolis on wound healing, such effect was not observed in this study. This study is deemed to constitute a unique experimental study that can be a resource for future similar studies to be performed with higher numbers of subjects and higher dosage of propolis.

Reversibility of Abnormal Mucociliary Clearance in Experimental Chronic Sinusitis

Normal mucociliary clearance in the paranasal sinuses must be restored to reverse the effects of chronic sinusitis. This study examined effects of middle meatal antrostomy (MMA) on ciliary beat frequency (CBF), mucociliary transport (MCT) velocity, MCT patterns, and histology of sinus mucosa in rabbits with chronic sinusitis to determine whether objective measures of mucociliary function and histology could be reversed. Two groups of rabbits were compared: uninfected (Group A controls, n = 9) and infected (Group B, n = 11). Maxillary sinus ostia were occluded; 108 cfu of Streptococcus pneumoniae were inoculated into sinuses of rabbits in group B, and chronic sinusitis developed. This was confirmed by histopathology and culture 6 weeks after infection. Middle meatal antrostomies were performed in the infected group, and sinuses were studied 6 weeks later. Control animals (Group A) had mean CBF = 11.5 Hz (±.39 Hz). Animals with chronic sinusitis (Group B) had mean CBF = 8.6 Hz (±.24 Hz). This was statistically different from control (P < 0.05). Six weeks following MMA, group B had mean CBF = 12.9 Hz (±.75 Hz). This was not different from control. There were changes in MCT velocity that correlated with the CBF (r = 0.72). Examination of MCT patterns after MMA demonstrated minimal pooling and stagnation; however, small areas of misdirected flow persisted. After MMA, there were decreased numbers of inflammatory and goblet cells and increased numbers of ciliated epithelial cells. This study demonstrated that mucociliary clearance and histological changes seen in rabbits with chronic sinusitis are reversed by MMA.

Paranasal Sinus Mucosal Regeneration: The Effect of Topical Retinoic Acid

Background

Paranasal sinus mucosa may suffer morphological and functional alterations as a result of surgical trauma. Mucosal stripping typically yields regenerated mucosa characterized by fibrosis, inflammatory infiltrate, and dysmorphic or absent cilia. The aim of this study was to determine the effect of topical retinoic acid (vitamin A) on regeneration of paranasal sinus mucosa.

Methods

Both maxillary sinuses of 12 New Zealand white rabbits were surgically opened and stripped of mucosa. Six rabbits received 0.01% topical retinoic acid gel treatment to the stripped left maxillary sinus (low concentration group). The remaining six rabbits received 0.025% topical retinoic acid gel to the stripped left maxillary sinus (high concentration group). The stripped right maxillary sinus of all 12 rabbits served as the operated, untreated control to reflect the normal healing process. Six other animals served as unoperated controls. The sinus mucosa was examined by light microscopy after 14 days.

Results

Untreated regenerated mucosa showed expected changes of submucosal gland loss, basal lamina and lamina propria fibrosis, cellular atypia, and loss of cilia. Topical retinoic acid treatment appeared to result in better mucosal regeneration marked by less cellular atypia and fibrosis. Although the regenerated mucosa was still grossly abnormal, the degree of ciliary loss and cellular derangement was reduced. The lower-concentration retinoic acid group had more favorable morphology than the higher-concentration retinoic acid group, and both were improved when compared with no treatment.

Conclusions

In a rabbit model, topical vitamin A in the form of retinoic acid gel appears to enhance regeneration of ciliated paranasal sinus mucosa. This preliminary study suggests that topical retinoids may have applicability in promoting sinus wound healing.

Healing Process of Sinus Mucosa after Endoscopic Sinus Surgery

In the treatment of chronic sinusitis, the mucosa should be preserved, or, when severely damaged, only the mucosal surface removed with cutting forceps. It is especially important not to expose the surface of the bone by complete removal of the mucosa. When the mucosa is conserved, or excision is limited to only the mucosal surface, ciliated cells regenerate within 6 months. However, where the mucosa was completely removed during surgery and the bone was exposed, the area was covered with nonciliated cells, and only scattered cilia were present.

Wound Healing of the Nasal and Paranasal Mucosa: A Review

Background

Wound healing is a highly coordinated process involving clot formation, inflammatory reaction, immune response, and, finally, tissue remodeling and maturation. Only few data regarding the specific healing of the nasal or sinusal mucosa are available.

Methods

After a short summary of the general principles of wound healing, the most important data regarding in vitro or in vivo models of wound healing of the nasal and paranasal mucosa are discussed. Attention is paid to clinical application.

Main Findings

First observations regarding the specific regulation of epithelial regeneration by growth factors have underlined the complex relationship between extracellular matrix and epithelium during the repair process. However, only poor and aspecific correlations can be described between endoscopically and histomorphologically defined postoperative phases.

Evaluation of Ultrastructural Changes in Paranasal Sinus Mucosa after Functional Endoscopic Sinus Surgery in Patients with Chronic Rhinosinusitis

The purpose of this study was to compare the preoperative and postoperative ultrastructural changes of paranasal sinus mucosa in patients treated with functional endoscopic sinus surgery for chronic rhinosinusitis. Twelve patients undergoing functional endoscopic sinus surgery for the treatment of chronic rhinosinusitis were involved. The ethmoid sinus mucosa was sampled during the operation and ∼6 months after the operation. The ciliated epithelium of sinus mucosa was evaluated with transmission electron microscopy. The samples were taken at the Otolaryngology Department of Istanbul University School of Medicine. Electron microscopic study was performed at the Histology and Embryology Department of the same University. Preoperatively, ciliated epithelial cells of the sinus mucosa of the patients showed degenerated ultrastructure with decreased number of cilia, cytoplasmic protrusions, cisternal dilatations of endoplasmic reticulum, and mitochondrial swellings. Remnants of degenerated cells and cellular separations at cell junctions were evident in the diseased epithelium. Goblet cells were frequent along the epithelial lining. Postoperatively, normal architecture and ultrastructure of the ciliated epithelium was restored. These observations showed that unlike other surgical operations, paranasal sinus mucosa can regenerate and the ciliated epithelium can return to normal after functional endoscopic sinus surgery.

Anatomy and Surgical Approaches to the Rabbit Nasal Septum

Importance

The rabbit is the primary animal model used to investigate aspects of nasal surgery. Although several studies have used this model, none has provided a comprehensive analysis of the surgical anatomy and techniques used to gain access to the rabbit nasal fossae and septum.

Objective

To describe and optimize the surgical anatomy and approach to the rabbit nasal vault and septal cartilage.

Design, Setting, and Participants

In an ex vivo animal study conducted at an academic medical center, preliminary cadaveric dissections were performed on rabbit head specimens to establish familiarity with relevant anatomy and rehearse various approaches. Live Pasteurella-free New Zealand white rabbits (3.5-4.0 kg) were used to further develop this surgical technique developed here. Access of the nasal vault was gained through a midline nasal dorsum incision and creation of an osteoplastic flap with a drill. Submucosal resection was performed with preservation of the mucoperichondrium. All rabbits were monitored daily for 4 weeks in the postoperative period for signs of infection, pain, and complications. The study was conducted from June 1, 2014, to December 1, 2014.

Main Outcomes and Measures

Surgical anatomy and techniques used to gain access to the rabbit nasal vault and harvest septal cartilage.

Results

Four Pasteurella-free New Zealand white rabbits (Western Organ Rabbit Co), ranging in age from 9 to 12 months and weighing between 3.5 and 4.0 kg, were used in this study. Initial dissections demonstrated the feasibility of harvesting septal cartilage while preserving the mucoperichondrial envelope. Access to the nasal vault through this 3-osteotomy approach allowed for maximal exposure to the nasal cavity bilaterally while maintaining the integrity of the mucoperichondrium following septal cartilage harvest. The maximum amount of bulk, en bloc, cartilage harvested was 1.0 × 2.5 cm. Following surgical dissection, all animals maintained adequate airway patency and support to midface structures. Furthermore, all specimens preserved the integrity of the mucoperichondrium, septum, vascular anatomy, and airway dynamics. No operative complications, postoperative airway compromise, or infections were observed.

Conclusions and Relevance

Access to the rabbit nasal vault and septal cartilage is feasible through a variety of surgical approaches and techniques. To date, this is the first study to meticulously document and review the surgical approaches to the rabbit nasal cavity. This approach describes a novel, 3-osteotomy method of accessing the nasal cavity bilaterally and successfully harvesting rabbit septal cartilage in a submucoperichondrial plane. The ability to preserve native anatomy and function allows for improved outcomes in translational and animal guided clinical research.

Level of Evidence

NA.

Effect of a combination of mometasone furoate, levofloxacin, and retinyl palmitate with an in situ gel-forming nasal delivery system on nasal mucosa damage repair in an experimental rabbit model

BACKGROUND

In this study a combination of Mometasone Furoate (MF)+Levofloxacin hemihydrate (LH)+Retinyl palmitate (RP) with an in situ gel-forming delivery system was evaluated at different stages of nasal mucosal damage repair in a rabbit maxillary sinus model.

METHODS

In this study, 28 rabbits were included and assigned randomly to four groups. In all rabbits, a standard ostium was opened in the medial wall of the maxillary sinus by using a drill. Two different subsequently prepared gels with an in situ gel-forming delivery system were used. Of these 14 nasal cavities, combination 1 (active combination) was applied daily to 5, combination 2 (placebo) to 5, while 4 did not receive any pharmaceutical treatment. The diameter of the ostium was measured. Histopathological assessment was performed.

RESULTS

After 2, 3 and 4 weeks, the ostium diameter was significantly wider in the group where gel 1 had been applied compared to both the placebo group and control group. In the group treated with gel 1, after 2, 3 and 4 weeks the presence of superficial cilia was significantly greater, surface epithelium significantly less. In the 4th week, histologic scores for fibroblastic proliferation and vascular proliferation in the group treated with gel 1 were better than in either the control group or the placebo group. With gel 1, chronic inflammation parameters were also significantly lower than in the other groups.

CONCLUSION

The MF+LH+RP mixture with an in situ gel-forming nasal delivery system applied for wound healing after FESS prevents the formation of stenosis and is favorable for proper wound healing.

The Healing Effects of Autologous Mucosal Grafts in Experimentally Injured Rabbit Maxillary Sinuses

OBJECTIVES

Healing processes of the nose and paranasal sinuses are quite complex, and poorly understood. In this study, we aimed to compare the effect of mucosal autologous grafts on the degenerated rabbit maxillary sinus mucosa with spontaneous wound healing. It is hypothesized that mucosal grafts will enhance ciliogenesis and improve the morphology of regenerated cilia.

METHODS

Ten female New Zealand rabbits were included in the study. They underwent external maxillary sinus surgery through a transcutaneous approach. A total of 20 maxillary sinuses were randomly divided into 2 groups: 'spontaneous healing group' and 'autologous graft group.' The animals were sacrificed at the 14th day after the surgery. Scanning electron microscope (SEM), and light microscope were used for the evaluation.

RESULTS

Cellular composition of the graft group is better than the spontaneous healing group. The graft group had larger areas covered with ciliary epithelium than the spontaneous healing group, and the mean length of the cilias were also longer. Additionally, there were wider cilia with abnormal morphology areas in the spontaneous healing group.

CONCLUSION

In our opinion, covering of the denuded areas with a graft improves re-epithelization, and may prevent the early complications after sinus surgeries.

Murine ciliotoxicity and rabbit sinus mucosal healing by polyhydrated ionogen

OBJECTIVES

Determine the toxicity and efficacy of a novel antiprotease topical irrigation, polyhydrated ionogen (PHI) ± MgBr2, in improving sinonasal remucosalization following surgery.

STUDY DESIGN

Blinded, randomized controlled study. Setting. Academic.

SUBJECTS AND METHODS

Ciliary beat frequency (CBF) of murine nasal septal explants was continuously recorded before and after addition of PHI solution to asses for ciliotoxicity. To evaluate for efficacy in remucosalization, 9 New Zealand white rabbits underwent bilateral medial-wall maxillary mucosal stripping followed by placement of an indwelling irrigation catheter. In a randomized fashion one side received 3 mL of normal saline (NS) daily, whereas the contralateral side received PHI ± MgBr2. Following a 14-day therapeutic trial, remucosalization was assessed by hematoxylin and eosin staining and immunohistochemistry for β-tubulin, a marker of cilia. A semiquantitative grading of ciliated remucosalization was applied with a chi-square test to compare the saline with the PHI ± MgBr2 treatment.

RESULTS

Safety evaluation of the PHI solutions demonstrated no evidence of ciliotoxicity. Histologic semiquantitative analysis of maxillary sinus remucosalization demonstrated significantly more ciliated epithelium (>60%) in the majority of PHI (n = 4) and PHI with MgBr2 (n = 5) treatment compared with the saline treatment (<30%) (n = 9). This was confirmed with immunohistochemical staining for type IV β-tubulin a marker of respiratory cilia.

CONCLUSIONS

Success of functional endoscopic sinus surgery depends on restoration of normal mucociliary clearance. Topical PHI application has previously been demonstrated to significantly increase dermal wound healing. PHI solution is not ciliotoxic, and daily topical PHI or PHI MgBr2 irrigation enhances ciliated remucosalization compared with saline.

Pre-clinical evaluation of the osteogenic potential of bone morphogenetic protein-2 loaded onto a particulate porcine bone biomaterial

AIM

The objective of study was to determine the osteogenic potential of bone morphogenetic protein-2 (BMP-2) loaded onto a particulate porcine bone mineral (PBM) biomaterial using a sinus augmentation model.

METHODS

Release kinetics of BMP-2/PBM was determined in vitro. Eight rabbits received BMP-2/PBM or PBM alone into contra-lateral sinus sites. The animals were killed following a 2-week healing interval for micro-CT and histometrical analysis.

RESULTS

Approximately 40% of the BMP-2 was released from PBM over the first 3 days in vitro; release maintained at a reduced level through day 21. In vivo, total augmented implant volume did not differ significantly between treatments. However, local bone formation was enhanced in the BMP-2/PBM group compared with PBM control (10.5% versus 6.6%; p = 0.03), specifically in the central aspect of the PBM implant (14.2% versus 5.5%; p < 0.01) and adjoining the Schneiderian membrane (11.9% versus 5.0%; p < 0.05). There were no significant overall differences in residual biomaterial and fibrovascular tissue.

CONCLUSION

Bone morphogenetic protein-2 enhanced local bone formation in the rabbit maxillary sinus model following implantation using a PBM carrier.

Mucociliary transport and histopathological changes in rotation flaps of the nasal mucosa

Normal mucociliary transport in the mucoperichondrium of the nasal septum is from a distal (anterior) to proximal (posterior) direction. This study was to determine the direction of mucociliary transport and histopathological changes in nasal mucosal rotation flaps when their transport directions were anatomically reversed. Thirty-two rabbits were divided into four groups. Surgical septal rotational flaps were prepared in the experimental groups. Group I was the control group. The distal aspect of the flap was sutured through a large septal window to the other side of the nasal septum, thus changing the direction of the flap. Evaluation was performed 1 week, 1 month and 9 months later with each of these groups named as groups II, III, and IV, respectively. The rate and direction of the mucociliary transport was determined and histopathological investigations were performed from the flaps. The direction of mucociliary transport was observed to continue as distal to proximal direction in the rotated segments. The mucociliary transport rate was found to be decreased in group II, nearly normal in group III, and in normal limits in group IV after surgery. Intense inflammation and decreased number of cilia were present in group II. The inflammation was milder in group III and the epithelium was found to be nearly normal in group IV. The originally programmed direction of mucociliary transport in the nasal rotation flaps is maintained and is not altered or reprogrammed. Histopathological changes revert back to normal from an inflammatory state to reach pre-surgical status over time.

The fungal microbiome in chronic rhinosinusitis: richness, diversity, postoperative changes and patient outcomes

BACKGROUND

Our understanding of fungi in chronic rhinosinusitis (CRS) has been limited by previously employed detection techniques. This study examines the fungal component of the microbiome in CRS patients and controls using a highly sensitive culture-independent molecular technique. The aims of this study include the characterization of fungal richness, prevalence, abundance, temporal changes, and their relationship with patient outcomes.

METHODS

Swabs were collected from the sinuses of 23 CRS patients and 11 controls. Collection occurred intraoperatively, and at 6 and 12 weeks postoperatively. DNA was extracted from the swabs and fungal outcomes were determined through 18S ribosomal DNA (rDNA) fungal tag-encoded FLX amplicon pyrosequencing.

RESULTS

Fungi were ubiquitous to all patients. A total of 207 fungal genera were detected, with a mean sample richness of 8.18 and 12.14 in the control and CRS groups, respectively. Malassezia was detected in all patients at surgery and was also the most abundant. Postoperatively, fungal richness decreased (p < 0.05) and was associated with declines in the prevalence of Fusarium and Neocosmospora (p < 0.05). Neocosmospora was also less abundant postoperatively (p < 0.05). No correlations were found with quality of life.

CONCLUSION

This is the first study to use a highly sensitive pyrosequencing technique to reveal the true diversity of fungi in the sinuses of CRS patients and postoperative changes in richness. The presence of Malassezia, a genus not previously described in the sinuses, is of great interest, and its potential as a disease modifier should see further investigation given its association with atopic disease.

Polyhydrated ionogen with MgBr2 accelerates in vitro respiratory epithelial healing

BACKGROUND

Remucoslization of the sinonasal cavity after sinus surgery is critical for successful outcomes. Recently, a novel antiprotease and antifibroblast compound, polyhydrated ionogen (PHI) with MgBr2, showed improved wound healing in a rabbit maxillary sinus mucosal wound model. We set out to determine if this effect was reproducible in an in vitro respiratory epithelial culture system.

METHODS

Fully differentiated mature murine nasal septal air-liquid interface cultures were injured by creating a full-thickness 400-mM-wide scratch through the monolayer. Cultures were then treated with nothing, saline, or PHI with MgBr2 for 1 hour on the apical surface. Twenty-four hours after the injury cultures were fixed and processed for immunofluorescence with type IV beta-tubulin and Hoechst stain.

RESULTS

Initial injury resulted in a wound of 394 micromolar (377-411 micromoler; 95% CI; n = 8). After 24 hours with no intervention the wound closed to 161 micromolar (138-184 micromolar; 95% CI; n = 9) and treatment with saline resulted in a residual gap of 88 micromolar (60-116 micromolar; 95% CI; n = 9; p < 0.05) and treatment with PHI with MgBr2 resulted in a gap of only 30 micromolar (14-46 micromolar; 95% CI; n = 9; p < 0.05).

CONCLUSION

Poor healing of the sinonasal mucosa after surgery with loss of ciliary function results in adverse clinical outcomes. In an in vitro sinonasal respiratory epithelial injury model, a one-time treatment with PHI with MgBr2 showed significantly improved wound healing compared with saline or nothing. This is a viable model to further investigate the mechanism by which PHI with MgBr2 improves sinonasal remucosolization.

Polyhydrated ionogen enhances postoperative sinonasal ciliated remucosalization

BACKGROUND

Mucosalization of the sinonasal cavity following surgery is critical for successful outcomes. Recently a novel anti-protease compound, polyhydrated-ionogen (PHI) with Mg(2+)/Br(-), demonstrated improved dermal wound healing. We set out to investigate the effect of PHI Mg(2+)/Br(-) on sinus remucosalization following surgery.

METHODS

A total of 24 rabbits underwent bilateral medial-wall maxillary mucosal stripping followed by placement of an indwelling irrigation catheter. In a randomized fashion 1 side received 3 cc normal saline (NS) daily, while the contralateral side received PHI Mg(2+)/Br(-). Following a 14-day therapeutic trial, remucosalization was assessed by hematoxylin and eosin (H&E) staining and immunohistochemistry for β-tubulin, a marker of cilia. A semiquantitative grading of ciliated remucosalization was applied with a chi-square test used to compare distributions for each treatment.

RESULTS

H&E staining comparison demonstrated NS treated sinuses (n = 24) had substantial bare areas with predominant ciliation scores under 30%. The PHI Mg(2+)/Br(-)-treated group (n = 24) achieved a statistically significant improvement in reciliation (>60%) when compared with NS (p < 0.01). These results were confirmed with Type IV β-tubulin staining (p < 0.01).

CONCLUSION

Poor postsurgical sinonasal mucosa healing results in adverse clinical outcomes. In a rabbit model of sinonasal mucosal healing, daily irrigation for 14 days with PHI Mg(2+)/Br(-)-enhanced ciliated remucosalization compared to saline.

Comparison of maxillary sinus specimens removed during Caldwell-Luc procedures and traditional maxillary sinus antrostomies

The cases of 80 patients who underwent Caldwell-Luc surgery for the treatment of chronic rhinosinusitis between 2002 and 2007 at Vanderbilt University Medical Center's Department of Otolaryngology were reviewed. Data on demographics, comorbidities, details of surgery, surgical pathology, and histology were collected. These data were compared with those of 40 patients who underwent standard functional endoscopic sinus surgery in 2007. Statistically significant differences were found in terms of mean patient age, sex, mean number of sinuses surgically addressed, number of prior surgeries, and tissue eosinophil counts. Microscopic examination revealed the presence of "necrotic bone" in 2 Caldwell-Luc specimens, and "necrotic debris" in 2 other Caldwell-Luc specimens. No similar finding was seen in the control group. Caldwell-Luc is a surgery of last resort for patients who fail aggressive interventions for maxillary sinus disease. The mucosal lining of this small group of patients appears to be different from that of patients who respond favorably to functional endoscopic sinus surgery.

Sinus augmentation using absorbable collagen sponge loaded with Escherichia coli-expressed recombinant human bone morphogenetic protein 2 in a standardized rabbit sinus model: a radiographic and histologic analysis

OBJECTIVES

The purpose of this pilot study was to determine the osteoinductive effect of absorbable collagen sponge (ACS) loaded with Escherichia coli-expressed recombinant human bone morphogenetic protein 2 (ErhBMP-2) and evaluate structural stability of ACS in a standardized rabbit sinus model.

MATERIAL AND METHODS

The maxillary sinuses were prepared bilaterally in six male white rabbits. The windows were prepared using a 6 mm trephine bur, and circular bony windows were carefully removed. Following reflection of the sinus membrane, a saline-soaked ACS alone and an ErhBMP-2-loaded ACS were inserted into the left and right maxillary sinuses, respectively. After a healing period of 8 weeks, sections of the augmented sinus and surrounding bone were made and analyzed by microcomputed tomography and histologically for signs of window closure and bone augmentation.

RESULTS

Radiographic analysis revealed new bone formation in both groups of augmented sinus (i.e., with and without ErhBMP-2). The maximum augmented height did not differ significantly between the groups; however, window closure was significantly more advanced in the ErhBMP-2 group than in the control group (P=0.02). The defect was significantly deeper in the control group than in the ErhBMP-2-treated group (P=0.02).

CONCLUSIONS

In conclusion, ErhBMP-2-loaded ACS showed enhanced osteoinductive potential, particularly with regard to bone closure of a sinus window and facilitated maturation of the newly formed bone within the rabbit sinus cavity. However, the structural durability of ACS was not sufficient to maintain the augmented volume in the sinus.

Physiology and pathophysiology of respiratory mucosa of the nose and the paranasal sinuses

In this review, anatomy and physiology of the respiratory mucosa of nose and paranasal sinuses are summarized under the aspect of its clinical significance. Basics of endonasal cleaning including mucociliary clearance and nasal reflexes, as well as defence mechanisms are explained. Physiological wound healing, aspects of endonasal topical medical therapy and typical diagnostic procedures to evaluate the respiratory functions are presented. Finally, the pathophysiologies of different subtypes of non-allergic rhinitis are outlined together with treatment recommendations.

An animal model for sinus floor elevation with great elevation heights. Macroscopic, microscopic, radiological and micro-CT analysis: ex vivo

OBJECTIVES

Different animal models are used for research and training concerning sinus floor elevation. However, there is little information regarding an animal model for elevation heights of approximately 10 mm. The aim of this study was to explore the anatomical aspects of the maxillary sinus of adult pigs and to investigate the suitability of this animal as a model for sinus floor elevation training and research with great elevation heights.

MATERIAL AND METHODS

Thirty-four bisected heads of adult domestic pigs were examined 6 h postmortem. Direct sinus floor elevation was performed with an elevation height of 10 mm. Localization, diameters, volume and septa of the maxillary sinus were recorded on lateral X-rays and macroscopically. The thickness and structure of the maxillary sinus were investigated microscopically. The osseous microstructure of the lateral sinus wall was assessed microscopically and via micro-CT.

RESULTS

The maxillary sinus of the adult pig exhibits an average length of 51±6.2 mm, a height of 31±4.1 mm, a width of 19±1.6 mm and a volume of 31±7.6 cm(3) . At least one septum could be observed on the floor of each sinus. The mucosal thickness amounted to a mean of 1692±138 μm, and the lateral bony wall of the sinus to a mean of 3±0.3 mm. A laceration of the Schneiderian membrane occurred in 25% during the elevation process.

CONCLUSION

The maxillary sinus of adult domestic pigs is a suitable model for sinus floor elevation training and research with greater elevation heights of up to 10 mm.

Serial cytokine levels during wound healing in rabbit maxillary sinus mucosa

CONCLUSION

Collagen deposition was increased in regenerative rabbit maxillary mucosa, and the elevated collagen deposition during wound healing was associated with increased interleukin (IL)-6 and IL-8, and decreased IL-10.

OBJECTIVES

To observe the natural progression of wound healing in rabbit maxillary sinus mucosa and to detect the expression of relevant cytokines.

METHODS

A rabbit wound-healing model was established in the maxillary sinus. At different times after injury, the sizes of maxillary ostia were recorded, and histological changes in the sinus mucosa were examined by means of hematoxylin and eosin (H&E) and Masson trichrome staining. Enzyme-linked immunosorbent assay (ELISA) was used to detect the concentrations of IL-6, IL-8, IL-10, and collagen types I and III.

RESULTS

A large amount of immature spindled collagen deposition was observed in the basal lamina and lamina propria of regenerative mucosa. IL-6 was increased significantly in regenerative mucosa after injury, especially at 14 days post wounding when compared with normal mucosa. IL-8 was also increased significantly in regenerative mucosa; however, IL-10 was decreased significantly when compared with normal mucosa. IL-6 and IL-8 showed a significant correlation with the expression level of collagen type I.

[Wound healing after endoscopic sinus surgery and postoperative management]

Understanding the physiological concepts of wound healing after rhinologic procedures facilitates detection and management of more or less obvious problems of wound healing. In this review, the physiologic processes involved in wound healing are explained, and typical clinical constellations are presented. Based on challenges of anatomy and physiology, recent findings are summarized, and possible conclusions for managing the postoperative mucosa are drawn.

Histological outcomes on the development of new space-making devices for maxillary sinus floor augmentation

BACKGROUND

Previous studies have pointed out that the mere elevation of the maxillary sinus membrane promotes bone formation without the use of augmentation materials.

PURPOSE

This experimental study aimed at evaluating if the two-stage procedure for sinus floor augmentation could benefit from the use of a space-making device in order to increase the bone volume to enable later implant installation with good primary stability.

MATERIALS AND METHODS

Six male tufted capuchin primates (Cebus apella) were subjected to extraction of the three premolars and the first molar on both sides of the maxilla to create an edentulous area. The sinuses were opened using the lateral bone-wall window technique, and the membrane was elevated. One resorbable space-making device was inserted in each maxillary sinus, and the bone window was returned in place. The animals were euthanatized after 6 months, and biopsy blocks containing the whole maxillary sinus and surrounding soft tissues were prepared for ground sections.

RESULTS

The histological examination of the specimens showed bone formation in contact with both the schneiderian membrane and the device in most cases even when the device was displaced. The process of bone formation indicates that this technique is potentially useful for two-stage sinus floor augmentation. The lack of stabilization of the device within the sinus demands further improvement of space-makers for predictable bone augmentation.

CONCLUSIONS

It is concluded that (1) the device used in this study did not trigger any important inflammatory reaction; (2) when the sinus membrane was elevated, bone formation was a constant finding; and (3) an ideal space-making device should be stable and elevate the membrane to ensure a maintained connection between the membrane and the secluded space.

Efficacy of different techniques of sinonasal irrigation after modified Lothrop procedure

BACKGROUND

Postoperative irrigation after endoscopic sinus surgery and endoscopic modified Lothrop procedure is used to remove nasal crusts and to improve wound healing. To evaluate the optimal application protocol for irrigation of the frontal sinus, a prospective cadaver study was performed.

METHODS

An endoscopic modified Lothrop procedure and complete sphenoethmoidectomy were performed in 19 heads. Each was irrigated with a 1.5% solution of water and different colors using nasal spray and a squeeze bottle filled with 50, 100, and 200 mL. Intensity of local staining and percentage of area were documented using standardized videoendoscopy after irrigation in "bending over the sink" or "vertex to floor" position. Grading was performed by two independent observers for 23 anatomic regions, including the stained circumference of maxillary and frontal ostia. To evaluate the influence of the anatomy, acoustic rhinometry was performed. ANOVA was used to evaluate effects of application methods and head positions using GenStat 8.2 (Lawes Agricultural Trust, Rothamsted Experimental Station, Harpenden, U.K.) using an appropriate block structure.

RESULTS

With regard to the frontal sinus, we were able to show clear superiority of the squeeze bottle technique filled with 200 mL and applied in the "vertex to floor position."

CONCLUSION

In a relatively fit and flexible patient the vertex to floor position using a squeeze bottle technique is advocated. There may be some patients, however, for whom this position is not feasible. In these patients "bending over the sink," while inferior to the "vertex to floor" position, still ensures some irrigation of the frontal sinus.

Maxillary sinus-floor elevation: an animal model

OBJECTIVES

To find an animal model for modified Caldwell-Luc procedure training. The animal model should have (1) a proper cortical thickness in the lateral wall; (2) a similar morphology and resistance of the Schneiderian membrane in humans; and, finally, (3) an oral approach.

MATERIALS AND METHODS

Twelve fresh heads (four Merino sheep, four Murciano-Granadina goats and four Large-White pigs). Two skulls from each of these species were also used. Several three-dimensional imagings from the skulls of each species were acquired using a C-arm. Two fresh heads of each species were used to perform the modified Caldwell-Luc procedure. Two fresh heads of each species were firstly frozen at -30 degrees C for 48 h and then sawed in blocks containing only the target region of the maxillary sinus.

RESULTS

The average thickness was 2.03 mm in goat and sheep and 2.80 in pig. Releasing and elevation of the Schneiderian membrane from the sinus floor were easy in the three species. The approach of the maxillary sinus in sheep, goat and pig from the buccal vestibule required a previous surgical enlargement of the buccal vestibule.

CONCLUSIONS

In conclusion, the cortical bone thickness and Schneider membrane characteristics in Merina sheep and Murciano-Granadina goat allow a perfect training for the modified Caldwell-Luc procedure. However, the approach from the oral cavity needs, in these species, a previous enlargement of the buccal vestibule. The excessive thickness of the cortical bone restricts the use of pigs for this technique.

Isolated posterior table frontal sinus fractures do not form mucoceles in a goat model

OBJECTIVE

The goal of this study was to investigate how patency of the nasofrontal outflow tract would affect frontal sinus healing in the setting of displaced, comminuted, posterior table fractures in the adult goat (Capra hircus).

STUDY DESIGN

Prospective animal study.

SUBJECTS AND METHODS

Posterior table fractures were created in 20 adult goats. The nasofrontal outflow tract was left patent in 10 goats (Group 1) and obstructed in 10 (Group 2). Gross, radiologic, and histologic evaluation were carried out six months postoperatively.

RESULTS

One of nine subjects subjects (11%) in Group 1 developed a mucocele while eight of 10 (80%) in Group 2 developed mucoceles (P = 0.004). No subjects (100%) in Group 1 had gross, radiologic, or histologic evidence of mucosal ingrowth into the posterior table, while two of 10 (20%) in Group 2 showed evidence of mucosal ingrowth into, but not through, the posterior table. In both groups 100% of the subjects had gross and histologic evidence of intact posterior tables abutting the dura.

CONCLUSION

An occluded nasofrontal outflow tract leads to an increased mucocele formation rate at six months. In an unobstructed nasofrontal outflow tract there is no gross, radiologic, or histologic evidence of mucosal ingrowth into the posterior table at six months. These findings would suggest that not all comminuted, significantly displaced posterior table fractures need to be surgically addressed if the nasofrontal outflow tract is patent.

Functional study of nasal mucosa in endoscopic sinus surgery and its correlation to electron microscopy of cilia

The effect of functional endoscopic sinus surgery (FESS) was evaluated in 20 patients with chronic sinusitis. The physiological function of sinus mucosa and its mucociliary transport mechanism was assessed pre and post operatively in patients undergoing FESS by performing Saccharin clearance test. The effect of functional sinus surgery on nasal mucosa was evaluated using scanning electron microscopy and study of the ultrastructure of cilia in pre and post operative patients and correlation with histopathological examination. The mucociliary transport mechanism of the sinus mucosa improved 6 weeks following surgery. Histopathologically there was evidence of improvement in the ciliary population and decrease in inflammation, ulceration, fibrosis, vascular congestion, edema, squamous cell metaplasia, basement membrane thickening and polyp formation in comparison to the diseased mucosa sampled preoperatively. Scanning electron microscopic examination revealed considerable increase in the ciliary area as well as the orientation of cilia. Subjective improvement 6 weeks following surgery was confirmed by decrease in saccharin test time. This study revealed that FESS is an effective surgical procedure in chronic sinusitis and improves the overall function of the sinuses.

Rehabilitation of surgically traumatized paranasal sinus mucosa using retinoic acid

BACKGROUND

Paranasal sinus mucosa that regenerates after surgical stripping is characterized by sparse, dysmorphic cilia. Although such dysfunctional mucosal changes are thought to be irreversible, the potential rehabilitation of deciliated mucosa by topical therapies has not been explored. This study evaluated the effect of topical retinoic acid (RA) in rehabilitating deciliated sinus mucosa that has regenerated after surgical stripping.

METHODS

Twelve New Zealand rabbits underwent bilateral maxillary sinus mucosal stripping and were allowed to remucosalize for 10 days. In the first treatment arm (n = 6), 0.01% RA was applied to the regenerated mucosa of the left maxillary sinus and an aqueous control was placed contralaterally. In the second treatment arm, the regenerated mucosa was surgically restripped bilaterally before applying RA and control. After 14 additional days, mucosa was harvested and examined by scanning electron microscopy for ciliary density, orientation, and morphology.

RESULTS

In the first treatment arm, no significant differences in ciliary density, orientation, or morphology were noted between RA-treated sinuses and controls. In the second arm, RA-treated sinuses showed improved ciliary density, morphology, and orientation compared with controls.

CONCLUSION

RA does not appear to significantly enhance ciliogenesis when applied after mucosal regeneration has occurred. However, if deciliated mucosa is restripped and allowed to regenerate in the presence of RA, ciliary ultrastructural features may be enhanced. RA may have therapeutic value in rehabilitating deciliated sinus mucosa when applied before mucociliary differentiation of regenerating mucosa.

Bone changes after maxillary sinus surgery: an experimental scanning electron microscopy study

AIMS

The purpose of this study was to explore the pathogenic role of bone in sinus surgery, and to determine whether mucosal disease after sinus surgery may be induced by underlying disease within the bone.

MATERIAL AND METHODS

Twenty-five rabbits were divided into five groups. In group one, wide surgical removal of the maxillary sinus mucosa and creation of a nasoantral window were undertaken. In group two, only nasoantral window creation was undertaken. In group three, the mucosa of the anterior maxillary sinus was removed. In group four, a strip of mucosa around the ostium was removed. Group five was used as a control.

RESULTS

After three months, in the groups which had undergone wide surgical removal, the medial sinus walls were observed to be retracted and the inner curtain of the bone disturbed, with alteration of the haversian canal system and osteoclastic bone resorption.

CONCLUSIONS

After radical sinus surgery, electron microscopic changes were observed in the bony walls, similar to those changes seen in osteomyelitis.

Cyanoacrylate adhesive for closing sinus membrane perforations during sinus lifts

INTRODUCTION

Sinus lift procedures depend greatly on fragile structures and anatomical variations. The procedure may cause sinus membrane perforations, which can lead to graft infection and early failure.

AIM

To assess the efficacy of cyanoacrylate adhesive in the management of large perforations of the maxillary sinus membrane during sinus lifts.

MATERIAL AND METHODS

Six rabbits were used in the study. Sinus membrane perforations (about 1.5 cm in length) were repaired with cyanoacrylate adhesive on one side of the maxillary sinus. On the contralateral side, an identical laceration was not repaired. Histological evaluation was performed 2 weeks after the operation.

RESULTS

Wounds repaired with cyanoacrylate adhesive showed newly formed continuous epithelium across the previous perforation site and there was sinusitis on the contralateral side.

CONCLUSION

These results support the clinical use of cyanoacrylate adhesive for repairing sinus membrane perforations.

Retinoic acid improves ciliogenesis after surgery of the maxillary sinus in rabbits

OBJECTIVES/HYPOTHESIS

Retinoids have been shown to be important cofactors in regulating the differentiation and proliferation of ciliated epithelial cells of the respiratory tract. In particular, retinoic acid has been shown to enhance the regeneration of paranasal sinus mucosa. The objective of this study is to use scanning electron microscopy techniques to evaluate the effect of topical retinoic acid on mucosal wound healing in a rabbit model of maxillary sinus surgery. It is hypothesized that the application of topical retinoic acid will enhance ciliogenesis and improve the morphology of regenerated cilia compared with controls.

STUDY DESIGN

Prospective multi-arm controlled animal trial.

METHODS

Eighteen New Zealand white rabbits underwent surgical opening of the maxillary sinuses through a midline incision. The rabbits were divided among four experimental groups: 1) mucosal stripping alone (stripped control), 2) stripping followed by topical application of an inert aqueous gel, 3) stripping followed by application of 0.01% retinoic acid in aqueous gel, and 4) no mucosal stripping and no topical treatment (nonstripped control). After 14 days, the medial wall of the maxillary sinus was harvested and examined by scanning electron microscopy at x2,000 and x5,000 magnification. The micrographs were then rated by a blinded review panel for ciliary density, orientation, and morphology.

RESULTS

Mean scores for ciliary density, orientation, and morphology were all significantly higher for the retinoic acid treatment group compared with both the inert aqueous gel treatment group and the stripped control group (P=.004-.03 for all comparisons, Student's t test). Mean scores for the retinoic acid treatment group were numerically lower than the nonstripped control group but did not approach statistical significance for any parameter (P=.23-.31).

CONCLUSIONS

In a rabbit model of maxillary sinus surgery, topically delivered retinoic acid enhances ciliogenesis. Qualitative assessment of ciliary density, orientation, and morphology shows improved healing in retinoic acid treated sinuses compared with both untreated control sinuses and aqueous gel treated sinuses.

Mucosal healing and mucociliary transport change after endoscopic sinus surgery in children with chronic maxillary sinusitis

OBJECTIVES

The aim of the study was to evaluate the effects of endoscopic sinus surgery for chronic maxillary sinusitis in children by investigating ultrastructure element changes in the sinus mucosa and nasal mucociliary clearance before and after operation.

METHODS

Twenty-five children with chronic maxillary sinusitis scheduled to undergo functional endoscopic sinus surgery and another five controls were enrolled. A saccharin transit test was performed before and after the operation for each subject. Forty specimens of diseased maxillary sinus mucosa were classified into edematous and polypoid types, with 20 specimens in each type. The mucosal specimens were taken from the superolateral wall of each maxillary sinus during surgery and at post-operative follow-up when the mucosal recovery had begun and the symptoms had subsided. The specimens were examined with a scanning electron microscope.

RESULTS

A significant increase in number of the submucosal gland openings (GO) was noted for the sinusitis group, of both edematous and polypoid types. In post-operative cases, the number of gland openings decreased, however, it remained higher than for the control group. The number of goblet cells (GC) decreased in the sinusitis cases, and significant difference was not demonstrated compared to postoperative and control groups. After endoscopic sinus surgery, the cilia in both types of antral mucosa were significantly regenerated compared to preoperative variants. Significant differences in postoperative saccharin transit time were demonstrated for both types of antral mucosa compared to the preoperative values.

CONCLUSION

After endoscopic sinus surgery for chronic pediatric sinusitis, the antral mucosa recovered and mucociliary clearance improved for both types of antral mucosa, with improved ventilation and drainage demonstrated for our patients. Based on our specimens, the edematous mucosa appear to regenerate sooner than the polypoid variant, with close post-operative follow-up for more than 2 and 4 months for the edematous and polypoid types of antral mucosa, respectively, necessary to prevent sinusitis relapse.

The use of autologous fibrin glue for closing sinus membrane perforations during sinus lifts

Sinus lift procedures depend greatly on fragile structures and anatomical variations. These procedures may cause sinus membrane perforations, which can lead to graft infection and early failure. The aim of this study was to assess the efficacy of autologous fibrin glue in the management of large perforations of the maxillary sinus membrane occurring during sinus lifts. After elevating the sinus membrane in the bilateral maxillary sinuses of 6 adult female mongrel dogs, a laceration (about 2.0 cm in length) was made in the membrane and either repaired with autologous fibrin glue or covered with a bioabsorbable collagen membrane as a control. Wounded areas were biopsied 2 weeks after the operation. Wounds repaired with autologous fibrin glue showed newly formed continuous epithelium across the previous perforation site. However, extensive fibrosis, inflammatory infiltration, and absent epithelium were observed in wounds treated with the collagen membrane control. Our results support the clinical use of autologous fibrin glue for repairing sinus membrane perforations.

Internal Fixation in Trapdoor-Type Orbital Blowout Fracture

BACKGROUND

The most common orbital blowout fracture is a trapdoor type. In many cases of trapdoor fracture, the bony segment has a stable hinge consisting of a greenstick fracture and the sinus mucoperiosteum that is attached to the intact orbital wall. If the displaced bony segment opposite the hinge is reduced into the original position and fixed on the unaffected bone, the orbital fracture may be reconstructed by internal fixation of the bony segment itself rather than requiring substitution with alloplastic implants or a bone graft.

METHODS

In 20 cases of orbital blowout fracture of a trapdoor type, internal fixation was performed using a cantilever fixation technique (with a piece of titanium micromesh or a titanium microplate plus a microscrew) or a ledge fixation technique (with a piece of micromesh).

RESULTS

In all cases, the orbital wall was accurately reconstructed in its normal anatomical position. The associated ocular problems disappeared except for mild diplopia in one patient and there were no surgical complications associated with the internal fixation.

CONCLUSIONS

The advantages of internal fixation include anatomical reconstruction of the orbital wall; preservation of the original orbital bone and the mucoperiosteum of the sinus as an osteomucoperiosteal flap resulting in rapid wound healing and normal mucus drainage function of the sinus; the simplicity of the procedure; and consequently, the absence of surgery-related complications. This technique is presented as one of the preferred treatments for trapdoor-type orbital blowout fractures.

[Contribution of computed tomography in experimental sinus surgery]

OBJECTIVES

To study the contribution of computed tomography (CT) to evaluate the intensity of the sinus mucosa's response to an inflammatory stimulus.

MATERIAL AND METHODS

Eight New-Zealand white rabbits where used. Rabbit n degrees 1 was the control. CT, macroscopic examination with analysis of secretion volumes, and histological examination were used to study the response of the sinuses to inflammation.

RESULTS

There was perfect match between the CT scan aspect and the quantity of secretions (kappa and Cohen's coefficient=1). The CT scan aspect well correlated with inflammatory cell infiltration (kappa and Cohen's coefficients=0.8).

CONCLUSION

The CT scan contributes usefully to the analysis of sinus contents and can be used to assess the intensity of the sinus mucosal inflammatory reaction. Consequently, the CT scan can be used not only to validate an animal model of acute or chronic sinusitis, but can also be used to evaluate medical or surgical treatments in such an animal model.

Effects of surgery on the function of maxillary sinus mucosa

For chronic maxillary sinusitis, the most popular surgical approach for treatment is endoscopic sinus surgery (ESS). After these operations, however, it is not clear how well the surgery restores the normal mucociliary function. We examined the mucociliary clearance (MCC) in maxillary sinuses in chronic sinusitis before ESS and 6 months after the operations. The correlation of histology to MCC was also studied. Measurements of the mean residual mucociliary clearance (MCC) of maxillary sinuses was studied pre- and postoperatively with an isotope method. Biopsies taken during ESS and 6 months postoperatively were studied by electron microscopy (EM). Preoperative residual MCC from the maxillary sinuses was 77+/-26% (mean+/-SD). Six months postoperatively, residual MCC was 70+/-22%, only slightly better than preoperatively. Residual MCC was considered good (< or = 50%) in 12% of sinuses preoperatively and in 20% postoperatively. In preoperative sinuses, 14% did not show any mucociliary clearance compared to 11% postoperatively. As a single EM finding, metaplasia gave the poorest MCC (91%) and microvilli the best (68%). Mucociliary function in maxillary sinusitis remains poor even 6 months postoperatively, with many pathological findings still visible in the sinus epithelium. MCC correlates well with the histology of the mucosa. Surgery does not significantly improve the mucociliary function of sinus mucosa in chronic maxillary sinusitis.

Results of Caldwell-Luc after failed endoscopic middle meatus antrostomy in patients with chronic sinusitis

OBJECTIVES/HYPOTHESIS

The Caldwell-Luc operation for treatment of medically refractory chronic maxillary sinusitis has largely been replaced by functional endoscopic sinus surgery. Despite this change, the Caldwell-Luc procedure still has well documented indications including treatment of both failed endoscopic middle meatus antrostomy and irreversible mucosal changes. The purpose of the study was to review the authors' experience and results of Caldwell-Luc procedure after failed endoscopic middle meatus antrostomy in patients clinically deemed to have irreversible mucosal changes.

STUDY DESIGN

Retrospective review of preoperative and postoperative results of patients who underwent Caldwell-Luc procedure for refractory chronic maxillary sinusitis after failed endoscopic middle meatus antrostomy.

METHODS

The preoperative and postoperative clinical course of patients treated with Caldwell-Luc procedure performed by a single surgeon between 1996 and 2001 were reviewed. Only patients with a history of chronic sinusitis after failed maximal medical therapy, no prior Caldwell-Luc procedure, prior endoscopic middle meatus antrostomy, and at least 6 months of follow-up were included. Outcome measurements including documented endoscopic examinations and the need for repeat surgery, and postoperative computed tomography scan results were evaluated to assess treatment success.

RESULTS

The study involved 11 men and 26 women who underwent 50 Caldwell-Luc procedures. Caldwell-Luc procedure was performed bilaterally in 13 patients. The average number of prior endoscopic middle meatus antrostomies before Caldwell-Luc procedure was 2. Of all patients, 92% responded to surgical treatment as demonstrated by an endoscopic examination or computed tomography scan revealing a disease-free maxillary sinus. Repeat Caldwell-Luc procedure was required in 8.0% (n = 3) because of continued sinusitis. Two of the three cases with repeat Caldwell-Luc procedures demonstrated clinical improvement during follow-up. Average follow-up was 23.5 months.

CONCLUSION

Caldwell-Luc procedure seems to be highly effective in the management of medically refractory chronic sinusitis after failed endoscopic middle meatus antrostomy. Caldwell-Luc procedure should remain in the otolaryngologist's surgical repertoire for these selected cases.

Modified endoscopic lothrop as a salvage for the failed osteoplastic flap with obliteration

OBJECTIVE

To evaluate the effectiveness of the modified endoscopic Lothrop (MEL) procedure for the management of failed osteoplastic flap (OPF) with obliteration of the frontal sinuses.

SETTING

Adelaide University Academic Hospital Complex.

STUDY TYPE

Prospective case study of 16 patients presenting with symptoms after OPF with obliteration of the frontal sinuses.

MATERIALS AND METHODS

Sixteen patients presented with symptoms of frontal sinus pain after having previously undergone OPF and fat obliteration of the frontal sinuses. All patients underwent computed tomography scanning; 13 underwent magnetic resonance imaging scanning, and 6 underwent a bone scan with technetium to exclude frontal osteitis. All patients underwent exploration of the frontal sinuses by way of the MEL procedure.

RESULTS

Fifteen patients were found to have a frontal sinus mucocele, whereas one patient had no mucocele with only new bone and fibrous tissue found at the MEL procedure. Twelve of the 16 patients with mucoceles had resolution of their frontal headaches, with 15 having a patent and healthy communication between the mucocele and the nasal cavity. The one patient without a mucocele continues to have frontal pain. One patient underwent a successful MEL procedure but had persistent symptoms until a supraorbital ethmoid mucocele was removed at a revision procedure. Two other patients continued to have frontal headaches and pain despite a healthy ostium into the frontal sinus mucocele.

CONCLUSIONS

MEL is a viable alternative to revision OPF for symptomatic patients who are shown to have a mucocele of the frontal sinuses.