Failure Pressures of Dural Repairs in a Porcine Ex Vivo Model: Novel Use of Titanium Clips Versus Tissue Glue.

OBJECTIVE: Endoscopic skull base surgery is advancing, and it is important to have reliable methods to repair the resulting defect. The objective of this study was to determine the failure pressures of 2 commonly used methods to repair large dural defects: collagen matrix underlay with fibrin glue and collagen matrix underlay with polyethylene glue, as well as a novel repair method: fascia lata with nonpenetrating titanium vascular clips. METHODS: The failure pressure of the 3 dural repairs was determined in a closed testing apparatus. Defects in porcine dura were created and collagen matrix grafts were used as an underlay followed by either fibrin glue (FG/CMG) or polyethylene glycol glue (PEG/CMG). A third condition using a segment of fascia lata was positioned flush with the edges of the dural defect and secured with titanium clips (TC/FL). Saline was infused to simulate increasing intracranial pressure (ICP) applied to the undersurface of the grafts until the repairs failed. RESULTS: The mean failure pressure of the PEG/CMG repair was 34.506 ± 14.822 cm H2O, FG/CMG was 12.413 ± 5.114 cm H2O, and TC/FL was 8.330 ± 3.483 cm H2O. There were statistically significant differences in mean failure pressures among the 3 repair methods. CONCLUSION: In this ex vivo model comparing skull base repairs' ability to withstand cerebrospinal fluid leak, the repairs that utilized PEG/CMG tolerated the greatest amount of pressure and was the only repair that exceeded normal physiologic ICP's. Repair methods utilizing glues generally tolerated higher pressures compared to the novel repair using clips alone.

Failure pressures after repairs of 2-cm × 2.5-cm rhinologic dural defects in a porcine ex vivo model.

BACKGROUND: The objective of this study was to determine failure pressures of 6 rhinologic repair techniques of large skull base/dural defects in a controlled, ex vivo model. METHODS: Failure pressures of 6 dural repairs in a porcine model were studied using a closed testing apparatus; 24-mm × 19-mm dural defects were created; 40-mm × 34-mm grafts composed of porcine Duragen (Integra), fascia lata, and Biodesign (Cook) were used either with or without Tisseel (Baxter International Inc.) to create 6 repairs: Duragen/no glue (D/NG), Duragen/Tisseel (D/T), fascia lata/no glue (FL/NG), fascia lata/Tisseel (FL/T), Biodesign/no glue (B/NG), and Biodesign/Tisseel (B/T). Saline was infused at 30 mL/hour, applying even force to the underside of the graft until repair failure. Five trials were performed per repair type for a total of 30 repairs. RESULTS: Mean failure pressures were as follows: D/NG 1.361 ± 0.169 cmH2 O; D/T 9.127 ± 1.805 cmH2 O; FL/NG 0.200 ± 0.109 cmH2 O; FL/T 7.833 ± 2.657 cmH2 O; B/NG 0.299 ± 0.109 cmH2 O; and B/T 2.67 ± 0.619 cmH2 O. There were statistically significant differences between glued (Tisseel) and non-glued repairs for each repair category (p < 0.05). CONCLUSION: All glued repairs performed better than non-glued repairs. Both D/T and FL/T repairs performed better than B/T repairs. No repair tolerated pressures throughout the full range of adult supine intracranial pressure.

Failure pressures of three rhinologic dural repairs in a porcine ex vivo model.

BACKGROUND: The objective of this work was to determine the failure pressures of 3 commonly performed repair techniques of 5-mm dural defects in a controlled setting. METHODS: This was a pig dura ex vivo study. A testing apparatus was fabricated to study failure pressures of 3 different repairs in a porcine model. Five-millimeter (5-mm) dural defects were created and plugged with autologous mucosa/Tisseel (MT) (Baxter International Inc.), fat graft (FG), and bath plug (BP) techniques. Saline solution was infused at 30 mL/hour to apply unidirectional pressure to the repair until failure occurred. Five dural repairs were performed for each arm of the trial, for a total of 15 trials. RESULTS: The mean failure pressure of the MT repair was 4.3 ± 1.9 cmH2 O, of the FG repair was 10.9 ± 4.2 cmH2 O, and of the BP repair was 20.7 ± 2.2 cmH2 O. Differences among mean failure pressures were statistically significant. CONCLUSION: The BP repair showed significantly higher tolerances for pressure than the other 2 repairs. The BP repair was the only technique that withstood adult physiologic supine cerebrospinal fluid (CSF) pressure.

Objective olfactory outcomes after revision endoscopic sinus surgery.

BACKGROUND: Patients who suffer from hyposmia and anosmia report a negative effect on their overall quality of life. Smell disturbance of patients with chronic rhinosinusitis (CRS) can improve after endoscopic sinus surgery (ESS). Although several studies have shown that 50-83% of patients may notice an improvement in olfactory function after ESS, the olfactory improvement after revision ESS (RESS), especially by objective measurements, is still lacking. METHODS: Olfactory function was assessed by the traditional Chinese version of the University of Pennsylvania Smell Identification Test (UPSIT-TC) preoperatively and postoperatively, recorded as smell identification test (SIT) score. Olfactory outcomes from anosmia to hyposmia/normosmia, or from hyposmia to normosmia, were considered as "improvement." Postoperative assessments were divided into two periods: period 1 (P1) is defined as >6 but <12 months postoperatively; period 2 (P2) is defined as >12 but <24 months postoperatively. RESULTS: Thirty-two patients with smell disturbance preoperatively (period 0 [P0]) and confirmed by UPSIT-TC were enrolled into this study. Mean SIT score at P0 was 13.3; mean SIT score at P1 was 18.6; mean SIT score at P2 was 20.4. The presence of nasal polyps blocking the olfactory cleft were associated with better olfaction improvements (p < 0.05) as was the degree of mucosal swelling. The overall improvement rates were 44.8 and 47.8% at P1 and P2, respectively. CONCLUSION: RESS resulted in objective evidence of olfactory improvement in approximately one-half of our cohort over 16 months of follow-up and offers a treatment option for an otherwise poor prognosis condition.

Endoscopic vidian neurectomy assisted by power instrumentation and coblation.

Vidian neurectomy has been used to manage intractable vasomotor rhinitis for decades. After the introduction of endoscopic sinus surgery in the 1980s, transnasal endoscopic vidian neurectomy (EVN) was subsequently reported. The most common problem in performing EVN was excessive bleeding from the pterygopalatine fossa. The complexity and vascularity of the pterygopalatine fossa can cause bloody surgical fields and prevent complete neurectomy. In response to this surgical problem, a procedure was developed to use powered instrumentation and coblation during EVN. There were eight cases of EVNs (16 neurectomies) assisted by power instrumentation and coblation from December 2011 to May 2012. The average blood loss of these cases was 37.5 mL (range, 25-50 mL). The average surgical time of each neurectomy was 27.4 minutes (range, 20-35 minutes). No complications occurred in any of the eight cases. Very limited bleeding and less thermal damage were noted while achieving a complete neurectomy.

Immunotherapy in allergic fungal sinusitis: The controversy continues. A recent review of literature.

Allergic fungal sinusitis (AFS), also referred to as allergic fungal rhinosinusitis (AFRS), is a noninvasive, eosinophilic form of recurrent chronic allergic hypertrophic rhinosinusitis. AFS has distinct clinical, histopathological, and prognostic findings that differentiate it from other forms of sinusitis. The core pathogenesis and optimum treatment strategies remain debated. Concerns surround the use of immunotherapy for AFS because allergen-specific immunoglobulin G (IgG) induced by immunotherapy could theoretically incite a Gell and Coombs type III (complex mediated) reaction. Type I hypersensitivity is established by high serum levels of allergen-specific IgE to various fungal antigens and positive Bipolaris skin test results. Type III hypersensitivity is established by an IgG-mediated process defined by the presence of allergen-specific IgG that forms complexes with fungal antigen inducing an immunologic inflammatory response. These reveal the multiple immunologic pathways through which AFS can impact host responses. Recent literature establishing benefits of fungal immunotherapy and no evidence of type III-mediated reactions, severe local reactions, or delayed reactions, indicate that application of AFS desensitization is a reasonable therapeutic strategy for this difficult to manage entity. Our review should encourage further clinical acceptance of AFS desensitization because the existing literature on this subject shows benefits of fungal immunotherapy and no evidence of type III-mediated reactions, severe local reactions, or delayed reactions.

Intravenous esmolol infusion improves surgical fields during sevoflurane-anesthetized endoscopic sinus surgery: a double-blind, randomized, placebo-controlled trial.

BACKGROUND: There is increasing evidence to support the use of anesthetics to affect operative fields during endoscopic sinus surgery and thus the speed, thoroughness, and safety of the surgery itself. Previous research has suggested preoperative beta-blockers improve surgical fields (SFs); our study is novel in showing the impact of a beta-blocker infusion on SFs during sinus surgery. METHODS: A prospective, randomized, double-blind, placebo-controlled trial was conducted in 40 patients. Patients undergoing endoscopic sinus surgery for chronic rhinosinusitis received a constant infusion of i.v. esmolol or saline in addition to a standard inhaled anesthetic protocol. At regular 15-minutes intervals, the quality of SF, heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were assessed. Total blood loss was also recorded. RESULTS: Average vital sign parameters (HR/SBP/DBP) were significantly lower in the esmolol group (69.1/90.2/55.1 versus 77.2/99.5/63.5; p < 0.01). The esmolol infusion improved SFs relative to control (2.3 versus 2.6; p = 0.045). Esmolol infusion resulted in good SFs (grades 1 and 2) more often than poor fields (grades 3 and 4); on the contrary, the control group showed more poor than good SFs (chi-square; p = 0.04). A correlation between increasing HR and worsening SFs was identified (r = 0.259; p = 0.002). The control group had significantly higher average blood loss (1.3 versus 0.8 mL/min; p = 0.037). CONCLUSION: Esmolol-induced relative hypotension and bradycardia during endoscopic sinus surgery achieves significantly improved SFs relative to saline control.

Retrospective study of full-house functional endoscopic sinus surgery for revision endoscopic sinus surgery.

BACKGROUND: Outcomes for revision endoscopic sinus surgery (RESS) are rarely reported in relation to technique. Our goal was to document the outcome of full-house functional endoscopic sinus surgery (FESS) (FHF) (complete sphenoethmoidectomy with Draf IIA frontal sinusotomy) for treatment of this recalcitrant group. METHODS: Twenty-one patients with chronic sinusitis having had at least 1 previous sinus surgery (mean, 2.14) underwent FHF, followed by postoperative nasal douching and oral antibiotics for 12 weeks. After a minimum 6 months of follow-up, patients were asked to complete a 5-item Patient Response Score (PRS) (graded on a 6-point scale from 1 = completely improved to 6 = much worse). Objective measures collected included computed tomography (CT) Lund MacKay score (L-M score, LMS), and endoscopic findings: mucosal swelling (MS) and mucopus (MP) (graded on a 4-point scale from 0 = none to 3 = severe). RESULTS: Patients were divided into 3 subgroups based on months of follow up from surgery: 6-12, 12-18, and 18-24. There was no statistical difference in any outcome based on length of follow up. Mean symptom outcome was reported as much improved (PRS = 1.9 ± 0.1). Both mucosal swelling and mucopus improved dramatically (2.48 vs 0.29, p < 0.001; 2.52 vs 0.29, p < 0.001, respectively). LMS also improved dramatically (11.52 vs 2.1, p < 0.001). Presence of nasal polyps did not affect any subjective or objective outcome. CONCLUSION: Marked improvements in symptoms and mucosal findings were consistently obtained with FHF between 6 and 24 months postoperatively.

Irrigation penetration of nasal delivery systems: a cadaver study.

BACKGROUND: To determine the sinus penetration potential of several commercially available irrigation systems in maximally operated sinus cavities; cadaveric study in a tertiary care center. METHODS: Seven fresh cadaver heads with brains removed were maximally dissected to include a Draf III frontal sinusotomy, wide maxillary antrostomy, and complete sphenoethmoidectomy. Drill-holes (4 mm) were created to allow visualization of the irrigations from within the respective sinus cavity. Seven commercially available irrigation systems were then tested according to manufacturer recommendation, and the data recorded using an ordinal scale for comparison. RESULTS: Among the 3 atomized particle delivery systems tested, the squeeze atomizer took 1.15 attempts, the pump atomizer took 1.85 attempts, and the mechanized atomizer required 30 seconds of continuous application for intrasinus delivery of aerosol (p = 0.009). Penetration with 4 heavy irrigators showed significant variability depending on the sinus cavity being tested. The NeilMed irrigator showed more consistent penetration than any other tested device (p < 0.01). The other systems tested had varying degrees of efficacy, dependent on sinus cavity irrigated. CONCLUSION: Delivery of irrigant to maximally operated sinus cavities is variable and highly dependent on the method of nasal delivery. Use of these systems should be tailored appropriately for the desired effect.

Cadaveric comparison of canine fossa vs transnasal maxillary sinus access.

OBJECTIVE: Anatomic limitations complicate complete eradication of debris from the maxillary sinus using an exclusively transnasal (TN) endoscopic technique. Creation of a canine fossa trephination (CFT) permits a more direct approach than removal via the maxillary ostium. METHODS: Microdebrider eradication of debris completely filling the maxillary sinus was performed on 5 thawed fresh-frozen cadaver heads (10 sides) using a TN or CFT approach. Postdebridement computed tomography (CT) scanning assessed remaining debris. Additional outcome measures included time of debris removal, number of different angled blades utilized, and clogging. RESULTS: A significantly greater amount of debris was left after the TN approach compared with CFT (3.88 cm(3) vs 2.88 cm(3), p = 0.015). Median blade utilization was significantly higher with the TN approach vs CFT (4 vs 1, p < 0.002). Time for debris eradication with CFT was similar regardless of expertise (323.4 vs 272.4 seconds, p = 0.21), but the TN approach showed a statistical difference in time-to-completion (698.8 vs 438.51 seconds, p = 1.7 × 10(-5)). CONCLUSION: Controversy surrounds the appropriate application of CFT due to disease process and approach-related morbidity. Rhinologists should have numerous well-studied options at their disposal. This model suggests that maxillary debris removal is accomplished more thoroughly with fewer microdebrider blades when a CFT approach is employed.

Effect of head position and surgical dissection on sinus irrigant penetration in cadavers.

BACKGROUND: Effective treatment for recalcitrant rhinosinusitis requires unobstructed surgical marsupialization of sinus cavities and use of delivery systems that will topically penetrate the sinuses. AIMS: To determine the extent of sinus penetration achieved with nasal irrigation by varying the ostial size and head position. METHODS: Ten thawed fresh-frozen cadaver heads were dissected in a staged manner. After each stage of dissection, sinus squeeze-bottle irrigations were performed in three head positions, and endoscopes placed via external ports into the sinus cavities viewed the sinus ostia. An ordinal scale was developed to grade ostial penetration of irrigations. Three reviewers independently graded the outcomes. RESULTS: Irrigant entry into sinuses increased with ostial size (P < .001) and the greatest differential of improvement in sinus penetration is obtained at an ostial size of 4.7 mm. Stages 2 and 3 (larger sinus ostia) of maxillary and sphenoid dissections have statistically greater irrigant penetration relative to earlier stages. Frontal sinus irrigation is worse in vertex to ceiling head position. There does not appear to be any significant advantage to head position with maxillary and sphenoid sinuses. CONCLUSIONS: This study shows that the larger the sinus ostium, the better the penetration of irrigant into the sinus, with an ostium of at least 4.7 mm allowing maximal penetration in the maxillary and sphenoid sinuses. The same benefit was not noted in the frontal sinus. Head position was only relevant to the frontal sinus where less penetration was seen with the head neutral (vertex to ceiling) position when compared to forward angled positions.

Validating the use of report-derived Lund-MacKay scores.

BACKGROUND: The Lund-MacKay score (LMS) is the standard for communicating radiological extent of chronic rhinosinusitis in research. However, retrospective analyses are often hindered by a substantial lack of radiological data. Calculating LMS from radiologists' reports may overcome this but has not been formally validated. METHODS: Twenty South Australian and 20 Texan patients with varying degrees of sinus disease were randomly chosen to undergo analysis. CT-derived LMSs were calculated directly by two expert rhinologists at each institution and compared with scores derived solely from accompanying radiology reports by two blinded reviewers. RESULTS: The total LMS obtained via the expert rhinologists correlated very highly with that obtained from radiology reports (Spearman rank correlation, 0.75-0.88; p < 0.001). However, when individual sinuses were specifically analyzed, the correlation was highly variable. CONCLUSION: The results show that in both South Australian and Texan tertiary rhinology centers, radiologists' reports can be reliably used to calculate the total LMS.

Otolaryngologic heuristics: a rhinologic perspective.

Rhinological heuristics are adapted from common principles within the field of otolaryngology. The most important principle in achieving quality endoscopic sinus surgery is good haemostatic control of the surgical field. Once this is achieved, the surgeon can then begin advancing to other heuristic principles. Thinking one to two moves in advance allows the surgeon to take advantage of the many dually purposed instruments available. Learning to visualize buried structures by their subtle projections quickly follows. Finally, an ergonomically positioned surgeon with intricate anatomical knowledge of the sinonasal cavities permits a second surgeon to assist and greatly expand the limit of what is possible.

A scientific review of middle meatal packing/stents.

BACKGROUND: Nasal packing usually is placed after endoscopic sinus surgery (ESS) to control hemorrhage, but also may be used to prevent adhesions from forming and promote faster healing of damaged mucosa. METHODS: A literature review was performed to identify all forms of scientifically evaluated absorbable packing for ESS. Only English studies identifiable within the PubMed database were included. Studies were categorized by level of evidence and evaluated for methodological errors. RESULTS: Thirty-eight studies met the inclusion criteria. There was a diverse range of article evidence and quality. CONCLUSION: The most effective hemostatic agent currently available is FloSeal; however, this product causes an increase in adhesion formation. For the purpose of preventing adhesions, resorbable packs appear to have no benefit over either nonresorbables or no packing. If the middle turbinate is unstable at the conclusion of surgery, suturing it to the septum may reduce adhesions. Although mitomycin C, hyaluronic acid, and retinoic acid all have shown potential in these roles, to date, none have shown to be useful in the post-ESS chronic sinusitis human patient.