Clinical and technical factors in endoscopic skull base surgery associated with reconstructive success.

BACKGROUND: In this study, we identified key discrete clinical and technical factors that may correlate with primary reconstructive success in endoscopic skull base surgery (ESBS). METHODS: ESBS cases with intraoperative cerebrospinal fluid (CSF) leaks at four tertiary academic rhinology programs were retrospectively reviewed. Logistic regression identified factors associated with surgical outcomes by defect subsite (anterior cranial fossa [ACF], suprasellar [SS], purely sellar, posterior cranial fossa [PCF]). RESULTS: Of 706 patients (50.4% female), 61.9% had pituitary adenomas, 73.4% had sellar or SS defects, and 20.5% had high-flow intraoperative CSF leaks. The postoperative CSF leak rate was 7.8%. Larger defect size predicted ACF postoperative leaks; use of rigid reconstruction and older age protected against sellar postoperative leaks; and use of dural sealants compared to fibrin glue protected against PCF postoperative leaks. SS postoperative leaks occurred less frequently with the use of dural onlay. Body-mass index, intraoperative CSF leak flow rate, and the use of lumbar drain were not significantly associated with postoperative CSF leak. Meningitis was associated with larger tumors in ACF defects, nondissolvable nasal packing in SS defects, and high-flow intraoperative leaks in PCF defects. Sinus infections were more common in sellar defects with synthetic grafts and nondissolvable nasal packing. CONCLUSIONS: Depending on defect subsite, reconstructive success following ESBS may be influenced by factors, such as age, defect size, and the use of rigid reconstruction, dural onlay, and tissue sealants.

Recurrence rates of de-novo versus inverted papilloma-transformed sinonasal squamous cell carcinoma: a meta-analysis.

BACKGROUND: There is a paucity of reporting on recurrence patterns of de-novo sinonasal squamous cell carcinoma (DN-SCC) and inverted-papilloma-transformed sinonasal squamous cell carcinoma (IP-SCC). METHOD: A systematic literature review queried studies comparing recurrence patterns in patients with both DN-SCC and IP-SCC. Primary outcomes included local and regional recurrence and rates of distant metastasis. Of the 595 studies screened, eight were included. RESULTS: Patients with DN-SCC had significantly higher rates of positive margins, advanced T classification (T3/T4), treatment with chemotherapy and radiotherapy. There were no significant differences in local recurrence or regional recurrence. Overall risk of distant metastasis was lower in IP-SCC. DN-SCC, compared to IP-SCC, is more likely to present with advanced TNM classification and have positive margins after surgical resection, which may affect rates of distant metastasis and recurrence. CONCLUSIONS: The findings in this study suggest IP-SCC may be a less aggressive malignancy compared to DN-SCC, with the possibility of a reduced role for adjuvant therapy in IP-SCC. Further studies are required to better understand differences in tumor biology and treatments strategies between IP-SCC and DN-SCC.

Computational fluid dynamic modelling of maxillary sinus irrigation after maxillary antrostomy and modified endoscopic medial maxillectomy.

OBJECTIVE: For recalcitrant chronic maxillary sinusitis, modified endoscopic medial maxillectomy has been shown to be clinically beneficial after failed maxillary antrostomy as endoscopic medial maxillectomy may offer improved topical therapy delivery. This study compared irrigation patterns after maxillary antrostomy versus endoscopic medial maxillectomy, using computational fluid dynamic modelling. CASE REPORT: A 54-year-old female with left chronic maxillary sinusitis underwent maxillary antrostomy, followed by endoscopic medial maxillectomy. Computational fluid dynamic models were created after each surgery and used to simulate irrigations. RESULTS: After maxillary antrostomy, irrigation penetrated the maxillary sinus at 0.5 seconds, initially contacting the posterior wall. The maxillary sinus was half-filled at 2 seconds, and completely filled at 4 seconds. After endoscopic medial maxillectomy, irrigation penetrated the maxillary sinus at 0.5 seconds and immediately contacted all maxillary sinus walls. The maxillary sinus was completely filled by 2 seconds. CONCLUSION: Computational fluid dynamic modelling demonstrated that endoscopic medial maxillectomy allowed faster, more forceful irrigation to all maxillary sinus walls compared with maxillary antrostomy.

Using 3D printed sinonasal models to visualize and optimize personalized sinonasal sinus irrigation strategies.

BACKGROUND: Topical sinus irrigations (neti-pot, squeeze bottles) play a critical role in the management of sinonasal disease. However, due to intricate nasal anatomy, penetration of topical irrigations to targeted sinus regions may be highly variable, and difficult to objectively predict. Variables, including head positions, injection angles, flow rates, etc. may vary significantly depending on the individual's anatomy. OBJECTIVE: The purpose of this study was to propose a novel idea: using a 3D printed model of sinonasal cavities to visualize and develop a patient-specific irrigation strategy. METHODS: As a proof of concept, 3D replicas of one patient's sinonasal cavities pre- and post-surgery were printed with a Form2 SLA 3D printer based on their CT scans. The setup included rubber/silicon seals attached to the model's nostrils to create a watertight seal with the irrigation device and food color dye added for better visualization of irrigation results. RESULTS: Irrigations were performed on the 3D models with various head positions, injection angles, and flow rates, and were successful to determine the optimal strategy to targeted sinuses. Significant differences were observed between different targeted sinuses and between pre and post-surgery models. CONCLUSION: With more affordable 3D printing, this technology may potentially improve patient care and patient education, allowing clinicians and patients to develop a personalized irrigation strategy and have visual confirmation.

Deposition of drugs in the nose and sinuses with an exhalation delivery system vs conventional nasal spray or high-volume irrigation in Draf II/III post-surgical anatomy.

BACKGROUND: Endoscopic sinus surgery is often performed to improve delivery of topical medication into sinus cavities. Intranasal steroids are guideline recommended in post-surgical patients, and experiments with cadavers suggest that surgery improves delivery of drug into sinuses. Exhalation delivery systems (EDS) use a new mechanism for intranasal delivery and have been shown to reach superior/posterior regions of the nasal cavity better than nasal sprays in unoperated patients. METHODS: Silicone casts of the nasal cavity and sinuses from a patient after Draf II, and then Draf III, were made from high-resolution computed tomography (CT) data using 3D printing. Internal surfaces were coated with liquid-sensitive, color-changing gel. Color changes were evaluated following conventional nasal spray delivery (0.1 mL x 2) (Nasonex), EDS delivery (0.1 mL x 2) (XHANCE), and high-volume, low-flow (HVLF) delivery (80 mL) with head tilted either 45° or 90°. RESULTS: Conventional nasal spray deposited liquid only in anterior nasal segments. EDS deposited liquid throughout the nasal cavity, in surgically opened ethmoid and maxillary spaces, at entrances of the frontal sinuses in Draf II geometry, and into frontal sinuses in Draf III. Tilted 45° HVLF delivery enters the maxillary sinuses but not the frontal sinuses or the ethmoid region. At full 90° inclination, HVLF delivery reaches most of the frontal and maxillary sinuses but not the roof and posterior wall of the ethmoid region. CONCLUSIONS: HVLF and EDS produced a deep intranasal/intrasinal deposition in the silicone cast compared with conventional nasal spray delivery; both deposited liquid inside the surgically opened sinuses. HVLF offers the benefit of lavage, whereas EDS may be more efficient and convenient.

The fate of the bone graft in cerebrospinal fluid rhinorrhea endoscopic repair for idiopathic intracranial hypertension: a retrospective case series analysis.

INTRODUCTION: Idiopathic intracranial hypertension (IIH) is a common cause of spontaneous cerebrospinal fluid (CSF) leaks necessitating surgical intervention, and grafting of septal, mastoid, or turbinate bone over the defect is increasingly performed to strengthen the repair of the primary defect. However, the postoperative fate of these grafted bone fragments is largely unknown. METHODOLOGY: We performed a retrospective study of patients at the University of Pennsylvania undergoing repair of spontaneous CSF leaks secondary to IIH. Preoperative and postoperative CTs were analyzed to determine the integration status of the transplanted bone. RESULTS: Fourteen patients with IIH and spontaneous CSF leak were analyzed, with a mean postoperative imaging follow-up period of four years. Thirteen patients (93%) had bone present on CT imaging, with 11 of these patients displaying evidence of bone integration. Two patients (14%) had a recurrent CSF leak in the same area, including the patient with absence of bone on imaging follow-up. CONCLUSIONS: Bone grafts frequently incorporate when used for repair of spontaneous CSF leaks associated with IIH. The rate of incorporation is comparable to bone grafts used for other etiologies of CSF leak, despite the increased pressure on the repair site. Any rigid repair of the leak site should likely be accompanied by treatment of the underlying intracranial hypertension to avoid leak recurrence.

Reconstructive challenges in the extended endoscopic transclival approach.

OBJECTIVE: We wanted to present our experience with the extended endoscopic approach to clival pathology, focusing on cerebrospinal fluid leak and reconstruction challenges. METHODS: We examined a consecutive series of 37 patients undergoing the extended endoscopic approach for skull base tumours, 9 patients with clival pathology. Patients were examined for the incidence of post-operative cerebrospinal fluid leak in relation to tumour pathology, location, size, reconstruction and lumbar drain. RESULTS: The overall incidence of post-operative cerebrospinal fluid leak was 10.8 per cent. Seventy-five per cent of patients who had a post-operative cerebrospinal fluid leak underwent a transclival approach (p < 0.05). All patients with clival pathology who underwent an intradural dissection had a post-operative cerebrospinal fluid leak (p < 0.05). CONCLUSION: Post-operative cerebrospinal fluid leak rates after the extended endoscopic approach have improved significantly after advancements including the vascularised nasoseptal flap. Despite this, transclival approaches continue to pose much difficulty. Further investigation is necessary to develop technical improvements that can meet the unique challenges associated with this region.

MR imaging evolution of endoscopic cranial defect reconstructions using nasoseptal flaps and their distinction from neoplasm.

BACKGROUND AND PURPOSE: Endoscopic endonasal approach is the procedure of choice for the resection of ventral skull base neoplasms, with defect closure requiring multilayer reconstruction. This study evaluates the temporal MR imaging evolution of nasoseptal flaps and free grafts used in endoscopic skull base reconstruction. MATERIALS AND METHODS: Sixty-nine follow-up brain MRIs of 22 patients who had endoscopic skull base reconstruction using 26 nasoseptal flaps combined with 8 collagen-matrix dural grafts, 10 fascia lata grafts, and 10 intracranial fat grafts were retrospectively reviewed. Temporal changes in signal intensity, enhancement, thickness, and the configuration of reconstructive layers were evaluated. Tissue with signal intensity or enhancement different from that of normal evolving reconstructive layers at the surgical bed was evaluated, and its association with clinically confirmed tumor was assessed with the Fisher exact test. RESULTS: All normal reconstructive layers were retracted to cranial defects and showed maturation of imaging features within 2-6 months. The immediate postoperative T2-isointensity to brain and enhancement of nasoseptal flaps persisted, but the flap thickness was reduced by 20%-30% (average thickness, 4.5 ± 1.3 mm); additionally, the C shape and vascular pedicle of the nasoseptal flaps became indistinct, but the flap location remained unchanged. The initial appearance of the nonenhancing fascia lata with variable T2 signal intensity became enhancing with increasing T2-hypointensity and a graft-thickness reduction of ≥50% (average thickness, 3.5 ± 1.6 mm). All fat grafts showed progressive resorption. In 6 patients, abnormal tissue represented residual or recurrent tumor (P = .0001). CONCLUSIONS: Maturation and stability of multilayer endoscopic skull base reconstructions on MR imaging occurs within 2-6 months postoperatively. Understanding of the normal imaging evolution of endoscopic skull base reconstructions is essential to distinguish them from neoplasms.

Biofilm accumulation on endotracheal tubes following prolonged intubation.

OBJECTIVE: To demonstrate that patients who have been intubated for prolonged periods of time will have an increased likelihood of developing bacterial biofilm on their endotracheal tubes. METHODS: We collected endotracheal tubes from patients at the time of extubation, and analysed representative sections with scanning electron microscopy for morphologic evidence of biofilms. RESULTS: From September 2007 to September 2008, 32 endotracheal tubes were analysed with electron microscopy. Patients who had been intubated for 6 days or longer had a significantly higher percentage of endotracheal tubes that exhibited bacterial biofilms, compared with patients intubated for less than 6 days (88.9 versus 57.1 per cent, p = 0.0439). CONCLUSIONS: Longer duration of intubation is associated with a higher incidence of bacterial biofilm. Further research is needed to link the presence of bacterial biofilms to acquired laryngotracheal damage.

Real-time computed tomography image update for endoscopic skull base surgery.

INTRODUCTION: The development of computer-aided systems for endoscopic sinus surgery has enabled surgical navigation through diseased or surgically altered sinus anatomy with increased confidence. However, conventional computer-aided systems do not provide intra-operative updated computed tomography imaging. We describe the technical aspects of the xCAT, a new intra-operative mobile volume computed tomography scanner. TECHNICAL REPORT: A patient with a malignant melanoma unwittingly removed at another hospital underwent surgery for removal of the lateral nasal wall and directed biopsies, in an attempt to identify the site of tumour origin. The procedure was performed with the GE InstaTrak 3500 Plus computer-aided system, updated with intra-operative computed tomography images. Intra-operative, updated images were integrated successfully into the InstaTrak system, and these images were consistent with the observed endoscopic anatomy. CONCLUSION: The xCAT intra-operative mobile volume computed tomography scanner is a technological advancement that can assist the endoscopic sinus surgeon when performing complex rhinological and skull base procedures.

Endoscopic repair of frontal sinus cerebrospinal fluid leaks.

OBJECTIVE: To describe endoscopic management of frontal sinus cerebrospinal fluid (CSF) leaks. STUDY DESIGN: Retrospective. METHODS: We reviewed all frontal sinus CSF leaks treated using an endoscopic approach at our institutions from 1998 to 2003. CSF leaks originated immediately adjacent to or within the frontal recess or frontal sinus proper for inclusion in the study. Data collected included demographics, presenting signs and symptoms, site and size of skull-base defect, surgical approach, repair technique, and clinical follow up. RESULTS: Seven frontal sinus CSF leaks in six patients were repaired endoscopically. Average age of presentation was 45 years (range 25-65 years). Aetiology was idiopathic (three), congenital (one), accidental trauma (one), and surgical trauma (two). All patients presented with CSF rhinorrhea; two patients presented with meningitis. Four defects originated in the frontal recess, while two others involved the posterior table and frontal sinus outflow tract. Four patients had associated encephaloceles. We performed endoscopic repair in all six patients with one patient requiring an adjuvant osteoplastic flap without obliteration. All repairs were successful at the first attempt with a mean follow up of 13 months. All frontal sinuses remained patent on both post-operative endoscopic and radiographic exam. CONCLUSIONS: Endoscopic repair of frontal sinus CSF leaks and encephaloceles can be an effective method if meticulous attention is directed toward preservation of the frontal sinus outflow tract, thus avoiding an osteoplastic flap and obliteration. The major limiting factor for an endoscopic approach is extreme extension superiorly or laterally within the posterior table beyond the reach of current instrumentation.

Efficacy of endoscopic sinus surgery in the management of patients with asthma and chronic sinusitis.

An association between chronic sinusitis and asthma has been noted for many years, although the precise nature of the relationship is poorly understood. Earlier studies, using traditional surgical techniques, have demonstrated subjective improvement in asthmatic complaints. Reports demonstrating improvement following endoscopic sinus surgery for chronic sinusitis are rare. To report our experience with endoscopic sinus surgery and asthmatics, we reviewed the charts of 75 consecutive patients with asthma and chronic sinusitis who underwent endoscopic sinus surgery between 1994 and 1996. Study criteria included the following: chronic sinusitis, one year preoperative and one year postoperative follow-up from endoscopic sinus surgery, and asthma requiring inhaled steroids and oral prednisone for control. Many patients required prednisone bursts for control of asthma. Number of days and total dose of oral prednisone were used as objective measures of asthma control. Number of weeks of antibiotics was used as a relative measure of sinusitis. Fourteen of the 15 patients meeting study criteria decreased their postoperative prednisone requirement by total number of days (preoperative 84 versus postoperative 63 days [p < 0.0001]). Postoperatively, patients required an average of 1300 mg less oral prednisone (p < 0.033). Antibiotic use also decreased, with an average use of antibiotic nine weeks preoperatively versus seven weeks postoperatively (p < 0.045). This study provides corroborative objective evidence that, at least in the short term, endoscopic sinus surgery is efficacious in the management of patients with chronic sinusitis and asthma.

Interleukin-1 beta induces cardiac myocyte growth but inhibits cardiac fibroblast proliferation in culture.

Interleukin-1 (IL-1), initially called "endogenous pyrogen," is primarily known as a mediator of inflammation. However, it also plays many other diverse physiologic roles including the stimulation and inhibition of both primary cells in culture and the interstitial and parenchymal cells of a number of organs including the heart. In the heart, IL-1 expression has traditionally been reported in situations where there is immunologic myocardial injury such as occurs during transplant rejection and congestive heart failure. For this reason, all of the effects of IL-1 have been presumed to be deleterious. Using a cell culture model which allows both the muscle cells (myocytes) and nonmuscle cells (fibroblasts) to be evaluated separately, we have found that IL-1 induces both cardiac myocyte hypertrophy and reinitiates myocyte DNA synthesis. In stark contrast, IL-1 exerts a potent anti-proliferative effect on cardiac fibroblasts. To our knowledge this is the first report concerning the differential effects of IL-1 on myocardial cell growth in culture and, given the inducible expression of IL-1 by myocardial cells during stress, underscores the importance of investigating the complex nature of the intracardiac cell-cell interactions that occur in the heart.