Skull Base Dural Thickness and Relationship to Demographic Features: A Postmortem Study and Literature Review.

Dural membrane is an important anatomic structure that surrounds and protects the entire central nervous system. Physical properties of the dura have many pathophysiological and therapeutic implications in cranial surgery, especially skull base disorders. The aim of this study is to investigate variation in skull base dural thickness and correlation with different demographic parameters. At the time of autopsy, the petrous apex dura with the underlying bone of 20 cadavers was harvested. Dural thickness was independently measured by two pathologists at the thinnest and thickest segments in the specimen. Correlational analyses were then performed to compare dural thickness with gender, age, neck circumference, height, weight, and body mass index (BMI). Mean, minimum, and maximum skull base dural thickness in our study was 0.36, 0.27, and 0.46 mm, respectively. Age demonstrated a negative correlation with dural thickness with significantly thinner dura in the older subjects, p = 0.01. There was a trend toward thinner dura in females that approached statistical significance, p = 0.06. No strong correlation could be found with body weight, height, neck circumference, or BMI. Our findings show a considerable intersubject and intrasubject variability in skull base dural thickness. Some demographic parameters also seem to impact dural thickness. Additional histological studies are needed for better understanding of the pathophysiological mechanisms pertaining to the tensile properties of the dural membrane.

The hybrid lid crease approach to address lateral frontal sinus disease with orbital extension.

OBJECTIVE: This study aimed to describe the hybrid lid crease approach in conjunction with functional endoscopic sinus surgery (FESS) for lateral frontal sinus disease with orbital extension. STUDY DESIGN: Retrospective case review. METHODS: Patients undergoing hybrid lid crease approach with FESS for frontal sinus disease were reviewed retrospectively. Surgical indications consisted of inverting papilloma with extension into the frontal sinus (n = 1) and frontal sinus mucocele (n = 2). Inclusion criteria included presence of disease in the lateral frontal sinus with extension into the orbital space and erosion of the superior orbital rim. Preoperative and postoperative parameters included complete ophthalmologic exam, endoscopic exam, and computed tomography scan. RESULTS: We were able to access the frontal sinus and orbit in all 3 cases and address sinus pathology of the lateral frontal sinus and orbit using the lid crease approach with FESS. All patients had improvement in ophthalmologic symptoms and interval disease resolution and were satisfied with their postoperative lid crease incision. CONCLUSION: The lid crease approach offers direct access to the frontal sinus with minimal dissection through a well-hidden incision. In our case series of lateral frontal sinus pathology with orbital extension, the hybrid lid crease approach with FESS allowed complete eradication of disease without recurrence.

The effect of geniglossal advancement on airway flow using a computational flow dynamics model.

OBJECTIVES/HYPOTHESIS: Obstructive sleep apnea (OSA) is a sleep disorder caused by partial or complete collapse of the pharyngeal airway. Genioglossal advancement (GGA) is a well-tolerated surgical procedure intended to address hypopharyngeal collapse, yet there are few studies that monitor changes in airflow dynamics at this site. Computation fluid dynamics (CFD) utilizes airflow simulation to predict changes in airflow after anatomic manipulation. STUDY DESIGN: We investigated the change in volume and airflow dynamics of the pharyngeal airway after GGA in a cadaveric model. METHODS: We performed serial GGA from 1 mm (control) to 3, 7, and 9 mm on a lightly preserved cadaver. After each intervention, we performed high-resolution computed tomography scans, reconstructed the pharyngeal airway, and quantified airspace volume and CFD analysis with both laminar and large eddy simulation models. RESULTS: Airway volume increased with linear GGA. In both CFD simulation models, velocity increased and pressure decreased after 9-mm advancement secondary to increased airway diameter and less abrupt changes in airway geometry. CONCLUSIONS: These results suggest that GGA may be effective in increasing airway volume and flow to address hypopharyngeal obstruction in OSA.

Adenoviral gene transfer corrects the ion transport defect in the sinus epithelia of a porcine CF model.

Cystic fibrosis (CF) pigs spontaneously develop sinus and lung disease resembling human CF. The CF pig presents a unique opportunity to use gene transfer to test hypotheses to further understand the pathogenesis of CF sinus disease. In this study, we investigated the ion transport defect in the CF sinus and found that CF porcine sinus epithelia lack cyclic AMP (cAMP)-stimulated anion transport. We asked whether we could restore CF transmembrane conductance regulator gene (CFTR) current in the porcine CF sinus epithelia by gene transfer. We quantified CFTR transduction using an adenovirus expressing CFTR and green fluorescent protein (GFP). We found that as little as 7% of transduced cells restored 6% of CFTR current with 17-28% of transduced cells increasing CFTR current to 50% of non-CF levels. We also found that we could overcorrect cAMP-mediated current in non-CF epithelia. Our findings indicate that CF porcine sinus epithelia lack anion transport, and a relatively small number of cells expressing CFTR are required to rescue the ion transport phenotype. These studies support the use of the CF pig as a preclinical model for future gene therapy trials in CF sinusitis.

Sinus hypoplasia precedes sinus infection in a porcine model of cystic fibrosis.

OBJECTIVES/HYPOTHESIS: Chronic sinusitis is nearly universal in humans with cystic fibrosis (CF) and is accompanied by sinus hypoplasia (small sinuses). However, whether impaired sinus development is a primary feature of loss of the cystic fibrosis transmembrane conductance regulator (CFTR) or a secondary consequence of chronic infection remains unknown. Our objective was to study the early pathogenesis of sinus disease in CF. STUDY DESIGN: Animal/basic science research. METHODS: Sinus development was studied in a porcine CF model. RESULTS: Porcine sinus epithelia expressed CFTR and exhibited transepithelial anion transport. Disruption of the CFTR gene eliminated both. Sinuses of newborn CF pigs were not infected and showed no evidence of inflammation, yet were hypoplastic at birth. Older CF pigs spontaneously developed sinus disease similar to that seen in humans with CF. CONCLUSIONS: These results define a role for CFTR in sinus development and suggest the potential of the CF pig as a genetic model of CF-sinus disease in which to test therapeutic strategies to minimize sinus-related CF morbidity.

Retrograde sialendoscopy: a new technique for avoiding retained ductal stones.

OBJECTIVES: Recurrent infection from stones retained in Wharton's duct after submandibular gland resection warrants intraoperative attention to the duct remnant. Our hypothesis was that retrograde sialendoscopy would help ensure complete stone removal in submandibular gland removal for sialolithiasis. METHODS: We reviewed 9 sequential cases of submandibular sialolithiasis treated surgically via open procedures at a tertiary care center by a single surgeon between November 2007 and December 2009. The review focused on the clinical history and intraoperative findings. RESULTS: We identified successful application of a new technique of retrograde sialendoscopy performed to detect and remove stones that were retained in Wharton's duct at the time of submandibular gland resection. An index case of complications from a stone retained after submandibular gland resection is presented in a sequential series of cases in which retrograde sialendoscopy was developed. CONCLUSIONS: Retrograde sialendoscopy is a novel technique that is useful as an adjunct to standard submandibular gland resection in the management of sialolithiasis.

Successful reconstruction of scalp and skull defects: lessons learned from a large series.

OBJECTIVE: To provide a framework for the management of scalp and skull defects. DESIGN: Retrospective chart review. SETTING: Two tertiary care hospitals. PATIENTS/INTERVENTION: Fifty-six consecutive patients who underwent reconstruction of scalp and/or skull defects with free flaps, rotational skin/fascia flaps, skin grafts, and implants. Defects closed primarily and those of the lateral temporal bone and skull base were excluded. RESULTS: Sixty-two reconstructions were performed. Treatment of skin cancers and intracranial tumors necessitated 31 (50%) and 22 (35%) of the reconstructions, respectively. Defects included partial-thickness soft tissue (9, 15%), full-thickness soft tissue (28, 45%), full-thickness soft tissue and skull (17, 27%), and full-thickness soft tissue, skull, and dura (8, 13%). Radiation or prereconstruction wound breakdown or infection was involved in 33 (53%) and 25 (40%) of cases, respectively. The most common method of reconstruction was free tissue transfer (27, 44%) followed by local skin (15, 24%) or fascia (9, 15%) flaps. There was a 15% (9/62) complication rate; 89% (8/9) of these occurred in radiated tissues and 44% (4/9) occurred in smokers. Seven of the nine patients with complications (78%) were managed with local wound care and/or removal of an implant, whereas 2 (22%) required a second reconstructive procedure. All patients ultimately achieved a safe outcome with no infection and no bone or dural exposure. CONCLUSIONS: In addition to defect location and extent, availability of surrounding tissue and wound healing characteristics direct reconstruction. Patients who receive radiation therapy are at increased risk of complications. Use of vascularized tissue is critical for successful management, making local flaps and free tissue transfer the mainstay of reconstruction.

Continued alcohol use in patients with head and neck cancer.

BACKGROUND: The effect of posttreatment alcohol consumption on health-related quality of life (QOL) and factors predicting overall QOL and continued alcohol consumption were examined in patients with head and neck cancer. METHODS: Self-reported alcohol use and abuse 1 year after diagnosis was analyzed. RESULTS: Although current drinkers (44.5% of 283 patients) had better overall QOL and fewer depressive symptoms, current social drinkers had the best scores, whereas current problem drinkers had the worst. Female sex, fewer depressive symptoms, less pain, and better eating function predicted better QOL. Oral function was the only predictor of 12-month alcohol use. CONCLUSION: Depression, pain, and eating function predicted overall QOL. Alcohol consumption was not associated with QOL, but was associated with better oral function, which in turn predicted better QOL. Alcohol consumption itself does not improve QOL in this population, and these patients should be counseled regarding detrimental effects of continued drinking after treatment.