Daniel Timperley

Using fixed anatomical landmarks in endoscopic skull base surgery

Background The identification of anatomic landmarks in endoscopic skull base or revision sinus surgery can be challenging. Normal anatomy is significantly altered with many paranasal tumors. Traditional endoscopic surgical landmarks extrapolated from inflammatory disease, such as the superior turbinate, may have been previously removed or involved in pathology. A frequently used rule to enter the sphenoid, “stay below or at the level of the orbital floor as dissection proceeds posteriorly and one will avoid the skull base,” is assessed anatomically. Methods The maxillary sinus roof height, relative to the nasal floor, was assessed as an operative landmark. Computed tomography (CT) performed on paranasal sinuses was studied. The relative height, ratio, and proportions of the maxillary sinus, ethmoid roof, cribriform fossa, and sphenoid planum were measured using computerized assessments. Results Three hundred paranasal sinus systems were evaluated. The roof of the maxillary sinus was below the level of the skull base in 100% relative to the cribriform and 100% relative to the sphenoid planum. The mean distance of the maxillary roof below the skull base was 10.1 ± 2.7 mm for the cribriform and 11.0 ± 2.9 mm for the sphenoid. Conclusion The maxillary sinus roof can be used as a robust landmark to allow safe dissection and debulking of pathology. Pathology removal can proceed posterior with this landmark to enable a safe entry to the sphenoid sinus, and thus the true skull base, when normal structures such as the superior turbinate and ostium are not available.

Minimal clinically important differences in nasal peak inspiratory flow.

INTRODUCTION Acoustic Rhinometry, Rhinomanometry, Nasal Spirometry and Nasal Peak Inspiratory flow (NPIF) all measure subtly different constructs of nasal function. All have limitations but NPIF is simple and quick to integrate into clinical practice. The minimum clinically important difference (MCID) for an outcome measure is an estimate of the smallest change that is experienced by a patient or group as being significant. Studies, particularly with large samples, may generate results that while statistically significant, have limited clinical effect. Defining MCID allows an assessment of the clinical impact of an intervention. This study defines the MCID for NPIF. METHODS Prospective study of patients from a tertiary clinic undergoing open septorhinoplasty. Nasal obstruction scores and NPIF were recorded before and after surgery. Global function and nasal obstruction scores were used to assess subjective change. Statistical based and patient anchored techniques were used to define MCID. RESULTS 51 patients with a mean age 36 +- 13 yrs (75% female) were recruited. All had open rhinoplasty, septal reconstruction, spreader grafts and turbinate reduction. Baseline NPIF was 101 +- 35 L/min. The statistically derived MCID (half standard deviation) was 18 L/min, the patient anchored approaches were 20 L/min and 20-25 L/min. DISCUSSION Although NPIF is effort dependant with the potential for poor test-retest reliability, it is simple, quick and a reliable technique can be quickly learnt. An MCID of 20L/min is recommended when NPIF is used as an outcome tool. Understanding the MCID is critical for assessing the impact of nasal surgery.

Functional Outcomes of Structured Nasal Tip Refinement

OBJECTIVE To describe a technique to refine the nasal tip and supratip while preserving structure; traditional attempts to reduce nasal tip bulbosity involve maneuvers that may result in loss of support, leading to poor functional and cosmetic outcomes. METHODS A prospective study of patients undergoing open structure nasal tip refinement using scroll joint excision with a septal-lateral crural suture to flatten the lateral crus. Outcomes assessed were nasal peak inspiratory flow (NPIF), nasal obstruction scores, 22-item Sinonasal Outcome Test (SNOT-22), 36-item Short-Form questionnaires (SF-36), and anchor scores for breathing and cosmesis. RESULTS The mean NPIF improved from 100 L/min to 139 L/min, nasal obstruction improved, and the mean (SD) SNOT-22 scores improved from 1.45 (0.86) to 0.63 (0.65) (P< .01 for all comparisons). All patients had improved cosmesis, and 2.2% had both subjectively and objectively impaired nasal breathing. CONCLUSIONS A technique is described allowing refinement of the nasal tip while maintaining or improving the nasal airway and providing a high level of patient satisfaction with the aesthetic outcome. Even in patients seen for cosmetic rhinoplasty, there may be a degree of preoperative nasal obstruction that should be recognized and addressed.

Perioperative and Intraoperative Maneuvers to Optimize Surgical Outcomes in Skull Base Surgery

There are many approaches to obtaining a workable endoscopic surgical field in sinus surgery. With extended sinus and transdural endoscopic surgery, a more rigid approach must be taken. There are 3 main factors that invariably lead to poor surgical outcomes in endoscopic sinus and skull base surgery: bleeding, inadequate access, and unidentified anatomic anomalies. Bleeding is arguably the most common reason for incomplete resection. An understanding of microvascular and macrovascular bleeding allows a more structured approach to improve the surgical field in extended endoscopic surgery. The endoscopic surgeon should always be comfortable in performing the same procedure as an open operation. However, converting or abandoning an endoscopic procedure should rarely occur because much of this decision making should take place preoperatively. Along with poor hemostasis, inadequate access is an important cause of poor outcome. Evaluation of the anatomy involved by pathology but also the anatomy that must be removed to allow adequate exposure is important. This article reviews the current techniques used to ensure optimal surgical conditions and outcomes.

Lateral frontal sinus access in endoscopic skull-base surgery.

The modified endoscopic Lothrop (MELP) or Draf III procedure can provide extended endoscopic access to the frontal sinus. The ability to access the entire frontal sinus entirely endoscopically is often debated and there is little published data to predict access based on tumor location.

Functional and cosmetic outcomes of external approach septoplasty.

Background The external approach for septoplasty is an important surgical technique to manage severe septal deviations, caudal deformities, and mid-dorsal abnormalities when a simple endonasal approach may not suffice. The procedure is longer in duration and draws on more resources than endonasal septoplasty. The outcome reporting of the external approach for septoplasty is important to provide evidence of benefit for both patients and health care providers. This study was designed to describe functional and cosmetic outcomes of the external approach for septoplasty. Methods A prospective assessment of consecutive patients undergoing the external approach for septoplasty at a tertiary center was performed. Pre- and postoperative nasal peak inspiratory flow (NPIF), symptom scores, 22-Item Sinonasal Outcome Test (SNOT-22), Nasal Obstruction Score, and Short Form 36 (SF-36) quality-of-life scores were assessed. A global Likert change scale was also used for both function and cosmesis. Results Thirty patients (mean age, 40 ± 15.9 years; 40% women) were assessed with a mean follow-up of 12.2 ± 9.5 months. Mean NPIF improved significantly from 93.3 ± 34.7 to 143.0 ± 44.3 (p < 0.001). Nasal obstruction score improved significantly from 3.6 ± 1.3 to 0.69 ± 1.2 (p < 0.001). SNOT-22 improved significantly from 34.1 ± 17.2 to 12.7 ± 14.9 (p < 0.001). Ninety-six percent had subjective improvement in nasal function, and 96% had no change or improvement in cosmesis. Seventy percent improved by the minimal clinically important difference for NPIF. Conclusion The external approach for septoplasty is an operation that produces significant improvements in subjective and objective nasal health measures. Although requiring greater training and operative time, it is an appropriate approach for the severely deviated nasal septum.

Radiological Features of the Intraosseous Lipoma of the Sphenoid

Objective. Benign intraosseous lesions of the skull base are often identified in the course of routine radiological investigation. Imaging features associated with suspected intraosseous lipoma (IOL) can mimic more aggressive pathology. The features of this poorly described entity in the skull base were analyzed to aid the otolaryngologist in differentiation from other pathology. Study Design. Retrospective analysis of computed tomography (CT) and magnetic resonance imaging (MRI) images over the period from March 2007 to March 2009. Setting. Radiology service, tertiary hospital, Sydney, Australia. Methods. Images with diagnosis of incidental suspected IOL within the sphenoid were selected. Radiological features including trabecular pattern, secondary calcification, cortical bone thinning, and size and the presence of fat (defined as <−5 HU) were recorded. Results. Ten patients (5 male) were identified. Seventy percent had unilateral, single lesions occurring within the sphenoid bone. The mean size was 13.1 ± 5.6 mm (range, 4-21 mm). Fat was demonstrated in all lesions. There were 3 cases of multiple lesions occurring within the sphenoid bone. In addition, 61.5% were associated with cortical bone thinning and 46.2% with secondary calcification within the lesion. Changes to normal trabecular bone occurred: 46.2% with a partial loss of and 53.8% with a complete absence of trabecular pattern. Histopathologic confirmation of IOL is presented. Conclusion. IOL is believed to be a more common benign intraosseous lesion within the skull base than previously reported. Cortical bone thinning and other features normally suggestive of aggressive pathology commonly occur. Otolaryngologists should be aware of these common lesions to avoid unnecessary further investigation.

Article Commentary: Chronic rhinosinusitis: An education and treatment model

Research into chronic rhinosinusitis (CRS) has rapidly expanded over the last decade, resulting in a plethora of proposed etiologic and disease-modifying factors. Potentially, advancement of knowledge in this field has developed more than any other disease in otolaryngologic science. However, the teaching and education of this complex and still evolving process has lagged behind. Trainees, students, and residents may find the heterogeneous group of pathophysiologic mechanisms difficult to learn and apply to treatment decision making. Identification of the propagating factor and subsequent microbial, inflammatory, or mucociliary disease-modifying effects for a specific patient allows individual tailoring of treatment to address these factors. This facilitates a logical strategic process, rather than using one broad, ill-defined approach for each and every CRS patient. A model of CRS is presented as a teaching aid for residents and those learning about the etiology and directed treatment of this complex problem.