Facial Nerve High-Resolution Microanatomy Analysis of the Distal Intratemporal to Extracranial Pes Segment: Reconstructive Implications.

BACKGROUND: Current knowledge of facial nerve topography between the stylomastoid foramen to the pes anserinus is very limited. Elucidating this segment's intraneural microanatomy may be advantageous in certain clinical settings: the planning of nerve grafts for gaps extending from the proximal facial nerve trunk to distal branches or in determining coaptation sites for hypoglossal jump grafts to provide selective upper and lower facial tone. This study is the first to provide high-definition intraneural topography of the aforementioned segment to optimize reconstructive outcomes. METHODS: Sixteen facial nerves extending from the second genu to the pes anserinus were harvested from eight cadavers en bloc to preserve orientation. Specimens were imaged by micro-computed tomography using a serial 6-µm protocol and digitally reconstructed three-dimensionally to be analyzed using bioinformatic tools. RESULTS: No clinically significant fascicular separation was noted between 14.4 mm proximal to the stylomastoid foramen until 4.4 mm distal to the foramen. Fascicles remained separate throughout the remainder of the specimen and were found to undergo a mean rotation of 45.5 degrees ( P = 0.0002) between 8.9 and 13.7 mm distal to the stylomastoid foramen. This reliable clockwise rotation in left nerves and counterclockwise rotation in right nerves resulted in superficially oriented fascicles entering the upper division of the pes anserinus, whereas deep-oriented fascicles entered the lower division. CONCLUSION: Intraneural facial nerve topography and rotation are consistent from 4 to 14 mm distal to the stylomastoid foramen, enabling surgeons to accurately place grafts targeted to either the upper or lower face, thus optimizing functional accuracy and minimizing synkinesis.

Improving Projection of the Nasal Tip in Primary Endonasal Rhinoplasty.

Gaining, improving, and maintaining nasal tip projection is one of the most essential elements of successful endonasal rhinoplasty. For years the hallmark of inadequate nasal tip projection following rhinoplasty has been the Polly beak deformity. Early rhinoplasty technique consisted of intracartilaginous excision of the cephalic margin of the lower lateral cartilages, cartilage and bony hump reduction, and osteotomies. Some of these simple rhinoplasties still look good decades later, however, many are conspicuous in their lack of nasal tip projection. The reason for this inconsistency in rhinoplasty results was the surgeon's inattention to the structural integrity and anatomical position of the LLC. The senior author uses a combination of suture, strut, and cartilage grafting techniques to achieve ideal projection in a manor tailored to each patient's unique anatomic needs.

A Novel Method to Gently Mix and Uniformly Suspend Particulates for Automated Assays.

The SpinVessel system provides a methodology using pulsed radial flow to gently mix and uniformly suspend particulates (cells, magnetic beads, silica beads, and microcarrier beads) for automated assays. SpinVessels are well suited for aliquoting on robotic liquid handlers and with robotic reagent dispensers, as well as manually. The SpinVessel system combines two critical features: (1) special internal side fins and projections in the bottom of the vessels and (2) an instrument that quickly spins the vessels and repeatedly reverses the spin direction. This rapid reversing motion sends multiple pulses of fluid up the side walls of the SpinVessel, creating a circular radial flow pattern. We tested five different particulates and six different SpinVessels with volume capacities varying from 50 mL to 1200 mL. SpinVessels are compatible with either single-, 8-, 12-, 96-, or 384-channel pipettors or with siphon tubing on robotic reagent dispensers. Experiments have demonstrated high viability of cells and undamaged morphology of microcarrier beads even after hours of constant agitation. The uniformity of aliquots collected at various vertical depths and horizontally across the SpinVessels demonstrated that cells, magnetic beads, and silica beads were uniformly suspended throughout the height and breadth of the SpinVessels, and uniformity of samples was consistent from the beginning to the end of the aliquoting procedure. Only 5 min of mixing is required to resuspend settled particulates. This novel mixing methodology has many applications in laboratory automation where particulate aliquot uniformity and/or particulate integrity are important to automating assays.

Orbital Trauma.

The orbit is contained within a complex bony architecture with overlying soft tissue that involves many important anatomical structures. Orbital trauma is a frequent cause of damage to these structures. The authors review the literature on reconstructive techniques focusing on fractures of the orbital rim, orbital roof, orbital floor, medial orbital wall, and naso-orbito-ethmoid complex. A thorough literature review was conducted using PubMed analyzing articles relevant to the subject matter. Various search terms were used to identify articles regarding orbital trauma presentation, diagnosis, management, as well as postoperative complications. Articles were examined by all authors and pertinent information was gleaned for the purpose of generating this review. Orbital trauma can result in a wide variety of complications in form and function. Not all orbital fractures require operative repair. However, bony disruption can cause enophthalmos, hypophthalmos, telecanthus, epiphora, cerebrospinal fluid leaks, orbital hematoma, and even blindness to name a few. Timing of operative repair as well as reconstructive method is dictated by the patient's individual presentation. Successful fracture management requires a detailed understanding of the anatomy and pathophysiology to ensure restoration of the patients' preoperative state. Orbital trauma encompasses a wide variety of mechanisms of injury and resulting fracture patterns. A variety of surgical approaches to the orbit exist as has been discussed allowing the surgeon access to all area of interest. Regardless of the fracture complexity, the principles of atraumatic technique, anatomic reduction, and stable fixation apply in all cases.

Predictors of complete endoscopic mucosal resection of flat and depressed gastrointestinal neoplasia of the colon.

OBJECTIVES: We evaluated risk factors for residual neoplasia on first follow-up endoscopy after colonic endoscopic mucosal resections (EMRs). METHODS: This retrospective study in a high-volume EMR tertiary-referral center examined EMRs on 423 colonic lesions in 313 patients. RESULTS: Residual neoplasia at first follow-up endoscopy was present following 12% of colonic EMRs. Single-variable analysis showed evidence of an increased risk of residual neoplasia for larger polyps, polyps without a lifting sign, and polyps removed piecemeal. In multivariable analysis, only use of the piecemeal method was independently associated with residual neoplasia. CONCLUSIONS: Additional procedures are needed to complete resection in more than 1 in 10 colonic EMRs. Residual neoplasia occurs more often with piecemeal resection. Close surveillance after EMR and the use of newer methods to further reduce residual neoplasia are needed.

Trainee participation is associated with increased small adenoma detection.

BACKGROUND: Previous studies examining the effect of fellow participation on adenoma detection rate in colonoscopy have yielded conflicting results, and factors such as adenoma size and location have not been rigorously evaluated. OBJECTIVE: To examine whether fellow participation during screening, surveillance, or diagnostic colonoscopy affects overall, size-specific, or location-specific adenoma or polyp detection rate. METHODS: This was a retrospective study of 2430 colonoscopies performed in our ambulatory surgical center between September 2006 and December 2007, comparing adenoma and polyp detection rates of colonoscopies performed by fellows with supervising staff endoscopists (n = 318) with colonoscopies performed by staff endoscopists without fellow participation (n = 2112). Study participants included patients who underwent screening, surveillance, or diagnostic colonoscopies in our GI suite. Logistic regression analysis was used to evaluate the association of fellow participation with adenoma and polyp detection. RESULTS: There was evidence of a higher rate of small (<5 mm) adenoma detection in colonoscopies with a fellow present (25% vs 17%, P = .001). This remained significant after multiple-testing adjustment (P ≤ .003 considered significant). Findings were similar, although not significant for small polyps (36% vs 29%, P = .007). There was a trend toward increased adenoma detection in colonoscopies with a fellow present compared with those without (30% vs 26%, P = .11). Multivariable adjustment for potentially confounding variables did not alter these associations. LIMITATIONS: The study had a retrospective design, and information regarding bowel preparation was not available for 37% of patients. CONCLUSION: Fellow involvement was associated with increased detection rates of small adenomas, providing evidence that the presence of a fellow during colonoscopy plays a role in enhancing the effectiveness of the examination.

Endoscopic mucosal resection with the grasp-and-snare technique through a double-channel endoscope in humans.

BACKGROUND: EMR is being used to manage premalignant lesions of the GI tract. Lifting of the lesion is required to perform EMR. Earlier biopsy or snare may cause scarring and preclude adequate lifting. OBJECTIVE: We report our experience with a novel grasp-and-snare EMR technique that can be used when a good lifting is not achieved or the location of the lesion is challenging for standard EMR, such as in a fold. DESIGN: Single-center case series. SETTING: Tertiary referral academic gastroenterology unit. PATIENTS: Patients referred for endoscopic treatment of flat gastrointestinal polyps. INTERVENTIONS: Single-session EMR performed with a grasp-and-snare technique through a double-channel gastroscope or colonoscope. MAIN OUTCOME MEASUREMENTS: Technical success, complication rates, and recurrence rates. RESULTS: Seventeen patients with flat gastrointestinal polyps were referred: mean age 70 years, 11 (65%) male, polyp size 0.8 to 6 cm; 13 colonic, 2 duodenal, 1 gastric, and 1 esophageal EMR performed with grasp-and-snare technique in single sessions. Six polyps (35%) did not lift after injection of hydroxypropylmethylcellulose. Fourteen polyps (82%) were resected completely. Two complications occurred (12%): 1 bleeding treated medically and 1 perforation treated surgically. Residual disease at 1 year was 18%, but 8 patients (47%) had not yet had their 1-year follow-up. LIMITATIONS: Single-center, uncontrolled, not randomized. Limited follow-up. CONCLUSIONS: The grasp-and-snare technique can be used to perform EMR with good outcomes and low complication rates in areas where poor lifting and accessibility are problems.

An evaluation of risk factors for inadequate cytology in EUS-guided FNA of pancreatic tumors and lymph nodes.

BACKGROUND: The factors associated with maximizing the cytological adequacy of EUS-guided FNA (EUS-FNA) in pancreatic tumor evaluation are not well-known. OBJECTIVE: To examine associations of physician and procedural factors with the endpoint: the presence of an adequate cytological specimen found by using EUS-FNA in patients with pancreatic tumors and lymph nodes. DESIGN: Retrospective cohort study. SETTING: A U.S. tertiary care center. PATIENTS: Patients undergoing EUS-FNA of pancreatic masses and lymph nodes. INTERVENTIONS: Analysis of EUS-FNA procedures performed in our institution from 1997 to 2007. MAIN OUTCOME MEASUREMENTS: Associations were evaluated between the primary endpoint of cytological adequacy and factors including the endoscopist, needle gauge, the number of needle passes attempted, the pathologist, and the presence of an onsite cytotechnologist to confirm an adequate specimen. EUS-FNA adequacy was determined by a pathologist based on the presence of definite benign or malignant tissue. RESULTS: EUS-FNA was performed in 247 pancreatic masses and 276 lymph nodes. An adequate cytological sample was obtained in 240 (97%) pancreatic tumors (95% CI, 94%-99%) and 252 (91%) lymph nodes (95% CI, 87%-94%). For pancreatic tumors, there was no evidence of any associations between factors and cytological adequacy. For lymph nodes, cytological adequacy was improved when an onsite cytotechnologist was present (96% vs 84%, P = .002); no other factors showed statistically significant associations with cytological adequacy. LIMITATIONS: Retrospective study, low power to detect associations. CONCLUSIONS: The presence of an onsite cytotechnologist is an important factor in achieving successful EUS-FNA of suspicious lymph nodes in patients with pancreatic masses.

High-definition colonoscopy detects colorectal polyps at a higher rate than standard white-light colonoscopy.

BACKGROUND & AIMS: Adenoma detection rates might be improved through use of high-definition colonoscopy, which can detect subtle mucosal changes. We investigated whether the use of high-definition white-light (HDWL) colonoscopy resulted in a higher rate of adenoma detection than standard-definition white-light (SDWL) colonoscopy in a clinical practice setting. METHODS: This retrospective study included 2430 patients who underwent colonoscopies from September 2006 to December 2007; 1226 received SDWL colonoscopy and 1204 received HDWL colonoscopy. We analyzed data from consecutive screening, surveillance, and diagnostic colonoscopies, comparing adenoma and overall polyp detection between procedures. Potentially confounding variables were controlled using multivariable logistic regression analysis. RESULTS: The adenoma detection rate was higher among patients who underwent HDWL compared with SDWL colonoscopies (28.8% vs 24.3%; P = .012), as was the polyp detection rate (42.2% vs 37.8%; P = .026). These findings remained after adjustments for potentially confounding variables (P = .018 and .022, respectively). CONCLUSIONS: In a general clinical practice setting, HDWL colonoscopy resulted in a higher adenoma detection rate compared with SDWL colonoscopy. The use of SDWL colonoscopy could reduce the number of missed adenomas and the subsequent risk for colorectal cancer.

Nanoliter dispensing for uHTS using pin tools.

Miniaturization of assays is an important objective in Ultra-HTS. One of the major obstacles has been to find fluid handling systems capable of reliably and accurately delivering between 2 and 200 nl of test compound to assay plates. New methods of forming pins, placing slots in the pins, and hydrophobic coatings bonded onto the pins solve many of the problems encountered by early pin tools. Unlike other low-volume liquid handlers, these new pin tools provide the ability to transfer approximately 2 nl-5 microl of compounds. These pin tools can also use low-volume source plates (2-10 microl) and achieve an accuracy of better than 5%. This, coupled with the ability to transfer small volumes directly from the compound library to assay plates without an intervening dilution plate, saves reagents, throughput time, and consumables and is, therefore, very cost effective. Pin tool compound transfers in the 2-100 nl range provide a simple method to dilute away from the toxic effect that dimethyl sulfoxide has on some assay target cells. The factors that affect liquid transfers by pin tools are discussed in detail as well as the advantages and limitations of pin tools.