Inner Ear Complications in Children and Adolescents with Sickle Cell Disease.

Hearing impairment is a reported complication of sickle cell disease, yet inner ear pathology is not fully understood. The study purpose was to examine the patterns of inner ear involvement in patients with sickle cell disease by magnetic resonance imaging (MRI) and to assess its association with auditory functions. A cross-sectional study included 22 children with sickle cell disease examined for inner ear pathology by audiogram, MRI inner ear and transcranial Doppler (TCD) with revision of their hospital records for transfusion, chelation and hydroxyurea (HU) therapy. Abnormal MRI in the form of intrinsic T1 hyperintensity within the lumen of inner ear structures and cochlear neuropathy was found in five (22.7%) patients; left middle cerebral artery (MCA) flow velocity was higher in patients with abnormal MRI (83.4 ± 5.3 cm/sec) compared to normal MRI (68.2 ± 11.1 cm/sec) (p = 0.015), however, none of the patients had TCD of >170 cm/sec. There was no significant difference between patients with normal and abnormal MRI as regards hearing level and speech audiometry. Sensorineural hearing loss (SNHL) was present in two (9.1%) and conductive hearing loss (CHL) in two (9.1%) patients. There was a significant negative correlation between right ear mean hearing level and right MCA flow velocity and significant negative correlation between left ear mean hearing level and basilar artery (BA) flow velocity. We concluded that inner ear pathology is not uncommon in asymptomatic patients with sickle cell anemia, yet it did not correlate with hearing impairment and may occur with normal TCD results.

Three-dimensional Printing in Developing Countries.

The advent of 3-dimensional (3D) printing technology has facilitated the creation of customized objects. The lack of regulation in developing countries renders conventional means of addressing various healthcare issues challenging. 3D printing may provide a venue for addressing many of these concerns in an inexpensive and easily accessible fashion. These may potentially include the production of basic medical supplies, vaccination beads, laboratory equipment, and prosthetic limbs. As this technology continues to improve and prices are reduced, 3D printing has the potential ability to promote initiatives across the entire developing world, resulting in improved surgical care and providing a higher quality of healthcare to its residents.

Use of tragal cartilage grafts in rhinoplasty: An anatomic study and review of the literature.

We conducted a cadaveric study to determine the size of cartilage grafts that can be taken from the tragus without distorting tragal anatomy. Our subjects included 7 fresh cadavers-3 male and 4 female (age at death: 61 to 87 yr). Tragal cartilage grafts were harvested while leaving the lateral 3 mm of the tragal cartilage in situ to preserve the anatomic shape of the tragus. The grafts were measured and their dimensions recorded. The craniocaudal dimensions of the tragal cartilages ranged from 15 to 30 mm (mean: 21.6), and the width of each specimen ranged from 10 to 23 mm (mean: 15.3). The thickness of the cartilage was approximately 1 mm. The grafts were slightly curved along their long axis. We also review the literature regarding the dimensions of different grafts used in rhinoplasty, knowledge of which can help in preoperative planning. Tragal cartilage grafts have been used as shield, alar contour, alar batten, lateral crural onlay, dorsal onlay, and infratip lobule grafts. When a straight and/or thick graft is needed, two strips of tragal cartilage can be sutured in a mirror-image configuration.

Common patterns of reconstruction for Mohs defects in the head and neck.

BACKGROUND: Skin cancer is the most common of all cancers. Mohs surgery is an effective technique for removing common types of skin cancer. The number of patients presenting for reconstruction after Mohs surgery has been increasing in recent years. Reconstructive surgeons are faced with diverse defects of different sizes and locations. The aim of this study was to examine reconstructive methods for Mohs defects to aid in preoperative planning. METHODS: We reviewed the charts of 245 patients who underwent Mohs defect reconstruction over a period of 5 years. The patients were categorized according to the reconstructive technique (eg, flap, full-thickness skin graft, split-thickness skin graft) used in relation to anatomic location and the size of the defect. RESULTS: One hundred twenty-nine patients (53%) had Mohs defects of the nose. Bilobed flap reconstruction was the most common for the nasal ala (17/42 [40%]), tip (19/41 [46%]), and nasal sidewall (8/25 [32%]). Forehead flap reconstruction was most common for nasal dorsum defects (9/16 [56%]). Linear closure was the most common reconstructive technique for the cheek (18/34 [53%]), the forehead (13/20 [65%]), the chin (4/4 [100%]), the lower lip (4/4 [100%]), the upper lip (8/13 [38%]), the auricle (4/10 [40%]), the eyelid (5/8 [62%]), and the temporal region (2/5 [40%]). Composite grafting was the most common in the nasal columella (2/3 [67%]) and full-thickness skin graft for nasal sill defects (2/2 [100%]). Split-thickness skin graft was the most common in the scalp (3/6 [50%]). CONCLUSIONS: Various options exist for Mohs repair. Understanding trends of reconstructing Mohs defects may help in planning the best method of reconstruction.

Vasopressors and reconstructive flap perfusion: a review of the literature comparing the effects of various pharmacologic agents.

INTRODUCTION: Use of intraoperative vasopressors is of debate in microvascular surgery. Anesthesia is an important factor in maintaining the rate of success of flap transfer by affecting regional blood flow and global hemodynamics. We conducted a review of the literature comparing the use of different vasoactive agents on different flaps in various human and animal models. METHODS: A systematic review of the literature was performed. Bibliographies of key articles were also reviewed for additional resources. Analysis was done to determine the overall trend of how flap perfusion is affected by the use of intraoperative vasoactive medication. RESULTS: The literature search identified 16 relevant articles. Flaps were studied in pigs in 7 studies, rats in 5, and humans in 4. The most common flap was the rectus abdominis musculocutaneous flap. Phenylephrine and norepinephrine were the most common pressor agents used. No significant statistical changes were noted in 8 of the 16 studies; initial ischemia followed by delayed improved perfusion was observed in 4 studies, "true ischemia" and hypoperfusion of the skin flaps was noted in 3. There was no consistency in their effect on flap perfusion: initial ischemia followed by delayed improved perfusion was observed in 4 studies, whereas true ischemia and hypoperfusion of the skin flaps was noted in 3. CONCLUSIONS: To date, there is no reliable prospective clinical evidence that supports the absolute contraindication of pressor agents during free flap surgery. This topic will continue to be a matter for debate until more definitive data can be obtained.

Dynamic rehabilitation of facial nerve injury: a review of the literature.

INTRODUCTION: Given the morbidity caused by facial nerve paralysis, there have been consistent approaches to treatment over the past 20 years in reanimation of the facial nerve. Treatment depends on accurate clinical examination, a good understanding of the anatomic course, and appropriate diagnostic tests. There are various options when it comes to dynamic facial nerve reanimation that range from nerve grafting, nerve anastomosis, crossover techniques and muscle transfer to microneurovascular muscle flaps, and-recently-potentially new concepts with microelectromechanical systems (MEMS) technology. The various dynamic facial nerve treatment modalities are discussed. METHODS AND RESULTS: A comprehensive review of the literature was performed detailing various techniques used for dynamic rehabilitation following facial nerve injury and their known results and complications. CONCLUSIONS: Currently, techniques have been attempted to achieve adequate dynamic facial reanimation of the paralyzed facial nerve. Despite the advances that have occurred in the last few years, it has been classically very difficult to achieve a House-Brackmann grade better than grade III. Outcomes are improving. Ultimately, the approach depends on the surgeon's experience.

Static treatment modalities in facial paralysis: a review.

INTRODUCTION: Facial nerve dysfunction can be attributed to several different causes. Several techniques have been developed to help treat the appearance and functional limitation of patients with sequelae of facial nerve dysfunction. There are options regarding static techniques of facial nerve injury treatment that range from facial musculature plication or shortening, fascial sling suspension via allograft or autograft, injectables and implants (ENDURAGen, AlloDerm, LifeCell, Bridgewater, New Jersey, USA) to techniques such as brow lift, open and endoscopic facelifts, and various eyelid surgeries with upper and lower lid procedures. In this review the various static facial nerve treatment modalities are discussed. METHODS AND RESULTS: A comprehensive review of the literature was performed detailing the most common static facial nerve treatment modalities and their known results and complications. CONCLUSIONS: There are individual issues associated with facial palsy for which individual solutions must be carefully tailored. Despite the presence of many surgical options, the results of reconstruction are limited. With the rapid advancement of surgical techniques, approaches to the management of facial nerve dysfunction have expanded, helping surgeons to improve and utilize alternative techniques for the treatment of patients with acute and chronic facial paralysis.

Microfabricated nerve-electrode interfaces in neural prosthetics and neural engineering.

Neural interfaces and implants are finding more clinical applications and there are rapid technological advances for more efficient and safe design, fabrication and materials to establish high-fidelity neural interfaces. In this review paper, we highlight new developments of the microfabricated electrodes and substrates with regard to the design, materials, fabrication and their clinical applications. There is a noticeable trend towards integration of microfluidic modules on a single neural platform. In addition to the microelectrodes for neural recording and stimulation, microfluidic channels are integrated into a nerve-electrode interface to explore the rich neurochemistry present at the neural interface and exploit it for enhanced electrochemical stimulation and recording of the central and peripheral nervous system.

Nanotechnology in plastic surgery.

BACKGROUND: Nanotechnology has made inroads over time within surgery and medicine. Translational medical devices and therapies based on nanotechnology are being developed and put into practice. In plastic surgery, it is anticipated that this new technology may be instrumental in the future. Microelectromechanical systems are one form of nanotechnology that offers the ability to develop miniaturized implants for use in the treatment of numerous clinical conditions. The authors summarize their published preliminary findings regarding a microelectromechanical systems-based electrochemical stimulation method through modulation of ions around the nerve that is potentially implantable and clinically efficacious, and expand upon current and potential usages of nanotechnology in plastic surgery. METHODS: Sciatic nerves (n = 100) of 50 American bullfrogs were placed on a microfabricated planar gold electrode array and stimulated electrically. Using Ca(2+)-selective membranes, ion concentrations were modulated around the nerve environment in situ. In addition, a comprehensive review of the literature was performed to identify all available data pertaining to the use of nanotechnology in medicine. RESULTS: A 40 percent reduction of the electrical threshold value was observed using the Ca(2+) ion-selective membrane. The uses of nanotechnology specifically applicable to plastic surgery are detailed. CONCLUSIONS: Nanotechnology may likely lead to advancements in the art and science of plastic surgery. Using microelectromechanical systems nanotechnology, the authors have demonstrated a novel means of modulating the activation of nerve impulses. These findings have potentially significant implications for the design of special nano-enhanced materials that can be used to promote healing, control infection, restore function, and aid nerve regeneration and rehabilitation.

Electrochemical activation and inhibition of neuromuscular systems through modulation of ion concentrations with ion-selective membranes.

Conventional functional electrical stimulation aims to restore functional motor activity of patients with disabilities resulting from spinal cord injury or neurological disorders. However, intervention with functional electrical stimulation in neurological diseases lacks an effective implantable method that suppresses unwanted nerve signals. We have developed an electrochemical method to activate and inhibit a nerve by electrically modulating ion concentrations in situ along the nerve. Using ion-selective membranes to achieve different excitability states of the nerve, we observe either a reduction of the electrical threshold for stimulation by up to approximately 40%, or voluntary, reversible inhibition of nerve signal propagation. This low-threshold electrochemical stimulation method is applicable in current implantable neuroprosthetic devices, whereas the on-demand nerve-blocking mechanism could offer effective clinical intervention in disease states caused by uncontrolled nerve activation, such as epilepsy and chronic pain syndromes.

A novel surgical technique for management of tinnitus due to high dehiscent jugular bulb.

OBJECTIVES: To assess the effectiveness of middle ear floor reconstruction in management of vascular tinnitus due to high jugular bulb with dehiscent middle ear floor. STUDY DESIGN: Case series with chart review. SETTING: Tertiary academic medical center. SUBJECTS AND METHODS: We reviewed the medical records of seven patients with high dehiscent jugular bulb, presenting with incapacitating pulsatile roaring tinnitus that was abolished by digital compression of the ipsilateral jugular vein, from January 2002 to December 2006. The diagnosis was confirmed by CT scan of the temporal bone (bone window, coronal views). The seven patients were surgically explored, five under local anesthesia (to monitor the results with possible intraoperative revision) and two under general endotracheal anesthesia, for middle ear floor reconstruction that was done using bone dust, perichondrium, and tragal cartilage (mean follow-up 28 months). RESULTS: Of the seven patients, tinnitus disappeared in four (57%) and decreased in one. The overall improvement was five of seven (71%). One patient had postoperative increased intracranial pressure. CONCLUSION: The preliminary results suggest that surgical reconstruction of the middle ear floor under local anesthesia offers valuable treatment for patients with incapacitating tinnitus due to dehiscent middle ear floor. However, the risk of sigmoid sinus thrombosis should be considered. To our knowledge, this is the first trial of multilayer reconstruction of the middle ear floor dehiscence to manage high jugular bulb causing tinnitus.