Midface lift: panel discussion.

Unlabelled: What is the most efficient dissection plane to perform midface lift? What is the best incision/approach (preauricular, transtemporal, transoral)? Why? What specific technique do you use? Why? What is the best method/substance for adding volume to midface lifting? In approaching the midface, how do you see the relationship of blepharoplasty versus fillers versus midface lifting?

Analysis: How has your procedure or approach evolved over the past 5 years? What have you learned, first-person experience, in doing this procedure?

A new model for facial nerve research: the novel transgenic Thy1-GFP rat.

Objective: To introduce a Thy1-GFP transgenic rat model, whose axons constitutively express green fluorescent protein (GFP), in order to study facial nerve regeneration. Facial nerve injury can cause devastating physical and social sequelae. The functional recovery of the facial nerve can result in synkinesis and permanent axonal misrouting.

Dynamic quantification of host Schwann cell migration into peripheral nerve allografts.

Host Schwann cell (SC) migration into nerve allografts is the limiting factor in the duration of immunosuppression following peripheral nerve allotransplantation, and may be affected by different immunosuppressive regimens. Our objective was to compare SC migration patterns between clinical and experimental immunosuppression regimens both over time and at the harvest endpoint. Eighty mice that express GFP under the control of the Schwann cell specific S100 promoter were engrafted with allogeneic, nonfluorescent sciatic nerve grafts.

Matching of motor-sensory modality in the rodent femoral nerve model shows no enhanced effect on peripheral nerve regeneration.

The treatment of peripheral nerve injuries with nerve gaps largely consists of autologous nerve grafting utilizing sensory nerve donors. Underlying this clinical practice is the assumption that sensory autografts provide a suitable substrate for motoneuron regeneration, thereby facilitating motor endplate reinnervation and functional recovery. This study examined the role of nerve graft modality on axonal regeneration, comparing motor nerve regeneration through motor, sensory, and mixed nerve isografts in the Lewis rat.

The differential effects of pathway- versus target-derived glial cell line-derived neurotrophic factor on peripheral nerve regeneration.

Object: Glial cell line-derived neurotrophic factor (GDNF) has potent survival effects on central and peripheral nerve populations. The authors examined the differential effects of GDNF following either a sciatic nerve crush injury in mice that overexpressed GDNF in the central or peripheral nervous systems (glial fibrillary acidic protein [GFAP]-GDNF) or in the muscle target (Myo-GDNF).

Methods: Adult mice (GFAP-GDNF, Myo-GDNF, or wild-type [WT] animals) underwent sciatic nerve crush and were evaluated using histomorphometry and muscle force and power testing.

The short- and long-term effects of Seprafilm on peripheral nerves: a histological and functional study.

Extraneural scar reduction is an important goal in peripheral nerve microsurgery. The use of biosynthetic materials, such as Seprafilm , reduces postoperative adhesions in abdominopelvic gynecologic and orthopedic surgery. The study evaluates the safety of Seprafilm in proximity to nerve tissue in a noninjury (phase 1) and injury (phase 2) model.

Processed allografts and type I collagen conduits for repair of peripheral nerve gaps.

Autografting is the gold standard in the repair of peripheral nerve injuries that are not amenable to end-to-end coaptation. However, because autografts result in donor-site defects and are a limited resource, an effective substitute would be valuable. In a rat model, we compared isografts with Integra NeuraGen (NG) nerve guides, which are a commercially available type I collagen conduit, with processed rat allografts comparable to AxoGen's Avance human decellularized allograft product.

Limitations of conduits in peripheral nerve repairs.

Nerve conduits have emerged as alternatives to autologous nerve grafts, but their use in large-diameter nerve deficits remains untested. We report four patients who underwent repair of large-diameter nerves using absorbable nerve conduits and discuss the failed clinical outcomes. The reported cases demonstrate the importance of evaluating the length, diameter, and function of nerves undergoing conduit repair.

Same modality nerve reconstruction for accessory nerve injuries.

The standard repair of a nerve gap under tension is to use a sensory autograft, such as the medial antebrachial cutaneous or the sural nerve. The practice of using sensory grafts to repair motor nerve defects is challenged by the discovery of preferential motor reinnervation and modality specific nerve regeneration. In this article, two clinical cases are presented where accessory nerve injuries are repaired with either a motor nerve transfer (a branch of C7) or a motor autograft (obturator nerve), and excellent functional results are reported.

Reinnervation of the tibialis anterior following sciatic nerve crush injury: a confocal microscopic study in transgenic mice.

Transgenic mice whose axons and Schwann cells express fluorescent chromophores enable new imaging techniques and augment concepts in developmental neurobiology. The utility of these tools in the study of traumatic nerve injury depends on employing nerve models that are amenable to microsurgical manipulation and gauging functional recovery. Motor recovery from sciatic nerve crush injury is studied here by evaluating motor endplates of the tibialis anterior muscle, which is innervated by the deep peroneal branch of the sciatic nerve.