In vitro fluid dynamics of the Ahmed glaucoma valve modified with expanded polytetrafluoroethylene.

Purpose: Long-term intraocular pressure reduction by glaucoma drainage devices (GDDs) is often limited by the fibrotic capsule that forms around them. Prior work demonstrates that modifying a GDD with a porous membrane promotes a vascularized and more permeable capsule. This work examines the in vitro fluid dynamics of the Ahmed valve after enclosing the outflow tract with a porous membrane of expanded polytetrafluoroethylene (ePTFE).

Expanded polytetrafluoroethylene membrane alters tissue response to implanted Ahmed glaucoma valve.

Purpose: Long-term intraocular pressure control by glaucoma drainage implants is compromised by the formation of an avascular fibrous capsule that surrounds the glaucoma implant and increases aqueous outflow resistance. It is possible to alter this fibrotic tissue reaction and produce a more vascularized and potentially more permeable capsule around implanted devices by enclosing them in a porous membrane.

Methods: Ahmed glaucoma implants modified with an outer 5-microm pore size membrane (termed porous retrofitted implant with modified enclosure or PRIME-Ahmed) and unmodified glaucoma implants were implanted into paired rabbit eyes.

Metabolic and functional characterization of human adipose-derived stem cells in tissue engineering.

Background: The use of adipose-derived stem cells for tissue engineering involves exposing them to metabolically adverse conditions. This study examines the metabolism, proliferation, and differentiation of adipose-derived stem cells under various conditions.

Methods: Adipose-derived stem cells were cultured in 16 media conditions containing 0.

Efficacy of ethyl nitrite in reversing surgical vasospasm.

Vasospasm leading to thrombosis is a major cause of free flap failure. Flap blood flow may improve by application of vasodilating agents to the pedicle. The purpose of this study is to evaluate the effect of a novel S-nitrosylating agent, O-ethyl nitrite, on flap blood flow and pedicle vessels diameter in a rat model, after induction of vasospasm.

Vein graft anastomoses with magnets.

Background: Performing vascular anastomoses requires complete circumferential access and is time-consuming and technically challenging. The purpose of our study was to assess a sutureless magnetic device for anastomosing vein grafts.

Methods And Results: Oval magnets with a lumen were placed in six male foxhounds.

Combined bone allograft and adipose-derived stem cell autograft in a rabbit model.

Currently available options for the repair of bony defects have substantial limitations. Much work has looked to the possibility of engineering bone using stem cells. These tissue-engineering efforts have focused on calvarial defect models, which have the advantages of minimal load-bearing and a large surface area.

Free flap reconstruction of the scalp and calvaria of major neurosurgical resections in cancer patients: lessons learned closing large, difficult wounds of the dura and skull.

Background: Reconstruction of major neurosurgical resections can present a significant challenge because of the morbidity of radiation therapy, cerebrospinal fluid leaks, bacterial contamination from sinus exposure, and functional and cosmetic deformity from the size and location of the defect. The authors present their experience with free tissue reconstruction of scalp and calvarial defects. In particular, the authors examine their results in relation to major comorbidities, such as preoperative cerebrospinal fluid leak, history of smoking, and perioperative radiation therapy.

Delay of transverse rectus abdominis myocutaneous flap reconstruction improves flap reliability in the obese patient.

Background: Since its introduction in 1982, the transverse rectus abdominis musculocutaneous (TRAM) flap has been a mainstay of breast reconstruction. However, in certain high-risk individuals, such as the obese, smokers, and irradiated patients, flap reliability is decreased, which leads to a higher rate of flap complications. The authors hypothesized that although the nonflap complication rate is increased in the obese patient, flap complications are not increased in those who undergo a delayed TRAM procedure.

Halofuginone inhibits collagen deposition in fibrous capsules around implants.

Fibrous capsule formation around implants remains a difficult problem that has been studied for decades. The etiology is elusive, but the end result is the deposition of a dense collagenous capsule around implanted materials. The purpose of this study was to determine the effects of a type I collagen synthesis inhibitor, halofuginone, on fibrous capsule formation around implanted materials.

Immunohistochemical identification of vascular endothelial growth factor in pig latissimus dorsi musculocutaneous flaps following ischemia-reperfusion injury.

Vascular Endothelial Growth Factor (VEGF), a potent angiogenic, mitogenic and vascular permeability enhancing protein, appears to improve survival of ischemic flaps independent of its route of administration. The purpose of this study was to examine VEGF protein expression in biopsies of surgical flaps with immunohistochemical techniques. In 6 male Yorkshire-type pigs, 10 cm x 15 cm Latissimus dorsi musculocutaneous flaps were elevated bilaterally.

Side-to-side sutureless vascular anastomosis with magnets.

Objective: Abbe and Payr introduced vascular techniques and devices to facilitate vessel anastomosis over a century ago. Obora published the idea of a sutureless vascular anastomosis with use of magnetic rings in 1978. The purpose of this study was to assess the performance of a new magnetic device to perform a side-to-side arteriovenous anastomosis in a dog model.

Basic fibroblast growth factor expression following surgical delay of rat transverse rectus abdominis myocutaneous flaps.

Partial transverse rectus abdominis myocutaneous (TRAM) flap loss in breast reconstruction can be a devastating complication for both patient and surgeon. Surgical delay of the TRAM flap has been shown to improve flap viability and has been advocated in "high-risk" patients seeking autogenous breast reconstruction. Despite extensive clinical evidence of the effectiveness of surgical delay of TRAM flaps, the mechanisms by which the delay phenomenon occurs remain poorly understood.

Vascular endothelial growth factor expression in pig latissimus dorsi myocutaneous flaps after ischemia reperfusion injury.

Exogenous administration of vascular endothelial growth factor (VEGF) improves long-term viability of myocutaneous flaps. However, endogenous expression of this substance in flaps following ischemia-reperfusion injury has not been reported previously. Endogenous production of VEGF was measured in myocutaneous pig latissimus dorsi flaps after ischemia-reperfusion injury.