Rubina Cocker

Endoscopic foreheadplasty: a histologic comparison of periosteal refixation after endoscopic versus bicoronal lift.

Endoscopic brow lift techniques using temporary fixation rely on rapid readherence of the periosteum to calvarial bone. Little is known about the histologic events that occur during the early postoperative period after these procedures. An animal study was designed to compare and contrast periosteal fixation to bone and unelevated periosteum, with endoscopic and bicoronal brow lift techniques. One method of temporary fixation is the use of absorbable (polylactic/polyglycolic acid copolymer) LactoSorb screws; a histologic analysis of implanted LactoSorb screws was also performed. Sixteen rabbits underwent brow lifts; eight underwent endoscopic brow lift and fixation with LactoSorb screws without skin excision, and another eight underwent traditional bicoronal brow lift with skin excision and closure under tension. Animals were killed 1, 2, 6, and 12 weeks after the procedures were performed to evaluate the interaction of periosteum and bone and the normal, unelevated periosteum/calvarium interface at a site distant from the operative area. Histologic specimens were examined for the degree of apposition of periosteum to bone and for any fibrous or bony reaction at this interface. Histologic analysis showed various degrees of periosteal fibrosis and fixation to calvarial bone. After an initial phase of minimal periosteal adherence and moderate inflammation, the periosteum became progressively more adherent to bone in both groups, with no significant differences between treatment groups in rates of fixation. Fixation required at least 6 weeks. LactoSorb screws were surrounded by an area of mild inflammation and were progressively hydrolyzed and digested. Periosteal fixation increases over time for bicoronal and endoscopic brow lifts with minimal differences between the two techniques. With this animal model, periosteal adherence to calvarium requires at least 6 weeks with complete adherence by 12 weeks. In addition, the use of absorbable fixation screws seems to be both effective and well tolerated. The histologic changes associated with periosteal healing observed in this study suggest that permanent or semipermanent fixation may improve the accuracy and early postoperative maintenance of forehead advancement.

Homologous collagen dispersion (dermalogen) as a dermal filler: persistence and histology compared with bovine collagen.

To assess the biological behavior and clinical efficacy of homologous collagen dispersion (Dermalogen) in augmenting human dermis, Dermalogen and bovine cross-linked collagen (Zyplast) were compared in a human postauricular injection model. Dermalogen (two sites implanted behind one ear) and Zyplast (two sites behind the contralateral ear) were injected into an upper to middermal level in 20 healthy adults. Digital photographs of all implant sites were taken over a 12-week period after injection. Biopsies of each implant type were taken at 4 and 12 weeks after injection. At 12 weeks after injection there was a small but significant difference in persistence rates between Dermalogen and Zyplast (4% vs. 2%;p = 0.005). Histologically, Dermalogen was identifiable at 4 weeks after implantation, with evidence of neovascularization. Zyplast was identified more uniformly than Dermalogen in specimens 12 weeks after implantation, and more chronic inflammatory cells and foreign body giant cells were seen in the Dermalogen specimen. Clinical persistence and the histological behavior of Dermalogen appears to be at least as favorable as Zyplast bovine collagen. Dermalogen does not require pretesting and can also be used in the patient already sensitized to bovine protein. For these reasons, the authors think Dermalogen is a reasonable alternative to bovine collagen for facial soft-tissue augmentation.

Three-dimensional ultrasonography of choroidal melanoma: extrascleral extension

PURPOSE To describe the results of three-dimensional ultrasonography used to evaluate extrascleral extension of a choroidal melanoma. METHODS Case report. The three-dimensional ultrasound system uses a 10-MHz B-mode transducer combined with a motorized rotating holder. The system acquires 180 sequential images that are stored and processed to create a three-dimensional block of the region of interest. RESULTS Unique coronal and oblique perspectives were obtained from interactive manipulation of the three-dimensional reconstruction. Examination of the three-dimensional image allowed us to detect the transscleral uveal-orbital connection. Extrascleral melanomatous extension was confirmed on histopathologic examination. CONCLUSION Three-dimensional ultrasonography is a promising imaging technique for evaluating melanomatous extrascleral extension.

Ultraviolent and blue 2D fluorescence mapping of gynecological tissues

Fluorescence images were acquired form gynecological tissues for multiple combinations of emission and excitation wavelengths in the UV and blue spectral regions. The wavelength combinations were selected to highlight different tissue molecules whose fluorescence signatures have been shown to potential in the detection of malignancy. These images were analyzed to determine the size, shape and location of different tissue structures.

Ultraviolet 2D fluorescence mapping system for the imaging of head and neck tumors

Fluorescence images of ex vivo head and neck tissues were acquired at multiple combinations of emission and excitation wavelengths. The wavelength combinations were selected to map different tissue molecules and structures whose fluorescence signatures have bene used to detect cancer. Fluorescence maps were generated by ratioing fluorescence image intensities. These ratio maps enhanced the ability to recognize regions of tumor and other features in tissues. Histopathological analysis was performed on the tissue samples. Location and shape of features observed in the fluorescence images were correlated with structures observed in histopathology.