Case series of branch retinal vein occlusion secondary to rhegmatogenous retinal detachment and its surgical management.

BACKGROUND: To review cases of branch retinal vein occlusion (BRVO) secondary to rhegmatogenous retinal detachment (RRD) and its surgical management and presume their mechanism. METHODS: Medical records of patients who underwent surgery for RRD between 2015 and 2019 at a single tertiary care center were retrospectively reviewed. New BRVO secondary to RRD or its surgical procedure was diagnosed based on the fundus examination and its clinical course. RESULTS: A total of 734 RRD surgeries were performed for five years, and six cases of new BRVOs were noticed in the first year after surgery (incidence was 0.68%: six cases of BRVO / 734 cases of surgical RRD); five cases occurred after vitrectomy, and one occurred after scleral buckling. In three cases, retinal veins were presumed to already be partially occluded related due to a kink of the retinal vein seen before surgery. In the other three cases, the retinal veins were presumed to have incurred damage during vitrectomy. CONCLUSION: In the present cohort, RRD or its related procedures caused BRVO within a year of surgery at an incidence of 0.68%. The proposed mechanisms are kinks of the retinal vein on the detached retina and damage to the retinal vein during vitrectomy.

Selective internal limiting membrane peeling for prevention of secondary epiretinal membrane after vitrectomy for rhegmatogenous retinal detachment.

PURPOSE: We introduce selective internal limiting membrane (ILM) peeling, a guideline procedure to determine whether to remove the ILM during vitrectomy for rhegmatogenous retinal detachment (RRD). STUDY DESIGN: Retrospective case series METHODS: Patients who underwent pars plana vitrectomy for RRD and were followed up for 12 months or longer were included. When vitreous cortex remnants (VCRs) were detected with triamcinolone acetonide, the ILM was removed; otherwise, the ILM was preserved ("selective ILM peeling"). The factors associated with the presence of VCRs and incidence of secondary epiretinal membrane (ERM) were analyzed. RESULTS: VCRs were detected in 87 of 133 eyes (65.4%) in which the ILM was removed. Younger age, better preoperative visual acuity, and vitreous hemorrhage were negatively correlated with the presence of VCRs. No ERM occurred in the eyes after ILM peeling. Among the eyes with ILM preservation, subclinical ERM was noticed in 4 eyes (8.7%), and 1 eye (2.1%) required additional surgery owing to ERM. ERM occurred more commonly in eyes with the ILM preserved (P = .004). However, no differences in the rate of additional surgeries were found between the 2 groups. CONCLUSION: Selective ILM peeling offers an alternative option to reduce the burden of ILM peeling or additional surgery.

Building mechanism for a high open-circuit voltage in an all-solution-processed tandem polymer solar cell.

Additional post-processing techniques, such as post-thermal annealing and UV illumination, were found to be required to obtain desirable values of the cell parameters in a tandem polymer solar cell incorporated with solution-processed basic n-type titanium sub-oxide (TiO(x))/acidic p-type poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) interlayers. Subsequent to the fabrication of the tandem polymer solar cells, the open-circuit voltage (V(OC)) of the cells exhibited half of the expected value. Only after the application of the post-treatments, the V(OC) of a tandem cell increased from the initial half-cell value (∼0.6 V) to its full-cell value (∼1.2 V). The selective light-biased incident photon-to-current efficiency (IPCE) measurements indicated that the initial V(OC) originated from the back subcell and that the application of the post-processing treatments revived the front subcell, such that the net photocurrent of the tandem cell was finally governed by a recombination process of holes from the back subcell and electrons from the front subcell. Based on our experimental results, we suggest that a V(OC) enhancement could be ascribed to two types of subsequent junction formations at the interface between the TiO(x) and PEDOT:PSS interlayers: an 'ion-mediated dipole junction', resulting from the electro-kinetic migration of cationic ions in the interlayers during post-thermal annealing in the presence of a low-work-function metal cathode, and a 'photoinduced Schottky junction', formed by increasing the charge carrier density in the n-type TiO(x) interlayer during UV illumination process. The two junctions separately contributed to the formation of a recombination junction through which the electrons in TiO(x) and the holes in PEDOT:PSS were able to recombine without substantial voltage drops.

Sinus augmentation using absorbable collagen sponge loaded with Escherichia coli-expressed recombinant human bone morphogenetic protein 2 in a standardized rabbit sinus model: a radiographic and histologic analysis.

OBJECTIVES: The purpose of this pilot study was to determine the osteoinductive effect of absorbable collagen sponge (ACS) loaded with Escherichia coli-expressed recombinant human bone morphogenetic protein 2 (ErhBMP-2) and evaluate structural stability of ACS in a standardized rabbit sinus model. MATERIAL AND METHODS: The maxillary sinuses were prepared bilaterally in six male white rabbits. The windows were prepared using a 6 mm trephine bur, and circular bony windows were carefully removed. Following reflection of the sinus membrane, a saline-soaked ACS alone and an ErhBMP-2-loaded ACS were inserted into the left and right maxillary sinuses, respectively. After a healing period of 8 weeks, sections of the augmented sinus and surrounding bone were made and analyzed by microcomputed tomography and histologically for signs of window closure and bone augmentation. RESULTS: Radiographic analysis revealed new bone formation in both groups of augmented sinus (i.e., with and without ErhBMP-2). The maximum augmented height did not differ significantly between the groups; however, window closure was significantly more advanced in the ErhBMP-2 group than in the control group (P=0.02). The defect was significantly deeper in the control group than in the ErhBMP-2-treated group (P=0.02). CONCLUSIONS: In conclusion, ErhBMP-2-loaded ACS showed enhanced osteoinductive potential, particularly with regard to bone closure of a sinus window and facilitated maturation of the newly formed bone within the rabbit sinus cavity. However, the structural durability of ACS was not sufficient to maintain the augmented volume in the sinus.

Prevalence and anatomic topography of mandibular tori: computed tomographic analysis.

PURPOSE: Mandibular tori are located above the mylohyoid ridge. These features are relatively common in most populations, but their prevalence varies with race. The purpose of this study was to identify the prevalence and features of mandibular tori in a Korean population using computed tomographic (CT) images. MATERIALS AND METHODS: The CT images of 726 patients were analyzed in this study. The presence or absence of a mandibular torus was identified on the CT images of each patient's quadrants and categorized according to gender and age. The most common location was also evaluated according to the corresponding teeth. The cortical thickness of each torus was evaluated using a 3-dimensional reconstruction software program. RESULTS: The prevalence of mandibular tori in the entire sample was 24.1%, and most cases were bilateral. Mandibular tori were observed more frequently in young adults, with the prevalence being inversely related to age. The most frequently observed location was the premolar region, and the mean cortical thickness was 6.9 mm. CONCLUSIONS: Mandibular tori seem to change with aging. The prevalence in the present sample composed of Koreans was 24.1%, and younger patients may be more likely to develop a mandibular torus. Most tori presented a medium size bilaterally in the lingual aspect of the premolar region, and all were composed of cortical bone.

Creating a Biological Breast Implant with an Omental Fat-Augmented Free Flap.

SUMMARY: Women with inadequate myocutaneous or fasciocutaneous soft-tissue donor sites for breast reconstruction after mastectomy are mostly limited to implants. Alternative substitutes are needed for those who do not want-or in whom there are contraindications for-implant-based reconstruction. The authors report a novel technique using an omental fat-augmented free flap to create an autologous breast mound that has comparable shape and projection to a breast implant. Three patients with breast cancer who desired unilateral reconstruction were identified in the period 2019 to 2020. All had insufficient traditional autologous sites and were averse to the use of implants. A nipple-sparing mastectomy was performed, and the omentum was laparoscopically harvested and fat-grafted ex vivo and then encased in acellular dermal matrix for microvascular anastomoses. The body mass indexes of the three patients were 17.6, 25, and 28.3 kg/m2. Each individual's mastectomy specimens and corresponding omentum plus fat-grafting weights were 113.7/228, 271/293, and 270/360 g. No postoperative complications occurred. The reconstructed breast remains soft, with stable breast volume at 6 months and without evidence of fat necrosis. This novel use of fat grafting into an omental flap enveloped in acellular dermal matrix, the omental fat-augmented free flap, provides a viable and successful autologous alternative for patients who are not candidates for traditional autologous breast reconstruction options because of body habitus or personal preference.

Management of Large Pediatric Wound Defects Using a Continuous External Tissue Expander.

Both internal and external tissue expanders take advantage of the innate adaptive mechanisms the skin exerts in response to mechanical tension, known as the stress-relaxation phenomenon. Internal tissue expander use is time-consuming and can be complicated by infection and extrusion. In this case series, continuous external tissue expanders used to manage large pediatric wounds were assessed. Fourteen patients (ages: 4 days to 17 years) with large wounds underwent continuous external tissue expansion intraoperatively. The success of wound closure was assessed. In addition, the size of the patient's wounds, duration of device application, and postoperative complications were evaluated. The continuous external tissue expander was applied to wound sizes ranging from 14.7 to 560 cm2 for 5 to 10 days until the wound was amenable for direct closure. In 11 of the 14 patients, delayed primary closure was achieved. The device significantly reduced the wound sizes of the remaining three cases (average 80% size reduction). There was no incidence of wound dehiscence or infection. This case series demonstrates the benefit of the continuous external tissue expansion in managing pediatric wounds that would not otherwise be amenable to primary closure. The method allows for timely closure with limited risk of infection or extrusion, and should be in the armamentarium of reconstructive plastic surgeons.

Blossom smart expander technology for tissue expander-based breast reconstruction facilitates shorter duration to full expansion: A pilot study.

BACKGROUND: This study evaluated the Blossom system, an innovative self-filling, rate-controlled, pressure-responsive saline tissue expander (TE) system. We investigated the feasibility of utilizing this technology to facilitate implant-based and combined flap with implant-based breast reconstruction in comparison to conventional tissue expansion. METHODS: In this prospective, single-center, single-surgeon pilot study, participants underwent either implant-based breast reconstruction or a combination of autologous flap and implantbased breast reconstruction. Outcome measures included time to full expansion, complications, total expansion volume, and pain scores. RESULTS: Fourteen patients (TEs; n=22), were included in this study. The mean time to full expansion was 13.4 days (standard error of the mean [SEM], 1.3 days) in the combination group and 11.7 days (SEM, 1.4 days) in the implant group (P=0.78). The overall major complication rate was 4.5% (n=1). No statistically significant differences were found in the complication rate between the combination group and the implant group. The maximum patient-reported pain scores during the expansion process were low, but were significantly higher in the combination group (mean, 2.00±0.09) than in the implant group (mean, 0.29±0.25; P=0.005). CONCLUSIONS: The reported average duration for conventional subcutaneous TE expansion is 79.4 days, but this pilot study using the Blossom system achieved an average expansion duration of less than 14 days in both groups. The Blossom system may accommodate single-stage breast reconstruction. The overall complication rate of this study was 4.5%, which is promising compared to the reported complication rates of two-stage breast reconstruction with TEs (20%-45%).

Are We Witnessing a Paradigm Shift?: A Systematic Review of Social Media in Residency.

As social media's applications continue to evolve, the pitfalls and dangers associated with misuse have been accentuated in the literature. Consequently, academic institutions across the nation have implemented social media policies. This study is aimed to evaluate the state of social media literature examining postgraduate trainees (residents/fellows). METHODS: A systematic search was performed identifying peer-reviewed publications presenting original research. Studies published through December 8, 2018, focusing on social media use among postgraduate trainees were considered for inclusion. RESULTS: Fifty-three studies were categorized into 4 domains: (1) resident recruitment, (2) graduate medical education, (3) professional development, and (4) academic scholarship. Thirty-four (64.15%) investigated social media's impact on professional development, of which 16 (47.05%) highlighted the detrimental potential on trainee professionalism. The remaining 18 (52.94%) focused on promoting social media training during residency, and/or enhancing social media competency to benefit professional development. Fourteen (26.42%) rationalized social media use in augmenting graduate medical education. Ten (18.87%) assessed social media's influence on resident recruitment, of which 7 (70%) depicted use as a screening instrument for program directors on resident applicants. Two (3.77%) of the studies introduced social media as a platform for academic scholarship with indicators as altmetrics. CONCLUSIONS: The well-established disadvantages of social media use by the postgraduate trainee continue to persist in the literature. However, there is recognition of social media as a valuable resource in influencing resident recruitment, graduate medical education, professional development, and academic scholarship, representing a paradigm shift-from cautiously avoidant to thoughtful capitalization on its immense potential.

Partial molecular characterization of the mitochondrial genome of Baylisascaris columnaris and prevalence of infection in a wild population of Striped skunks.

Members of the genus Baylisascaris utilize omnivores or carnivores as their definitive hosts. The best known member of this genus is Baylisascaris procyonis, which is an intestinal parasite of raccoons. The closest relative of B. procyonis is B. columnaris, which utilizes the common skunk as its definitive host. Although B. procyonis has been extensively studied, relatively little is known of B. columnaris. For example, the mitochondrial genome of B. procyonis has been sequenced in its entirety. Conversely, the mitochondrial genome of B. columnaris remains largely unexplored. Likewise, the prevalence of this parasite in its wild host has not been documented. In this study, we collected parasites from a wild population of skunks in the state of Utah, United States. The cytochrome c oxidase subunit 1 and 2 genes, NADH dehydrogenase 2 and several tRNA genes were sequenced from the mitochondrial genome of these parasites. We also determined the prevalence of B. columnaris in a wild population of skunks. In this work we identify several novel polymorphic genetic loci between B. procyonis and B. columnaris. These findings provide additional molecular targets for the differentiation of Baylisascaris species through clarification of genetic differences between B. columnaris and B. procyonis.

Recombinant human bone morphogenetic protein-2 stimulates the osteogenic potential of the Schneiderian membrane: a histometric analysis in rabbits.

This study evaluated the osteoinductive effect of the recombinant human bone morphogenetic protein-2 (rhBMP-2)-coated biphasic calcium phosphate (BCP) carrier system on the grafted sinus area, including surrounding tissues and the Schneiderian membrane. A total of 18 male rabbits were used in this study; two for in vitro and 16 for in vivo experiments. Schneiderian membranes taken from two animals were cultured with or without rhBMP-2, and quantitative reverse transcriptase-polymerase chain reaction analysis was performed. Both maxillary sinuses in each of the 16 animals were used to compare the in vivo effects of rhBMP-2-coated BCP (experimental group) and BCP alone (control group). In each animal, rhBMP-2-coated BCP was grafted into one of the maxillary sinuses, and the same amount of BCP alone was grafted into the contralateral site in random order. Radiologic and histometric analyses were performed at 2 and 8 weeks after surgery. After 2 days of culturing with or without rhBMP-2, a significant increase in the expression of early osteoblasts (RUNX2, type I collagen, alkaline phosphatase, and osteopontin) could be observed. Different histologic healing patterns were observed in experimental and control sites: newly formed bone lining the reflected sinus membrane without bone formation was observed at the central areas of experimental sites (window=0.06%; center=0%; membrane=20.86% of new bone), whereas evenly distributed new bone formation was observed at the control sites (window=7.27%; center=7.41%; membrane=15.58% of new bone).The augmented volume was well maintained at both the experimental and control sites during the experimental period, but at 2 weeks, the augmented volume was greater at the experimental sites than at the control sites (232.62 and 195.29 mm(3), respectively; p<0.001). These results suggest that good space maintenance in sinus augmentation is achieved with BCP, while the osteoinductive potential of the sinus membrane is activated at the early stage of healing with rhBMP-2.

Investigation of bone formation using calcium phosphate glass cement in beagle dogs.

PURPOSE: Among available biomaterials, bioceramics have drawn special interest due to their bioactivity and the possibility of tailoring their composition. The degradation rate and formulation of bioceramics can be altered to mimic the compositions of the mineral phase of bone. The aim of this study was to investigate the bone formation effect of amorphous calcium phosphate glass cement (CPGC) synthesized by a melting and quenching process. METHODS: In five male beagle dogs, 4 x 4 mm 1-wall intrabony defects were created bilaterally at the mesial or distal aspect of the mandibular second and fourth premolars. Each of the four defects was divided according to graft materials: CPGC with collagen membrane (CM), biphasic calcium phosphate (BCP) with CM, CM alone, or a surgical flap operation only. The dogs were sacrificed 8 weeks post-surgery, and block sections of the defects were collected for histologic and histometric analysis. RESULTS: There were significant differences in bone formation and cementum regeneration between the experimental and control groups. In particular, the CPGC and BCP groups showed greater bone formation than the CM and control groups. CONCLUSIONS: In conclusion, CPGC was replaced rapidly with an abundant volume of new bone; CPGC also contributed slightly to regeneration of the periodontal apparatus.

A simple approach to preserve keratinized mucosa around implants using a pre-fabricated implant-retained stent: a report of two cases.

PURPOSE: There is no consensus regarding the relationship between the width of keratinized mucosa and the health of peri-implant tissues, but clinicians prefer to provide enough keratinized mucosa around dental implants for long-term implant maintenance. An apically positioned flap during second stage implant surgery is the chosen method of widening the keratinized zone in simple procedures. However, the routine suture techniques used with this method tend to apply tension over the provisional abutments and decrease pre-existing keratinized mucosa. To overcome this shortcoming, a pre-fabricated implant-retained stent was designed to apply vertical pressure on the labial flap and stabilize it in a bucco-apical direction to create a wide keratinized mucous zone. METHODS: During second stage implant surgery, an apically displaced, partial thickness flap with a lingualized incision was retracted. A pre-fabricated stent was clipped over the abutments after connecting to the provisional abutment. Vertical pressure was applied to displace the labial flap. No suture was required and the stent was removed after 10 days. RESULTS: A clinically relevant amount of keratinized mucosa was achieved around the dental implants. Buccally displaced keratinized mucosa was firmly attached to the underlying periosteum. A slight shrinkage of the keratinized zone was noted after the healing period in one patient, but no discomfort during oral hygiene was reported. Clinically healthy gingiva with enough keratinized mucosa was achieved in both patients. CONCLUSIONS: The proposed technique is a simple and time-effective technique for preserving and providing keratinized tissue around dental implants.