Mechanisms of delayed indocyanine green fluorescence and applications to clinical disease processes.

BACKGROUND: Delayed indocyanine green fluorescence imaging is under investigation in various clinical disease processes. Understanding the mechanisms of indocyanine green accumulation and retention is essential to correctly interpreting and analyzing imaging data. The purpose of this scoping review was to synthesize what is known about the mechanism of indocyanine green retention at the cellular level to better understand the clinical nuances of delayed indocyanine green imaging and identify critical gaps in our knowledge to guide future studies. METHODS: We performed a scoping review of 7,087 citations after performing database searches of PubMed, Scopus, the Cochrane Library, and the Web of Science Core Collection electronic databases. Studies were eligible for inclusion if they were peer-reviewed original research discussing the mechanism of indocyanine green retention in the results section in disease processes involving inflammation and/or necrosis, including cancer, and were available in English. Data were extracted using Covidence software. RESULTS: Eighty-nine studies were included in the final analysis. Several features of indocyanine green retention were identified. CONCLUSION: We identified several mechanistic features involved in indocyanine green accumulation in diseased tissue that overall had distinct mechanisms of indocyanine green retention in tumors, nontumor inflammation, and necrosis. Our study also reveals new insight on how inflammatory infiltrate influences indocyanine green fluorescence imaging. These findings are noteworthy because they add to our understanding of how fluorescence-guided surgery may be optimized based on the pathology of interest via specific indocyanine green dosing and timing of image acquisition.

Lighting the Way for Necrosis Excision Through Indocyanine Green Fluorescence-Guided Surgery.

BACKGROUND: No objective technique exists to distinguish necrotic from viable tissue, risking over-excision in burns and loss of wound healing potential. Second window indocyanine green (SWIG) is a novel fluorescence-imaging modality being studied to identify residual solid tumors during oncological surgery. SWIG has also been shown to have avidity for necrosis in animal models, but translation of these findings to humans is lacking. The objective of this study was to evaluate SWIG in the identification of burn wound necrosis and compare it with previously published indocyanine green angiography (ICGA) techniques. STUDY DESIGN: This study used mouse, human skin xenograft and human patient burn models. Brightfield and SWIG near-infrared imaging were performed on macroscopic tissue samples, which were then cryopreserved, sectioned, and analyzed for microscopic fluorescence. SWIG fluorescence findings were correlated to visual assessment of the burn wound as well as histological markers of necrosis using hematoxylin and eosin and lactate dehydrogenase stains. RESULTS: We found that SWIG identified burn necrosis in a manner dependent on the dose and timing of indocyanine green (ICG) administration and had an inverse fluorescence signal compared with ICGA. Furthermore, SWIG fluorescence identified the interface of viable and nonviable tissue. CONCLUSION: Our study confirmed that ICGA is an inconsistent and nonstandardized modality to evaluate burn injuries. In contrast, SWIG imaging is a potential imaging modality to objectively prognosticate burn wound healing potential and guide intraoperative burn excision. Further studies are needed to define ratios of fluorescence intensity values to guide surgical decision-making in burn excision and to better define how ICG is retained in necrotic tissue to enhance utility of SWIG in other disease processes.

#Botox 101: Subgroup Analysis of Twitter's Top 101 Neurotoxin Influencers.

BACKGROUND: Recent studies demonstrate that board-certified plastic surgeons and dermatologists are underrepresented in posting public-directed marketing content about botulinum toxin A on YouTube. However, educational content and peer-to-peer social media influence regarding the topic of neurotoxins has not been studied. Twitter is a social media platform that has emerged as a unique network for public education and for the exchange of ideas among physicians. OBJECTIVE: The purpose of this study is to identify Twitter's top social media influencers on #botox, to describe their characteristics and to relate their social media influence to academic influence. METHODS: Twitter influence scores for the topic search #botox were collected in January 2019 with Right Relevance software. #Botox was the only neurotoxin term with sufficient activity to generate an influencer list. The user accounts associated with top influencers were connected to individual names, identification as a plastic surgeon or dermatologist, board certification status, location, and academic h-index. RESULTS: The top 101 Twitter influencers on #botox are presented. Seventy-five percent of influencers are physically located in the United States. Academic h-index of #botox social media influencers ranged from 0 to 62 (mean, 8.6). CONCLUSION: This study shows that the top #botox social media influencers on Twitter and primarily board-certified or eligible plastic surgeons located in the United States. This study also elucidates the influencer network within which other plastic surgeons and dermatologists can interact to augment their own influence within the social media network. This is the first study to describe social media influencers in this way.

Dental Topics for Plastic Surgeons, Part Three: Infection and Trauma of the Dentition.

ABSTRACT: Conditions that affect dental and periodontal structures receive sparse coverage in the plastic surgery literature, yet a working knowledge of this subject matter is important in certain areas of clinical practice and a fundamental understanding is part of plastic surgery competency tested on the in-service and written board examinations. This 4-part series written to provide plastic surgeons with a working knowledge of dental topics that may be relevant to their clinical practice. This section, Part III, covers inflammatory and infectious conditions of the dentition and related structures, as well as dentoalveolar trauma.

Dental Topics for Plastic Surgeons, Part Two: Abnormal Tooth Development, Conditions, and Treatment.

Conditions that affect dental and periodontal structures receive sparse coverage in the plastic surgery literature, yet a working knowledge of this subject matter is important in certain areas of clinical practice and a fundamental understanding is part of plastic surgery competency tested on the in-service and written board examinations. This four-part series written to provide plastic surgeons with a working knowledge of dental topics that may be relevant to their clinical practice. This section, Part II, covers abnormal tooth development and related conditions.

Dental Topics for Plastic Surgeons, Part One: Normal Anatomy, Growth and Development.

Normal and abnormal conditions affecting the dentition and the periodontal structures receive sparse coverage in the plastic surgery literature, textbooks, and training programs. Nevertheless, a working knowledge of this subject matter is important in certain areas of clinical practice, and a fundamental understanding is often part of plastic surgery competency tested for in the In-service and written board examinations. This four-part series is written to provide plastic surgeons with a working knowledge of relevant dental topics. Part 1 covers fundamental aspects of normal dental embryology, growth and anatomy.

Is Epinephrine Safe for Infant Digit Excision? A Retrospective Review of 402 Polydactyly Excisions in Patients Younger than 6 Months.

BACKGROUND: Conventional dogma suggests that the use of local anesthetic with epinephrine is contraindicated in the digits because of fear of ischemia and necrosis. Although several reports have refuted this notion, the precept is still propagated in many clinical forums. For many years, the authors have used lidocaine with epinephrine to perform removal of postaxial polydactyly in infants and have observed few complications and no cases of digital ischemia or necrosis. This investigation details the authors' outcomes with this anesthetic modality in neonates and supports the growing body of literature documenting the safety of using lidocaine with epinephrine in the digits. METHODS: A retrospective review of all infants younger than 6 months who underwent preaxial and postaxial polydactyly excision and removal of their sequelae of the hand or foot under local anesthesia, from 2011 to 2017, was completed. All demographic characteristics, frequency of complications, and descriptive statistics of the sample clinical group were documented. RESULTS: In the 215 patients who met inclusion criteria, a total of 402 procedures were performed. Mean follow-up was 19.9 months for 140 patients, or 264 procedures (65.7 percent). The total complication rate was 2.6 percent. There were two cases of minor bleeding, one wound dehiscence, and four surgical-site infections. CONCLUSIONS: In 402 procedures of surgical excision of polydactyly in infants, there were few short-term complications, none of which were necrosis or any vascular complication related to the use of epinephrine. The authors believe that, with the use of a low-dose epinephrine injection (1:200,000), the risk for digital infarction is low in this population. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Neonatal Compartment Syndrome as a Result of Thromboembolic Event.

Neonatal compartment syndrome is a rare condition characterized by progressive limb ischemia and tissue necrosis manifesting at birth or in the immediate postpartum period. Early recognition of clinical features and immediate surgical intervention offer the best prognosis, but unfamiliarity with this uncommon entity often results in delayed diagnosis and catastrophic consequences, including limb amputation. We present a case in a preterm neonate who developed a proximal arterial thrombus after sustaining limb ischemia in utero. This case demonstrated that even delayed treatment with appropriate therapy can result in salvage of the limb. Clinicians should be aware of the characteristic skin findings and institute appropriate measures to determine the presence or absence of compartment syndrome.

Death following traumatic brain injury in Drosophila is associated with intestinal barrier dysfunction.

Traumatic brain injury (TBI) is a major cause of death and disability worldwide. Unfavorable TBI outcomes result from primary mechanical injuries to the brain and ensuing secondary non-mechanical injuries that are not limited to the brain. Our genome-wide association study of Drosophila melanogaster revealed that the probability of death following TBI is associated with single nucleotide polymorphisms in genes involved in tissue barrier function and glucose homeostasis. We found that TBI causes intestinal and blood-brain barrier dysfunction and that intestinal barrier dysfunction is highly correlated with the probability of death. Furthermore, we found that ingestion of glucose after a primary injury increases the probability of death through a secondary injury mechanism that exacerbates intestinal barrier dysfunction. Our results indicate that natural variation in the probability of death following TBI is due in part to genetic differences that affect intestinal barrier dysfunction.

The roles of αV integrins in lens EMT and posterior capsular opacification.

Posterior capsular opacification (PCO) is the major complication arising after cataract treatment. PCO occurs when the lens epithelial cells remaining following surgery (LCs) undergo a wound healing response producing a mixture of α-smooth muscle actin (α-SMA)-expressing myofibroblasts and lens fibre cells, which impair vision. Prior investigations have proposed that integrins play a central role in PCO and we found that, in a mouse fibre cell removal model of cataract surgery, expression of αV integrin and its interacting ß-subunits ß1, ß5, ß6, ß8 are up-regulated concomitant with α-SMA in LCs following surgery. To test the hypothesis that αV integrins are functionally important in PCO pathogenesis, we created mice lacking the αV integrin subunit in all lens cells. Adult lenses lacking αV integrins are transparent and show no apparent morphological abnormalities when compared with control lenses. However, following surgical fibre cell removal, the LCs in control eyes increased cell proliferation, and up-regulated the expression of α-SMA, ß1-integrin, fibronectin, tenascin-C and transforming growth factor beta (TGF-ß)-induced protein within 48 hrs, while LCs lacking αV integrins exhibited much less cell proliferation and little to no up-regulation of any of the fibrotic markers tested. This effect appears to result from the known roles of αV integrins in latent TGF-ß activation as αV integrin null lenses do not exhibit detectable SMAD-3 phosphorylation after surgery, while this occurs robustly in control lenses, consistent with the known roles for TGF-ß in fibrotic PCO. These data suggest that therapeutics antagonizing αV integrin function could be used to prevent fibrotic PCO following cataract surgery.