Computed tomography is commonly used to evaluate patients with blunt facial trauma. With the high definition of the current scanners, even small fractures of the facial skeleton can be visualized. In complex midface injuries, it can be difficult for the radiologist to know which fractures are important to point out to the surgeon. An understanding of the anatomically relevant and surgically accessible craniofacial buttresses is critical for management of these injuries. Naso-orbitoethmoid fractures are classified according to the degree of injury to the medial canthal attachment. If the nasofrontal ducts are disrupted, surgical obliteration of the frontal sinus is needed to prevent formation of a mucocele. Displaced fractures of the zygomaticomaxillary complex often increase orbital volume due to angulation of the lateral orbital wall at the zygomaticosphenoid suture. If the zygomatic arch is severely comminuted or angulated, surgical exposure is indicated. In orbital fractures, the position and shape of the medial and inferior rectus muscles can indicate whether entrapment and diplopia are likely. Pediatric “trapdoor” orbital fractures and fractures of the orbital apex associated with decreasing vision represent surgical emergencies. Le Fort fractures involve disruption of the pterygoid plates from the posterior maxilla; any combination of Le Fort I, II, and III patterns can occur. © RSNA, 2006

https://pubs.rsna.org/doi/pdf/10.1148/rg.263045710

Diagnosis of Midface Fractures with CT: What the Surgeon

Hydrogen sulfide can signal through 3 distinct mechanisms: 1) reduction and/or direct binding of metalloprotein heme centers, 2) serving as a potent antioxidant through reactive oxygen species/reactive nitrogen species scavenging, or 3) post-translational modification of proteins by addition of a thiol (-SH) group onto reactive cysteine residues: a process known as persulfidation. Below toxic levels, hydrogen sulfide promotes mitochondrial biogenesis and function, thereby conferring protection against cellular stress. For these reasons, increases in hydrogen sulfide and hydrogen sulfide-producing enzymes have been implicated in several human disease states. This review will first summarize our current understanding of hydrogen sulfide production and metabolism, as well as its signaling mechanisms; second, this work will detail the known mechanisms of hydrogen sulfide in the mitochondria and the implications of its mitochondrial-specific impacts in several pathologic conditions.-Murphy, B., Bhattacharya, R., Mukherjee, P. Hydrogen sulfide signaling in mitochondria and disease.

https://faseb.onlinelibrary.wiley.com/doi/pdf/10.1096/fj.201901304R

Hydrogen sulfide signaling in mitochondria and disease.

Cystathionine-β-synthase (CBS), the first (and rate-limiting) enzyme in the transsulfuration pathway, is an important mammalian enzyme in health and disease. Its biochemical functions under physiological conditions include the metabolism of homocysteine (a cytotoxic molecule and cardiovascular risk factor) and the generation of hydrogen sulfide (H2S), a gaseous biological mediator with multiple regulatory roles in the vascular, nervous, and immune system. CBS is up-regulated in several diseases, including Down syndrome and many forms of cancer; in these conditions, the preclinical data indicate that inhibition or inactivation of CBS exerts beneficial effects. This article overviews the current information on the expression, tissue distribution, physiological roles, and biochemistry of CBS, followed by a comprehensive overview of direct and indirect approaches to inhibit the enzyme. Among the small-molecule CBS inhibitors, the review highlights the specificity and selectivity problems related to many of the commonly used "CBS inhibitors" (e.g., aminooxyacetic acid) and provides a comprehensive review of their pharmacological actions under physiological conditions and in various disease models.

Cystathionine-β-Synthase: Molecular Regulation and Pharmacological Inhibition.

To enable survival in adverse conditions, cancer cells undergo global metabolic adaptations. The amino acid cysteine actively contributes to cancer metabolic remodelling on three different levels: first, in its free form, in redox control, as a component of the antioxidant glutathione or its involvement in protein s-cysteinylation, a reversible post-translational modification; second, as a substrate for the production of hydrogen sulphide (H2S), which feeds the mitochondrial electron transfer chain and mediates per-sulphidation of ATPase and glycolytic enzymes, thereby stimulating cellular bioenergetics; and, finally, as a carbon source for epigenetic regulation, biomass production and energy production. This review will provide a systematic portrayal of the role of cysteine in cancer biology as a source of carbon and sulphur atoms, the pivotal role of cysteine in different metabolic pathways and the importance of H2S as an energetic substrate and signalling molecule. The different pools of cysteine in the cell and within the body, and their putative use as prognostic cancer markers will be also addressed. Finally, we will discuss the pharmacological means and potential of targeting cysteine metabolism for the treatment of cancer.

/pdf/cysteine-metabolic-circuitries-druggable-targets-in-cancer-3nhh8402ns.pdf

Cysteine metabolic circuitries: druggable targets in cancer

Tumor cells have increased requirements for NAD+. Thus, many cancers exhibit an increased reliance on NAD+ production pathways. This dependence may be exploited therapeutically through pharmacological targeting of NAMPT, the rate-limiting enzyme in the NAD+ salvage pathway. Despite promising preclinical data using NAMPT inhibitors in cancer models, early NAMPT inhibitors showed limited efficacy in several early phase clinical trials, necessitating the identification of strategies, such as drug combinations, to enhance their efficacy. While the effect of NAMPT inhibitors on impairment of energy metabolism in cancer cells has been well-described, more recent insights have uncovered a number of additional targetable cellular processes that are impacted by inhibition of NAMPT. These include sirtuin function, DNA repair machinery, redox homeostasis, molecular signaling, cellular stemness, and immune processes. This review highlights the recent findings describing the effects of NAMPT inhibitors on the non-metabolic functions of malignant cells, with a focus on how this information can be leveraged clinically. Combining NAMPT inhibitors with other therapies that target NAD+-dependent processes or selecting tumors with specific vulnerabilities that can be co-targeted with NAMPT inhibitors may represent opportunities to exploit the multiple functions of this enzyme for greater therapeutic benefit.

/pdf/beyond-energy-metabolism-exploiting-the-additional-roles-of-pntngy0zqp.pdf

Beyond Energy Metabolism: Exploiting the Additional Roles of NAMPT for Cancer Therapy

Transoral Robotic Surgery for the Tongue Base.

Panfacial and Naso‐Orbito‐Ethmoid (NOE) Fractures

Surgical cases where the anesthesiologist has to maintain a patient’s airway and ventilation in the same anatomical space in which the surgeon operates are referred to as shared airway anesthesia. Shared airways are commonly encountered with several surgical and dental specialties that operate within the head and neck. These cases require open communication and careful planning between anesthesiologist and surgeon in order to prevent catastrophic complications. The first step in minimizing complications in shared airway anesthesia is a preoperative assessment with particular emphasis on the airway exam. The airway examination should include, at a minimum, an evaluation of the maximum incisal opening, Mallampati-Samsoon classification, condition of dentition, range of motion of the neck, thyromental distance, tracheal deviation or neck masses, facial hair, and assessment of tonsillar size. Shared airway anesthesia cases, occurring both in- and outside the hospital, often employ open airway techniques. These techniques include (1) monitored anesthesia care, (2) mask ventilation, (3) insufflation with spontaneous respiration, (4) jet ventilation, and (5) laryngeal mask airway. When endotracheal intubation is required, standard oral tubes can be used; however, nasal RAE tubes are often preferred due to better visualization of the oral cavity. For shared airway cases with difficult airways, videolaryngoscope-guided intubation, fiber-optic-guided intubation, or a surgical airway may have to be considered as alternatives to standard intubation techniques. Respiratory compromise is the most feared complication in shared airway anesthesia. Complications that can lead to respiratory compromise in the perioperative period include failed intubation, loss of airway due to laryngospasm or foreign body aspiration, surgical fire, and vocal cord paralysis.

Shared Airway: Techniques, Anesthesia Considerations, and Implications

BACKGROUND The authors reported the first pediatric case of a craniocerebral gunshot injury successfully treated with a wound vacuum-assisted closure (VAC) device after dehiscence and infection of the initial cranial wound. OBSERVATIONS A 17-year-old boy suffered several gunshots to the left hemisphere, resulting in significant damage to the scalp, calvaria, and brain. Emergency hemicraniectomy was performed, with reconstruction of a complicated scalp wound performed at the initial surgery. The scalp was devitalized and ultimately dehisced, resulting in a cranial infection. It was treated first with a repeated attempt at primary closure, which failed because of persistent devitalized tissue, and was then treated with aggressive debridement followed by placement of a wound VAC device over the exposed brain as a bridge therapy to reconstruction. This procedure was deemed necessary given the active infection. LESSONS The patient received delayed reconstruction with a free split-thickness skin graft and made a remarkable recovery, with cranioplasty performed 6 months later. The authors reviewed the literature on wound VAC use in cranial wound treatment and proposed it as a legitimate bridge therapy to definitive reconstruction in the setting of dirty wounds, active infection, or even hemodynamically unstable patients.

https://thejns.org/downloadpdf/journals/j-neurosurg-case-lessons/3/8/article-CASE21489.pdf

Wound vacuum-assisted closure as a bridge therapy in the treatment of infected cranial gunshot wound in a pediatric patient: illustrative case

Perioperative dental injury is the result of mechanical trauma typically sustained during upper airway management for general anesthesia. Despite well-documented risk factors and a simplistic mechanism, iatrogenic damage to the dentition remains very prevalent. In fact, both the Accreditation Council for Graduate Medical Education and the American Association of Oral and Maxillofacial Surgeons have had to publish guidelines specifically addressing this complication (Miller and Pardo (2011). Airway management. Basics of anesthesia, 6th edn. Elsevier, Philadelphia, p 219–251; AAOMS parameters of care: clinical practice guidelines for oral and maxillofacial surgery. (AAOMS ParCare 2012)). A decrease in the rate of patient edentulism coupled with an increased predominance and cost of dental restorations has made this complication even more significant (Thomson and Ma. Singap Dent J 35:3–8, 2014). This chapter briefly discusses the most common causes of perioperative dental injury with specific focus on direct laryngoscopy and tracheal intubation. Risk factors are also discussed with the most pertinent including preexisting dental disease as well as a predicted difficult intubation (de Sousa and Mourao. Braz J Anesthesiol 65(6):511–518, 2013). A review of the necessary dental anatomy, dental pathology, and dental restorations is provided for the perioperative personnel without dental training. Next reviewed are preventative measures including correct laryngoscopy technique, preoperative patient-provider communication, and various other clinical aids to minimize risk. The treatment of perioperative dental injury always begins with a rapid diagnosis in order to identify any possible acute stage treatment necessary to prevent further damage. Once stable, the provider must then consult the treating service with an urgency determined by the morbidity of the injury. Finally, a discussion of the most relevant medical legal implications is provided.

Andrew T. Meram

Papers

Transoral Robotic Surgery for the Tongue Base.

Panfacial and Naso‐Orbito‐Ethmoid (NOE) Fractures

Shared Airway: Techniques, Anesthesia Considerations, and Implications

Wound vacuum-assisted closure as a bridge therapy in the treatment of infected cranial gunshot wound in a pediatric patient: illustrative case

Dental Injury: Anatomy, Pathogenesis, and Anesthesia Considerations and Implications