• A Rare Case of Aortoatrial Fistula from Streptococcal Endocarditis

      Arshad, Hammad; Young, Meilin; Rali, Parth (2017-07-05)
      We represent an unfortunate case of postinfluenza streptococcal endocarditis in a 34-year-old healthy male. He presented with hypoxic respiratory failure and was found to have mitral and aortic valve vegetation. Hospital course was complicated by the presence of an aortoatrial fistula from an aortic root abscess, persistent septic shock, and multiorgan failure.
    • Is non-invasive indocyanine-green angiography a useful adjunct for the debridement of infected sternal wounds?

      Tyrell, Richard O.; Kilmartin, Catherine; Acevedo, Edwin; Keshavamurthy, Suresh; Gassman, Andrew; 0000-0002-5578-1911 (2018-05-01)
      Laser-assisted indocyanine-green imaging (ICG) has a wide range of surgical applications, and has been used in reconstructive surgery to aid in assessing the viability of free tissue transfers and to help predict poor tissue perfusion. However, its indications for use is limited to assessing free flap tissue perfusion, coronary artery perfusion during coronary artery bypass (CABG), and tissue perfusion in diabetic foot ulcers, to name a few. This system has been proven to be a safe, reliable adjunctive modality to assess microvascular compromise or poor perfusion peri-operatively, which could minimize skin necrosis and other post-operative complications (Further et al., 2013).1 The ability to objectively assess tissue perfusion has led to improved post-operative outcomes in breast, abdominal wall, colorectal, and cardiac surgery. To date, no studies have reviewed the use of ICG in delineating devitalized bone during sternal wound debridement after cardiac surgery. At our institution, we have encountered a cohort of patients with post-cardiac surgery sternal wound infections who have required debridement of infected and devitalized bone. We propose that SPY technology aids in delineating this devitalized bone, and may aid in the timing muscle flap coverage. In this paper, we will demonstrate two cases of patients who had post-operative sternal wound infections after undergoing cardiac surgery for which ICG was used to demarcate debridement zones and subsequent flap coverage. In these cases, ICG allowed for efficient and reliable intraoperative evaluation of bony perfusion and has aided in early adequate debridement and flap coverage.
    • Primary extranodal jejunal diffuse large B cell lymphoma as a diagnostic challenge for intractable emesis: a case report and review of literature

      Vien, Linda; Bains, Ashish; Yeung, Ho-Man; 0000-0001-9257-0200 (2019-12-14)
      Introduction: The gastrointestinal tract is the most common extranodal site for non-Hodgkin’s lymphoma, with the most common being diffuse large B cell lymphoma. Unlike the stomach or the ileum, the jejunum is a rare site for primary extranodal lymphomas, given the scarcity of lymphoid tissue. Due to its location, inflammation in the jejunum may not be visualized on routine imaging or endoscopy, making jejunal lymphoma difficult to diagnose. Case Description: We present a case of a 90-year-old male with 1 week of intractable emesis, initially thought to be due to viral gastroenteritis. His symptoms never improved and he underwent serial CT imagings in addition to esophagogastroduodenoscopy. A stomach biopsy and a diagnostic paracentesis did not reveal any malignant cells, but a CT enterography revealed significant jejunal inflammation with obstruction. After a month of hospitalization, a jejunal biopsy was obtained, which showed proliferation of neoplastic B cells. He was ultimately diagnosed with primary jejunal diffuse large B cell lymphoma. Discussion: Chemotherapy and surgical resection are typically the definitive treatment for extranodal lymphoma. Clinicians, however, must carefully consider the patient’s functional and nutritional statuses before offering such interventions. This case was a diagnostic challenge and demonstrated a rare GI malignancy’s convoluted mimicking nature.
    • Reducing Wound Hemorrhage: Use of Bilayer Collagen Matrix in Chronic Myelogenous Leukemia

      Lo, Alexis L.; Tyrell, Richard O.; Golarz, Scott R.; Jones, Christine M. (2019-11-27)
      Summary: Donor site preparation is a critical step before the application of an autologous split-thickness skin graft (STSG). Comorbidities can lead to complications and graft loss, including that due to hematoma. In this case, a bilayer collagen matrix was used as a temporary wound dressing in a 25-year-old woman with active chronic myelogenous leukemia. She presented with a bleeding diathesis and spontaneous intramuscular and intracompartmental hematomas of the right leg. She experienced ongoing high-volume blood loss from her fasciotomy wounds, requiring wound care to be performed in the operating room under general anesthesia, and requiring multiple blood and platelet transfusions. Instead of immediate STSG, a bilayer collagen matrix was placed to reduce the bleeding and further prepare the wound bed over a 9-week period while she underwent medical optimization. Once stabilized from a hematologic standpoint, STSG was performed with total graft take. Both uncontrolled chronic myelogenous leukemia and its therapy, tyrosine kinase inhibitors, have a risk of hemorrhagic and thrombotic complications. Bilayer collagen matrix serves as an adjunct in the limb salvage algorithm that can reduce transfusion needs whereas a temporary bleeding diathesis is medically corrected before the application of an autologous skin graft.
    • Spine-to-Dendrite Calcium Modeling Discloses Relevance for Precise Positioning of Ryanodine Receptor-Containing Spine Endoplasmic Reticulum

      Breit, Markus; Kessler, Marcus; Stepniewski, Martin; Vlachos, Andreas; Queisser, Gillian (2018-10-23)
      The endoplasmic reticulum (ER) forms a complex endomembrane network that reaches into the cellular compartments of a neuron, including dendritic spines. Recent work discloses that the spine ER is a dynamic structure that enters and leaves spines. While evidence exists that ER Ca2+ release is involved in synaptic plasticity, the role of spine ER morphology remains unknown. Combining a new 3D spine generator with 3D Ca2+ modeling, we addressed the relevance of ER positioning on spine-to-dendrite Ca2+ signaling. Our simulations, which account for Ca2+ exchange on the plasma membrane and ER, show that spine ER needs to be present in distinct morphological conformations in order to overcome a barrier between the spine and dendritic shaft. We demonstrate that RyR-carrying spine ER promotes spine-to-dendrite Ca2+ signals in a position-dependent manner. Our simulations indicate that RyR-carrying ER can initiate time-delayed Ca2+ reverberation, depending on the precise position of the spine ER. Upon spine growth, structural reorganization of the ER restores spine-to-dendrite Ca2+communication, while maintaining aspects of Ca2+ homeostasis in the spine head. Our work emphasizes the relevance of precise positioning of RyR-containing spine ER in regulating the strength and timing of spine Ca2+ signaling, which could play an important role in tuning spine-to-dendrite Ca2+ communication and homeostasis.