Massive pneumomediastinum following orotracheal intubation in an emergency setting

We admitted in our intensive care unit, a 34-year old, Female patient from the emergency room, with a hypothesis of COVID-19 disease, who was intubated before transportation due to hypoxemic respiratory insufficiency. In physical examination the patient showed a massive subcutaneous emphysema. A computed tomography confirmed the hypothesis of pneumomediastinum/pneumothorax (Figure 1A). Refractory hypoxemia issued despite optimized mechanical ventilation, so we opted to submit the patient to Extracorporeal Membrane Oxygenation (ECMO). A diagnostic bronchoscopy showed an important laceration of the trachea (Figure 1B, black arrow, and Figure 1C), near the carina. Despite rare, tracheal lesion after intubation may have a dramatic outcome.

Urachal Sinus Surgery: Clinical Picture

The urachus is a fibrous cord, a remnant of the duct, which in the embryo, connects the bladder with the allantois duct [1]. The urachus can be the site of two types of lesions: on the one hand, congenital anomalies resulting from a defect in the obliteration of the allantois duct (diverticula, fistulas, cysts, sinus), and on the other hand, acquired lesions, essentially of a tumoral nature and most often malignant (urachus carcinoma) [2]. We report the clinical picture of a 28-year-old patient, with a history of uropathology since childhood (hypospadias), chronic renal failure since 2017 under dialysis, neobladder type Mitrofanoff since 2009, admitted for the management of an umbilical abscessed collection. Abdominal MRI revealed a superinfected urachus sinus. The treatment consisted of complete open excision of the sinus (Figure 1) from the umbilicus to the urinary bladder. The postoperative course was simple. Figure 1: The resected specimen (urachal sinus (black arrow), bladder wall (white arrow). A purulent umbilical discharge is often indicative of the presence of a urachus sinus; ultrasound and fistulography are sufficient for the diagnosis [3]. Excision of the urachus sinus by surgery is the standard treatment in this clinical situation [4].

POS1150 ANATOMICAL LOCATIONS AND CORRELATES OF CALCIUM PYROPHOSPHATE CRYSTAL DEPOSITS OF THE SPINE – PATHOLOGIC EXAMINATION OF 77 SURGICAL CASES

Background:Spinal involvement in calcium pyrophosphate deposition disease (CPPD) is thought to be a rare occurrence and is seen infrequently as crowned dens syndrome. Furthermore, data on anatomical locations and correlates of calcium pyrophosphate (CPP) deposits in spinal CPPD are scarce.Objectives:To describe the anatomical locations and correlates of pathologically confirmed CPPD of the spine.Methods:Consecutive patients with spinal CPPD were identified via retrospective chart review of individuals who underwent spine surgery for intractable chronic neck or back pain at Massachusetts General Hospital between 2009 and 2014. These deposits and surrounding anatomical structures were surgically resected and confirmed to have calcium pyrophosphate deposition upon pathologic review. We reviewed musculoskeletal imaging (CT, MRI, XR) and laboratory data from these pathologically confirmed cases.Results:From April 2009 to August 2014, we identified 77 individuals with pathologically confirmed CPPD of the spine. The mean age was 68 years; 41 (53%) were female; mean BMI was 28.7. Calcium pyrophosphate (CPP) was grossly identified intraoperatively by the surgeon in 38 cases (50%), typically as “chalky white deposits” (Figure 1). CPP deposits were seen most frequently in the ligamentum flavum (23%) and intervertebral disc (23%), followed by other less common locations (Table 1). Imaging findings in the soft tissue or intervertebral disc suggestive of CPPD were found in 5 cases (6%), whereas findings of spinal canal narrowing, facet arthropathy, or ligamentum flavum thickening were eventually correlative with CPP deposits in pathologic specimens. Only 7 (9%) experienced a prior episode of acute CPP arthritis (pseudogout). Chondrocalcinosis on x-ray was seen in 26 cases (34%), most commonly in the wrist and/or knees. Osteoarthritis was present in all spinal imaging, and 65% had comorbid scoliosis. Laboratory abnormalities associated with secondary causes of CPPD (hypercalcemia, hypomagnesemia, hyperparathyroidism) were not seen with spinal CPPD.Conclusion:Spinal CPPD may occur more frequently than previously perceived. The ligamentum flavum and intervertebral discs were common anatomical locations for spinal CPPD. Advanced imaging of the spine showed low sensitivity for detecting spinal CPPD. Only a small minority had typical peripheral joint involvement or imaging with peripheral joint chondrocalcinosis. Thus, without pathologic confirmation, the vast majority of cases would remain unidentified. These findings call for the need to seek pathologic confirmation to determine the robust epidemiology and also raise the potential role for preoperative CPPD treatment.Table 1.Spinal Anatomic Locations of Pathologically Confirmed CPPDSpinal Anatomic LocationNo. of Sites (%)*ligamentum flavum29 (23)Intervetebral Disc28 (23)Other Location19 (15)Posterior Elements18 (15)Facet14 (11)Synovium8 (6)Interspinous Ligament3 (2)Subarticular/Lateral Recess2 (2)Fibrocartilaginous Tissue1 (1)Inner Spine1 (1)Other Ligament1 (1)*Some patients had more than one anatomic location where CPP was isolatedFigure 1.Gross visualization of calcium pyrophosphate deposition (black arrow)Disclosure of Interests:Jonathan Dau: None declared, Gary Ho: None declared, Hyon Choi Consultant of: Ironwood, Selecta, Horizon, Takeda, Kowa, Vaxart, Grant/research support from: Ironwood, Horizon, Joseph Schwab: None declared, Minna Kohler Speakers bureau: Eli Lily, Consultant of: Novartis.

Sir Walter Scott and the Medievalist Novel

This chapter focuses primarily on Sir Walter Scott’s Ivanhoe (1819) and the novels—including Scott’s subsequent crusading fictions—that paid tribute to it through their engagement with roughly the same period of English history. In the hands of writers such as Edward Bulwer-Lytton and Charles Kingsley, the historical novel after Scott tended to present the Norman invasion as an enduringly formative moment in the making of modern imperial Britain. Popular fictions by Charlotte Yonge and G. A. Henty, composed for child readers, were similarly inspired by Scott, though in their reductive rewriting of Ivanhoe they further contributed to Scott’s ‘descent to the school-room’. Robert Louis Stevenson’s The Black Arrow (1883), by contrast, I will argue in conclusion, recovers the playfully reflexive scepticism of Ivanhoe and detaches the adolescence of its confused hero from any idea of an analogous national emergence.

Esophageal perforations: one is bad, two is worse

A 48-year-old man was admitted for medical management of recurrent Clostridium difficile (C-dif) colitis. One month prior to presentation, he underwent right thoracotomy and lower lobectomy for a carcinoid tumor at another hospital. His postoperative course was complicated by C-dif colitis, gastroesophageal reflux, and epigastric pain. He underwent two esophagogastroduodenoscopy (EGD) procedures demonstrating mild esophagitis on the first procedure, followed by a linear ulcer on the second procedure 2 weeks later. On hospital day 9 of his current admission, he developed an acute abdomen and underwent an urgent exploratory laparotomy for presumed fulminant colitis. Findings included a healthy-appearing colon with only moderate distension, so a loop ileostomy was created for antegrade colonic irrigation. Postoperatively, a chest X-ray demonstrated a tension-appearing left pleural effusion, prompting tube thoracostomy placement. Initial output was greater than 2L of thin dark-brown fluid. An esophagram demonstrated a distal esophageal perforation (EP) and EGD was performed. Two medium-sized EPs were identified which appeared to arise from chronic-appearing ulcerations, one at 39 cm and one at 45 cm from the incisors (figure 1). A single 19mm×100 mm EndoMAXX fully covered stent was placed. Video-assisted thoracoscopic (VATS) drainage of the left hemithorax was performed in addition to placement of a right tube thoracostomy. Due to continued high output from the left thoracostomy tube, the stent was exchanged for a longer 23mm×100mm EndoMAXX fully covered stent. The patient stabilized for several days but again developed worsened sepsis, with EGD demonstrating inadequate coverage of the proximal perforation.Figure 1Endoscopic photograph showing left-sided esophageal perforation/fistula (black arrow). Gastroesophageal junction indicated by white arrow. NG, Nasogastric tube.What would you have done?Repeat esophageal stenting with wide drainage of the thoracic cavity.Esophageal T-tube placement and wide drainage of the thoracic cavity.Esophageal resection with gastrostomy drainage and proximal diversion.Bilateral tube thoracostomies and antibiotic/antifungal therapy.

A Key Commitment Step In Erythropoiesis Is Synchronized with the Cell Cycle Clock through Mutual Inhibition Between PU.1 and S-Phase Progression

Abstract 839 Hematopoietic progenitors undergo differentiation while navigating several cell division cycles, but it is unknown whether these two processes are functionally coupled. We addressed this question by studying erythropoiesis in mouse fetal liver in vivo. We used flow cytometry and the cell surface markers CD71 and Ter119 to subdivide freshly isolated fetal liver cells into a developmental sequence of six subsets, from the least mature, Subset 0 (S0), to the most mature, Subset 5 (S5). We found that the upregulation of cell surface CD71, which marks the transition from S0 (CD71lowTer119negative) to S1 (CD71highTer119negative), identifies a key S-phase dependent step in erythropoiesis, that precedes, and is essential for, expression of erythroid-specific genes (Figure 1). Specifically, we found that erythroid progenitors at the transition from S0 to S1 are tightly synchronized in S-phase of the last generation of erythroid colony-forming cells (CFU-e). DNA replication within this, but not subsequent cycles, was required for a number of simultaneous committal transitions whose precise timing was previously unknown. These include the onset of erythropoietin dependence, activation of the erythroid master transcriptional regulator GATA-1, and a switch to an active chromatin conformation at the b-globin locus control region (LCR). The S-phase dependent chromatin switch at the b-globin LCR was characterized by the formation of DNase I hypersensitivity sites, by a change in the timing of replication of the b-globin locus, by altered covalent modifications of histone tails, and by the rapid onset of DNA demethylation. An arrest of S-phase progression during the transition from S0 to S1 arrested the formation of DNase I hypersensitivity sites and prevented DNA demethylation. It also halted the subsequent transcription of b-globin and other erythroid genes. By contrast, an arrest of S-phase progression in cells that had already traversed the S0/S1 transition, no longer interfered with the erythroid transcriptional program. Mechanistically, we found that S-phase progression during this key committal step was dependent on downregulation of the cyclin-dependent kinase p57KIP2, and in turn caused the downregulation of PU.1, an antagonist of GATA-1 function. These findings therefore highlight a novel regulatory role for a cyclin-dependent kinase inhibitor early in erythroid maturation, distinct to their known function in cell cycle exit at the end of terminal differentiation. Furthermore, we identified a novel, mutual inhibition between PU.1 expression and S-phase progression, that provides a “synchromesh” mechanism, “locking” the erythroid differentiation program to the cell cycle clock and ensuring precise coordination of critical differentiation events. Figure 1: Regulation of the S0 to S1 transition in fetal liver erythropoiesis. Multiple differentiation milestones are synchronous with early S-phase in the last CFU-e generation (CFU-elast, black arrow), and are dependent on DNA replication. Figure 1:. Regulation of the S0 to S1 transition in fetal liver erythropoiesis. Multiple differentiation milestones are synchronous with early S-phase in the last CFU-e generation (CFU-elast, black arrow), and are dependent on DNA replication. Disclosures: No relevant conflicts of interest to declare.