Large Arrow Research Articles

Isolated Superior Mesenteric Artery Dissection, A Rare Cause Of Abdominal Pain.

A 42-year-old previously healthy male presented with 5 days of spontaneous mid-epigastric intense abdominal pain and mild epigastric tenderness on palpation. CT angiography revealed a Sakamoto type 2 isolated superior mesenteric artery dissection (SMA) with a "cul-de-sac" shaped false lumen (B- C: large arrow), side branch perfusion from both lumens, andcompression of the true (A-D: small arrow) by the false lumen (A-D: large arrow). Dissection flap presented just distal to an aberrant right hepatic artery arising from the SMA (B.D: star). CT, clinical and analytic findings did not suggest visceral compromise and was successfully treated with bowel rest and anticoagulation. He is now on close clinical and imaging follow-up.

Calcific uremic arteriolopathy in a young man on intermittent hemodialysis

A 42‐year‐old man with ESKD who has been on intermittent hemodialysis for 7 years, presented with extremely painful inguinal ulcer and abdominal mass. The lesion was developed 2 weeks after repairing aneurysmal cubital AVF. At first, it was a small and painful red nodule but then its size increased and a large ulcer was developed. In addition, the physical examination revealed a palpable and painful large mass at left lower side of abdominal wall. He did not have important risk factors such as diabetes mellitus, treatment with warfarin, and use of calcium containing phosphate binders, vitamin D or calcium supplements. The patient suffered a long standing and severe secondary hyperparathyroidism. The parathyroid hormone level was too high (3100 pg/ml). In addition, serum calcium and phosphorus levels were 9.4 mg/dl and 9.8 mg/dl respectively. The SPECT-CT scan with 99 m Tc-MIBI of parathyroid glands confirmed persistence of an adenoma in right lower parathyroid gland (Figure 1, green arrow). The BMI was 32 kg/m2. He had no adherence to use of phosphate binder or calcimimetic drugs. The radiological studies showed extensive microvascular calcification in soft tissues (Figure 1, small arrow) and osteitis fibrosa cystica in long bones (Figure 1, star). The patient underwent surgical debridement of ulcer and palpable abdominal mass, wound care, intensive dialysis therapy with low calcium dialysis bath, cinacalcet, sevelamer carbonate, antibiotic and analgesic therapy. The histological sample (H&E, 200X) shows Intramural calcification and obliteration of arteriole (large arrow) with extensive calcification in fat tissue (Figure 1, arrow head) which was consistent with Calcific Uremic Arteriolopathy (CUA). In addition to patient’s poor compliance to treatment of severe secondary hyperparathyroidism, the recent surgery of aneurismal AVF could also be an important trigger to development of calcific uremic arteriolopathy.

Design and accuracy test of polar moment of inertia measuring equipment for projectile and rocket

The moment of inertia is an important mass characteristic parameter. It has a direct impact on the trajectory, flight stability, strike accuracy, and service life of the projectile. To meet the measurement of the polar moment of inertia of large projectiles and arrows, this paper uses the vibration compound pendulum method to measure the polar moment of inertia of large projectiles and arrows, deeply analyzes the measurement principle, and designs a polar moment of inertia test equipment. Through the measurement of standard samples, the measurement accuracy of the equipment is tested, and the causes of error are analyzed. The experimental results show that the maximum relative error is less than 0.5 %, and the relative uncertainty is 0.813 %, which meets the requirements of expected technical indicators.

A 17-Year-old Boy With Nodular Lesions in the Thyroid and Lymphadenopathy.

A 17-Year-old Boy With Nodular Lesions in the Thyroid and Lymphadenopathy.

Structural Design and Optimization of Φ 5 m Diameter Large Arrow Body

The launch vehicle structure, as one of the important systems of launch vehicle, is the foundation of launch vehicle and directly relates to the overall performance of the launch vehicle. A series of technical problems are faced with the huge leap from Φ3.35 m to Φ5 m in the product size of the launch vehicle structure. To solve these problems, a set of theoretical and methodological system suitable for the design of the Φ5 m launch vehicle structure products is established by adopting innovative design concept. At the same time, the upgrading of the material system of launch vehicle structure is vigorously promoted. With the implementation of these methods, the product system of theφ5m launch vehicle structure, and the fine design and multi-function integrated design of the Φ5 m launch vehicle structure are realized.

Aortic Root Sign

Appearance: The aortic root sign describes an anomalous circumflex coronary artery (ACCA) that emerges from the contralateral coronary sinus, and travels underneath the aorta to supply blood to its normal vascular territory. Explanation: The moniker, “aortic root sign,” was first coined by Page et al1 on conventional angiography to describe ACCA as arising from the proximal right coronary artery or right coronary sinus. The aberrant vessel courses inferiorly behind the aortic root within the groove between the left atrium and aorta,2 hence the term “aortic root sign” (Fig. 1).FIGURE 1: Fifty-six-year-old patient with atypical chest pain. A, Right anterior oblique ventriculogram from left heart catheterization demonstrates anomalous course of the left circumflex (LCX) en face below the aortic root (classic aortic root “dot” sign; thin arrow) (LV=left ventricle). B, Electrocardiogram-gated cardiac computed tomography (CT) matched in projection of the cardiac catheterization reveals the same signature appearance of the anomalous LCX (thin arrow). C, CT correlate of the conventional aortic root “dot” sign seen on an axial image from an electrocardiogram-gated CT reveals the anomalous LCX coursing inferior to the noncoronary sinus of the aortic root (medium arrow) (RA=right atrium, RV=right ventricle, LA=left atrium). D, Volume-rendered image of the aortic root demonstrates coronary origin from the right sinus of Valsalva (asterisk) with immediate takeoff of the anomalous LCX (arrowhead) from the normal right coronary artery (large arrow).Discussion: Traditionally coronary artery anomalies (CAAs) were thought to have little significance, and were often discovered as incidental findings on angiography. However, patients may present with clinically significant disease.2 In fact, CAAs are the second most common cause of sudden cardiac death in young athletes in the United States.2 ACCA was first described by Antopol and Kugel.3 The prevalence of ACCA reported in the coronary angiography literature ranges from 0.18% to 0.67%, making it the most common CAA. Some authors postulate that the oblique angulation of its origin predisposes ACCA to atherosclerosis. However, most clinicians agree that ACCA is a benign, asymptomatic anomaly. Indeed, the retroaortic course of ACCA, as described by the aortic root sign, rarely leads to ischemia or sudden cardiac death. On the contrary, CAAs that travel along an interarterial course between the aorta and pulmonary artery are more prone to ischemia during strenuous exercise.2 Despite the low risk of ischemia and sudden death with ACCA, recognition of this anomaly is still of great clinical importance because failure to identify this aberrant vessel can lead to adverse patient outcomes, especially during cardiac surgery. Therefore, it is crucial for the angiographer as well as the radiologist to be adept at recognizing ACCA and the other coronary anomalies, especially given the ease of diagnosis with noninvasive coronary imaging techniques, such as multidetector computed tomography4 and cardiac magnetic resonance imaging.5

A Rare Case of Periampullary Tumor

Gangliocytic paraganglioma is a rare tumor that can affect anywhere in the gastrointestinal tract, though it is most frequently found in the second portion of the duodenum. They commonly present with abdominal pain, gastrointestinal bleeding, or rarely with obstructive jaundice. This is a case of an asymptomatic periampullary gangliocytic paraganglioma. A 45 year old male with a history gastroesophageal reflux well controlled on a PPI was referred for iron deficiency anemia with no overt bleeding. He underwent an upper endoscopy that revealed a submucosal nodule involving the ampulla. The endoscopic ultrasound subsequently revealed a 2.3x1.5cm hypoechoic heterogeneous mass of the periampullary region. Fine needle aspiration showed a neoplasm with neuroendocrine differentiation. The immunohistochemical stain was strongly positive for synaptophysin and negative chromogranin, S-100, CD-117, and DOG-1. The periampullary mass was resected using endoscopic mucosal resection, with the final pathology consistent with gangliocytic paraganglioma. The patient had further testing with negative urine metanephrines and catecholamines. There was no radiographic evidence of distal metastatic disease. Gangliocytic paraganglioma (GP) is a rare neuroendocrine tumor, with only around 200 cases reported. It consists of three distinct cellular elements: spindle cells, epithelial cells, and ganglion cells. In spindle-cell predominant tumors, the differential diagnosis includes schwannomas and GIST. When visualized endoscopically, GPs are difficult to distinguish from other submucosal tumors and may appear as a pedunculated or sessile polypoid mass that may be smooth or ulcerated. Endoscopic biopsies are frequently negative since the tumor is submucosal. An EUS is frequently necessary to obtain a fine-needle aspiration as well as evaluate for local spread of the tumor and detect metastatic lymph nodes. The majority of GPs are benign without local or distant spread. However, lymph nodes metastases and distant metastases to other organs have been reported. Treatment is dependent on the size of the tumor and the presence of any metastatic lymph nodes or other metastatic sites. Case reports have shown that overall the prognosis is good but there have been reported deaths from metastatic tumors. In conclusion, we present the case of an incidental periampullary gangliocytic paraganglioma.Figure: Ganglion cells have abundant cytoplasm, round nuclei, and prominent nucleoli (small arrows). Spindle cells are arranged in fascicles (large arrows).Epithelioid endocrine cells are arranged in trabeculae (arrowheads).Figure: Endoscopic image of the periampullary mass.Figure: Endoscopic ultrasound image of the periampullary mass.

Endoscopic Ultrasonography-Guided Intrapyloric Sphincter Injection of Botulinum Toxin into Muscularis Propria to Treat Refractory Diabetic Gastroparesis

A 46 year-old African American woman with past medical history of diabetes mellitus type 1 for 22 years and gastroparesis for 12 years status post gastric pacemaker placement 2 years ago presented with abdominal pain, nausea, and recurrent vomiting for 2 days. The severity of her symptoms on the day of admission, as measured by the gastrointestinal symptom rating scale (GSRS), was 16. Due to the refractory nature of her symptoms, EUS-guided intrapyloric injection of botulinum toxin was performed. 100 units of botulinum toxin was diluted with normal saline to 25 U/ml and injected into 4 quadrants of muscularis propria of pyloric sphincter, with a 25-gauge FNA needle (Figure 1). On post procedure day one the patient demonstrated significant improvement in her symptoms and scored 11 on the GSRS. She was discharged from the hospital soon after. During follow up 3 weeks post procedure, she reported one episode of vomiting since being discharged and scored 8 on the GSRS. She was again seen on post procedure week 4 and reported only intermittent nausea with no further episodes of vomiting. Her GSRS score at 4 and 12 weeks post procedure were 5 and 4, respectively. Diabetic gastroparesis is a relatively common and often difficult to manage chronic motility disorder where there is delayed gastric emptying in the absence of mechanical obstruction. It is thought to arise from a complex interplay of factors including disturbances in fundic accommodation, gastric arrhythmia, impaired corpus-antral contractility, vagal neuropathy and pyloric dysfunction (in the form of pylorospasm). Symptoms include nausea, vomiting, early satiety and epigastric pain. The currently available modalities of treatment for this condition, including prokinetic medications and placement of gastric pacemaker, are often sub-optimally efficacious. Based on the theory that gastric emptying improves with decreased pyloric resting pressure, intrapyloric sphincter botulinum toxin injection was introduced in 1998. Since that time, its use has been reported to have variable clinical response in the medical literature. We postulate that inconsistencies in clinical response from botulinum toxin injection may be due, in part, to variability in injection sites, and propose that its efficacy may be improved by precise injection (via EUS guidance) into the muscularis propria of pyloric sphincter, as was demonstrated in our case. Further clinical studies in patients with are required to confirm our hypothesis.Figure: Linear array endoscopic ultrasonography-guided botulinum toxin injection by a 25-gauge needle (large arrow) into the muscularis propria (small arrow) of pylorus in a patient with refractory diabetic gastroparesis.

A Rare and Fatal Case of Dobhoff Tube Placement-Associated Small Bowel Perforation Presenting With Acute Leukopenia

Enteral feeding with Dobhoff tubes is a common mode of nutrition in acute or chronically ill patients. Common adverse events associated with Dobhoff placement include epistaxis and sore throat. More serious complications such as esophageal perforation and pneumothorax have been reported. We report a case of small bowel perforation after Dobhoff placement with acute leukopenia as an initial laboratory manifestation. A 75-year-old female presented to the hospital with a 3-year history of worsening hoarseness and shortness of breath. Bedside laryngoscopy demonstrated a large laryngeal mass. Biopsy results were positive for squamous cell carcinoma. Bronchoscopy and esophagoscopy (to pre-pyloric region) were unremarkable. Due to severe protein malnutrition, a Dobhoff was placed for pre-operative optimization for laryngectomy. Post-placement KUB showed tube overlying the body of stomach. 12 hours post Dobhoff insertion, vital signs were notable for hypotension to 72/48 mmHg. Physical exam was notable for diminished bowel sounds. Laboratory results showed an acute leukopenia of 1100 mcL, and lactate of 3.6 mmol/L. KUB showed advancement of the Dobhoff tube, with visualization of bowel wall lumen suggesting pneumoperitoneum. The patient remained hypotensive despite fluid resuscitation and was transferred to the ICU for pressor support. A CT scan of the abdomen revealed intraperitoneal and retroperitoneal air, with the enteric tube noted to be extraluminal with suspected perforation of the second part of the duodenum. Surgery was consulted, however due to the patient progressing to multi-system organ failure, and high surgical mortality risk, the patient was made DNR/Comfort Care and expired 6 hours later. Dobhoff placement is a common procedure performed across the country. Although a relatively safe procedure, it can have complications such as bowel perforation. One of the initial presenting clues may be acute leukopenia. Acute leukopenia has also been reported in laparoscopic bowel perforations during urological surgery. The mechanism of acute leukopenia in bowel perforation could be due to peritonitis leading to sepsis. Sepsis has been shown to cause acute bone marrow suppression leading to leukopenia. Another explanation is the marginalization of leukocytes in conditions of decreased blood flow such as hypotension. Leukocytes are shifted outward by RBCs in laminar flow, and in slow flow the leukocytes will adhere to the endothelial surface in larger number.Figure: Enteric tip overlying the gastric pylorus. Arrow showing “Rigler's Sign”, suggesting air on both sides of bowel concerning for extraluminal air.Figure: Large arrow showing intraperitoneal air in the anterior extraluminal space. Small arrow shows enteric tube possibly in extraluminal space.

A Spiral Stomach after Vertical Sleeve Gastrectomy

Clinical Image: A patient presented with dysphagia and vomiting after undergoing a vertical sleeve gastrectomy, which was performed for surgical treatment of medically-complicated obesity. A barium gastrogram outlined a small, remaining proximal stomach (indicated by a small black arrow in Figure 1) connected to the gastric antrum (indicated by a large white arrow in Figure 1) by a spiral of gastric sleeve. At upper endoscopy, a guide wire was passed under fluoroscopic guidance through the gastric sleeve and into the antrum. A Boston Scientific controlled radial expansion (CRE) single use esophageal balloon dilator was passed over the guide wire under fluoroscopic guidance, and segmental balloon dilation of the gastric sleeve was then performed. After dilation of the gastric sleeve, the patient noted minimal residual dysphagia when eating solid foods and a repeat barium gastrogram revealed a straight gastric sleeve.

Assemblages of submarine landforms in the glacial troughs of the northern Barents Sea, east of Svalbard

The Barents Sea is a wide, relatively deep epicontinental sea consisting of shallower banks ( c. 50–100 m depth) separated by broad, flat-bottomed troughs ( c. 200–400 m depth) that radiate out towards its western and northern margins (Fig. 1a). These troughs have been excavated by grounded ice during multiple glaciations through the Plio-Pleistocene (Jakobsson et al. 2014). During the Last Glacial Maximum (LGM) the Barents Sea Ice Sheet (BSIS) extended across the entire northern Barents Sea to the shelf break (Svendsen et al. 2004; Jakobsson et al. 2014). Fast-flowing ice drained the ice sheet through these troughs and produced a suite of seafloor landforms that preserves both a record of former ice-flow patterns and of how the ice sheet retreated during deglaciation (Dowdeswell et al. 2010; Hogan et al. 2010 a ). Fig. 1. Bathymetric images and sub-bottom profiles of landforms in glacial troughs east of Svalbard. Acquisition system Kongsberg EM120. Frequency 12 kHz. Grid-cell size 10–20 m. Acquisition system for profiles Kongsberg TOPAS PS018 parametric sub-bottom profiler (secondary beam frequency 0.5–6 kHz). ( a ) Location of study area (red boxes; map from IBCAO v. 3.0). KT, Kvitoya Trough; OT, Olga Trough; E, eastern Erik Eriksen Trough; W, western Erik Eriksen Trough; KKL, Kong Karls Land; No, Nordaustlandet; FVT, Franz Victoria Trough. ( b ) Glacial lineations (long dashes) overprinted in part by a debris-flow deposit (dotted) in western Erik Eriksen Trough; recessional moraine orientations shown by solid lines. Large black arrow indicates former ice-flow direction. ( c ) Saw-tooth-shaped recessional moraines in Olga Trough. ( d ) Hill–hole pairs and glacial lineations in eastern Olga Trough; same depth scale as (c). ( e ) Streamlined crag-and-tail landforms in Kvitoya Trough. ( f ) Sub-bottom profile over the till sheet and recessional moraines shown in (c). ( g ) Acoustic facies on the upper slope north of Kvitoya Trough. ( h ) Subglacial meltwater channels …

The Threats and Challenges of a Multipolar World: A Ukraine Crisis Case Study

IntroductionThe crisis in and around Ukraine has clearly demonstrated that the world has changed. This is not news for the most observant politicians and researchers. The changes accumulated slowly, and many of the consequences were predictable.

Building SuperModels: emerging patient avatars for use in precision and systems medicine.

The era is approaching when each individual can be mapped to a patient avatar—not a life-sized 3D blue form of the patient filled with physical substance (as in the movie “Avatar”), but a hologram of the patient that simulates key medical components. Patient avatars will be composed of computational models combined with various data types and analytics to form what might be called SuperModels (Figure ​(Figure1).1). These SuperModels (comprehensive virtual representations of the patient, not fashion models) will be important to help realize visionary precision medicine initiatives that have recently been announced (Collins and Varmus, 2015; Nature Biotechnology, 2015). Figure 1 Building SuperModels for precision and systems medicine, with incorporation of computational avatars. Input: A feedforward loop (top left panel X connects to patient avatar Z both indirectly via bottom left panel Y and also directly, by large blue arrows) ... Precision medicine tailors prevention, diagnosis, therapeutics, and prognosis for each patient (Garay and Gray, 2012; Highnam and Mittelman, 2012; Mirnezami et al., 2012). Related to precision medicine is systems medicine (Auffray et al., 2009; Capobianco, 2012; Emmert-Streib and Dehmer, 2013; Wolkenhauer, 2013), which leverages systems biology (Noble, 2008) for clinical application, with resulting data termed “systems medicine data” (Brown et al., 2015b). Systems biology studies the behavior of organisms or cells as whole systems, and uses various advances in biotechnology, including genomics, transcriptomics, proteomics, metabolomics, methylomics, microbiomics, and elucidation of cellular interaction networks by network biology (Figure ​(Figure1,1, top left panel labeled X). Often, systems medicine data from these various advances can be modeled and simulated with complementary computer science, mathematics, chemistry, physics, and engineering concepts in computational biology. A variety of fields have used computational models as virtual surrogates of specific portions of patient physiology. These individual models can be considered computational avatars of a subset of the patient's organic identity. This is akin to cancer avatars in mice, which involve mouse models mapped to individual patients, for example, by injection of tumor cells from a particular individual. These cancer avatars facilitate personalized study of the pathophysiology and response to drugs of a particular patient's cancer cells. Similarly, biomathematical or computational cancer avatars simulate the micro-environment of individualized cancer cells. Beyond such in silico exemplars, a computational avatar may also be thought of as any finite representation of a specific portion of the patient, that harnesses computing power. This includes electronic health records (EHR), patient portals, and a variety of other precision medicine tools. However, this paper focuses on individual biomathematical models as computational avatars that can be incorporated into comprehensive patient avatars for use in precision and systems medicine. The following section describes a non-exhaustive sample of biomathematical models, including genome-scale metabolic models (GEMs) that use computational approaches to integrate omics data (Yizhak et al., 2015). These computational avatars can serve as ingredients for SuperModels, forming the first portion (X → Z) of a positive feedback loop in Figure ​Figure11.

Preliminary Report on the 22 November 2014Mw 6.1/Ms 6.3 Kangding Earthquake, Western Sichuan, China

Online Material: Relocated aftershock catalog figures of moment rate function, magnitude–time distribution, observed strong-motion accelerograms, spectral accelerations versus period, and photos of damaged buildings. The M s 6.3 ( M w 6.1) Kangding earthquake struck western Sichuan Province on 22 November at 08:55:27 UTC (16:55:27 p.m. local time). Its epicenter was located approximately 37 km northwest of Kangding country and 236 km southwest of Chengdu city. The China Earthquake Networks Center (CENC) reported that the epicenter was located at 30.3° N, 101.7° E with a hypocentral depth of 18 km (Fig. 1). Three days after the first shock, another moderate earthquake ( M s 5.8/ M w 5.7) hit the area to the southeast. The distance between the two events is about 10 km. Detailed information of this earthquake is available on the website of China Earthquake Administration (CEA) (http://www.cea.gov.cn/publish/dizhenj/468/553/101420/index.html; last accessed December 2014, in Chinese) and on the website of U.S. Geological Survey (http://earthquake.usgs.gov/earthquakes/eventpage/usb000syy0; last accessed December 2014). The Kangding earthquake was located near the left-lateral, strike-slip Xianshuihe fault system (Allen et al. , 1991). The mainshock was characterized by a strike-slip mechanism, with two nearly vertical nodal planes striking approximately north-northwest and northeast-east, respectively. The maximum intensity was VIII on the Chinese intensity scale (http://en.wikipedia.org/wiki/China\_Seismic\_Intensity_Scale; last accessed December 2014), with the areas above intensity VI being 11,060 km2. The earthquake caused 5 deaths and 80 injuries. The direct economic loss has been estimated as more than 4.2 billion Renminbi (RMB; or about $0.7 billion U.S.). Figure 1. Tectonic blocks and strong earthquakes since 1997 in the Tibetan plateau. Dashed rectangle indicates the region in Figure 2. Large red arrow indicates the crustal motion direction. Black-and-white circles are the focal mechanism of recent strong earthquakes with magnitude larger than M s 7.0. Red-and-white circles are the focal mechanism of the M s 6.3 and 5.8 Kangding …

A Rare Cause of Intermittent, Occult Lower Gastrointestinal Bleeding

56-year-old man presented with fatigue and inAtermittent, occult lower gastrointestinal bleeding since a percutaneous transluminal coronary angioplasty with bare metal stent implantation was performed for critical stenosis of the left anterior descending. Associated medical treatment was aspirin 80 mg and clopidogrel 75 mg daily. One episode of massive lower gastrointestinal bleeding (hemoglobin 5.0 g/dL) occurred 1 day after endoscopic polypectomy, which was treated with 6 units of packed cells. Endoscopic work-up included a negative gastroscopy and colonoscopy. A double-balloon enteroscopy revealed pulsatile waves in the distal ileal mucosa. Contrast-enhanced computed tomography scan revealed a hypertrophied ileocolic artery (arrowheads) feeding a preterminal ileal small bowel loop presenting with a hyperdense contrast enhancement (small arrows); early filling of a hypertrophied ileal draining vein (large arrow) is also seen (Figure A). A catheter-directed selective angiogram showed a hypertrophied ileocolic artery (small arrows) and end-branches (arrowheads) and an early draining hypertrophied ileal vein (large arrow) (Figure B), suggesting an ileal high-flow arterioportal vascular malformation. Because of the large intestinal territory the high-flow malformation was extended, it was decided to resect the affected small bowel segment. Pathologic analysis of the resected specimen (hematoxylin-eosin; original magnification, 25) revealed a submucosal high-flow arteriovenous malformation with very large, thick-walled vessels in the submucosa (yellow arrows); the muscularis propria is indicated by a yellow star (Figure C). Clinical follow-up after surgery was uneventful. High-flow arterioportal vascular malformations are extremely rare and are mostly seen as spontaneously formed vascular lesions within a hepatocellular carcinoma; extrahepatic arterioportal fistulas are extremely rare and can be isolated or associated with a visceral aneurysm, eroding into the portal circulation. Intestinal angiodysplasia is characterized by the presence of thin, ectatic vessels with little or no smooth muscle but without early draining veins. Clinically these lesions tend to bleed intermittently, especially in patients on antiplatelet or anticoagulation drug regimens. In the present case, there was radiologic, macroscopic, and microscopic pathologic evidence of a highflow arterioportal vascular malformation located in the preterminal ileum. Because of the intermittent bleeding episodes and the potential for progression to symptomatic portal hypertension and liver cirrhosis, surgical resection seemed to be justified. These are our main findings. A small bowel highflow arterioportal vascular malformation may cause

Pancreatic Duct Dilatation in Elderly Patient With Abdominal Pain

Question: An 87-year-old woman with history of dementia, atrial fibrillation, hypertension, and gastroesophageal reflux disease presented with abdominal pain. CT demonstrated abnormal location of a portion of the pancreas (Figure A–D, arrowheads) and dilation of the corresponding segment of the main pancreatic duct (arrows) on transverse and coronal images. A 3-dimensional, volume-rendered image from subsequent MR cholangiopancreatography examination demonstrated abnormal course of pancreatic duct, along with localized pancreatic ductal narrowing (small arrows) and segmental dilation (large arrows) (Figure E). Laboratory tests done on the same day as the CT examination revealed lipase of 116 U/L (normal range, 20–300), aspartate aminotransferase 19 U/L (normal range, 2–44), alanine aminotransferase 28 U/L (normal range, 0–54), alkaline phosphatase 64 U/L (normal range, 50–135), and total bilirubin 0.8 mg/dL (normal range, 0.2–1.0). What is the etiology for the abnormal appearance of the pancreatic duct? Look on page 293 for the answer and see the Gastroenterology web site (www.gastrojournal.org) for more information on submitting your favorite image to Clinical Challenges and Images in GI. The CT images demonstrate a type IV hiatal hernia, containing a portion of the pancreatic body in addition to the stomach. There is resultant relative focal narrowing of the main pancreatic duct at both the entry and exit sites through the diaphragmatic hiatus, and dilation of the pancreatic duct in the intervening superiorly herniated segment of the pancreas. Differential diagnosis for the imaging findings also potentially includes pancreatic malignancy, sequelae of pancreatitis, and segmental main duct intraductal papillary mucinous tumor. Superior herniation of the pancreas via the diaphragmatic hiatus can be an incidental finding, but associated occurrence of pancreatitis has also been reported, with proposed mechanisms for pancreatitis, including pancreatic injury from repetitive pancreatic movement, vascular compromise, volvulus, as well as intermittent obstruction or folding of the pancreatic duct.1Gremmels J.M. Broome D.R. Fisher K.L. Pancreatic herniation through the gastroesophageal hiatus: magnetic resonance imaging, magnetic resonance cholangiopancreatography, and computed tomography evaluation.J Comput Assist Tomogr. 2003; 27: 616-618Crossref PubMed Scopus (8) Google Scholar, 2Chevallier P. Peten E. Pellegrino C. et al.Hiatal hernia with pancreatic volvulus: a rare cause of acute pancreatitis.AJR Am J Roentgenol. 2001; 177: 373-374Crossref PubMed Scopus (23) Google Scholar In the presented case, given the advanced age of the patient, normal lipase level, and stable appearance of the pancreas compared to a prior CT scan done 2 years earlier, the patient was managed conservatively.

Repairing peripheral nerve injury using tissue engineering techniques.

Each year approximately 360,000 people in the United States suffer a peripheral nerve injury (PNI), which is a leading source of lifelong disability (Kelsey et al., 1997; Noble et al., 1998). The most frequent cause of PNIs is motor vehicle accidents, while gunshot wounds, stabbings, and birth trauma are also common factors. Patients suffering from disabilities as a result of their PNIs are also burdensome to the healthcare system, with average hospital stays of 28 days each year (Kelsey et al., 1997; Noble et al., 1998).

Hepatic Portal Venous Gas: Findings on Ultrasound and CT

A 76-year-old female with a history of Parkinson’s, dementia, and hypertension presented to the emergency department with non-bilious, non-bloody vomiting and abdominal pain for 2 days. Her exam was significant for borderline hypotension without tachycardia, abdominal distension and a palpable ventral hernia. An emergency physician performed ultrasound showed free intraperitoneal air and gas in the liver (Video). A computed tomography showed pneumoperitoneum, pneumatosis intestinalis, and hepatic portal venous gas (HPVG) (Figure). At laparotomy, she was found to have a sigmoid colon perforation from adenocarcinoma, ischemic small bowel, and a colovesicular fistula. Post-operatively her clinical status worsened, and she was transitioned to comfort care and expired on hospital day 2. Figure Computed tomography without contrast of the abdomen and pelvis showing free air (asterisks), pneumatosis intestinalis (thin arrows), and hepatic portal venous gas (large arrow). HPVG was first reported in infants with necrotizing enterocolitis.1 In adults, it is most commonly associated with mesenteric ischemia and pneumatosis intestinalis, accounting for 43% of HPGV cases2 and an associated mortality of 75%.2–3 It has been reported with other diseases such as diverticulitis, inflammatory bowel disease, obstructive pyelonephritis, pancreatitis, cholangitis, uterine gangrene, and severe shock.4 HPVG is attributed to either bacterial gas production in bowel entering mesenteric circulation4 or intraluminal air entering capillaries from impaired mucosal barrier or increased intraluminal pressure.5 HPVG spreads to the periphery of the liver whereas pneumobilia collects centrally, in the direction of bile flow. Treatment is always aimed at the underlying etiology of HPVG.

Unexpected Cause of Acute Recurrent Vomiting

Question: A 70-year-old woman who was visiting our city presented to the emergency department with a 24-hour history of nausea, voluminous, recurrent vomiting, and epigastric pain. Medical history disclosed gastroesophageal reflux disease, osteoporosis, and chronic cognitive impairment. There was no antecedent of trauma or surgical interventions. She was taking omeprazole and raloxifene hydrochloride as regular medications. At presentation, vital signs were unexceptional and she did not look seriously ill. On examination her abdomen was soft, nontender, and without palpable masses. Laboratory testing was notable for a white blood cell count of 11,300/mm3, erythrocyte sedimentation rate and renal function parameters being within normal limits. Chest radiography displayed no subdiaphragmatic free air but a plain abdominal x-ray demonstrated a significant abnormality (Figure A). What is the diagnosis? Look on page 1223 for the answer and see the Gastroenterology web site () for more information on submitting your favorite image to Clinical Challenges and Images in GI. Plain abdominal x-ray at admission revealed air in the theoretical localization of the biliary tree and paucity of intestinal gas. In view of the history and these radiographic findings, a computed tomography (CT) was requested. Abdominal CT (Figure B; medial view; Figure C, axial view) showed the classic Rigler’s triad of pneumobilia (small black arrows), ectopic gallstone (white arrow), and bowel obstruction, which is specific for gallstone ileus. A cholecystoduodenal fistula (large black arrow), gastric distension, and pericholecystic inflammatory changes could also be appreciated. Because the gallstone was impacted into the second part of the duodenum, a diagnosis of Bouveret’s syndrome was established. After early conservative management, the patient’s relatives asked us for permission to transfer her to their reference center. Once there and while discussing about the most appropriate therapeutic procedure to be performed, the gallstone (4 cm in size) was surprisingly eliminated with feces (Figure D) and she was discharged asymptomatic without need of surgical intervention. Throughout the following year, she has remained symptom free. Leon Bouveret described in 1896 the two first patients with gastric outlet obstruction caused by impacted gallstones into the duodenum after passage through a cholecystoduodenal fistula.1Bouveret L. Stenose du pylore adherent à la vesicule.Rev Med (Paris). 1896; 16: 1-16Google Scholar Risks factors for this uncommon form of gallstone ileus are female sex, advanced age (>60 years), long history of cholelithiasis, recurrent cholecystitis, and large size of the calculi.2Mavroeidis V.K. Matthioudakis D.I. Economou N.K. et al.Bouveret syndrome—the rarest variant of gallstone ileus: a case report and literature review.Case Rep Surgery. 2013; 2013: 839370PubMed Google Scholar, 3Cappell M.S. Davis M. Characterization of Bouveret’s syndrome: a comprehensive review of 128 cases.Am J Gastroenterol. 2006; 101: 2139-2146Crossref PubMed Scopus (124) Google Scholar In this context, minimally invasive treatment, such as endoscopic retrieval or lithotripsy, has a rather low success rate.3Cappell M.S. Davis M. Characterization of Bouveret’s syndrome: a comprehensive review of 128 cases.Am J Gastroenterol. 2006; 101: 2139-2146Crossref PubMed Scopus (124) Google Scholar Although enterolithotomy or gastrostomy, with or without cholecystectomy and fistula repair, are the most common therapeutic approaches, spontaneous resolution can exceptionally occur.3Cappell M.S. Davis M. Characterization of Bouveret’s syndrome: a comprehensive review of 128 cases.Am J Gastroenterol. 2006; 101: 2139-2146Crossref PubMed Scopus (124) Google Scholar

Alerting enhances attentional bias for salient stimuli: Evidence from a global/local processing task

The present study examined the role of alerting in modulating attentional bias to salient events. In a global/local processing task, participants were presented with a large arrow (global level) comprised of smaller arrows (local level) pointing in the same or opposite directions and had to indicate the direction of the large or small arrows in different blocks. Saliency of the global and local levels was manipulated, creating global-salient and local-salient conditions. Alerting signals were presented in half of the trials prior to the target. Results revealed a double dissociation in the effects of alerting on global/local interference effects. In a global salient condition, alerting increased global interference and decreased local interference. In a local salient condition, alerting reduced global interference and increased local interference. We demonstrate that within a single task, alerting can increase and reduce conflict based on perceptual saliency. These findings help to better understand disorders like hemispatial neglect in which both arousal and attention to salient events are impaired. These results also challenge previous theories suggesting that alerting acts to increase conflict interference. We argue that alerting is an adaptive mechanism that diverts attention to salient events, but comes at a cost when selective attention to less salient details is required.