Portal vein thrombosis after laparoscopic splenectomy: an ongoing clinical challenge.

ObjectivesPortal vein thrombosis (PVT) following open splenectomy is a potentially lethal complication with an incidence of up to 6%. The objective of this report is to describe our management of a recent laparoscopic case, discuss current therapies, and consider antiplatelet therapy for prophylaxis.MethodsMedical records, laboratory studies, and imaging studies pertaining to a recent case of a laparoscopic splenectomy were examined. Current literature related to this topic was reviewed.ResultsA 16-year-old girl underwent laparoscopic splenectomy for idiopathic thrombocytopenic purpura. Her preoperative platelet count was 96K. She was discharged on postoperative day 1 after an uneventful operation including division of the splenic hilum with an endoscopic linear stapler. On postoperative day 20, she presented with a 5-day history of epigastric pain, nausea, and low-grade fevers without peritoneal signs. Her white blood cell count was 17.3; her platelets were 476K. Computed tomography demonstrated thrombosis of the splenic, superior mesenteric, and portal veins propagating into the liver. Heparinization was begun followed by an unsuccessful attempt at pharmacologic and mechanical thrombolysis by interventional radiology. Over the next 5 days, her pain resolved, she tolerated a full diet, was converted to oral anticoagulation and sent home. Follow-up radiographic studies demonstrated the development of venous collaterals and cavernous transformation of the portal vein.DiscussionNo standard therapy for PVT exists; several approaches have been described. These include systemic anticoagulation, systemic or regional medical thrombolysis, mechanical thrombolysis, and surgical thrombectomy. Unanswered questions exist about the most effective acute therapy, duration of anticoagulation, and the potential efficacy of routine prophylaxis with perioperative antiplatelet agents. PVT following splenectomy occurs with both the open and laparoscopic approach

Fundamental differences between SPH and grid methods

We have carried out a hydrodynamical code comparison study of interacting multiphase fluids. The two commonly used techniques of grid and smoothed particle hydrodynamics (SPH) show striking differences in their ability to model processes that are fundamentally important across many areas of astrophysics. Whilst Eulerian grid based methods are able to resolve and treat important dynamical instabilities, such as Kelvin-Helmholtz or Rayleigh-Taylor, these processes are poorly or not at all resolved by existing SPH techniques. We show that the reason for this is that SPH, at least in its standard implementation, introduces spurious pressure forces on particles in regions where there are steep density gradients. This results in a boundary gap of the size of the SPH smoothing kernel over which information is not transferred.Comment: 15 pages, 13 figures, to be submitted to MNRAS. For high-resolution figures, please see http://www-theorie.physik.unizh.ch/~agertz

A search for steep spectrum radio relics and halos with the GMRT

Context: Diffuse radio emission, in the form of radio halos and relics, traces regions in clusters with shocks or turbulence, probably produced by cluster mergers. Some models of diffuse radio emission in clusters indicate that virtually all clusters should contain diffuse radio sources with a steep spectrum. External accretion shocks associated with filamentary structures of galaxies could also accelerate electrons to relativistic energies and hence produce diffuse synchrotron emitting regions. Here we report on Giant Metrewave Radio Telescope (GMRT) observations of a sample of steep spectrum sources from the 74 MHz VLSS survey. These sources are diffuse and not associated with nearby galaxies. Aims: The main aim of the observations is to search for diffuse radio emission associated with galaxy clusters or the cosmic web. Methods: We carried out GMRT 610 MHz continuum observations of unidentified diffuse steep spectrum sources. Results: We have constructed a sample of diffuse steep spectrum sources, selected from the 74 MHz VLSS survey. We identified eight diffuse radio sources probably all located in clusters. We found five radio relics, one cluster with a giant radio halo and a radio relic, and one radio mini-halo. By complementing our observations with measurements from the literature we find correlations between the physical size of relics and the spectral index, in the sense that smaller relics have steeper spectra. Furthermore, larger relics are mostly located in the outskirts of clusters while smaller relics are located closer to the cluster center.Comment: 20 pages, 26 figures, accepted for publication in A&A on October 7, 200

Fundamental differences between SPH and grid methods

We have carried out a comparison study of hydrodynamical codes by investigating their performance in modelling interacting multiphase fluids. The two commonly used techniques of grid and smoothed particle hydrodynamics (SPH) show striking differences in their ability to model processes that are fundamentally important across many areas of astrophysics. Whilst Eulerian grid based methods are able to resolve and treat important dynamical instabilities, such as Kelvin-Helmholtz or Rayleigh-Taylor, these processes are poorly or not at all resolved by existing SPH techniques. We show that the reason for this is that SPH, at least in its standard implementation, introduces spurious pressure forces on particles in regions where there are steep density gradients. This results in a boundary gap of the size of an SPH smoothing kernel radius over which interactions are severely dampe

Development of Anaplastic Wilms Tumor and Subsequent Relapse in a Child With Diaphanospondylodysostosis

Diaphanospondylodysostosis (DSD) is a rare skeletal dysplasia syndrome resulting from disordered mesenchymal differentiation. Children with DSD generally die in utero or during the first month of life from severe thoracic insufficiency syndrome. An association of DSD with nephroblastomatosis has been observed, but the natural history of such nephroblastomatosis remains poorly characterized due to the rarity of the underlying condition. We describe a patient with DSD who developed bilateral hyperplastic nephroblastomatosis that ultimately evolved into therapy-resistant anaplastic Wilms tumor (nephroblastoma)

Portal vein thrombosis after laparoscopic splenectomy: an ongoing clinical challenge.

ObjectivesPortal vein thrombosis (PVT) following open splenectomy is a potentially lethal complication with an incidence of up to 6%. The objective of this report is to describe our management of a recent laparoscopic case, discuss current therapies, and consider antiplatelet therapy for prophylaxis.MethodsMedical records, laboratory studies, and imaging studies pertaining to a recent case of a laparoscopic splenectomy were examined. Current literature related to this topic was reviewed.ResultsA 16-year-old girl underwent laparoscopic splenectomy for idiopathic thrombocytopenic purpura. Her preoperative platelet count was 96K. She was discharged on postoperative day 1 after an uneventful operation including division of the splenic hilum with an endoscopic linear stapler. On postoperative day 20, she presented with a 5-day history of epigastric pain, nausea, and low-grade fevers without peritoneal signs. Her white blood cell count was 17.3; her platelets were 476K. Computed tomography demonstrated thrombosis of the splenic, superior mesenteric, and portal veins propagating into the liver. Heparinization was begun followed by an unsuccessful attempt at pharmacologic and mechanical thrombolysis by interventional radiology. Over the next 5 days, her pain resolved, she tolerated a full diet, was converted to oral anticoagulation and sent home. Follow-up radiographic studies demonstrated the development of venous collaterals and cavernous transformation of the portal vein.DiscussionNo standard therapy for PVT exists; several approaches have been described. These include systemic anticoagulation, systemic or regional medical thrombolysis, mechanical thrombolysis, and surgical thrombectomy. Unanswered questions exist about the most effective acute therapy, duration of anticoagulation, and the potential efficacy of routine prophylaxis with perioperative antiplatelet agents. PVT following splenectomy occurs with both the open and laparoscopic approach

Intra-abdominal inverted umblical cord in gastroschisis: a unique ultrasound finding

A relatively new surgical technique allows for sutureless closure of a gastroschisis defect. Immediately after birth, a long umbilical cord stump is temporarily inverted into the abdominal cavity and later retracted and used to close the abdominal wall defect. Knowledge of this entity is important since the inverted umbilical cord simulates an intra-abdominal mass on cross-sectional imaging. While this procedure is well described in the surgical literature, the imaging features of inverted umbilical cord have yet to be reported. The case presented here highlights the sonographic imaging findings of the umbilical cord during the intestinal decompression phase of sutureless repair of gastroschisis

Matrix metalloproteinase inhibition decreases ischemia-reperfusion injury after lung transplantation

Increased microvascular permeability and extravasation of inflammatory cells are key events of lung ischemia-reperfusion (IR) injury. The purpose of this study was to investigate the role of matrix metalloproteinases (MMP) in IR-induced alveolar capillary membrane disruption after experimental lung transplantation. We used a rat model of lung orthotopic transplantation (n = 86) with a prolonged cold ischemic phase. MMP2 and MMP9 were elevated 4 h after the onset of ischemia and further increased during reperfusion. Compared to sham values, the alveolar-capillary membrane permeability increased by 105% and 82.6% after 4 h of ischemia and 2 h or 24 h of reperfusion, respectively. A 4- and 5-fold increase of the infiltration of ischemic tissue by neutrophils was also observed after 2 h and 24 h of reperfusion. The PO2/FIO2 ratio dropped significantly from 244 to 76.6 after 2 h of reperfusion and from 296.4 to 127.6 after 24 h of reperfusion. A nonselective inhibitor of MMP, administered to the rats and added to the preservation solution, reduced significantly the alveolar-capillary leakage, the transmigration of neutrophils and improved gas exchanges in animals submitted to 4 h of ischemia combined with 2 h or 24 h of reperfusion. We conclude that inhibition of MMP attenuates IR injury after experimental lung transplantation

Alterations in maternal-fetal cellular trafficking after fetal surgery.

BACKGROUND/PURPOSE: Bidirectional trafficking of cells between the mother and the fetus is routine in pregnancy and a component of maternal-fetal tolerance. Changes in fetal-to-maternal cellular trafficking have been reported in prenatal complications, but maternal-to-fetal trafficking has never been studied in the context of fetal intervention. We hypothesized that patients undergoing open fetal surgery would have altered maternal-fetal cellular trafficking. METHODS: Cellular trafficking was analyzed in patients with myelomeningocele (MMC) who underwent open fetal surgical repair (n = 5), patients with MMC who had routine postnatal repair (n = 6), and healthy control healthy patients (n = 9). As an additional control for the fetal operation, trafficking was also analyzed in patients who were delivered by an ex utero intrapartum treatment procedure (n = 6). Microchimerism in maternal and cord blood was determined using quantitative real-time polymerase chain reaction for nonshared alleles. RESULTS: Maternal-to-fetal trafficking was significantly increased in patients who underwent open fetal surgery for MMC compared with healthy controls, patients who underwent postnatal MMC repair, and patients who underwent ex utero intrapartum treatment. There were no differences in fetal-to-maternal cell trafficking among groups. CONCLUSION: Patients undergoing open fetal surgery for MMC have elevated levels of maternal microchimerism. These results suggest altered trafficking and/or increased proliferation of maternal cells in fetal blood and may have important implications for preterm labor