Misplacement of Tunneled Hemodialysis Catheter into Azygos Vein: Left or Right Jugular Insertion Has Similar Susceptibility.

BACKGROUND: Central venous catheter (CVC) is commonly used to provide access for hemodialysis (HD) when arteriovenous access is not available. The misplacement of CVC into azygos vein (AV) is a rare but a potential serious complication. Previous reports communicated the opinion that left-sided catheterization predisposed to AV misplacement, but these reports concentrated on peripherally inserted CVCs, placed for indications rather than HD. Unintended AV misplacement of HD catheters (HDCs) has not been well studied. We seek to investigate factors associated with inadvertent AV miscannulation during HDC placement. METHODS: We are to present a case of unintentional misplacement of a tunneled HD catheter (tHDC) into the azygos arch from right internal jugular vein (RIJV) despite real-time fluoroscopy guidance. Additionally, we have undertaken a systematic literature search in Pubmed to study the anatomical and other factors related to unintended AV misposition in HD setting. RESULTS: From 2005 to August 31, 2018, a total of 11 articles containing 16 cases of misplacement of HDCs into AV were identified. Of the 17 cases of unintentional AV misposition including ours, the majority of the misguided HDCs (94.1%, 16/17) were tHDCs and only 1 case was related to a temporary (non-tunneled) catheter. Most catheter misplacements (88.2%, 15/17) were performed without real-time radiological guidance. The reported incidence of inadvertent AV cannulation from different institutions varied between 0.6% and 3.8%. Among the 16 misplaced tHDCs, the rates of AV misposition that arose from RIJV and left internal jugular vein (LIJV) insertion are even at 50%. CONCLUSIONS: Based upon anatomical and case studies, we have found that AV may join posterior aspect of superior vena cava at different directions and levels. Hence, this might explain why AV misplacement might occur whether an HDC is inserted from the LIJV or RIJV approach. By raising the awareness of this potential complication and how we may minimize it, we hope to reduce the future complication of AV misposition.

Characterization and Identification of Prenylated Flavonoids from Artocarpus heterophyllus Lam. Roots by Quadrupole Time-Of-Flight and Linear Trap Quadrupole Orbitrap Mass Spectrometry.

In this study, a combination of quadrupole time-of-flight mass spectrometry (Q-TOF-MS) and linear trap quadrupole orbitrap mass spectrometry (LTQ-Orbitrap-MS) was performed to investigate the fragmentation behaviors of prenylated flavonoids (PFs) from Artocarpus plants. Fifteen PFs were selected as the model molecules and divided into five types (groups A-E) according to their structural characteristics in terms of the position and existing form of prenyl substitution in the flavone skeleton. The LTQ-Orbitrap-MSn spectra of the [M - H]- ions for these compounds provided a wealth of structural information on the five different types of compounds. The main fragmentation pathways of group A were the ortho effect and retro Diels-Alder (RDA), and common losses of C4H10, CO, and CO2. The compounds in group B easily lose C6H12, forming a stable structure of a 1,4-dienyl group, unlike those in group A. The fragmentation pathway for group C is characterized by obvious 1,4A-, 1,4B- cracking of the C ring. The diagnostic fragmentation for group D is obvious RDA cracking of the C ring and the successive loss of CH3 and H2O in the LTQ-Orbitrap-MSn spectra. Fragmentation with successive loss of CO or CO2, ·CH3, and CH4 in the LTQ-Orbitrap-MSn spectra formed the characteristics of group E. The summarized fragmentation rules were successfully exploited to identify PFs from Artocarpus heterophyllus, a well-known Artocarpus plant, which led to the identification of a total of 47 PFs in this plant.