Endoluminal dilatation for embedded hemodialysis catheters: A case-control study of factors associated with embedding and clinical outcomes.

BACKGROUND:With the increasing frequency of tunneled hemodialysis catheter use there is a parallel increase in the need for removal and/or exchange. A small but significant minority of catheters become embedded or 'stuck' and cannot be removed by traditional means. Management of embedded catheters involves cutting the catheter, burying the retained fragment with a subsequent increased risk of infections and thrombosis. Endoluminal dilatation may provide a potential safe and effective technique for removing embedded catheters, however, to date, there is a paucity of data. OBJECTIVES:1) To determine factors associated with catheters becoming embedded and 2) to determine outcomes associated with endoluminal dilatation. METHODS:All patients with endoluminal dilatation for embedded catheters at our institution since Jan. 2010 were included. Patients who had an embedded catheter were matched 1:3 with patients with uncomplicated catheter removal. Baseline patient and catheter characteristics were compared. Outcomes included procedural success and procedure-related infection. Logistic regression models were used to determine factors associated with embedded catheters. RESULTS:We matched 15 cases of embedded tunneled catheters with 45 controls. Among patients with embedded catheters, there were no complications with endoluminal dilatation. Factors independently associated with embedded catheters included catheter dwell time (> 2 years) and history of central venous stenosis. CONCLUSION:Embedded catheters can be successfully managed by endoluminal dilatation with minimal complications and factors associated with embedding include dwell times > 2 years and/or with a history of central venous stenosis

Review of literature.

<p>Review of literature.</p

Access characteristics.

<p>Access characteristics.</p

Causes for catheter removal.

<p>Causes for catheter removal.</p

Endoluminal dilatation for embedded hemodialysis catheters: A case-control study of factors associated with embedding and clinical outcomes - Fig 1

<p>Endoluminal Dilation: (A, B and C) An 8 x 80mm balloon is inserted over a guidewire into the venous lumen of an embedded tunneled dialysis catheter and inflated along the length of the catheter from its distal tip to the cuff. Balloon inflation pressure of between 12 (rated burst pressure) and 20atm is used and maintained until there is complete or near complete effacement of areas of narrowing, assumed to represent the principle points of tethering of the catheter to the venous wall. The catheter is then easily removed. (D and E) If performing a catheter exchange, a 0.035inch guidewire is inserted through the arterial lumen of the embedded catheter just before its removal and used for insertion and inflation of a 12 x 40mm balloon along the length of the SVC and brachiocephalic vein. The balloon is then removed followed by insertion of a new tunneled dialysis over the guidewires and through the initial subcutaneous tract.</p

Demographic characteristics.

<p>Demographic characteristics.</p

COSMO-RS Studies: Structure–Property Relationships for CO₂ Capture by Reversible Ionic Liquids

The quantum-chemical approach COSMO-RS was used to develop structure–property relationships of reversible ionic-liquid (RevIL) solvents for CO₂ capture. Trends predicted for the thermodynamic properties of the RevILs using COSMO-RS, such as CO₂ solubility, solvent regeneration enthalpy, and solvent reversal temperature, were verified by experimental data. This method was applied to a range of structures, including silylamines with varying alkyl chain lengths attached to the silicon and amine functionality, silylamines with fluorinated alkyl chains, sterically hindered silylamines and carbon-based analogues. The energetics of CO₂ capture and release and the CO₂ capture capacities are compared to those of the conventional capture solvent monoethanolamine. The results of this study suggest that the simple COSMO-RS computational approaches reported herein can act as a guide for designing new RevILs. COSMO-RS allows for the determination of the relative thermodynamic properties of CO₂ in these and related systems