Peel-away sheath

A 67-year-old woman was provided with a totally implantable venous device in the right subclavian vein by the Seldinger technique with a peel-away sheath. The device was used for a course of chemotherapy. After about 1 month there was subcutaneous extravasation of the drug. A chest X-ray showed that the sihcone catheter had fractured below the clavicle and the distal portion of the catheter had embolized into the right atrium. The fragments were removed. 

More recently, a peel-away sheath with a hemostatic valve has been developed that completely avoids the problem of air embolization. 

The stent is advanced across the stricture until the tip is 3-4 cm beyond the ampulla. It is preferable to start deployment with the stent too far in, rather than not far enough, because it is easier to withdraw the stent into the correct position than it is to move it forward (Fig. 1.5). The peel-away sheath is retracted (not peeled) to above the stricture. The delivery-system outer sheath is retracted a few centimeters, which allows the distal uncovered end of the stent to partially expand. Accurate placement, with the tip just through the ampulla, is achieved by pulling back the whole assembly over the wire. As the partially expanded stent is withdrawn across the ampulla, the stent is mildly compressed, which corresponds to the location of the ampulla. The stent is positioned so that the distal 1-2 cm projects into the duodenum. After confirming that the upper end of the stent is within the ducts and well above the stricture, the stent is fuUy released by full retraction of... 

The collateral venous channels are initially demonstrated by venography. If there is a dominant pathway that can accommodate a long-term device, the procedure proceeds with catheterization of that channel (Kaufman et al. 1995 McLean et al. 1985). Once the right atrium is reached, a tunnel or pocket is created. The final catheter is placed in the usual fashion via a peel-away sheath. There is a potential complication of occluding the dominant collateral channel resulting in symptoms of venous outflow obstruction. 

Translumbar IVC catheterization is performed via a right-sided flank approach slightly above the iliac crest. A guidewire placed into the IVC via the femoral vein can be used as a target. The cava is punctured at the L3 level utilizing oblique fluoroscopy. Once access is obtained, the tunnel or pockets are created in similar fashions. A long peel-away sheath is often needed in large adults (Jaques et al. 1990 Lund et al. 1990). 

Initial access into either the IJV or the SCV is gained with standard ultrasound guidance using micropuncture techniques. The 0.018-in. mandril guidewire is placed into the right atrium (RA). The tract is dilated over the mandril wire and then the non-tapered catheter is advanced over the wire until the tip is in the superior aspect of the RA. In patients with excessive soft tissue thickness, it is often difficult to directly insert the soft silicone non-tapered catheter. In these cases, it will be necessary to use a peel-away sheath to insert the catheter into the venous system. The catheter is fiushed, heparinized, and secured with no absorbable 3-0-suture material (Mauro and Weeks 1998b). 

Fig. 6.10. Catheter insertion through the peel-away sheath. During catheter insertion, the sheath is pinched between the fingers to prevent an air embolism...

Following venous access, the transition dilator is exchanged over a working wire for the peel-away sheath. The catheter with its end clamped is inserted into the right atrium and flushed. The port is then created, followed by the creation of the subcutaneous tunnel. The end of the catheter is brought through the tunnel. The catheter tip is placed in its desired location fluoroscopically and the end of the catheter is cut and attached to the port The port is then re-positioned... 

Polakovic V, Svara F, DvofakovA M Dialysis catheter insertion with and without peel-away sheaths. Nephrol Dial Transplant 2007 22 2359. 

A gastr oscope is inserted and the stomach inflated maximally. The puncture site is chosen in the same way as above. A flexible J-wire is inserted through the puncture needle into the stomach. A dilator within a peel-away sheath is introduced over the guidewire, and again introduced into the stomach. The dilator is exchanged with a gastrostomy tube with an inner balloon that is filled with water. The introducer sheath is peeled away and the tube placed in the sleeve of the outer retention disc and fixed to the skin with adjusted tension. The whole procedure is controlled endoscopically. 

Fig. 11.19a-f. After dilatation of the track, a peel-away sheath is inserted and the lubricated tube inserted through this. The sheath is split, peeled away and removed and the balloon (arrow) inflated. The outer retention disc (arrowheads) needs readjusting after removal of the gastropexy sutures... 

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