Types of esophageal stents

Currently, there are three esophageal stents used in the United States. They are as follows (Table 1).

Gianturco Z-stents are made from 0.018-in stainless steel wire bent in a zig-zag fashion to form segments 2-cm long, which are connected using nonabsorbable suture to form lengths from 6 to 14 cm. The stent is 18 mm in its internal diameter, with the proximal and distal ends flared to 25 mm. The Z-stents are available in fully covered and

Table 1

Gianturco-Z stent1

Ultraflex2

Wallstent II

Material

Stainless steel

Nickel titanium

Elgiloy

(Nitinol)

Covering

Yes

Yes

Yes

Design

Zig-zag configuration

Mesh

Mesh

Self-expanding

+

+

+

Diameter before

Implantation

28F

16F

18F

Shaft diameter

Post implantation

18 mm

18,23 mm

20 mm

Flange diameter

21,25 mm

23,28 mm

28 mm

Degree of

Shortening

0%-10%

30%-40%

30%

Radial force

++

+

+++

Fistula Closure

Yes

Yes

Yes

1Gianturco Z-Stent (Wilson-Cook Medical, Winston-Salem, NC) 2Ultraflex stent (Microvasive, Inc., Natick, MA) 3Wallstent II (Microvasive)

1Gianturco Z-Stent (Wilson-Cook Medical, Winston-Salem, NC) 2Ultraflex stent (Microvasive, Inc., Natick, MA) 3Wallstent II (Microvasive)

Esophageal
Fig. 2. Esophageal stents. (A) Covered Gianturco Z-Stent (Wilson-Cook Medical, Winston-Salem, NC). (B) Uncovered Gianturco Z-Stent (Wilson-Cook Medical, Winston-Salem, NC). (C) Ultraflex stent (Microvasive, Inc., Natick, MA). (D) Wallstent II (Microvasive) Covered Z stent.

partially covered versions (Fig. 2A,B), and some have a Dua antireflux valve for gastroesophageal junction tumors to prevent reflux of gastric contents.

The Ultraflex stent (Fig. 2C) is a self-expanding stent made of 0.15-in nitinol wire with a luminal diameter of 18 mm and a proximal flange diameter of 23 or 28 mm upon deployment. Nitinol is a nickel titanium alloy that is unique for its shape memory properties. The stents vary in length from 7 to 15 cm. Ultraflex stents have less radial force that Wallstents (12). They are available coated and uncoated. The uncoated stent is more susceptible to tumor ingrowth and overgrowth (36%) (13).

The Wallstent (Fig. 2D) consists of eight stainless steel wires arranged in a spiral shape, forming a wire mesh. They are available in lengths of 10 cm and 15 cm. The stent is partially covered with a polyurethane coating. The conical configuration of the stent is designed to limit distal stent migration. It is available in two sizes: 1) small (proximal diameter of 24 mm, distal diameter 16 mm, total length 12 cm) for tumors without prestenotic dilatation; and 2) large (30-mm proximal diameter, 20-mm distal diameter, and a total length of 14 cm).

Brain Research And Your Child

Brain Research And Your Child

Enchanted Learning Experiences -Why They Should Be The Norm For Our Children. The latter part of the twentieth century has seen more discoveries about the human brain than in all previous history of mankind. It is as though we have been paddling in the shallows of a vast ocean hitherto unaware of its existence.

Get My Free Ebook


Post a comment