VAC Stent

The VAC stent combines elements of both a self-expanding metal stent and endoscopic vacuum therapy in a single instrument.

The nitinol stent is fully covered with a silicone membrane that is impermeable to liquids and gases and is encased by a polyurethane sponge cylinder.

A 2.5 m long polyurethane suction catheter with a diameter of 10 French and a removable Luer-Lock connector is embedded in the open-pore sponge. After transnasal redirection, it connects to an adjustable vacuum pump. The ends of the covered stent are in contact with the intestinal wall and seal the lumen.

The metal stent has a body length of 50 mm and an expanded diameter of 14 mm, as well as two dumbbell-shaped ends, each 10 mm long, expanding to a diameter of 30 mm. This results in a total stent length of 70 mm. The stent body contains six radiopaque titanium markers to assist positioning under fluoroscopic control. The sponge is attached to the stent body with a suture thread.

The stent is delivered pre-assembled on a 1 m long over-the-wire introduction system.

The Esophagus-VACStent® is available in only one size and is CE-certified (Conformité Européenne).

The VACStent® treatment set is an introducer device with an outer diameter of 42 French (14 mm). It contains the self-expanding metal stent enveloped with a sponge, mounted on an inner catheter and held together by an outer tube.

Before placement, both the blue suction tube and the stent lumen are each flushed with 20 ml of physiological saline solution.

This arrangement includes a soft transparent cap at the end of the system, into which the opening for the guidewire is integrated. After removing the metal core of the inner catheter, the channel for the guidewire is also flushed with 20 ml of saline solution.

In the presented case, it involves the prophylactic use of the VAC stent with intraoperative placement after subtotal esophagectomy. As the first step, a transoral endoscopy is performed to determine the exact location of the anastomosis.

Note: In the event of an anastomotic leakage, the stent position is determined according to the following criteria:
(1) Adequate coverage of the leakage by the polyurethane foam and
(2) a minimum distance of 1 cm from both stent ends to the leakage.

Under endoscopic guidance, a 0.035-inch guidewire is inserted into the gastric conduit.

Now the stent placement is performed according to the procedure for a standard esophageal SEMS.

The end of the guidewire is threaded through the olive-shaped opening of the inner catheter, allowing controlled advancement of the prepared stent. While the guidewire remains securely fixed, the stent is advanced transorally to the previously determined position and visually checked before final release.

Note 1: The positioning and release can be monitored either with fluoroscopy or more simply with a small endoscope introduced parallel to the loaded stent. If optical control is performed, the stent position is determined based on the measured distance from the anastomosis or leakage to the incisors, while the proximal release of the sponge is visually observed.

In principle, the VAC stent can also be inserted and changed without radiological fluoroscopy, for example, in an intensive care unit.

Note 2: Since it is a distal release system, it is advantageous to place the stent slightly further distally. A stent that has already been released can be more easily retracted than advanced afterward if it ends too proximally.

Note 3: Precise intraoperative placement in preventive cases is facilitated by the additional digital control of the surgeon.

After positioning, the stent is released distally by retracting the outer sheath. To do this, the orange cap is loosened. Subsequently, the outer tube is pushed back to the end of the insertion system, which may initially feel somewhat resistant.

After release, the stent expands into a dumbbell-shaped structure with an inner diameter of 14 mm. The flange-shaped ends of the stent have a lumen of 30 mm and seal the sponge against the intestinal lumen, enabling circular vacuum therapy over the entire length of the sponge cylinder.