VAC Stent

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.

Once the stent has been released, the introduction system and the guide wire can be removed under endoscopic control, ensuring that the blue suction catheter remains in place. This catheter should be fixed at the mouth once the system has been passed by it.

Subsequently, the endoscope is reintroduced to verify the final position and expansion of the VAC stent.

Note: The free passage through the VAC stent can be checked endoscopically in principle. If necessary, the position of the distal end of the stent can additionally be controlled by inversion.

The suction catheter is redirected retrogradely through the throat into the nose with the help of a suction catheter introduced through the nose, in order to be able to guide it out here and fix it.

The suction catheter is connected to a vacuum pump via a plastic Y-adapter, which allows easy docking to most clinically available vacuum pumps from various manufacturers.

Currently, there are no strict guidelines regarding the vacuum pressure to be applied. The manufacturer recommends initially setting the pump to 125 mmHg for the first 12 – 24 hours to facilitate tissue adaptation, followed by a reduction to 75 mmHg. Available studies have used continuous suction therapy with a vacuum pressure range of 65 to 125 mmHg. The vacuum mode should be set to continuous operation.

Note 1: In the example presented here with a fresh anastomosis, a vacuum pressure of 85 mmHg is primarily recommended.

Note 2: Continuous secretion suction and the fixation of the VAC stent to the intestinal wall are also possible in principle with a vacuum pressure of up to 50 mmHg.

After 5 – 7 days, the VAC stent should be removed or changed. To facilitate the removal process, the vacuum pump is turned off 4 – 6 hours before the procedure. First, the blue suction catheter is disconnected from the Y-adapter and the nasal plasters are removed.
Then, the sponge is flushed retrogradely over the suction catheter with at least 40 ml of 0.9% NaCl solution. Flushing the sponge with saline can facilitate its detachment from the esophageal wall.

Next, the endoscope is introduced and the stent, along with the sponge, is carefully detached from the mucosa by guiding the endoscope in a downward motion on all sides between the VAC stent and the mucosa.

Note: A conically shaped attachment cap for the endoscope can help simplify the procedure.

Finally, the retrieval loops attached to the proximal end of the stent are grasped with an endoscopic grasping forceps and the system is removed by simultaneous traction on the suction catheter. After removal, the anastomosis or defect site is inspected to assess whether a new VAC stent is required.

Note: If there is uncertainty about the integrity of the anastomosis or closure of the defect, a new VAC stent can be placed. Alternatively, a CT scan with water-soluble oral contrast is possible.