BMI

After the initial (and highly popular, if I may say so) posts on the subject (see Parts One and Two), we will now talk about what we have gained in terms of experience and insight about this subject.

I had jokingly noted how BMI has not had a leak in many years. This year (obviously our busiest year so far) we have had three leaks, each unique in mechanism, presentation and treatment.

I will discuss the cases separately later in my posts, and share some thoughts about this important topic.

Sleeve gastrectomy leaks behave totally differently compared to any other type. The reasons are multiple, and all lead to a persistent and nagging leak that may end up as a fistula (a tract between the stomach and the skin).

The causative factors are:

1. The pylorus (ring of muscle that acts a the gateway from the stomach into the duodenum) is normally closed, and the pressure in the gastric tube increases because of that, especially when a peristaltic wave builds up in the organ. The pressure may be as high as 45 mm Hg pressure, whereas the lower esophageal pressure is 20 mm Hg at most. The resultant gradient of pressure is from the pyloric end towards the esophagus. This leads to high pressure acting on the highest end of the staple line (near the GE junction). Greater the pressure, the higher the leak rate.
2. The GE junction area is least supplied by blood vessels. This would lead to relatively weaker healing.
3. The intrathoracic pressure is negative, and the pressure differential in the upper stomach, therefore, is high.
4. The gastric tube may twist in a corkscrew manner in the postoperative phase, perhaps as a result of the staple line running in different directions and the muscle layers getting transected at different levels.
5. The incisura of the stomach may be narrowed by the stapling. This would not only lead to high pressure build up in the stomach but also make leak management doubly difficult.

Whatever be the cause, leaks may increase mortality (10%), and certainly do increase hospitalisation and costs of treatment. In fact, in the Indian context, where insurance is nowhere in the picture, it is scary to imagine a leak in a patient with limited resources.

Some other points about sleeve leaks:

* The most leaks occur when both staple line buttresses and overrunning sutures are used (Gagner).

* Intersections of staple lines must always be oversewn to prevent leaks.

* The narrow sleeves leak the most compared to the wider ones (typically 32 Fr versus 40 Fr).

* Leaks may occur even as late as 2 to 4 weeks after operation, though this is not common.

* A leak mandates immediate re-exploration, drainage and insertion of a feeding tube (nasojejunal or jejunostomy or parenteral).  Many experts now routinely insert a stent intraoperatively during the re-exploration. This possibly reduces hospital stay.

* A chronic leak persisting over three months is not amenable to endoscopic stenting and would need surgery.

Endoscopic stent management of sleeve leaks (some major points to bear in mind):

For stents to work, the defect should be less than 3 cm or less than 50% of the circumference of the organ.

As mentioned above, the consensus seems to be emerging that leaks should be stented during the re-exploration. At this re-exploration, an attempt may be made to identify the leak, suture it with an omental pedicle as buttress and drain the area. If the leak is not easily visible, one should not hunt it, for fear of causing injuries in the friable and inflamed area.

If a stricture is present along with a leak, two stents may be used to cover the entire sleeve, or the single stent has to reach up to the incisura/stricture.

SEMS for Sleeve Leak (video)

The stents used may be Self Expanding Plastic Stents (SEPS) known as Polyflex or SEMS (self expanding metal stents). The problem with the Polyflex or plastic stents is that they tend to migrate, while the SEMS stents are very difficult to remove. To this end, the two stents have different problems and different solutions have been tried successfully: to prevent migration of the SEPS stent, a thread is passed through the edge of the stent and brought out through the nose and tied to the patient’s ears (!). Ingenious and cheap. With the SEMS stent, double coating may make for easier removal. I have seen one presenter at IFSO 2011 at Hamburg mention and show esophageal avulsion injury during removal of a metal stent.

Stents cause problems:

• Reflux
• Salivation in the morning
• Chest pain
• Dislodgment
• Erosion
• Difficult removal

Stenting should be accompanied by endoscopic pyloric dilatation, using 20 psi pressure. This reduces the intra-sleeve pressure.

Checking the stent position every week or month (depending on the policy) is necessary.

Endoscopic methods other than stents:

• For leaks less than 1 cm, several injections of fibrin sealant may lead to 100% success rates.
• For the same kind of leak, argon laser coagulation has also been used (Basso).
• Through-the-scope clips may be used for defects less than 1 cm.
• Over-the-scope clips may be used for larger defects.
• A Brazilian center advocates an endoscopic septotomy (division of a ridge like elevation that forms beside a chronic fistula) and cleaning up of the abscess adjoining the fistula, thereby leading to an internal drainage of the leak. This allows immediate removal of the drain. This is an unorthodox method of treatment.

Surgery:

For a chronic leak, surgery may be a last resort.

1. The simplest is to connect a jejunal loop to the fistula defect
2. The sleeve is converted to a gastric bypass and the fistula is left untouched. This converts the high pressure sleeve leak to a low pressure bypass leak. The fistula then dries out.
3. Conversion to bypass and stoma constructed at the leak site.
4. Total gastrectomy with esophagojejunostomy (Neto).

I hope this series has been educational for you, whether you are a patient, relative, doctor or student.