Thomas Auer, MD, Johann Pfeifer, MD, Andreas Puntschart, MD, Herwig Cerwenka, MD. University of Graz, Department of General Surgery
1.Objective of the technology
A new type of film for controlled negative pressure therapy (CNP) was designed as double layer foil building an inner space with conical perforations at both sides. This film shows a high fluid transportation capacity when loaded even with low negative pressure.
2.Description of the technology and method of its use or application
Intestinal fistulae are known as very challenging surgical treatments with actually no standards. Vacuum therapy was mentioned a contraindication except exclusion of the fistula. Results from our animal study, using the spaced foil encouraged us to use the system to treat fistulae with direct CNP. The main idea was to affect the fistula surface of the intestine with negative pressure, using its known healing effect from wound therapy, instead of excluding fistulae from negative pressure areas.
Necrotic pancreatitis (NP) is a surgical treatment indication for massive necrosis and deterioration of the vital parameters. CNP with the spaced foil was a helpful and effective therapy after necrosectomy with subsequent open abdominal treatment.
In both treatments, the foil was used in one piece covering the intestinal convolute and/or by tailoring so called suction pads (Kerlix gauze or Polyurethane foam were wrapped in the foil), and adding a drainage into the pad. In all cases direct contact of the foil was applied to the fistula (closed with single stiches) and pancreas tissue. Abdominal lavage and renewing of the system was repeated every 2 to 6 days, according to the kind of abdominal fluids and clinical status of the patients.
3. Preliminary results:
8 patients were treated for small bowel, large bowel, duodenal and gastric fistulae using the spaced foil.
In 6 Patients fistulae were healing and the abdominal-wall has been closed entirely after15 to 28 (mean 13,4) days of treatment. In 1 Patient, the fistula was closed after small bowel stoma outlet, 1 Patient was died during the close follow up due to comorbidities.
12 patients were treated with severe NP after necrosectomy. 2 patients died due to multi organ failure and comorbidities. In all remaining patients the abdomen was clean at the end of open abdomen therapy and the full abdominal wall was closed after 15 to 47 (mean 21,4) days of CNP therapy.
Conclusions / future directions:
Our results confirm that negative pressure is not a risk factor for developing fistulae during CNP therapy. In contrast, we have observed a healing effect by using the spaced foil system that can transport the negative pressure to the intestinal surface. Using suction pads with a drainage core, a minimal access is needed and wound closure can be finished subtotal while treating the fistula. The transport capacity of the foil system is also helpful with transporting necrotic material out of hidden areas of the abdomen.
In future, we plan to use the system in more minimal invasive ways to treat pancreatitis direct through a retroperitoneal access with endoscopic guidance.