- Accidental intraperitoneal placement of the sponge with the risk of triggering an intestinal fistula. Peritonitis is not to be feared, as the vacuum causes a pressure reversal, thereby draining the infectious secretion.
- Ascending infection with generalized peritonitis → Relaparotomy with targeted drains and antibiotic therapy, possibly dissolution of the anastomosis with end colostomy. However, this is not a consequence of sponge therapy, but rather a result of inadequate wound secretion drainage. The most common causes are insufficient vacuum in the drainage container, a clogged sponge/catheter, a focus not fully drained due to multiple chambers/burrows of the wound cavity, or a sponge that is too small.
- Entero-anal fistula due to contact of the sponge with the small intestine.
- Blood loss in smaller septic erosion bleedings, which are maintained by the vacuum (overall very rare!).
- Sponge loss due to catheter detachment during removal. Removal with endoscopic grasping forceps can then be very time-consuming.
- Ingrowth of the sponge into the granulation tissue with resulting difficulties in removal and possibly triggering bleeding from the granulation tissue.
- Dislocation intraluminally with obstruction of the intestinal lumen. An ileus usually does not occur because the sponge quickly becomes clogged by stool, making the system non-functional. The mucosa itself is completely resistant to the vacuum and the polyurethane sponge, so no erosion or perforation is caused (unlike the serosal side!).