Table 1 Protocol for testing the Mini Sponge Dressing in a ewe model

Step 1

Complete blood count (CBC) obtained prior to abdominal incision.

Step 2

General anesthesia was induced and a laparotomy incision was made.

Step 3

Uterus evacuated by hysterotomy.

Step 4

Following evacuation of fetus, the umbilical cord was unclamped and the placentomes (sections of the sheep placenta) cut at the base and curetted to cause bleeding for approximately 60 s. Placentomes are composed of the maternal caruncle and fetal cotyledon. Several entire placentomes were cut off at their bases to promote hemorrhage. The endometrium/myometrium was gently curetted at each extirpated placentome site to increase hemorrhage.

Step 5

The hysterotomy incision was closed in the usual fashion until only a 1–2 cm opening remained.

Step 6

The MSD obstetrical applicator was then placed through the partially closed hysterotomy (to mimic the cervix) and the sponges deployed to fill the uterus.

Step 7

The remaining aspect of the hysterotomy incision was then closed, followed by the abdominal skin incisions using standard technique.

Step 8

Anesthesia was then reversed.

Step 9

All experimental ewes were treated with non steroidal anti-inflammatory drugs for pain (flunixin meglumine (Banamine)) at the conclusion of surgery and 24 h later. Animals were carefully monitored throughout this period for signs or symptoms of pain, fever and bleeding. If signs of discomfort (reluctance to rise, grinding of teeth, head pressing, loss of appetite, fever) were still evident the day after surgery, additional analgesia (meloxicam, 1 mg/kg q24 h po) was provided.

Step 10

At 24 h post-operative, a second CBC was obtained.

Step 11

For the first three animals, 24 h after the initial surgery, the animal was euthanized, and the entire uterus removed for tissue analysis, with the sponges left in place.

For the remaining six animals, 24 h after the initial surgery, the sponges were removed by laparotomy. The animal was then observed for an additional six days. At one week following initial deployment, the animal was euthanized, and the entire uterus removed for tissue analysis, with the sponges left in place.

Step 12

Histologic analysis of the uterus was then performed to evaluate for signs of infection or trauma from the sponges.