Anastomotic Perfusion Pressure Expressed in a Bowel-Arm Index and Gastric Conduit-Arm Index; a New Variable to Predict Anastomotic Leakage.

Anastomotic leakage remains a serious complication following colorectal surgery
and esophageal resection with gastric conduit. Its reported prevalence varies
between 1% and 39%. Currently, before making an anastomosis, viability of the
bowel or gastric conduit is estimated by the color of the tissue. This remains
very subjective and based on the experience of the surgeon. The aim of this
study is to investigate if measurements of perfusion at the site of anastomosis
expressed by a bowel-arm index or gastric conduit-arm index can help to predict
anastomotic dehiscence.

First a pilot study will be conducted.

A new device has been developed in the VU University Medical Center enabling us
to measure perfusion pressure in mmHg in the bowel wall or wall of the gastric
conduit. Correlating this measurement to systemic blood pressure in mmHg
subsequently provides us a bowel-arm index or gastric conduit-arm index. In the
future, an anastomosis could subsequently be made where the bowel-arm index in
the bowel or gastric conduit-arm index is adequate and thus minimize the chance
of anastomotic leaks.

All patients undergoing colorectal, small intestinal surgery and esophageal
resection in the VU University Medical Center (VUmc), Academic Medical Center
(AMC), Zaans Medical Center (ZMC) and Medical Center Alkmaar (MCA), receiving a
primary anastomosis will be entered into this prospective study. Patients must
be 18 years and older. Informed consent must be obtained from all patients.
Patients undergoing palliative treatment or emergency surgery will be excluded
from this study. Standard anesthesia is given in all patients included in this
study.
Just before performing the anastomosis the bowel perfusion of the bowel wall is
measured in mmHg opposite of the mesenterium on both the oral and aboral side
of the anastomosis. This is believed to be the site of poorest perfusion in the
bowel wall. At the same time the systemic perfusion is measured using an
arterial catheter in the radial artery. Bowel perfusion in mmHg is divided by
the systemic pressure in mmHg providing us the bowel-arm index. Also the
surgeon is asked to subjectively evaluate the bowel perfusion.
In case of esophageal resection, after performing the gastric conduit, just
before the anastomosis is made, perfusion of the gastric conduit wall is
measured in mmHg opposite of the left gastric artery at the side of the
anastomosis. This is believed to be the site of poorest perfusion in the
gastric conduit. At the same time the systemic perfusion is measured using an
arterial catheter in the radial artery. Gastric conduit perfusion in mmHg is
divided by the systemic pressure in mmHg providing us the gastric conduit-arm
index. Also the surgeon is asked to subjectively evaluate the gastic conduit
perfusion.
Postoperatively patients are clinically followed for signs of anastomotic
leakage. Patients with an increase in abdominal pain, leukocyte level and/or
C-reactive protein level past postoperative day 3 will be evaluated for
anastomotic leakage by CT-scan with oral, rectal and IV contrast. In case of
esophageal resection this will be a CT scan of the chest with possibly a
gastroscopy. In addition, a CT-scan of the abdomen or thorax will be made at
any other postoperative day if deemed necessary by the treating physician.
We will investigate if a threshold in bowel-arm index or gastric conduit-arm
index will be able to help predict anastomotic leakage.

First a pilot study will be conducted.

No additional risk or burden is expected. The new device only exerts pressure
on the bowel wall and wall of the gastric conduit as would a surgical clamp for
instance. The perfusion measuring device has a CE approval. No addition out
patien clinic visits are planned.