Impact of different crystalloid volume regimes on intestinal anastomotic stability.
BACKGROUND
Anastomotic insufficiency still remains an unsolved problem in digestive surgery. Little clinical data, regarding the impact of perioperative volume management exist, which suggest lower complication rates in intestinal surgery under restrictive volume regimens. The aim of our study was to investigate the effect of the extent of intraoperative fluid administration with crystalloids on the stability of intestinal anastomoses.


METHODS
Twenty-one rats were randomly assigned to 3 experimental groups (n = 7 rats/group): control group CO (9 mL kg h crystalloid infusion), volume restriction group V (-) (3 mL kg h), and animals with volume overload V (+) (36 mL kg h). After midline incision, all animals received the corresponding infusion for a 30-minute period. Infusion was continued for further 30 minutes whereas an end-to-end small bowel anastomosis was performed 15 cm proximal to the Bauhin valve with 8 nonabsorbable interrupted inverting sutures. At reoperation on the 4th postoperative day, the anastomotic segment was dissected and the bursting pressure [mmHg] was measured. As a second parameter for the quality of anastomotic healing, hydroxyproline concentration was examined with a spectrophotometric method [microg/g dry tissue]. Histologically, structural changes of the anastomotic segments were assessed by 2 pathologists. Data are given as mean +/- SEM.


RESULTS
Anastomotic insufficiency was not seen in all animals. Bursting pressure of CO animals was 102 +/- 8 mmHg. Bursting pressure was lowest in V (+) with high volume exposure at 77 +/- 6 mmHg and significantly lower than V (-) (112 +/- 9 mmHg; P = 0.01) whereas the difference compared with the CO group did not reach significant values. Hydroxyproline concentration in V (+) (64.4 microg/g dry tissue +/- 7.7) was significantly lower compared with V (-) (91.7 microg/g dry tissue +/- 9.1) animals (P < 0.05). In all animals with volume overload a marked submucosal edema was found.


CONCLUSIONS
We could demonstrate for the first time in a systematic investigation, that the quantity of crystalloid infusion, applied intraoperatively, has a significant impact on functional (bursting pressure) and structural (hydroxyproline) stability of intestinal anastomoses in the early postoperative period. Because the stability and quality of an intestinal anastomosis have an impact on insufficiency rates, it should be noted that volume overload may have deleterious effects on anastomotic healing and postoperative complications in digestive surgery, possibly because of a marked bowel wall edema.
Marjanovic
Goran
G
Department of General and Digestive Surgery, University of Freiburg, Germany. goran.marjanovic@uniklinik-freiburg.de
Villain
Christian
C
Juettner
Eva
E
zur Hausen
Axel
A
Hoeppner
Jens
J
Hopt
Ulrich Theodor
UT
Drognitz
Oliver
O
Obermaier
Robert
R
D000714:Anastomosis, Surgical; D000818:Animals; D000077324:Crystalloid Solutions; D004195:Disease Models, Animal; D005440:Fluid Therapy / Q000009:adverse effects / Q000379:methods*; D007082:Ileum / Q000601:surgery*; D007552:Isotonic Solutions / Q000008:administration & dosage*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D015532:Rehydration Solutions / Q000008:administration & dosage*; D014883:Water-Electrolyte Imbalance / Q000209:etiology / Q000517:prevention & control; D014945:Wound Healing / Q000502:physiology*
D000077324:Crystalloid Solutions; D007552:Isotonic Solutions; D015532:Rehydration Solutions