ANTIBACTERIAL PDT EFFECT IN EXPERIMENTAL PERITONITIS

R.D. MUSTAFAYEV, R.I. KIZEVADZE, G.V. TIKHOV

State Research and Clinical Center for Laser Medicine, Moscow, RUSSIA

Purpose: To study antibacterial properties of photodynamic therapy (PDT) in acute experimental peritonitis caused by intraabdominal inoculation of colibacillus monoculture (strain 25922) in rats.

Materials and methods: To evaluate the effectiveness of various sanation techniques in the abdominal cavity with peritonitis a definite number of colony-forming units in the postoperative period is an important parameter. Concentration of colibacillus microbial bodies was counted in both control and main groups. In the main group abdominal cavity sanation was done with PDT technique. Experimental animals were injected photosensitizer Photoditazine intravenously in the dosage 0.8 мг/кг. 2 – 2.5 hours later – as it was thought to be the time of maximal photosensitizer accumulation in the inflamed abdominal cavity – the animals were irradiated with laser light. Laser apparatus “Atkus-2” with output power 1-2Wt, continuous mode, red optic range, wavelength 661 nm was used for PDT session.

In the control group the mostly common technique for abdomen sanation was used: 0.02% chlorhexidine solution. Animals were taken out from the experiment using overdosaged anesthetic preparation Trepental in 24 hours, in 72 hours and from 5^th till 7^th days of the postoperative period.

Results: Before sanation the level of microbial contamination with colibacillus monoculture in animals with acute generaliazed peritonitis was 10⁷-10⁸ of microbial bodies in 1 ml of exudate. In a day after PDT sanation of the abdominal cavity microbial contamination markedly decreased and was 10² in 1 ml; no microflora signs were revealed in three days after the surgery. In the control group where abdominal sanation was done with 2% chlorhexidine solution microbial contamination in 1 ml of exudate was the following: 24 hours after surgery - 10⁴; in 72 hours – 10³; in 5 days – 10². By the 7^th day the abdominal cavity was found sterile.

Conclusion: The results obtained have indicated a high PDT sterilizing effect in rats with experimental peritonitis caused by colibacillus monoculture. The discussed technique is simple to handle, safe, no thermal damage to the peritoneum. All these findings suggest a necessity for further researches on PDT application for treating acute peritonitis.

Date: 2014-12-28; view: 960