1) Patient refusal or non-compliance to continue with the trial

2) Patient undergoes surgical intervention related to the abscess during the study period

3) Patient suffers a serious adverse event as a result of the study

- drop in hemoglobin greater than 20 g/L

- bleeding requiring transfusion

- allergic reaction requiring medical intervention

4) Findings observed during the study lead to early termination either due to clear benefit or disadvantages of therapy

5) Imaging findings demonstrate worsening of the abscess either as dissemination or increase in volume > 25%

6) White blood cell count remains elevated above the baseline recorded value 48 hours beyond intervention

7) The drainage catheter becomes dislodged from the abscess cavity (determined by routine imaging examinations)

8) Technical malfunction of the catheter during drug administration (fracture or hole in the catheter or the catheter is occluded)