The overall complication rate associated with leech therapy
November 4, 2015
The overall complication rate associated with leech therapy of 21.8% was relatively high. The infective complication rate of 14.4% (N 5 33) gives more credence to the policy of antibiotic prophylaxis such as quinolones, which have good resistance profiles to Aeromonas species. Previous reviews have reported infection rates of between 4.1 and 20%. The review by de Chalain et al. (1960–1994) reported an infection rate of 17.59%, though there was no clear methodology on how the literature review was conducted and which reports were included or excluded. Aeromonas hydrophila was reported as the commonest cause of infection (87.9% of total infections), but we now know that these were likely to have been misidentified, and Aeromonas veronii was the likely pathogen. Isolated reports of infections due to Serratia marsescens, and Vibrio fluvialis were also reported.
The knowledge regarding leech microbiota is advancing due to new molecular methods to identify the culturable and non-culturable symbionts of the leech. In the noninfected group the salvage rate was 88.3% which dropped to 37.4%, when the tissue became infected. These results are broadly in line with the second largest series from the literature reporting on the effect of infection, de Chalain’s meta-analysis, which reported on a total of cases of Aeromonas infection (nine replants, three free flaps, and seven pedicled flaps) with an overall salvage rate of 31.8%, compared with a salvage rate of 60–80% in noninfected tissues. In our experience, and that of others, surgical site infections (SSIs) due to leech application result in additional antibiotic therapy, extended hospital stays, rehospitalization or removal of nonviable tissues. A recent clinical study has shown the proportion of patients becoming infected after leech therapy was significantly greater in the group of patients that did not receive a prophylactic antibiotic treatment. There is emerging evidence from recent studies that high levels of resistance to first generation cephalosporins, penicillins (via b-lactamases), tetracyclines, and augmentin are present.
Fluoroquinoles seem to be consistently active, and our experience suggests that prophylactic fluoroquinolones seem to be mandatory given the preponderance of infection. The recently reported case of a MDR (multi drug resistant) Aeromonas strain is concerning when you combine this finding with recent environmental isolates from European natural water sources demonstrating a plasmid mediated fluoroquinolone resistance in Aeromonas strains. Isolates obtained from a Swiss lake and the Seine River containing Aeromonas with the qnrS2 plasmid that encodes fluoroquinolone resistance.N It is important to note the limitations of this study. The flap size is not mentioned in the papers, and the whole idea of ‘‘success and failure’’ is easier to address with relatively small replantations, whereas it is much more difficult in large flaps. Several articles did not include information regarding complications, the need for blood transfusion, or whether and adjunctive medication was used. A significant number of papers do not comment on antibiotic prophylaxis or treatment, or what type of antimicrobials was used. The number of leeches was highly variable, ranging from one leech per day to as many as one every hour, indicating there is no scientific basis as yet to guide us. The time interval between applications was similarly varied, ranging from hourly to once a day for 22 days.