Abstract
The waterjet debridement is now a standard practice in contaminated or infected diabetic lower extremity wounds. The bacterial clearance of the waterjet debridement remains an important parameter that should be predicted in this application. This study aimed to investigate the waterjet in reducing the diabetic lower extremity wound contaminants. A retrospective cohort study was conducted. Patients' etiology and pathogen diagnosis were established as diabetic lower extremity contaminated wound. The high-power waterjet (Versajet™, Smith-Nephew) was used in the treatment group and conventional surgical methods were used in the control group. The bacteriological swab samples were collected before and after the debridement. The results of bacterial culture were analyzed. A total of 74 patients were included in our study, 40 patients in the treatment group and 34 in the control group. Patient characteristics were well matched. The preoperative bacteriological swab samples of the 2 groups showed no significant difference between each other with a P value of .1022. The culture result of postoperative bacteriological swab samples in the treatment group was significantly lower than control with a P value of .0099. The odds of bacterial clearance were greater in the treatment group than in the control group (odds ratio, 5.139; 95% confidence interval, 1.386-18.41). As demonstrated by this retrospective research, waterjet debridement reduced the bacterial load in the diabetic lower extremity contaminated wounds.
Keywords
Introduction
With the improved survival of patients with diabetes as well as the development of advanced treatment methods, there have been more and more patients with diabetic lower extremity ulcers. 1 Infections in lower extremity wound in patients with diabetes are a main cause of morbidity, including discomfort, and reduced physical and mental quality of life. 2 More than half of diabetic lower extremity ulcers are clinically infected at presentation, 3 and these infections are particularly associated with poor prognosis. 4 Ince et al 5 and Wu et al 6 found that, on average, 20% of patients with diabetic lower extremity contaminated wounds underwent at least partial amputation and 10% died in 12 months. Thus, early control of infection is crucial for patients with diabetic lower extremity contaminated wounds.
Debridement has been considered as a fundamental step in the management of all cutaneous wounds of different etiology, it enhances wound healing and improves the efficacy of advanced therapies and surgical closure. Nowadays, medical institutions are becoming more knowledgeable about the essential role of debridement in achieving a wound with good healing potential. Debridement has become the focus of surgical wound care, especially in contaminated or infected diabetic lower extremity wound.
Sharp excision with steel scalpel was once the only option for debridement. 7 In the latest 20 years, a waterjet wound debridement was introduced to provide a more accurate wound debridement and has proven to be an effective alternative to the traditional approach. 8 Waterjet can safely accomplish debridement with sufficient tissue selectivity and eclecticism. 9 This new device can remove necrosis, unhealthy tissue, and foreign matter while preserving normal tissue like tendons.
Critical to debridement is the clearance of bacteria. However, data on the bacteria removal of waterjet in diabetic lower extremity contaminated wounds is scarce. This study aimed to evaluate the high-power waterjet (Versajet™, Smith-Nephew) in the bacteria reduction or eradication of the diabetic lower extremity contaminated wounds.
Materials and Methods
A retrospective cohort study was conducted at our institution. Patients’ etiology and pathogen diagnosis were established as diabetic lower extremity contaminated wound (ICD-9 code: E14.500). Information including demographics, wound characteristics, blood glucose level, and details of treatment methods was obtained from the hospital information system of our institution.
This study set up the treatment group and control group. The treatment group included patients who had an excisional debridement of their wounds with Versajet in 2019. The procedure of Versajet debridement was performed as previously described. 10 A control group consisted of patients whose wound was debrided by conventional methods consisted of scalpel and curette in 2018. All patients were treated in the department of plastic surgery. Patients with any of the following were excluded from the study: missing characteristics details, refused to disclose information, lacking bacteriological evidence, multiple ulcers, needing amputation, suspected postoperative nosocomial infection, and history of any other surgical debridement before presented in our hospital. The inclusion and exclusion criteria are presented in Figure 1.
Flow chart of the selection of study participants. Of 184 patients assessed for eligibility, 74 were identified according to the inclusion and exclusion criteria, 40 were in the treatment group, and 34 were in the control group.
The microbiological department of our hospital expressed results of bacterial culture in a qualitative way from 1+ to 3+. The plain cottonwood swab was used for bacteriological sampling. The bacteriological swab samples were collected before and after the debridement. Preoperatively, we collected swab samples 3 times from 1 same wound, and the result that was used to analyze was the maximum score of all 3 results. Postoperative bacteriological swab samples were collected 3, 4, 5 days separately after the debridement and the highest score was documented.
The primary outcome was the success rate of bacterial clearance of diabetic lower extremity contaminated wounds. The bacterial clearance was defined as a decrease of postoperative bacteria score compared to preoperative, according to the qualitative result of bacterial culture. Secondary outcomes were the distribution of microorganisms in the entire cohort and in each subgroup, and debridement related adverse events.
This study was approved by the institutional review board. All patients provided informed written consent. Informed consent was not obtained as this was a retrospective cohort study.
Statistical Analysis
Descriptive statistics were used for continuous data. The assumption of normal distribution of continuous variables was tested by the Shapiro–Wilk test. If variables were normally distributed, the central tendency was expressed as the mean ± standard deviation.
Means were compared by Student’s t-test or 1-way ANOVA depending on the situation. Nonparametric statistics (Mann–Whitney U-test/Wilcoxon signed-rank test; Kruskal–Wallis equality-of-populations rank test among grades) were used to analyze the nonnormally distributed continuous variables.
Categorical data are expressed as the count and percentages or ratios. Categorical data were analyzed by the χ2 or Fisher exact test. If P < .05, the difference is significant. Statistical analysis was performed using Statistical Package for Social Sciences software (SPSS version 20.0, IBM Corp.).
Results
Patients
Of 184 patients assessed for eligibility, 74 were identified according to the inclusion and exclusion criteria, 40 were in the treatment group, and 34 were in the control group (Figure 1). Patient samples matched well in terms of age, gender, body-mass index (BMI), fasting blood glucose level, wound area, smoking, alcoholism, and anesthesia. Patients who received waterjet treatment had a mean age of 68.55 years, and 55% were female. Patients who received conventional surgical debridement had a mean age of 66.62 years, and 47.06% were female. The mean BMI was 24.37 in the treatment group and 24.51 in the control group. The mean fasting blood glucose level was 7.158 mmol/L in the treatment group and 7.071 in the control group. The mean wound area was 52.8cm2 in the treatment group and 55.82 cm2 in the control group. The characteristics of treatment and control groups are listed in Table 1.
Demographic and Clinical Characteristics of the Patients at Baseline. All Results are Means ± Standard Deviation, Except Where Indicated.
Primary Outcome
There was no significant difference in the culture result of preoperative bacteriological swab samples between 2 groups with P = .1022. In the culture results of postoperative swab samples, the treatment group results were significantly lower than control with a P value of .0099. In the treatment group, there were 30 patients with negative results and 10 patients with 1+. In the control group, there were 16 patients with negative results, 13 patients with 1+, and 5 with 2+. The bacteriological results were listed in Table 2. We then analyzed the bacterial clearance effectiveness of the waterjet debridement, 92.5% of patients showed a decrease in bacterial load in the treatment group, as compared with 70.59% of patients in control group. The bacterial clearance rate was higher in the treatment group (P = .0167). The odds of bacterial clearance treated with waterjet were greater in the treatment group than in the control group (odds ratio, 5.139; 95% confidence interval, 1.386-18.41) (Supplemental Table s1).
The Bacterial Load in Diabetic Lower Extremity Contaminated Wounds.
Secondary Outcome
The presented bacteria in 74 patients were Staphylococcus aureus (24 patients), Pseudomonas aeruginosa (21 patients), Proteus mirabilis (15 patients), Corynebacterium (7 patients), Escherichia coli (4 patients), and Klebsiella pneumoniae (3 patients). The bacterial distribution in 2 groups was: 12 S aureus in treatment and control group, respectively; 11 P aeruginosa in the treatment group and 10 in the control group; 7 P mirabilis in the treatment group and 8 in the control group; 5 Corynebacterium in the treatment group and 2 in the control group; 1 K pneumoniae in the treatment group and 2 in the control group. Four E coli results only presented in the treatment group. The proportion and distribution of above bacteria were shown in Figures 2 and 3.
Pie chart of proportion for each bacterium. The presented bacteria in 74 patients were Staphylococcus aureus (33%), Pseudomonas aeruginosa (28%), Proteus mirabilis (20%), Corynebacterium (10%), Escherichia coli (5%), and Klebsiella pneumoniae (4%).
Histogram representing the number of each bacterium for each group.
Versajet™ is a high-power water jet. It utilizes a reusable power console with foot pedal activation, disposable handpiece, and tubing assembly in conjunction with saline and standard waste receptacle. A stream of saline is pumped into the handpiece through the feed hose, where it is forced into the nozzle and ejected through a tiny hole. 11 The saline is forced out under high pressure, and it creates water steam with very high power. The high-power steam has the capability of cutting through tissue including dense fascia, but not bone or tendon (Figure 4 and Supplemental Material 1). We did not observe waterjet-related adverse events.
Example of the waterjet debridement in the treatment of diabetic lower extremity contaminated wounds. (A) Sixty-four-year-old woman was diagnosed as diabetic lower extremity contaminated wounds in her dorsum of the foot covered with eschar. (B) The Versajet™ removed the eschar along with the fibrinous debris and granulation tissue. (C) We got a pristine wound bed immediately after the waterjet debridement.
Discussions
In the present study, bacterial clearance of diabetic lower extremity contaminated wounds treated by waterjet and surgical methods was analyzed. Greater bacterial clearance and higher bacterial clearance rate were observed in waterjet treated group. Another observation, which was not evaluated in our data, was that Versajet™ was very fast and easy to use. Any surgeon who is good at debridement can quickly master Versajet™. In our institution, it has been widely used in a variety of cases requiring debridement, including chronic wound necrosis, fibrous debris, fasciitis, and a variety of acute wounds with necrosis or debris. Waterjet debridement was also patient friendly. We did not observe waterjet-related adverse events. Pain associated with the waterjet was mild.
Arterial, venous, and diabetic ulcers are often referred to as lower extremity wounds. Managing these contaminated wounds can be difficult, exacting a costly toll on the patients’ health. Of all lower limb ulcers, diabetic foot ulcers are the most susceptible to infection, more than half of them involve clinical infections when patients present to health care practitioners. 12 When considering various types of diabetic lower extremity wound, infection wound had poorer outcomes than others. 13 Therefore, the latest guideline emphasized the management of infected diabetic foot ulcer. 14 Waterjet has been a widely used method for contaminated wound debridement. 15 and it has shown its superiority especially in infected wounds. However, previous large cohort studies tended not to recruit diabetes patients with infected wound. 16 Therefore, the efficiency of waterjet in removing infection in diabetic lower extremity contaminated wounds has not been well studied. This study met this gap.
We designed a cohort study because this type of study especially appropriates to research exposures for which randomization is not possible for ethical reasons. 17 Currently, in clinical practice, waterjet debridement is a fundamental step in the management of chronic and contaminated wounds. There is a lack of ethical support for artificially determining which patients do not receive this fundamental treatment they deserve, even if we use a randomized method. Our institution was equipped with Versajet™ in 2019. Therefore, before 2019, the traditional debridement has been adopted. This results in a natural grouping, which makes it possible for us to design a cohort research.
This study also has limitations. A cohort study is the best way to identify the incidence and natural history of a disease and can be used to examine multiple outcomes after a single exposure. However, in this type of study, the control group (unexposed) rarely achieves the similarity in all important respects to the exposed. 18 In our study, we analyzed characteristics in terms of age, gender, BMI, blood glucose level, and wound area. Statistically, they matched well. However, we observed differences in bacterial species between groups. E coli only presented in the treatment group. The impact of this difference on our result was unknown. Recognition of infection in lower extremity wound is essential, however, it can be difficult. Swab cultures often do not represent the causative pathogenic organisms since bacteria often colonize chronic wounds. 19 Although cultural results are sometimes negative, patients with chronic, extensive, or severe diabetic foot infections often have polymicrobial infections. 20 In our clinical practice, we performed bacterial biopsy in some patients interoperatively, and we are working on the data.
Thirty-five years ago, diabetic foot ulcer was the “Cinderella” of diabetic complications, there was little evidence-based research taking place on the diabetic foot, let alone the management of diabetic foot infection. Now, the number of articles on diabetic foot published in high-impact journals has increased exponentially and there is a comprehensive evidence base for many areas of diagnosis and treatment. Although conventional diagnostic methods such as swabs, culture, and biopsies have been widely used, new molecular techniques have been exploring the identification and quantification of bacteria. Understanding the microbial etiology of diabetic low extremity wound infection and antibiotic resistance is also very important for the effective treatment and treatment of these infected wounds. 21 Without the treatment of infection, any known treatment will not be effective. 22 Although waterjet is safe and effective, there is still room for improvement in diabetic lower extremity contaminated wounds outcomes. We still believe that education initiatives and early prevention strategies through outpatient multidisciplinary care targeted at high-risk populations are essential to preventing further increases in diabetic advent events. 23
Conclusions
Waterjet debridement had a high bacterial clearance rate in diabetic lower extremity contaminated wounds.
Supplemental Material
sj-docx-1-ijl-10.1177_15347346211024204 - Supplemental material for Waterjet in Bacterial Clearance of Diabetic Lower Extremity Contaminated Wounds: A Retrospective Cohort Study
Supplemental material, sj-docx-1-ijl-10.1177_15347346211024204 for Waterjet in Bacterial Clearance of Diabetic Lower Extremity Contaminated Wounds: A Retrospective Cohort Study by Jiaqi Liu, Yining Ge, Qiang Wang, Leqi Qian, Yuyan Pan, Shaoluan Zheng and Yuedong Shi in The International Journal of Lower Extremity Wounds
Supplemental Material
sj-mov-2-ijl-10.1177_15347346211024204 - Supplemental material for Waterjet in Bacterial Clearance of Diabetic Lower Extremity Contaminated Wounds: A Retrospective Cohort Study
Supplemental material, sj-mov-2-ijl-10.1177_15347346211024204 for Waterjet in Bacterial Clearance of Diabetic Lower Extremity Contaminated Wounds: A Retrospective Cohort Study by Jiaqi Liu, Yining Ge, Qiang Wang, Leqi Qian, Yuyan Pan, Shaoluan Zheng and Yuedong Shi in The International Journal of Lower Extremity Wounds
Footnotes
Author Contributions
JL, YG, QW, LQ, YP, SZ and YS designed research, performed research, analyzed data, and wrote the paper.
Declaration of Conflicting Interests
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the Xiamen Municipal Bureau of Science and Technology (grant numbers 3502Z20209042, and by the National Natural Science Foundation of China (grant number 81802724).
Ethical Approval
This study adhered to the guidelines set of the declaration of Helsinki and was approved by the Institutional Review Board.
Supplemental Material
Supplemental material for this article is available online.
References
Supplementary Material
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