The Debridement of Chronic Leg Ulcers by Means of a New, Fluidjet-Based Device

Wound healing, a complex process, can be divided schematically into 4 phases in acute wounds, including hemostasis, inflammation, proliferation, and remodeling.¹ In chronic, hard-to-heal wounds, the healing process is disrupted by several general and local causes (eg, tissue senescence, infection, underlying vascular disease, hypoxia, anemia, diabetes and other metabolic disorders, drugs),^2–7 and the wound can remain in the inflammatory phase.^8–13 When this occurs, the wound will be characterized by necrotic tissue or fibrin slough with tissue loss, tendon or bone exposure, and contaminants. The wound may also be infected and undermined. In wounds at this stage, debridement is mandatory to promote resumption of the healing process¹⁴ and can be achieved through several methods: autolytic, osmotic, enzymatic, biological, mechanical, and surgical debridement.^15–25
The authors report their experience with a new hydrosurgery device used for debridement of exudating ulcers.

Material and Methods

The hydrosurgery device (Versajet™ Hydrosurgery System, Smith & Nephew, Hull, UK) is based on fluidjet technology: incompressible fluids (usually water), when forced through a tiny orifice under high pressure, form jets that demonstrate remarkable abilities to cut materials.
The thin waterjet (0.1 mm) of the hydrosurgery device runs at high pressure and velocity (103–827 bar and 426–1078 km) through a suitable hose to the tip of a procedure-specific hand piece where the “operating window” is placed between a jet nozzle and a “collector” that is 8 mm or 14 mm in length (Figure 1); crossing the operating window, the waterjet runs parallel to its axis and is eventually collected by a “collector” device while concomitantly creating a vacuum at the point of capture.
By means of the Venturi effect, the waterjet can hold, cut, and remove the damaged tissue and the contaminants centered in the operating window and intake them at the collection point (Figure 2). This operating method allows good visibility, prevents vaporization, and eliminates the risk of the operators inhaling contaminated particles.
Hand piece orientation determines the effect the waterjet will have on tissue: irrigation and tissue removal are obtained with the operating window positioned obliquely, whereas controlled, precise excision can be achieved when the operating window is positioned parallel to the tissue. The excising effect of the waterjet can be further regulated by the surgeon by adjusting its pressure and velocity (10 power settings): as the waterjet speed increases, the excising effect on the unwanted tissue increases, so it is possible to excise hard, necrotic tissue, tendons, and bone (Figures 3–5).
From November 2003 to May 2005, the authors treated 142 patients (47 men and 95 women; mean age 71.3 ± 12.7 years; range 29–91 years; 245 ulcers) with the hydrosurgery device out of 469 patients who were hospitalized with hard-to-heal vascular leg ulcers in the inflammatory stage of healing and were candidates for skin grafting. The patients underwent hydrosurgical debridement after meeting the following criteria: 1) ≥ 70% of the ulcer surface was covered by necrotic tissue or thick fibrin slough with or without abundant and/or malodorous exudate and/or greenish material; 2) presence of hypertrophic granulation tissue; 3) exposed tendon or bone.
The remaining 327 patients (105 men and 222 women; mean age 70.8 ± 15 years; range 22–91 years; 532 ulcers) were treated with moist dressings (ie, hydrogel and hydrocolloid dressings) and comprised the control group.
The etiologies of the ulcers, patient characteristics, baseline demographics, and ulcer data are listed in Table 1.
In the hydrosurgery device-treated group, 5 patients were on anticoagulant treatment, while 16 patients in the control group were on anticoagulant treatment.
The mean baseline surface was 192 ± 188.6 cm² (range 6–1000 cm²) for ulcers in the treatment group and 140.4 ± 194.6 cm² (range 1–800 cm²) for ulcers in the control group.
The mean duration was 54.6 ± 95.8 months (range 1–480 months) for ulcers in the treatment group and 35.9 ± 79.3 months (range 4–444 months) for ulcers in the control group.
After being fully informed about the risks and benefits associated with the procedure, each patient signed a consent form.
Patients in whom sharp debridement was considered for large, painful ulcers were moved to the surgical theater and administered general, short-term, intravenous anesthesia. Whenever possible, according to patient and ulcer conditions, the procedure was performed in the ward. Depending on the level of pain, local anesthesia (lidocaine/prilocaine ointment or xilocaine infiltration) was administered.
In wounds with necrotic tissue or fibrin slough firmly adhered to the ulcer bed, gentle debridement with the hydrosurgery device was performed daily or every other day, and moist dressings were used concurrently to soften the necrotic tissue and ease the hydrosurgery procedure.
In 53 patients with clinical signs of infection, the wound bacterial burden was measured before and after the hydrosurgery procedure with quantitative swab culture by firmly twirling the end of a sterile cotton-tipped applicator on a 1-cm² area of the wound for 5 seconds.^26,27
At discharge, each patient completed a satisfaction form that resulted in scores ranging from 1 to 3; the goal of the department was to exceed 2.7.
The authors studied 4 aspects of treatment with the hydrosurgery device: 1) time to complete debridement; 2) effect on bacterial burden; 3) procedure-related pain measured with the Visual Analogue Scale (VAS); and 4) bleeding complications.
Patients were followed until wound closure, although this was not a study goal.
The effects of the 2 debriding methods on exudate composition were compared in a small number of patients (3) that had large, bilateral ulcers. One patient had an ulcer debrided with the hydrosurgical device, while another was treated with moist dressings (hydrogel and hydrocolloid dressings). Before treatment and at 24 and 48 hours after treatment, 2 mL of exudate were collected, and the levels of IL-1b, IL-6, TNF-α, ICAM-1, VCAM-1, MMP-9, IL-10 were measured.

Results

In the majority of hydrosurgery device-treated patients (108), 1 operative procedure (Figures 2–5) was sufficient to achieve an adequately debrided wound bed, while 2 procedures were required in 27 cases and 3 procedures in 7. When several treatments were required, they were performed daily or every other day.
Each hydrosurgical procedure lasted a mean 5.9 ± 3.6 minutes (range 2–20 minutes). The average time to obtain a clean wound bed in the hydrosurgery device-treated patients was 1.3 ± 0.6 days, compared to the 4.3 ± 3.9 days observed with traditional moist dressings. Hospitalization time was reduced accordingly.
The bacterial burden decreased from 106 (range 25,000 to 10,000,000) to 103 (range 0 in 28 patients [52.8%] to 30,000) CFU/cm². Several strains of bacteria were isolated including Pseudomonas aeruginosa, Pseudomonas putida, Staphylococcus aureus, Staphylococcus epidermidis, Group D Streptococcus, Streptococcus faecalis, Escherichia coli, Serratia marcescens, and Proteus mirabilis. None of these was resistant to hydrosurgery device therapy.
The pain caused by the hydrosurgery device was acceptable; many patients did not need anesthesia, because the power level can be adjusted according to the patient’s tolerance. Some form of anesthesia was given to patients with painful ulcers: a local lidocaine-prilocaine ointment was used in 43 patients; a local anesthetic xilocaine infiltration in 14; and general, intravenous, short-term anesthesia was given in the surgical theater to 19 patients with large, painful ulcers.
The physician rated the pain level induced by the hydrosurgical debridement using the VAS in all patients (123) who did not receive general anesthesia. The mean VAS score was 4.3 ± 1.9. Of the total number of patients, 108 patients (87.8%) found the pain level with the hydrosurgical debridement comparable to that induced by cleansing with gauze and saline solution. Also, it is necessary to add that no anesthesia was given before cleansing with gauze and saline solution. In only 15 patients (10.5%), 6 of whom received local anesthesia, the procedure was considered painful (VAS score ≥ 7).
In the control group, the pain induced by the dressing change and ulcer cleansing, rated by the staff (physician or nurse) using the VAS, was 5.3 ± 2.1. None of the patients in the control group received any general or local anesthesia.
Minor bleeding of the ulcer bed stopped spontaneously, even in patients on anticoagulant therapy. Hemostasis was achieved by wrapping the affected limb with an elastic bandage. In 2 patients, the authors performed a sharp debridement in the surgical theater and cut a small vessel. For these patients, electrocautery was used to achieve hemostasis.
The healing rate was 82% in the hydrosurgery group compared to 88% in the control group.
The patient satisfaction score was 2.8 ± 0.1 in both groups.
Few adverse effects were noted: in 2 cases, 1 patient affected by critical limb ischemia and the other by diabetic microangiopathy, new necrosis of the ulcer edges and bed was noticed the day after a sharp debridement (considered adequate) with the hydrosurgery device set at maximum power. These patients were excluded from further hydrosurgical debridement and treated with moist dressings; they achieved a well prepared ulcer bed in 4 and 7 days, respectively.
In 3 patients, the exudate composition changed with both debriding methods, but in the hydrosurgery device-treated ulcers, TNF-α increased by 59%, IL-10 had a 15-fold increase, and ICAM-1 and VCAM-1 showed a slight increase. In the control group, TNF-α increased by 16%, IL-10 decreased up to 1/3, and ICAM-1 and VCAM-1 decreased dramatically. The other mediators were not modified by either debriding method.

Discussion and Conclusions

The hydrosurgery device seems to be a valuable device for debridement of ulcers that remain in the inflammatory stage. In the authors’ experience, the device can be used in 2 basic ways: for “gentle” debridement in the ward as an alternative or adjunct to other kinds of debridement and, at high settings, as an alternative to surgical debridement.
Debridement is selective with proper use of the hydrosurgery device. Healthy tissue will be spared, because only the tissue centered in the operating window is debrided. The treated ulcer bed remains clean, even if minor bleeding occurs, because the suction effect at the collection point removes excised tissue, debris, and contaminants. It often achieves an adequately clean bed in a single debridement step and leaves a smooth surface that is prepared to receive a skin graft.
Minor bleeding caused by the hydrosurgery device stops spontaneously; this may be facilitated by the application of an elastic bandage to the affected limb. In rare cases, a hemostatic procedure may be required. This minor bleeding requires a 1-day postponement of graft application in order to obtain complete coagulation and a better graft take. Anticoagulant treatment does not influence bleeding and appears to be only procedure related.
The hydrosurgery device dramatically reduces bacterial burden; hence, its application in infected ulcers is justified.
Although the device is powerful, with the recommended pump speed (less than 5), most patients generally tolerate the associated pain well; however, more extensive use of anesthetic procedures (local ointment or infiltration) is necessary in order to further minimize pain. Patients with large, necrotic, and painful ulcers were moved to the surgical theater for the administration of general anesthesia to prevent intolerable pain.
Pain is a major issue with every debriding procedure, even when cleansing an ulcer with gauze and saline solution. Similar pain levels were reported for the hydrosurgery device and debridement with gauze/saline solution and dressing change (in most of the patients in the control group), even though 46% of the hydrosurgery device-treated patients were given local anesthesia. Considering the “global exposure” to pain, inducing a quick debridement with the hydrosurgery device helps decrease the cumulative pain level by reducing the number of required procedures in comparison to the longer debridement time necessary with moist dressings.
When performing a debriding procedure, effectiveness must be combined with selectivity. After the patient has received general anesthesia, the hydrosurgery device can sharply debride hard, necrotic tissue and/or fibrin slough firmly adhered to the ulcer bed in a single procedure; however, healthy tissue may be wasted as well. Therefore, when possible, daily, gentler treatments with the hydrosurgery device should be performed and moist dressings used concurrently, thus preparing the wound for the next debridement session.
A synergistic effect results from the combined use of the hydrosurgery device and moist dressings. The moist dressing acts lytically to soften necrotic tissue, facilitating more thorough hydrosurgical debridement, during which the softened necrotic tissue is mechanically removed by the device.
These characteristics permit adequate debridement that is limited to the superficial, necrotic layer of the ulcer bed and spare the healthy tissue as much as possible (Figures 6 and 7).
Particular care is necessary when debriding ischemic ulcers. In these cases, when removing necrotic tissue with the hydrosurgery device set at a high setting, it can induce new necrosis at the ulcer edges or bed. Debriding these ulcers with the device set at a lower power setting—and, in the case of inadequate debridement, continuing with multiple treatments—is preferable.
Based on experience with the hydrosurgery device, the authors can compare the device to other debridement types:
• Use of gauze and saline solution, during which the wound bed is mechanically rinsed, firmly wiped, and scrubbed, is more painful and less effective than debridement with the hyrdosurgery device
• The hydrosurgery device allows for more effective and less time-consuming debridement than with moist dressings; decreasing the debridement time in turn considerably shortens the in-hospital stay compared to moist dressings
• Compared to surgical debridement with a scalpel, the hydrosurgery device displays several advantages: the physician can use the device in the ward; use of the hydrosurgery device results in less aggressive and more selective debridement, sparing healthy tissue; deeper microbial contamination of the wound is prevented; and less pain and only minor bleeding are induced. The resulting surface is less irregular, smooth, and ready for skin grafting or another suitable dressings.
When considered in the framework of the T.I.M.E. approach to wound healing,²⁸ the hydrosurgical device favorably impacts all the components:
• Tissue: necrotic tissue and fibrin slough are completely removed
• Infection: bacterial load is dramatically reduced
• Moisture: although limited in size, the presently described assessments point out a dramatic change in exudate composition after hydrosurgical debridement: the dramatic increase in TNF-α and of IL-10 may suggest that the procedure transforms a chronic wound into an acute wound and re-initiates the healing process; a more consistent number of cases will be necessary to confirm this observation
• Edge: the procedure has a definite effect on ulcer edge advancement.
As previously mentioned, to evaluate the effectiveness of the hydrosurgery device, the authors did not consider the healing rate as an endpoint, because the device was designed to perform a quick, safe, and complete ulcer debridement. Furthermore, the 2 groups differed at baseline in important characteristics that influence wound healing. The hydrosurgery device was chosen in the presence of extensive necrosis, hypertrophic granulation tissue, and tendon or bone exposure. The ulcer surface and duration were greater at the beginning in the hydrosurgery device group. Nevertheless, the observed healing rates were similar (82% for the hydrosurgery device group and 88% for the control group).
A major drawback of debridement with the hydrosurgery device is the high cost of the unit and the disposable hand piece, especially if one would like to extend its use as an alternative or complementary procedure to moist dressings. On the other hand, one can consider that the device promotes a quicker ulcer debridement and shortens time to healing and hospitalization (by a mean of 3 days), thus allowing a global cost saving in wound management.
The authors recommend the hydrosurgery device for debridement of chronic ulcers.