Clinical and Economic Impact of Hydrosurgical Debridement on Chronic Wounds

Chronic wounds affect many people, causing morbidity, interference with quality of life, hardship for the patient, and economic strain on the healthcare system. In order for chronic wounds to be treated effectively, several conditions must be met. An appropriate diagnosis is critical because treatment of the underlying or associated pathology is important in resolving these ulcers.^1,2 Once these basic issues are addressed, the direct management of the ulcer requires a process of wound bed preparation. The concept of wound bed preparation evolved as a means of codifying the process of converting a chronic wound into a wound with the potential to heal. The acronym “TIME” describes this process:³ “T” refers to the need to remove necrotic and diseased tissue; “I” indicates the need to control bacterial burden and infection; “M” refers to restoration of moisture balance; “E” stands for the healing edge, which essentially means the point at which the wound is optimally primed for healing. Surgical debridement is a technique for rapidly accomplishing the “TIM” components of wound bed preparation. The US Food and Drug Administration (FDA) has approved a new surgical instrument (Versajet™ Hydrosurgery System, Smith & Nephew, Hull, UK) that utilizes a high-powered parallel waterjet for wound debridement. This study assesses the clinical and economic impact of this new technology when used to debride chronic wounds in an operating room.

Methods

This retrospective study was conducted at University Hospital (Newark, NJ). Hospital medical records were searched for ICD-9-CM code 86.22 (excisional debridement of wound, infection, or burn) during the calendar years 2002 and 2003. In 2003, 20 patients with chronic wounds present for more than 6 weeks underwent operative debridement using the waterjet as documented in the operative note. In 2002, prior to the introduction of the waterjet, 14 patients with similar wounds underwent operative debridement using a standard surgical technique. Data were collected for demographics (age, gender), wound characteristics (decubitus, venous, other source, wound description), and surgical details (number of debridements, time per procedure). The costs of surgical debridement were estimated from individual billing records at University Hospital. These figures were used to estimate differences in treatment costs between patients debrided with the waterjet and patients debrided by conventional means. Since this is a retrospective (relatively uncontrolled) study, there are limitations to the interpretability of the data. This study was Institutional Review Board approved as protocol M-099-2004.

Results

All patients had debridements performed under anesthesia in an operating room. Patient demographics are summarized in Table 1. The waterjet-treated group was comprised of 55% men with a mean age of 46. The control group was comprised of 57% women with a mean age of 54. The ulcer types included a mix of decubitus ulcers, venous ulcers, and other chronic ulcerations primarily from traumatic and post-surgical wounds.
The surgical details are presented in Table 2. There was no statistically significant difference in the time of debridement between the 2 treatment groups (P = 0.522, Wilcoxon rank sum test). However, a statistical difference was noted between the number of debridements required to adequately prepare the wound bed for closure or secondary healing. Control wounds required a median of 2 procedures, while the waterjet-treated wounds required a median of 1 procedure (P < 0.001, Wilcoxon rank sum test). The mean cost of a surgical debridement at University Hospital was $3,393. On this basis, the expected cost of debridement was $6,700 per patient with conventional techniques (mean of 2 procedures per patient) compared with $3,900 with the waterjet (mean of 1.14 procedures).
No health and safety issues (eg, sharps injuries, splash-back contamination) were reported with the use of the waterjet during the study period.

Discussion

The high-powered parallel waterjet is a FDA-approved medical device with the ability to focus a high-powered stream of water into a high-energy cutting implement. Waterjets have been used in industry to cut soft materials, such as textiles, and for precision cutting of high-density metals. Waterjets have been used in surgery for decades.⁴ The pulse irrigator is an example of a low-energy waterjet that operates at approximately 40 psi. The high-powered parallel waterjet, however, is an entirely different device that was introduced in 2003. The saline used in the waterjet is enclosed in a sterile circuit that passes though a small but highly powerful pump. The saline is directed through high-pressure tubing into a hand piece where it is directed into a 180-degree turn and forced through a nozzle 0.005” in diameter.⁵ The energized saline emerges in a focused beam of up to 15,000 psi. The stream of saline is collected passively through an opposing eductor port. Due to the Venturi effect, all wound debris impacted and ablated by the saline beam is evacuated along with the saline, leaving a pristine wound. The saline beam is directed parallel to the wound so that the cutting mechanism is a highly controlled form of tangential excision. This cutting action provides the surgeon control over the wound surface. Consequently, all of the necrotic tissue, fibrinous debris, and granulation tissue can be removed with no injury to the healthy underlying collateral tissue.^6–8 Surgeons can perform more aggressive wound debridement while simultaneously removing less surrounding tissue (Figures 1 and 2). The need for significantly fewer waterjet debridements to adequately prepare wounds results in improved wound management and improved patient outcomes. In the scheme of the “TIME” sequence, waterjet debridement quickly moves the wound through the “TIM” phase to the point at which the healing edge (“E”) can be managed with definitive topical or surgical care.
Wound debridement removes necrotic tissue, lessens bioburden, and stimulates the healing cascade. Options for debridement include mechanical, enzymatic, autolytic, biologic, and surgical. Mechanical debridement involves the removal of necrotic tissue by pulling it off (eg, a wet-to-dry dressing) and necessarily damages underlying healthy tissues. Enzymatic debridement with papain-urea or collagenase topical agents is slow, labor intensive, and of limited efficacy in heavily necrotic wounds.⁹ Autolytic debridement is similarly slow and uncontrolled with enhanced risk of infection.⁹ The use of biologic agents, such as maggots, is effective but distasteful to many patients and staff.⁹ Surgery remains the gold standard for wound debridement. Tangential debridement with the waterjet hydrosurgery system adds considerable control and precision to this process.
While the device is an example of highly sophisticated engineering, it is relatively simple to use and easy to master. The waterjet is useful in a wide variety of applications but tends to be most effective in wounds with necrosis, fibrinous debris, or granulation tissue. In its current form, the device does not effectively debride desiccated eschar. In pressure ulcers covered with dry eschar, the preferred approach is to sharply remove the eschar and then use the waterjet to debride the underlying necrotic tissue. This approach to chronic wounds has changed the authors’ debridement paradigm. In the past, the authors usually preferred a wide excision technique to assure that all of the necrosis was removed. This technique is typically bloody, time consuming, and necessarily removes a considerable quantity of adjacent healthy tissue. Using standard surgical techniques, multiple debridements were often necessary to rid the wound of all necrotic debris while minimizing damage to collateral tissue. In some cases, particularly in vasculopathic patients, leaving some necrotic tissue behind led to progressive necrosis, whereas aggressive debridement could expose bone, tendon, or joints. In these settings, the hydrosurgical approach permitted precise tangential removal of all necrosis while preserving tenuous viable tissue, such as paratenon or periosteum. The hydrosurgery system allows the surgeon to work from inside the wound rather than from the outside. Usually, the wound can be precisely debrided of all unwanted tissue in a single operative sitting. This facilitates a more rapid time to surgical closure or the application of effective topical therapy.
While the use of the waterjet involves the added cost of the hand piece, other surgical equipment (eg, pulse irrigator, saline, large surgical trays) can be eliminated. The major economic impact of the hydrosurgical technique parallels the improved patient outcomes. In this study, patient outcomes improved, and the hospital decreased expenditure for patient care by reducing the number of operative procedures required to prepare the wound bed. The hospital saved approximately $2,800 per patient.

Conclusion

The introduction of the waterjet hydrosurgery system in 2003 has led to a paradigm shift in the surgical management of chronic wounds. Wound beds are prepared faster and with more precision resulting in less damage to healthy tissue. Patients require less surgery, and the hospital has realized a significant cost saving associated with improved patient outcomes.