Life Can’t Be Any Easier than This—Introduction of the Portable and Disposable V.A.C. Machines ()
1. Introduction
The method of using sub-atmospheric pressure for a prolonged period of time on a wound to promote debridement and wound healing was first documented by Fleischmann et al. in 1993 [1]. This topical negative pressure therapy (TNPT) dressing can be used in the treatment of many types of soft tissue wounds. This includes degloving injuries [2,3], donor sites, chronic radiation ulcers [4], infected sternotomy wounds [5,6] and various soft tissue injuries prior to surgical closure, grafting or reconstructtive surgery. The use of vacuum therapy has also been described in patients with compartment syndromes of the lower limb [7] and in patients with acute and chronic infections of various types [8] and in non-healing or chronic wounds like pressure sores has also been published. [9,10].
Smith et al. [11], in a retrospective review, described the use of vacuum pack technique as the treatment method of choice for open abdomen management and temporary abdominal closure. TNPT has also been used following split thickness skin grafting in the treatment of burns and is claimed to be particularly useful for body sites with irregular or deep contours such as the perineum, hand or axilla [12,13] as it increases graft bed contact by reduceing the chance of fluid accumulation under the graft and effectively splints the graft.
Microbiological studies showed that, compared with control values, tissue bacterial counts of vacuum-treated wounds decreased significantly after four days [14]. The optimum level of negative pressure for wound healing is thought to be around 125 mmHg below ambient and a continuous pressure is proved to be the most effective for splinting or bolstering grafts in place.
2. How the Portable, Disposable V.A.C. Machine (V.A.C. Via) Works
Disposable V.A.C. Via™ System (also called vacuum therapy, vacuum assisted closure, vacuum sealing or topical negative pressure therapy) is a sophisticated and modern development of a standard surgical technique.
A portable and disposable V.A.C. therapy system provides simplicity, mobility, and convenience like never before. The technique used in setting up the dressing and V.A.C. Via™ is very simple. The wound is covered in all directions with an air tight seal and then connected to a vacuum in a light weight disposable machine via a tube through which all fluid and air is sucked out in to a container. The machine comes with foam and transparent adhesive dressings (Figure 1).
The entire wound area is covered with the foam and then a transparent adhesive membrane is firmly secured on the top of the wound area and to the healthy skin around the wound margin ensuring air seal. Then a hole is created in the film and a self adhesive drain is attached over the hole. The drain tube is then connected to the vacuum source, where the fluid and debris from the wound is drawn out through the foam into a reservoir for subsequent disposal.
3. Clinical Experience with Disposable V.A.C. Machine
We used the disposable V.A.C. Via™ in 52 yrs of age gentleman, who presented with a pretibial abscess on the right lower leg. He underwent debridement twice under general anaesthetic and following debridement, the resulting wound measured the size of 5 cm by 4 cm as shown in Figure 2.
The wound was covered with split skin graft and to secure the graft, staples were used as shown in Figure 3.
Mepitel was applied on the graft, and then covered with foam with the disposable V.A.C. Via™ as shown in Figure 4.
The patient was discharged home the same day and followed up in the dressing clinic one week later. V.A.C.
dressing was removed and graft was 100% taken. (Figure 5(a) & 5(b))
Figure 3. Split skin graft on the wound.
Figure 4. V.A.C. Via™ system applied on the lower leg wound.
(a)(b)
Figure 5. (a) and (b)—Post op pictures with taken grafts.
Patient didn’t find it difficult to cope with the dressing and the machine as thorough post op instructions were given to the patient. This type of portable and disposable dressing has proved to be a very effective treatment modality for a variety of wounds because of its simplicity, mobility, ease and availability as whenever one is needed; all the equipment is present in a single box stored in theatre.
4. Cost Effectiveness of the Disposable V.A.C. Machines
The cost of the traditional TNPT therapy is not insignificant. In addition to the purchase cost (£15,000) or hire charges (£26/day) of the machine itself, it is necessary to purchase disposable foam dressings and drainage tubes (small simplace granufoam dressing kit costs £23.40), canisters (£28.35) and adhesive drapes. Secondly, it is often necessary to keep the patient in the hospital until community V.A.C. is organized. Each bed in the hospital costs almost £450 per day.
With the introduction of the disposable V.A.C. machines (V.A.C. Via™), this cost has gone down remarkably. Discharge to the community is easy as there are no finances to be arranged. Subsequent dressings are done in the hospital dressing clinic. The machine works for a week and the whole pack (V.A.C. Via™ unit; charger; lanyard; pouch; medium granufoam dressing kit; 250ml canister and adhesive drapes) costs £260. This cost is less than the cost incurred in the use of the traditional machines. With the disposable V.A.C., the patient can be discharged home early therefore saving additional expenses.
5. Statistical Analysis
We divided the patients in 3 groups, who underwent similar procedures and compared costs in the use of traditional V.A.C. machines versus the V.A.C. Via™ unit, costs of hospital stay is also considered. All data is compiled into the following tables and a student t-test value is used to calculate a p-value.
Patients example group 1—Debridement of lower leg infected ulcer + graft
Patients example group 2—Debridement of heal ulcer + graft
Patient example group 3—Elective skin lesion excisions + grafts
Cumulative Data—Traditional vs. Disposable
Using the above data and a student t-test, we conclude with a two-tailed P-value of 0.02, which is considered to be statistically significant.
6. Benefits of the Disposable and Portable V.A.C. Therapy System
There are various benefits of a disposable and portable V.A.C. Via™ system over current TNPT therapy products:
1) Potentially decreases in hospital stay due to quicker patient discharge process.
2) Uninterrupted V.A.C. Therapy at discharge.
3) Simple application requiring minimal staff training, V.A.C. Via™ is much easier to use than the traditional TNPT machines.
4) Reduced administrative coordination by eliminating the steps to activate and discontinue therapy.
5) Increased patient satisfaction with ability to conceal device and silent nature of therapy.
Increased patient compliance since therapy will not disturb patient’s environment.
NOTES