Th. Ferber, R. Mähr, A. Staub

A consequence of rising life expectancy is among others an increase of chronic disease, and thereby also of chronic wounds. Defective wounds of the skin are defined as chronic if customary medical measures do not lead to wound closure or if the wound does not show any healing tendency within 8 weeks. Typical examples in this respect are the decubitus ulcer and the ulcus cruris. They confront not only patients, but also relatives and medical staff with incessant problems.

Treatment of chronic wounds is furthermore associated with considerable costs. About 10 billion Swiss francs ought to be spent worldwide in their purpose. A qualified and optimized wound therapy that contributes to cost reduction is therefore also for economical reasons the need of the moment.

With TenderWet, a new type of wound dressing is now available that unfolds a “self-acting rinsing mechanism” in the wound, thus going beyond efficacy of any other dressings system for moist wound treatment. To clarify this differentiation the term “wet therapy” was coined to characterize the new treatment alternative.

In Switzerland, TenderWet has now been used three years in clinics and ambulatories in the treatment of chronic and badly healing wounds of varied genesis. A first interim balance of experience shows amazing results in parts – almost all wounds could be completely cured.

In addition, a definite cost reduction could be attained through savings on treatment and nursing time due to the easier mode of application of TenderWet on one side and accelerated healing courses on the other.

The main findings from three years practical experience with TenderWet will be briefly summarized below.

PROBLEMS WITH CHRONIC WOUND HEALING AND THERAPEUTIC CONSEQUENCES

Wound healing is a sequential process where “the right cells have to do the right thing at the right time” to restore integrity of the integument at maximum rapidity. Apart from nutri-tional and metabolic substances (proteins, lipids, vitamins, trace elements and oxygen) that are provided through blood circulation, this repairing effort of the cells necessitates in particular a successfully operating information system to coordinate single cell activities. Vehicles for this information system are a series of chemotactic agents, mediators and growth factors that again are produced by the cells themselves and regulate their mitosis, migration, and even transformation.

Spontaneous wound healing is only possible at prevalence of a physiologically balanced wound milieu (sufficient moisture content, adequate pH value) that effectively promotes the course of cell activities in their complexity. Nutrition and cell metabolism have to be ensured through sufficient blood circulation, and as a further prerequisite inhibitory factors, such as bacterial contamination and toxic debris should altogether not exceed the autolytic abilities of the wound.

When these requirements cannot be met due to the influence of various harmful events (desiccation of the wound floor, insufficient blood supply with hypoxia, wound infections, etc.), wound healing is impaired to a more or less expressed degree, and a chronic wound will develop if intervention does not occur soon enough.

Cells deteriorate. Necroses are formed to such an extent that they cannot be dissolved by bodily cleansing mechanisms. At the same time toxic debris from the tissue and bacteria infiltrate the surrounding wound area, leading to additional loss of tissue. Wound healing comes to a standstill.

It is the great crux of chronic wounds that they rarely develop from acute wounds, but in most cases are the last stage of progressive tissue distruction caused by venous, arterial or metabolic vessel disease, or pressure damage. The repairing efforts of the cells have to be initiated in skin areas that are extremely metabolically disturbed, so that it is not guaranteed from the very beginning that the right cells will do the right thing at the right time.

In the meantime, a number of theoretical models have been developed to study abnormal cellular mechanisms of chronic wounds. Research also concentrates on the detection of substances that may specifically influence inhibitory factors, so that under their stimulative action, the whole wound healing process may again get on its way. An example in this respect is the local application of growth factors.

As long as there are no practical solutions in sight, it remains, however, the main therapeutic goal in wound treatment to transfer a chronic wound to the greatest possible extent into the stage of an acute injury via thorough cleansing of the wound surface. That means nothing else but to give the organism the chance to restart the wound healing process.

The method of choice for wound cleansing is surgical débridement that represents the most rapid and most thorough way of removing everything from the wound that may impede healing. When the wound is bleeding, cells and cytokines important for wound closure can again reach the wound area.

In practice, surgical débridement may, however, not always be possible (general condition, age or refusal of the patient) so that careful necrectomy, as well as continuous wound cleansing have to occur via physical measures. Moist wound treatment proved to be very effective in this purpose and is also of principal importance during subsequent wound conditioning and epithelisation.

THE PRINCIPLE OF MOIST WOUND TREATMENT

Moist wound treatment is regarded as standard therapy for chronic and badly healing wounds, even though its practical application is nowhere near approaching a desirable extent.

With the aid of “moist” dressings, wounds are supplied with external moisture leading to the following effects: Necrotic and devitalised tissue is softened and can be detached more easily. The generally enhanced absorbent power of moist dressings supports accelerated wound cleansing. Furthermore, desiccation of the wound can be avoided during the whole healing process, that would otherwise inhibit proliferation of new cells or rather cause cell destruction.

The most simple type of a moist wound dressing is a gauze swab soaked with physiological saline solution or Ringer’s solution. It is, however, at the same time the most problematic type. Swabs tend to dry out rather quickly and adhere to the wound. During dressing replacements newly formed cells are stripped off along with the fabric, even wetting of the desiccated gauze just before removal cannot revitalise the cells. Maintaining the gauze swab at a permanently stable moisture level is, in addition, very time-consuming and requires frequent changes of the dressings, every two to four hours, even at night.

A considerable improvement not only in the sense of efficiency, but also concerning practicability of moist wound treatment are the so-called hydroactive wound dressings, such as gel forming calcium alginate swabs, hydrocolloids, and hydrogels. They allow problem-free maintenance of permanent moist wound conditions and facilitate good drainage of wound exudates through their suction power.

Hydrocolloids and hydrogels also promote formation of new capillaries and sprouting of blood vessels into the wound area.

THE PRINCIPLE OF WET THERAPY WITH TENDERWET

Wet therapy with the new wound dressing TenderWet is capable of affecting the pathophysiological wound milieu to an extent that exceeds the effect of mere moisture supply.

TenderWet is a multilayered wound dressing pad that contains as the central component an absorbent core made of superabsorbent polyacrylate. Before use, the superabsorber is activated with an adequate volume of Ringer’s solution that is then continuously given off to the wound for up to 12 hours. At the same time, wound exudates containing bacterial toxins, germs, and detritus are taken up and reliably bound to the absorptive core. This exchange mechanism is successfully operating because the superabsorber has a higher affinity for protein than for salt solutions so that Ringer’s solution in the dressing pad is displaced by wound exudates.

This procedure, best characterized as permanent “rinsing” of the wound, exerts its positive effects particularly during the wound cleansing phase, but also during wound conditioning.

INFOBOX 1: THE PRINCIPLE OF TENDERWET

THE ACTION OF TENDERWET DURING THE CLEANSING PHASE

If surgical débridement is impossible, necrotic and devitalised tissue can be detached with the aid of TenderWet. Practical experience showed that necroses come off or are sufficiently softened during the first days of treatment, so that they can be removed mechanically without effort.

Thorough cleansing is also possible in the treatment of greater wound cavities. The enveloping polypropylene knitted fabric of the absorptive pad gives TenderWet a high plasticity so that it easily adapts to all contoures. Furthermore, the dressing pad, depending on size, can absorb up to 60 ml Ringer’s solution, swells upon activation, and thus fits well into the cavity.

In some cases, an enlargement of the wound is observed in the starting phase of treatment when wound cleansing with TenderWet is performed for the first time. This indicates additional removal of irreversibly damaged tissue that was previously not recognized.

Shortly after beginning therapy with TenderWet, the flow of exudate stops almost completely suggesting rapid normalization of blood vessel reactions. Therapeutically, this effect proved especially useful in primary treatment of burns because the dangerous flow of exudate caused through burn shock can thus be controlled.

As the cleansing phase develops, germs, tissue- and bacterial toxins are “washed” out of the wound with TenderWet until a wound milieu is generated that allows proliferative cell activities. In this phase, slight bleeding may be registered indicating the onset of vascularisation at satisfactory blood supply. TenderWet should, therefore, by no means be withdrawn at slight bleeding.

In the course of wound cleansing, nerve endings that were previously covered with scab or necrotic tissue become exposed or are even regenerated. The wound may thus temporarily cause or be sensitive to pain until sufficient granulation tissue has formed for its protection. The rules for pain therapy of wounds, in particular those concerning dressing replacements, do also apply to the use of TenderWet.

The stage of bacterial contamination is of no concern for the application of TenderWet. TenderWet is permeable to gas and can also be used on manifest infections, in which case the rapid elimination of germs due to the rinsing action of TenderWet makes it unnecessary to add local anti-infectives.

THE ACTION OF TENDERWET DURING THE GRANULATION PHASE

Wound conditioning with formation of granulation tissue to refill wound defects is a complex problem for the damaged area that requires complex therapeutic concepts. Basic principle is here the treatment of the cause having lead to ulcus formation, a strategy that is, however, limited, especially with multimorbid, old patients. Surprisingly, in some cases, wound closure could be achieved in spite of continuous aggravation of the patient’s general condition. This aspect ought to be of special interest in palliative treatment of tumor wounds, in order to contribute as painrelieving measure.

An absolute must during wound conditioning is, furthermore, prevention of desiccation. Until now, it was not unusual that this should fail due to inappropriate dressing material. TenderWet can gradually release Ringer’s solution for 8 to 12 hours so that even during the night a constant moisture level is guaranteed without change of the dressing.

In addition, isotonic Ringer’s solution stabilizes the pH value in the wound, as well as it supplies the cells with sodium, potassium, and calcium. The latter is according to today’s knowledge necessary for cell proliferation and accelerates the course of wound healing.

THE ACTION OF TENDERWET DURING THE EPITHELISATION PHASE

For complete closure of a well conditioned wound, covering with skin grafts should always be taken into consideration. A continuation of TenderWet treatment for several days subsequent to transplantation may then be discussed.

TenderWet can be recommended for spontaneous epithelisation as long as the dressing pad is still in close contact with the wound floor and a supply with Ringer’s solution seems useful. Otherwise, continuation of the treatment with hydrogels (e.g. Hydrosorb) may be more reasonable, as they can at that stage stay on the wound for up to seven days, if no disturbances are registered. The transparency of Hydrosorb allows for easy wound inspection.

CASE REPORTS

Some applications of TenderWet will be presented below, the examples referring to cases, where initial therapeutic attempts with conventional methods had been ineffective. Photographic documentation is available for all treatments, however, not all cases will be illustrated due to limited space.

Diabetic
ulcerations

Mal perforant (Fig. 2a/b): 70-year-old patient with insulin-dependent diabetes in connection with neuropathy/micro-angiopathy. The mal perforant had been existing for 3 years and shown no healing tendency under conventional therapy. As surgical débridement was refused, change-over to TenderWet treatment was the only alternative. Complete cure was observed within five months. Healing certainly could have been shortened down to about two weeks using surgical débridement, however, considering the circumstances the healing course with TenderWet can also be regarded as great success.

Diabetic gangrene (no figure): 69-year-old female patient, who had been conventionally treated for three months before starting therapy with TenderWet. 14 days after onset of TenderWet application, the wound could be covered with a Thiersch’s graft and showed complete healing without complication in 16 more days.

Decubital ulcera

Example I (no figure): A female psychiatric patient confined to bed had been suffering for two months from a sacral ulcus without recognizable healing tendencies under conventional treatment.

Change-over to TenderWet therapy lead to complete healing within two more months.

Example II (Fig. 3a-c): A 73-year-old bed ridden female patient developed a postoperative pressure sore on the heel. After 14 days of conventional wound management, change-over to TenderWet was initialized. Complete cure of the ulcus was observed within 43 days.

Example III (no figure): A 94-year-old non-insulin-dependent female patient with micro-angiopathy had been suffering from a decubital ulcus on the heel for three months. Surgical débridement was not possible; diverse therapies remained ineffective. Wet therapy with TenderWet, however, produced complete healing within six months.

Wound defects
after surgical interventions and traumas

Example I (Fig. 4a-c): A 41-year-old patient with status after operative care for detachment of the patellar tendon developed a postoperative wound hematoma. Therapy consisted in extensive débridement followed by suction- and through-drainage for 17 days. The wound was subsequently conditioned for 30 days with TenderWet and finally successfully covered with a transplant.

Example II (no figure): A 71-year-old female patient after nephrectomy was suffering from postoperative superinfection of the wound. Therapy with TenderWet was completed within five months of ambulatory treatment without complications. 

Ulcera cruri

Example I (Fig. 6a-c): A 90-year-old female patient with arterial angiopathy developed an ulcus on the left leg. The ulcus could be completely cured with TenderWet within two months.

Example II (no figure): A 87-year-old female patient had been suffering for 35 (!) years from a leg ulcer. All therapeutic attempts remained ineffective. Despite massive aggravation of the general condition of the patient, the ulcus was completely cured within only eleven months.

Chronic wounds of other genesis

A 59-year-old patient on chronic dialysis (Fig. 5a/b) sustained a radiation injury. After six months of conventional wound therapy, change-over to treatment with TenderWet was performed. In spite of progressive bronchial cancer, the wound was cured within four months and completely closed two days before exitus. 

FINAL REMARKS

Up until today, about 500 patients with varying basic disease and wound defects have been treated with TenderWet.

TenderWet was in particular employed when various other therapeutic attempts had previously proved ineffective. In almost all cases the chronic course of wound healing could be stopped and complete healing was attained. This was especially helpful when desirable surgical débridement or adequate treatment of the basic disease causing chronic wound development were impossible, due to the high age or impaired general condition of the patients.

TenderWet acts via a successfully operating exchange mechanism as it continuously delivers Ringer’s solution to the wound and takes up germ- and debris-laden exudates, in turn. This active cleansing mechanism did in each case optimally support the formation of granulation tissue. Patients treated with TenderWet had fewer wound infections as compared to prior therapy and suffered a relapse less often. As from the point of view of time, treatment with TenderWet could in many cases be successfully completed in shorter time spans than therapeutic attempts with conventional methods.

Due to easier handling of TenderWet compared to other wound dressings, important advantages also emerged for the nursing staff, as for example a significant saving of time. This, in principle, permits earlier discharge of clinical patients to attend outpatient treatment, leading to further reduction in costs and effort. All these factors revealed that TenderWet therapy is altogether more economical than other conventional wound therapies.

Dr. sc. nat. Rudolfo Mähr
Hospital Marketing Director
IVF Internationale Verbandstoff-Fabrik Schaffhausen
CH-8212 Neuhausen am Rheinfall