Standard, Appropriate, and Advanced Care and Medical-Legal Considerations: Part Two—Venous Ulcerations (B)
This is part B of "Standard, appropriate, and advanced care and medical-legal considerations: Part two—Venous Ulcerations.
There are numerous references concerning surgical options for the treatment of venous ulcers. The surgical interventions are divided into those that address the underlying venous hemodynamics and those that are specific to the wound bed. Surgical procedures have focused on the treatment of varicose veins and the correction of reflux or obstruction. Despite advances, such venous valve transplantation, cross-over bypass, banding techniques, and valvuloplasty, there are few agreements in the literature as to the long-term benefits for any of these procedures.[139–142] As noted in the compression therapy literature, one major problem is the use of a consistent classification system to describe patient populations. Inconsistencies in the performance of surgical procedures also complicates the issue. In one prospective audit for surgery on varicose veins, inadequate surgical elimination of incompetent veins was noted in 13 of 15 cases. Inadequate success rates and patient morbidity led to the development of subfascial endoscopic perforator ligation surgery.[144–147] This modern day “Linton procedure” allows the surgeon to visualize the perforator veins with video equipment and minimizes morbidity through the use of small endoscopic trocar incisions. Another interesting approach has been the removal of periwound lipodermatosclerotic tissue as well as the ulcer with the use of a dermatome.
The other focus of surgical treatments for venous ulcers addresses the wound bed itself. Many clinicians employ local wound debridement to prepare the wound for grafting, which may jump start the wound by converting a chronic wound into an acute wound. Another benefit of surgery is to remove debris and lower the wound bioburden. There are numerous methods of debridement, including autolytic, enzymatic, mechanical, and surgical. The surgical approach is the most expeditious, but good results can be obtained with the use of occlusive dressings and autolytic debridement. Again, the literature offers us little in the way of randomized, controlled trials to select the best method for any given clinical scenario. One highly cited paper offers insight into improved clinical outcomes through the use of debridement as part of the standard wound healing protocol.
Skin grafting. The ultimate goal for all chronic wounds is total closure. Skin grafting is, therefore, an attractive option because with one procedure a patient can potentially be healed. Skin grafting is defined as the transfer of free, unattached donor skin to a noncontiguous recipient area. Skin grafts can be partial or full thickness, and the donor can be human (allograft) or animal (xenograft). Initially, it was thought that skin grafts functioned as tissue replacement therapy, with the graft surviving in the recipient wound bed. Recent work with cultured tissues and bioengineered products has led to the observation that donor tissues may not be visually rejected but may be slowly replaced after providing a stimulus for the wound to go on towards healing (silent rejection). Allografts are thought to behave this way, and autografts may follow a similar process. There is a negative perception in the medical community about the clinical success of skin grafting for venous ulcers. In fact, one European consensus paper recommended utilizing standard care for a full year before considering skin grafting. Seventy-eight percent of ulcers treated with split-thickness skin grafts were healed completely or partially in a retrospective review from an academic dermatology group. Others have reported 20-percent healing rates for venous ulcers treated with skin grafts. Attempts have been made to identify risk factors, which would identify graft success rates. One group has evaluated the use of the immunosuppressive agent, FK506, as a topical to prolong the survival of skin allografts. A novel approach has been proposed using a hyaluronic acid-based topical dressing to prepare the wound bed followed by the application of cultured keratinocytes. The recent explosion of work in the field of bioengineered tissue has given clinicians another option for advanced care for venous ulcers when standard therapy fails or is not appropriate for the individual patient. The Cochrane library has produced a review of seven randomized, controlled trials concerning the use of autologous and bioengineered tissue. The results showed limited evidence supporting bioengineered tissue, but further research would be required to support the use of standard skin grafting at this time based on this meta-analysis.
Bioengineered tissue. The first attempt to develop bioengineered skin tissue was with acellular collagen-chondroitin-6-sulphate lamina as a matrix scaffold to regenerate dermal tissue. Later, an epidermal replacement using cultured autologous epithelium was attempted for burn wounds. Eventually, a bilayered model of skin was developed using a contracted collagen lattice containing live fibroblasts with an overlying lamina of epidermal cells. This living skin equivalent (LSE) (Apligraf®, Novartis Pharmaceuticals Inc., East Hanover, New Jersey) is a Food and Drug Administration (FDA)-approved bilayered construct for the treatment of venous ulcers. The healing response of LSE is a result of its impact as a biological dressing, potential frank take of the graft, and the stimulation of the wound bed through the release of growth factors. Several reports have identified positive clinical outcomes using this technology for hard-to-heal venous ulcers.[160–162]
The decision to use this technology is still left to clinician preference. As stated before, if a patient can be identified as recalcitrant or be classified into a category with known poor outcomes, should this technology be used earlier in the course of care? It has yet to be determined if a more aggressive approach on the front end of the treatment course will achieve cost efficiency.
There are many treatment modality options for the treatment of chronic wounds including venous ulcers. These include but are not limited to ultrasound, electrical stimulation, laser light, warming therapy, radio frequency, pulsed short wave diathermy, and hyperbaric oxygen. These modalities are well described in the literature and textbooks.[163,164] Several ongoing trials may help identify the roles of these treatment options in the near future. Electrical stimulation has been recently shown in a meta-analysis to provide significant benefit for healing chronic wounds of many etiologies including venous ulcers and at this point has the most literature-based support. As described in the section on bioengineered tissue, modalities have a definite role in the treatment of venous ulcers but a question still remains: Which modality, what combination, and when during the course of therapy should they be used? Once again the identification of a recalcitrant patient might lead a clinician to use a modality earlier in the treatment plan. In addition, many of these modalities aid in microcirculation support, and, therefore, patients identified with deficits in tissue oxygen or laser Doppler wound bed microcirculatory flow should be considered candidates for these techniques.
An attempt has been made in this paper to review the physiology of venous ulcers and treatment options. Literature has been cited heavily throughout the body of the report in an attempt to provide an evidence-based review. Standard of care consists of compression therapy and moist wound healing.28(2):36–9. This protocol should be followed strictly and reevaluated in two to four weeks. If there is no significant improvement then the clinician needs to address the individual needs of the patient and reevaluate the appropriateness of care. In recalcitrant cases, advanced therapeutic options may be required. The use of skin grafting, venous surgery, bioengineered tissues, growth factors, and modalities may turn out to be cost effective if they can significantly reduce the overall time to healing and eliminate the long treatment programs currently used by many clinicians. Quality of life and work return also may be improved by proposing a more aggressive approach to the venous ulcer patient. It is important to note that standard of care may not be adequate and, in some cases, may be inappropriate. Guidelines and standard-of-care papers are being developed and implemented at a rapid pace. From a legal point of view, it must be clear whether a guideline was developed to improve quality of care or whether other concerns and considerations were the basis for the project. There is not yet clear consensus on whether guidelines will be used as the standard of care or will simply be another piece of evidence that a jury would use to determine the outcome of a medical liability litigation. In order for guidelines to develop legal standing as standard of care, tort reform would be needed. State legislatures would need to unify the medical standard of care and the legal standard of care. Statutes would then recognize the guideline as defining the appropriate standard of care without, possibly, the need for expert testimony. At this time, there is still much confusion, and the clinician, therefore, needs to be aware of the guidelines that apply to the clinical situation but must be cognizant of the fact that some patients will require guideline modifications and deviations. Identifying those patients will, therefore, be the challenge we all face.