Providing A Biofilm Explanation For Ablative Treatment of Recalcitrant Wounds

This article provides current treatment advice as well as recent patient case studies.

What the wound care provider believes about the wound bed will determine how that wound will be managed. That’s to say, it’s the clinician’s perception of exactly what processes are taking place locally on the chronic wound (the wound bed reality) that provides the organizational principles that will direct which treatments are chosen (and when) for that particular wound. If we consider chronic wounds as primarily caused by impairments of the host, such as diabetes, poor perfusion, repetitive trauma, etc., then our treatments will mainly be focused on resolving these host issues. However, if the wound care provider perceives the wound bed reality as one where the primary cause of the chronic wound is a chronic infection produced by biofilm, then many of the management strategies will be quite different. 

There's no question that host impairments contribute to the establishment of, and sometimes to the persistence of, chronic wounds. It’s also clear there are a small number of wounds for which the host impairment is sufficient to be the primary cause, such as infarction of small- or medium-sized arteries that leads to dry, necrotic toes (trash toe) or patches of dry, black skin (calciphylaxis). But, the clinical behaviors of these wounds are quite different than the majority of chronic wounds we deal with each day. The majority of chronic wounds show accumulation of slough (primarily fibrin and other plasma proteins) and exudate at a macroscopic level while at a microscopic level demonstrate the presence of biofilm, elevated inflammatory cytokines, and excessive neutrophils. These macroscopic and microscopic attributes of chronic wounds are the clinical features that should lead us to question our view that chronic wounds are “caused” by host impairments (the broken-host theory).¹

There are several reasons we should consider host impairments as contributory rather than primary causes of chronic wounds. First, satellite wounds in the area of a chronic wound (experiencing the same host impairments as the chronic wound) will often heal normally while the chronic wound persists (Figure 1 A-D). Along the same line, biopsies taken across the margin of the wound will heal on the side with normal tissue back to the margin of the wound, yet will progress no further after two weeks (Figure 2 A-C).² This demonstrates that even in the periwound area there is normal host healing despite the host comorbidities. Second, in an impaired host living with a chronic wound related to an injury that microbes cannot reach, such as a hematoma or fat/muscle necrosis due to blunt trauma, none of the characteristics of a chronic wound, such as hyperinflammation, cellular senescence, or excessive neutrophils, are seen. These regions of tissue death underneath intact skin never develop into chronic lesions, but rather resolve through host-healing mechanisms over an appropriate length of time. Third, animal models are incredibly valuable in understanding what makes a chronic wound “chronic.” The methods used to develop a chronic wound in an animal reveal common themes for the production of a chronic wound model. Whether dealing with pigs,³ mice,⁴ or rabbits,⁵ the chronic wound model often relies on animals with impaired immunity, impaired circulation, a foreign body, or external factors (pressure, heat, etc.). Yet, even in these impaired animals an experimental lesion with nothing else added will heal. These animals with only host impairments are used as controls. In the animal models referenced here, it’s only when microorganisms are introduced in the experimental lesion that the macroscopic and microscopic findings consistent with the majority of chronic wounds develop and wound healing is stalled. These findings should lead us to consider the wound microbiota as the primary cause of the majority of chronic wounds.  These findings also support the position of the European Infectious Disease Society that states biofilm causes chronic infection.⁶ Further, in the same guidelines, the authors use chronic wounds as an example of chronic infection. Under the broken-host theory, the wound bed is viewed as a garden. This theory holds that it’s host impairments that slow the host wound healing processes, therefore the wound bed must be nurtured. If the host is the reason for nonhealing, then harsh treatments (highly cytotoxic) to the wound bed would further slow these degraded processes. This has led to such maxims as “never placing anything in the wound that you would not place in your eye.” Also, it’s widely held that no cytotoxic substances should be placed in the wound, or else the delicate regeneration taking place by fibroblasts, endothelial cells, growth factors, and other molecular entities will be suppressed.^7,8 A different view, supported by already cited evidence, suggests a far different wound bed reality. If chronic wounds are chronic infections, then each chronic wound bed should be viewed more as a “warzone” with multiple microbial strategies being employed to inflame and sustain the wound bed while the host vainly attempts countermeasures.⁹ 

This “warzone” is made up of biofilm phenotype microorganisms with multiple colony defenses that do not allow the penetration of white blood cells, antibodies, complement, and other host immune strategies. Also, the colony defenses make the biofilm tolerant to antibiotics at very high levels; tolerant to biocides at very high levels; and tolerant to physical measures such as desiccation, ultraviolet light, pH changes, osmolality, etc. Biofilm has resided in harsh physical environments for more than 3.25 billion years and has survived and thrived with these multiple defenses.¹⁰ As usual, the truth about the wound bed reality for many chronic wounds lies somewhere between a “garden needing to be nurtured” and a “host-microbe warzone.” These two extreme wound bed perspectives define the endpoints of the chronic wound healing continuum. Therefore, it may be best to start with an untreated chronic wound with its host-microbe interactions and work backwards to a healing wound. A naive chronic wound that has not undergone any assessment or management is a chronic infection dominated by biofilm regardless of its appearance (Figure 3 A-B). The chronic wound bed is covered with significant biofilm that easily evades host immunity and produces host cell senescence in a fairly observable diffusion zone into the skin and sub-skin structures.  The interface between viable tissue and the biofilm-controlled senescent tissue is characterized by high levels of proinflammatory cytokines, matrix metalloproteases, and excessive neutrophils.¹¹ This biofilm-induced, hyperinflammatory region, along with host cellular senescence, is sufficient to prevent healing but also explains the clinical behaviors of chronic wounds. This biofilm-controlled region will also degrade the effectiveness of advanced wound care treatments such as cell-based therapies, scaffoldings, growth factor, etc. Multiple treatment strategies used simultaneously are usually more effective than the sequential use of single strategies against biofilm since it’s usually polymicrobial, possesses multiple colony defenses, fosters heterogenicity among its members, and has many other capabilities.¹¹ By physically disrupting biofilm, the protective properties of the matrix are lost while the individual constituent microbes must become metabolically active to reform the biofilm. During this period of activity, the individual microbial cells are more sensitive to treating agents such as biocides and antibiotics.¹² The addition of quorum-sensing inhibitors further degrades colony defenses, allowing biocides and antibiotics to be more effective. Also, by providing false metabolites, agents that the individual microbes may ingest but interfere with their metabolic machinery (gallium, alcohol sugars, etc.), the biofilm is further challenged. As biofilm is being suppressed, host immunity and host-healing mechanisms are no longer bathed in microbial-produced molecules that impair their function. These host systems, however meager, create beachheads of normal host function in the wound bed. Clinically, we would see this as emerging granulation buds, wound contraction, reepithelialization at the edges, etc. As biofilm remains suppressed, inflammatory pathways come back under control of the host while functional white blood cells migrate into the area, cleaning up the senescent immune apparatus as well as senescent wound bed cells. Most importantly, however, angiogenesis and host extracellular matrix formation begins to take place. As this transition to a wound bed garden emerges, treatments that are cytotoxic to host cells must be tapered while antimicrobial therapies that are sparing of host cells must ramp up. It’s at this time that advanced wound healing strategies that augment host-healing pathways are most effective. Guiding a chronic wound through the aforementioned wound management paradigm is the essence of biofilm-based wound care. This management strategy works well most times. Yet, we are left unresponsive chronic wounds. These recalcitrant wounds have persisted despite the most advanced evaluation and therapeutic options available. As seen in the case histories accompanying this article, many of these wounds underwent extensive molecular diagnostics, including imaging, microbial metagenomics of the wound microbiota, microbial and host transcriptomics of the host wound bed cells, and some proteomic evaluations. These highly inflammatory and recalcitrant chronic wounds that have persisted for years demonstrated no significant differences in terms of microbial species present, genes present, genes expressed, or any difference in molecular host response.  Trying to define why these wounds are fundamentally different than the majority of chronic wounds has been unsuccessful. One hypothesis is there are host impairments at some level (macro or molecular) that preclude the host from assisting in the clearing of wound microbiota or there are host impairments that preclude healing. In an effort to better understand if the recalcitrance of the wound lies on the microbial side or the host side, ablative management strategies to the wound bed were employed (the “nuclear option”). 

LASER DEBRIDEMENT 

The Joule Aesthetic Laser Platform (Sciton, Palo Alto, CA) series is designed for use in surgical applications that require the excision, incision, ablation, vaporization, and coagulation of soft tissue as well as for skin resurfacing. The Joule device is an erbium: yttrium aluminium garnet (Er:YAG) laser used at 2940 nm (neodymium-doped), the peak absorption wavelength for water, that is approved by the U.S. Food and Drug Administration (FDA) for …“indications including epidermal nevi, actinic cheilitis, keloids, verrucae, skin tags, anal tags, keratosis, scar revision, debulking benign tumors, and decubitus ulcers …”. The use of the Joule 2940 for chronic wounds other than decubitus ulcers is a permitted off-label use of the device for non-decubitus ulcer wounds and on label for ablation of soft tissue in general. Patients were consented through a protocol (Western Institutional Review Board PRO NUMBER: 20111320) that allows for the evaluation of their debridement materials with advanced molecular testing and reporting the results. The method of laser debridement is based upon the well-established efficacy of laser skin resurfacing utilized in dermatology and plastic surgery. The laser energy provides controlled vaporization of the superficial layers of the ulcer bed. The potential advantages of laser debridement include precision and uniformity of tissue ablation, reduced trauma to the ulcer bed, improved patient comfort, enhanced biofilm clearance, and promotion of ulcer healing. Anecdotally, laser debridement has shown a decrease in procedural pain scores, thereby facilitating a more complete debridement. The laser also provides precise control over the depth of ablation per pass, ranging from 25-200 microns. Depth can be increased by executing multiple sequential passes. The laser system handpiece allows the laser beam spot to be scanned in two dimensions, creating adjustable patterns. The handpiece scanner provides complete, uniform application of the laser energy. This application will cover 100% of the surface within the scanned pattern. Experimental findings¹³ in humans and animals suggest biofilm may be free-floating (not attached to contiguous host tissue) or attached and even integrated into host tissues several millimeters below the wound bed. These biofilm structures have been shown to organize around capillaries and then extend into other host tissues. These penetrations into the host are not contiguous and seem to have some space between each penetration. Also, it’s clear biofilm infections on a host surface are not successful unless the biofilm can produce host cell senescence, which prevents turnover of the attachment site. If the host cells are able to apoptose or neutrophils are able to effectively lyse the infected host tissue, the biofilm is released off the surface and the biofilm is not successful. It’s the senescence (dysfunction) of the host wound bed cells that limits any proactive treatments applied to stimulate angiogenesis, wound bed contraction, or deposition of host matrix. Therefore, the principles for using laser technology to ablate the wound bed to a precise depth is that any biofilm present in the ablated layer will be vaporized and the senescent host cells can be sacrificed to a discreet depth. Clearly, there will be biofilm structures at penetration sites below the level of the ablation. These biofilm remnants will attempt to reconstitute the biofilm across the surface of the wound. However, functional cells are now present across the majority of the wound bed and, with the adjunctive management of the wound bed with antimicrobial strategies, may prevent the biofilm from reestablishing itself. The findings conclude that for recalcitrant wounds, especially wounds such as pyoderma gangrenosum, the use of the Er:YAG laser is of great benefit.  Case studies 1-3 demonstrate this important finding.  

SULFONATED HYDROCARBONS

Sulfonated hydrocarbons  (HYBENX,^® EPIEN Medical Inc., St. Paul, MN) is a dental product approved by the FDA as a root canal cleanser that has been used in millions of patients. The use of HYBENX in treating chronic wounds is a permitted off-label application. 

Patients were consented through a protocol (Western Institutional Review Board PRO NUMBER: 20111320) that allowed for the evaluation of their debridement materials with advanced testing and reporting of results. HYBENX contains hydrocarbons and sulfuric acid, a strong acid that can hydrolyze sugar bonds — a proposed mechanism for the removal of plaque (biofilm) from the tooth as well as its bactericidal activity. The advantage of sulfonated hydrocarbons is their liquid form and they can be applied on irregular surfaces and between crevices, which is especially suitable for deep, cavernous wounds such as decubitus ulcers that cannot be reached effectively by the light of a Er:YAG laser. Because the cytotoxicity of sulfuric acid is concentration dependent, the cytotoxic activity of sulfuric acid can be somewhat regulated by irrigation with saline. This gives the provider the advantage of applying the sulfonated hydrocarbons and (3-10 seconds later) irrigating the surface and stopping the reaction. For highly fibrotic wounds with heavy microbiota, sulfonated hydrocarbons can remain. In the soft wound bed in an elderly impaired host, sulfonated hydrocarbons can be irrigated in 3-5 seconds. The downside of the hydrocarbons is they can diffuse too far into the wound bed and some good tissue can be lost. However, as noted with biopsies and satellite wounds, normal tissue quickly regenerates itself to the level of the active wound microbiota. Sulfonated hydrocarbons have proven extremely effective in decubitus ulcers.  Prior to this use of the hydrocarbons, the bias was decubitus ulcers persisted because the patient continued to bear weight. However, as the three case studies with the hydrocarbons demonstrate, all patients have remained upright in their chairs while the wounds have progressed toward healing. This suggests the wound microbiota has been responsible for the persistence of these recalcitrant wounds, not some macro or molecular impairment in the host.  

DISCUSSION

The case studies within this article do not constitute scientifically meaningful levels of evidence that prove wound microbiota is a major barrier to healing in the chronic wound. But this preliminary data can help structure high-quality studies that will unlock the microbial mysteries of the chronic wound bed. What exactly takes place on the wound bed when using the nuclear options? What are the indications for when and how often these therapies should be used? Do some wounds really require such harsh interventions? If so, why? There are many other microbial questions raised by these cases. It has been documented that harsh treatments such as peroxide, alcohol, and bleach may cause more treatment failures than normal saline.¹⁴ So why would a more cytotoxic substance such as sulfuric acid seem to improve healing in the cases presented? It could be the sulfuric acid sacrifices dysfunctional host extracellular matrix, which has “forgotten” how to heal. But if this was purely a host problem, sharp debridement on a weekly basis should have been sufficient. Why do 90% of chronic wounds respond to targeted antimicrobial therapies that are noncytotoxic, yet the chronic wounds in the cases presented would not? These recalcitrant wounds were treated with aggressive sharp debridement followed by appropriate antibiotics at roughly 1,000 times minimal inhibitory concentration in combination with high-dose, noncytotoxic biocides; and yet the wound microbiology seems to have been successful in maintaining the chronic wound. Why, in the cases presented, were these nonspecific highly cytotoxic nuclear options successful when the aforementioned targeted therapy failed? There’s much more to the chronic wound microbiota and the wound bed reality than we currently understand. Our null hypothesis was molecular host cell impairments are not the primary cause of recalcitrance in nonhealing chronic wounds. The indirect evidence from the use of the Er:YAG laser and sulfonated hydrocarbons is that the null hypothesis is true.  

It seems the wound microbiota, primarily in biofilm phenotype, may be the main cause for the recalcitrance of wounds that persist despite aggressive biofilm-based wound management. It’s important for the clinician not to think of a chronic wound as a single etiology. That is, DFUs are treated one way and decubitus ulcers are treated another. Chronic wounds are infections that are unique in the microbial species present and their relative abundance. The wound microbiota, depending on the species of microorganisms and their combined synergies, can produce varying degrees of difficulty for the management and healing of the chronic wound.¹⁵ The addition of treatment products and technologies that have the ability to “reset” the wound microbiota and the wound bed surface not only provide good evidence that the wound microbiota is a main wound healing barrier, they are effective wound treatments in their own right. These methods should be incorporated carefully in the treatment of chronic wounds, but seem to have some efficacy in the management of recalcitrant chronic wounds.   

Case Studies — Use of Laser Treatment 

Editor’s Note: For images associated with these case studies, see the online version of this article at www.todayswoundclinic.com/issue. For those reading this article after Oct. 1, the article may be archived — visit www.todayswoundclinic.com/archive.

Case 1: Male patient aged 54 when he initially presented May 18, 2005, soon to be retiring and soon to have his wound completely healed. Diagnosed by wound biopsy of findings consistent with pyoderma gangrenosum of the left lower leg in 2006. No significant comorbidities and only prescribed one medication (for hypertension). Wound was aggressively managed with biofilm-based wound management, with the molecular identifications of microbes over the years always demonstrating dominant Pseudomonas aeruginosa in the wound. The size of the wound would improve slowly over time only to exacerbate to its original size. 

Wound microbiota was visualized by running the entire genome of the P. aeruginosa, which was unremarkable. Also, transcriptomics, metagenomics, and proteomics revealed nothing clinically useful about the bacteria. The host transcriptome showed nothing statistically. Patient’s bacteria were grown in in vitro biofilm model and it acted normally. After 11 continuous years of care, the patient was asked why he kept coming in with no end seemingly in sight. He replied, “palliative care is not an option” and “I’d rather try something instead of doing nothing,” that he was “grateful that [his healthcare providers] were trying.” That “trying” has included aforementioned advanced diagnostics, systemic and topical antibiotics, new and commercially available biocides, all known dressings, honey, bacteriophage, enzymes, phage lysins, nitric oxide, ozone, plasma cutting device, ultrasound, and much more. 

In January 2016, the patient underwent erbium: yttrium aluminium garnet (Er:YAG) laser ablation of the wound bed added to his care plan at monthly intervals. After three treatments (January, February, March) he began driving 200 miles round trip for weekly visits to obtain laser treatments. By August, the patient’s wound was almost totally reepithelialized.  

Case 2: Male patient aged 63 when he initially presented in April 2015. Presenting with diabetes, venous insufficiency, and other comorbidities as well as multiple severe wounds of the lower legs. After nine months, the wounds were slightly larger despite aggressive biofilm-based wound management. The microorganisms identified by molecular identification were mainly Corynebacterium striatum with some contribution of P. aeruginosa. 

After about seven more months, coagulase-negative Staphylococcus species started to emerge within the wound microbiota. Antimicrobial strategies were tailored to the specific microorganisms identified at each time point, and yet wounds failed to respond. Venous ultrasound, noninvasive vascular studies, and other diagnostic testing were negative. There appeared to be no host abnormalities that would contribute to the persistence of the wounds. In January 2016, patient was started on weekly treatments with a Er:YAG laser and, four months later, the patient’s severe lower extremity wounds were totally resolved and reepithelialized. It appears the addition of Er:YAG laser ablation dramatically improved the patient’s wound healing.  

Case 3: Male patient aged 37 when he initially presented in October 2014. Biopsy evidence of pyoderma gangrenosum of the right leg — severe. Patient also presents with severe circumferential lesion of entire right lower leg. Microbial identification identified 99% P. aeruginosa. Over the years there have been some components of anaerobes, mainly Porphyromonas and Peptoniphilus. Overall, the patient’s multiple molecular identifications have always shown a high percentage of P. aeruginosa. The patient was treated with systemic antipseudomonal antibiotics; topical amikacin and colistin; and multiple adjunctive treatments including gallium, alcohol sugars, quorum-sensing inhibitors, etc. None of these treatments significantly affected the severe chronic wound of his right lower leg. 

In November 2015, the patient was the first to try Er:YAG laser therapy in addition to his biofilm-based wound management. There was rapid decrease in exudate as well as swelling of the right lower extremity. By June 2016 there were bridges of epithelium between previous circumferential wounds. By August there was extensive reepithelialization of most of the wounded area of the ankle and foot. There has been continuous decrease in the size of the wound on his leg. Most important, the patient’s pain is much less, the wound drainage is acceptable, and the wound no longer exudes odor. The change occurred only after the addition of laser surface ablation.

Case Studies — Use of Sulfonated Hydrocarbon  

Editor’s Note: For images associated with these case studies, see the online version of this article at www.todayswoundclinic.com/issue. For those reading this article after Oct. 1, the article may be archived — visit www.todayswoundclinic.com/archive.

Case 4: Female patient aged 70, morbidly obese (356 pounds), living with difficult-to-control diabetes, renal disease (one short session of dialysis during a hospitalization), and experiencing generalized weakness. Patient had been bedridden and developed a stage IV decubitus ulcer of the coccyx when presenting in February 2013. Ulcer was to the bone following initial debridement. Patient had been living in a skilled nursing facility that allowed for monthly visits to the clinic, yet the patient missed many appointments due to many hospitalizations over a two-year period. Patient underwent several short trials of negative pressure wound therapy (NPWT) while hospitalized in long-term acute care settings. NPWT would always be discontinued when she returned to the nursing home. 

The initial microbial identification showed Enterococcus faecium at 86%.  All subsequent molecular identifications showed coagulase negative Staphylococcus between 70-83% for any one sample. Wound treated with topical clindamycin and linezolid. However, all targeted therapies to suppress wound microbiota were unsuccessful. A metagenomics evaluation looking for mobile genetic resistance factors that would negate antimicrobial treatments found none. In May 2016, sulfonated hydrocarbons were applied to the wound post-debridement. In Image 4C, the discoloration from the application of sulfonated hydrocarbons can be seen. The patient also received applications of sulfonated hydrocarbons in June and July, for a total of three applications. Wound measurements showed the size had improved from 3cm x 2cm x 3cm deep (18 cubic cm) in May to just 1cm x 2cm x 1cm deep (2 cubic cm) in August (approximately 90% smaller during 12 weeks of sulfonated hydrocarbons). There’s been no significant change in her comorbidities (her sitting times were very long each day), and the improvement in healing appears to be due to the addition of sulfonated hydrocarbons to biofilm-based wound management.  

Case 5: Male patient aged 37 living with spina bifida and paraplegia presenting in July 2011 with a severe decubitus ulcer on the left ischium and buttock region. Extensive tissue loss would occur, with maximum diameter of the wound reaching 28 cm in 2012.  The ischium and much of the pelvis were exposed from as early as 2011. Patient had been living in skilled nursing at time of first clinic visit and would return to the clinic monthly for biofilm-based wound care. The molecular microbial identification demonstrated mainly anaerobes in all samples from 2011 to present day. Most of the anaerobes were Peptostreptococcus, Peptoniphilus, Porphyromonas, and Finegoldia. Patient was treated with topical clindamycin and metronidazole along with several 2-3-week courses of metronidazole (he could not tolerate oral clindamycin). Wound was foul smelling with copious exudate, making the patient’s management problematic for the nursing home.  

Many different interventions, including systemic antibiotics, topical antibiotics, topical biocides (mainly Dakin’s solution), antibiofilm agents, debridement, etc., were attempted to no avail over five years. Biopsies for microbial and human transcriptomics revealed no statistically significant abnormalities. In November 2015, sulfonated hydrocarbons were applied to the wound (this was repeated the following December and January). Nursing facility staff reported tremendous improvement in the wound, marked decrease in the wound exudate and, most importantly, the foul odor almost completely subsided.  

Because of these changes, the nursing home allowed the patient to be seen on a weekly basis. Image 5C represents the visit during which sulfonated hydrocarbons were first applied. The length of the wound measured 26 cm x 14.5 cm, and the depth was to bone and recorded as 7 cm. Eight months later, the wound was far from healed, but the improvement is quite dramatic given the five years of absolutely no improvement despite aggressive management. On Aug. 3, 2016, the wound measured < 14 cm x 6.5 cm x 3.5 cm deep. The bone was completely covered. 

Other wound metrics such as exudate, odor, and quality of the wound bed all showed marked improvement. Again, the only variable that changed was the addition of sulfonated hydrocarbons on a weekly basis used in conjunction with biofilm-based wound care.  

Case 6: Male patient aged 43, a paraplegic since 2013 who developed a left ischial decubitus ulcer in April 2014. The wound was to the ischium. The patient’s need to be upright in his chair for extended hours each day to fulfill his job requirements as a school principal complicated the case. Despite aggressive biofilm-based wound care weekly, the wound persisted and actually eroded into a bigger wound by February 2016. 

Sulfonated hydrocarbons were first applied to the wound in February 2016 (Image 6C), when the wound measured 5 cm x 3 cm and was 6 cm deep. Biofilm wound management continued and a molecular identification was conducted Feb. 12, 2016, which showed Staphylococcus aureus at 50%, P. aeruginosa at 44%, and Proteus mirabilis at 3%. The patient was started on a personalized gel containing amikacin and colistin for the P. aeruginosa and P. mirabilis, and linezolid to cover S. aureus. Once the gel was applied to the surface of the decubitus ulcer, IodoFoam^® (Progressive Wound Care,^® Savannah, GA) was packed in the wound and the foam was used at the primary dressing with tape to hold dressing in place. 

At each visit, the wound was debrided and sulfonated hydrocarbons were applied. By March 24, 2016, (Image 6D) the wound was about 1 cm in diameter and the depth measured 1.25 cm. 

After almost two years of progressive worsening, which was attributed to the pressure of prolonged sitting, the patient’s wound showed dramatic turnaround healing of about 90% in six months with the addition of the “nuclear option.” There was no change in the patient’s comorbidity, sitting time, or any other factor that might have influenced the healing of the wound. The only significant change in the treatment regimen was addition of sulfonated hydrocarbons.

Randall Wolcott is founder of Southwest Regional Wound Care Center, Lubbock, TX, and serves on the TWC editorial board.

References

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