By Elliot Fialkoff and James McGuire DPM, PT, CPed, FAPWHc

There are numerous causes for ulcerations including pressure, venous insufficiency, arterial insufficiency, and neuropathic wounds. All have very different characteristics and require very different interventions. One thing that all chronic wounds have in common is the accumulation of necrotic material, biofilm or non-viable materials secondary to a prolonged inflammatory stimulus to the wound. In order for an ulcer to heal properly this "slough" must be regularly removed from the wound base so that healthy granular tissue can develop.

Mechanism of Action

Collagenase is used to augment the normal autolytic process the body uses to remove slough from the wound surface. Derived from the fermentation of the bacteria Clostridium histolyticum, collagenase is used by the bacteria to help it proliferate in a healthy wound. In its medication form, it is able to digest the exposed denatured collagen strands attaching necrotic tissues to the wound bed without significantly affecting the healthy granulation tissue. Collagenase SANTYL® Ointment utilizes this enzyme in a petrolatum ointment base to loosen slough from the wound bed which can then be removed by successive cleansing and dressing changes.

Patients who are poor candidates for surgical debridement are good candidates for the gentle slow action of the collagenase ointment. Working under the visible slough on the surface, the mass of material is slowly loosened by the enzyme working its way toward the center of the slough. Macro-debridement is frequently performed by clinicians using sharp debridement to remove large pieces of necrotic material and accumulated wound biofilms. Regardless of the thoroughness of the debridement a large amount of micro-necrotic debris is always left behind that can be removed effectively using SANTYL® between debridements.

Research on Collagenase SANTYL® Ointment

Much research has been done on enzymatic debridement. Shi and Carson found that collagenase ointment is an effective, selective, and safe wound debriding agent.¹ Rao et al. found that collagenase ointment is an excellent adjunct to therapy in the treatment of decubitus ulcers.² And Soroff and Sasvary found that a combination of collagenase ointment and polymyxin B sulfate/bacitracin spray versus silver sulfaldiazine cream in partial-thickness burns resulted in significantly shorter time to achieve a clean wound bed than silver sulfadiazine alone.³ Milne et al. demonstrated that enzymatic debridement has greater efficacy in the debridement of non-viable tissue in pressure ulcers than hydrogel alone.⁴

Application of Collagenase SANTYL® Ointment

When applying SANTYL® Collagenase to the wound, the affected area should be macro-debrided if indicated, cleansed with saline and then patted dry with gauze. SANTYL® is then applied evenly to the wound surface in a layer approximately equal to the thickness of a nickel, avoiding the periwound skin. This is important so that a proper amount of SANTYL® is available to infiltrate under the slough and provide the needed debridement. A recent paper felt that for hard eschars it was not necessary to do the traditional cross-hatching to improve the contact of the collagenase with the wound bed but this is counter intuitive to us and we still do it.

Prescriptions for SANTYL® should be based on a calculation of the amount of ointment needed for daily nickel thick applications based on the area of the wound for the period of debridement anticipated by the clinician. A dosage calculator provided by the company is helpful for this. Gauze or a tongue depressor may be used to help with the application. It states on the company website that if the wound becomes infected you can use antibiotic powder on the wound before applying SANTYL®. I think the better term is "critically colonized" or "if biofilm formation develops". Once a true infection develops with local or systemic host response, SANTYL® should be held until appropriate steps have been taken to control the infection.

It is recommended by the company that the use of SANTYL® be discontinued when debridement is no longer needed and granulation tissue is well formed however there is no contraindication to using it to closure and some evidence that collagenase may even help edge migration of epithelial cells.^5,6 It is important to not use any dressings that contain silver, iodine, mercury, or lead as antimicrobials since these metals will inactive the collagenase and prevent SANTYL® from working.

Citations:
1. Shi L, Carson D. Collagenase Santyl ointment: a selective agent for wound debridement. Journal of Wound Ostomy & Continence Nursing. 2009;36.6S:S12-S16.
2. Rao DB, Sane PG, Georgiev EL. Collagenase in the treatment of dermal and decubitus ulcers. Journal of the American Geriatrics Society. 1975;23.1:22-30.
3. Soroff HS, Sasvary DH. Collagenase ointment and polymyxin B sulfate/bacitracin spray versus silver sulfadiazine cream in partial-thickness burns: a pilot study. Journal of Burn Care & Research. 1994;15.1:13-17.
4. Milne CT, Ciccarelli AO, Lassy M. A comparison of collagenase to hydrogel dressings in wound debridement. Wounds. 2010;22:270-274.
5. Planus E, Galiacy S, Matthay M, et al. Role of collagenase in mediating in vitro alveolar epithelial wound repair. Journal of Cell Science. 1999;112:243-252.
6. Pilcher B, Dumin JA, Sudbeck B, Krane SM, Welgus HG, Parks WC. The activity of collagenase-1 is required for keratinocyte migration on a type I collagen matrix. J Cell Biology. 1997:137(6);1445-57.

About the Authors:
A current fourth year student at Temple University School of Podiatric Medicine, Eli Fialkoff completed his Bachelor’s degree in 2007 from Touro College in Queens, NY. He is the current president of the Jewish Podiatric Medical Student Association at TUSPM where he together with fellow members hosted several Lunch and Learns on topics ranging from gait analysis and bio mechanics to APMLE board preparation. Eli resides in Lower Merion Township and enjoys running and spending time with his wife and daughters.

Dr. James McGuire is the director of the Leonard S. Abrams Center for Advanced Wound Healing and an associate professor of the Department of Podiatric Medicine and Orthopedics at the Temple University School of Podiatric Medicine in Philadelphia.

The views and opinions expressed in this blog are solely those of the author, and do not represent the views of WoundSource, Kestrel Health Information, Inc., its affiliates, or subsidiary companies.