Tina:

This is a very difficult case, so let's start at the beginning. My preference is to involve plastic surgery from the start. They will discuss and plan flaps, grafts, etc. And, this may require a vascularized flap from another part of the body in order to get those defects closed.

As far as the product, I think Jeff will answer that part of the question for you. In my opinion, there is no problem with enhanced fire risk with Mepitel or Mepilex , etc. This would allow you to treat the patient without having to take off dressings and replace the dressings before every treatment.

Clinical management (which you did not ask for) is more difficult. This wound and most of the rest of the scalp area needs to be surgically derided. To add more to the complexity, I would ask the surgeon about fenestrating the outer bony layer of skull while exposing the inner layer to granulation tissue growth. Then, the entire area can be skin grafted with some success. It will involve asking the surgeon to destroy every bit of devitalized bone during the debridement. I would consider the wound vac after this surgery. It helps stimulate granulation tissue forming in the marrow space between layers of skull and begin filling over the exposed bone.

I've taken care of a melanoma patient with this exact looking wound. We ultimately got this covered by some heroics and STSG. Unfortunately, her cancer came back with brain lesions and she died shortly after she was healed from STSG.

As far as the biologic injections, I would not stop HBOT due to that alone. I see no problems with this and HBOT. Some of the other physicians might chime in here for a second/third opinion.

Summary; Complicated head/scalp wound with potential for a poor outcome. You don't have many choices except for complicated free flap to help cover this wounded area. I think that wound bed preparation is key to success here. You need a bed of granulation tissue ... and I wouldn't think about flaps/grafts/etc until your patient has at least 30 preoperative HBOT sessions.

Hope this helps.

Tina:
As Dr. Worth mentioned I have completed a risk assessment for the Woun'Dres Collagen Hydrogel and Mepilex Transfer and included the Safety Data Sheet with each product's risk assessment. The risk assessments can be viewed in the Go/ NO-Go Tool public repository at https://woundreference.com/gonogo/

I highly recommend that you perform a risk assessment for each product and use the repository strictly as a reference, and not as a final determination. Each product must be evaluated on a case-by-case basis in accordance with the established NFPA 99 2021 Hyperbaric Safety Guidelines. Please feel free to reach out to me if you would like assistance with this process or to discuss it further.

Hi Tina

Dr Worth and Jeff have already provided comprehensive answers, so just sharing some info specific on T-VEC, which reinforces their answers above.

About T-VEC:
Talimogene laherparepvec (T-VEC) is the first oncolytic virus therapy approved by the United States Food and Drug Administration (in 2015) for the treatment of advanced-stage melanoma. As you pointed out, it is a modified oncolytic herpes virus. Despite a paucity of Phase III trials for T-VEC as a therapy for non-melanoma cancers such as SCC, successful off-label use of T-VEC for this purpose has been reported in the literature [1] Case reports, case series, and Phase I and Phase II trials have shown that T-VEC has demonstrated efficacy for non-melanoma cancers [1]

Mode of action
T-VEC is injected locally into the tumor and then selectively recognizes, infects, and destroys malignant cells with minimal effects on normal human cells.[2]
Oncolytic viruses selectively target cancer cells, and their replication within these cells induces tumor cell lysis. As with other injectable agents, local oncolysis is thought to activate T cells that may induce a distant immune response [2]. Several preclinical studies support this by demonstrating tumor infiltration by CD8+ T cells in noninjected metastases [2]

Use with HBOT (experimental study)
An experimental study evaluated the effect of HBOT combined with oncolytic herpes simplex virus on the growth of solid tumor (U87 human glioblastoma cell line) implanted subcutaneously in mice [4]
42 days after tumor implantation authors found that tumors treated with:
- control (saline) showed 80-fold growth of the tumor
- oncolytic herpes simplex virus alone showed a 7-fold growth of the tumor
- hyperbaric oxygen+oncolytic herpes simplex virus exhibited 22-fold growth of the tumor
- erythropoietin+oncolytic herpes simplex virus exhibited 25-fold growth of the tumor
Even though tumors treated with HBOT+oncolytic herpes simplex virus didn't suppress tumor growth as much as oncolytic virus alone, tumor growth in that group was still significantly smaller than in the control group. In this experimental study though, mice didn't have any condition that warranted the use of HBOT, such as soft tissue radiation or bone necrosis (i.e, an approved indication). As with any experimental study, evidence is considered of lower certainty compared with evidence derived from a randomized controlled clinical trial. Assuming similar results were observed clinically, if there was another condition for which HBOT would be warranted (e.g. soft tissue radiation, osteoradionecrosis), HBOT benefits would most likely justify the decrease (if any) in the effects of oncolytic herpes simplex virus on the tumor, as this therapy would still be much more effective in killing tumor cells compared with placebo or no therapy, and patient would benefit from HBOT treatment for the condition being treated.

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8675341/
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4519012/
[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8336507/
[4] https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC2823294/