Case 1: Treatment of Complex Wound on Foot with NovoSorb and Split-thickness Skin Graft
Keywords: Novosorb; wound treatment; necrotizing fascitis; soft tissue infection; split-thickness skin graft
Authors: Kirstine Nanna La Cour (MD) and Annika Gottholt Hansen (StudMed). Roskilde, SUH, Denmark
A 47-year-old male, previously healthy apart from a kidney stone, was referred to the Plastic Surgery Department at Zealand University Hospital, Roskilde, presenting with a full-thickness skin lesion and exposed extensor tendons on the dorsum of the left foot/ankle. The lesion was the result of a severe soft tissue infection (necrotizing fasciitis) caused by Hemolytic Streptococcus group A (Pyogenes).
Thirty-three days prior to the referral, the patient experienced severe distal pain in the left lower extremity, and three days later presented in the emergency room with septic shock originating from the left foot. In the emergency room, the foot exhibited reddish-purple blisters, violet subcutaneous bleeding, and overall swelling of the lower extremity. Lymphangitis was observed along the thigh and groin, affecting the entire scrotum. The condition rapidly deteriorated, with exacerbation of subcutaneous bleeding and blistering, prompting clinical suspicion of necrotizing soft tissue infection. Immediate surgical excision of the infected necrotic tissue was performed upon admission. Subsequently, the patient was transferred to the intensive care unit, where treatment included hyperbaric oxygen therapy, broad-spectrum antibiotic therapy, and multiple revisions of the wound on the left foot. The patient’s clinical course was complicated by acute myocardial infarction (AMI), respiratory failure, and Acute Tubular Injury Nephropathy (ATIN). After a sixteen-day period of treatment in both the intensive care unit and semi-intensive care unit, the patient was transferred to the orthopedic ward, where wound management utilizing VAC therapy was initiated. Following consultation with the Plastic Surgery Department, application of NovoSorb® Biodegradable Temporising Matrix (Novosorb) was administered prior to the patient’s initial physical evaluation by a plastic surgeon. A chronological summary of the patient’s clinical course is outlined below: •
Day -3: Onset of severe pain in the left foot. •
• Day 0: Admission to the emergency department due to necrotizing fasciitis and septic shock, primary wound revision, and transfer to the intensive care unit.
• Day 9: Transition to the semi-intensive care unit.
• Day 17: Transfer to the orthopedic ward.
• Day 30: Initial referral to the Plastic Surgery Department.
• Day 40: Application of Novosorb.
• Day 55: First physical assessment by a plastic surgeon.
• Day 62: Discharge from the orthopedic surgery department for outpatient wound monitoring.
• Day 92: Performance of a split-thickness skin graft.
• Day 165: Most recent imaging assessment of the left foot.
Before and after
Patient examination
First physical assessment by a plastic surgeon (55 days after primary revision): 47-year-old male presents for wound assessment on the left dorsum of the foot in the outpatient clinic at the Plastic Surgery Department, Roskilde. Currently undergoing treatment with Novosorb. Edges were stapled. Biatain absorbent dressing was applied over the wound.
Patient reports feeling well. Not currently receiving antibiotic treatment. Otherwise, unremarkable. Objective: On the left foot, there is a well-healing defect measuring 20×10 cm located at the dorsum, with no signs of infection or fluid collections.
There is no wound rupture or necrosis observed. Novosorb appears to be well-adhered; however, exposed tendons are still present, indicating that the area is not yet ready to receive a split-thickness skin graft. Dorsalis pedis pulse not palpable. Mild dependent edema noted in the left lower leg, without signs of erysipelas or cellulitis. No pitting edema.
Pre-Operative Considerations
Two treatment options were considered for treating the complex wound on this patient’s foot. 1. Free flap 2. Novosorb and split-thickness skin graft (STSG) Free flap surgery involves longer operative times, hospital stays, specialized equipment, and carries higher risks of complications such as flap failure, infection, and donor site morbidity compared to STSGs. However, STSGs may yield less natural appearance and are prone to graft loss if subjected to excessive tension or trauma. Considering these factors, treatment with Novosorb and STSG was preferred due to its less invasive nature and manageable defect size. Novosorb, a wound dressing fostering moist environment, composed of biocompatible materials, aids tissue regeneration, exudate management, wound protection, and granulation tissue formation. Its combination with STSG is viable as Novosorb promotes wound healing while STSG facilitates closure and functional restoration.
- Plan: The defect should be covered with Novosorb, which can be ordered through the medical supplier. Application of Novosorb can be facilitated with assistance from a Novosorb Consultant at the Orthopedic Department. Novosorb can either be stapled or sutured in place and should remain in place for a minimum of 14 days – inspection of the area after 7 days. Skin grafting can proceed once there is full granulation tissue over exposed tendons, which may take 3-5 weeks. When the time comes for the skin graft, the patient can be transferred to the Plastic Surgery Department.
- Advice regarding Novosorb: It is advised not to apply VAC over Novosorb but only foam and dressing. Dressing should be changed one to two times a week, using foam and circular lightly compressive bandages. The thin plastic film should be left in place, and if it falls off, it should be replaced with Jelonet and foam until the wound bed is ready for transplantation. Additionally, it is recommended to elevate the foot generously during the initial days after placing Novosorb. It is ideal to keep the foot still to optimize conditions for Novosorb, but the patient is allowed to support on foot and mobilize for toilet and short walks, preferably with a Walker. A new layer of Novosorb is never applied, as it would be like starting over.
Step 1: Primary wound revision, including debridement procedure (day 0)
The procedure commenced with a seal-shaped biopsy from the femur for cultivation and resistance testing and direct microscopy, reaching healthy tissue with intact, normal fascia. Subsequently, a biopsy was taken from the dorsum of the foot for cultivation and resistance testing and direct microscopy, uncovering distinctly avital tissue with necrotic skin and subcutaneous tissue, easily distinguishable from the fascia by touch of fingers. Following the biopsies, antibiotics were administered (Meropenem 2g x3 iv and Clindamycin 600mg x3 iv). Plenty of seepage with cloudy, dishwater-like fluid was observed. The dorsalis pedis artery was found to be coagulated and avital, prompting its removal along with deemed avital cutaneous nerve branches. Excision extended to healthy tissue with tightly bound fascia. An approximately 25×17 cm area was excised, reaching proximally to the mid-calf and creating a seal-shaped opening, revealing vital, tightly bound fascia. Dressing was applied using lightly moistened towels and blue mats.
Step 2: Sixth revision (15 days after primary revision)
No new necrosis. No granulation tissue. The tendons were clean and smooth, with no signs of drying out. Incision at the level of the 1st and 3rd interstices. Here, completely clean and vital musculature. Lohr ointment, Meithel, and absorbent bandage was applied over this.
Step 3: Ninth revision (28 days after primary revision)
Extensor tendon to the 5th toe was excised. It was cut distally and tapered proximally. VAC gel was applied between all toes, followed by application dorsally across the foot. Subsequently, filming was done, and white sponge is applied to the tendons. Subsequently, black sponge. VAC was tested and sealed.
Step 4: Application of Novosorb (40 days after primary revision)
After removal of the VAC, a nicely granulating wound bed was observed, without signs of infection and with only very sparse fibrin along the wound edges. There were still exposed extensor tendons to the 2nd-4th rays as well as exposed 2 cm below the tibialis anterior. The wound bed was cleaned with Debrisoft, and the wound edges were refreshed with a scalpel. Two sheets of Novosorb were applied, tailored to fit the wound, sutured longitudinally, and secured to the wound edges with staples. Jelonet, fluff, and dressing were placed over this.
Step 5: Novosorb follow-up (48 days after primary revision, 8 days after application of Novosorb)
Removal of the outer dressing over the Novosorb on the left foot dorsum. It appears to have good attachment over the entire defect. No accumulations.
Step 6: Ready for skin graft (92 days after primary revision, 52 days after application of Novosorb)
Image is taken in the operation room before the skin-grafting procedure is carried out.
Step 7: Detachment of the silicone membrane from Novosorb
First, marking was done for harvesting split-thickness skin. Then the silicone membrane was detached from Novosorb. Good integration of Novosorb was found, approximately 90%. Some areas showed exposed tendons, and distally there were fibrin coatings and inadequate integration.
Step 8: Revision of fibrin coating
Revision of fibrin coating was performed with a sharp spoon to induce pinpoint bleeding throughout. The defect measured 20×20 cm.
Step 9: Harvesting of split-thickness skin graft and attachment to defect
From the right thigh, two suitable pieces of split-thickness skin were harvested, meshed, and sutured into the defect using Surgipro 4-0 continuously at the edges and vicryl 4-0 to connect the grafts in the middle.
Step 10: Application of bolus
Above the skin graft a bolus dressing consisting of nitrofurantoin gauze, Jelonet, and foam was applied and secured with staples.
Step 11: Further dressing
Coban2 dressing was applied over the bolus.
Step 12: Skin graft follow up (107 days after primary revision, 15 days after skin graft)
Observed 99% adherence of skin graft and mesh holes started to close. A few small areas with white-ish dead graft exposing the tendon. Overall good graft healing and no signs of infection.
Step 13: Donor site follow up (107 days after primary revision, 15 days after skin graft)
Donor site was inspected with good healing and no signs of infection.
Step 14: Most recent follow-up (165 days after primary revision, 93 days after skin graft application)
Excellent healing almost everywhere. Two very small defects above one of the extensor tendons measuring 2x4mm which was treated with Jelonet.
Post-Operative Plan
Post operative plan (after skin grafting): The patient is to be admitted to the department for 5-6 days until unpacking of bolus. Mobilization: Bed rest with elevated leg. With toilet permission. Pain relief: Tab. paracetamol 1 g p.n. maximum 4 times daily. Suture removal: Unpacking of the transplant at the ward 5-6 days postoperatively. Donor site dressing: Removed after 14 days in the outpatient clinic. Outpatient follow-up: 3 months postoperatively. Antibiotics: Tablet erythromycin 500 mg x3 for 5 days, as the patient has observed CAVE penicillin.
- After discharge from hospital: Dressing can be changed every 2-3 days and aired in between. Lohr salve is to be applied over the exposed tendons, the remaining area is to be covered with Jelonet and gauze dressing. Compression bandaging is to be applied on top of this. Mobilization an additional 25% per day.
References
- Schlottmann F, Obed D, Bingöl AS, März V, Vogt PM, Krezdorn N. Treatment of Complex Wounds with NovoSorb® Biodegradable Temporising Matrix (BTM)-A Retrospective Analysis of Clinical Outcomes. J Pers Med. 2022 Dec 3;12(12):2002. doi: 10.3390/jpm12122002. PMID: 36556223; PMCID: PMC9781929.