An overview of negative pressure wound therapy for the lower extremity

Effectiveness of incisional negative pressure wound therapy after major lower extremity amputation: a randomised controlled trial

INTRODUCTION

The aim was to study the effect of incisional negative pressure wound therapy (iNPWT) in wound healing compared with standard sterile gauze dressings after major lower extremity amputation in patients with peripheral arterial disease (PAD).

METHODS

This prospective, randomised controlled trial included 50 patients undergoing major lower extremity amputations for PAD. Patients were randomised into iNPWT and standard dressing groups. The patency of blood vessels at the level of the stump was ensured with or without revascularisation. The primary outcome was wound-related complications such as surgical site infection (SSI), wound dehiscence, seroma/haematoma formation or the need for revision amputation. The secondary outcome was the time taken for the eligibility of prosthesis placement.

RESULTS

It was found that only 12% of the patients in the iNPWT group had SSI compared with 36% in the standard dressing group (p = 0.047). Rates of wound dehiscence, seroma/haematoma formation and revision amputation were decreased in the iNPWT group but this was not statistically significant (p > 0.05). There was a significant reduction in the time taken for eligibility of prosthesis placement in the iNPWT group (5.12 ± 1.53 vs 6.8 ± 1.95 weeks, p = 0.002).

CONCLUSIONS

iNPWT is effective in reducing the incidence of SSI and the time taken for rehabilitation in patients undergoing major lower limb amputation due to PAD.

A Novel Strategy to Manage Below-Knee-Amputation (BKA) Stump Complications for Early Wound Healing and BKA Salvage

INTRODUCTION

The optimal management of major stump complications (operative infection or dehiscence) following below-knee-amputation (BKA) is unknown. We evaluated a novel operative strategy to aggressively treat major stump complications hypothesizing it would improve our rate of BKA salvage.

METHODS

Retrospective review of patients requiring operative intervention for BKA stump complications between 2015 and 2021. A novel strategy employing staged operative debridement for source control, negative pressure wound therapy, and reformalization was compared to standard care (less structured operative source control or above knee amputation).

RESULTS

32 patients were studied, 29 of which were male (90.6%) with an average age of 56.1 ± 9.6 y. 30 (93.8%) had diabetes and 11 (34.4%) peripheral arterial disease (PAD). The novel strategy was used in 13 patients and 19 had standard care. Novel strategy patients had higher BKA salvage rates, 100% vs 73.7% (P = .064), and postoperative ambulatory status, 84.6% vs 57.9% (P = .141). Importantly, none of the patients undergoing the novel therapy had PAD, while all progressing to above-knee amputation (AKA) did. To better assess the efficacy of the novel technique, patients progressing to AKA were excluded. Patients undergoing novel therapy who had their BKA level salvaged (n = 13) were compared to usual care (n = 14). The novel therapy's time to prosthetic referral was 72.8 ± 53.7 days vs 247 ± 121.6 days (P < .001), but they did undergo more operations (4.3 ± 2.0 vs 1.9 ± 1.1, P < .001).

CONCLUSION

Utilization of a novel operative strategy for BKA stump complications is effective in salvaging BKAs, particularly for patients without PAD.

Delayed open abdomen closure using a combination of acellular dermal matrix and skin graft in Korea: a case report

Delayed closure of an open abdomen (OA) is a clinically challenging task despite its various modalities. It is substantially more difficult when the duration of OA treatment is prolonged due to a patient's condition. We introduced the management of a patient who had a delayed OA treatment spanning approximately 3 months due to severe abdominal contamination. The 64-year-old male patient had an injured pelvis pressed by a road roller. After visiting a trauma center, the patient initially underwent damage control surgery and OA management; however, early primary abdominal closure failed due to severe peritonitis. After negative pressure wound therapy for several months, an acellular dermal matrix graft followed by a skin graft were successfully used as treatments. A combination of acellular dermal matrix graft, negative pressure wound therapy, and skin graft techniques is a considerable management sequence for patients subjected to delayed OA treatment.

How to isolate and manage a colo-atmospheric fistula in a wound requiring negative pressure dressing: a novel technique using a plastic syringe

We describe the management of a colo-atmospheric fistula following extensive debridement for abdominal wall necrotising fasciitis. This was a novel technique performed with VAC dressing and a plastic syringe to isolate the fistula from the surround tissue.

A bioreactor for studying negative pressure wound therapy on skin grafts

Negative pressure wound therapy (NPWT) has become the prevailing standard of care for treating complex soft tissue wounds and is now being considered for use in alternative applications including improving skin graft take. While it is generally agreed that negative pressure leads to improved wound healing, universal consensus on its optimal application is not supported in the literature. We describe the design and validation of a bioreactor to determine the prospective benefits of NPWT on skin grafts and engineered skin substitutes (ESS). Clinically relevant pressures were applied, and the native human skin was able to withstand greater negative pressures than the engineered substitutes. Both skin types were cultured under static, flow‐only, and −75 mm Hg conditions for 3 days. While it remained intact, there was damage to the epidermal‐dermal junction in the ESS after application of negative pressure. The normal skin remained viable under all culture conditions. The engineered skin underwent apoptosis in the flow‐only group; however, the application of negative pressure reduced apoptosis. Vascular endothelial growth factor levels were significantly higher in the normal flow‐only group, 152.0 ± 75.1 pg/mg protein, than the other culture conditions, 81.6 ± 35.5 pg/mg for the static and 103.6 ± pg/mg for the negative pressure conditions. The engineered skin had a similar trend but the differences were not significant. This bioreactor design can be used to evaluate the impacts of NPWT on the anatomy and physiology of skin to improve outcomes in wounds after grafting with normal or engineered skin.

Consensus on the application of negative pressure wound therapy of diabetic foot wounds

Because China is becoming an aging society, the incidence of diabetes and diabetic foot have been increasing. Diabetic foot has become one of the main health-related killers due to its high disability and mortality rates. Negative pressure wound therapy (NPWT) is one of the most effective techniques for the treatment of diabetic foot wounds and great progress, both in terms of research and its clinical application, has been made in the last 20 years of its development. However, due to the complex pathogenesis and management of diabetic foot, irregular application of NPWT often leads to complications, such as infection, bleeding and necrosis, that seriously affect its treatment outcomes. In 2020, under the leadership of Burns, Trauma and Tissue Repair Committee of the Cross-Straits Medicine Exchange Association, the writing group for ‘Consensus on the application of negative pressure wound therapy of diabetic foot wounds’ was established with the participation of scholars from the specialized areas of burns, endocrinology, vascular surgery, orthopedics and wound repair. Drawing on evidence-based practice suggested by the latest clinical research, this consensus proposes the best clinical practice guidelines for the application and prognostic evaluation of NPWT for diabetic foot. The consensus aims to support the formation of standardized treatment schemes that clinicians can refer to when treating cases of diabetic foot.

Development of a Peptide Derived from Platelet-Derived Growth Factor (PDGF-BB) into a Potential Drug Candidate for the Treatment of Wounds

Objective: This study evaluated the use of novel peptides derived from platelet-derived growth factor (PDGF-BB) as potential wound healing stimulants. One of the compounds (named PDGF2) was subjected for further research after cytotoxicity and proliferation assays on human skin cells. Further investigation included evaluation of: migration and chemotaxis of skin cells, immunological and allergic safety, the transcriptional analyses of adipose-derived stem cells (ASCs) and dermal fibroblasts stimulated with PDGF2, and the use of dorsal skin wound injury model to evaluate the effect of wound healing in mice. Approach: Colorimetric lactate dehydrogenase and tetrazolium assays were used to evaluate the cytotoxicity and the effect on proliferation. PDGF2 effect on migration and chemotaxis was also checked. Immunological safety and allergic potential were evaluated with a lymphocyte activation and basophil activation test. Transcriptional profiles of ASCs and primary fibroblasts were assessed after stimulation with PDGF2. Eight-week-old BALB/c female mice were used for dorsal skin wound injury model. Results: PDGF2 showed low cytotoxicity, pro-proliferative effects on human skin cells, high immunological safety, and accelerated wound healing in mouse model. Furthermore, transcriptomic analysis of ASCs and fibroblasts revealed the activation of processes involved in wound healing and indicated its safety. Innovation: A novel peptide derived from PDGF-BB was proved to be safe drug candidate in wound healing. We also present a multifaceted in vitro model for the initial screening of new compounds that may be potentially useful in wound healing stimulation. Conclusion: The results show that peptide derived from PDGF-BB is a promising drug candidate for wound treatment.

Step-up approach combined with negative pressure wound therapy for the treatment of severe necrotizing pancreatitis: a case report

A step-up approach and continuous drainage using NPWT was an effective strategy for the treatment of severe necrotizing pancreatitis. A 62-year-old woman developed severe necrotizing pancreatitis after endoscopic retrograde cholangiopancreatography, extending from the left anterior pararenal space to the interior renal pole. Endoscopic transluminal drainage and percutaneous catheter drainage were unsuccessful in controlling the disease. We proceeded with video-assisted retroperitoneal necrosectomy, at the pancreas and splenic hilum, and drainage, with two additional surgical drains located at the left inferior renal pole and, subcutaneously, at the incision wound. NPWT enhanced fluid drainage and facilitated surgical wound closure, which was infected and opened. Four subsequent endoscopic necrosectomy procedures were required, at the site of the draining fistula, to achieve complete resolution of fluid collection and wound closure.

Closed Incisional Negative Pressure Wound Therapy at Flap Suture Line: An Innovative Approach for Improving Outcomes in Suboptimal Wound Conditions

Background  Persistent dead space following flap cover is a frequently encountered challenge following the reconstruction of complex wounds. It may lead to a hematoma, seroma, wound infection, and wound dehiscence. Wound dehiscence could be a devastating complication. Closed incisional negative pressure wound therapy (ciNPWT) over the surgical incisions was found to reduce surgical site infection (SSI) and wound dehiscence. We applied this principle at the closed flap suture line and through this article, we share the indications, technique, and outcomes.

Methods  A retrospective analysis (January 2018–June 2019), in which selected high-risk patients who underwent ciNPWT at the flap suture following complex reconstruction (pedicled or free flap) were included in the study. The indications include deep incisional/organ SSI after debridement and flap coverage, persistent dead space following flap coverage, chronic osteomyelitis. Patients were analyzed in the follow-up period in terms of complications, wound healing.

Results  Nine patients underwent ciNPWT over the flap suture line. The mean age was 32.2 years (range: 10–48 years). The mean duration of the NPWT application was 7.3 days (range: 3–21 days). Three of the nine patients had flap-related minor complications. One patient had marginal flap necrosis and required skin grafting, one patient had minor wound dehiscence (1 cm) which required secondary skin suturing and one patient had chronic discharging sinus related to osteomyelitis of ischium, which subsequently healed with antibiotics and local wound care. None of the patients had NPWT-related complications.

Conclusion  Closed incisional NPWT decreases the untoward effects of dead space following the reconstruction of complex wounds. The incidence of SSI and wound gaping can be reduced.

Combination of negative pressure wound therapy (NPWT) and integra dermal regeneration template (IDRT) in the lower extremity wound; Our experience with 4 cases

The treatment of de-gloving injuries in the lower limb with exposed tendons, bone, and/or nerve is a challenging reconstruction problem. The standard management of de-gloving injuries involve either direct closure if the skin is viable or immediate grafting with the avulsed skin or full- or split-thickness graft when the skin flap is not viable. Alternative methods are flap coverage especially when the underlying structures are not suitable for grafting such as extensive loss of paratenon and/or exposed bone or open joints The use of negative pressure wound therapy (NPWT) followed by use of Integra dermal regeneration template (IDRT) and subsequent split-thickness skin grafting (STSG) as an alternative to the previously mentioned surgical options has been described. In this series we describe the successful management of four patients with exposed tendons, bones, and joints of the distal lower extremity following road traffic accidents (RTA) using NPWT, Integra and thin split-thickness skin grafts.

Negative-pressure wound therapy in the management of diabetic Charcot foot and ankle wounds

As the prevalence of diabetes mellitus continues to rise, innovative medical and surgical treatment options have increased dramatically to address diabetic-related foot and ankle complications. Among the most challenging clinical case scenarios is Charcot neuroarthropathy associated with soft tissue loss and/or osteomyelitis. In this review article, the authors present a review of the most common utilizations of negative-pressure wound therapy as an adjunctive therapy or combined with plastic surgery as it relates to the surgical management of diabetic Charcot foot and ankle wounds.

A topical negative-pressure technique with skin flap transplantation to repair lower-limb wounds with bone exposure

The treatment of chronic skin ulcers with exposed bone in the lower extremity is difficult. The development of topical negative pressure (TNP) technology and microsurgical techniques have achieved good clinical results in the repair of such ulcers. Between January 2007 and March 2012, TNP combined with flap transfer was applied to repair lower-limb skin and soft-tissue defects associated with exposed bone in 22 cases at our hospital, and good results were achieved that are reported herein.

Negative pressure wound therapy for at-risk surgical closures in patients with multiple comorbidities: a prospective randomized controlled study

PURPOSE

The purpose of this study is to evaluate the effect of Negative Pressure Wound Therapy (NPWT) on closed surgical incisions. We performed a prospective randomized controlled clinical trial comparing NPWT to standard dry dressings on surgical incisions.

METHODS

Patients presenting to a high-volume wound center were randomized to receive either a V.A.C. (KCI, San Antonio, TX) or a standard dry dressing over their incision at the conclusion of surgery. These were primarily high-risk patients with multiple comorbidities. The 2 groups were compared, and all incisions were evaluated for infection and dehiscence postoperatively.

RESULTS

Eighty-one patients were included for analysis. Thirty-seven received dry dressings, and 44 received NPWT. Seventy-four of these underwent lower extremity wound closure. Average follow-up was 113 days. There were no differences in demographic, preoperative, and operative variables between groups; 6.8% of the NPWT group and 13.5% of the dry dressing group developed wound infection, but this was not statistically significant (P = 0.46). There was no difference in time to develop infection between the groups. There was no statistical difference in dehiscence between NPWT and dry dressing group (36.4% vs 29.7%; P = 0.54) or mean time to dehiscence between the 2 groups (P = 0.45). Overall, 35% of the dry dressing group and 40% of the NPWT group had a wound infection, dehiscence, or both. Of these, 9 in the NPWT group (21%) and 8 in the dry dressing group (22%) required reoperation.

CONCLUSIONS

There is a significant rate of postoperative infection and dehiscence in patients with multiple comorbidities. There was no difference in the incidence of infection or dehiscence between the NPWT and dry dressing group. This study is registered with ClinicalTrials.gov. The unique registration number is NCT01366105.

Negative pressure wound therapy in acute, contaminated wounds: documenting its safety and efficacy to support current global practice

Negative pressure wound therapy (NPWT) is in widespread use and its role in wound care is expanding worldwide. It is estimated that 300 million acute wounds are treated globally each year. Currently, sporadic data exist to support NPWT in acutely contaminated wounds. Despite lack of data, use of negative pressure wound therapy in such cases is increasing across the globe. We retrospectively reviewed 86 consecutive patients, totalling 97 contaminated wounds. All wounds were Class IV based on US Center for Disease Control criteria. Sepsis criteria were present in 78/86 (91%) of patients. All patients were managed with NPWT. Wound type, degree of tissue destruction, presence of infection, wound dimension, timing of initial NPWT, type and timing of wound closure and patient comorbidities were recorded. Outcome endpoints included durability of wound closure and death. Wound location was 41/97 (42%) in the torso; 56/97 (58%) at the extremities. Tissue necrosis was present in 84/97 (87%) of wounds. Infection was present in 86/97 (89%) of wounds. Average wound size was 619 cm(2) when square surface area measured; 786 cm(3) when volume measurements taken. Mean time to wound closure was 17 days, median 10 days and mode 6 days. Durability of wound closure 73/79 (92%). Deaths were noted in 6/86 (7%) of patients. No deaths appeared related to NPWT. Contemporary NPWT related acute wound care is expanding empirically, in quantity and scope across the globe. However, several areas of concern are known regarding this contemporary use of NPWT in acute wounds. Thus, it is important to assess the safety and efficacy of such expanded empiric NPWT practice. Based on our findings with NPWT in the largest known patient cohort of this type, NPWT appears safe and effective in managing acute, contaminated wounds including patients meeting sepsis criteria. These findings provide evidence-based support for current worldwide empiric NPWT-related acute wound care.

Evaluation of chronic wound treatment with the SNaP wound care system versus modern dressing protocols

BACKGROUND

Traditional negative-pressure wound therapy systems use an electrically powered pump to generate negative pressure at the wound bed. The SNaP Wound Care System is a novel, ultraportable device that delivers negative-pressure wound therapy without the use of an electrically powered pump.

METHODS

At an outpatient wound care clinic, 21 subjects with difficult-to-treat lower extremity ulcers received treatment with the SNaP System and were evaluated for wound healing for up to 4 months. Outcomes were then compared with 42 patient-matched controls treated at the same center with modern wound care protocols that included the use of Apligraf, Regranex, and skin grafting.

RESULTS

In the SNaP-treated group, 100 percent of subjects demonstrated improvement in wound size and 86 percent (18 of 21) exhibited a statistically significant healing trend (p < 0.05). Using Kaplan-Meier estimates of wound healing, SNaP-treated subjects healed in an average of 74.25 ± 20.1 days from the start of SNaP treatment and the matched controls healed in an average of 148.73 ± 63.1 days from the start of conventional treatment. This significantly faster healing time represents a 50 percent absolute reduction in time to healing (p < 0.0001) for subjects treated with the SNaP device.

CONCLUSIONS

The findings reported here for the SNaP Wound Care System are similar to published reports for powered negative-pressure wound therapy devices for the treatment of highly challenging lower extremity wounds. This study suggests that the SNaP Wound Care System may be a useful addition to the techniques available to the wound care clinician.

Abductor hallucis muscle flap and staged medial column arthrodesis for the chronic ulcerated charcot foot with concomitant osteomyelitis

Midfoot ulceration is a common sequela of the diabetic Charcot rocker-bottom deformity. Because redundant soft tissue from a non- weight-bearing area is often scarce in this area of the foot, soft-tissue coverage may be challenging. Wound closure may be difficult to achieve with local wound care and off-loading techniques if the predisposing deformity that caused the ulceration is not addressed. In the same setting, surgical reconstruction is often feared when open wounds are present, given the potential for infection. Approaching these wounds with a rational stepwise and staged approach is prudent to eradicate the underlying infection and also to achieve durable wound closure and long-term deformity correction. The authors present the use of a local muscle flap and circular external fixation for closure of a recalcitrant Charcot plantar-medial midfoot ulceration and also discuss different adjunctive modalities to facilitate soft-tissue reconstruction in the diabetic foot.

Soft tissue reconstruction pyramid in the diabetic foot

Foot complications and ulceration are well-known sequelae to uncontrolled diabetes. Patients with chronic foot ulcers or wounds resulting from surgical debridement of deep-space infections are at continued risk for development of osteomyelitis and potential amputation. Moreover, these wounds often necessitate multiple outpatient clinic visits, daily dressing care, and prolonged periods of non-weight bearing, all of which have been shown to adversely affect the patient's quality of life. After a prudent period of wound-healing response, the authors believe that early and aggressive soft tissue reconstruction is in the patient's best interest and is crucial for resolution of the chronic nonhealing wound. The options for soft tissue coverage and the logical progression of application of these techniques in the diabetic foot will be described.