Negative Pressure Wound Treatment of Infections Caused By Extensively Drug-Resistant Gram-Negative Bacteria After Liver Transplantation: Two Case Reports

Colistimethate sodium-chitosan hydrogel for treating Gram-negative bacterial wound infections

The drug resistance is higher among Gram-negative bacteria and demands the usage of strong antibiotics which can in turn result in systemic toxicity. In the treatment of the chronic wounds harboring pathogenic Gram-negative bacteria, the demand for an antimicrobial product that can be topically administered has been on the rise. In an effort to address the above issue, we have developed Colistimethate sodium (a high-end antibiotic) loaded chitosan hydrogel and characterized. The prepared hydrogel is very stable and observed to be bio- and hemo-compatible in nature. The antibacterial activity of the prepared hydrogel was studied against both ATCC (American Type Culture Collection) strains and clinical isolates of Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae. The CMS incorporated hydrogel is also capable of inhibiting the biofilm formation. The developed hydrogel can be potentially being used for the treatment of Gram-negative bacterial infected wounds.

EWMA Document: Negative Pressure Wound Therapy

1. Introduction Since its introduction in clinical practice in the early 1990's negative pressure wounds therapy (NPWT) has become widely used in the management of complex wounds in both inpatient and outpatient care.¹ NPWT has been described as a effective treatment for wounds of many different aetiologies^2,3 and suggested as a gold standard for treatment of wounds such as open abdominal wounds,^4-6 dehisced sternal wounds following cardiac surgery^7,8 and as a valuable agent in complex non-healing wounds.^9,10 Increasingly, NPWT is being applied in the primary and home-care setting, where it is described as having the potential to improve the efficacy of wound management and help reduce the reliance on hospital-based care.¹¹ While the potential of NPWT is promising and the clinical use of the treatment is widespread, highlevel evidence of its effectiveness and economic benefits remain sparse.^12-14 The ongoing controversy regarding high-level evidence in wound care in general is well known. There is a consensus that clinical practice should be evidence-based, which can be difficult to achieve due to confusion about the value of the various approaches to wound management; however, we have to rely on the best available evidence. The need to review wound strategies and treatments in order to reduce the burden of care in an efficient way is urgent. If patients at risk of delayed wound healing are identified earlier and aggressive interventions are taken before the wound deteriorates and complications occur, both patient morbidity and health-care costs can be significantly reduced. There is further a fundamental confusion over the best way to evaluate the effectiveness of interventions in this complex patient population. This is illustrated by reviews of the value of various treatment strategies for non-healing wounds, which have highlighted methodological inconsistencies in primary research. This situation is confounded by differences in the advice given by regulatory and reimbursement bodies in various countries regarding both study design and the ways in which results are interpreted. In response to this confusion, the European Wound Management Association (EWMA) has been publishing a number of interdisciplinary documents^15-19 with the intention of highlighting: The nature and extent of the problem for wound management: from the clinical perspective as well as that of care givers and the patients Evidence-based practice as an integration of clinical expertise with the best available clinical evidence from systematic research The nature and extent of the problem for wound management: from the policy maker and healthcare system perspectives The controversy regarding the value of various approaches to wound management and care is illustrated by the case of NPWT, synonymous with topical negative pressure or vacuum therapy and cited as branded VAC (vacuum-assisted closure) therapy. This is a mode of therapy used to encourage wound healing. It is used as a primary treatment of chronic wounds, in complex acute wounds and as an adjunct for temporary closure and wound bed preparation preceding surgical procedures such as skin grafts and flap surgery. Aim An increasing number of papers on the effect of NPWT are being published. However, due to the low evidence level the treatment remains controversial from the policy maker and health-care system's points of view-particularly with regard to evidence-based medicine. In response EWMA has established an interdisciplinary working group to describe the present knowledge with regard to NPWT and provide overview of its implications for organisation of care, documentation, communication, patient safety, and health economic aspects. These goals will be achieved by the following: Present the rational and scientific support for each delivered statement Uncover controversies and issues related to the use of NPWT in wound management Implications of implementing NPWT as a treatment strategy in the health-care system Provide information and offer perspectives of NPWT from the viewpoints of health-care staff, policy makers, politicians, industry, patients and hospital administrators who are indirectly or directly involved in wound management.

Chinese Trauma Surgeon Association for management guidelines of vacuum sealing drainage application in abdominal surgeries-Update and systematic review

Vacuum sealing drainage (VSD) is frequently used in abdominal surgeries. However, relevant guidelines are rare. Chinese Trauma Surgeon Association organized a committee composed of 28 experts across China in July 2017, aiming to provide an evidence-based recommendation for the application of VSD in abdominal surgeries. Eleven questions regarding the use of VSD in abdominal surgeries were addressed: (1) which type of materials should be respectively chosen for the intraperitoneal cavity, retroperitoneal cavity and superficial incisions? (2) Can VSD be preventively used for a high-risk abdominal incision with primary suture? (3) Can VSD be used in severely contaminated/infected abdominal surgical sites? (4) Can VSD be used for temporary abdominal cavity closure under some special conditions such as severe abdominal trauma, infection, liver transplantation and intra-abdominal volume increment in abdominal compartment syndrome? (5) Can VSD be used in abdominal organ inflammation, injury, or postoperative drainage? (6) Can VSD be used in the treatment of intestinal fistula and pancreatic fistula? (7) Can VSD be used in the treatment of intra-abdominal and extra-peritoneal abscess? (8) Can VSD be used in the treatment of abdominal wall wounds, wound cavity, and defects? (9) Does VSD increase the risk of bleeding? (10) Does VSD increase the risk of intestinal wall injury? (11) Does VSD increase the risk of peritoneal adhesion? Focusing on these questions, evidence-based recommendations were given accordingly. VSD was strongly recommended regarding the questions 2-4. Weak recommendations were made regarding questions 1 and 5-11. Proper use of VSD in abdominal surgeries can lower the risk of infection in abdominal incisions with primary suture, treat severely contaminated/infected surgical sites and facilitate temporary abdominal cavity closure.

Efficacy of Prophylactic Negative Pressure Wound Therapy After Pediatric Liver Transplant

OBJECTIVES

Wound dehiscence is a common surgical complication, especially among pediatric liver transplant recipients in our center. In 2013, we introduced negative pressure wound therapy as a preventive treatment. We herein report the clinical outcomes of this intervention.

MATERIALS AND METHODS

We conducted a retrospective review of the 26 pediatric liver transplant recipients in our center since 2011. We excluded 1 girl whose wound could not be closed due to bowel edema. The first 13 of the 25 remaining patients were treated with conventional wound management (conventional group). The latter 12 were treated with prophylactic negative pressure wound therapy (prophylactic group). Incidences of surgical complications and patient characteristics were compared between groups.

RESULTS

Wound dehiscence occurred in 7 of the 13 patients in the conventional group and 3 of the 12 patients in the prophylactic group. When restricted to dehiscence that required surgical debridement, there were 6 cases in the conventional group and no cases in the prophylactic group. Although background data showed that liver insufficiency in the prophylactic group was more severe, this group had a lower incidence of wound dehiscence (P = .015).

CONCLUSIONS

Prophylactic negative pressure wound therapy is thought to be effective for preventing wound dehiscence among pediatric liver transplant recipients.

Prolonged Negative Pressure Wound Therapy Followed by Split-Thickness Skin Graft Placement for Wide Dehiscence of Clamshell Incision After Bilateral Lung Transplantation: A Case Report

Clamshell incision is a standard approach for bilateral lung transplantation, providing a good operative field; however, once wide dehiscence occurs, its management is sometimes difficult because of intense immunosuppression and malnutrition of the recipient. A 22-year-old man with idiopathic pulmonary arterial hypertension underwent cadaveric bilateral lung transplantation through a clamshell incision using standard cardiopulmonary bypass. He developed wound dehiscence on postoperative day (POD) 20 that resulted in exposure of the bilateral fifth ribs and open pneumothorax. Considering the extreme malnutrition and emaciation of the recipient, we avoided initial closure of the dehiscence. After the debridement of necrotic tissue, negative pressure wound therapy was initiated on POD 25 and was continued for approximately 6 months with trafermin spray application. Eventually, the wound, including the fifth ribs, was completely covered with granulation tissue except for the wire tying the sternum. On POD 217, the patient underwent removal of the sternal wire followed by split-thickness skin grafting. His wound was successfully closed and he was discharged without activity limitation on POD 265.