Negative Pressure Wound Therapy: Mechanism of Action and Clinical Applications

Negative pressure wound therapy (NPWT) promotes healing by evenly applying negative pressure on the surface of the wound. The system consists of a sponge, a semiocclusive barrier, and a fluid collection system. Its effectiveness is explained by four main mechanisms of action, including macrodeformation of the tissues, drainage of extracellular inflammatory fluids, stabilization of the environment of the wound, and microdeformation. Rarely will complications linked to NPWT occur, but special care must be taken to prevent events such as toxic shock syndrome, fistulization, bleeding, and pain. New NPWT modalities have been recently developed to make NPWT suitable for a wider variety of wounds. These include NPWT with instillation therapy (NPWTi-d), different cleansing options, and application of NPWT on primarily closed incisions. Finally, vacuum-assisted wound closure therapy has been demonstrated to be efficient for various clinical settings, such as the management of diabetic foot ulcers, pressure ulcerations, chronic wounds, and skin grafts.

Effectiveness of Steroid Pulse Therapy for Systemic Side Effects after Bacillus Calmette-Guérin Intravesical Instillation Therapy: A Series of Five Cases

Introduction. Bacillus Calmette-Guérin (BCG) instillation is an established therapy for the treatment of carcinoma in situ (CIS) of the bladder and prevention of recurrence after transurethral resection of bladder tumor noninvasive bladder cancer. However, serious systemic side effects may occur in less than 5% of patients with BCG intravesical instillation. Systemic side effects can sometimes be fatal and require early and accurate treatment. We describe five cases wherein steroid pulse therapy was effective for treating the systemic side effects after BCG intravesical instillation. Case Presentations. BCG intravesical instillation was used to prevent the recurrence of nonmuscle invasive bladder cancer and treat CIS of the bladder; the dose used was 40–80 mg each time, and the Tokyo strain was used. The patients developed fever, impaired consciousness, arthralgia, conjunctival hyperemia, and symptoms of cystitis. The median time from installation to side effect manifestation was 6 days (0–8). One to two courses of steroid pulse therapy were administered (1 course in 3 days), and the dose of methylprednisolone was 500–1000 mg/day. BCG sepsis was observed in one case; however, in the other four cases, one course of steroid pulse therapy showed a rapid improvement in symptoms. In the case of BCG sepsis, hemodialysis and mechanical ventilation were required because of septic shock and acute renal failure. Antituberculosis drugs (isoniazid, rifampicin, and ethambutol) were started promptly; however, no improvement was noticed. Two courses of steroid pulse therapy improved the patient’s general condition, and hemodialysis and mechanical ventilation were no longer required. All patients survived without relapse of symptoms. Conclusion. Our cases suggest that early steroid pulse therapy may be effective for rapid symptom improvement of the systemic side effects of BCG instillation therapy.

High Androgen Receptor mRNA Expression Is Associated with Improved Outcome in Patients with High-Risk Non-Muscle-Invasive Bladder Cancer

The role of the androgen receptor (AR) in non-muscle-invasive bladder cancer (NMIBC) remains controversial. We retrospectively analyzed the mRNA expression of AR using RT-qPCR in 95 patients with high-risk NMIBC treated with a bladder-sparing approach and correlated AR with clinical data and recurrence-free survival (RFS), cancer-specific survival (CSS), and overall survival (OS). The mRNA expression of AR and KRT5, i.e., the basal-like subtype, was strongly correlated (rs = 0.456; p < 0.001). AR (p = 0.053) and KRT5 (p = 0.029) mRNA expression was negatively correlated with tumor grade. Kaplan–Meier analyses indicated significantly prolonged CSS (p = 0.020) and OS (p = 0.015) and a trend towards longer RFS (p = 0.051) in patients with high AR expression. High KRT5 expression was associated with significantly longer RFS (p = 0.033), CSS (p = 0.029) and OS (p = 0.030), while high KRT20 expression was associated with reduced RFS (p = 0.042). In multivariable analysis, none of the molecular markers was an independent prognostic factor. When performing a substratification with regard to molecular markers and clinicopathological parameters, high AR expression showed improved OS in patients with high KRT20 mRNA expression (p = 0.041). Women showed significantly longer OS in cases with high AR expression (p = 0.011). High AR was associated with significantly improved CSS in males (p = 0.044) and patients with instillation therapy (p = 0.040), while OS was improved regardless of instillation therapy. Younger patients with high AR expression had significantly improved RFS (p = 0.021), CSS (p = 0.014) and OS (p = 0.007). RFS was also improved in patients with high AR and low expression of either KRT5 (p = 0.003) or KRT20 (p = 0.014), but not in patients with high expression of KRT5 or KRT20. In conclusion, high AR mRNA expression is correlated with KRT5 mRNA expression and is associated with an improved outcome in high-risk NMIBC.

Successful Treatment of Driveline Infection with Vacuum-Assisted Closure Therapy and Instillation Therapy

Background Driveline infection is a serious complication in left ventricular assist device (LVAD) patients. We report the case of a patient who was successfully treated by combining instillation and vacuum-assisted closure (VAC) therapy. Case Description A 65-year-old LVAD patient presented with recurrent driveline infection. Local therapy with VAC therapy in combination with instillation of polyhexanide was performed for 2 weeks. The patient remains free from infection for twelve months by now. Conclusion This case is the first to present the combination of polyhexanide instillation with VAC as treatment for driveline infection. This therapy may thus be an option for patients who lack any other surgical option.

VACUUM INSTILLATION THERAPY IN THE TREATMENT OF PURULENT-NECROTIC FORMS OF DIABETIC FOOT

Lack of control over the course of the disease (diabetes), ignoring measures to prevent the development of complicated forms of diabetic foot, late referral of patients with existing complications on the foot, contributes to an increase in the number of patients with destructive forms of diabetic foot. Purpose of the study. To evaluate the technique of vacuum instillation therapy (NPWTi) in comparison with the use of an isolated vacuum and the classical surgical method for treating purulentnecrotic forms of diabetic foot. Materials and methods. The results of local treatment of 41 patients with purulent-necrotic forms of diabetic foot corresponding to III and IV stages (Meggitt-Wagner) were analyzed. The patients are divided into groups depending on the method of topical treatment. The cellular composition and microflora of the wounds were studied, and the change in the area of the wound surface was assessed before the start of treatment and in the 4–5th and 8–9th days. Results and discussion. The use of NPWT showed better treatment results in comparison with group 1, where signs of phase II of the wound process were diagnosed by 8–9 days from the start of topical treatment in 83,3% of patients. The highest efficiency in topical treatment was noted in the 3rd group using the NPWTi method, where by the 4th–5th day, ½ patients were cytologically diagnosed with phase II of the wound process. Conclusions. The NPWTi technique is most effective in the treatment of purulent-necrotic forms of diabetic foot, which makes it possible to reduce the time of wound cleaning, the time of the patient's stay in the hospital, and save the limb. Keywords: purulent-necrotic forms of diabetic foot, topical therapy, NPWT technique, NPWTi technique.