Dynamic computational simulations for evaluating tissue loads applied by regulated negative pressure-assisted wound therapy (RNPT) system for treating large wounds.

Regulated negative pressure-assisted wound therapy (RNPT) is one of the most important wound treatment technologies developed and applied over the last two decades. To-date RNPT has been proven to be clinically effective in treating chronic wounds, however, the effects of different specific pressure delivery protocols on the progress and quality of tissue repair are not adequately understood yet. Here, we suggest a viscoelastic, three-dimensional finite element modeling framework of RNPT, with several realistic features such as a non-symmetrically configured multi-layered tissue structure. The effects of the RNPT system on the wound-bed were simulated by applying time varying pressure boundary conditions. Three commonly-used operation modes were simulated: continuous, non-continuous intermittent and dynamic, and each mode was applied at four different pressure levels. Outcome measures of strain and stress magnitudes and distributions were acquired from the dermis and subcutaneous fat. Taken together, the strain and stress data from the different simulated RNPT modes and intensities demonstrated that tissue loads which are actually applied in and around the wound, and at the different tissue components of the wound, can differ substantially from the pressure levels that are set in the device during therapy sessions. This is critical information for understanding the potential effects of RNPT, for setting the device prior to therapy and for designing the next generation of these systems.

Tissue loads applied by a novel medical device for closing large wounds.

Closure of large soft tissue defects following surgery or trauma as well as closure of large chronic wounds constitutes substantial but common reconstructive challenges. In such cases, an attempt to use conventional suturing will result in high-tension closure, therefore alternative external skin stretching systems were developed. These types of devices were meant to reduce local mechanical loads in the skin and the underlying tissues, taking advantage of the viscoelastic properties of the skin, especially mechanical creep, for primary wound closure. Studies have shown the clinical advantages of skin stretching systems, however, quantitative bioengineering models, demonstrating closure of large wounds, are lacking. Here we present finite element (FE) modeling of the TopClosure(®) tension relief system (TRS) and its biomechanical efficacy in three (real) wound cases, compared with the alternative of a conventional surgical suturing closure technique. Our simulations showed that peak effective stresses on the skin were at least an order of magnitude greater (and sometimes nearly 2 orders-of-magnitude greater) when tension sutures were used with respect to the corresponding TRS data. For the tension suture simulations, the tensile stress was in the range of 415-648 MPa and in the TRS simulations, it was 16-30 MPa. Based on the present computational FE modeling, the TRS reduces localized tissue deformations and stress concentrations in skin and underlying tissues while closing large wounds, compared to the deformations and stresses that are inflicted during the process of suturing. This substantial reduction of loads allows surgeons to better employ the viscoelastic properties of the skin for primary wound closure.

A substitute for skin grafts, flaps, or internal tissue expanders in scalp defects following tumor ablative surgery.

BACKGROUND: The skin of the scalp is relatively thick, minimally mobile, with distinct hair distribution. TopClosure® is a novel device for skin stretching and secure wound closure. OBJECTIVES: To evaluate the efficacy of the TopClosure® system in primary closure of moderate and large scalp defects, as a substitute for skin grafts, flaps, and tissue expanders. METHODS: We report a retrospective series of 8 patients requiring resection of 9 scalp tumors resulting with moderate to large size defects that otherwise would have required reconstruction with skin grafts, flaps, or tissue expanders. TopClosure® was applied for intraoperative cycles of stress-relaxation, followed, when indicated, by additional steps of mechanical creep and scar secure. RESULTS: Skin defects, averaging 3.5 cm, were managed by TopClosure®, enabling, primary closure in all wounds. Immediate wound edge approximation was reached through stress-relaxation in 2 wounds by heavy tension sutures within one hour. Further skin stretching by mechanical creep was required in 7 wounds, achieving staged primary closure in an outpatient setting. TopClosure® was further applied to secure the skin for up to 3 weeks following surgery. CONCLUSIONS: The TopClosure system, effectively, aided closure of moderate and large scalp defects by stress-relaxation and mechanical creep and serving as a topical tension-relief platform for tension sutures, allowing mobilization of skin and subcutaneous tissue without undermining or need of drainage, for early, direct wound closure. Local complications were minimal and donor site morbidity was eliminated. Surgical time, hospital stay and costs were reduced, and post-operative wound aesthetics were improved.

Regional Antibiotic Delivery for Implanted Cardiovascular Electronic Device Infections.

BACKGROUND: Present guidelines endorse complete removal of cardiovascular implantable electronic devices (pacemakers/defibrillators), including extraction of all intracardiac electrodes, not only for systemic infections, but also for localized pocket infections. OBJECTIVES: The authors evaluated the efficacy of delivering continuous, in situ-targeted, ultrahigh concentration of antibiotics (CITA) into the infected subcutaneous device pocket, obviating the need for device/lead extraction. METHODS: The CITA group consisted of 80 patients with pocket infection who were treated with CITA during 2007-2021. Of them, 9 patients declined lead extraction because of prohibitive operative risk, and 6 patients had questionable indications for extraction. The remaining 65 patients with pocket infection, who were eligible for extraction, but opted for CITA treatment, were compared with 81 patients with pocket infection and similar characteristics who underwent device/lead extraction as primary therapy. RESULTS: A total of 80 patients with pocket infection were treated with CITA during 2007-2021. CITA was curative in 85% (n = 68 of 80) of patients, who remained free of infection (median follow-up 3 years [IQR: 1.0-6.8 years]). In the case-control study of CITA vs device/lead extraction, cure rates were higher after device/lead extraction than after CITA (96.2% [n = 78 of 81] vs 84.6% [n = 55 of 65]; P = 0.027). However, rates of serious complications were also higher after extraction (n = 12 [14.8%] vs n = 1 [1.5%]; P = 0.005). All-cause 1-month and 1-year mortality were similar for CITA and device/lead extraction (0.0% vs 3.7%; P = 0.25 and 12.3% vs 13.6%; P = 1.00, respectively). Extraction was avoided in 90.8% (n = 59 of 65) of extraction-eligible patients treated with CITA. CONCLUSIONS: CITA is a safe and effective alternative for patients with pocket infection who are unsuitable or unwilling to undergo extraction. (Salvage of Infected Cardiovascular Implantable Electronic Devices [CIED] by Localized High-Dose Antibiotics; NCT01770067).

Pediatric Wound Closure by a Tension-Relief System.

Surgical reconstruction in pediatric patients can often be complex. Primary wound closure is almost always the preferred technique in the reconstructive ladder; however, it is not always possible in pediatric patients. We report the pediatric use of the TopClosure Tension-Relief System, an innovative skin-stretching technique for secure primary wound closure of large defects. We modified the technique by fixating it to a protective dressing instead of the patient's skin, thus avoiding both staple scars and pain. A retrospective review of 112 patients aged 7 days to 18 years who underwent Tension-Relief System-assisted surgery at a tertiary medical center from 2010 to 2020 was conducted. Cases included congenital deformities, traumatic wounds, burn scars, and complicated-wounds, with or without hardware or deep tissue exposure. The use of the system avoided the need for multiple surgical sessions and for local or regional flaps. The technique was simple to use, with few complications, and led to satisfactory aesthetic and functional outcomes. The findings support using the technique in children and adolescents with challenging tension wounds. Herein, we report on our experience with the Tension-Relief System and detail four cases in which early or immediate closure was successfully achieved.

In-vitro model for bacterial growth inhibition of compartmentalized infection treated by an ultra-high concentration of antibiotics.

BACKGROUND: Pseudomonas aeruginosa (P. aeruginosa), Escherichia coli (E. coli), and Staphylococcus aureus (S. aureus) are common pathogens encountered in infected cardiovascular-implantable electronic device (CIED). Continuous, in-situ targeted, ultra-high concentration antibiotic (CITA) treatment is a novel antibiotic treatment approach for localized infections. CITA provides sufficient local antibiotic concentrations to heavily infected cavities while avoiding systemic toxicity. AIM: In-vitro confirmation of the efficacy of the CITA treatment approach in simulated compartmentalized infections. MATERIALS AND METHODS: A rapid automated bacterial culture analyzing system) Uro4 HB&L™ (was applied to compare the efficacy of selected antibiotics at a standard minimal inhibitory concentration (1MIC), 4MIC, and CITA at 103MIC, for growth inhibition of high bacterial loads (106 colony-forming-units/ml) of ATCC strains of P. aeruginosa, E. coli, and S. aureus. RESULTS: The addition of gentamicin and amikacin at 1MIC concentrations only temporarily inhibited the exponential growth of E. coli and P. aeruginosa. 4MIC level extended the delay of exponential bacterial growth. Increasing concentrations of vancomycin similarly temporarily delayed S. aureus growth. All tested antibiotics at CITA of 103MIC totally inhibited the exponential growth of the tested bacteria through 72 hours of exposure. (P<0.001). CONCLUSION: In this in-vitro model, CITA at 103MIC effectively inhibited exponential bacterial growth of high loads of P. aeruginosa, E. coli, and S. aureus. This model offers preliminary laboratory support for the benefit of the in-situ antibiotic treatment, providing ultra-high concentrations directly at the compartmentalized infection site, not achievable by the conventional intravenous and oral routes.

Case Report: Delayed Primary Wound Closure After Extensive Abdominal Wall Resection for Infection and Malignancy Using TopClosure®.

The closure of a massive abdominal wall defect is illustrated using a novel dynamic closure technique - the TopClosure® tension relief system. This system attaches to the abdominal wall immediately after laparotomy and allows for early approximation of the skin, avoiding an open abdomen and the complications associated with this. The technique in this case was employed after extensive resection of the abdominal wall for infected skin metastases of colonic adenocarcinoma and circumvented post-operative ventilation and open abdomen. Early recovery after such extensive surgery is important in terms of patient morbidity and mortality. In this case, primary surgery may not have been an acceptable risk to undertake without the option of Top Closure of the abdomen. We illustrate the technique of abdominal wall closure through a series of images of the procedure.

Minimizing treatment complexity of combat-related soft tissue injuries using a dedicated tension relief system and negative pressure therapy augmented by high-dose in situ antibiotic therapy and oxygen delivery: a retrospective study.

BACKGROUND: Following combat-related, extensive soft tissue injury from gunshot wounds or blasts, prolonged duration from injury to full wound closure is associated with infection, increased morbidity and mortality, failure to mobilize, poor functional outcome and increased cost. The purpose of this study was to evaluate a novel treatment enabling early primary closure of combat wounds. METHODS: This was a retrospective study of 10 soldiers and civilians with extensive combat-related soft tissue limb injuries (5 gunshot wounds, 5 blasts) treated using the TopClosure® Tension Relief System (TRS) with simultaneous administration of regulated oxygen-enriched and irrigation negative pressure-assisted wound therapy (ROINPT) via the Vcare α® device. RESULTS: Nine patients were treated during the acute phase of injury and one was treated following removal of a flap due to deep infection 20 years after injury and flap reconstruction. Two patients had upper limb injury and the rest lower limb injury. With the aid of the TRS and/or ROINPT, immediate primary closure during reconstruction was achieved in 6 patients and delayed primary closure in three. Only one patient required a skin graft to close a small area of the wound after most of the wound had been closed by delayed primary closure. Wound closure was achieved within 0-37 days (median: 12.5 days, interquartile range: 2.75-19.75) from injury. CONCLUSIONS: The TRS is a novel device for effective, early skin stretching and secure wound closure through the application of stress relaxation and mechanical creep, achieving primary closure of large defects using a simplified surgical technique and reducing the need for closure using skin grafts and flaps and the use of tissue expanders. Delivering supplemental oxygen to the wound by ROINPT reverses the reduced oxygen levels inherent in conventional negative pressure-assisted wound therapy, mitigating anaerobic contamination and reducing infection. Irrigation may accelerate the evacuation of infectious material from the wound and provide a novel method for antibiotic administration. The combination of TRS and ROINPT devices allow for early primary closure with improved functionality of combat-related limb injuries.

Simplified management of a giant forehead congenital nevus allows for early reconstruction.

We report simplified surgical management of giant congenital forehead nevus that customarily requires the use of tissue expander for complete excision. Commencing treatment at the age of 3 months, the TopClosure tension relief system (TRS) was applied as an external tissue expander allowing preoperative skin stretching by mechanical creep. This was followed by partial excision of the nevus. Intraoperative stress-relaxation allowed further expansion of the skin. Postoperative wound closure was secured with the aid of the TRS. Repeated, six simple staged excisions of the forehead lesion and a minor skin graft to the eyelid part, allowed for delayed primary closure of the entire lesion by the age of 2. This simple alternative approach, which allows the early start and early conclusion of the reconstructive process, should be considered as the primary option in the treatment of these patients.

Relaxation systems of the skin for the closure of large mammary defects. / Sistemas de relajación de la piel para el cierre de grandes defectos mamarios.

In mammary tumors that are large relative to breast-size, complex reconstructive methods are required. We describe an alternative system of closure. In circumstances such as this, primary closure of this skin defect may be enabled by stress relaxation of the skin and the use of a tension-relief system. Tension-relief systems secures immediate primary closure of large skin defects in patients with large for breast-size tumors by placing the tension away from the skin edges. This enables early skin closure and rapid mobilization with good functionality. Optimal healing facilitates postoperative radiotherapy on time without reconstruction failure.

Innovative approach to open abdomen: converting an enteroatmospheric fistula into an easily manageable stoma.

A 52-year-old super morbidly obese patient underwent elective laparoscopic conversion of a failed silastic ring vertical gastroplasty to a Roux-en-Y gastric bypass. Following surgery, she developed an anastomotic leak which required emergent laparotomy. The patient then suffered from a complex postoperative course during which she developed an intestinal fistula which freely drained into the wound and gradually led to its complete dehiscence. Her course was further complicated by the surfacing of an enteroatmospheric fistula. This devastating complication was managed by employing the TopClosure Tension Relief system. Using the inverse maturation technique, further described in this report, we were able to progressively approximate and invert the edges of the skin around the enteroatmospheric fistula, thereby facilitating its conversion to an easily manageable stoma. Using this technique, we were able to achieve delayed primary wound closure of a grade 4 open abdomen complicated by an enteroatmospheric fistula in just under 5 weeks' time.

Phacoemulsification-induced injury in corneal endothelial cells mediated by apoptosis: in vitro model.

PURPOSE: To characterize the mechanism of injury caused by phacoemulsification and examine the protective effect of ascorbic acid in cultured bovine corneal endothelial cells (CECs). SETTING: Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel. METHODS: To minimize the direct mechanical effects of phacoemulsification on CECs, cells cultured on gas-permeable flexible membranes were exposed to phacoemulsification. Apoptosis was assayed by immunohistochemistry using anticaspase-3 antibody. RESULTS: Phacoemulsification caused a significantly higher rate of apoptosis (mean apoptotic nuclei per square millimeter, 334+/-29 [SD] versus 45+/-12) 48 hours after exposure (P<.001). Results were similar in CECs exposed to hydrogen peroxide for 48 hours as a positive control (mean 345+/-6 and 376+/-1 at hydrogen peroxide concentrations of 50 microM and 100 microM, respectively). Addition of ascorbic acid (1 or 10 mM) significantly decreased the 48-hour apoptotic nuclei count induced by phacoemulsification (mean 219+/-15 and 130+/-29, respectively) (P<.001). Application of shear forces up to 2000 seconds(-1) for 60 minutes did not increase the rate of apoptotic nuclei. CONCLUSIONS: Flexible membranes covered with cultured CECs, used as a new model that mimics in vivo conditions, minimized the mechanical damage caused by ultrasonic vibrations and turbulent currents, which destroy cells grown on hard surfaces. Phacoemulsification damage was not mediated by mechanical or shear forces but resulted from free-radical formation that apparently triggered cellular cascades, leading to apoptosis. Cell death was significantly reduced by the addition of ascorbic acid, probably via a free radical-scavenging mechanism.

Gold nanoparticles for tracking bacteria clearance by regulated irrigation and negative pressure-assisted wound therapy.

AIM: Regulated negative pressure-assisted wound therapy is a fundamental, nonpharmaceutical technology for acute and chronically infected wounds, yet bacterial clearance and biofilm buildup remain a challenge for healing. Regulated irrigation combined with negative pressure (RI-NPT) is emerging as an alternative therapeutic strategy for reducing bacterial load. Here, we analyzed RI-NPT hydrokinetics and efficacy of bacterial load reduction in wounds. MATERIALS & METHODS: Escherichia coli were loaded with gold nanoparticles, quantified by flame atomic absorption spectroscopy. Computed tomography (CT) imaging tracked bacterial distribution over time in a low-flow rat wound model. Bacterial load was quantified using a novel CT ruler. RESULT: Flame atomic absorption spectroscopy showed loading of 1.7 × 103 ± 0.2 gold nanoparticles/cell. CT tracking revealed that while regulated negative pressure-assisted wound therapy reduced bacterial load to a limited extent (5%), RI-NPT significantly increased bacterial outflow and clearance (by 45%). CONCLUSION: This nanotechnology-based approach demonstrates that RI-NPT is essential for reducing bacterial load and, thus, for promoting wound healing.

Acoustic cavitation in phacoemulsification and the role of antioxidants.

Cataract surgery by phacoemulsification generates acoustic cavitation, resulting in formation of reactive oxygen species. The aim of this study was to establish the mechanism of damage by phacoemulsification in an in vitro setting simulating cataract surgery and to assess the protective effects of water-soluble antioxidants. Electron paramagnetic resonance spectroscopy was used to analyze generation of radicals in an intraocular irrigating solution by phacoemulsification instrumentation, operating at an ultrasonic frequency range of 40--60 kHz. Hydroxyl radicals were generated by phacoemulsification under conditions simulating cataract surgery. The effects of water-soluble antioxidants in the irrigating solution on the amounts of radicals were evaluated by electron paramagnetic resonance spectroscopy. The water-soluble antioxidant glutathione, applied in either oxidized or reduced form, decreased hydroxyl radicals concentration measured in the sonicated medium. The effective concentrations of oxidized and reduced glutathione in irrigating solution that significantly eliminate the hydroxyl radical signal were determined in the range of 10(-3)-10(-2) M. Antioxidants should be applied clinically to reduce damage to the corneal endothelium induced by phacoemulsification, thereby improving biosafety.

Early Surgical Management of Large Scalp Infantile Hemangioma Using the TopClosure® Tension-Relief System.

Infantile hemangiomas (IHs) are the most common benign vascular neoplasms of infancy and childhood. The majority do not need medical intervention. However, large ulcerated scalp IHs may lead to fatal bleeding as well as severe cosmetic disfigurement that indicate early surgical excision, inflicting substantial surgical risks, with short- and long-term morbidity.The TopClosure Tension-Relief System (TRS) is an innovative skin stretching and wound closure-secure system that facilitates primary closure of relatively large skin defects. This system has been shown as a substitute for skin grafts, flaps, or tissue expanders.We describe a case of a giant IH of the scalp usually requiring a complex surgical approach, which was immediately primarily closed applying the TRS.A 3-day-old female infant presented with a giant scalp hemangioma at birth that rapidly grew in the neonatal period with early signs of ulceration. The patient underwent surgical resection of the giant scalp hemangioma with immediate primary closure of the defect using the TRS. Surgical procedure and postoperative period were uneventful.Early surgical resections of IHs at infancy carry substantial surgical risks and morbidity. This is the first reported case of early resection of a scalp hemangioma in the neonatal period, with successful immediate primary closure by application of stress-relaxation technique through the TRS. The application of the TopClosure TRS in this age group has significant advantages. It reduces the complexity and length of surgery, reducing blood loss, eliminating donor site morbidity, improving wound aesthetics, and minimizing the need for future reconstructive procedures.

International importance of robust breast device registries.

BACKGROUND: Breast implants are high-risk devices that have been at the epicenter of much debate and controversy. In light of the Poly Implant Prothèse crisis, data registries among 11 national societies around the world are cooperatively calling for the urgent need to establish robust national clinical quality registries based on international best practice within a framework of international collaboration. METHODS: A survey was conducted on the historic and current status of national breast device registries. Eleven countries participated in the study, illustrating different data collection systems and registries around the world. Data collection was designed to illustrate the capabilities of current national registries, with particular focus on capture rate and outcome reporting mechanisms. RESULTS: A study of national breast implant registries revealed that less than half of the participating countries had operational registries and that none of these had adequately high data capture to enable reliable outcome analysis. The study revealed that the two most common problems that discouraged participation are the complexity of data sets and the opt-in consent model. CONCLUSIONS: Recent implant crises have highlighted the need for robust registries. This article argues the importance of securing at least 90 percent data capture, which is achievable through the opt-out consent model. Since adopting this model, the Australian Breast Device Registry has increased data capture from 4 percent to over 97 percent. Simultaneously, it is important to foster international collaboration from the outset to avoid duplication of efforts and enable the development of effective international early warning systems.

Acoustic cavitation in phacoemulsification: chemical effects, modes of action and cavitation index.

High-intensity ultrasound (US) energy (HIUE) has been extensively used in the last 3 decades in a wide range of surgical procedures, including phacoemulsification. The generation of radicals and sonoluminescence (SL) by application of continuous-wave (CW) HIUE to an aqueous medium under conditions simulating cataract phacoemulsification surgery is demonstrated by electron paramagnetic resonance (EPR) spectroscopy and a sensitive photon-detecting system. The findings provide direct evidence for the generation of acoustic cavitation in the simulated intraocular environment, pointing out that generation of acoustic cavitation in clinical phacoemulsification and other surgical applications of US is possible. The findings imply that the effects of acoustic cavitation in aqueous medium may contribute to the endothelial damage observed clinically following phacoemulsification cataract surgery. Saturation of the irrigating solution with various gases modifies the acoustic cavitation. Saturation of the irrigating solution with CO2 practically eliminates acoustic cavitation, with the concomitant elimination of radicals and SonL. CO2 may be utilized clinically to suppress acoustic cavitation in phacoemulsification and other medical applications. A cavitation index (CI) is introduced for the purpose of standardizing phacoemulsification instrumentation and other medical US devices that employ HIUE.

Stress-relaxation and tension relief system for immediate primary closure of large and huge soft tissue defects: an old-new concept: new concept for direct closure of large defects.

Stress-relaxation is a well-established mechanism for laboratory skin stretching, with limited clinical application in conventional suturing techniques due to the inherent, concomitant induction of ischemia, necrosis and subsequent suture failure. Skin defects that cannot be primarily closed are a common difficulty during reconstructive surgery. The TopClosure tension-relief system (TRS) is a novel device for wound closure closure, providing secured attachment to the skin through a wide area of attachment, in an adjustable manner, enabling primary closure of medium to large skin defects. The aim of this study was to evaluate the efficiency of the TopClosure TRS as a substitute for skin grafting and flaps for primary closure of large soft tissue defects by stress-relaxation. We present three demonstrative cases requiring resection of large to huge tumors customarily requiring closure by skin graft or flaps. TRS was applied during surgery serving as a tension-relief platform for tension sutures, to enable primary skin-defect closure by cycling of stress-relaxation, and following surgery as skin-secure system until complete wound closure. All skin defects ranging from 7 to 26 cm in width were manipulated by the TRS through stress-relaxation, without undermining of skin, enabling primary skin closure and eliminating the need for skin grafts and flaps. Immediate wound closure ranged 26 to 135 min. TRS was applied for 3 to 4 weeks. Complications were minimal and donor site morbidity was eliminated. Surgical time, hospital stay and costs were reduced and wound aesthetics were improved. In this case series we present a novel technology that enables the utilization of the viscoelastic properties of the skin to an extreme level, extending the limits of primary wound closure by the stress-relaxation principle. This is achieved via a simple device application that may aid immediate primary wound closure and downgrade the complexity of surgical procedures for a wide range of applications on a global scale.