Negative pressure wound therapy with instillation: International consensus guidelines update.

The use of negative pressure wound therapy with instillation and dwell time (NPWTi-d) has gained wider adoption and interest due in part to the increasing complexity of wounds and patient conditions. Best practices for the use of NPWTi-d have shifted in recent years based on a growing body of evidence and expanded worldwide experience with the technology. To better guide the use of NPWTi-d with all dressing and setting configurations, as well as solutions, there is a need to publish updated international consensus guidelines, which were last produced over 6 years ago. An international, multidisciplinary expert panel of clinicians was convened on 22 to 23 February 2019, to assist in developing current recommendations for best practices of the use of NPWTi-d. Principal aims of the meeting were to update recommendations based on panel members\u27 experience and published results regarding topics such as appropriate application settings, topical wound solution selection, and wound and patient characteristics for the use of NPWTi-d with various dressing types. The final consensus recommendations were derived based on greater than 80% agreement among the panellists. The guidelines in this publication represent further refinement of the recommended parameters originally established for the use of NPWTi-d. The authors thank Karen Beach and Ricardo Martinez for their assistance with manuscript preparation

Numerical simulation of blood flow and pressure drop in the pulmonary arterial and venous circulation

A novel multiscale mathematical and computational model of the pulmonary circulation is presented and used to analyse both arterial and venous pressure and flow. This work is a major advance over previous studies by Olufsen et al. (Ann Biomed Eng 28:1281–1299, 2012) which only considered the arterial circulation. For the first three generations of vessels within the pulmonary circulation, geometry is specified from patient-specific measurements obtained using magnetic resonance imaging (MRI). Blood flow and pressure in the larger arteries and veins are predicted using a nonlinear, cross-sectional-area-averaged system of equations for a Newtonian fluid in an elastic tube. Inflow into the main pulmonary artery is obtained from MRI measurements, while pressure entering the left atrium from the main pulmonary vein is kept constant at the normal mean value of 2 mmHg. Each terminal vessel in the network of ‘large’ arteries is connected to its corresponding terminal vein via a network of vessels representing the vascular bed of smaller arteries and veins. We develop and implement an algorithm to calculate the admittance of each vascular bed, using bifurcating structured trees and recursion. The structured-tree models take into account the geometry and material properties of the ‘smaller’ arteries and veins of radii ≥ 50 μ m. We study the effects on flow and pressure associated with three classes of pulmonary hypertension expressed via stiffening of larger and smaller vessels, and vascular rarefaction. The results of simulating these pathological conditions are in agreement with clinical observations, showing that the model has potential for assisting with diagnosis and treatment for circulatory diseases within the lung

Special Considerations in the Management of Osteomyelitis Defects (Diabetes, the Ischemic or Dysvascular Bed, and Irradiation)

Although osteomyelitis is a difficult problem, certain conditions make it even more difficult to address. Diabetes, peripheral vascular disease, and radiation are all comorbidities that interfere with wound healing and therefore make the treatment of osteomyelitis challenging. In this article, we discuss these conditions, their pathophysiology, and highlight the special considerations in treating osteomyelitis in patients with these comorbidities

Functional Reconstruction of the Diabetic Foot

The diabetic triad of neuropathy, vasculopathy, and foot deformity can be surgically challenging to the reconstructive surgeon. Soft tissue deficits must be closed to protect underlying structures from infection and to provide a stable environment for healing. It is critical to have adequate blood flow and to debride the wound to clean healthy tissue before considering reconstruction. Surgical options commonly used include healing by secondary intention, local flap closure, skin grafts, pedicled flaps, and free tissue transfer. Despite a surgeon's best operative efforts, these strategies may fail perioperatively due to postoperative shear forces created by premature joint motion and/or pressure (either weight bearing or decubitus). In the properly selected patient population, external fixators serve as an indispensable adjunct to wound healing in the Charcot foot by providing temporary but reliable offloading and/or immobilization of joints. Using a team approach is critical to the success of diabetic limb reconstruction

Soft tissue coverage of lower extremity defects: pearls and pitfalls in the chronic wound population

The incidence of chronic lower extremity (LE) wounds continues to increase. Lower limb amputations are associated with increased cardiovascular exertion, further decline in functional ability, and higher mortality rates. As such, there has been a shift towards limb salvage modalities. These include local debridement with advanced wound care, revascularization, bony reconstruction, and soft tissue reconstruction. Perioperative planning for soft tissue reconstruction requires careful consideration of several factors, including patient comorbidities, wound size and location, exposed underlying structures, and in the case of possible free flap, patency of donor and recipient vessels. This article reviews the perioperative factors that should be considered in preparation for successful soft tissue reconstruction of the LE

The importance of limb preservation in the diabetic population

Limb salvage in the diabetic population is complex, controversial, costly and variable throughout the world. Within the diabetic population, the indications and morbidity surrounding major leg amputation have not been well defined. A retrospective study of the Georgetown Limb Salvage Registry was conducted to determine outcomes in diabetic patients undergoing proximal forefoot/midfoot (PF/M) amputations and to help define the indications for major leg amputation in ambulatory diabetic patients. Of the 937 ambulatory diabetic patients identified during this time period, 808 who presented with superficial ulcers or distal forefoot disease and who did not go on to PF/M or higher amputation were eliminated. Records of 88 patients (92 limbs) in the PF/M amputation group and 25 patients in the below the knee amputation (BKA) group were reviewed (no above knee amputations were performed). At 2 years in the PF/M amputation group, 80% (70/88) of patients were still alive, 73% (68/92) of the limbs remained intact, and 64% of patients (56/88) were ambulatory. In contrast, in the BKA population at 2 years, 52% (13/25) of patients were deceased and 64% (16/25) were ambulating with a prosthetic limb (or had been ambulating at the time of death). The only statistically significant difference between these two groups was the presence of Charcot collapse and rear-foot disease in the BKA group. Aggressive efforts at salvage with PF/M amputation procedures should be entertained prior to higher level amputations due to the increased morbidity and mortality evidenced

Through Knee Amputation: Technique Modifications and Surgical Outcomes

Background Knee disarticulations (KD) are most commonly employed following trauma or tumor resection but represent less than 2% of all lower extremity amputations performed in the United States annually. KDs provide enhanced proprioception, a long lever arm, preservation of adductor muscle insertion, decreased metabolic cost of ambulation, and an end weight-bearing stump. The role for KDs in the setting of arterial insufficiency or overwhelming infection is less clear. The purpose of this study is to describe technique modifications and report surgical outcomes following KDs at a high-volume Limb Salvage Center. Methods A retrospective study of medical records for all patients who underwent a through-knee amputation performed by the senior author (C.E.A.) between 2004 and 2012 was completed. Medical records were reviewed to collect demographic, operative, and postoperative information for each of the patients identified. Results Between 2004 and 2012, 46 through-knee amputations for 41 patients were performed. The mean patient age was 68 and indications for surgery included infection (56%), arterial thrombosis (35%), and trauma (9%). Postoperative complications included superficial cellulitis (13%), soft tissue infection (4%), and flap ischemia (4%) necessitating one case of surgical debridement (4%) and four trans-femoral amputations (9%). 9 (22%) patients went on to ambulate. Postoperative ambulation was greatest in the traumatic cohort and for patients less than 50 years of age, P<0.05. Alternatively, diabetes mellitus and infection reduced the likelihood of postoperative ambulation, P<0.01. Conclusions Knee disarticulations are a safe and effective alternative to other lower extremity amputations when clinically feasible. For patient unlikely to ambulate, a through-knee amputation maximizes ease of transfers, promotes mobility by providing a counterbalance, and eliminates the potential for knee flexion contracture with subsequent skin breakdown