Management of Acute Wounds-Expert Panel Consensus Statement.

Significance: The Wound Healing Foundation recognized the need for consensus-based unbiased recommendations for the treatment of wounds. As a first step, a consensus on the treatment of chronic wounds was developed and published in 2022. The current publication on acute wounds represents the second step in this process. Acute wounds may result from any number of conditions, including burns, military and combat operations, and trauma to specific areas of the body. The management of acute wounds requires timely and evidence-driven intervention to achieve optimal clinical outcomes. This consensus statement provides the clinician with the necessary foundational approaches to the causes, diagnosis, and therapeutic management of acute wounds. Presented in a structured format, this is a useful guide for clinicians and learners in all patient care settings. Recent Advances: Recent advances in the management of acute wounds have centered on stabilization and treatment in the military and combat environment. Specifically, advancements in hemostasis, resuscitation, and the mitigation of infection risk through timely initiation of antibiotics and avoidance of high-pressure irrigation in contaminated soft tissue injury. Critical Issues: Critical issues include infection control, pain management, and the unique considerations for the management of acute wounds in pediatric patients. Future Directions: Future directions include new approaches to preventing the progression and conversion of burns through the use of specific gel formulations. Additionally, the use of three-dimensional bioprinting and photo-modulation for reconstruction is a promising area for continued discovery.

Effect of arteriovenous graft flow rate on vascular access hemodynamics in a novel modular anastomotic valve device.

PURPOSE: Perturbed vascular access hemodynamics is considered a potential driver of intimal hyperplasia, the leading cause of vascular access failure. To improve vascular access patency, a modular anastomotic valve device has been designed to normalize venous flow between hemodialysis periods while providing normal vascular access during hemodialysis. The objective of this study was to quantify the effects of arteriovenous graft flow rate on modular anastomotic valve device vascular access hemodynamics under realistic hemodialysis conditions. METHODS: Modular anastomotic valve device inlet and outlet flow conditions and velocity profiles were measured by ultrasound Doppler in a vascular access flow loop replicating arteriovenous graft flow rates of 800, 1000, and 1500 mL/min. Fluid-structure interaction simulations were performed to identify low wall shear stress regions on the vein wall and to characterize them in terms of temporal shear magnitude, oscillatory shear index, and relative residence time. The model was validated with respect to the Doppler measurements. RESULTS: The low wall shear stress region generated downstream of the anastomosis under low and moderate arteriovenous graft flow rates was eliminated under the highest arteriovenous graft flow rate. Increase in arteriovenous graft flow rate from 800 to 1500 mL/min resulted in a substantial increase in wall shear stress magnitude (27-fold increase in temporal shear magnitude), the elimination of wall shear stress bidirectionality (0.20-point reduction in oscillatory shear index), and a reduction in flow stagnation (98% decrease in relative residence time). While the results suggest the ability of high arteriovenous graft flow rates to protect the venous wall from intimal hyperplasia-prone hemodynamics, they indicate their adverse impact on the degree of venous hemodynamic abnormality.

Perioperative Outcomes are Adversely Affected by Poor Pretransfer Adherence to Acute Limb Ischemia Practice Guidelines.

BACKGROUND: The accepted treatment for acute limb ischemia (ALI) is immediate systemic anticoagulation and timely reperfusion to restore blood flow. In this study, we describe the retrospective assessment of pretransfer management decisions by referring hospitals to an academic tertiary care facility and its impact on perioperative adverse events. METHODS: A retrospective analysis of ALI patients transferred to us via our Level I Vascular Emergency Program from 2010 to 2013 was performed. Patient demographics, comorbidities, Rutherford ischemia classification, time to anticoagulation, and time to reperfusion were tabulated and analyzed for correlation to incidence of major adverse limb events (MALEs), mortality, and bypass patency in the perioperative period (30-day postoperative). All intervals were calculated from the onset of symptoms and categorized into 3 subcohorts (<6 hr, 6-48 hr, and >48 hr). RESULTS: Eighty-seven patients with an average age of 64.0 (±16.2) years presented to outlying hospitals and were transferred to us with lower extremity ALI. The mean delay from symptom onset to initial referring physician evaluation was 18.3 hr. At that time of evaluation, 53.8% had Rutherford class IIA ischemia and 36.3% had class IIB ischemia. Seventy-six patients (87.4%) were started on heparin previous to transfer. However, only 44 patients (57.9%) reached therapeutic levels as measured by activated partial thromboplastin time before definitive revascularization. A delay of anticoagulation initiation >48 hr from symptom onset was associated with increased 30-day reintervention rates compared with the <6 hr group (66.7% vs. 23.5%; P < 0.05). However, time to reperfusion had no statistically significant impact on MALE, 30-day mortality, or 30-day interventional patency in our small cohorts. Additionally, patients with a previous revascularization had a higher 30-day reintervention rate (46.5%; P < 0.05). CONCLUSIONS: The practice of timely therapeutic anticoagulation of patients referred for ALI from community facilities occurs less frequently than expected and is associated with an increased perioperative reintervention rate.

Ex Vivo Reconstruction and Autotransplantation for Hilar Renal Artery Aneurysms in Patients with Congenital Anomalies.

Renal artery aneurysms (RAAs) are an uncommon finding but are more often associated with other congenital disorders. The complex (hilar) RAAs constitute a subset of RAAs that present a therapeutic dilemma for the vascular surgeon because of their anatomic location. This dilemma worsens when hilar RAAs occur with a solitary kidney where organ preservation is vital. Ex vivo reconstruction with autotransplantation is especially suitable for hilar RAAs, even when they are associated with a solitary kidney. We report 2 of such cases of RAAs with a solitary kidney in patients with pertinent congenital anomalies. In 1 case, the hilar RAA was associated with a significant accessory renal artery, whereas in the other case, the hilar RAA was associated with a significant connective tissue disorder. Ex vivo reconstruction and autotransplantation was successful in both cases; however, treatment modalities had to be adapted to the patient's unique conditions.

Novel modular anastomotic valve device for hemodialysis vascular access: preliminary computational hemodynamic assessment.

PURPOSE: Arteriovenous graft patency is limited by terminal occlusion caused by intimal hyperplasia (IH). Motivated by evidence that flow disturbances promote IH progression, a modular anastomotic valve device (MAVD) was designed to isolate the graft from the circulation between dialysis periods (closed position) and enable vascular access during dialysis (open position). The objective of this study was to perform a preliminary computational assessment of the device ability to normalize venous flow between dialysis periods and potentially limit IH development and thrombogenesis. METHODS: Computational fluid dynamics simulations were performed to compare flow and wall shear stress (WSS) in a native vein and MAVD prototypes featuring anastomotic angles of 90° and 30°. Low WSS (LWSS) regions prone to IH development were characterized in terms of temporal shear magnitude (TSM), oscillatory shear index (OSI), and relative residence time (RRT). Thrombogenic potential was assessed by investigating the loading history of fluid particles traveling through the device. RESULTS: The closed MAVD exhibited the same flow characteristics as the native vein (0.3% difference in pressure drop, 3.5% difference in surface-averaged WSS). The open MAVD generated five LWSS regions (TSM <0.5 Pa) exhibiting different degrees of flow reversal (surface-averaged OSI: 0.03-0.36) and stagnation (max RRT: 2.50-37.16). Reduction in anastomotic angle resulted in the suppression of three LWSS regions and overall reductions in flow reversal (surface-averaged OSI <0.21) and stagnation (max RRT <18.05). CONCLUSIONS: This study suggests the ability of the MAVD to normalize venous flow between dialysis periods while generating the typical hemodynamics of end-to-side vein-graft anastomoses during dialysis.

Managing recurrent carotid artery disease with redo carotid endarterectomy: a 10-year retrospective case series.

BACKGROUND: Choosing the optimal treatment modality for patients with recurrent carotid artery stenosis depends upon many variables, including the etiology of the recurrent plaque morphology and the location of the recurrent lesion. The most important considerations for interventions are the safety, short- and long-term durability of the repair, and the surgical team's skills and experience. We reviewed the results of our operative series on primary and redo carotid endarterectomy (CEA) data to evaluate the short- and long-term outcomes of surgical intervention. We also evaluated the relationship between plaque lesion characteristics with respect to the development of recurrent stenosis. METHODS: The charts of all patients who underwent CEAs and redo CEAs (RCEAs) performed by one vascular surgeon were retrospectively reviewed for a 10-year period. Preoperative data, including patients' demographics and interval between the primary CEAs and RCEAs, were recorded and summarized. The surgical procedure, location, and morphologic characteristics of the carotid lesions (primary or recurrent) were also recorded. Surgical outcomes, including local complications, systemic complications, length of stay, restenosis rate, and short-and long-term stroke rates, were reviewed. RESULTS: From 1997 to 2007, one vascular surgeon performed 1324 consecutive CEA procedures on a total of 1198 patients. Restenosis that required RCEA was performed on 212 patients, which included 192 first RCEAs and 27 second RCEAs. All patients who underwent primary CEAs were original patients of the senior author. RCEAs were performed on 7 of our original patients, and the remaining RCEA cases were referred patients. The interval from primary CEA to first RCEA ranged from 2 months to 29 years, with an average of 4.4 years. In this group of patients, the male/female ratio was 45%/55% and average age was 61 years (range 38-74 years). Eighty-three percent (159 of 192) used tobacco, compared with 54% in the primary CEA group. Also, in this group of patients, cranial nerve injuries occurred in 25 of the 192 patients (13%). The majority of these injuries were temporary, but 4 patients had prolonged injury and 1 patient had a permanent injury. One nonfatal myocardial infarction (MI) occurred. There were no incidents of stroke or death. Significant restenosis occurred in 3 patients (1.5%) over an average of 2.1 years. These statistics compare favorably with finding from our series of primary CEAs, in which cranial nerve injury was 4% (44 of 1105), postoperative myocardial infarction was 0.5% (6 of 1105), stroke rate was 0.18% (2 of 1105), and death rate was 0%, with significant restenosis occurring in 0.36% (4 of 1105) of patients over an average of 4.4 years. CONCLUSIONS: In our retrospective study, the stroke and restenosis rates after RCEAs were similar to those after primary CEA. Therefore, we consider RCEA to be a viable therapeutic option in patients with carotid disease that recurs after a primary CEA.

Steady flow hemodynamic and energy loss measurements in normal and simulated calcified tricuspid and bicuspid aortic valves.

The bicuspid aortic valve (BAV), which forms with two leaflets instead of three as in the normal tricuspid aortic valve (TAV), is associated with a spectrum of secondary valvulopathies and aortopathies potentially triggered by hemodynamic abnormalities. While studies have demonstrated an intrinsic degree of stenosis and the existence of a skewed orifice jet in the BAV, the impact of those abnormalities on BAV hemodynamic performance and energy loss has not been examined. This steady-flow study presents the comparative in vitro assessment of the flow field and energy loss in a TAV and type-I BAV under normal and simulated calcified states. Particle-image velocimetry (PIV) measurements were performed to quantify velocity, vorticity, viscous, and Reynolds shear stress fields in normal and simulated calcified porcine TAV and BAV models at six flow rates spanning the systolic phase. The BAV model was created by suturing the two coronary leaflets of a porcine TAV. Calcification was simulated via deposition of glue beads in the base of the leaflets. Valvular performance was characterized in terms of geometric orifice area (GOA), pressure drop, effective orifice area (EOA), energy loss (EL), and energy loss index (ELI). The BAV generated an elliptical orifice and a jet skewed toward the noncoronary leaflet. In contrast, the TAV featured a circular orifice and a jet aligned along the valve long axis. While the BAV exhibited an intrinsic degree of stenosis (18% increase in maximum jet velocity and 7% decrease in EOA relative to the TAV at the maximum flow rate), it generated only a 3% increase in EL and its average ELI (2.10 cm2/m2) remained above the clinical threshold characterizing severe aortic stenosis. The presence of simulated calcific lesions normalized the alignment of the BAV jet and resulted in the loss of jet axisymmetry in the TAV. It also amplified the degree of stenosis in the TAV and BAV, as indicated by the 342% and 404% increase in EL, 70% and 51% reduction in ELI and 48% and 51% decrease in EOA, respectively, relative to the nontreated valve models at the maximum flow rate. This study indicates the ability of the BAV to function as a TAV despite its intrinsic degree of stenosis and suggests the weak dependence of pressure drop on orifice area in calcified valves.

A lumen sizing workhorse guidewire for peripheral vasculature: two functions in one device.

OBJECTIVES: Ideally, guidewires used during peripheral vasculature (PV) interventions could serve both as a therapy delivery platform and a diagnostic tool for real-time vessel sizing (2-in-1 function). BACKGROUND: Vascular imaging modalities, like intravascular ultrasound (IVUS), used during lower PV interventions, can improve outcomes versus angiographic assessment alone, but are rarely used due to added time, cost, and required clinical training/interpretation. METHODS: A 0.035″ bodied 0.035″ conductance guidewire (CGW) is described here as a vascular navigation and diagnostic real-time PV sizing tool. When attached to a console, the CGW creates a safe, electric field to determine vascular size through simultaneous voltage measurements. RESULTS: The CGW showed functionality as a workhorse guidewire on the bench (torqueability and trackability equivalent to a Wholey guidewire) and in vivo (over-the-wire stent deployment in domestic swine and first-in-man study with no major adverse events). Validation of CGW sizing versus the true diameter and IVUS was completed in 4-10 mm diameter phantoms on the bench and in swine and showed virtually no bias with excellent repeatability and accuracy (i.e., CGW repeatability: swine phantom bias = 0.03 ± 0.09 mm (1.3% error). CGW vs. true diameter: in vivo bias = 0.14 ± 0.15 mm (2.7% error). IVUS vs. true diameter: swine phantom bias = 0.01 ± 0.36 mm (4.7% error). CCW vs. IVUS: swine phantom bias = 0.13 ± 0.26 mm (3.8% error)). CONCLUSIONS: Real-time, accurate, and safe PV dimension assessment and therapy-delivery (2-in-1 function) is possible using a novel workhorse 0.035″ bodied CGW.

Conductance sizing balloon for measurement of peripheral artery minimal stent area.

BACKGROUND: Because stent underdeployment occurs frequently, accurate minimal stent area (MSA) measurement during postdilatation is necessary. This study investigated the accuracy and repeatability for MSA determination using a novel conductance balloon (CB) catheter for peripheral vessels. METHODS: The CB catheter is a standard balloon catheter that measures electrical conductance (ratio of current/voltage drop) in real-time during inflation, which directly relates to the balloon cross-sectional area through Ohm's law. CB measurements were made in 4- to 10-mm phantoms on the bench, ex vivo in stents fully deployed in diseased human peripheral arteries, and in vivo in stents fully deployed in peripheral vessels in six swine. CB measurement accuracy and repeatability were calculated and compared with the known dimension (bench phantoms) or with intravascular ultrasound (IVUS) measurement after stent deployment (ex vivo and in vivo). RESULTS: CB measurements were highly accurate (error: 1.8% bench, 5% ex vivo, and 5% in vivo) and repeatable (error: 0.9% bench, 1.8% ex vivo, and 1.3% in vivo), with virtually no bias (average difference in measurements: -0.05 mm bench CB vs known phantom diameters, -0.06 mm ex vivo CB vs IVUS, and -0.11 mm in vivo CB vs IVUS). CONCLUSIONS: The CB sizing capability can be integrated within a standard balloon catheter (two-in-one function) to provide accurate, real-time assessment of MSA to ensure full stent apposition rather than the use of pressure as a surrogate for size.

Management of vascular trauma from dog bites.

BACKGROUND: Vascular trauma from large-dog bites present with a combination of crush and lacerating injuries to the vessel, as well as significant adjacent soft tissue injury and a high potential for wound complications. This retrospective case series evaluates our 15 years of experience in managing this uncommonly seen injury into suggested treatment recommendations. METHODS: From our database, 371 adult patients presented with dog bites between July 1997 and June 2012. Twenty (5.4%) of those patients had vascular injuries requiring surgical intervention. Patient demographics, anatomic location of injury, clinical presentation, imaging modality, method of repair, and complication rates were reviewed to assess efficacy in preserving limb function. Pediatric patients were managed at the regional children's hospital and, therefore, not included in this study. RESULTS: Among the 20 surgically treated vascular injuries, there were 13 arterial-only injuries, two venous-only injuries, and five combination arterial and venous injuries. Seventeen patients (85%) had upper extremity injuries; three patients had lower extremity injuries (15%). The axillobrachial artery was the most commonly injured single vessel (n = 9/20; 45%), followed by the radial artery (n = 4/20; 20%). Surgical repair of vascular injuries consisted of resection and primary anastomosis (four), interposition bypass of artery with autogenous vein (13), and ligation (two), with (one) being a combination of bypass and ligation. All patients had debridement of devitalized tissue combined with pulse lavage irrigation and perioperative antibiotics. Associated injuries requiring repair included muscle and skin (n = 10/20; 50%), bone (n = 1/20; 5%), nerve (n = 1/20; 5%), and combinations of the three (n = 5/20; 25%). Postoperative antibiotic therapy was administered for 14.7 ± 8.2 days in all 20 patients. Four patients (20%) developed postoperative wound infections, although this did not compromise their vascular repair. Of the patients compliant with postoperative surveillance, all limbs (100%) were viable at discharge and at 1-year follow-up. CONCLUSIONS: Dog bite vascular injuries are an uncommon occurrence, where extremity pulse abnormalities are the most common presentation. These injuries are also associated with significant adjacent soft tissue trauma, which warrants aggressive debridement and perioperative antibiotic therapy. Despite vigilant management, nearly one-fifth of our patients sustained wound infections. All infections were successfully managed with broad-spectrum antibiotics, and all limbs were preserved 1-year postoperatively.

Marvels, mysteries, and misconceptions of vascular compensation to peripheral artery occlusion.

Peripheral arterial disease is a major health problem and there is a significant need to develop therapies to prevent its progression to claudication and critical limb ischemia. Promising results in rodent models of arterial occlusion have generally failed to predict clinical success and led to questions of their relevance. While sub-optimal models may have contributed to the lack of progress, we suggest that advancement has also been hindered by misconceptions of the human capacity for compensation and the specific vessels which are of primary importance. We present and summarize new and existing data from humans, Ossabaw miniature pigs, and rodents which provide compelling evidence that natural compensation to occlusion of a major artery (i) may completely restore perfusion, (ii) occurs in specific pre-existing small arteries, rather than the distal vasculature, via mechanisms involving flow-mediated dilation and remodeling (iii) is impaired by cardiovascular risk factors which suppress the flow-mediated mechanisms and (iv) can be restored by reversal of endothelial dysfunction. We propose that restoration of the capacity for flow-mediated dilation and remodeling in small arteries represents a largely unexplored potential therapeutic opportunity to enhance compensation for major arterial occlusion and prevent the progression to critical limb ischemia in the peripheral circulation.

Circadian variations of stellate ganglion nerve activity in ambulatory dogs.

BACKGROUND: The presence of circadian variations in sympathetic outflow from the stellate ganglia is unclear. OBJECTIVES: The purpose of this study was to continuously record stellate ganglion nerve activity (SGNA) in ambulatory dogs. METHODS: We performed continuous 24-hour left (N = 3) or bilateral (N = 3) SGNA recordings in normal ambulatory dogs using implanted Data Sciences International transmitters. We also performed simultaneous ECG recording (n = 5) or simultaneous ECG and blood pressure recordings (n = 1). RESULTS: The total duration of continuous ambulatory recording averaged 41.5 +/- 16.6 days. Five dogs had persistent stable recording, and one dog developed hardware malfunction in week 3. SGNA was followed immediately (<1 second) by heart rate and blood pressure elevation and a reduced standard deviation of consecutive activation cycle length (SDNN) from 236 +/- 93 ms to 121 +/- 51 ms (P = 0.007). Heart rate correlated significantly with SGNA. When there was a sudden increase of SGNA, the sudden increase occurred bilaterally in 90% of the episodes. Both heart rate and SGNA showed statistically significant (P <.01) circadian variation. Nadolol (20 mg/day for 5 days) reduced average heart rate from 99 +/- 8 bpm at baseline to 88 +/- 9 bpm (N = 6, P = .001) but did not significantly alter SGNA. Immunohistochemical staining of the stellate ganglia showed tyrosine hydroxylase-positive ganglion cells and nerves at the recording site. CONCLUSION: There is a circadian variation in sympathetic outflow from canine stellate ganglia. Circadian variation of SGNA is an important cause of circadian variations of cardiac sympathetic tone.