Point-of-care tissue oxygenation assessment with SnapshotNIR for alloplastic and autologous breast reconstruction

UNLABELLED: In breast reconstruction, mastectomy and free flaps are susceptible to vascular compromise and tissue necrosis. The SnapshotNIR device (Kent Imaging, Calgary, AB, Canada) utilizes near-infrared spectroscopy to measure tissue oxygen saturation (StO METHODS: Patients receiving immediate alloplastic reconstruction after mastectomy or autologous reconstruction were enrolled. Preoperative, intraoperative, and postoperative images were taken of the flaps. StO RESULTS: Thirty-two breasts underwent alloplastic reconstruction; 38 breasts underwent autologous reconstruction. No enrollees developed skin necrosis. StO CONCLUSIONS: The SnapshotNIR device detected normal spatial and temporal differences in tissue oxygenation over the operative course of alloplastic and autologous breast reconstruction. A multi-institutional, prospective clinical trial is needed to determine the sensitivity and specificity of this device for detecting skin flap necrosis

Investigating weekend effect in the management of upper and lower extremity degloving injuries

BACKGROUND: Weekend presentation has been associated with adverse outcomes in emergent conditions, including stroke, myocardial infarction, and critical limb ischemia. We examine whether a weekend effect exists in the management of and outcomes after extremity degloving injuries. METHODS: The cohort included adults presenting with open extremity degloving injuries to a tertiary level one trauma center between June 2018 and May 2022. We collected demographics, comorbidities, injury information, interventions, and complications. Propensity score weighting was used to minimize confounding differences between those presenting on weekends (Sat-Sun) versus weekdays (Mon-Fri). Weighted regressions were used to examine differences in interventions by day of presentation. Multivariable weighted regressions accounting for differences in interventions received were used to examine whether weekend presentation was associated with amputation risk, complications, or functional deficits. RESULTS: Ninety-five patients with 100 open extremity degloving injuries were included. In total, 39% of injuries were weekend-presenting. There was a higher rate of noninsulin-dependent diabetes among patients presenting on weekends ( CONCLUSION: Weekend presentation may impact interventions received and amputation risk in patients presenting with open extremity degloving injuries

Cutaneous collateral axonal sprouting re-innervates the skin component and restores sensation of denervated Swine osteomyocutaneous alloflaps.

PMC3799840Reconstructive transplantation such as extremity and face transplantation is a viable treatment option for select patients with devastating tissue loss. Sensorimotor recovery is a critical determinant of overall success of such transplants. Although motor function recovery has been extensively studied, mechanisms of sensory re-innervation are not well established. Recent clinical reports of face transplants confirm progressive sensory improvement even in cases where optimal repair of sensory nerves was not achieved. Two forms of sensory nerve regeneration are known. In regenerative sprouting, axonal outgrowth occurs from the transected nerve stump while in collateral sprouting, reinnervation of denervated tissue occurs through growth of uninjured axons into the denervated tissue. The latter mechanism may be more important in settings where transected sensory nerves cannot be re-apposed. In this study, denervated osteomyocutaneous alloflaps (hind- limb transplants) from Major Histocompatibility Complex (MHC)-defined MGH miniature swine were performed to specifically evaluate collateral axonal sprouting for cutaneous sensory re-innervation. The skin component of the flap was externalized and serial skin sections extending from native skin to the grafted flap were biopsied. In order to visualize regenerating axonal structures in the dermis and epidermis, 50 um frozen sections were immunostained against axonal and Schwann cell markers. In all alloflaps, collateral axonal sprouts from adjacent recipient skin extended into the denervated skin component along the dermal-epidermal junction from the periphery towards the center. On day 100 post-transplant, regenerating sprouts reached 0.5 cm into the flap centripetally. Eight months following transplant, epidermal fibers were visualized 1.5 cm from the margin (rate of regeneration 0.06 mm per day). All animals had pinprick sensation in the periphery of the transplanted skin within 3 months post-transplant. Restoration of sensory input through collateral axonal sprouting can revive interaction with the environment; restore defense mechanisms and aid in cortical re-integration of vascularized composite allografts.JH Libraries Open Access Fun

Vascularized lymph node transfer for the treatment of lymphedema: a systematic review and meta-analysis of clinical and patient-reported outcomes

Aim: The aim of this systematic review was to summarize clinical and patient-reported outcomes (PROs) for various vascularized lymph node transfer (VLNT) donor sites and identify gaps in the literature to guide future research.Methods: A literature search of five databases was performed for articles related to VLNT that were published prior to November 2021. Studies that included clinical outcomes or PROs from at least five adult patients who received VLNTs to treat lymphedema were included.Results: Sixty-six studies met the study criteria. Most studies reported improved limb circumference/volume, reduction or discontinuation of conservative therapy, infection rate reduction, improved PROs, or postoperative imaging findings reflecting functional lymph nodes. There were significantly lower infection rates (P < 0.05) and a trend towards improved PROs in patients who received intra-abdominal flaps, but overall few studies reported these outcomes. There were no significant differences in complication rates at the donor or recipient site based on VLNT donor sites, or between intra-abdominal vs. extra-abdominal VLNT donor sites, although these outcomes are not uniformly reported.Conclusion: This meta-analysis identified that intra-abdominal donor sites have the potential to reduce postoperative infectious episodes more than extra-abdominal donor sites. Though recent investigations address many understudied VLNT donor sites, larger comparative studies and a standardized methodology are needed to better characterize postoperative outcomes, which can offer more concrete evidence to guide surgical practice

Injectable bioadhesive hydrogels with innate antibacterial properties.

Surgical site infections cause significant postoperative morbidity and increased healthcare costs. Bioadhesives used to fill surgical voids and support wound healing are typically devoid of antibacterial activity. Here we report novel syringe-injectable bioadhesive hydrogels with inherent antibacterial properties prepared from mixing polydextran aldehyde and branched polyethylenimine. These adhesives kill both Gram-negative and Gram-positive bacteria, while sparing human erythrocytes. An optimal composition of 2.5 wt% oxidized dextran and 6.9 wt% polyethylenimine sets within seconds forming a mechanically rigid (~1,700 Pa) gel offering a maximum adhesive stress of ~2.8 kPa. A murine infection model showed that the adhesive is capable of killing Streptococcus pyogenes introduced subcutaneously at the bioadhesive\u27s surface, with minimal inflammatory response. The adhesive was also effective in a cecal ligation and puncture model, preventing sepsis and significantly improving survival. These bioadhesives represent novel, inherently antibacterial materials for wound-filling applications

Investigating Weekend Effect in the Management of Upper and Lower Extremity Degloving Injuries

Background:. Weekend presentation has been associated with adverse outcomes in emergent conditions, including stroke, myocardial infarction, and critical limb ischemia. We examine whether a weekend effect exists in the management of and outcomes after extremity degloving injuries. Methods:. The cohort included adults presenting with open extremity degloving injuries to a tertiary level one trauma center between June 2018 and May 2022. We collected demographics, comorbidities, injury information, interventions, and complications. Propensity score weighting was used to minimize confounding differences between those presenting on weekends (Sat–Sun) versus weekdays (Mon–Fri). Weighted regressions were used to examine differences in interventions by day of presentation. Multivariable weighted regressions accounting for differences in interventions received were used to examine whether weekend presentation was associated with amputation risk, complications, or functional deficits. Results:. Ninety-five patients with 100 open extremity degloving injuries were included. In total, 39% of injuries were weekend-presenting. There was a higher rate of noninsulin-dependent diabetes among patients presenting on weekends (P = 0.03). Weekend-presenting injuries had higher median Injury Severity Scores (P = 0.04). Propensity-weighted regression analysis revealed differences in interventions received on weekends, including lower rates of pedicled and free flaps and bone graft, and increased rates of negative-pressure wound therapy (P ≤ 0.02). Multivariable regression analysis revealed weekend presentation was a significant independent risk factor for amputation of the affected extremity [odds ratio 2.27, 95% CI (1.01–5.33), P = 0.05]. Conclusion:. Weekend presentation may impact interventions received and amputation risk in patients presenting with open extremity degloving injuries

Monocytes loaded with indocyanine green as active homing contrast agents permit optical differentiation of infectious and non-infectious inflammation.

Distinguishing cutaneous infection from sterile inflammation is a diagnostic challenge and currently relies upon subjective interpretation of clinical parameters, microbiological data, and nonspecific imaging. Assessing characteristic variations in leukocytic infiltration may provide more specific information. In this study, we demonstrate that homing of systemically administered monocytes tagged using indocyanine green (ICG), an FDA-approved near infrared dye, may be assessed non-invasively using clinically-applicable laser angiography systems to investigate cutaneous inflammatory processes. RAW 264.7 mouse monocytes co-incubated with ICG fluoresce brightly in the near infrared range. In vitro, the loaded cells retained the ability to chemotax toward monocyte chemotactic protein-1. Following intravascular injection of loaded cells into BALB/c mice with induced sterile inflammation (Complete Freund's Adjuvant inoculation) or infection (Group A Streptococcus inoculation) of the hind limb, non-invasive whole animal imaging revealed local fluorescence at the inoculation site. There was significantly higher fluorescence of the inoculation site in the infection model than in the inflammation model as early as 2 hours after injection (p<0.05). Microscopic examination of bacterial inoculation site tissue revealed points of near infrared fluorescence, suggesting the presence of ICG-loaded cells. Development of a non-invasive technique to rapidly image inflammatory states without radiation may lead to new tools to distinguish infectious conditions from sterile inflammatory conditions at the bedside