Age-related changes in wound healing

Acute Compartment Syndrome with Multiple Metacarpal Fractures in the Hand of a 5-Year-Old Boy: A Case Report of Successful Resolution with Delayed Primary Closure

Background: acute compartment syndrome (ACS) is an orthopedic emergency characterized by pathological pressure elevation within a confined anatomical space, posing a significant challenge in pediatric patients. ACS affects children in a very limited proportion, particularly involving the upper extremities, and diagnosis is complicated by subtle manifestations compared to adults. Case Presentation: we report on the case of a 5-year-old boy who sustained a crush injury to his right hand, resulting in multiple metacarpal fractures and subsequent ACS. The patient presented with severe pain, hand deformity, and restricted mobility. Radiological evaluation confirmed displaced fractures of multiple metacarpals. Emergency surgical intervention involved six incisions to decompress the dorsal and palmar compartments, release muscles, and decompress the median nerve. Healing involved delayed primary closure monitored every 72 h, resulting in an optimal outcome without complications. Conclusions: pediatric upper extremity ACS is rare, complicating diagnosis and treatment due to limited guidelines. This case underscores the effectiveness of early surgical decompression and delayed primary closure in achieving favorable outcomes. Individualized treatment strategies tailored to anatomical considerations and ACS severity are crucial to optimize patient care in pediatric surgical settings.

Free Flap Reconstruction of the Extremities in Patients Who are ≥65 Years Old: A Single-Center Retrospective 1-to-1 Matched Analysis

Purpose

Demographic changes are leading to population aging, and free flap reconstructions for various indications are expected to become increasingly common among older patients. Therefore, this study evaluated free flap reconstruction of the extremities in older patients and compared the outcomes to those from younger patients who underwent similar procedures during the same period.

Patients and Methods

This single-center retrospective study used a case-control design to compare older and younger patients who underwent free flap reconstruction of soft tissue defects in the extremities. One-to-one matching was performed for older patients (≥65 years) and younger patients (≤64 years) according to indication, flap recipient site, and flap type. The parameters of interest were clinico-demographic characteristics, flap type, defect location, indication for free flap reconstruction, number of venous anastomoses, and postoperative complications (flap loss, infection, and wound healing disorders).

Results

The study included 48 older patients and 133 younger patients, with a mean follow-up of 12 months after discharge. The free flap reconstruction was performed at a mean interval of 19.8±22.8 days (range: 0–88 days). The 1:1 matching created 38 pairs of patients, which revealed no significant differences in the rates of flap necrosis and flap failure.

Conclusion

This study failed to detect a significant age-related difference in the flap necrosis rate after free flap reconstruction of extremity defects. Therefore, with careful perioperative management and patient selection, microsurgical free flap reconstruction is a feasible option for older patients.

Outcomes of the Extreme Elderly Undergoing Anaesthesia and Surgery amongst Southeast Asians

Introduction

With a rapidly ageing population in Singapore, we see an increasing number of elderly patients undergoing surgery, both elective and emergency. This study aims to look at the anaesthesia techniques employed in a subset of very elderly population undergoing surgery and their subsequent postoperative outcomes, in particular their 30-day mortality, postoperative complication rates, and length of hospital stays.

Materials and Methods

We searched from our hospital records between 2012 and 2013 for patients equal to or older than 90 years old who have undergone surgery and retrospectively analysed the types of surgery and mode of anaesthesia used.

Results

Sixty-two patients were identified. The mean age is 93.6 years. Majority were ASA 2 and ASA 3 patients. The most common type of surgery performed was orthopaedic, followed by vascular and urologic. Seven of the 62 patients required re-operations. Regional was the predominant anaesthetic technique employed, followed by general anaesthesia. Intraoperative hypotension was seen in 16 of the patients, all of whom recovered uneventfully. Hypothermia, desaturation, and hypertension were the top three complications observed in the recovery. Seventeen patients were admitted to a high-dependency facility postoperatively. The mean length of stay was 13.7 days. The 30-day mortality was 1.6 percent.

Conclusions

We have provided a snapshot of very elderly patients coming for surgery. The results show that this group of elderly patients do well postoperatively with relatively low complication and 30-day mortality rates. The outcomes presented can be used as a guide for risk counseling in the perioperative period.

Management of Fasciotomy Incisions After Acute Compartment Syndrome: Is Delayed Primary Closure More Feasible in Children Compared With Adults?

BACKGROUND

Recent adult literature has demonstrated that in the setting of acute compartment syndrome (ACS), if fasciotomy wounds are not closed after the first debridement, they are unlikely to be closed via delayed primary closure (DPC). The purpose of this study was to report the success of DPC through serial debridement in children with fasciotomy wounds secondary to ACS and to determine whether length of hospital stay is negatively affected by adopting a DPC strategy.

METHODS

We identified all patients treated with fasciotomy for ACS (aged 0 to18 y). Patient, injury, and treatment characteristics were summarized by fasciotomy treatment type. Patients were grouped as: primary closure, DPC, and flap or skin graft (F/SG). For patients who required additional debridements after initial fasciotomy, treatment success was defined as closure by DPC (without requiring F/SG). Multivariable logistic regression was used to determine factors associated with additional surgeries, complications, and treatment success.

RESULTS

A total of 82 children underwent fasciotomies for ACS. Fifteen (18%) patients were treated with primary closure at the time of their initial fasciotomy and were excluded from the remainder of the analysis, 48 (59%) patients underwent DPC, and 19 (23%) patients were treated with F/SG. The majority of delayed fasciotomy wounds were successfully closed by DPC (48/67, 72%) and the rate of successful closure remained consistent with each successive operative debridement. There were no differences across DPC and F/SG groups with respect to age, method of injury, or injury severity. Patients who underwent F/SG remained in the hospital for an average of 12 days compared with 8 days for those who underwent DPC (P<0.001).

CONCLUSIONS

In the setting of ACS, pediatric fasciotomy wounds that are not closed after the first postfasciotomy debridement still have a high likelihood of being closed through DPC with serial surgical debridement. In children, persisting with DPC strategy for fasciotomy closure after ACS is more successful than it is in adults.

LEVEL OF EVIDENCE

Level III.

Prediction of stump healing in lower limb amputation: a narrative review

Both types of diabetes, as well as different forms of acquired diabetes, are associated with diabetic peripheral neuropathy. Diabetic foot ulcers (DFU) is the condition most commonly related to somatic peripheral neuropathy, often leading to gangrene and limb amputation. Independent from large-vessel disease, sensory loss may result in DFU development and even amputation. The crucial part of any lower limb amputation is the stump healing process, which represents the central goal of postoperative management. Despite the importance attributed to this process, a standard set of guidelines regarding efficient healing methods is yet to be formulated. Health professionals are faced with the challenge of assessing the different risk factors and deciding which has a greater influence on the stump healing rate. There is currently an insufficient number of studies regarding factors effecting lower limb amputation. The main purpose of this review is to discuss the markers that can be helpful in the prediction of stump healing in patients who have undergone lower limb amputation.

Profile and outcome of patients with recurrent urogenital fistula in a fistula centre in Nigeria

INTRODUCTION AND HYPOTHESIS

Management of a recurrent urogenital fistula is very challenging and requires experienced surgeons. The aim of this study was to describe the characteristics, success rates, and associated factors related to surgical repairs of patients with recurrent urogenital fistulas by an experienced team at a fistula centre in Nigeria.

METHODS

This was a retrospective cohort study of 154 patients that had repeat urogenital fistula repairs at the National Obstetric Fistula Centre, Abakaliki, Nigeria, between January 2014 and December 2016. Information was retrieved from their hospital records. Successful repair was defined by continent status at 3 months after repair. Data were analyzed with SPSS version 20 by IBM Inc., and p < 0.05 was taken as statistically significant. Chi-square test was used to determine the association between the factors and successful repair.

RESULTS

The mean age was 36.27 ± 12.96 years. Obstetric fistula occurred in 92.2% of the patients. The success rates for the first, second, third, and fourth repeat repairs were 68.8%. 56.2%, 50%, and 0% respectively. Significant factors were the number of previous attempts at repair (χ² = 20.44, p = 0.002), age group (χ² = 16.95, p = 0.03), Waaldijk's classification (χ² = 13.31, p = 0.04), duration of fistula (χ² = 19.6, p = 0.03), surgeons' experience (χ² = 7.11, p = 0.04), and place of previous attempt at repair (χ² = 6.35, p = 0.02). There were no complications in 86.4%.

CONCLUSIONS

The success rate was good. Patients who had previous failed repairs at the fistula centre had better outcomes after the repeat surgeries. Centralizing fistula care will enhance optimal outcomes. It may also boost training and research in this specialty.

Extracellular matrix regulation of fibroblast function: redefining our perspective on skin aging

The dermal extracellular matrix (ECM) comprises the bulk of skin and confers strength and resiliency. In young skin, fibroblasts produce and adhere to the dermal ECM, which is composed primarily of type I collagen fibrils. Adherence allows fibroblasts to spread and exert mechanical force on the surrounding ECM. In this state, fibroblasts display a "youthful" phenotype characterized by maintenance of the composition and structural organization of the dermal ECM. During aging, fibroblast-ECM interactions become disrupted due to fragmentation of collagen fibrils. This disruption causes loss of fibroblast spreading and mechanical force, which inextricably lead to an "aged" phenotype; fibroblasts synthesize less ECM proteins and more matrix-degrading metalloproteinases. This imbalance of ECM homeostasis further drives collagen fibril fragmentation in a self-perpetuating cycle. This article summarizes age-related changes in the dermal ECM and the mechanisms by which these changes alter the interplay between fibroblasts and their extracellular matrix microenvironment that drive the aging process in human skin.

Topical Reformulation of Valsartan for Treatment of Chronic Diabetic Wounds

Chronic wounds are among the most devastating and difficult to treat consequences of diabetes. Dysregulation of the skin renin-angiotensin system is implicated in abnormal wound healing in diabetic and older adults. Given this, we sought to determine the effects of topical reformulations of the angiotensin type 1 receptor blockers losartan and valsartan and the angiotensin-converting enzyme inhibitor captopril on wound healing in diabetic and aged mice with further validation in older diabetic pigs. The application of 1% valsartan gel compared with other tested formulations and placebo facilitated and significantly accelerated closure time and increased tensile strength in mice, and was validated in the porcine model. One percent of valsartan gel-treated wounds also exhibited higher mitochondrial content, collagen deposition, phosphorylated mothers against decapentaplegic homologs 2 and 3 and common mothers against decapentaplegic homolog 4, alpha-smooth muscle actin, CD31, phospho-vascular endothelial growth factor receptor 2, and p42/44 mitogen-activated protein kinase. Knockout of the angiotensin subtype 2 receptors abolished the beneficial effects of angiotensin type 1 receptor blockers, suggesting a role for angiotensin subtype 2 receptors in chronic wound healing.

The effectiveness of inpatient physical therapy compared to outpatient physical therapy in older adults after total hip replacement in the post-discharge period: a systematic review

BACKGROUND

Total hip replacement is the most effective and safest method for treating severe degenerative, traumatic and other diseases of the hip joint. Total hip replacement can reliably relieve pain and improve function in the majority of patients for a period of 15 to 20 years or more postoperatively. Physical therapy follows each total hip replacement surgery. Physical therapy protocols after total hip replacement in the post-discharge period vary widely in terms of setting (inpatient, outpatient), content (the particular set of exercises used), and frequency (e.g. daily versus twice a week). In current literature, there is no systematic review which has compared the effectiveness of inpatient and outpatient physical therapy in patients after total hip replacement in the post-discharge period.

OBJECTIVES

The objective of this systematic review was to compare the effectiveness of inpatient physical therapy with outpatient physical therapy on the quality of life and gait measures in older adults after total hip replacement in the post-discharge period.

INCLUSION CRITERIA

This review considered studies that include older adults (over 65 years) who have had total hip replacement and are in the post-discharge period. Adults with bilateral or multiple simultaneous surgeries and also patients who have had hemiarthroplasty of the hip joint were excluded.This review considered studies that included any type of physical therapy delivered in inpatient settings provided by professionals with education in physical therapy. Inpatient physical therapy delivered at any frequency and over any duration was included.This review considered studies that included as a comparator any type of physical therapy delivered in outpatient settings provided by professionals with education in physical therapy or no physical therapy.This review considered studies that included the following primary and secondary outcomes. The primary outcome was quality of life, assessed by any validated assessment tool. The secondary outcome was measures of gait assessed by any valid methods.This review considered both experimental and observational study designs including randomized controlled trials, non-randomized controlled trials, quasi-experimental, before and after studies, prospective and retrospective cohort studies, case control studies and analytical cross sectional studies for inclusion.

SEARCH STRATEGY

The search strategy aimed to find both published and unpublished studies. A three-step search strategy was utilized in 12 databases. Studies published in all languages and any date were considered for inclusion in this review.

METHODOLOGICAL QUALITY

Assessment of methodological quality was not conducted as no studies were identified that met the inclusion criteria.

DATA EXTRACTION AND SYNTHESIS

Data extraction and synthesis was not performed because no studies were included in this systematic review.

RESULTS

During to the three-step search strategy 4330 papers were identified. The primary and secondary reviewer independently retrieved 42 potentially relevant papers according to the inclusion criteria by title and abstract screening. Following assessment of full text all of the retrieved papers were excluded based on the inclusion criteria.

CONCLUSIONS

There is no scientific evidence comparing the effectiveness of inpatient physical therapy with outpatient physical therapy in older patients after total hip replacement in the post-discharge period.

IMPLICATIONS FOR RESEARCH

This systematic review has identified gaps in the literature for comparing the effectiveness of inpatient physical therapy with and outpatient physical therapy on the quality of life and gait measures in older adults after total hip replacement in the post-discharge period. Prospective randomized double blind multicenter controlled trials are needed to answer this important clinical question.

Knockout of Angiotensin AT2 receptors accelerates healing but impairs quality

Wounds are among the most common, painful, debilitating and costly conditions in older adults. Disruption of the angiotensin type 1 receptors (AT₁R), has been associated with impaired wound healing, suggesting a critical role for AT₁R in this repair process. Biological functions of angiotensin type 2 receptors (AT₂R) are less studied. We investigated effects of genetically disrupting AT₂R on rate and quality of wound healing. Our results suggest that AT₂R effects on rate of wound closure depends on the phase of wound healing. We observed delayed healing during early phase of wound healing (inflammation). An accelerated healing rate was seen during later stages (proliferation and remodeling). By day 12, fifty percent of AT₂R^−/− mice had complete wound closure as compared to none in either C57/BL6 or AT₁R^−/− mice. There was a significant increase in AT₁R, TGFβ₁ and TGFβ₂ expression during the proliferative and remodeling phases in AT₂R^−/− mice. Despite the accelerated closure rate, AT₂R^−/− mice had more fragile healed skin. Our results suggest that in the absence of AT₂R, wound healing rate is accelerated, but yielded worse skin quality. Elucidating the contribution of both of the angiotensin receptors may help fine tune future intervention aimed at wound repair in older individuals.

Cutaneous wound healing in aging small mammals: a systematic review

As the elderly population grows, so do the clinical and socioeconomic burdens of nonhealing cutaneous wounds, the majority of which are seen among persons over 60 years of age. Human studies on how aging effects wound healing will always be the gold standard, but studies have ethical and practical hurdles. Choosing an animal model is dictated by costs and animal lifespan that preclude large animal use. Here, we review the current literature on how aging effects cutaneous wound healing in small animal models and, when possible, compare healing across studies. Using a literature search of MEDLINE/PubMed databases, studies were limited to those that utilized full-thickness wounds and compared the wound-healing parameters of wound closure, reepithelialization, granulation tissue fill, and tensile strength between young and aged cohorts. Overall, wound closure, reepithelialization, and granulation tissue fill were delayed or decreased with aging across different strains of mice and rats. Aging in mice was associated with lower tensile strength early in the wound healing process, but greater tensile strength later in the wound healing process. Similarly, aging in rats was associated with lower tensile strength early in the wound healing process, but no significant tensile strength difference between young and old rats later in healing wounds. From studies in New Zealand White rabbits, we found that reepithelialization and granulation tissue fill were delayed or decreased overall with aging. While similarities and differences in key wound healing parameters were noted between different strains and species, the comparability across the studies was highly questionable, highlighted by wide variability in experimental design and reporting. In future studies, standardized experimental design and reporting would help to establish comparable study groups, and advance the overall knowledge base, facilitating the translatability of animal data to the human clinical condition.

Femoral Nerve Block vs Periarticular Bupivacaine Liposome Injection After Primary Total Knee Arthroplasty: Effect on Patient Outcomes

Context: Patients receiving femoral nerve blocks for total knee arthroplasty (TKA) have been shown to have a high incidence of postoperative falls, which has been attributed to weakening of the quadriceps muscles. Local injection of analgesic medication that allows for full motor function of the quadriceps and, therefore, better progress through inpatient physical therapy and decreased hospital stay, has been suggested as an option for postoperative pain relief.

Objective: To compare the number of inpatient physical therapy sessions and hospital days needed in patients receiving periarticular injection of extended-release bupivacaine liposome vs femoral nerve block after TKA.

Methods: Data were retrospectively reviewed from the records of patients who underwent bilateral primary TKA, in which femoral nerve block was administered at the first operation and periarticular injection of an extended-release bupivacaine liposome mixture at the second operation. An average of 2.3 years had passed between the 2 procedures. The number of inpatient physical therapy sessions and hospital days needed were compared between both procedures for each patient.

Results: Sixteen patients (14 women) were included in the study, with a mean (SD) age of 63.8 (6.7) years. Compared with femoral nerve block, periarticular injection of analgesic medication resulted in fewer inpatient physical therapy sessions (femoral nerve block: mean [SD], 3.5 [1.3] sessions; periarticular injection: mean [SD], 2.3 [1.0] sessions; P=.002) and fewer hospital days (femoral nerve block: mean [SD], 1.9 [0.6] days; periarticular injection: mean [SD], 1.5 [0.6] days; P<.032).

Conclusion: Compared with femoral nerve block, periarticular injection of analgesia was found to quicken postoperative recovery in patients hospitalized for TKA. The use of periarticular injections in patients undergoing TKA could yield substantial cost savings given the high frequency of this procedure.

Risk factors for early-occurring and late-occurring incisional hernias after primary laparotomy for ovarian cancer

OBJECTIVE

To evaluate a cohort of gynecologic oncology patients to discover risk factors for early- and late-occurring incisional hernia after midline incision for ovarian cancer.

METHODS

We collected retrospective data from patients undergoing primary laparotomy for ovarian cancer at the University of Wisconsin Hospitals and Clinics from 2001 to 2007. Patient characteristics and potential risk factors for hernia formation were noted. Physical examination, abdominal computerized assisted tomography scans, or both were used to detect hernias 1 year after surgery (early hernia) and 2 years after surgery (late hernia).

RESULTS

There were 265 patients available for the 1-year analysis and 189 patients for the 2-year analysis. Early and late hernia formation occurred in 9.8% (95% confidence interval [CI] 6.2-12%) and an additional 7.9% (95% CI 4.1-12%) of patients, respectively. Using multiple logistic regression, poor nutritional status (albumin less than 3 g/dL) and suboptimal cytoreductive surgery (1 cm or greater residual tumor) were significantly associated with the formation of early incisional hernia after midline incision (P<.001 for both). Late hernia formation was associated only with age 65 years or older (P=.01).

CONCLUSION

The formation of early incisional hernias after midline incision is associated with poor nutritional status and suboptimal cytoreductive surgery, whereas late hernia formation is associated with advanced age.

Predictors of Adverse Events After Parotidectomy

Objective:

There is a current paucity of large-scale, multi-institutional studies that explore the risk factors for major complications following parotidectomy.

Methods:

The American College of Surgeons National Surgical Quality Improvement Program participant use file was reviewed to identify all patients who had undergone parotidectomy between 2006 and 2011. Risk factors that predicted adverse events were estimated by using multivariate logistic regression.

Results:

Of 2919 included patients, 202 patients experienced adverse outcomes within the first 30 days of surgery. These included surgical complications in 76 (2.6%) patients; medical complications in 90 (3.1%) patients; death in 7 (0.2%) patients; and reoperation in 77 (2.6%) patients. Predictors of any complication included disseminated cancer (odds ratio [OR] = 2.28; 95% confidence interval [CI], 1.05-4.95; P = .036) and increasing total relative value units (OR = 1.01; 95% CI, 1.00-1.02; P = .027). Active smoking was a major risk factor for surgical complications (OR = 1.81; 95% CI, 1.08-3.05; P = .025). Dyspnea (OR = 2.93; 95% CI, 1.37-6.27; P = .006) significantly predicted medical complications.

Conclusion:

Although complication rates after parotidectomy are generally low, avoidance of specific and nonspecific postoperative complications still remains an area for improvement. Future outcomes databases should include procedure-specific complications, including facial nerve injury.

Synergistic interactions with a high intraoperative expander fill volume increase the risk for mastectomy flap necrosis

Purpose

Prosthetic-based breast reconstruction is performed with increasing frequency in the United States. Major mastectomy skin flap necrosis is a significant complication with outcomes ranging from poor aesthetic appearance to reconstructive failure. The present study aimed to explore the interactions between intraoperative fill and other risk factors on the incidence of flap necrosis in patients undergoing mastectomy with immediate expander/implant-based reconstruction.

Methods

A retrospective review of 966 consecutive patients (1,409 breasts) who underwent skin or nipple sparing mastectomy with immediate tissue expander reconstruction at a single institution was conducted. Age, body mass index, hypertension, smoking status, premastectomy and postmastectomy radiation, acellular dermal matrix use, and application of the tumescent mastectomy technique were analyzed as potential predictors of flap necrosis both independently and as synergistic variables with high intraoperative fill. The following three measures of interaction were calculated: relative excess risk due to interaction, attributable proportion of risk due to interaction, and synergy index (SI).

Results

Intraoperative tissue expander fill volume was high (≥66.7% of the maximum volume) in 40.9% (576 of 1,409 breasts) of cases. The unadjusted flap necrosis rate was greater in the high intraoperative fill cohort than in the low fill cohort (10.4% vs. 7.1%, p=0.027). Multivariate logistic regression did not identify high intraoperative fill volume as an independent risk factor for flap necrosis (odds ratio 1.442, 95% confidence interval 0.973-2.137, p=0.068). However, four risk factors were identified that interacted significantly with intraoperative fill volume, namely tumescence, age, hypertension, and obesity. The SI, or the departure from additive risks, was largest for tumescence (SI, 25.3), followed by hypertension (SI, 2.39), obesity (SI, 2.28), and age older than 50 years (SI, 1.17).

Conclusion

In the postmastectomy, hypovascular milieu, multiple risk factors decreasing flap perfusion interact with high intraoperative fill volume to cross a threshold and synergistically increase the risk of flap necrosis.

Aging is associated with increased activities of matrix metalloproteinase-2 and -9 in tenocytes

Background

Most tendon pathology is associated with degeneration, which is thought to involve cyclic loading and cumulative age-related changes in tissue architecture. However, the association between aging and degeneration of the extracellular matrix (ECM) in tendons has not been investigated extensively.

Methods

We examined tenocytes from Achilles tendons taken from rats of three different ages (2, 12, and 24 months). Tenocyte viability was assessed using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. Quantitative real-time polymerase chain reaction (PCR) was used to determine the levels of mRNAs that encode type-I collagen, matrix metalloproteinase (MMP)-2 and −9, tissue inhibitor of metalloproteinase (TIMP)-1 and −2 and transforming growth factor (TGF)-β1. Gelatin zymography was used to evaluate the enzymatic activities of MMP-2 and −9. Furthermore, the concentration of TGF-β1 in conditioned medium was evaluated using enzyme-linked immunosorbent assay (ELISA).

Results

The results of the MTT assay showed that the number of viable tenocytes decreased with age. No differences were observed in the levels of mRNAs that encode type-I collagen and TGF-β1 among the three age groups, and the TGF-β1 concentration did not change with age. However, mRNAs that encode MMP-2 and −9 were significantly more abundant in tenocytes from the aging group, and gelatin zymography revealed that the enzymatic activities of MMP-2 and −9 also increased significantly with age. Furthermore, as compared with young group, mRNAs that encode TIMP-1 and −2 were significantly decreased in tenocytes from the aging group.

Conclusions

Activities of MMP-2 and MMP-9 in tenocytes increase with age. This might provide a mechanistic explanation of how aging contributes to tendinopathy or tendon rupture with age.

Enhanced healing of diabetic wounds by subcutaneous administration of human umbilical cord derived stem cells and their conditioned media

Objective. Mesenchymal stem cells (MSCs) isolated from the umbilical cord and their conditioned media (CM) can be easily obtained and refined compared with stem cells from other sources. Here, we explore the possibility of the benefits of these cells in healing diabetic wounds. Methodology and Results. Delayed wound healing animal models were established by making a standard wound on the dorsum of eighteen db/db mice, which were divided into three groups with six mice in each: groups I, II, and III received PBS, UC-MSC, and CM, respectively. UC-MSC and their CM significantly accelerated wound closure compared to PBS-treated wounds, and it was most rapid in CM-injected wounds. In day-14 wounds, significant difference in capillary densities among the three groups was noted (n = 6; P < 0.05), and higher levels of VEGF, PDGF, and KGF expression in the CM- and UC-MSC-injected wounds compared to the PBS-treated wounds were seen. The expression levels of PDGF- β and KGF were higher in CM-treated wounds than those in UC-MSC-treated wounds. Conclusion. Both the transplantation of UC-MSC and their CM are beneficial to diabetic wound healing, and CM has been shown to be therapeutically better than UC-MSC, at least in the context of diabetic wound healing.

Lesion size correlates with Leishmania antigen-stimulated TNF-levels in human cutaneous leishmaniasis

Cutaneous leishmaniasis (CL) is a worldwide disease endemic in several regions of the globe. The hallmark of CL is skin ulcers likely driven by efforts of the immune system to control Leishmania growth. Cytokines, such as tumor necrosis factor (TNF) and interferon-gamma can control disease progression in animal models. Nevertheless, the impact of these cytokines in CL ulcer outcome is not well established in humans. In this study, 96 CL patients from an endemic area of Leishmania braziliensis were enrolled for a follow-up study that consisted of clinical and immunological evaluations in a 2-year period. Statistical analysis revealed that healing time (P = 0.029), age (P = 0.002), and TNF levels (P = 0.0002) positively correlate with ulcer size at the time of the first clinical evaluation. Our findings suggest that ulcer size correlates with healing time and TNF levels support the use of TNF inhibitors combined with standard therapy to improve healing in CL patients with severe lesions.

Potential benefits of allogeneic bone marrow mesenchymal stem cells for wound healing

INTRODUCTION

It is becoming increasingly evident that select adult stem cells have the capacity to participate in repair and regeneration of damaged and/or diseased tissues. Mesenchymal stem cells have been among the most studied adult stem cells for the treatment of a variety of conditions, including wound healing.

AREAS COVERED

Mesenchymal stem cell features potentially beneficial to cutaneous wound healing applications are reviewed.

EXPERT OPINION

Given their potential for in vitro expansion and immune modulatory effects, both autologous and allogeneic mesenchymal stem cells appear to be well suited as wound healing therapies. Allogeneic mesenchymal stem cells derived from young healthy donors could have particular advantage over autologous sources where age and systemic disease can be significant factors.

Biomechanical properties of skin in massive weight loss patients

BACKGROUND

The aim of this study is to assess skin strength in MWL patients relative to control cosmetic abdominoplasty patients biophysically, biochemically, and histologically. Growing success of weight loss programs has brought about an increase in the MWL population. Skin quality is thought to be impaired by MWL, but there are no compelling studies that have fully addressed the structural mechanisms involved.

METHODS

Skin from the medial and lateral abdomen was harvested fresh from patients undergoing cosmetic abdominoplasty (n = 6) or abdominal panniculectomy for MWL (n = 35), and burst strength was tested in the horizontal and vertical directions. Collagen content was measured, and histological studies were performed to assess epidermal and dermal thickness, vascularity as well as the morphology and density of the collagen fibers.

RESULTS

In all groups, skin stretched horizontally was stronger than skin stretched vertically (p < 0.001). The skin of MWL patients was stronger medially compared to the skin of cosmetic patients. (p = 0.047) Newly formed collagen was diminished in MWL than that in the control group, but the results were not statistically significant. Epidermal thickness was significantly higher medially in MWL (p = 0.049). Elastin fibers were decreased in the MWL group, while dermal vascularity was higher in the MWL group.

CONCLUSIONS

The skin of MWL patients demonstrated stronger mechanical parameters than that of cosmetic patients in the medial part of the abdomen; however, the decrease in elastic fibers associated with a decrease in newly formed collagen seemingly provides a contradiction. Skin changes with MWL merits further study to understand it more completely.

Immune Measures in Behavioral Medicine Research: Procedures and Implications

Immune system activity is heavily influenced by the central nervous system. These interactions provide us the means to study mind–body interactions and how they affect health. In general, measures of immune system activity can be divided into two categories: those that are evident in the circulation and those that need to be elicited. For example, leukocytes can be collected from the circulation, counted, and their function accessed in cell culture. To test the ability of the immune system to respond to an experimental challenge more directly, studies involving wound healing, or involving the response to an infectious agent, can be performed. The purpose of this chapter is briefly to describe immune assays that are commonly employed in behavioral medicine research, including a rationale for their use as well as a brief description of the methodology. This chapter also describes previous studies in which circulatory and elicited immune measures have been studied in human subjects experiencing different psychological stressors, with an emphasis on studies involving medical students experiencing academic stress and caregivers of a spouse with Alzheimer’s disease. Finally, the chapter discusses the important role that the employment of animal models can play in studies of stress and health and in defining how nervous system activity can influence the immune response.

[Pathogenesis of chronic wounds]

Chronic, nonhealing wounds and their therapy are not only a medical problem but a severe economic one as well. Such wounds have a great effect on quality of life. Basic research has enhanced our understanding of the stimulation and inhibition of wound healing and provides the basis for introducing new and innovative treatment methods. This paper reviews the most relevant in- and extrinsic factors that disturb physiologic wound healing to result in chronic nonhealing wounds. In addition, molecular intervention modalities targeting various aspects of wound repair are demonstrated.

The αvβ6 integrin plays a role in compromised epidermal wound healing

The alphavbeta6 integrin is an exclusively epithelial integrin that is highly expressed during fetal development. In adult tissue, alphavbeta6 integrin is expressed during inflammation, carcinogenesis, and in wound healing. We previously reported that alphavbeta6 integrin is highly expressed in poorly healing human wounds and its over-expression is associated with chronic wounds in a mouse model. The objective of this study was to investigate the role of alphavbeta6 integrin in compromised wound healing induced by hydrocortisone treatment or aging by using young and old mice deficient in or overexpressing the beta6 integrin subunit in the epidermis. Untreated aged beta6 integrin-deficient (beta6-/-) animals showed a significant delay in wound healing when compared to their age-matched controls or younger beta6-/- mice. The most significant delay was observed at the stages where granulation tissue deposition was occurring. Hydrocortisone treatment significantly delayed wound healing in wild-type and beta6 integrin-deficient mice in comparison with the untreated controls. However, hydrocortisone treatment in beta6 integrin overexpressing animals did not cause a significant delay in wound healing. The results of this study suggest that alphavbeta6 integrin plays an important role in wound healing in animals compromised by either age or stress mimicked by hydrocortisone.

Wound Healing: An Overview

Understanding wound healing today involves much more than simply stating that there are three phases: inflammation, proliferation, and maturation. Wound healing is a complex series of reactions and interactions among cells and "mediators." Each year, new mediators are discovered and our understanding of inflammatory mediators and cellular interactions grows. This article will attempt to provide a concise overview on wound healing and wound management.

How much do we understand about the effects of ageing on healing?

Poor experimental design has contributed to a perceived association of ageing with delayed wound healing. Continuing research on the influence of ageing will allow more focused therapeutic strategies.

How does ageing affect the wound healing process?

Ageing is thought to impair wound healing, but this review of current research shows that there is conflicting evidence concerning many cellular mechanisms, while concomitant factors in older people may result in delayed healing.

An evaluation of the Waterlow pressure ulcer risk-assessment tool

The National Institute for Clinical Excellence (NICE, 2001) stated that in order to achieve clinical governance strategies, risk management in the form of pressure ulcer risk assessment will contribute to improved quality of patient care. Risk-assessment tools must display high-predictive values, be highly sensitive and specific, reliable, and easy and convenient to use. Despite their extensively documented poor performance, pressure ulcer risk-assessment scales play a primary role in the prevention and management of pressure ulcers. The tools attempt to determine patients' risk status by quantifying a range of the most commonly recognized risk factors. Although there are over 40 different assessment tools, the Waterlow pressure ulcer risk-assessment tool is the tool that is most widely used in the UK. This article aims to review studies relating to the reliability, content validity, predictive validity, concurrent validity and the construct validity of the Waterlow pressure ulcer risk-assessment tool.

Evidence-Based Protocol: Treatment of Pressure Ulcers

Those who provide direct care to older adults with pressure ulcers play a significant role in ensuring the environment is optimal for wound healing. Use of the evidence-based guideline "Treatment of Pressure Ulcers" (Folkedahl, Frantz & Goode, 2002b) can provide a template for implementation of interventions to maximize the repair process.

Differentiation kinetics of in vitro 3T3-L1 preadipocyte cultures

Engineering autologous adipose constructs from cell culture is a promising strategy to overcome limitations of conventional soft-tissue implants. A methodology is presented to experimentally determine and mathematically model the differentiation kinetics of in vitro 3T3-L1 preadipocyte cultures that can aid in construct design. Relative rates of morphological and interfacial events during adipogenesis were compared. Model results suggest that maturation of an intermediate multilocular phenotype was the rate-limiting step in morphological differentiation and had an intrinsic rate of 0.012 day(-1). Dislodgment of multilocular fat cells was the primary mechanism of cell loss during adipogenesis. The maximum rate of lipid droplet nucleation was predicted to precede that of coalescence by 10 days and to be three times faster. Coalescence probability was estimated to decrease from 33 to 11% for 4- and 8-microm-diameter droplets, respectively. Fluid drainage and the cytoskeleton between droplets could have impeded coalescence. The kinetic analysis suggests that droplet ripening was the dominant mechanism of lipid production. Applications of this research include engineering of an adipose construct and predicting surgical outcome of patients requiring soft-tissue augmentation.

Age-dependent response of energy metabolism of human skin to UVA exposure: an in vivo study by 31P nuclear magnetic resonance spectroscopy

PURPOSE

The aim of our study was to evaluate the in vivo energy metabolism of human skin as a function of age, in conditions of rest and after a mild stress caused by a suberythemal UVA irradiation.

METHODS

The kinetics of UVA-induced modifications in high-energy phosphorylated metabolites of young and old skins were non-invasively monitored over a period of 24 h using 31P nuclear magnetic resonance spectroscopy. In vivo 31P spectra were obtained on the ventral aspect of the wrist, using a NMR Imaging Spectrometer equipped with a double-tuned surface coil. Concentrations of phosphocreatine, inorganic phospate, adenosine tri-phosphate, phosphomono and phosphodiesters were calculated from the spectra and results were expressed as relative concentrations. A total of 20 subjects were enrolled in this study (n = 10 for the age group below 25 years and n = 10 for the age group above 55 years). A second experiment was then performed on 10 old subjects (mean age 60) who were treated on one wrist, twice a day for one month prior to UVA irradiation, with a product that contained active ingredients to restore barrier function and modulate the inflammatory response, the other wrist being an untreated control.

RESULTS

Baseline levels of phosphorylated metabolites were similar in young and old skins. A suberythemal dose of UVA (6 J.cm-2) led to a significant decrease in the PCr/Pi ratio (index of energy status) and a significant increase in the PME/PDE ratio (index of cellular turnover rate of lipid-related metabolites) within 1 h. The observed variations were transient and the recovery was complete at T + 24 h post-UVA, although recovery was significantly slower in the older group. The disturbances were significantly reduced after treatment of the older skin with a formula that restored barrier function of the stratum corneum and modulated the inflammatory response.

CONCLUSION

(i) baseline levels of energy metabolites in skin do not seem to vary with age; (ii) low dose UVA irradiation induces a rapid response in the energy metabolism of the skin; (iii) the kinetics of the response and recovery after an aggression by UVA suggest that older skin has significantly less energy rebound after a stress situation than younger skin; (iv) the energy reserve in older skin can be protected efficiently against UVA-induced stress by restoring barrier function and modulating the inflammatory response.

Minimizing perioperative adverse events in the elderly

Elderly patients still have the highest postoperative mortality and morbidity rate in the adult surgical population. Preoperative clinical assessment to detect patients at high risk of postoperative events, and specific intraoperative and postoperative anaesthesia management are important to minimize postoperative adverse events in the elderly.

Delayed wound healing in aged rats is associated with increased collagen gel remodeling and contraction by skin fibroblasts, not with differences in apoptotic or myofibroblast cell populations

Aging has been anecdotally reported to result in prolonged wound healing. Measurement of punch biopsy wound closure in young (4 month old) and old (36 month old) rats indicated there was a significant delay in wound closure by old rats during the early phase of repair, after which closure rates were equivalent. The delay in granulation tissue accumulation in older animals could involve premature programmed cell death (apoptosis); however, apoptotic fibroblasts in sponge granulation tissue and tissue culture were less abundant in samples from old rats relative to young rats. Myofibroblasts express alpha-smooth muscle actin, and they are believed to be important in wound contraction. There were no significant differences in overall abundance or distribution of alpha-smooth muscle actin containing myofibroblasts in granulation tissue and in cultured granulation tissue fibroblasts regardless of the age of the donor rat. The spatial distribution of myofibroblasts and apoptotic cells was distinct. Fibroblasts from granulation tissue and skin explants were placed in a collagen gel contraction assay prior to the 5th passage to determine their in vitro contractility. While granulation tissue fibroblasts from young and old rats showed similar collagen gel contractility, skin fibroblasts from old rats displayed greater collagen gel contractile behavior than young skin fibroblasts. Greater gel contractility of fibroblasts from old rats appeared to result, in large part, from the ability of those cells to cause generalized gel degradation. Gelatin zymography indicated a greater abundance of matrix metalloproteinase-2 in supernatants from gels containing skin fibroblasts from old rats. Taken together, these results suggest that the age-associated healing delay in the rat may not be related to the appearance or abundance of distinct myofibroblast or apoptotic cell populations. Proteolysis may have a significant role in delayed wound healing in aged animals.

Differential activation of migration by hypoxia in keratinocytes isolated from donors of increasing age: implication for chronic wounds in the elderly

Chronic wound healing conditions are often observed in elderly patients with poor tissue oxygenation. Impaired re-epithelialization is a hallmark of these wounds, which is seen in both clinical studies and in our animal models of impaired healing. To investigate the pathogenic mechanism of chronic wounds, we studied the effect of hypoxia on migration of keratinocytes isolated from human donors of increasing age. Keratinocytes from elderly donors had depressed migratory activity when exposed to hypoxia, as opposed to an increase in migration in young cells. Analysis of underlying biochemical changes demonstrated a differential activation of matrix metalloproteinases by hypoxia in keratinocytes isolated from the young and the old. Matrix metalloproteinases-1 and -9 and tissue inhibitor of matrix metalloproteinase-1 were strongly upregulated by hypoxia in young cells, whereas no induction was observed in aged cells. Furthermore, transforming growth factor-beta 1 signaling appears to be involved in the keratinocyte differential response to hypoxia, as transforming growth factor-beta type I receptor was upregulated by hypoxia in young cells, while there was no induction in aged cells. Transforming growth factor-beta neutralizing reagents blocked hypoxia-induced matrix metalloproteinase-1, matrix metalloproteinase-9 expression, and hypoxia-induced cell migration as well. Our results suggest that an age-related decrease in response to hypoxia plays a crucial part in the pathogenesis of retarded re-epithelialization in wound.

Impaired wound contraction in stromelysin-1-deficient mice

OBJECTIVE

To determine whether the deletion of stromelysin-1, a single metalloproteinase gene product, will alter the time course and quality of dermal wound repair in mice.

SUMMARY BACKGROUND DATA

After dermal injury, a highly coordinated program of events is initiated by formation of a fibrin clot, followed by migration of keratinocytes, contraction of the dermis, recruitment of inflammatory macrophages, formation of granulation tissue with angiogenesis, and finally tissue remodeling. Matrix metalloproteinases are rapidly induced in the dermis and granulation tissue and at the leading edge of the epidermis in the healing wounds.

METHODS

Incisional and circular full-thickness wounds 2 to 10 mm were made in the dermis of stromelysin-1-deficient and wild-type mice. The wounds were analyzed for rate of cellular migration and epithelialization. The wound contraction was examined by immunohistochemical staining for alpha-smooth muscle actin and fluorescent staining for fibrillar actin.

RESULTS

Independent of the age of the animal, excisional wounds in stromelysin-1-deficient mice failed to contract and healed more slowly than those in wild-type mice. Cellular migration and epithelialization were unaffected in the stromelysin-1-deficient animals. The functional defect in these mice is failure of contraction during the first phase of healing because of inadequate organization of actin-rich stromal fibroblasts.

CONCLUSIONS

Excisional dermal wound healing is impaired in mice with a targeted deletion in the stromelysin-1 gene. Incisional wound healing is not affected. These data implicate stromelysin-1 proteolysis during early wound contraction and indicate that stromelysin-1 is crucial for the organization of a multicellular actin network.

Effects of keratinocyte growth factor-2 (KGF-2) on wound healing in an ischaemia-impaired rabbit ear model and on scar formation

Keratinocyte growth factor-2 (KGF-2), also described as fibroblast growth factor-10 (FGF-10), is a member of the fibroblast growth factor family. KGF-2 shares 57 per cent sequence homology to previously reported KGF-1 (FGF-7). In skin, both growth factors are expressed in the dermal compartment. KGF-1 and KGF-2 bind to the same receptor with high affinity, the KGFR isoform of FGFR2, which is exclusively expressed by epithelial cells. This study examines the in vivo function of topically applied KGF-2 on wound healing using an ischaemia-impaired rabbit dermal ulcer model, in young and aged animals. Histological analysis of the wounds showed that KGF-2 significantly promoted re-epithelialization in both young and old animals. Similar results have been observed with KGF-1 in this model. In addition, KGF-2 enhanced granulation tissue formation in both young and old rabbits, a biological effect not found with KGF-1, suggesting a possible indirect mechanism which enhances neo-granulation tissue formation. Immunohistological staining of day 7 wounds with proliferating cell nuclear antigen (PCNA) antibody demonstrated a significant increase of dermal cell proliferation in KGF-2-treated wounds compared with placebo wounds. These results suggest a mesenchymal-epithelial interaction that is mediated by a paracrine feedback loop of KGF-2. Because of the wound healing impairment observed with ageing, the wound healing response to KGF-2 was also studied in ischaemic wounds of aged animals. Administration of KGF-2 led to significant stimulation of epithelial growth and granulation tissue formation. The effects seen in the old animals were delayed compared with the young animals. Lastly, the effect of KGF-2 was examined in a rabbit model of scar formation. Quantification of scar elevation index showed no significant differences in scar formation when KGF-2 was compared with buffer placebo. Compared with other growth factors, including KGF-1 and TGF-beta which have previously been examined in these models, KGF-2 is the most effective and causes no obvious scarring.

Transforming growth factor-beta1 fails to stimulate wound healing and impairs its signal transduction in an aged ischemic ulcer model: importance of oxygen and age

Clinical trials of exogenous growth factors in treating chronic wounds have been less successful than expected. One possible explanation is that most studies used animal models of acute wounds in young animals, whereas most chronic wounds occur in elderly patients with tissue ischemia. We described an animal model of age- and ischemia-impaired wound healing and analyzed the wound-healing response as well as the transforming growth factor (TGF)-beta1 effect in this model. Rabbits of increasing ages were made ischemic in the ear where dermal ulcers were created. Histological analysis showed that epithelium ingrowth and granulation tissue deposition were significantly impaired with increased age under ischemia. TGF-beta1 stimulated wound repair under both ischemic and non-ischemic conditions in young animals, although it showed no statistical difference in aged animals. Procollagen mRNA expression decreased under ischemic conditions and with aging. Neither TGF-beta1 nor procollagen alpha1(I) mRNA expression increased in response to TGF-beta1 treatment under ischemia in aged animals. Therefore, the wound-healing process is impaired additively by aging and ischemia. The lack of a wound-healing response to TGF-beta1 in aged ischemic wounds may play a role in the chronic wounds.

Retrospective evaluation of postoperative intralesional steroid injections on wound healing

Steroids have been implicated as an etiology in delayed wound healing. Although there is much documentation in the literature that steroids delay wound healing, most studies are in vitro or use high systemic doses. No studies have used a one-time, postoperative, intralesional steroid injection and evaluated wound healing. This study retrospectively reviewed 73 patients with 115 foot and ankle surgeries over 12 years. Seventy-two patients had steroid injections and 43 did not. The average healing time for the steroid group was 17.1 +/- 10.5 days, and for the non-steroid group 17.3 +/- 8.75 days. There were two infections in the non-steroid group, and one infection in the steroid group. There were five dehiscences in each group. The patients were further subdivided into groups based on age, gender, number of procedures, type of surgery, health status, steroid type, and steroid dose. The healing time increased in patients > 60 years old, and in immunocompromised patients. The patients who had more complex surgery had increased healing time. The males had a longer healing time than the females. Overall, there was not a statistically significant difference between the steroid groups and the non-steroid group. Therefore, one-time postoperative intralesional steroid injections were not found to delay wound healing.