Acute wound healing: the biology of acute wound failure

The Efficacy of Local Autologous Platelet-Rich Plasma Prepared by Single and Double Spin Methods in the Treatment of Chronic Ulcer

BACKGROUND

Chronic nonhealing ulcers present significant challenges in diabetic, dermatological, and surgical patients. Platelet-rich plasma (PRP), enriched with bioactive factors, offers promise for wound healing enhancement. This study evaluates PRP's efficacy, prepared via single and double spin methods in nonhealing chronic ulcers.

METHODS

 Twenty-two patients aged 18-65 years participated and 100 mL of blood was drawn into citrate phosphate dextrose adenine (CPDA) bags with all aseptic precautions. PRP was prepared by single and double spin methods. Patient serum and 10% calcium gluconate were added to fibrin gel. PRP was injected around the ulcer and then dressed. Dressings were changed on the fifth, 15th, and 20th days with PRP. Evaluation occurred on day 30 using surface area and volume assessments by both methods.

RESULTS

The single spin PRP group and double spin PRP group had 11 patients each with hemoglobin range of 10.79±1.88 to 12.63±2.22 g/dL. Initial lesions (16.27 cm²) significantly reduced to 14.76 cm² after double spin PRP sessions (p=0.005) and Initial lesions (9.87 cm²) significantly reduced to 7.65 cm² after single spin PRP sessions (p=0.005). Platelet count differences between whole blood and PRP were significant (p<0.05).

CONCLUSIONS

The single spin PRP method exhibited considerable improvements in healing parameters, showcasing its potential for chronic ulcer management.

Prediction values of a novel prognostic index hypoproteinemia combined with contaminated wounds for wound dehiscence after abdominal surgery in neonates.. [DOI: 10.21203/rs.3.rs-2517931/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Background Abdominal Wound Dehiscence (AWD), occupying a large proportion of neonatal surgery is an essential complication of abdominal surgery, which can leads to severe consequences, including life-threatening. This study aims at exploring prediction value for AWD with potential joint factors of hypoproteinemia and incision type. Method The Cox proportional-hazards model (the Cox model) was applied to analyze clinical data came from 453 patients underwent neonatal laparotomy from June 2009 to June 2020. According to application of the random numbers, 453 cases were divided into two separate models randomly involving training set with 318 observations (70%) and validation set with 135 observations (30%), and then the models trained were validated based on the validation set. Investigation in the connection between hypoproteinemia, incision type, combined factors and AWD, were used for comparing those prediction values for AWD. Results With a median follow-up of 15 months, the incidence of neonatal AWD was 6.0% (27/453). Based on the univariate and multivariate Analysis using the Cox Regression Analysis, hypoproteinemia(HR = 7.005, P = 0.001) and joint factor༈HR = 6.901, P < 0.001༉were both the independent risk factors for neonatal AWD in training set. Meanwhile, hypoproteinemia and joint factor༈HR = 5.497, P = 0.045༉were both also the independent risk factors for neonatal AWD in validation models, which indicated that joint factor was the independent risk factor in both models. The summary ROC curve was estimated, and the area under the ROC curve (AUC) was calculated as a criterion for validating the models trained. The findings illustrated that AUC of joint prediction factor for AWD was higher than either that of hypoproteinemia༈0.759 vs. 0.638) or incision type factor ༈0.759 vs. 0.671༉singly. Conclusion The contribution of hypoproteinemia and incision type combined factor for predicting AWD is superior than that of them individually, resulting in a significant promotion in prediction efficiency and accuracy of predicting neonatal AWD.

Collagen fabricated delivery systems for wound healing: A new roadmap

Collagen is a biopolymer found in the animal body. It is one of the most abundant proteins in the extracellular matrix that provides strength to the skin, joints, and bones in the human body. It is an important source of elasticity and strength in the extracellular matrix and contributes to the structural and physiological integrity of tissues. Collagen plays an important role in regulating the wound healing process. It helps in wound healing by attracting fibroblasts and encouraging new collagen formation in the wound bed. Therefore, it can be used as a supplementary aid for wound treatment to accelerate the healing process. A prominent benefit of incorporating collagen in wound dressings is its ability to enhance the healing process for critical wounds. Not only collagen but various collagen-containing systems are being prepared to boost its efficacy in wound healing. Different strategies like nanoscale reductions, biopolymers, and incorporating anti-inflammatory and antimicrobial drugs with collagen have been reported. This review article emphasizes the use of collagen for wound healing and various collagen fabricated delivery systems such as nanofibres, nanoparticles, hydrogels, films, and sponges that aid in the healing of wounds.

Risk Factors for Infection of Sutured Maxillofacial Soft Tissue Injuries

Background: Maxillofacial soft tissue injuries (STIs) are common and frequent in emergency departments. The aim of this study was to analyze factors causing infection of maxillofacial STIs. Patients and Methods: Patients with maxillofacial STIs who received sutures and had complete medical records were evaluated. Gender, age, American Society of Anesthesiologists (ASA) grade, diabetes mellitus, wound age, wound length, wound contamination, wound type, and sites were analyzed using univariable analysis and binary logistic regression. Results: There were 3,276 cases included. In the univariable analysis, there was no significant difference in the infection rate between genders or between the wound age groups. In binary logistic regression, age, wound length, wound type, and physician level were risk factors for infection: age of 18-44 years (odds ratio [OR], 2.2; 95% confidence interval [CI], 1.7-2.9), 44-64 years (OR, 3.1; 95% CI, 2.3-4.3), and ≥65 years (OR, 2.6; 95% CI, 1.7-4.1); wound length of 4-8 cm (OR, 1.7; 95% CI, 1.3-2.2) and >8 cm (OR, 2.4; 95% CI, 1.1-5.1); intra-oral wounds (OR, 1.6; 95% CI, 1.1-2.4) and communicating wounds (OR, 3.2; 95% CI, 2.3-4.4); junior specialists (OR, 1.6; 95% CI, 1.2-2.2); and lip (OR, 3.7; 95% CI, 1.1-12.0) and cheek (OR, 4.7; 95% CI, 2.3-17.1) sites. Wound contamination, ASA grade, and diabetes mellitus were not significantly different from wound infection in binary regression analysis. Conclusions: Age (>18 years old), wound length (>4 cm), intra-oral wounds, communicating wounds, suturing by junior surgeons, and lip or cheek injuries may be risk factors for maxillofacial STI infection. Even if the penetrating wound age exceeds 24 hours, it is meaningful to suture if there is no serious infection. For wounds at high risk of infection, further measures should be considered to reduce the possibility of infection, such as improving the surgical training of junior surgeons and improving the patient's wound care.

Oxygenation therapies for improved wound healing: Current trends and technologies

Degree of oxygenation is one of the important parameters governing various processes, including cell proliferation, angiogenesis, extracellular matrix production, and even combating the microbial burden at the wound site, all...

Risk factors for evisceration in gynecological oncology surgeries

Background/aim

To investigate the risk factors for evisceration in a gynecological oncology population. The secondary aim was to evaluate the impact of evisceration on survival.

Materials and methods

Inclusion criteria consisted of having had an elective surgery performed through a xiphoidopubic incision in our institution and having a gynecological malignancy based on pathology. A total of 198 patients were evaluated, 54 with evisceration and 144 without evisceration. Due to the widely varied prognosis of female genital cancers, the survival was analyzed on a homogenized group, including only 62 patients with primary advanced stage epithelial ovarian-tubal-peritoneal cancer.

Results

The preoperative factors associated with evisceration in the univariate analysis were old age, high body mass index (BMI), hypertension, smoking, comorbidities, high American Society of Anesthesiologist (ASA) score (3 and 4), and low preoperative albumin level. The associated intraoperative factors were bleeding volume, receiving more than two units of erythrocyte suspension or fresh frozen plasma, and having had a major operation. The associated postoperative factors were the albumin transfusion and the antibiotic use in the early postoperative period. In the multivariate analysis, smoking, low levels of preoperative albumin, high BMIs, and high ASA scores (3 and 4) were independent prognostic factors for evisceration. Evisceration was not associated with recurrence and survival in the patients with primary advanced stage epithelial ovarian-tubal-peritoneal cancer.

Conclusion

Smoking, preoperative hypoalbuminemia, obesity, and high ASA scores (3and 4) were the prognostic factors for evisceration. Short-term modifiable factors such as smoking cessation and improved nutritional status should be considered in elective gynecological oncology surgeries. Evisceration had no impact on survival and recurrence in the patients with primary advanced stage epithelial ovarian-tubal-peritoneal cancer.

Nanoceutical Adjuvants as Wound Healing Material: Precepts and Prospects

Dermal wound healing describes the progressive repair and recalcitrant mechanism of 12 damaged skin, and eventually, reformatting and reshaping the skin. Many probiotics, nutritional supplements, metal nanoparticles, composites, skin constructs, polymers, and so forth have been associated with the improved healing process of wounds. The exact mechanism of material-cellular interaction is a point of immense importance, particularly in pathological conditions such as diabetes. Bioengineered alternative agents will likely continue to dominate the outpatient and perioperative management of chronic, recalcitrant wounds as new products continue to cut costs and improve the wound healing process. This review article provides an update on the various remedies with confirmed wound healing activities of metal-based nanoceutical adjuvanted agents and also other nano-based counterparts from previous experiments conducted by various researchers.

Wound dressings as growth factor delivery platforms for chronic wound healing

Introduction: Years of tissue engineering research have clearly demonstrated the potential of integrating growth factors (GFs) into scaffolds for tissue regeneration, a concept that has recently been applied to wound dressings. The old concept of wound dressings that only take a passive role in wound healing has now been overtaken, and advanced dressings which can take an active part in wound healing, are of current research interest.Areas covered: In this review we will focus on the recent strategies for the delivery of GFs to wound sites with an emphasis on the different approaches used to achieve fine tuning of spatial and temporal concentrations to achieve therapeutic efficacy.Expert opinion: The use of GFs to accelerate wound healing and reduce scar formation is now considered a feasible therapeutic approach in patients with a high risk of infections and complications. The integration of micro - and nanotechnologies into wound dressings could be the key to overcome the inherent instability of GFs and offer adequate control over the release rate. Many investigations have led to encouraging outcomes in various in vitro and in vivo wound models, and it is expected that some of these technologies will satisfy clinical needs and will enter commercialization.

Intestinal anastomotic healing models during experimental colitis

BACKGROUND

Anastomotic leakage represents a major complication following resections in colorectal surgery. Among others, intestinal inflammation such as in inflammatory bowel disease is a significant risk factor for disturbed anastomotic healing. Despite technical advancements and several decades of focused research, the underlying mechanisms remain incompletely understood. Animal experiments will remain the backbone of this research in the near future. Here, instructions on a standardized and reproducible murine model of preoperative colitis and colorectal anastomosis formation are provided to amplify research on anastomotic healing during inflammatory disease.

METHODS

We demonstrate the combination of experimental colitis and colorectal anastomosis formation in a mouse model. The model allows for monitoring of anastomotic healing during inflammatory disease through functional outcomes, clinical scores, and endoscopy and histopathological examination, as well as molecular analysis.

DISCUSSION

Postoperative weight loss is used as a parameter to monitor general recovery. Functional stability can be measured by recording bursting pressure and location. Anastomotic healing can be evaluated macroscopically from the luminal side by endoscopic scoring and from the extraluminal side by assessing adhesion and abscess formation or presence of dehiscence. Histologic examination allows for detailed evaluation of the healing process.

CONCLUSION

The murine model presented in this paper combines adjustable levels of experimental colitis with a standardized method for colorectal anastomosis formation. Extensive options for sample analysis and evaluation of clinical outcomes allow for detailed research of the mechanisms behind defective anastomotic healing.

Advances of hydrogel dressings in diabetic wounds

The hydrogel dressings with various functions for diabetic wound treatment.

Prospects for the application of growth factors in wound healing

As the largest organ of the body, human skin is multifunctional and enjoys two layers, the epidermis and the dermis, the separation of which is performed by a basement membrane zone. Skin protects the body against mechanical forces and infections. Skin wounds represent large and growing challenges to the healthcare systems globally. Skin wound healing, as a protective shield for the body against the external environment, includes interactions among cell types, the neurovascular system, cytokines, and matrix remodeling. Growth factors (GFs) affect the microenvironment of the wound, and cause rises in cell differentiation, proliferation, and migration. Administrating exogenous GFs has revealed potential in enhancing wound healing outcomes. The use of human GFs in the field of wound healing is becoming gradually more interesting, because of the low-invasive techniques required for their use. Reviewed here are the literatures on the healing of skin wounds with emphasize on the role of GFs and their future prospects, containing profits, and probable long-standing side effects accompanied with their use.

Advanced drug delivery systems and artificial skin grafts for skin wound healing

Cutaneous injuries, especially chronic wounds, burns, and skin wound infection, require painstakingly long-term treatment with an immense financial burden to healthcare systems worldwide. However, clinical management of chronic wounds remains unsatisfactory in many cases. Various strategies including growth factor and gene delivery as well as cell therapy have been used to enhance the healing of non-healing wounds. Drug delivery systems across the nano, micro, and macroscales can extend half-life, improve bioavailability, optimize pharmacokinetics, and decrease dosing frequency of drugs and genes. Replacement of the damaged skin tissue with substitutes comprising cell-laden scaffold can also restore the barrier and regulatory functions of skin at the wound site. This review covers comprehensively the advanced treatment strategies to improve the quality of wound healing.

Metalloproteinases in chronic and acute wounds: A systematic review and meta-analysis

A systematic review and meta-analysis were undertaken in order to explore the influence of matrix metalloproteinases and their diagnostic methods in chronic and acute wounds. Searches were conducted in the PubMed (Medline) and Embase (Elsevier) databases from inception to late November 2017. We included clinical trials enrolling patients with cutaneous chronic and acute wounds where a validated diagnostic method was employed for metalloproteinases. We excluded in vitro, animal or preclinical studies, nonoriginal articles, and studies without available data for analysis. In addition, references of narrative and systematic reviews were scrutinized for additional articles. Eight studies met the inclusion criteria. Results revealed that the most frequently determined matrix metalloproteinases were MMP-2 and MMP-9, and were found in 54.5% of wounds. MMP-9 was present in more than 50% of the chronic wounds with a range from 37 to 78%. However, metalloproteinases were found in only 20% of acute wounds, and other types of metalloproteinases were also observed (MMP-2 and MMP-3). On the basis of the available evidence, high levels of metalloproteinases have been correlated with significantly delayed wound healing in wounds of a variety of etiologies.

Making better wound management decisions

Clinicians make wound management decisions based on scientific research of varying quality as well as personal and observed habits, anecdotal evidence, and even misinterpreted data. This article examines some common traumatic wound management topics and discusses appropriate decision-making for wound management.

Solid Organ Infections: Rare Complications After Laparoscopic Sleeve Gastrectomy: a Report of Four Cases

BACKGROUND

Laparoscopic sleeve gastrectomy (LSG) is gaining popularity for the treatment of morbid obesity. It is a simple, low-cost procedure resulting in significant weight loss within a short period of time. LSG is a safe procedure with a low complication rate. The most significant complications are staple-line bleeding, stricture, and staple-line leak. Formation of liver and splenic abscesses is an extremely rare consequence of LSG. Liver abscess has been reported in one case report while splenic abscess has been reported in five case reports after LSG.

METHODS

This study is a case report and literature review.

RESULTS

We report two cases of a pyogenic liver abscesses and two cases of splenic abscesses after LSG.

CONCLUSIONS

As LSG becomes more popular, clinicians need to be aware of uncommon but potentially serious complications related to it.

Evaluation of Risk Factors of Surgical Wound Dehiscence in Adults After Laparotomy

Objectives:

The percentage of patients with difficult and prolonged healing of the wound is still high, while the immediate complications such as wound dehiscence occurs in up to 3 % of all treated patients in abdominal surgery. The aim of study was to analyze the risk factors and comorbidities in the group patients undergoing laparotomy and associated with early postoperative wound dehiscence.

Methods:

The retrospective study included all patients treated surgically at Clinic of General and Abdominal surgery, Clinical Center of the University of Sarajevo in the period from January 1, 2013 until January 1, 2016, with clinically verified surgical wound dehiscence.

Results:

The results showed statistically proportion of male patients (70%) compared to female (30%). The largest number of respondents were in age group 71-80. Surgical wound infection was evident in 61% of patients, malignant staining in 52%, hypoproteinemia was found in 50% of patients, anemia in 43%, peritonitis in 36% and diabetes in 14% of respondents. Of the total respondents with surgical wound dehiscence, 30 (68%) had comorbidities present. By analyzing the prevalence of comorbidity and risk factors recorded in relation to comorbidity, it was noted that hypertension is most often associated with hypoproteinemia (X²=4.399; p=0.036), wound infection (X²=4.112; p=0.043) and malignant diseases (X²=4.016; p=0.045). The frequency of the anemia, peritonitis and diabetes in the sample was not different in relation to the comorbidity conditions (p >0.05).

Conclusions:

The risk factors occurrence of surgical wound dehiscence in our study were identified as hypoproteinemia, malignant disease, anemia and peritonitis. The highest incidence of dehiscence was in patients operated on in medical emergencies, and in patients with malignant disease.

Essential bariatric emergencies for the acute care surgeon

Bariatric surgery is the most effective treatment for morbid obesity. Due to the high volume of weight loss procedures worldwide, the general surgeon will undoubtedly encounter bariatric patients in his or her practice. Liberal use of CT scans, upper endoscopy and barium swallow in this patient population is recommended. Some bariatric complications, such as marginal ulceration and dyspepsia, can be effectively treated non-operatively (e.g., proton pump inhibitors, dietary modification). Failure of conservative management is usually an indication for referral to a bariatric surgery specialist for operative re-intervention. More serious complications, such as perforated marginal ulcer, leak, or bowel obstruction, may require immediate surgical intervention. A high index of suspicion must be maintained for these complications despite "negative" radiographic studies, and diagnostic laparoscopy performed when symptoms fail to improve. Laparoscopic-assisted gastric band complications are usually approached with band deflation and referral to a bariatric surgeon. However, if acute slippage that results in gastric strangulation is suspected, the band should be removed immediately. This manuscript provides a high-level overview of all essential bariatric complications that may be encountered by the acute care surgeon.

A retrospective analysis of early and late term complications in patients who underwent application of retention sutures for gastrointestinal tract malignancies

OBJECTIVE

Complications associated with wound healing after abdominal tumor operations continue to be a significant problem. This study aimed to determine the significance of retention sutures in preventing these complications. For this purpose, early and late term results of patients who underwent application of polydioxanone (PDS) and additional retention sutures for abdominal closure were retrospectively evaluated.

MATERIAL AND METHODS

Clinical files of 172 patients who were operated due to gastrointestinal tract malignancies in our clinic between January 2007 and January 2011 were retrospectively analyzed. Patients in whom the fascia was repaired only with PDS (Group 1) were compared to patients in whom the fascia was repaired with PDS and retention sutures (Group 2) in terms of age, gender, postoperative evisceration-wound infection (<1 month), incisional hernia (>1 month), incision type, co-morbid factors, and operative time.

RESULTS

There was no significant difference between the two groups in terms of age or gender (p=0.680 and p=0.763). No significant difference was detected in terms of postoperative incisional hernia (p=0.064). Evisceration and post-operative wound infection were significantly lower in Group 2 as compared to Group 1 (p=0.008 and p=0.002). Operative time was significantly longer in Group 1 than in Group 2 (p<0.0001). Co-morbid features were significantly higher in Group 2 than in Group 1 (p<0.0001). There were no significant differences between the groups in terms of incision type (p=0.743).

CONCLUSION

In the presence of co-morbid factors that disrupt wound healing in surgical patients with gastrointestinal malignancy, retention suture can be safely used as a supplement for optimal wound care.

Characterisation and comparison of the host response of 6 tissue-based surgical implants in a subcutaneous in vivo rat model

BACKGROUND

Hernia repair often involves fascial augmentation using biologic prostheses. Small processing changes during preparation modulate host tissue response, which influence material efficacy and longevity. In this pilot study, a rat model was used to determine the specific influence of tissue origin, decellularisation treatment and 1,6-hexamethylene diisocyanate (HMDI) cross-linking.

METHODS

Materials (1 cm2) were implanted subcutaneously into 6-week-old Wistar rats (4 materials per animal, n=6/material per time point) for 2, 5, 7, 14 and 28 days. Histologic processing was carried out after resin infiltration, observing classical histopathology and pathologic indexing. Materials comprised 6 tissue-based grafts covering both experimental and commercial porcine decellularised dermal and small intestinal submucosal materials.

RESULTS

Subcutaneous delivery of biologics demonstrated material-specific inflammatory/host responses. Controlled variations of the PermacolTM manufacturing process showed sodium dodecyl sulfate (SDS) was the most proinflammatory decellularisation reagent, and HMDI cross-linking had no effect on host response. All materials remained recoverable after 28 days, although SurgisisTM had partially resorbed.

CONCLUSION

Differences in host responses exist between biologic implants for hernia repair in this rat model. It is postulated that these modifications are induced during processing and may have an effect on the clinical outcome of hernia repair.

A review of biocompatibility in hernia repair; considerations in vitro and in vivo for selecting the most appropriate repair material

PURPOSE

Repair of hernia typically makes use of a prosthetic material; synthetic or biologic in nature. Any material which enters the body is subject to interrogation by the inflammation and immune system in addition to numerous other cell families, the outcome of which ultimately determines the success of the repair. In this review, we discuss the fundamental biology which occurs in situ when a biomaterial associates with a tissue, compare and contrast the techniques available to predict this in vitro, and review how features of hernia repair materials specifically may manipulate tissue interrogation and integration. Finally, we conclude our article by examining how biocompatibility impacts surgical practise and how a better understanding of the manner by which materials and tissues interact could benefit hernia repair.

MATERIALS AND METHODS

A review of the literature was conducted using appropriate scientific search engines in addition to inclusion of findings from the groups' primary research.

RESULTS

Using pre-clinical assays to anticipate the biocompatibility of a medical device is critical; however, to maximise the scientific power of in vitro findings, we must carefully consider the in vivo niche of the cells with which we are working. Excessive in vitro culture or contact to non-self materials can add compounding complexity to studies involving leucocytes for instance; therefore, we must ensure careful and stringent assay design when developing techniques for assaying pre-clinical biocompatibility. Furthermore, many of the features associated with hernia repair material design specifically, included to enhance their mechanical or biodegradation characteristics, are inadvertently instructive to cells, and therefore, throughout the prototype stages of a materials development, regular biocompatibility assessment must be performed.

CONCLUSION

The biocompatibility of a material is rate limiting in its ability to function as a medical device. The future of hernia repair materials will rely on close cohesion between the surgical and scientific communities to ensure the most robust biocompatibility assessment techniques, and models are utilised to predict the efficacy of a given material in a particular surgical application.

Management of suspected anastomotic leak after bariatric laparoscopic Roux-en-y gastric bypass

Background

Anastomotic leak is one of the most serious complications following bariatric laparoscopic Roux-en-Y gastric bypass (LRYGB), and associated with high morbidity rates and prolonged hospital stay. Timely management is of utmost importance for the clinical outcome. This study evaluated the approach to suspected leakage in a high-volume bariatric surgery unit.

Methods

All consecutive patients who underwent LRYGB performed by the same team of surgeons were registered prospectively in a clinical database from September 2005 to June 2012. Suspected leaks were identified based on either clinical suspicion and/or associated laboratory values, or by a complication severity grade of at least II using the Clavien–Dindo score.

Results

A total of 6030 patients underwent LRYGB during the study period. The leakage rate was 1·1 per cent (64 patients). Forty-five leaks (70 per cent) were treated surgically and 19 (30 per cent) conservatively. Eight (13 per cent) of 64 patients needed intensive care and the mortality rate was 3 per cent (2 of 64). Early leaks (developing in 5 days or fewer after LRYGB) were treated by suture of the defect in 20 of 22 patients and/or operative drainage in 13. Late leaks (after 5 days) were managed with operative drainage in 19 of 23 patients and insertion of a gastrostomy tube in 15. Patients who underwent surgical treatment early after the symptoms of leakage developed had a shorter hospital stay than those who had symptoms for more than 24 h before reoperation (12·5 versus 24·4 days respectively; P < 0·001).

Conclusion

Clinical suspicion of an anastomotic leak should prompt an aggressive surgical approach without undue delay. Early operative treatment was associated with shorter hospital stay. Delays in treatment, including patient delay, after symptom development were associated with adverse outcomes.

Obesity and surgical wound healing: a current review

Objective. The correlation between obesity and deficient wound healing has long been established. This review examines the current literature on the mechanisms involved in obesity-related perioperative morbidity. Methods. A literature search was performed using Medline, PubMed, Cochrane Library, and Internet searches. Keywords used include obesity, wound healing, adipose healing, and bariatric and surgical complications. Results. Substantial evidence exists demonstrating that obesity is associated with a number of postoperative complications. Specifically in relation to wound healing, explanations include inherent anatomic features of adipose tissue, vascular insufficiencies, cellular and composition modifications, oxidative stress, alterations in immune mediators, and nutritional deficiencies. Most recently, advances made in the field of gene array have allowed researchers to determine a few plausible alterations and deficiencies in obese individuals that contribute to their increased risk of morbidity and mortality, especially wound complications. Conclusion. While the literature discusses how obesity may negatively affect health on various of medical fronts, there is yet to be a comprehensive study detailing all the mechanisms involved in obesity-related morbidities in their entirety. Improved knowledge and understanding of obesity-induced physiological, cellular, molecular, and chemical changes will facilitate better assessments of surgical risks and outcomes and create efficient treatment protocols for improved patient care of the obese patient population.

Is combined therapy more effective than growth hormone or hyperbaric oxygen alone in the healing of left ischemic and non-ischemic colonic anastomoses?

OBJECTIVE

Our aim was to investigate the effects of growth hormone (GH), hyperbaric oxygen and combined therapy on normal and ischemic colonic anastomoses in rats.

METHODS

Eighty male Wistar rats were divided into eight groups (n = 10). In the first four groups, non-ischemic colonic anastomosis was performed, whereas in the remaining four groups, ischemic colonic anastomosis was performed. In groups 5, 6, 7, and 8, colonic ischemia was established by ligating 2 cm of the mesocolon on either side of the anastomosis. The control groups (1 and 5) received no treatment. Hyperbaric oxygen therapy was initiated immediately after surgery and continued for 4 days in groups 3 and 4. Groups 2 and 6 received recombinant human growth hormone, whereas groups 4 and 8 received GH and hyperbaric oxygen treatment. Relaparotomy was performed on postoperative day 4, and a perianastomotic colon segment 2 cm in length was excised for the detection of biochemical and mechanical parameters of anastomotic healing and histopathological evaluation.

RESULTS

Combined treatment with hyperbaric oxygen and GH increased the mean bursting pressure values in all of the groups, and a statistically significant increase was noted in the ischemic groups compared to the controls (p<0.05). This improvement was more evident in the ischemic and normal groups treated with combined therapy. In addition, a histopathological evaluation of anastomotic neovascularization and collagen deposition showed significant differences among the groups.

CONCLUSIONS

Combined treatment with recombinant human growth hormone and hyperbaric oxygen resulted in a favorable therapeutic effect on the healing of ischemic colonic anastomoses.

Evaluation of six synthetic surgical meshes implanted subcutaneously in a rat model

The long-term efficacy and mechanical integrity of implanted materials is largely determined by early host response. Therefore, implanting materials with well-characterized tissue responses provides the greatest chance of 'one-hit' surgical successes, without repeated interventions to replace, repair or remove non-compliant biomaterials. Six synthetic meshes were implanted subcutaneously in a rat model to deduce and quantify modulations in host response, based on material fabrication variables. The materials consisted of knitting variations of polypropylene (PP), polyethyleneterephthalate (PET) and polyglycolic acid (PGA) yarns and were implanted for 2, 5, 7, 14 and 28 days before fixation and both semi- and fully quantitative histopathology. In a subcutaneous niche, material weight did not influence foreign body response. PET stimulated earlier inflammation than PP and PGA, which normalized over 28 days. Multifilament meshes recruited foreign body giant cells, which were largely absent from monofilaments. Using CD68, PGA was demonstrated to be the greatest leukocyte-activating polymer at a number of the time points analysed. This research therefore highlights that underlying polymer composition may be more over-arching in deciding the inflammatory properties of surgical meshes, based on increased macrophagic responses to PGA vs alternative base polymers of comparable weights and porosities. Copyright © 2013 John Wiley & Sons, Ltd.

Upregulation of the proinflammatory cytokine-induced neutrophil chemoattractant-1 and monocyte chemoattractant protein-1 in rats' intestinal anastomotic wound healing--does it matter?

BACKGROUND

The proinflammatory cytokines and growth-promoting factor are essential components of the wound healing process. We hypothesized that under healthy conditions, faster healing of intestinal anastomotic wound is due to an early upregulation of proinflammatory cytokines, cytokine-induced neutrophil chemoattractant-1 (CINC-1) that is followed by a quicker upregulation of homeostatic chemokine, monocyte chemoattractant protein-1 (MCP-1) and late upregulation of transforming growth factor (TGF-β).

METHODS

We characterized the time course of CINC-1, MCP-1 and TGF-β release at four wounds (skin, muscle, small bowel, and colonic anastomosis) after surgery on 38 juvenile male Sprague Dawley rats. The tissue samples of each site were harvested at 0 (control), 1, 3, 5, 7 and 14 days postoperatively (n = 6-8/group) and analyzed by ELISA kits for CINC-1, MCP-1 and TGF-β.

RESULTS

CINC-1 expression peaked earlier in muscle and colonic wounds when compared to skin and small bowel. MCP-1 levels were elevated early in skin and muscle wounds, but later expression of MCP-1 was shown in colonic wounds. TGF-β levels were unchanged in all wound sites.

CONCLUSION

An earlier peak in CINC-1 levels and later expression of MCP-1 were seen in colonic wounds, but no significant increase in TGF-β levels was observed. These findings support the early healing process in intestinal anastomotic wounds.

Nonwoven polypropylene prosthesis in large abdominal wall defects in rats

PURPOSE

To evaluate, in large abdominal wall defects surgically shaped in rats, if a synthetic polypropylene nonwoven prosthesis could be used as a therapeutic option to conventional polypropylene mesh.

METHODS

Twenty four (24) Wistar rats were enrolled into three groups. Group 1 (Simulation group) with an abdominal wall defect of 3 X 3 left untreated and Groups 2 and 3, respectively treated with a conventional polypropylene mesh and a polypropylene nonwoven (NWV) prosthesis to cover the breach. At the 45th postoperatively day, adhesion (area and strength) and vascularization of Groups 2 and 3 were evaluated. The histological preparations with Hematoxylin-Eosin, Tricromium of Masson, Pricrosirius red and polarization with birefringence, and also the structural analysis of the prostheses carried on by Thermogravimetry and Differential Scanning Calorimetry were also assessed.

RESULTS

There were no significant differences between the Groups 2 and 3.

CONCLUSION

In rats, the polypropylene nonwoven prosthesis showed to be safe and has to be considered as an alternative to conventional mesh manufactured by weaving in the treatment of great defects of the abdominal wall.

Reactive oxygen species mediate microRNA-302 regulation of AT-rich interacting domain 4a and C-C motif ligand 5 expression during transitions between quiescence and proliferation

Normal cell growth consists of two distinct phases, quiescence and proliferation. Quiescence, or G(0), is a reversible growth arrest in which cells retain the ability to reenter the proliferative cycle (G(1), S, G(2), and M). Although not actively dividing, quiescent cells are metabolically active and quiescence is actively maintained. Our results from microRNA PCR arrays and Taqman PCR assays showed a significant decrease (4-fold) in miR-302 levels during quiescence compared to proliferating normal human fibroblasts, suggesting that miR-302 could regulate cellular proliferation. Results from a Q-RT-PCR and dual-luciferase-3'-UTR reporter assays identified ARID4a (AT-rich interacting domain 4a, also known as RBP1) and CCL5 (C-C motif ligand 5) as targets for miR-302. Ionizing radiation decreased miR-302 levels, which was associated with an increase in its target mRNA levels, ARID4a and CCL5. Such an inverse correlation was also observed in cells treated with hydrogen peroxide as well as SOD2-overexpressing cells. Overexpression of miR-302 suppresses ARID4a and CCL5 mRNA levels, and increased the percentage of S-phase cells. These results identified miR-302 as an ROS-sensitive regulator of ARID4a and CCL5 mRNAs as well as demonstrate a regulatory role of miR-302 during quiescence and proliferation.

In vitro activation of human leukocytes in response to contact with synthetic hernia meshes

OBJECTIVES

Evaluation of an in vitro chemiluminescent screen to predict leukocyte ROS in response to surgical materials.

DESIGN AND METHODS

6 surgical meshes; manufacture and knitting variations of polypropylene (PP), polyester terephtalate (PET) and polyglycolic acid (PGA) trialled healthy human blood (n=5). Materials and blood were incubated with pholasin. Pholasin emits photons in the presence of reactive oxygen species; secreted by activated leukocytes.

RESULTS

Multifilament-PGA mesh stimulated the greatest ROS response from blood derived human leukocytes. Multifilament-PET light weight and multifilament-PP meshes stimulated similar levels of ROS production which were greater than monofilament-PP light, monofilament-PP and monofilament-PET light meshes. Data demonstrated statistical variations in trans-donor response to the materials.

CONCLUSIONS

An in vitro chemiluminescent assay can be used to assess leukocyte respiratory burst response to biomaterials. PGA mesh elicited the greatest ROS response. PP and PET monofilament meshes induce less ROS than multifilament equivalents. In vitro results correlate with previously published clinical responses to these materials.

Oral administration of marine collagen peptides from Chum Salmon skin enhances cutaneous wound healing and angiogenesis in rats

BACKGROUND

A wound is a clinical entity which often poses problems in clinical practice. The present study was aimed to investigate the wound healing potential of administering marine collagen peptides (MCP) from Chum Salmon skin by using two wound models (incision and excision) in rats.

RESULTS

Ninety-six animals were equally divided into the two wound models and then within each model animals were randomly divided into two groups: vehicle-treated group and 2 g kg(-1) MCP-treated group. Wound closure and tensile strength were calculated. Collagen deposition was assessed by Masson staining and hydroxyproline measurement. Angiogenesis was assessed by immunohistological methods. MCP-treated rats showed faster wound closure and improved tissue regeneration at the wound site, which was supported by histopathological parameters pertaining to wound healing. MCP treatment improved angiogenesis and helped form thicker and better organised collagen fibre deposition compared to vehicle-treated group.

CONCLUSION

The results show the efficacy of oral MCP treatment on wound healing in animals.

Loss of mechanical strain impairs abdominal wall fibroblast proliferation, orientation, and collagen contraction function

BACKGROUND

Laparotomy wound load forces are reduced when dehiscence and incisional hernia formation occur. The purpose of this study was to determine the effects of strain loss on abdominal fascial fibroblast proliferation, orientation, and collagen compaction function.

METHODS

Cultured rat linea alba fibroblasts were subjected to continuous cyclic strain (CS), CS interrupted at 24 or 48 hours followed by culture at rest (IS-24 and IS-48) or were cultured without mechanical strain (NS). Cell number was measured and images analyzed for cell orientation. Fibroblasts from these groups were seeded onto the surface of (FPCL-S) or mixed into (FPCL-M) a collagen gel matrix and gel area was measured over time.

RESULTS

Continuous strain stimulated proliferation when compared with the nonstrained cells. The loss of strain (IS) delayed proliferation compared with CS throughout (P < .05). CS fibroblasts aligned perpendicular to the direction of strain within 12 hours. Within 12 hours of strain loss, IS-48 fibroblasts became significantly less aligned (P < .0001), and seemed similar to the randomly organized NS fibroblasts 48 hours after strain removal. The CS and IS-24 groups demonstrated faster and greater overall FPCL-M compaction than both the IS-48 and NS groups (P < .0002). The CS group contracted the gel faster than the NS group in FPCL-S (P = .029).

CONCLUSION

Mechanical strain rapidly induces a proliferative, morphologic, and functional response in abdominal wall fibroblasts that is dependent on the continued presence of the strain signal and quickly lost when the load force is removed. The loss of wound edge tension that occurs during laparotomy wound separation and hernia formation may contribute to impaired wound healing through loss of a key stimulatory mechanical signal with important implications for abdominal wall reconstruction.

VEGF-A and FGF gene therapy accelerate healing of ischemic colonic anastomoses (experimental study)

BACKGROUND

Reducing ischemic damage is one of the goals of surgery. The aim of this study was to apply human VEGF-A and FGF-2 DNA-mediated gene therapy in order to identify their effects in the healing of ischemic colon anastomoses and eliminating the negative effects of ischemia.

METHODS

Forty male Wistar albino rats weighing 250-280 g were divided into five equal groups (n = 8) as follows: group 1: control, ischemic left colonic anastomosis; group; 2: ischemic left colonic anastomosis with control plasmid delivery; group 3: ischemic left colonic anastomosis with VEGF plasmid delivery; group 4: ischemic left colonic anastomosis with FGF plasmid delivery; group 5: ischemic left colonic anastomosis with VEGF and FGF plasmid delivery. All rats were sacrificed on the 4th postoperative day. Anastomosis burst pressures were measured for mechanical examination of anastomosis. Tissue hydroxyprolin, VEGF and FGF levels were determined as biochemical parameters. Necrosis, epithelisation, inflammatory processes, fibroblastic activity, collagen deposition and neovascularisation at the anastomic site were studied.

RESULTS

VEGF, FGF and combined therapy significantly accelerated many of the histological parameters of healing, including fibroblast activation, collagen deposition, and angiogenesis, and augmented the levels of hydroxyproline and bursting pressure.

CONCLUSIONS

This is the first study to use gene therapy with growth factors for the healing of ischemic colonic anastomosis. This therapy can be effectively used in increasing ischemic anastomosis wound healing.

Navigating new technologies in negative pressure wound therapy

Plastic surgeons and their support staff are tasked with proficient management of a wide variety of complex wounds. Since its introduction, negative pressure wound therapy (NPWT) has increasingly been used within the plastic surgery specialty to improve and simplify wound management. Increased usage of the therapy has prompted the development of a myriad of new NPWT systems. While an expanded product selection allows greater choice to maximize patient outcomes, sound decision-making also requires a clear understanding of the characteristics of various NPWT systems and applications. Wound-specific NPWT systems of varying size are available for low- to moderate-severity wounds, clean closed incisions, and acute abdominal wounds. Wound size and severity, amount of exudate, and patient mobility issues have become important considerations when choosing an NPWT device. The purpose of this article is to familiarize the reader with the latest sophistications in NPWT systems to guide decision making and usage.

Intra-abdominal healing: gastrointestinal tract and adhesions

The abdominal cavity represents one of the most active areas of surgical activity. Surgical procedures involving the gastrointestinal (GI) tract are among the most common procedures performed today. Healing of the GI tract after removal of a segment of bowel and healing of the peritoneal surfaces with subsequent adhesion formation remain vexing clinical problems. Interventions to modify both the responses are myriad, yet a full understanding of the pathophysiology of these responses remains elusive. Different aspects of GI and peritoneal healing, with associated factors, are discussed in this article.

Mesenchymal stem cells improve the healing of ischemic colonic anastomoses (experimental study)

OBJECTIVE

The goal of this study is to examine if allogenic mesenchymal stem cell (MSC) transplantation is a useful therapy for left ischemic colon anastomosis in rats. Problems with anastomosis healing may lead to serious postoperative complications. Bone marrow-derived mesenchymal stem cells (BM-MSCs), which are also referred to as stromal progenitor cells, are self-renewing and expandable stem cells. Recent studies have suggested that BM-MSCs play a crucial role in the processes of intestinal repair and accelerate angiogenesis.

METHODS

MSCs were isolated from rats before analysis by light and scanning electron microscopy. Forty male Wistar albino rats weighing 250-280 g were divided into four equal groups (n = 10) as follows: group 1: control, ischemic left colonic anastomoses (fourth day); group 2: control, ischemic left colonic anastomoses (seventh day); group 3: ischemic left colonic anastomoses + locally transplanted BM-MSCs (fourth day); group 4: ischemic left colonic anastomoses + locally transplanted BM-MSCs (seventh day). Histopathological features and anastomotic strength were evaluated.

RESULTS

BM-MSCs therapy significantly accelerated all of the healing parameters for ischemic colonic anastomosis except for inflammation on the fourth day. On the seventh day, BM-MSCs augmented the levels of the hydroxyproline and bursting pressure. Histological parameters, especially angiogenesis, were also found to be important for healing of ischemic colonic anastomoses.

CONCLUSIONS

This is the first study to use locally transplanted cell therapy for the healing of ischemic colonic anastomosis. BM-MSCs therapy significantly accelerated all of the healing parameters for ischemic colonic anastomosis.

The effect of glucagon-like Peptide-2 receptor agonists on colonic anastomotic wound healing

Background. Glucagon-like peptide 2 (GLP-2) is an intestinal specific trophic hormone, with therapeutic potential; the effects on intestinal healing are unknown. We used a rat model of colonic healing, under normoxic, and stress (hypoxic) conditions to examine the effect of GLP-2 on intestinal healing. Methods. Following colonic transection and reanastomosis, animals were randomized to one of six groups (n = 8/group): controls, native GLP-2, long-acting GLP-2 (GLP-2- MIMETIBODY, GLP-2-MMB), animals were housed under normoxic or hypoxic (11%  O₂) conditions. Animals were studied five days post-operation for anastomotic strength and wound characteristics. Results. Anastomotic bursting pressure was unchanged by GLP-2 or GLP-2-MMB in normoxic or hypoxic animals; both treatments increased crypt cell proliferation. Wound IL-1β increased with GLP-2; IFNγ with GLP-2 and GLP-2-MMB. IL-10 and TGF-β were decreased; Type I collagen mRNA expression increased in hypoxic animals while Type III collagen was reduced with both GLP-2 agonists. GLP-2 MMB, but not native GLP-2 increased TIMP 1-3 mRNA levels in hypoxia. Conclusions. The effects on CCP, cytokines and wound healing were similar for both GLP-2 agonists under normoxic and hypoxic conditions; anastomotic strength was not affected. This suggests that GLP-2 (or agonists) could be safely used peri-operatively; direct studies will be required.

Biomarker use in tailored combat casualty care

Modern war wounds are complex and primarily involve extremities. They require multiple operative interventions to achieve wound closure and begin rehabilitation. Current assessment of the suitability of surgical wound closure is based upon subjective methods coupled with a semiquantitative determination of the wound bacterial burden. Measurement of the systemic and local response to injury using inflammatory biomarkers may allow for accelerated wound closure and treatment of other combat-related morbidity. This article presents the introduction of personalized medicine into combat casualty care.

Temporal expression of cytokines in rat cutaneous, fascial, and intestinal wounds: a comparative study

BACKGROUND

Previous studies have shown that healing in intestinal wounds is proportionally faster than skin. Cytokines and growth factors play a major role in these coordinated wound-healing events. We hypothesized that this more rapid intestinal healing is due to an early upregulation of proinflammatory cytokines (IL-1beta, TNF-alpha, and IFN-gamma), followed by increases in the expression of the anti-inflammatory cytokine IL-10 and growth factor TGF-beta.

METHODS

Four wounds (skin, fascia, small intestinal, and colonic anastomosis) were created in each of 48 juvenile male Sprague Dawley rats; tissue samples of each site were harvested at 0, 1, 3, 5, 7, and 14 days postoperatively (n = 8/group) and levels of IL-1beta, IFN-gamma, TNF-alpha, IL-10 and TGF-beta expression from each site were measured using ELISA kits.

RESULTS

IL-1beta expression peaked earlier in small-intestinal and colonic wounds when compared to skin or fascia (e.g., small intestine: day 3 and colon day 5, P < 0.05 by ANOVA). Post-wounding levels of TNF-alpha were elevated in fascial wounds, but decreased in small-intestinal and colonic wounds. IFN-gamma levels were not significantly altered in any wounds. IL-10 showed a similar downregulation pattern in all wounds, while TGF-B levels were decreased in colonic and fascial wounds, but relatively unchanged in SI and skin.

CONCLUSIONS

An earlier peak in IL-1beta levels and a consistent decrease in TNF-alpha were seen in healing intestinal tissues; but no clear pattern of increased anti-inflammatory or regulatory cytokines was seen, which might explain the earlier healing of intestinal tissues. Additional studies are required to determine the role of individual cytokines, or the intrinsic reactivity of the tissues may explain the site specific differences of healing rates in different tissues.