Collagen type I:III ratio of the gastroesophageal junction in patients with paraesophageal hernias

Risk factors associated with hiatal hernia: a retrospective study and two-sample Mendelian randomization

OBJECTIVES

The existing literature has demonstrated that variables such as gender, body mass index (BMI), and age play a significant role in the risk assessment of hiatal hernia. This study aims to comprehensively investigate the association between these risk factors and hiatal hernia through a retrospective analysis and Mendelian randomization (MR) analysis.

METHODS

In this study, the examination results and basic information of 685 patients who underwent routine esophagogastroduodenoscopy (EGD) at the gastroesophageal Reflux Center of Xuanwu Hospital from 2018 to 2024 were retrospectively collected. logistic regression was used to analyze the potential risk factors. Meanwhile, a two-sample MR analysis was used to further validate and supplement these risk factors.

RESULTS

A retrospective study showed that the incidence of hiatal hernia diagnosed by endoscopy was 28.7%, in the population without GERD, the incidence was 22.8%In the multivariate logistic regression analysis, male sex (P = 0.033), age (P < 0.001), heavy physical labor (P < 0.001), and gastroesophageal reflux disease (GERD) (P < 0.001) were independent risk factors for hiatal hernia, while an increase in BMI, smoking, alcohol consumption, and the number of pregnancies and deliveries in women were not statistically significant. The inverse variance weighting (IVW) results of the MR analysis showed that an increased waist-hip ratio (ORIVW = 2.57, CI 1.32-5.01, P = 0.0057), trunk fat (ORIVW = 3.53, CI 1.76-7.07, P = 0.0004), smoke initiation (ORIVW = 1.47, CI 1.02-2.13, P = 0.0408), and alcohol intake frequency (ORIVW = 2.23, CI 1.18-4.20, P = 0.0134) were associated with hiatal hernia, but the causal relationship between alcohol intake frequency and hiatal hernia was not established.

CONCLUSION

This study showed that male gender, age, heavy physical labor, and GERD were independent risk factors for hiatal hernia. MR analysis showed that abdominal obesity and smoking may be genetically associated with hiatal hernia. However, there was no statistical significance between increased BMI and hiatal hernia in multivariate analysis and MR analysis.

Giant Paraesophageal Hernia Presenting With Dyspnea: A Case Report With Surgical Considerations

Giant paraesophageal hernias (PEH) are uncommon and primarily affect older adults. While gastroesophageal reflux disease (GERD) symptoms are the most frequent presentation, some patients develop atypical manifestations, such as dyspnea, due to mechanical compression and impaired diaphragmatic function. We present the case of an elderly patient with a giant type IV PEH who underwent successful laparoscopic hiatal hernia repair with fundoplication. Her postoperative course was uneventful, highlighting the effectiveness of minimally invasive techniques. While surgical repair remains the gold standard for symptomatic and complicated PEH, recurrence remains a concern, necessitating ongoing refinements in surgical strategies. This report reinforces the importance of considering PEH in the differential diagnosis of dyspnea and the role of early recognition and timely surgical intervention in optimizing outcomes.

Dynamics of hiatal hernia recurrence: how important is a composite crural repair?

INTRODUCTION

Hiatal hernia recurrence rates vary widely. The true causes of recurrences are not fully understood but likely multifactorial. Surgical approaches and techniques have evolved over time to try and reduce recurrence rates after hiatal hernia repair. Our objective is to provide a current review on the physiology of hiatal hernias and the importance of a composite crural repair on hiatal hernia recurrence rates; more specifically, for this review, a composite repair is defined as a repair requiring more than primary closure of the crura.

METHODS

A recent review of the literature was conducted to identify studies reporting on hiatal hernia pathophysiology, stress, and tension, as well as the role of composite repair.

RESULTS

There is a paucity of studies focusing on the pathophysiology of hiatal hernias and recurrence rates. Articles that report on the pathophysiology of the hiatus were found to have alterations of the extracellular matrix, collagen composition, changes in metalloproteinases (MMPs), and differences in genetic composition. The role of composite repair on reducing recurrence rates is not well studied.

CONCLUSIONS

Hiatal hernias remain a complex problem with no ideal surgical technique. It is likely that the pathophysiology of hiatal hernias is multifactorial, and more studies need to be done to better understand the potential underlying mechanisms for hiatal hernias so this may also further identify the ideal surgical repair.

Genetic and biologic risk factors associated with hernia formation: A review

BACKGROUND

This systematic review aims to identify genetic and biologic markers associated with abdominal hernia formation.

METHODS

Following PRIMSA-guidelines, we searched PubMed, MEDLINE, Embase, Scopus, and COCHRANE databases.

RESULTS

Of 5946 studies, 65 were selected, excluding parastomal hernias due to insufficient data. For inguinal hernias, five studies unveiled 92 susceptible loci across 66 genes, predominantly linked to immune responses. Eleven studies observed elevated MMP-2 levels, with seven highlighting greater MMP-2 in direct compared to indirect inguinal hernias. One incisional hernia study identified unique gene-expression profiles in 174 genes associated with inflammation and cell-adhesion. In hiatal hernias, several genetic risk loci were identified. For all hernia categories, type I/III collagen ratios diminished.

CONCLUSIONS

Biological markers in inguinal hernias appears consistent. Yet, the genetic predisposition in incisional hernias remains elusive. Further research to elucidate these genetic and biological intricacies can pave the way for more individualized patient care.

Macromolecular crowding in human tenocyte and skin fibroblast cultures: A comparative analysis

Although human tenocytes and dermal fibroblasts have shown promise in tendon engineering, no tissue engineered medicine has been developed due to the prolonged ex vivo time required to develop an implantable device. Considering that macromolecular crowding has the potential to substantially accelerate the development of functional tissue facsimiles, herein we compared human tenocyte and dermal fibroblast behaviour under standard and macromolecular crowding conditions to inform future studies in tendon engineering. Basic cell function analysis made apparent the innocuousness of macromolecular crowding for both cell types. Gene expression analysis of the without macromolecular crowding groups revealed expression of tendon related molecules in human dermal fibroblasts and tenocytes. Protein electrophoresis and immunocytochemistry analyses showed significantly increased and similar deposition of collagen fibres by macromolecular crowding in the two cell types. Proteomics analysis demonstrated great similarities between human tenocyte and dermal fibroblast cultures, as well as the induction of haemostatic, anti-microbial and tissue-protective proteins by macromolecular crowding in both cell populations. Collectively, these data rationalise the use of either human dermal fibroblasts or tenocytes in combination with macromolecular crowding in tendon engineering.

Ultraviolet light induces mechanical and structural changes in full thickness human skin

While the detrimental health effects of prolonged ultraviolet (UV) irradiation on skin health have been widely accepted, the biomechanical process by which photoaging occurs and the relative effects of irradiation with different UV ranges on skin biomechanics have remained relatively unexplored. In this study, the effects of UV-induced photoageing are explored by quantifying the changes in the mechanical properties of full-thickness human skin irradiated with UVA and UVB light for incident dosages up to 1600 J/cm2. Mechanical testing of skin samples excised parallel and perpendicular to the predominant collagen fiber orientation show a rise in the fractional relative difference of elastic modulus, fracture stress, and toughness with increased UV irradiation. These changes become significant with UVA incident dosages of 1200 J/cm2 for samples excised both parallel and perpendicular to the dominant collagen fiber orientation. However, while mechanical changes occur in samples aligned with the collagen orientation at UVB dosages of 1200 J/cm2, statistical differences in samples perpendicular to the collagen orientation emerge only for UVB dosages of 1600 J/cm2. No notable or consistent trend is observed for the fracture strain. Analyses of toughness changes with maximum absorbed dosage reveals that no one UV range is more impactful in inducing mechanical property changes, but rather these changes scale with maximum absorbed energy. Evaluation of the structural characteristics of collagen further reveals an increase in collagen fiber bundle density with UV irradiation, but not collagen tortuosity, potentially linking mechanical changes to altered microstructure.

Histopathological Study on Collagen in Full-Thickness Wound Healing in Fraser's Dolphins (Lagenodelphis hosei)

Fraser's dolphins (Lagenodelphis hosei) possess great healing abilities. Their skin composition can be restored after wounding, including collagen spacing, orientation, and bundle thickness. However, it remains unclear how collagens are involved in the wound-healing process and eventually regain normality in Fraser's dolphins. Learned from the other two scarless healing animals, changes in type III/I collagen composition are believed to modulate the wound healing process and influence the scarring or scarless fate determination in human fetal skin and spiny mouse skin. In the current study, Herovici's, trichrome, and immunofluorescence staining were used on normal and wounded skin samples in Fraser's dolphins. The results suggested that type I collagens were the main type of collagens in the normal skin of Fraser's dolphins, while type III collagens were barely seen. During the wound healing process, type III collagens showed at early wound healing stages, and type I collagen increased in the mature healed wound. In an early healed wound, collagens were organized in a parallel manner, showing a transient hypertrophic-like scar, and eventually restored to normal collagen configuration and adipocyte distribution in the mature healed wound. The remarkable ability to remove excessive collagens merits further investigation to provide new insights into clinical wound management.

Distinctive structure, composition and biomechanics of collagen fibrils in vaginal wall connective tissues associated with pelvic organ prolapse

Collagen is the predominant structural protein within connective tissues. Pelvic organ prolapse (POP) is characterized by weakening of the pelvic floor connective tissues and loss of support for pelvic organs. In this study, we examined the multiscale structure, molecular composition and biomechanics of native collagen fibrils in connective tissues of the posterior vaginal fornix collected from healthy women and POP patients, and established the correlation of these properties with clinical POP quantification (POP-Q) scores. The collagen characteristics, including collagen amount, ratio of Collagen I and Collagen III, collagen fibril d-period, alignment and stiffness, were found to change progressively with the increase of the clinical measurement of Point C, a measure of uterine descent and apical prolapse. The results imply that a severe prolapse is associated with stiffer collagen fibrils, reduced collagen d-period, increased fibril alignment and imbalanced collagen synthesis, degradation and deposition. Additionally, prolapse progression appears to be synchronized with deterioration of the collagen matrix, suggesting that a POP-Q score obtained via a non-invasive clinical test can be potentially used to quantitatively assess collagen abnormality of a patient's local tissue. STATEMENT OF SIGNIFICANCE: Abnormal collagen metabolism and deposition are known to associate with connective tissue disorders, such as pelvic organ prolapse. Quantitative correlation of the biochemical and biophysical characteristics of collagen in a prolapse patient's tissue with the clinical diagnostic measurements is unexplored and unestablished. This study fills the knowledge gap between clinical prolapse quantification and the individual's cellular and molecular disorders leading to connective tissue failure, thus, provides the basis for clinicians to employ personalized treatment that can best manage the patient's condition and to alert pre-symptomatic patients for early management to avoid unwanted surgery.

Risk factors for the development of a parastomal hernia in patients with enterostomy: a systematic review and meta-analysis

PURPOSE

Parastomal hernia (PSH) is a common and serious complication in patients with enterostomy, but there is no current consensus for the risk factors for PSH from previous studies. Therefore, this study systematically analyzed the risk factors for PSH to provide a reference for prevention and treatment of this condition.

METHODS

Seven databases and 3 registers were systematically searched from database inception to January, 2021. Study quality was assessed by Newcastle-Ottawa Scale. Review Manager 5.3 software was used for statistical analysis. The data that could not be combined quantitatively were only analyzed qualitatively.

RESULTS

Sixteen studies with 2031 patients were included. Higher BMI (OR, 1.29; 95% CI,1.02-1.63), older age (OR, 1.04; 95% CI, 1.02-1.07), female (OR, 2.55; 95% CI,1.39-4.67), lager aperture size (OR, 2.8; 95%CI, 1.78-4.42), transperitoneal stoma creation (OR, 2.4; 95% CI, 1.33-4.35), and lager waist circumference (OR, 1.01; 95% CI,1.0-1.01) were significant risk factors for PSH. The laparoscopic approach was not a risk factor for PSH (OR, 2.09; 95% CI, 0.83-5.27). Other risk factors, including the thickness of abdominal subcutaneous fat, no mesh, a stoma not through the middle of the rectus abdominis, atrophy of left lower medial part of rectus abdominis, α1(III) procollagen expression level, emergency surgery, no preoperative stoma site marking, end colostomy, smoking, diabetes, peristomal infection, severe abdominal distention, severe cough, chronic obstructive pulmonary disease, operation time and hypertension, were significant on the multivariate analysis of each individual study.

CONCLUSIONS

The current available evidence showed that higher BMI, older age, female, larger aperture size, the creation of a transperitoneal stoma, and a larger waist circumference were independent risk factors for PSH. For factors without exact cutoff value, further explorations are needed in the future. In addition, reference to the limited number of studies in the pooled analysis, these factors still need to be interpreted carefully.

Picrosirius Red Staining: Revisiting Its Application to the Qualitative and Quantitative Assessment of Collagen Type I and Type III in Tendon

Collagen has a major role in the structural organization of tendons. Picrosirius red (PSR) staining viewed under polarized light microscopy is the standard method to evaluate the organization of collagen fibers in tissues. It is also used to distinguish between type I and type III collagen in tissue sections. However, accurate analysis and interpretation of PSR images are challenging because of technical factors and historical misconceptions. The aim of this study was to clarify whether collagen types I and III can be distinguished by PSR staining in rat Achilles tendons, using double immunohistochemistry as the positive control. Our findings showed that PSR staining viewed with polarized light microscopy was suitable for qualitative and quantitative assessment of total collagen but was not able to distinguish collagen types. We found it critical to use a polarizing microscope equipped with a rotating stage; tendon section orientation at 45° with respect to crossed polarizers was optimal for the qualitative and quantitative assessment of collagen organization. Immunohistochemistry was superior to PSR staining for detection of collagen type III. We also compared formalin and Bouin solution as fixatives. Both produced similar birefringence, but formalin-fixed tendons provided higher quality histological detail with both hematoxylin-eosin and immunostaining.

The safety of additional procedures at the time of revisional bariatric surgery

BACKGROUND

The third most common bariatric operation is revisions of previous bariatric surgeries. Patients may require revisional bariatric surgery for inadequate weight loss or complications. Patients undergoing revisional bariatric surgery may also have other conditions that require surgery. This study evaluates the 30-day postoperative outcomes of patients undergoing revisional bariatric surgery and additional procedures.

METHODS

A retrospective review of the 2005-2017 ACS NSQIP database identified 7249 patients who underwent revisional bariatric surgery with 3115 (48%) occurring with additional procedures. A 1:1 propensity score matching analysis was completed for 13 patient demographics and comorbidities. Postoperative variables were then analyzed as available in the NSQIP database. Subgroup analyses were completed for those undergoing paraesophageal hernia repair and abdominal wall hernia repair at the time of revisional bariatric surgery.

RESULTS

The most common bariatric surgery that was converted or revised was the AGB (57%) and the most common additional procedure was paraesophageal hernia repair (n = 181, 15%). When additional procedures were completed at the time of revisional bariatric surgery, overall complications (p < 0.001), major systemic complications (p = 0.009) and mortality/major complications (p = 0.018) were all significantly increased. After matching for operative time, only postoperative sepsis remained significant with additional procedures (p = 0.042). In the subgroup analyses on paraesophageal and abdominal wall hernias there were no differences in postoperative complications after matching for operative time.

CONCLUSIONS

Additional procedures, including paraesophageal and abdominal wall hernia repairs at the time of revisional bariatric surgery increase postoperative complications. Operative time was longer when additional procedures were performed. Postoperative sepsis was the only complication which remained significant after propensity matching when additional procedures are completed at the time of revisional bariatric surgery.

Stem cells in the periodontal ligament differentiated into osteogenic, fibrogenic and cementogenic lineages for the regeneration of the periodontal complex

OBJECTIVE

Human periodontal ligament stem cells (hPDLSCs) are promising for periodontal regeneration. However, to date, there has been no report of hPDLSC differentiation into the fibrogenic lineage. There has been no report demonstrating hPDLSC differentiation into all three (osteogenic, fibrogenic and cementogenic fibrogenic) lineages in the same report. The objectives of this study were to harvest hPDLSCs from the periodontal ligaments (PDL) of the extracted human teeth, and use the same vial of hPDLSCs to differentiate into all three (osteogenic, fibrogenic and cementogenic) lineages for the first time.

METHODS

hPDLSCs were harvested from PDL tissues of the extracted premolars. The ability of hPDLSCs to form bone, cementum and collagen fibers was tested in culture mediums. Gene expressions were analyzed using quantitative real-time polymerase chain reaction (qRT-PCR). Immunofluorescence, alizarin red (ARS), Xylenol orange, picro sirius red staining (PSRS), alcian blue staining (ABS) and alkaline phosphatase (ALP) staining were evaluated.

RESULTS

In osteogenic medium, hPDLSCs had high expressions of osteogenic genes (RUNX2, ALP, OPN and COL1) at 14 and 21 days (15-20 folds of that of control), and produced mineral nodules and ALP activity (5 and 10 folds those of the control). hPDLSCs in fibrogenic medium expressed high levels of PDL fibrogenic genes (COL1, COL3, FSP-1, PLAP-1 and Elastin) at 28 days (20-70 folds of control). They were stained strongly with F-actin and fibronection, and secreted PDL collagen fibers (5 folds of control). hPDLSCs in cementogenic medium showed high expressions of cementum genes (CAP, CEMP1 and BSP) at 21 days (10-15 folds of control) and synthesized mineralized cementum (50 folds via ABS, and 40 folds via ALP staining, compared to those of control).

CONCLUSIONS

hPDLSCs differentiated into bone-, fiber- and cementum-forming cells, with potential for regeneration of periodontium to form the bone-PDL-cementum complex.

Decreased collagen type III synthesis in skin fibroblasts is associated with parastomal hernia following colostomy

Parastomal hernia (PH) is a common complication following stoma formation. Abnormal collagen synthesis has been suggested to be involved in PH. The aim of the present study is to explore the effect and mechanism of the collagen synthesis on PH. Data from 157 patients with rectal cancer who received permanent colostomy were retrospectively collected and analyzed to identify the risk factors for PH. Primary culture of skin fibroblasts from patients with or without PH were performed. Cell viability, migration and invasion levels were detected by Cell Counting Kit‑8, and wound healing and Transwell assays, respectively. Reverse transcription quantitative polymerase chain reaction and western blot analysis assays were performed to measure the gene and protein expression levels, respectively. The risk factors of sex, body mass index, aperture size and collagen expression were closely associated with the occurrence of PH. α1 (III) procollagen expression levels were significantly increased in patients with PH, while no marked difference in α1 (I) procollagen mRNA expression levels were observed in patients with or without PH. The viability and motility of fibroblasts from the patients with hernia were suppressed. The expression levels of matrix metalloproteinase (MMP)‑2 and MMP‑9 were decreased while the levels of collagen III and metalloproteinase inhibitor 1 (TIMP‑1) were increased in the fibroblasts from the patients with PH. Silencing TIMP‑1 expression promoted fibroblast migration and invasion and reversed the patterns of MMP‑2, MMP‑9 and collagen III expression in fibroblasts from the patients with PH. Decreased collagen III may inhibit the development of PH, potentially through decreases in TIMP‑1 expression. Therefore, the results from the present study may provide a novel target for PH therapy.

Increasing rate of para-oesophageal hiatus hernia surgical repair within Australia

BACKGROUND

Symptomatic para-oesophageal hiatus (PEH) hernias are treated by surgical intervention, and are associated with older age (>50 years) and higher body mass index (>25 kg/m² ). Both risk factors are increasing within the Australian population. Given these trends, this study aimed to determine if the rate of PEH repair is increasing within Australia.

METHODS

The study used publically available Medicare Benefits Scheme service data for operations claimed under the item number 31468 (PEH hernia, repair of, with complete reduction of hernia, resection of sac and repair of hiatus, with or without fundoplication) between 1 January 2001 and 31 December 2016. Directly age-standardized rates per 100 000 population were calculated using the 2001 Australian standard population and compared using Poisson regression models.

RESULTS

Repair of PEH significantly increased (P < 0.0001) in Australia during this period, with the average number of services increasing by 14.6% per annum. Average rates of repair increased significantly (P < 0.001) with increasing age up to 75 years after which they significantly reduced (P < 0.001) in each successive age group. Western Australia had the greatest increase in annual claims and Northern Territory had the least, but the state-specific average claim rate over the whole period was highest in Queensland and lowest in Northern Territory.

CONCLUSION

Operations claimed under Medicare Benefits Scheme item number 31468 have significantly increased in Australia since January 2001. Reasons for this rise are likely multifactorial, and may indicate increasing PEH incidence, increased diagnosis and investigation or increased surgical capability to manage the issue laparoscopically with reduced peri-operative morbidity.

P2X7R Blockade Prevents NLRP3 Inflammasome Activation and Pancreatic Fibrosis in a Mouse Model of Chronic Pancreatitis

OBJECTIVES

The aim of this study was to investigate the role of P2X7R (purinergic 2X7 receptor) and NLRP3 (NACHT, LRR, and PYD domains-containing protein 3) inflammasome activation in the process of pancreatic fibrosis in a mouse model of chronic pancreatitis (CP).

METHODS

Chronic pancreatitis was induced by repeated intraperitoneal injections of 50 μg/kg cerulein for 6 weeks in mice. P2X7R antagonist oxidized ATP (OxATP) or brilliant blue G (BBG) was administered after the last cerulein injection for 2 weeks. Pancreatic chronic inflammation and fibrosis were evaluated by histological score, Sirius red staining, and alpha-smooth muscle actin immunohistochemical staining. We further determined pancreatic P2X7R, NLRP3, and caspase-1 expressions in gene and protein levels and the pancreatic concentrations of caspase-1, interleukin 1β (IL-1β), and IL-18.

RESULTS

The pancreatic P2X7R, NLRP3, and caspase-1 expressions in gene and protein levels and the pancreatic concentrations of caspase-1, IL-1β, and IL-18 were all reduced significantly in both the OxATP and BBG groups (P < 0.05). The pancreatic chronic inflammation and the fibrosis indices were all remarkably attenuated (P < 0.05).

CONCLUSIONS

P2X7R antagonist OxATP and BBG significantly decreased pancreatic chronic inflammation and fibrosis in a mouse CP model and suggested that blockade of P2X7R-NLRP3 inflammasome signaling pathway may represent a novel therapeutic strategy for CP and its fibrotic process.

Remodeling Characteristics and Collagen Distributions of Biologic Scaffold Materials Biopsied From Postmastectomy Breast Reconstruction Sites

OBJECTIVE

The study purpose was to evaluate the associations between patient characteristics and the histologic remodeling scores of acellular dermal matrices (ADMs) biopsied from breast reconstruction sites in the first attempt to generate a multivariable risk prediction model of nonconstructive remodeling. It was hypothesized that host characteristics and surgical site assessments predict the degree of graft remodeling for ADMs used during breast reconstruction.

METHODS

The ADMs were biopsied from the breast reconstruction sites of n = 62 patients during a subsequent breast procedure, stained with hematoxylin-eosin, and evaluated according to a semi-quantitative scoring system for remodeling characteristics (cell types, cell infiltration, extracellular matrix deposition, scaffold degradation, fibrous encapsulation, and neovascularization) and a mean composite score. Biopsies were stained with Sirius Red and Fast Green, and analyzed to determine the collagen I:III ratio. Based on univariate analyses between subject clinical characteristics and the histologic remodeling scores, cohort variables were selected for multivariable regression models using a P value of 0.20 or less.

RESULTS

The composite score model yielded 3 variables: pack-year history, corticosteroid use, and radiation timing (r pseudo = 0.81). The model for collagen I yielded 2 variables: corticosteroid use and reason for reoperation (r pseudo = 0.78). The model for collagen III yielded 1 variable: reason for reoperation (r pseudo = 0.35).

CONCLUSIONS

These preliminary results constitute the first steps in generating a risk prediction model that predicts the patients and clinical circumstances most likely to experience nonconstructive remodeling of biologic grafts used to reconstruct the breast.

Identifying distinct nanoscopic features of native collagen fibrils towards early diagnosis of pelvic organ prolapse

Pelvic organ prolapse (POP) is characterized by weakening of the connective tissues and loss of support for the pelvic organs. Collagen is the predominant, load-bearing protein within pelvic floor connective tissues. In this study, we examined the nanoscopic structures and biomechanics of native collagen fibrils in surgical, vaginal wall connective tissues from healthy women and POP patients. Compared to controls, collagen fibrils in POP samples were bulkier, more uneven in width and stiffer with aberrant D-period. Additionally, the ratio of collagen I (COLI) and collagen III (COLIII) is doubled in POP with a concomitant reduction of the amount of total collagen. Thus, POP is characterized by abnormal biochemical composition and biophysical characteristics of collagen fibrils that form a loose and fragile fiber network accountable for the weak load-bearing capability. The study identifies nanoscale alterations in collagen as diagnostic markers that could enable pre-symptomatic or early diagnosis of POP.

FROM THE CLINICAL EDITOR

Pelvic organ prolapse (POP) occurs due to abnormalities of the supporting connective tissues. The underlying alterations of collagen fibers in the connective tissues have not been studied extensively. In this article, the authors showed that collagen fibrils in POP patients were much different from normal controls. The findings may provide a framework for the diagnosis of other connective diseases.

Incorporation of aligned PCL-PEG nanofibers into porous chitosan scaffolds improved the orientation of collagen fibers in regenerated periodontium

The periodontal ligament (PDL) is a group of highly aligned and organized connective tissue fibers that intervenes between the root surface and the alveolar bone. The unique architecture is essential for the specific physiological functionalities of periodontium. The regeneration of periodontium has been extensively studied by researchers, but very few of them pay attention to the alignment of PDL fibers as well as its functionalities. In this study, we fabricated a three-dimensional multilayered scaffold by embedding highly aligned biodegradable poly (ε-caprolactone)-poly(ethylene glycol) (PCE) copolymer electrospun nanofibrous mats into porous chitosan (CHI) to provide topographic cues and guide the oriented regeneration of periodontal tissue. In vitro, compared with random group and porous control, aligned nanofibers embedded scaffold could guide oriented arrangement and elongation of cells with promoted infiltration, viability and increased periodontal ligament-related genes expression. In vivo, aligned nanofibers embedded scaffold showed more organized arrangement of regenerated PDL nearly perpendicular against the root surface with more extensive formation of mature collagen fibers than random group and porous control. Moreover, higher expression level of periostin and more significant formation of tooth-supporting mineralized tissue were presented in the regenerated periodontium of aligned scaffold group. Incorporation of aligned PCE nanofibers into porous CHI proved to be applicable for oriented regeneration of periodontium, which might be further utilized in regeneration of a wide variety of human tissues with a specialized direction.

STATEMENT OF SIGNIFICANCE

The regeneration of periodontium has been extensively studied by researchers, but very few of them give attention to the alignment of periodontal ligament (PDL) fibers as well as its functionalities. The key issue is to provide guidance to the orientation of cells with aligned arrangement of collagen fibers perpendicular against the root surface. This study aimed to promote oriented regeneration of periodontium by structural mimicking of scaffolds. The in vitro and in vivo performances of the scaffolds were further evaluated to test the topographic-guiding and periodontium healing potentials. We also think our research may provide ideas in regeneration of a wide variety of human tissues with a specialized direction.

Histologic, Molecular, and Clinical Evaluation of Explanted Breast Prostheses, Capsules, and Acellular Dermal Matrices for Bacteria

BACKGROUND

Subclinical infections, manifest as biofilms, are considered an important cause of capsular contracture. Acellular dermal matrices (ADMs) are frequently used in revision surgery to prevent recurrent capsular contractures.

OBJECTIVE

We sought to identify an association between capsular contracture and biofilm formation on breast prostheses, capsules, and ADMs in a tissue expander/implant (TE/I) exchange clinical paradigm.

METHODS

Biopsies of the prosthesis, capsule, and ADM from patients (N = 26) undergoing TE/I exchange for permanent breast implant were evaluated for subclinical infection. Capsular contracture was quantified with Baker Grade and intramammary pressure. Biofilm formation was evaluated with specialized cultures, rtPCR, bacterial taxonomy, live:dead staining, and scanning electron microscopy (SEM). Collagen distribution, capsular histology, and ADM remodeling were quantified following fluorescent and light microscopy.

RESULTS

Prosthetic devices were implanted from 91 to 1115 days. Intramammary pressure increased with Baker Grade. Of 26 patients evaluated, one patient had a positive culture and one patient demonstrated convincing evidence of biofilm morphology on SEM. Following PCR amplification 5 samples randomly selected for 16S rRNA gene sequencing demonstrated an abundance of suborder Micrococcineae, consistent with contamination.

CONCLUSIONS

Our data suggest that bacterial biofilms likely contribute to a proportion, but not all diagnosed capsular contractures. Biofilm formation does not appear to differ significantly between ADMs or capsules. While capsular contracture remains an incompletely understood but common problem in breast implant surgery, advances in imaging, diagnostic, and molecular techniques can now provide more sophisticated insights into the pathophysiology of capsular contracture.

LEVEL OF EVIDENCE

4 Therapeutic.

The impact of chemotherapy and radiation therapy on the remodeling of acellular dermal matrices in staged, prosthetic breast reconstruction

BACKGROUND

An acellular dermal matrix will typically incorporate, in time, with the overlying mastectomy skin flap. This remodeling process may be adversely impacted in patients who require chemotherapy and radiation, which influence neovascularization and cellular proliferation.

METHODS

Multiple biopsy specimens were procured from 86 women (n = 94 breasts) undergoing exchange of a tissue expander for a breast implant. These were divided by biopsy location: submuscular capsule (control) as well as superiorly, centrally, and inferiorly along the paramedian acellular dermis. Specimens were assessed for cellular infiltration, cell type, fibrous encapsulation, scaffold degradation, extracellular matrix deposition, neovascularization, mean composite remodeling score, and type I and III collagen. Patients were compared based on five oncologic treatment groups: no adjuvant therapy (untreated), neoadjuvant chemotherapy with or without radiation, and chemotherapy with or without radiation.

RESULTS

Biopsy specimens were procured 45 to 1805 days after implantation and demonstrated a significant reduction in type I collagen over time. Chemotherapy adversely impacted fibrous encapsulation (p = 0.03). Chemotherapy with or without radiation adversely impacted type I collagen (p = 0.02), cellular infiltration (p < 0.01), extracellular matrix deposition (p < 0.04), and neovascularization (p < 0.01). Radiation exacerbated the adverse impact of chemotherapy for several remodeling parameters. Neoadjuvant chemotherapy also caused a reduction in type I (p = 0.01) and III collagen (p = 0.05), extracellular matrix deposition (p = 0.03), and scaffold degradation (p = 0.02).

CONCLUSION

Chemotherapy and radiation therapy limit acellular dermal matrix remodeling.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Remodeling characteristics and collagen distribution in biological scaffold materials explanted from human subjects after abdominal soft tissue reconstruction: an analysis of scaffold remodeling characteristics by patient risk factors and surgical site classifications

OBJECTIVE

The study purpose was to evaluate the associations between patient characteristics or surgical site classifications and the histologic remodeling scores of biologic meshes biopsied from abdominal soft tissue repair sites in the first attempt to generate a multivariable risk-prediction model of nonconstructive remodeling.

BACKGROUND

Host characteristics and surgical site assessments may predict remodeling degree for biologic meshes used to reinforce abdominal tissue repair sites.

METHODS

Biologic meshes were biopsied from the abdominal tissue repair sites of n = 40 patients during an abdominal reexploration, stained with hematoxylin and eosin, and evaluated according to a semi-quantitative scoring system for remodeling characteristics (cell types, cell infiltration, extracellular matrix deposition, scaffold degradation, fibrous encapsulation, and neovascularization) and a mean composite score. Biopsies were stained with Sirius Red and Fast Green and analyzed to determine the collagen I:III ratio. On the basis of univariate analyses between subject clinical characteristics or surgical site classification and the histologic remodeling scores, cohort variables were selected for multivariable regression models using P ≤ 0.200.

RESULTS

The model selection process for cell infiltration score yielded 2 variables: age at mesh implantation and mesh classification (C statistic = 0.989). For the mean composite score, the model selection process yielded 2 variables: age at mesh implantation and mesh classification (r = 0.449).

CONCLUSIONS

These preliminary results constitute the first steps in generating a risk-prediction model that predicts the patients and clinical circumstances most likely to experience nonconstructive remodeling of abdominal tissue repair sites with biologic mesh reinforcement.

Remodeling characteristics and collagen distribution in synthetic mesh materials explanted from human subjects after abdominal wall reconstruction: an analysis of remodeling characteristics by patient risk factors and surgical site classifications

BACKGROUND

The purpose of this study was to evaluate the associations between patient characteristics or surgical site classifications and the histologic remodeling scores of synthetic meshes biopsied from their abdominal wall repair sites in the first attempt to generate a multivariable risk prediction model of non-constructive remodeling.

METHODS

Biopsies of the synthetic meshes were obtained from the abdominal wall repair sites of 51 patients during a subsequent abdominal re-exploration. Biopsies were stained with hematoxylin and eosin, and evaluated according to a semi-quantitative scoring system for remodeling characteristics (cell infiltration, cell types, extracellular matrix deposition, inflammation, fibrous encapsulation, and neovascularization) and a mean composite score (CR). Biopsies were also stained with Sirius Red and Fast Green, and analyzed to determine the collagen I:III ratio. Based on univariate analyses between subject clinical characteristics or surgical site classification and the histologic remodeling scores, cohort variables were selected for multivariable regression models using a threshold p value of ≤0.200.

RESULTS

The model selection process for the extracellular matrix score yielded two variables: subject age at time of mesh implantation, and mesh classification (c-statistic = 0.842). For CR score, the model selection process yielded two variables: subject age at time of mesh implantation and mesh classification (r (2) = 0.464). The model selection process for the collagen III area yielded a model with two variables: subject body mass index at time of mesh explantation and pack-year history (r (2) = 0.244).

CONCLUSION

Host characteristics and surgical site assessments may predict degree of remodeling for synthetic meshes used to reinforce abdominal wall repair sites. These preliminary results constitute the first steps in generating a risk prediction model that predicts the patients and clinical circumstances for which non-constructive remodeling of an abdominal wall repair site with synthetic mesh reinforcement is most likely to occur.

Localization of human mesenchymal stem cells from umbilical cord blood and their role in repair of diabetic foot ulcers in rats

The aim of this study is to explore the localization of human mesenchymal stem cells from umbilical cord matrix (hMSCs-UC) and the role of these cells in the repair of foot ulcerate tissue in diabetic foot ulcers in rats. A diabetic rat model was established by administering Streptozotocin. Diabetic foot ulceration was defined as non-healing or delayed-healing of empyrosis on the dorsal hind foot after 14 weeks. hMSCs-UC were delivered through the left femoral artery. We evaluated the localization of hMSCs-UC and their role in tissue repair in diabetic foot ulcers by histological analysis, PCR, and immunohistochemical staining. A model for diabetes was established in 54 out of 60 rats (90% success rate) and 27 of these rats were treated with hMSCs-UC. The area of ulceration was significantly and progressively reduced at 7 and 14 days following treatment with hMSCs-UC. This gross observation was strongly supported by the histological changes, including newly developed blood vessels and proliferation of inflammatory cells at 3 days post-treatment, significant increase in granulation tissue at 7 days post-treatment and squamous epithelium or stratified squamous epithelium at 14 days post-treatment. Importantly, human leukocyte antigen type-I (HLA-1) was confirmed in ulcerated tissue by RT-PCR. The expression of cytokeratin 19 was significantly increased in diabetic model rats, with no detectable change in cytokeratin 10. Additionally, both collagens I and III increased in model rats treated with hMSCs-UC, but the ratio of collagen I/III was less significant in treated rats compared with control rats. These results suggest that hMSCs-UC specifically localize to the target ulcerated tissue and may promote the epithelialization of ulcerated tissue by stimulating the release of cytokeratin 19 from keratinocytes and extracellular matrix formation.