Collagenopathies-Implications for Abdominal Wall Reconstruction: A Systematic Review

Inactive metallopeptidase homologs: the secret lives of pseudopeptidases

Inactive enzyme homologs, or pseudoenzymes, are proteins, found within most enzyme families, that are incapable of performing catalysis. Rather than catalysis, they are involved in protein-protein interactions, sometimes regulating the activity of their active enzyme cousins, or scaffolding protein complexes. Pseudoenzymes found within metallopeptidase families likewise perform these functions. Pseudoenzymes within the M14 carboxypeptidase family interact with collagens within the extracellular space, while pseudopeptidase members of the M12 "a disintegrin and metalloprotease" (ADAM) family either discard their pseudopeptidase domains as unnecessary for their roles in sperm maturation or utilize surface loops to enable assembly of key complexes at neuronal synapses. Other metallopeptidase families contain pseudopeptidases involved in protein synthesis at the ribosome and protein import into organelles, sometimes using their pseudo-active sites for these interactions. Although the functions of these pseudopeptidases have been challenging to study, ongoing work is teasing out the secret lives of these proteins.

Outcomes of complex abdominal wall reconstruction in patients with connective tissue disorders: a single center experience

INTRODUCTION

Individuals diagnosed with connective tissue disorders (CTD) are known to be predisposed to incisional hernia formation. However, there is a scarcity of data on outcomes for these patients undergoing hernia repair. We sought to describe our outcomes in performing abdominal wall reconstructions in these complex patients.

METHODS

Adult patients with CTD undergoing open, elective, posterior component separation with permanent synthetic mesh at our institution from January 2018 to October 2022 were queried from a prospectively collected database in the Abdominal Core Health Quality Collaborative. We evaluated 30-day wound morbidity, perioperative complications, long-term hernia recurrence, and patient-reported quality of life.

RESULTS

Twelve patients were identified. Connective tissue disorders included Marfan's n = 7 (58.3%), Loeys-Dietz syndrome n = 2 (16.7%), Systemic Lupus Erythematosus n = 2 (16.7%), and Scleroderma n = 1 (8.3%). Prior incisions included three midline laparotomies and nine thoracoabdominal, mean hernia width measured 14 cm, and 9 were recurrent hernias. Surgical site occurrences (SSOs) were observed in 25% of cases, and 16.7% necessitated procedural intervention. All twelve patients were available for long-term follow-up, with a mean of 34 (12-62) months. There were no instances of reoperation or mesh excision related to the TAR procedure. One patient developed a recurrence after having his mesh violated for repair of a new visceral aneurysm. Mean HerQLes scores at 1 year were 70 and 89 at ≥ 2 years; Mean scaled PROMIS scores were 30.7 at 1 year and 36.3 at ≥ 2 years.

CONCLUSION

Ventral hernia repair with TAR is feasible in patients with connective tissue disorder and can be a suitable alternative in patients with large complex hernias.

Inguinal hernia leads to worse immediate urinary continence after robot-assisted radical prostatectomy

OBJECTIVES

Patients with inguinal hernia (IH) may have voiding dysfunction and weak urethra-stabilizing periurethral fascial tissues, contributing to urinary incontinence. This study aimed to review the association between IH and urinary continence after robotic-assisted radical prostatectomy (RARP).

METHODS

This single-institution retrospective study included 251 consecutive cases of RARP between April 2019 and June 2022. Patients with concurrent IH or a history of adult IH repair were examined. The urine loss rate (ULR), defined as 24-h urine loss volume divided by the total urine volume immediately after urinary catheter removal (i.e., 6 or 7 postoperative days), was compared between the groups with (n = 33) and without IH (n = 214). Possible contributing factors for ULR were assessed, including age, body mass index (BMI), after benign prostatic hyperplasia surgery, prostate weight, and nerve-sparing. ULR was compared intergroup after propensity score matching countering selection biases.

RESULTS

Patients with IH were older (71.3 versus. 66.8 years, p < 0.01), had lower BMI (22.8 versus. 24.3, p < 0.01), and had higher ULR (14.5% versus. 5.1%, p < 0.01). In a multiple linear regression analysis (adjusted R2 = 0.084), IH (p < 0.01) was an independent contributing factor for ULR besides advancing age (p < 0.03). After propensity score matching adjusted for patient's age and nerve-sparing, patients with IH had higher ULR (14.1% versus. 5.7%, p < 0.03) as well.

CONCLUSIONS

This study first reported that IH may be one of the risk factors of urinary incontinence after RARP.

Role of Collagen in the Etiology of Inguinal Hernia Patients: A Case-Control Study

Introduction Technical faults are no longer accepted as the sole reason for recurrence following inguinal hernia (InH) repairs. Medical literature has been studied to find any contributing factors and collagen has emerged as a promising marker. Owing to their long half-lives, it has been found to best reflect the process of scarring, which is central to ensuring the formation of a proper fibrous tissue that incorporates the mesh with the abdominal wall. Methods Sixty participants were divided into two groups. The case group were patients diagnosed with InH and the control group had patients undergoing abdominal surgeries for indications other than abdominal wall hernias. A 0.5x0.5cm specimen of skin and transversalis fascia were biopsied and subsequently stained to determine the amount of collagen I and III. Results Collagen I, collagen III and the ratio of collagen I to III was measured. Collagen I was normal in the skin of both groups but decreased in transversalis fascia of cases. Collagen III was found to be normal in transversalis fascia of both cases and controls, but increased in the skin of cases. Ratio of collagen I to III was decreased in both skin and transversalis fascia of cases. Statistical analysis was carried out using an unpaired t-test, non-parametric Mann-Whitney test, ANOVA and chi-square test. Conclusions Our study has reported that in patients with inguinal hernia, collagen III or immature collagen is increased in skin and collagen I or mature collagen is decreased in the transversalis fascia. The ratio of collagen I/III is decreased in both skin and transversalis fascia.

Collagen Deposition and Inflammatory Response Associated with Macroporous Mesh Shrinkage in Incisional Hernia Repair: A Rat Model

Background: Mesh repair is the current recommendation for the treatment of incisional hernia; however, the best mesh has yet to be determined. The objective of this study was to compare the inflammatory response and collagen deposition in primary incisional hernia repair (P) and different macroporous mesh materials, including polypropylene with poliglecaprone (PP-PG), polyvinylidene fluoride (PVDF), and polyester (PE), using quantitative methods. Methods: Sixty male rats were divided into four groups. Anterior abdominal wall defects were created and either suture or mesh repair was done. Rats were euthanized on days 14, 90, and 180, and the gross findings were recorded. The inflammatory and collagen levels in the abdominal wall tissues were measured using enzyme-linked immunosorbent assay (ELISA). Results: The PE group demonstrated significant mesh shrinkage at 180 days. The extent of PE mesh shrinkage ranged from 22-42% (mean = 30.49%). At 14 days, the PVDF group had higher interleukin-6 (IL-6) levels than the PP-PG (P = .004) and PE groups (P = .019). At 90 days, the collagen type I (Col I) levels in the PE group were significantly lower than those in the others, and the collagen type I/III (Col I/III) ratios in the PE group were lower than those in the P group (P = .006). Conclusions: The persistently high IL-6 levels until 180 days and the decrease in Col I levels and Col I/III ratio at 90 days seem to predict mesh shrinkage at 180 days. The mesh induces high Col I levels, but those associated with low Col III levels should be preferred.

Imaging Insights Into Abdominal Wall Function

Purpose

The successful repair of any complex ventral hernia requires a thorough understanding of the underlying anatomical defect and its functional context. We describe an improved “functional” approach to CT imaging of the abdominal wall that can facilitate this understanding and assist surgical planning.

Methods

This invited article reports the observational experience gained from the functional abdominal wall CT examinations of 88 patients who underwent complex ventral hernia repair using pre-operative Botulinum toxin A (BTA) infiltration of the lateral oblique abdominal muscles as well as a further eight patients with diastasis rectus abdominis who were examined to exclude ventral hernia.

Results

The use of a functional CT protocol which supplements resting images with additional “crunching” images (acquired with the abdominal wall muscles all strongly contracted) can significantly improve the demonstration of ventral hernia defects. Crunching acquisitions can also help differentiate true hernias from dysfunctional bulges, identify muscle denervation or atrophic changes, reveal otherwise occult hernias that may be missed on resting or Valsalva images alone, and assist the pre-operative assessment of BTA effect.

Conclusion

A more functional approach to pre-operative CT imaging of the abdominal wall can significantly improve the understanding of complex ventral hernia defects and help formulate effective surgical plans that achieve low recurrence rates and good functional outcomes.

Congenital collagenopathies increased the risk of inguinal hernia developing and repair: analysis from a nationwide population-based cohort study

Herein, we aimed to explore whether male patients with congenital collagen diseases had a higher risk of inguinal herniation than patients without these diseases. Data were retrospectively collected from the National Health Insurance Research Database of Taiwan. The study cohort included 1,801 male patients diagnosed with congenital collagen diseases based on the ICD-9 CM diagnostic codes; after propensity score matching, the control group comprised 6,493 men without congenital collagen diseases. The primary endpoint was inguinal hernia repair during the observation period. During a median follow-up period of 133.9 months, the risk of inguinal herniation in the collagen group was significantly higher than that in the control group (HR = 2.237, 95% CI 1.646-3.291, p < 0.001). This phenomenon was observed in patients younger than 18 years (HR: 3.040, 95% CI 1.819-5.083, p < 0.001) and in those aged 18-80 years (HR: 1.909, 95% CI 1.186-3.073, p < 0.001). Asian men with congenital collagen diseases are at a high risk of developing inguinal hernias, regardless of age. Detailed physical examination and patient education should be performed for these patients to prevent inguinal herniation.

The relationship between glycine levels in collagen in the anterior rectus sheath tissue and the onset of indirect inguinal hernia: A cross-sectional study

Introduction

An inguinal hernia is a protrusion of abdominal-cavity contents through the inguinal canal. Protection against an inguinal hernia depends on the integrity of fascial tissue, which is maintained by collagen. Collagen is a structural protein consisting of amino acids, the most common of which is glycine. This study aimed to determine the relationship between glycine and the appearance of lateral inguinal hernias. To this end, the researchers examined the profile of collagen and glycine levels in the tissue of the sheath of the rectus femoris in patients with lateral inguinal hernia (indirect inguinal hernia).

Methods

The study used a cross-sectional design to determine glycine levels in rectus anterior sheath tissue in patients with indirect inguinal hernia. Examination of collagen glycine levels was conducted using the ELISA (Enzyme-Linked immunosorbent assay) method. Data were analyzed using the Statistical Package for the Social Science (SPSS) program. An ANOVA test, Pearson's correlation test, and Spearman's correlation test were also performed. A p-value <0.05 was said to be significant.

Results

Across 72 samples, the mean body mass index (BMI) was 22.5 kg/m2 and, the mean clinical onset was 28.02 months. Correlation tests showed a correlation between glycine levels and clinical onset (p = 0.026). The ANOVA test showed a difference between glycine levels with age group (p = 0.025) and BMI (p = 0.015). The correlation between glycine levels and clinical-grade (p = 0.416) was not statistically significant.

Conclusion

There is a significant relationship between glycine levels and age, BMI, and clinical onset of indirect inguinal hernia.

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The stability of the abdominal wall depends on the integrity of muscle and fascial tissue.

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Collagen is a structural protein that helps tissues maintain their mechanical characteristics, structure, and shape.

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The collagen structure contains amino acids such as glycine, proline, hydroxyproline, alanine, and hydroxylysine.

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The high glycine content of collagen is vital to promoting collagen turnover, as its deficiency reduces collagen turnover.

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There is a relationship between glycine levels and age, body mass index, and clinical onset of indirect inguinal hernia.

Laparoscopic sacral hysteropexy for pelvic organ prolapse in a patient affected by marfan syndrome: a case report

Background: Marfan Syndrome (MS) is a dominantly inherited connective tissue disorder with consequences on the strength and resilience of connective tissues that may predispose to Pelvic Organ Prolapse (POP). Literature lacks studies investigating POP surgery in patients affected by MS that might help surgical management decisions. Objective: The objective of this paper is to describe the surgical procedure of laparoscopic sacral hysteropexy (LSHP) in a 37 years old woman affected by MS with symptomatic POP. Materials and Methods and main outcome measures: We performed a nerve-sparing laparoscopic sacral hysteropexy without complications and looked for anatomical and subjective outcomes. The patient completed The Female Sexual Distress Scale (FSDS), Pelvic Floor Disability Index (PFDI-20), and Wexner questionnaires preoperatively and postoperatively. Results: The patient stated a complete resolution of all POP related symptoms and there was a total correction of the descensus. Furthermore, no perioperative and postoperative complications were noted. Conclusions: LSHP could be an effective and safe procedure for the treatment of POP in women affected by MS and this case report is the first to describe a reconstructive procedure in this category of patients. What is new? The literature lacks studies investigating POP surgery in women with MS, that might help surgeons, thus we present this case to describe surgical and functional outcomes in this patient category, underlying the higher risk of complications and relapses related to the weakness of connective tissue. This case report may represent the basis of future studies to confirm the safety, efficacy and feasibility of LSHP and sacral colpopexy in patients with MS.

Modified Halsted's operation for inguinal hernia repair: A new technique

Background

Inguinal hernia is a frequent problem presented to surgical clinic in Iraq. Surgical treatment options for inguinal hernia are numerous, selecting the appropriate method or technique depends on different factors.

Aim of study

To find a new technique for open inguinal hernia repair with no recurrence even in recurrent cases, without major complications during or after surgery, and can be used even by new surgeons with little experience.

Patients & methods

A retrospective cross sectional study conducted in the Medical City teaching hospital and Private Hospitals in Baghdad, during the period from January 1, 2000, to December 30, 2016 on convenient sample of 408 Iraqi patients with inguinal hernia. The patients were treated by modified Halsted's technique by open surgery applying polypropylene mesh. The patients were followed up through frequent visits and phone calls to assess the recurrence and complications.

Results

No recurrence of inguinal hernia was reported after 5-10 years follow up, while 94.9% of patients reported postoperative complications commonly oedema of spermatic cord. There was a highly significant association between male gender hernia patients and post Modified Halsted operation complications (p < 0.001). A highly significant association was observed between direct hernia and post Modified Halsted operation complications (p < 0.001). The significant risk factors related to complications were anemia and collagen disease.

Conclusions

The modified Halsted's operation for inguinal hernia repair is effective in treatment of inguinal hernia with low recurrence and complications rate.

Maternal risk factors for paediatric inguinal hernia

BACKGROUND

Risk factors for paediatric inguinal hernia are poorly understood. This longitudinal cohort study assessed whether children with a maternal history of inguinal hernia or connective tissue disorders have a higher risk of developing inguinal hernias before 13 years of age.

METHODS

The study included children followed up between birth and 13 years of age in Quebec, Canada, 2006-2019. Newborns whose mothers had inguinal hernias or connective tissue disorders were followed over time to identify future hospital admissions for inguinal hernia. Cox proportional hazards regression adjusted for patient characteristics was used to estimate hazard ratios (HRs) and 95 per cent confidence intervals for the association between maternal hernia or connective tissue disorders and future childhood hernias. Associations in girls and boys were examined separately.

RESULTS

The study included 786 322 children with 6 186 448 person-years of follow-up. There were 6861 children with inguinal hernias, corresponding to an incidence of 11.1 per 10 000 person-years. Children with a maternal history of inguinal hernia had 2.92 (95 per cent c.i. 2.39 to 3.58) times the risk of having inguinal hernias relative to children whose mothers had no such history. Children with a maternal history of connective tissue disorders had 1.30 (1.00 to 1.68) times the risk. Maternal hernias were strongly associated with risk of inguinal hernias in girls (HR 5.34, 3.82 to 7.47), whereas maternal connective tissue disorders were associated with inguinal hernias in boys (HR 1.35, 1.02 to 1.79).

CONCLUSION

Paediatric inguinal hernias may be associated with maternal inguinal hernias and connective tissue disorders, but the underlying reason for this relationship requires further investigation.

Management of Postoperative Complications Following Common Pediatric Operations

This review discusses complications unique to pediatric surgical populations. Here the authors focus primarily on five of the most common procedures performed in children: appendectomy, central venous catheterization, pyloromyotomy, gastrostomy, and inguinal/umbilical hernia repair.

The male rectus diastasis: a different concept?

PURPOSE

More interest in the treatment of rectus diastasis has been evoked lately. Following the postpartum females from a great distance, the middle-aged males living with obesity are the second most common group of rectus diastasis patients. Although gender differences are considered frequently in regard to cosmetic appearance and symptoms, it is less obvious in classifications and subsequent treatment strategies. Is a unisex approach of rectus diastasis still applicable? The lack of a firm answer warrants this review of the current literature.

METHODS

An explorative free-text multi-database bibliographic search (Pubmed/CENTRAL/EMBASE/PEDro/Scholar) was performed with the focus on the rectus diastasis in males. Anticipating the limited references, the design was a non-systematic review. All studies, regardless of study type, language or time period, describing etiology, symptoms, classification and/or treatment options were eligible for inclusion. From the articles retrieved out of this search, additional references were identified by a manual search among the cited references.

RESULTS

The multi-database search resulted in a total of 7633 records. Based on the title and abstract 95 records were full text assessed for eligibility. Eleven studies were identified as relevant, six by cross-reference and another four by hand-search were added to provide an insight in gender-specific aspects in rectus diastase. Hereditary causes are differences in collagen-like composition of types and concomitant abdominal aneurysm as well as gender differences in the linea alba architecture. Acquired etiology is distributed into both absolute pressure by visceral obesity and relative pressure caused by weight lifting or improper exercises. Furthermore, the impact of muscle thickness and age are considered as influencers of biomechanics. Gender differences can also play a role in symptoms of body image and core stability. It is known that there are anatomical differences between male and female persons; more transverse fibers are found in infra-umbilical region in women. In classifications the awareness of male rectus diastasis is limited, treatment outcome studies are scarce on males.

CONCLUSION

An overview of male-specific aspects of rectus diastasis is provided, underlining that key aspects surrounding rectus diastasis in males differ from females. Although males are the minority of rectus diastasis patients, we recommend that the male rectus diastasis as a concept should be specifically acknowledged in classifications systems and study outcome reporting to evaluate this subgroup more accurately in the future.

Strategies for Mesh Fixation in Abdominal Wall Reconstruction: Concepts and Techniques

SUMMARY

Ventral hernias have numerous causes, ranging from sequelae of surgical procedures to congenital deformities. Patients suffering from these hernias experience a reduced quality of life through pain, associated complications, and physical disfigurement. Therefore, it is important to provide these patients with a steadfast repair that restores functionality and native anatomy. To do this, techniques and materials for abdominal wall reconstruction have advanced throughout the decades, leading to durable surgical repairs. At the cornerstone of this lies the use of mesh. When providing abdominal wall reconstruction, a surgeon must make many decisions with regard to mesh use. Along with the type of mesh and plane of placement of mesh, a surgeon must decide on the method of mesh fixation. Fixation of mesh provides an equal distribution of tension and a more robust tissue-mesh interface, which promotes integration. There exist numerous modalities for mesh fixation, each with its own benefits and drawbacks. This Special Topic article aims to compare and contrast methods of mesh fixation in terms of strength of fixation, clinical outcomes, and cost-effectiveness. Methods included in this review are suture, tack, fibrin glue, mesh strip, and self-adhering modes of fixation.

Profile of collagen prolines level of anterior rectus sheath tissue in indirect inguinal hernia: A cross-sectional study

Introduction

A hernia is a protrusion of an organ or tissue through an abnormal anatomical channel or opening. Epidemiological data indicated an increased prevalence of inguinal hernias in patients with connective tissue diseases. The biomechanical strength of connective tissue is highly dependent on the constituent of the matrix, including collagen. Fibroblasts produce and secrete procollagen containing high concentrations of proline and lysine. Collagen integrity plays an essential role in preventing hernia formation in the abdominal wall. To investigate the relationship between collagen proline levels of the anterior rectus sheath tissue in patients with lateral inguinal hernias (indirect inguinal hernia).

Methods

The study participants consisted of 67 inguinal hernia patients. A sample of anterior rectus tissue was obtained at the time of surgery, then being washed in a PBS buffer (pH 7.4). The measurement of collagen proline levels was subsequently carried out with enzyme linked immunosorbent assay (ELISA).

Results

All study participants were male with mean age of 44 years, mean body mass index of 22.6 kg/m² and mean onset of events of 27 months. Study subjects with reducible, irreducible, and incarcerated hernias were 45.7% (44/67 cases), 14.9% (10/67) and 19.4% (13/67), respectively. The mean proline level of the study subjects was 9.20. Correlation tests showed a correlation of proline levels and age (p = 0.001), body mass index (p = 0.006), and the onset of events (p = 0.023). Meanwhile, correlation of proline levels and occupation (p = 0.235) and clinical degree (p = 0.164) were not statistically significant.

Conclusion

Presence if relationship between proline levels with age, and onset of incidence among indirect inguinal hernia patients.

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Collagen is the main structural protein in the muscle wall layer.

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Defects in collagenases will result in abnormal collagen synthesis leading to pathological collagen degradation.

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Decreases in hydroxyproline and collagen were observed in the fascia and muscle tissue of patients with inguinal hernias.

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There are a relationship between proline levels with age, and onset of incidence among indirect inguinal hernia.

The evaluation of functional small intestinal submucosa for abdominal wall defect repair in a rat model: Potent effect of sequential release of VEGF and TGF-β1 on host integration

Ineffective vessel penetration and extracellular matrix (ECM) remodeling are responsible for the failure of porcine small intestinal submucosa (SIS)-repaired abdominal wall defects. Combined growth factors could be used as directing signals in a nature-mimicking strategy to improve this repair through mesh functionalization. In this work, vascular endothelial growth factor (VEGF) and transforming growth factor β1 (TGF-β1) were incorporated into a silk fibroin membrane via coaxial aqueous electrospinning to exploit their benefits of biological interactions. The membrane was sandwiched into the SIS bilayer as a functional mesh to repair partial-thickness defects in a rat model. Membrane characterization demonstrated that the core-shell structure ensured the independent distribution and sequential release of two regulators and protection of their bioactivities, which were confirmed by cell viability and protein expression. The mesh was further assessed to facilitate vasculature formation and collagen secretion in vitro, and exhibited better host integration than VEGF- or TGF-β1-containing mesh and developed reinforced mechanical properties compared with the VEGF-containing mesh after 28 days in vivo. Determination of the underlying biological interactions revealed that rapid VEGF release promotes angiogenesis and collagen secretion but initially potentiates the inflammatory response. Sustained TGF-β1 release at relatively low concentrations promoted VEGF for vessel permeation and maturation and steadily induced ECM remodeling under milder foreign body reactions. The functionalization of SIS improves repair by sufficient integration with timely remodeling and helps elucidate the related regulatory interactions.

Biomarkers and heterogeneous fibroblast phenotype associated with incisional hernia

Development of incisional hernia (IH) is multifactorial but inflammation and abdominal wall ECM (extracellular matrix) disorganization are key pathological events. We investigated if the differential expression of fibroblast biomarkers reflects the cellular milieu and the dysregulated ECM in IH tissues. Expression of fibroblast biomarkers, including connective tissue growth factor, alpha-smooth muscle actin (α-SMA), CD34 (cluster of differentiation 34), cadherin-11 and fibroblast specific protein 1 (FSP1), was examined by histology and immunofluorescence in the hernial-fascial ring/neck tissue (HRT) and hernia sack tissue (HST) harvested from the patients undergoing hernia surgery and compared with normal fascia (FT) and peritoneum (PT) harvested from brain-dead healthy subjects undergoing organ procurement for transplantation. The H&E staining revealed alterations in tissue architecture, fibroblast morphology, and ECM organization in the IH tissues compared to control. The biomarker for undifferentiated fibroblasts, CD34, was significantly higher in HST and decreased in HRT than the respective FT and PT controls. Also, the findings revealed an increased level of CTGF (connective tissue growth factor) with decrease in α-SMA in both HRT and HST compared to the controls. In addition, an increased level of FSP1 (fibroblast specific protein 1) and cadherin-11 in HRT with decreased level in HST were observed relative to the respective controls (FT and PT). Hence, these findings support the heterogeneity of fibroblast population at the laparotomy site that could contribute to the development of IH. Understanding the mechanisms causing the phenotype switch of these fibroblasts would open novel strategies to prevent the development of IH following laparotomy.

Prevalence of comorbidities in a surgical pectus excavatum population

Background

Pectus excavatum is the most common chest wall deformity and is associated to various connective tissue, cardiopulmonary, and skeletal abnormalities. Several conditions and syndromes have been associated to pectus excavatum, although the overall health implications of the pectus excavatum phenotype are unclear. Therefore, in this study we aimed to examine the health implications of the pectus excavatum phenotype by assessing all comorbidities and previous medical conditions in a cohort of patients undergoing pectus excavatum surgery.

Methods

This single-centre retrospective prevalence study included 1,046 patients undergoing minimal invasive repair of pectus excavatum from 2001 to 2012. Hospital medical charts were assessed and comorbidities and previous medical conditions were registered systematically and categorized according to the affected organ system.

Results

In our study population of 1,046 patients, we registered 623 conditions. The median age was 17 years and the majority of patients (56%) had no previous or present conditions. Notable prevalence of asthma (8.8%), allergies (12.3%), previous hernia surgery (5.2%), and psychiatric conditions (4.9%) were found.

Conclusions

The majority of patients undergoing pectus excavatum surgery have no comorbidities or previous medical conditions. It seems that this patient category is comparable to the background population in this regard and our findings do not support screening this patient category for associated conditions.

KDIGO Clinical Practice Guideline on the Evaluation and Management of Candidates for Kidney Transplantation

The 2020 Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline on the Evaluation and Management of Candidates for Kidney Transplantation is intended to assist health care professionals worldwide who evaluate and manage potential candidates for deceased or living donor kidney transplantation. This guideline addresses general candidacy issues such as access to transplantation, patient demographic and health status factors, and immunological and psychosocial assessment. The roles of various risk factors and comorbid conditions governing an individual's suitability for transplantation such as adherence, tobacco use, diabetes, obesity, perioperative issues, causes of kidney failure, infections, malignancy, pulmonary disease, cardiac and peripheral arterial disease, neurologic disease, gastrointestinal and liver disease, hematologic disease, and bone and mineral disorder are also addressed. This guideline provides recommendations for evaluation of individual aspects of a candidate's profile such that each risk factor and comorbidity are considered separately. The goal is to assist the clinical team to assimilate all data relevant to an individual, consider this within their local health context, and make an overall judgment on candidacy for transplantation. The guideline development process followed the Grades of Recommendation Assessment, Development, and Evaluation (GRADE) approach. Guideline recommendations are primarily based on systematic reviews of relevant studies and our assessment of the quality of that evidence, and the strengths of recommendations are provided. Limitations of the evidence are discussed with differences from previous guidelines noted and suggestions for future research are also provided.

Staphylococcus aureus Biofilm Infection Compromises Wound Healing by Causing Deficiencies in Granulation Tissue Collagen

OBJECTIVE

The objective of this work was to causatively link biofilm properties of bacterial infection to specific pathogenic mechanisms in wound healing.

BACKGROUND

Staphylococcus aureus is one of the four most prevalent bacterial species identified in chronic wounds. Causatively linking wound pathology to biofilm properties of bacterial infection is challenging. Thus, isogenic mutant stains of S. aureus with varying degree of biofilm formation ability was studied in an established preclinical porcine model of wound biofilm infection.

METHODS

Isogenic mutant strains of S. aureus with varying degree (ΔrexB > USA300 > ΔsarA) of biofilm-forming ability were used to infect full-thickness porcine cutaneous wounds.

RESULTS

Compared with that of ΔsarA infection, wound biofilm burden was significantly higher in response to ΔrexB or USA300 infection. Biofilm infection caused degradation of cutaneous collagen, specifically collagen 1 (Col1), with ΔrexB being most pathogenic in that regard. Biofilm infection of the wound repressed wound-edge miR-143 causing upregulation of its downstream target gene matrix metalloproteinase-2. Pathogenic rise of collagenolytic matrix metalloproteinase-2 in biofilm-infected wound-edge tissue sharply decreased collagen 1/collagen 3 ratio compromising the biomechanical properties of the repaired skin. Tensile strength of the biofilm infected skin was compromised supporting the notion that healed wounds with a history of biofilm infection are likely to recur.

CONCLUSION

This study provides maiden evidence that chronic S. aureus biofilm infection in wounds results in impaired granulation tissue collagen leading to compromised wound tissue biomechanics. Clinically, such compromise in tissue repair is likely to increase wound recidivism.

Reduction Mammaplasty in a Patient with Kniest Dysplasia: Case Report and Literature Review

Collagen plays a fundamental role in wound healing and consequently defective collagen can impair normal wound healing processes. Kniest dysplasia (KD) is a collagenopathy that results from a pathogenic mutation in a gene that codes for type II collagen. Clinical manifestations of the dysplasia include short-trunk dwarfism, kyphoscoliosis, hand arthropathy, cleft palate, hearing loss, and ocular abnormalities. We present the case of a 21-year-old woman who desired reduction mammaplasty. A review of the literature was performed, and there were no published reports of any plastic surgery procedures in patients with KD. The patient proceeded with surgery and healed without any complications. Given that wound healing appears normal in this patient population, it is reasonable to consider elective plastic surgical procedures in patients with KD.

Subcutaneous fat area as a risk factor for extraction site incisional hernia following gastrectomy for gastric cancer

PURPOSE

To identify the incidence of extraction site incisional hernia following gastrectomy for gastric cancer and its significant risk factors, including the subcutaneous fat area.

METHODS

We reviewed data gathered prospectively on patients with gastric cancer, who underwent gastrectomy between 2008 and 2012 at Kyushu University Hospital, Fukuoka, Japan. The subcutaneous fat area (SFA) and visceral fat area (VFA) were measured using axial computed tomography at the level of the L4 and L3 transverse processes, and the L2-L3 intervertebral disc. The primary endpoint of the rate of extraction site incisional hernia was based on the computed tomography and clinical data including hospital follow-up reports.

RESULTS

After applying the inclusion and exclusion criteria, 320 patients were included in this retrospective analysis: 3.1% (10/320) had extraction site incisional hernias after a mean follow-up of 11 months. Multivariate analysis revealed that age and the SFA were independent risk factors (age ≥ 70.5 years: P = .013, odds ratio: 9.116, 95% confidence interval 1.581-52.553; L4 SFA ≥ 124 cm²: P = .004, odds ratio: 13.752, 95% confidence interval 2.290-82.582).

CONCLUSION

Age and the SFA were independent risk factors for extraction site incisional hernia in patients undergoing gastrectomy for gastric cancer.

Comparative study of collagen and elastin content of abdominal wall fascia in inguinal hernia and non-hernia patients in an African population

PURPOSE

Altered composition of collagen and elastin in abdominal fascia has been linked with the pathogenesis of hernias. This has not been studied amongst Africans who have hernia presentations which vary significantly from Caucasian cohorts. The aim of this study was to determine, and compare, the collagen and elastin contents of the transversalis fascia and rectus sheath of inguinal hernia patients with non-hernia controls.

METHODS

Twenty-five patients with solitary, primary, uncomplicated inguinal hernia and twenty-five non-hernia controls were evaluated. Biopsies of the transversalis fascia and anterior rectus sheath were stained with Masson Trichrome and Verhöeff van-Gieson to isolate collagen and elastin respectively, which were quantified using the ImageJ/Fiji® image analysis software.

RESULTS

Inguinal hernia patients were aged 19-85 years with a mean age of 45.2 years, mean body mass index (BMI) of 23.3 kg/m² and mean duration of hernia of 42.5 months. Lateral hernias with no hernia defect or posterior wall defect [PL0] were the predominant clinical type. There were significantly lower collagen and higher elastin content in the transversalis fascia and rectus sheath of inguinal hernia patients [P < 0.001]. Regression analysis identified smoking and long duration of hernias as independent predictors of low collagen levels in this study CONCLUSION: Inguinal hernia patients in the study population demonstrated depleted collagen in the connective tissue of the inguinal canal. This might justify the routine use of prosthetic mesh for the reinforcement of the posterior wall during hernia repair.

Can Electric Nose Breath Analysis Identify Abdominal Wall Hernia Recurrence and Aortic Aneurysms? A Proof-of-Concept Study

Introduction. This pilot study evaluates if an electronic nose (eNose) can distinguish patients at risk for recurrent hernia formation and aortic aneurysm patients from healthy controls based on volatile organic compound analysis in exhaled air. Both hernia recurrence and aortic aneurysm are linked to impaired collagen metabolism. If patients at risk for hernia recurrence and aortic aneurysms can be identified in a reliable, low-cost, noninvasive manner, it would greatly enhance preventive options such as prophylactic mesh placement after abdominal surgery. Methods. From February to July 2017, a 3-armed proof-of-concept study was conducted at 3 hospitals including 3 groups of patients (recurrent ventral hernia, aortic aneurysm, and healthy controls). Patients were measured once at the outpatient clinic using an eNose with 3 metal-oxide sensors. A total of 64 patients (hernia, n = 29; aneurysm, n = 35) and 37 controls were included. Data were analyzed by an automated neural network, a type of self-learning software to distinguish patients from controls. Results. Receiver operating curves showed that the automated neural network was able to differentiate between recurrent hernia patients and controls (area under the curve 0.74, sensitivity 0.79, and specificity 0.65) as well as between aortic aneurysm patients and healthy controls (area under the curve 0.84, sensitivity 0.83, and specificity of 0.81). Conclusion. This pilot study shows that the eNose can distinguish patients at risk for recurrent hernia and aortic aneurysm formation from healthy controls.

Transcriptome analysis identifies genes involved with the development of umbilical hernias in pigs

Umbilical hernia (UH) is one of the most frequent defects affecting pig production, however, it also affects humans and other mammals. UH is characterized as an abnormal protrusion of the abdominal contents to the umbilical region, causing pain, discomfort and reduced performance in pigs. Some genomic regions associated to UH have already been identified, however, no study involving RNA sequencing was performed when umbilical tissue is considered. Therefore, here, we have sequenced the umbilical ring transcriptome of five normal and five UH-affected pigs to uncover genes and pathways involved with UH development. A total of 13,216 transcripts were expressed in the umbilical ring tissue. From those, 230 genes were differentially expressed (DE) between normal and UH-affected pigs (FDR <0.05), being 145 downregulated and 85 upregulated in the affected compared to the normal pigs. A total of 68 significant biological processes were identified and the most relevant were extracellular matrix, immune system, anatomical development, cell adhesion, membrane components, receptor activation, calcium binding and immune synapse. The results pointed out ACAN, MMPs, COLs, EPYC, VIT, CCBE1 and LGALS3 as strong candidates to trigger umbilical hernias in pigs since they act in the extracellular matrix remodeling and in the production, integrity and resistance of the collagen. We have generated the first transcriptome of the pig umbilical ring tissue, which allowed the identification of genes that had not yet been related to umbilical hernias in pigs. Nevertheless, further studies are needed to identify the causal mutations, SNPs and CNVs in these genes to improve our understanding of the mechanisms of gene regulation.

Recessive marfanoid syndrome with herniation associated with a homozygous mutation in Fibulin-3

We have previously reported on a consanguineous family where 2 siblings, a girl and a boy, presented with tall stature, long and triangular faces, prominent forehead, telecanthus, ptosis, everted lower eyelids, downslanting palpebral fissures, large ears, high arched palate, long arm span, arachnodactyly, advanced bone age, joint laxity, pectus excavatum, inguinal hernia, and myopia, suggestive of a new subtype of connective tissue disorder (Megarbane et al. AJMG, 2012; 158(A)5: 1185-1189). On clinical follow-up, both patients had multiple inguinal, crural, and abdominal herniae, intestinal occlusions, several huge diverticula throughout the gut and the bladder, and rectal prolapse. In addition, the girl had a mild hearing impairment, and the boy a left diaphragmatic hernia. Here we describe the molecular characterization of this disorder using Whole Exome Sequencing, revealing, in both siblings, a novel homozygous missense variant in the EFEMP1 gene, c.163T > C; p.(Cys55Arg) whose homozygous by descent, autosomal recessive transmission was confirmed through segregation analysis by Sanger sequencing. In addition, the girl exhibited a homozygous mutation in the MYO3A gene, c.1370_1371delGA; p.(Arg457Asnfs*25), associated with non-syndromic deafness. The siblings were also found to harbor a homozygous nonsense variant in the VCPKMT gene. We review the literature and discuss our updated clinical and molecular findings that suggest EFEMP1 to be the probable candidate gene implicated in this novel connective tissue disease.

Prophylactic Mesh for Hernia Prevention: Has the Time Arrived?

Incisional and parastomal hernias continue to be vexing problems for patients and surgeons. Risk factors are generally patient-related and/or technical in nature, and in some cases, can be altered, resulting in improved outcomes. Improved fascial closure techniques can only partly reduce the risk of incisional hernia formation. Even under optimal circumstances, using time tested closure techniques and materials, the rate remains high, due primarily to factors that are not modifiable or are unidentifiable. In such cases, there may be a beneficial role for prophylactic mesh augmentation (PMA), wherein mesh is implanted at the time of initial surgery or stoma formation. Several high-risk groups that might benefit from PMA have been identified, including patients undergoing open abdominal aneurysm repair or colorectal procedures, obese patients, and patients requiring creation of permanent gastrointestinal or urological stomas. Although the initial results of PMA are promising, the benefits of this strategy must be weighed against potential risks. Outcome measures to assess efficacy should include not only hernia recurrence but also quality of life, surgical-site occurrences, and cost. Further studies are warranted to predict which specific patient populations might benefit most from PMA and to identify ideal mesh materials as well as preferred implantation sites and methods of mesh fixation.

Hypermobile Ehlers-Danlos syndrome (a.k.a. Ehlers-Danlos syndrome Type III and Ehlers-Danlos syndrome hypermobility type): Clinical description and natural history

The hypermobile type of Ehlers-Danlos syndrome (hEDS) is likely the most common hereditary disorder of connective tissue. It has been described largely in those with musculoskeletal complaints including joint hypermobility, joint subluxations/dislocations, as well as skin and soft tissue manifestations. Many patients report activity-related pain and some go on to have daily pain. Two undifferentiated syndromes have been used to describe these manifestations-joint hypermobility syndrome and hEDS. Both are clinical diagnoses in the absence of other causation. Current medical literature further complicates differentiation and describes multiple associated symptoms and disorders. The current EDS nosology combines these two entities into the hypermobile type of EDS. Herein, we review and summarize the literature as a better clinical description of this type of connective tissue disorder. © 2017 Wiley Periodicals, Inc.