Shared and nonshared familial susceptibility to surgically treated inguinal hernia, femoral hernia, incisional hernia, epigastric hernia, and umbilical hernia

Risk factors for inguinal hernia repair among US adults

PURPOSE

To investigate demographic, clinical, and behavioral risk factors for undergoing inguinal hernia repair within a large and ethnically diverse cohort.

METHODS

We conducted a retrospective case-control study from 2007 to 2020 on 302,532 US individuals from a large, integrated healthcare delivery system with electronic health records, who participated in a survey of determinants of health. Participants without diagnosis or procedure record of an inguinal hernia at enrollment were included. We then assessed whether demographic (age, sex, race/ethnicity), clinical, and behavioral factors (obesity status, alcohol use, cigarette smoking and physical activity) were predictors of undergoing inguinal hernia repair using survival analyses. Risk factors showing statistical significance (P < 0.05) in the univariate models were added to a multivariate model.

RESULTS

We identified 7314 patients who underwent inguinal hernia repair over the study period, with a higher incidence in men (6.31%) compared to women (0.53%). In a multivariate model, a higher incidence of inguinal hernia repair was associated with non-Hispanic white race/ethnicity, older age, male sex (aHR = 13.55 [95% confidence interval 12.70-14.50]), and more vigorous physical activity (aHR = 1.24 [0.045]), and alcohol drinker status (aHR = 1.05 [1.00-1.11]); while African-American (aHR = 0.69 [0.59-0.79]), Hispanic/Latino (aHR = 0.84 [0.75-0.91]), and Asian (aHR = 0.35 [0.31-0.39]) race/ethnicity, obesity (aHR = 0.33 [0.31-0.36]) and overweight (aHR = 0.71 [0.67-0.75]) were associated with a lower incidence. The use of cigarette was significantly associated with a higher incidence of inguinal hernia repair in women (aHR 1.23 [1.09-1.40]), but not in men (aHR 0.96 [0.91-1.02]).

CONCLUSION

Inguinal hernia repair is positively associated with non-Hispanic white race/ethnicity, older age, male sex, increased physical activity, alcohol consumption and tobacco use (only in women); while negatively associated with obesity and overweight status. Findings from this large and ethnically diverse study may support future prediction tools to identify patients at high risk of this surgery.

The inheritance of groin hernias: an updated systematic review with meta-analyses

PURPOSE

The aim of this systematic review was to assess the inheritance of groin hernias.

METHODS

The primary outcome was to assess the inheritance based on the family history of groin hernias. We included studies that reported family history in patients with groin hernias, assessed the development of groin hernias in patients with a positive family history, or assessed the development of groin hernias in twins. Searches were conducted in PubMed, EMBASE, and Cochrane CENTRAL in November 2021. Results were synthesized narratively and with meta-analyses.

RESULTS

Twenty-two studies with unique participants were included. While two twin studies did not show convincing results of a genetic origin in children, database studies with low risk of bias showed that a positive history in parents or siblings increased the risk of inguinal hernia in children, and the risk was highest between mothers and daughters and between sisters. In adults, patients with inguinal hernia had higher odds of having a positive family history compared with patients without groin hernia (odds ratio 5.3, 95% confidence interval 3.3-8.7), and a nationwide study found the highest risk of inguinal hernia repair when a sister had been repaired compared with a brother. This study also found that having a sibling repaired for a groin hernia increased the risk of femoral hernia repair.

CONCLUSION

Despite studies being heterogeneous, there is overwhelming evidence that a positive family history is a risk factor for developing inguinal hernia in both children and adults, seemingly with a pronounced female-female inheritance pattern.

Familial clustering of psychiatric disorders and low IQ

BACKGROUND

Although the ICD and DSM differentiate between different psychiatric disorders, these often share symptoms, risk factors, and treatments. This was a population-based, case-control, sibling study examining familial clustering of all psychiatric disorders and low IQ, using data from the Israel Draft-Board Registry on all Jewish adolescents assessed between 1998 and 2014.

METHODS

We identified all cases with autism spectrum disorder (ASD, N = 2128), severe intellectual disability (ID, N = 9572), attention-deficit hyperactive disorder (ADHD) (N = 3272), psychotic (N = 7902), mood (N = 9704), anxiety (N = 10 606), personality (N = 24 816), or substance/alcohol abuse (N = 791) disorders, and low IQ (⩾2 SDs below the population mean, N = 31 186). Non-CNS control disorders were adolescents with Type-1 diabetes (N = 2427), hernia (N = 29 558) or hematological malignancies (N = 931). Each case was matched with 10 age-matched controls selected at random from the Draft-Board Registry, with replacement, and for each case and matched controls, we ascertained all full siblings. The main outcome measure was the relative recurrence risk (RRR) of the sibling of a case having the same (within-disorder RRR) or a different (across-disorder RRR) disorder.

RESULTS

Within-disorder RRRs were increased for all diagnostic categories, ranging from 11.53 [95% confidence interval (CI): 9.23-14.40] for ASD to 2.93 (95% CI: 2.80-3.07) for personality disorders. The median across-disorder RRR between any pair of psychiatric disorders was 2.16 (95% CI: 1.45-2.43); the median RRR between low IQ and any psychiatric disorder was 1.37 (95% CI: 0.93-1.98). There was no consistent increase in across-disorder RRRs between the non-CNS disorders and psychiatric disorders and/or low IQ.

CONCLUSION

These large population-based study findings suggest shared etiologies among most psychiatric disorders, and low IQ.

Shared genetic architecture of hernias: A genome-wide association study with multivariable meta-analysis of multiple hernia phenotypes

Abdominal hernias are common and characterised by the abnormal protrusion of a viscus through the wall of the abdominal cavity. The global incidence is 18.5 million annually and there are limited non-surgical treatments. To improve understanding of common hernia aetiopathology, we performed a six-stage genome-wide association study (GWAS) of 62,637 UK Biobank participants with either single or multiple hernia phenotypes including inguinal, femoral, umbilical and hiatus hernia. Additionally, we performed multivariable meta-analysis with metaUSAT, to allow integration of summary data across traits to generate combined effect estimates. On individual hernia analysis, we identified 3404 variants across 38 genome-wide significant (p < 5×10-8) loci of which 11 are previously unreported. Robust evidence for five shared susceptibility loci was discovered: ZC3H11B, EFEMP1, MHC region, WT1 and CALD1. Combined hernia phenotype analyses with additional multivariable meta-analysis of summary statistics in metaUSAT revealed 28 independent (seven previously unreported) shared susceptibility loci. These clustered in functional categories related to connective tissue and elastic fibre homeostasis. Weighted genetic risk scores also correlated with disease severity suggesting a phenotypic-genotypic severity correlation, an important finding to inform future personalised therapeutic approaches to hernia.

Hernia recurrence after primary repair of small umbilical hernia defects

BACKGROUND

An evidence-based approach to the repair of umbilical hernias (UH)<1 cm has yet to be defined.

METHODS

A prospectively maintained, institutional hernia database was queried for patients undergoing primary suture repair of UH ≤ 1 cm. The primary outcome was recurrence and secondary outcomes were wound complications.

RESULTS

Of 332 patients included (226-primary, 106-incisional), recurrence was identified in 4 (1.8%) primary versus 8 (7.5%) incisional-UH (p = 0.022), with follow-up of 4.7 ± 4.4 years. There were 10 (3.0%) wound complications: 4 (1.2%) superficial wound infections, 1 (0.3%) superficial wound dehiscence, and 5 (1.5%) seromas. On multivariable analysis of recurrence, incisional-UH had an odds ratio of 4.2 compared to primary. Suture choice, diabetes, BMI, tobacco-use history, and wound complications were not significant.

CONCLUSIONS

With long term follow-up, recurrence after primary suture repair of UH ≤ 1 cm occurred in 1.8% of primary and 7.5% of incisional UH. On multivariable analysis, incisional-UH increased recurrence odds by 4.2 times compared to primary.

Comprehensive genome-wide association study of different forms of hernia identifies more than 80 associated loci

Hernias are characterized by protrusion of an organ or tissue through its surrounding cavity and often require surgical repair. In this study we identify 65,492 cases for five hernia types in the UK Biobank and perform genome-wide association study scans for these five types and two combined groups. Our results show associated variants in all scans. Inguinal hernia has the most associations and we conduct a follow-up study with 23,803 additional cases from four study groups giving 84 independently associated variants. Identified variants from all scans are collapsed into 81 independent loci. Further testing shows that 26 loci are associated with more than one hernia type, suggesting substantial overlap between the underlying genetic mechanisms. Pathway analyses identify several genes with a strong link to collagen and/or elastin (ADAMTS6, ADAMTS16, ADAMTSL3, LOX, ELN) in the vicinity of associated loci for inguinal hernia, which substantiates an essential role of connective tissue morphology.

Inguinal Hernia in Nonhuman Primates: From Asymptomatic to Life-Threatening Events

In this study, a review of available data and literature on the epidemiology and anamnesis of inguinal hernias in nonhuman primates, as well as on their clinical evaluation and surgical management, was conducted. Inguinal hernias are assumed to be relatively common in male nonhuman primates. Clinical signs are usually limited to a visible or palpable mass in the groin region without pain or systemic illness. Most hernias contain omentum. Careful monitoring is an acceptable treatment option for those animals. Size, the danger of incarceration, and the presence of strangulation are important factors when considering surgical repair. A strangulated inguinal hernia is an emergency, requiring prompt surgery to avoid tissue necrosis and death. Imaging techniques, as well as computed tomography (CT), ultrasonography, and magnetic resonance imaging (MRI), provide information about the anatomical characteristics of the suspected region, allowing for a diagnosis and treatment. An inguinal hernia repair can be performed with either open surgery or laparoscopic surgery. The hernia repair can be achieved by mesh or suture. Decisions regarding which repair technique to use depend on the surgeon′s skill level and preference. Complication and recurrence rates are generally low. The most common postsurgical complication is a recurrence of the hernia. Contraceptive measures are not indicated in breeders, as there is no known hereditary component, and the presence of hernia does not appear to affect fertility, nor does it predispose to occurrence, recurrence, or incarceration.

Ancestry- and sex-specific effects underlying inguinal hernia susceptibility identified in a multiethnic genome-wide association study meta-analysis

Inguinal hernias are some of the most frequently diagnosed conditions in clinical practice and inguinal hernia repair is the most common procedure performed by general surgeons. Studies of inguinal hernias in non-European populations are lacking, though it is expected that such studies could identify novel loci. Further, the cumulative lifetime incidence of inguinal hernia is nine times greater in men than women, however, it is not clear why this difference exists. We conducted a genome-wide association meta-analysis of inguinal hernia risk across 513 120 individuals (35 774 cases and 477 346 controls) of Hispanic/Latino, African, Asian and European descent, with replication in 728 418 participants (33 491 cases and 694 927 controls) from the 23andMe, Inc dataset. We identified 63 genome-wide significant loci (P < 5 × 10⁻⁸), including 41 novel. Ancestry-specific analyses identified two loci (LYPLAL1-AS1/SLC30A10 and STXBP6-NOVA1) in African ancestry individuals. Sex-stratified analyses identified two loci (MYO1D and ZBTB7C) that are specific to women, and four (EBF2, EMX2/RAB11FIP2, VCL and FAM9A/FAM9B) that are specific to men. Functional experiments demonstrated that several of the associated regions (EFEMP1 and LYPLAL1-SLC30A10) function as enhancers and show differential activity between risk and reference alleles. Our study highlights the importance of large-scale genomic studies in ancestrally diverse populations for identifying ancestry-specific inguinal hernia susceptibility loci and provides novel biological insights into inguinal hernia etiology.

Summary of Utah Project on Exfoliation Syndrome (UPEXS): using a large database to identify systemic comorbidities

The purpose of the Utah Project on Exfoliation Syndrome (UPEXS) is to identify associations between exfoliation syndrome (XFS) and other diseases that share the commonality of abnormalities in elastin and Lysyl Oxidase-Like 1 gene regulation. The UPEXS is unique because it uses the Utah Population Database, which is linked to the Utah genealogy, that contains a compilation of large pedigrees of most families in the state of Utah that go back multiple generations (3 to ≥11). The health and medical records of these family members are linked to vital records and can be used effectively in studies focused on genetic disorders like XFS, where familial clustering of a disorder is a trend. There is increasing evidence that patients with XFS have a higher risk of certain systemic disorders that reflect the systemic tissue abnormalities of XFS. Epidemiological studies focused on patients with XFS have shown that there is an increased risk of these individuals developing other pathologies that have abnormalities in extracellular matrix metabolism and repair. UPEXS has focused on suspected comorbidities that involve abnormalities in elastin maintenance, a protein that plays a role in the makeup of the extracellular matrix. In this paper, the results from the analysis of chronic obstructive pulmonary disease, inguinal hernias, pelvic organ prolapse, obstructive sleep apnoea and atrial fibrillation are summarised along with the utility of using such a large dataset.

Umbilical hernia repair and recurrence: need for a clinical trial?

INTRODUCTION

Umbilical hernia repair, despite its perceived simplicity, is associated with recurrence between 2.7 and 27%, in mesh repair and non mesh repair respectively. Many factors are recognized contributors to recurrence however multiple defects in the linea alba, known to occur in up to 30% of patients, appear to have been overlooked by surgeons.

AIMS

This systematic review assessed reporting of second or multiple linea alba defects in patients undergoing umbilical hernia repair to establish if these anatomical variations could contribute to recurrence along with other potential factors.

METHODS

A systematic review of all published English language articles was undertaken using databases PubMed, Embase, Web of Science and Cochrane Library from January 2014 to 2019. The search terms 'Umbilical hernia' AND 'repair' AND 'recurrence' were used across all databases. Analysis was specified in advance to avoid selection bias, was registered with PROSPERO (154173) and adhered to PRISMA statement.

RESULTS

Six hundred and forty-six initial papers were refined to 10 following article review and grading. The presence of multiple linea alba defects as a contributor to recurrence was not reported in the literature. One paper mentioned the exclusion of six participants from their study due multiple defects. In all 11 factors were significantly associated with umbilical hernia recurrence. These included: large defect, primary closure without mesh, high BMI in 5/10 publications; smoking, diabetes mellitus, surgical site Infection (SSI) and concurrent hernia in 3/10. In addition, the type of mesh, advanced age, liver disease and non-closure of the defect were identified in individual papers.

CONCLUSION

This study identified many factors already known to contribute to umbilical hernia recurrence in adults, but the existence of multiple defects in the linea, despite it prevalence, has evaded investigators. Surgeons need to be consider documentation of this potential confounder which may contribute to recurrence.

The effect of surgery on the levels of matrix metalloproteinases in patients with inguinal hernia

Matrix metalloproteinases (MMPs) are associated with the alteration of extracellular matrix. The purpose of this study was to investigate how the levels of matrix metalloproteinases and their inhibitors - TIMPs are influenced by the presence of inguinal hernia as well as by its surgical treatment. The studied group consisted of 25 patients with inguinal hernia and 21 healthy controls for comparison. Two blood samples - before and after the treatment were collected from patients. Serum concentrations of MMPs and TIMPs were analysed by multiplex immunoassays. There was a difference in circulating levels of MMPs in patients before the surgery compared to healthy controls - the concentrations of MMP-2 and MMP-9 were significantly lower (p=0.026, p=0.018, respectively). After the surgery, the levels of MMPs, especially MMP-2 (p<0.0001), were significantly decreased in patients compared to the preoperative values, apart from MMP-9. On the contrary, MMP-9 showed significant increase after the surgery (p<0.0001). Circulation levels of TIMP-2 in patients were significantly decreased in comparison with controls (p=0.004), whereas levels of TIMP-1 were similar to controls. Both tested metalloproteinase inhibitors showed a significant decrease in detected levels (TIMP-1 p=0.0004; TIMP-2 p<0.0001) after the procedure compared to the preoperative values. The levels of MMPs, especially MMP-2 and MMP-9, and their inhibitors TIMP-1 and TIMP-2 are involved by the presence of inguinal hernia as well as are influenced by the surgery.

Identification of fifty-seven novel loci for abdominal wall hernia development and their biological and clinical implications: results from the UK Biobank

PURPOSE

Familial aggregation is known for both hernia development and recurrence. To date, only one genome-wide association study (GWAS) limited to inguinal hernia has been reported that identified four risk-associated loci. We aim to investigate polygenic architecture of abdominal wall hernia development and recurrence.

METHODS

A GWAS was performed in 367,394 subjects from the UK Biobank to investigate the polygenic architecture of abdominal wall hernia subtypes (inguinal, femoral, umbilical, ventral) and identify specific single nucleotide polymorphisms (SNPs) that are associated with their risk. Expression quantitative trait loci (eQTL) analysis was performed to identify genes whose expression levels are associated with these SNPs. A genetic risk score (GRS) was used to assess the cumulative effect of multiple independent risk-associated SNPs on hernia development and recurrence in independent subjects (n = 82,064).

RESULTS

Heritability (h²) was 0.12, 0.06, 0.16, and 0.07 for inguinal, femoral, umbilical, and ventral hernias, respectively. A high-level of genetic correlation (r_g) was found among these subtypes of hernia. We confirmed the aforementioned four loci and identified 57 novel loci (P < 5 × 10^-8), including 55, 3, 5, and 3 loci for inguinal, femoral, umbilical, and ventral hernias, respectively. Significantly different expression levels between risk/reference alleles of SNPs were found for 145 genes, including TGF-β2 and AIG1 for inguinal hernia risk and CALD1 for umbilical hernia risk. Finally, higher GRS deciles were significantly associated with increased risk for hernia development (P_trend = 3.33 × 10^-38) and recurrent hernia repair surgery (P_trend = 3.64 × 10^-14).

CONCLUSION

These novel results have potential biological and clinical implications for hernia management in high-risk patients.

Matrix Metalloproteinases (MMP-2) and Tissue Inhibitors of Metalloproteinases (TIMP-2) in Male Inguinal Hernia Patients at Different Ages

BACKGROUND

Collagen metabolism, controlled by matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs), might be related to inguinal hernia formation. It was reported that the incidence of inguinal hernia and the recurrence rate after inguinal hernia repair were higher in the elderly. The objective of the research was to assess the amounts of MMP-2 and TIMP-2 in patients at different ages in order to examine the relationship between age and inguinal hernia occurrence.

METHODS

The research included 40 primary inguinal hernia male patients, and four groups were created: 50-59 years old (A group); 60-69 years old (B group); 70-79 years old (C group); 80-89 years old (D group). We got the samples from anterior rectus sheath fascia. Real-time fluorescence quantitative polymerase chain reaction (RT-PCR) and immunohistochemistry were applied to estimate the levels of MMP-2 and TIMP-2.

RESULTS

The MMP-2 amounts in C and D group were statistically higher than control group (P < 0.05), and the TIMP-2 levels in C and D group were statistically lower than control group (P < 0.05). We found a positive correlation between age and expression levels of MMP-2 (r = 0.537, P < 0.001; r = 0.569, P < 0.001) and a negative correlation between age and TIMP-2 in inguinal hernia patients (r = - 0.759, P < 0.001; r = - 0.759, P < 0.001).

CONCLUSIONS

Increased MMP-2 and reduced TIMP-2 may have some relationships with higher inguinal hernia incidence of the elderly.

Matrix Metalloproteinases (MMP-2) and Tissue Inhibitors of Metalloproteinases (TIMP-2) in Patients with Inguinal Hernias

BACKGROUND

The development of inguinal hernia might be related with collagen metabolism, which was regulated by matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs). The aim of this study was to evaluate the mRNA and protein expression levels of MMP-2 and TIMP-2 in anterior rectus sheath fascia to investigate the function of them in inguinal hernia formation.

METHODS

The study enrolled 48 primary inguinal hernia patients: 32 participants had indirect inguinal hernia and 16 patients suffered direct inguinal hernia. Specimens were taken from the anterior rectus sheath fascia. The amounts of MMP-2 mRNA and TIMP-2 mRNA were evaluated by real-time fluorescence quantitative polymerase chain reaction (RT-PCR), and immunohistochemistry was performed to assess the protein expression of them.

RESULTS

The mRNA and protein expression levels of MMP-2 in direct group were significantly higher than those of control group (P < 0.05) and indirect group (P < 0.05), while the expression levels of TIMP-2 in direct group were significantly lower than those of control group (P < 0.05) and indirect group (P < 0.05). The ratio of MMP-2 mRNA/TIMP-2 mRNA in direct group was significantly higher than that of control group (P < 0.05) and indirect group (P < 0.05), and the ratio of indirect group was significantly higher than that of control group (P < 0.05). According to receiver operating characteristic (ROC) curve, MMP-2/TIMP-2 can diagnose direct hernia from controls with area under the curve (AUC) of 0.950 and indirect hernia with AUC of 0.730 effectively.

CONCLUSIONS

Elevated level of MMP-2 and decreased level of TIMP-2 may play a role in direct inguinal hernia development. The ratio of MMP-2/TIMP-2 may be useful in identification of direct hernia.

Hernia incidence following a randomized clinical trial of single-incision versus multi-port laparoscopic colectomy

BACKGROUND

The short-term results of single-incision laparoscopic colectomy (SILC) showed the safety, feasibility, and effectiveness when performed by skilled laparoscopic surgeons. However, the long-term complications, such as SILC-associated incisional hernia, have not been evaluated. The aim of this study was to determine the incidence of incisional hernia after SILC compared with multi-port laparoscopic colectomy (MPC) for colon cancer.

METHODS

From March 2012, to March 2015, a total of 200 patients were enrolled in this study. The patients were randomized to the MPC arm and SILC arm. A total of 200 patients (MPC arm; 100 patients, SILC arm; 100 patients) were therefore analyzed. In all cases the specimen was extracted through the umbilical port, which was extended according to the size of the specimen. A diagnosis of incisional hernia was made either based on a physical examination or computed tomography.

RESULTS

The baseline factors were well balanced between the arms. The median follow-up period was 42.4 (range 9.4-70.0) months. Twenty-one patients were diagnosed with incisional hernia, giving an incidence rate of 12.1% in the MPC arm and 9.0% in the SILC arm at 36 months (P = 0.451). In the multivariate analysis, the body mass index (≥ 25 kg/m²) (hazard ratio [HR] 3.03; 95% confidence interval [CI] 1.03-8.92; P = 0.044), umbilical incision (≥ 5.0 cm) (HR 3.22; 95% CI 1.16-8.93; P = 0.025), and history of umbilical hernia (HR 3.16; 95% CI 1.02-9.77; P = 0.045) were shown to be correlated with incisional hernia.

CONCLUSIONS

We found no significant difference in the incidence of incisional hernia after SILC arm versus MPC arm with a long-term follow-up. However, this result may be biased because all specimens were harvested through the umbilical port. The study was registered with the Japanese Clinical Trials Registry as UMIN000007220.

A network analysis revealed the essential and common downstream proteins related to inguinal hernia

Although more than 1 in 4 men develop symptomatic inguinal hernia during their lifetime, the molecular mechanism behind inguinal hernia remains unknown. Here, we explored the protein-protein interaction network built on known inguinal hernia-causative genes to identify essential and common downstream proteins for inguinal hernia formation. We discovered that PIK3R1, PTPN11, TGFBR1, CDC42, SOS1, and KRAS were the most essential inguinal hernia-causative proteins and UBC, GRB2, CTNNB1, HSP90AA1, CBL, PLCG1, and CRK were listed as the most commonly-involved downstream proteins. In addition, the transmembrane receptor protein tyrosine kinase signaling pathway was the most frequently found inguinal hernia-related pathway. Our in silico approach was able to uncover a novel molecular mechanism underlying inguinal hernia formation by identifying inguinal hernia-related essential proteins and potential common downstream proteins of inguinal hernia-causative proteins.

Association of Exfoliation Syndrome With Risk of Indirect Inguinal Hernia: The Utah Project on Exfoliation Syndrome

Importance

Exfoliation syndrome (XFS) is a systemic connective tissue disease, and abnormal connective tissue metabolism is implicated in inguinal hernias (IH). Associating XFS with comorbid conditions may illuminate their underlying pathophysiology and affect clinical screening and treatment. Exfoliation syndrome involves altered systemic extracellular matrix (ECM) homeostasis involving elastin metabolism. Hernias occur owing to abnormal ECM synthesis, metabolism, or repair. Inguinal hernias involve weakening or rupture of the abdominal/groin wall.

Objective

To determine an association between patients with XFS and patients with IH in Utah, possibly differing between direct or indirect hernia.

Design, Setting, and Participants

Cross-sectional study in a large health care system of Utah hospitals and clinics. Conditional logistic regression odds ratios were used to estimate risk of XFS in patients with IH overall and by subtype (direct or indirect) compared with control individuals. Codes specific to direct and indirect IH with additional medical records review of 186 procedures were used to classify IH subtypes that were not prespecified. Bootstrap resampling with jackknife estimation used to calculate 95% confidence intervals. The model accounted for matching on sex and age and adjusted for body mass index and tobacco use. Population-based sample using medical records from 1996 to 2015 that identified 2594 patients 40 years or older on January 1, 1996, with surgical IH repair and 12 966 random control patients with no IH history matched 5:1 on sex and birth year. Data were analyzed between September 10, 2017, and October 23, 2017.

Main Outcomes and Measures

Exfoliation syndrome outcome defined by diagnosis codes for XFS or exfoliation glaucoma from 1996 to 2015.

Results

Participants were primarily white (2532 of 2594 patients, [96.1%]; 12 454 of 12 966 control individuals [97.6%]) and non-Hispanic (2396 of 2594 patients [92.4%]); 250 participants were women (9.6%). Of study participants, 22 patients with IH and 43 control individuals were diagnosed as having XFS, respectively. Patients with IH had a 2.3-fold risk for an XFS diagnosis compared with control individuals (95% CI, 1.4-3.5; P = .03), and XFS risk with indirect IH appeared especially pronounced.

Conclusions and Relevance

Inguinal hernia was associated with an increased risk of XFS in this Utah population. Further work is needed to understand the pathophysiology, genetics, and environmental factors contributing to both diseases.

Hernia and Cancer: The Points Where the Roads Intersect

Introduction: This review aimed to present common points, intersections, and potential interactions or mutual effects for hernia and cancer. Besides direct relationships, indirect connections, and possible involvements were searched. Materials and Methods: A literature search of PubMed database was performed in July 2018 as well as a search of relevant journals and reference lists. The total number of screened articles was 1,422. Some articles were found in multiple different searches. A last PubMed search was performed during manuscript writing in December 2018 to update the knowledge. Eventually 427 articles with full text were evaluated, and 264 included, in this review. Results: There is no real evidence for a possible common etiology for abdominal wall hernias and any cancer type. The two different diseases had been found to have some common points in the studies on genes, integrins, and biomarkers, however, to date no meaningful relationship has been identified between these points. There is also some, albeit rather conflicting, evidence for inguinal hernia being a possible risk factor for testicular cancer. Neoadjuvant or adjuvant therapeutic modalities like chemotherapy and radiotherapy may cause postoperative herniation with their adverse effects on tissue repair. Certain specific substances like bevacizumab may cause more serious complications and interfere with hernia repair. There are only two articles in PubMed directly related to the topic of "hernia and cancer." In one of these the authors claimed that there was no association between cancer development and hernia repair with mesh. The other article reported two cases of squamous-cell carcinoma developed secondary to longstanding mesh infections. Conclusion: As expected, the relationship between abdominal wall hernias and cancer is weak. Hernia repair with mesh does not cause cancer, there is only one case report on cancer development following a longstanding prosthetic material infections. However, there are some intersection points between these two disease groups which are worthy of research in the future.

Increased incidence of inguinal hernia in offspring of female survivors of childhood central nervous system tumors

Female survivors of childhood central nervous system (CNS) tumors experience an increased risk of infertility and various pregnancy complications. We aimed to explore whether the incidence of inguinal hernia could be higher in offspring of female CNS tumor survivors as compared to the general population. Girls who were younger than 15 years of age and diagnosed with CNS tumors between 1958 and 2013 were identified from the Swedish Cancer Registry. By linking with the Swedish Medical Birth Registry, we identified 580 children who were born to mothers of CNS tumor survivors. After 9,662 person-years of follow-up, 23 of them were diagnosed with inguinal hernia, giving an incidence rate (IR) of 2.4 per 1,000 person-years, whereas the IR was 1.2 for the matched controls. Cox regression analysis was used to calculate the hazard ratio (HR) of inguinal hernia. After adjusting for some confounding factors, the incidence of inguinal hernia was significantly increased with an HR of 1.92 (95%CI 1.08-3.41). The association was predominant in offspring whose mothers were diagnosed with CNS tumors at the age of 10 and older, and with CNS tumors located in the brain.

Etiology of Inguinal Hernias: A Comprehensive Review

Background

The etiology of inguinal hernias remains uncertain even though the lifetime risk of developing an inguinal hernia is 27% for men and 3% for women. The aim was to summarize the evidence on hernia etiology, with focus on differences between lateral and medial hernias.

Results

Lateral and medial hernias seem to have common as well as different etiologies. A patent processus vaginalis and increased cumulative mechanical exposure are risk factors for lateral hernias. Patients with medial hernias seem to have a more profoundly altered connective tissue architecture and homeostasis compared with patients with lateral hernias. However, connective tissue alteration may play a role in development of both subtypes. Inguinal hernias have a hereditary component with a complex inheritance pattern, and inguinal hernia susceptible genes have been identified that also are involved in connective tissue homeostasis.

Conclusion

The etiology of lateral and medial hernias are at least partly different, but the final explanations are still lacking on certain areas. Further investigations of inguinal hernia genes may explain the altered connective tissue observed in patients with inguinal hernias. The precise mechanisms why processus vaginalis fails to obliterate in certain patients should also be clarified. Not all patients with a patent processus vaginalis develop a lateral hernia, but increased intraabdominal pressure appears to be a contributing factor.

Discovery of novel plasma proteins as biomarkers for the development of incisional hernias after midline incision in patients with colorectal cancer: The ColoCare study

BACKGROUND

Ventral incisional hernia is the most common long-term complication after an abdominal operation. Among newly diagnosed colorectal cancer patients, we screened the preoperative plasma proteome to explore predictive markers for the development of an incisional hernia.

METHODS

We utilized preoperative plasma samples of 72 newly diagnosed colorectal cancer patients who underwent midline incision for tumor resection between 2010 and 2013. A total of 21 patients with incisional hernia occurrence were matched with 51 patients with at least 18 months follow-up without an incisional hernia by sex, age, and body mass index. To assess predictive markers of incisional hernia risk, we screened the plasma proteome for >2,000 distinct proteins using a well-validated antibody microarray test. Paired t tests were used to compare protein levels between cases and controls. A gene-set-enrichment analysis (Gene Ontology and Kyoto Encyclopedia of Genes and Genomes) was applied to test for differences in signaling pathways between the 2 groups.

RESULTS

The proteome screen identified 25 proteins that showed elevated or reduced plasma levels in the hernia group compared to the control group (nominal P values < .05). Several proteins were in pathways associated with wound healing (CCL21, SHBG, BRF2) or cell adhesion (PCDH15, CDH3, EPCAM).

CONCLUSION

Our study shows that there are multiple individual and groups of plasma proteins that could feasibly predict the personal hernia risk prior to undergoing an operation. Further investigations in larger, independent sample sets are warranted to replicate findings and validate clinical utility of potential biomarkers. After validation, such a biomarker could be incorporated into a multifactorial risk model to guide clinical decision-making.

Whole-exome sequencing identifies a potential TTN mutation in a multiplex family with inguinal hernia

Purpose

Inguinal hernia repair is one of the most common procedures in general surgery. Males are seven times more likely than females to develop a hernia and have a 27 % lifetime ‘risk’ of inguinal hernia repair. Several studies have demonstrated that a positive family history is an important risk factor for the development of primary inguinal hernia, which indicates that genetic factors may play important roles in the etiology of the disease. So far, the contribution of genetic factors and underlying mechanisms for inguinal hernia remain largely unknown. The aim of this study was to investigate a multiplex Estonian family with inguinal hernia across four generations.

Methods

The whole-exome sequencing was carried out in three affected family members and subsequent mutation screening using Sanger sequencing was performed in ten family members (six affected and four unaffected).

Results

Whole-exome sequencing in three affected family members revealed a heterozygous missense mutation c.88880A>C (p.Lys29627Thr; RefSeq NM_001256850.1) in the highly conserved myosin-binding A-band of the TTN gene. Sanger sequencing demonstrated that this mutation cosegregated with the disease in this family and was not present in ethnically matched control subjects.

Conclusion

We report that missense variant in the A-band of TTN is the strongest candidate mutation for autosomal-dominant inguinal hernia with incomplete penetrance.

Electronic supplementary material

The online version of this article (doi:10.1007/s10029-016-1491-9) contains supplementary material, which is available to authorized users.

Abdominal wall hernias-A local manifestation of systemically impaired quality of the extracellular matrix

BACKGROUND

Throughout life, inguinal hernia develops in approximately every fourth man, some of whom develop multiple hernias. If patients at risk of developing multiple hernias could be identified by a serologic biomarker, treatment might be able to be tailored and improved. Evidence suggests that abdominal wall hernia formation is associated with altered collagen metabolism. The aim of this study was to evaluate biomarkers for type IV and V collagen turnover in patients with multiple hernias and control subjects without hernia.

METHODS

Venous blood was collected from 88 men (mean age, 62 years) with a history of more than 3 hernia repairs and 86, age-matched men without hernias. Biomarkers for synthesis of collagen type IV (P4NP) and type V (P5CP) as well as breakdown (C4M and C5M) were measured in serum by validated, solid-phase, competitive assays. Collagen turnover was indicated by the ratio between the biomarker for synthesis and breakdown.

RESULTS

Type IV collagen turnover was 1.4-fold increased in patients with multiple hernias compared to control subjects (P < .001), whereas type V collagen turnover was 1.7-fold decreased (P < .001). Diagnostic power of P5CP was 0.83 (95%C.I.:0.77-0.89), P < .001.

CONCLUSION

Patients with multiple hernias exhibit increased turnover of type IV collagen and a decreased turnover of type V collagen, demonstrating systemically altered collagen turnover. Biomarkers for type V collagen turnover may be used to identify patients at risk for or with multiple hernias.

A genome-wide association study identifies four novel susceptibility loci underlying inguinal hernia

Inguinal hernia repair is one of the most commonly performed operations in the world, yet little is known about the genetic mechanisms that predispose individuals to develop inguinal hernias. We perform a genome-wide association analysis of surgically confirmed inguinal hernias in 72,805 subjects (5,295 cases and 67,510 controls) and confirm top associations in an independent cohort of 92,444 subjects with self-reported hernia repair surgeries (9,701 cases and 82,743 controls). We identify four novel inguinal hernia susceptibility loci in the regions of EFEMP1, WT1, EBF2 and ADAMTS6. Moreover, we observe expression of all four genes in mouse connective tissue and network analyses show an important role for two of these genes (EFEMP1 and WT1) in connective tissue maintenance/homoeostasis. Our findings provide insight into the aetiology of hernia development and highlight genetic pathways for studies of hernia development and its treatment.

Inguinal hernia has high lifetime prevalence, especially in men. This genome-wide association study identifies 4 loci to be associated with inguinal hernia, and shows expression of nearby genes in mouse connective tissues.

Risk Factors for the Development of an Incisional Hernia after Sigmoid Resection for Diverticulitis: An Analysis of 33 Patient, Operative and Disease-associated Factors

Incisional hernia (IH) is a relatively common sequelae of sigmoidectomy for diverticulitis. The aim of this study was to investigate factors that may predict IH in diverticulitis patients. Two hundred and one diverticulitis patients undergoing sigmoidectomy between January 2002 and December 2012 were identified (mean follow-up 5.15 ± 2.33 years). Patients with wound infections were excluded. Thirteen patient-associated, three diverticular disease-related, and 17 operative variables were evaluated in patients with and without IH. Volumetric fat was measured on pre-operative CTs. Fischer's exact, χ2, and Mann–Whitney tests and multivariate regression analysis were used for statistics. Thirty-four (17%) patients had an IH. On multivariate analysis, wound packing (OR 3.4, P = 0.017), postoperative nonwound infection (OR 7.4, P = 0.014), and previous hernia (OR 3.6, P = 0.005) were as independent predictors of IH. Fifteen of 34 (44%) patients who developed a hernia had a history of prior hernia. Of 33 potential risk factors analyzed, including smoking, chronic obstructive pulmonary disease, and obesity, the only patient factor present preoperatively associated with increased risk of a postsigmoidectomy hernia after multivariate analysis was a history of a previous hernia. Preoperative identification of patients with a history of hernia offers the opportunity to employ measures to decrease the likelihood of IH.

Incisional hernia repair after caesarean section: a population-based study

BACKGROUND

Incisional hernias occur at surgical abdominal incision sites, but the association with caesarean section (CS) has not been examined.

AIM

To determine whether CS is a risk factor for incisional hernia repair.

MATERIALS AND METHODS

Population-based cohort study in Australia using linked birth and hospital data for women who gave birth from 2000 to 2011. Survival analysis was used to explore the association between CS and subsequent incisional hernia repair. Analyses were adjusted for confounding factors, including other abdominal surgery. The main outcome measure was surgical repair of an incisional hernia.

RESULTS

Of 642,578 women, 217,555 (33.9%) had at least one CS and 1,554 (0.2%) women had a subsequent incisional hernia repair. The rate of incisional hernia repair in women who had ever had a caesarean section was 0.47%, compared to 0.12% in women who never had a caesarean section. After controlling for the duration of follow-up and known explanatory variables (eg other abdominal surgery, parity and multiple pregnancy), the adjusted hazard ratio (aHR) was 2.73 (95% confidence interval (CI) 2.45-3.06, P < 0.001). Incisional hernia repair risk increased with number of caesarean sections: women with two CS had a threefold increased risk of incisional hernia repair, which increased to sixfold after five CS (aHR = 6.29, 95% CI 3.99-9.93, P < 0.001) compared to women with no CS.

CONCLUSIONS

There was a strong association between maternal CS and subsequent incisional hernia repair, which increased as the number of CSs increased, but the absolute risk of incisional hernia repair was low.

[Recurrence after hernia surgery: complication or natural course?]

Recurrence after hernia surgery remains a relevant measure of surgical quality. In order to correctly assess the recurrence rate the surgeon needs to distinguish clinical relevant recurrence, clinically irrelevant recurrence and pseudo-recurrence. Current surgical techniques for inguinal hernia repair using mesh are associated with a low rate of recurrence. Thus, recurrence after inguinal hernia surgery is seen as a surgical complication. Conversely, the recurrence rate for large incisional hernias remains above 10 % and in rare cases a recurrence might represent the natural course. Recurrent hernia can depend on the indication, choice of operation and surgical technique. Therefore, postoperative hernia recurrence probably does not represent the natural course but rather a surgical complication that needs to be prevented by an optimized surgical technique.