Background:

The aetiology and pathogenesis of abdominal wall hernia formation is complex. Optimal treatment of hernias depends on a full understanding of the pathophysiological mechanisms involved in their formation. The aim of this study was to review the literature on specific collagen alterations in abdominal wall hernia formation.



Methods:

A computer-assisted search of the medical databases PubMed and Embase was performed, together with a cross-reference search of eligible papers.



Results:

Fifty-two papers were included. Collagen alteration depended on the type of hernia; there were more pronounced changes in patients with a direct inguinal hernia than in those with an indirect inguinal hernia, recurrent inguinal hernia or incisional hernia. A consistent finding was a significant increase in immature type III collagen relative to the stronger type I collagen in patients with a hernia. This resulted in thinner collagen fibres with a correspondingly diminished biomechanical strength. It has been suggested that these alterations are due to variation in the synthesis, maturation or degradation of collagen by matrix metalloproteinases, in combination or alone.



Conclusion:

Hernia formation and recurrence is associated with altered collagen metabolism manifested by a decreased type I:III collagen ratio. Copyright © 2010 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.

Connective tissue alteration in abdominal wall hernia

Background
Umbilical and epigastric hernias are common in the adult population and prompt repair is advised. We aimed to evaluate the impact of concomitant rectus diastasis on the outcome of patients who underwent primary sutured fascia closure of a hernia without mesh.

Sutured Repair of Primary Small Umbilical and Epigastric Hernias: Concomitant Rectus Diastasis Is a Significant Risk Factor for Recurrence

AbstractBackground
Umbilical and epigastric hernias are common in the adult population and prompt repair is advised. We aimed to evaluate the impact of concomitant rectus diastasis on the outcome of patients who underwent primary sutured fascia closure of a hernia without mesh.MethodsWe performed a retrospective analysis of 231 consecutive adult patients who had undergone elective suture-based repair of small (<2 cm) and primary umbilical or epigastric hernias with respect to complications, recurrence, and chronic pain.ResultsPatients with rectus diastasis suffered from a significantly increased rate of hernia recurrence (29/93 vs. 9/108; p < 0.001). The use of absorbable sutures also had a negative influence on the recurrence rate (26/90 vs. 12/111; p = 0.001). Obesity (body mass index > 35 kg/m2) was associated with more complications (p = 0.02). Wound infections following hernia repair also were associated with a higher rate of recurrence (p = 0.08) and chronic pain (p = 0.02). The mean follow-up via a structured questionnaire was 31 months (range 3–59) and data were available for 201 of 231 patients (87 %).ConclusionWe strongly recommend preoperatively checking for rectus diastasis and using nonabsorbable sutures as an alternative to mesh repair only when repairing small umbilical or epigastric hernias (<2 cm) and there is no concomitant rectus diastasis. Patients with coexistent rectus diastasis definitely benefit from mesh-based repair of the midline to decrease the recurrence rate.

Sutured repair of Primary small umbilical and epigastric hernias: Concomitant rectus diastasis is a significant risk factor

Background High BMI is often used as a proxy for obesity and has been considered a risk factor for the development of an incisional hernia after abdominal surgery. However, BMI does not accurately reflect fat distribution. Objective The purpose of this work was to investigate the relationship among different obesity measurements and the risk of incisional hernia. Design This was a retrospective cohort study. Settings The study included a single academic institution in New York from 2003 to 2010. Patients The study consists of 193 patients who underwent colorectal cancer resection. Main outcome measures Preoperative CT scans were used to measure visceral fat volume, subcutaneous fat volume, total fat volume, and waist circumference. A diagnosis of incisional hernia was made either through physical examination in medical chart documentation or CT scan. Results Forty-one patients (21.2%) developed an incisional hernia. The median time to hernia was 12.4 months. After adjusting for patient and surgical characteristics using Cox regression analysis, visceral obesity (HR 2.04, 95% CI 1.07-3.91) and history of an inguinal hernia (HR 2.40, 95% CI 1.09-5.25) were significant risk factors for incisional hernia. Laparoscopic resection using a transverse extraction site led to a >75% reduction in the risk of incisional hernia (HR 0.23, 95% CI 0.07-0.76). BMI > 30 kg/m was not significantly associated with incisional hernia development. Limitations Limitations include the retrospective design without standardized follow-up to detect hernias and the small sample size attributed to inadequate or unavailable CT scans. Conclusions Visceral obesity, history of inguinal hernia, and location of specimen extraction site are significantly associated with the development of an incisional hernia, whereas BMI is poorly associated with hernia development. These findings suggest that a lateral transverse location is the incision site of choice and that new strategies, such as prophylactic mesh placement, should be considered in viscerally obese patients.

Visceral obesity, not elevated BMI, is strongly associated with incisional hernia after colorectal surgery.

Background The aim of this study was to analyze the constituents of total and types I and III collagen fibers in the transversalis fascias of patients with indirect inguinal hernias, compared with samples removed from nonherniated cadavers. Methods Biopsy samples from 26 patients and 26 cadavers were analyzed. Hematoxylin-eosin and picrosirius staining techniques were used. The images obtained were analyzed using a video morphometric technique to determine the constituents of total collagen and types I and III collagen in the transversalis fascia. The picrosirius-stained tissues were submitted to observation under polarized-light microscopy. Results The results showed 17.3% less total collagen in patients with hernias compared with the control group ( P P P Conclusion The lower percentages of total collagen and type I collagen in the transversalis fascias of patients with indirect inguinal hernias could be a factor in hernia formation.

Collagen in the transversalis fascia of patients with indirect inguinal hernia: a case-control study.

The purpose of this study was to evaluate the amount of total and types I and III collagens of samples from the linea alba in patients with hernias (epigastric, umbilical, and incisional) on the anterior wall of the abdomen, comparing them to findings obtained from a cadaver control group without hernias. Samples of the linea alba aponeurosis from 26 patients with hernias on the anterior abdominal wall and from 32 cadavers without hernias were analyzed and compared for qualitative and quantitative evaluation of the total and the types I and III collagens. Sirius-red staining was used to evaluate the total collagen, and for types I and III collagens, immunohistochemistry was used with monoclonal antibody anticollagen types I and III, respectively. The amount of total collagen was 18.05% smaller in patients with hernias than in cadavers (p<0.05). Type I collagen was 20.50% smaller in patients than in cadavers (p<0.05). There was no significant difference in the amount of type III collagen between cases and controls (p=0.383). The results of this study indicate a relationship between hernias of the anterior abdominal wall and smaller amounts of total and type I collagens.

Aldo Fachinelli

Papers

Qualitative and quantitative evaluation of total and types I and III collagens in patients with ventral hernias