Are collagens the culprits in the development of incisional and inguinal hernia disease?

[Physical Strain after Abdominal Surgery - Results of a Patient Survey]

INTRODUCTION

Incision hernias are common complications after abdominal surgery and affect the recommendations on postoperative physical strain, as it is thought that excessively early strain causes incisional hernias. However, there is no evidence to justify this. This study evaluates the effect of postoperative strain on the risk of incisional hernia.

MATERIALS AND METHODS

Patients with a laparoscopy (LS) or laparotomy (LT) were asked to complete a questionnaire on postoperative strain, complaints and quality of life. Patients with hernia surgery, or open abdomen therapy for complicated courses (Clavien-Dindo > III) were excluded.

RESULTS

393 patients completed the questionnaire (43.6%). 274 were LS and 128 LT. The incidence of incisional hernias was 5.2% (LS) and 18.0% (LT, p = 0.001). Incisional hernia patients were younger and more commonly males. 30.5% of incisional hernia patients did not return to normal physical strain postoperatively. Abdominal binders did not affect the hernia rate. The incisional hernia patients showed decreased quality of life scores in both mental and physical domains.

CONCLUSION

Early postoperative physical strain was not a risk factor for incisional hernia development in this study. However, prospective studies are needed to create necessary evidence to recommend earlier postoperative return to normal physical strain.

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.

Recommendations on postoperative strain and physical labor after abdominal and hernia surgery: an expert survey of attendants of the 41st EHS Annual International Congress of the European Hernia Society

BACKGROUND

There are no valid recommendations or reliable guidelines available to guide patients how long they should refrain from lifting weights or returning to heavy physical labor after abdominal or hernia surgery. Recent studies found that surgeons' recommendations not to be evidence-based and might be too restrictive considering data on fascial healing and incisional hernia development. It is likely that this impairs the patient's quality of life and leads to remarkable socio-economic costs. Hence, we conducted this survey to gather international expert's opinions on this topic.

MATERIALS AND METHODS

At the 41st Annual International Congress of the EHS, attending international experts were asked to complete a questionnaire concerning recommendations on given proposals for postoperative refrain from heavy work or lifting after abdominal surgery and also after hernia repairs.

RESULTS

In total, 127 experts took part in the survey. 83.9% were consultants with a mean experience since specialization of more than 11 years. Two weeks of no heavy physical strain after laparoscopic surgery were considered sufficient by more than 50% of the participants. For laparotomy, more than 50% rated 4 weeks appropriate. For mesh-augmented sublay and IPOM repair of ventral or incisional hernias, more than 50% rated 4 weeks of rest appropriate. For complex hernia repair, 37% rated 4 weeks reasonable. Two weeks after, groin hernia surgery was considered sufficient by more than 50% of the participants.

CONCLUSION

Following groin hernia repair (Lichtenstein/endoscopic technique) and laparoscopic operation, the majority agreed on the proposal of 2 weeks refraining from physical strain. Four weeks of no physical strain were considered appropriate by a majority after laparotomy and open incisional hernia repair. However, the results showed substantial variation in the ratings, which indicates uncertainty even in this selected cohort of hernia surgery experts and emphasizes the need for further scientific evaluation. This is particularly remarkable, because a lack of evidence that early postoperative strain leads to higher incisional hernia rates.

TRIAL REGISTRATION

Number DRKS00023887.

Recommendations on Postoperative Activities After Abdominal Operations and Incisional Hernia Repair-A National and International Survey

Background: There is no conclusive data on postoperative recommendations after abdominal and hernia surgery, and there is significant variation in the literature on that question. Thus, this study evaluates the status quo of recommendations of postoperative activity restriction after abdominal surgery. Materials and Methods: A national (German) and international survey of general surgeons on postoperative recommendations after abdominal and hernia surgery was pooled and analyzed. Results: A total of 74.6% recommended postoperative reduced activity for 2 weeks or less after laparoscopy. For midline laparotomy, 48.8% considered a reduced activity of 4 weeks or less to be sufficient. A majority from the national survey recommended more than 4 weeks instead (60.2%), whereas only 31.5% from the international survey did so (p = 0.000). In the pooled analysis, 258 of 450 (57.3%) rated 4 weeks or less suitable. However, the recommendations differed significantly between the surveys (4 weeks or less: a national survey, 47.1% vs. international survey, 64.6%; p = 0.000). Conclusion: There was substantial variation in the given recommendations. However, we found no evidence against immediate mobilization, reduced physical activity, and lifting for up to 2 weeks after laparoscopic surgery and for up to 4 weeks after open abdominal surgery and open incisional/ventral hernia repair in uncomplicated and standard cases. There might be individual and socioeconomic benefits to allow patients to return to their whole personal level of activity and work without putting them at risk of complications. Due to lack of evidence, both retrospective and prospective, controlled studies are in need to develop reliable recommendations.

Enhanced Skin Incisional Wound Healing With Intracellular ATP Delivery via Macrophage Proliferation and Direct Collagen Production

This study sought to use a newly developed intracellular ATP delivery to enhance incisional wound healing to reduce surgical wound dehiscence and to explore possible mechanism for this effect. Thirty-five adult New Zealand white rabbits were used. Skin incisions were made on the back and closed. ATP-vesicles were mixed with a neutral cream for one side of the wounds while the neutral cream alone was used on the other side of the wounds. Laser speckle contrast imaging (LSCI), biomechanical, histological, and immunohistochemical analyses were performed 7 and 14 days after surgery, and macrophage culture was used to test the enhanced collagen production ability. Among them, 10 were used for wound perfusion study and 25 were used for wound biomechanical and histological/immunohistochemical studies. Wound tissue perfusion was reduced after surgery especially in early days. Wound tissue tensile strength, breaking stress, and elasticity were all much higher in the ATP-vesicle treated group than in the cream treated group at days 7 and 14. The healing was complemented by earlier macrophage accumulation, in situ proliferation, followed by direct collagen production. The results were further confirmed by human macrophage culture. It was concluded that intracellular ATP delivery enhanced healing strength of incisional wounds via multiple mechanisms.

A Dedicated Lightweight Titanized Mesh Prevents Incisional Hernias After Open Abdominal Aortic Aneurysm (AAA) Repair: Results of an Initial Prospective Cohort Study

Background

Incisional hernia (IH) is a common, late complication of open repair of an abdominal aortic aneurysm (AAA), with a variable high incidence. A cohort study was conducted to investigate the role of a lightweight titanized mesh placed in the pre-peritoneal space after AAA repair. The primary endpoint was to determine the incidence of IH at eight weeks and 12 months.

Methods

Consecutive patients who underwent open repair of AAA with the prophylactic implantation of a mesh after abdominal wall closure were recruited. The development of IH was evaluated using clinical examination, ultrasonography scan (USS), and computed tomography (CT) scan during the follow-up period.

Results

Thirty-nine of 45 patients (34 male, 5 female, mean age 69.6 +/- 6.5 years) undergoing open repair of AAA over a five-year period via a preferred roof-top incision were analyzed for this study. One additional (2.5%) patient had the mesh explanted following a re-laparotomy for colonic ischemia and later developed an incisional hernia. There was no incidence of wound or mesh infection overall. One radiologically detected early IH closed spontaneously. There were five (12.8%) radiologically detected late cases of midline or paramedian defects beyond the one-year follow-up though this was not clinically significant; compared to this, there was no incidence of lateral defects in the wound (p<0.01, McNemar’s test).

Conclusion

These preliminary results suggest that a dedicated lightweight titanized mesh is usable for primary reinforcement of rooftop incisions at the time of wound closure. Whilst this study supports the role of a mesh as a useful adjunct, larger studies and long-term follow-up would provide more sensitive assessments of its efficacy.

[Ventral hernias and extracellular matrix of connective tissue]

Ventral hernia is still one of the most common reason for scheduled and emergency surgery. The review is designed to reveal relationships between metabolism in extracellular matrix of connective tissue and pathogenesis of ventral hernias. These data will be valuable to develop a personalized approach to the treatment of these patients.

Incisional Hernia Following Open Abdominal Aortic Aneurysm Repair: A Contemporary Review of Risk Factors and Prevention

While the endovascular approach has been the treatment of choice for abdominal aortic aneurysm (AAA) repair in the modern era, open AAA repair remains a treatment option and may have a resurgence after the recent release of draft guidelines from the National Institute for Health and Care Excellence (NICE). Incisional hernia is a common long-term complication of open AAA repair and causes significant patient morbidity. As the number of patients undergoing open AAA repair increases, it is imperative that vascular surgeons are aware of and aim to reduce the complications associated with open surgery. This article summarises current evidence, highlighting the risk factors for incisional hernia and the modern surgical techniques that can prevent complications.

Correlation of Baseline Plasma and Inguinal Connective Tissue Metalloproteinases and Their Inhibitors With Late High-Pressure Endoleak After Endovascular Aneurysm Repair: Long-term Results

Purpose: To investigate whether plasma and connective tissue matrix metalloproteinases (MMP) and their inhibitors (TIMP) may predict late high-pressure endoleak after endovascular aneurysm repair (EVAR). Materials and Methods: Samples of inguinal fascia and blood were collected in 72 consecutive patients (mean age 73.1 years; 68 men) undergoing primary EVAR with the Endurant stent-graft. Baseline plasma levels of MMP-2, MMP-9, TIMP-1, and TIMP-2 and baseline MMP-2 and MMP-9 activity estimated using gelatin zymography (GZ) were compared between patients who developed late endoleak in follow-up and those who did not. Subgroup analyses were performed between patients with (n=18) and without inguinal hernias and between patients with moderate-diameter (50–59 mm; n=45) or large-diameter (≥60 mm; n=27) abdominal aortic aneurysms (AAA) at primary EVAR. Results: The mean follow-up period was 63.1 months (range 7.5–91.5), during which time 13 (18.1%) patients developed type I (6 Ia and 5 Ib) or 2 type III endoleaks. Only GZ-analyzed proMMP-9 concentrations were higher in the endoleak group than in patients without endoleak (mean difference 8.44, 95% CI −19.653 to −1.087, p=0.03). The patients with primary inguinal hernia at presentation had significantly higher tissue TIMP-2 values (0.8±0.7 vs 0.5±0.4, p=0.018) but lower plasma total (pro- + active) MMP-9 values (11.9±7.8 vs 16.2±7.4, p=0.042) than patients without hernias at the time of EVAR. Patients with AAAs ≥60 mm had significantly higher mean tissue homogenate levels of total (pro- + active) MMP-9 (p=0.025) and total (pro- + active) MMP-2 (p=0.049) as well as higher proMMP-9 (p=0.018) and total (pro- + active) MMP-9 (p=0.021) levels based on GZ compared to patients with moderate-diameter AAAs. Regression analysis revealed a significant association between total (pro- + active) MMP-9 plasma samples and the presence of hernia (OR 0.899, 95% CI 0.817 to 0.989, p=0.029) and between GZ-analyzed proMMP-9 and late endoleak (OR 1.055, 95% CI 1.007 to 1.106, p=0.025). GZ-analyzed proMMP-9 and active MMP-9 were strong predictors of late endoleak in patients with hernia (p=0.012 and p=0.044, respectively) and in patients with AAAs ≥60 mm (p=0.018 and p=0.041 respectively). Conclusion: Inguinal fascial tissue proMMP-9 significantly predicted late endoleak. ProMMP-9 and active MMP-9 biomarkers are significantly associated with late endoleak in hernia patients and in patients with AAAs ≥60 mm. Considering the clinical association between hernia and AAA and the fact that the AAA wall connective tissue environment remains exposed to systemic circulation after EVAR, inguinal fascia extracellular matrix dysregulation and altered MMP activity may reflect similar changes in AAA biology, leading to complications such as endoleak.

Incidence of Ventral Hernia Repair after Open Abdominal Aortic Aneurysm and Open Aortofemoral or Aortoiliac Bypass Surgery: An Analysis of 17,594 Patients in the State of New York

The purpose of our study was to evaluate the rate of ventral hernia repair (VHR) after open abdominal aortic anneurysm in New York State compared with the rate of VHR after open abdominal aortic bypass procedures. The Statewide Planning and Research Cooperative System database was queried for all abdominal aortic aneurysm (AAA) and bypass procedures performed between 2000 and 2010. Social security death index was used to identify patients who died. The cause-specific Cox proportional hazard model was applied to compare the risk of having follow-up VHR between patients with AAA and bypass with death as a competing risk event. A multivariable model was used to explore independent relationship with the risk of having follow-up ventral hernia after adjusting for other factors. There were 9314 patients who underwent open AAA repair, 739 (7.93%) of which had subsequent VHR. Comparatively, 8280 patients underwent aortofemoral or aortoiliac bypass procedures, with 480 (5.8%) undergoing subsequent VHR. The observed one-year, five-year, and 10-year VHR rates for AAA versus bypass were 2.8 versus 1.8 per cent, 10.0 versus 8.0 per cent, 10.7 versus 9.38 per cent, respectively. After controlling for all other factors, patients undergoing AAA repair were more likely and elderly patients were less likely to undergo VHR (P < 0.0001). Patients with serious comorbid conditions such as valvular disease, diabetes mellitus, and neurologic disorders were less likely to undergo subsequent VHR controlling for other factors. VHR after AAA procedures is more common compared with bypass procedures for occlusive disease. Because this patient population has significant comorbidity, prophylactic mesh placement may play a role in preventing necessity for future procedures.

Type V Collagen is Persistently Altered After Inguinal Hernia Repair

BACKGROUND AND AIMS

Hernia formation is associated with alterations of collagen metabolism. Collagen synthesis and degradation cause a systemic release of products, which are measurable in serum. Recently, we reported changes in type V and IV collagen metabolisms in patients with inguinal and incisional hernia. The aim of this study was to determine if the altered collagen metabolism was persistent after hernia repair.

MATERIAL AND METHODS

Patients who had undergone repairs for inguinal hernia (n = 11) or for incisional hernia (n = 17) were included in this study. Patients who had undergone elective cholecystectomy served as controls (n = 10). Whole venous blood was collected 35-55 months after operation. Biomarkers for type V collagen synthesis (Pro-C5) and degradation (C5M) and those for type IV collagen synthesis (P4NP) and degradation (C4M2) were measured by a solid-phase competitive assay.

RESULTS

The turnover of type V collagen (Pro-C5/C5M) was slightly higher postoperatively when compared to preoperatively in the inguinal hernia group (P = 0.034). In addition, the results revealed a postoperatively lower type V collagen turnover level in the inguinal hernia group compared to controls (P = 0.012). In the incisional hernia group, the type V collagen turnover was higher after hernia repair (P = 0.004) and the postoperative turnover level was not different from the control group (P = 0.973).

CONCLUSION

Patients with an inguinal hernia demonstrated a systemic and persistent type V collagen turnover alteration. This imbalance of the collagen metabolism may be involved in the development of inguinal hernias.

Effects of various stages of nephropathy on wound healing in patients with diabetes: an observational cohort study encompassing 731 diabetics

BACKGROUND AND OBJECTIVE

In diabetics genetic predisposition, poor glycemic control and arterial hypertension contribute to nephropathy development in patients affected by diabetes mellitus. We set up the hypothesis that diabetic nephropathy and incisional hernia formation may have in common alterations of collagen composition and tested whether the occurrence of diabetic nephropathy coincides with wound healing disturbance (incisional herniation) or connective tissue diseases (inguinal herniation, umbilical herniation, aortic aneurysm, varicose veins, disc herniation).

DESIGN

A questionnaire on surgical procedures, wound healing and connective tissue disorders was performed with 731 diabetics. Furthermore, test results for kidney function and damage (creatinine clearance, proteinuria) and blood sugar control (HbA1c) were recorded. Correlations between aforementioned connective tissue diseases and "advanced" diabetic nephropathy were calculated. "Advanced" diabetic nephropathy was assumed in patients with macroproteinuria, CKD stage 5 and/or end-stage renal disease. All diabetics with CKD stages 1 and 2 without proteinuria were included in the "control" group. A subgroup analysis on incisional hernia formation coinciding with diabetic nephropathy was performed in patients with previously performed abdominal surgery.

RESULTS

In patients with advanced nephropathy, some diseases with connective tissue alterations, such as inguinal herniation, aortic aneurysms and varicose veins, did not occur more frequently than in patients without nephropathy. In diabetics with nephropathy, umbilical herniation (3 vs. 8.2 %, p = 0.04) and disc herniation rates (5.7 vs. 16.1 %, p = 0.002) were significantly lower. Subgroup analysis of patients with previously performed abdominal surgery (n = 381) revealed significantly higher incisional herniation rates when "advanced" diabetic nephropathy was present (16 % compared to 5.7 % without nephropathy, p = 0.016).

CONCLUSION

Our findings support the hypothesis that incisional hernia formation and diabetic nephropathy are positively correlated. Conversely, umbilical and disc herniation pathomechanisms are distinct, as these negatively correlate with the presence of advanced diabetic nephropathy.

Early outcome of incisional hernia repair using polypropylene mesh: A preliminary report

Background:

The use of prosthetics for open repair of incisional hernia is very recent in our practice. We highlight our experience repairing incisional hernias with polypropylene mesh.

Patients and Methods:

Patients presenting with incisional hernia >5 cm in length or width received open polypropylene mesh repair and were followed for two years. Data obtained included age, sex, primary surgery causing the hernia, the length of the fascial defect and previous attempts at repair. Post-operative wound complications were recorded. The integrity of the scar and patient satisfaction or concerns with the repair was assessed at each visit.

Results:

Nineteen females with a mean age of 35 years (range 30-54) underwent repair; most arising from obstetric or gynaecological procedures. Sixteen (82.2%) had midline, 2 (10.5) transverse and 1 (5.3) Pfannenstiel scars. One patient had no previous repair (R0), 7 had undergone one repair (R1), 9 had undergone two repairs (R2) and 1 had three previous repairs (R3). The length of fascial defects ranged from 8 to 18 cm and seroma collection and stitch sinus were the common problems encountered. Two (10.5%) recurrences were recorded in two years.

Conclusion:

Open mesh repair of incisional hernia carries a low risk of infection and recurrence in two years.

Nationwide survey to evaluate medical utilization by patients with inguinal hernia and the risk of developing varicocele in Taiwan

BACKGROUND

The purpose of this study was to analyze age, geographical and seasonal variations in medical service utilization by patients with inguinal hernia in Taiwan, and the influence of herniorrhaphy on development of ipsilateral varicocele in male patients.

METHODS

Between 2001 and 2008, comprehensive data on the characteristics of medical service utilization by patients with inguinal hernia was evaluated via a retrospective nationwide population-based study. Data were obtained from the National Health Insurance Research Database in Taiwan. Parameters for comparison included newly diagnosed inguinal hernia cases, number of herniorrhaphies, and incidence rates every year, number of outpatient visits for inguinal hernia, and herniorrhaphy by age, season, and area of Taiwan.

RESULTS

There was an average of 1,466 newly diagnosed inguinal hernia cases and 871.9 herniorrhaphies performed per year per million population during the study period. The male ratio for both newly diagnosed inguinal hernia cases and number of herniorrhaphies increased significantly by age. The number of newly diagnosed inguinal hernia cases and outpatient visits for inguinal hernia was highest during summer, followed by spring, autumn, and winter, and in the north of Taiwan, followed by the center, south, and east. Additionally, the incidence of developing ipsilateral varicocele after herniorrhaphy was low in male patients.

CONCLUSION

The number of newly diagnosed inguinal hernia cases and outpatient visits for inguinal hernia is highest during summer and lowest in eastern Taiwan. In addition, the incidence of developing ipsilateral varicocele after herniorrhaphy is higher in patients aged 10-19 years.

Skin and diabetes mellitus: what do we know?

Diabetes mellitus (DM) is becoming increasingly prevalent worldwide. Although major complications of this condition involve kidney, retina and peripheral nerves, the skin of diabetic patients is also frequently injured. Hence, interest is mounting in the definition of the structural and molecular profile of non-complicated diabetic skin, i.e., before injuries occur. Most of the available knowledge in this area has been obtained relatively recently and, in part, derives from various diabetic animal models. These include both insulin-dependent and insulin-resistant models. Structural work in human diabetic skin has also been carried out by means of tissue samples or of non-invasive methods. Indications have indeed been found for molecular/structural changes in diabetic skin. However, the overall picture that emerges is heterogeneous, incomplete and often contradictory and many questions remain unanswered. This review aims to detail, as much as possible, the various pieces of current knowledge in a systematic and synoptic manner. This should aid the identification of areas in which key questions are still open and more research is needed. A comprehensive understanding of this field could help in determining molecular targets for the prevention and treatment of skin injuries in DM and markers for the monitoring of cutaneous and systemic aspects of the disease. Additionally, with the increasing development of non-invasive optics-based deep-tissue-imaging diagnostic technologies, precise knowledge of cutaneous texture and molecular structure becomes an important pre-requisite for the use of such methods in diabetic patients.

Association of collagen type I alpha 1 gene polymorphism with inguinal hernia

PURPOSE

A positive family history is an important risk factor for inguinal hernia development, suggesting a genetic trait for hernia disease. However, gene mutations responsible for abdominal wall hernia formation in humans have not yet been studied. We aimed to evaluate whether the functional Sp1 binding site polymorphism within intron 1 of the collagen type I, alpha 1 (COL1A1) gene was associated specifically with inguinal hernia disease.

METHODS

85 participants with surgically diagnosed inguinal hernia disease, and 82 physically active controls without any history of connective tissue disease and hernia were recruited for this case-control genetic association study. Polymerase chain reaction and restriction fragment length polymorphism and agarose gel electrophoresis techniques were used to detect these polymorphisms.

RESULTS

Significantly, more patients gave a positive family history for an inguinal hernia compared to healthy controls (OR 3.646, 95 % CI 1.375-9.670, P = 0.006). COL1A1 Sp1 SNP (rs 1800012) was identified. Results demostrated statistically significant deviation from HWE for cases (P = 0.007), but not for the controls (P = 0.276). Our results revealed an increased frequency of COL1A1 Sp1 Ss genotype in inguinal hernia patients (OR 3.593, 95 % CI 1.867-6.915, P = 0.000).

CONCLUSIONS

This results suggest that polymorphism of the COL1A1 Sp1 binding site is associated with an increased risk for developing inguinal hernias. So, rs 1800012 locus is a potential candidate region for susceptibility in molecular mechanism of inguinal hernia pathophysiology.

Direct and recurrent inguinal hernias are associated with ventral hernia repair: a database study

BACKGROUND

A systemically altered connective tissue metabolism has been demonstrated in patients with abdominal wall hernias. The most pronounced connective tissue changes are found in patients with direct or recurrent inguinal hernias as opposed to patients with indirect inguinal hernias. The aim of the present study was to assess whether direct or recurrent inguinal hernias are associated with an elevated rate of ventral hernia surgery.

METHODS

In the nationwide Danish Hernia Database, a cohort of 92,457 patients operated on for inguinal hernias was recorded from January 1998 until June 2010. Eight-hundred forty-three (0.91 %) of these patients underwent a ventral hernia operation between January 2007 and June 2010. A multivariate logistic regression analysis was applied to assess an association between inguinal and ventral hernia repair.

RESULTS

Direct (Odds Ratio [OR] = 1.28 [95 % CI, 1.08-1.51]) and recurrent (OR = 1.76, [95 % CI, 1.39-2.23]) inguinal hernias were significantly associated with ventral hernia repair after adjustment for age, gender, and surgical approach (open or laparoscopic).

CONCLUSIONS

Patients with direct and recurrent inguinal herniation are more prone to ventral hernia repair than patients with indirect inguinal herniation. This is the first study to show that herniogenesis is associated with type of inguinal hernia.

Comparative study of shrinkage, inflammatory response and fibroplasia in heavyweight and lightweight meshes

PURPOSE

In this manuscript, the authors describe an animal study comparing shrinkage, inflammatory response and fibroplasia in heavyweight (HW-PP) and lightweight polypropylene (LW-PP) meshes.

METHODS

Both meshes were fixed on abdominal fascia of 25 Wistar rats (epifascial onlay placement). They were killed at 7, 28 and 90 days to measure the prostheses. Histological analysis was performed with hematoxylin-eosin for cellular counting and immunohistochemistry to measure collagen types I and III.

RESULTS

The authors found that the LW-PP mesh presented greater median shrinkage than HW-PP mesh at 7 (P = .036), 28 (P = .674) and 90 days (P = .038) postoperatively. There were more neutrophils on LW-PP mesh (P = .008) at 7 days, gradually diminishing in both prostheses. Lymphocytes were similar between the implants at 7 days, diminishing about 50 % on LW-PP mesh (P < .001) at 90 days. Macrophages and giant cells diminished on LW-PP and increased on HW-PP meshes (P < .001). Collagen I/III ratio presented a progressive, almost fivefold rise at 90 days, on both mesh types (P < .001). The collagen I/III ratio was similar between LW-PP and HW-PP meshes at the three times studied.

CONCLUSIONS

It is concluded that LW-PP showed more shrinkage than HW-PP mesh at 7 and 90 days, despite the fact that HW-PP presented more lately foreign body reaction. The collagen I/III ratio was similar between the prostheses and increased during the postimplant period.

Mesh size in Lichtenstein repair: a systematic review and meta-analysis to determine the importance of mesh size

PURPOSE

Small mesh size has been recognized as one of the factors responsible for recurrence after Lichtenstein hernia repair due to insufficient coverage or mesh shrinkage. The Lichtenstein Hernia Institute recommends a 7 × 15 cm mesh that can be trimmed up to 2 cm from the lateral side. We performed a systematic review to determine surgeons' mesh size preference for the Lichtenstein hernia repair and made a meta-analysis to determine the effect of mesh size, mesh type, and length of follow-up time on recurrence.

METHODS

Two medical databases, PubMed and ISI Web of Science, were systematically searched using the key word "Lichtenstein repair." All full text papers were selected. Publications mentioning mesh size were brought for further analysis. A mesh surface area of 90 cm(2) was accepted as the threshold for defining the mesh as small or large. Also, a subgroup analysis for recurrence pooled proportion according to the mesh size, mesh type, and follow-up period was done.

RESULTS

In total, 514 papers were obtained. There were no prospective or retrospective clinical studies comparing mesh size and clinical outcome. A total of 141 papers were duplicated in both databases. As a result, 373 papers were obtained. The full text was available in over 95 % of papers. Only 41 (11.2 %) papers discussed mesh size. In 29 studies, a mesh larger than 90 cm(2) was used. The most frequently preferred commercial mesh size was 7.5 × 15 cm. No papers mentioned the size of the mesh after trimming. There was no information about the relationship between mesh size and patient BMI. The pooled proportion in recurrence for small meshes was 0.0019 (95 % confidence interval: 0.007-0.0036), favoring large meshes to decrease the chance of recurrence. Recurrence becomes more marked when follow-up period is longer than 1 year (p < 0.001). Heavy meshes also decreased recurrence (p = 0.015).

CONCLUSION

This systematic review demonstrates that the size of the mesh used in Lichtenstein hernia repair is rarely discussed in clinical studies. Papers that discuss mesh size appear to reflect a trend to comply with the latest recommendations to use larger mesh. Standard heavy meshes decrease the recurrence in hernia repair. Even though there is no evidence, it seems that large meshes decrease recurrence rates.

Muscle degeneration in inguinal hernia specimens

BACKGROUND

There are few articles in the literature reporting the histological changes of groin structures affected by inguinal hernia. A deeper knowledge of this matter could represent an important step forward in the identification of the causes of hernia protrusion. This study aimed to recognise the pathological modifications of muscular structures in autopsy specimens excised from tissues surrounding the hernia orifice.

METHODS

Inguinal hernia was identified in 30 autopsied cadavers, which presented different varieties of hernia, including indirect, direct and mixed. Tissue specimens were resected for histological study from structures of the inguinal area surrounding the hernia opening, following a standardised procedure. The histological examination was focussed on the detection of structural changes in the muscle tissues. The results were compared with biopsy specimens resected from corresponding sites of the inguinal region in a control group of 15 fresh cadavers without hernia.

RESULTS

Significant modification of the muscular arrangement of the inguinal area was recognized. Pathological alterations such as atrophy, hyaline and fibrotic degeneration, as well as fatty dystrophy of the myocytes were detected. These findings were observed consistently in the context of multistructural damage also involving vessels and nerves. In cadavers with hernia these alterations were always present independent of hernia type. No comparable damage was found in control cadavers without hernia.

CONCLUSIONS

The high degree of degenerative changes in the muscle fibres in the inguinal area involved in hernia protrusion described in this report seems to be consistent with chronic compressive damage. These alterations could embody one important factor among the multifactorial sources of hernia genesis. Conjectures concerning its impact on the physiology and biodynamics of the inguinal region are made. The relationship between the depicted degenerative injuries and the genesis of inguinal hernia is also a focus of discussion in this article.

Abdominal aortic aneurysm and abdominal wall hernia as manifestations of a connective tissue disorder

BACKGROUND

Abdominal aortic aneurysms (AAAs) and abdominal wall hernias represent chronic degenerative conditions. Both aortic aneurysms and inguinal hernias share common epidemiologic features, and several investigators have found an increased propensity for hernia development in patients treated for aortic aneurysms. Chronic inflammation and dysregulation in connective tissue metabolism constitute underlying biological processes, whereas genetic influences appear to be independently associated with both disease states. A literature review was conducted to identify all published evidence correlating aneurysms and hernias to a common pathology.

METHODS

PubMed/Medline was searched for studies investigating the clinical, biochemical, and genetic associations of AAAs and abdominal wall hernias. The literature was searched using the MeSH terms "aortic aneurysm, abdominal," "hernia, inguinal," "hernia, ventral," "collagen," "connective tissue," "matrix metalloproteinases," and "genetics" in all possible combinations. An evaluation, analysis, and critical overview of current clinical data and pathogenic mechanisms suggesting an association between aneurysms and hernias were undertaken.

RESULTS

Ample evidence lending support to the clinical correlation between AAAs and abdominal wall hernias exists. Pooled analysis demonstrated that patients undergoing aortic aneurysm repair through a midline abdominal incision have a 2.9-fold increased risk of developing a postoperative incisional hernia compared with patients treated for aortoiliac occlusive disease (odds ratio, 2.86; 95% confidence interval, 1.97-4.16; P < .00001), whereas the risk of inguinal hernia was 2.3 (odds ratio, 2.30; 95% confidence interval, 1.52-3.48; P < .0001). Emerging evidence has identified inguinal hernia as an independent risk factor for aneurysm development. Although mechanisms of extracellular matrix remodeling and the imbalance between connective tissue degrading enzymes and their inhibitors instigating inflammatory responses have separately been described for both disease states, comparative studies investigating these biological processes in aneurysm and hernia populations are scarce. A genetic predisposition has been documented in familial and observational segregation studies; however, the pertinent literature lacks sufficient supporting evidence for a common genetic basis for aneurysm and hernia.

CONCLUSIONS

Insufficient data are currently available to support a systemic connective tissue defect affecting the structural integrity of the aortic and abdominal wall. Future investigations may elucidate obscure aspects of aneurysm and hernia pathophysiology and create novel targets for pharmaceutical and gene strategies for disease prevention and treatment.

Damage to the vascular structures in inguinal hernia specimens

BACKGROUND

Few scientific reports to date describe the histological modification of structures outlining a hernia opening. This article is focused on the identification of the pathological changes in vascular structures in tissues excised from cadavers with inguinal hernia. A deeper comprehension of this topic could lead to essential improvements in the detection of hernia genesis.

MATERIALS AND METHODS

Different kinds of hernia, including indirect, direct and mixed, were identified in 30 autopsied subjects. Tissue samples were resected for histological study from abdominal wall structures close to the hernia opening. Histological examination focused on the detection of structural changes in arteries and veins. The results were compared with tissue specimens excised from equivalent sites of the inguinal area in a control group of 15 fresh cadavers without hernia.

RESULTS

Significant modification of vascular structures were identified in the tissue specimens examined. The veins demonstrated parietal fibrosis, perivascular edema and vascular dilation due to congestion and stasis. The arterial structures detected showed thickening of the media due to medial hyperplasia, ranging from luminal sub-occlusion to a manifest artery occlusion. These findings are present independent of hernia type in cadavers with inguinal hernia. These pathological changes were lacking in the control group of cadavers without hernia.

CONCLUSIONS

The notable changes in vascular structures described in the report could be the result of a steady compressive effect exerted by the abdominal viscera in the inguinal area. These pathological changes could represent one of the factors involved in the weakening of the inguinal region leading to hernia protrusion.

The value of copper and zinc levels in hernia formation

BACKGROUND

A defect in collagen metabolism is suspected to be one of the factors responsible for hernia formation. Lysyl oxidase is a copper-dependent enzyme in the process that provides for the structural integrity of collagen molecules, while zinc is essential for tissue maintenance.

MATERIALS AND METHODS

In a prospective fashion, copper and zinc levels were measured in plasma and tissue specimens obtained from indirect (n=23), direct (n=20) and incisional hernia patients (n=19) and from healthy controls (laparoscopic cholecystectomy patients, n=15) by enzymatic colorimetric analysis.

RESULTS

Groups were similar in age, comorbid diseases and body mass index. Whereas plasma levels of Cu and Zn in hernia and control patients were similar, and tissue levels were significantly lower in all hernia groups (especially the incisional hernia group) compared to controls (P<0·001). The incisional hernia group had significantly lower tissue copper levels than direct hernia patients and lower zinc levels than indirect hernia patients.

CONCLUSIONS

Patients with all types of hernia, especially those with incisional hernias, have significantly lower tissue copper and zinc levels than control patients, despite having similar plasma levels. This finding might reflect excessive consumption or dysfunction of lysyl oxidase as playing a role in the aetiology of hernias.

Connective tissue alteration in abdominal wall hernia

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.

Biocompatibility of prosthetic meshes in abdominal surgery

Surgical meshes today represent a group of implants mainly used for hernia repair. Modern hernia surgery is no longer imaginable without the application of these special biomaterials leading to millions of implantations each year worldwide. Because clinical trials are insufficient to evaluate the distinct effects of modified mesh materials in regard to tissue biocompatibility and functionality, a basic understanding of the physicochemical properties of mesh materials, as well as the underlying cause for hernia formation, is essential for a rational selection of the most appropriate device. The most important properties of meshes were found to be the type of filament, tensile strength, and experimental data, which indicate that particularly the mesh's porosity is of outstanding importance.

Site-specific prolapse surgery. II. Vaginal paravaginal repair augmented with either synthetic mesh or remodelling xenograft

INTRODUCTION AND HYPOTHESIS

This study aims to answer the question, "Does tissue augmentation improve the mechanical repair of displacement cystourethrocoele?"

METHODS

A retrospective cohort study comparing 108 bridging graft vaginal paravaginal repairs (89 tissue-inductive xenografts and 19 polypropylene mesh) to 59 native tissue historical controls was conducted. Main outcome measures were same-site prolapse recurrence and time to failure. Initial reliability was evaluated by chi-squared test, 10-year durability by Kaplan-Meier survival analysis and risk factors by Cox regression.

RESULTS

Late recurrence was 17.7% lower with augmentation (logrank test χ (2) = 8.4, p value = 0.0038 < 0.05, adjusted regression analysis χ (2) = 2.94; p value = 0.0866 <0.10), implicating collagen degeneration in repair failure.

CONCLUSIONS

Rebuilding the pubocervical septum, from arcus to arcus and pubic ramus to pericervical ring, satisfies the mechanical but not the metabolic hernia principles. Bridging grafts simplify technical repair (reducing prolapse persistence from 10.2% to 4.6%), and also rejuvenate adjacent connective tissue (reducing late recurrence from 22.6% to 4.9%).

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

BACKGROUND

The purpose of this study was to examine the biological environment of the esophageal hiatus through analysis of the collagen content within the gastrohepatic ligament (GHL), gastrophrenic ligament (GPL), and phrenoesophageal ligament (PEL) in patients with type I hiatal hernias (HH) and type III paraesophageal hernias (PEH).

METHODS

A control group (N=10) and patients with type I HH (N=10) and type III PEH (N=10) were included in the analysis. Specimens of the GHL, PEL, and GPL were collected intraoperatively. Slides stained with sirius red/fast green were created and ten photos at 400×magnification were taken of each specimen. Axiovision 4.7 (Zeiss) photo analysis software was employed for quantification of collagen I (red) and III (green) by calculating color area (μm2). Statistical significance (p<0.05) was determined using a one-way ANOVA and Fisher's LSD post-test.

RESULTS

Cross-polarization microscopy revealed that the collagen I content was similar in the three study groups for the GHL, greater in the type III PEH group and in the control group compared to the type I HH group for the PEL, and greater in the type III PEH group compared to control group for the GPL. Collagen III quantity was greater in the control group than in the type I HH group for each ligament, and greater in the GHL and PEL when compared to the type III PEH group. Type III PEH patients had greater collagen III quantity than did type I HH patients for each ligament. Collagen type I:III ratio of the GHL was greater in both hernia groups compared to the control group. Type III PEH patients contained a higher I:III ratio than both the control and type I HH groups with respect to the PEL. There was no difference in the ratio with evaluation of the GPL for the three groups.

CONCLUSION

Evaluation of the esophageal hiatus revealed that patients with PEH have a different biological environment with regard to collagen content compared to control patients. The collagen I:III ratio of the study groups was equal to or greater than the control group. Collagen deficiency in the GE junction supporting ligaments does not appear to be an etiology of PEH formation.

Nerve degeneration in inguinal hernia specimens

BACKGROUND

The histological study of the herniated inguinal area is rare in the literature. This report is focused on the detection of structural changes of the nerves within tissues bordering the inguinal hernia of cadavers. Their physiopathological consequences are hypothesized.

MATERIALS AND METHODS

Primary inguinal hernia was diagnosed in 30 fresh cadavers. Tissue specimens from the inguinal region close to and around the hernia opening were excised for histological examination. A control of the data was achieved through tissue samples excised from equivalent sites of the inguinal region in 15 cadavers without hernia.

RESULTS

The detected nerves in the inguinal area demonstrated pathological changes such as fibrotic degeneration, atrophy, and fatty dystrophy of the axons. The thickening of the perineural sheath was constantly seen. These findings were consistently present, independent of the hernia type.

CONCLUSIONS

The detected nerve alterations lead us to imagine a worsening, or even the cessation, of the nervous impulse to the muscles, leading to atrophy and weakening of the abdominal wall. This could represent one of the multifactorial causes of hernia genesis.

Morphine enhances tissue content of collagen and increases wound tensile strength

PURPOSE

Morphine is a commonly prescribed analgesic for wound pain. Previous studies have shown that morphine enhances accumulation of collagen in cultured fibroblasts. Because fibroblasts are important for the remodeling of connective tissue in incisional wound, this study investigates the biological effects of morphine on cutaneous collagen content and wound tensile strength.

METHODS

A full-thickness incisional wound (2 cm in length) was created on the dorsum of mice followed by treatment with placebo or morphine (5 and 20 mg/kg/day, i.p.). Fourteen days later, tensile strength of the healed incisional wound was measured using a tensiometer. Protein expression of transforming growth factor (TGF)-beta1 and matrix metalloproteinases (MMP)-2 in the incisional wound tissue was analyzed. Degree of tissue remodeling and levels of collagen were determined by histological examination and a dye-binding collagen assay, respectively.

RESULTS

Morphine enhanced the breaking strength of incisional wound 14 days after treatment (92 +/- 10, 102 +/- 10 and 134 +/- 12 mg for control, morphine 5 mg/kg/day and morphine 20 mg/kg/day, respectively; P = 0.03, n = 6-7). Protein expression of TGF-beta1 and MMP-2 was significantly enhanced in mice treated with morphine. Histological examination of the wound tissue showed evidence of increased thickness of the cutaneous fibrous layer and deposition of collagen in the high-dose morphine treatment group. Collagen assays also demonstrated that tissue concentrations of collagen were significantly increased in the wound tissue of morphine-treated animals on day 2 of drug treatment.

CONCLUSION

The present study demonstrates that systemic administration of morphine enhances tissue collagen deposition in the cutaneous tissue, thereby increasing the tensile strength of the incisional wound.

Zinc deficiency impairs wound healing of colon anastomosis in rats

BACKGROUND

Anastomotic leakage is a relevant surgical complication. The aim of the study was to investigate the influence of a controlled preoperative zinc deficiency on the extracellular matrix composition of colon anastomosis.

MATERIALS AND METHODS

Forty male Wistar rats were randomized to either a zinc deficiency group (n = 20) or a control group (n = 20). In each animal, a transverse colonic end-to-end anastomosis was performed. On postoperative day 7, the surface of the mucosal villi, expression of matrix metalloproteinases (MMP) 2, 8, 9, and 13, and both the number of proliferating cells (Ki67) and apoptotic cells, as well as the collagen types I/III ratio were analyzed. Within the anastomotic area the mesenterial region and the antimesenterial region were analyzed separately.

RESULTS

In each group, one anastomotic leakage was detected. Expression of both MMP 2, 9, and 13 was significantly higher, and expression of Ki67 was significantly reduced in the zinc deficient group both mesenterial and antimesenterial. The collagen types I/III ratio was reduced in the zinc deficiency group by trend, without statistical significance neither mesenterial nor antimesenterial. Likewise, zinc deficiency affected neither the expression of MMP 8 nor the rate of apoptotic cells, respectively. Analyses of the surface of the mucosal villi revealed no significant differences comparing the groups with neither mesenterial nor antimesenterial.

CONCLUSIONS

Our study constitutes the known negative effect of zinc deficiency on wound healing. Zinc deficiency significantly increased the activity of MMPs (2, 9, and 13), caused a reduced collagen type I/III ratio, and delayed cell proliferation and quality of intestinal wound healing.

Differential regulation of MMP-2 in the gastrohepatic ligament of the gastroesophageal junction

INTRODUCTION

Ligamentous attachments maintain the normal anatomic position of the gastroesophageal (GE) junction. Failure of these elastic ligaments through an alteration in collagen synthesis, deposition, and metabolism may be a primary etiology of hiatal hernia formation. Differential expression of zinc-dependent matrix metalloproteinases (MMPs) is largely responsible for collagen remodeling. The purpose of this study was to survey baseline levels of MMPs in supporting ligaments of the GE junction from patients without hiatal hernia.

METHODS

Following an institutional review board-approved protocol, plasma and tissue biopsies of the gastrohepatic ligament (GHL), gastrophrenic ligament (GPL), and phrenoesophageal ligament (PEL) were obtained in six patients without a hiatal hernia during laparoscopic anterior esophageal myotomy for achalasia. Total protein extracts from tissue biopsies were analyzed for elastases MMP-2, -9, and -12 and collagenases MMP-1, -3, -7, -8, and -13 using a multiplex profiling kit (R&D Systems, Minneapolis, MN). Data are reported as mean +/- standard deviation. Statistical significance (p < 0.05) was determined using Tukey's test and analysis of variance.

RESULTS

In control patients without hiatal hernias, increased levels of MMP-2 (p < 0.02) were detected in the GHL compared with the GPL and PEL, respectively. Tissue levels of MMP-1, -12, and -13 were not detectable.

CONCLUSIONS

Gelatinase-A (MMP-2) is present in the GHL and plasma of control patients. The GHL may provide the primary GE junction supporting ligament to compare tissue from patients with type I (sliding) and type III (paraesophageal) hiatal hernias to examine the role of altered collagen metabolism in hiatal hernia formation.

Diastasis Recti and Abdominal Aortic Aneurysm

An association between abdominal aortic aneurysm (AAA) and abdominal wall hernia has been suggested, possibly reflecting a common collagen disorder. The same mechanism may also cause a greater frequency of diastasis recti among patients at risk of developing AAA. Diastasis recti could be used to identify patients at risk of AAA, with implications for AAA screening. The aim of this study was to determine whether an association between diastasis recti and AAA could be demonstrated.

The preoperative computed tomographic (CT) scans of 75 male patients undergoing elective AAA repair were retrospectively examined and linea alba width recorded at supraumbilical and subumbilical levels. Measurements were compared with controls frequency matched for age.

Fifty patients with AAA were observed to have supraumbilical diastasis recti on preoperative CT compared with 47 controls. Mean linea alba width was not significantly different between the two groups at either the supraumbilical (19.3 mm vs 20.7 mm, p = .45) or subumbilical (3.6 mm vs 4.3 mm, p = .43) level.

The findings do not support the hypothesis that the presence of diastasis recti can serve as an indication to select male patients for screening for AAA.

Herniology: past, present, and future

INTRODUCTION

Despite herniorrhaphy being performed frequently, most surgeons consider it to be a minor procedure. However, a few surgeons' views differed.

THE PAST

The Master was Bassini (1884), who introduced a radical cure for inguinal hernia. Incising his triple layer, internal oblique, transversus, and transversalis, he entered the preperitoneal space, allowing high ligation of the sac and mass suturing to the inguinal ligament. A 2.7% recurrence rate evoked worldwide emulation. Corruption ensued. The cremaster remained and few unincised layers were stitched, without imbrications, along with reinforcement using the cremaster or rectus muscles, fascial flaps, relaxing incisions, and silver coils. Little improvement cast doubt on Bassini's work. Russell's (Lancet 2:1197-1203, 1906) ligation of the hernial sac was adopted until 1953, when the Shouldice clinic revived Bassini's tenets, becoming the gold standard for decades. Cheatle (Br Med J 2:68-69, 1920) introduced posterior pre-peritoneal repair. Acquaviva and Bourret (Presse Med 73:892, 1948) designed the first plastic prosthesis (nylon), replaced by polypropylene. Usher (Surg Gynecol Obstet 117:239-240, 1963) parietalized the cord. These contributions paved the way for the Rives, Stoppa, Wantz, and Gilbert repairs, Ger's laparoscopic approach, and less common herniorrhaphies.

THE PRESENT

Chevrel (1979) formed the GREPA, which evolved into the European Hernia Society (EHS), joining with the American Hernia Society (AHS) to form the journal 'Hernia.' Nilsson (1993) instituted national hernia registries, enabling less recurrences and better prospective research.

THE FUTURE

In the 21st century, the Lichtenstein procedure has dominated inguinal herniorrhaphy. Herniologists accepted systemic connective tissue disorder as the etiology of abdominal hernia and pelvic prolapses. This malady explains why prostheses slow but do not eliminate recurrence. Antidotes need to be developed and employed.

CONCLUSION

This malady explains why prostheses slow but do not eliminate recurrence. Antidotes need to be developed and employed.

Herniology: past, present, and future

INTRODUCTION

Despite herniorrhaphy being performed frequently, most surgeons consider it to be a minor procedure. However, a few surgeons' views differed.

THE PAST

The Master was Bassini (1884), who introduced a radical cure for inguinal hernia. Incising his triple layer, internal oblique, transversus, and transversalis, he entered the preperitoneal space, allowing high ligation of the sac and mass suturing to the inguinal ligament. A 2.7% recurrence rate evoked worldwide emulation. Corruption ensued. The cremaster remained and few unincised layers were stitched, without imbrications, along with reinforcement using the cremaster or rectus muscles, fascial flaps, relaxing incisions, and silver coils. Little improvement cast doubt on Bassini's work. Russell's (Lancet 2:1197-1203, 1906) ligation of the hernial sac was adopted until 1953, when the Shouldice clinic revived Bassini's tenets, becoming the gold standard for decades. Cheatle (Br Med J 2:68-69, 1920) introduced posterior pre-peritoneal repair. Acquaviva and Bourret (Presse Med 73:892, 1948) designed the first plastic prosthesis (nylon), replaced by polypropylene. Usher (Surg Gynecol Obstet 117:239-240, 1963) parietalized the cord. These contributions paved the way for the Rives, Stoppa, Wantz, and Gilbert repairs, Ger's laparoscopic approach, and less common herniorrhaphies.

THE PRESENT

Chevrel (1979) formed the GREPA, which evolved into the European Hernia Society (EHS), joining with the American Hernia Society (AHS) to form the journal 'Hernia.' Nilsson (1993) instituted national hernia registries, enabling less recurrences and better prospective research.

THE FUTURE

In the 21st century, the Lichtenstein procedure has dominated inguinal herniorrhaphy. Herniologists accepted systemic connective tissue disorder as the etiology of abdominal hernia and pelvic prolapses. This malady explains why prostheses slow but do not eliminate recurrence. Antidotes need to be developed and employed.

CONCLUSION

This malady explains why prostheses slow but do not eliminate recurrence. Antidotes need to be developed and employed.

Delayed wound healing in sacrococcygeal pilonidal sinus coincides with an altered collagen composition

BACKGROUND

Although patients with pilonidal sinus are young and, thus, are expected to heal well, a delayed healing with high risk of recurrence frequently is observed. This study was initiated to test whether disorders in the extracellular matrix (ECM) may be detected in patients with pilonidal sinus and delayed wound healing or recurrent disease, respectively.

METHODS

In 48 patients, tissue specimens were obtained at the index operation. All patients were treated by local excision and primary wound closure. The collagen type I/III ratio, the expression of matrix metalloproteinase (MMP)-1, -9, and -13, as well as the proliferation index (Ki67) and the macrophage infiltrate (CD68) were measured. Patients with an uneventful wound healing by primary intention were compared with those in which the healing by primary intention fails (secondary healing), and patients suffering first onset of pilonidal sinus or to those patients who had undergone previous surgery for pilonidal sinus. Clinical parameters and comorbidity were evaluated.

RESULTS

Patients with secondary healing, exhibited at the index operation a significantly lower collagen type I/III ratio (2.34+/-0.4) compared with patients with problem-free wound healing (3.04+/-0.7). Furthermore, significantly higher expression of MMP-1, -9, and 13, and a significantly higher proliferation index (Ki67) were found in the specimens of the patients with secondary healing. In patients in whom the operation was performed because of a recurrence expression of both Ki67 and CD68 were significantly higher. Smokers had an increased risk for suffering recurrent disease, but did not show differences in the collagen ratio.

CONCLUSIONS

As a novel finding, this study indicates that disturbances of the ECM may predict a delayed wound healing after pilonidal sinus surgery.

Association and haplotype analyses of positional candidate genes in five genomic regions linked to scrotal hernia in commercial pig lines

Scrotal hernia in pigs is a complex trait likely affected by genetic and environmental factors. A large-scale association analysis of positional and functional candidate genes was conducted in four previously identified genomic regions linked to hernia susceptibility on Sus scrofa chromosomes 2 and 12, as well as the fifth region around 67 cM on chromosome 2, respectively. In total, 151 out of 416 SNPs discovered were genotyped successfully. Using a family-based analysis we found that four regions surrounding ELF5, KIF18A, COL23A1 on chromosome 2, and NPTX1 on chromosome 12, respectively, may contain the genetic variants important for the development of the scrotal hernia in pigs. These findings were replicated in another case-control dataset. The SNPs around the ELF5 region were in high linkage disequilibrium with each other, and a haplotype containing SNPs from ELF5 and CAT was highly significantly associated with hernia development. Extensive re-sequencing work focused on the KIF18A gene did not detect any further SNPs with extensive association signals. These genes may be involved in the estrogen receptor signaling pathway (KIF18A and NPTX1), the epithelial-mesenchymal transition (ELF5) and the collagen metabolism pathway (COL23A1), which are associated with the important molecular characteristics of hernia pathophysiology. Further investigation on the molecular mechanisms of these genes may provide more molecular clues on hernia development in pigs.