[Inguinal hernia operations-Always outpatient?] / Leistenhernienoperationen ­ immer ambulant?

Inguinal hernia operations represent the most frequent operations overall with 300,000 interventions annually in Germany, Austria and Switzerland (DACH region). Despite the announced political willingness and the increasing pressure from the legislator to avoid costly inpatient treatment by carrying out as many outpatient operations as possible, outpatient treatment has so far played a subordinate role in the DACH region. The Boards of the specialist societies the German Hernia Society (DHG), the Surgical Working Group Hernia (CAH of the DHG), the Austrian Hernia Society (ÖHG) and the Swiss Working Group Hernia Surgery (SAHC) make inroads into this problem, describe the initial position and assess the current situation.

Perioperative outcome in groin hernia repair: what are the most important influencing factors?

INTRODUCTION: Using registry analyses, a large number of influencing factors on the perioperative outcome of groin hernia repair has been identified. The interactions between several influencing factors and differences in the influencing value have to date been inadequately investigated. METHODS: This retrospective analysis of prospectively collected data from the Herniamed Registry included all fully documented cases with minimum age of 16 years and groin hernia repair. Patients were assigned to the risk groups unilateral, bilateral, recurrent and emergency groin hernia repair. Multivariable analysis was performed to investigate the influence of confirmatory defined patient- and procedure-related characteristics on the outcome parameters intraoperative, postoperative general and postoperative surgical complications, complication-related reoperation and total perioperative complications. RESULTS: A highly significantly unfavorable association with the total perioperative complication rate was identified for emergency groin hernia repair, scrotal hernia, anticoagulant medication and coagulopathy. A significantly unfavorable relation with the total perioperative complication rate was found for recurrence procedure, bilateral repair, high age, ASA score III/IV, femoral hernia, antithrombotic medication, smoking, COPD and corticosteroid medication. A significantly favorable correlation with the total perioperative complication rate was observed for the laparo-endoscopic techniques, smaller defects, female gender, normal weight and medial hernia. CONCLUSION: Both the number of potential influencing factors and their influencing value on the perioperative outcome should be considered when estimating the individual risk of a patient with groin hernia repair.

What is the reality in outpatient vs inpatient groin hernia repair? An analysis from the Herniamed Registry.

INTRODUCTION: Groin hernia repair is performed increasingly more often as an outpatient procedure across the world. However, the rates are extremely different and vary between below 10% and above 90%. The outpatient procedure appears to negatively impact the proportion of laparo-endoscopic repairs. To date, only very few studies have compared inpatient vs outpatient groin hernia repair. METHODS: All outpatient and inpatient primary elective unilateral groin hernia repairs performed between 2010 and 2019 were identified in the Herniamed Registry and their treatment and outcomes compared. RESULTS: The 737 participating hospitals/surgeons performed a total of 342,072 primary elective unilateral groin hernia repairs from 2010 to 2019. The proportion of outpatient repairs was 20.2% in 2013 and 14.3% in 2019. Whereas the proportion of laparo-endoscopic repairs among the inpatient cases was 71.9% in 2019, the last year for which data are available, it was only 34.3%.for outpatient repairs. In outpatient groin hernia repairs, the rates of patients aged ≥ 60 years, with ASA score III and IV and risk factors were highly significantly lower. Given this rigorous patient selection for outpatient groin hernia repair, a more favorable perioperative outcome was achieved. At 1-year follow-up there were no significant differences in the pain and recurrence rates. CONCLUSION: With an appropriate patient selection, outpatient primary elective unilateral groin hernia repair can be performed with acceptable risks and good outcomes. Since to date no studies have compared inpatient vs outpatient groin hernia repair, the impact of a higher rate of outpatient groin hernia repair cannot currently be evaluated.

Comparison of outcomes in rectus abdominis diastasis repair-which data do we need in a hernia registry?

INTRODUCTION: Rectus abdominis diastasis (RAD) ± concomitant hernia is a complex hernia entity of growing significance in everyday clinical practice. Due to a multitude of described surgical techniques, a so far missing universally accepted classification and hardly existing comparative studies, there are no clear recommendations in guidelines. Therefore, "RAD ± concomitant hernia" will be documented as a separate hernia entity in the Herniamed Registry in the future. For this purpose, an appropriate case report form will be developed on the basis of the existing literature. METHODS: A systematic search of the available literature was performed in March 2021 using Medline, PubMed, Google Scholar, Scopus, Embase, Springer Link, and the Cochrane Library. 93 publications were identified as relevant for this topic. RESULTS: In total 45 different surgical techniques for the repair of RAD ± concomitant hernia were identified in the surgical literature. RAD ± concomitant hernia is predominantly repaired by plastic but also by general surgeons. Classification of RAD ± concomitant hernia is based on a proposal of the German Hernia Society and the International Endohernia Society. Surgical techniques are summarized as groups subject to certain aspects: Techniques with abdominoplasty, open techniques, mini-less-open and endoscopic sublay techniques, mini-less-open and endoscopic subcutaneous/preaponeurotic techniques and laparoscopic techniques. Additional data impacting the outcome are also recorded as is the case for other hernia entities. Despite the complexity of this topic, documentation of RAD ± concomitant hernia has not proved to be any more cumbersome than for any of the other hernia entities when using this classification. CONCLUSION: Using the case report form described here, the complex hernia entity RAD ± concomitant hernia can be recorded in a registry for proper analysis of comparative treatment options.

Shouldice standard 2020: review of the current literature and results of an international consensus meeting.

INTRODUCTION: For many years the Shouldice technique was the gold standard for inguinal hernia repair. Nowadays mesh repair has been proven to entail better results in randomized trials. Since the first publication 1953 the Repair has been described in detail in many textbooks, articles and You Tube videos. It appears that the original technique is used almost exclusively in the Shouldice Hospital in Thornhill/ Canada and despite the success of the Shouldice Hospital many surgeons inexplicably modify this original technique in their daily practice. In the last couple of years there appears to be an increasing interest in pure tissue repairs for various reasons, often fear of mesh-related pain. The aim of the study was to review the current evidence and to define an updated standard with key principles of the Shouldice repair. METHODS: Because of unpublished evidence regarding many operative details the organizing group decided to create a technical update via a consensus meeting with 13 international designated hernia surgeons from six countries. In preparation of the meeting a review of the current literature regarding Shouldice repair was done by the organizing group. A questionnaire was prepared and sent to all participants before the meeting to get an independent answer on all critical aspects. RESULTS: All questions regarding a detailed standard of the operation technique could be outlined. As result of the consensus meeting the participants have formulated all key-points of preparation/dissection and repair of the Shouldice technique. For 5 of 6 critical technical surgical steps a strong consensus could be defined in the group. There was no consensus among the group regarding the cremaster resection and the ideal indication for Shouldice repair. CONCLUSION: After a 75-year history of the Shouldice repair the technique should continue to merit consideration by all hernia surgeons. After this consensus meeting a clear binding standard of the Shouldice technique for all interested surgeons is proposed.

[HerniaSurge: international guidelines on treatment of inguinal hernia in adults : Comments of the Surgical Working Group Hernia (CAH/DGAV) and the German Hernia Society (DHG) on the most important recommendations]. / HerniaSurge: internationale Leitlinie zur Therapie der Leistenhernie des Erwachsenen : Kommentar der Chirurgischen Arbeitsgemeinschaft Hernie (CAH/DGAV) und der Deutschen Herniengesellschaft (DHG) zu den wichtigsten Empfehlungen.

SURGICAL TECHNIQUES: The HerniaSurge guidelines have the highest evidence with respect to a strong recommendation for mesh-based surgical techniques. This evidence is equally valid for the Lichtenstein procedure as for the minimally invasive procedures TEP/TAPP. In the case of discrete symptomatic or asymptomatic inguinal hernias, watchful waiting can be an option, taking into account health status and social circumstances. Femoral hernias, on the other hand, should be treated promptly with mesh insertion. Also favored are laparoendoscopic techniques. The Shouldice repair achieves the least recurrences from the suturing procedures and may be an acceptable alternative when indicated or when the patient does not desire mesh reinforcement. In this case, a detailed patient education is necessary. MESH CHOICE: The complication potential of plastic meshes should be explained. The weight is no longer considered a suitable parameter for the classification of meshes and is no longer recommended for mesh selection. Large pore (>1-1.5 mm) monofilament implants have the best integration potential and should have a tear strength of approximately 16 Nm2. Traumatic mesh fixation is only recommended for large medial hernias (M3-EHS). Primarily not recommended are Plug & Patch, double-layered plastic implants (such as the PHS system) or other three-dimensional devices, as this could affect both the anterior and posterior planar layers and complicate the complementary surgical technique in the event of recurrence. In addition, the higher costs have to be considered. PERIOPERATIVE AND POSTOPERATIVE ASPECTS: Perioperative antibiotic prophylaxis in open repair procedures is recommended only in patients with an increased risk of infections. In laparoendoscopic procedures, antibiotic prophylaxis should not be performed or used with the utmost restraint. Careful preparation reduces chronic inguinal and testicular pain. In the case of interference of mesh and nerve, the nerve can be resected. A return to daily activity is recommended within 3-5 days. QUALITY ASSURANCE: The documentation of patient data should be done by establishing hernia registers for quality assurance and for the development of further treatment options. The implementation of the guidelines is supported by HerniaSurge.

European Hernia Society guidelines on prevention and treatment of parastomal hernias.

BACKGROUND: International guidelines on the prevention and treatment of parastomal hernias are lacking. The European Hernia Society therefore implemented a Clinical Practice Guideline development project. METHODS: The guidelines development group consisted of general, hernia and colorectal surgeons, a biostatistician and a biologist, from 14 European countries. These guidelines conformed to the AGREE II standards and the GRADE methodology. The databases of MEDLINE, CINAHL, CENTRAL and the gray literature through OpenGrey were searched. Quality assessment was performed using Scottish Intercollegiate Guidelines Network checklists. The guidelines were presented at the 38th European Hernia Society Congress and each key question was evaluated in a consensus voting of congress participants. RESULTS: End colostomy is associated with a higher incidence of parastomal hernia, compared to other types of stomas. Clinical examination is necessary for the diagnosis of parastomal hernia, whereas computed tomography scan or ultrasonography may be performed in cases of diagnostic uncertainty. Currently available classifications are not validated; however, we suggest the use of the European Hernia Society classification for uniform research reporting. There is insufficient evidence on the policy of watchful waiting, the route and location of stoma construction, and the size of the aperture. The use of a prophylactic synthetic non-absorbable mesh upon construction of an end colostomy is strongly recommended. No such recommendation can be made for other types of stomas at present. It is strongly recommended to avoid performing a suture repair for elective parastomal hernia. So far, there is no sufficient comparative evidence on specific techniques, open or laparoscopic surgery and specific mesh types. However, a mesh without a hole is suggested in preference to a keyhole mesh when laparoscopic repair is performed. CONCLUSION: An evidence-based approach to the diagnosis and management of parastomal hernias reveals the lack of evidence on several topics, which need to be addressed by multicenter trials. Parastomal hernia prevention using a prophylactic mesh for end colostomies reduces parastomal herniation. Clinical outcomes should be audited and adverse events must be reported.

[Sportsmen's groin. Definition, differential diagnostics and therapy]. / Sportlerleiste. Begriffsbestimmung, Differenzialdiagnostik und Therapie.

Groin pain in athletes is a common problem and can have extensive consequences for professional athletes. The anatomical and functional complexity of the groin as well as radiating pain from remote anatomical regions can make the differential diagnostic a challenge and requires special attention. As there are a wide variety of possible causes for groin pain, a multidisciplinary approach is required. The treating orthopedic surgeon needs to pay special attention to prearthritic hip deformities to avoid irreversible damage of the hip joint. By a meticulous patient history and identification of the pain character, followed by clinical, sonographic and radiographic investigations, a differential diagnosis can usually be achieved. Besides typical orthopedic causes pathological findings particularly in the area of the groin need to be considered, clarified and adequately treated; therefore, a clear terminology of the different diseases is necessary. Sportsmen's groin is not a hernia but should be perceived as a separate entity due to its typical pain character and detection of a measurable protrusion of the posterior wall of the inguinal canal by ultrasound.

European Hernia Society guidelines on the closure of abdominal wall incisions.

BACKGROUND: The material and the surgical technique used to close an abdominal wall incision are important determinants of the risk of developing an incisional hernia. Optimising closure of abdominal wall incisions holds a potential to prevent patients suffering from incisional hernias and for important costs savings in health care. METHODS: The European Hernia Society formed a Guidelines Development Group to provide guidelines for all surgical specialists who perform abdominal incisions in adult patients on the materials and methods used to close the abdominal wall. The guidelines were developed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach and methodological guidance was taken from Scottish Intercollegiate Guidelines Network (SIGN). The literature search included publications up to April 2014. The guidelines were written using the AGREE II instrument. An update of these guidelines is planned for 2017. RESULTS: For many of the Key Questions that were studied no high quality data was detected. Therefore, some strong recommendations could be made but, for many Key Questions only weak recommendations or no recommendation could be made due to lack of sufficient evidence. RECOMMENDATIONS: To decrease the incidence of incisional hernias it is strongly recommended to utilise a non-midline approach to a laparotomy whenever possible. For elective midline incisions, it is strongly recommended to perform a continuous suturing technique and to avoid the use of rapidly absorbable sutures. It is suggested using a slowly absorbable monofilament suture in a single layer aponeurotic closure technique without separate closure of the peritoneum. A small bites technique with a suture to wound length (SL/WL) ratio at least 4/1 is the current recommended method of fascial closure. Currently, no recommendations can be given on the optimal technique to close emergency laparotomy incisions. Prophylactic mesh augmentation appears effective and safe and can be suggested in high-risk patients, like aortic aneurysm surgery and obese patients. For laparoscopic surgery, it is suggested using the smallest trocar size adequate for the procedure and closure of the fascial defect if trocars larger or equal to 10 mm are used. For single incision laparoscopic surgery, we suggest meticulous closure of the fascial incision to avoid an increased risk of incisional hernias.

In vivo MRI visualization of parastomal mesh in a porcine model.

INTRODUCTION: After two-dimensional plane MRI-visible mesh implants could be successfully visualized in phantom and small animal model, the aim of the underlying study was to explore the feasibility of an MRI visualization of complex three-dimensional mesh geometry in close contact to the intestine. We therefore used a MR-visible three-dimensional intra-peritoneal stoma (IPST) mesh in a porcine model. MATERIALS AND METHODS: Laparoscopic terminal sigmoid colostomy has been done with implantation of a prophylactic MRI-visible IPST mesh in two animals. MRI investigations were done after 1 week, 6 months and in case of clinical impairment. These findings were compared to endoscopy and makroscopical and histological investigation of the preparation. RESULTS: The first animal has to be killed because of an ileus 4 weeks after operation. The second animal has to be killed after 7 weeks because of recurrent obstipation. In all cases MRI investigation could identify the IPST mesh and could clearly separate between mesh and intestine. MRI revealed a big bowl ileus due to a funnel dislocation in the first animal. In the second animal, MR diagnostic explored a functional stenosis because of a too small diameter of the central funnel in combination with sticky feces and distension of the terminal sigmoid before discharging into the funnel. Endoscopy, makroscopical and histological investigation of the preparation supported MRI findings. CONCLUSION: Although complicate clinical course was a diagnostic challenge exploring 3D implants such as IPST, visualization of this new MRI-visible IPST mesh could be proved and turned out as an effective diagnostic possibility. Further studies are necessary to analyze long-time effects such as shrinkage, mesh migration and tissue integration using MRI scanning.

Update with level 1 studies of the European Hernia Society guidelines on the treatment of inguinal hernia in adult patients.

PURPOSE: In 2009, the European Hernia Society published the EHS Guidelines for the Treatment of Inguinal Hernia in Adult Patients. The Guidelines contain recommendations for the treatment of inguinal hernia from diagnosis till aftercare. The guidelines expired January 1, 2012. To keep them updated, a revision of the guidelines was planned including new level 1 evidence. METHODS: The original Oxford Centre for Evidence-Based Medicine ranking was used. All relevant level 1A and level 1B literature from May 2008 to June 2010 was searched (Medline and Cochrane) by the Working Group members. All chapters were attributed to the two responsible authors in the initial guidelines document. One new chapter on fixation techniques was added. The quality was assessed by the Working Group members during a 2-day meeting and the data were analysed, especially with respect to any change in the level and/or text of any of the conclusions or recommendations of the initial guidelines. In the end, all relevant references published until January 1, 2013 were included. The final text was approved by all Working Group members. RESULTS: For the following topics, the conclusions and/or recommendations have been changed: indications for treatment, treatment of inguinal hernia, day surgery, antibiotic prophylaxis, training, postoperative pain control and chronic pain. The addendum contains all current level 1 conclusions, Grade A recommendations and new Grade B recommendations based on new level 1 evidence (with the changes in bold). CONCLUSIONS: Despite the fact that the Working Group responsible for it tried to represent most kinds of surgeons treating inguinal hernias, such general guidelines inevitably must be fitted to the daily practice of every individual surgeon treating his/her patients. There is no doubt that the future of guideline implementation will strongly depend on the development of easy to use decision support algorithms tailored to the individual patient and on evaluating the effect of guideline implementation on surgical outcome. At the 35th International Congress of the EHS in Gdansk, Poland (May 12-15, 2013), it was decided that the EHS, IEHS and EAES will collaborate from now on with the final goal to publish new joint guidelines, most likely in 2015.

European Hernia Society classification of parastomal hernias.

PURPOSE: A classification of parastomal hernias (PH) is needed to compare different populations described in various trials and cohort studies, complete the previous inguinal and ventral hernia classifications of the European Hernia Society (EHS) and will be integrated into the EuraHS database (European Registry of Abdominal Wall Hernias). METHODS: Several members of the EHS board and invited experts gathered for 2 days to discuss the development of an EHS classification of PH. The discussions were based on a literature review and critical appraisal of existing classifications. RESULTS: The classification proposal is based on the PH defect size (small is ≤5 cm) and the presence of a concomitant incisional hernia (cIH). Four types were defined: Type I, small PH without cIH; Type II, small PH with cIH; Type III, large PH without cIH; and Type IV, large PH with cIH. In addition, the classification grid includes details about whether the hernia recurs after a previous PH repair or whether it is a primary PH. Clinical validation is needed in the future to assess if the classification allows us to differentiate the treatment strategy and if the classification impacts outcome in these different subgroups. CONCLUSION: A classification of PH divided into subgroups according to size and cIH was formulated with the aim of improving the ability to compare different studies and their results.

Criteria for definition of a complex abdominal wall hernia.

PURPOSE: A clear definition of "complex (abdominal wall) hernia" is missing, though the term is often used. Practically all "complex hernia" literature is retrospective and lacks proper description of the population. There is need for clarification and classification to improve patient care and allow comparison of different surgical approaches. The aim of this study was to reach consensus on criteria used to define a patient with "complex" hernia. METHODS: Three consensus meetings were convened by surgeons with expertise in complex abdominal wall hernias, aimed at laying down criteria that can be used to define "complex hernia" patients, and to divide patients in severity classes. To aid discussion, literature review was performed to identify hernia classification systems, and to find evidence for patient and hernia variables that influence treatment and/or prognosis. RESULTS: Consensus was reached on 22 patient and hernia variables for "complex" hernia criteria inclusion which were grouped under four categories: "Size and location", "Contamination/soft tissue condition", "Patient history/risk factors", and "Clinical scenario". These variables were further divided in three patient severity classes ('Minor', 'Moderate', and 'Major') to provide guidance for peri-operative planning and measures, the risk of a complicated post-operative course, and the extent of financial costs associated with treatment of these hernia patients. CONCLUSION: Common criteria that can be used in defining and describing "complex" (abdominal wall) hernia patients have been identified and divided under four categories and three severity classes. Next step would be to create and validate treatment algorithms to guide the choice of surgical technique including mesh type for the various complex hernias.

Serum analyses for protein, albumin and IL-1-RA serve as reliable predictors for seroma formation after incisional hernia repair.

PURPOSE: The aim of this study was to identify potential parameters as predictors for seroma formation after incisional hernia mesh repair. METHODS: The incidence of postoperative seroma was determined prospectively in 37 patients who underwent incisional hernia repair with lightweight polypropylene-polyglactin composite mesh (Vypro-II®). Postoperative seroma manifestation was related to patient characteristics (gender, age, BMI, comorbidity, nicotine abuse) and to preoperative serum concentration of total protein, albumin, interleukin-1-receptor-antagonist (IL-1-RA), propeptid-III-procollagen, hyaluronan and fibronectin. Ultrasound investigation was performed on postoperative days 1, 2, 3, 8 and 10. RESULTS: Ten patients (27%) developed seroma with a mean volume of 77 ± 88 ml. Higher BMI correlated with increased seroma formation (P = 0.038). In patients with seroma, total protein (67 ± 7 vs 72 ± 4 g/l; P = 0.037), albumin (42 ± 3 vs 40 ± 4 g/l; P = 0.018) and IL-1-RA (1.4 ± 1 vs 0.8 ± 0.6 U/ml; P = 0.048) exhibited significantly altered serum concentrations in comparison to patients without seroma formation. No significant differences were seen in any other parameters. CONCLUSIONS: High BMI, lowered preoperative serum concentration of total protein and albumin, and high serum concentration of IL-1-RA are related to an elevated risk for postoperative seroma formation.

[Conventional reparation of parastomal hernia]. / Konventionelle Reparation der parastomalen Hernie.

The reparation of parastomal hernias and their recurrence remain problematic although the implementation of mesh techniques has lowered recurrences rates. Conventional surgical techniques include suture repair, relocation of the stoma as well as diverse hernia repair procedures with mesh implantation. Suture repair has been abandoned due to its high recurrence rate. Simple relocation is not recommended because of high rates of recurrent parastomal hernias. Conventional hernia repair using mesh implants is classified according to the mesh position into epifascial (onlay), retromuscular (sublay) and intraperitoneal (IPOM) techniques. Furthermore, a combination of relocation with additional mesh enforcement is also possible. The value of the different mesh techniques and of new biological mesh prostheses must be evaluated in randomized controlled studies.

Different methods of mesh fixation in open retromuscular incisional hernia repair: a comparative study in pigs.

PURPOSE: Reinforcement of the abdominal wall with alloplastic mesh material in incisional hernia repair is well established. To avoid dislocation and migration of the prostheses, mesh fixation is recommended. However, there seems to be a correlation between postoperative pain and mesh fixation. Furthermore, it remains unclear whether mesh fixation is necessary at all. METHODS: A retromuscular mesh implantation was performed in 36 pigs using a polypropylene-polyglecaprone 25 composite mesh (Ultrapro(®), 12 × 18 cm). In group 1, the mesh was fixed to the posterior rectus sheet with non absorbable single sutures (Prolene(®) 2-0), in group 2 fixation was with absorbable sutures (Vicryl(®) 2-0), in group 3 mesh fixation was with 5 ml fibrin sealant (Quixil(®)), and, as a control, there was no fixation in group 4. The abdominal wall was explanted on postoperative day 7, 14 and 56. Mesh size and position was measured, and pull-out force of the mesh was analysed mechanically by tensiometry. The ratio of collagen type I/III was analysed to determine the quality of mesh integration. RESULTS: Neither mesh dislocation nor mesh migration was detected. Mesh size showed no significant differences, whether comparing time points or groups. No significant differences in the tensile strength of mesh integration were found when comparing the groups (group 1: 155 ± 17 mmHg; group 2: 175 ± 9 mmHg; group 3: 166 ± 24 mmHg; group 4: 172 ± 28 mmHg). Though the type I/III collagen ratio increased over time, no significant differences according to the type of fixation used were detected. CONCLUSION: Mesh fixation in open incisional hernia repair with retromuscular mesh augmentation to avoid mesh dislocation or migration in the early postoperative period appears to be unnecessary.

[Incisional hernia - how do I do it? Standard surgical approach]. / Narbenhernie - Wie ist zu verfahren? Chirurgische Standardversorgung.

Various techniques for repair of an incisional hernia are available for the surgeon. Conventional suture techniques are quick and easy to perform but they are associated with an unacceptable rate of recurrence and therefore should only be used in exceptional cases. An underlying systemic disturbance of collagen metabolism is assumed to exist in patients with an incisional hernia. In such patients the mechanisms of wound healing and remodeling of the abdominal wall following laparotomy are insufficient, which necessitates reinforcement of the abdominal wall with a non-resorbable alloplastic mesh prosthesis to enable a long-term cure. The implantation of such meshes can be carried out laparoscopically or by an open approach. The gold standard of open repair techniques is the retromuscular placement of a mesh prosthesis. The retromuscular mesh placement as a reinforcement of the abdominal wall (augmentation) must be categorically differentiated into the abdominal wall replacement by mesh bridging. In this technique the mesh is likewise placed in the retromuscular space, however a complete closure of the ventral fascia is not necessary. Retromuscular augmentation enables an extra-peritoneal placement of the prosthesis, an optimization of tissue integration by plane coverage of the prosthesis by well vascularized muscular tissue and a sufficient overlap in cranio-caudal and lateral directions. Mesh fixation is best made with absorbable suture material but is better suited for technical simplification. The use of a prophylactic drainage should be decided depending on the individual patient's risk factors, because sufficient evidence-based data are currently not available. If augmentation is not possible bridging is necessary and then the mesh has to be fixed without underlying support. Current data reveal that the recurrence rate following incisional hernia repair by retromuscular mesh augmentation has decreased promisingly in comparison to simple suture techniques. In total the recurrence rate following retromuscular mesh placement ranges between 2 and 12%. Current results of prospective randomized multicentre trials are not available. However, it is to be expected that further development of mesh materials as well as improvement of surgical techniques with avoidance of typical pitfalls will lead to further reduction of the recurrence rate with an improvement in patient satisfaction.

Hernia repair: the search for ideal meshes.

BACKGROUND: Effective repair of hernia is a difficult task. There have been many advances in hernia repair techniques over the past 50 years, but new strategies must be considered to enhance the success of herniorrhaphy. DISCUSSION: At the 30th International Congress of the European Hernia Society, nine experts in hernia repair and experimental mesh evaluation participated in a roundtable discussion about today's unmet needs in hernia repair, including what constitutes an "ideal" hernia repair and the portfolio of "ideal" mesh prostheses. Defining characteristics of lightweight mesh, mesh alternatives, the surgeon's role in hernia repair, adverse events, the unmet requirements for today's hernia repair, and optimized animal models were among the topics discussed. CONCLUSION: The ideal mesh's construction is still in progress, but greater understanding of its critical characteristics was explored. It is hoped that these suggestions will lead to the development of improved hernia treatments and a maximally effective portfolio of hernia mesh prostheses.

Impact of mesh positioning on foreign body reaction and collagenous ingrowth in a rabbit model of open incisional hernia repair.

BACKGROUND: Incisional hernia remains as one of the most common surgical complications. Different mesh techniques are used in 75-80% of hernia repair. The aim of this study was to evaluate the dependence of mesh positioning and the type of mesh implanted on foreign body reaction and collagenous ingrowth. MATERIALS AND METHODS: In 24 male Chinchilla rabbits, an incisional hernia repair was performed with mesh reinforcement either by sublay (n = 12) or by onlay technique (n = 12). In each group, two different types of mesh prosthesis were investigated: polypropylene (PP, Prolene) and polypropylene-polyglecaprone 25 composite (PP-PG, UltraPro). On postoperative day 60, the inflammatory and connective tissue formation was characterised by measuring the diameter of inner cellular infiltrate and outer fibrous capsule of the foreign body granuloma, and by verifying the collagen type I/III ratio. Furthermore, the expression of matrix metalloproteinase-2 (MMP-2) was analysed. RESULTS: Microscopic investigation of the mesh/host-tissue interface showed typical formation of foreign body granuloma. The diameters of the inner part of the foreign body granuloma representing the amount of inflammatory cell infiltrate were significantly increased in the PP mesh compared to the PP-PG mesh, both in the sublay group (PP 13.1 +/- 1.21 microm vs. PP-PG 11.7 +/- 0.34 microm; P = 0.026) and in the onlay group (PP 13.1 +/- 1.24 microm vs. PP-PG 11.2 +/- 0.55 microm; P = 0.009). The diameter of the fibrous capsule as the outer ring of the granuloma was significantly increased when investigating the PP mesh in sublay position (29.5 +/- 1.12 microm) compared to the PP mesh in onlay position (27.9 +/- 0.73 microm) (P = 0.026). Investigating the quality of perifilamentary collagen deposition expressed as collagen type I/III ratio, the sublay group showed significantly elevated values compared to the onlay group (PP sublay 3.1 +/- 0.18 vs. PP onlay 2.4 +/- 0.41; P = 0.004) (PP-PG sublay 3.5 +/- 0.34 vs. PP-PG onlay 2.6 +/- 0.13; P = 0.002). The analysis of MMP-2 expression revealed no significant differences. CONCLUSION: The beneficial results of mesh reinforcement in the sublay technique might be due to a superior quality of postoperative connective tissue formation. Mesh incorporation, irrespective of positioning, is favourable in low-weight, large, porous mesh material represented by a reduced inflammatory part of the foreign body granuloma.