Unplanned readmissions after hernia repair.

INTRODUCTION: Several quality indices have been set up for evaluating the impact of the reduction of the length of stay (LOS), such as the 30-day unplanned readmission (UR30) rate. The main goal of our study was to analyze the UR30 following groin hernia repair (GHR), primary- (PVHR), and incisional ventral hernia repairs (IVHR). METHODS: A French registry-based multicenter study was conducted using prospective data from all consecutive patients registered from 2015 to 2021. RESULTS: The overall incidence of UR30 was 1.32%. This included 160/18,042 (0.87%) for GHR, 41/4012 (1.02%) for PVHR, and 145/3754 (3.86%) for IVHR. The leading cause of UR30 was postoperative complications (POC). The nature of the predominant complications varied among the three categories. The correlation between UR30 and POC (and risk factors for POC) was strong in GHR but was not in IVHR due to a 'protective' longer LOS in this subgroup. As the LOS has decreased over the last years, this has 'mechanically' resulted in an increase in the occurrence of UR30, but not in a rise of POC, neither in volume nor in severity. The reduction of LOS just shifted the problem from inpatient to outpatient settings. CONCLUSION: Since the steady development of day-care surgery, the prevention of the UR not only hinges on the prevention of the POC but newly on a better organization of outpatient care which is currently a huge challenge due to a GPs' and nurses' shortage in France.

Obesity increases the surgical complexity and risk of recurrence after midline primary ventral hernia repair: results on 2307 patients from the French Society of hernia surgery (SFCP-CH) registry database.

PURPOSE: Obesity is a known risk factor of recurrence after hernia surgery, but available data often concern pooled cases of primary and incisional hernia, with short follow-up. We aimed to analyze the impact of severe obesity (BMI ≥ 35 kg/m2) on the results of midline primary ventral hernia repair (mPVHR), in comparison with non-severely obese patients. METHODS: Data were extracted from a multicentric registry, in which patients' data are consecutively and anonymously collected. We conducted a retrospective comparative study on patients with severe obesity (sOb) versus non-severely obese patients (non-sOb), who underwent surgery, with a minimal 2-year follow-up after their mPVHR. RESULTS: Among 2307 patients, 267 sOb and 2040 non-sOb matched inclusion criteria. Compared with non-sOb, sOb group gathered all the worse conditions and risk factors: more ASA3-4 (39.3% vs. 10.2%; p < 0.001), symptomatic hernia (15.7% vs. 6.8%; p < 0.001), defect > 4 cm in diameter (24.3% vs. 8.8%; p < 0.001), emergency surgery (6.1% vs. 2.5%; p = 0.003), and Altemeir class > 1 (9.4% vs. 2.9%; p < 0.001). Laparoscopic IPOM was used more often in sOb patients (40% vs. 32%; p = 0.016), but with smaller Hauters' ratio (46 vs. 73; p < 0.001). Compared with the non-sOb, the rate of day-case surgery was lower (48% vs. 68%; p < 0.001), the surgical site occurrences were significantly more frequent (6.4 %vs. 2.5%; p < 0.001). The main outcome, 2-year recurrence, was 5.9% in the sOb vs. 2.1% (p = 0.008), and 2-year reoperations was 3% vs. 0.3% (p = 0.006). In the adjusted analysis, severe obesity was an independent risk factor for recurrence [OR = 2.82, (95%CI, 1.45; 5.22); p = 0.003]. CONCLUSION: In patients with severe obesity, mPVHR is technically challenging and recurrence rate is three times higher than that of non-severely obese patients.

Open IPOMs for medium/large incisional ventral hernia repairs in the French Hernia Registry: factors associated with their use and mesh-related outcomes.

PURPOSE: The use of open intra-peritoneal onlay mesh repairs (O-IPOMs) for treating medium/large incisional ventral hernias has come into question due to the development of minimally invasive and sublay procedures. This study aimed to identify factors that are associated with the use of O-IPOMs in France. METHODS: We analysed prospectively collected data from the French Hernia Registry on incisional ventral hernia repairs (IVHR) for hernias ≥ 4 cm in width. RESULTS: We obtained data for 2261 IVHR (from 11/09/2011 to 30/03/2020): 733 O-IPOMs and 1,528 other techniques. We found that the O-IPOMs were performed on patients with more patient-related risk factors compared with the other techniques. Specifically, there was a higher proportion of patients with ASA III/IV (40.47% vs. 28.02%; p < 0.00001) and at least one patient-related risk factor (66.17% vs. 58.51%; p = 0.0005). Of the 733 O-IPOMs, 195 used Ventrio ST™ (VST), the most commonly used mesh for such IPOMs in our database; the other 538 O-IPOMs used other meshes (OM). The VST subgroup had a higher proportion of patients with ASA III/IV (52.58% vs. 36.07%; p < 0.0001) and on anticoagulants (26.04% vs. 18.41%; p = 0.0229) compared with the OM subgroup; they also had a lower recurrence rate after 2 years (5.83% vs. 15.41%; p = 0.008). However, large (≥ 10 cm) or lateral defects were more common in the OM subgroup, and their mesh/defect area ratio was lower. CONCLUSION: O-IPOMs were performed on patients with more comorbidities and/or complex incisional hernias compared with other techniques.

Significant factors influencing chronic postoperative inguinal pain: A conditional time-dependent observational cohort study.

BACKGROUND: Inguinal hernia (IH) repair is a common surgical procedure. Focus has shifted from recurrences to chronic postoperative inguinal pain (CPIP). To assess the natural course of CPIP and identify patient factors influencing the onset of CPIP, an observational registry-based study was performed. MATERIALS AND METHODS: Data prospectively collected from the Club-Hernie national database was retrieved from 2011 until 2021. Patients who underwent elective surgery for inguinal hernia were divided in an irrelevant pain group and relevant pain group. Relevant pain at one year and two years were compared with patients with irrelevant pain at all-time points (preoperatively, one month, one year and two years). Quality of life questions were compared between relevant pain at one year and two years. RESULTS: 4.016 patients were included in the analysis. Mean age was 65.1 years, 90.3% of patients was male. Factors correlated with CPIP onset were age, gender, ASA, recurrent surgery, surgical technique, nerve handling and fixation type. Relevant pain at one month was a greater risk for CPIP than preoperative pain (12.3% vs 3.6%). In the majority of patients (83.2%) CPIP was ameliorated at two years. Hernia related complaints differed significantly between CPIP at one year and two years. CONCLUSION: Postoperative pain after one month was a greater risk factor for CPIP development than preoperative pain. CPIP at one year seems to have a different pain etiology than CPIP at two years. Patient and surgical factors influence the onset of CPIP at one year, however the natural course of these complaints shows great decline at two years, largely without reinterventions.

Longitudinal cohort study on preoperative pain as a risk factor for chronic postoperative inguinal pain after groin hernia repair at 2-year follow-up.

PURPOSE: To assess the rate of late chronic postoperative inguinal pain (CPIP) after groin hernia repair in patients with different categories of preoperative VRS (Verbal Rating Scale) pain and to make a pragmatic evaluation of the rates of potentially surgery-related CPIP vs. postoperative continuation of preexisting preoperative pain. METHODS: Groin pain of patients operated from 01/11/2011 to 01/04/2014 was assessed preoperatively, postoperatively and at 2-year follow-up using a VRS-4 in 5670 consecutive groin hernia repairs. A PROM (Patient Related Outcomes Measurement) questionnaire studied the impact of CPIP on the patients' daily life. RESULTS: Relevant (moderate or severe VRS) pain was registered preoperatively in 1639 of 5670 (29%) cases vs. 197 of 4704 (4.2%) cases at the 2-year follow-up. Among the latter, 125 (3.7%) cases were found in 3353 cases with no-relevant preoperative pain and 72 (5.3%) in 1351 cases with relevant preoperative pain. Relevant CPIP consisted of 179 (3.8%) cases of moderate pain and 18 (0.4%) cases of severe pain. The rate of severe CPIP was independent of the preoperative VRS-pain category while the rate of moderate CPIP (3.1%, 3.4%, 4.1%, 6.8%) increased in line with the preoperative (none, mild, moderate, and severe) VRS-pain categories. The VRS probably overestimated pain since 71.6% of the relevant CPIP patients assessed their pain as less bothersome than the hernia. CONCLUSION: At the 2-year follow-up, relevant CPIP was registered in 4.2% cases, of which 63.5% were potentially surgery-related (no-relevant preoperative pain) and 36.5% possibly due to the postoperative persistence of preoperative pain. The rate of severe CPIP was constant around 0.4%.

Risk factors for surgical site infection after groin hernia repair: does the mesh or technique matter?

INTRODUCTION: Surgical site infections (SSIs) following groin hernia repair (GHR) are getting rarer in high income countries despite a wider use of meshes. Among the risk factors for SSIs, those related to the mesh and the surgical technique have rarely been described. METHODS: A registry-based multicenter study using prospectively collected data, including SSIs and their potential risk factors, was conducted in the French Hernia-Club. RESULTS: Between 2012 and 2019, 21,976 consecutive unselected adult patients aged 64.8 ± 15.4 years old (88.9% male) underwent GHR (83.5% unilateral). Fifty four percent were laparoscopic; 97.6% used mesh. The overall incidence of SSI was 0.26%. The incidence of SSI was respectively, 0.24% and 0.19% (p = 0.420) in open vs laparoscopic repairs; 0.19% and 0.25% (p = 0.638) for polyester vs polypropylene mesh; In adjusted multivariate analysis focusing on macroporous meshes (which were the most implanted meshes: 23,148 out of 24,099), there were no differences in terms of SSIs' rates regarding the technique: open versus laparoscopy (p = 0.762) nor the type of mesh used: polypropylene versus polyester (p = 0.557). CONCLUSION: The rate of SSI following GHR was low in this large registry study. Mesh type and surgical technique did not affect SSIs rates. Caution is advised when interpreting these data due to this very low rate of SSI and the potential for a type II error.

Hernia width explains differences in outcomes between primary and incisional hernias: a prospective cohort study of 9159 patients.

PURPOSE: Data on primary (PH) and incisional hernias (IH) are often pooled, even though several studies have illustrated that these are different entities with worse outcomes for IHs. The aim of this study is to validate previous research comparing PHs and IHs and to examine whether hernia width is an important contributor to the differences between these hernia types. METHODS: A registry-based, prospective cohort study was performed, utilizing the French Hernia Club database. All patients undergoing PH or IH repair between September 8th 2011 and May 22nd 2019 were included. Baseline, hernia and surgical characteristics, and postoperative outcomes were collected. Outcomes were analyzed per width category (≤ 2 cm, 3-4 cm, 5-10 cm and > 10 cm). RESULTS: A total of 9159 patients were included, of whom 4965 (54%) had PH and 4194 (46%) had IH. PHs and IHs differed significantly in 12/15 baseline characteristics, 9/10 hernia and surgical characteristics, and all outcomes. Overall, complications and re-interventions were more common in patients with IH. After correcting for width, the differences between PH and IH were no longer significant, except for medical complications, which were more common after IH repair compared to PH. CONCLUSION: After correcting for hernia width, most outcomes do not significantly differ between PH and IH, indicating that not hernia type, but hernia width is an important factor contributing to the differences between PH and IH.

A registry-based 2-year follow-up comparative study of two meshes used in transinguinal preperitoneal (TIPP) groin hernia repair.

PURPOSE: Onflex™ mesh has replaced Polysoft™ patch on the market, without being clinically evaluated thus far in the transinguinal preperitoneal (TIPP) technique. METHODS: All consecutive TIPP registered in our registry during the overlap period of availability of both meshes were included and studied with the chronic postoperative inguinal pain (CPIP) as primary endpoint, assessed with a verbal rating scale (VRS), and included in a patient-related outcome measurement (PROM) phone questionnaire. RESULTS: A total of 181 Onflex cases vs 182 Polysoft cases were studied with a 2-year follow-up rate of 92% vs 88%. The overall rate of pain or discomfort was not statistically different in the 2 studied subgroups (16.5% vs 17.6%; p = 0.71), while moderate or severe pain were significantly more frequent in the Polysoft subgroup (5.5% vs 11.6%; p = 0.01). These symptoms did not interfere with the patient daily life in 16% vs 16.5% of cases, and they were self-assessed as more bothersome than the hernia in only 0.5% vs 0.5% of cases, suggesting an overestimation of the pain by the VRS. Patients assessed the result of their hernia repair as excellent or good in 97.8% vs 96.7% and medium or bad in 2.2% vs 3.3% (p = 0.53). The cumulative recurrence rate was 0% vs 2.2%. Two reoperations (one for early and one for late recurrence) were reported in the Polysoft subgroup (1%), none related to the non-absorbable memory ring. CONCLUSIONS: These results suggest that TIPP with Onflex provides results at least similar than those with Polysoft.

Readmissions at 30 days after inguinal hernia repair: A series of 5126 patients.

INTRODUCTION: The evaluation of the re-admission rate within 30 days of inguinal hernia repair represents a patient management quality indicator. The goal of our study was to evaluate the re-admission rate at 30 days after inguinal hernia repair and identify the risk factors for re-admission. METHODS: Based on a prospective national registry, patient data were collected during two years. The number of and reasons for re-admissions were compiled. RESULTS: A total of 5126 patients, mean age 61 years, underwent inguinal hernia repair. Ambulatory surgery was performed in 4013 (78%) patients. Failed ambulatory surgery was recorded for 100 (2%) patients. Thirty-three (0.64%) patients were re-admitted within 30 days following surgery for 34 various reasons. The re-admission rate after ambulatory surgery was 0.5%. Half of patients re-admitted presented with a severe complication that required re-intervention. In multivariable analysis, emergency hernia repair (OR 4.899 [1.309-18.327]; P=0.01) and prolonged duration of operation (OR 1.023 [1.009-1.037]; P=0.001) were identified as independent risk factors for re-admission within 30 days after surgery. CONCLUSION: Within this prospective national cohort, the overall re-admission rate after inguinal hernia repair was 0.64%, slightly less among the patients undergoing ambulatory surgery. Half of re-admitted patients required surgical re-operation. Emergency hernia repair and prolonged duration of operation were risk factors for re-admission.

Correction to: European Hernia Society (EHS) guidance for the management of adult patients with a hernia during the COVID­19 pandemic.

The originally published article: The surname and given name of authors, M. Pawlak and A.C. de Beaux has been incorrectly published.

The reality of general surgery training and increased complexity of abdominal wall hernia surgery.

INTRODUCTION: The Accreditation and Certification of Hernia Centers and Surgeons (ACCESS) Group of the European Hernia Society (EHS) recognizes that there is a growing need to train specialist abdominal wall surgeons. The most important and relevant argument for this proposal and statement is the growing acceptance of the increasing complexity of abdominal wall surgery due to newer techniques, more challenging cases and the required 'tailored' approach to such surgery. There is now also an increasing public awareness with social media, whereby optimal treatment results are demanded by patients. However, to date the complexity of abdominal wall surgery has not been properly or adequately defined in the current literature. METHODS: A systematic search of the available literature was performed in May 2019 using Medline, PubMed, Scopus, Embase, Springer Link, and the Cochrane Library, with 75 publications identified as relevant. In addition, an analysis of data from the Herniamed Hernia Registry was performed. The percentage of patients with hernia- or patient-related characteristics which unfavorably impacted the outcome of inguinal and incisional hernia repair was also calculated. RESULTS: All present guidelines for abdominal wall surgery recommend the utilization of a 'tailored' approach. This relies on the prerequisite that any surgical technique used has already been mastered, as well as the recognized learning curves for each of the several techniques that can be used for both inguinal hernia (Lichtenstein, TEP, TAPP, Shouldice) and incisional hernia repairs (laparoscopic IPOM, open sublay, open IPOM, open onlay, open or endoscopic component separation technique). Other hernia- and patient-related characteristics that have recognized complexity include emergency surgery, obesity, recurrent hernias, bilateral inguinal hernias, groin hernia in women, scrotal hernias, large defects, high ASA scores, > 80 years of age, increased medical risk factors and previous lower abdominal surgery. The proportion of patients with at least one of these characteristics in the Herniamed Hernia Registry in the case of both inguinal and incisional hernia is noted to be relatively high at around 70%. In general surgery training approximately 50-100 hernia repairs on average are performed by each trainee, with around only 25 laparo-endoscopic procedures. CONCLUSION: A tailored approach is now employed and seen more so in hernia surgery and this fact is referred to and highlighted in the contemporaneous hernia guidelines published to date. In addition, with the increasing complexity of abdominal wall surgery, the number of procedures actually performed by trainees is no longer considered adequate to overcome any recognized learning curve. Therefore, to supplement general surgery training young surgeons should be offered a clinical fellowship to obtain an additional qualification as an abdominal wall surgeon and thus improve their clinical and operative experience under supervision in this field. Practicing general surgeons with a special interest in hernia surgery can undertake intensive further training in this area by participating in clinical work shadowing in hernia centers, workshops and congresses.

Two-year patient-related outcome measures (PROM) of primary ventral and incisional hernia repair using a novel three-dimensional composite polyester monofilament mesh: the SymCHro registry study.

PURPOSE: This study examined patient-related outcome measures (PROMs) after repair of ventral primary or incisional hernias using Symbotex™ composite mesh (SCM), a novel three-dimensional collagen-coated monofilament polyester textile. METHODS: Pre-operative, peri-operative, and post-operative data were obtained from the French "Club Hernie" registry with 12- and 24-month follow-up. RESULTS: One-hundred consecutive patients (mean age 62.0 ± 13.7; 51% female) underwent repair of 105 hernias: primary (39/105, 37.1%, defect area 5.2 ± 5.6 cm2) and incisional (66/105, 62.9%, 31.9 ± 38.7.8 cm2). The mean BMI was 29.7 (± 5.6 kg/m2). American Society of Anesthesiologists classifications were I 39.4%, II 37.4% and III 23.2%. 75% had risk factors for healing and/or dissection. Of 38 primary repairs, 37 were completed laparoscopically (combined approach n = 1), and of 62 incisional hernia repairs, 40 were completed laparoscopically, and 20 by open repair (combined approach n = 2). Laparoscopic was quicker than open repair (36.2 ± 23.5 min vs. 67.4 ± 25.8, p < 0001). Before surgery, 86.3% of hernias were reported to cause discomfort/pain or dysesthesia. At 24 months (93 of 100 patients), 91 (97.8%) reported no lump and 81 (87.1%) no pain or discomfort. Of 91 patients, 86 (94.5%) rated their repair "good" or "excellent." There were nine non-serious, surgeon-detected adverse events (ileus, n = 3; seroma, n = 6) and one hernia recurrence (6-12 months). CONCLUSIONS: Compared to baseline, open and laparoscopic surgery improved PROMs 24 months after primary and incisional hernia repair. Minimal complications and recurrence support the long-term efficacy of SCM.

Accreditation and certification requirements for hernia centers and surgeons: the ACCESS project.

INTRODUCTION: There is a need for hernia centers and specialist hernia surgeons because of the increasing complexity of hernia surgery procedures due to new techniques, more difficult cases and a tailored approach with an increasing public awareness demanding optimal treatment results. Therefore, the requirements for accredited/certified hernia centers and specialist hernia surgeons should be formulated by the international and national hernia societies, while taking account of the respective health care systems. METHODS: The European Hernia Society (EHS) has appointed a working group composed of 18 hernia experts from all regions of Europe (ACCESS Group-Hernia Accreditation and Certification of Centers and Surgeons-Working Group) to formulate scientifically based requirements for hernia centers and specialist hernia surgeons while taking into consideration different health care systems. A consensus was reached on the key questions by means of a meeting, a telephone conference and the exchange of contributions. The requirements formulated below were deemed implementable by all participating hernia experts in their respective countries. RESULTS: The ACCESS Group suggests for an adequately equipped hernia center the following requirements: (a) to be accredited/certified by a national or international hernia society, (b) to perform a higher case volume in all types of hernia surgery compared to an average general surgery department in their country, (c) to be staffed by experienced hernia surgeons who are beyond the learning curve for all types of hernia surgery recommended in the guidelines and are responsible for education and training of hernia surgery in their department, (d) to treat hernia patients according to the current guidelines and scientific recommendations, (e) to document each case prospectively in a registry or quality assurance database (f) to perform follow-up for comparison of their own results with benchmark data for continuous improvement of their treatment results and ensuring contribution to research in hernia treatment. To become a specialist hernia surgeon, the ACCESS Group suggests a general surgeon to master the learning curve of all open and laparo-endoscopic hernia procedures recommended in the guidelines, perform a high caseload and additionally to implement and fulfill the other requirements for a hernia center. CONCLUSION: Based on the above requirements formulated by the European Hernia Society for accredited/certified hernia centers and hernia specialist surgeons, the national and international hernia societies can now develop their own programs, while taking account of their specific health care systems.

Factors of selection and failure of ambulatory incisional hernia repair: A cohort study of 1429 patients.

BACKGROUND: Ambulatory surgery for incisional hernia repair (IHR) is not a widespread practice and is mainly performed for small incisional hernias. AIM: To assess outpatient IHR practice in France and to identify predictive factors of selection and failure of ambulatory procedures. METHOD: Surgeons of the French "Club Hernie" prospectively gathered data concerning IHR over a period of almost 5years within a nationwide database. RESULTS: A number of patients (1429) were operated on during the period of the study. The mean age was 63.3 (22-97) years old. An ambulatory procedure was planned in 305 (21%) patients. Among these, 272 (89%) IHR were effectively performed as one-day procedures. Upon multivariate analysis, predictive factors influencing practitioners for not propose an ambulatory care were increasing age (OR 0.97, P<0.001), body mass index (OR 0.95, P<0.001), ASA grade≥III (OR 0.23, P<0.001), hernia width≥4cm (OR 0.44, P<0.001), recurrent hernia (OR 0.55, P=0.01) and a laparoscopic IHR (OR 0.54, P<0.001). A number of patients (1157) were not selected preoperatively for outpatient IHR mainly because of organizational issues or an ASA grade≥III. Medical or social reasons were the main causes of failure of initially planned ambulatory settings. CONCLUSION: Ambulatory IHR is a safe and feasible practice subject to a good preoperative selection of the patients. Increasing age, body mass index, ASA grade≥III, hernia width≥4cm, recurrent hernia and a laparoscopic IHR were identified to be preoperative factors for not proposing an ambulatory care. One-day surgery for IHR could be systematically proposed for IHR of small incisional hernias (<4cm) in young patients with few comorbidities.

Patient's satisfaction at 2 years after groin hernia repair: any difference according to the technique?

BACKGROUND: Long-term patient's satisfaction after groin hernia repair is rarely studied in the literature. The aim of this study was to compare the four main techniques of inguinal hernia repair in terms of patient's satisfaction and quality of life at the 2-year follow-up in a prospective registry. METHODS: From September 2011 to March 2014, consecutive patients underwent groin hernia repair and were prospectively included in the Club Hernie registry, which also consisted of expert surgeons in parietal repair. The data on patient demographics, clinical presentation, initial workup, operative technique, postoperative course, clinical follow-up, and quality of life at 2 years (2Y-FU) were recorded. RESULTS: Overall, 5670 patients were included in the study: 1092 undergoing Lichtenstein's technique, 1259 for trans-inguinal preperitoneal technique (TIPP), 1414 for totally extraperitoneal approach (TEP) and 1905 for transabdominal preperitoneal approach (TAPP). The patients undergoing Lichtenstein's technique were significantly older, with more inguinoscrotal hernias and co-morbidities than those undergoing other techniques. A total of 83% patients had a complete 2Y-FU. The patient's satisfaction at 2Y-FU was similar between the different techniques. In the univariate and multivariate analyses, pain on postoperative day 1 was the only independent prognostic factor of the patient's satisfaction at 2Y-FU. CONCLUSION: In this large series, no statistical differences were found between the four studied techniques regarding the 2Y-Fu results and patients' satisfaction. Provided the technique has been done properly (expert surgeon) the results and the patients' satisfaction are fair and equivalent among the four studied techniques. In a multivariate analysis, the only factor predictive of bad late results was severe pain at D1.

Comparison of hernia registries: the CORE project.

INTRODUCTION: The aim of the international CORE project was to explore the databases of the existing hernia registries and compare them in content and outcome variables. METHODS: The CORE project was initiated with representatives from all established hernia registries (Danish Hernia Database, Swedish Hernia Registry, Herniamed, EuraHS, Club Hernie, EVEREG, AHSQC) in March 2015 in Berlin. The following categories were used to compare the registries: initiation and funding, data collection and use for certification of hernia centers, patient data and data protection, operative data, registration of complications and follow-up data. RESULTS: The Danish Hernia Database is the only one to qualify as a genuine national registry where participation is compulsory for entry of all procedures by all surgeons performing a hernia operation. All other registries have to be considered as voluntary and completeness of data depends upon the participating hospitals and surgeons. Only the Danish Hernia Database and the Swedish Hernia Registry are publicly funded. All other registries are reliant on financial support from the medical technology industry. As an incentive for voluntary participation in a hernia registry, hospitals or surgeons are issued a certificate confirming that they are taking part in a quality assurance study for hernia surgery. Due to data protection and privacy regulations, most registries are obliged or have chosen to enter their patient data anonymously or coded. The Danish Hernia Database and Swedish Hernia Registry utilize a national personal patient code. In the Herniamed Registry, patient data are saved in a coded and anonymous format after obtaining the patient's informed consent. CONCLUSION: Despite the differences in the way data are collected for each of the listed hernia registries, the data are indispensable in clinical research.