Pereira et al. BMC Surgery (2019) 19:103 https://doi.org/10.1186/s12893-019-0569-6 RESEARCH ARTICLE Open Access Incisional hernia recurrence after open elective repair: expertise in abdominal wall surgery matters J. A. Pereira1,2* , A. Bravo-Salva1, B. Montcusí1, S. Pérez-Farre1, L. Fresno de Prado2 and M. López-Cano3,4 Abstract Background: Recurrence after incisional hernia repair is one of the major problems related with this operation. Our objective is to analyze the influence of abdominal wall surgery expertise in the results of the open elective repair of incisional hernia. Methods: We have compiled the data of a cohort of patients who received surgery for an incisional hernia from July 2012 to December 2015 in a University Hospital. Data were collected prospectively and registered in the Spanish Register of Incisional Hernia (EVEREG). The short- and long-term complications between the groups of patients operated on by the Abdominal Wall Surgery (AWS) unit and groups operated on by surgeons outside of the specialized abdominal wall group (GS) were compared. Results: During the study period, a total of 237 patients were operated on by the open approach (114 AWS; 123 GS). One hundred seventy-five patients completed a median follow-up of 36.6 months [standard deviation (SD) = 6]. Groups were comparable in terms of age, sex, body mass index (BMI), comorbidities, and complexity of hernia. Complications were similar in both groups. Patients in the AWS group presented fewer recurrences (12.0% vs. 28.9%; P = 0.005). The cumulative incidence of recurrence was higher in the GS group [log rank 13.370; P < 0.001; odds ratio (OR) = 37.8; 95% confidence interval (CI) = 30.3–45.4]. In the multivariate analysis, surgery performed by the AWS unit was related to fewer recurrences (OR = 0.19; 95%CI = 0.07–0.58; P < 0.001). Conclusion: Incisional hernia surgery is associated with better results in terms of recurrence when it is performed in a specialized abdominal wall unit. Keywords: Incisional hernia, Open repair, Expertise, Recurrence, Abdominal wall unit Incisional hernia repair is one of the most frequent pro- that were previously repaired (18.1% primary vs. 30.6% cedures performed in General Surgery [1]. Although it is recurrence) [5]. a common operation, real-world evidence shows high Risk factors for IHR have been related to patient figures of incisional hernia recurrence (IHR) [2]. The characteristics (e.g., older age, obesity, diabetes, smoking, Danish hernia registry reported a 12.7% IHR in 3212 immunosuppression) [6], hernia characteristics (e.g., patients [3]. A Swedish registry reported up to 23% IHR transverse diameter, location, recurrence, mesh) [6], and when the hernia width was greater than 3 cm and in surgical performance (e.g., experience, dexterity, previ- onlay mesh repair [4] and, a Spanish registry reported ous training) [7, 8]. 20.7% IHR after 1-year follow-up, especially in hernias Surgical expertise in abdominal wall surgery as a risk factor for IHR has been poorly studied [7, 8]. However, in other fields such as colorectal or bariatric surgery, a * Correspondence: jose.pereira@upf.edu positive relationship of specialization and better results 1 Servicio de Cirugía General y del Aparato Digestivo, Parc de Salut Mar. has been found [9–12]. Also, in heart surgery, expertise Hospital del Mar. P, Marítim 23-25, 08003 Barcelona, Spain 2 Departament de Ciències Experimentals i de la Salut, Universitat Pompeu has been related to better outcomes [13]. Fabra, Dr. Aiguader 80, 08003 Barcelona, Spain Full list of author information is available at the end of the article © The Author(s). 2019 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Pereira et al. BMC Surgery (2019) 19:103 Page 2 of 6 In the previous context, the aim of our study is to component separation and sub lay mesh position as pri- analyze the influence of surgeon specialization and ex- mary option and composite meshes are only used when pertise in abdominal wall surgery in incisional hernia doubt of possible bowel contact is suspected. Despite outcomes, especially in recurrence. hernia repair preferences each case is studied to give an individual tailored treatment. Variables related to tech- Patients and methods nique (i.e., use of mesh, mesh position, type of mesh, asso- This is an observational cohort study of patients who ciated procedures, and use of abdominal wall component received an open elective incisional hernia repair in a separation) and variables related to the operation (i.e., single center between July 2012 and December 2015. time of surgery, intraoperative and postoperative com- Data were compiled prospectively into the Spanish plications, and length of stay) were also collected. Incisional Hernia Registry (EVEREG) [14]. Postoperative complications were stratified using the Patients were distributed in two groups: patients oper- Clavien–Dindo system [21]. ated on by surgeons non-specialized in abdominal wall After hospital discharge, patients were followed up at surgery (GS group), and patients who were operated on 1 and 6 months, 1 year, and 2 years. In each visit, the in the Abdominal Wall Surgery Unit (AWS group). presence of complications (e.g., chronic pain, chronic The AWS unit is comprised of a senior surgeon who infection, presence of bowel fistula, and mesh removal) specializes in abdominal wall surgery, a fellow, and a was assessed and recorded. Recurrence was evaluated on resident. In our General Surgery department 300 groin each follow-up visit by clinical exploration, and in case hernia, 150 primary or recurrent ventral hernia and 70 of doubt, an image exploration was indicated (ultra- incisional hernia repairs are performed per year. The sound or computed tomography). AWS unit performs approximately 150 inguinal hernia, All patients and data analyzed in our study are regis- 100 primary or recurrent ventral hernias and 50 inci- tered and available for properly follow-up into Spanish sional hernias elective repairs per year. All surgeries in- Incisional Hernia Registry database, EVEREG [14]. We cluded in the AWS group were performed by the senior included all patients with at least one year follow-up for surgeon, or at least with the senior surgeon as first as- long-term outcomes and recurrence analysis. Time to sistant. According to this parameters, our abdominal hernia recurrence was calculated as the time from wall surgeon and center would achieve specialist re- surgery to diagnosed recurrence. quired parameters published by different national orga- Statistical analysis was performed using the SPSS nizations. [15–17] The rest of the surgeries performed v.20.0 (IBM Inc., Rochester, MN) statistical package. were done by the GS group, conformed by 10 surgeons Quantitative variables are presented as the mean ± specialized in other fields. Due to the absence of criteria standard deviation (SD), and categorical variables are for the definition of specialization in abdominal wall presented as proportions. The association between quali- surgery, we established some for this category, according tative variables was assessed using contingency tables to that suggested previously: high surgical volume and (Chi-square test and Fisher test, when necessary) and more than 5 years of surgical dedication to abdominal the quantitative test using the Student t test for unpaired wall surgery [18]. data or the Mann-Whitney U test when necessary. The All the risk factors related to abdominal wall complica- normality of the distribution of quantitative variables tions were recorded [6]: age, sex, body mass index was checked using the Kolmogorov-Smirnov test. Statis- (BMI), surgical risk score from the American Society of tical significance was established at p < 0.05. The odds Anesthesiologists (ASA), presence of chronic obstructive ratio (OR) of hernia recurrence was calculated for each pulmonary disease (COPD), diabetes mellitus (DM), group with its confidence intervals (CI). history of cancer, and immunosuppression. Multivariate analysis of risk factors for incisional her- Incisional hernias were classified according to location, nia was performed. Predictive capacity of each variable width and length of hernia defect, and by complexity as and its independence were analyzed using survival defined by Slater [19] in three grades: severe, moderate, curves for Incisional hernia incidence was estimated by or minor. a non-parametric Kaplan-Meier method. A Cox propor- The Carolinas Equation for Determining Associated tional hazards regression model was used to select risk Risks (CeDAR) score [20], which predicts complications of IH recurrence. and cost previous to surgery, was calculated for all The development of the study was performed follow- patients. ing international guidelines of clinical investigation Space mesh placement, type of mesh or fixation selec- (Ethics Code and Helsinki Declaration) and according to tion is chosen according to individual hernia cases and legal regulations for confidentiality and personal data. preference of each surgeon. AWS unit tendency during The study protocol was approved by the local ethics study period was to use anterior abdominal wall committee. Pereira et al. BMC Surgery (2019) 19:103 Page 3 of 6 Results Table 2 Incisional Hernia Characteristics A total of 237 patients received an open elective inci- AWS N = 114 GS N = 123 P value sional hernia repair during the study period, with 114 Location patients in the AWS group and 123 in the GS group. No Midline N (%) 50 (43.9) 51 (41.5) 0.71 differences were found in preoperative characteristics Trocar Umbilical N (%) 29 (25.4) 38 (30.9) 0.35 between the groups, except a higher rate of previous cancer surgery in the GS group (GS 28.3% vs. AWS 19%; Parastomal N (%) 4 (4.6) 10 (8.1) 0.13 P = 0.01). In addition, the probability of surgical compli- Subcostal N (%) 5 (4.4) 6 (4.9) 0.86 cations graded by the CeDAR equation score [20] was Lumbar N (%) 3 (2.6) 0 (0) 0.07 higher in patients in the AWS group (GS 15.33 vs. AWS Pfannenstiel N (%) 7 (6.1) 6 (4.9) 0.67 18.96; P = 0.02) (Table 1). Others N (%) 16 (14.2) 12 (9.8) 0.30 Comparing hernia characteristics, we found no differ- Previous repair N (%) 30 (26.3) 19 (15.4) 0.02 ences between groups in terms of location or grade of complexity. Moderate grade hernias were the most com- Complexitya mon in both groups, and there were more severe grade Minor N (%) 22 (19.3) 34 (27) 0.14 hernias in the AWS group without reaching statistical Moderate N (%) 65 (57) 69 (56.1) 0.31 significance. Otherwise, hernias in the AWS group were Severe N (%) 27 (23.7) 20 (16.3) 0.13 larger (length > 10 cm; GS 5.6% vs. AWS 27.2%; P = 0.01; Length > 10 cm N (%) 31 (27.2) 7 (5.6) < 0.001 width > 10 cm; GS 13.8% vs. AWS 40.4%; P = 0.01), and Width > 10 cm N (%) 46 (40.4) 17 (13.8) < 0.001 more patients in the AWS group had a previous repair a Slater NJ et al. Hernia 2014; 18:7–17 [19] (GS 15.4% vs. AWS 26.3%; P = 0.02) (Table 2). Surgeries were performed mainly by senior surgeons in both groups (GS 61.8% vs. AWS 78.9%; P = 0.09). Some meshes were fixated combining suture and staples Comparison of repair techniques detected some differ- into general surgery group (Table 3). ences. The most common technique in the GS group The length of surgery was longer into the AWS group, was suprafascial onlay mesh. The preferred type of mesh whereas in-hospital and postoperative complications and in the GS group was reticular polypropylene; whereas in length of hospital stay were similar in both groups. Two the AWS group, it was composite. The sandwich tech- patients in the AWS group died due to intestinal ische- nique (2 meshes in different layers) and abdominal com- mia and acute heart failure, respectively (Table 4). ponents separation were used more frequently in AWS One-year follow-up was completed by 175 patients patients. Staples were the most frequent type of fixation (median: 36.06 mo). The long- term complications in the GS group (56.8%); whereas, suturing was the most showed no difference between groups. A higher percent- frequent type of fixation in the AWS group (97.4%) age of recurrences was detected in the GS group com- pared with the AWS group (GS 28.9% vs. AWS 12.0%; Table 1 Preoperative Patient characteristics and comorbidities P = 0.005) (Table 4). This difference was also significative AWS N = 114 GS N = 123 P value excluding parastomal hernias (GS 26.5% vs. AWS 9.2%; Age, years (SD) 63.8 (12.5) 66.2 (10.9) 0.45 P = 0.001). Age > 70 N (%) 46 (40.4) 54 (43.9) 0.33 The cumulative incidence of recurrences using a Cox survival analysis was higher in the GS group (HR = 3.73; Sex M/F N (%) 69 (60.5)/45 (39.5) 62 (50.4)/61(49.6) 0.11 95%; CI = 1.86–7.51) (Fig. 1). BMI kg/m2 (SD) 29.1(4.7) 29.0 (4.3) 0.55 Finally, using a multivariate analysis with a forward BMI > 25 N (%) 93 (81.6) 92 (74.8) 0.15 stepwise conditional logistic regression, only those sur- BMI > 30 N (%) 46 (40.4) 50 (40.7) 0.53 geries performed by the AWS unit were related to less COPD N (%) 30 (26.3) 36 (29.3) 0.35 recurrence (OR = 0.19; 95%; CI = 0.07–0.58; P < 0.001; DM N (%) 20 (17.5) 28 (22.8) 0.20 Otherwise, three factors were strongly related to higher recurrence: midline (OR = 5.81; 95%; CI = 2.16–15.63; Cancer N (%) 45 (39.5) 67 (54.5) < 0.001 P = 0.003) and parastomal location (OR = 2.47; 95%; CI = Immunosuppression 14 (12.3) 8 (6.5) 0.09 2.16–15.63; P < 0.001) and previous hernia repair (OR = N (%) 3.21; 95%; CI = 1.26–8.14; P = 0.01) (Table 5). ASA class III/IV N (%) 49 (43.0) 41 (33.3) 0.08 CeDAR Points (SD) 18.96 (14.0) 15.33 (9.9) 0.02 Discussion AWS abdominal wall surgeon, GS general surgeon, COPD chronic obstructive Specialization in General and Digestive Surgery is com- pulmonary disease, BMI body mass index, DM diabetes mellitus, ASA class American Society of Anesthesia Score, CeDAR Carolinas Equation for mon in some areas such as Colorectal Surgery, Hepato- Determining Associated Risks score biliary and Pancreatic Surgery, Gastrointestinal Surgery, Pereira et al. BMC Surgery (2019) 19:103 Page 4 of 6 Table 3 Characteristics of repair technique has had no specific regulation for specialization or to AWS GS P value certify expertise. N = 114 N = 123 Our study shows that surgeon specialization in ab- Mesh position dominal wall surgery is one main factor to reduce recur- Onlay N (%) 45 (39.5) 75 (62) < 0.001 rences in open elective incisional hernia repair. This fact Sublay N (%) 66 (57.9) 37 (30.6) < 0.001 also has been described in the Shouldice technique for inguinal hernia repair, performed at the Shouldice Hos- Intraperitoneal N (%) 3 (2.6) 9 (7.4) < 0.001 pital, which has a four-fold decreased risk of recurrence Type of mesh compared with mesh repair performed in generalist hos- Reticular N (%) 49 (43) 74 (61.2) < 0.001 pitals in Canada [25]. Low recurrence rates also have Laminar N (%) 1 (0.9) 2 (1.7) 0.52 been related to specific techniques for ventral hernia re- Composite N (%) 63 (55.3) 46 (38) < 0.001 pair, such as preperitoneal ventral hernia repair [26], Mesh fixation achieving a 5.2% rate of recurrence; and, reoperation rates for recurrence, operative time, and costs were lower in Suture N (%) 111 (97.4) 63 (52.1) < 0.001 high-volume surgeons (> 36 operations/year) [27]. Staples N (%) 17 (14.9) 68 (56.2) < 0.001 No differences between groups of patients were ob- Sandwich technique N (%)a 34 (29.8) 7 (5.8) < 0.001 served, except a high percentage of patients with previ- Anterior Components separation 24 (21) 2 (1.6) < 0.001 ous oncological surgery in the GS group. These patients (ACS) N(%)b received surgery for a previous oncologic condition from a two mesh repair in different lays positioning the same surgeon who performed the hernia repair. For b Anterior component separation as described by Ramirez with mesh reinforcement this reason, also, there are more parastomal hernia re- pairs in GS group, patients were operated by the same Obesity Surgery, Emergency Surgery, Surgical Oncol- surgeon that performed previous stoma surgery. ogy, Breast Surgery, and Endocrine Surgery, and this The complexity and type of hernia were similar in specialization is regulated and audited by boards both groups. However, a higher percentage of patients in using examinations and practice requirements [22]. In the AWS group had a previous hernia repair and higher previous papers [23, 24], better outcomes have been transversal and longitudinal diameters. Both factors demonstrated in high-level centers and by specialized point to a higher probability of recurrences and compli- surgeons. However, although some suggestions have cations in this group [28], whereas in our study, the been made [15, 16], until now abdominal wall surgery results showed fewer recurrences during follow-up. Table 4 Postoperative outcomes Short-term outcomes (30 postop days) AWS N = 114 GS N = 123 P value Length of stay days (SD) 4.9 (10.15) 4.4 (7.27) 0.50 Operative time min (SD) 103.8 (73.21) 83.3 (52.58) 0.01 Intraoperative complications N (%) 2 (1.8) 2 (1.6) 0.94 Postoperative short term complications N (%) 26 (22.8) 36 (29.3) 0.26 Exitus N (%) 2 (1.8) 0 (0) 0.14 Hematoma N (%) 2 (1.8) 6 (4.9) 0.18 Seroma N (%) 13 (11.4) 16 (13) 0.71 Wound infection N (%) 8 (7) 11 (8.9) 0.58 Skin necrosis N (%) 1 (0.9) 3 (2.4) 0.35 Urinary infection N (%) 2 (1.8) 4 (3.3) 0.46 Respiratory infection N (%) 2 (1.8) 4 (3.3) 0.46 Other complications N (%) 5 (4.4) 8 (6.5) 0.47 Reoperations N (%) 1 (0.9) 4 (3.3) 0.20 Follow-up outcomes (min. 1 year) N = 92 (80.7) a N = 83 (67.7) a P value Chronic infection N (%) 0 1 (0.6) 0.47 Mesh removal N (%) 0 0 Recurrence N (%) 11 (12) 24 (28.9) 0.008 a Percentage of completed follow-up from initial sample population Pereira et al. BMC Surgery (2019) 19:103 Page 5 of 6 Fig. 1 Cumulative incidence of recurrence The AWS group patients had a greater variability in abdominal wall surgeon or unit definition. On the other the type of surgical techniques compared with the GS hand, our unit and specialized surgeon had both accom- group. In our opinion, this fact could be related to a plished the requirements for certified hernia centers more tailored surgical approach and rational use of sur- suggested in Italy and Germany [15, 16]. gical resources in the AWS group. The GS surgeons more frequently used a reticular onlay mesh with staple Conclusions fixation. These data are similar to those of our National In conclusion, in this study, we found that any type of Registry [5]. In our opinion, this suggests that more open elective incisional hernia repair performed by a education in abdominal wall surgery should be provided specialized abdominal wall unit has a lower recurrence in our country, and guidelines for the treatment of inci- rate. sional hernias based on result of national and inter- national registries should be developed. Further, Abbreviations membership on an international board for abdominal ASA: American Society of Anesthesiologists; AWS: Abdominal wall surgeons; BMI: Body mass index; CeDAR: Carolinas Equation for Determining Associated wall surgery should be mandatory for the leadership of Risks; COPD: Chronic obstructive pulmonary disease; DM: Diabetes mellitus; specialized units. GS: General surgeons; IHR: Incisional hernia recurrence The results of our study support the idea that elective Acknowledgements incisional hernia repair should be performed by an Ab- Not applicable. dominal Wall Surgery Specialized Unit, and that the choice of the best surgical approach guided by expertise Authors’ contributions may be more important than the surgeon’s surgical JP and ABS were major contributors to writing the manuscript, and they contributed equally to this work, JP, BM and MLC were involved in the performance. design of the study and drafting the manuscript, SPF and LFP collected and The strengths of our study are that all data were analysed data, MLC critically revised the manuscript till the final version was collected prospectively and registered so they can be reached. All the authors read and approved the final manuscript. checked and audited. The weaknesses are that, by the Funding time of the study, our center had available only one spe- No financial support was obtained for this study. cialized surgeon, and there is no clear consensus of Availability of data and materials Table 5 Multivariate analysis of risk factors for recurrence The datasets generated during and/or analysed during the current study are B OR Wald 95%CI P value available from the corresponding author on reasonable request. AWS unit −1.61 0.20 8.75 0.07–0.58 0.003 Ethics approval and consent to participate Midline location 1.76 5.81 12.14 2.16–15.63 < 0.001 Written informed consent was obtained from all individual participants included in the study. Data collection in EVEREG was approved by the Ethical Parastomal location 2.47 11.86 4.67 1.26–111.82 0.031 Committee CEIC Parc de Salut Mar with number 2012/4908/I. Sutured mesh −0.93 0.39 3.20 0.14–1.09 0.073 Consent for publication Previous repair 1.35 3.85 6.95 1.14–10.50 0.008 Not applicable. 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