Volume 2, Issue 2 - Highlight: Outcomes in inguinal hernia repair / Guest Editor: Ferdinand Köckerling

The current literature suggests that perioperative complications occur in 8%–10% of all inguinal hernia repairs. However, the clinical relevance of these complications is currently unknown. In our review, based on 571,445 hernia repairs reported in 39 publications, we identified the following potential risk factors: patient age, ASA score, diabetes, smoking, mode of admission (emergency vs. elective surgery), surgery in low resource settings, type of anesthesia, and (in men) bilateral and sliding hernias. The most commonly reported complications are bleeding (0.9%), wound infection (0.5%), and pulmonary and cardiovascular complications (0.2%). In 3.9% of the included publications, a reliable grading of the reported complications according to Clavien-Dindo classification was possible. Using this classification retrospectively, we could show that, in patients with complications, these are clinically relevant for about 22% of these patients (Clavien-Dindo grade ≥IIIa). About 78% of all patients suffered from complications needing only minor (meaning mostly medical) intervention (Clavien-Dindo grade <III). Especially with regard to the low incidence of complications in inguinal hernia repair, future studies should use the Clavien-Dindo classification to achieve better comparability between studies, thus enabling better correlation with potential risk factors.

Despite all the progress made in inguinal hernia surgery driven by the development of meshes and laparoendoscopic operative techniques, the proportion of recurrent inguinal hernias is still from 12% to 13%. Recurrences can present very soon after primary inguinal hernia repair generally because of technical failure. However, they can also develop much later after the primary operation probably due to patient-specific factors. Supported by evidence-based data, this review presents the surgical risk factors for recurrent inguinal hernia after the primary operation. The following factors are implicated here: choice of operative technique and mesh, mesh fixation technique, mesh size, management of medial and lateral hernia sac, sliding hernia, lipoma in the inguinal canal, operating time, type of anesthesia, participation in a register database, femoral hernia, postoperative complications, as well as the center and surgeon volume. If these surgical risk factors are taken into account when performing primary inguinal hernia repair, a good outcome can be expected for the patient. Therefore, they should definitely be observed.

Introduction: Chronic postoperative inguinal pain (CPIP) is the most common complication after inguinal hernia operation. Eighteen percent (range, 0.7%–75%) of patients suffered from CPIP after open inguinal hernia repair and 6% (range, 1%–16%) reported CPIP after laparoendoscopic groin hernia repair. The incidence of clinically significant CPIP with impact on daily activities ranged between 10% and 12%. Debilitating CPIP with severe impact on normal daily activities or work was reported in 0.5%–6% of the cases. Materials and methods: PubMed, Medline, Embase, and the Cochrane Database were searched for studies on risk factors for chronic pain after open and endoscopic hernia repair. A systematic review of the literature was conducted using the grading of recommendations, assessment, development, and evaluations (GRADE) methodology. Results: Risk factors for CPIP with strong evidence include female gender, young age, high intensity of preoperative pain, high early postoperative pain intensity, history of chronic pain other than CPIP, operation for a recurrent hernia, and open repair technique. Risk factors for CPIP with moderate evidence include postoperative complications, neurolysis, and preservation of the ilioinguinal nerve in Lichtenstein repair. Risk factors for CPIP with low evidence include genetic predisposition (DQB1*03:02 HLA haplotype), lower preoperative optimism, high pain intensity to tonic heat stimulation, inadequate suture/staple/clip mesh fixation, ignorance of the inguinal nerves, less experienced surgeon, sensory dysfunction in the groin, and worker’s compensation. Conclusion: Detailed knowledge of the risk factors, meticulous operative technique with profound knowledge of the anatomy, proper nerve identification and handling, optimization of prosthetic materials, and careful fixation are of utmost importance for the prevention of CPIP.

Register-based observational studies in inguinal hernia repair deliver real-world data from very large patient populations and give answers to important clinical questions never evaluated in randomized controlled trials. Data from hernia registers can provide evidence of effectiveness of therapies in the general population. Hernia registers with high case load have existed in Sweden since 1992, in Denmark since 1998, and in Germany/Austria/Switzerland since 2009. In this review, the most important findings of register-based observational studies in inguinal hernia repair are presented. After an intensive literature search, 85 articles are relevant for this review. Numerous findings from these register-based studies have been incorporated into the various guidelines on inguinal hernia repair. These highlight the particular importance of hernia registers in answering key scientific and clinical questions in hernia surgery. The myriad of surgical techniques described – spanning more than 100 and with ongoing new additions – as well as the large number of associated medical devices call for, more than in other surgical disciplines, meticulous documentation of the methods used for the treatment of inguinal hernias.

Background: This study analyzes the myocardial force-generating capacity in infective endocarditis (IE) using an experimental model of isolated human atrial myocardium. In vivo , it is difficult to decide whether or not alterations in myocardial contractile behavior are due to secondary effects associated with infection such as an altered heart rate, alterations of preload and afterload resulting from valvular defects, and altered humoral processes. Our in vitro model using isolated human myocardium, in contrast, guarantees exactly defined experimental conditions with respect to preload, afterload, and contraction frequency, thus not only preventing confounding by in vivo determinants of contractility but also excluding effects of other factors associated with sepsis, hemodynamics, humoral influences, temperature, and medical treatment. Methods: We analyzed right atrial trabeculae (diameter 0.3–0.5 mm, initial length 5 mm) from 32 patients undergoing aortic and/or mitral valve replacement for acute valve incompetence caused by IE and 65 controls receiving aortic and/or mitral valve replacement for nonendocarditic valve incompetence. Isometric force amplitudes and passive resting force values measured at optimal length in the two groups were compared using Student’s t-test. Results: There were no significant differences between the groups in terms of the passive resting force. The isometric force amplitude in the endocarditis group, however, was significantly lower than in the nonendocarditis group (p=0.001). In the endocarditis group, the calculated active force, defined as the isometric force amplitude minus the resting force, was significantly lower (p<0.0001) and the resting force/active force ratio was significantly higher (p<0.0001). Using linear regression to describe the function between resting force and active force, we identified a significant difference in slope (p<0.0001), with lower values found in the endocarditis group. Conclusion: Our data suggest that the force-generating capacity of atrial myocardium is significantly reduced in patients with IE. In these patients, an elevated resting force is required to achieve a given force amplitude. It remains unclear, however, whether this is due to calcium desensitization of the contractile apparatus, presence of myocardial edema, fibrotic remodeling, disruption of contractile units, or other mechanisms.

Background: Patients with a rectal foreign body (RFB) are still a rare entity in general surgery departments but with an increasing incidence over the last years. This case is sometimes difficult to treat, and due to a lack of standardized treatment options, the aim of the study was to present our clinical experiences with the diagnostic and therapeutic approach to RFBs and a review of the currently available literature. Materials and methods: Data were collected retrospectively from the patient’s records of 20 patients who were treated due to an RFB between 2006 and 2016. Patient’s demographics, circumstances of insertion, inserted objects, clinical presentation, laboratory and imaging results, as well as surgical treatment and duration of hospital stay were analyzed. Additionally, a review of the literature was performed with the search items “rectal foreign body” and “surgical therapy”. Because many publications were just case reports, we did not perform a meta-analysis or a systematic review. Results: Twenty-two cases in 20 patients (80% male) presented to the emergency room. The mean age was 38.5±13.7 years. In 68.2% of the cases, the cause of RFB was due to sexual preferences. The following objects were inserted: six dildos, three vibrators, two bottles, one glass, one deodorant, one apple, one fever thermometer, multiple glass fragments and razor blades in one patient and six unknown objects. For 18 RFBs, manual peranal removal without anesthesia was possible in the emergency room, but two patients required intravenous analgesia. Two patients were transferred to the operating room and the foreign body was removed via the anus under general anesthesia. Open surgery with a laparotomy was necessary for two complicated cases. One patient was in need of surgery due to a vacuum generated by the RFB, whereas the second patient suffered from a sigmoid perforation. In all cases, there was no morbidity or mortality. Conclusion: In most cases, the removal of an RFB can be performed peranally in the emergency room without further complications, therefore representing the therapy of choice for RFB. Only in cases with perforation, acute abdomen, or failed peranal approaches, surgery is indicated to remove the foreign body.

Background: Robot-assisted surgery is considered to improve ergonomics over standard endoscopic surgery. Nevertheless, previous research demonstrated ergonomic deficits in the current console set-up. Aim: This study was designed to objectively assess body posture in the da Vinci console during robot-assisted endoscopic surgery. Methods: Multiple sagittal photographs from six physicians were taken during robot-assisted procedures. Trunk, neck, shoulder, elbow, hip, and knee angles were calculated and compared to ergonomic preferable joint angles. A 2D geometric model was developed using individual anthropometrics. Optimal seat height, armrest height, and viewer height were calculated. These results were compared to the findings of the sagittal photographs. Results: Mean joint angles show potentially harmful neck angles for all participants. Trunk angles vary between surgeons, from inadequate to correct. In short and very tall individuals, optimal armrest height is outside the adjustment range of the console. Conclusion: The da Vinci Surgical System console seating position results in a nonergonomic neck and trunk angle. The developed geometric model revealed that armrest height has a limited adjustment range. Adjustments to the console and optimization of preoperative settings are goals to further improve ergonomics in robot-assisted surgery.