Risk factors for long-term pain after hernia surgery

Comparison of open and laparoscopic inguinal hernia repair in the elderly patients: a randomized controlled trial

PURPOSE

It is well known that inguinal hernia repair in geriatric patients carries a higher risk of postoperative complications compared to younger patients. One of the key factors influencing these complications is the surgical technique employed. However, there is limited knowledge regarding the impact of laparoscopy on elderly patients. This prospective randomized study aims to compare the outcomes of laparoscopic and open hernia repair techniques in this patient population.

METHODS

Between April 2023 and April 2024, 120 consecutive patients aged 65 years and older with inguinal hernia were randomly assigned to one of two groups: the laparoscopic TEP group (n = 60) and the open (Lichtenstein) procedure group (n = 60). The study was registered at ClinicalTrials.gov (NCT06417346). The primary outcome of this study was the comparison of postoperative complication rates. Secondary outcomes included comparisons of hernia types, operative times, postoperative pain levels, and recurrence rates.

RESULTS

A total of 120 patients were followed up for 12 months. The mean age was 71.7 ± 6.5 years in the open group and 69.6 ± 3.9 years in the TEP group (p = 0.18). The mean operative time was 35.8 ± 7.8 min in the open group and 36.3 ± 8.7 min in the TEP group (p = 0.92). The mean time to return to normal daily activities was 10.6 ± 4.3 days in the open group and 7.5 ± 2.4 days in the TEP group (p < 0.001). On postoperative day 1, the VAS score was 3.7 ± 1.3 in the open group and 2.9 ± 1.1 in the TEP group (p < 0.001). At the end of the first month, the VAS score was 2.6 ± 1.0 in the open group and 1.7 ± 0.9 in the TEP group (p < 0.001). Chronic pain was observed in 6 patients (10%) in the open group and 1 patient (1.7%) in the TEP group (p = 0.05). No complications occurred in 51 patients (85%) in the open group and 52 patients (86.7%) in the TEP group (p = 0.84). Recurrent inguinal hernia was detected in 4 patients (6.7%) in the open group and 1 patient (1.7%) in the TEP group (p = 0.17).

CONCLUSION

Based on the data obtained from our study, laparoscopic inguinal hernia repair in elderly patients was found to offer advantages such as faster recovery, reduced postoperative and chronic pain, without an increase in complications. Given these benefits, laparoscopic hernia repair can be considered a safe and preferable approach for elderly patients.

TRIAL REGISTRATION

Clinical trials number: NCT06417346.

Evaluation of the Adjuvant Effect of Dexmedetomidine on Ropivacaine for Transversus Abdominis Plane Block in Inguinal Hernia Repair: A Prospective Double-Blind Randomized Trial

Background and goal of study: The aim of this double-blind randomized study was to investigate the efficacy of dexmedetomidine as an adjuvant to the local anesthetic in transversus abdominis plane (TAP) block for unilateral inguinal hernioplasty. Materials and Methods: Eighty eligible patients were randomly allocated into ultrasound-guided TAP block with either dexmedetomidine 0.5 mcg/kg diluted to a volume of 2 mL and ropivacaine 0.5% 25 mL (DR group) or ropivacaine 0.5% 25 mL and normal saline 2 mL (R group). The primary endpoint of this study was the numeric rating scale (NRS) score during coughing 24 h postoperatively. Secondary parameters were also evaluated. Results: Patients in the RD group demonstrated significantly less pain at rest three, six and 12 h postoperatively as compared to patients in the R group (p = 0.002, 0.032 and 0.049, respectively). Significant differences between the two groups were also demonstrated for NRS scores during coughing at 3, 6 and 12 h postoperatively (p = 0.013, 0.035 and 0.042, respectively). Additionally, the RD group demonstrated lower intraoperative remifentanil consumption (p < 0.001), lower PACU morphine requirement (p = 0.012) and lower overall PCA morphine requirement postoperatively (p < 0.001). Sedation scores, the incidence of hypotension, bradycardia and the occurrence of postoperative nausea and vomiting were no different between the two groups. Finally, the incidence of chronic pain at 6 months was significantly lower in the RD group compared to the R group (5.55% vs. 25%, p = 0.049). Conclusions: Dexmedetomidine as an adjuvant to ropivacaine reduces postoperative pain scores, has opioid-sparing effects and is associated with a favorable effect on chronic pain without side effects in patients subjected to TAP block for inguinal hernia repair.

Recurrence and complications after laparoscopic inguinal hernia repair using a self-adherent mesh: a patient-reported follow-up study

BACKGROUND

Recurrence and postoperative pain are major concerns after laparoscopic surgery for inguinal hernia. Follow-up on all patients is difficult and time consuming for both the hospital and the patient. We conducted a patient-reported follow-up study to estimate the rate of recurrence and postoperative pain in our department.

METHOD

Patients undergoing the TAPP (TransAbdominal PrePeritoneal) procedure with a self-adherent mesh at Copenhagen University Hospital - North Zealand from 2016 to 2019 received an online survey about signs of recurrence, postoperative pain, and complications. Patients reporting signs of recurrence or pain were contacted and invited for a clinical examination if relevant. Forty-five randomly selected patients who did not report any symptoms of recurrence or pain were contacted by phone for validation.

RESULTS

871 patients received a questionnaire, and 546 responded, leaving a response rate of 62.7%. Median follow-up time was 34 months (IQR 23-47). The self-reported recurrence rate was 8.1% (95% CI: 6.0-11.0%). On examination, recurrence was diagnosed in 2.4% (95% CI: 1.4-4.1%) of the patients. When including the patients with self-reported recurrence who did not accept the offer of clinical examination, the recurrence rate was 3.8% (95% CI: 2.5-5.8%). Four patients (0.7%, 95% CI: 0.2-2.0%) underwent herniotomy for recurrence. The rate of chronic postoperative pain impairing daily activity was 0.5%.

CONCLUSION

We found an acceptable low rate of recurrence and postoperative pain compared to other studies. The patient-reported recurrence rate was significantly higher than the clinical recurrence rate after the examination, indicating that patient-reported recurrence seems to overestimate true recurrence after TAPP.

A bionic 3D-printed hydrogel microneedle of composite mesh for abdominal wall defect repair

The use of mesh repair is a frequently employed technique in the clinical management of abdominal wall defects. However, for intraperitoneal onlay mesh (IPOM), the traditional mesh requires additional fixation methods, and these severely limit its application in the repair of abdominal wall defects. We drew inspiration from the adhesion properties of mussels for the present study, functionalized carboxymethyl cellulose (CMC) with dopamine (DA), and added polyvinyl alcohol (PVA) to the composite to further improve the wet adhesive ability of hydrogels. The CMC-DA/PVA hydrogel microneedles (MNs) were fabricated using an inverse molding technique, incorporating a 3D-printed thermoplastic polyurethane mesh to enhance mechanical strength. The tensile test and porcine skin adhesion test demonstrated that the hydrogel mesh exhibited satisfactory mechanical properties and adhesion in vitro, thus replacing the traditional fixed mesh in the treatment of rat full-thickness abdominal wall defects. The results of animal experiments revealed that the hydrogel mesh promoted the growth of new granulation tissue and inhibited inflammatory responses, thereby paving the way for a novel approach in treating full-thickness abdominal wall defects.

A retrospective study of 3D laparoscopy and 2D laparoscopy in transabdominal preperitoneal (TAPP) for unilateral inguinal hernia in elderly patients

This study aims to explore the safety and efficacy of 3D laparoscopy in elderly patients undergoing transabdominal preperitoneal (TAPP) surgery for inguinal hernia. Patients were divided into two groups based on the laparoscopic equipment used during surgery. Clinical data preoperatively, intraoperatively, and postoperatively were collected and subjected to statistical analysis. From January 2020 to August 2023, a total of 127 patients with primary unilateral inguinal hernia were evaluated in this study, 61 in the 3D TAPP group and 66 in the 2D TAPP group. There were no statistically significant differences in baseline data, including average age, gender distribution, BMI index, hernia type, hernia defect size and location, comorbidities, and usage of anticoagulant drugs between the two groups (P > 0.05). In terms of operative indicators, the 3D group showed shorter mean operation time (51.61 ± 7.16 min vs. 78.59 ± 13.51 min, P < 0.001), mean mesh placement time (6.07 ± 1.40 min vs. 9.77 ± 1.21 min, P < 0.001), and mean peritoneal suture time (7.34 ± 1.85 min vs. 9.73 ± 1.32 min, P < 0.001) compared to the 2D group. However, there were no statistically significant differences in mean blood loss, postoperative pain scores, postoperative hospital stay, and total hospital costs between the two groups (P > 0.05). The incidence of postoperative complications did not differ significantly between the two groups (P > 0.05). No adverse reactions such as dizziness or nausea were reported by surgeons during the procedures in either group. Three-dimensional laparoscopy in TAPP surgery provides high-definition, three-dimensional surgical images, reducing the difficulty of operations and effectively shortening the operation time.

Matching males and females undergoing non mesh primary unilateral inguinal hernia repair: evaluating sex differences in preoperative and acute postoperative pain

PURPOSE

The objective was to compare pain and related psychological factors during the preoperative and acute postoperative period between male and female patients, who underwent non mesh primary unilateral inguinal hernia repair.

METHODS

After ethics approval, informed consent was obtained, and data were collected. Male and female participants were compared by manually matching one-to-one on 10 variables. Descriptive statistics (mean ± standard deviation and frequency) as well as numerical rating scales from 0 to 10 were used. Comparison tests were performed using Chi-square or Fisher's Exact test for categorical data and independent samples t-test or non-parametric equivalent tests for numerical scores. p < 0.05 is reported as statistically significant. To control type I error, Bonferroni correction was used.

RESULTS

72 participants with 36 matched pairs were included. Sex differences were found for operation length (p = .006), side of operation (p = .002), and hernia type (p = .013). Significant differences between the sexes were not found at the preoperative or postoperative time for resilience, pain interference or pain severity related measures, postoperative hernia pain incidence, pain catastrophizing, depression and anxiety symptoms, or return to normal activities.

CONCLUSION

When controlling for known confounders and using a conservative Type I error rate, pain and related factors between the sexes did not differ significantly.

Perioperative Risk Factors for Persistent Postsurgical Pain After Inguinal Hernia Repair: Systematic Review and Meta-Analysis

Persistent postsurgical pain (PPSP) is one of the most bothersome and disabling long-term complications after inguinal hernia repair surgery. Understanding perioperative risk factors that contribute to PPSP can help identify high-risk patients and develop risk-mitigation approaches. The objective of this study was to systematically review and meta-analyze risk factors that contribute to PPSP after inguinal hernia repair. The literature search resulted in 303 papers included in this review, 140 of which were used for meta-analyses. Our results suggest that younger age, female sex, preoperative pain, recurrent hernia, postoperative complications, and postoperative pain are associated with a higher risk of PPSP. Laparoscopic techniques reduce the PPSP occurrence compared to anterior techniques such as Lichtenstein repair, and tissue-suture techniques such as Shouldice repair. The use of fibrin glue for mesh fixation was consistently associated with lower PPSP rates compared to tacks, staples, and sutures. Considerable variability was observed with PPSP assessment and reporting methodology in terms of study design, follow-up timing, clarity of pain definition, as well as pain intensity or interference threshold. High or moderate risk of bias in at least one domain was noted in >75% of studies. These may limit the generalizability of our results. Future studies should assess and report comprehensive preoperative and perioperative risk factors for PPSP adjusted for confounding factors, and develop risk-prediction models to drive stratified PPSP-mitigation trials and personalized clinical decision-making. PERSPECTIVE: This systematic review and meta-analysis summarizes the current evidence on risk factors for persistent pain after inguinal hernia repair. The findings can help identify patients at risk and test personalized risk-mitigation approaches to prevent pain. PROSPERO REGISTRATION: htttps://www.crd.york.ac.uk/prospero/display_record.php?RecordID=154663.

Incidence and predictors of chronic pain after inguinal hernia surgery: a systematic review and meta-analysis

PURPOSE

The mesh is currently the preferred treatment option for hernia repair surgery. Chronic postoperative inguinal pain (CPIP), lasting more than 3 months after surgery, is a complication that significantly impacts patients' quality of life. Currently, there is a lack of evidence-based information describing the incidence and independent predictive factors of chronic pain, posing a serious challenge in clinical practice for devising personalized prevention strategies. Hence, we conducted this systematic review and meta-analysis to investigate the incidence and predictive factors, aiming to provide a reference for developing plans to prevent chronic pain.

METHODS

We conducted a systematic search of PubMed, Cochrane, Embase, and Web of Science, with the retrieval cutoff date set at December 17, 2022. The included studies underwent assessment using the NOS scale, and subgroup analysis for the incidence was carried out based on different regions.

RESULTS

Ultimately, 18 studies were included, involving 29,466 patients. Meta-analysis showed that the pooled incidence of chronic pain was 17.01% (95%CI 12.78% ~ 21.71%). The incidence was 18.65% (95%CI 13.59% ~ 24.29%) in Europe, 14.70% (95%CI 7.87% ~ 23.17%) in Asia, and 6.04%(95%CI 4.62 ~ 7.64) in North America. Furthermore, We also found that the risk factors for CPIP are younger age [OR = 2.261 (95%CI 1.126 ~ 4.549)], presence of other postoperative complications [OR = 1.849 (95%CI 1.034 ~ 3.305)], hernial sac defect < 3 cm [OR = 1.370 (95%CI 1.012 ~ 1.853)], being female [OR = 1.885 (95%CI 1.024 ~ 3.472)], postoperative pain [OR = 1.553 (95%CI 1.276 ~ 1.889)], preoperative pain [OR = 2.321 (95%CI 1.354 ~ 3.979)], and having a history of ipsilateral inguinal hernia repair [OR = 2.706 (95% CI 1.445 ~ 5.069)].

CONCLUSIONS

The incidence of persistent pain following hernia repair surgery is high in current clinical practice, a concern that should not be overlooked. Stratified assessment tools need to be established for patients experiencing early chronic pain, and personalized follow-up strategies and preventive interventions should be developed for those with potentially high risks. These measures aim to enhance the quality of life for patients after hernia repair.

The association of permanent versus absorbable fixation on developing chronic post-herniorrhaphy groin pain in patients undergoing laparoscopic inguinal hernia repair

INTRODUCTION

Fixation of mesh during minimally invasive inguinal hernia repair is thought to contribute to chronic post-herniorrhaphy groin pain (CGP). In contrast to permanent tacks, absorbable tacks are hypothesized to minimize the likelihood of CGP. This study aimed to compare the rates of CGP after laparoscopic inguinal hernia repair between absorbable versus permanent fixation at maximum follow-up.

METHODS

This is a post hoc analysis of a randomized controlled trial in patients undergoing laparoscopic inguinal hernia repair (NCT03835351). All patients were contacted at maximum follow-up after surgery to administer EuraHS quality of life (QoL) surveys. The pain and restriction of activity subdomains of the survey were utilized. The primary outcome was rate of CGP, as defined by a EuraHS QoL pain domain score ≥ 4 measured at ≥ 1 year postoperatively. The secondary outcomes were pain and restriction of activity domain scores and hernia recurrence at maximum follow-up.

RESULTS

A total of 338 patients were contacted at a mean follow-up of 28 ± 11 months. 181 patients received permanent tacks and 157 patients received absorbable tacks during their repair. At maximum follow-up, the rates of CGP (27 [15%] vs 28 [18%], P = 0.47), average pain scores (1.78 ± 4.38 vs 2.32 ± 5.40, P = 0.22), restriction of activity scores (1.39 ± 4.32 vs 2.48 ± 7.45, P = 0.18), and the number of patients who reported an inguinal bulge (18 [9.9%] vs 15 [9.5%], P = 0.9) were similar between patients with permanent versus absorbable tacks. On multivariable analysis, there was no significant difference in the odds of CGP between the two groups (OR 1.23, 95% CI [0.60, 2.50]).

CONCLUSION

Mesh fixation with permanent tacks does not appear to increase the risk of CGP after laparoscopic inguinal hernia repair when compared to fixation with absorbable tacks. Prospective trials are needed to further evaluate this relationship.

Fibroblast matrix implants-a better alternative for incisional hernia repair?

The standard surgical procedure for abdominal hernia repair with conventional prosthetic mesh still results in a high recurrence rate. In the present study, we propose a fibroblast matrix implant (FMI), which is a three-dimensional (3D) poly-L-lactic acid scaffold coated with collagen (matrix) and seeded with fibroblasts, as an alternative mesh for hernia repair. The matrix was seeded with fibroblasts (cellularized) and treated with a conditioned medium (CM) of human Umbilical Cord Mesenchymal Stem Cells (hUC-MSC). Fibroblast proliferation and function were assessed and compared between treated with CM hUC-MSC and untreated group, 24 h after seeding onto the matrix (n= 3). To study the matricesin vivo,the hernia was surgically created on male Sprague Dawley rats and repaired with four different grafts (n= 3), including a commercial mesh (mesh group), a matrix without cells (cell-free group), a matrix seeded with fibroblasts (FMI group), and a matrix seeded with fibroblasts and cultured in medium treated with 1% CM hUC-MSC (FMI-CM group).In vitroexamination showed that the fibroblasts' proliferation on the matrices (treated group) did not differ significantly compared to the untreated group. CM hUC-MSC was able to promote the collagen synthesis of the fibroblasts, resulting in a higher collagen concentration compared to the untreated group. Furthermore, thein vivostudy showed that the matrices allowed fibroblast growth and supported cell functionality for at least 1 month after implantation. The highest number of fibroblasts was observed in the FMI group at the 14 d endpoint, but at the 28 d endpoint, the FMI-CM group had the highest. Collagen deposition area and neovascularization at the implantation site were observed in all groups without any significant difference between the groups. FMI combined with CM hUC-MSC may serve as a better option for hernia repair, providing additional reinforcement which in turn should reduce hernia recurrence.

Clinical application of the dissection of the preperitoneal space without electrocoagulation in laparoscopic transperitoneal inguinal hernia repair throughout of the whole process

Introduction

The dissection of the preperitoneal space is performed using a monopolar instrument to prevent bleeding in laparoscopic transabdominal preperitoneal hernia repair (TAPP). It may also cause energy injuries and nerve damage.

Aim

To assess the effectiveness and safety of dissection of the preperitoneal space without electrocoagulation (DPSWE) in TAPP throughout the process.

Material and methods

A retrospective analysis of data of 134 patients was made. The electrocoagulation group (EG) relied on monopolar instruments. In the non-electrocoagulation group (NEG) mainly scissors were used without electrocoagulation. The patients were followed for up for 3 months. Intraoperative and postoperative conditions and other complications were observed.

Results

The VAS scores in the NEG were lower than those in the EG (p < 0.05). The operation time in the NEG was shorter than that in the EG (p < 0.05). Hospitalization expenses, scrotal seroma formation, and rupture of hernia sac in the NEG were lower than those in the EG (p < 0.05). The intraoperative bleeding volume above 20 ml in the NEG was higher than that in the EG. There was no significant difference in the incidence of postoperative bleeding, vas deferens injury, intestinal injury, surgical site infection, length of hospital stay, urinary retention and hernia recurrence in the NEG and the EG (p > 0.05). There was no significant difference in the incidence of surgical site infections (SSIs) in the NEG and the EG.

Conclusions

DPSWE is effective and safe. DPSWE may reduce postoperative pain and have no significant increase in postoperative bleeding.

Comprehensive systematic review on the self-gripping mesh vs sutured mesh in inguinal hernia repair

Objective

The objective of this systematic review is to analyse the randomised control trials (RCTs) comparing the self-gripping mesh (SGM) with sutured mesh fixation (SMF) in open inguinal hernia repair.

Materials and methods

RCTs comparing SGM with SMF in open inguinal hernia repair were selected from medical electronic databases and analysis was performed using the principles of meta-analysis with RevMan version 5 statistical software.

Results

Seventeen RCTs involving 3863 patients were used for the final analysis. In the random effect model analysis, the operative time [mean difference - 7.72, 95 %, CI (-9.08, -6.35), Z = 11.07, P = 0.00001] was shorter for open inguinal hernia repair with SGM. However, there was noteworthy heterogeneity (Tau2 = 4.24; Chi2 = 1795.04, df = 12; (P = 0.00001; I2 = 99 %) among the included studies. The incidence of chronic groin pain [odds ratio 1.17, 95 %, CI (0.88, 1.54), Z = 1.09, P = 0.28], postoperative complications [odds ratio 0.92, 95 %, CI (0.73, 1.16), Z = 0.71, P = 0.48] and recurrence [odds ratio 1.31, 95 %, CI (0.80, 2.12), Z = 1.08, P = 0.28] were statistically similar between both groups, without heterogeneity.

Conclusion

SGM failed to demonstrate a clinical advantage over SMF in terms of perioperative outcomes although the duration of surgery was shorter in SGM.

Investigating the safety and efficacy of nerve stimulation for management of groin pain after surgical herniorrhaphy: a systematic review and meta-analysis

PURPOSE

Chronic post-operative inguinal pain (CPIP) following inguinal hernia repair has been a major sequela affecting 4000-48000 patients annually. Optimal management of CPIP has been a challenge, and pharmacological management particularly with opioids has shown unsatisfactory results. The main objective of this systematic review is to investigate the safety and efficacy of neuromodulation as an alternative intervention for the management of post-operative inguinal pain.

METHODS

A literature search was conducted by three reviewers to identify all relevant studies on the use of neuromodulatory interventions for treating post-operative inguinal pain. Data on study characteristics, neuromodulatory modalities, and patient's clinical data such as pre/post-interventional pain scores and analgesic requirements were extracted and reported.

RESULTS

A total of 389 patients with 357 (95.9%) males and 15 (4.1%) females were evaluated. The mean age of study participants was 47.9 ± 10.4 years. There were 187 (48.1%) and 202 (51.9%) patients allocated to the control and trial groups, respectively. The most common neuromodulation modality was TENS (4, 36.4%), followed by SCS (3, 27.3%), PNS (3, 27.3%), and acupuncture-assisted (2, 18.2%). The overall mean follow-up duration of the entire cohort was 3.8 months. The mean difference between pre-operative and post-operative VAS scores in the trial groups was 4.65 (95% Confidence Interval [CI], 2.97, 6.33), which was statistically significant (P value < 0.05). Patient-reported outcome measures showed significant responsiveness toward their treatments.

CONCLUSION

Nerve stimulation, in its many forms, is a safe and feasible option for the management of post-operative inguinal pain.

Efficacy and safety of mesh non-fixation in patients undergoing laparo-endoscopic repair of groin hernia: a systematic review and meta-analysis

PURPOSE

To examine updated evidence on the efficacy and safety of mesh non-fixation in patients undergoing laparo-endoscopic repair of groin hernias.

METHODS

We searched MEDLINE, Cochrane Central Library, Embase, ClinicalTrials. gov, and ICTRP databases to identify randomized controlled trials. The primary outcomes were recurrence, chronic pain, and return to daily life. The certainty of evidence (CoE) was assessed by grading recommendations, assessments, developments, and evaluations. We performed a subgroup analysis based on the surgical type. This study was registered with PROSPERO (CRD 42022368929).

RESULTS

We included 25 trials with 3,668 patients (4,038 hernias) were included. Mesh non-fixation resulted in little to no difference in hernia recurrence (relative risk [RR]:1.40, 95% confidence interval [CI]:0.59-3.31; I2 = 0%; moderate CoE) and chronic pain (RR:0.48, 95% CI:0.13-1.78; I2 = 77%; moderate CoE), but reduced return to daily life (mean difference [MD]: - 1.79 days, 95% CI: - 2.79 to -0.80; I2 = 96%; low CoE). In subgroup analyses, the transabdominal preperitoneal approach (TAPP) (MD: - 2.97 days, 95% CI: - 4.87 to - 1.08; I2 = 97%) reduced return to daily life than total extraperitoneal inguinal approach (MD: - 0.24 days, 95% CI - 0.71 to 0.24; I2 = 61%) (p = 0.006).

CONCLUSIONS

Mesh nonfixation improves the return to daily life without increasing the risk of hernia recurrence or chronic pain. Surgeons and patients may discuss mesh nonfixation options to accommodate a patient's desired return to daily life. Further trials focusing on TAPP are required to confirm these findings.

Efficacy and Safety of Transcutaneous Electrical Nerve Stimulation in Patients Undergoing Inguinal Hernia Repair: A Systematic Review and Meta-analysis

Background

Postoperative pain is a major cause of delayed recovery following inguinal hernia repair. Transcutaneous electrical nerve stimulation (TENS) is a simple, low-cost method of noninvasive analgesia. This study aimed to assess the efficacy and safety of TENS for pain management following inguinal hernia repair.

Methods

We searched nine electronic databases and trial registries to identify randomized controlled trials (RCTs). The primary outcomes were postoperative pain and the use of rescue analgesics. The Risk of Bias 2 tool was used to evaluate the risk of bias in the included trials. The certainty of the evidence was assessed using Grading of Recommendations, Assessment, Development, and Evaluations (GRADE). Subgroup analyses were conducted based on the anesthesia type or TENS dose and frequency. This study is registered with PROSPERO (CRD42022353932).

Results

Eleven RCTs, with a total of 559 patients, were included. The overall risk of bias was concerning due to the lack of information about concealment or published protocols. TENS may reduce pain on postoperative day (POD) 0 (standardized mean difference [SMD], -2.14; 95% confidence interval [CI], -3.54 to -0.73; moderate certainty of the evidence), POD 1 (SMD, -1.22; 95% CI, -1.92 to -0.52; moderate certainty of the evidence), and POD 2 (SMD, -0.97; 95% CI, -2.04 to 0.10; low certainty of the evidence). According to the subgroup analyses, postoperative pain was reduced, particularly with local anesthesia or repetitive and frequent TENS (P < 0.05). TENS may result in little-to-no difference in rescue analgesic use (risk ratio, 0.75; 95% CI, 0.47-1.18; low certainty of the evidence). No serious adverse events occurred (moderate certainty of the evidence).

Conclusions

TENS may reduce pain in patients who have undergone inguinal hernia repair. Further trials are warranted to confirm our findings.

Postoperative Analgesics Score as a Predictor of Chronic Postoperative Inguinal Pain After Inguinal Hernia Repair: Lessons Learned From a Retrospective Analysis

BACKGROUND

Chronic postoperative inguinal pain (CPIP) is a common complication after inguinal hernia surgery and occurs in up to 10-14% of cases. CPIP has a significant impact on daily life, work ability and thus compromises quality of life. The aim of this retrospective study was an in-depth analysis of patients undergoing inguinal hernia repair to further refine the prediction of the onset of CPIP reliably.

METHODS

A single center retrospective analysis of patients with who underwent open or minimally invasive inguinal hernia repair from 2016 to 2021 was carried out. Complication rates, detailed analysis of postoperative pain medication and quality of life using the EuraHS Quality of Life questionnaire were assessed.

RESULTS

Out of 596 consecutive procedures, 344 patients were included in detailed analyses. While patient cohorts were different in terms of age and co-morbidities, and the prevalence of CPIP was 12.2% without differences between the surgical procedures (Lichtenstein: 12.8%; TEP 10.9%; TAPP 13.5%). Postoperative pain was evaluated using a newly developed analgesic score. Patients who developed CPIP later had a significant higher consumption of analgesics at discharge (p = 0.016). As additional risk factors for CPIP younger patient age and postoperative complications were identified.

CONCLUSION

The prospective use of the analgesic score established here could be helpful to identify patients that are at risk to develop CPIP. These patients could benefit from a structured follow-up to allow early therapeutic intervention to prevent chronification and restore the quality of life.

An international survey of 1014 hernia surgeons: outcome of GLACIER (global practice of inguinal hernia repair) study

INTRODUCTION

The practice of inguinal hernia repair varies internationally. The global practice of inguinal hernia repair study (GLACIER) aimed to capture these variations in open, laparoscopic, and robotic inguinal hernia repair.

METHODS

A questionnaire-based survey was created on a web-based platform, and the link was shared on various social media platforms, personal e-mail network of authors, and e-mails to members of the endorsed organisations, which include British Hernia Society (BHS), The Upper Gastrointestinal Surgical Society (TUGSS), and Abdominal Core Health Quality Collaborative (ACHQC).

RESULTS

A total of 1014 surgeons from 81 countries completed the survey. Open and laparoscopic approaches were preferred by 43% and 47% of participants, respectively. Transabdominal pre-peritoneal repair (TAPP) was the favoured minimally invasive approach. Bilateral and recurrent hernia following previous open repair were the most common indications for a minimally invasive procedure. Ninety-eight percent of the surgeons preferred repair with a mesh, and synthetic monofilament lightweight mesh with large pores was the most common choice. Lichtenstein repair was the most favoured open mesh repair technique (90%), while Shouldice repair was the favoured non-mesh repair technique. The risk of chronic groin pain was quoted as 5% after open repair and 1% after minimally invasive repair. Only 10% of surgeons preferred to perform an open repair using local anaesthesia.

CONCLUSION

This survey identified similarities and variations in practice internationally and some discrepancies in inguinal hernia repair compared to best practice guidelines, such as low rates of repair using local anaesthesia and the use of lightweight mesh for minimally invasive repair. It also identifies several key areas for future research, such as incidence, risk factors, and management of chronic groin pain after hernia surgery and the clinical and cost-effectiveness of robotic hernia surgery.

Does the Weight Matter? Short-Term Outcomes of Lightweight Versus Heavyweight Three-Dimensional Anatomical Mesh in Minimally Invasive Inguinal Hernia Repair

Background: The type of mesh used in inguinal hernia repairs remains controversial. There are limited data looking at specific mesh-related complications. The objective of this study is to assess postoperative 90-day outcomes in lightweight (LW) and heavyweight (HW) anatomical mesh in minimally invasive inguinal hernia repairs. Methods: A retrospective single-center database was queried for all adult minimally invasive inguinal hernia repairs with anatomical mesh from July 2016 to March 2021. Demographics and surgical outcomes were analyzed. Univariate analysis and multivariate logistic regression were performed. Results: Six hundred forty-seven minimally invasive inguinal hernia repairs were performed with 423 (65.3%) using HW and 224 (24.7%) using LW mesh. There was no difference in mean body mass index between the groups (26.9 ± 4.2 kg/m2 in the LW group and 27.1 ± 4.2 kg/m2 in the HW group; P = .69). There was no difference in type of mesh fixation used in either group, with tacker being the most common. There was no difference in postoperative emergency department (ED) visit (P = .625), readmission rates (P = .562), or postoperative complications between the two groups. Fifty patients presented with seroma within 90 days. There were five recurrences in each group and only one surgical site infection in the LW within 90 days. Multivariate logistic regression was performed, and predictors of seroma formation included age (odds ratio [OR] 1.02; confidence interval [CI] 1-1.04; P = .02) and hypertension (HTN) (OR 1.8; CI 1.03-3.4; P = .039). HW mesh was not associated with seroma formation (OR 1.04; CI 0.5-1.9; P = .895). Similarly, HW mesh was not associated with surgical site occurrences (SSO) (OR 1.04; CI 0.5-1.8; P = .872). HTN was associated with SSO (OR 1.74; CI 1-3.05; P = .048). Conclusion: Our study did not favor the use of LW or HW mesh when comparing postoperative complications or clinical outcomes. HW mesh was not associated with either seroma formation or SSO.

Cytomorphological Effects of Lightweight and Heavyweight Polypropylene Mesh on the Ilioinguinal Nerve: An Experimental Study

Objective This study aimed to investigate the cytomorphological effects of heavyweight and lightweight mesh on the ilioinguinal nerve in an experimental animal model. Methods Sixteen New Zealand male rabbits were included in the study. The left inguinal regions of the first six animals were assigned as controls and the right inguinal regions were assigned as the sham group. The left inguinal regions of the remaining 10 animals were assigned as the lightweight mesh group and the right inguinal regions were assigned as the heavyweight mesh group. No intervention was performed in the control group. In the sham group, only ilioinguinal nerve exploration was performed. In mesh groups, ilioinguinal nerve exploration was performed and the mesh was implanted on the ilioinguinal nerve. After three months, ilioinguinal nerve specimens were excised from both sides for cytomorphological examination. Results Myelin sheath thickening, separation of the myelin layers, and myelin vacuolization were more pronounced in the heavyweight mesh group compared to the lightweight mesh group. The G-ratio was moderately increased in the heavyweight mesh group when compared to other groups. The ratio of fibers with ≤4 µm diameter was higher in the lightweight mesh group compared to other groups, and the ratio of fibers with ≥9 µm diameter was higher in the heavyweight mesh group than in the other groups (p<0.05). Conclusion Both of the meshes induce cytomorphological alterations on the adjacent nerve tissues caused by foreign body reaction and compression. Ilioinguinal nerve degeneration was more pronounced in the heavyweight mesh than in the lightweight mesh. Histological alterations on the ilioinguinal nerves caused by different meshes may be related to chronic pain after hernia surgery. We believe our study will serve as a guide for future studies on the topic.

Transinguinal preperitoneal (TIPP) vs endoscopic total extraperitoneal (TEP) procedure in unilateral inguinal hernia repair: a randomized controlled trial

PURPOSE

The Lichtenstein hernioplasty has long been seen as the gold standard for inguinal hernia repair. Unfortunately, this repair is often associated with chronic pain, up to 10-35%. Therefore, several new techniques have been developed, such as the transinguinal preperitoneal patch (TIPP) and the endoscopic total extraperitoneal (TEP) technique. Several studies showed beneficial results of the TIPP and TEP compared to the Lichtenstein hernioplasty; however, little is published on the outcome when comparing the TIPP and TEP procedures. This study aimed to evaluate outcomes after the TIPP vs the TEP technique for inguinal hernia repair.

METHODS

A single-center randomized controlled trial was carried out between 2015 and 2020. A total of 300 patients with unilateral inguinal hernia were enrolled and randomized to the TIPP- or TEP technique. Primary outcome was chronic pain (defined as any pain following the last 3 months) and quality of life, assessed with Carolinas comfort scale (CCS) at 12 months. Secondary outcomes were: wound infection, wound hypoesthesia, recurrence, readmission within 30 days, and reoperation.

RESULTS

A total of 300 patients were randomized (150 per group). After a follow-up of 12 months, we observed significantly less postoperative chronic groin pain, chronic pain at exertion, wound hypoesthesia, and wound infections after the TEP when compared to the TIPP procedure. No significant differences in quality of life, reoperations, recurrence rate, and readmission within 30 days were observed.

CONCLUSION

We showed that the TEP has a favorable outcome compared to the TIPP procedure, leading to less postoperative pain and wound complications, whereas recurrence rates and reoperations were equal in both the groups.

A Critical Appraisal of the Chronic Pain Rate After Inguinal Hernia Repair

Purpose: To critically appraise highly cited studies reporting on the rate of chronic pain after inguinal hernia repair. Methods: Google Scholar was searched on 23 May 2022. We only included publications with more than 10 citations per year since publication and more than 100 citations in total. Both reports of original data and systematic reviews were included. Risk of bias and quality of the included studies were assessed with either the Joanna Briggs Institute Checklist for Prevalence Studies or the AMSTAR 2 depending on study design. Results: Twenty studies were included and evaluated. The rate of chronic postoperative inguinal pain of any degree ranged from 10%-63%, and the rate of moderate-to-severe pain ranged from 1%-18%. All studies reported the rate of pain of any degree, and most studies reported the rate of moderate-to-severe pain influencing daily activities. Studies used different temporal definitions of chronic pain, but most studies defined it as pain persisting either three or six months postoperatively. Ten studies used unvalidated questionnaires or significantly modified versions of validated questionnaires. Eleven studies primarily included patients receiving open repair. Included studies had median 21 citations per year (range 10-39) and median 387 citations in total (range 127-788). Conclusion: The rates of chronic postoperative inguinal pain reported in the included highly cited studies are possibly inaccurate, excessive, and outdated. New prospective studies based on uniform definitions and standards of measurement are warranted to better assess a contemporary chronic pain rate after inguinal hernia repair.

Do postoperative complications correlate to chronic pain following inguinal hernia repair? A prospective cohort study from the Swedish Hernia Register

PURPOSE

To analyse if postoperative complications constitute a predictor for the risk of developing long-term groin pain.

METHODS

Population-based prospective cohort study of 30,659 patients operated for inguinal hernia 2015-2017 included in the Swedish Hernia Register. Registered post-operative complications were categorised into hematomas, surgical site infections, seromas, urinary tract complications, and acute post-operative pain. A questionnaire enquiring about groin pain was distributed to all patients 1 year after surgery. Multivariable logistic regression analysis was used to find any association between postoperative complications and reported level of pain 1 year after surgery.

RESULTS

The response rate was 64.5%. In total 19,773 eligible participants responded to the questionnaire, whereof 73.4% had undergone open anterior mesh repair and 26.6% had undergone endo-laparoscopic mesh repair. Registered postoperative complications were: 750 hematomas (2.3%), 516 surgical site infections (1.6%), 395 seromas (1.2%), 1216 urinary tract complications (3.7%), and 520 hernia repairs with acute post-operative pain (1.6%). Among patients who had undergone open anterior mesh repair, an association between persistent pain and hematomas (OR 2.03, CI 1.30-3.18), surgical site infections (OR 2.18, CI 1.27-3.73) and acute post-operative pain (OR 7.46, CI 4.02-13.87) was seen. Analysis of patients with endo-laparoscopic repair showed an association between persistent pain and acute post-operative pain (OR 9.35, CI 3.18-27.48).

CONCLUSION

Acute postoperative pain was a strong predictor for persistent pain following both open anterior and endo-laparoscopic hernia repair. Surgical site infection and hematoma were predictors for persistent pain following open anterior hernia repair, although the rate of reported postoperative complications was low.

Long-term Follow-up of Patients With Hernia Using the Hernia-Specific Quality-of-Life Mobile App: Feasibility Questionnaire Study

BACKGROUND

Hernia repair is one of the most common surgical procedures; however, the long-term outcomes are seldom reported due to incomplete follow-up.

OBJECTIVE

The aim of this study was to examine the use of a mobile app for the long-term follow-up of hernia recurrence, complication, and quality-of-life perception.

METHODS

A cloud-based corroborative system drove a mobile app with the HERQL (Hernia-Specific Quality-of-Life) questionnaire built in. Patients who underwent hernia repair were identified from medical records, and an invitation to participate in this study was sent through the post.

RESULTS

The response rate was 11.89% (311/2615) during the 1-year study period, whereas the recurrence rate was 1.0% (3/311). Causal relationships between symptomatic and functional domains of the HERQL questionnaire were indicated by satisfactory model fit indices and significant regression coefficients derived from structural equational modeling. Regarding patients' last hernia surgeries, 88.7% (276/311) of the patients reported them to be satisfactory or very satisfactory, 68.5% (213/311) of patients reported no discomfort, and 61.1% (190/311) of patients never experienced mesh foreign body sensation. Subgroup analysis for the most commonly used mesh repairs found that mesh plug repair inevitably resulted in worse symptoms and quality-of-life perception from the group with groin hernias.

CONCLUSIONS

The mobile app has the potential to enhance the quality of care for patients with hernia and facilitate outcomes research with more complete follow-up.

Design, synthesis, and biological evaluation of low-toxic lappaconitine derivatives as potential analgesics

The C₁₈-diterpenoid alkaloid lappaconitine (LA) is a non-addictive analgesic used in China. The toxicity (LD₅₀ = 11.7 mg/kg) limits its application. Two series of LA derivatives, including amides and sulfonamides (1-93), were designed and synthesized by modification on their C4 acetamidobenzoate side chains in this work. In vivo analgesic activity and toxicity of all derivatives were evaluated, and the structure-activity relationship was summarized. Six lead compounds (35, 36, 39, 49, 70, and 89) exhibited approximate analgesic activity to LA but with significantly reduced toxicity. The therapeutic index of these compounds is 14-30 times that of LA. In vivo metabolism study of the lead compounds 39, 49, 70, and 89 were conducted by UPLC-MS^E, indicating the reason for the low toxicity of the potential derivatives might be they are difficult to metabolize to toxic metabolite N-deacetyllappaconitine compared to LA. The effects of lead compounds on sodium channels and hERG channels were also studied by ion channel reader (ICR) which further revealed their analgesic and toxicity-attenuating mechanisms. Sodium channel assay revealed that the analgesic mechanism of these lead compounds was inhibiting the Na_v 1.7 channels. Taken together, compound 39 was provided as a new analgesic lead compound with significantly low toxicity and comparable activity to LA.

Similar collagen distribution in full-thickness skin grafts in intraperitoneal and onlay positions, an experimental mice-study

PURPOSE

Autologous full-thickness skin grafting (FTSG) has the potential to become an option in abdominal wall repair. An understanding of tissue remodelling in the extracellular matrix (ECM) is crucial as this interplay determines such parameters as tissue strength and flexibility. This cross-sectional preclinical laboratory study in mice provides information on the distribution of collagen types and matrix metalloproteinases (MMPs) in the ECM of FTSGs in the intraperitoneal and onlay positions compared with internal controls. The aim was to evaluate morphologic changes after tissue remodelling and repair in FTSGs applied in the two positions and to detect any adverse host response.

METHODS

ECM components were evaluated as follows: qualitative examination of collagen bundle thickness using Picrosirius Red staining (collagen types I, III and IV); and evaluation of collagen types IV and V, as well as MMPs 1, 8 and 9 using immunohistochemical staining. Full-thickness grafts transplanted between female twin mice were examined as this best mimics autologous transplantation.

RESULTS

At 8 weeks, FTSGs in the intraperitoneal position did not show any noticeable differences in morphologic appearance to those in the onlay position. Both intraperitoneal and onlay FTSGs showed increases in the amount of thick collagen bundles compared to internal controls. No correlation was seen between distribution of MMPs 1, 8 or 9 and distribution of collagen types I, III, IV or V.

CONCLUSION

This preclinical study shows that FTSGs in both intraperitoneal and onlay positions are possible application site options and, by extension, promising application site options for abdominal wall reinforcement in hernia surgery. Clinical studies in humans are required to confirm these findings.

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.

Comparison of glue versus suture mesh fixation for primary open inguinal hernia mesh repair by Lichtenstein technique: a systematic review and meta-analysis

BACKGROUND

The use of glue as a mesh fixator in open Lichtenstein inguinal hernia repair (IHR) has gained popularity to reduce recurrence and postoperative complications. This meta-analysis aims to provide an up-to-date review to compare glue versus suture fixation in primary open Lichtenstein IHR.

METHODS

PubMed, Embase, The Cochrane Library, Web of Science, and Springer were systematically searched till June 2021 for randomized controlled trials (RCTs) comparing glue versus suture fixation in open Lichtenstein IHR. Primary outcomes were early (at 1 year) and late recurrence (5 years or more). Secondary outcomes were the length of operation, postoperative haematoma and seroma, and chronic pain at 1 year.

RESULTS

A total of 17 RCTs with 3150 hernias (glue n = 1582, suture n = 1568) were included. Only three studies reported late recurrence. Glue fixation was associated with shorter operative duration (MD - 4.17, 95% CI - 4.82, - 3.52; p < 0.001 and a lower incidence of haematoma formation (OR 0.51, 95% CI 0.32, 0.81; p = 0.004). There was no significant difference in postoperative seroma (OR 0.72, 95% CI 0.35, 1.49; p = 0.38), chronic pain after 1 year (OR 1.10, 95% CI 0.73, 1.65; p = 0.65), early recurrence (OR 1.11, 95% CI 0.45, 2.76; p = 0.81, I2 = 0%), and late recurrence (OR 1.23, 95% CI 0.59, 2.59; p = 0.59, I2 = 0%).

CONCLUSION

Early and late recurrence were comparable between glue and suture fixation in open Lichtenstein IHR patients. Glue fixation had shorter operating time and lower haematoma formation than suture fixation. Chronic pain and seroma formation were comparable. More RCTs should report long-term outcomes.

Surgical outcomes of laparoscopic total extraperitoneal (TEP) inguinal hernia repair compared with Lichtenstein tension-free open mesh inguinal hernia repair: A prospective randomized study

Inguinal hernia repair is one of the most frequently performed surgery. The ideal procedure for inguinal hernia repair remains controversial. Open Lichtenstein tension-free mesh repair (LMR) is one of the most preferred open techniques with satisfactory outcomes. Laparoscopic approach in inguinal hernia surgery remains controversial, especially in comparison with open procedures. In this study, we have reported a comparison of laparoscopic total extraperitoneal (TEP) inguinal hernia repair with LMR. Postoperative pain, operative time, complications like seroma, wound infection, chronic groin pain, and recurrence rate were parameters to evaluate the outcome. One hundred seventy-four patients were included in the study by consecutive randomized prospective sampling. The patients were divided into 2 groups: group A, laparoscopic TEP inguinal hernia repair, and group B, LMR. The procedures were performed by experienced surgeons. The primary outcomes were evaluated based on postoperative pain and recurrence rate. Secondary outcomes considered for evaluation were operative time, complications like seroma, infection, and chronic groin pain. Severe pain was reported in group A (7.9%) compared to group B (15.1%), which was statistically significant (P < .001). Moderate pain was reported more in group B (70.9%) compared to group A (29.5%) (P < .001). The mean operative time in group A was 84.6 ± 32.2, which was significantly higher than that in group B, 59.2 ± 14.8. There was no major complication in both groups. The chronic pain postoperatively was significantly in higher number of patients in group B vs group A (22.09% vs 3.4%). The postoperative hospital stay period was significantly lesser for group A vs for group B (2.68 ± 1.52 vs 3.86 ± 6.16). Time duration taken to resume normal activities was significantly lower in group A (13.6 ± 6.8) vs (19.8 ± 4.6) in group B (P < .001). Although there is definite evidence of longer operative time and learning curve, laparoscopic TEP has added advantages like less postoperative pain, early resumption of normal activities, less chronic groin pain, and comparable recurrence rate compared to open Lichtenstein repair. Laparoscopic TEP can be performed with acceptable outcomes and less postoperative complications if performed by experienced hands.

Asymptomatic inguinal hernia: does it need surgical repair? A systematic review and meta-analysis

BACKGROUND

The aim of this review is to compare the outcomes of surgical repair versus watchful waiting in asymptomatic or minimally symptomatic inguinal hernias.

METHODS

Preferred reporting items for systematic reviews and meta-analyses guidelines were employed. We analysed primary outcomes: pain, quality of life, pain during daily activities and visual analogue scale (VAS that measures pain at rest and on movement) and secondary outcomes: postoperative complications and recurrence.

RESULTS

Pain and quality of life were not comparable due to differences in the parameters used in different articles. Pain interfering with normal daily activity was evaluated in one study and appears more favourable in the post-repair group respect to the watchful waiting (WW) group (5.1% versus 2.2%). VAS, measured in one study, at 6 months was more favourable in the surgery group (37% versus 44%). After 12 months the outcome was better in the control group than in the repair group (28% versus 30%). Conversion rate of the patient cohorts from watchful waiting to elective surgery was between 35.03% and 57.8%. The meta-analysis did not find significant statistical differences in the two groups examined for postoperative complications [RR = 0.95, 95% CI (0.50, 1.80), P = 0.88], as for hernia recurrence [RR = 1.01, 95% CI (0.50, 2.02), P = 0.98].

CONCLUSION

WW seems to be an acceptable option for the patient with asymptomatic or minimally symptomatic inguinal hernias. Delaying surgical repair until symptoms appear is safe. Acute hernia incarcerations are not particularly frequent. The incidence of chronic pain after the repair is high. Physicians must select patients carefully and explain to them the risks and benefits of surgery.

The efficacy and safety of preoperative glucocorticoids in herniorrhaphy: a systematic review and meta-analysis

Postoperative pain is the main reason for delayed recovery after herniorrhaphy. Preoperative glucocorticoid administration may improve postoperative recovery. The present study assessed the efficacy of preoperative glucocorticoids in facilitating recovery after herniorrhaphy. Randomized controlled trials (RCTs) conducted up to January 2021 were searched in electronic databases and trial registries. Meta-analyses were performed using random effects models. The Grading of Recommendations, Assessment, Development, and Evaluation approach was used to assess the certainty of evidence. Seven RCTs (744 patients) were included in the meta-analysis. Preoperative glucocorticoid administration reduced patients' pain on postoperative day 0 (standard mean difference [SMD] = - 0.73, 95% confidence interval [CI] - 1.45 to - 0.01; I² = 94%). However, there was no marked difference in rescue analgesic use (risk ratio [RR] = - 0.06, 95% CI - 0.28 to - 0.16; I² = 0%) or vomiting (RR = 0.78, 95% CI 0.50-1.20; I² = 30%) between preoperative glucocorticoid administration and control. The certainty of evidence was moderate because of inconsistencies or imprecision. No serious adverse effects were observed. Preoperative glucocorticoid administration reduced pain in patients following herniorrhaphy without increasing the occurrence of adverse events. Further studies will be required to confirm the efficacy of preoperative glucocorticoids.

Full-thickness skin grafts to reinforce the abdominal wall: a cross-sectional histological study comparing intra- and extraperitoneal onlay positions in mice

INTRODUCTION

In the repair of complex abdominal wall hernia, there can be a strong preference to avoid synthetic or biological implants as reinforcement material. Autologous full-thickness skin grafts (FTSG) have shown promising results. However, there are few clinical data on the use of FTSG in an intraperitoneal position and rudimentary knowledge about postoperative histological appearance of tissue remodelling and repair.

OBJECTIVE

To investigate the histological appearance of FTSG in the intraperitoneal onlay mesh (IPOM) position.

METHODS

Isogeneic FTSG was positioned in the IPOM (10 mice) and the onlay position (10 mice). After eight weeks, tissues were harvested for histological analysis. Tissue structure, inflammation and cell survival were investigated with histological and immunohistochemical staining.

RESULTS

Morphology was similar in both positions. Luciferase staining indicated both onlay and IPOM graft cell survival, with microvascular networks present. In both positions, FTSG showed ongoing tissue remodelling processes and cystic formations containing hair and epidermis. Low-grade acute phase and chronic inflammation were present. Integration was observed in 50% of the mice with similar appearances in IPOM and onlay grafts.

CONCLUSION

FTSG is tolerated, with comparable results either inside or outside the abdominal cavity, and in line with historic histological evaluations. The results suggest further research on FTSG as a potential future reinforcement material in selected cases of complex abdominal wall hernia repair.

ARE THERE DIFFERENCES IN CHRONIC PAIN AFTER LAPAROSCOPIC INGUINAL HERNIA REPAIR USING THE TRANSABDOMINAL TECHNIQUE COMPARING WITH FIXATION OF THE MESH WITH STAPLES, WITH GLUE OR WITHOUT FIXATION? A CLINICAL RANDOMIZED, DOUBLE-BLIND TRIAL

ABSTRACT BACKGROUND: Regarding postoperative pain, it remains unclear whether non-fixation of the polypropylene prosthesis in transabdominal preperitoneal inguinal hernia repair produces the same outcomes as mesh fixation with glue or tackers. In addition, hernia recurrence is another aspect to be assessed in the comparison between non-fixation and mesh-fixation techniques (tackers and glue). AIMS: This study aimed to evaluate the incidence, quality of pain, and recurrence in patients undergoing laparoscopic inguinal hernioplasty (transabdominal preperitoneal) technique, comparing the fixation of the mesh with tackers versus with glue versus without fixation. METHODS: This is a prospective, double-blind study in which 63 patients presenting with primary unilateral inguinal hernia underwent laparoscopic transabdominal preperitoneal inguinal hernia repair and were randomized into three groups: no mesh fixation (n=21), mesh tacked (n=21), and mesh fixed with fibrin glue (n=21). Patients also responded to questionnaires in order to assess pain and pain quality and were followed up for 2 years. RESULTS: Neither mesh-fixation nor non-fixation techniques were found to affect postoperative chronic pain (p=0.535), but patients undergoing tacker fixation reported more pain descriptors (p=0.0021) and a higher pain index (p=0.002) on the McGill scale in the first 15 postoperative days (T0 and T1). No hernia recurrences were observed. CONCLUSIONS: Both mesh-fixation techniques (tackers and glue) used with the transabdominal preperitoneal approach did not influence the onset of inguinodynia, but tacker fixation was more likely to increase patient sensitivity to pain. Mesh placement without fixation produced the same pain and recurrence outcomes as mesh-fixation techniques. Also, no recurrence was observed in patients without mesh fixation in this study. Consequently, it has become an alternative therapy deserving consideration for hernia repair.

Cell-based therapies for reinforcing the treatment efficacy of meshes in abdominal wall hernias：A systematic review and meta-analysis

To achieve a tension-free repair and reduce the recurrence rate of abdominal wall hernias (AWHs), various kinds of meshes have been applied in surgery. However, these meshes are reported to have problems with adhesion, infection, chronic pain and foreign body sensation. Recently, the introduction of cellular components on meshes seems to provide a new alternative to resolve these problems. This study aimed to evaluate the treatment efficacy of meshes seeded with cells (mesh-cell group) for AWHs, compared to meshes without cells (mesh group). Cochrane Library, Web of Science and PubMed were searched for studies that provided data about meshes, cells and AWHs. Twenty-six studies involving 578 animals were included. We found that the mesh-cell group could better control hernia recurrent than the mesh group (OR = 0.25, 95% CI = 0.15-0.42). Although the mesh-cell group did not reduce the incidence of adhesions (OR = 0.67, 95% CI = 0.26-1.74), it alleviated the extent of adhesions (WMD = -1.48, 95% CI = -1.86 to -1.10). In addition, the capillary density of mesh-cell group was also higher than that of mesh group (WMD = 26.27, 95% CI = 14.45-38.09). For incidence of infection, the two groups had no significant differences (OR = 0.94, 95% CI = 0.39-2.31). On the basis of our current evidence, AWHs were likely to receive a satisfied outcome in animal models when treated by meshes seeded with cells. Future studies with human trial data are needed to validate these findings.

Watchful waiting vs repair for asymptomatic or minimally symptomatic inguinal hernia in men: a systematic review

PURPOSE

One-third of patients presenting with inguinal hernia are asymptomatic and the best treatment for these patients is unclear. The aim of this study was to assess the feasibility of applying a watchful waiting strategy for asymptomatic or minimally symptomatic inguinal hernia in men.

METHODS

PubMed, EMBASE, and Cochrane Library were searched from database inception to May 14, 2020. Included were all types of original data written in English, German, Danish, Swedish, or Norwegian involving ≥ 5 male patients aged ≥ 18 years old with asymptomatic or minimally symptomatic inguinal hernia and undergoing watchful waiting. This review was reported according to the PRISMA guideline.

RESULTS

A total of nine studies were included; three randomized controlled trials, three prospective cohort studies, and three retrospective cohort studies. Data on a total of 858 unique patients following a watchful waiting strategy were included. Approximately one-third of patients crossed over from watchful waiting to surgery after 3 years increasing to more than two-thirds after 10 years. The most frequent reason for crossover was hernia-related pain (median 79%, range 48-91%). The rate of acute hernia-related operations was low (2-3%), and watchful waiting was not associated with increased mortality or postoperative complications. Levels of pain and discomfort after randomization were similar over time between patients undergoing elective repair or watchful waiting.

CONCLUSION

Applying a watchful waiting strategy to men with asymptomatic or minimally symptomatic inguinal hernia was safe, but two-thirds of patients crossed over to surgical repair within 10 years mainly due to pain.

Surgical treatment for chronic pain after inguinal hernia repair: a systematic literature review

PURPOSE

Chronic postoperative inguinal pain (CPIP) is a frequent complication after inguinal surgery with a significant decrease in quality of life. There is still no clear algorithm regarding surgical treatment. The aim of this systematic review was to provide an overview on the principles and outcome of surgical interventions for CPIP based on the available literature.

MATERIALS AND METHODS

A literature search was performed using the databases PubMed and SCOPUS following the PRISMA statement. Used Mesh terms and keywords were "postoperative pain," "chronic pain," "inguinal hernia," and "surgical treatment." All articles were reviewed regarding surgical technique and outcome. MINORS criteria for the assessment of the methodological quality of non-randomized surgical studies were applied.

RESULTS

Eighteen articles, of which 17 cohort studies and one randomized controlled trial (RCT), described the surgical management of CPIP. Selective as well as triple neurectomy, often in combination with mesh removal and removal of suture material, was performed. Success rate, defined as significant or complete relief of pain, ranged from 33 until 100%, with most articles reaching success rates above 70%, showing a clear advantage of surgical therapy for chronic pain.

CONCLUSIONS

The use of surgical triple neurectomy seems effective and helpful in a high percentage of patients with CPIP. Surgical treatment should only be considered after adequate preoperative diagnostic evaluation of which the dermatome sensory mapping seems a useful tool for detailed neurophysiological assessment of patients with persistent post-herniorrhaphy pain undergoing remedial neurectomy.

Filament-anchored hydrogel layer on polypropylene hernia mesh with robust anti-inflammatory effects

The efficacy of implanted polypropylene (PP) hernia meshes is often compromised by an inflammatory response. Thus, engineering an anti-inflammatory mesh has significant implications for hernioplasty. Here, we report a facile strategy to develop a filament-anchored hydrogel layer (FAHL) on PP mesh (FAHL-P). The network of FAHL, made up of chondroitin sulfate and gelatin (CG), provided a biomimetic surface with immunoregulatory properties. The use of tannic acid (TA) as a crosslinker for CG additionally enhanced its anti-inflammatory properties. In addition, the fabrication protocol ensured that the hydrogel maintained the properties of the knitted mesh and the firmly adherent FAHL during general handling (dry state) and in the simulated body environment (wet state). CG/TA-PP killed 99.99% of S. aureus and retained 73% of its original antioxidant properties after 7 d. The FAHL durably performed with a controlled release of TA for 15 d. The strong anti-inflammatory effects of FAHL-P reduced collagen deposition and increased vascularization, which promoted native tissue generation. The fabrication strategy has potential applications in hernioplasty and may provide new insights into the design of other anti-inflammatory implants. STATEMENT OF SIGNIFICANCE: A hydrogel layer with robust anti-inflammatory effects was anchored firmly on mesh filament for hernia repair. Requiring no drug loading, this chondroitin sulphate -gelatin (CG) based hydrogel itself could inhibit the immunological attack owing to the biomimetic microenvironment created by the CG. Moreover, the hydrogel's crosslinker (tannic acid) content served as an effective scavenger for reducing pro-inflammatory factors, significantly mitigating the inflammation. Interestingly, the antibacterial effect of such hydrogel layer was also observed. In terms of the synergistic outcome of the design, our mesh can remarkably attenuate inflammation and promote constructive tissue regeneration in vivo. Furthermore, considering the relatively simple and easily scaled up formulation process, our strategy may indeed have great potential in alleviating post-implantation outcomes.

Sex Differences, Sleep Disturbance and Risk of Persistent Pain Associated With Groin Hernia Surgery: A Nationwide Register-Based Cohort Study

Persistent pain after groin hernia repair is a major health problem. Sleep disturbance is associated with heightened pain sensitivity. The main objective of this study was to examine the role of sleep disturbance in the development and long-term maintenance of chronic postherniorrhaphy inguinal pain (CPIP), with exploration of sex differences. From 2012 to 2017, a national cohort of patients with prior groin hernia repair (n = 2084;45.8% females) were assessed for the development of CPIP 12 months after surgery. Patients then underwent long-term (median 5.0 years) follow-up to evaluate the contribution of sex and sleep disturbance on the maintenance of CPIP. Associations between pre- and postoperative sleep problems (assessed at long-term follow-up) and CPIP were tested using logistic regression. Females had higher rates of CPIP with negative impact on daily activities 12 months after surgery as compared to males (14.6 vs 9.2%, P < .0005), and were more likely to have moderate-severe CPIP in the long-term (3.1 vs 1.2%, P = .003). Preoperative sleep problems predicted development of CPIP 12 months after surgery (adjusted odds ratio [aOR] 1.76 [95%CI 1.26-2.46], P = .001) and CPIP in the long-term (aOR 2.20 [1.61-3.00] , P < .0001). CPIP was associated with insomnia and depression. Sleep disturbance may increase the risk for CPIP, and contribute to maintenance of postsurgical pain. PERSPECTIVE: Females are at heightened risk for CPIP as compared to males. Increased severity of pain symptoms are linked to poorer sleep and psychiatric morbidity. Given the robust associations between sleep disturbance and CPIP, interventions which consolidate and promote sleep, especially in females, may improve long-term pain control.

Ilioinguinal Nerve Neurectomy is better than Preservation in Lichtenstein Hernia Repair: A Systematic Literature Review and Meta-analysis

OBJECTIVE

This study aimed to evaluate the incidence of chronic groin pain (primary outcome) and alterations of sensitivity (secondary outcome) after Lichtenstein inguinal hernia repair, comparing neurectomy with ilioinguinal nerve preservation surgery. The exact cause of chronic groin postoperative pain after mesh inguinal hernia repair is usually unclear. Section of the ilioinguinal nerve (neurectomy) may reduce postoperative chronic pain.

METHODS

We followed PRISMA guidelines to identify randomized studies reporting comparative outcomes of neurectomy versus ilioinguinal nerve preservation surgery during Lichtenstein hernia repairs. Studies were identified by searching in PubMed, Scopus, and Web of Science from April 2020. The protocol for this systematic review and meta-analysis was submitted and accepted from PROSPERO: CRD420201610.

RESULTS

In this systematic review and meta-analysis, 16 RCTs were included and 1550 patients were evaluated: 756 patients underwent neurectomy (neurectomy group) vs 794 patients underwent ilioinguinal nerve preservation surgery (nerve preservation group). All included studies analyzed Lichtenstein hernia repair. The majority of the new studies and data comes from a relatively narrow geographic region; other bias of this meta-analysis is the suitability of pooling data for many of these studies. A statistically significant percentage of patients with prosthetic inguinal hernia repair had reduced groin pain at 6 months after surgery at 8.94% (38/425) in the neurectomy group versus 25.11% (113/450) in the nerve preservation group [relative risk (RR) 0.39, 95% confidence interval (CI) 0.28-0.54; Z = 5.60 (P < 0.00001)]. Neurectomy did not significantly increase the groin paresthesia 6 months after surgery at 8.5% (30/353) in the neurectomy group versus 4.5% (17/373) in the nerve preservation group [RR 1.62, 95% CI 0.94-2.80; Z = 1.74 (P = 0.08)]. At 12 months after surgery, there is no advantage of neurectomy over chronic groin pain; no significant differences were found in the 12-month postoperative groin pain rate at 9% (9/100) in the neurectomy group versus 17.85% (20/112) in the inguinal nerve preservation group [RR 0.50, 95% CI 0.24-1.05; Z = 1.83 (P = 0.07)]. One study (115 patients) reported data about paresthesia at 12 months after surgery (7.27%, 4/55 in neurectomy group vs. 5%, 3/60 in nerve preservation group) and results were not significantly different between the two groups [RR 1.45, 95% CI 0.34, 6.21;Z = 0.51 (P = 0.61)]. The subgroup analysis of the studies that identified the IIN showed a significant reduction of the 6th month evaluation of pain in both groups and confirmed the same trend in favor of neurectomy reported in the previous overall analysis: statistically significant reduction of pain 6 months after surgery at 3.79% (6/158) in the neurectomy group versus 14.6% (26/178) in the nerve preservation group [RR 0.28, 95% CI 0.13-0.63; Z = 3.10 (P = 0.002)].

CONCLUSION

Ilioinguinal nerve identification in Lichtenstein inguinal hernia repair is the fundamental step to reduce or avoid postoperative pain. Prophylactic ilioinguinal nerve neurectomy seems to offer some advantages concerning pain in the first 6th month postoperative period, although it might be possible that the small number of cases contributed to the insignificancy regarding paresthesia and hypoesthesia. Nowadays, prudent surgeons should discuss with patients and their families the uncertain benefits and the potential risks of neurectomy before performing the hernioplasty.

In-vitro Characterization of a Hernia Mesh Featuring a Nanostructured Coating

Abdominal hernia repair is a frequently performed surgical procedure worldwide. Currently, the use of polypropylene (PP) surgical meshes for the repair of abdominal hernias constitutes the primary surgical approach, being widely accepted as superior to primary suture repair. Surgical meshes act as a reinforcement for the weakened or damaged tissues and support tissue restoration. However, implanted meshes could suffer from poor integration with the surrounding tissues. In this context, the present study describes the preliminary evaluation of a PCL-Gel-based nanofibrous coating as an element to develop a multicomponent hernia mesh device (meshPCL-Gel) that could overcome this limitation thanks to the presence of a nanostructured biomimetic substrate for enhanced cell attachment and new tissue formation. Through the electrospinning technique, a commercial PP hernia mesh was coated with a nanofibrous membrane from a polycaprolactone (PCL) and gelatin (Gel) blend (PCL-Gel). Resulting PCL-Gel nanofibers were homogeneous and defect-free, with an average diameter of 0.15 ± 0.04 μm. The presence of Gel decreased PCL hydrophobicity, so that membranes average water contact angle dropped from 138.9 ± 1.1° (PCL) to 99.9 ± 21.6°, while it slightly influenced mechanical properties, which remained comparable to those of PCL (E = 15.7 ± 2.7 MPa, σ R = 7.7 ± 0.6 ε R = 118.8 ± 13.2%). Hydrolytic and enzymatic degradation was conducted on PCL-Gel up to 28 days, with maximum weight losses around 20 and 40%, respectively. The meshPCL-Gel device was obtained with few simple steps, with no influences on the original mechanical properties of the bare mesh, and good stability under physiological conditions. The biocompatibility of meshPCL-Gel was assessed by culturing BJ human fibroblasts on the device, up to 7 days. After 24 h, cells adhered to the nanofibrous substrate, and after 72 h their metabolic activity was about 70% with respect to control cells. The absence of detectable lactate dehydrogenase in the culture medium indicated that no necrosis induction occurred. Hence, the developed nanostructured coating provided the meshPCL-Gel device with chemical and topographical cues similar to the native extracellular matrix ones, that could be exploited for enhancing the biological response and, consequently, mesh integration, in abdominal wall hernia repair.

Psychological Characteristics, Female Sex, and Opioid Use Predict Acute Postoperative Pain in Patients Surgically Treated for Thumb Base Osteoarthritis: A Cohort Study

BACKGROUND

It is unclear which factors predict acute postoperative pain in patients surgically treated for thumb base osteoarthritis. The authors investigated the influence of type of surgery, preoperative sociodemographics, preoperative patient-reported outcome measures, psychological characteristics, and postoperative opioid use on acute postoperative pain 24 hours postoperatively following surgery for thumb carpometacarpal osteoarthritis. In addition, preoperative and acute postoperative pain were compared.

METHODS

In this prospective cohort study, 215 patients surgically treated for thumb carpometacarpal osteoarthritis were included. Data were collected in 16 clinics for hand surgery and therapy in The Netherlands. Hierarchical regression was used to identify whether type of surgery, preoperative sociodemographics, preoperative patient-reported outcome measures, psychological characteristics (including treatment credibility and expectations, illness perception, pain catastrophizing, anxiety, and depression), and postoperative opioid use predicted acute postoperative pain 24 hours postoperatively, measured using the Numeric Pain Rating Scale (range, 0 to 10).

RESULTS

Female sex, opioid use, higher preoperative satisfaction with hand, and higher self-reported consequences and coherence predicted greater postoperative pain, with 31 percent explained variance in the final model including psychological factors. Mean postoperative Numeric Pain Rating Scale score was lower (5.1 ± 2.4) than preoperative pain, measured using visual analogue scales (during the past week, 6.7 ± 1.7; physical load, 7.5 ± 1.7) and the Michigan Hand Outcomes Questionnaire (6.4 ± 1.4; p < 0.001).

CONCLUSIONS

Psychological factors, female sex, and opioid use enhance the prediction of acute postoperative pain beyond surgery type, preoperative sociodemographics, and patient-reported outcome measures. Female sex and opioid use were the strongest predictors, even after controlling for psychological factors. Future studies may investigate sex-based approaches and patient education for reducing acute postoperative pain.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, II.

Single-blind randomized clinical trial of transinguinal preperitoneal repair using self-expanding mesh patch vs. Lichtenstein repair for adult male patients with primary unilateral inguinal hernia

PURPOSE

The aim of the study was to compare proportions of chronic postoperative inguinal pain (CPIP) and other surgical outcomes between transinguinal preperitoneal repair with modified Kugel patch (MK) and Lichtenstein repair (LR).

METHODS

Two-hundred adult male patients with primary unilateral inguinal hernia were randomized into MK or LR groups. The primary endpoint was CPIP, pain at 6 months after surgery. Secondary outcomes included recurrence rate, incidence of postoperative complications, time until return to activities, inguinal pain and sensory disturbances assessed at 1 week, 1 month, 3, 6, and 12 months after the operation using an 11-point numerical rating scale (NRS). The study was an intention-to-treat analysis.

RESULTS

In comparison of MK (n = 100) and LR (n = 100) with similar backgrounds, proportions of CPIP were similar (7.2 vs. 11.1%, p = 0.3452). Favorable outcomes for MK were duration of operation (32 vs. 40 min, p < 0.0001), NRS of foreign body sensation at 1 year (0 [0-1] vs. 0 [0-2], p = 0.0067), and NRS of numbness at 1 month (0 [0-1] vs. 0 [0-3], p = 0.0078) after the operation.

CONCLUSIONS

In regard to CPIP, the short-term results of MK and LR were similar.

Chronic pain after groin hernia repair: pain characteristics and impact on quality of life

Background

Chronic postsurgical pain (CPSP) after hernia repair research has mainly relied on unconfirmed self-reporting. We aimed to describe confirmed CPSP incidence, management, and quality of life (QoL) in a 2-year prospective study.

Methods

Multicenter study (GENDOLCAT) of 3890 patients undergoing 4 common surgical procedures in 23 hospitals to develop a risk model for CPSP; 2352 men underwent open hernia repair. Patients with pain were identified by telephone at 1 and 3 months and referred to the hospital 4 months after surgery for a physical examination to confirm CPSP. Three validated tools were used: the Brief Pain Inventory (BPI) for severity, analgesic use, and interference with activities; the SF-12 questionnaire for QoL (validated Spanish version), and the Douleur Neuropathique 4 (DN4). Patients with CPSP were called again at 1 and 2 years.

Results

In 1761 patients who underwent hernia repair and were eligible for physical examination for CPSP, the incidence of confirmed pain at 4 months was 13.6% (patient-reported pain, 6.2% at 1 year and 4.0% at 2 years). Neuropathic pain was diagnosed in 38.5% of the CPSP patients at 4 months. The incidences of neuropathic CPSP in patients with mesh or non-mesh repairs were similar (38.6 and 33.3%, respectively). SF-12 physical component scores changed little in all patients, whether or not they developed CPSP. The SF-12 mental component decreased significantly in all patients, but the decrease was clinically significant only in CPSP patients. CPSP interfered with activities (18%), work (15.6%), walking (15%) and mood (10.2%). At 2 years 52.1% of CPSP patients had moderate/intense pain and 28.2% took analgesics.

Conclusion

CPSP affects QoL-related activities, and although it diminishes over the course of 2 years after surgery, many patients continue to have moderate/intense pain and take analgesics. CPSP and neuropathic pain rates seem to be similar after mesh and non-mesh repair. BPI and SF-12 mental component scores detect effects on QoL.

Trial registration

ClinicalTrials.gov NCT01510496.

Dopamine-Mediated Zwitterionic Polyelectrolyte-Coated Polypropylene Hernia Mesh with Synergistic Anti-inflammation Effects

Over 20 million ventral hernia repairs are performed worldwide annually and only a minority (<10%) of cases are not mesh-based. However, even polypropylene (PP), endorsed as the "gold standard" of all prosthetic materials used in this field, is still subject to many complications caused by the foreign body reaction (FBR). Here, we describe the buildup of dopamine-mediated zwitterionic poly(sulfobetaine methacrylate) (PSBMA) coatings to inhibit nonspecific protein adsorption. Based on the universal adhesive ability of polydopamine (PDA), PSBMA has been coated on the PP mesh surface via two strategies: sequential deposition (PSBMA-PDA-PP) and co-deposition (PSBMA@PDA-PP). The presence of PSBMA shows great contribution to obviously decreased hydrophobicity of the PP surface (WCA_co = 36.3° and WCA_seq = 30.7°) as well as improved protein resistance (Reduction_co = 74% and Reduction_seq = 82%). Notably, as the intermedia between PP and PSBMA, PDA can endow the PP mesh with antioxidant activity, further featuring synergistic anti-inflammation therapeutic effect when coupled with PSBMA. With almost equal surface content of PSBMA, PSBMA-PDA-PP exhibited a more superior ability against macrophage adhesion and proliferation and showed more significantly decreased releases of TNF-α and IL-6 (p < 0.05) than those of PSBMA@PDA-PP, fundamentally attributed to its more neutral surface potential and the protection for polyphenols of PDA from oxidation with PSBMA as the outer layer. Furthermore, the coating layers demonstrated good stability and no sacrifice of the pristine mechanical property. The proposed dopamine-mediated PSBMA coatings possess high potential in biomedical implant areas for attenuating the FBR.

Chronic postoperative inguinal pain: A narrative review

Inguinodynia or chronic postoperative inguinal pain is a growing problem between patients who undergo surgical repair of an inguinal hernia. The change in results measurement proposed by many authors towards Patient Reported Outcome Measurement has underlined the importance of chronic postoperative inguinal pain, because of the great limitations in everyday life and the huge socioeconomic impact that it causes. In this article a narrative review of the available literature in PUBMED, EMBASE and Cochrane Library is performed and the most relevant aspects about epidemiology, etiology prevention, diagnosis and treatment of chronic postoperative inguinal pain are discussed. A new management algorithm is also proposed. The variability in its incidence and clinical presentation makes diagnosis of chronic postoperative inguinal pain a very challenging issue. There is no standardized therapy and an adequate etiological diagnosis is key point for a successful treatment. There are many treatment options that have to be sequentially used and adjusted to each patient and their clinical features.

Magnetic resonance visualization of iron-loaded meshes in patients with pain after inguinal hernia repair

PURPOSE

Chronic post-operative inguinal pain (CPIP) is defined as pain lasting more than 3 months and the incidence is less than 4% after laparoscopic hernia repair. CPIP can have several causes. In this study, we aimed to show that 3D-iron loaded mesh preparations are useful in radiological evaluation of post-operative complications, especially patients with chronic pain and the mesh status of operated inguinal hernia cases.

METHODS

A total of 450 cases who had been operated for inguinal hernia with 3D-iron loaded mesh and who had ongoing pain at the post-operative period were included in this study. MRI (Magnetic Resonance Imaging) was performed at the post-operative 90th day of the seven symptomatic (groin pain, limitation of movement) cases which were operated using a 3D-iron loaded mesh, 10 × 15 cm in size, (DynaMeshEndolap visible with 25% MRI-visible filaments, FEG TextiltechnikmbH, Aachen, Germany) for inguinal hernia repair to evaluate mesh status, localization, and local complications. Gradient echo sequences in the sagittal, axial, and coronal sections on MRI were discussed by two radiologists. Mesh localizations, their relationship with surrounding structures and their complications related with mesh were evaluated by two radiologists (D.Y, D.E.T.Ş).

RESULTS

No significant radiological findings related to defined anatomical structures were found in the MRI images of the study group. The dimensions measured on the sagittal, axial and coronal images were correlated with original mesh sizes and no significant shrinkage was detected.

CONCLUSION

Mesh position and deformation as shrinkage can be the mesh-related cause of pain. The incidence of CPIP in our patients is less than 2%. 3D-iron loaded meshes were monitored with MRI in CPIP patients and there was no mesh-related changes found in our study. The use of MRI-visible meshes will most likely help us to monitor mesh preparations and show potential time-dependent changes in mesh characteristics and consequent complications. In case of doubtful clinical postoperative hernia recurrence or chronic groin pain, mesh position can be identified by MRI and unnecessary surgical intervention can be avoided.

Propensity score analysis of outcomes between the transabdominal preperitoneal and open Lichtenstein repair techniques for inguinal hernia repair: a single-center experience

BACKGROUND

The mechanism of persistent chronic pain after TAPP and OLR remains controversial. Therefore, more prospective and well-designed studies are needed to determine the predictive risk factors that will lead to better pain prevention and possibly elimination. The aim of the present study was to investigate the risk factors of chronic pain after TAPP repair and OLR in a single institution.

METHODS

A single-center, retrospective study of propensity score-matched patients who underwent TAPP or OLR surgery between 2008 and 2018 was conducted. To overcome selection bias, we performed 1:1 matching using 6 covariates to generate the propensity score.

RESULTS

A total of 400 patients treated with TAPP and 424 patients treated with OLR were balanced to 400 pairs of matched patients. The patients' age (P < 0.001), BMI (P < 0.001), foreign body sensation within 3 months after surgery (P < 0.001), and persistent sensation loss (P = 0.002) were different between the two groups. The OLR group had a shorter operative time than did the TAPP group (P < 0.001). The univariate analysis of factors predicting a difference in VAS between the preoperative assessment and the assessment 3 months after surgery showed that the type of surgery (P = 0.004), hernia grade (P = 0.001), type of mesh (P < 0.001), presence of scrotal invasion (P = 0.024), and foreign body sensation within 3 months (P = 0.047) were risk factors. The multivariate analysis revealed that only hernia grade III (CI - 8.524, - 2.783; P < 0.001), OLR operation type (CI 1.069, 4.987; P = 0.002), and the use of polypropylene mesh (CI - 5.400, - 1.489; P = 0.001) were independently associated with chronic pain.

CONCLUSION

These results suggest that compared to OLR, TAPP leads to less postoperative pain and a better long-term quality of life.