Prognostic value of age for chronic postoperative inguinal pain

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.

No Reason to Use Mesh in Groin Hernia Repair in Adolescents

Groin hernias are common and hernia repair is one of the most frequent surgical procedures performed worldwide. Despite this, there is no international guideline on the management of groin hernias in adolescents. Mesh reinforcement is used for repair in adults but not in young children. Adolescents, positioned between these age groups, pose unique challenges for surgeons due to their varying growth patterns. Placing a synthetic mesh in growing patients is a concern, particularly in relation to chronic pain. Traditionally, the hernia literature has defined adults as individuals aged 18 years and above. Considering that growth can continue until age 19, this review proposes a revised definition of adolescence for patients with groin hernias encompassing ages 10 to 19. Symptomatic groin hernias in adolescents should be repaired with an open non-mesh technique because of acceptable recurrence rates and the desire to avoid introducing synthetic foreign materials into young patients with ongoing growth potential. Watchful waiting is suggested for asymptomatic groin hernias, postponing repair until the adolescent has become a fully grown adult and symptoms from the hernia develop. Most groin hernias in adolescents are lateral hernias, but before pursuing a watchful waiting strategy in females, an ultrasound or magnetic resonance imaging scan is suggested to rule out the presence of a femoral hernia that may need repair.

Outcome of incisional hernia repair in patients 80 years and older: results from the Herniamed-Registry

INTRODUCTION

More and more often complex abdominal surgeries are performed in the elderly. Together with the ageing population these patients are at risk for incisional hernias. We aimed on assessing outcomes following incisional hernia surgery in patients 80 years and older.

MATERIAL AND METHODS

Using the Herniamed-Registry, a prospective multi-institutional database, data on patients undergoing surgery for incisional hernias were retrospectively assessed. 46,040 patients were included and divided by age. Intraoperative-, general-, and postoperative complications as well as 1-year follow-up outcomes were assessed and compared between patients 80 years and older vs younger than 80 years.

RESULTS

Intra- (2.3% vs 1.5%; p < 0.001) and postoperative (8.6% vs 7.2%; p = 0.001) complications, general complications (5.5% vs 3.0%; p < 0.001), as well as reoperations (3.8% vs 3.0%; p = 0.007) were more likely to occur in elderly patients. By contrast, recurrences (3.6% vs 4.5%; p = 0.007), pain at rest (7.3% vs 10.1%; p < 0.001) and on exertion (11.3% vs 18.3%; p < 0.001), as well as pain requiring treatment (5.4% vs 7.7%; p < 0.001) was less likely in the group of patients aged ≥ 80 years.

CONCLUSION

Incisional hernia repair in patients 80 years and older is associated with a slightly higher complication risk but is quite acceptable and also have improved pain scores. The recurrence difference is also clinically unimportant.

A prospective study of chronic postsurgical pain in elderly patients: incidence, characteristics and risk factors

BACKGROUND

Due to the continued growth of surgical procedures in older adults and the significant impact of chronic postsurgical pain (CPSP), it is crucial to improve our understanding of the occurrence of CPSP as well as the appropriate prevention and treatment. We therefore conducted this study to determine the incidence, characteristics and risk factors of CPSP in elderly patients at both 3 and 6 months after surgery.

METHODS

Elderly patients (aged ≥ 60 years) undergoing elective surgery in our institution between April 2018 and March 2020 were prospectively enrolled in this study. Data on demographics, preoperative psychological well-being, intraoperative surgical and anesthesia management, and acute postoperative pain intensity were collected. At 3 and 6 months after surgery, patients received telephone interview and completed the questionnaires regarding chronic pain characteristics, analgesic consumption, and interference of the pain with activities of daily living (ADL).

RESULTS

A total of 1065 elderly patients were followed up for 6 postoperative months and included in final analysis. At 3 and 6 months after operation, the incidence of CPSP was 35.6% [95% confidence interval (95% CI) 32.7 - 38.8%] and 21.5% (95% CI 19.0% - 23.9%), respectively. CPSP cause negative impacts on patient's ADL and most particularly on mood. Neuropathic features were found in 45.1% of the patients with CPSP at 3 months. At 6 months, 31.0% of those with CPSP reported that the pain had neuropathic features. Preoperative anxiety [3 months: Odds ratio (OR) 2.244, 95% CI 1.693 to 2.973; 6 months: OR 2.397, 95% CI 1.745 to 3.294], preoperative depression (3 months: OR 1.709, 95% CI 1.292 to 2.261; 6 months: OR 1.565, 95% CI 1.136-2.156), orthopedic surgery (3 months: OR 1.927, 95% CI 1.112 to 3.341; 6 months: OR 2.484, 95% CI 1.220 to 5.061), higher pain severity on movement within postoperative 24 h (3 months: OR 1.317, 95% CI 1.191 to 1.457; 6 months: OR 1.317, 95% CI 1.177 to 1.475) were associated with a higher risk for CPSP independently at both 3 and 6 months after surgery.

CONCLUSIONS

CPSP is a common postoperative complication in elderly surgical patients. Preoperative anxiety and depression, orthopedic surgery, and greater intensity of acute postoperative pain on movement are associated with an increased risk for CPSP. It should be kept in mind that developing psychological interventions to reduce anxiety and depression and optimizing the management of acute postoperative pain will be effective in reducing the development of CPSP in this population.

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.

Mesh versus non-mesh repair of groin hernias: a rapid review

BACKGROUND

Mesh is frequently utilized intraoperatively for the repair of groin hernias. However, patients may request non-mesh hernia repairs owing to adverse events reported in other mesh procedures. To inform surgical safety, this study aimed to compare postoperative complications between mesh and non-mesh groin hernia repairs and identify other operative and patient-related risk factors associated with poor postoperative outcomes.

METHODS

Ovid MEDLINE and grey literature were searched to 9 June 2021 for studies comparing mesh to non-mesh techniques for primary groin hernia repair. Outcomes of interest were postoperative complications, recurrence of hernia, pain and risk factors associated with poorer surgical outcomes. Methodological quality was appraised using the AMSTAR 2 tool.

RESULTS

The systematic search returned 4268 results, which included seven systematic reviews and five registry analyses. Mesh repair techniques resulted in lower hernia recurrence rates, with no difference in chronic pain, seroma, haematoma or wound infection, compared to non-mesh techniques. Risk factors associated with increased risk of hernia recurrence were increased body mass index (BMI), positive smoking status and direct hernia. These were independent of surgical technique. Patients under 40 years of age were at increased risk of postoperative pain.

CONCLUSIONS

Surgical repair of primary groin hernias using mesh achieves lower recurrence rates, with no difference in safety outcomes, compared with non-mesh repairs. Additional risk factors associated with increased recurrence include increased BMI, history of smoking and hernia subtype.

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.

Evaluation of Postsurgical Hyperalgesia and Sensitization After Open Inguinal Hernia Repair: A Useful Model for Neuropathic Pain?

Cutaneous mechanical hyperalgesia can be induced in healthy volunteers in early phase analgesic studies to model central sensitization, a key mechanism of persistent pain. However, such hyperalgesia is short-lived (a matter of hours), and is used only for assessing only single drug doses. In contrast, postsurgical peri-incisional hyperalgesia may be more persistent and hence be a more useful model for the assessment of the efficacy of new analgesics. We undertook quantitative sensory testing in 18 patients at peri-incisional and nonoperated sites before open inguinal hernia repair and up to the 24th postsurgical week. The spatial extent of punctate hyperalgesia and brush allodynia at the peri-incisional site were greatest at weeks 2 and 4, but had resolved by week 24. Heat allodynia, suggestive of local inflammation or peripheral sensitization, was not observed; instead, there were deficits in cold and heat sensory detection that persisted until week 24. The findings suggest that central sensitization contributes significantly to mechanical hyperalgesia at the peri-incisional site. The prolonged duration of hyperalgesia would be advantageous as a pain model, but there was considerable variability of mechanical hyperalgesia in the cohort; the challenges of recruitment may limit its use to small, early phase analgesic studies. PERSPECTIVE: Peri-incisional mechanical hyperalgesia persists for ≥4 weeks after open inguinal hernia repair and reflects central sensitization; this may have usefulness as a model of chronic pain to assess the potential of antineuropathic analgesics.

Decreasing prevalence of chronic pain after laparoscopic groin hernia repair: a nationwide cross-sectional questionnaire study

PURPOSE

Up to 6-7% of patients who have undergone laparoscopic groin hernia repair suffer from chronic pain, depending on various factors; however, the long-term course is unclear. The purpose of this study was to assess the prevalence of chronic pain 1-5 years after laparoscopic groin hernia repair.

METHODS

The subjects of this nationwide cross-sectional questionnaire study were adults who underwent laparoscopic mesh repair of an inguinal or a femoral hernia. The patients were identified from the Danish Hernia Database, which has a follow-up rate of almost 100%. The prevalence of chronic pain was assessed 1-5 years postoperatively by the validated inguinal pain questionnaire (IPQ).

RESULTS

A total of 1383 groins were included in this study, based on a 66% response rate to the questionnaire. The prevalence of pain decreased, especially 3.5 years postoperatively. There were no statistically significant differences when each postoperative year was compared with the second postoperative year. However, the prevalence of chronic pain 3.5-5 years postoperatively was significantly lower (4.4%) than that 1-3.5 years postoperatively (8.1%) (p = 0.014). The prevalence of pain that could not be ignored was still 5-6% in the fifth postoperative year.

CONCLUSIONS

The prevalence of chronic pain seems to decline 1-5 years after laparoscopic groin hernia repair, with a distinct decrease 3.5 years postoperatively.

Chronic pain after mesh versus nonmesh repair of inguinal hernias: A systematic review and a network meta-analysis of randomized controlled trials

BACKGROUND

Chronic pain affects 10%-12% of patients after inguinal hernia repairs. Some have suggested that less foreign material may theoretically prevent pain. If the prevalence of chronic pain is less after nonmesh repairs, selected hernias might be repaired without mesh. Our aim was to clarify if nonmesh repairs are superior to mesh repairs regarding chronic pain.

METHODS

For this systematic review, searches were conducted in five databases. The main outcome was chronic pain reported a minimum of six months after mesh and nonmesh repair in adult patients with a primary inguinal hernia. Only randomized controlled trials (RCTs) were included.

RESULTS

A total of 23 RCTs with 5,444 patients were included. The median follow up was 1.4 years (range 0.5-10). Twenty-one studies reported crude chronic pain rates, and when considering moderate and severe pain, the prevalences of pain after nonmesh repairs and mesh repairs were similar: median 3.5% (0%-16.2%) versus median 2.9% (0%-27.6%), respectively. Both the meta-analyses and the network meta-analysis indicated no difference in chronic pain rates when comparing nonmesh repairs with open- and laparoscopic mesh repairs.

CONCLUSION

Mesh may be used without fear of causing a greater rate of chronic pain.

Outcomes of surgery on patients with a clinically inapparent inguinal hernia as diagnosed by ultrasonography

BACKGROUND

Chronic post-operative inguinal pain (CPIP) is the most significant complication following inguinal hernia repair. Patients without a palpable hernia prior to surgery seemed to report more CPIP. Our aim was to evaluate the effects of surgery on patients with a clinically inapparent inguinal hernia as diagnosed using ultrasonography.

METHODS

A total of 179 hernia repairs in patients with a positive ultrasonography but negative physical examination were analysed retrospectively. Patients with recurrent hernias, femoral hernias or previous surgery to the inguinal canal were excluded. The primary outcome was the presence of chronic postoperative inguinal pain (pain > 3 months postoperatively). Data on preoperative complaints, surgical technique and findings during ultrasonography and surgery were also studied in relation to the development of CPIP.

RESULTS

A quarter (25.1%) of the patients reported chronic postoperative pain. Female gender (p = 0.03), high BMI (p = 0.04) and atypical symptoms prior to surgery (p < 0.001) were significant univariate risk factors for developing CPIP. Logistic regression showed a significant association between atypical symptoms and CPIP [OR = 6.31, p < 0.001, 95% CI (2.32, 17.16)], which was still present after correction for the significant univariate variables [OR = 4.23, p = 0.02, 95% CI (1.26, 14.21)].

CONCLUSION

Patients with a clinically inapparent inguinal hernia as diagnosed using ultrasonography report a high incidence of CPIP after elective hernia repair. Patients with atypical groin pain prior to surgery are especially prone to CPIP. It is questionable whether these hernias should be classified and treated as symptomatic inguinal hernias. The results advocate taking other causes of groin pain into consideration before choosing surgical treatment.

Etiology of Inguinal Hernias: A Comprehensive Review

Background

The etiology of inguinal hernias remains uncertain even though the lifetime risk of developing an inguinal hernia is 27% for men and 3% for women. The aim was to summarize the evidence on hernia etiology, with focus on differences between lateral and medial hernias.

Results

Lateral and medial hernias seem to have common as well as different etiologies. A patent processus vaginalis and increased cumulative mechanical exposure are risk factors for lateral hernias. Patients with medial hernias seem to have a more profoundly altered connective tissue architecture and homeostasis compared with patients with lateral hernias. However, connective tissue alteration may play a role in development of both subtypes. Inguinal hernias have a hereditary component with a complex inheritance pattern, and inguinal hernia susceptible genes have been identified that also are involved in connective tissue homeostasis.

Conclusion

The etiology of lateral and medial hernias are at least partly different, but the final explanations are still lacking on certain areas. Further investigations of inguinal hernia genes may explain the altered connective tissue observed in patients with inguinal hernias. The precise mechanisms why processus vaginalis fails to obliterate in certain patients should also be clarified. Not all patients with a patent processus vaginalis develop a lateral hernia, but increased intraabdominal pressure appears to be a contributing factor.

Chronic postoperative pain: recent findings in understanding and management

Chronic postoperative pain is a poorly recognized potential outcome from surgery. It affects millions of patients every year, with pain lasting for months to years, resulting in patient suffering and ensuing economic consequences. The operations with the highest incidence of chronic postoperative pain are amputations, thoracotomies, cardiac surgery, and breast surgery. Other risk factors include preoperative pain, psychological factors, demographics, and the intensity of acute postoperative pain. Attempts to prevent chronic postoperative pain have often led to debatable results. This article presents data from recently published studies examining the incidence, risk factors, mechanisms, treatment options, and preventive strategies for chronic postoperative pain in adults. In summary, many of the previously identified risk factors for chronic postoperative pain have been confirmed and some novel ones discovered, such as the importance of the trajectory of acute pain and the fact that catastrophizing may not always be predictive. The incidence of chronic postoperative pain hasn’t changed over time, and there is limited new information regarding an effective preventive therapy. For example, pregabalin may actually cause more harm in certain surgeries. Further research is needed to demonstrate whether multimodal analgesic techniques have the best chance of significantly reducing the incidence of chronic postoperative pain and to determine which combination of agents is best for given surgical types and different patient populations.

Impact of postoperative complications on the risk for chronic groin pain after open inguinal hernia repair

BACKGROUND

Chronic pain is common after inguinal hernia repair and has become one of the most important outcome measures for this procedure. The purpose of this study was to determine whether or not there is a relationship between specific postoperative complications and risk for chronic pain after open inguinal hernia repair.

METHODS

A prospective cohort study was designed in which participants responded to the Inguinal Pain Questionnaire regarding postoperative groin pain 8 years after inguinal hernia repair. Responses to the questionnaire were matched with data from a previous study regarding reported postoperative complications after open inguinal hernia repair. Participants were recruited originally from the Swedish Hernia Register. Response rate was 82.4% (952/1,155). The primary outcome was chronic pain in the operated groin at follow-up. Grading of pain was performed using the Inguinal Pain Questionnaire.

RESULTS

A total of 170 patients (17.9%) reported groin pain and 29 patients (3.0%) reported severe groin pain. The risk for developing chronic groin pain was greater in patients with severe pain in the preoperative or immediate postoperative period (odds ratio 2.09; 95% confidence interval 1.28-3.41). Risk for chronic pain decreased for every 1-year increase in age at the time of operation (odds ratio 0.99, 95% confidence interval 0.98-1.00).

CONCLUSION

Both preoperative pain and pain in the immediate postoperative period are strong risk factors for chronic groin pain. Risk factor patterns should be considered before operative repair of presumed symptomatic inguinal hernias. The problem of postoperative pain must be addressed regarding both pre-emptive and postoperative analgesia.