Stina Öberg

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.

Absorbable Meshes in Inguinal Hernia Surgery: A Systematic Review and Meta-Analysis.

Purpose. Absorbable meshes used in inguinal hernia repair are believed to result in less chronic pain than permanent meshes, but concerns remain whether absorbable meshes result in an increased risk of recurrence. The aim of this study was to present an overview of the advantages and limitations of fully absorbable meshes for the repair of inguinal hernias, focusing mainly on postoperative pain and recurrence. Methods. This systematic review with meta-analyses is based on searches in PubMed, Embase, Cochrane, and Psychinfo. Included study designs were case series, cohort studies, randomized controlled trials (RCTs), and non-RCTs. Studies had to include adult patients undergoing an inguinal hernia repair with a fully absorbable mesh. Results. The meta-analyses showed no difference in recurrence rates (median 18 months follow-up) and chronic pain rates (1 year follow-up) between absorbable- and permanent meshes. Crude chronic pain rates for the RCTs were 2.1% for the absorbable meshes and 7.6% for the permanent meshes. For the absorbable meshes, medial hernias were more susceptible for recurrence compared with lateral hernias (P < .0005). None of the studies reported allergic reactions or other serious adverse events related to the absorbable mesh. Conclusions. Patients with an absorbable mesh seem to have less chronic pain following inguinal hernia surgery compared with permanent meshes, without increased risk of recurrence.

MRI is unable to illustrate the absorption time of the absorbable TIGR mesh in humans: a case report

A male patient had a bilateral laparoscopic inguinal hernia repair in 2012. The right-sided hernia was treated with a permanent mesh, and the left-sided hernia received an absorbable mesh. The absorbable TIGR mesh has been proved to be completely absorbed and replaced by new connective tissue after 3 years in sheep. The patient was therefore followed for 3 years by annual magnetic resonance imagings (MRIs) to illustrate the absorption time in humans. During follow-up, the thickness of the absorbable mesh slightly decreased, and at the last clinical examination, the patient was without a recurrence. However, MRI failed to illustrate absorption of the TIGR mesh, perhaps since new connective tissue and the mesh material had the same appearance on the images. In conclusion, MRI was unable to confirm an absorption time of 3 years for the TIGR mesh, and further studies are needed to investigate if the mesh also completely absorbs in humans.

Systematic review and network meta-analysis of methods of mesh fixation during laparoscopic ventral hernia repair

Ventral hernia repairs are common and have high recurrence rates. They are usually repaired laparoscopically with an intraperitoneal mesh, which can be fixed in various ways. The aim was to evaluate the recurrence rates for the different fixation techniques.

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.

How to Surgically Remove the Permanent Mesh Ring after the Onstep Procedure for Alleviation of Chronic Pain following Inguinal Hernia Repair

A promising open inguinal hernia operation called Onstep was developed in 2005. The technique is without sutures to the surrounding tissue, causing minimal tension. A specific mesh is used with a memory recoil ring in the border, which may cause pain superficial to the lateral part of the mesh for slender patients. The aim of this study was to illustrate an easy procedure that alleviates/removes the pain. A male patient had persistent pain six months after the Onstep operation and therefore had a ring removal operation. The procedure is presented as a video and a protocol. At the eleven-month follow-up, the patient was free of pain, without a recurrence. It is advised to wait some months after the initial hernia repair before removing the ring, since the mesh needs time to become well integrated into the surrounding tissue. The operation is safe and easy to perform, which is demonstrated in a video.

Surgical techniques and convalescence recommendations vary greatly in laparoscopic groin hernia repair: a nationwide survey among experienced hernia surgeons

BackgroundLaparoscopic groin hernia repair has become increasingly popular. In Denmark, all groin hernia repairs are registered in the Danish Hernia Database. However, many surgical technical parameters are not registered in neither the hernia database nor in other national registries or the patient files. Our aim was to characterize differences in surgical techniques and variations in convalescence recommendations in laparoscopic groin hernia repair that are not available elsewhere.MethodsA questionnaire was sent to all surgeons in Denmark regularly performing unsupervised laparoscopic groin hernia repair. The questionnaire was developed in collaboration with an experienced chief surgeon and face-validated on the target group. It contained demographic details and items on surgical parameters such as the creation of pneumoperitoneum, size of the optic, choice of closure methods, preoperative information, and postoperative recommendation of convalescence.ResultsA total of 71 surgeons were eligible for inclusion, and 61 (86%) responded. We found large variations in almost all surgical parameters, i.e. there was no uniform way of performing laparoscopic groin hernia repair. The variation was not due to the level of experience. The median recommended convalescence period was 1.5 (range 0–28) days for activities of daily living, 4.5 (range 0–28) days for light physical activity, and 14 (range 0–35) days for hard physical activity. Three percent of surgeons routinely informed patients about the risk of sexual dysfunction prior to operation, and 98% informed about the risk of chronic pain.ConclusionsSurgical technical parameters and convalescence recommendations in laparoscopic groin hernia surgery vary widely in a national cohort of experienced hernia surgeons.

Decreased re-operation rate for recurrence after defect closure in laparoscopic ventral hernia repair with a permanent tack fixated mesh: a nationwide cohort study

PurposeTo investigate whether defect closure in laparoscopic ventral hernia repair reduces the re-operation rate for recurrence compared with no defect closure.MethodsData were extracted from the Danish Ventral Hernia Database. Adults with an elective laparoscopic ventral hernia repair with tacks used as mesh fixation were included, if their first repair was between the 1st of January 2007 and the 1st of January 2017. Patients with defect closure were compared with no defect closure. Re-operation rates are presented as crude rates and cumulated adjusted re-operation rates. Sub-analyses assessed the effect of the suture material used during defect closure and also whether defect closure affected both primary and incisional hernias equally.ResultsAmong patients with absorbable tacks as mesh fixation, 443 received defect closure and 532 did not. For patients with permanent tacks, 393 had defect closure and 442 did not. For patients with permanent tacks as mesh fixation, the crude re-operation rates were 3.6% with defect closure and 7.2% without defect closure (p = 0.02). The adjusted cumulated re-operation rate was significantly reduced with defect closure and permanent tacks (hazard ratio = 0.53, 95% confidence interval = 0.28–0.999, p = 0.05). The sub-analysis suggested that defect closure was only beneficial for incisional hernias, and not primary hernias. We did not find any benefits of defect closure for patients with absorbable tacks as mesh fixation.ConclusionThis nationwide cohort study showed a reduced risk of re-operation for recurrence if defect closure was performed in addition to permanent tacks as mesh fixation during laparoscopic incisional hernia repair.

Reply to comment to: Recurrence mechanisms after inguinal hernia repair by the Onstep technique: a case series

We thank the researchers for the comment [1] on our study about recurrence mechanisms after the Onstep repair of inguinal hernias [2]. The authors criticize the partly preperitoneal Onstep method and recommend a complete preperitoneal mesh position [1]. The most common inguinal hernia repairs are the Lichtenstein repair (anterior approach) and laparoscopic repairs (posterior approach with a preperitoneal mesh placement), but the chronic pain rates are high [3]. In Lichtenstein repair, both the anterior dissection and the placement of the mesh in close relation to nerves may be potential sources of chronic pain. The laparoscopic repairs avoid potential nerve damage to a greater extent, and have a lower chronic pain rate compared with Lichtenstein repairs [3]. However, pain seems to equalize after 3–4 years [3] and the etiology to pain is most likely multifactorial, depending on surgical approach, nerve damage, mesh material etc. Even though laparoscopic repairs are promising, there are problems with a long learning curve, the requirement for general anesthesia, and high cost. Therefore, we believe that a new technique is interesting, and the Onstep technique is currently assessed with regards to recurrenceand chronic pain rates. Before implementing a new surgical repair, it should be properly investigated with well-designed randomized controlled trials (RCTs). Onstep is an anterior approach, with partly external and partly preperitoneal placement of the mesh [4]. The digital dissection, combined with no fixation of the mesh to the surrounding tissue, may theoretically result in a low chronic pain rate. Two surgeons developed the Onstep technique, and since both recurrenceand chronic pain rates were low [4], we performed further investigations of the repair with standardized assessment methods in general surgical departments across the country. A pilot study was carried out with standardized pain questionnaires and registration of recurrences [5], which justified two double-blinded RCTs. Both studies are reported according to the CONSORT statement [6] and with published protocols [7, 8]. The studies compare Onstep with Lichtenstein repair [6] and Onstep with laparoscopy [8]. With 12 months follow-up, there were no differences in chronic painor recurrence rates between Onstep and Lichtenstein repair [6]. Two patients had severe chronic pain after Lichtenstein repair, which made them unable to work—this was not seen in the Onstep group. New techniques require an implementation period before they are standardized, which also seems true for the Onstep repair, where the majority of the recurrences occurred early after introduction of the technique [2, 6]. We agree that new surgical techniques should be evaluated based on evidence from well-designed RCTs. The relatively new Onstep repair for inguinal hernias has indeed followed this procedure. Chronic painand recurrence rates do not differ between Onstep and Lichtenstein repair, and we are awaiting the results from an RCT comparing Onstep with laparoscopy. Depending on the results, Onstep might be an alternative to the standard This reply refers to the article available at doi:10.1007/s10029-0171578-y.