Description of the health problem
Introduction
Surgical repair (herniorrhaphy) is undertaken in most people presenting with inguinal hernia in order to close the defect, alleviate symptoms of discomfort and prevent serious complications. Inguinal hernia repair is the most frequent and resource-consuming surgical intervention in the UK.1,2 It is also the most common general surgical intervention performed in Europe1,3,4 and the USA.5 Various surgical techniques and approaches are available for inguinal hernia. These can be classified in three main categories: open repair with suture (e.g. Bassini and Shouldice repair), open repair with mesh (e.g. Liechtenstein repair or preperitoneal repair) and laparoscopic repair with mesh [e.g. totally extraperitoneal (TEP) repair or transabdominal preperitoneal (TAPP) repair].
Open and laparoscopic ‘tension-free’ repairs, which are based on the use of ‘mesh’ (prosthetic and biological), are widely performed and considered superior to the traditional ‘tissue-suture’ repairs, such as the Bassini or Shouldice techniques.6,7 Compared with the traditional sutured techniques, a reduction in the risk of recurrence between 50% and 75% has been demonstrated after mesh repair.8,9 However, the laparoscopic mesh repair has a longer learning curve and higher resource cost compared with the open mesh repair.2,7,10–12 Different open repairs with mesh, such as the Lichtenstein repair and the preperitoneal repair, have shown similar results and very low recurrence rates, ranging from 2% to 5%.13,14 The preperitoneal mesh repair has demonstrated similar or better outcomes compared with the laparoscopic mesh repair.15
Considering the low recurrence rate reported in the literature after surgical repair of inguinal hernia, the current key outcomes on which to measure the clinical success of hernia recovery include chronic pain, complications, time to return to normal activities and quality of life (QoL).16,17 Published evidence assessing the effects of common mesh techniques (including open preperitoneal repair, Lichtenstein repair and laparoscopic repair) in lowering chronic pain and improving major clinical outcomes have produced inconsistent results.3,15,18–20 The aim of this assessment was to evaluate the clinical effectiveness and cost-effectiveness of open preperitoneal repair compared with Lichtenstein repair in adults presenting with a clinically diagnosed primary unilateral inguinal hernia.
Aetiology, pathophysiology and clinical presentation
An inguinal hernia is a protrusion of the contents of the abdominal cavity through a defect in the inguinal canal. It manifests as a lump or swelling in the groin that may cause discomfort and pain, and impact on daily activities and ability to work. Unilateral hernias occur on one side of the lower abdominal wall, whereas bilateral hernias occur on both sides of the lower abdomen wall. Symptoms of inguinal hernia include swelling, pain or aching sensation in the groin, which develops gradually over time. Pain worsens with prolonged activities.21 The bulge of the hernia increases in size with activities that cause intra-abdominal pressure, such as coughing, lifting or straining. Occasionally the hernia sac contents may get incarcerated causing obstruction or strangulation of the intestine, leading to ischaemia, necrosis and even perforation of the intestine. Rarely, inguinal hernias are asymptomatic.
Inguinal hernia is commonly diagnosed by clinical physical examination. Physical examination involves careful inspection of inguinal areas for bulges or impulses while the patient is standing and during a Valsalva manoeuvre (i.e. forceful attempted exhalation while keeping the mouth and nose closed). The sensitivity and specificity of physical examination for the diagnosis of inguinal hernia have been reported to be 75% and 96%, respectively.22 In specific clinical situations such as recurrent hernia, hernia in female patients, surgical complications with chronic pain or uncertain aetiology, diagnosis of inguinal hernia can be improved by various imaging techniques (e.g. ultrasonography, magnetic resonance imaging or computerised tomography).21 In particular, magnetic resonance imaging and ultrasonography have shown high sensitivity and specificity estimates (> 80% and > 90%, respectively) for the diagnosis of groin hernia.22
The classification of hernia is a prerequisite to describe the anatomy or size of inguinal hernia and to choose the best management.3,23 Many classifications of inguinal hernia have been proposed and they are all based on the presence of indirect hernia (occurs because of the natural weakness in the internal inguinal ring), direct hernia (caused by the weakness in the floor of inguinal canal) and femoral hernia (less common groin hernia occurring mostly in women).23
illustrates a number of different classifications currently available.
Overview of the different inguinal hernia classifications
Epidemiology and prevalence
A large population-based prospective study conducted in the USA (National Health and Nutrition Examination Survey, 1971–5) reported a 20-year cumulative incidence of hospitalisation with inguinal hernia of 6.3%.24 The condition is observed more frequently in males and incidence increases with age.24 The lifetime chance of getting inguinal hernia is estimated to be 27% in men and 3% in women.25 Most inguinal hernias are found in men because of the vulnerability of the male anatomy to the formation of hernias in this region.26 The average age group for the manifestation of inguinal hernia has been reported to be 10 years older in women (60–79 years) than in men (50–69 years).27
A register-based 5-year study conducted in Denmark found that 97% of all groin hernia repairs (n = 46,717) were inguinal hernias.4 In the Netherlands, approximately 30,000 inguinal hernia repairs are carried out annually. In the USA, data from the National Centre for Health Statistics suggest that approximately 800,000 groin hernia repairs were performed in 2003, with over 90% of these surgeries performed on an outpatient basis.5
Impact of health problem: significance for the NHS and burden of disease
Symptomatic patients often present with pain and discomfort. Patients may experience a localised pain or aching (burning or gurgling) sensation at the site of hernia defect or a heavy or dragging sensation in the groin. There are various factors that may contribute to pain, including stretching or tearing of the tissue around the hernia defect, prolonged activity or Valsalva manoeuvres.21 A prospective study by Hair and colleagues,28 evaluated the association between hernia symptoms and time from hernia presentation in 699 patients. About 65% (457) of patients complained of pain and discomfort at the hernia site on presentation, with the cumulative probability of pain increasing to almost 90% at 10 years, whereas more than one-third of patients (267/699) were asymptomatic. Patients with inguinal hernia are at risk of bowel strangulation, which requires emergency resection. A retrospective study,29 reported a cumulative probability of strangulation for inguinal hernias of 2.8% at 3 months and 4.5% after 2 years.
Severe chronic pain, wound infection and recurrence are among the postoperative complications that are reported after inguinal hernia repair.16,17 With incidence rates ranging from 10% to 54%, chronic pain is undoubtedly the dominant complication after inguinal hernia repair.16,30,31 The reason for long-term postoperative pain is complex and often related to intraoperative nerve damage, which is often associated with technical aspects of the surgical procedures as well as with surgeon’s dexterity and expertise.32 The position of the mesh is likely to be another crucial factor.
Management of condition and current service provision
Conservative management
Asymptomatic inguinal hernias, which do not cause symptoms, can be managed through watchful waiting. However, asymptomatic patients need to be monitored over time for occurrence of symptoms, especially those indicating strangulation or incarceration, which require immediate medical attention.7,21
Trusses are often recommended for the temporary management of hernia while patients are waiting for an operation. A truss is a type of surgical appliance that provides support for the herniated area during daily and working activities.3 However, the benefit achieved through the use of a truss is debatable, as up to 64% of the patients have declared that they find it uncomfortable.33 Nevertheless, in the UK, 40,000 trusses are issued every year with the rate of supply being very high as compared with other industrialised countries.3
Surgical management
Inguinal hernias are commonly repaired using surgery, where the abdominal bulge is pushed back into place and the weakness in the abdominal wall is strengthened. Most hernia repairs are undertaken as elective procedures.34 Surgical procedures for inguinal hernia include open repair with suture (e.g. Shouldice or McVay), open repair with mesh (e.g. Liechtenstein repair or preperitoneal repair) and laparoscopic repair with mesh.34
Open mesh repair is recommended for the management of primary unilateral inguinal hernia6,7 because of its low recurrence rates. Laparoscopic mesh repair is restricted to bilateral inguinal hernias, recurrent hernias, younger patients, patients with other chronic pain problems and those with severe groin pain.3,6,35 When a mesh approach is not affordable or suitable (e.g. in older patients with significant comorbidity), a non-mesh repair is usually considered.6,7
Current service cost
An increasing trend of primary inguinal hernia repairs performed as day-case procedures has been observed in England over the last decade.2 In 2012/13, 41,384 out of 61,280 (68%) finished consultant episodes for primary inguinal hernia were performed as day-case procedures.1 Based on national average reference costs, the costs for elective inpatient and day-case procedures are £2041 and £1471, respectively [see Appendix 1 for a derivation of the unit costs from Healthcare Resource Group (HRG) activity code FZ18]. The total annual cost to the NHS in England for primary hernia repair is estimated to be in the region of £114M per year, representing a substantial cost burden to the NHS. An implementation and uptake report completed by National Institute for Health and Care Excellence (NICE) in 201035 indicates an increasing proportion of procedures performed as laparoscopic repair (16% of all primary inguinal hernia repairs in 2008/9). Therefore, assuming a similar breakdown of elective inpatient and day-case procedures for laparoscopic repair, the total cost to the NHS of open mesh hernia repairs is likely to be around £95M per annum.
Earlier studies show that the most important cost parameters for economic evaluation of inguinal hernia include the time patients spent in the operating room and recovery room, and the length of overall hospital stay.5 The resources required for open surgery are less than those required for laparoscopic surgery.6,10,11,13 Although there is little evidence comparing the costs of different types of open mesh repair, it can be assumed that operative costs are similar owing to the fact that open mesh procedures are technically comparable. Recent studies indicate that because of the observed low recurrence rates, one of the most important components for total NHS cost is that related to the management of chronic pain after surgery.36 Evidence shows that laparoscopic repair may reduce postoperative chronic pain, but with the trade-off of additional resources required to perform the surgical mesh procedure.13 There is no evidence comparing the total costs (including surgical and postoperative costs) or cost-effectiveness of different open preperitoneal mesh repairs from the perspective of health-care providers in the UK.
Variation in services and/or uncertainty about best practice
The relevant mesh techniques commonly used for the treatment of primary inguinal hernia in the UK are open mesh repairs (e.g. Lichtenstein repair and preperitoneal repair) and laparoscopic mesh repairs (TAPP repairs and TEP repairs). The choice of open versus laparoscopic repair, as well as the choice of specific mesh material, is usually based on surgeons’ preference and patients’ characteristics. There is a considerable variation (more than a twofold variation) in the rate of inguinal hernia repair across the NHS.2
illustrates the number of inguinal hernia repair procedures per 100,000 population per clinical commissioning group across England. Of the 67.2% of inguinal hernia repairs performed in 2011/12 as day cases, the rate varied from 32% to 100% across providers. Owing to the lack of a national audit and of an established follow-up system, and taking into consideration the current low recurrence rate after inguinal hernia repair, it is difficult to rule out with certainty which technique is best.
National variation plot by clinical commissioning group for inguinal hernia repair (from 1 July 2013 to 30 June 2014) (Emma Fernandez, The Royal College of Surgeons of England, 2015, personal communication; permission gained from The Royal College of (more...)
Relevant national guidelines, including National Service Framework
The recent guidance from the British Hernia Society6 indicates that all adult inguinal hernias should be repaired using a flat mesh technique (or a non-mesh Shouldice technique, if experience is available). For the management of primary unilateral inguinal hernia, the British Hernia Society guidance suggests that an open technique under local anaesthesia should be regarded as an acceptable and cost-effective approach in suitable patients, that is those with significant comorbidity, those without other chronic pain problems and, in particular, older patients. A laparoscopic approach may be considered in bilateral inguinal hernias, groin hernias in women, younger patients, patients with other chronic pain problems or those with a severe groin pain even in the presence of a small hernia. The guidance concludes that at present there is conflicting information on whether or not laparoscopic repairs are better than open mesh repairs in terms of lowering the incidence and severity of pain.6
Guidance from NICE on laparoscopic surgery for inguinal hernia repair suggests that laparoscopic repair should be considered one of the treatment options for inguinal hernia.34 A shared decision-making model should be used for the choice of surgery by fully informing patients about the risks and benefits of open and laparoscopic repairs. Only trained and experienced surgeons should perform laparoscopic surgery for inguinal hernia repair. NICE guidance also provides recommendations for bilateral and recurrent hernias.34
Description of interventions under assessment
The concept of ‘tension-free’ repair using a ‘mesh’ (prosthetic and biological) was introduced initially in the 1960s to overcome the drawbacks of tissue-suture techniques, which resulted in serious complications including ischaemia, pain, necrosis and recurrent hernia. A mesh technique repairs a defect in the posterior wall of the inguinal canal by blocking it with a plug or by placing the flat mesh prosthesis over the fascia transversalis to strengthen the inguinal wall. Meshes can be placed into the defect either anteriorly through open inguinal incision (i.e. Lichtenstein technique) or posteriorly in the peritoneal space through open (i.e. preperitoneal repair) or laparoscopic surgery.
Anterior Lichtenstein repair (open mesh)
Irving Lichtenstein developed the anterior open tension-free approach in 1984.37 It is a very common and reproducible approach, and is relatively easy to perform.7 The technique involves the placement of flat mesh (polypropylene) on top of the hernia defect through anterior dissection of the inguinal wall under local or general anaesthesia. Mesh is positioned between the internal and external oblique muscle and is sutured to the inguinal ligament such that there is adequate overlap of the posterior wall. At present, the Lichtenstein repair is considered the gold standard among open inguinal hernia procedures. Since its advent, the incidence of hernia recurrence has reduced up to 2%.14
Different meshes and/or devices used for anterior open approach have been developed, including the mesh plug, the Prolene Hernia System (Ethicon, Somerville, NJ, USA) and the Hertra sutureless mesh (Herniamesh, Chivasso, Italy). Systematic reviews6,15,38,39 and clinical guidelines have assessed the effect of mesh plug repair and the Prolene Hernia System compared with Lichtenstein mesh repair. The Groin Hernia Guidelines published in 2013 included a meta-analysis of eight randomised controlled trials (RCTs), with a total of 2912 patients assessing the effects of mesh plug repair versus Lichtenstein repair. Meta-analyses results were similar with regard to postoperative complications and return to daily activities.6 Similarly, a meta-analysis of 10 RCTs with a total of 2708 patients did not find significant differences in the number of recurrences between the Lichtenstein mesh repair, mesh plug repair and the Prolene Hernia System.38 Another meta-analysis of six RCTs and a total of 1313 patients, which assessed the effects of the Prolene Hernia System versus the Lichtenstein repair, showed that the Prolene Hernia System was associated with a higher rate of perioperative complications. However, no significant differences were observed between the two techniques with regard to duration of operation, time to return to work, chronic groin pain or incidence of recurrences.39 A more recent report commissioned by the US Agency for Healthcare Research and Quality (AHRQ), assessed the effectiveness of Lichtenstein open mesh with various mesh plug techniques.15 Based on the findings of 21 studies (20 RCTs and one non-RCT), the report concluded that return to work was shorter after Lichtenstein mesh repair. No other significant differences were observed between the surgical procedures. In conclusion, current evidence seems to indicate that the standard Lichtenstein mesh repair performs better than mesh plug repairs and the Prolene Hernia System.
Posterior open repair (open preperitoneal mesh)
The open preperitoneal mesh approach involves incision of the abdominal wall and implantation of the mesh in the space between the peritoneum and the muscle layers. The mesh is held in place with intra-abdominal pressure and requires less or no fixation. Implantation of the mesh can be achieved through (1) a transinguinal method (e.g. Rives), (2) a small incision (2–3 cm) made in broad abdominal muscles [e.g. Kugel repair (Davol, Warwick, RI, USA)] or (3) a lower midline abdominal incision (e.g. Stoppa repair).40 Open preperitoneal mesh repairs are mostly performed under general anaesthesia. The first open preperitoneal technique was reported by Stoppa in 1980 (i.e. Stoppa repair).7 Since then a number of different techniques have been developed including the Kugel patch, the Nyhus repair, the Read–Rives repair and the transinguinal preperitoneal (TIPP) technique. There is a lack of robust evaluations comparing the clinical efficacy of each of these techniques. Kugel, using a specially designed hernia patch, observed only five recurrences out of 808 hernia repairs.41 A retrospective study found similar results between the participants who underwent TIPP repair and those who underwent Lichtenstein mesh repair, with low incidence of chronic pain in both intervention groups.11
The open preperitoneal technique with soft mesh has been reported to be a safe and potentially cost-effective approach with a short learning curve.41–44 Irrespective of either open or laparoscopic techniques, the position of the mesh is considered an important factor in the interpretation of chronic pain because of the location of the nerves in the inguinal canal. Recent systematic reviews and meta-analyses, which assessed the effects of common open mesh techniques in lowering chronic pain and improving major clinical outcomes, have failed to provide definite conclusions.15,18–20 A Cochrane review20 based on the findings of three RCTs showed some potential benefits of the open preperitoneal mesh repair compared with the Lichtenstein mesh repair in terms of incidence of acute and chronic pain and recurrence rate. However, the evidence base of this review was limited. A recent meta-analysis of 12 RCTs19 found that open preperitoneal mesh repair was associated with a lower risk of developing chronic groin pain than the Lichtenstein mesh repair, and the two techniques were comparable with regard to rate of recurrences and complications. It is worth noting that this meta-analysis did not focus exclusively on people with primary unilateral inguinal hernia but included people with recurrent and incarcerated hernias. Two further systematic reviews in the literature15,18 confirmed that various open repair procedures yielded similar results with further potential benefits for the open preperitoneal mesh techniques. The results of these systematic reviews were, however, inconclusive as both included trials assessing the Prolene Hernia System versus the Lichtenstein mesh repair.
Ralph Ger first introduced the use of a laparoscopic approach in 1982.45 Laparoscopic repairs are minimally invasive and are performed under general anaesthesia. Small incisions are made for the insertion of the operating instruments and prosthetic mesh is placed to close the hernia defect. Mesh is placed in the preperitoneal plane by using one of the two approaches:
TAPP repair: the abdominal cavity is entered and a flap of the peritoneum is deflected to expose the preperitoneal plane. A mesh is inserted to cover the hernia defect in the inguinal region. The peritoneum is then closed over the mesh.
TEP repair: the mesh is inserted via the preperitoneal plane without entering the peritoneal cavity to cover hernia defects while remaining outside the peritoneum.
The effects of open versus laparoscopic techniques have been assessed in a considerable number of RCTs. A UK Health Technology Assessment (HTA) report published in 200513 identified 37 RCTs that compared open mesh repairs with laparoscopic mesh repairs. A more recent report by the AHRQ, published in 2012, assessed the effectiveness and adverse effects of various surgical interventions for inguinal hernia in both adults and children.15 The report identified 123 RCTs, two clinical registries and 26 non-randomised studies published between January 1990 and November 2011.15 Thirty-six of the included 123 RCTs compared open mesh repairs versus laparoscopic mesh repairs for primary inguinal hernia (indicating that the size of the evidence base for this comparison has not significantly changed since 2003), while 20 RCTs assessed various open mesh repairs (some of which no longer reflect the repairs commonly performed in clinical practice). Both these reports concluded that people who underwent laparoscopic mesh repair had faster return to normal activities, less chronic pain and numbness, and fewer postoperative complications (infection and haematoma), while those patients who underwent open mesh repair had lower rates of serious complications (especially visceral injuries). The AHRQ showed a lower risk of recurrence after open surgery (2.49%) than after laparoscopic surgery (4.46%) for the treatment of painful primary hernias in adults,15 while the UK HTA report observed similar recurrence rates between laparoscopic (2.47%, 26/1052) and open procedures (2.07%, 22/1062).13 However, there is conflicting information on whether or not laparoscopic repair is better than open mesh repair in terms of lowering the incidence and severity of pain outcomes.6,21,34 The uptake of laparoscopic technique by surgeons is very low (16% in the UK, ≈ 10% in the USA), probably owing to the complexity of the procedure, potential serious complications, long learning curve and high cost.3,35
Current usage in the NHS
Inguinal hernia repair is the most common general surgical intervention performed in the UK. In England, 71,490 inguinal hernia procedures were carried out in 2012/13, with over 100,000 NHS bed-days of hospital resources utilised.1,2 Of these procedures, 65,759 repairs (92%) were for the repair of primary hernias and 5731 repairs (8%) were for the repair of recurrent hernias.1 Out of 65,759 procedures for primary inguinal hernia, 61,280 (93%) were procedures involving the use of a mesh. Of 71,427 admissions for unilateral or unspecified inguinal hernia, 6.8% (4867) were emergency admissions while almost 90% (64,017) were on a waiting list, with a mean waiting time of 62.5 days. In 86% of cases (61,169), primary repair of inguinal hernia was performed using mesh techniques (i.e. biological/prosthetic). The majority of inguinal hernia repairs were performed as day surgery procedures (> 80%) to overcome the demand of hospital bed requirement in the NHS.2
The Lichtenstein open mesh repair is the most commonly performed procedure for hernia repair in the UK (performed by 96% of surgeons).16 A NICE uptake report published in 201035 indicates that of all surgical repairs of inguinal hernia performed in 2008/9 in England, approximately 16% were performed using laparoscopic techniques.35 In Scotland, the uptake of laparoscopic surgery in 2007/8 was lower, with only 13% of inguinal hernia repairs performed using a laparoscopic approach.46
