Guidelines for laparoscopic treatment of ventral and incisional abdominal wall hernias (International Endohernia Society [IEHS])—Part 2

Search terms: ‘‘Incisional Hernia,’’ ‘‘Ventral Hernia,’’ ‘‘Laparoscopic Incisional Hernia Repair,’’ ‘‘Laparoscopic Ventral Hernia Repair,’’ ‘‘Hernia Repair and Meshes,’’ ‘‘Meshes,’’ ‘‘Mesh Repair,’’ ‘‘Laparoscopic Ventral Hernia Repair and Meshes,’’ ‘‘Incisional Hernia Repair and Meshes.’’ A systematic search of the available literature was performed in July 2012 of Medline, PubMed, Cochrane Library, and relevant journals and reference lists using the above-listed search terms. The first search detected 78 relevant articles. In a second-level search, two articles were added. Twenty-six articles were thus used for this review.

Introduction The first laparoscopic repair of a ventral incisional hernia (LVHR) was reported by LeBlanc and Booth [1] in 1993. Approximately 90,000 ventral incisional hernia repairs are performed in the United States each year. The LVHR procedure continues to gain increasing popularity over open repair. The recurrence rates for LVHR and open repairs are similar. Complications of the laparoscopic technique tend to be fewer but may be more serious, mainly due to a higher incidence of iatrogenic enterotomies [2,3].
Avoiding bowel injury during LVHR The management of bowel injury during LVHR remains controversial. In a recent review, LeBlanc et al. [4] reported an iatrogenic enterotomy incidence of 1.78 % with LVHR and an overall mortality rate of 2.8 %. In the subset of patients whose injury was missed during the initial operation (18 %), the mortality rate reached 7.7 %. Predictably, the small bowel was injured in 92 % of the reported cases. A recent Cochrane review showed an iatrogenic enterotomy rate of 1.55 % with LVHR versus 0.63 % with the open approach [2][3][4][5][6].
Bowel injuries are classified in one of three categories. Immediately recognized injuries result either from bowel trauma during initial port insertion or from bowel manipulation, especially adhesiolysis. Bowel injuries sustained during adhesiolysis may be missed, to be recognized postoperatively by the development of sepsis during the first 24 h. Delayed injuries occur from progression of a thermal injury caused by energized dissection such as monopolar electrosurgery or ultrasonic dissection. These present within the first 5 days postoperatively [7][8][9].
Avoiding bowel injury is of utmost importance during LVHR. It is advisable to gain access to the abdominal cavity via an open technique far removed from the hernia or scar. Sharp dissection should always be used in areas of dense adhesions, particularly when the presence of bowel is suspected. Again, the use of energized dissection close to bowel may cause delayed injuries, with significantly increased morbidity and mortality [7].
Conversion to laparotomy for bowel injury sustained during LVHR Management is best dictated by the extent of injury and contamination and by the level of the surgeon's skill and experience. Options include immediate conversion for open bowel and hernia repair with or without mesh. If the surgeon is adept at laparoscopic bowel repair and contamination is limited, the injury may be repaired laparoscopically and the LVHR performed immediately. An alternative is to repair the bowel and delay the hernia repair until after a period of inpatient observation and administration of parenteral antibiotics [7,10].
If the surgeon lacks experience with laparoscopic bowel repair, an immediate conversion to a laparotomy is advisable. In such a case, the bowel injury is repaired and the hernia defect managed according to the extent of contamination. In the presence of gross spillage and contamination, the hernia should be repaired primarily without the use of mesh [6,11].
In 2010, Itani et al. [3] reported a series of 73 patients who underwent conversion to an open technique for bowel injury with minimal contamination during LVHR. In three patients, the enterotomy was repaired, and the herniorrhaphy was performed with polypropylene (PP) mesh laparoscopically. None of the patients who underwent conversion to laparotomy, including those in whom mesh was placed, experienced a surgical-site infection.
Alternative methods for dealing with bowel injury during LVHR In the event of a bowel injury, there are several alternatives to conversion to laparotomy. Carbajo et al. [11] and Heniford et al. [6] both have described a case in which a minilaparotomy was performed to repair the bowel injury. The incision was made away from the hernia and under direct visualization with the laparoscope. The injured bowel was exteriorized through the incision and repaired extracorporeally. The incision then was closed, and the LVHR was resumed.
In the presence of gross contamination, another valid option entails laparoscopic repair of the injury, with postponement of the herniorrhaphy to a later date. Lederman and Ramshaw [5] reported a series of nine patients who sustained an iatrogenic enterotomy during LVHR. After repair of the injury, the patients were observed for an average of 3 days while receiving intravenous antibiotics. With this regimen, seven of the nine patients had successful completion of their LVHR [7]. These authors identified several factors that increased the risk of enterotomy including extensive adhesiolysis taking longer than 3 h, chronic obstruction, inflamed bowel, and mesh incorporation into bowel. The presence of these factors or the recognition of a visceral injury should prompt the surgeon to consider delaying the repair of the hernia until it is certain that the patient shows no signs of intraabdominal infection.
Some authors advocate immediate repair of bowel injuries and completion of the LVHR in the same setting. Carbajo et al. [11] reported eight patients who underwent laparoscopic repair of enterotomies followed by immediate LVHR. Similarly, Heniford et al. [6] reported five patients with hollow organ injuries that were repaired, with the herniorrhaphy completed laparoscopically. The overriding principles in such cases dictate that contamination be minimal or absent and that the surgeon be skilled at laparoscopic repair of bowel.
Finally, the use of biologic mesh also has been described as a safe method for completing LVHR in the presence of contamination. Although synthetic mesh generally is preferred over biologic mesh in terms of recurrence prevention, biologic mesh has been used successfully in contaminated and infected fields.
In 2004, Franklin et al. [12] described their experience with the use of porcine-derived prosthetic mesh in 43 patients who underwent successful LVHR in a contaminated field. Details of the contamination are vague but included bowel resection, strangulation, and prior mesh infection. One patient experienced a wound infection and a fistula. The authors report no recurrences. The search was limited to English literature and non-English literature with an English abstract. The search was based on Pub Med and Embase databases as well as on the Cochrane register using the aforementioned search terms from 1960 to 2011. A total of 174 articles met the search criteria, but only 78 of these articles adequately dealt with the subject matter. Of these, 32 qualified with respect to levels of evidence.

Statements
Introduction The first report describing repair of incisional and ventral hernias by the laparoscopic method did not usher in a rapid adoption as did laparoscopic cholecystectomy a few years earlier [1]. Since the initial report, subsequent reports have confirmed the efficacy of laparoscopic repair. Despite its success, one of the most feared complications is an unrecognized iatrogenic enterotomy. The risk of this complication existed with open repair, but its recognition during laparoscopic repair is more difficult, and the injury may be missed. This is further compounded by the earlier discharge of the patient.
Enterotomy is not completely unavoidable in either the open or the laparoscopic repair, and the consequences of this complication are always serious.
Discussion This systematic review identified a total of 174 articles that met the search criteria, but only 78 adequately dealt with the subject matter. Of these, only 32 qualified for evidence-based surgical recommendations. Collectively, these publications contained very little specific information on unrecognized (missed) enterotomy or its management during reoperation, including management of the hernia itself.
Two level 1A publications evaluated the laparoscopic repair of incisional and ventral hernias but did not specifically deal with the subject of missed enterotomy. Both concluded that a higher rate of injury to an intraabdominal organ appeared to associated with the laparoscopic approach, but this difference was not statistically significant [2,16].
We found only two papers that discussed the method for repair of the intestinal injury, and only one of which discussed the management of the hernia defect at level 2A. The one paper concluded that for unrecognized enterotomy, ''reoperation with closure/resection of the injury in conjunction with mesh explantation is necessary'' [18]. The other paper reported that no one method of repair was superior and concluded that either suture or staple closure could be used for primary repair of the injury with equal success [4]. However, it should be noted that, depending on the nature of the injury, including the viscus involved, the clinical condition of the patient, and the reoperative findings, some patients will require creation of an ostomy as part of the treatment. This is supported by the single level 2B study in which the stoma was closed and the hernia repaired 3 months later [19]. The level 4 evidence is summarized in (Table 1) Baccari et al. [20] are the only authors who perform a laparoscopic examination of the abdomen to ascertain the presence of an iatrogenic enterotomy, and if such an injury is discovered, perform a formal laparotomy and open repair. In the remaining publications, mesh explantation, intestinal resection, and primary repair of the hernia constitute the preferred management of the unrecognized injuries.
Despite the numerous reports on laparoscopic repair of incisional hernias, very few (in fact, only 2) have addressed this problem. As LeBlanc [10] advocated, ''a laparotomy will generally be required with bowel resection and explant of the mesh.'' Serala [26] recommended that ''if there is a high index of suspicion of a missed enterotomy, a planned re-laparoscopy after 24-48 h…should be done.'' However, this report does not provide any specific recommendations for the management of either the intestinal injury or the hernia.
Conclusions Based on the relative paucity of high-level data on the management of this serious problem, it seems that the safest approach is repair, resection of the injury, mesh explantation, and primary repair of the fascial defect. If this is not possible laparoscopically or if the clinical condition warrants, open surgical treatment is essential.

P. Chowbey
Search terms: ''risk factors for SSI,'' ''risk factors for infection,'' ''causes of mesh infection,'' ''laparoscopic ventral/incisional hernia repair,'' ''perioperative risk factor for infection'' The recommendations relating to the risk factors for infection in laparoscopic ventral/incisional hernia are based on a systematic search and review of the literature performed in Pubmed, Medline, Cochrane Library, EMBASE, the British Journal of Surgery database, UK Pubmed Central, Google, Google scholar, Scirus, Ovid, and Directory of Open Journal Access (DOAJ). Of the 38 publications found that covered the topic, 15 statements were considered useful for this research.

Statements
Level 1 Preoperative transfusion may increase the risk of surgicalsite infection (SSI) Laparoscopic operations lead to a lower incidence of SSI than open operations because the total length of the incisions is shorter, reducing the risk of bacteria entering the subcutaneous space Level 2 In elderly patients, chronic obstructive pulmonary disease (COPD) and low preoperative serum albumin are independent predictors of wound infections; coronary artery disease (CAD), COPD, low preoperative serum albumin, and steroid use are independent predictors of a longer hospital stay Patients who undergo ventral hernia repair with a simultaneous bowel resection show a higher incidence of infectious and noninfectious complications with mesh use Wound infection is lower in laparoscopic hernia repair than in open repair due to the decreased extent of tissue dissection Mesh, wherever possible, should not be brought in contact with skin to avoid contamination by skin flora. Polyester meshes are associated with the highest incidence of infection, fistualization, and recurrence Patients given a prophylactic antibiotic have a lower incidence of SSI The pathogens that frequently cause SSI are Staphylococcus aureus, Enterococcus species, and Escherichia coli, which usually are sourced from patient's skin, mucous membranes, or bowel, and rarely from another infected site in the body [32,33]. The risk factors for infection can be divided into patient-and surgery-related factors.
Patient-related risk factors. Gender and SSI are not correlated, but wound infection in 15-to 24-year-old patients averages 10 % and increases significantly in patients older than 65 years [34]. Dunne et al. [35] reported CAD, COPD, and low preoperative serum albumin as independent predictors for infection in elderly patients.
Smokers and patients receiving immunosuppressants and steroids also have a greater risk of contracting infection. The risk of infection increases fivefold for smokers and by 9 % for patients receiving steroids [34]. Diabetes and malnutrition also are significant risk factors for infection [36]. Obesity decreases the blood circulation in fat tissue and increases the risk of infection [37]. Other factors such as history of infection, high ASA grades, hypoxia, hypothermia, radiation, and peripheral vascular disease also contribute to an increased risk of SSI [38][39][40][41].
Surgery-related risk factors. The preoperative factors increasing the risk of infection include shaving of the surgical site, short duration of scrubbing, antiseptic use, and blood transfusion. The SSI rate was 5.6 % for patients who had hair removed by razor compared with 0.6 % for patients who either had their hair removed by depilatory agents or had no hair removal [42]. Blood transfusion increases the risk twofold [43]. Long operating time also predisposes to the risk of infection. Procedures longer than 3-4 h increase the risk [38].
In addition, mesh infection is a major factor contributing to infection. The reported incidence of infection after laparoscopic repairs is 0-3.6 % [44]. A mesh infection rate as low as 0.78 % after laparoscopic repair was reported in a systematic review by Carlson et al. [18]. Polyester meshes and meshes positioned subcutaneously are associated with a high incidence of infection [44,45]. The use of prosthetic mesh with bowel resection or injury increases the risk of infection many-fold [46]. Also, blood loss during the surgery is a significant risk factor. Postsurgery complications such as seroma, thromboembolism, pulmonary embolism, post-procedure pneumonia, and anemia make the patient more susceptible to infection [47].
To prevent infection, management of these risk factors is important. The risk factors that can be modified should be addressed and managed by adherence to established guidelines and protocols [48]. Cessation of smoking before the surgery reduces the risk of postoperative SSI in addition to other cardiovascular and respiratory benefits. No data are reported on the effect of preoperative parenteral or enteral nutrition on the incidence of SSI [49]. Strict preoperative glycemic control with maintenance of intraoperative normothermia is necessary [50]. Remote infection, especially when mesh is being implanted, should be treated and resolved completely before the surgery. Preoperative hair removal should be avoided, and clipping should be performed instead [42]. Prophylaxis with antibiotics administered half an hour before surgery produces the best results [51]. During surgery, careful attention to proper surgical technique and timely completion of the operation also reduce the risk of SSI. A systematic search of the available literature was performed in July 2012 based on Medline, PubMed, and the Cochrane Library, as well as relevant journals and reference lists using the aforementioned search terms. The first search found 118 relevant articles. In a second-level search, four articles were added. A total of 15 publications were used for this systematic review.

Mesh infection
Key questions • How should a mesh infection be treated?
• When a mesh has to be removed?
• Should the hernia defect be closed?
• Does implantation of biologic meshes play any significant role? • When is it safe to re-implant a synthetic mesh after an infection had occurred? • How long should be waited for the reoperation? • In which cases is a vacuum-assisted therapy indicated? , the local infection rate in the laparoscopic group was 3.1 versus 13.4 % in the open group (p \ 0.00001). A local infection requiring mesh removal was found in 0.7 % of the laparoscopic group and 3.5 % of the open group (p = 0.09). This trend also was seen for infections resulting in mesh removal. In this metaanalysis, the rate of wound infections after laparoscopic repair was 2.23 %.
Out of these 2.3 % wound infection did not lead to mesh removal in two third of cases, but one third of wound infections did result in mesh removal [16]. In a pooled data analysis Treatment of mesh infection also depends on the material used. In a comparative study (level 2B), Hawn et al. [56] demonstrated significantly less need to remove a PP mesh than a PTFE mesh because of a mesh infection (p \ 0.0001). Petersen et al. [57] also showed that for mesh repair of incisional hernias, with which mesh infection occurring in 8.1 % of cases after the use of ePTFE and in 3.9 % after the use of PP, in no case was it possible to salvage the infected ePTFE mesh, whereas all the infected PP meshes were preserved. Hence the chances of mesh salvage after infection are greater with PP meshes than with ePTFE meshes, which usually have to be explanted.
If an interventional conservative attempt at treating a mesh infection after laparoscopic IPOM proves unsuccessful or if from the outset the circumstances no longer allow preservation of the mesh, various options can be used for mesh infections after mesh repair of incisional and ventral hernias [58][59][60][61], including • Mesh removal and primary skin closure, with the repair repeated after 6-9 months. Because the treatment options available in the literature relate only to individual cases or to small case series, currently, no concrete evidence-based recommendation can be made for the optimal management that gives the best results. Instead, the surgeon must decide in the individual case which option is best for the individual patient. There is an absolute need for further studies. The reported incidence of seroma after laparoscopic ventral hernia repair varies widely from 3 to 100 %, with a peak presentation at 7 days postoperatively and almost complete resolution by 90 days after surgery [16,62,65,66,68,83]. Whether all seromas constitute a complication or represent only an inconsequential epiphenomenon of laparoscopic ventral incisional hernia repair is unclear. According to the current surgical literature, up to 35 % of patients will become symptomatic, with pain, pressure, or erythema [66]. In some cases, chronic seroma will develop. Most of the studies reviewed for these Guidelines did not distinguish between clinically significant and asymptomatic seromas.
Whereas clinical retrospective studies often report the incidence of seroma to be 4-78 % [6, 74, 77, 84], a prospective study with close and ongoing ultrasound follow-up assessment reported a 100 % incidence of seroma at 7 days, with all but complete spontaneous resolution by 90 days [66]. The study used mesh, tacks, and sutures. Up to 30 % of patients become symptomatic from the seroma [71].

Level 2B
Laparoscopic and open repairs are compared (trials with opposing results)

Level 2B Nonreducible hernia is a risk factor
Level 3 Seroma may be more common with IPOM than with transabdominal preperitoneal PP (TAPP) LVHR

Level 2B
The incidence increases with the number of prior abdominal incisions

Level 2B
The hospital center (within the VA system) is an independent predictor of seroma

Recommendations
Grade C Surgeons can attempt cauterization of the hernia sac to prevent seroma formation Grade C Surgeons may place a pressure dressing in an attempt to reduce the incidence of seroma To prevent seroma, a small randomized study (JADAD score: 0) determined that if the hernia sac was cauterized by electrocautery or ultrasonic energy, the seroma frequency was decreased from 25 to 4 % [85]. Other similar trials have reported that placing a quilting stitch or doublecrown stapling to decrease the dead space did not affect seroma formation [67]. Studies suffer from small numbers. One study reported that the placement of a compression dressing for 1 week reduced the occurrence of seroma [82].

Level 2B
The majority of seromas resolve spontaneously The recommendations are strongest for informing patients about the possible occurrence of seromas and the expectation that the majority will resolve spontaneously [62,63,66,83]. Given the clinically important consequences of mesh infection as a possible complication of repeated seroma aspiration, this recommendation also may be considered stronger (level B), although it is based on only level 4 evidence [62,74].
The importance of applying a pressure dressing was supported by one study with methodologic limitations [82] and may be contradicted by the findings regarding binder placement, a circumferential pressure dressing.

M. Rohr
Search terms: ''laparoscopic hernia repair'' AND ''LVHR'' AND ''incisional hernia'' AND ''ventral hernia'' AND ''postoperative bulging abdominal wall'' AND ''abdominal wall bulging'' AND ''abdominal wall hernia and bulging'' AND ''complication bulging'' AND ''incisional hernia and bulging'' AND ''bulging after hernia repair'' AND ''long term results'' A systemic search of the available literature was performed in August 2011 based on Medline, PubMed, the Cochrane Library, and relevant journals and reference lists using the aforementioned search terms. Of the 54 articles found, only four dealt with ''bulging'' after laparoscopic hernia repair.
Key questions • Is it a real problem?
• Is it avoidable?

Statements
Level 2B Abdominal bulging is a specific problem associated with laparoscopic repair of large incisional hernias In Introduction Besides pain, patients sometimes report postoperative abdominal bulging, which can be cosmetically dissatisfying. The anatomic basis for this problem lies in the fact that neither the hernia orifice nor the rectus diastasis (if present) was closed during laparoscopic hernia repair. These issues, relevant mainly with large hernias, should be discussed with the patient preoperatively [2].
Bulging: is it a real problem and avoidable? This section concerns the prevalence, diagnosis, clinical significance, and treatment of bulging in the area of laparoscopic repair of ventral hernia caused by mesh protrusion through the hernia opening, but with intact peripheral fixation of the mesh forming an adequate repair [86]. In a study of 765 patients who underwent laparoscopic ventral hernia repair, all the patients with swelling in the repaired area (n = 29) were identified and subjected to further examination by computed tomography (CT). The exam showed that 17 patients (2.2 %) had a recurrence hernia. For an additional 12 patients (1.6 %), the CT indicated only bulging of the mesh but no recurrence. Bulging was associated with pain in four patients, who underwent relaparoscopy and got a new, larger mesh tightly stretched over the entire previous repair. Eight asymptomatic patients agreed to ''watchful waiting.'' All the patients remained symptom free during a median follow-up period of 22 months.
Symptomatic bulging requires a new repair and must be considered as an important negative outcome of laparoscopic ventral hernia repair. In asymptomatic patients, ''watchful waiting'' seems justified [86].
In the prospective study of Kurmann et al. [87], the long-term results after laparoscopic repair of large incisional hernias remain to be determined. The study was designed to compare early and late complications between laparoscopic and open repairs in patients with large incisional hernias. In this study, 56 patients with a hernia diameter of 5 cm or larger who underwent open incisional hernia repair were compared with 69 patients who underwent laparoscopic repair. The median follow-up period was 32.5 months (range 1-62 months) in the laparoscopic group versus 65 months (range 1-80 months) in the open group [3]. The recurrence rate did not differ between the two techniques, but abdominal bulging was identified as a specific problem associated with laparoscopic repair of large incisional hernias (17.4 %) because it was rare (7.1 %) after open repair [87].
To reduce the incidence of seromas or bulging, Orenstein et al.
[88] modified their LVHR approach to routine closure of the transabdominal defect (''shoelacing'' technique) before mesh placement. In their study, 47 consecutive patients undergoing LVHR with shoelacing were reviewed retrospectively. The LVHR technique with defect closure confers a strong advantage in hernia repair, shifting the paradigm toward more physiologic abdominal wall reconstruction.
Orenstein et al. [88] reported this approach to be safe and comparable with historic control studies. While providing reliable hernia repair, the addition of defect closure in their patients essentially eliminated postoperative seroma, and routine use of the shoelace technique reduced bulging. Both procedures are thus advocated in ventral hernia repair.
Comment Symptomatic bulging, although not a recurrence, requires a new repair and must be considered as an important negative outcome of laparoscopic ventral hernia repair. For asymptomatic patients, ''watchful waiting'' seems justified.
Abdominal bulging is a specific problem associated with laparoscopic repair of large incisional hernias. It occurs in 2-20 % of patients. This wide range may be attributable in part to interpretation by the examiner and the opinion of the patient, but evidence for this is limited. There is an urgent need for more studies regarding this topic. The search resulted in a total of 946 citations from Ovid milliner for the period 1948-August 2011, PubMed including prepublication, Embase for the period 1988 to the 33rd week of 2011, evidence-based medicine reviews and the Cochrane Register, and the Web of Science for the period 1993-2011.
Chronic pain after laparoscopic ventral hernia repair has been addressed by 3 metaanalysis/systematic reviews, 13 RCTs, 5 comparative-cohort studies, and 19 single-cohort studies [2,3,17,19,52,74,76,79,81,82, The randomized trials were of fair to poor quality, which influenced the levels of evidence assigned to the statements and recommendations. From this review, the following statements and recommendations are made. The studies on this topic included in the review showed substantial heterogeneity, with varying definitions of pain. The definition of chronic/prolonged pain was often vague, ranging from longer than 24 h to longer than 6 months. Furthermore, the trial designs and reporting were not uniform, further limiting the comparability of the outcomes. This also was noted in the reported metaanalyses of laparoscopic ventral hernia repair [2,17,92].
Specific studies examining chronic pain in patients with ventral hernia repair are infrequent. We may be able to extrapolate some findings from other studies relevant to the assessment of pain syndromes and chronic pain. In inguinal hernia repair, e. g., other preoperative chronic pain conditions not related to the groin [122-124] as well as severe early postoperative pain [124][125][126][127][128] after groin hernia repair are significant risk factors for chronic pain. Ventral hernia recurrence was reported as a risk factor for chronic pain in a large Veteran's Affairs Medical Centers survey [94]. A nonmidline (e.g. lumbar) location is accompanied by both more pre-and postoperative pain [97].
Attempts at prevention of chronic pain after laparoscopic ventral hernia repair have involved mainly different mesh fixation techniques. Unfortunately, the results of these studies often are contradictory [93,96,98,101,102,[118][119][120][121]. Local anesthetic infiltration is reported to be of benefit [103,104]. However, one report on infusion of local anesthetic showed no benefit [95]. Regrettably, the treatment of chronic pain after laparoscopic ventral hernia repair is described in small case series that address local and systemic pain treatment as well as removal of fixation or mesh components or excision of neuroma [102,120].
Recurrence after laparoscopic ventral and incisional hernia repair: risk factors, mechanism, and prevention

P. Chowbey
Search terms: ''incisional hernia'' and ''recurrence'', ''recurrence'' and ''risk factors'' and ''incisional hernia'', ''incisional hernia'' and ''prevention of recurrence'', ''incisional hernia'' and ''mechanisms of recurrence'' A systematic search of the literature was performed using Pubmed, Medline, the Cochrane Library, EMBASE, the British Journal of Surgery database, Google scholar, Scirus, Ovid, and the Directory of Open Journal Access (DOAJ). The search found 34 publications that covered the topic, 19 of which were useful for this systematic review. Conventional hernia repair by suture approximation has a high recurrence rate of 54-63 %, which decreases to 32 % with the use of mesh [133,134]. Insufficient coverage of the incision scar also is a risk factor for recurrence after laparoscopic repair of ventral and incisional hernia [135]. Dual mesh is reported to increase the risk of recurrence [136].

Statements
Postoperative factors contributing to the recurrence after ventral or incisional hernia repair include SSI, mesh infection, wound infection, deep abscesses, and gastrointestinal complications [137].
Most common causes for the recurrence include mesh overlap less than 3 cm, displacement of the mesh, mesh contraction, and invagination into the hernia defect [82]. Improperly placed transfascial sutures together with large suture bites of mesh cause excessive tension and ultimately a hole in the mesh, which results in recurrence [138]. Mesh shift also may be a precursor to hernia recurrence, beginning with intraoperative mesh shift, followed by additional accentuating factors such as mesh contraction [139]. Most surgeons report using both transfascial sutures and laparoscopically placed tacks to secure prostheses in laparoscopic ventral hernia repair, but no firm evidence shows that this reduces the hernia recurrence rate significantly [120].
Increased intraabdominal pressure also predisposes to recurrence. This accounts for the increased recurrence in patients with morbid obesity, COPD, or chronic cough [6,87].
Recurrence after repair can be minimized by taking precautions for patients at high risk for recurrence. Patients with conditions such as COPD and chronic cough should be treated preoperatively, and for morbidly obese patients, larger mesh should be used. Because mesh repair decreases the incidence of recurrence by half, it should be performed for all eligible patients with a hernia defect larger than 2 cm [133,134,140]. Laparoscopic approaches should be considered in preference to open repair because these approaches decrease the recurrence rate.
Recurrences also can be prevented by using increased overlap of the biomaterial and by placing dual devices of fixation [141]. For suprapubic hernias, mesh overlap of at least 5 cm and fixation of the mesh's lower margin under direct vision to Cooper's ligaments confers increased strength and durability to the repair and thus contributes to low hernia recurrence rates [142]. In addition the whole incision and not just the hernia must be repaired to reduce risk of recurrence [135]. In conclusion, applying proper technique and addressing the patients' underlying risk factors can significantly reduce hernia recurrence. A systemic search of the available literature was performed in August 2011 based on Medline, PubMed, and the Cochrane Library, as well as relevant journals and reference lists using the aforementioned search terms. The first search culled 322 relevant articles. In a second-level search, 339 articles were added. Altogether, 501 articles were identified, but only 59 articles were relevant, and 38 formed the basis for this systematic review.
Key questions • Is there a difference regarding operating time?
• Is there a difference regarding frequency of bowel injury? • Is there a difference regarding frequency of seroma formation? • Is there a difference regarding frequency of wound infection?

Statements
Operating room time Only one study reported more bowel injuries in the laparoscopic group (OR 2, 19), but the significance of the difference was low (p = 0.88) [152]. The remaining studies reported too few injuries (0-5), but all were small retrospective series. Nine studies reported more bowel injuries in the laparoscopic group [2,3,16,19,73,116,149,152,155], and three studies reported the same rates [108,113,148]. One study reported no injuries at all [109], and none reported more bowel injuries for open surgery. Thus it appears that laparoscopic hernia repair poses a greater risk of bowel injury, but clearly, more data are needed, and the increased compared with the open approach is low and acceptable.
The reported finds on the incidence of seroma again are heterogeneous, as shown in the following chart: Study Comment Overall, the published experimental and clinical studies outline an unclear picture compounded by differences in techniques used (stapler, sutures) and levels of experience. These account for the variability of reported data such as OR times. In essence, high-quality, high-volume studies are too few. The reported studies often do not differentiate between ventral, umbilical, and incisional hernias, rendering interpretation of the outcomes more difficult. In addition, complications often are grouped together, making it difficult to analyze specific complications.
Ten level 3 studies [5,87,148,150,154,155,163,[168][169][170] reported a hospital length of stay and a follow-up evaluation ranging from 4 to 44 months. The hospital stay ranged from 3 to 8.1 days for open repair and 2.1 to 6 days for laparoscopic repair. Five studies showed a significantly shorter hospital stay in the laparoscopic repair group [150,154,155,163,169].

Comments
The hospital stay is shorter after laparoscopic incisional and ventral hernia repair than after open repair. Few studies have compared the hospital stay after laparoscopic incisional and ventral hernia repair in relation to defect size, and no available study has reported data for hospital stay with respect to the type of mesh fixation and type of mesh.

Return to activity
Search terms: ''return to work'' AND ''laparoscopic incisional hernia'' AND ''ventral hernia repair'' AND ''return to activity'' AND ''mesh fixation'' AND ''suture'' AND ''tacker'' AND ''defect size'' AND ''defect site'' AND ''recurrent incisional hernia'' AND ''type of mesh'' The search yielded eight publications, only three of which were relevant to the search questions, and a further five publications were found by manual search. Return to daily activities or work is an important measure for assessment of any surgical intervention. The Cochrane review [2] included two RCTs with reports on return to activity. Pring et al. [109] reported no significant difference in return to activity, whereas Itani et al. [3] reported that the time to resumption of work was shorter for the laparoscopic group (median, 23.0 vs. 28.5 days; p = 0.06).
From an RCT, Olmi et al. [143] reported that patients in the laparoscopic group could return to work in a significantly shorter time (13 vs. 25 days; p = 0.005). From a level 2b study, Kurmann et al. [87] reported an earlier return to work after LIVHR, but the difference between the two groups was not significant (21 vs. 42 days; p [ 0.05).
From a level 3 study Raftopoulos et al. [150], reported significantly earlier return to work after LIVHR (25.9 vs. 47.8 days; p = 0.036), although the mean time to resumption of activity did not differ significantly. Six level 4 studies [171,177,178,195,198,199] reported return to activities after LIVHR. Kua et al. [179] reported that 82 % of patients returned to household duties within 1 week after laparoscopic repair. Eriksen et al. [101] concluded that the time until smokers and patients with hard physical work demands could return to work was significantly longer.
Return to activities after suture versus tacks fixation In their RCT,Bansal et al. [165] reported a significantly shorter time until resumption of activity after suture fixation than after tacks fixation (p \ 0.001). In their level 2b study, Nguyen et al. [96] reported no significant difference in time until return to activity after the two fixation techniques (respectively 50 vs. 42 % of the patients after 1 week).
Comments Few RCTs compare return to work. Time until return to work is the same or shorter after laparoscopic compared with open repair. No available study reports on return to activity considering different methods of mesh fixation, mesh types, and defect characteristics. More RCTs are needed to analyze different aspects of laparoscopic repair such as fixation method, mesh type, and defect characteristics.

Level 1a
The cost of surgery is higher for laparoscopic procedure, but a shorter hospital stay may make laparoscopic surgery more cost effective Level 1b Suture fixation is a cost-effective alternative to tacks fixation for small and medium-sized defects in anatomically accessible areas Open repair is nine times cheaper than laparoscopic repair A shorter hospital stay is likely to reduce the total direct hospital cost Level 3 Laparoscopic repair is costlier than open repair in terms of hospital cost but has a decreased mean overall cost Level 5 A self-adhering prosthesis may decrease the cost of these procedures

Recommendations
Grade A Suture fixation in laparoscopic incisional hernia repair is recommended Grade D Laparoscopic incisional hernia repair can be recommended as a cost-effective repair The reports in the literature regarding comparison of costs between laparoscopic and open repairs are conflicting. The laparoscopic approach has been shown to result in higher operative costs but better cost effectiveness because it is associated with significantly lower mortality, reduced morbidity, fewer intensive care unit (ICU) admissions and 30-day readmissions, shorter hospital stay, and thus significantly reduced hospital costs.
The search identified 42 studies analyzing costs in incisional and ventral hernia repair, but only 14 papers were considered relevant. In the Cochrane review [2], only one study by Misra et al. [112] performed an economic analysis comparing open and laparoscopic repairs. That study found open repair to be nine times cheaper than laparoscopic repair. Theoretical calculation by Olmi et al. [143] showed the cost of laparoscopic surgery to be higher than the cost of open repair (1,900 vs. 300 euros) but the overall cost to be less than that of the open technique, probably due to a shorter hospital stay.
Three prospective studies [96,167,198] comparing cost showed laparoscopic repair cheaper. DeMaria et al. [167] attributed the lower costs to lower readmission rates, whereas Earle et al. [153], attributed the lower costs to a shorter hospital stay and a lower readmission cost.
Four retrospective comparative studies comparing laparoscopic and open repairs [87,150,154,198] in terms of cost showed that the direct costs of hernia repair surgery in terms of longer OR time and cost of equipment and materials, is higher in laparoscopy group but that the overall costs are lower or equivalent due to a shorter hospital stay and lower complication rates.
Bencini et al. [155] showed that despite a higher mesh cost, laparoscopic repair was cheaper due to the shorter hospital stay. Beldi et al. [148] also showed similar results. These findings were complemented in two other studies by Holzman et al. [168] and Wright et al. [200].
Many variables such as mesh type, fixation technique, and technique of repair come into play in cost calculation. Any modification of these cost variables influences the overall cost of either procedure. An RCT published by Bansal et al. [106,165] comparing suture mesh fixation with tacks mesh fixation showed that the overall cost for suture fixation was significantly less than for tacks fixation of small to mediumsize defects ($575.42 more expensive; p = \ 0.001).
Type of mesh also dictates the overall cost. A prospective study by Alkhoury et al. [201] comparing costs and clinical outcomes with the use of non-heavyweight PP mesh and other meshes showed that PP meshes were substantially cheaper. The cost saving was $436 per patient with Proceed (Ethicon Inc. Somerville, NJ, USA), $770 per patient with Composix (Davol, Warwick, RI, USA), and $931 per patient with ePTFE mesh. In a retrospective comparative study by Bencini et al.
Comments None of the reported studies showed full economic evaluation focused on the relevant alternatives. The studies did not primarily aim to investigate costs or cost effectiveness. The cost analysis studies reported to date were inadequate, so proper health technology assessment (HTA) studies are needed to address cost efficacy and cost utility.

Quality of life
Search terms: ''quality of life'' AND ''laparoscopic'' AND ''incisional hernia'' AND ''ventral hernia repair'' AND ''open incisional hernia repair'' AND ''patient satisfaction'' AND ''cosmesis'' AND ''mesh fixation'' and ''suture'' AND ''tacker'' AND ''defect size'' AND ''recurrent incisional hernia'' The search resulted in 27 publications, but only seven were relevant to the search question. An additional four publications were identified by manual search, giving a total of 11 publications for the study.

Level 1a
Quality of life ( In recent years, the QOL experienced by patients has become an essential evaluation parameter for chronic illness and chronic morbidity and is increasingly used in decisions related to treatment strategies.

QOL in open versus laparoscopic ventral hernia repair
In the Cochrane review [2], only two of nine RCTs compared QOL, with these two RCTs reporting no significant difference in QOL between open and laparoscopic ventral hernia repairs [3,116]. Patient satisfaction with cosmetic appearance was studied in only one of the trials [112], and no significant difference in cosmetic outcomes was reported (p = 0.26).
In a level 2b study, Mussack et al. [202]  QOL and fixation technique Different fixation techniques (suture or tacks) may be associated with varying degrees of early postoperative and chronic pain and may affect QOL postoperatively. Bansal et al. [165] in an RCT compared QOL after fixation with either sutures only or tacks and found no significant difference between the two groups. Wassenaar et al. (RCT) [203] evaluated QOL after three fixation techniques: tacks plus absorbable sutures, double crown of tacks, and tacks plus nonabsorbable sutures. They found that the tacks plus absorbable sutures group was significantly better than the double-crown tacks group in physical functioning and role limitation due to emotional problems (p = 0.02).

Patient satisfaction in laparoscopic ventral hernia repair
Patient satisfaction is an indicator of postoperative QOL and cosmetic outcomes. Only two studies commented on patient satisfaction. Bansal et al. [106,165] from an RCT of suture versus tacks fixation in laparoscopic repair reported that patients were satisfied cosmetically after suture fixation but that the patient satisfaction scores did not differ significantly between suture and tacks fixation. Perrone et al. [24] reported that the patient satisfaction score was high after laparoscopic incisional hernia repair.
Comments Few RCTs have compared QOL between laparoscopic and open ventral hernia repair. Very few studies have compared QOL for different aspects of laparoscopic ventral hernia repair such as type of mesh, fixation method, and defect characteristics. Different methods have been used for QOL assessment in different studies, making analyses and comparisons difficult. More RCTs are needed to evaluate different parameters of laparoscopic ventral hernia repair using one standardized method.

Level 1a
The Postoperative pain rather than recurrence is the most important outcome measure after laparoscopic incisional and ventral hernia repair. The use of transfascial sutures and tacks can cause substantial early postoperative pain and chronic pain even months or years after surgery. Consequently, current interest focuses increasingly on the genesis of pain after laparoscopic ventral hernia repair and methods to reduce such pain. Various factors responsible for chronic pain have been cited including type of mesh fixation, defect closure, recurrent incisional hernias, and type of mesh.
Acute pain Two systematic reviews of RCTs (level 1a) report on postoperative pain after laparoscopic versus open incisional hernia repair. The Cochrane review [2] (metaanalysis of ten RCTs), comprising 880 patients, included four RCTs (Asencio et al. [116], Barbaros et al. [19],Misra et al. [112] and Pring et al. [109]) that measured pain after surgery, and in all RCTs, the intensity of pain was similar between the open and laparoscopic repair groups. Sajid et al. [92] analyzed five RCTs, and reported similar findings of no difference in overall postoperative pain between laparoscopic and open repairs (p = 0.84).
Chronic pain The incidence of chronic pain after laparoscopic incisional and ventral hernia repair is reported to range from 1 to 3 % [204]. Only two RCTs reported on chronic pain in laparoscopic ventral hernia repair versus open repair. Asencio et al. [116] in a level 1b study reported no significant difference in mean pain scores in follow-up assessments at 3 months and 1 year. Also in a level 1b study, Itani et al. [3] reported that the mean worst pain after 1 year was significantly less in the laparoscopic group (15.2 mm lower on a visual analog score of 0-100 mm), but the mean pain score values for both groups are not included.
Three systematic reviews of nonrandomized studies (level 2a) were identified. These reviews by Pierce et al.  Cassar et al. [205] reported the mean incidence of chronic pain to be 1.8 % in 4 of 19 studies.
Pain and type of fixation: suture or tacks? The pain in laparoscopic incisional and ventral hernia repair is related to mesh fixation with either tacks or sutures. The pain due to fixation differs from that at port sites.
Three RCTs (level 1b) studied the association of pain with the type of fixation. Wassenaar et al. [203] conducted an RCT of three fixation techniques (tacks with absorbable sutures, nonabsorbable sutures, and only tacks) and found no significant difference in VAS scores among the three techniques of mesh fixation at any time during a follow-up period of 3 months. On the other hand, Bansal et al. [106] reported higher pain scores in the tacks fixation group than in the suture fixation group during the early postoperative period, which became insignificant at 3 months and during further long-term follow-up assessment [167]. In an RCT during 211, Beldi et al.
[105] also did not find any significant difference in VAS scores between tacks and suture fixations during 6 months of follow-up evaluation. Three nonrandomized comparative studies (level 2b) reported chronic pain after suture and tacks fixation. Nguyen et al. [96] reported no significant difference between the two fixation groups in their nonrandomized comparative trial comparing suture and tacks. Beldi et al. [148] and Kurmann et al. [87] reported that pain after laparoscopic ventral hernia repair is mostly at the transfixation suture site.
In four noncomparative trials (level 4) [6, 82, 84, 105] consisting of 2,649 patients and follow-up periods ranging from 1 to 120 months, the incidence of chronic pain was 16.4 % in the suture groups and 12.7 % in the tacks groups. Chronic pain was highest for patients in whom both tacks and sutures were used (Sharma et al. [82]). However, in a study by Chelala et al. [102] using transfascial suture fixation only, 97.5 % of the patients were pain free. Seven of the patients (1.75 %) reported chronic pain, which resolved gradually, and only three patients (0.75 %) required excision of a neuroma at the suture fixation site.
Bedi et al. [207] in a review of 34 original studies commented that sutures for mesh fixation might cause ischemic injuries to anterior abdominal wall musculature or neurovascular bundle, resulting in pain. Nerve entrapment due to a tack is another possible explanation for postoperative pain (Level 5).
Association of chronic pain In a level 2b study, McKinlay et al. [208] analyzed the incidence of chronic pain after laparoscopic ventral hernia repair of primary and recurrent incisional hernias and reported chronic postoperative pain during more than 6 months. Their report of 101 primary cases showed two cases (2.8 %) of recurrent pain verses 69 cases of no chronic pain.
The mesh material also may play an important role in the causation of pain. In a level 1b study, Bansal et al. [106,165] investigated the association of acute and chronic pain with the type of mesh and did not find any difference in pain scores between heavyweight PP mesh and lightweight barrier coated meshes.
The efficacy of mesh repair is based on the formation of a strong mesh aponeurotic scar tissue complex (MAST complex). But inflammation beyond the optimum range may entrap neural structures, leading to chronic pain.
Currently, large numbers of lightweight composite meshes are available that are claimed to produce optimum fibrotic reaction and to decrease the incidence of chronic pain. However, not many available studies have compared the composite meshes with the PP meshes.
Chelala et al. [102] and Franklin et al. [45] reported chronic pain incidences of 2.5 and 3.1 %, respectively, after defect closure. This may indicate that closure of the defect with subsequent traction may even contribute to chronic postoperative pain.
No study was found depicting the association of chronic pain with acute pain, preoperative pain, or site and size of the defect.
Comments None of the studies evaluated pain as the primary outcome. No study compared the association of pre-and postoperative pain. Few RCTs have reported pain after laparoscopic incisional and ventral hernia repair. Their comparisons mainly involve open repair. Even fewer studies have reported on chronic pain. The sample is small in all RCTs. Very few studies have evaluated the association of pain with the method of fixation or the type of mesh. No data are available regarding the relation of pain with defect site, defect size, acute pain, or recurrent hernias. More RCTs are needed with greater numbers of patients and longer follow-up periods. Larger trials also should include separate analyses of primary ventral and incisional hernias. Studies are strongly needed to assess the relation of pain with fixation, type of mesh, defect size and site, and recurrent hernias.

Recurrence
Search terms: ''laparoscopic incisional hernia repair'' AND ''LIVHR'' AND ''incisional hernia'' AND ''ventral hernia'' AND ''open hernia repair'' AND '' recurrence rates'' AND ''relapse'' In eight systematic reviews [17,52,146,152,205,207,209,210]  Various potential causes for recurrence also have been identified. Cassar et al. [205] reviewed 19 prospective comparative studies comprising of a total of 1,896 patients (1,598 laparoscopic and 298 open repairs) and found higher recurrence rates for large hernias and patients with a wound infection. They also found that staples alone were inadequate for fixation of mesh and that the interval between two staples should be less than 1 cm. Bedi et al. [207] stated that recurrence decreases with the use of transfacial sutures and with experience.

Statements
Nine prospective comparative studies were identified [73,113,154,157,167,208,211,212] [87,157] are associated with significantly higher recurrence rates. Patients with recurrent or multiple hernias also have shown a higher rate of recurrence, although the difference has not been statistically significant [87]. McKinlay et al. [208] compared laparoscopic repair for 69 recurrent hernias and 101 primary hernias. The recurrence rate was comparable (7 vs. 5 %), but the mean time to recurrence was shorter in the recurrent hernia group (p = \ 0.0001).
In eight retrospective studies [5, 155, 169-171, 194, 208, 212] comprising 765 patients, the recurrence rate ranged from 0 to 15.7 % in laparoscopic group during a follow-up period of 6-40 months. Zografos et al. [171] analyzed 106 patients retrospectively (30 laparoscopic and 76 open repairs) during 40 months. The recurrence rates in the two groups were comparable (3.3 vs. 2.6 %). Ceccarelli et al. [212] postulated that the causes for recurrence in laparoscopic repair were rolling up of mesh, incomplete stretching of mesh, and incomplete covering of the defect.
It has been noted that recurrences commonly occur at the mesh margins along the mesh-tissue interface. This finding has been validated by an experimental study, which found that increasing the mesh overlap to 4 cm eliminated mesh disruption [186]. In many studies, a mesh overlap of 3-5 cm or more has been used, and reports have shown recurrence rates to be less than 5 % [177,186,197].
The study by Park et al.
[157] had a recurrence rate of 11 %, but the mesh overlap was only 2.5 cm, which likely was responsible for the high recurrence rate. Theodoropoulou et al. [216] had a recurrence at the periphery of the mesh despite a 3-cm overlap. LeBlanc [209], reviewing the literature on fixation techniques, recommended that the minimum mesh overlap should be 4-5 cm if transfascial sutures are not used, and at least 3 cm when transfascial sutures are used.
Mesh size is equally important. Wassenaar et al. [193] stated that the mesh should cover not only the defect but also the entire incision to prevent recurrence. A larger mesh may protrude through the defect, causing recurrence. Mesh contraction and migration into the defect are common with a smaller mesh.
[72] studied recurrence rates after laparoscopic repair of recurrent hernias and reported that the risk was similar to that for primary repair (3.5 %). Chelala et al. [102], in their series of 400 cases, noted that recurrence could be due to nonclosure of the defect with extrusion of mesh into the defect, especially when the mesh size is insufficient.
Mesh fixation is an important determinant of recurrence rates. Variable recurrence rates have been reported in the literature with the use of different mesh fixation techniques. Three RCTs comparing various fixation devices and techniques were identified. None of them showed a significant difference in terms of the recurrence rate between suture only, suture with tacks, and tacks only fixations.
Similarly, two systematic reviews with a total of 6,824 patients also were identified, which showed no significant difference between suture and tacks fixations [209,210]. In a collective review of 23 studies and 12 comparative studies by LeBlanc [209], mesh fixation with sutures only resulted in the lowest recurrence rate (0.8 %) compared with that by tacks alone (1.5 %). Mesh fixation with tacks and sutures resulted in a recurrence rate of 3.5 % during a mean follow-up period of 22 months. Studies using tacks and sutures for mesh fixation In an RCT,Bansal et al. [165] randomized 106 patients to compare suture and tacks fixation. They reported two recurrences, both in the tacks fixation group, during a mean follow-up period of 31 months.  presented a retrospective study of 100 patients who underwent ePTFE mesh fixation with both transfascial sutures and tacks. The exact mesh fixation technique and mesh overlap size were not mentioned. The recurrence rate was 2 % during a mean follow-up period of 19 months. The proposed mechanisms of recurrence included detachment of tacks and inadequate mesh overlap.
[6] published the largest series (850 patients) of laparoscopic hernia repair with tacks and suture mesh fixation. A higher recurrence was noted in the patients who had undergone a previous open repair. The overall recurrence rate was 4.7 % during 20 months of follow-up evaluation. LeBlanc et al. [186], in a series of 200 patients (43 patients with multiple defects) reported a decreased rate of recurrence, from 9 to 4 %, when they combined tacks with suture fixation. Franklin et al. [45], in a retrospective series of 384 patients, found 11 recurrences (2.9 %) during a mean follow-up period of 47 months for patients, most of whom had mesh fixation with tacks and sutures. The findings showed that most of the recurrences (n = 8) occurred for patients in whom transfascial sutures were not used. Bower et al. [206] in a series of 100 patients who underwent mesh fixation with both transfascial sutures and tacks, reported a recurrence rate of 2 % during a mean follow-up period of 6.5 months. Patients with a body mass index higher than 30 kg/m 2 accounted for 73 % of the complications.
Perrone et al.
[24] presented a series of 116 patients (28.9 % with recurrent hernias) whose hernia recurrence rate was found to be 9.3 %. In 2009, Berrevoet et al. [194] published a multicenter study of 114 patients who underwent composite mesh (Proceed) fixation with tacks and transfascial sutures. The mean recurrence rate was 3.5 % during a mean follow-up period of 27 months.
Studies using tacks only for mesh fixation In a large study, Carbajo et al. [11] followed 270 patients prospectively for a median follow-up period of 44 months. Approximately 95 % of the patients had hernia defects larger than 5 cm including 147 patients with defects size 5-10 cm and 108 patients with defects larger than 10 cm. They demonstrated a recurrence rate of 4.4 %. Frantzides et al. [222] followed up 208 patients for a median of 24 months and demonstrated a recurrence rate of 1.4 % in a retrospective review. Their operative technique involved only tacks, placed 1 cm apart.
A long-term retrospective study by Bageacu et al.
[107] collected data on 159 patients with a median follow-up period of 49 months. In contrast to the study by Carbajo et al. [11], this study included smaller hernia defects, with 46 % smaller than 5 cm, 24 % size 5-10 cm, and 23 % larger than 10 cm. The recurrence rate was high (15.7 %), and all recurrences were confirmed with a CT scan after clinical suspicion. The authors suggested that their higher recurrence rate might have been attributable to a technical learning curve because their recurrence rate dropped from 20 to 10 % between the periods 1993-1995 and 1996-1998, respectively. Another study using only tacks fixation was performed by Kirshtein et al. [183] in which 103 patients were analyzed during a mean follow-up period of 26 months. They demonstrated a recurrence rate of 4 %. All four recurrences occurred within the first month, suggesting a technical cause for the failures. Gillian et al.
[219] published a study of 100 patients with a mean follow-up period of 27 months. Mesh fixation was performed using a double-crown technique, and the recurrence rate was 1 %. Chowbey et al.
[213] presented a series of 202 patients in whom mesh was fixed with a single crown of tacks. The recurrence rate was 1 % during a mean follow-up period of 29 months.
Wassenaar et al. [193] published a randomized controlled trial comparing mesh fixation using double-crown tacks alone, tacks with nonabsorbable sutures, and tacks with absorbable sutures and found no difference in the recurrence rate at 2 weeks, 6 weeks, and 3 months postoperatively among the three groups (p = 0.38, 0.76, and 0.41, respectively).
Studies using only transfascial suture fixation Chelala et al. [102] analyzed 400 cases in which mesh was fixed with transfascial suture only. They also closed the hernia defect with nonabsorbable sutures. The mean operative time was 74 min, and no recurrent hernias were detected during a mean follow-up period of 28 months. Varghese et al. [181], reported that tacking of mesh to Cooper's ligament was not sufficient. Berger et al.
[182] described a case involving dislodgement of tacks when tacks alone were used to fix mesh to the pubic symphysis.
No studies have compared recurrence rates and types of mesh.
Comments The current data do not give precise rates of recurrence. The total number of patients is small, and the follow-up period is short. Theoretically, laparoscopic exploration allows us to inspect the entire previous incision and to cover it with a mesh, thus reducing the probability for a recurrent hernia. On the other hand, laparoscopic repair does not always include closure of the defect and therefore often relies solely on the strength of the mesh and its fixation. More studies are required to consider these issues.