Practice guidelines on endoscopic surgery for qualified surgeons by the endoscopic surgical skill qualification system: Hernia

In Europe and the United States, adult inguinal hernia treatment shifted from conventional tissue suture repair to mesh repair around 1970 and then the appreciation of the Lichtenstein repair with stable results was established.1, 2 On the other hand, in 1990, Schultz et al. reported results from laparoscopic inguinal herniorrhaphy (from here onward referred to as "laparoscopic surgery"),3 and the procedure spread to Europe and the United States. In Japan, the use of laparoscopic surgery began to spread after a report at an academic conference by Matsumoto et al. in 1992.4 In the past 30 years in Japan, it was a period where each facility freely selected various new mesh methods in a process that was very different from that in the United States and Europe.5 Therefore, it is essential to consider the optimal material and shape for mesh repair in the future. This guideline combines TAPP (transabdominal preperitoneal repair) and TEP (totally extraperitoneal repair) as the laparoscopic surgery. Laparoscopic surgery has increased significantly in recent years. According to the 2015 Diagnosis Procedure Combination (DPC) medical remuneration data released by the Ministry of Health, Labour and Welfare (MHLW),6 a total of 150 880 inguinal hernia surgeries were performed among which 36 123 (27.3%) were performed by laparoscopic surgery. The percentage has been increasing since then. In Europe and the United States, Lichtenstein repair and laparoscopic surgery are the mainstays of inguinal hernia surgical treatment. In Japan, mesh repairs other than Lichtenstein repair are the mainstream.5 As international guidelines, in 2009, the European Hernia Society (EHS) published a guideline on the treatment of inguinal hernia in adult patients.7 Subsequently, five regional hernia societies from Europe, the United States, Asia-Pacific, Africa/Middle East, and Australia as well as the International Endohernia Society and the European Association for Endoscopic Surgery, participated in the latest "International Guidelines for Groin Hernia Management," which was reported in 2018.8 Unfortunately, the position of laparoscopic surgery in these guidelines is mild, although it is recommended in facilities having an adequate level of technology and a suitable environment. The guidelines are not absolute but vary according to various medical environments and patient backgrounds. There are few articles available appropriate for Japanese medical settings since these do not have the high level of evidence seen in Japanese papers. Therefore, this guideline has been developed based on evidence from overseas literature mainly comparing Lichtenstein repair and laparoscopic surgery. We should also take into account that there are significant differences in surgical treatment between Japan and Western countries at this time, and we look forward to future reports on surgical results from Japan. In 1892, Lucas-Chanpionniere9 reported a simple high ligation technique for inguinal hernia surgery in children. In this technique, the inguinal canal was incised from the external inguinal ring to just above the internal inguinal ring with sufficient field of view. Although the basic concept had already been established by that time, in 1950, Potts10 advocated a minimal operation which has been widely used as "Pediatric inguinal hernia repair" also called "Potts' procedure." In the 1990s, with the development of laparoscopic surgery, laparoscopic closure of the internal inguinal ring was also performed for pediatric inguinal hernias. In 1995, Takahara et al.11 began performing laparoscopic percutaneous extra-peritoneal hernia closures (LPEC), and laparoscopic inguinal hernia repair was then grouped into two major methods: conventional "suture closure of internal inguinal ring" and "closure of internal inguinal ring with LPEC." Currently, in Japan, laparoscopic surgery for pediatric inguinal hernias is almost exclusively performed by the LPEC method. However, there are still many reports on "laparoscopic intraperitoneal closure of the internal inguinal ring" in overseas articles, and reports based on clinical data from laparoscopic surgery have been mixed with the LPEC method, so there are few papers with a high level of evidence based purely on the LPEC method alone. We are awaiting future reports from Japan with a high level of evidence on using just the LPEC method. Still, the current guideline analyzes laparoscopic inguinal hernia repair that does not distinguish between the "suture closure method" and the "closure method." An abdominal incisional hernia occurs in up to 20% of abdominal surgeries and should not be ignored as a complication, so it is essential for all abdominal surgeons to be familiar with repair techniques. Primary closure is very prone to recur and requires mesh repair, but there is concern about wound complications due to extensive subcutaneous dissection. Since the first laparoscopic abdominal incisional hernia repair was reported by LeBlanc et al.12 in 1993, the technique has become widespread due to its ability to implant extensive mesh without subcutaneous dissection and further progress was made with the advent of mesh having an anti-adhesion effect. In Japan, reimbursement was established in 2012 for this procedure, and the number of surgeries according to the National Clinical Data annual report also increased from 1494 (2013) to 3291 (2017).13 In 2014, the International Endohernia Society published detailed guidelines,14, 15 and standardization is currently underway. This guideline is mainly based on a 2011 Cochrane systematic review comparing open abdominal surgery and on laparoscopic surgery and meta-analyses reported from 2014 to 2015 based on randomized control studies from 1999 to 2013. The results have shown that the advantage of laparoscopic surgery is an apparent reduction in wound infection, and other surgical outcomes are similar to those of open abdominal surgery. However, laparoscopic surgery had a high potential for increasing intestinal injury, suggesting the need for caution when introducing laparoscopic surgery. Also, abdominal wall hernias have more diverse pathologies than expected. It is therefore necessary to consider repair methods for hernias in the suprapubic, lateral abdominal, epigastric, or loss of domain hernias (LOD) (although there is no fixed definition, this generally refers to when more than half of the intra-abdominal organs in an abdominal wall hernia have prolapsed out of the abdominal cavity from Society of American Gastrointestinal and Endoscopic Surgeons: SAGES website), which are considered challenging to repair and also the timing of open abdominal surgery after mesh repair and hernia repair surgery after cancer surgery. Furthermore, in recent years, reevaluation of the Rives-Stoppa technique16 and results from laparoscopic surgery with defect closure,17 transversus abdominis release (TAR),18 and robot-assisted surgery19 have also been reported. The indications and recommended procedures are likely to change. It is therefore essential to continue to monitor these trends with great care. Compared to inguinal incisional mesh repair, laparoscopic inguinal hernia repair in adults causes less surgical site infections or postoperative pain. It also allows an early return to society, resulting in high patient satisfaction. However, although the incidence is low, complications during surgery such as organ damage are common, the recurrence rate is high, and medical costs during surgery are high. Recommended level 2 Evidence level A. In reports comparing laparoscopic inguinal hernia repair (hereafter referred to as "laparoscopic surgery") and inguinal incisional mesh repair (hereafter referred to as "inguinal mesh repair"), large RCTs (randomaized controlled trial), systematic reviews, and meta-analyses found there was a low incidence but relatively higher incidence of organ damage and other complications during surgery with laparoscopic surgery, with no deaths in either group.1-3 A meta-analysis on the postoperative complications between the two groups showed no difference in the incidence of seroma with or without puncture (odds ratio OR = 1.14, 95% confidence interval 95% CI = 0.80–1.62),4-14 postoperative ileus (OR = 3.90, 95% CI = 0.64–23.89),4, 5, 13, 15 but surgical site infection was significantly lower with laparoscopic surgery (OR = 0.47, 95% CI = 0.29–0.74).1, 4-9, 13-18 Recurrence rates were significantly higher with laparoscopic surgery (OR = 1.66, 95% CI = 1.29–2.14).1, 4-23 In randomized comparative trials on the postoperative pain in first-time male cases between the two groups, excluding those with complicated hernias including incarceration or a surgical history in the lower abdomen, laparoscopic surgery was associated with less acute postoperative pain (several hours to 2 weeks after surgery) and less chronic pain when performed by surgeons skilled in laparoscopic surgery.1, 7-9, 11, 13, 16-19 The incidence of chronic pain was reported to be 0%–25% and 1.3%–28% for laparoscopic surgery and inguinal mesh repair, respectively.1, 7, 9, 11, 13, 16-18, 20-22, 24 There were reports that sensory disturbances such as the sensation of a foreign body and hypoesthesia were less common with laparoscopic surgery,8, 13, 17, 20 but the scale was not consistent, and there was no strong evidence. The time to return to work was significantly shorter for laparoscopic surgery in four RCTs12, 15, 16, 18 and four meta-analyses24-27 (mean difference − 5.02 days, 95% CI = −5.62 to −4. 43). In regard to the length of hospital stay, three RCTs4, 5, 15 and two meta-analyses25, 26 found no significant difference between the two groups (mean difference of −0.03 days; 95% CI = −0.09 to 0.03). Laparoscopic surgery deserves a recommendation in terms of rehabilitation compared with inguinal mesh repair. In seven RCTs4, 5, 8, 17, 28-30 that examined patient satisfaction, laparoscopic surgery was significantly superior within 2 weeks after surgery, on postoperative day 730 and day 14.28 Although one article28 showed that laparoscopic surgery was superior 6 months after surgery, there was no significant difference between the two techniques 1 year4, 28 and 2 years28 after surgery. There are no articles expressing a high level of evidence for family and staff satisfaction. Direct medical costs during laparoscopic surgery were high.15, 17, 20, 28, 31-33 However, there have been opinions that laparoscopic surgery is favorable based on the reduced postoperative pain, early recovery, and the social cost-effectiveness analysis results considering early reintegration into society.15, 20, 24, 34 The insurance and medical treatment systems in the United States and Europe, however, differ significantly from those in Japan, so caution is needed when simply applying the same evaluation to medical care in Japan. Committee voting results In children, laparoscopic inguinal hernia repair is associated with lower contralateral incidence, shorter operative time in bilateral cases, and fewer common postoperative complications than inguinal incisional repair. Recommended level 2 Evidence level B. There have been five systematic reviews and meta-analyses comparing laparoscopic inguinal hernia surgery (laparoscopic herniotomy; LH) and inguinal incisions (open herniotomy; OH) in children,1-5 including RCT, five papers.6, 7 In addition, two articles from cohort studies8, 9 were also adopted to make up for some information deficiencies. Regarding the incidence of contralateral hernia after unilateral surgery, three meta-analyses,1-3 two RCTs,7, 10 and two cohort studies8, 9 showed a decrease in the contralateral incidence after LH. Regarding operative time for one side, one meta-analysis5 reported that it was shorter with OH, one cohort study6 reported that it was shorter with LH, three meta-analysis articles1, 3, 4 found no difference, and two articles2, 9 did not mention any difference. In bilateral cases, all 12 articles found that the operative time was shortened with LH.1-12 As for recurrence, two RCTs10, 12 and six meta-analyses1, 3-5, 8, 9 reported no apparent difference between LH and OH. As for LH, all papers referred to short-term recurrence and did not include any long-term reports. Regarding postoperative pain, two RCT articles,6, 10 one meta-analysis article,1 and one cohort article9 showed no significant difference, but one RCT paper11 described more pain with LH after hospital discharge. However, in another RCT article,7 LH was reported to result in less immediate postoperative pain based on acetaminophen use before discharge from the hospital. As for common postoperative complications (hydrocele and scrotal edema, subcutaneous hematoma, testicular elevation, testicular atrophy, etc.), the total number of cases reported after LH (15 cases) was significantly smaller than that after OH (31 cases) from five RCT articles.6, 7, 10-12 Furthermore, as for the total number of cases of testicular elevation/atrophy and scrotal enlargement, which are relatively important for boys, there was a significant difference between LH (4 cases) and OH (14 cases) from two RCT articles.6, 12 Although no serious complications have been observed as far as we could find in the literature, the history of LH is still short compared to that of OH, and establishing it as a standard technique requires a good understanding of basic perioperative management, surgical procedure, and anatomy before attempting to perform surgery. Committee voting results Laparoscopic surgery for abdominal incisional hernia can clearly reduce wound infections, and other surgical outcomes are similar to open abdominal surgery. However, caution must be exercised due to the high likelihood of intestinal injury. Recommended level 2 Evidence level A. Twelve RCTs and 27 meta-analyses comparing laparoscopic versus open surgery for abdominal incisional hernia were searched. The main meta-analysis evaluation was based on the 2011 Cochrane review1 and seven meta-analyses from 2014.2-8 However, we excluded the meta-analysis by Awaiz et al. on wound infections because the results of the RCT by Itani et al. might have been erroneously entered in their report. All meta-analyses selected 4 to 9 RCTs for analysis from 11 RCTs9-19 with no major differences in results. Many RCTs13, 15, 16, 18 reported a longer operative time for laparoscopic abdominal surgery for abdominal incisional hernia than open abdominal surgery. However, we have confirmed that the difference tended to be insignificant after meta-analysis. Bleeding volume was studied in two RCTs and was lower with laparoscopic surgery.10, 18 Although the overall complications are similar,1, 5 meta-analyses specific only to intestinal injuries found it significantly more common with laparoscopic surgery,4-6 although the frequency (of intestinal injuries) is low. There was no difference in the recurrence rate between the two procedures based on five RCTs14-17 since 2009 and the meta-analysis7 that compiled them. Although there was a variation in the incidence of seroma either by the analysis including seroma and hematoma or by the analysis of seroma only, there was no significant difference in the meta-analysis.5 Postoperative ileus was not a problem with few events in either group. Although wound infection was less common in laparoscopic surgery or no different from that in open abdominal surgery in RCTs, a Cochrane review in 20111 and a meta-analysis by Chalabi et al.7 summarizing RCTs from 2008 onward15-18 demonstrated that wound infection was significantly less common with laparoscopic surgery. In addition, the study focusing exclusively on bulging was only a retrospective evaluation by Liang et al.,20 but they reported that bulging was significantly more common with laparoscopic surgery. As for postoperative pain, no significant difference was found in RCTs10, 12, 16-18 and a meta-analysis,5 except for the RCTs by Itani et al. indicating that the most severe pain was significantly lower with laparoscopic surgery. Furthermore, no difference was found in the length of hospital stay or time to return to work in recent RCTs.14-18 Finally, there was no difference concerning patient satisfaction.10 As for the cost, laparoscopic surgery was six to nine times more expensive than open abdominal surgery in the 2006–2007 RCTs,10, 12 indicating that laparoscopic surgery is more costly when limited to surgery. However, the total cost depends on complications and length of hospital stay. There have been few studies using RCTs so it is not possible to show the superiority of one method over the other. In conclusion, laparoscopic surgery for abdominal wall hernias can clearly reduce wound infections, and other surgical outcomes are mostly equivalent to open abdominal surgery. However, caution is required due to the high possibility of intestinal injury. Committee voting results Data sharing not applicable to this article as no datasets were generated or analysed during the current study. The authors declare no conflicts of interest.