The incarcerated inguinal hernia was a common emergency surgical manifestation, accounting for about 9% of the admission of inguinal hernia [11]. Because incarcerated hernia needed to consider the treatment of incarcerated contents and hernia repair, the standard surgical treatment scheme of emergency was debatable. At present, the commonly used surgical methods of incarcerated and strangulated hernia include open surgery through inguinal incision, lower abdominal midline incision, and laparoscopic transabdominal preperitoneal surgery. In general, many surgeons preferred open surgical approach, which could quickly and easily reduce the contents and avoid iatrogenic injury [9]. A survey of surgeons' choice of treatment for incarcerated and strangulated hernia showed that, 66% and 74% of surgeons chose open surgery, respectively [12]. For patients with strangulated inguinal hernia, even if there was intestinal necrosis without perforation, open preperitoneal mesh repair was safe as long as the repair position was clean and without contamination [5, 13, 14]. Mesh repair was safe for the strangulated inguinal hernia requiring enterectomy, and the incisional infection rate was 2.5%-8.6% [15, 16]. The recurrence rate of mesh repair was low, while the recurrence rate of tissue suture repair was as high as 21.4% [17]. LAMI approach could keep the preperitoneal space strictly separate from the intraperitoneal space of intestinal resection, so the rate of mesh repair was higher than that of inguinal incision [4, 5]. The LAMI approach and the TAPP could effectively avoid the pollution of intestinal resection on the patch repair site, so they both had a high rate of 1st stage mesh repair.
In our study, patients in the LAMI group were older, had a higher proportion of femoral hernia and had a higher proportion of preoperative intestinal obstruction than those in the TAPP group. First, elderly patients had many complications, poor tolerance of pneumoperitoneum and general anesthesia, and preferred LAMI approach with short operation time. Second, the patients with incarcerated femoral hernia had preoperative intestinal obstruction and obvious intestinal dilatation, and the surgeons chose open repair because of the smaller operation space of laparoscopy. Third, incarcerated femoral hernia was more common in elderly women, and the risk of intestinal necrosis resection was higher. Our previous research showed that LAMI approach had a good clinical effect of incarcerated femoral hernia, so the LAMI method was often used to treat incarcerated femoral hernia [5]. The higher intestinal resection rate of femoral hernia led to the lower rate of 1st stage mesh repair. The postoperative complications and mortality of incarcerated indirect hernia and femoral hernia were similar.
The operation time of TAPP group was about 15min longer than that of LAMI group. The median operation time of TAPP was 107 min, which was similar to 81.3–126 min reported in the literature [8, 10]. Among 42 cases in TAPP group, 41 cases were completed under surgical endoscopy, and 1 case (2.4%) was converted to laparotomy for intestinal resection. 37 cases (88.1%) completed 1st stage patch repair without mesh infection complications. Among the 7 cases of intestinal resection, 3 cases completed preperitoneal patch repair without serious infection complications. The total complication rate of TAPP in our study was 9.5%, and other studies reported 20.2% and 10.4% respectively [6, 9]. The rate of 1st stage mesh repair in the LAMI group was similar to that in the TAPP group, and 9 cases (14.5%) extended incision or made another incision. The total complication rate was 25.8% in the LAMI group and 9.5% in the TAPP group. The operation time in TAPP group was longer, but the hospital stay and recovery time of normal activities were shorter. Therefore, for the selected cases, TAPP was safe and effective without increasing the risk of postoperative complications. The contents of hernia in TAPP group were spontaneous reduction and gentle traction /manual pressure, while hernia ring incision was more common in the LAMI group. In our study, the surgical treatment of patients in the LAMI group was more difficult because of the elderly, the severity of intestinal obstruction and the high rate of incarcerated hernia ring enlargement. However, there was no significant increase the rate of surgical complications in the LAMI group, so the LAMI method may be more suitable for complex strangulated inguinal hernia with higher rate of enterectomy.
LAMI preperitoneal repair retained the advantages of the traditional groin incision approach, which was convenient to release the incarceration. Reduction of the incarcerated contents under direct vision could avoid intestinal injury. Compared with the inguinal incision, the rate of 1st stage patch repair was improved [5]. Mesh was placed in preperitoneal space, covering the myopectineal orifice, that is, to cover all defects in the groin area, the risk of recurrence would be reduced. The time of operation and general anesthesia was shorter, which was beneficial to the recovery of elderly patients. Cases of abdominal surgery (radical prostatectomy, cystectomy, rectal cancer surgery and gynecological surgery) and Obese were not recommended.
TAPP had minimally invasive effect and some other advantages. TAPP had better visual field and comprehensive examination for patients with incarcerated hernia who underwent spontaneous reduction or manual pressure reduction before operation. Laparoscopic exploration could avoid the risk of intestinal necrosis, intestinal perforation, abdominal abscess and so on. Missed intestinal resection might lead to abdominal abscess and septic shock, resulting in increased morbidity and mortality [18]. There was much more time to evaluate the activity of incarcerated contents and reduce intestinal resection. The color change of intestine and bowel viability could be clearly observed under laparoscopy. TAPP provided longer observation time and sufficient recovery period for incarcerated organs, so as to avoid unnecessary resection [10]. TAPP was helpful in the treatment of contralateral hernia [7]. The main challenges of TAPP repair were the difficulty of hernia reduction caused by inguinal ring stenosis and the risk of iatrogenic injury [9]. Our study founded that TAPP did not increase iatrogenic injury to doctors with advanced experience in endoscopy. Incarcerated hernia could be released by manual pressure, gentle traction and enlargement of the hernia ring after anesthesia, which could effectively avoid iatrogenic injury. Manual reduction was safe and effective in patients with incarcerated inguinal hernia, which might reduce the risk and complications of anesthesia and surgery in emergency situations [19]. General anesthesia and painkillers were conducive to the reduction of hernia. Contents of hernia sac reduced spontaneously after anesthesia sometimes. With the help of anesthetics and analgesics, non-strangulated hernia could be manually reduced safely, which was effective for about 70% of patients [20]. 55.3% reduction during anesthesia and direct traction with manual compression, only 44.7% needed incision of hernia ring [6]. TAPP was suitable for the cases with successful manual reinfusion, because it was convenient to check the abdominal cavity and then complete the patch repair. In our study, only 16.7% of the TAPP group needed enlargement of the hernia ring. Enlarging the hernia ring in the anterior peritoneal plane avoided the iatrogenic injury of intestine. The indirect groin hernia ring was incised ventrolaterally with electronic hook. Direct or femoral hernia ring was incised ventromedially. Laparoscopic resection of necrotic bowel and 1st stage mesh repair were also safe and feasible. In our TAPP group, 7 cases completed endoscopic intestinal resection, of which 3 cases completed patch repair without serious complications. When the intestine was completely dilated, open surgery was recommended. Because in this case, intra-abdominal mechanical anastomosis was easy to contaminate the abdominal cavity. The disadvantages of TAPP were that the operation time was prolonged, extensive intestinal dilatation affected the laparoscopic operation space, and should be tolerated general anesthesia and pneumoperitoneum. The reason for the lower complication rate of TAPP treatment was that patients were selected. In our study, LAMI approach was recommended for patients with severe intestinal dilatation, intestinal gangrene with abdominal wall infection and peritonitis.
Our study had some limitations. (1) It was a single-center retrospective research with unavoidable selection bias. TAPP was easily accepted by young patients without bowel distension and peritonitis. However, elderly patients with more concomitant illnesses and intestinal obstruction or necrosis were more likely to choose the LAMI surgery. (2) All operations were not performed by the same doctor, and there might lead to operator bias. All operations were performed by the same group of doctors according to the same surgical standards and procedures, so as to minimize the impact of different doctors. (3) The small sample size might have bias. A randomized multicenter large sample study is needed for further verification.
Even so, the current results told us that TAPP was safe and effective in the treatment of incarcerated hernia. Endoscopic release of incarcerated hernia and patch repair after intestinal resection did not increase iatrogenic injury. Selecting appropriate cases, TAPP had minimally invasive effect, which could reduce hospitalization and time to return to normal activities. For complex incarcerated hernia such as severe intestinal obstruction, obvious dilatation and peritonitis, the LAMI approach was more appropriate. It is believed that with the improvement of endoscopic operation, TAPP will be more widely used in the treatment of incarcerated hernia. Whether TAPP is the standard treatment for incarceration needs further prospective or multicenter randomized controlled studies.