Acute appendicitis laparoscopic indications and techniques [Abstract] Acute appendicitis is the most common surgical emergency abdomen, and laparoscopic appendectomy has become the method of choice for appendectomy. The management of the appendiceal tract and stump is a key aspect in laparoscopic appendectomy. For perforated appendicitis, the management of abdominal pus and drainage are still debated. With the improvement of minimally invasive concept and the advancement of surgical instruments, the clinical application of single-port laparoscopic appendectomy will become more widespread. In 2010, the Society of American Gastrointestinal Endoscopic Surgeons (SAGES) guidelines pointed out that LA has significant advantages over open appendectomy (OA), such as faster postoperative recovery, shorter hospital stay, fewer postoperative complications, better cosmetic incision, and the possibility of intraoperative exploration of other organs in the abdominal cavity. The U.S. inpatient database shows that of the 2,593,786 patients with acute appendicitis who had appendectomies from 2004 to 2011, LA accounted for 60.5%, including 58.1% of children, 63% of adults, and 48.7% of the elderly, and the proportion of LA increased from 43.3% in 2004 to 75% in 2011. LA increased by 66% in the treatment of non-perforated appendicitis and by 100% in the treatment of perforated appendicitis. LA is performed at different levels of hospitals in China, and there is a lack of national data. In this paper, we discuss the indications and techniques of laparoscopic surgery for acute appendicitis based on the author’s experience and the literature. 1. indications for laparoscopic surgery for acute appendicitis In western developed countries, LA has become the standard procedure for the treatment of appendicitis, which shortens the search time for the appendix and enables accurate differential diagnosis. At present, the indications for LA include acute simple, purulent, gangrenous appendicitis and chronic appendicitis, ectopic appendicitis, etc. With the advancement of surgical techniques, those with severe periappendiceal wrapping adhesions, periappendiceal abscess, ileocecal and malignant appendiceal tumors are also gradually changed from absolute contraindications to relative indications for surgery. Severe cardiopulmonary disease and coagulation disorders are still contraindications to surgery. In patients with appendicitis in pregnancy, Wilasrusmee et al. reviewed the literature and concluded that the likelihood of fetal abortion after LA is significantly higher than that of OA, which may be due to increased intra-abdominal pressure due to carbon dioxide pneumoperitoneum leading to impaired venous return and maternal hypotension and fetal acidosis. Masoomi et al. concluded that LA has become the standard procedure for the treatment of both perforated and nonperforated appendicitis and is superior to OA in all indices. Whether perforated or non-perforated appendicitis, LA significantly reduces the incidence of surgical complications, morbidity and mortality, shortens the average hospital stay and reduces the average hospital cost compared with OA. 2. Surgical techniques for laparoscopic appendectomy 2.1 Anesthesia and perforation hole layout. Laparoscopic exploration and treatment are routinely chosen to be performed under general anesthesia. Although LA under continuous epidural anesthesia can reduce the economic burden of patients, the anesthesia plane is limited, intraoperative carbon dioxide stimulates shoulder and back pain, and intraoperative traction and abdominal irrigation will also produce pain. three hole method is routinely chosen for LA. Most commonly, the umbilical puncture hole is used as the observation hole, and the Mack’s point and anti-Mack’s point are the operation holes. In addition, there are also operating holes for the right and left pubic tuberosities or for the right lateral border of the rectus abdominis muscle next to the armpit and the antimaculature point. In the author’s department, general anesthesia is usually used, and the conventional three-hole method LA takes 1.0 cm of the supraumbilical incision as the observation hole, 1.0 cm of the right supraumbilical rectus abdominis muscle outer edge as the main operation hole, and 0.5 cm of the antimaculature point as the auxiliary operation hole. The operator is located on the left side of the patient, and the assistant holding the mirror is located on the side of the patient’s head. This layout is conducive to the formation of a diamond plane, easy operation, convenient abdominal exploration, and adequate treatment of abdominal and pelvic pus. 2.2 Appendiceal stump management The management of the appendiceal stump during LA is a critical step, and improper management will lead to serious postoperative complications such as fecal fistula and peritonitis. Initially, the appendiceal stump was treated by surgical knot ligation, purse string suture and “Z” suture (double suture). There are many methods reported in the literature, such as En-doloop ligation, titanium clip, absorbable clip, Hem-o-lok clip closure, suture ligation, lumpectomy suture, endostapler cut closure, double coagulation electrode, ultrasonic knife curing method, etc. Among them, the Endoloop ligation method is relatively easy to use. Among them, the Endoloop ligation method is relatively inexpensive but is not suitable for managing cases with severe inflammation or gangrene of the appendiceal root, such cases are more reliable with endoscopic closures but more expensive. Sajid et al. reviewed 5 randomized studies of 622 patients treated with both Endoloop and Endosta-pler methods of appendiceal stump and showed that the operative time was longer in the Endoloop group, while there was no statistically significant difference between the two groups in terms of length of hospital stay and abdominal abscess formation (P>0.05). appendiceal stump and showed a mean operative time of 31.4 min, a complication rate of infection of 6.7%, and an intermediate open abdomen in 1.9% of patients, with no complications directly related to metal clips; however, the use of metal clips for cases with excessive appendiceal swelling diameter and severe appendiceal root necrosis may require laparoscopic suture management or even the use of an obturator. One study showed no statistically significant difference in complication rate, infection rate, and length of hospital stay in the management of appendiceal stumps using Hem-o-lok compared with the use of endoscopic closures, but with a significant price advantage. The use of bipolar electrocoagulation or ultrasonic knife to close the appendiceal stump has also been reported in the literature as being foreign body free and inexpensive, but with caution about the risk of stump fistula. In my department, titanium clips or Hem-o-lok clips are routinely used for closure in patients with insignificant appendiceal root swelling. When using titanium clips to close the stump, it is important to avoid using too much force to sever the appendix or too little force to close it firmly, resulting in a stump fistula. The Hem-o-lok clip is available in a variety of models with a flexible material and a locking mechanism to avoid tissue cutting and provide reliable closure. For thicker appendices, a silk ligature can be used to thin the appendix before using the Hem-o-lok clip. When the root of the appendix is perforated or the ileocecal wall is severely edematous, sutures are used to fully expose the appendiceal root and the ileocecal region, and the appendiceal stump is tied with 3-0 sutures followed by a purse-string or “Z” suture. For patients who are financially able to do so, endoscopic closure can be chosen to remove part of the appendiceal wall and appendix. 2.3 Management of the appendiceal tract The LA appendiceal tract can be treated with various methods, including silk ligation, titanium clips, Hem-o-lok clips or simple electrocoagulation, ultrasonic knife, etc. In patients with acute appendicitis with periappendicitis, the tract is edematous and adherent to the surrounding area, especially to the cecum and terminal ileum, so retrograde resection is often performed. Wire ligation or suture ligation of the tract is time-consuming and technically demanding. Titanium clips are metallic foreign bodies and are easily loosened. It is difficult to precisely control the treatment of the appendiceal tract using simple electrocoagulation, which has a strong coagulation ability but risks causing conductive heat damage to the intestine and produces smoke that affects the operative field. The author’s department routinely uses both ultrasonic knife or Hem-o-lok clamps to treat the appendiceal tract. The use of ultrasonic knife makes the treatment of the mesentery easier and enables coagulation of vessels up to 5 mm in diameter. For congested and edematous vessels of the tract, cutting and hemostasis can be done in one step. Intraoperative bleeding is reduced, with less smoke and clearer visualization, while shortening the operative time. For the treatment of appendiceal stump, 2 to 3 Hem-o-lok clips are required, while the product is packed with 6 clips. From the economical point of view, Hem-o-lok clips are also used for the treatment of appendiceal tract, usually 1 to 3 clips, which are simple and reliable. However, it must be noted that in cases with severe swelling of the appendiceal tract, it should be clamped in stages and 1 to 2 mm should be retained when cutting off the tract to avoid bleeding caused by dislodging the clamp after surgery. 2.4 Treatment and drainage of abdominal pus Currently, there are different views on the treatment and drainage of abdominal pus in patients with acute appendicitis. One view is that extensive flushing and drainage should be placed. At least 3000 mL of saline should be used to flush the right and left paracolic sulcus, pelvic cavity, subdiaphragm, perihepatic and perisplenic areas after aspiration of pus. This dilutes the abdominal contamination, which is difficult to do with open surgery. At the end of the operation, 300-500 mL of saline remains in the abdominal cavity, and a drainage tube is left in the pelvis to dilute the contamination and drain it adequately. The results of clinical studies suggest that this method results in a significant decrease in the incidence of abdominal infection and abscess. Another view is that abdominal irrigation and drainage should be avoided in patients with localized abscesses and free intra-abdominal pus in perforated appendicitis. Extensive abdominal irrigation does not reduce the incidence of postoperative abdominal infection and abscess formation, and irrigation tends to cause dissemination of bacteria and intestinal contents throughout the abdominal cavity. Drainage tubes can only drain the local area, but not the whole peritoneum; at the same time, they may lead to retrograde abdominal infection and increase the length of hospital stay. The peritoneum itself, which has a strong immune function, can play a defensive role. The author’s department takes selective treatment for abdominal pus. For common pus confined to the right lower abdomen and pelvis, it is sufficient to use suction to aspirate the pus without placing drains; for pus located in two quadrants of the abdomen, usually the right upper and lower abdomen, after aspirating the pus, a small amount of warm saline is used each time to repeatedly flush the area until the flushing fluid is clear to avoid contamination spread without leaving drains; for diffuse peritonitis where the pus exceeds two quadrants of the abdomen, the pus is first aspirated as much as possible and then the abdomen is flushed. Then the abdominal cavity is flushed. Adjust the angle of the surgical bed with the flushing of the abdominal cavity, including the perihepatic, perisplenic, both sides of the paracolic sulcus, iliac fossa, pelvic cavity, needing warm saline about 5000mL or more, pelvic cavity drainage tube from the left Mack’s point operation hole. The patient is placed in a semi-recumbent position after surgery, and is allowed to move on the floor 6 h after surgery. The drainage tube is usually left in place for no more than 72 h. 3. Single-hole versus conventional LA In recent years, single-hole LA has been gradually used in clinical practice. Early studies suggested that transumbilical removal of the appendix may lead to an increased risk of wound infection and even reports of increased postoperative pain. In three recent Meta-analysis studies, the results of literature studies showed that single-port LA has more intraoperative bleeding than conventional LA, and the literature showed that single-port LA has a longer operative time than conventional LA. However, there were no statistically significant differences between groups in the 3 studies in terms of postoperative pain, incidence of complications (intestinal obstruction, incisional infection, and incisional hernia), incidence of abdominal abscess, and length of hospital stay. Therefore, single-port LA is considered safe and effective for benign appendiceal disease with better cosmetic results.Yamamoto et al. performed single-port LA using a laparoscopic cutting closure with shorter operative time than conventional LA and no statistically significant difference in postoperative complication rates. At present, although there is a lack of prospective large sample studies to support this, single-port LA is expected to be gradually promoted and applied with the advancement of technology and instruments. The author’s department started to explore single-port laparoscopic techniques from 2009 and tried to improve single-port laparoscopic instruments, and gradually formed single-port LC and LA techniques without pneumoperitoneum (suspension method). The main indications are early acute suppurative appendicitis and chronic appendicitis, etc. The advantages are as follows: the distance from the umbilicus to the appendix is short, the operation is simple and can be assisted by using open instruments through the umbilical channel; no expensive consumables for single-port access are needed; the incision protection sleeve is convenient for removing the swollen appendix and avoiding contamination of the incision; the median longitudinal incision of about 2 cm can be completely hidden in the umbilical fossa, achieving the cosmetic purpose of single-port surgery through the umbilicus. Therefore, single-port LA is a useful supplement to conventional LA and can be selectively applied according to patient and operator conditions.