Colorectal cancer is one of the common malignant tumors in China, and the incidence is on the rise. The 5-year survival rate after radical colorectal cancer surgery hovers between 50% (rectal cancer) and 70% (colon cancer). At present, the diagnosis and treatment of colorectal cancer still emphasize early diagnosis and comprehensive treatment mainly based on surgery.
Radical colorectal cancer surgery can choose between traditional open approach and laparoscopic-assisted radical colorectal cancer surgery. Laparoscopic colorectal surgery has been widely performed worldwide and is the most mature surgical procedure in laparoscopic gastrointestinal surgery. Existing clinical studies have shown that the intraoperative and postoperative complications of laparoscopic colorectal surgery are not significantly different from those of open surgery, while the operative time and intraoperative bleeding are comparable or even better than those of open surgery. The feasibility and safety of laparoscopic colorectal surgery in terms of operation technique have been confirmed. In principle, laparoscopic gastrointestinal tumor surgery must also follow the principles of radical tumor treatment in traditional open surgery, including ① emphasis on the whole block resection of tumor and surrounding tissues; ② no-contact principle of tumor operation; ③ sufficient cutting edge; ④ thorough lymphatic clearance.
Most rectal cancers in China occur in the middle and lower rectum. There are various surgical methods for radical rectal cancer treatment, but the classical operation is still transabdominal anterior rectal resection (anus-preserving) and combined abdominal perineal radical rectal cancer treatment (non-anus-preserving). The total mesorectal excision (TME) concept significantly reduces local recurrence and improves 5-year survival rates after rectal cancer surgery. Laparoscopic radical rectal cancer resection should follow the principles of TME: (1) sharp separation in the anterior sacral space under direct vision; (2) maintaining the integrity of the pelvic fascia visceral layer; (3) total resection of the distal rectal mesentery or not less than 5 cm from the tumor, and distal bowel resection at least 2 cm from the tumor. (2) clearer visualization of the inferior abdominal plexus to avoid injury; (3) no need to pull and squeeze the tumor, which is more in line with the principle of no contact.
Indications and contraindications of surgery
I. Indications
Most of colorectal cancers are indicated for laparoscopic surgery
Contraindications
1. Tumor diameter greater than 6 cm or/and extensive infiltration with surrounding tissues; serious abdominal adhesions, heavy obesity, acute surgery for colorectal cancer (such as acute obstruction, perforation, etc.) and poor cardiopulmonary function are relative contraindications to surgery.
2. Poor general condition, which cannot be corrected despite preoperative treatment; serious cardiopulmonary, hepatic and renal disorders, which cannot tolerate surgery, are contraindications to surgery.
Surgical equipment and surgical instruments
Types of laparoscopic colorectal cancer surgery
Mainly: ① laparoscopic right hemicolectomy; ② laparoscopic transverse colectomy; ③ laparoscopic left hemicolectomy; ④ laparoscopic sigmoid colectomy; ⑤ laparoscopic anterior rectal resection (rectal cancer anal preservation); ⑥ laparoscopic combined perineal resection (rectal cancer non-anal preservation).
Basic principles of surgery
I. Scope of surgical resection
It is equivalent to open surgery. The resection margin of colon should be at least 10 cm from the tumor, and the distal end of rectum should be at least 2 cm, together with the primary foci, mesentery and regional lymph nodes; the operation of rectal area should follow the principle of TME.
II. Principles of tumor-free operation
First ligate the veins and arteries at the root of the vessels, while clearing the lymph nodes, and then separate the resected specimens. Operate gently, apply sharp separation, use less blunt separation, and try not to contact the tumor directly to prevent cancer cell spreading and local implantation; on the basis of radical treatment of cancer tumor, preserve the function (especially the function of anal sphincter) as much as possible.
Pre-operative preparation
① Pre-operative examination should be performed to understand the distant metastases such as liver and the situation of retroperitoneum and mesenteric lymph nodes.
Post-operative observation and treatment
① Closely observe the patient’s vital signs, the nature and quantity of drainage; ② Maintain the water-electrolyte acid-base metabolic balance and give antibiotics to prevent infection; ③ Give a liquid diet after anal discharge, and gradually develop to a regular diet with low residue; ④ Post-surgery comprehensive anti-cancer treatment, according to the nature of the tumor to develop a plan, chemotherapy, radiotherapy and immunotherapy.
Common complications of surgery
Postoperative complications of laparoscopic colorectal cancer are basically the same as those of open surgery, except for those unique to laparoscopic surgery (subcutaneous emphysema, vascular and gastrointestinal tract injury complicated by puncture, gas embolism, etc.). The main complications are: ① anastomotic leakage; ② presacral bleeding; ③ intestinal adhesions and intestinal obstruction; ④ incisional infection; ⑤ urinary and sexual dysfunction; ⑥ difficult or frequent defecation; and ⑦ complications of artificial stoma.
Annex: Surgical methods.
I. Laparoscopic colon cancer surgery
1.Laparoscopic radical surgery for right hemicolectomy: it is suitable for treating malignant tumors of appendix, cecum and ascending colon and hepatic flexure of colon.
(1) The end of ileum 10-15cm, the right half of cecum, ascending colon, transverse colon and part of large omentum and gastric omentum vessels should be removed; the ileocolic vessels, right colonic vessels and right branch of mesocolic vessels and their accompanying lymph nodes should be removed.
(2) Endotracheal intubation was used for general anesthesia. The operating table was tilted 30° to the left after the completion of pneumoperitoneum to avoid obstruction of the view by the small intestine. The operator stands in the middle of the patient’s legs, and the first and second assistants stand on both sides of the patient, and the operator can also stand on the left side of the patient.
(3) The umbilical port is punctured and a pneumoperitoneum is established, which may also be open. Maintain intra-abdominal pressure at 12-15 mm Hg. Usually, the lens can also be placed at the umbilical port by performing a 10 mm poke hole on the pubic bone, a 12 mm poke hole 5 cm below the left side of the umbilicus as the main operating hole, and a 5 mm poke hole in the right lower abdomen and the midline of the left and right upper abdomen.
(4) Abdominal exploration: to determine the lesion site, the presence of lymph nodes and abdominal metastases. If necessary, laparoscopic ultrasound can be used to investigate the liver for metastases.
(5) The operation is often performed from the inside to the outside, from the bottom to the top, dealing with the vessels and non-contacting tumor first. The colonic mesentery is opened along the projection of the superior mesenteric vessels, and the ileocolic vessels, right colonic vessels and mid-colonic vessels are dissected out and clamped with vascular clips and cut respectively, and the lymph nodes at the root of the vessels are cleared. The gastrocolic ligament should be severed outside the gastroretinal arch, and the right vascular branch of the gastroretinal retina should be severed to remove the lymph node group below the pylorus.
(6) Along the lateral side of the colon from the iliac fossa to the hepatic flexure of the colon, the retroperitoneum is incised and the ascending colon is freed from the posterior abdominal wall. Take care not to damage the posterior duodenal peritoneum, ureters, kidneys, and intra-seminal (or ovarian) vessels.
(7) A small incision is made in the upper abdomen or under the umbilicus corresponding to the size of the specimen, and a plastic sleeve is used to protect the incision. In vitro resection of the right hemicolectomy includes the tumor, colonic mesentery and sufficient intestinal segments (terminal ileum, cecum, ascending colon and right transverse colon). An end-to-end ileo-transverse colon anastomosis is usually performed (end-to-side anastomosis may also be performed). Dilute povidone-iodine (PVP-I) is first applied to both intestinal ends, and then the anastomosis is performed. The free edge of the transverse colonic mesentery and ileocecal mesentery can be closed with or without sutures.
(8) After closing the small incision, re-establish the pneumoperitoneum, flush the abdominal cavity, place drainage, and close the abdomen after checking that there is no bleeding.
2.Laparoscopic transverse colectomy: Applicable to cancer of the middle transverse colon.
(1) Adopt general anesthesia with endotracheal intubation. The patient is placed in supine position with legs separated by 30°~45°, head high foot low position by 15°~20°, and the tilt direction and angle of the operating table can be adjusted according to the need of surgery. The operator stands on the left side of the patient when separating the right half of the gastrocolic ligament, and on the right side when separating the left half, with the laparoscopist standing between the patient’s legs and the other assistant standing on the opposite side of the operator.
(2) The 4-hole method is generally used. The lens is placed in a 10 mm poke hole below the umbilicus, a 10 mm poke hole in the right mid-abdomen and a 10-12 mm poke hole in the left mid-abdomen. The 5-mm poke hole between the glabella and umbilicus is used. The puncture site can be adjusted according to the location of the tumor, and the position of the ultrasonic knife and operating forceps or even the laparoscope can be switched according to the actual situation.
(3) Exploration: 30° laparoscope is placed to explore the abdominal cavity, to understand the location and size of the lesion and its relationship with the surrounding organs, to understand the metastasis of lymph nodes and other organs, and to determine the scope of bowel resection.
(4) Free the transverse colon: incise the right gastrocolic ligament along the great curvature of the stomach below the vascular arch of the omentum, loosen the hepatic flexure and pay attention not to damage the duodenum and bile duct. Dissect the left gastrocolic ligament, loosen the splenic flexure, lift the transverse colon, identify the vessels of the transverse colonic mesentery, separate the root of the transverse colonic mesentery, cut the root of the middle colonic artery after the titanium clip, and cut the transverse colonic mesentery.
(5) Remove the diseased intestinal segment: enlarge the ④th hole to the corresponding size, protect the incision with a plastic bag and then remove the free diseased intestinal segment.
(6) Excisional anastomosis: excise the intestinal segment 10-15 cm away from the tumor in vitro, perform end-to-end intestinal anastomosis, and close the mesenteric fissure with sutures.
(7) Suture poke: after anastomosis, the intestinal segment is retracted into the abdominal cavity, the small incision is sutured, the pneumoperitoneum is reconstructed, the abdominal cavity is checked for bleeding, the abdominal cavity is flushed, drainage is placed, the trocar is removed, and the poke is sutured under the skin.
3. laparoscopic left hemicolectomy: it is suitable for malignant tumors of the splenic flexure of the colon, descending colon and sigmoid colon. The resection should include the left half of the transverse colon, splenic flexure, descending colon, sigmoid colon and the corresponding mesentery and blood vessels, if there are enlarged lymph nodes in the splenic portal, they should also be removed.
(1) General anesthesia with endotracheal intubation, usually with the patient in a truncated position, head low and feet high 15o~20o, tilted 15o~20o to the right.
(2) Poke hole selection: umbilical hole for lens placement; a 5mm poke hole on the midclavicular line 3~5cm below the right and left rib margins; a 12mm poke hole on the left side of the umbilicus at the outer edge of the rectus abdominis muscle, which can be used to remove the specimen after expansion; a 5mm poke hole on the right lower abdomen.
(3) Open the peritoneum on the right side of the colon in front of the abdominal aorta, separate the left colonic artery and vein as well as 1-2 branches of the sigmoid artery and vein, ligate and cut them off, and separate the colonic mesentery, paying attention to the blood supply of the intestinal segment.
(4) Cut open the descending colon and the lateral retroperitoneum of the sigmoid colon, and separate the left colon and its mesentery, taking care not to damage the ureter and the arterioles in the spermatic cord (or ovaries).
(5) Open the gastrocolic ligament and separate the splenic flexure of the colon. Separate and sever the left branch of the middle colonic artery.
(6) Cut the root of the transverse colonic mesentery attached to the body of the pancreas and the lower edge of the tail, taking care not to damage the mesocolic vessels.
(7) Ex vivo resection of the left hemicolectomy including the tumor, sufficient intestinal segment and colonic mesentery, and end-to-end transverse colon-sigmoid anastomosis. Close the mesenteric foramen.
(8) After closing the small incision, re-establish the pneumoperitoneum, flush the abdominal cavity, check for no bleeding, place drainage and close the abdomen.
4 Laparoscopic sigmoid colectomy: Applicable to cancer of the middle and lower sigmoid colon. Laparoscopic sigmoid colectomy is similar to laparoscopic low anterior rectal resection (Dixon procedure) in terms of position, poking hole and surgical steps. If the tumor site is high or the sigmoid colon is free, the intestinal segment can be pulled out of the abdominal cavity for resection and anastomosis, which can simplify the operation and save the cost of expensive anastomoses.
Laparoscopic rectal cancer surgery
1. Transabdominal rectal resection and anastomosis (anal preservation): applicable to cancer of the middle and upper rectum.
(1) General anesthesia with tracheal intubation and static suction. The patient is placed in a 30° head-low-foot-high cystotomy position.
(2) The operator stands on the right side of the patient, the first assistant stands on the left side of the patient, and the mirror holder stands on the same side of the operator.
(3) The umbilical or supraumbilical 10 mm poke hole is used to place the 30° oblique lens. A 5-mm poke hole on the external edge of the rectus abdominis muscle next to the left and right umbilicus is used to place the instrument, and a 12-mm poke hole on the right lower abdomen is used as the main operating hole. If the ligature is not used to traction the colon during the operation, an additional 5mm poke hole can be performed in the left lower abdomen.
(4) Separate the right side of the sigmoid mesentery, pay attention to the position and direction of the ureters on both sides during separation, dissect and expose the submesenteric artery and vein, clear the lymph nodes at the root of the vessels, and cut the submesenteric artery or superior rectal artery and its accompanying veins. However, care should sometimes be taken to preserve the left colonic artery in order to avoid anastomotic fistula due to insufficient blood supply to the anastomosis.
(5) Perform sharp separation along the gap between the intrinsic rectal fascia and the pelvic wall fascia, and the presacral separation of low rectal tumors should reach the tip of the tailbone.
(6) Dissect the anterior rectal peritoneal fold and separate the anterior rectal wall from the seminal vesicles at the gap between Denonvillier’s fascia (in women, the separation is performed at the level of the rectal genital diaphragm). The lateral ligaments on both sides are cut and care is taken to protect the autonomic nerves of the pelvis. Finally, the rectum is freed to at least 3 cm below the tumor.
(7) The rectum is cut with a laparoscopic suture 3 cm below the tumor. A small incision of corresponding size is made in the lower abdomen, and the incision is protected with a plastic bag, and the proximal rectosigmoid colon with tumor is pulled out of the abdominal cavity and the intestinal segment is removed. The circular anastomotic anvil is placed into the proximal colon, the pneumoperitoneum is re-established, and the sigmoid-rectal end-to-end anastomosis is performed using the anastomosis under direct laparoscopic view. The anastomosis must be free of tension.
(8) For patients with excessive obesity, narrow pelvic cavity, suboptimal surgical field exposure and difficulties in surgical manipulation, hand-assisted laparoscopic anterior rectal resection can be used instead.
(9) After flushing the pelvis, a drainage tube is placed near the anastomosis.
2. Laparoscopic perineal proctocolectomy (non-anal preservation): it is suitable for patients with cancer of the lower rectum and anal canal and some patients with cancer of the middle rectum who are not eligible for anal preservation. Patient position and Trocar placement are the same as for anterior rectal resection.
(1) The retroperitoneum is opened in front of the abdominal aorta, and the inferior mesenteric artery or sigmoid artery and its accompanying veins are freed and dissected. The colonic mesentery is separated from medial to lateral and the adipose tissue in front of the left common iliac artery and vein is stripped. Care should be taken not to damage the bilateral ureters and their surrounding tissues, and to pay attention to their course.
(2) The left posterior peritoneum is incised and the sigmoid mesentery is freed from the posterior peritoneal wall.
(3) When freeing the rectum, it should be performed within the gap between the intrinsic fascia and the pelvic wall, and the operation should be performed gently. The posterior and lateral parts of the rectum should be separated first, reaching the tip of the coccyx and the plane of the levator muscle on both sides, and then separating the rectum anteriorly to the plane of the prostate tip.
(4) Cut the ligaments on both sides, free the rectum downward near the pelvic wall, and remove the fatty lymphatic tissue of both pelvic walls.
(5) According to the aseptic technique, the sigmoid colon was cut intraperitoneally with a linear cutter or directly outside the body, and an abdominal wall stoma was made at an appropriate location in the left lower abdomen.
(6) Perineal group: double purse-string sutures are required for the anus. A skin shuttle incision is made around the anus, and the adipose tissue of the colorectal fossa should be more extensively excised.
(7) The caudal ligament is severed in front of the tailbone, and the anal levator muscle is separated and severed on both sides near the pelvic wall. The anal canal is pulled forward, the superior levator muscle fascia is incised transversely, the posterior presacral space of the rectum is entered, the superior levator muscle fascia is cut and enlarged on both sides, and the free and severed sigmoid colon and rectum are pulled out from the presacral area to facilitate the separation of the anterior rectal wall.
(8) Cut off the deep forward crossed fibers of the external anal sphincter, place the index and middle fingers into the pelvis between the prostate (posterior vaginal wall) and the rectum, cut off the muscles attached to the front of the rectum, and remove the rectum. When separating the anterior rectal wall, it is necessary to prevent damage to the urethra and posterior vaginal wall, and to pay attention to avoid penetration of the anterior rectal wall and contamination of the wound.
(9) After rectal resection, the specimen was removed from the perineum and the pelvic cavity was flushed with a large amount of sterile water or anti-cancer drug solution via the abdomen several times to completely stop bleeding. The subcutaneous tissue and skin of the perineal incision were sutured in layers, and drainage tubes were placed. For contaminated wounds, the perineal incision should not be sutured, and should be filled with oil gauze or iodoform gauze.