Robot-assisted radical resection of rectal and sigmoid cancers
Robotic surgical procedures are used for rectal and sigmoid cancers, including radical resection of sigmoid cancer, (low) anterior resection and abdominoperineal resection of rectal cancer.
Surgical position
The herringbone position or the modified lithotomy position [14] is used for radical resection of sigmoid cancer and (low) anterior resection of rectal cancer; the lithotomy position is used for abdominoperineal resection of rectal cancer. After the patient is secured, the operating table is turned to the Trendelenburg position with the right side inclined downward. The patient’s left leg is placed downward to avoid colliding with the robotic arms.
Trocar number and location
Usually, 4–5 trocars are placed for the surgery: 1 for the camera (Trocar C), 3 for the robotic arms (Trocar R1, R2, and R3), and 1 for the assistant (Trocar A). If the left colic flexure is mobilized during the surgery, Trocar R4 should be used instead of Trocar R2 for the robotic arms. Details are shown in Fig. 1.
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1.
Trocar C: 12 mm in diameter, placed 3–4 cm to the upper right of the umbilicus.
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2.
Trocar R1: 8 mm in diameter, placed at the McBurney’s point (one-third of the distance from the right anterior superior iliac spine to the umbilicus).
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Trocar R2: 8 mm in diameter, placed at the intersection of the left mid-clavicular line and the horizontal line through Trocar C.
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4.
Trocar R3: 8 mm in diameter, placed at the intersection of the left anterior axillary line and the horizontal line through Trocar C. This trocar is always used to help mobilize the lower rectum.
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Trocar R4: 8 mm in diameter, placed 3–4 cm below the xiphoid process, in the middle of the anterior midline and the right mid-clavicular line. This trocar is used to mobilize the left colic flexure.
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Trocar A: 5 or 12 mm in diameter, placed at the intersection of the vertical line through the McBurney’s point and the horizontal line through Trocar C.
The location of Trocar C is relatively fixed. The locations of other trocars could be adjusted according to the tumor site, the patient’s body shape, and the surgeon’s operating habits, although the operating center should be fixed to the tumor. The adjacent trocars should be 8–10 cm from each other to avoid collisions of robotic arms. All measurements should be based on the tension after the pneumoperitoneum. Trocars R1, R2, and/or R3 are used to mobilize the rectum, and trocars R1, R4, and/or R3 are used to mobilize the left colic flexure.
Abdominal exploration
After establishing pneumoperitoneum at a pressure of 8–15 mmHg, the camera on either the laparoscope or the surgical robot can be used for abdominal exploration. If tissue adhesions are found to interfere with the trocar puncture, laparoscopic instruments should be used to release them. Before the robot system is connected, the patient’s position should be adjusted to ensure sufficient exposure of the operative field.
Robot system connections
The patient cart is placed on the left side of the patient, with the direction line through the left anterior superior iliac spine, trocar C, and the center column of the patient cart (Fig. 1). All robotic arms should surround the operating center: the camera arm is located in the middle, and the instrument arms on the sides, with joints fully extended outward to avoid collisions. The digital pattern on the instrument arms should face straight ahead. When connecting robotic arms with trocars, movements should be gentle to avoid pulling up the trocars. After the robotic arms are fixed, neither the patient nor the operating table should be moved again.
Surgical procedure
1. Exposure of the operative field
The medial-to-lateral approach is recommended for the surgery. To improve the exposure of operative field, the uterus could be suspended in female patients, and the bladder could be suspended in male patients. With Trocar A, the assistant moves the small intestine and greater omentum to the right upper abdominal cavity. The mesenteric junction of the rectosigmoid and posterior peritoneum is tilted upward and outward to identify the abdominal aortic bifurcation.
2. Division of vessels
A “mesenteric window” is opened just at the sacral promontory plane. The inferior mesenteric vessels are dissected through the space between the visceral and parietal peritoneum (the Toldt’s space) and ligated at their origin points using Hemo-locks. Lymph nodes are also swept clearly.
3. Mobilization of the side peritoneum
The sigmoid is tilted rightward, and the Toldt’s space is dissected. The left ureter should be exposed and safeguarded during the mobilization.
4. Mobilization of the left colic flexure
First, the robotic arms should be removed. Then, the patient cart should be replaced beside the left shoulder of the patient, with the direction line through Trocar C and at an angle of 15° from the horizontal line (Fig. 2). The surgical robot system should also be re-connected. Trocars R1 and R4 are used to mobilize the left colic flexure. For patients with short sigmoid as confirmed in preoperative evaluation, the left colic flexure can be mobilized before the rectosigmoid.
5. Mobilization of the descending and sigmoid colon
The descending and sigmoid colon are mobilized along the prerenal fascia on the surface of the ureter. The nerve plexus should be safeguarded during the mobilization. The mesocolon is cut according to the proximal resection margin.
6. Mobilization of the rectum
The rectum is mobilized in a circular route, following the principles of total mesorectal excision (TME). The mobilization starts from the posterior rectum wall and gradually extends to the lateral sides; the anterior rectum wall is dissected last. For patients with contracted pelvis, lateral sides can also be dissected after the posterior and anterior wall. Trocar R3 is always used to help tilt the rectum. The tension of the arms should be controlled to avoid soft tissue avulsion. The tumor site is the basis for determining whether to open the peritoneal reflection and the length of the mobilized rectum, and the rectum can be mobilized till the levator plane if necessary. In mobilizing the lower rectum, electric scissors and hook may be more flexible.
7. Division of the distal mural margin
The distal mural margin can be dissected using electric scissors and hook or ultrasonic energy instruments. The margin should be more than 2 cm below the inferior edge of the tumor.
8. Anastomosis
Extracorporeal or intracorporeal anastomosis should be selected according to the tumor site and the patient’s body shape. In extracorporeal anastomosis, the incision is made in the left lower abdomen. The bowel with the tumor is pulled out for anastomosis under direct vision. A reinforcement suture can be made if necessary. In intracorporeal anastomosis, the tumor is removed through a small incision in the left lower abdomen or an enlarged puncture incision. A purse-string suture is placed in the proximal resection margin, and the anvil is tied around the margin of the colon. Then, the proximal colon along with the anvil is returned to the abdomen. The incision is closed, and the pneumoperitoneum is reestablished. The circular stapler is inserted through the anus, and the anastomosis is made under visualization of the surgical robot system. For small tumors, the affected bowel can be pulled out through the anus to remove the tumor. The anvil is tied to the proximal resection margin and is returned through the anus. The anastomosis is made under visualization of the surgical robot system and is checked for any leaks by air or methylene blue perfusion. A reinforcement suture can be made under visualization of the surgical robot system if necessary.
9. Perineal surgery and colostomy
For patients who are undergoing abdominoperineal resection, perineal surgery is continued manually after the rectum is mobilized till the levator plane. The procedure is the same as that for conventional open surgery. The affected bowel is removed from the perineal incision, and the robotic arms are also removed. The colostomy is then performed manually. The perineal incision is closed after the perineal surgery colostomy is completed.
10. Incision closure
To close the pelvic peritoneum, the pneumoperitoneum should be reestablished, and the surgical robot system should also be reconnected. The abdominal cavity is irrigated with normal saline or distilled water and drain adequately. Then, all incisions are closed.
Robot-assisted radical resection of left-sided colon cancer
Robotic surgical procedures are used for cancers located at the left transverse colon, left colic flexure, and descending colon.
Surgical position
The herringbone position or the modified lithotomy position [14] is used for the surgery. After the patient is secured, the operating table is turned to the reverse Trendelenburg position with the right side inclined downward. The patient’s left leg is placed downward to avoid collision with the robotic arms.
Trocar number and location
Usually, 5 trocars are placed for the surgery: 1 for the camera (Trocar C), 3 for the robotic arms (Trocars R1, R2, and R3), and 1 for the assistant (Trocar A). Details are shown on Fig. 3.
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1.
Trocar C: 12 mm in diameter, placed 3–4 cm to the upper right of the umbilicus.
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2.
Trocar R1: 8 mm in diameter, placed at the McBurney’s point (one-third of the distance from the right anterior superior iliac spine to the umbilicus).
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Trocar R2: 8 mm in diameter, placed at the right side of the anterior midline, 3–4 cm below the xiphoid process. Ensure that it is placed above the transverse colon.
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Trocar R3: 8 mm in diameter, placed on the anterior midline, 3–4 cm above the symphysis pubis.
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Trocar A: 5 or 12 mm in diameter, placed outside the right midclavicular line in the middle of Trocar C and Trocar R2.
The location of Trocar C is relatively fixed; the locations of other trocars could be adjusted according to the tumor site, the patient’s body shape, and the surgeon’s operating habits. The operating center should be fixed to the tumor. The adjacent trocars should be 8–10 cm from each other to avoid collisions of the robotic arms. All measurements should be based on the tension after the pneumoperitoneum.
Abdominal exploration
The same procedures apply as those mentioned above in “Robot-assisted radical resection of rectal and sigmoid cancers” section.
Robot system connections
The patient cart is placed beside the left shoulder of the patient, with the direction line through Trocar C and the center column of the cart at an angle of 15° from the horizontal line (Fig. 3). Other considerations are the same as those mentioned above in “Robot-assisted radical resection of rectal and sigmoid cancers” section.
Surgical procedure
1. Exposure of the operative field
The medial-to-lateral approach is recommended for the surgery. Through Trocar A, an assistant moves the small intestine and greater omentum to the right abdominal cavity. The mesenteric junction of the descending and sigmoid colon is tilted upward and outward, and the junction of the sigmoid colon and rectum is tilted downward and outward to identify the abdominal aortic bifurcation.
2. Division of vessels
A “mesenteric window” is opened just at the sacral promontory plane. The first and second branches of the sigmoid vessels and the left colic vessels are dissected through the Toldt’s space along the inferior mesenteric vessels. The vessels are ligated at their origin points from the inferior mesenteric vessels, using Hemo-locks. Lymph nodes are also swept clearly.
3. Mobilization of the descending colon
From the left side of the inferior mesenteric vein, the descending colon is mobilized through the Toldt’s space between the mesocolon and the left prerenal fascia. Mobilization is from up to down, or from up to down and from the inside to the outside, on the surface of the left spermatic or ovarian vessels and the left ureter.
4. Mobilization of the left colic flexure
The left colic flexure is mobilized through the Toldt’s space inward and upward. The left branch of middle colic artery is ligated, and the left gastrocolic and splenocolic ligaments are dissected to fully mobilize the left colic flexure.
5. Mobilization of the sigmoid colon and upper rectum
The descending and sigmoid colon are fully mobilized through the Toldt’s space; the upper rectum can also be mobilized if necessary. The length of resected bowel is decided, and the affected bowel is dissected.
6. Anastomosis
The affected bowel is pulled out through a left rectus incision to remove the tumor. An alternative is side-to-side or end-to-side anastomosis of the transverse and sigmoid colon.
7. Incision closure
The abdominal cavity is irrigated with normal saline or distilled water and drain adequately. Then, all incisions are closed.
Robot-assisted radical resection of right-sided colon cancer
Robotic surgical procedures are used for cancers located at the cecum, ascending colon, hepatic flexure, and right-sided transverse colon.
Surgical position
Supine position is used for radical resection. The patient should be set close to the cranial side of the operating table, and the anterior superior spine should be higher than the middle plane. After the patient is secured, the operating table is turned to the Trendelenburg position with an angle of 15°–30°, and left side downward with an angle of 10°–15°.
Trocar number and location
Usually, 5 trocars are placed in the surgery: 1 for the camera (Trocar C), 3 for the robotic arms (Trocar R1, R2, and R3), and 1 for the assistant (Trocar A). Details are shown on Fig. 4.
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1.
Trocar C: 12 mm in diameter, placed 3–4 cm to the lower left of the umbilicus.
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2.
Trocar R1: 8 mm in diameter, placed on the left midclavicular line, 7–8 cm below the costal margin.
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3.
Trocar R2: 8 mm in diameter, placed on the anterior midline, 6–8 cm above the symphysis pubis.
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Trocar R3: 8 mm in diameter, placed at the McBurney’s point (one-third of the distance from the right anterior superior iliac spine to the umbilicus).
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Trocar A: 5 or 12 mm in diameter, placed outside the left midclavicular line, 6–8 cm below Trocar R1, and more than 8 cm away from Trocar C.
The location of Trocar C is relatively fixed. The locations of other trocars could be adjusted according to the tumor site, the patient’s body shape, and the surgeon’s operating habits. The operating center should be fixed to the tumor. The adjacent trocars should be 8–10 cm away from each other, avoiding collisions of robotic arms. All measurement should be based on the tension after pneumoperitoneum.
Abdominal exploration
The same as mentioned above in “Robot-assisted radical resection of rectal and sigmoid cancers” section.
Robot system connections
The patient cart is placed beside the right shoulder of the patient, with the direction line through Trocar C and the center column of the patient cart, with an angle of 45° from the horizontal line (Fig. 4). There should be enough space beside the patient’s hip to avoid collision with robotic arms when mobilizing the hepatic flexure. Other considerations are the same as those mentioned above in “Robot-assisted radical resection of rectal and sigmoid cancers” section.
Surgical procedure
1. Exposure of the operative field
The medial-to-lateral approach is recommended for the surgery. With Trocar A, the assistant moves the small intestine to the left abdomen, and lift the right mesocolon to expose the junction of the ileocolic artery and the superior mesenteric vein.
2. Division of vessels
Dissection is performed upward along the superior mesenteric vessels to divide each branch and sweep the lymph nodes. Hemo-locks are used to ligate the ileocolic vessels, right colic vessels, and (the right branch of) middle colic vessels. For tumors located at or near the hepatic flexure which need expanded surgery, the right gastroepiploic vessels are also ligated at the inferior edge of pancreas.
3. Mobilization of the ascending colon
From the right side of the superior mesenteric vein, the ascending colon is mobilized through the Toldt’s space between the mesocolon and right prerenal fascia. Mobilization is performed from downside to upside, from inner to outside, on the surface of the right spermatic or ovarian vessels, right ureter pancreas, and duodenum.
4. Mobilization of the hepatic flexure
Gastrocolic ligament is opened to mobilize the hepatic flexure rightward. The right gastroepiploic vessels and corresponding lymph nodes should be swept if the tumor locates at or near the hepatic flexure. More than 10 cm length of greater omentum should be dissected and cut off.
5. Mobilization of the side peritoneum
From the ileocecal junction, the right-sided peritoneum is mobilized upward and converged with the hepatic flexure.
6. Anastomosis
The mesentery of the colon and small intestine is mobilized till resection margin. The bowel is resected according to the tumor site. Intracorporeal anastomosis and extracorporeal anastomosis with assistant incision are both feasible. In intracorporeal anastomosis, the terminal ileum is get close to the colon. Linear stapler is used for a side-to-side anastomosis. Then another linear stapler is used to cut off the specimen.
The affected bowel is pulled out through the left rectus incision to remove the tumor. It is alternative to make side-to-side or end-to-side anastomosis of the transverse and sigmoid colon. Circular stapler can also be used for end-to-side anastomosis.
7. Incision closure
The abdominal cavity is irrigated with normal saline or distilled water and put drainage adequately. Then, all incisions are closed.