The robotic technique described herein aims to detail a stepwise approach to robot-assisted total mesorectal excision and lateral pelvic lymph node dissection for locally advanced (T3/T4) rectal cancer located below the peritoneal reflection.
Since their approval for clinical use, da Vinci surgical robots have shown great advantages in gastrointestinal surgical operations, especially in complex procedures. The high-quality 3-D visual, multijoint arm and natural tremor filtration allow the surgeon to expose and dissect more accurately with minimal invasion. Total mesorectal excision is the standard surgical technique for the treatment of resectable rectal cancer. To reduce the lateral recurrence rate, lateral pelvic lymph node dissection can be performed, as it is a safe and feasible procedure for locally advanced middle-low rectal cancer with a high possibility of metastasis to the lateral lymph nodes. However, the complexity of the anatomic structures and the high postoperative complication rate limit its application. Recently, several surgeons have increasingly used robotic techniques for total mesorectal excision and lateral pelvic lymph node dissection. Compared with open and laparoscopic surgery, the robotic technique has several advantages, such as less blood loss, fewer blood transfusions, minimal trauma, shorter postoperative hospitalization, and quicker recovery. A robotic approach is generally regarded as a reasonable alternative for complicated procedures such as lateral pelvic lymph node dissection, although there are a limited number of high-quality prospective randomized controlled studies reporting direct evidence. Here, we provide the detailed steps of robot-assisted total mesorectal excision and lateral pelvic lymph node dissection performed at the First Affiliated Hospital of Xi'an Jiaotong University.
Since their approval for clinical use by the United States Food and Drug Administration in 2000, da Vinci surgical robots have been increasingly utilized across different surgical specialties1. The robotic surgical system has the advantages of using flexible multijoint arms, a high-quality three-dimensional camera, tremor filtration, and greatly improved ergonomics, which can minimize the invasiveness of the operation and thus making it ideal for complex procedures.
For decades, total mesorectal excision (TME) has been the standard for the treatment of resectable rectal cancer. However, for advanced (T3/T4) rectal cancer located below the peritoneal reflection, lateral pelvic lymph node (LPLN) metastasis is a major cause of local recurrence after surgery2. Clinical evidence clearly shows that lateral pelvic lymph node dissection (LPLND) could significantly reduce the local recurrence rate3. Compared with the open procedure, robot-assisted TME and LPLND have been associated with less blood loss, fewer blood transfusions and fewer postoperative complications4. In addition, the long-term outcomes are not significantly different between the two procedures5. The results of these reports indicate that robot-assisted LPLND may be a feasible modality for locally advanced rectal cancer. However, it should be noted that robot-assisted TME and LPLND are complex procedures and should be performed by an experienced surgeon.
Herein, a standard systematic approach to robot-assisted TME and LPLND is described step by step. This procedure was developed at the center having experience in performing more than three thousand robotic procedures6. In addition, this approach was based on normal anatomical characteristics; rare anatomical variations should be noted.
We present the case of a 64-year-old male patient who had intermittent hematochezia for approximately 3 months. Digital rectal examination revealed that a mass was located on the anterior and right lateral wall of the rectum, 5 cm from the anus. An enhanced computed tomography (CT) scan and endoscopic ultrasound (EUS) revealed lower rectal cancer with internal iliac lymph node metastasis. Colonoscopic biopsy confirmed the presence of moderately differentiated adenocarcinoma. The preoperative evaluation suggested that the clinical stage was cT3N+M0. Accordingly, we decided to perform robot-assisted TME and LPLND. Patient consent was obtained prior to performing these procedures.
This protocol complies with the guidelines of the Ethics Committee of the First Affiliated Hospital of Xi 'an Jiaotong University (No. 2019ZD04).
1. Preoperative preparation, patient position, and anesthesia
2. Operation settings and port placement
NOTE: These measures can be appropriately adapted according to the experience of each surgeon.
3. Total mesorectal excision
4. Lateral pelvic lymph node dissection
NOTE: Bilateral LPLND can commence on either the left or the right side. The current technique guideline suggests starting on the left. After releasing and mobilizing the sigmoid colon and rectum, the left common/external iliac artery and left ureter can be identified clearly, which facilitates starting the lymphadenectomy on this side. The lateral pelvic lymph nodes involve the common iliac area (No. 273), external iliac area (No. 293), obturator area (No. 283), and internal iliac area (No. 263). However, previous studies indicate that common iliac and external iliac lymph node metastases are rare9. Therefore, treatment guidelines for colorectal cancer recommend primarily focusing on the obturator area (No. 283) and internal iliac area (No. 263) for dissection9.
5. Reconstruction of the digestive tract
NOTE: Here, depending on the experience and preference of the primary surgeon, either a stapled colorectal or handsewn anastomosis can be chosen via open or robotic laparoscopic methods. Methods of anastomosis include straight end-to-end anastomosis, small reservoir end-to-side colorectal anastomosis, or colonic J-pouch anastomosis10. Here, we provide a basic, open, straight end-to-end stapled colorectal anastomosis technique.
6. Diverting loop ileostomy
NOTE: Whether a diverting loop ileostomy is performed depends on the height and quality of the anastomosis and whether the patient was treated with radiation preoperatively. If ileostomy is not chosen, please skip steps 6.1.1-6.1.7.
The detailed perioperative information of the case presented in the video is shown in Table 1 and Figure 3. The procedure was performed in April 2019 by the corresponding author using the da Vinci Si Robot system. The estimated blood loss during the operation was 90 mL, and no transfusions were required. Postoperative management adhered to the principles of ERAS. After the first defecation on the 6th day after the operation, we administered a meglumine diatrizoate enema and performed X-ray radiography to determine whether anastomotic leakage occurred. We then removed the drain after confirming no evidence of leakage. The patient did not report any urinary or sexual dysfunction during follow-up.
The pathologic examination of the specimen indicated adenocarcinoma with moderate differentiation (Figure 4). No positive lymph nodes were detected in any of the 19 mesorectal nodes or 18 lateral lymph nodes. The final pathologic stage was T3N0M0. There was no evidence of lymphatic, venous, or perineural invasion. We recommended that the patient receive adjuvant chemotherapy with FOLFOX. Until January 2021, the patient still remained without any evidence of recurrence or metastasis.
At our center, robot-assisted TME and LPLND have been performed in 89 patients. All procedures were successfully completed under robotic assistance without conversion to open surgery. The detailed information is shown in Table 2. The mean operative time was 173.5 min. Postoperative complications developed in 14.6% of the patients. The median number of lymph nodes detected was 32. The total lateral pelvic lymph node metastasis rate reached 22.5%. As of April 2021, there were 3 patients who presented local recurrence in the pelvic lateral wall and anastomotic stoma, with a median follow-up time of 1.9 years. Urinary dysfunction was defined as ≥50 mL of residual urine occurring at the 3rd month after the operation. A total of 74 patients accepted the evaluation, and 5 patients met the criterion. Sexual dysfunction in men was measured using the International Index of Erectile Function, a 5-item version (IIEF-5) questionnaire, and the Female Sexual Function Index (FSFI) questionnaire was used for women. A total of 49 patients accepted the postoperative evaluation. A score of less than 17 on the IIEF-5 questionnaire or less than 28 on the FSFI questionnaire was considered indicative of sexual dysfunction. Two patients reported sexual dysfunction.
Table 1: Representative results. This table shows the detailed baseline clinical characteristics, intraoperative and postoperative outcomes and pathology results of the representative case. BMI: body mass index; ASA: American Society of Anesthesiologists; LPLND: lateral pelvic lymph node dissection; TME: total mesorectal excision. *Here, we counted only complications requiring additional therapeutic intervention. Please click here to download this Table.
Figure 1: Operation setting. This figure has been adapted from Napoli, N., Kauffmann, E. F., Menonna, F., Iacopi, S., Cacace, C., Boggi, U. Robot-Assisted Radical Antegrade Modular Pancreatosplenectomy Including Resection and Reconstruction of the Spleno-Mesenteric Junction. J. Vis. Exp. (155), e60370, doi:10.3791/60370 (2020)11. Please click here to view a larger version of this figure.
Figure 2: Port placement. This figure shows the important anatomic landmarks of the abdomen and port placement, including 3 robotic arms, 1 camera and 2 assistant ports. MCL: midclavicular line; AAL: anterior axillary line; C: camera port; U: umbilicus; R1, 2, 3: robotic arm 1, 2, 3; A1, 2: assistant port 1, 2. This figure has been modified from Shi F, Li Y, Pan Y, et al. Clinical feasibility and safety of third space robotic and endoscopic cooperative surgery for gastric gastrointestinal stromal tumors dissection: A new surgical technique for treating gastric GISTs. Surg Endosc. 2019;33(12):4192-4200. doi:10.1007/s00464-019-07223-w12. Please click here to view a larger version of this figure.
Figure 3: Robotic TME and LPLND. (A) Dissection of the retrorectal plane was performed between mesorectal fascia and prehypogastric nerve fascia. The yellow dashed line indicates the sacral promontory. (B) Incision along the yellow dashed line to open the anterior plane between Denonvilliers' fascia and the mesorectal fascia. (C) Dissection of the obturator nodes. The yellow dashed line indicates the range of obturator nodes (#283). The blue dashed line indicates the umbilical artery. (D) Dissection of the internal iliac lymph node. The yellow dashed line indicates the range of internal iliac lymph nodes (#263). (E) The LPLND was completed. (F) Whole specimen of resected lateral lymphatic and adipose tissue. MRF: mesorectal fascia; PHNF: prehypogastric nerve fascia. Please click here to view a larger version of this figure.
Figure 4: The pathologic examination of the specimen indicated adenocarcinoma with moderate differentiation (Hematoxylin-Eosin staining). Scale bar, 50 µm. Please click here to view a larger version of this figure.
Table 2: Results of 89 consecutive robot-assisted TME and LPLND. This table shows the detailed baseline clinical characteristics, intraoperative and postoperative outcomes and pathology results. BMI: body mass index; ASA: American Society of Anesthesiologists; LPLND: lateral pelvic lymph node dissection; TME: total mesorectal excision. *Here, we counted only complications requiring additional therapeutic intervention. Please click here to download this Table.
Colorectal cancer (CRC) is one of the most common cancers worldwide13. Among them, more than a third are rectal cancer. Due to the higher postoperative functional requirement and the sophisticated neuro- and fascial anatomy of the pelvis and perineum, the best surgical approach for rectal cancer, especially low or ultralow rectal cancer, is still under great debate. Since its first report in 1979, total mesorectal excision (TME) has been the standard surgical technique for the treatment of resectable rectal cancer14. With complete excision of the mesorectum, the local recurrence rate decreases significantly. However, this approach is still challenging to perform in low rectal cancer patients, and a high conversion rate and positive resection margins remain concerns15,16. Sylla et al. developed the transanal total mesorectal excision (TaTME) strategy as a novel approach to the surgical treatment of rectal cancer17. Indeed, it has been proposed that TaTME has the advantages of fewer abdominal incisions, better visualization of the mesorectal plane and distal resection margin and better feasibility in the narrow pelvis space15. However, some controversy over long-term oncological outcomes and postoperative quality of life remains. Nationwide data show that TaTME has a higher local recurrence rate than laparoscopic TME18. In addition, due to a long period of intraoperative anal traction, patients who undergo TaTME may endure long-term (over 6 months) anal pain19. This emerging technique may require improvements to the procedure itself, standardized guidelines and structured training programs to be applied widely.
Another technique has emerged and has been increasingly accepted among colorectal surgeons as a popular option. A hospital in Seoul performed and reported the first da Vinci robotic-assisted TME in 200720. Robot-assisted surgical procedures overcome the limitations of the open (limited visual field and narrow operating space) and laparoscopic approaches (reduction in manual dexterity, a counterintuitive motion mode, magnified natural tremors of the hand and flat visuals). Compared with laparoscopic procedures, the da Vinci surgical robot system trades a flat, 2-dimensional misplaced visual that must be obtained through additional personnel for a 3-dimensional high-quality visual field that can display more detailed anatomical structures. In addition, the da Vinci system adopts a multijoint arm with 7 degrees of freedom to perfectly copy the motion of a natural human hand instead of awkward straight "chopstick" motions. Moreover, several ergonomic inventions have greatly reduced natural tremors to ensure the stability of the surgical instruments and to minimize unanticipated injury. However, the loss of tactile sense and force feedback has still not been addressed. Recent systematic reviews and meta-analyses have shown that the robotic TME has a significantly lower conversion to open surgery rate than laparoscopic procedures, although they included patients with a higher body mass index and lower tumor location as well as a higher proportion of patents receiving neoadjuvant therapy, which are all adverse factors for surgical procedures21,22. The long-term oncological outcomes of robotic and laparoscopic procedures are equivalent23. A robotic approach is generally regarded as a reasonable alternative for complicated procedures such as TME and LPLND. However, it should be acknowledged that robotic TME still has several limitations, such as a higher cost for both patients and departments and additional training requirements16.
The standard TME procedure does not include dissection of the lateral pelvic lymph nodes (LPLNs). However, according to the results of previous studies from the Japanese Society for Cancer of the Colon and Rectum (JSCCR), the total metastasis rate of LPLN in patients whose lower tumor border was distal to the peritoneal reflection and whose cancer invaded beyond the muscularis propria was 20.1%9. A multicenter, randomized controlled trial (RCT) for clinical stage II/III lower rectal cancer (JCOG0212) showed that a high-quality TME procedure with LPLN dissection (LPLND) can reduce the local recurrence rate after surgery (12.6% in TME alone vs. 7.4% in TME with LPLND, P=0.024)3. In Western countries, neoadjuvant radiotherapy/chemoradiotherapy (NART/CRT) has become standard treatment for clinical stage II/III rectal cancer rather than LPLND24. However, a recent multicenter study showed that NART/CRT followed by TME alone is not sufficient to prevent local recurrence in rectal cancer patients with enlarged LPLNs. The addition of LPLND can significantly reduce the recurrence rate (19.5% in TME alone versus 5.7% in TME with LPLND, P=0.042)25. Therefore, a standard TME procedure selectively combined with LPLND according to the clinical and imaging features of the patient should be a standard surgical treatment for locally advanced middle-low rectal cancer. However, the major factor limiting the development and wide use of LPLND is the high incidence rates of postoperative urinary and sexual dysfunction. Two meta-analyses reported that compared with TME alone, additional LPLND markedly increased the incidence of urinary dysfunction, while only one meta-analysis reported a higher incidence of sexual dysfunction26,27.
Currently, we use the robotic surgical system to perform TME and additional LPLND. According to our preliminary results, the use of robotic TME and LPLND leads to favorable perioperative outcomes and equivalent medium-term oncological outcomes. As the da Vinci robot system has several characteristics, as we described previously, the system shows inherent advantages in the identification and dissection of important nerves and vessels to possibly reduce the risk of postoperative complications. However, it should be noted that the decision to combine LPLND should depend on clinical features and patient factors. Until now, widely preventive LPLND has not been recommended for patients without any evidence of lateral lymph node metastasis due to its high risk of injury, the low metastasis rate and high rates of postoperative urinary and sexual dysfunction28. In addition, some patient factors should be considered. One question arises: For older rectal cancer patients, are they going to die with cancer or of cancer?29 For older rectal cancer patients, surgical procedures should be more circumspectly decided. In general, older patients have various comorbidities and frailty, leading to higher rates of intra- and postoperative complications. In addition, unlike younger patients, maintaining function and quality of life are more important for older patients rather than achieving optimal oncological benefits. Thus, comprehensive preoperative evaluation of the benefits and risk of harm is absolutely necessary.
Based on our experience, several key points of this technique should be emphasized to ensure a successful procedure. The most important is adequate familiarity with anatomical structures. During the TME phase, the major consideration is how to effectively protect autonomic pelvic nerves. It should be noted that the dissection was performed by a harmonic scalpel instead of electrocautery, which could reduce the risk of thermal injury. In addition, a radical understanding of the fascia and planes surrounding the rectum is needed30. There are three planes to consider when performing dissection and mobilization of the rectum. The first is the classical TME plane between the mesorectal fascia and prehypogastric nerve fascia (posterior and lateral to the rectum) or Denonvilliers' fascia (anterior to the rectum). By developing this plane, the surrounding autonomic nerves can be safeguarded. Outside the TME plane, there is a second plane between the prehypogastric nerve fascia and presacral fascia (posterior) or vesicohypogastric fascia (lateral) and anterior to Denonvilliers' fascia, which carries a higher risk of injury to the pelvic plexus. The third plane is close to the endopelvic fascia and is rarely adopted. In addition, during the LPLND phase, the anatomical structure of the lateral pelvic region is complex, especially the obturator and internal iliac artery regions. We should clearly identify three planes: the lateral wall plane, composed of the psoas and internal obturator muscles; the medial plane, composed of the ureter and the hypogastric nerve fascia and pelvic plexus; and the dorsal plane, composed of the internal iliac vessels and the sciatic nerve. These three planes define the boundaries of dissection. In addition, the vesicohypogastric fascia divides the area into the obturator and internal iliac compartments, with the easily identifiable umbilical artery as its superior border. Selective ligation of the vessels can control bleeding and expose the anatomic structures. However, it should be noted that the obturator nerve and superior vesical artery should be preserved carefully. If the bleeding is not controlled, a quick and safe open conversion should be performed while the assistant temporarily applies pressure. In addition, the R3 arm plays an important role in retraction of the organ and tissue to allow for optimal exposure. An experienced surgeon can properly place the R3 arm to expose the target structures more clearly and ensure accurate dissection.
In conclusion, the robotic TME and LPLND technique is safe and feasible for patients with locally advanced middle-low rectal cancer. This technique enables better exposure of complicated anatomic structures and can reduce unanticipated injury, following the development trend of minimally invasive surgery. An appropriate selection of surgical indications and a radical understanding of anatomic structures are critical factors of successful procedures. In addition, we suggest appropriately individualized adjustments based on the preferences and experiences of individual surgeons.
The authors have nothing to disclose.
This project was supported by the National Natural Science Foundation of China (No. 81870380) and the Shaanxi Province Science Foundation (2020ZDLSF01-03 and 2020KWZ-020).
0 Silk suture | N/A | N/A | Secure the anvil |
12mm Trocar | Medtronic (Minneapolis, MN) | NONB12STF | Assistant port 1 |
19 Fr drain | N/A | N/A | Pelvic drain |
2-0 Silk suture | N/A | N/A | Close skin incisions |
2-0 V-Loc sutures | Covidien (Dublin, Ireland) | VLOCL0315 | Barbed Absorable Suture |
4-0 PDS | Ethicon (Somerville, NJ) | SXPP1A400 | Synthetic Absorbable Suture |
8mm Trocar | Medtronic (Minneapolis, MN) | NONB8STF | Assistant port 2 |
Bipolar forceps | Intuitive (Sunnyvale, CA) | 470172 | Operation |
Cadiere grasping forceps | Intuitive (Sunnyvale, CA) | 470049 | Operation |
Circular stapler | EzisurgMed (Shanghai, China) | CS2535 | Laparoscopic Surgical Stapler |
Da Vinci Si | Intuitive (Sunnyvale, CA) | N/A | Surgical Robot |
Da Vinci Xi | Intuitive (Sunnyvale, CA) | N/A | Surgical Robot |
Hem-o-lok ligation clip | Weck (Morrisville, NC) | 544995 | Ligation of vessel |
Laparoscopic single use linear cutting stapler | EzisurgMed (Shanghai, China) | U12M45 | Laparoscopic Surgical Stapler |
Large needle driver | Intuitive (Sunnyvale, CA) | 470006 | Operation |
Monopolar scissors | Intuitive (Sunnyvale, CA) | 470179 | Operation |
Ribbon retractor | N/A | N/A | Control movement of rectum |
Specimen Bags | N/A | N/A | Extract specimen |
Veress needle | N/A | N/A | Saline drop test |