Perioperative management - Rectal resection, robot-assisted with total mesorectal excision (TME)

In rectal cancer, curative therapy usually requires not only the resection of the primary tumor in healthy tissue (i.e., with sufficient safety margin) but also the partial or total removal of the mesorectum (PME, TME) and thus the removal of the regional lymphatic drainage area. Only in strictly selected cases is a curative resection possible through local measures.

The indications for robot-assisted deep anterior rectal resection therefore include:

• histologically confirmed malignant neoplasm of the rectum
• endoscopically non-removable or incompletely removable tumor with high-grade intraepithelial neoplasia
• any deeper tumor mass in the rectum with a high suspicion of a malignant process

The indication for the surgical procedure in rectal cancer fundamentally depends on the tumor localization, especially the relations to the dentate line and the levator muscle, the depth of infiltration, and the sphincter function. Whenever possible, sphincter-preserving procedures should be preferred, assessing the long-term quality of life. In cases of poor sphincter function, a permanent colostomy should be preferred instead of a deep anterior resection, which is then performed depending on the safety margin to be achieved from the pelvic floor as rectal extirpation or pelvic floor preserving. If an adequate aboral safety margin cannot be ensured through a low anterior resection of the rectum, the following procedures should be applied depending on the exact height localization and potential infiltration:

• intersphincteric rectal resection
• abdominoperineal rectal extirpation,

In Germany, the recommendations for the treatment of colon and rectal cancer are anchored in the S3 guidelines (S3 Guidelines Colorectal Cancer (Guideline Program Oncology (German Cancer Society, German Cancer Aid, AWMF): S3 Guidelines Colorectal Cancer. Status: 30.11.2017, valid until 29.11.2022, Retrieved on: 14.04.2023)

The following table summarizes the therapeutic concepts depending on the existing tumor situation and spread:

Notes:

• A full wall excision is only sufficient for T1 tumors with a diameter of less than 3 cm with good to moderate differentiation without lymphatic vessel invasion and after R0 resection. However, even here, a higher recurrence risk is to be expected with an overall significantly lower complication rate and better functional results. Technically, transanal microsurgery appears to be advisable.
• UICC II and III situations are usually subjected to a neoadjuvant concept with the operation preceded by radiotherapy or radio-chemotherapy for tumors of the middle and lower thirds. The concept for tumors of the upper third follows that of colon cancer (see contribution to robot-assisted oncological sigmoid resection).
• cT3 tumors of the middle third without lymphatic vessel or vascular invasion and with very limited perirectal fat tissue infiltration in MRI are usually also subjected to primary surgery.
• Complete response: In the (rather rare) cases where no tumor is detectable after neoadjuvant radio-chemotherapy clinically, endoscopically, and through imaging procedures (endosonography and MRI, alternatively possibly also CT), any surgery can be omitted. A prerequisite for a purely observational approach is the thorough explanation to the patient about the still insufficient validation of this approach and the patient's willingness to undergo very close follow-ups for at least 5 years. The optimal design for follow-ups or "watch & wait" is the subject of studies; the following follow-up procedure can be recommended according to an international expert commission: Follow-ups for 5 years after documentation of cCR; for three years every 3 months CEA, then every six months; for two years every 3 months digital-rectal examination, MRI, and endoscopy, then every six months; for 5 years CT thorax/upper abdomen months 6,12,24,36,48,60.

The general contraindications for robotic procedures are based on the general contraindications for minimally invasive procedures. This includes:

• Contraindications for the establishment of a pneumoperitoneum, e.g.
  • due to severe systemic disease,
  • or a manifest ileus with massive bowel distension
  • all clinical situations with an abdominal compartment syndrome
  • massive adhesions (hostile abdomen)

Additionally, relative contraindications should be considered, where preoperative optimization may be possible, such as:

• Severe coagulation disorders (Quick < 50%, PTT > 60 sec., platelets < 50/nl),
• severe portal hypertension with caput medusae

• Staging
  • Complete colonoscopy 
    • Gold standard in the diagnosis of colorectal carcinoma
    • for localization diagnostics and for histological confirmation and to rule out a second carcinoma (about 5% of cases)
    • If the entire colon is visible during colonoscopy, a CT or MR colonography can be used.
    • After emergency surgery (ileus, tumor perforation, colonoscopy not controllable bleeding): postoperative colonoscopy after anastomosis healing and patient recovery to rule out a synchronous double carcinoma 
  • Histopathological evidence of malignancy
  • CEA

Note: Other tumor markers such as CA 19-9, CA 125 are discussed, but without a positive vote from the guidelines  

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  • X-ray of the chest in 2 planes or CT of the chest
  • Ultrasound of the abdomen or CT of the abdomen
  • MRI of the small pelvis 
  • Rectal endosonography
  • If necessary, CEUS (contrast-enhanced ultrasound) in case of suspected hepatic filiation
  • If necessary, MRI of the liver in case of suspected hepatic filiation

Note: Even if a CT of the abdomen or CT of the thorax-abdomen is considered non-mandatory in the S3 guidelines, it is still performed in most clinics. 

• Further preoperative environmental diagnostics
  • Clinical examination
  • Laboratory tests (surgical routine: complete blood count, CRP, electrolytes, blood sugar, coagulation, kidney values, liver values, bilirubin, blood group) + if necessary 2 RBC´s (red blood cell units) depending on clinic standard
  • ECG
  • Pulmonary function diagnostics in case of history
  • Blood gas analysis (BGA) in case of COPD/COLD
  • Cardiac echo with ejection fraction (EF) in case of suspected heart failure

Caution: After the diagnostics are completed, the therapeutic phase of each rectal carcinoma begins with the presentation in an interdisciplinary tumor conference to determine the further course of action.

• Preoperative preparation on the ward
  • Breathing exercises: from the day of admission for pneumonia prophylaxis
  • Body care: shower on the evening before (antiseptics)
  • Shaving: from nipples to the genitalia
  • Stoma supply: if necessary, mark waterproof
  • Premedication by anesthesia: if no contraindications, always Epiduralcatheter
  • in case of reduced general and physical condition additionally high-calorie enteral nutrition solution (3 days preoperatively)
  • Thrombosis prophylaxis
  • Preoperative bowel preparation: Current data supports anterograde bowel irrigation with synchronous addition of topical oral antibiotics (e.g., 8g Paromomycin on the evening before the surgery).
  • On the morning of the surgery: administration of a double enema.
  • Thrombosis prophylaxis: (usually "Clexane 40"), compression stockings

Caution: Preoperative review and adjustment of therapy with anticoagulants:

•  
  • The perioperative therapy with aspirin can be continued.
  • Clopidogrel (ADP inhibitor) should be paused at least 5 days before surgery.
  • Vitamin K antagonists should be paused for 7-10 days under INR control.
  • DOACs (direct oral anticoagulants) should generally be paused 48 hours preoperatively
  • Always consult with the treating cardiologist if necessary
• Bridging:
  • for Vitamin K antagonists: bridging with short-acting heparins if INR is outside the target range
  • For DOACs, bridging can usually be omitted due to the short half-life. In case of very high closure/insulin risk: bridging under inpatient conditions with UFH and aPTT control
• Preoperative preparation in the OR
  • Insertion of a permanent catheter
  • Epidural placement
  • central-line placement: usually during anesthesia induction.
  • If necessary, arterial access during induction
  • Perioperative antibiotic therapy with e.g. Unacid

Important points of informed consent:

• Indication, planned surgical procedure (including stoma placement), aftercare, possible alternatives
• Bleeding/rebleeding with administration of allogeneic blood
• Drain placement, catheter placement
• Possible necessity for surgical revision due to a complication
• Anastomotic insufficiency with local or generalized peritonitis and sepsis, reoperation, open abdomen treatment, discontinuity resection
• Placement of a protective ileostomy as a fixed part of the surgical planning, e.g., for deep tumors after neoadjuvant therapy
• Possibility/necessity of optional and unplanned stoma placement (protective ileostomy vs. terminal stoma)
• Intra-abdominal abscess formation with the necessity of an interventional or surgical measure
• Wound infection
• Abdominal compartment syndrome
• Incisional hernia/trocar hernia
• Tumor recurrence
• Injury to the ureter, iliac vessels, bladder, spleen, kidney, pancreas, small intestine, other sections of the colon
• Injury to the sphincter apparatus
• Necessity for surgical extension, possibly extirpation
• Conversion to a laparotomy
• Change in bowel habits
• When entering the small pelvis: impotence coeundi in men, fecal incontinence and bladder emptying disorders due to injury of the inferior hypogastric nerves, injury of the internal genitalia in women