Perioperative management - Open rectal resection, low anterior with total mesorectal excision (TME)

This surgical procedure is used for rectal carcinomas that, in terms of height localization by rigid rectoscopy, can be resected with a safety margin of 1 – 2 cm to the linea dentata measured from the lower tumor edge.

For rectal carcinomas where this safety margin cannot be maintained or where the sphincter is additionally infiltrated, abdominoperineal rectal extirpation is indicated. For early carcinomas (clinical category T1, N0, G1 or G2), local excision can be performed as an alternative to anterior rectal resection in accordance with guidelines.

Depending on the height of the anastomosis above the sphincter, the reconstruction after anterior or low anterior rectal resection can be performed as colorectal, coloanal, or colo-pouch-anal anastomosis.

Through the establishment of total mesorectal excision (TME) as the gold standard for tumors of the middle and lower third, the local recurrence rate could be reduced to below 10%.

In the example shown, it is a carcinoma of the middle rectal third (uT3,uN1). Therefore, neoadjuvant radiochemotherapy was performed in accordance with guidelines. After re-staging, which showed no evidence of distant metastasis, the indication for oncological tumor resection was established.

Neoadjuvant Radiotherapy

Neoadjuvant radiotherapy can be administered with or without chemotherapy and is recommended according to S3 guidelines for rectal carcinoma in UICC stages II (pT3-4 pN0) and III (pT1-4 pN+).

Neoadjuvant radiochemotherapy (RCT) lasts about 6 weeks, followed by a treatment break of 6-8 weeks until surgery.

Neoadjuvant short-term irradiation (RT) is administered on 5 consecutive days. Here, surgery follows after 2-7 days. Since tumor downsizing is not expected, RCT is preferred for tumors that reach the enveloping fascia or are located close to the sphincter.

27% of patients show histological complete remission through RCT. These patients have a particularly good oncological prognosis. Since response assessment is difficult and requires DRE (digital rectal examination), endoscopy, and MRI for detection, a “watch-and-wait” strategy can only be applied to tumors up to 7 cm from the anus and preferably in studies.

• severe comorbidity

Limited operability e.g. due to severe lung disease, heart failure, liver cirrhosis, etc.; whether this comorbidity represents a contraindication to surgery must be assessed individually.

• Severe, pre-existing anal incontinence.

If a significant anal incontinence already existed in the medical history before the development of the rectal carcinoma, it should be considered in consultation with the patient whether a Hartmann's operation with a deep Hartmann stump or an abdominoperineal rectal extirpation with terminal descending colostomy represents the more sensible surgical procedure. It should be noted that a well-manageable stoma offers a better quality of life than severe anal incontinence without a stoma.

• Sphincter infiltration or insufficient safety distance between the lower tumor edge and the distal resection margin

Here, an abdominoperineal rectal extirpation must be performed. The same applies to the situation where, despite discontinuation at the level of the linea dentata, macroscopic or microscopic (frozen section) infiltration with tumor cells is present in the specimen. In this case, too, a switch to abdominoperineal rectal extirpation is necessary to ensure oncologically sufficient radicality.

Clinical Examination, incl. rectal-digital examination. This already enables an assessment of the tumor's distance to the anocutaneous line and allows evaluation of the tumor's mobility relative to the surroundings. 

Rectoscopy: Only rigid rectoscopy enables exact tumor localization ideally measured by the distance of the tumor to the dentate line or the distance of the tumor from the anus.

Biopsy: Preoperative histological confirmation of the tumor diagnosis is mandatory. Multiple biopsies should be taken, as carcinomas often arise from adenomas.

Complete Colonoscopy: Complete colonoscopy is required to diagnose and remove additional adenomas or to exclude a second carcinoma. If the tumor is not passable due to stenosis, a colon contrast enema, intraoperative colonoscopy, or virtual colonoscopy can be performed alternatively.

Abdominal Sonography: Liver sonography is performed to exclude liver metastasis. Alternatively, this examination can be replaced by computed tomography of the abdomen or magnetic resonance imaging.

Computed Tomography of the Pelvis: CT has no value for local staging. Its value lies in the detection of distant metastases.

Positron Emission Tomography (PET): This procedure is usually not used in the primary diagnosis of rectal carcinoma, but is very suitable for differentiating locoregional recurrences from scars or inflammatory changes.

Decision Criterion CRM=circumferential resection margin

In recent years, the circumferential resection margin (CRM) has established itself as the most important prognostic parameter. Patients with close proximity of the enveloping fascia to the tumor have a higher local recurrence rate and poorer survival.

To select suitable patients for neoadjuvant RT or RCT, the following criteria need to be diagnostically elaborated:

• Tumor height
• Transmural infiltration depth (T-stage)
• Presence of mesorectal tumor-involved lymph nodes (N-stage)
• Distance of the tumor or tumor-suspicious LN to the mesorectal fascia (CRM). CRM (“circumferential resection margin”) is the distance of the tumor extensions from the mesorectal enveloping fascia, which can be predicted very accurately by MRI.

Endosonography: Endosonography enables the clinical T-category to be determined with relatively high sensitivity and specificity, based on which, among other things, it must be decided whether neoadjuvant therapy is to be performed. Furthermore, endosonography enables the diagnosis of suspicious lymph nodes in some patients due to their size. Overall, it is inferior to MRI except in T1 tumors.

Magnetic Resonance Imaging: Magnetic resonance imaging enables even clearer delineation than endosonography of a tumor infiltrating into the mesorectum from the boundary lamella and allows the distance to this structure to be determined very precisely. The prediction of involvement of the resection margin is the decisive prognostic factor and MRI is thus the most important diagnostic tool. It has the potential to select patients in stage T3 for whom RCT can be omitted due to a safely predictable negative CRM. Corresponding studies are ongoing. Preoperative LN diagnostics are very inaccurate in all cross-sectional imaging procedures.

• Written informed consent of the patient
• Clarification of operability, if necessary, involvement of other departments for consultative assessment of operability.
• Anesthesiological presentation
• Informative discussion regarding stoma care and marking of a stoma exit site
• Due to the significantly increased insufficiency rate in TME, a protective stoma should be created in every case. Since the protection is achieved through stool deviation, the colon must be flushed, otherwise the contents of the entire colon frame can still empty into the abdominal cavity in the event of an insufficiency. The current data situation speaks for an antegrade bowel lavage with the addition of topical antibiotics.
• Shaving of the surgical area
• Provision of blood products

• Anastomotic insufficiency
• Wound infection/intra-abdominal abscess/infection
• Postoperative bleeding
• Thrombosis/Embolism
• Injury to intra-abdominal structures, especially ureter, spleen
• Disturbance of urinary bladder and sexual function
• Impairment of postoperative fecal continence
• If necessary, discussion and documentation of a possible extension of the operation depending on findings (e.g., towards abdominoperineal rectal extirpation in case of very low-seated carcinoma)

Intubation anesthesia

Peridural catheter (PDK)

The positioning is performed in flat lithotomy position. When positioning in the leg holders, care must be taken to ensure that the peroneal nerve at the fibular head is padded and that it lies as freely as possible. Both arms are positioned alongside. To prevent the patient from slipping during extreme positioning, a base should be chosen that provides a firm hold and, if necessary, shoulder supports should be attached.

The surgeon stands on the right side, the 1st assistant opposite. The 2nd assistant stands alternately between the legs and also on the left side. The instrumenting OR nurse stands on the left side, the instrument table over the left leg.

For the laparotomy, a holding system is generally used. In our own procedure, this is a Rochard hook and a Mercedes retractor. Alternatively, other holding systems such as an Omni-Tract® system can be used.

• Stapler with curved instrument head advantageous
• transluminal, circular stapler
• Purse-string suture (0-0, monofilament, non-absorbable)
• linear stapler (GIA)
• Silicone drainage with suture and drainage bag

postoperative analgesia: The postoperative treatment includes in particular a consistent pain therapy, which is usually ensured by means of an epidural catheter or via peripheral analgesics, or via systemic analgesic administration (opiates, non-steroidal anti-inflammatory drugs).
Follow the link here to PROSPECT (Procedure Specific Postoperative Pain Management).
Follow the link here to the current guideline Treatment of acute perioperative and posttraumatic pain.

medical follow-up: The focuses of postoperative treatment are in the first 1–2 days after the operation the recognition of complications such as secondary bleeding, respiratory insufficiency, cardiac decompensation, etc. In the further course of treatment, from the 3rd and 4th postoperative day, the monitoring and management of possible infections and their detection are in the foreground (e.g. urinary tract infection, pneumonia, wound infection, anastomotic insufficiency). As soon as the patient is able to do so, stoma care should be initiated and practiced to ensure a prompt discharge (if a stoma was created).

Thrombosis prophylaxis: in the absence of contraindications, due to the high risk of thromboembolism (major abdominal surgical procedure for malignancy), in addition to physical measures, low-molecular-weight heparin should be administered in prophylactic, possibly weight- or disposition risk-adapted dosage until full mobilization is achieved. Continuation of medicinal thromboembolism prophylaxis for e.g. 6 weeks is discussed.
Note: renal function, HIT II (history, platelet control)
Follow the link here to the current guideline Prophylaxis of venous thromboembolism (VTE).

Mobilization: Prompt mobilization to the sink and into the hallway, depending on the condition, should be aimed for.

Physical therapy: In addition to breathing exercises, regular mobilization of the patient takes place depending on the condition and strength to the edge of the bed or into the armchair.

Diet build-up: The diet build-up can be carried out within the framework of fast-track concepts from the 1st postoperative day, especially in the presence of an ileostomy.

Bowel regulation: Bowel regulation should, if it does not start spontaneously, be stimulated by prokinetics (e.g. Prostigmin s.c. or i.v.).

Inability to work: Depending on convalescence, an inability to work of at least 4-6 weeks after the operation must be expected as a rule.