Total mesorectal neglect in the age of total mesorectal excision

The Effectiveness and Safety of Rectal Modular Resection in Low Rectal Cancer: A Retrospective Study

Background: Described by Heald in 1982, total mesorectal excision (TME) is now routinely performed as the standard procedure for mid-low rectal cancer, with remarkable decrease in local recurrence and improved oncology outcome. However, the integrity of the resected mesentery and damage to autonomic nerves still remain challenging for general surgeons, especially in the cohort of neoadjuvant therapy patients. The concept of rectal modular resection (RMR), based on an integral understanding of the regional anatomy, was proposed as a surgical skill for dissociation of the rectum with shorter surgical duration, function preservation, and improved oncology outcome. Methods: This was a retrospective trial. Patients with resectable rectal lesions, ranging between 3 and 7 cm from the anal verge, were enrolled and grouped by TME surgery based on RMR or classical procedure resection (CPR). We estimated perioperative outcomes, including surgery complications such as anastomotic leak, urine retention, and others. Pathological properties, including distal clearance, harvested lymph nodes, tumor differentiation, and specimen grading, were also taken into account. Patients were followed postoperatively and functional evaluation was recorded at the 3-month and 1-year postoperation visits. Results: From January 2019 to December 2021, a total of 92 patients were enrolled in this study. TME surgery complying with the RMR methodology was performed with a back-to-bilateral-to-front modular proceeding. Duration of operation was significantly shortened in the RMR group, without increase in blood loss or failure rate of anus preservation. The quality of the specimen, graded according to integrity of the mesorectum, stands out in the RMR group. Functional evaluation revealed no statistical difference between RMR and CPR groups regarding sexual ability impairment and defecation disorder since follow-up is still ongoing. Conclusions: RMR-based TME was efficient with compressed operation duration compared with CPR and its safety was well validated with regard to the occurrence of complications and function loss.

Long-term results of minimally invasive transanal surgery for rectal tumors in 249 consecutive patients

PURPOSE

To delineate the long-term results of minimally invasive transanal surgery (MITAS) for selected rectal tumors.

METHODS

We analyzed data, retrospectively, on consecutive patients who underwent MITAS between 1995 and 2015, to establish the feasibility, excision quality, and perioperative and oncological outcomes of this procedure.

RESULTS

MITAS was performed on 243 patients. The final histology included 142 cancers, 47 adenomas, and 52 neuroendocrine tumors (NET G1). A positive margin of 1.6% and 100% en bloc resection were achieved. The mean operative time was 27.4 min. Postoperative morbidity occurred in 7% of patients, with 0% mortality. The median follow-up was 100 months (up to ≥ 5 years or until death in 91.8% of patients). Recurrence developed in 2.9% of the patients. The 10-year overall survival rate was 100% for patients with NET G1 and 80.3% for those with cancer. The 5-year DFS was 100% for patients with Tis cancer, 90.6% for those with T1 cancer, and 87.5% for those with T2 or deeper cancers. MITAS for rectal tumors ≥ 3 cm resulted in perioperative and oncologic outcomes equivalent to those for tumors < 3 cm.

CONCLUSION

MITAS is feasible for the local excision (LE) of selected rectal tumors, including tumors ≥ 3 cm. It reduces operative time and secures excision quality and long-term oncological outcomes.

Local Excision Techniques for Rectal Cancer After Neoadjuvant Chemoradiotherapy: What Are We Doing?

BACKGROUND

Recent evidence shows that the majority of rectal cancers demonstrate occult tumor scatter after neoadjuvant chemoradiotherapy that can extend for several centimeters under adjacent normal-appearing mucosa beside the residual mucosal abnormality or scar.

OBJECTIVE

This systematic review aimed to determine all of the published selection criteria and technical descriptions for local excision to date with regard to this phenomenon.

DATA SOURCES

PubMed, MEDLINE, and Embase were searched using the following key words: rectal cancer, local excision, radiotherapy, and neoadjuvant.

STUDY SELECTION

Studies that assessed local excision of rectal cancer after neoadjuvant chemoradiotherapy were included. Duplicate series were excluded from final analysis.

INTERVENTION

All of the data points were tabulated and analyzed using Microsoft Excel.

MAIN OUTCOME MEASURES

Criteria for patient selection, surgical technique, clinical restaging, pathologic assessment, and indications for completion surgery were analyzed.

RESULTS

After exclusions, data from 25 studies that in total evaluated local excision in 1001 patients were included. Compared with the single accepted technique of total mesorectal excision, described techniques for local excision after neoadjuvant therapy demonstrate significant variability in many critical technical issues, such as marking/tattooing original tumor margins before neoadjuvant therapy, using pretreatment tumor size/stage as exclusion criteria, and specifically stating lateral excision margins. Where detailed, the majority of local recurrences occurred in patients with clear pathological margins, yet significant variation existed for pathological assessment and reporting, with few studies detailing R status and some not reporting margin status at all. Significant variability also existed for adverse tumor features that mandated completion surgery, and, importantly, many series describe patients refusing completion surgery where indicated.

LIMITATIONS

We were unable to perform meta-analysis because studies lacked sufficient methodologic homogeneity to synthesize.

CONCLUSIONS

The observations from this study prompt additional study, standardization of technique, and cautious use of local excision of rectal cancer in the setting of neoadjuvant chemoradiotherapy.

Comparison of trans-anal endoscopic operation and trans-anal excision of rectal tumors

Background

Trans-anal endoscopic operation (TEO) has developed to facilitate proper tumor location and ensure excision safely.

Methods

We reviewed 92 patients enrolled in our database between 2006 and 2014 who were diagnosed with early rectal tumors and who underwent conventional trans-anal excision (TAE) or TEO. Clinical data were collected prospectively to compare safety and feasibility between two techniques.

Results

Ninety-two patients underwent trans-anal local excision for lower rectal tumors. TEO and TAE were performed in 48 and 44 patients, respectively. Age, sex, and comorbidities were similar. There was no significant difference in tumor diameter (1.6 ± 1.68 cm vs. 1.17 ± 1.17, respectively). Tumor height, however, was higher in the TEO (7.46 ± 3 cm) than the TAE group (3.84 ± 1.88 cm, p < 0.001). Four complications, perianal abscess, and two perforations, occurred in the TEO group, whereas no major complications occurred in the TAE. Seven patients (14.6%) underwent TEO underwent a salvage operation compared to only a single patient in TAE group (2.3%, p = 0.039). Eight patients (17.4%) diagnosed with adenocarcinoma developed recurrence, four in each group. Disease-free survival was similar between groups (TEO – 41.8 months, 95% RI 39.4–44.1; TAE 79.7 months, 95% RI 72.2–87.3). However, more TAE patients (n = 7, 15.9%) than TEO patients (n = 2, 4.2%) underwent chemotherapy.

Conclusions

TEO treatment of local rectal tumors is safe and feasible and can achieve an adequate resection margin. Local recurrence was similar in both groups. However, the numbers of salvage operations and minor complications were higher in the TEO group.

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TEO is treatment modality of choice in addressing lower rectal lesions.

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Evolving of TEO technique facilitate higher standard of academic teaching.

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TEO has few drawbacks; first, long term learning curve; second, technique is demanding (through single port + narrow space).

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TEO has promising results in the field of surgical oncology with equivalent results to conventional surgery.

Transanal endoscopic microsurgery for rectal cancer

Since its introduction in the 1980s, total mesorectal excision (TME) has been the standard surgical technique for treating rectal cancer. This procedure involves removing the rectum and the surrounding envelope of fat along the plane of the mesorectal fascia. Resecting this embryological unit reduces the local recurrence rate by removing all local lymph nodes, including those with occult metastatic disease; however, this surgery is associated with mortality and morbidity. Complications include incontinence for patients given an anastomosis, long-term stoma formation, and sexual and bladder dysfunction. Local excision of rectal cancer using the transanal endoscopic microsurgery (TEM) technique is associated with fewer complications, and therefore, is used as an alternative in specific circumstances. We outline the technique, its indications, imaging appearances and complications.