Rectal adenocarcinoma and transanal endoscopic microsurgery. Diagnostic challenges, indications and short term results in 142 consecutive patients

Transanal endoscopic microsurgical submucosal dissection (TEM-ESD) for rectal adenomas: a retrospective cohort study of 145 consecutive cases

PURPOSE

Transanal endoscopic microsurgery (TEM) and endoscopic submucosal dissection (ESD) are currently the two most popular methods for resecting large rectal adenomas en bloc. However, damage to the mesorectum in the case of TEM, plus the technical challenges and long procedure times of flexible ESD, are major disadvantages of these procedures. Transanal endoscopic microsurgical submucosal dissection (TEM-ESD) is a new technique, combining the ergonomic features of TEM with the minimally invasive approach of ESD. The aim of our study was to assess the feasibility and safety of TEM-ESD for resection of large rectal adenomas.

METHODS

We retrospectively analyzed all TEM-ESD procedures performed in Karlsruhe Municipal Hospital between 2012 and 2019, isolated all cases of adenomas, and analyzed the perioperative and follow-up data of the patients.

RESULTS

We identified 145 cases matching our criteria. The median size of the lesions was 4.2 cm, and the median operating time was 45 min. The en bloc resection rate was 100%, and the complete en bloc resection rate was 78.6%. The overall morbidity rate was 6.9%. In a median follow-up period of 24 months, there was a local recurrence in 4.8% of the cases.

CONCLUSIONS

TEM-ESD is a safe and feasible therapeutic option for resecting large rectal adenomas, offering high en bloc resection and low recurrence rates combined with short operating time and low morbidity. TRIAL REGISTRATION NUMBER (CLINICALTRIALS.GOV): NCT04870931.

Transanal endoscopic microsurgical submucosal dissection (TEM-ESD): A novel approach to the local treatment of early rectal cancer

BACKGROUND

Complete local resection is currently the treatment of choice for low-risk early rectal cancer; however, the ideal resection technique for such tumours is still debated. Transanal endoscopic microsurgical submucosal dissection (TEM-ESD) is a new technique which combines the ergonomic advantages of transanal endoscopic microsurgery (TEM) with the minimally invasive approach of endoscopic submucosal dissection (ESD). The aim of our study was to assess the feasibility, safety, and long-term outcomes of TEM-ESD in treating early rectal cancer.

MATERIALS AND METHODS

We retrospectively analysed all cases of rectal adenocarcinomas treated with TEM-ESD in Karlsruhe Municipal Hospital between 2012 and 2019, as well as the perioperative and follow-up data of the patients.

RESULTS

We identified 40 cases (19 low-risk and 21 high-risk carcinomas) matching our criteria. The median size of the lesions was 3.8 cm and the median operating time 48.5 min. En bloc resection was possible in all cases, while histologically complete resection was confirmed in 18 of 19 low-risk tumours and in 30 out of all lesions. The resection was curative in 19 cases. No scarring of the mesorectum was reported during the completion of total mesorectal excision for high-risk tumours. There was only 1 case of local recurrence among patients treated with curative intent, with an overall survival rate of 100% and a disease-free survival rate of 96% at both 2 and 5 years for these patients.

CONCLUSION

TEM-ESD is a safe and feasible therapeutic option for resecting early rectal cancer, offering very good long-term outcomes.

Completion total mesorectal excision following transanal endoscopic microsurgery does not compromise outcomes in patients with rectal cancer

BACKGROUND

Transanal endoscopic microsurgery (TEM) represents a choice of treatment in patients with neoplastic lesions in the rectum. When TEM fails, completion total mesorectal excision (cTME) is often required. However, a concern is whether cTME increases the rate of abdominoperineal resections (APR) and is associated with higher risk of incomplete mesorectal fascia (MRF) resection. The aim of this study was to compare outcomes of cTME with primary TME (pTME) in patients with rectal cancer.

METHODS

This was a nationwide study on all patients with cTME from the Danish Colorectal Cancer Group database between 2005 and 2015. Patients with cTME were compared to patients with pTME after propensity score matching (matching ratio 1:2). Matching variables were age, gender, tumor distance from anal verge, American Society of Anesthesiologists (ASA) score and American Joint Committee on Cancer (AJCC) stage.

RESULTS

A total of 60 patients with cTME were compared with 120 patients with pTME. Patients with cTME experienced more intraoperative complications as compared to pTME patients (18.3% vs. 6.7%, p = 0.021). However, there was no difference in the rate of perforations at or near the tumor/previous TEM site (6.7% vs. 2.5%, p = 0.224), conversion to open surgery (p = 0.733) or 30-day morbidity (p = 0.86). On multivariate analysis, cTME was not a risk factor for APR (OR 2.49; 95% CI 0.95-6.56; p = 0.064) or incomplete MRF (OR 1.32; 95% CI 0.48-3.63; p = 0.596). There was no difference in the rate of local recurrence between cTME and pTME (5.2% vs. 4.3%, p = 0.1), distant metastases (6.8% vs. 6.8%, p = 1), or survival (p = 0.081). The mean follow-up time was 6 years.

CONCLUSION

In our study, the largest so far on the subject, we find no difference in postoperative short- or long-term outcomes between cTME and pTME.

Transanal endoscopic microsurgery for giant circumferential rectal adenomas

AIM

Transanal endoscopic microsurgery (TEM) was originally invented by Buess et al. (Chirurg, 1984, 55, 677-80) for the treatment of infraperitoneal rectal adenomas. Its indications have progressively expanded to include larger and more advanced lesions. The aim of the study was to report the results of TEM used for the treatment of circumferential rectal lesions.

METHOD

We retrospectively reviewed the medical records of 17 consecutive patients [median age 69 (32-89) years; nine men] who underwent TEM for a circumferential rectal lesion in our department between September 2010 and January 2015.

RESULTS

The median distance from the anal verge was 4 (3-11) cm, the median longitudinal extent was 7 (3-10) cm and the median surface area was 75 (40-255) cm(2) . An end-to-end anastomosis without proximal bowel mobilization was completed endoscopically in all cases. The median operating time was 120 (40-240) min. Persistent, endoscopically uncontrollable endoluminal bleeding in one patient was successfully treated with a second TEM procedure. One patient underwent preoperative radiotherapy for adenocarcinoma detected at the preoperative assessment. Surgical histology showed a pT3 cancer in one patient who refused further surgery, a pT2 cancer in two who subsequently underwent abdominoperineal resection, a pT1 cancer in four and a ypT0 in one patient. All are at present free of disease. No patients developed faecal incontinence or urinary or sexual dysfunction. Four patients required endoscopic balloon dilatation for stenosis.

CONCLUSION

Transanal endoscopic microsurgery is a feasible and safe technique for large circumferential lesions with a satisfactory outcome. Preoperative staging may be inaccurate.

Endorectal ultrasonography, strain elastography and MRI differentiation of rectal adenomas and adenocarcinomas

AIM

Strain elastography is a method for recording tissue hardness. Strain in different areas may be compared using strain ratio (SR). The aims of this study were to validate a previously proposed SR cut-off value of 1.25 for differentiating adenocarcinomas from adenomas and to compare the performance of endorectal ultrasonography (ERUS), strain elastography and MRI in the same patients.

METHOD

A prospective evaluation of 120 consecutive patients with rectal neoplasia, using a predetermined elastography strain ratio cut-off value, was performed to differentiate adenomas from adenocarcinomas. ERUS and MRI were performed according to standard routine at Haukeland University Hospital, defining T0 as adenomas and T1-T4 as adenocarcinomas. Subsequent histopathology was used as the reference standard.

RESULTS

Histopathological evaluation revealed 21 adenomas and 99 adenocarcinomas. Sensitivity, specificity and accuracy (with 95% CI) were as follows: ERUS: 0.96 (0.90-0.99), 0.62 (0.40-0.80) and 0.90 (0.83-0.94); elastography SR: 0.96 (0.90-0.99), 0.86 (0.66-0.96) and 0.94 (0.88-0.97); and MRI: 0.99 (0.94-1.00), 0.07 (0.00-0.31) and 0.87 (0.80-0.93).

CONCLUSION

This study confirms that the elastography SR assessment accurately differentiates sessile adenomas from adenocarcinomas. SR assessment has a superior ability to differentiate adenomas and adenocarcinomas when compared with ERUS and MRI. MRI examination seems unable to recognize adenomas and should be interpreted with care when early-stage rectal neoplasia is suspected.

Combined endorectal ultrasonography and strain elastography for the staging of early rectal cancer

AIM

Strain elastography is a novel approach to rectal tumour evaluation. The primary aim of this study was to correlate elastography to pT stages of rectal tumours and to assess the ability of the method to differentiate rectal adenomas (pT0) from early rectal cancer (pT1-2). Secondary aims were to compare elastography with endorectal ultrasonography (ERUS) and to propose a combined strain elastography and ERUS staging algorithm.

METHOD

In all, 120 consecutive patients with a suspected rectal tumour were examined in this staging study. Patients receiving surgery without neoadjuvant radiotherapy were included (n = 59). All patients were examined with ERUS and elastography. Treatment decisions were made by multidisciplinary team (MDT) assessment, without considering the strain elastography examination.

RESULTS

Histopathology identified 21 adenomas, 13 pT1, 9 pT2, 15 pT3 and one pT4. Mean elastography strain ratios were predictive of T stage (P = 0.01). Differentiation of adenomas from early rectal cancer (pT1-2) had sensitivity, specificity and accuracy of 0.82, 0.86 and 0.84 for elastography and 0.82, 0.62 and 0.72 for ERUS. A combined staging algorithm was developed to identify tumours eligible for local resection. Based on MDT evaluation 32% of tumours later identified as pT0 or pT1 were treated with total mesorectal excision, even though a local excision might have sufficed. Combined ERUS and elastography evaluation would have significantly reduced this number to 9% (P = 0.008).

CONCLUSION

Elastography may improve the staging of adenomas and early rectal cancer compared with ERUS alone. Combined ERUS and elastography assessment is likely to further improve the selection of patients for local resection.

[TEO: minimally invasive surgery of the rectum. A short review]

The equipment and technique of transanal endoscopic microsurgery was developed by Buess in the early 80s. The technique was more refined, and the indication was widened since then. Excellent oncological results can be achieved with good patient selection with this less invasive technique and the complication rate is very low in contrast to conventional techniques. Nowadays the transanal endoscopic microsurgery is the "gold standard" in the treatment of benign lesions and low risk T1 cancer of the rectum.

Does the incidence of unexpected malignancy in 'benign' rectal neoplasms undergoing trans-anal endoscopic microsurgery vary according to lesion morphology?

AIM

Mucosectomy by trans-anal endoscopic microsurgery (TEMS) allows safe and effective excision of benign rectal lesions. Preoperative endoscopic, clinical and ultrasonographic assessment aims to select benign lesions whilst avoiding inappropriate mucosectomy in lesions with malignancy. This study examines the relationship between lesion morphology and accurate benign preoperative classification of rectal lesions undergoing TEMS.

METHOD

Primary lesions preoperatively assessed as benign were identified from a prospective TEMS database. Operative specimen morphology was independently classified by two blinded investigators, using photographs, into flat-sessile, exophytic or mixed morphology. The accuracy of the preoperative assessment by rectal ultrasonography was compared with the results of histological examination of the excised specimen (χ(2) and Fisher's exact tests).

RESULTS

Of 167 lesions with adequate data, the morphological classification showed 60 flat-sessile, 56 mixed morphology and 51 exophytic tumours, of which 5, 7 and 9, respectively, contained unexpected malignancy (P=0.48). Accurate preoperative assessment of a lesion as benign occurred in 89% of flat-sessile and mixed morphology (n=55 and 49, respectively) and in 70% of exophytic lesions (n=36) (P=0.01). Only the exophytic group contained patients in whom preoperative endoscopic and ultrasonographic staging could not be confidently made (uTx). Histology demonstrated six of the seven uTx cases to be benign.

CONCLUSION

In this study exophytic polyps were less likely to be accurately classified as benign using preoperative ultrasonography/endoscopy when compared with flat-sessile or mixed morphology polyps.

Transanal endoscopic microsurgery for rectal tumors: a review

Since its introduction in 1983, transanal endoscopic microsurgery (TEM) has emerged as a safe and effective method to treat rectal lesions including benign tumors, early rectal cancer, and rectal fistulas and strictures. This minimally invasive technique offers the advantages of superior visualization of the lesion and greater access to proximal lesions with lower margin positivity and specimen fragmentation and lower long-term recurrence rates over traditional transanal excision. In addition, over two decades of scientific data support the use of TEM as a viable alternative to radical excision of the rectum with less morbidity, faster recovery, and greater potential cost savings when performed at specialized centers.

Endorectal elastography in the evaluation of rectal tumours

AIM

Real-time elastography visualizes tissue compliance using an ultrasound platform. Elastography has been used, particularly in the breast, to characterize indeterminate lesions on B-mode imaging as either benign or malignant. The primary aim of this study was to assess the feasibility of routine endorectal elastography to evaluate rectal neoplasia. The secondary aim was to correlate elastography data with histopathological end-points.

METHOD

Sixty-nine patients referred to the outpatient clinic of the Department of Colorectal Surgery at Haukeland University Hospital for the evaluation of rectal tumours were included in this prospective cohort study. All patients underwent digital rectal examination, rigid rectoscopy with biopsy, endorectal ultrasonography and endorectal elastography. In each case a strain ratio was calculated, comparing the tumour tissue with adjacent reference tissue that appeared normal on ultrasound scanning.

RESULTS

Histopathologically there were 23 adenomas and 45 adenocarcinomas. One patient died before surgical treatment. Adequate elastography images were obtained in 66/69 (96%) patients. Optimal discrimination of malignant and benign lesions was obtained using a strain ratio cut-off value of 1.25 (sensitivity, 0.93; specificity, 0.96; and accuracy, 0.94).

CONCLUSION

Endorectal elastography can be performed as an integral part of the clinical evaluation of rectal tumours and has good patient compliance. The method is a promising modality for the discrimination between adenocarcinoma and adenoma of the rectum.

Benign rectal strictures managed with transanal resection--a novel application for transanal endoscopic microsurgery

OBJECTIVE

Six cases of management of rectal strictures by transanal endoscopic microsurgery (TEM) are described.

METHOD

Patients are placed in the lithotomy - Trendelenburg position and the stricture is resected from 4-8 o'clock through the entire thickness of the fibrosis. The upper resection edge is mobilized including all layers of the rectal wall and the defect is sutured along the circumference.

RESULTS

Satisfactory anatomical and functional long-term results were obtained in 5 of 6 patients.

CONCLUSION

TEM resection of benign strictures is feasible in some patients and should be tested in a randomized study against known procedures.

Staging anal cancer: prospective comparison of transanal endoscopic ultrasound and magnetic resonance imaging

PURPOSE

The staging of anal cancer is extremely important for therapy and prognosis. Transanal endoscopic ultrasound and magnetic resonance imaging are routinely applied. The aim of this prospective comparative study is to evaluate whether tumor staging is concordant between these techniques.

METHODS

Forty-five anal cancer patients underwent endoscopic ultrasound and magnetic resonance imaging. Histological confirmation was obtained in all patients. The two test methods were compared with the kappa concordance index and sensitivity for the initial method of tumor detection was calculated. For six patients who were operated upon because of tumor progression, the results were evaluated against the histological tumor stage.

RESULTS

High concordance was found in the assessment of tumor size and nodal status (kappa index 0.63 and 0.77). Cancer patients were correctly identified with 100% sensitivity (45/45) by endoscopic ultrasound and with 88.9% (40/45) sensitivity by magnetic resonance imaging. In the six operated patients, T stage was correctly assessed in four of six patients by endoscopic ultrasound and in three of six patients by magnetic resonance imaging.

CONCLUSION

The results of endoscopic ultrasound strongly coincide with those of magnetic resonance imaging. Endoscopic ultrasound may be superior to magnetic resonance imaging for detection of small superficial tumors. However, magnetic resonance imaging is needed for N staging.

Preoperative staging and treatment options in T1 rectal adenocarcinoma

BACKGROUND

Major rectal resection for T1 rectal cancer offers more than 95% cancer specific five-year survival to patients surviving the first 30 days after surgery. A significant further improvement by development of the surgical technique may not be possible. Improvements in the total survival rate have to come from a more differentiated treatment modality, taking patient and procedure related risk factors into account. Subgroups of patients have operative mortality risks of 10% or more. Operative complications and long-term side effects after rectum resection are frequent and often severe.

RESULTS

Local treatment of T1 cancers combined with close follow-up, early salvage surgery or later radical resection of local recurrences or with chemo-radiation may lead to fewer severe complications and comparable, or even better, long-term survival. Accurate preoperative staging and careful selection of patients for local or non-operative treatment are mandatory. As preoperative staging, at present, is not sufficiently accurate, strategies for completion, salvage or rescue surgery is important, and must be accepted by the patient before local treatment for cure is initiated.

RECOMMENDATIONS

It is recommended that polyps with low-risk T1 cancers should be treated with endoscopic snare resection in case of Haggitt's stage 1 or 2. TEM is recommended if resection margins are uncertain after snare resection for Haggitt's stage 3 and 4, and for sessile and flat, low-risk T1 cancers. Average risk patients with high-risk T1 cancers should be offered rectum resection, but old and comorbid patients with high-risk T1 cancers should be treated individually according to objective criteria as age, physical performance as well as patient's preference. All patients treated for cure with local resection or non-surgical methods should be followed closely.

Transanal endoscopic microsurgery in 143 consecutive patients with rectal adenocarcinoma: results from a Danish multicenter study

OBJECTIVE

The long-term results are presented on total survival, cancer-specific survival and recurrence in 143 consecutive patients treated with transanal endoscopic microsurgery (TEM) for adenocarcinoma of the rectum.

METHOD

Four Danish centres established in 1995 a database for registration of all TEM procedures. Data were supplemented from pathology reports and death certificates were checked in the Danish patient registry. Data were analysed with multivariance regression and survival analysis.

RESULTS

The T stage was as follows: T1 50%, T2 33%, T3 14%, and stage unknown 3%. TEM was performed with curative intent in 43%, for compromise in 52% and for palliation in 5%. Five-year total survival was 66% and 5-year cancer-specific survival 87%. Cancer-specific survival for T1 was 94%. The significant predictors for total survival were age and tumour size. For cancer-specific survival T stage, radical resection, tumour size and recurrence were significant predictors. Eighteen per cent had recurrence and 15% had immediate reoperation.

CONCLUSION

The TEM provides good long-term results for pT1 cancers. In old patients and patients with co-morbidity TEM may provide acceptable long-term results for T2 cancers. Tumours larger than 3 cm should not be treated with TEM for cure.