Transanal endoscopic microsurgery as optimal option in treatment of rare rectal lesions: A single centre experience

Comparing surgical and endoscopic resection approaches for colorectal neuroendocrine tumors within the diameter range of 10-20mm: an inverse probability weighting analysis based on the SEER database

Background

Currently, the primary treatment modalities for colorectal neuroendocrine tumors (CRNET) with a diameter between 10mm and 20mm are surgical resection (SR) and endoscopic resection (ER). However, it remains unclear which surgical approach yields the greatest survival benefit for patients.

Methods

This study included data from patients diagnosed with CRNET with tumor diameters ranging from 10mm to 20mm between the years 2004 and 2019, obtained from the Surveillance, Epidemiology, and End Results (SEER) database. Patients were categorized into ER and SR groups based on the respective surgical approaches. Inverse probability weighting (IPTW) was employed to mitigate selection bias. Kaplan-Meier analysis and log-rank tests were utilized to estimate overall survival (OS) and cancer-specific survival (CSS). Cox regression analysis (univariate and multivariate) was performed to evaluate potential factors influencing survival.

Results

A total of 292 CRNET patients were included in this study (ER group: 108 individuals, SR group: 184 individuals). Prior to IPTW adjustment, Kaplan-Meier analysis and Cox proportional hazard regression analysis demonstrated that the OS and CSS of the SR group were inferior to those of the ER group. However, after IPTW adjustment, no statistically significant differences in prognosis were observed between the two groups. Subgroup analyses revealed that patients with muscular invasion, positive lymph nodes, or distant metastasis derived greater survival benefits from SR. Significant differences in OS and CSS between the two groups were also observed across different age groups.

Conclusion

For patients with mucosal-limited lesions and without local lymph node or distant metastasis, ER is the preferred surgical approach. However, for patients with muscular invasion or positive lymph nodes/distant metastasis, SR offers a better prognosis. The choice of surgical approach should be based on the specific clinical characteristics of patients within different subgroups.

Rectal neuroendocrine tumors: Current advances in management, treatment, and surveillance

Rectal neuroendocrine neoplasms (r-NENs) are considered among the most frequent digestive NENs, together with small bowel NENs. Their incidence has increased over the past few years, and this is probably due to the widespread use of endoscopic screening for colorectal cancer and the advanced endoscopic procedures available nowadays. According to the current European Neuroendocrine Tumor Society (ENETS) guidelines, well-differentiated r-NENs smaller than 10 mm should be endoscopically removed in view of their low risk of local and distant invasion. R-NENs larger than 20 mm are candidates for surgical resection because of their high risk of distant spreading and the involvement of the muscularis propria. There is an area of uncertainty regarding tumors between 10 and 20 mm, in which the metastatic risk is intermediate and the endoscopic treatment can be challenging. Once removed, the indications for surveillance are scarce and poorly codified by international guidelines, therefore in this paper, a possible algorithm is proposed.

Unusual intra-rectal "laterally spreading tumour" in immunosuppressed patient with ulcerative colitis

Condyloma acuminatum (CA) is a manifestation of Human Papillomavirus (HPV) infection which usually occurs in genital and perianal regions. We report a 46-year-old man with an ulcerative proctitis diagnosed four years earlier, asymptomatic for a long time under azathioprine but without any follow-up for three years. A colonoscopy was performed prior to potential immunosuppressive treatment discontinuation and showed a circumferential "laterally spreading tumour" in the rectum. Surprisingly biopsies revealed a CA with a very focally high-grade intra-epithelial lesion. Azathioprine was stopped and a transanal surgical resection was performed. At guided anamnesis, patient confirmed to be a former active "men who have sex with men". No recurrence of proctitis occurred despite azathioprine discontinuation. A retrospective review of the histological sections suggests that it was, in fact, an intestinal spirochetosis misdiagnosed as inflammatory bowel disease. Involvement of the rectal mucosa by HPV is a rare condition and this may have been promoted by inappropriate immunosuppressive treatment.

Non-conventional applications for Transanal endoscopic microsurgery. A single centre experience and a systematic review of literature

BACKGROUND

Transanal endoscopic microsurgery (TEM) and Transanal endoscopic operation (TEO) have been initially described for local excision of rectal adenomas and selected cases of rectal carcinomas. In the past decade, however, several new indications raised, and others could raise in the future. The aim of this review was to evaluate, both in the literature and in our personal experience, the use of TEM and TEO for nonconventional applications, different from rectal tumors.

METHODS

We conducted a systematic review of published papers and we selected articles reporting patients who underwent endoscopic surgery for other medical reason than polyp cancer resection, with TEM or TEO. PubMed, MEDLINE, EMBASE and bibliographies of the selected studies were searched for articles in English published up to May 2020 to identify all relevant articles. We excluded articles reporting TEM and TEO used for classical indications. We finally report our experience of non-conventional use of TEO in 5 patients with different diseases.

RESULTS

The research revealed 800 papers and among them we selected 52 articles for a total of 697 patients. Of all patients, only 52 had intraoperative or postoperative complications, with only 10 patients requiring major surgery.

CONCLUSIONS

Our study suggest that TEM and TEO may be valid alternatives to traditional surgery in situations other than its classical indication. These findings can positively impact on the care of patients, who could benefit from less invasive surgical procedures associated with lower morbidity.

Diagnosis and Management of Rectal Neuroendocrine Tumors (NETs)

Rectal neuroendocrine tumors (NETs) are rare, with an incidence of 0.17%, but they represent 12% to 27% of all NETs and 20% of gastrointestinal NETs. Although rectal NETs are uncommon tumors, their incidence has increased over the past few years, and this is probably due to the improvement in detection rates made by advanced endoscopic procedures. The biological behavior of rectal NETs may be different: factors predicting the risk of metastases have been identified, such as size and grade of differentiation. The tendency for metastatic diffusion generally depends on the tumor size, muscular and lymphovascular infiltration, and histopathological differentiation. According to the current European Neuroendocrine Tumor Society (ENETS) guidelines, tumors that are smaller than 10 mm and well differentiated are thought to have a low risk of lymphovascular invasion, and they should be completely removed endoscopically. Rectal NETs larger than 20 mm have a higher risk of involvement of muscularis propria and high metastatic risk and are candidates for surgical resection. There is controversy over rectal NETs of intermediate size, 10–19 mm, where the metastatic risk is considered to be 10–15%: assessment of tumors endoscopically and by endoanal ultrasound should guide treatment in these cases towards endoscopic, transanal, or surgical resection.

Endoscopic full thickness resection vs. transanal endoscopic microsurgery for local treatment of rectal neuroendocrine tumors - a retrospective analysis

PURPOSE

Local treatment of small well-differentiated rectal neuroendocrine tumors (NETs) is recommended by current guidelines. However, although several endoscopic methods have been established, the highest R0 rate is achieved by transanal endoscopic microsurgery (TEM). Since a recently published study about endoscopic full thickness resection (eFTR) showed a R0 resection rate of 100%, the aim of this study was to evaluate both methods (eFTR vs. TEM).

METHODS

We retrospectively analyzed all patients with rectal NET treated either by TEM (1999-2018) or eFTR (2016-2019) in two tertiary centers (University Hospital Wuerzburg and Ulm). We analyzed clinical, procedural, and histopathological outcomes in both groups.

RESULTS

Twenty-eight patients with rectal NET received local treatment (TEM: 13; eFTR: 15). Most tumors were at stage T1a and grade G1 or G2 (in the TEM group two G3 NETs were staged T2 after neoadjuvant chemotherapy). In both groups, similar outcomes for en bloc resection rate, R0 resection rate, tumor size, or specimen size were found. No procedural adverse events were noted. Mean procedure time in the TEM group was 48.9 min and 19.2 min in the eFTR group.

CONCLUSION

eFTR is a convincing method for local treatment of small rectal NETs combining high safety and efficacy with short interventional time.

Transanal Endoscopic Microsurgery (TEM) for rectal GI stromal tumor

BACKGROUND

Transanal endoscopic microsurgery (TEM) is effective in treating adenomas and select early rectal cancers. Our objective is to evaluate TEM in treating early rectal GISTs.

METHODS

Patients were identified in a prospective database with pathology confirmed rectal GIST prior to TEM over 10 years. Demographic, pathologic, operative and follow-up data was analysed and presented with descriptive statistics.

RESULTS

7 cases of rectal GIST were treated with TEM with a follow-up time of 31 months (0-71). Median tumor distance from the anal verge was 4 cm (2.5-6) and median tumor size was 3 cm (2-5.7). Negative margins were achieved in 4/7 patients. Those with positive margins were treated with repeat TEM or imatinib. 1 patient had local recurrence successfully treated by TEM.

CONCLUSIONS

Overall, TEM is safe for locally excising GISTs. As rectal GISTs are rare, a multicenter registry may better elucidate outcomes with this treatment.

Digestive Neuroendocrine Neoplasms (NEN): French Intergroup clinical practice guidelines for diagnosis, treatment and follow-up (SNFGE, GTE, RENATEN, TENPATH, FFCD, GERCOR, UNICANCER, SFCD, SFED, SFRO, SFR)

INTRODUCTION

This document is a summary of the French Intergroup guidelines regarding the management of digestive neuroendocrine neoplasms (NEN) published in February 2020 (www.tncd.org).

METHODS

All French medical societies involved in the management of NEN took part in this work. Recommendations were graded into four categories (A, B, C or D), according to the level of evidence found in the literature until May 2019.

RESULTS

The management of NEN is challenging because of their heterogeneity and the increasing complexity of diagnostic and therapeutic procedures. Pathological analysis is required for their diagnostic and prognostic characterization, which mainly relies on differentiation, grade and stage. The two main emergency situations are functioning syndromes and poorly-differentiated carcinoma. Chromogranin A is the main biochemical marker of NET, although of limited clinical interest. Initial characterization relies on morphological and isotopic imaging. The treatment of localized NET relies on watchful follow-up and local or surgical resection depending on its supposed aggressiveness. Treatment options for metastatic disease include surgery, somatostatin analogues, chemotherapy, targeted therapies, organ-driven locoregional therapies and peptide-receptor radionuclide therapy. As specific predictive factors of treatment efficacy are yet to be identified and head-to-head comparisons have not or only rarely been performed, the therapeutic strategy currently depends on prognostic factors. Cumulative toxicity and the impact of treatment on quality of life must be considered since survival is relatively long in most patients with NET.

CONCLUSION

These guidelines are proposed to achieve the most beneficial therapeutic strategy in clinical practice as the therapeutic landscape of NEN is becoming ever more complex. These recommendations are permanently being reviewed.

Is Local Resection of Anal Canal Tumors Feasible with Transanal Endoscopic Surgery?

BACKGROUND

An important drawback of local surgery for lesions in the anal canal is the difficulty of achieving en bloc full-thickness resections. The aim of this study is to evaluate TEM/TEO in lesions of this type from the point of view of morbidity, mortality and the quality of the pathology specimen.

METHODS

This is an observational study with prospective data collection from June 2004 to July 2018. Two groups are defined: group A (rectal tumors with proximal margin between 0 and ≤4 cm from anal verge) and group B (distal margin > 4 cm from anal verge). A technical description is provided; resections and postoperative complications in both groups are compared.

RESULTS

During the study period, 757 patients underwent TEM/TEO. Finally, 692 patients were included, 192 patients in group A and 500 patients in group B. An en bloc surgical specimen was obtained in 176/192 patients (91.7%), although the defect was completely sutured in 132 (68.8%). In the comparative analysis, group A did not present significantly greater fragmentation of the resected piece [16/192 (8.3%) vs. 36/500 (7.2%), p = 0.630], although group A was associated with greater involvement of the surgical margin [28/192 (14.6%), 32/500 (6.4%), p = 0.001] and clinically relevant morbidity [16/192 (8.3%), 20/500 (4%), p = 0.034]. There was no mortality.

CONCLUSIONS

The use of TEM/TEO to remove lesions originating in the anal canal is feasible. But we have to take into account that there is an increase in complications, technical difficulties and affected margins resection.

Endoscopic, transanal, laparoscopic, and transabdominal management of rectal neuroendocrine tumors

Rectal neuroendocrine tumors (RNET) are rare tumors but their prevalence is constantly increasing due to a prolonged survival and rising incidence related to a growing number of colonoscopies and improved knowledge. Their main prognostic determinant is tumor stage. While most RNET are localized, their management should be tailored depending on the presence or absence of the factors predictive of lymph-node metastases including tumor size, endoscopic aspect, T stage, grade and lymphovascular invasion. Endoscopic ultrasonography is the most relevant technique for locoregional assessment. Low-risk RNET can be treated using advanced endoscopic resection techniques or transanal endoscopic microsurgery, in expert centers because they require technicity and experience. Conversely, radical surgery with lymphadenectomy should be proposed in the presence of any pejorative factor. The long-term evolution of RNET remains to be specified, and prospective studies should be conducted in order to determine the relevance of the current management strategies.

Transanal Endoscopic Microsurgery for Patients with Rare Rectal Tumors

BACKGROUND

Transanal endoscopic microsurgery (TEM) has been accepted worldwide for the treatment of local rectal lesions. Rare rectal tumors consist of several different types of malignant or benign tumors. Surgical management is considered to be the only curative option. The aim of this study is to investigate the role of TEM in the treatment of rare rectal tumors.

MATERIALS AND METHODS

A total of 147 patients with rare rectal tumors underwent TEM in our center from April 2006 to May 2017. Clinical data were collected and a retrospective accurate database was constructed. Demographic characteristics, operative details, tumor details, complications, and follow-up data were analyzed.

RESULTS

Seventy-eight patients were male. Mean tumor diameter was 1.2 ± 0.7 cm and mean distance from the anal verge was 6.6 ± 2.3 cm. Full-thickness and complete resection with negative margins was achieved in all patients. Complications occurred in 3 patients during surgery and in 20 patients after surgery. Histopathologic results were neuroendocrine tumors in 104 patients; gastrointestinal stromal tumors in 35; melanoma, lymphoma, and leiomyoma each in 2; lipoma, and squamous carcinoma each in 1. One hundred thirty-five patients were followed up for 49.3 ± 33.2 months. Two patients died, 1 had local recurrence and 1 had a rectovaginal fistula 1 month after surgery. No local recurrence or metastasis, or fecal incontinence was observed in the remaining patients.

CONCLUSION

TEM is an optimal treatment option for selected rare rectal tumors. The complication rate is low and the therapeutic effect is satisfactory.

Transanal endoscopic microsurgery for the treatment of uncommon rectal lesions

INTRODUCTION

Transanal endoscopic microsurgery (TEM) was developed as a less aggressive alternative treatment for rectal lesions (mainly adenomas and adenocarcinomas). However, its use for other rectal lesions has become more frequent, trying to reduce the morbidity associated with more invasive techniques. The aim of this study is to describe our experience in the use of TEM in other rectal lesions.

METHODS

Retrospective and descriptive study including patients operated with TEM (from June 2008 to December 2016) for the treatment of rectal lesions different from adenomas or adenocarcinomas.

RESULTS

Among the 138 patients treated by TEM in our department, 10 patients were operated on for rectal lesions other than adenomas or adenocarcinomas. Rectal lesions were 3neuroendocrine tumours, a neuroendocrine tumour metastasis, a rectal stenosis, a cloacogenic polyp, an endometrioma, a retrorrectal tumour, a presacral abscess and a lesion in the rectovaginal septum. Mean operative time was 72min and postoperative stay was 4.2 days. Only one patient needed a reoperation, due to rectal bleeding.

CONCLUSIONS

TEM could be a useful tool for the treatment of rectal lesions different from adenomas or adenocarcinomas, potentially decreasing the morbidity associated with more aggressive surgical techniques.