Lokale Nachexzision nach endoskopischer R1/R2-Polypektomie von pT1-„low-risk”- Karzinomen des Rektums durch transanale endoskopische Mikrochirurgie (TEM)

Abstract

The transanal endoscopic microsurgery (TEM) is an adequate method for the local full-thickness excision of large rectum polyps and pT1 "low-risk" rectal carcinomas. We studied prospectively the relevance of this surgical technique concerning complete tumour excision after R1/R2-polypectomy of malignant rectal polyps. 16 patients with pT1 "low-risk" rectal carcinoma and macroscopic (R2) or microscopic (R1) incomplete endoscopic polypectomy were locally resected by TEM. In 12 patients (75 %) no residual tumour was found. In the remaining four cases (25 %), one adenoma with high-grade atypia, two pT1 "low-risk" carcinomas and one tumour infiltration in the mesorectal fat were diagnosed. The patient with the mesorectal infiltration was immediately operated on with radical resection. No further tumour cells were found in this specimen. The median follow-up was 21 months. One patient with a pT1 "low-risk" carcinoma developed a local recurrence and a single hepatic metastasis in the left liver lobe after TEM. Both were completely resected. Currently, all patients are living without evidence of tumour recurrence. Transanal endoscopic microsurgery is a suitable method for the treatment of pT1 "low-risk" rectal carcinomas after incomplete endoscopic polypectomy. In cases of a "high-risk" tumour or deeper tumour infiltration (pT> 1) after TEM radical resection must be carried out.

The Role of Transanal Endoscopic Surgery for Early Rectal Cancer

“…Overall, TES serves as a valuable diagnostic tool following incomplete polypectomy of unsuspected malignant pT1 polyps. Across various studies, TEM is reported to identify residual adenomatous and/or adenocarcinoma in up to 14.8 to 70% 20 21 22 23 of cases. When full-thickness TEM excision is performed for a residual pT1 tumor deemed low risk for nodal metastasis based on histologic review and/or staging with endoscopic ultrasound and/or pelvic MRI, TEM achieves good local control with acceptable local recurrence rates (see later section).…”

“…In such event, additional attempt at curative local excision using full-thickness TAE or TES may be considered, if no high-risk histopathological features are identified that warrant an oncologic resection. 20 21 22 23 However, if ESD was performed for an unsuspected malignant polyp, R0 resection might have been achieved if the focus of invasion was limited to the upper submucosal layer. If pathology review of the specimen determines that deep and lateral margins are conclusively negative, and if no adverse risk factors are identified to indicate a high risk of lymph node metastasis, ESD can, in some cases, achieve curative resection of superficial T1 rectal tumors.…”

R1-Resektion im Bereich des unteren Gastrointestinaltrakts

“…Bei R1-Resektion, unklaren Resektionsgrenzen (Rx), einem Resektionsrand <1 mm oder High-risk-Histologie war die Lokalrezidivrate signifikant höher (39%) als bei adäquater Resektion und Low-risk-Konstellation (6%). Dementsprechend sollte bei R1-Histologie oder ungenügendem Resektionsabstand eine radikale Nachresektion erfolgen [37].…”

Adjuvant chemoradiotherapy versus radical surgery after transanal endoscopic microsurgery for intermediate pathological risk early rectal cancer: A single-center experience with long-term surveillance

“…Transanal endoscopic microsurgery (TEM), which was invented by Dr. Buess in 1983, was put into constant use for the treatment of rectal carcinoma over years of practice [8][9][10]. The full-thickness resection makes it an advisable approach for low-risk early rectal cancer, according to several guidelines [9,[11][12][13][14]. Despite of the advantages, the de ciency of resecting lymph nodes in TEM resection remains highly controversial.…”