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Published on: February 12, 2022
Transrectal sentinel lymph node biopsy for early rectal cancer during transanal endoscopic microsurgery
Alberto Arezzo1, Simone Arolfo, Massimiliano Mistrangelo
1Department of Surgical Sciences, University of Torino , Torino , Italy.
Background:
Local excision of invasive cancer by transanal endoscopic microsurgery (TEM) entails the risk of lymphnode metastases that obliges to radical surgery. A determination of metastatic lymph-nodes would avoid major surgery in the vast majority of cases. We applied the concept of sentinel lymphnode (SLN) biopsy to suspected invasive rectal cancers treated by TEM.
Methods:
Indocyanine green (ICG) is injected in the submucosa underneath the lesion. The tumor is dissected full-thickness until the perirectal fat. A near infra-red (NIR) optic provides a map of mesorectal lymphatics, on which guide the perirectal fat is dissected and lymph-nodes are excised.
Results:
The technique was tested in three patients. In all cases the pathologist confirmed presence of lymphnodes in the excised tissue, no case showed metastasis. In all cases final pathology of the rectal neoplasm did not indicate radical surgery.
Conclusion:
In suspected invasive cancers, SLN mapping could be a useful technique to identify the first lymph node receiving drainage from the tumour, whose accurate pathological examination could predict the status of the remaining nodes and indicate further radical surgery. An ongoing study on a prospective case series will assess sensitivity and negative predictive value of SLN biopsy.
Insights
Sentinel lymphnode (SLN) biopsy using indocyanine green (ICG) can accurately identify metastatic lymph nodes in rectal cancer patients undergoing transanal endoscopic microsurgery (TEM). This technique helps avoid unnecessary radical surgery by confirming the absence of metastasis.
Area of Science:
- Surgical Oncology
- Gastroenterology
- Medical Imaging
Background:
- Transanal endoscopic microsurgery (TEM) for invasive rectal cancer carries a risk of lymph node metastasis, often necessitating radical surgery.
- Accurate detection of metastatic lymph nodes can help patients avoid extensive surgical procedures.
- Sentinel lymph node (SLN) biopsy is a technique explored to identify the primary lymph node drainage of a tumor.
Purpose of the Study:
- To apply the sentinel lymph node (SLN) biopsy concept to patients with suspected invasive rectal cancers treated with TEM.
- To evaluate the feasibility and effectiveness of SLN biopsy in guiding surgical decisions for rectal cancer.
Main Methods:
- Indocyanine green (ICG) dye was injected submucosally beneath the rectal lesion.
- The tumor was dissected full-thickness to the perirectal fat, followed by near-infrared (NIR) optic visualization.
- Mesorectal lymphatics were mapped, and lymph nodes were excised based on this guidance.
Main Results:
- The technique was successfully tested in three patients.
- Pathologists confirmed the presence of lymph nodes in all excised tissues.
- No instances of metastasis were detected in the sentinel lymph nodes, and final pathology did not mandate radical surgery for any patient.
Conclusions:
- SLN mapping in suspected invasive rectal cancers can identify the primary lymph node basin.
- Accurate pathological examination of SLN can predict the status of other lymph nodes, potentially avoiding radical surgery.
- An ongoing prospective study aims to determine the sensitivity and negative predictive value of SLN biopsy in this context.
