The middle rectal artery detected by contrast-enhanced magnetic resonance imaging predicts lateral lymph node metastasis in lower rectal cancer

Yosuke Iwasa,Hiroyuki Kuge,Kimihiko Kichikawa,Satoshi Yamauchi,Satoshi Nishiwada,Tomomi Sadamitsu,Nagaaki Marugami,Masayuki Sho,Takeshi Takei,Takayuki Nakamoto,Fumikazu Koyama,Shinsaku Obara

doi:10.1007/s00384-021-03887-w

Yosuke Iwasa, Hiroyuki Kuge + Show 10 more

Open Access

https://doi.org/10.1007/s00384-021-03887-w

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Abstract

PurposeLateral lymph node (LLN) metastasis is one of the leading causes of local recurrence in patients with lower rectal cancer. Unfortunately, no diagnostic biomarkers are currently available that can predict LLN metastasis preoperatively. Accordingly, we investigated the relationship between the middle rectal artery (MRA) identified by contrast-enhanced magnetic resonance imaging (ceMRI) and LLN metastases.MethodsData from 102 patients with lower rectal cancer who underwent surgery, and were evaluated by preoperative ceMRI, between 2008 and 2016 were reviewed retrospectively. Two expert radiologists evaluated the MRA findings. The diagnostic performance of MRA for LLN metastasis was evaluated by a multivariate analysis with conventional clinicopathological factors.ResultsThe MRA was detected in 67 patients (65.7%), including 32 (31.4%) with bilateral MRA and 35 (34.3%) with unilateral MRA. The tumor size, presence of the MRA, and clinical LLN status were significantly correlated with LLN metastasis. A multivariate analysis demonstrated that the presence of MRA (P = 0.045) and clinical LLN status (P = 0.001) were independent predictive factors for LLN metastasis. Furthermore, the sensitivity and negative predictive value of MRA for LLN metastasis were 95% and 97.1%, respectively.ConclusionWe successfully demonstrated that MRAs could be clearly detected by ceMRI, and the presence of MRA robustly predicted LLN metastasis in patients with lower rectal cancer, highlighting its clinical significance in the selection of more appropriate treatment strategies.Trial registrationTrial registration number: retrospectively registered 2126Trial registration date of registration: August 23, 2019

Highlights

Local recurrence of rectal cancer remains an important clinical problem associated with poor survival, severe morbidity, andInt J Colorectal Dis (2021) 36:1677–1684 decision-making for reducing unnecessarily excessive treatment for Lateral lymph node (LLN) in patients with lower rectal cancer.the pre-treatment diagnosis of the presence of LLN metastasis remains clinically challenging
The identification of enlarged LLNs evaluated on computed tomography (CT) and/or magnetic resonance imaging (MRI) is reportedly a risk factor for LLN metastasis [14,15,16]; the clinical LLN status as diagnosed by preoperative radiological modalities has not been established
In the present exploratory study, for the first time, we investigated the frequency of the middle rectal artery (MRA) detected by contrastenhanced MRI and successfully confirmed the utility of MRI-detectable MRAs for the identification of LLN metastasis, highlighting the clinical significance of this biomarker for the management of patients with lower rectal cancer

Summary

Introduction

Local recurrence of rectal cancer remains an important clinical problem associated with poor survival, severe morbidity, andInt J Colorectal Dis (2021) 36:1677–1684 decision-making for reducing unnecessarily excessive treatment for LLNs in patients with lower rectal cancer.the pre-treatment diagnosis of the presence of LLN metastasis remains clinically challenging. Local recurrence of rectal cancer remains an important clinical problem associated with poor survival, severe morbidity, and. Int J Colorectal Dis (2021) 36:1677–1684 decision-making for reducing unnecessarily excessive treatment for LLNs in patients with lower rectal cancer. The pre-treatment diagnosis of the presence of LLN metastasis remains clinically challenging. The identification of enlarged LLNs evaluated on computed tomography (CT) and/or magnetic resonance imaging (MRI) is reportedly a risk factor for LLN metastasis [14,15,16]; the clinical LLN status as diagnosed by preoperative radiological modalities has not been established. LLN metastasis has been considered associated with lateral lymphatic drainage along the middle rectal artery (MRA) [17, 18]. The MRA has been described as an artery that penetrates the pelvic plexus from the lateral side along the lateral ligament. Cadaveric anatomical studies have shown the existence of other types of MRAs and a wide range of MRA detection rates, ranging from 12 to 97% [19,20,21,22,23,24,25]

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