Endorectal Ultrasound (ERUS): an Accurate and Invaluable Tool for Identifying Suitable Candidates for Transanal Excision/Transanal Endoscopic Microsurgery (TAE/TEM) in Early-Staged Rectal Tumors

Journal of Gastrointestinal Surgery https://doi.org/10.1007/s11605-023-05868-6 RESEARCH COMMUNICATION Endorectal Ultrasound (ERUS): an Accurate and Invaluable Tool for Identifying Suitable Candidates for Transanal Excision/Transanal Endoscopic Microsurgery (TAE/TEM) in Early‑Staged Rectal Tumors Charlotte Campbell1 · Jason Conway1 · Laura Elizabeth Lavette1 · Darius Jahann1 · Gregory Waters1 · Jean Ashburn1 · Girish Mishra1 Received: 9 June 2023 / Accepted: 10 October 2023 © The Author(s) 2023 Keywords Endorectal ultrasound · Staging · Transanal excision/transanal endoscopic microsurgery Colorectal cancer is the third-most common cancer diagnosed in the USA.1 Surgical resection of disease remains the mainstay of curative therapy. Efforts to improve morbidity have focused on minimally invasive procedures such as transanal excision (TAE) and transanal endoscopic microsurgery (TEM) for early-stage lesions. Differentiating early-stage lesions that can be resected with minimally invasive techniques from locally advanced cancers that require radical resection (with its inherent morbidity and mortality) is critical.2,3 We hypothesized that endorectal ultrasound (ERUS) can accurately discriminate early versus advanced neoplastic lesions, especially in low-lying rectal tumors that can achieve R0 resection via TAE/TEM. This study was approved by our institutional review and ethics board. * Girish Mishra Charlotte Campbell Jason Conway Laura Elizabeth Lavette Darius Jahann Gregory Waters Jean Ashburn 1 Atrium Health Wake Forest Baptist Medical Center, Medical Center Blvd, Winston‑Salem, NC 27157, USA We extracted data on all patients undergoing ERUS between January 2011 and December 2020. All staging ERUS were performed using the Olympus GF-UE 160-AL5 radial echoendoscope. Patients with adenomatous polyps, carcinoma in situ, or adenocarcinoma on pathology were included; other patients with benign pathology, surveillance ERUS, or non-carcinomatous malignancy were excluded (see Fig. 1). In total, 371 patients with qualifying criteria were identified (median age = 64; range = 19-96) with the average lesion size 3.76 cm [0.3–15.0 cm]. Postoperative pathology was available on 175 patients of the 264 patients who were found to undergo surgical procedures. Test characteristics for ERUS are presented in Table 1 and include the following: Agreement = 0.90; Sensitivity = 0.96; Specificity = 0.84; PPV = 0.88; NPV = 0.94, with no differences based on gender, age (<65 vs 65+) or lesion size (<3.0 cm vs 3+ cm). In our study, over 98% of patients staged T0/Tis were <T2. Furthermore, no patients undergoing an APR had T0/ Tis disease. Very early studies performed by Hildebrandt and colleagues similarly showed that the most significant impact of endosonography was that the proportion of abdominoperineal excisions dropped from 46 to 15% over a 5-year period.4 We report phenomenal success using ERUS in determining which patients should undergo a TAE/TEM procedure (PPV and NPV = 0.97 and 0.95 respectively). Our study has several limitations including the following: (1) it was a single-center trial performed at a tertiary referral center with endoscopists highly specialized in performing ERUS and (2) most patients in this study did not have MR data to create additional conclusions about direct comparisons of the tools’ efficacies. Our study primarily looked at the overstaging and understaging of mucosal- vs submucosal-based lesions and does 13 Vol.:(0123456789) Journal of Gastrointestinal Surgery Table 1  Test characteristics of ERUS Overall Gender Female Male Age <65 65+ Lesion size <3 cm 3+ cm Procedure TAE/TEM LAR APR N Sensitivity Specificity PPV NPV 175 0.96 0.84 0.88 0.94 73 102 0.97 0.95 0.86 0.82 0.88 0.87 0.97 0.92 87 88 0.98 0.93 0.76 0.89 0.87 0.89 0.96 0.93 62 87 0.94 0.95 0.92 0.82 0.94 0.83 0.92 0.95 92 60 21 0.90 0.98 1.0 0.98 0.50 0.0 0.97 0.89 0.71 0.95 0.86 -- Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. References Fig. 1  Schema for patient inclusion and exclusion criteria not address the complexities of distinguishing T1 and T2 lesions. We were highly proficient in not overstaging, as no patients underwent an APR based on our ERUS findings — this point alone is of great solace to our patients and management team so as to avoid the untoward challenges of a more morbid and invasive APR. Given its ability to identify early rectal cancer, we exhort our surgical colleagues to not abandon ERUS as it remains a wonderful, additive tool to MRI for properly identifying these lesions most amenable to minimally invasive surgery. Declarations Conflict of Interest The authors declare no competing interests. 13 1. Cronin KA, Lake AJ, Scott S, Sherman RL, Noone AM, Howlader N, Henley SJ, Anderson RN, Firth AU, Ma J, Kohler BA, Jemal A. Annual report to the nation on the status of cancer, part I: National cancer statistics. Cancer 2018;124(13)2785-2800. 2. Rawla P, Sunkara T, and Barsouk A. Epidemiology of colorectal cancer: incidence, mortality, survival, and risk factors. Prz Gastroenterology 2019; 14(2): 89-103. 3. Gagliardi G, Bayar S, Smith R, Salem RR. Preoperative Staging of Rectal Cancer Using Magnetic Resonance Imaging With External Phase-Arrayed Coils. Archives of Surgery 2002; 137(4): 447-451. 4. Hildebrandt U, Schüder G, Feifel G. Preoperative staging of rectal and colonic cancer. Endoscopy 1994; 26(9) 810-2. Publisher’s Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.  (...truncated)