Colorectal endoscopic submucosal dissection up-to-date

Abstract

Colorectal endoscopic submucosal dissection (ESD) has emerged as a pivotal organ-preserving strategy for the management of superficial colorectal neoplasms. This review summarizes the current evidence on colorectal ESD, highlighting its indications, technical principles, clinical outcomes, limitations, and learning requirements. Careful preoperative lesion characterization using high-definition endoscopy combined with virtual chromoendoscopy and magnification, is essential for estimating invasion depth and selecting the appropriate candidate. Colorectal ESD is especially indicated for lesions requiring en bloc resection to enable precise histopathological assessment. Compared with endoscopic mucosal resection, colorectal ESD provides substantially higher en bloc and complete resection rates with markedly lower local recurrence, thereby overcoming the limitations of piecemeal resection in large lesions. In eligible patients, colorectal ESD offers a minimally invasive alternative to laparoscopic surgery, with favorable efficacy, shorter procedure-related burden, and preservation of bowel anatomy. Nonetheless, colorectal ESD operations requires a high-level of expertise and technical difficulty is mostly influenced by lesion size, submucosal fibrosis, and proximal colonic location. In addition, colorectal ESD demands structured training, appropriate case selection, and progressive experience, with rectal lesions and low-fibrosis tumors representing the most suitable starting point for novice operators. Colorectal ESD represents a cornerstone of modern therapeutic endoscopy, offering oncologic precision, organ preservation, and durable outcomes, and continues to expand its role in the management of early colorectal neoplasia.

Key Words: Colorectal neoplasms; Endoscopic mucosal resection; Adenoma; Colonoscopy; Endoscopic submucosal dissection

Core Tip: Colorectal endoscopic submucosal dissection (ESD) is an established organ-preserving treatment for selected superficial colorectal neoplasms, particularly early colorectal cancer with suspected superficial submucosal invasion. International guidelines recognize ESD as the preferred technique when en bloc resection is required for accurate histopathological evaluation and curative treatment. Compared with endoscopic mucosal resection, ESD achieves higher en bloc and complete resection rates, improving assessment of invasion depth and resection margins. In appropriately selected lesions, colorectal ESD provides favorable long-term oncologic outcomes comparable to surgery while preserving the native organ through a minimally invasive approach.

INTRODUCTION

Colorectal cancer (CRC) is the second leading cause of cancer-related death worldwide, according to the World Health Organization[1]. Therefore, adopting and disseminating new strategies for its early detection through the implementation of CRC screening programs in the population older than 45 years, associated with the increasing adoption of innovative image-enhanced endoscopy (IEE) techniques, has enabled the detection of early-stage neoplasms more frequently. In addition, the development of advanced endoscopic resection (ER) techniques, such as endoscopic submucosal dissection (ESD) has permitted a minimally invasive and organ-sparing approach to superficial colorectal neoplasms regardless of its size.

This review discusses the recent advances and current status of colorectal ESD to manage colorectal superficial neoplasms, based on updated scientific evidence[2-5].

ROLE OF IMAGE-ENHANCED ENDOSCOPY IN THE CHARACTERIZATION OF COLORECTAL LESIONS

A comprehensive endoscopic assessment of the target lesion is essential to determine the best resection strategy, such as endoscopic mucosal resection (EMR), ESD, or surgical resection. This evaluation should begin with meticulous analysis of the lesion with high-definition white-light endoscopy, observing certain features such as size, presence of depression, mucosal irregularity, fold convergence, irregular borders, and friability. Afterwards, the lesion should be closely inspected with IEE technologies that are useful to characterize the degree of tumor invasion and the eligibility for ER. Endoscopic ultrasound is also an alternative for evaluating carcinomatous invasion into deeper layers, particularly in rectal lesions; however, it has not demonstrated superiority compared to IEE assessment and it has more limited availability[6-8].

Two classifications based on virtual chromoendoscopy and magnification have demonstrated clinical utility to characterize the colorectal lesions: Narrow band imaging (NBI) international colorectal endoscopic and Japan NBI Expert Team. These classifications are based on the analysis of surface pattern (crypts) and vascular components, identifying findings suggestive of carcinoma transformation within the colorectal lesions, as well as the degree of submucosal (SM) invasion[8,9].

INDICATIONS FOR COLORECTAL ESD

The majority of colorectal neoplasms can be successfully eradicated using low- to moderate-complexity resection techniques (polypectomy, standard EMR, and underwater EMR). ESD is best indicated for certain specific clinical scenarios[2-4], as outlined in Table 1 with the recommendations for colorectal ESD according to guidelines from the Japan Gastroenterological Endoscopy Society (JGES)[2]. Laterally spreading tumors (LSTs) are flat neoplasms with a lateral extension greater than 10 mm, and are divided into two main subtypes: Granular and non-granular. The granular type with nodule may contain carcinoma foci and SM invasion. The non-granular LST also present a higher risk of SM invasion. Thus, in these cases, ESD should be the preferred strategy in order to obtain an en bloc, complete, and potentially curative resection[10-15]. Furthermore, subsequent studies have reinforced the role of ESD as the preferred treatment modality for selected colorectal lesions with features suggestive of deep neoplastic involvement or a higher likelihood of incomplete resection by conventional techniques[16-18]. Figure 1 shows a flowchart of the different LST subtypes and their corresponding recommended management. Figure 2 presents an illustrative case of granular type LST with nodule.

Figure 1 Flowchart about Japan NBI Expert Team subtypes and the correlation with the histological findings and management. CT: Computed tomography; EMR: Endoscopic mucosal resection; ESD: Endoscopic submucosal dissection; JNET: Japan NBI Expert Team; PET: Positron emission tomography.

Figure 2 Representative case of colorectal endoscopic submucosal dissection. A: Flat-elevated laterally spreading tumor in the rectum with a nodule in white-light imaging; B: Virtual chomoendoscopy assessment (Blue light imaging); C: Magnifying view assessing the nodule at the center of the lesion revealing enlarged crypts and slightly dilated and tortuous microvessels; D: Markings were placed with diathermic knife surrounding the lesion; E: Mucosal incision is performed in the anal side of the lesion; F: Pocket-creation method is initiated from anal side to oral side of the lesion; G: Pocket-creation method is advanced. Note that the dissection plane is at the deep submucosal layer, close to the muscularis propria layer; H: Perforating vessels should be identified, isolated and then coagulated with the knife or hemostatic forceps before transection; I: After endoscopic submucosal dissection is finished the defect should be closely inspected for blood vessel coagulation and closure of any muscularis propria layer damage with endoclips; J: The specimen should be fixed for histological assessment; K: The specimen measured 47.2 mm.

Table 1 Indications for colorectal endoscopic submucosal dissection.

Indications for colorectal ESD
Non-granular LST (Especially: Pseudo depressed LST)
Large and protruded lesions suspicious for carcinoma transformation
Large depressed neoplasms
Neoplasms with high suspicion of superficial submucosal invasion (Sm1) (but particularly rectal)
Neoplasms with type VI crypt pattern
Intramucosal tumors with high submucosal fibrosis component
Sporadic Tumors in chronic inflammatory bowel disease: Ulcerative colitis
Residual/recurrent lesions after endoscopic resection for carcinoma

ESD: Endoscopic submucosal dissection; LST: Laterally spreading tumor; Sm1: Superficial submucosa.

COLORECTAL ESD PROCEDURE STEPS

Colorectal ESD procedure consists of five mains steps: (1) Marking of the lesion with diathermy; (2) Submucosal injection; (3) Mucosal incision; (4) Submucosal dissection; and (5) Hemostasis of blood vessels.

Step 1

Marking of the lesion borders during colorectal ESD is optional because usually the tumor borders are clearly visualized during the procedure (Figure 2D). Nevertheless, the operator always need to take into account an adequate margin of 5-10 mm outside the tumor border during the mucosa incision.

Step 2

Creation of the SM cushion is one of the most important steps during the ESD procedure because optimal elevation of the lesion will reduce the risk of perforation and it will facilitate the dissection of the SM layer. The main international clinical guidelines establish viscous solutions as the substances of choice for this purpose, with hyaluronic acid (MucoUp, Japan) being the most recommended at least in Eastern countries like Japan, where this solution is more widely available[19-23]. Recently, the off-label use of 0.4% sodium hyaluronate in its ophthalmic drops presentation has been proposed as a less costly and readily available alternative to MucoUp for the creation of the SM cushion, showing optimal efficacy-safety profiles[24,25]. Other solutions frequently used for SM injection are: Hydroxypropyl methylcellulose, manitol, hydroxyethyl starch (Voluven^®), glycerol-based solutions (glycerol 10%, fructose 5%, and normal saline solution), carboxymethylcellulose solutions, sodium lactate solutions (Geloplasma^®), fibrinogen solutions[2-5].

Step 3

Mucosal incision is performed using the endoscopic knife after SM injection. A shallow mucosal incision using Endocut current followed by SM trimming is the best approach to avoid vessel transection and excessive bleeding during the mucosal incision (Figure 2E).

Step 4

Dissection of the SM layer can be performed using different methods such as the pocket-creation method (Figure 2F), C-shaped dissection, or complete circumferential dissection[24-26]. The dissection in the pocket-creation method should be conducted at the deep SM layer, close to the muscularis propria (MP) layer (Figure 2G). Another important aspect during the SM dissection phase is the traction mechanism of the flap generated during the procedure. Optimal traction during ESD adequately exposes SM fibers and blood vessels, thereby reducing procedure time and preventing adverse events. This acquires greater clinical relevance in large colorectal lesions over 30 mm in size. In the early period of colorectal ESD, this traction mechanism was performed using only the effects of gravity; however, devices have recently been specifically designed for this purpose, showing significant benefits in terms of reducing procedure time and shortening the learning curve[27-29]. A study evaluating the effect of traction devices on the learning curve of colorectal ESD divided trainees into two groups: A traction device group (202 cases) and a control group without traction devices (114 cases). The number of cases required to master the colorectal ESD technique was 10 cases in the traction group and 21 cases in the control group. Dissection speed was 19.5 mm²/minute in the traction group and 15.9 mm²/minute in the control group. En bloc and complete resection rates in the traction group were 100% and 96%, respectively. In the control group, en bloc resection was 90% and complete resection was 83%[30]. This study indicated that traction devices might be advantageous particularly for novice operators. Currently, there are several methods of traction available that could be divided into two groups: External traction (Clip-and-line, Clip-and-snare, External forceps, Endotrac, Tracmotion, Endolifter) and internal traction (double-clip traction, ProdiGI traction wire, magnet-assisted traction)[3,4].

Step 5

Coagulation of blood vessels and control of the perforating vessels (Figure 2H) are a fundamental component during the ESD procedure, because the vessel inadvertent rupture could prolong the procedure time, obscure the visibility of the SM layer and increase the incidence of adverse events. The instruments used to sealing the blood vessels depend on its caliber: Larger diameters (hemostatic forceps) and smaller diameters (endoscopic knife). In addition, after the ESD procedure is finished the resection be should be closely inspected and protruding vessels coagulates, and any damage to MP layer approximated with endoclips (Figure 2I).

The need for antibiotic prophylaxis in colorectal ESD is controversial. Some studies have demonstrated that the antibiotic prophylaxis reduced the systemic inflammatory markers (C-reactive protein, serum leukocytes) as well as clinical parameters (abdominal pain, fever). It also demonstrated a decrease in the incidence of post-ESD coagulation syndrome (PECS)[31-33]. A prospective randomized study included 100 patients that underwent colorectal ESD, who were divided into two groups: Group 1: With antibiotic prophylaxis and Group 2: Without antibiotic prophylaxis. The authors demonstrated higher levels of C-reactive protein (≥ 1 mg/dL) (P = 0.008) and abdominal pain (using a score measured the morning after ESD) (P = 0.023) in Group 2 compared with Group 1. In addition, a higher incidence of PECS was observed in Group 2 (8/50) compared to Group 1 (1/50) (P = 0.031)[34]. Taken together, the available evidence suggests a potential benefit of antibiotic prophylaxis in mitigating post-ESD inflammatory events, although the overall strength of the evidence remains limited[35,36].

FACTORS THAT INCREASE THE LEVEL OF DIFFICULTY IN COLORECTAL ESD

It is very important to identify, prior to performing colorectal ESD, the factors that could increase the degree of difficulty, in order to plan in detail the procedure and to avoid complications. The main factors that increase difficulty during colorectal ESD are: Lesion size, degree of SM fibrosis, and lesion location. Fibrosis in the SM layer is the issue that most frequently increases the degree of difficulty and procedure time during colorectal ESD. This occurs more frequently in previously manipulated lesions alike recurrent tumors or after failed/incomplete resections. In addition SM deep invasion, endoscopic tattooing and multiple biopsy attempts are predisposing factors for SM fibrosis[19,20].

Regarding location, lesions located in the proximal colon (cecum, ascending colon, transverse colon) usually have a higher degree of difficulty compared to lesions located in the distal colon (descending colon, sigmoid colon, and rectum). This is because proximal neoplasms location might be associated with reduced maneuverability and a thinner intestinal wall, which is more susceptible to perforation or thermal injury[20,21].

Although colorectal ESD achieves high rates of en bloc and curative resection, several technically demanding scenarios including severe SM fibrosis, residual or recurrent lesions after previous endoscopic therapy, and lesions located in the proximal colon continue to limit its broader implementation. These complex cases are frequently associated with prolonged procedure times, lower complete resection rates and an increased risk of adverse events, even in expert hands. Accordingly, current international guidelines recommend that such lesions be managed in high-volume centers with extensive expertise in advanced therapeutic endoscopy. In this context, traction-assisted ESD techniques have emerged as an important technical advancement by improving exposure of the SM plane and facilitating safer, more controlled dissection. Recent evidence suggests that traction devices may enhance procedural efficiency by reducing dissection time while also decreasing the risk of perforation and other procedure-related adverse events, particularly in fibrotic lesions and anatomically challenging colorectal locations[22,23].

CRITERIA FOR CURATIVE RESECTION

A curative resection is the ideally expected outcome upon completion of colorectal ESD; however, it is not always possible to achieve this objective due to two factors: (1) Endoscopist-dependent factors when generating fragmented and/or incomplete resection (R1 resection); and (2) Factors dependent on the oncologic status of the neoplasm. The specimen should always be fixed and measured by the operator (Figure 2J and K), in order to facilitate a proper histological assessment (Figure 3). Figure 4 demonstrates an algorithm of curability criteria in colorectal ESD and the management plan according to the risk of lymph node metastasis[4]. A non-curative ESD is defined when there is a substantial risk of lymph node metastasis, and for this cases additional non-endoscopic adjuvant therapy such as surgery and/or chemoradiotherapy should be considered[2,37,38]. It is important to recommend to all patients colonoscopy surveillance, in order to exclude any residual/recurrent lesion or the occurrence of metachronous tumors. In cases of fragmented ESD and piece-meal resection, colonoscopic follow-up should be carried out in the first 6 postoperative months. In contrast, after an en bloc, R0 and potentially curative resection the initial surveillance exam could be postponed to 1 year[39-41]. Figure 5 demonstrates the risk of SM invasion for each LST subtype.

Figure 3 Histopathological evaluation. A: Histological assessment revealed lateral and deep free margins; B: Histology revealed an intramucosal adenocarcinoma without lymph-vascular invasion, findings consistent with a potentially curative resection. (Courtesy, Dr. Bernardo F P Ricardo, Department of Pathology of Hospital Mater Dei Contorno).

Figure 4 Criteria for a curative and non-curative procedure. CT: Computed tomography; ESD: Endoscopic submucosal dissection; PET: Positron emission tomography.

Figure 5 Laterally spreading subtypes and the corresponding risk of submucosal invasion. ESD: Endoscopic submucosal dissection; LST: Laterally spreading tumor; LST-G: Granular laterally spreading tumor; LST-NG: Non-granular laterally spreading tumor.

COLORECTAL ESD VS EMR

EMR is an optimal therapeutic strategy when correctly indicated and properly performed. However, one of its greatest limitations is large lesions over 2 cm or 3 cm in size because most likely a piece-meal resection will be necessary. In such cases, histopathological analysis of the resected specimen may be less precise in determining SM invasion depth, as well as horizontal and vertical margins. Fragmented resections are also more strongly associated with local recurrence and residual lesions, which increase proportionately to the number of pieces obtained during ER. Thus, EMR is more efficiently indicated to colorectal lesions with a low suspicion for SM invasion, according to international guidelines[14].

Colorectal ESD overcomes the limitations of EMR by achieving high en bloc resection rates regardless of lesion size, allowing more precise and reliable histopathological assessment and demonstrating lower rates of local recurrence in the medium and long term. Different studies have shown that, in expert hands, adverse event rates are similar between colorectal EMR and ESD, despite the high technical complexity required for ESD[15]. A meta-analysis including 12 studies (3062 laterally spreading colorectal lesions: 1906 treated with EMR and 1156 treated with ESD) demonstrated an en bloc resection rate of 95% (1098/1156) for ESD and 42.8% (815/1906) for EMR (P < 0.00001). Complete resection rates were 93.2% (109/117) for ESD and 71.9% (92/128) for EMR (P < 0.00001). Delayed bleeding rates were 3.5% for ESD and 4.2% for EMR (P = 0.85), and perforation rates were 2.4% for ESD and 1.8% for EMR (P = 0.04). Local recurrence rates were 0.5% for ESD and 15.9% for EMR (P < 0.00001)[16]. These data indicates that colorectal ESD should be the strategy of choice in cases where en bloc resection is needed.

COLORECTAL ESD VS LAPAROSCOPIC SURGERY

Colorectal ESD has emerged as an alternative to surgery for early-stage colorectal carcinomas (intramucosal or with superficial SM invasion) over 2 cm in size, that ideally should be resected en bloc with free margins. ESD has demonstrated efficacy profiles similar to those obtained with surgical techniques in eligible patients, but with a lower rate of adverse events and with the benefit of organ preservation[10-12]. A retrospective study included 589 patients with stage T1 CRC, divided into two groups: 297 patients underwent ESD and 292 patients underwent laparoscopic surgery. The ESD group showed an en bloc resection rate of 87% and a curative resection rate of 80%, with adverse events consisting of 14 perforations (4.7%) and 5 cases of post-procedure bleeding (1.7%), most of which were successfully managed endoscopically. In the laparoscopic group, adverse events included 31 cases of surgical wound infection, 2 pelvic abscesses, 3 anastomotic leaks, and 1 anastomotic bleeding. Procedure time was 106 minutes and 206 minutes for the ESD and laparoscopic groups, respectively[13].

ADVERSE EVENTS ASSOCIATED WITH COLORECTAL ESD

Some endoscopists still hesitate to adopt colorectal ESD procedures in clinical practice due to the fear of adverse events. However, different studies have demonstrated that despite the high technical complexity of colorectal ESD, the incidence of adverse events is low in expert hands and after adequate training. The main adverse events described in colorectal ESD are: Bleeding, perforation, PECS and seldomly postoperative stricture after circumferential ESD. It is important to emphasize that the majority of adverse events occurring during colorectal ESD can be successfully managed exclusively by endoscopic means, and only a small percentage of patients with delayed perforation will ultimately require emergency surgery[42].

In the case of post-procedure bleeding, the management usually consist on hemostatic endoclips application. A strategy to reduce the incidence of delayed bleeding is the prophylactic closure of the resection site immediately after the procedure[43]. As regards to colorectal perforation, in most cases those are microperforations that can be immediately repaired with endoclips in addition to intravenous antibiotic coverage, fasting and postoperative clinical monitoring. In cases of large perforations, the management should be individualized and surgical intervention should be considered if secure endoscopic closure is not achieved.

PECS occurs as a consequence of thermal injury to the MP layer, which induces inflammation of the serosal layer. Early diagnosis of this clinical entity is important because PECS may evolve to delayed perforation if timely and appropriate management is not performed. Post-ESD colorectal stenosis is a rare adverse event secondary to the healing process resulting from circumferential ESDs involving > 90% of the colorectal circumference. To prevent this adverse event, one of the main strategies is to preserve at least 5%-10% of the mucosal layer, thereby inducing epithelial regeneration to originate from the mucosal layer and not from the MP. The most appropriate management in ESDs involving > 90% of the circumference is close colonoscopic follow-up to early detect the stenosis and start immediately the treatment with balloon dilation. Unlike post-ESD stenosis of the esophagus, there is currently no standardized scientific evidence supporting the use of corticosteroids in the prevention of this adverse event after colorectal ESD[44,45].

LEARNING CURVE IN COLORECTAL ESD

Endoscopists interested in embarking on colorectal ESD must follow the international guidelines in order to acquire the technique knowledge and skills[46]. Ideally the candidates must have extensive experience in ER and closure methods. Moreover, it is suggested that previous experience with gastric and esophageal ESD, in this order, be obtained before attempting colorectal ESD. Additionally, it is advisable to start from rectal lesions of medium size before advancing to proximal colon ESD.

The rectum has a more favorable anatomical configuration and thicker walls, with easier accessibility as compared to the proximal colon, which confers a higher degree of maneuverability to the endoscopist. In addition, it is recommended that novice endoscopists select carefully the initial cases: Size less than 30 mm, lesions with low suspicion of SM invasion (granular LST), rectal location, and absence of SM fibrosis[47-49]. The presence of a proctor for the initial cases is also strongly recommended. A retrospective study analyzing the learning curve in colorectal ESD included 420 patients, who were divided into two phases: Phase 1: From case 1 to case 20, Phase 2: From case 21 to the end. For Phase 1, en bloc, complete, and curative resection rates were 93% (278/300), 83% (250/300), and 80% (241/300), respectively. For Phase 2, they were 96% (122/127) (P = 0.19), 88% (112/127) (P = 0.20), and 82% (104/127) (P = 0.71), respectively. Regarding adverse events, in Phase 1: Perforation 3% (8/300); Delayed bleeding 1% (3/300). In Phase 2: Perforation 1% (1/127) (P = 0.17); Delayed bleeding 2% (3/127) (P = 0.27). The authors concluded that a novice endoscopist, under optimal conditions and dealing with lesions without risk factors that increases the technical difficulty, should perform at least 20 colorectal ESD to perform this procedure safely and efficiently[50].

FUTURE RESEARCH DIRECTIONS AND CLINICAL IMPLICATIONS

Despite the increasing global adoption of colorectal ESD, several important challenges remain and warrant further investigation. Current international guidelines from the JGES, European Society of Gastrointestinal Endoscopy, and American Society for Gastrointestinal Endoscopy consistently recognize colorectal ESD as the preferred strategy for selected superficial colorectal neoplasms requiring en bloc resection and accurate histopathological assessment[2,4]. However, further evidence is still needed to optimize patient selection, procedural standardization, and peri-procedural management in Western practice.

An important academic contribution of the present study is that it provides additional real-world evidence regarding contemporary colorectal ESD practice in an area where robust prospective evidence remains limited. In particular, although prophylactic antibiotic use has been explored in several studies, current international evidence remains insufficient to support its routine use during colorectal ESD, and major guidelines do not currently recommend universal antibiotic prophylaxis. Future prospective multicenter studies may help identify specific high-risk subgroups that could potentially benefit from individualized preventive strategies.

Another highly promising field for future research is the integration of artificial intelligence (AI) into the detection, characterization, and therapeutic planning of superficial colorectal neoplasms. Recent advances in computer-aided diagnosis, IEE, magnification endoscopy, and AI-assisted optical characterization systems may significantly improve the prediction of superficial SM invasion and help optimize the selection between EMR, ESD, and surgical treatment. This is particularly relevant because accurate lesion characterization remains one of the most critical factors for achieving curative and organ-preserving ER. Furthermore, future developments combining AI-assisted optical diagnosis with advanced resection techniques such as colorectal ESD may contribute to improving en bloc resection rates, reducing unnecessary surgery, and facilitating broader implementation of precision endoscopic oncology in Western centers. These technologies may also play an important role in shortening the learning curve of colorectal ESD and improving procedural standardization among less experienced operators[51,52].

From a clinical translation perspective, our findings may contribute to a more individualized and evidence-based approach to colorectal ESD, supporting safer and more effective implementation of advanced ER strategies. Additional large-scale international collaborative studies with standardized methodologies and long-term oncological follow-up will be essential to further refine global recommendations and optimize the future role of colorectal ESD in minimally invasive CRC management.

ETHICAL CONSIDERATIONS

This study was conducted as a narrative review and update of the current evidence regarding colorectal ESD, based exclusively on previously published scientific literature and international guidelines. No patients were prospectively or retrospectively enrolled for the development of this manuscript, and no identifiable patient data were collected or analyzed. Therefore, institutional ethics committee approval and informed consent were not required for this study.

SUMMARY BOX

Colorectal ESD is indicated when en bloc resection is required, particularly in cases of large lesions that cannot be resected en bloc by EMR, or when superficial cancer with limited SM invasion is suspected.

Colorectal ESD is effective but technically demanding, involving longer procedure times and a higher risk of adverse events than EMR; for this reason, international guidelines recommend careful case selection, advanced training, and performance at experienced centers.

The main advantage of ESD over EMR is en bloc resection regardless of the size of the lesion, as well as accurate histological evaluation, which allows for the assessment of lateral and deep margins, the degree of cellular differentiation, lymphovascular invasion, tumor budding, and depth of invasion. This determines whether the resection was curative or whether additional adjuvant treatment is required.

Most superficial colorectal neoplasms can be successfully treated with EMR, which remains the standard technique for most large benign colorectal lesions due to its high efficacy, lower complexity, and reduced procedural risk. However, major international guidelines emphasize that ESD should be reserved for precise and specific indications, particularly when en bloc resection is required for adequate histological evaluation and potential oncological cure, such as in lesions with suspected superficial SM invasion, pseudo depressed non-granular laterally spreading tumors, lesions with a high component of SM fibrosis, or recurrent neoplasms.

Currently, there is no solid scientific evidence to support the routine use of prophylactic antibiotics in colorectal ESD. Major international guidelines and reviews indicate that routine antibiotic prophylaxis after ESD is not recommended due to the limited quality of available evidence and the lack of consistent benefits demonstrated in prospective studies. Although some studies and meta-analyses have suggested a possible reduction in PECS, the results remain heterogeneous and have not altered current international recommendations. Therefore, the use of antibiotics should be individualized based on specific clinical factors and should not be applied universally.

CONCLUSION

This article reviewed the updated scientific evidence regarding colorectal ESD, demonstrating the significant benefits of this procedure in the management of superficial colorectal neoplasms, as well as disseminating new strategies and innovative alternatives to optimize the execution of colorectal ESD. In addition, we aimed to encourage novice endoscopists interested in initiating responsibly a personal experience in colorectal ESD in daily clinical practice.

ACKNOWLEDGEMENTS

The authors sincerely thank Dr. Bernardo F P Ricardo, Department of Pathology of Hospital Mater Dei Contorno, for providing the histopathological images used in this study and for his valuable support in the histological documentation of the analyzed specimens. These images were specifically supplied for the purposes of the present research and have not been previously published or disseminated elsewhere. Their inclusion in this manuscript was authorized exclusively for this study.