Efficacy and safety of endoscopic transcecal appendectomy: a systematic review and meta-analysis

Introduction

Appendiceal orifice polyps are rare, typically found incidentally during surgery or autopsy, with a prevalence of 0.08% (1). Increased colon cancer screening has led to more frequent identification of appendiceal and/or cecal lesions involving the appendiceal orifice (2). Additionally, diverticular disease of the appendix (DDA) represents a related, albeit rare, appendiceal pathology that warrants recognition, as it is associated with complicated disease and an elevated risk of concomitant neoplasm (3). Surgical approaches including right hemicolectomy or partial cecectomy have historically been the standard for appendiceal orifice lesions not amenable to endoscopic resection, though these carry significant morbidity and may be excessive for benign pathology (4,5).

The advancement of endoscopic instruments enabled novel techniques such as endoscopic mucosal resection (EMR), endoscopic submucosal resection (ESR) and endoscopic full thickness resection (EFTR) to be the standard for treatment of colorectal lesions such as polyps, laterally spreading tumors (LSTs), and submucosal lesions (SMLs) (6,7). Recent evidence continues to refine advanced endoscopic resection strategies for colorectal tumors, supporting the ongoing expansion of minimally invasive endotherapy (8). However, complete resection of appendiceal orifice lesions by these techniques is fundamentally limited by three anatomical constraints: inability to visualize the distal resection margin once a lesion extends into the appendiceal lumen, insufficient traction and countertraction within the narrow orifice, and the risk of thermal injury or mechanical trauma precipitating post-procedural appendicitis (5,9). In such cases, surgical resection is often required (10). Surgery, including right hemicolectomy and partial cecectomy, carries a relatively high risk of post-operative complications and is considered excessive for benign lesions (10,11). In 2018, Liu et al. described the first full-thickness resection of appendiceal orifice lesions and simultaneous appendiceal dissection later known as endoscopic transcecal appendectomy (ETA) (12). Compared to standard endoscopic resection techniques, ETA allows complete resection of appendiceal lesions, regardless of appendiceal orifice extension and decreases the likelihood of post-operative appendicitis (4). ETA carries several potential advantages when compared to surgery including direct visualization of the appendiceal orifice, shorter recovery, absence of abdominal incision and an alternative to non-surgical candidates (5,13). The limitations of ETA include longer procedure time and hospital length of stay. It is also not appropriate for complicated appendicitis (e.g., gangrene, abscess or perforation) or malignant lesions where lymphadenectomy is needed (5).

In this study, we conducted a systematic review and meta-analysis to review the efficacy and safety of ETA for the management of appendiceal lesions. We present this article in accordance with the PRISMA reporting checklist (available at https://tgh.amegroups.com/article/view/10.21037/tgh-2026-0003/rc) (14).

Methods

Search strategy and data extraction

This systematic review and meta-analysis was not registered in PROSPERO. A comprehensive literature search was conducted across Embase, Scopus, Web of Science, MEDLINE/PubMed, and Cochrane databases from inception to June 1st, 2025. Boolean operators were used to combine terms related to the intervention and target population. The following search strategy was used (appendectomy OR Appendicectomy OR Appendectomies OR “appendix removal” OR “excision of appendix” OR “removal of the appendix” OR “extirpation of the appendix”) AND (transcolonic OR Transcecal OR Endoluminal OR Intraluminal OR Translumenal OR “Flexible Endoscopic”).

The search strategy aimed to identify studies evaluating outcomes in terms of efficacy and safety of ETA. Two independent reviewers performed the literature screening and data extraction using a standardized form. Disagreements were resolved by consensus or through consultation with a third reviewer. Extracted data included study characteristics, patient demographics, intervention details and comparators, and reported outcomes (15,16).

Inclusion criteria and study outcomes

Studies were eligible if they involve adult patients with appendiceal orifice lesions managed with ETA. Eligible study designs included randomized controlled trials (RCTs) and observational studies. Exclusion criteria were non-English language publications without adequate translation, conference abstracts without full text, case reports, systematic reviews, editorials, letters, animal studies, or studies not involving human subjects. No RCTs were identified; all included studies were retrospective case series.

The primary outcome was the efficacy of ETA in achieving technical success and en-bloc resection. Secondary outcomes included recurrence rate, bleeding events, the mean hospital stay, and adverse events.

Risk of bias assessment

Two reviewers independently assessed the risk of bias. The Joanna Briggs Institute (JBI) Critical Appraisal Checklist for Case Series was applied. Any disagreements were resolved through discussion or with a third reviewer. Given the procedural nature of the interventions, blinding of participants and investigators was not feasible, which was considered during risk of bias assessment (17).

Statistical analysis

Meta-analysis was conducted using R (version 4.3.0) and RStudio (2023.03.0) with the metafor, and meta packages. Due to expected heterogeneity across study populations and designs, a random-effects model was applied. The overall effect size estimated from the combination of the retrieved studies included in the meta-analysis was presented as a point estimate with corresponding 95% CIs. Statistical significance was set at P<0.05. Heterogeneity was assessed using the I² statistic, with values above 50% indicating substantial heterogeneity per the Cochrane Handbook (18). For outcomes with zero events (e.g., bleeding, recurrence), a continuity correction of 0.5 was applied. Confidence intervals (CIs) for individual proportions were calculated using the Clopper-Pearson exact method, and pooled estimates were generated using a random-effects model with logit transformation.

Outcome definitions

The following outcomes were defined prior to data extraction: Technical success was defined as achieving complete removal of the appendix along with the associated appendiceal orifice lesion, En bloc resection was defined as complete removal in one continuous specimen, without fragmentation, Recurrence was defined as the reappearance of neoplastic tissue at the site of ETA during follow-up endoscopic evaluation, perforation was considered present when there was a full-thickness defect of the cecal wall noted during the procedure

Results

A total of 555 records were initially identified; 256 duplicates were removed, leaving 299 for title and abstract screening, among which 12 were selected for full text review. Following the application of inclusion and exclusion criteria, and removal of duplicates, 3 retrospective studies (4-6) were eligible for the meta-analysis (Figure 1).

Figure 1 PRISMA 2020 flow diagram of study selection showing 555 records identified, 299 screened, 12 assessed for eligibility, and 3 studies included in the review.

All three studies demonstrated an overall low risk of bias according to JBI criteria. All studies reported inclusion criteria, demographic and clinical data, outcomes, and used valid diagnostic methods. Guo and Keihanian’s studies were single center studies which were performed by a single operator, raising concerns about generalizability. Wang et al.’s multicenter design improved external validity; however, inclusion of patients was not confirmed. All studies used appropriate statistical methods for descriptive reporting. A visual comparison of the risk of bias assessment across studies is presented in Figure 2.

Figure 2 Risk of bias (JBI) assessment for ETA case series studies, showing overall low risk across included studies. ETA, endoscopic transcecal appendectomy; JBI, Joanna Briggs Institute.

A total of 45 patients were included. The mean age was 61.8±14.22 years. Females constituted 53.3% of the included patients. The mean lesion size is 21.6±10.54 mm. Tubular adenoma was the most common pathology, with 12 adenomas (Table 1).

Two studies reported technical success rate of 100% (95% CI: 92–100%). No heterogeneity was noticed between the studies (I²=0%, τ²=0, P>0.99).

The en bloc resection was reported by two studies with success rate of 97% (95% CI: 90–100%). No heterogeneity was noticed between the studies (I²=0%, P=0.59) (Figure 3A).

Figure 3 Forest plots of pooled outcomes for ETA: (A) en bloc resection showing high success rates, (B) hospital stay with a pooled mean of ~7 days, (C) perforation with a low incidence (~3%), and (D) bleeding with no reported events across included studies. CI, confidence interval; ETA, endoscopic transcecal appendectomy.

Recurrence rates, reported in two studies, showed recurrence rate of 0.0% (95% CI: 0.0–5.0%) with no heterogeneity between studies (I²=0%, P>0.99).

The pooled mean hospital stay was 7.27 days (95% CI: 2.94–11.60). The heterogeneity across studies was (I²=95.8%, P<0.001), indicating variation in reported durations (Figure 3B).

The average procedure duration was 123.30 minutes (95% CI: 82.37–164.24) (I²=91.6%, P<0.001).

Perforation was observed in 2 of 45 patients. The pooled perforation rate was 3.0% (95% CI: 0.0%–9.0%), with no heterogeneity observed (I²=0%, P=0.48) (Figure 3C).

No bleeding events were observed with bleeding rate of 0.0% (95% CI: 0.0%–5.0%), and no heterogeneity detected (I²=0%, P>0.99) (Figure 3D).

Safety outcomes analysis revealed that, surgical rescue occurred in 2/45 patients (4.4%), both due to delayed perforation requiring laparoscopic intervention (Wang et al.). One intra-abdominal abscess was reported (1/13, 7.7%) and was successfully managed with percutaneous drainage without surgical intervention (Guo et al.). Additionally, one case of loculated fluid collection was observed at 9 days post-procedure, resolving with oral antibiotics without readmission or need for surgical rescue (Keihanian et al.). No cases of stump appendicitis, delayed peritonitis, or hospital readmissions were reported.

Discussion

The systematic review evaluated the safety and efficacy of ETA for the management of appendiceal orifice lesions. Surgical approaches including right hemicolectomy or partial cecectomy have historically been the standard for appendiceal orifice lesions not amenable to endoscopic resection, though these carry significant morbidity and may be excessive for benign pathology (10,19). It is worth acknowledging, however, that the comparator landscape has evolved; many experienced centers now employ EFTR or hybrid endoscopic approaches as an intermediate step prior to formal surgical resection for complex appendiceal orifice lesions, though direct comparative data between ETA and these modalities remains limited and was not captured in the included studies. Compared with surgery, ETA enables direct endoscopic assessment of the lesion’s extent at the appendiceal orifice, potentially allowing greater preservation of the ileocecal valve and adjacent bowel. Additionally, ETA may be particularly advantageous in patients with prior abdominal surgeries due to improved intraluminal access and reduced risk of collateral injury (20).

No bleeding events were reported across all studies suggesting favorable safety profile of this technique. Hospital stays and procedure duration varied considerably, with operative times ranging from 91 to 161 minutes, which could be due to the differences in operator experience and technique. However, shorter average time of surgery could be achieved by the utilization of stabilization devices and application of different points of traction with rubber-band clips, resulting in faster and efficient dissection. Perforation was rare, and no cases of recurrence were documented, nevertheless these results should be interpreted with caution given the limited number of patients, limited follow up period and the predominance of benign lesions among included patients. The pooled technical success rate was 100%, with no procedural failures observed.

Several recommendations have been proposed by experts to minimize the risk of potential complications during the procedure. First one is to precisely identify the appendiceal artery to prevent its injury during mesoappendix removal. It is also advised to use stabilization device, as it provides stability for proper caecal dissection. The use of colonoscopy lens cleaning is also recommended during mesoappendix dissection as the high fat content leads to fogginess over the lens. Complete dissection through the mesoappendix and the removal of the tip of the appendix is crucial to prevent stump appendicitis. It is also advised to advance the scope to the peritoneal cavity to suction any residual fluid secondary to the cautery and manipulation to prevent delayed infection (4-6).

There is no consensus on when to start oral feeding after the procedure, Guo et al. [2021] recommended keeping the patient nil per os (NPO) for at least three days, while Keihanian et al. [2024] started liquid diet directly after the procedure with no noticeable complications leading to shortening hospital stay (4,6).

From a practical standpoint, several considerations are important for clinicians seeking to implement ETA. The procedure requires advanced endoscopic equipment including a high-definition therapeutic colonoscope, electrosurgical knives (hook knife or insulated-tip knife), an electrosurgical unit, hemostatic forceps, endoclips, endoloops, and a traction device such as a rubber-band clip or suture-line system to facilitate mesoappendix dissection (21). Given the procedure’s extended duration, averaging over two hours in the current pooled analysis, deep sedation or general anesthesia administered by an anesthesiologist is strongly recommended to ensure patient immobility and optimize endoscopist performance (20). Regarding the learning curve, ETA demands a high level of pre-existing endoscopic expertise; all operators in the included studies had performed a minimum of 400 colorectal ESD procedures prior to undertaking ETA (4-6). Drawing from the broader advanced endoscopy training literature, structured programs for analogous procedures recommend at least 20 supervised cases on animal or ex vivo models before human practice, followed by proctored live cases until competency benchmarks are achieved (20,22). Formal credentialing for ETA should adhere to institutional privileging frameworks, require demonstrated proficiency in colorectal ESD, and ideally involve structured proctorship given the absence of procedure-specific thresholds in the current literature (22). In terms of patient selection, ETA is most appropriate for patients with benign or premalignant appendiceal orifice lesions exceeding 2 cm, lesions completely obstructing the appendiceal orifice with indeterminate distal margins, or cases where standard EMR or EFTR have failed or are deemed inadequate (4,6,21). Conversely, ETA is contraindicated in the setting of complicated appendicitis, malignant lesions requiring lymphadenectomy, prior appendectomy, or patients who are poor surgical candidates if conversion is required (4,5,21).

This study has several strengths including that it is the first meta-analysis evaluating the ETA technique. It employed comprehensive search across multiple databases, low heterogeneity in the key outcomes and highlighted the clinical relevance as a novel minimally invasive technique. However, the study is limited by the small sample size of 45 patients, lack of control group and inclusion of only three retrospective studies which may limit the generalizability. Additionally, the short follow up period limited the ability to assess long-term complications or recurrence.

Conclusions

ETA is a promising technique, minimally invasive with a high success rate for managing appendiceal orifice lesions and possible favorable safety profile. However, the current evidence is limited as all included studies were retrospective. Future prospective studies should aim to: (I) standardize the procedural technique across centers to enable meaningful comparisons; (II) prospectively capture the learning curve with clearly defined competency thresholds and formal credentialing frameworks; (III) incorporate a minimum follow-up of at least 12 months to adequately assess recurrence and delayed complications including stump appendicitis; (IV) include patient-reported outcome measures; and (V) evaluate cost-effectiveness and length-of-stay as co-primary or secondary endpoints to inform institutional adoption decisions.

Acknowledgments

The abstract of this work was presented at the American College of Gastroenterology (ACG) Annual Scientific Meeting 2025, held at the Phoenix Convention Center, Phoenix, Arizona, USA, October 24–29, 2025.

Footnote

Reporting Checklist: The authors have completed the PRISMA reporting checklist. Available at https://tgh.amegroups.com/article/view/10.21037/tgh-2026-0003/rc

Peer Review File: Available at https://tgh.amegroups.com/article/view/10.21037/tgh-2026-0003/prf

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://tgh.amegroups.com/article/view/10.21037/tgh-2026-0003/coif). M.O. was a consultant for Olympus, Boston Scientific Corporation, Abbvie, ConMed, Neptune Medical, Creo Medical, Lumendi, and Apollo; and received research grants from Lucid Diagnostics, AbbVie, Nestle, ConMed, Olympus and Boston Scientific. The other authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Patel AP, Khalaf MA, Riojas-Barrett M, et al. Expanding endoscopic boundaries: Endoscopic resection of large appendiceal orifice polyps with endoscopic mucosal resection and endoscopic submucosal dissection. World J Gastrointest Endosc 2023;15:386-96. [Crossref] [PubMed]
2. Tang SJ, Wu R. Ilececum: A Comprehensive Review. Can J Gastroenterol Hepatol 2019;2019:1451835. [Crossref] [PubMed]
3. Chia ML, Chan SWY, Shelat VG. Diverticular Disease of the Appendix Is Associated with Complicated Appendicitis. GE Port J Gastroenterol 2021;28:236-42. [Crossref] [PubMed]
4. Keihanian T, Khalaf MA, Aloor FZ, et al. Transcecal endoscopic appendectomy for management of complex appendiceal polyps extending into the appendiceal orifice. Endosc Int Open 2024;12:E932-9. [Crossref] [PubMed]
5. Wang L, Li XQ, Qu YF, et al. Feasibility of a novel unassisted single-channel transcolonic endoscopic appendectomy for the treatment of appendiceal lesions (with video). Surg Endosc 2024;38:6146-55. [Crossref] [PubMed]
6. Guo L, Ye L, Feng Y, et al. Endoscopic transcecal appendectomy: a new endotherapy for appendiceal orifice lesions. Endoscopy 2022;54:585-90. [Crossref] [PubMed]
7. Tanaka S, Kashida H, Saito Y, et al. JGES guidelines for colorectal endoscopic submucosal dissection/endoscopic mucosal resection. Dig Endosc 2015;27:417-34. [Crossref] [PubMed]
8. Chen Y, Wu Z. The efficacy and safety of precutting-endoscopic mucosal resection for colorectal tumors: a systematic review and meta-analysis. Minim Invasive Ther Allied Technol 2025;34:177-86. [Crossref] [PubMed]
9. Fahmawi Y, Hanjar A, Ahmed Y, et al. Efficacy and Safety of Full-thickness Resection Device (FTRD) for Colorectal Lesions Endoscopic Full-thickness Resection: A Systematic Review and Meta-Analysis. J Clin Gastroenterol 2021;55:e27-36. [Crossref] [PubMed]
10. Kulaylat AS, Boltz MM, Moyer M, et al. Management of Large Cecal Polyps: When Can the Ileocecal Valve Be Spared? Dis Colon Rectum 2018;61:1089-95. [Crossref] [PubMed]
11. Young S, Sueda SK, Hotta M, et al. Surgical management of appendiceal mucinous neoplasm: Is appendectomy sufficient? J Surg Oncol 2020;122:1173-8. [Crossref] [PubMed]
12. Liu BR, Song JT, Liu ZH, et al. Endoscopic transcecal appendectomy: the first human case report. Gastrointest Endosc 2018;87:311-2. [Crossref] [PubMed]
13. Liu BR, Ullah S, Ye L, et al. Endoscopic transcecal appendectomy: a novel option for the treatment of appendiceal polyps. VideoGIE 2019;4:271-3. [Crossref] [PubMed]
14. Moher D, Liberati A, Tetzlaff J, et al. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. Int J Surg 2010;8:336-41. [Crossref] [PubMed]
15. Munn Z, Barker TH, Moola S, et al. Methodological quality of case series studies: an introduction to the JBI critical appraisal tool. JBI Evid Synth 2020;18:2127-33. [Crossref] [PubMed]
16. Wallace BC, Lajeunesse MJ, Dietz G, et al. OpenMEE: Intuitive, open-source software for meta-analysis in ecology and evolutionary biology. Methods Ecol Evol 2017;8:941-7.
17. Munn Z, Barker TH, Moola S, et al. Methodological quality of case series studies: an introduction to the JBI critical appraisal tool. JBI Evid Synth 2020;18:2127-33. [Crossref] [PubMed]
18. Cumpston M, Li T, Page MJ, et al. Updated guidance for trusted systematic reviews: a new edition of the Cochrane Handbook for Systematic Reviews of Interventions. Cochrane Database Syst Rev 2019;10:ED000142. [Crossref] [PubMed]
19. Kim HS, Kim HG, Yang SY, et al. Single-incision laparoscopic surgery compared to conventional laparoscopic surgery for appendiceal mucocele: a series of 116 patients. Surg Endosc 2022;36:244-51. [Crossref] [PubMed]
20. Pimentel-Nunes P, Dinis-Ribeiro M, Ponchon T, et al. Endoscopic submucosal dissection: European Society of Gastrointestinal Endoscopy (ESGE) Guideline. Endoscopy 2015;47:829-54. [Crossref] [PubMed]
21. Nduma BN, Mofor KA, Tatang J, et al. Endoscopic Transcecal Appendectomy (ETA): A Literature Review on Risks and Benefits. Cureus 2023;15:e40827. [Crossref] [PubMed]
22. Yang D, Wagh MS, Draganov PV. The status of training in new technologies in advanced endoscopy: from defining competence to credentialing and privileging. Gastrointest Endosc 2020;92:1016-25. [Crossref] [PubMed]