Introduction

Large non-pedunculated colorectal polyps (LNPCP) and laterally spreading tumours (LST) >10mm involving the appendix orifice (AO) are notoriously challenging to treat with endoscopic resection (ER). Few studies report outcomes of conventional ER to treat these lesions. The optimal therapy and expected outcomes remain unclear.

Aims & Methods

We report the outcome after EMR and ESD of lesions involving the AO from a large series of ER performed at a tertiary referral centre. Patients undergoing ER at a tertiary referral centre between January 2011 and September 2023 were included. Involvement of the AO was defined as any LNPCP or LST encroaching within 5mm of the orifice. These were classified as encroaching the AO, involving part of the circumference of the AO and involving the full circumference of the AO. Techniques and outcomes of ER of lesions involving the AO were compared with other colorectal locations.

Results

ER was performed for 1596 LNPCP and LSTs during the study period. 40 lesions involved the AO: 10 encroached within 5mm of the AO, 14 involved part of the circumference and 16 involved the full circumference. 25 (63%) were resected by EMR, 8 by ESD (20%) and 7 by Hybrid ESD (18%). Initial successful ER was similar for lesions involving the AO and other colonic LNPCP (95.0% versus 97.6%, p=0.27). Clinically significant perforation occurred in 3 patients with lesions involving the AO (2 with partial circumference involvement and 1 with complete circumference involvement) and was more frequent after ER of these lesions than others (7.5% versus 1.2%, p<0.001). 2 of these patients required surgery. The incidence of post procedure bleeding was similar (p=0.44). One patient developed appendicitis, more than 12 months after resection. Recurrent/residual adenoma at first surveillance was significantly more likely after ER of AO lesions than others (22.2% versus 4.8%, p<0.001). Significantly more patients with lesions involving the AO ultimately required surgery for any reason than patient with other colorectal lesions (12.5% versus 3.9%, p=0.02). This was significantly more likely for AO lesions involving the complete or partial circumference (18.8% versus 14.3% partial circumference involvement versus 0% encroaching AO versus 3.9% other locations, p=0.004).

Conclusion

These results demonstrate the challenging nature of ER for lesions involving the AO. Safe and effective ER without recurrence is achieved for many patients, including those with lesions involving the complete circumference, but significant complications, recurrence and surgery are more common with these lesions. Given there are relatively low risk minimal access surgical options to treat these lesions, these data will help inform detailed discussions with patients regarding the risks and benefits of ER (which differ from LNPCP elsewhere in the colon).

Introduction

Resection of large non-pedunculated colorectal polyps (LNPCP) located in the rectum varies by institution and region with some, particularly colorectal surgeons, favouring TEM and others endoscopic resection (ER). There is a paucity of data directly comparing these strategies and the procedure of choice remains under debate. Our unit is a tertiary referral centre for complex polyps and early colorectal cancer. All rectal LNPCP were treated by TEM until a change in practice from 2011 when the first-line therapeutic strategy for rectal LNPCP changed to ER.

Aims & Methods

We aimed to report the outcomes of TEM and ER of rectal LNPCP from a large tertiary cohort. Large (≥20mm) rectal adenomas resected by TEM or ER (2009 – 2023) were analysed. From 2009-2011 all rectal adenomas were treated by TEM, after which the primary resection strategy changed to ER. Outcomes were compared between techniques. Given the difference in resection strategy, a composite outcome of septic complications included clinically significant perforation for ER (early or delayed perforation requiring any form of unplanned medical or surgical treatment) and septic complications for TEM (peritonitis or pelvic/anorectal sepsis).

Results

704 rectal adenomas were resected by TEM (n=71), EMR (n=145) and ESD/Hybrid ESD (n=488) with a mean size of 45mm for TEM vs 55mm for ER (p<0.001). 100% of patients undergoing TEM required hospital admission vs 15% for ER (p<0.001), and 100% required general anaesthesia (GA) for TEM vs 26%% for ER (GA or propofol sedation, p<0.001). En bloc resection was achieved for 96% of ESD resections, 54% of TEMS, 28% of EMR and 14% of hybrid ESD (p<0.001). The incidence of complications were similar (9.9% for TEM versus 5.0% for ER, p=0.10). Recurrence occurred in 2.7% after ESD, 21.1% after EMR, 23.6% after Hybrid ESD and 36.4% after TEM (p<0.001). No patients undergoing ER or TEM required surgery as a result of a complication.

Conclusion

Despite significantly larger lesion sizes, ER in our institution provides far superior results for patients than TEM with relatively fewer patients requiring hospital admission and lower recurrence rates, especially with ESD. En bloc resection was more likely with ER as a result of the difficulty achieving en bloc resection for extremely large lesions with TEM, which can invariably be resected en bloc by ESD. These results have led to a policy of ER for all apparently benign rectal tumours regardless of size and, in recent years, ESD as the primary approach for all rectal lesions.

Introduction

Endoscopic submucosal dissection (ESD) is increasingly employed for colorectal endoscopic resection (ER) in specialist units around the world. Abundant Japanese series and more recent western series report the outcomes of ESD, invariably reporting en bloc resection and R0 resection rates as a quality reporting measure. Whilst en bloc resection is well established to result in very low levels of recurrent/residual adenoma, evidence for recommending R0 resection is lacking. Furthermore, determining R0 status is subject to variations in specimen processing and histopathological examination.

Aims & Methods

We aimed to determine the significance of histopathological R0 resection on residual/recurrent adenoma at 6 month surveillance. Patients with LNPCP treated by ESD with en bloc resection at a tertiary referral centre between September 2011 and September 2023 and who had completed the first surveillance at 6 months (SC1) were included. During surveillance the scar from ER was identified and examined with magnification chromoendoscopy and NBI/BLI. Only abnormal scars were biopsy sampled. The incidence of recurrent/residual adenoma at 6 months in patients who had confirmed histopathological R0 resection was compared with patients who did not have confirmed R0 resection.

Results

1400 LNPCP underwent an initial successful ER over the study period, 665 by ESD and 735 by EMR/pEMR. 796 LNPCP were resected en bloc and were included for analysis. Of these, Histopathological R0 resection was confirmed in 690 (86.9%). The mean lesion size was 44.5mm +/-25.6 mm (median 38.5mm, range 20mm-210mm). 518 patients had undergone SC1. Only 4 patients had residual/recurrent adenoma (0.77%). Only 1 patient who did not have confirmed R0 resection experienced recurrence and there was no association between confirmed R0 resection and recurrence (OR 0.41, 95% CI 0.04-4.02, p=0.41).

Conclusion

Histopathological R0 resection has no impact on outcome. In the colorectum, the margins of LNPCP are readily apparent and complete resection is straightforward to confirm during ESD. Therefore, if high quality ESD is performed by experienced practitioners, in many cases lack of confirmation of R0 resection is likely to be a result of the difficulties in histopathological interpretation of often very large specimens. Recurrent/residual adenoma rates at surveillance would be a better quality metric for ESD along with en bloc resection rate.

Introduction

Endoscopic resection (ER) techniques for treating large non-pedunculated colorectal polyps (LNPCP) have advanced significantly and the relevance of early studies reporting outcomes may diminish with time. EMR remains the predominant therapeutic option for LNPCP in western practice, but ESD is increasingly employed. Limited studies demonstrate safety and efficacy for highly selected patients, but no studies examine the practical introduction of ESD (which has a steep learning curve) as a standard component of ER strategies in real-world practice.

Aims & Methods

Patients with LNPCP treated by ER at a tertiary referral centre between January 2011 and September 2023 were included. ERs were divided into 2 time periods (Period 1: January 2011 – May 2018 and Period 2: June 2018 – September 2023). Resection technique and outcomes including en bloc resection, successful single-session resection and complications were compared for procedures between Period 1 and Period 2.

Results

1563 LNPCP were treated with ER over the study period. ER was successful in 1517 (97%). The mean lesion size was 46.9mm +/- 26.3mm (median 40mm, range 20mm–210mm). 774 LNPCP were resected using EMR/pEMR and 743 by ESD/Hybrid ESD. ESD was used to resect 476 (64%) LNPCP during Period 2 compared to 267 (34.7%) during Period 1 (p<0.001). Whilst introducing ESD into practice during Period 1, a combination of Hybrid ESD and ESD were used with an en bloc resection rate of 64%, but en bloc resection for ESD increased to 98% during Period 2 (p<0.001). 97% of rectal LNPCP were resected by ESD during period 2 compared to 62% during period 1 (p<0.001). 45% of colonic LNPCP were resected by ESD during period 2 compared to 17% during period 1 (p<0.001). Complications occurred less frequently in Period 2 compared to Period 1 (2.9% versus 5.1%, p=0.04) and there was no difference in the rate of clinically significant perforation (1.2% versus 1.0%, p=0.76) or post-procedure bleeding (1.5% versus 1.6%, p=0.89). Fewer patients were admitted to hospital during period 2 compared to period 1 (5.6% versus 14.8%). Training occurred more frequently in Period 2 with 258 (35%) ERs performed in part or completely by an endoscopy fellow compared to 126 (16%) in period 1. 105 (22%) ESDs were performed in part or completely by an endoscopy fellow during Period 2 compared to 30 (11%) during period 1.

Conclusion

These data demonstrate the evolving nature of endoscopic resection practice in modern advanced practice. Large volume ESD can safely be incorporated into standard practice with a near-exclusive policy of ESD to treat all rectal LNPCP and nearly half of colonic LNPCP resected by ESD. En bloc resection rates comparable to Japanese expert centres can be achieved with no effect on complications. Moreover, regular training in ESD can safely be introduce.

Disclosure

Nothing to disclose

Clinical Case Summary

Lesions involving the appendiceal orifice pose an endoscopic therapeutic challenge. The characteristics of the cecal wall and the complexity of exposing the appendiceal lumen make for demanding and often incomplete resections. While various techniques have been proposed, each has its limitations, including lesion size, technical difficulty, and increased risk of complications. We aim to introduce a new alternative: complete resection using a diathermic snare assisted by traction with rubber band and clip.

We present the case of a 62-year-old woman with a lesion in the cecum involving the appendiceal orifice. Previous histological examination revealed a tubular adenoma with low-grade dysplasia (LGD). Complete colonoscopy revealed a lesion with a Paris 0-IIa morphology, LST non-granular, measuring 18mm in diameter, located at the cecum and involving the appendiceal orifice. During examination with high-definition white light imaging and virtual chromoendoscopy using BLI, the lesion exhibited a Kudo IV crypt and JNET2A. Mucosectomy was performed piecemeal using the "underwater" technique. Residual lesion partially involved the appendiceal orifice, with the intra-appendicular lesion limits being indiscernible. Therefore, a novel approach involving traction and exteriorization of the appendicular mucosa was applied using a rubber band and TTS clip to achieve adequate exposure of the entire residual lesion. Subsequently, the lesion was completely resected using a diathermic snare. There were no complications. Histological examination confirmed the presence of a tubular adenoma with LGD.

Endoscopic resection of lesions involving the appendiceal orifice can be challenging. Traction methods have previously been described solely in the context of submucosal endoscopic dissection. We present an effective and safe alternative for adequately exposing the appendiceal lumen using a traction method, allowing for complete resection through endoscopic mucosal resection.

References

Justiniano CF, Ozgur I, Liska D, Valente MA, Steele SR, Gorgun E. The role of advanced endoscopy in appendiceal polyp management and outcomes. Surg Endosc. 2024 Apr;38(4):2267-2272. doi: 10.1007/s00464-024-10726-w.
Obri M, Ichkhanian Y, Brown P, Almajed MR, Nimri F, Taha A, Agha Y, Jesse M, Singla S, Piraka C, Zuchelli TE. Full-thickness resection device for management of lesions involving the appendiceal orifice: Systematic review and meta-analysis. Endosc Int Open. 2023 Oct 6;11(9):E899-E907. doi: 10.1055/a-2131-4891

Introduction

The safety and efficacy of endoscopic resection (ER) as a first-line treatment for large non-pedunculated colorectal polyps (LNPCP) is well established. Significant complications are infrequent. Risk factors for immediate perforation have been described although it is frequently amenable to endoscopic closure and rarely results in significant deleterious sequelae. Delayed perforation or sepsis is a rare complication with potentially devastating consequences. Emergent surgery may be necessary with its attendant major complications. Risk factors for delayed perforation/sepsis after ER of LNPCP are not well established.

Aims & Methods

We analysed a large series of advanced ER of LNPCP to identify factors associated with delayed perforation.
Consecutive patients with LNPCP treated by ER at a tertiary referral centre between September 2011 and September 2023 were included. Lesions were resected using EMR, piecemeal EMR and ESD. Univariate analysis was used to examine clinicopathological factors potentially associated with delayed perforation.

Results

1883 ER for LNPCP were performed over the study period with a mean size of 46.4mm +/- 26.4mm (median 40mm, range 20-210mm). ESD was used for 890. Delayed perforation or sepsis occurred in 24 (1.3%) patients of which 8 (0.4%) required emergent surgery and 1 required CT guided drainage of an abscess. 3 patients developed sepsis after ESD of rectal lesions without evidence of perforation on CT with luminal contrast and required intensive care unit (ICU) management. There was no mortality. In patients who suffered a delayed perforation or sepsis, 54% of LNPCP were in the right colon, 8% in the left colon and 38% in the rectum. Delayed perforation/sepsis was significantly associated with extreme size (OR 3.02, 95% CI 1.35-6.76, p<0.001); difficult access (OR 2.63, 95% CI 1.16-5.97, p=0.02); ESD (OR 4.08, 95% CI 1.52-10.98, p=0.003) and long procedure time over 240 min (OR 5.20, 95% CI 2.02-13.36, p<0.001) but not location, F2 fibrosis, or age.

Conclusion

Delayed perforation/sepsis after ER of LNPCP is rare, and a requirement for surgery extremely rare, but varies according to lesion and procedure characteristics. The consequences can be severe and include surgery, guided drainage or ICU admission. Delayed perforation/sepsis can affect patients with LNPCP in any location including the rectum. Given the risk factors identified in this study, these data could help realistically counsel patients with LNPCP of extreme size, difficult access and requiring complex prolonged procedures regarding the risks of delayed perforation and sepsis.