Endoscopic submucosal dissection of esophageal squamous cell neoplasms

Development of Deep Learning-Based Virtual Lugol Chromoendoscopy for Superficial Esophageal Squamous Cell Carcinoma

BACKGROUND

Lugol chromoendoscopy has been shown to increase the sensitivity of detection of esophageal squamous cell carcinoma (ESCC). We aimed to develop a deep learning-based virtual lugol chromoendoscopy (V-LCE) method.

METHODS

We developed still V-LCE images for superficial ESCC using a cycle-consistent generative adversarial network (CycleGAN). Six endoscopists graded the detection and margins of ESCCs using white-light endoscopy (WLE), real lugol chromoendoscopy (R-LCE), and V-LCE on a five-point scale ranging from 1 (poor) to 5 (excellent). We also calculated and compared the color differences between cancerous and non-cancerous areas using WLE, R-LCE, and V-LCE.

RESULTS

Scores for the detection and margins were significantly higher with R-LCE than V-LCE (detection, 4.7 vs. 3.8, respectively; p < 0.001; margins, 4.3 vs. 3.0, respectively; p < 0.001). There were nonsignificant trends towards higher scores with V-LCE than WLE (detection, 3.8 vs. 3.3, respectively; p = 0.089; margins, 3.0 vs. 2.7, respectively; p = 0.130). Color differences were significantly greater with V-LCE than WLE (p < 0.001) and with R-LCE than V-LCE (p < 0.001) (39.6 with R-LCE, 29.6 with V-LCE, and 18.3 with WLE).

CONCLUSIONS

Our V-LCE has a middle performance between R-LCE and WLE in terms of lesion detection, margin, and color difference. It suggests that V-LCE potentially improves the endoscopic diagnosis of superficial ESCC.

Safety and efficacy of endoscopic submucosal dissection with gel immersion technique for superficial esophageal neoplasms

BACKGROUND AND AIM

Gel immersion (GI) endoscopy provides a good visual field in endoscopic submucosal dissection (ESD); however, its clinical outcomes are poorly understood. This study aimed to compare the treatment outcomes between esophageal gel immersion endoscopic submucosal dissection (GI-ESD) and conventional ESD (C-ESD) to determine the safety and efficacy of GI-ESD.

METHODS

The data of 71 consecutive patients who underwent esophageal ESD between April 2021 and March 2023 at a Japanese tertiary center were retrospectively reviewed. GI was achieved using an additional irrigation tube. The treatment outcomes between the GI-ESD and C-ESD groups were compared using inverse probability of treatment weighting (IPTW) to control for confounding factors.

RESULTS

A total of 75 superficial esophageal epithelial neoplasms (41 in the C-ESD and 34 in the GI-ESD groups) were treated using ESD. The mean procedure time in the GI-ESD group was significantly shorter than that in the C-ESD group (59.2 ± 36.2 vs 85.3 ± 45.7 min, P = 0.008). After IPTW adjustment, the mean procedural times were 62.6 ± 36.6 and 82.9 ± 41.7 min in the GI-ESD and C-ESD groups, respectively (P = 0.037), and the incidence rate of muscle layer damage was 4.2% in the GI-ESD group and 30.6% in the C-ESD group (P = 0.001). In the multivariate analysis, specimen size ≥ 30 mm (odds ratio [OR]: 9.44, 95% confidence interval [CI]: 2.46-36.30, P = 0.001) was positively correlated with longer procedural time (≥ 90 min), whereas GI-ESD (OR: 0.19, 95%CI: 0.05-0.68, P = 0.011) showed a negative association.

CONCLUSIONS

Esophageal GI-ESD may be useful in terms of safety and time efficiency. The GI technique could be an option for esophageal ESD.

Characteristics of cases for which esophageal endoscopic submucosal dissection under general anesthesia is recommended

BACKGROUND/AIMS

Esophageal endoscopic submucosal dissection (ESD) performed under general anesthesia can potentially provide more stable treatment in difficult cases than that under sedation. We evaluated the clinical characteristics and outcomes of ESD performed under general anesthesia compared with those under propofol sedation and discussed the cases in which general anesthesia is recommended.

PATIENTS AND METHODS

In total, 292 lesions in 265 consecutive patients undergoing esophageal ESD at Yamaguchi University Hospital from 2013 to 2023 were included in this retrospective study.

RESULTS

ESD was performed under general anesthesia for 92 lesions in 81 patients and under propofol sedation for 200 lesions in 184 patients. Tumor long-axis diameter was larger (39.8 ± 14.4 mm vs. 32.4 ± 9.9 mm, p < 0.01) and dissection speed was faster (10.5 ± 5.9 mm2/min vs. 7.5 ± 4.2 mm2/min, p < 0.01) in the general anesthesia group versus the sedation group. In the sedation group, a treatment history of pharyngeal cancer was significantly associated with a slower dissection speed (p = 0.037). The sedation group showed higher frequencies of hypoxemia (0% vs 9.8%, p < 0.01), interruption due to body movement (0% vs 13%, p < 0.01), and acute adverse events (21.7% vs 33.5%, p = 0.05). A treatment history of pharyngeal cancer was shown to be the significant factor contributing to acute adverse events (p = 0.018).

CONCLUSION

Esophageal ESD under general anesthesia can be a treatment option in patients with difficulty in performing stable procedures with propofol sedation. Especially in patients with a treatment history of pharyngeal cancer in whom ESD is more difficult to be performed and who are at higher risk for acute adverse events, general anesthesia can be considered.

Endoscopic submucosal dissection for superficial esophageal cancer in the remnant esophagus after esophagectomy

Treatment of esophageal cancer in the remnant esophagus after esophagectomy is highly invasive, therefore, early detection and minimally invasive treatment are considered necessary. Consequently, we aimed to clarify the safety and efficacy of endoscopic submucosal dissection (ESD) for residual esophageal cancer compared to that for esophageal cancer in a normal cervical esophagus. This study involved 47 patients with 59 residual esophageal cancers and 92 patients with 107 cervical esophageal cancers in normal esophagus who underwent ESD between January 2008 and December 2023. Their clinicopathological findings and long-term outcomes were retrospectively collected and evaluated. The median tumor diameter was 13 mm, and the median procedure time was 31 minutes in remnant esophagus group, with no significant difference between the two groups. No serious complications such as perforation, massive intraoperative bleeding, and pneumonia were observed in the remnant group, except for one case of postoperative bleeding. The rates of complete resection and disease specific survival were not significantly different between two groups, with complete resection rate of 86.4% and 5-year disease-specific survival rate of 95.7% in the remnant esophagus group. No local recurrence was observed during the median observation period of 43 months in the remnant esophagus group. ESD for superficial cancer of the remnant esophagus showed a high complete resection rate without serious complications and good local-regional control with no evidence of local recurrence. This indicates that ESD is a safe and useful treatment for superficial cancer of the remnant esophagus.

Prospective multicenter trial of the cryoballoon ablation system for superficial esophageal squamous cell carcinoma on post-endoscopic resection scars: a CRYO-SCAR study (EPOC1902)

BACKGROUND AND AIMS

Endoscopic resection is a minimally invasive treatment for superficial esophageal squamous cell carcinoma (SESCC). Post-endoscopic resection scars complicate en-bloc resection, even with advanced techniques, such as endoscopic submucosal dissection. The cryoballoon ablation system (CBAS) effectively manages Barrett's esophagus but has limited evidence in SESCC treatment, particularly on post-endoscopic resection scars. This study aimed to evaluate the efficacy and safety of the CBAS for treating SESCC on post-endoscopic resection scars.

METHODS

This prospective study was conducted at 2 tertiary referral centers in Japan in patients endoscopically diagnosed with T1a SESCC on the post-endoscopic resection scar. Focal CBAS was used for cryoablation, with specific criteria for lesion selection and treatment method. The primary endpoint was the rate of local complete response (L-CR) of the primary lesion 48 weeks after the first cryoablation as evaluated by an independent central evaluation committee.

RESULTS

From October 2020 to October 2021, 15 patients with 17 lesions underwent cryoablation, with 2 requiring repeat cryoablation. The L-CR rate for primary and all lesions evaluated by the central evaluation committee was 100%. The endoscopist's evaluation was consistent with these results. The median procedure time was 9 minutes. Eight patients experienced no pain, and the highest pain score reported on a numeric rating scale from 1 to 10 was 3. The technical success rate was 94.7% (18/19). Throughout the median follow-up period of 14.3 months, recurrences, deaths, or severe treatment-related adverse events were not reported.

CONCLUSIONS

CBAS is a potentially safe and effective approach for SESCC on post-endoscopic resection scars and represents an encouraging alternative to traditional endoscopic treatments. (Clinical trial registration numbers: NCT03097666 and jRCT1080225331.).

Intensive triamcinolone acetonide injection regimen can highly prevent stricture after extensive esophageal endoscopic submucosal dissection

BACKGROUND

This study aimed to investigate the utility of intensive triamcinolone acetonide (TA) injections after extensive esophageal endoscopic submucosal dissection (ESD).

METHODS

This retrospective study included 27 lesions in 27 consecutive patients who underwent ESD (ulcers encompassing ≥3/4 of the esophageal circumference) and received TA injections without oral steroid administration. Groups A and B included patients undergoing ESD with and without complete circumferential resection, respectively. All patients received TA injections (100 mg/session) immediately after ESD. In Group A, weekly based TA injections were performed until near-complete ulcer epithelialization. In Group B, patients did not receive additional injections or received weekly or biweekly TA injections. The primary outcome was stricture rate, and the secondary outcomes were the proportion of patients requiring endoscopic balloon dilation (EBD) and the number of TA injections.

RESULTS

Group A included 7 lesions, and Group B included 20 lesions. The median (range) tumor lengths were 40 (30-90) and 45 (30-110) mm in Groups A and B, respectively. In Group A, the median circumferential resection diameter was 40 (20-80) mm. The stricture rate and the proportion of patients requiring EBD were 0 (0%) in Group A and 1 (5.0%) in Group B. The number of TA injection sessions was significantly higher in Group A than in Group B (8 [5-25] vs 1.5 [1-3]; p < 0.001).

CONCLUSIONS

Intensive weekly or biweekly based TA injections might aid in preventing post-ESD stricture and the need for EBD in patients undergoing extensive resection involving the entire esophageal circumference.

Development of a novel multipoint traction device for gastric and colorectal endoscopic submucosal dissection and evaluation of its efficacy and safety

BACKGROUND

Proper traction allows safer and easier endoscopic submucosal dissection; however, single-point traction may not be sufficient. In this study we assessed the safety, efficacy, and feasibility of our newly developed multipoint traction device.

METHODS

During an ex vivo study using a Konjac training model, two experts and two trainees resected 80 mock lesions of 20-mm diameter by performing endoscopic submucosal dissection with and without multipoint traction. The primary outcome was the success rate of the procedure involving traction. The secondary outcomes were the submucosal dissection time, dissection speed, and perforation during endoscopic submucosal dissection. During the in vivo study, to clarify the initial clinical outcomes, we used data from the electronic medical record of patients at our institution who underwent gastric and colorectal endoscopic submucosal dissection, which was performed by experts with our newly developed multipoint traction device, from March to December 2022.

RESULTS

The ex vivo study indicated that all traction procedures were successful. Higher resection speeds were observed with endoscopic submucosal dissection with traction than without traction (P < 0.001). Perforations were not observed. During the first in vivo clinical study, traction was feasible during 20 gastric and colorectal endoscopic submucosal dissection procedures. No adverse events occurred.

CONCLUSIONS

Our multitraction device can increase the submucosal dissection speed and simplify endoscopic submucosal dissection techniques, thus safely reducing technical challenges. The application of this device for endoscopic submucosal dissection could lead to safer and more efficient procedures. Clinical registration UMIN Clinical Trials Registry, Japan (registration number UMIN000053384).

Automated artificial intelligence-based phase-recognition system for esophageal endoscopic submucosal dissection (with video)

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) for superficial esophageal cancer is a multistep treatment involving several endoscopic processes. Although analyzing each phase separately is worthwhile, it is not realistic in practice owing to the need for considerable manpower. To solve this problem, we aimed to establish a state-of-the-art artificial intelligence (AI)-based system, specifically, an automated phase-recognition system that can automatically identify each endoscopic phase based on video images.

METHODS

Ninety-four videos of ESD procedures for superficial esophageal cancer were evaluated in this single-center study. A deep neural network-based phase-recognition system was developed in an automated manner to recognize each of the endoscopic phases. The system was trained with the use of videos that were annotated and verified by 2 GI endoscopists.

RESULTS

The overall accuracy of the AI model for automated phase recognition was 90%, and the average precision, recall, and F value rates were 91%, 90%, and 90%, respectively. Two representative ESD videos predicted by the model indicated the usability of AI in clinical practice.

CONCLUSIONS

We demonstrated that an AI-based automated phase-recognition system for esophageal ESD can be established with high accuracy. To the best of our knowledge, this is the first report on automated recognition of ESD treatment phases. Because this system enabled a detailed analysis of phases, collecting large volumes of data in the future may help to identify quality indicators for treatment techniques and uncover unmet medical needs that necessitate the creation of new treatment methods and devices.

Self-expandable metallic stents may be more efficient than balloon dilatation alone for esophageal stricture after circumferential endoscopic submucosal dissection: a retrospective cohort study in China

INTRODUCTION

Self-expandable metallic stents (SEMSs) can be used to treat esophageal stricture after circumferential endoscopic submucosal dissection (ESD), but its efficacy and placement timing remain to be determined. In this study, the treatment time and number of dilatations were compared between the SEMS placement group and the balloon dilatation (BD) group to clarify the efficacy and placement time of SEMSs in the treatment of esophageal stricture after circumferential esophageal ESD.

METHODS

This was a retrospective cohort study. Patients with esophageal stricture after circumferential ESD between January 2015 and January 2020 were included. Data on the patients' demographic characteristics, esophageal lesion-related factors, esophageal stricture occurrence, and measures taken to treat the stricture were collected. The primary outcome was the treatment time, and the secondary outcome was the number of dilatations.

RESULTS

The total number of dilatations was 30 in the SEMS group and 106 in the BD group. The average number of dilatations in the SEMS group (1.76 ± 1.64) was significantly lower than that in the BD group (4.42 ± 5.32) (P = 0.016). Among the patients who underwent SEMS placement first had a shorter treatment time (average 119 days) than those who underwent BD first (average 245 days) (P = 0.041), and the average number of dilatations inpatients who underwent SEMS placement first (0.71 ± 1.07) was significantly lower than that in the patients who underwent BD first (2.5 ± 1.54).

CONCLUSION

SEMSs were more efficient in the treatment of esophageal stricture in a cohort of patients after circumferential esophageal ESD.

Clinical outcomes of endoscopic submucosal dissection for esophageal squamous cell carcinoma with esophageal varices: Multicenter retrospective study

OBJECTIVES

Clinical outcomes of endoscopic submucosal dissection (ESD) for esophageal squamous cell carcinoma (ESCC) with esophageal varices (EVs) are obscure. We aimed to elucidate the clinical outcomes of ESD for ESCC with EVs in a multicenter, retrospective study.

METHODS

We established a retrospective cohort of 30 patients with ESCC complicating EVs, who underwent ESD at 11 Japanese institutions. Rates of en bloc resection and R0 resection, procedure time, and adverse events were evaluated as indicators of the feasibility and safety of ESD. Additional treatment, recurrence, and metastasis of the lesions were evaluated as indicators of the long-term efficacy of ESD.

RESULTS

Portal hypertension was caused by cirrhosis, of which alcohol was the most common cause. En bloc resection was achieved in 93.3% and R0 resection in 80.0% of the patients. The median procedure time was 92 min. Adverse events included a case of uncontrolled intraoperative bleeding leading to discontinuation of ESD and a case of esophageal stricture due to extensive resection. During the follow-up period of a median for 42 months, a patient with local recurrence and another patient with liver metastasis were observed. One patient died of liver failure after receiving chemoradiotherapy as an additional treatment after ESD. No patient died of ESCC.

CONCLUSION

This multicenter, retrospective cohort study demonstrated the safety and efficacy of ESD for ESCC with EVs. Further studies are needed to establish appropriate treatment methods for EVs before ESD and additional treatments for patients with insufficient ESD.

An Ailment with Which I Will Contend: A Narrative Review of 5000 Years of Esophagogastric Cancers and Their Treatments, with Special Emphasis on Recent Advances in Immunotherapeutics

Esophagogastric cancers are among the most common and deadly cancers worldwide. This review traces their chronology from 3000 BCE to the present. The first several thousand years were devoted to palliation, before advances in operative technique and technology led to the first curative surgery in 1913. Systemic therapies were introduced in 1910, and radiotherapy shortly thereafter. Operative technique improved massively over the 20th century, with operative mortality rates reducing from over 50% in 1933 to less than 5% by 1981. In addition to important roles in palliation, endoscopy became a key nonsurgical curative option for patients with limited-stage disease by the 1990s. The first nonrandomized studies on combination therapies (chemotherapy ± radiation ± surgery) were reported in the early 1980s, with survival benefit only for subsets of patients. Randomized trials over the next decades had similar overall results, with increasing nuance. Disparate conclusions led to regional variation in global practice. Starting with the first FDA approval in 2017, multiple immunotherapies now encompass more indications and earlier lines of therapy. As standards of care incorporate these effective yet expensive therapies, care must be given to disparities and methods for increasing access.

Red Dichromatic Imaging Improves the Recognition of Bleeding Points During Endoscopic Submucosal Dissection

BACKGROUND

Previous studies have indicated that red dichromatic imaging (RDI) improved the visibility of gastrointestinal bleeding.

AIMS

To investigate the recognition of bleeding points during endoscopic submucosal dissection (ESD) under RDI compared with that under white light imaging (WLI).

METHODS

Consecutive patients scheduled to undergo esophageal or gastric ESD at a single center were enrolled. Paired videos of active bleeding during ESD under WLI and RDI were created. Six endoscopists identified the virtual hemostasis point on still images after random video viewing. The distance between virtual hemostasis and actual bleeding points was scored in four levels (0-3 points), and the association with the color value was analyzed in both WLI and RDI.

RESULTS

We evaluated 116 videos for 58 bleeding points. The median visibility score and recognition rate were significantly higher for RDI than for WLI (2.17 vs. 1.42, p < 0.001 and 62.1% vs 27.6%, p < 0.001). Additionally, the recognition rate of trainees in RDI was higher than that of experts in WLI (60.3% vs. 43.1%, p = 0.067). The median color difference of RDI was significantly higher than that of WLI (8.97 vs. 3.69, p < 0.001). Furthermore, the correlation coefficient between the visibility score and color difference was 0.712 (strong correlation).

CONCLUSION

RDI can provide better recognition of bleeding points than WLI during ESD. Therefore, further studies are warranted to investigate whether RDI improves ESD outcomes.

Clinical outcomes of endoscopic submucosal dissection for giant rectal tumors larger than 8 cm: A European referral center experience

BACKGROUND AND AIMS

To date, western data on colorectal ESD are limited. This study aimed to assess the efficacy and safety of rectal ESD for superficial lesions ≥ 8 cm.

METHODS

A total of 138 superficial rectal neoplasms treated by ESD were allocated in two groups: 25 in the "giant" ESD group and 113 in the control group.

RESULTS

En bloc resection was achieved in 96% of cases in both groups. En bloc R0 resection rate was similar between the "giant" ESD group and the control group (84% vs 86%; p: 0.5) and curative resection was higher in the control group (81%) than in "giant" ESD group (68%) without reaching statistical significance (p: 0.2). Dissection time was significantly longer in the "giant" ESD group (251 vs 108 min; p <0.001), however, dissection speed was significantly higher (0.35 vs 0.17 cm2/min; p: 0.02).). Post-ESD stenosis was observed in 2 patients from the "giant" ESD group (8% vs 0% of control group, p: 0.03). No significant differences were found in delayed bleeding, perforation, local recurrences, and need for additional surgery.

CONCLUSIONS

ESD for superficial rectal tumors ≥ 8 cm is a feasible, safe, and effective therapeutic option.

Local recurrence risk of esophageal squamous cell carcinoma due to intralesional damage during endoscopic submucosal dissection

BACKGROUND AND AIM

It is unclear whether additional treatment should be considered given the recurrence risk after endoscopic submucosal dissection (ESD) for esophageal squamous cell carcinoma (ESCC) when the vertical margin is positive or unclear (VM1/VMX) due to intralesional damage. This study aimed to elucidate the local recurrence risk of ESCC caused by intralesional damage during ESD.

METHODS

Among consecutive patients with pT1a ESCCs initially treated by ESD at our institution between January 2006 and December 2018, ESCCs diagnosed as VM1/VMX were retrospectively reviewed. Exclusion criteria were piecemeal resection and any additional treatment after ESD. Intralesional damage included the following three types: a macroscopic hole inside the lesion, an incision from the lateral margin of the specimen into the lesion, and crushing injury or burn effect into the deepest area of the lesion without an obvious hole. The local recurrence rate after ESD was primarily analyzed.

RESULTS

Of 1174 pT1a ESCCs initially treated using ESD, 22 lesions were histopathologically diagnosed as VM1/VMX due to intralesional damage (1.9%; 95% confidence interval [CI], 1.2-2.8%). At a median follow-up period of 60.0 (interquartile range, 15.0-84.0) months, no local recurrence was observed (0.0%; 95% CI, 0.0-13.3%) among 21 lesions finally evaluated.

CONCLUSIONS

The impact of intralesional damage during ESD for ESCC on local recurrence might be negligible. Follow-up without additional treatment may be acceptable even if intralesional damage occurs and results in VM1/VMX after ESD for pT1a ESCCs.

Clinical Outcomes of Follow-Up Observation After Endoscopic Submucosal Dissection for Esophageal Squamous Cell Carcinoma Invading the Muscularis Mucosa Without Lymphovascular Involvement

BACKGROUND

The therapeutic approach after endoscopic submucosal dissection (ESD) for esophageal squamous cell carcinoma (ESCC) diagnosed as pathological T1a-muscularis mucosa (pT1a-MM) without lymphovascular involvement (LVI) remains uncertain. We aimed to determine whether observation after ESD is acceptable for patients without LVI showing pT1a-MM cancer.

METHODS

We retrospectively registered 566 ESCC patients who were treated with ESD at ten institutions between January 2007 and December 2015. Of those, 447 cases showing pT1a-epithelium/lamina propria mucosa (EP/LPM) without LVI and vertical margin (VM) (EP/LPM group), and 41 cases showing pT1a-MM without LVI and VM (MM group) were analyzed in this investigation. The clinical outcomes were assessed between the groups.

RESULTS

The 5 year cumulative incidence of metastatic recurrence was 0.5% and 3.3% in the EP/LPM and MM groups, respectively (P = 0.121). Two cases showing pT1a-EP/LPM and one showing pT1a-MM experienced lymph node recurrence. The 5 year cumulative incidence of local recurrence was 1.5% and 3.8% in the EP/LPM and MM groups, respectively (P = 0.455). The 5 year disease-specific survival (DSS) rate was 99.3% and 96.6% in the EP/LPM and MM groups, respectively (P = 0.118), whereas the 5 year overall survival rate was significantly higher in the EP/LPM group than in the MM group (92.6% versus 81.1%, respectively; P = 0.021).

CONCLUSIONS

As regards metastatic recurrence and DSS, ESCC patients with pT1a-MM without LVI showed favorable outcomes that were equivalent to those with pT1a-EP/LPM, even when they were not treated with additional therapy after ESD.

Clinicopathological characteristics of synchronous multiple primary early esophageal cancer and risk factors for multiple lesions

Background

With the development of endoscopic technology, the detection rate of synchronous multiple primary early esophageal cancer (SMPEEC) is increasing; however, the risk factors remain unclear. We aimed to assess the clinicopathological characteristics of patients with SMPEEC and investigate the risk factors contributing to the development of multiple lesions.

Methods

A retrospective cohort study was conducted on 911 consecutive patients who underwent Endoscopic submucosal dissection (ESD) for primary esophageal neoplasms from January 2013 to June 2021. The patients were divided into the SMPEEC group and the solitary early esophageal cancer (SEEC) group. We compared the differences in clinicopathological characteristics between the two groups and investigated the risk factors linked to multiple lesions. Additionally, we investigated the relationship between the main and accessory lesions.

Results

A total of 87 SMPEEC patients were included in this study, and the frequency of synchronous multiple lesions was 9.55% in patients with early esophageal cancer. The lesions in the SMPEEC group were mainly located in the lower segment of the esophagus (46[52.9%]), whereas those in the SEEC group were in the middle segment (412[50.0%]). The pathology type, tumor location, and circumferential rate of lesions were independent risk factors(P<0.05) for SMPEEC by logistic regression analysis. Significant positive correlations were observed between the main and accessory lesions in terms of morphologic type (r=0.632, P=0.000), tumor location(r=0.325, P=0.037), pathologic type (r=0.299, P=0.003), and depth of invasion (r=0.562, P=0.000).

Conclusion

Pathology type, tumor location, and circumferential rate of lesions were identified as independent risk factors for SMEPPC. Understanding these risk factors and the correlation between the main and accessory lesions could significantly improve the detection rate of SMPEEC.

Prophylactic use of steroids for a mucosal defect with a circumference of less than three-fourths prevents both symptomatic and asymptomatic stricture after esophageal endoscopic submucosal dissection

BACKGROUND

Subclinical stricture after esophageal endoscopic submucosal dissection (ESD) makes the detection and re-ESD of metachronous lesions difficult. This study aimed to investigate the effectiveness of prophylactic steroid use after esophageal ESD for mucosal defects with a circumference less than 75% for the prevention of symptomatic and asymptomatic stricture.

METHODS

In 80 retrospectively enrolled patients, we collected paired endoscopic images of a mucosal defects immediately after resection and a scar thereafter. After calculating circumference by image analysis software, all patients were classified into three groups in reference to mucosal defect circumference (MDC; ≤ 50%, 50-75%, ≥ 75%). Frequency of steroid use and symptomatic stricture were compared, and in < 75% MDC patients, a degree of asymptomatic stricture with or without steroid was compared by calculating a scar contraction rate (SCR).

RESULTS

In the ≤ 50% (43 patients), 50-75% (27 patients) and ≥ 75% (10 patients) MDC groups, steroids were used in 12%, 59% and 100%, respectively, and symptomatic stricture occurred in 0%, 7% and 40%, respectively. In < 75% MDC patients, SCR in the steroid cohort was significantly lower than that in the nonsteroid cohort (42% vs. 65%, p = 0.002). No steroid-related adverse events occurred.

CONCLUSION

Steroid use even for mucosal defects with < 75% circumference appears effective for the reduction of the risk on both symptomatic and asymptomatic stricture after esophageal ESD.

The relationship between the esophageal endoscopic submucosal dissection technical difficulty and its intraoperative process

BACKGROUND

Estimating the esophageal endoscopic submucosal dissection (ESD) technical difficulty is important to reduce complications. Endoscopic duration is one of the related factors to a technical difficulty. The relationship between the esophageal ESD technical difficulty and its intraoperative process was analyzed as a first step toward automatic technical difficulty recognition using artificial intelligence.

METHODS

This study enrolled 75 patients with superficial esophageal cancer who underwent esophageal ESD. The technical difficulty score was established, which consisted of three factors, including total procedure duration, en bloc resection, and complications. Additionally, technical difficulty-related factors, which were perioperative factors that included the intraoperative process, were investigated.

RESULTS

Eight (11%) patients were allocated to high difficulty, whereas 67 patients (89%) were allocated to low difficulty. The intraoperative process, which was shown as the extension of each endoscopic phase, was significantly related to a technical difficulty. The area under the curve (AUC) values were higher at all the phase duration than at the clinical characteristics. Submucosal dissection phase (AUC 0.902; 95% confidence intervals (CI) 0.752-1.000), marking phase (AUC 0.827; 95% CI 0.703-0.951), and early phase which was defined as the duration from the start of marking to the end of submucosal injection (AUC 0.847; 95% CI 0.701-0.992) were significantly related to technical difficulty.

CONCLUSIONS

The intraoperative process, particularly early phase, was strongly associated with esophageal ESD technical difficulty. This study demonstrated the potential for automatic evaluation of esophageal ESD technical difficulty when combined with an AI-based automatic phase evaluation system.

Endoscopic submucosal dissection for superficial esophageal squamous cell carcinoma in patients with cirrhosis and esophageal varices

Endoscopic submucosal dissection (ESD) has become the standard treatment for superficial esophageal squamous cell carcinoma (SESCC). However, the treatment strategy for SESCC complicated by esophageal varices (EVs) has not been established. We report two cases of SESCC in patients with alcoholic cirrhosis complicated by EVs who underwent ESD. Case 1 presented with EVs on the anal side of the SESCC, and endoscopic variceal ligation (EVL) was performed before ESD. After EVL, the SESCC was successfully treated by ESD without any adverse events. Case 2 presented EVs from the anal side of the SESCC to the submucosa just below the SESCC. Then, EVL and endoscopic injection sclerotherapy with polidocanol were performed before ESD. However, ESD was not completed because of severe bleeding by uncontrolled blood flow below and around the SESCC. Bleeding during ESD was controlled in case 1, but not in case 2.

Effect of particle size on the tissue adhesion and particle floatation of a colloidal wound dressing for endoscopic treatments

Endoscopic submucosal dissection (ESD) is a minimally invasive technique that is widely used to remove gastrointestinal tumors. However, because the walls of the duodenum and large intestine are thin, perforation can easily occur after ESD. We have previously reported that alkyl group-modified Alaska pollock gelatin-based microparticles (C10Ps) formed a colloidal gel that could adhere to defects and close perforations, driven by hydrophobic interactions. The present study focused on the effect of particle size on the colloidal gel properties and the floatation of C10Ps in the air in the delivery of C10Ps. We prepared C10Ps with different particle sizes from 0.1 to 100 µm. The storage modulus and adhesion strength of the C10P colloidal gel increased with decreasing particle size. All the C10Ps formed a colloidal gel layer on duodenum tissue after being sprayed from an endoscopic device. The underwater stability and burst strength of C10Ps with a particle size of 0.1 and 1 µm were higher than for larger C10Ps. Floating of the small-sized C10Ps in the air was observed. The results indicated that C10Ps with a size of 1 µm had suitable properties for use in endoscopic treatments. STATEMENT OF SIGNIFICANCE: We previously reported tissue adhesive microparticles as a spray-deliverable wound dressing in gastrointestinal tissues. However, their functions depending on particle size have not yet been clarified. In the present study, we prepared decyl group-modified Alaska pollock gelatin nano and microparticles (C10Ps) with different particle sizes from 0.1 to 100 µm and evaluated the effect of particle size on the colloidal gel properties (rheological property, underwater stability and perforation-closing ability) and the floatation of C10Ps in the air in the delivery of C10Ps.

Clinical outcomes of endoscopic submucosal dissection for superficial circumferential esophageal squamous cell carcinoma

BACKGROUND AND AIMS

Our aim was to elucidate the clinical outcomes of endoscopic submucosal dissection (ESD) for superficial circumferential esophageal squamous cell carcinoma (cESCC).

METHODS

Consecutive patients who underwent ESD for cESCC between 2009 and 2020 were retrospectively reviewed. Short-term outcomes were en-bloc resection, R0 resection, procedure time, and adverse events, whereas long-term outcomes were overall survival (OS), disease-specific survival (DSS), cumulative recurrence rate (CRR), and clinical course.

RESULTS

Fifty-two patients with 52 cESCCs (median tumor length, 5.0 cm; interquartile range [IQR], 4.0-6.3) were evaluated. The en-bloc resection and R0 resection rates were 100% (95% confidence interval [CI], 94.4-100) and 69.2% (95% CI, 54.9-81.3), respectively. The median procedure time was 112 minutes (IQR, 87-162). Intraoperative perforations and delayed bleeding occurred in 4 (7.7%) and 1 (1.9%) patients, respectively. Among the 42 patients who underwent ESD alone, 36 (85.7%) experienced esophageal strictures. Within a median follow-up of 49.1 months (IQR, 25.7-74.7), the 4-year OS, DSS, and CRR were 86.2% (95% CI, 71.6-93.6), 95.5% (95% CI, 83.1-98.9), and 11.5% (95% CI, 4.1-23.1), respectively. There was no significant difference in the OS between patients with low-risk cESCC (pT1a, negative lymphovascular invasion, and negative vertical margin) and high-risk lesions, regardless of undergoing additional treatment (P = .93). In 31 patients with low-risk cESCC who were treated with ESD alone, the 4-year OS, DSS, and CRR were 93.2%, 100%, and 0%, respectively.

CONCLUSIONS

ESD is a highly curative treatment for cESCC with favorable long-term outcomes, especially in low-risk patients. Stricture-prevention techniques should be improved to optimize the benefits of ESD for cESCC.

Usefulness of endoscopic ultrasound in predicting treatment efficacy of salvage endoscopic therapy for local failure after chemoradiotherapy for esophageal squamous cell carcinoma

BACKGROUND

Salvage endoscopic therapy, including endoscopic resection (ER) and photodynamic therapy (PDT), is effective for esophageal squamous cell carcinoma (ESCC) in local failure after chemoradiotherapy (CRT). Resection with pathologically vertical margin-negative (VM0) for ER and local complete response (L-CR) for PDT are important surrogate prognostic markers for each therapy's efficacy. We aimed to evaluate the usefulness of endoscopic ultrasound (EUS) in predicting the efficacy of salvage endoscopic therapy in local failure after CRT for ESCC.

METHODS

We included patients who underwent EUS followed by ER or PDT for local failure after CRT or radiotherapy for ESCC from 2006 to 2020. We evaluated EUS findings associated with VM0 resection for ER and L-CR for PDT, which included the status of the outermost part of the submucosal layer, tumor thickness, and tumor invasion length into the muscularis propria (MP) layer.

RESULTS

Thirty and 47 patients were enrolled into the ER and PDT groups, respectively. The VM0 resection rate in the ER group was 87% (26/30). The EUS findings associated with VM0 resection were tumor thickness < 2.3 mm (p = 0.01) and preserved hyperechoic line of the outermost part of the submucosa layer (p < 0.01). The L-CR rate in the PDT group was 69% (32/47). The EUS findings associated with L-CR were tumor thickness < 5.0 mm (p < 0.01) and tumor invasion length into the MP layer < 1.6 mm (p = 0.03).

CONCLUSIONS

EUS can be useful in predicting the efficacy of salvage endoscopic treatment for local failure after CRT for ESCC.

Blood biomarkers as predictors of pathological lymph node metastasis in clinical stage T1N0 esophageal squamous cell carcinoma

Accurate preoperative evaluation of lymph node (LN) metastasis is important for determining the treatment strategy for superficial esophageal cancer. Blood biomarkers, such as the neutrophil-lymphocyte, platelet-lymphocyte, and lymphocyte-monocyte ratios (NLR, PLR, and LMR, respectively), have clinical applications as predictors of LN metastasis for different cancers. Here, we investigated the use of these ratios as predictors of pathological LN metastasis and prognosis in patients with clinical stage T1N0M0 esophageal squamous cell carcinoma (ESCC). Patients (n = 185) with cT1N0M0 ESCC who underwent esophagectomy with R0 resection between April 2003 and August 2021 were enrolled. We investigated the ability of pretreatment NLR, PLR, and LMR to predict pathological LN metastasis. The optimal cutoff values of NLR, PLR, and LMR to predict pathological LN metastasis were 2.1, 122, and 4.8, respectively. Univariate and multivariate analyses revealed that the primary tumor length, depth of invasion, and NLR were significant predictors of LN metastasis. Furthermore, similar to the 5-year overall survival, the 5-year relapse-free survival was significantly better in the low NLR group than in the high NLR group. The NLR was the most useful predictor of pathological LN metastasis. Patients diagnosed with clinical stage I ESCC and with a high NLR require adequate LN dissection and may be good candidates for preoperative adjuvant therapy.

Comparison of treatment outcomes between endoscopic submucosal dissection with the needle-type knife and insulated-tip knife for superficial esophageal neoplasms

Our study aimed to compare the treatment outcomes between endoscopic submucosal dissection (ESD) with an insulated-tip knife (ESD-IT) and a needle-type knife (ESD-N) for large superficial esophageal neoplasms, as no study of this kind has been previously reported. We used the dataset of a multicenter, randomized controlled trial that compared conventional ESD (C-ESD) and traction-assisted ESD (TA-ESD) for superficial esophageal neoplasms. We compared the procedural outcomes between ESD-IT and ESD-N in a post hoc analysis and conducted sub-analyses based on traction assistance and electrical knife type. We included 223 (EST-IT, n = 169; ESD-N, n = 54) patients with no significant differences in baseline characteristics. The operator handover rate due to ESD difficulties was significantly higher in ESD-N (ESD-IT = 0.6% vs. ESD-N = 13.0%, P = 0.001), while the injection volume was significantly higher in ESD-IT than in ESD-N (40.0 vs. 20.5 mL, P < 0.001). Other outcomes were comparable between both groups (procedural time: 51.0 vs. 49.5 minute, P = 0.89; complete resection: 90.5% vs. 90.7%, P > 0.99; and complication rate: 1.8% vs. 3.7%, P = 0.60 for ESD-IT and ESD-N, respectively). In the sub-analyses, the handover rate was significantly lower with TA-ESD than with C-ESD for ESD-N (3.2% vs. 26.1%, P = 0.034), and a significantly smaller injection volume was used in TA-ESD than in C-ESD for ESD-IT (31.5 vs. 47.0 mL, P < 0.01). ESD with either endoscopic device achieved favorable treatment outcomes with low complication rates. The handover rate in ESD-N and the injection volume in ESD-IT improved with the traction method.

Studies on endoscopic submucosal dissection in the past 15 years: A bibliometric analysis

Background and aims

Endoscopic submucosal dissection (ESD) is an advanced minimally invasive technique for en bloc resection of superficial gastrointestinal lesions, which is drawn an increasing attention from its emergence. This bibliometric analysis is to evaluate the origin, current hotspots, and research trends on ESD.

Methods

A total of 2,131 publications on ESD from 2006 to 2020 were obtained from the Web of Science Core Collection (WoSCC) database. Bibliometric visualization analyses of countries/regions, institutes, authors, journals, references and keywords were performed by CiteSpace V.5.8.R3.

Results

The quantity of publications on ESD increased significantly during the past 15 years. Japan occupied the leading position in terms of research power. Professor Yutaka Saito, together with the institute he belongs, the Endoscopy Division, National Cancer Center Hospital, Tokyo, Japan, were the most productive author and institute, respectively. Colorectal ESD led the main thematic concentrations in ESD research. The most prolific journal was Gastrointestinal Endoscopy. European ESD Guideline was the most frequently co-cited reference. Guideline, meta-analysis, endoscopic resection, poly-glycolic acid sheet, Barrett's esophagus, fibrin glue, risk and colorectal neoplasm will be the active research hotspots in the future.

Conclusions

These findings provide the trends and frontiers in the field of ESD, as well as valuable information for clinicians and scientists to discover the future perspectives with potential collaborators.

Associated risk factor analysis and the prognostic impact of positive resection margins after endoscopic resection in early esophageal squamous cell carcinoma

Endoscopic resection for early esophageal cancer has a risk of residual margins. The risk these residual margins pose have not been fully evaluated. The present study aimed to investigate the associated risk factors and prognosis of residual margins following the endoscopic resection of early esophageal squamous cell carcinoma. In total, 369 patients (381 lesions) with early esophageal squamous cell carcinoma treated in the Fourth Hospital of Hebei Medical University (Shijiazhuang, China) with endoscopic resection were retrospectively analyzed. Sex, age, location, tumor diameter, depth of tumor invasion, endoscopic treatment, endoscopic ultrasonography (EUS) before resection, work experience of endoscopists and the degree of tumor differentiation were all evaluated as potential risk factors. In addition, the prognosis of patients with positive margins were analyzed. A total of 73 patients (73/381, 19.2%) had positive margins after endoscopic resection. Amongst the 65 patients who were successfully followed up, five patients succumbed to cardiovascular and cerebrovascular diseases, one patient received radiotherapy, two patients received radiotherapy and chemotherapy whilst one patient received chemotherapy. By contrast, 12 patients received surgery and 20 patients received additional endoscopic mucosal resection or endoscopic submucosal dissection. The other 29 patients were followed up regularly and no recurrence could be found. Univariate analysis revealed that tumor diameter, endoscopic treatment, depth of invasion, EUS before resection, degree of tumor differentiation and direction of invasion were all associated with the positive margin. Multivariate logistic regression analysis then found that EUS before resection, degree of tumor differentiation and depth of tumor invasion are independent risk factors for positive margins after endoscopic resection. These results suggest that poorly differentiated lesions and deeper invasion depth can increase the risk of positive margin after endoscopic resection. As a result, EUS evaluation before resection may reduce the risk of invasion depth. In addition, for poorly differentiated lesions, more aggressive treatment regimens may be recommended for preventing recurrence.

Advances in the application of regenerative medicine in prevention of post-endoscopic submucosal dissection for esophageal stenosis

Endoscopic submucosal dissection (ESD) is a curative treatment for superficial esophageal cancer with distinct advantages. However, esophageal stenosis after ESD remains a tough problem, especially after large circumferential proportion of esophageal mucosa is removed, which limits the wide use of ESD, especially in circumferential lesions. In this scenario, preventive procedures are highly recommended against post-ESD esophageal stenosis. However, the efficacy and safety of traditional prophylactic methods (steroids, metal and biodegradable stents, balloon dilation, radial incision, etc.) are not satisfactory and novel strategies need to be developed. Regenerative medicine has been showing enormous potential in the reconstruction of organs including the esophagus. In this review, we aimed to describe the current status of regenerative medicine in prevention of post-ESD esophageal stenosis. Cell injection, cell sheet transplantation, and extracellular matrix implantation have been proved effective. However, numerous obstacles still exist and further studies are necessary.

Endoscopic resection of esophageal squamous cell carcinoma: Current indications and treatment outcomes

Endoscopic resection (ER) is an alternate minimally invasive treatment for superficial esophageal squamous cell carcinoma (SESCC). We aimed to review the clinical indications and treatment outcomes of ER for SESCC. Endoscopic mucosal resection is relatively easy and efficient for SESCC ≤ 15 mm. In contrast, endoscopic submucosal dissection (ESD) is recommended to achieve en bloc resection for lesions >15 mm, in view of the accurate pathological evaluation. The Japan Gastroenterological Endoscopy Society guidelines recommend ER for non-circumferential cT1a-EP/LPM (epithelium/lamina propria mucosae), cT1a-MM/T1b-SM1 (muscularis mucosa/superficial submucosa ≤ 200μm) SESCC, and whole-circumferential T1a-EP/LPM SESCC ≤ 50 mm (upon implementing preventive measures for stenosis), considering the risk-benefit balance of ER. It defines pT1a-EP/LPM without lymphovascular invasion as a curative endoscopic resection. The guidelines recommend additional esophagectomy or chemoradiotherapy for pT1b SESCC or any SESCC, with lymphovascular invasion. However, there is no recommendation for or against the administration of additional treatments for pT1a-MM without lymphovascular invasion, owing to limited evidence. Researchers have reported on high en bloc and R0 resection rates of ESD, and a randomized controlled trial demonstrated that clip-line traction-assisted ESD could significantly reduce the ESD procedural time. Moreover, steroid treatment has been developed to prevent post-ESD esophageal strictures. There have been reports on favorable long-term outcomes of ESD. However, most of them are retrospective studies. Further robust data in prospective trials are warranted to achieve a definitive evidence of ESD, which will be beneficial to patients with SESCC.

Effects of steroid use for stenosis prevention after endoscopic submucosal dissection for cervical esophageal cancer

BACKGROUND AND AIM

Esophageal stenosis is a serious complication after endoscopic submucosal dissection (ESD) for thoracic esophageal cancer (TEC), and steroid has been applied for stenosis prevention. However, the rate of stenosis and effect of steroid for ESD of cervical esophageal cancer (CEC) remain unknown. The aim was to clarify the rate and managements of post-ESD stenosis for CEC.

METHODS

A total of 325 lesions with 272 patients who underwent ESD for esophageal cancers were enrolled and were divided to the CEC group (43 lesions) or the TEC group (282 lesions). Patient characteristics, clinicopathological features, procedure-related outcomes of esophageal ESD, stenosis rate and clinical outcome of steroid use cases were evaluated.

RESULTS

More patients in the CEC group received preventive steroid treatment compared to the TEC group (37.2% vs 14.5%, P = 0.001). The rate of post-ESD stenosis tended to be higher in the CEC group (11.6%) than in the TEC group (6.7%). For cases of 3/4 ≤ of circumference, local injection with oral steroid had lower stenosis rate than local injection only in both groups (CEC 40% vs 100%, TEC 30.7% vs 56.3%). More sessions and longer duration of dilation were needed to release the stenosis in the CEC group (20 times vs. 5 times, P = 0.015; 196 days vs. 55 days, P = 0.043).

CONCLUSION

The post-ESD stenosis rate of CEC tended to be higher than that of TEC. More intensive preventive measures for post-ESD stenosis may be needed for CEC than TEC.

Long-term clinical outcomes of patients diagnosed with pT1a-muscularis mucosae with lymphovascular invasion or pT1b after endoscopic resection for cT1N0M0 esophageal squamous cell carcinoma

BACKGROUND

Endoscopic resection (ER) is performed for early esophageal squamous cell carcinoma (ESCC) cases. Additional esophagectomy or chemoradiotherapy is recommended for non-curative resection (NCR) even with pathologically negative vertical margins (pVM0); however, their clinical outcomes remain unknown. We examined the long-term clinical outcomes of NCR for ESCCs according to additional treatments.

METHODS

We retrospectively analyzed the data of patients who underwent ER for cT1N0M0 ESCC between 2009 and 2017 judged to have NCR, which defined when pathologically diagnosed as invading the submucosa (SM) or muscularis mucosae (MM) involving lymphovascular invasion (LVI), pVM0, and endoscopically judged as negative horizontal margin. Additional esophagectomy (involving three-field lymphadenectomy), chemoradiotherapy [mainly cisplatin and 5-fluorouracil with concurrent radiotherapy (41.4 Gy)], or observation was undertaken. Thereafter, computed tomography was performed every 6-12 months. The cumulative recurrence (CRR) and recurrence-free survival (RFS) rates were evaluated.

RESULTS

Eighty-nine patients were included. Among them, 14 had pathologically diagnosed pMM with LVI; 9 and 6, and 32 and 28 patients had pSM1 and pSM2 without and with LVI. Twenty-one patients underwent observation, whereas 18 and 50 underwent esophagectomy and chemoradiotherapy. During the 60.6-month median follow-up period, nine patients had recurrence; among them, six patients had occurrence at > 4 years after ER. The 5-year CRR/RFS rates were 35.7%/48.1%, 13.4%/80.4%, and 0.0%/98.0% in the observation, esophagectomy, and chemoradiotherapy groups, respectively (observation vs. chemoradiotherapy; P < 0.001).

CONCLUSIONS

Additional treatments showed better long-term outcomes than observation for patients with NCR. As recurrence may occur at > 4 years after ER, careful long-term follow-up examinations are needed.

Feasibility of endoscopic ultrasonography using a 60-MHz ultrasound miniature probe in the upper gastrointestinal tract

PURPOSE

The use of higher frequencies in ultrasound allows for a more detailed image. This study aimed to investigate the feasibility of delineating the gastrointestinal wall using a 60-MHz miniature ultrasound probe.

METHODS

A phantom study was performed using a multipurpose ultrasonic phantom model, and the depth of imaging was evaluated using 60-MHz and 20-MHz miniature probes and 7.5-MHz conventional convex-type endoscopic ultrasonography. A total of 25 visualized areas from a total of 16 specimens from 16 patients were enrolled. The structures of the layers of the esophagus, stomach, and duodenum were evaluated using a 60-MHz probe and a pathological specimen created from endoscopically or surgically resected specimens.

RESULTS

The 60-MHz probe was able to render to a depth of 2 mm and visualize the esophagus, stomach, and duodenum in five layers, respectively, within the depiction range. The depiction ranges of the 20-MHz probe and 7.5-MHz conventional endoscopic ultrasonography were 5 mm and 60 mm, respectively. The 60-MHz probe visualized the muscularis mucosae as the fourth layer in the esophagus, the fourth layer in the stomach, and the second layer in the duodenum. Muscularis mucosae were delineated in almost all cases, except in two cases where the layered structure disappeared.

CONCLUSION

The 60-MHz probe provided good visualization of the muscularis mucosae and structure of the layers down to the submucosa, which improves the ability to diagnose the depth of early cancer invasion of the upper gastrointestinal tract, leading to more appropriate treatments.

Delineating the extent of esophageal squamous cell carcinoma

BACKGROUND

Lugol chromoendoscopy has been conventionally used for the detection and delineation of esophageal squamous cell carcinoma (SCC). However, the boundaries of some lesions are unclear even with Lugol chromoendoscopy, and there is a risk of residual lesions or over-excision. This study aimed to evaluate the utility of narrow-band imaging (NBI) for the delineation of esophageal SCC in endoscopic resection.

METHODS

Among 367 esophageal SCCs endoscopically resected between January and December 2019 at our institute, this retrospective study included consecutive lesions, which were first marked with NBI, followed by Lugol chromoendoscopy. The proportion of residual cancer, which was defined as histologically proven cancer confirmed adjacent to the scar within 1 year after endoscopic resection, was evaluated. To evaluate whether the marks added by Lugol chromoendoscopy after NBI marking were more reliable, we evaluated the presence of cancer in the iodine-unstained area outside the NBI-determined marks, i.e., the cancerous area missed by NBI. The presence of cancer in the iodine-stained areas inside the NBI-determined marks, i.e., the cancerous area missed by Lugol, was also evaluated. These were compared to assess the risk of residual cancer in endoscopic resection with NBI and Lugol chromoendoscopy.

RESULTS

Among 304 lesions, 2 (0.7%) residual cancers were detected. The cancerous area missed by NBI and the cancerous area missed by Lugol were identified in 18 (6%) and 43 (14%) lesions, respectively (P = 0.001).

CONCLUSIONS

NBI might be acceptable for delineating the extent of esophageal SCCs that are difficult to delineate with Lugol chromoendoscopy.

Long-term outcomes of salvage endoscopic submucosal dissection for local failure after chemoradiotherapy for esophageal squamous cell carcinoma

BACKGROUND

Salvage endoscopic submucosal dissection is considered a minimally invasive treatment for local failure after chemoradiotherapy for esophageal squamous cell carcinoma. However, the long-term outcomes have not been fully evaluated. This study investigated the short-term and long-term outcomes of salvage endoscopic submucosal dissection.

METHODS

Patients who underwent endoscopic submucosal dissection for local recurrence or residual tumor after chemoradiotherapy from January 2006 to December 2017 were retrospectively investigated. Follow-up included endoscopic examination and computed tomography at least once every 6 months after salvage endoscopic submucosal dissection. Risk factors for disease recurrence after salvage endoscopic submucosal dissection were assessed using the Cox hazards model.

RESULTS

A total of 30 patients (33 cases of esophageal squamous cell carcinoma: local recurrence, n = 27; residual tumor, n = 6) were included. The median endoscopic submucosal dissection procedure time was 40 min (interquartile range [IQR], 33-58.5 min). En bloc resection was achieved in 31 (94%) of 33 esophageal squamous cell carcinoma cases. One patient with intraoperative perforation did not require surgical intervention and recovered with conservative treatment. A total of 16 patients (53%) had disease recurrence at a median follow-up of 51 months (IQR, 33-81 months). The 3-year overall, disease-specific, recurrence-free and local recurrence-free survival rates were 75%, 82%, 58% and 90%, respectively. The positive vertical margin, submucosal invasion in the endoscopic submucosal dissection specimen and piecemeal resection were significantly associated with disease recurrence after salvage endoscopic submucosal dissection.

CONCLUSIONS

Salvage endoscopic submucosal dissection is a feasible treatment for local failure after chemoradiotherapy for esophageal squamous cell carcinoma with acceptable long-term outcomes. However, for cases with positive vertical margins and submucosal invasion in the endoscopic submucosal dissection specimen, salvage endoscopic submucosal dissection outcomes were insufficient and additional treatment might be required.

Radial incision and cutting for dilation before endoscopic submucosal dissection in patients with esophageal cancer on the distal side of severe benign esophageal strictures

We investigated the efficacy and safety of radial incision and cutting as a novel dilation method for strictures just before endoscopic submucosal dissection in patients with metachronous esophageal cancer localized on the distal side of strictures and determined the optimal dilation method. Consecutive patients who underwent endoscopic submucosal dissection for superficial esophageal squamous cell carcinomas localized on the distal side of severe strictures were investigated retrospectively and assigned to a radial incision and cutting (19 patients; 23 lesions) or an endoscopic balloon dilation (20 patients; 20 lesions) group. We evaluated the passage success rates of cap-wearing endoscopes with diameters ≥8.9 mm, the procedural success, en bloc resection, complete resection, major adverse event rates, and total procedure times. Compared to the endoscopic balloon dilation group, the passage success rate of a conventional endoscope with a transparent cap (87% vs. 50%) and procedural success rate (96% vs. 63%) were significantly higher in the radial incision and cutting group. The mean procedure time of 'dilation and ESD' was significantly shorter in the radial incision and cutting group than in the endoscopic balloon dilation group. Neither group experienced any serious adverse events. Radial incision and cutting followed by endoscopic submucosal dissection was effective and safe in patients with superficial esophageal squamous cell carcinomas localized on the distal side of severe benign esophageal strictures. Endoscopic submucosal dissection using a cap-wearing endoscope was possible with radial incision and cutting, and the procedure time was shorter than that for endoscopic balloon dilation.

Recommendations for Surveillance and Management of Recurrent Esophageal Cancer Following Endoscopic Therapies

With advancing endoscopic technology and screening protocols for Barrett disease, more patients are being diagnosed with early-stage esophageal cancer. These early-stage patients may be amendable to endoscopic therapies, such as endomucosal resection and ablation. These therapies may minimize morbidity, but the elevated risk of recurrence cannot be overlooked. This article reports outcomes and recommendations for surveillance and management of recurrent esophageal cancer following endoscopic therapies.

Endoscopic resection combined with the Cryoballoon focal ablation system in the porcine normal esophagus: a preclinical study

BACKGROUND

The Cryoballoon focal ablation system (CbFAS) for dysplastic Barrett's esophagus is simple, time-saving and has high therapeutic efficacy. This study aimed to evaluate the technical feasibility and tissue damage with combination therapy of endoscopic resection (ER) and CbFAS in porcine models.

METHODS

Three pigs (A, B, and C) were included, and all ER procedures were performed by endoscopic mucosal resection using the Cap method (EMR). Combination therapy for each pig was performed as follows: (a) CbFAS was performed for a post-EMR mucosal defect for Pig A; (b) CbFAS for post-EMR scar for Pig B, and (c) EMR for post-CbFAS scar for Pig C. All pigs were euthanized at 32 days after the initial procedure, and the tissue damage was evaluated.

RESULTS

All endoscopic procedures were followed as scheduled. None of the subjects experienced anorexia, rapid weight loss, bleeding, and perforation during the observation period. They were euthanized at 32 days after the initial endoscopic procedure. On histological assessment, there was little difference between the tissue that was treated with CbFAS alone and that treated with CbFAS in combination with ER.

CONCLUSION

Combination therapy with ER and CbFAS can be technically feasible, and its outcome was not significantly different from CbFAS alone in terms of tissue damage.

Close Observation versus Additional Surgery after Noncurative Endoscopic Resection of Esophageal Squamous Cell Carcinoma

INTRODUCTION

After noncurative endoscopic submucosal dissection (ESD) of superficial esophageal squamous cell carcinoma (SESCC), additional esophagectomy is generally recommended. However, considering its high mortality and morbidity, it is uncertain if additional surgery improves the clinical outcomes. This study aimed to compare the clinical outcomes between patients who were observed without additional treatment and those who underwent radical esophagectomy.

METHODS

A total of 52 patients with SESCC who underwent complete but noncurative ESD from January 2008 to December 2016 at the Samsung Medical Center and Asan Medical Center in Korea were retrospectively analyzed. Clinicopathologic characteristics and oncologic outcomes were compared between the observation group (n = 23) and the additional surgery group (n = 29).

RESULTS

During a mean follow-up of 34.4 and 41.7 months, respectively, the rates of death (observation vs. surgery, 17.4 vs. 10.3%; p = 0.686), recurrence (observation vs. surgery, 13 vs. 17.2%; p = 1.000), and disease-specific death (observation vs. surgery, 4.3 vs. 6.9%; p = 1.000) did not significantly differ between the 2 groups. The 3-year overall survival was 86.3 and 96.4%, respectively (p = 0.776). The 3-year recurrence-free survival (observation vs. surgery, 85.0 vs. 88.7%; p = 0.960) and disease-specific survival (observation vs. surgery, 95.2 vs. 96.4%; p = 0.564) also did not significantly differ.

CONCLUSIONS

The clinical outcomes of close observation of noncuratively resected SESCC are comparable to those of additional surgery, at least in the midterm. The wait-and-see strategy could be a feasible management option after noncurative ESD of SESCC in selected patients.

Prognostic risk factors associated with esophageal squamous cell carcinoma patients undergoing endoscopic submucosal dissection: a multi-center cohort study

BACKGROUND

Long-term outcomes of endoscopic submucosal dissection (ESD) for esophageal squamous cell carcinoma (ESCC) have not been assessed in a large, multicenter cohort. We aimed to evaluate long-term outcomes of ESD for ESCC in a real-world setting.

METHODS

We retrospectively recruited 659 patients who underwent ESD for ESCC at ten institutions from January 2007 to December 2015. Of these, 566 patients were analyzed and classified into three groups according to the pathologic invasion depth after ESD: epithelium/lamina propria mucosa (EP/LPM group: 454 patients), muscularis mucosa/submucosa invasion ≤ 200 μm below the inferior margin of the muscularis mucosa (MM/SM1 group: 81 patients), and submucosa invasion > 200 μm below the MM inferior margin (SM2 group: 31 patients).

RESULTS

The 5-year overall survival rates in the EP/LPM, MM/SM1, and SM2 groups were 92.6%, 80.0%, and 62.7%, respectively, while the 5-year disease-specific survival rates were 99.7%, 96.9%, and 88.3%, respectively. Multivariate analyses revealed that the invasion depth, Charlson Comorbidity Index (CCI), and prognostic nutritional index (PNI) were independent prognostic factors. Hazard ratios in the MM/SM1 and SM2 groups were 2.25 (95% confidence interval [CI] 1.04-4.83; P = 0.038) and 3.18 (95% CI 1.08-9.34; P = 0.036), respectively, compared to those in the EP/LPM group, while those for patients with a CCI ≥ 3 and PNI ≤ 47.75 were 3.25 (95% CI 1.79-5.89; P < 0.001) and 2.42 (95% CI 1.26-4.65; P = 0.008), respectively.

CONCLUSIONS

This study identified that invasion depth, presence of comorbid diseases and preoperative nutritional status are independent prognostic risk factors associated with ESCC patients undergoing ESD.

A Review of Endoscopic Full-thickness Resection, Submucosal Tunneling Endoscopic Resection, and Endoscopic Submucosal Dissection for Resection of Subepithelial Lesions

Gastrointestinal subepithelial tumors (SETs) are often found while performing routine endoscopy. Recently, there has been the development of new endoscopic techniques such as endoscopic submucosal dissection, submucosal tunnel endoscopic resection, and endoscopic full-thickness resection, all minimally invasive approaches which have made it possible to resect SETs that were previously resected with surgery. This review discusses the endoscopic treatment of patients with SETs, outcomes for endoscopic treatment, procedure-related complications, and advantages and disadvantages of these endoscopic techniques.

Clinical outcomes of endoscopic resection of preoperatively diagnosed non-circumferential T1a-muscularis mucosae or T1b-submucosa 1 esophageal squamous cell carcinoma

In Japan, preoperatively diagnosed T1a-muscularis mucosae or T1b-submucosa 1 (MM/SM1) esophageal squamous cell carcinoma (ESCC) is a relative indication for endoscopic resection (ER). We evaluated long-term outcomes in patients after ER for non-circumferential ESCC with a preoperative diagnosis of MM/SM1 invasion. We retrospectively reviewed 66 patients with a preoperative diagnosis of non-circumferential MM/SM1 ESCC endoscopically resected between 2010 and 2015. Patients were divided into low- (adequate follow-up) and high-risk (requiring additional treatment) groups for lymph node metastasis according to risk factors (submucosal invasion, lymphovascular invasion, or droplet infiltration) and long-term outcomes were analyzed. Pathological invasion to T1a-lamina propria mucosa, MM/SM1, and T1b-SM2 was seen in 22, 38, and 6 lesions, respectively. Overall, 71.2% patients were classified into the "adequate follow-up" group. Of these, only one patient had a lymph node recurrence, which was successfully treated by additional therapy. The remaining 28.8% patients were classified into the "requiring additional treatment" group, where no recurrences were observed after additional treatments. After a median follow-up of 58.6 months, no deaths happened due to ESCC. The 3- and 5-year overall survival rates were 93.6% and 88.7%, respectively. ER is a valid initial treatment for non-circumferential ESCC with preoperatively diagnosed MM/SM1 invasion.

Robust closure of post-endoscopic submucosal dissection perforation by microparticle-based wound dressing

Endoscopic submucosal dissection (ESD) has been used as a minimally invasive cancer treatment for early-stage gastrointestinal cancer. However, cancer dissection in thin tissues, such as the duodenum and large intestine, often cause post-ESD and delayed perforation, which elicit severe complications. In this study, we report a microparticle-based wound dressing with hydrophobically-modified gelatin that can close the perforation after ESD. Hydrophobized microparticles were prepared using a coacervation method in a water/ethanol mixed solvent. The optimized alkyl chain length and degree of substitution of hydrophobic groups improved the mechanical strength of the hydrogel formed by hydration and fusion of the microparticles. The hydrogels formed on tissue defects revealed higher burst strength in ex vitro perforation models using duodenum, large intestine, and stomach under wet conditions compared with hydrogels without hydrophobic modification. The particle fusion was determined to be a crucial step to yield a high burst strength. An in vivo degradability evaluation showed that microparticle hydrogels subcutaneously implanted in rats degraded within 14 days. The microparticle wound dressing is expected to be applicable to post-ESD perforation and prevent delayed perforation.

Prevention of Stricture after Endoscopic Submucosal Dissection for Superficial Esophageal Cancer: A Review of the Literature

Endoscopic resection has been the standard treatment for intramucosal esophageal cancers (ECs) because of the low risk of lymph node metastases in the lesions. In recent years, endoscopic submucosal dissection (ESD), which can resect large ECs, has been performed. However, the risk of esophageal stricture after ESD is high when the mucosal defect caused by the treatment exceeds 3/4 of the circumference of the lumen. Despite the subsequent high risk of luminal stricture, ESD has been performed even in cases of circumferential EC. In such cases, it is necessary to take measures to prevent stricture. Therefore, in this review, we aimed to clarify the current status of stricture prevention methods after esophageal ESD based on previous literature. Although various prophylactic methods have been reported to have stricture-preventing effects, steroid injection therapy and oral steroid administration are mainstream. However, in cases of circumferential EC, both steroid injection therapy and oral steroid administration cannot effectively prevent luminal stricture. To solve this issue, clinical applications, such as tissue shielding methods with polyglycolic acid sheet, autologous oral mucosal epithelial sheet transplantation, and stent placement, have been developed. However, effective prophylaxis of post-ESD mucosal defects of the esophagus is still unclear. Therefore, further studies in this research field are needed.

Is a proton-pump inhibitor necessary after endoscopic submucosal dissection for superficial esophageal neoplasms? A propensity score analysis

BACKGROUND

Little is known about the efficacy of proton-pump inhibitor (PPI) therapy in the management of esophageal ulcers after endoscopic submucosal dissection (ESD). Therefore, the objective of this study was to investigate the efficacy of PPI in ulcer healing following ESD for superficial esophageal neoplasms, using a propensity score analytic approach.

METHODS

This retrospective cohort study was conducted at a single referral center. Between April 2005 and August 2015, 199 consecutive patients with superficial esophageal cancer and esophageal dysplasia underwent ESD. For patients with PPI administration, intravenous PPI therapy was commenced immediately after ESD, and oral PPI was administered daily from post-operative day 3, until ulcer healing was identified. We compared the remnant-ulcer rate at 4 weeks after esophageal ESD between the PPI administration and non-PPI groups, using propensity scores and the inverse probability of treatment weighting (IPTW) method.

RESULTS

After exclusions, a total of 88 patients were analyzed. The remnant-ulcer rate at 4 weeks after ESD was 25.5% (12/47) and 14.6% (6/41) in the PPI administration and non-PPI groups (p = 0.21). After adjusting for background factors using IPTW, the risk of a remnant ulcer in the PPI administration group was not decreased significantly compared with that in the non-PPI group [odds ratio (OR) = 2.42, 95% confidence interval (CI): 0.73-7.97, p = 0.15]. Furthermore, PPI therapy did not decrease significantly the remnant-ulcer rate on logistic regression analysis after adjusting for the propensity score (OR = 2.40, 95% CI: 0.69-8.32, p = 0.15).

CONCLUSION

PPI administration does not promote ulcer healing after ESD for superficial esophageal squamous cell carcinoma.

Perforation of a Gastric Tear during Esophageal Endoscopic Submucosal Dissection under General Anesthesia

Mallory-Weiss tears (MWT) are occasionally encountered during endoscopic procedures. Esophageal endoscopic submucosal dissection (ESD) is widely performed under general anesthesia to avoid unexpected body movements. We present the case of a 68-year-old woman with squamous cell carcinoma. Although ESD was performed under general anesthesia, a gastric perforation at the MWT caused by gastric inflation was observed after the procedure. The perforation was closed endoscopically, and she was discharged without any sequelae. Although general anesthesia is useful for esophageal ESD, it should be noted that it can cause MWT, and in rare cases, gastric perforation, due to gastric inflation during the procedure.

Prophylactic steroid administration against strictures is not enough for mucosal defects involving the entire circumference of the esophageal lumen after esophageal endoscopic submucosal dissection (ESD)

BACKGROUNDS

The width of mucosal defects after endoscopic submucosal dissection (ESD) of esophageal squamous cell carcinoma (ESCC) is known to be a risk factor for esophageal strictures. Although steroid injection and oral steroid have recently been reported as prophylactic treatments, these were shown to be ineffective in a subset of patients with post-ESD mucosal defects involving the entire circumference of the esophagus. The aim of this study was to demonstrate outcome with prophylactic steroid administration for post-ESD mucosal defects involving the entire circumference, and to explore risk factors for esophageal strictures except for circumference of the esophagus.

METHODS

Between November 2012 and August 2018, we enrolled patients with post-ESD mucosal defects involving the entire circumference of the esophagus who had received steroid injection (triamcinolone acetonide 50-100 mg, given immediately after ESD) followed by oral steroid (prednisolone 30 mg/day, tapered gradually over 8 weeks) as prophylactic treatment. Esophageal stricture was defined as case where ordinary-sized endoscope could not pass through post-ESD site, thus requiring endoscopic balloon dilation (EBD) repeatedly until relief of stricture was achieved. We retrospectively evaluated the rates of strictures, refractory strictures (requiring ≥ 6 EBD procedures) and unimproved strictures (not improvable by repeated EBD alone) and explored risk factors for strictures.

RESULTS

A total of 26 patients met the including criteria. The rates of strictures, refractory strictures, and unimproved strictures were 62%, 38%, and 12%, respectively. The pre-ESD longitudinal extension of the lesion > 5 cm was identified as a risk factor for refractory strictures, suggesting that lesions with this factor had a shorter time to stricture development, required more EBD procedures, and longer EBD durations.

CONCLUSION

Although additional study is required in a larger number of patients, careful consideration needs to be given to ESD as an indication for large spreading ESCC involving the entire circumference of esophagus given its high stricture risk.

Usefulness of argon plasma coagulation for superficial esophageal squamous cell neoplasia in patients at high risk or with limited endoscopic resectability

BACKGROUND/AIMS

Endoscopic resection is the standard treatment for superficial esophageal squamous-cell neoplasia (SESCN). However, we encounter patients in whom endoscopic resection is difficult to perform. We retrospectively studied the usefulness of argon plasma coagulation (APC) in patients with SESCN.

MATERIALS AND METHODS

The study comprised 45 patients with SESCN (81 lesions) who underwent APC in our hospital from March 1999 through August 2016. Clinicopathological characteristics, treatment time, the presence or absence of metastasis and recurrence, adverse events, and outcomes were studied.

RESULTS

The median follow-up was 40 months. The median age was 70 years. The tumor diameter was 10 mm or longer in 48 lesions and less than 10 mm in 33 lesions. The median treatment time was 22 minutes. The reasons for selecting APC were as follows: technical difficulty caused by the presence of metachronous multiple lesions in the radiation field after chemoradiotherapy or close proximity to the ulcer scar remaining after endoscopic treatment in 49 lesions (60.4%), and the presence of underlying diseases in 26 lesions (32.0%). Adverse events occurred in 2 patients (4.4%) who had hypoxemia due to over-sedation. Two lesions (2.5%) recurred locally but could be locally controlled by additional APC. No patient had metastasis or recurrence or died of esophageal neoplasia. The 3-year overall survival rate was 87.0%, and the 3-year recurrence-free survival rate was 97.2%.

CONCLUSION

APC can be a useful treatment option for SESCN in patients with a limited life expectancy, poor performance status, or technical difficulty in resection of superficial neoplasms.

Long-Term Prognostic Predictors of Esophageal Squamous Cell Carcinoma Potentially Indicated for Endoscopic Submucosal Dissection

INTRODUCTION

Patients with esophageal squamous cell carcinoma (ESCC) have various comorbidities. Thus, it is necessary to determine the appropriateness of performing treatment based on the patient's general condition.

AIM

This study aimed to clarify the prognostic predictors of ESCC indicated for endoscopic submucosal dissection (ESD).

METHODS

This retrospective study enrolled 241 patients with superficial ESCC endoscopically diagnosed as ESD-indicated lesions at the Nagoya University Hospital between January 2007 and December 2017. We evaluated the 3- and 5-year overall survival (OS) rates and prognostic predictors, such as the Prognostic Nutritional Index (PNI), Charlson Comorbidity Index (CCI), Psoas Muscle Index, and Controlling Nutritional Status score. Furthermore, we created a score-based classification using the prognostic predictors identified by multivariate analysis, and the 3- and 5-year OS rates were compared among the calculated scores.

RESULTS

In the multivariate analysis, PNI < 45 (hazard ratio [HR]: 2.39; 95% confidence interval [CI]: 1.28-4.46; p = 0.006) and CCI ≥ 3 (HR: 4.42; 95% CI: 2.40-8.12; p < 0.001) were significantly associated with the OS. Based on the HR, 0 and 1 were assigned to PNI and 0, 2, and 4 were assigned to CCI, and the score classification of 0-5 points was created. The 3- and 5-year OS rates in patients with a score 3 were significantly higher than in those with scores 4 and 5. As a result of scoring, the prognosis was stratified; the 3- and 5-year OS rates in patients with scores 4 and 5, that is, CCI ≥ 6, were clearly low, at approximately 10%.

CONCLUSIONS

CCI and PNI can be prognostic predictors of patients with superficial ESCC indicated for ESD. Observation without ESD might be an acceptable strategy among patients with CCI ≥ 6.

Risk factors of metachronous recurrence after endoscopic submucosal dissection for superficial esophageal squamous cell carcinoma

Esophageal endoscopic submucosal dissection (ESD) can be a curative treatment for superficial esophageal squamous cell carcinoma (SESCC). However, it is unclear whether the development of metachronous recurrence after ESD may be explained based on several risk factors. This study aimed to assess the incidence and the risk factors of metachronous recurrence of SESCC after ESD. This retrospective analysis was conducted at Samsung Medical Center, Seoul, Korea, from April 2007 to May 2018. Two hundred and fifty-three SESCC patients treated with ESD were followed using surveillance endoscopy after the procedure. Risk factors for metachronous esophageal SCC were analyzed using the Kaplan-Meier method and Cox's proportional hazards model. Metachronous esophageal SCCs were found in 21 (8.3%) of the 253 patients. Six patients (2.4%) with extraesophageal recurrence such as lymph node metastasis confirmed by imaging were excluded from patients with metachronous recurrence and data were censored from the recurrence date. Univariate analysis revealed that the presence of many (>10) irregularly shaped multiform Lugol-voiding lesions (LVLs) around the main lesion, margin of the main LVL, and tumor differentiation were risk factors for the development of metachronous cancer. Multivariate analysis also revealed that many (>10) LVLs (hazard ratio [HR], 6.32; 95% confidence interval [CI], 1.62-24.72; p = 0.047) and unclear or spiculated margin of the main LVL (HR, 6.51; 95% CI, 1.44-29.42; p = 0.029) were associated with the risk of metachronous recurrence. Metachronous esophageal SCC develops in patients treated with ESD for SESCC. A risk assessment is important for surveillance before and after ESD for SESCC. Number of LVLs and tumor edge type are associated with an increased risk of metachronous cancer in SESCC. Patients will benefit from careful endoscopic surveillance when endoscopists pay attention to these tumor characteristics.

EMR/ESD: Techniques, Complications, and Evidence

PURPOSE OF REVIEW

To discuss endoscopic resection techniques of early gastrointestinal malignancy. The review will focus on the indications and outcomes of endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD).

RECENT FINDINGS

EMR is indicated for upper GI lesions less than 20 mm provided they can be easily lifted and have a low risk of submucosal invasion (SMI). ESD should be considered for esophageal and gastric lesions that are bulky, show intramucosal carcinoma, or have a risk of superficial submucosal invasion. With regard to colonic polyps, EMR is acceptable for the removal of large colonic polyps using a piecemeal technique. ESD can be reserved for rectal neuroendocrine tumors, fibrotic polyps, or polyps harboring early malignancy. In selected cases, particularly in lesions less than 2 cm in size, EMR can be safe and effective. For larger lesions or lesions with submucosal invasion, ESD is effective and curative. Choosing the best approach can be tailored for each patient depending on lesion size, pathology, and availability of local expertise.