Endoscopic Submucosal Dissection for Gastrointestinal Superficial Lesions: Initial Experience in a Single Portuguese Center

Outcomes and Learning Curve in Endoscopic Submucosal Dissection of Rectal Neoplasms with Severe Fibrosis: Experience of a Western Center

<b><i>Introduction:</i></b> Endoscopic submucosal dissection (ESD) of lesions with severe submucosal fibrosis has been associated with worse outcomes, such as lower curative resection rate and higher incidence of adverse events. This study aims to investigate its true impact on rectal ESD performed in the West and to assess predictive factors of severe fibrosis. <b><i>Methods:</i></b> We conducted a retrospective study including all rectal ESDs performed at our tertiary center from January 2013 to January 2021. Lesions were grouped as nonsevere fibrosis or severe fibrosis. ESD outcomes, predictors of severe fibrosis, and the learning curve were evaluated. <b><i>Results:</i></b> ESD was performed in 195 lesions, 45 with severe fibrosis. Three resections were interrupted (one due to severe fibrosis). The presence of severe fibrosis was related to a significantly lower resection speed (16.93 mm²/min vs. 24.66 mm²/min, <i>p</i> = 0.007), en bloc (86.4% vs. 96.6%, <i>p</i> = 0.019), R0 (61.4% vs. 79.7%, <i>p</i> = 0.013), and curative (54.5% vs. 78.4%, <i>p</i> = 0.003) resection rates and a higher rate of hybrid ESD required to complete resection (13.6% vs. 2.0%, <i>p</i> = 0.005). No significant difference was noted regarding adverse events rate (18.2% vs. 8.1%, <i>p</i> = 0.09). Male sex, ulcerative colitis, pelvic radiotherapy, a lesion on the anastomotic site, previous manipulation, and deep submucosal invasion were independent predictors for severe fibrosis. En bloc resection rate improved during time (60.0% vs. 94.1%, <i>p</i> = 0.018). <b><i>Conclusions:</i></b> Severe submucosal fibrosis is an important factor related to noncurative resections and challenging rectal ESD. Factors predicting its severity are extremely important and could allow more experienced endoscopists to be assigned to more difficult cases, allowing safer procedures.

Colorectal Endoscopic Submucosal Dissection in a Western Center: Analysis of Outcomes and Safety Profile

Introduction

Endoscopic submucosal dissection (ESD) is a well-established endoscopic technique for the treatment of gastrointestinal lesions. Colorectal ESD outcomes are less reported in the Western literature, and Portuguese data are still very scarce. Our aim was to describe our experience on colorectal ESD regarding its outcomes and safety profile.

Methods

We conducted a retrospective evaluation of recorded data on ESDs performed between 2015 and 2020. Only ESDs performed on epithelial neoplastic lesions were selected for further analysis.

Results

Of a total of 167 colorectal ESDs, 153 were included. Technical success was achieved in 147 procedures (96%). The lesions were located in the colon (n = 24) and rectum (n = 123). The en bloc resection rate was 92% and 97%, the R0 resection rate was 83% and 82%, and the curative resection rate was 79% and 78% for the colon and the rectum, respectively. The need for a hybrid technique was the only risk factor for piecemeal or R1 resection. We report a perforation rate of 3.4% and a 4.1% rate of delayed bleeding; all the adverse events were manageable endoscopically, without the need of blood transfusions or surgery. Most of the lesions were laterally spreading tumours of the granular mixed type (70%), and 20% of the lesions were malignant (12% submucosal and 8% intramucosal cancer).

Conclusion

Our series on colorectal ESD reports a very good efficacy and safety profile. This technique can be applied by endoscopists experienced in ESD.

A highly intuitive and ergonomic redundant joint master device for four-degrees of freedom flexible endoscopic surgery robot

BACKGROUND

Studies have been conducted on slave-specific master devices with a similar kinematic structure to the slave to enhance intuitiveness. However, for the four-degrees of freedom (DOFs) slave of a flexible endoscopic surgery robot, only four DOFs in the master device causes low ergonomic performance.

METHODS

To enhance ergonomic performance, a second yaw joint was added as a redundant joint after considering the range of wrist motion and the workspace shape. Three experiments were performed to compare the intuitiveness and ergonomic performance of the proposed device with four-DOFs slave-specific and six-DOFs general-purpose master devices.

RESULTS

Significant differences were observed in terms of intuitiveness performance between the slave-specific and the general-purposed master device. On the other hand, there was no significant difference in ergonomic performance between the master devices with redundant joint.

CONCLUSIONS

Compared with a general-purpose master device, the proposed one exhibited noticeably improved intuitiveness performance and comparable ergonomic performance.

Effect of backlash hysteresis of surgical tool bending joints on task performance in teleoperated flexible endoscopic robot

BACKGROUND

The tendon-sheath mechanism provides flexibility but degrades the task performance of the flexible endoscopic robot because of the inherent backlash hysteresis problem. Previous studies have only focused on reducing backlash hysteresis. The goal of this study is to identify the backlash hysteresis criteria of surgical tool bending joints to maintain efficient surgical performance.

METHODS

A test platform for a surgical tool has been developed that has initial backlash hysteresis under 5° and can adjust the backlash hysteresis intentionally. Performance variation has been investigated in three bench-top endoscopic tasks in which various backlash hysteresis conditions were intentionally adjusted.

RESULTS

A clear drop-off in task performance has been observed when the backlash hysteresis of the bending joints was greater than 10° regardless of the type of task and link length.

CONCLUSIONS

The backlash hysteresis of surgical tool bending joints should be reduced to at least 10° to maintain efficient performance in robotic endoscopic surgery.

Endoscopic Submucosal Dissection for the Treatment of Superficial Epithelial Gastric Neoplasia in a Portuguese Centre

Background

The emergence of endoscopic submucosal dissection (ESD) made possible en bloc resection of neoplastic gastric lesions, regardless of lesion size, with reduced rates of complications and recurrence. This technique has become the preferred method for curative resection, instead of conventional endoscopic mucosal resection and surgery, when distant metastases have negligible risk. In Western countries experience with this technique has evolved quickly, with an increasing number of case series reported in the literature. This study aims to report the short- and long-term outcomes of ESD in gastric epithelial neoplastic lesions by a single operator in a Portuguese centre.

Methods

A retrospective analysis of all gastric ESDs in a tertiary specialised unit during a 5-year period, between May 2012 and September 2017, was performed.

Results

A total of 114 ESDs of gastric epithelial lesions were performed during this period; 96.5% of them were removed en bloc and 87.6% with R0 resection. A curative treatment was achieved in 83.2% of the cases. Complications occurred in 13.2% of the procedures, including early and delayed bleeding in 12 patients (10.5%) and one perforation (0.9%). With a median follow-up period of 12 months (interquartile range [IQR] = 18), 6 cases of recurrence at the previous ESD site were diagnosed: 4 residual lesions and 2 local recurrences in previous R0 resections. Residual lesions occurred more often in patients with larger lesions (median = 40.0 mm, IQR = 26 vs. median = 20.0 mm, IQR = 15, p = 0.008) and with positive horizontal margins (HMs) after resection (50.0 vs. 0.0%, Fisher exact test, p < 0.001). The cumulative incidence of metachronous gastric lesions at 34 months was 16.1%. All new lesions were effectively treated using an endoscopic technique. The disease-specific survival at 12 months was 100%.

Conclusion

This study showed that ESD is an effective resection technique for gastric lesions with a good safety profile, confirming other European series. Regardless, high en bloc resection positive HM is still a problem in some specimens resected by ESD. Endoscopic surveillance can detect local recurrence and new lesions during early stages, potentially treatable by endoscopy.

Safety analysis of laparoscopic endoscopic cooperative surgery versus endoscopic submucosal dissection for selected gastric gastrointestinal stromal tumors: a propensity score-matched study

BACKGROUND

Laparoscopic endoscopic cooperative surgery (LECS) is a safe alternative to endoscopic submucosal dissection (ESD) for select gastric gastrointestinal stromal tumors (GISTs) that are <2 cm in size. To date, there have been no randomized studies comparing the feasibility of these two techniques. Therefore, we compared their feasibility and safety using the propensity score matching method in this study.

METHODS

This was a single-center, retrospective, propensity score-matched study of patients who underwent resection of selected gastric GISTs between 2004 and 2014. All patients underwent curative resection for pathologically diagnosed small gastric GISTs. The primary aim was to determine intraoperative complications and postoperative courses. To overcome selection biases, we performed a 1:1 match using five covariates, including age, gender, body mass index, Charlson comorbidity index, and tumor location, to generate propensity scores.

RESULTS

In total, 32 patients treated with LECS and 102 patients treated with ESD were balanced into 30 pairs. The rate of intraoperative complications was significantly lower in the LECS group than in the ESD group (P = 0.029). LECS patients had less intraoperative bleeding than did ESD patients (15.0 ml [range 9.5-50.0 ml] vs. 43.5 ml [range 22.3-56.0 ml], P = 0.004). The two groups had similar postoperative courses. There was no difference in the reoperation rate between the two groups (P = 0.112). The ESD group had a shorter operating time than did the LECS group (41.5 min vs. 96.5 min, P < 0.001). However, during a follow-up of 57.9 (±28.9) months, the recurrence rate did not differ significantly between the two groups (0.0 vs. 6.7 %, respectively; P = 0.256).

CONCLUSIONS

LECS for selected gastric GIST patients is feasible and is associated with a better intraoperative outcome and an equal postoperative course compared with the results of ESD.