Novel technique for submucosal tunneling and endoscopic resection of submucosal tumors (with video)

A deep learning-based system to identify originating mural layer of upper gastrointestinal submucosal tumors under EUS

Background and Objective

EUS is the most accurate procedure to determine the originating mural layer and subsequently select the treatment of submucosal tumors (SMTs). However, it requires superb technical and cognitive skills. In this study, we propose a system named SMT Master to determine the originating mural layer of SMTs under EUS.

Materials and Methods

We developed 3 models: deep convolutional neural network (DCNN) 1 for lesion segmentation, DCNN2 for mural layer segmentation, and DCNN3 for the originating mural layer classification. A total of 2721 EUS images from 201 patients were used to train the 3 models. We validated our model internally and externally using 283 images from 26 patients and 172 images from 26 patients, respectively. We applied 368 images from 30 patients for the man-machine contest and used 30 video clips to test the originating mural layer classification.

Results

In the originating mural layer classification task, DCNN3 achieved a classification accuracy of 84.43% and 80.68% at internal and external validations, respectively. In the video test, the accuracy was 80.00%. DCNN1 achieved Dice coefficients of 0.956 and 0.776 for lesion segmentation at internal and external validations, respectively, whereas DCNN2 achieved Dice coefficients of 0.820 and 0.740 at internal and external validations, respectively. The system achieved 90.00% accuracy in classification, which is comparable with that of EUS experts.

Conclusions

Our proposed system has the potential to solve difficulties in determining the originating mural layer of SMTs in EUS procedures, which relieves the EUS learning pressure of physicians.

Treatment of leakage via metallic stents placements after endoscopic full-thickness resection for esophageal and gastroesophageal junction submucosal tumors

OBJECTIVE

The objective of this study is to evaluate the feasibility and efficacy of endoscopic full-thickness resection (EFTR) and fully covered retrievable self-expandable metal stents (SEMSs) placement for this kind of tumors.

METHODS

A total of six consecutive patients, presenting with esophageal and GE junction SMTs, received EFTR and SEMSs placement at the our endoscopic center between January 2015 and June 2015. Their medical records were thoroughly investigated.

RESULTS

EFTR was performed successfully in all cases. The en bloc resection rate was 100%. The final pathological diagnoses were leiomyomas in all six cases. No patients developed delayed bleeding. SEMSs were placed immediately after EFTR during the same endoscopic session except patient #1. Complete healing of esophageal leakage after stent placement was achieved for 6/6 patients (100%) without the need for surgical interventions. Stent migration occurred in one patient. No residual tumor or tumor recurrence was observed during the follow-up period.

CONCLUSIONS

EFTR combined with fully covered retrievable self-expandable metallic stents placement is a feasible and effective new method for providing radical treatments for SMTs from the deep MP layer of esophagus and GE junction. Standardization of the procedure should be studied further.

Submucosal tunneling endoscopic resection for gastrointestinal submucosal tumors originating from the muscularis propria layer

Submucosal tunneling endoscopic resection (STER) is a novel endoscopic technique for gastrointestinal submucosal tumors (SMT) originating from the muscularis propria layer, and has been proved to be effective by clinical studies. STER was initially created for esophageal and cardia SMT, but its indications have expanded due to the implication and modification of this technique. Herein, we review the indications, procedure, efficacy and complications of STER.

Submucosal Tunneling Endoscopic Resection (STER) and Other Novel Applications of Submucosal Tunneling in Humans

The submucosal tunneling technique was originally developed to provide safe access to the peritoneal cavity for natural orifice transluminal endoscopic surgery procedures. With this technique, the submucosal tunnel becomes the working space for partial myotomy and tumor resection. The submucosal space has come to represent the "third space" distinguished from gastrointestinal lumen (first space) and peritoneal cavity (second space). New applications continue to be developed and further clinical applications in the future are anticipated. This article summarizes the current applications of submucosal tunneling endoscopic resection for subepithelial tumors and describes other related uses of submucosal tunneling.

Endoscopic treatments for small gastric subepithelial tumors originating from muscularis propria layer

Minimally invasive endoscopic resection has become an increasingly popular method for patients with small (less than 3.5 cm in diameter) gastric subepithelial tumors (SETs) originating from the muscularis propria (MP) layer. Currently, the main endoscopic therapies for patients with such tumors are endoscopic muscularis excavation, endoscopic full-thickness resection, and submucosal tunneling endoscopic resection. Although these endoscopic techniques can be used for complete resection of the tumor and provide an accurate pathological diagnosis, these techniques have been associated with several negative events, such as incomplete resection, perforation, and bleeding. This review provides detailed information on the technical details, likely treatment outcomes, and complications associated with each endoscopic method for treating/removing small gastric SETs that originate from the MP layer.

Clinical impact of submucosal tunneling endoscopic resection for the treatment of gastric submucosal tumors originating from the muscularis propria layer (with video)

BACKGROUND

Submucosal tunneling endoscopic resection (STER) can be adequately adopted as an effective treatment for submucosal tumors (SMTs) originating from the muscularis propria (MP) layer at the esophagus and cardia. However, it has been seldom used for gastric SMTs. Our purpose was to evaluate the clinical impact of STER for gastric SMTs arising from the MP layer.

METHODS

Thirty-two patients with gastric SMTs from the MP layer were retrospectively included. The main outcome measurements were complete resection rate, adverse events, local recurrence, and distant metastases during follow-up.

RESULTS

Of the 32 lesions, 12 were located in the gastric corpus close to the cardia, 3 in the gastric fundus close to the cardia, 6 in the lesser curvature of the gastric corpus, and 11 in the greater curvature of the gastric antrum. STER was successfully performed in all patients with en bloc resection of tumors. The mean tumor size was 2.3 cm (range 1.0-5.0 cm). The complete resection rate was 100%. The operation time ranged from 25 to 125 min (mean 51.8 min). All complications related to STER were successfully managed with conservative treatments. Local recurrence or distant metastasis did not occur during a follow-up period of 6-32 months.

CONCLUSION

STER is a safe and effective therapeutic strategy for eligible gastric SMTs originating from the MP layer. Submucosal tunneling in the stomach may be more challenging than that in the esophagus, but does not increase procedure-related adverse events or prevent successful STER for eligible gastric SMTs.

Submucosal tunneling and endoscopic resection of submucosal tumors at the esophagogastric junction

AIM: To evaluate the safety and efficacy of submucosal tunneling and endoscopic resection (STER) for treating submucosal tumors (SMTs).

METHODS: Between August 2012 and October 2013, 21 patients with SMTs originating from the muscularis propria (MP) layer at the esophagogastric junction were treated by STER of their tumors. Key steps of the procedure include: (1) mucosal incision: a 2-cm longitudinal mucosal incision was made 5 cm proximal to the tumor; (2) submucosal tunneling: a submucosal tunnel was created 5 cm proximal to and 1 to 2 cm distal to the tumor; (3) tumor resection: the SMT was resected under direct endoscopic viewing; (4) hemostasis: while finishing the tumor resection, careful hemostasis of the MP defect and the tunnel was performed; and (5) mucosal closure: the mucosal incision site was closed by using hemostatic clips. During the operation, equipment used included a cap-fitted endoscope, an insulated-tip knife, a hook knife, hemostatic forceps, an injection needle, a snare, an endoclip, and a high-frequency generator. Carbon dioxide (CO₂) insufflation was achieved by using a CO₂ insufflator.

RESULTS: The median age of the patients was 46.2 years (range, 35-59 years), and the majority were male (18 male vs 3 female). Complete resection rate was 100% (21/21). Eighteen lesions were resected en bloc. Mean tumor size was 23 mm (range, 10-40 mm), and mean procedure time was 62.9 min (range, 45-90 min). Pathological diagnosis of these tumors included leiomyoma (15 out of 21) and gastrointestinal stromal tumor (6 out of 21). Full-thickness MP resection was performed in 9 of 21 patients (42.9%), with mediastinal and subcutaneous emphysema occurring in all nine. At the completion of the procedure, all patients received closure of the incision with hemoclips. One patient required percutaneous drainage. The remaining 20 patients required no further endoscopic or surgical intervention. There were no incidents of massive or delayed bleeding. The median follow-up period after the procedure was 6 mo (range, 2-14 mo). During follow-up, no patients were found to have residual or recurrent tumor or esophageal stricture.

CONCLUSION: STER is safe, effective and feasible, which provides accurate histopathologic evaluation and curative treatment for SMTs originating from the MP layer at the esophagogastric junction.

Developments in flexible endoscopic surgery: a review

Flexible endoscopy is increasingly developing into a therapeutic instead of a purely diagnostic discipline. Improved visualization makes early lesions easily detectable and allows us to decide ad hoc on the required treatment. Deep enteroscopy allows the exploration of even the small bowel - for long a "white spot" for gastrointestinal endoscopy - and to perform direct treatment. Endoscopic submucosal dissection is a considerable step forward in oncologically correct endoscopic treatment of (early) malignant lesions. Though still technically challenging, it is increasingly facilitated by new manipulation techniques and tools that are being steadily optimized. Closure of wall defects and hemostasis could be improved significantly. Even the anatomy beyond the gastrointestinal wall is being explored by the therapeutic use of endoluminal ultrasound. Endosonographic-guided surgery is not only a suitable fallback solution if conventional endoscopic retrograde cholangiopancreatography fails, but even makes necrosectomy procedures, abscess drainage, and neurolysis feasible for the endoscopist. Newly developed endoscopic approaches aim at formerly distinctive surgical domains like gastroesophageal reflux disease, appendicitis, and cholecystitis. Combined endoscopic/laparoscopic interventional techniques could become the harbingers of natural orifice transluminal endoscopic surgery, whereas pure natural orifice transluminal endoscopic surgery is currently still in its beginnings.

Endoscopic excavation for gastric heterotopic pancreas: an analysis of 42 cases from a tertiary center

BACKGROUND

Because of the difficulty associated with making an accurate diagnosis of gastric heterotopic pancreas (HP) before surgery, surgical resection is usually performed in suspected cases. However, this is an invasive procedure and prone to certain surgical complications.

AIMS

This study was designed to evaluate the feasibility of endoscopic excavation for gastric HP, as well as the value of endoscopic ultrasonography (EUS) in diagnosing gastric HP.

METHODS

Between January 2007 and January 2013, 42 consecutive patients with gastric HP were enrolled in this retrospective study. Key steps: (1) Injection of a solution (100 ml saline + 2 ml indigo carmine + 1 ml epinephrine) into the submucosal layer after making several dots around the lesion; (2) Incision of the mucosa outside the marker dots with a needle-knife, and then circumferential excavation until complete resection of the lesion; (3) Closure of the artificial ulcer with several clips after tumor removal.

RESULTS

In this study, 18 cases (42.9%) were suspected as gastric HP (assessed by two experienced endoscopists before endoscopic excavation), 8 (19.0%) were suspected as gastrointestinal stromal tumors, 7 (16.7%) as gastric polyp, and the remaining 9 cases (21.4%) were still unknown. The mean procedure duration was 28.6 min. En bloc resection by endoscopic excavation was achieved in 40 cases (95.2%), and no massive bleeding, delayed bleeding, perforation, or other severe complication occurred in these patients. Among the 42 lesions, a tube echo could be detected in 11 cases by EUS. Those 11 cases were diagnosed as gastric HP by histopathology.

CONCLUSIONS

Endoscopic excavation appears to be a safe and feasible procedure for accurate histopathologic evaluation and curative treatment in gastric HP. Use of EUS has some value in the diagnosis of gastric HP before the procedure

Endosonography-assisted diagnosis and therapy of gastrointestinal submucosal tumors

Submucosal tumors (SMTs) are usually discovered fortuitously during routine endoscopy, including various non-neoplastic and neoplastic conditions. Endoscopic ultrasound (EUS) is considered to be the best imaging procedure to characterize SMTs and to determine the need for further treatment. In this review, the following issues will be addressed: The role of EUS in diagnosis for SMTs, tissue diagnosis for SMTs and the influence of EUS on endoscopic resection techniques for SMTs.

Endosonography-assisted diagnosis and therapy of gastrointestinal submucosal tumors

Submucosal tumors (SMTs) are usually discovered fortuitously during routine endoscopy, including various non-neoplastic and neoplastic conditions. Endoscopic ultrasound (EUS) is considered to be the best imaging procedure to characterize SMTs and to determine the need for further treatment. In this review, the following issues will be addressed: The role of EUS in diagnosis for SMTs, tissue diagnosis for SMTs and the influence of EUS on endoscopic resection techniques for SMTs.

Pilot study of 'Scissorhands' technique for gastric endoscopic submucosal dissection using novel gel and endoscopic scissors in a porcine model (with video)

BACKGROUND AND AIM

Endoscopic submucosal dissection (ESD) is a complex procedure and is associated with significant risks. The aims of this pilot study were to study feasibility and procedural times of gastric ESD using a novel gel and endoscopic scissors in a porcine model.

METHODS

Simulated 3-cm gastric submucosal lesions were created in a porcine model. Subsequently, viscous gel was injected into the created bleb. A needle knife was used to create an initial incision when needed. Endoscopic scissors were then used for circumferential incision around the simulated submucosal lesions. The inserted coil (i.e. submucosal lesion) was then removed. The submucosal surface was carefully examined for signs of injury. Procedural times were recorded.

RESULTS

ESD was carried out in four consecutive pigs using the 'Scissorhands' technique. A small submucosal incision was created a using needle knife in the first pig and electrocautery was not used in the remaining three pigs. Circumferential incision using the scissors was done successfully in all pigs. Submucosal dissection was not required in any case. 'Auto-dissection' of created lesions by the gel was noted to be complete in all cases. Inserted coils were noted in the submucosal space during all experiments and were removed. All lesions were successfully resected en bloc. The mean procedure time was 19 min (range 13-22 min).

CONCLUSION

The combined technique of endoscopic scissors for circumferential incision and viscous gel for submucosal dissection permitted easy, safe and efficient gastric ESD. Electrocautery may be avoided and its consequent adverse events (e.g. perforation).

Submucosal tunneling endoscopic resection for small upper gastrointestinal subepithelial tumors originating from the muscularis propria layer

BACKGROUND

This prospective study was designed to evaluate the safety and efficacy of submucosal tunneling endoscopic resection (STER) for small (≤3 cm) upper gastrointestinal (GI) subepithelial tumors (SETs) originating from the muscularis propria (MP) layer.

METHODS

Between August 2011 and February 2013, a total of 85 patients with upper GI SETs originating from the MP layer were treated with STER. The key steps were as follows: (1) locating the tumor by injection of methylene blue or indigo carmine and then creating a submucosal tunnel from 5 cm above the tumor between the submucosal and muscular layers; (2) resecting the tumor by endoscopic resection techniques; (3) closing the mucosal incision site with several clips after the tumor is removed.

RESULTS

Of the 85 SETs, 60 were located in the esophagus, 16 in the cardia, and 9 in the stomach. STER was successfully performed in all cases (success rate: 100 %). The mean tumor size was 19.2 mm. The mean procedure time was 57.2 min. The average hospital stay after the procedure was 5.9 days. Pathological diagnosis of the tumors were leiomyoma (65/85), gastrointestinal stromal tumor (GIST) (19/85), and calcifying fibrous tumor (1/85). During the procedure, eight patients developed pneumothorax, subcutaneous emphysema, and/or pneumoperitoneum. These patients recovered after conservative treatment. The rate of all complications was significantly higher for lesions originating in the deeper MP layer (70 %) than in the superficial MP layer (1.3 %; p < 0.001). The total complication rate for different histological diagnoses was also significantly different (26.3 % for GISTs, 4.6 % for leiomyomas, 0 % for calcifying fibrous tumors, p < 0.05). No residual or recurrent tumors were detected during the follow-up period (median: 8 months).

CONCLUSIONS

Submucosal tunneling endoscopic resection appears to be a feasible, safe, and effective procedure for treatment of small (≤3 cm) upper GI SETs originating from the MP layer.