Endoscopic partial resection with the unroofing technique for reliable tissue diagnosis of upper GI subepithelial tumors originating from the muscularis propria on EUS (with video)

Diagnostic yield of endoscopic and EUS-guided biopsy techniques in subepithelial lesions of the upper GI tract: a systematic review

BACKGROUND AND AIMS

Obtaining adequate tissue samples in subepithelial lesions (SELs) remains challenging. Several biopsy techniques are available, but a systematic review including all available techniques to obtain a histologic diagnosis of SEL is lacking. The aim of this study was to evaluate the diagnostic yield and adverse event rates of endoscopic biopsies, EUS-guided FNA (EUS-FNA), EUS-guided fine-needle biopsy (FNB) (EUS-FNB), and mucosal incision-assisted biopsy (MIAB) for SELs in the upper GI tract.

METHODS

A search strategy in multiple databases was performed. The primary outcome was diagnostic yield, defined as the percentage of procedures in which histology was obtained and resulted in a definitive histopathologic diagnosis. Secondary outcome measures included reported procedure-related adverse events, which were graded according to the AGREE (Adverse Events in Gastrointestinal Endoscopy) classification.

RESULTS

A total of 94 original articles were included. Studies were classified per endoscopic technique to obtain histopathology. This resulted in 8 included studies for endoscopic biopsy methods, 55 studies for EUS-FNA, 33 studies for EUS-FNB, and 26 studies for MIAB. Pooled rates for diagnostic yield were 40.6% (95% confidence interval [CI], 30.8-51.2) for endoscopic biopsy, 74.6% (95% CI, 69.9-78.7) for EUS-FNA, 84.2% (95% CI, 80.7-87.2) for EUS-FNB, and 88.2% (95% CI, 84.7-91.1) for MIAB. Reported procedure-related adverse events graded AGREE II or higher were 2.8% to 3.9% for endoscopic biopsies, 1.0% to 4.5% for EUS-FNA, .9% to 7.7% for EUS-FNB, and 1.9% to 7.9% for MIAB.

CONCLUSIONS

Based on the available evidence, MIAB and EUS-FNB seem to be most effective in terms of achieving a high diagnostic yield, with similar rates of adverse events.

Tissue diagnosis necessary for small endoscopic ultrasound-suspected gastric gastrointestinal stromal tumors 2 cm or less in size: A prospective study focusing on the endoscopic incisional biopsy

BACKGROUND AND AIM

The small endoscopic ultrasound (EUS)-suspected gastric gastrointestinal stromal tumors (GISTs), gastric subepithelial tumors at the muscularis propria layer on EUS, are detected frequently. Bite-on-bite forceps biopsy and EUS-guided tissue sampling yield variable results. This study aimed to analyze clinicopathologic features of the small EUS-suspected gastric GISTs 2 cm or less in size and to evaluate the efficacy and safety of the endoscopic incisional biopsy (EIB) for these small tumors.

METHODS

This prospective study investigated 70 patients with small EUS-suspected gastric GISTs 2 cm or less in size in two stages. Firstly, 30 patients were recruited for the efficacy and safety evaluation of the EIB. Secondly, 40 patients were randomly assigned to receive either EIB or the bite-on-bite biopsy for comparison of the diagnostic yield, procedure time, and adverse event rate.

RESULTS

Combining two study stages, leiomyoma (74%) was diagnosed histologically to outnumber GIST (26%) with a diagnostic rate of 94% for patients receiving EIB. KIT exon 11 mutations (50%) and PDGFRA exon 12 mutations (16%) were detected in the small gastric GISTs. In the direct comparison, the diagnostic yield of EIB and the bite-on-bite biopsy was 85% and 50%, respectively (P = 0.018). There was no statistically significant difference of the mean procedure time or adverse event rate between these two groups.

CONCLUSIONS

Leiomyoma is more common than expected among these small tumors. Tissue diagnosis with an effective and safe sampling technique, such as EIB, is necessary for making further clinical decisions.

The necessarity of treatment for small gastric subepithelial tumors (1-2 cm) originating from muscularis propria: an analysis of 972 tumors

Background and objectives

Up till now, there are still controversies about the specific indication of endoscopic resection for small gastric subepithelial tumors (gSETs) originating from muscularis propria. We aimed to investigate the safety of endoscopic resection and postoperative pathology analysis.

Method

The patients with primary small gSETs originating from muscularis propria, treated by endoscopic resection in the endoscopic center of Shengjing Hospital between January, 2011 and September, 2019 were enrolled. The complete resection rate, adverse events and clinicopathological features were recorded.

Result

A total of 936 patients with 972 gastric SETs ≤ 2 cm originating from muscularis propria were included in our study. All the lesions were successfully treated by endoscopic resection. Nearly half of lesions were proved to be gastrointestinal stromal tumor (GIST) [n = 411 (42.3%)] according to postoperative pathology. All the objects were further subdivided into 2 groups, ≤ 1 cm, > 1 and ≤ 2 cm gSETs. The risk of gastric GIST of intermediate/high risk in the group (> 1 and ≤ 2 cm gSETs) is 8.41 times as that of gastric GIST in the group (the size of gastric ≤ 1 cm gSETs) (P < 0.05).

Conclusion

Endoscopic resection is a safe and effective treatment for small gSETs. gSETs (1–2 cm) is more risky than gSETs (≤ 1 cm) and should be resected. This should be evaluated by further studies.

Endoscopic Resection of Gastrointestinal Stromal Tumor: Is It Safe?

Recently, results from clinical studies of endoscopic resection of gastrointestinal stromal tumor (GIST) in the stomach are being reported. This procedure has several advantages, such as the provision of a definite diagnosis and therapeutic plan, avoidance of frequent follow-up examination, and reduction of patients’ anxiety. However, several concerns also exist such as a limited number of studies, low R0 resection rate, and relatively shorter follow-up period compared with surgical resection. Nevertheless, it is encouraging that most of the post-procedural complications have been treated with conservative management and that some of the patients did not show recurrence of the tumor during long-term follow-up. The selection of suitable cases and the experience of the endoscopists are the most important factors for successful endoscopic resection of gastric GIST. Development of novel procedures as well as collaboration with laparoscopic surgeons are currently in progress.

Tunneled biopsy is an underutilised, simple, safe and efficient method for tissue acquisition from subepithelial tumours

BACKGROUND

Tissue acquisition from subepithelial lesions is often attempted by endoscopic ultrasound (EUS)-sampling as conventional endoscopic biopsy usually fails to reach deeper layers of the gastrointestinal wall.

AIM

To investigate the utilisation, safety and diagnostic yield of an intensified “bite-on-bite” tunnel biopsy technique.

METHODS

In this retrospective cohort study, all patients presenting with subepithelial masses in the upper gastrointestinal tract from March 2013 to July 2019 were included. Data were analysed for size and location of the subepithelial mass, use of intensified tunnel biopsy protocol (more than 10 double bite-on-bite biopsies) or superficial conventional biopsies, histology and imaging results, occurrence of readmission and adverse events after endoscopy.

RESULTS

Two hundred and twenty-nine patients with subepithelial lesions were included. Superficial conventional biopsies were taken in 117 patients and were diagnostic only in one lipoma (0.9 %). Tunnel biopsies taken in 112/229 (48.9%) patients were significantly more likely to provide histological diagnosis (53.6%; P < 0.001). For lesions ≥ 10mm the diagnostic yield of tunnel biopsies further increased to 41/67 (61.2%). No immediate or delayed complications were reported. Only 8 of the 51 endoscopists (15.7%) regularly attempted tunnel biopsies.

CONCLUSION

Tunnel biopsy is a simple, safe and efficient but underutilised diagnostic modality for tissue acquisition in subepithelial masses. It should be routinely attempted at the initial endoscopy.

Diagnosis of Pancreatic Solid Lesions, Subepithelial Lesions, and Lymph Nodes Using Endoscopic Ultrasound

Currently, endoscopic ultrasound (EUS) has become widely accepted and has considerable advantages over computed tomography (CT) and other imaging modalities, given that it enables echostructure assessment in lesions with <1 cm diameter and permits high resolution imaging. EUS-guided tissue acquisition (EUS-TA) provides consistent results under ultrasound guidance and has been considered more effective compared to CT- or ultrasound-guided lesion biopsy. Moreover, complication rates, including pancreatitis and bleeding, have been extremely low, with <1% morbidity and mortality rates, thereby suggesting the exceptional overall safety of EUS-TA. The aggressive use of EUS for various lesions has been key in facilitating early diagnosis and therapy. This review summarizes the diagnostic ability of EUS for pancreatic solid lesions, subepithelial lesions, and lymph nodes where it is mainly used. EUS has played an important role in diagnosing these lesions and planning treatment strategies. Future developments in EUS imaging technology, such as producing images close to histopathological findings, are expected to further improve its diagnostic ability. Moreover, tissue acquisition via EUS is expected to be used for precision medicine, which facilitates the selection of an appropriate therapeutic agent by increasing the amount of tissue collected and improving genetic analysis.

Gastric carcinoma with lymphoid stroma diagnosed by endoscopic ultrasound-guided fine-needle aspiration

A 78-year-old man with a subepithelial lesion (SEL) in the gastric body and two carcinomas in the gastric antrum was referred to our hospital. Following a diagnosis of SEL, the patient was followed-up by esophagogastroduodenoscopy annually for 4 years. Although the SEL had increased in size over the years, histological evaluation of the forceps biopsies did not reveal any significant findings. We detected a hypoechoic mass in the submucosa by endoscopic ultrasonography, and suspected the lesion to be an aberrant pancreas or mesenchymal tumor. The patient first underwent endoscopic submucosal dissection for the 2 gastric cancers. Histological examination of the resected specimens revealed intramucosal well-differentiated tubular adenocarcinomas. Next, endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) was performed for the gastric SEL. Aspirated specimens revealed an adenocarcinoma with lymphocyte infiltration. The lesion was diagnosed as a gastric carcinoma with lymphoid stroma (GCLS). Subsequently, he underwent distal gastrectomy, and the surgical specimen was confirmed as GCLS corresponding to preoperative diagnosis. In addition, the adenocarcinoma cells were positive for Epstein-Barr (EB) virus-encoded small RNA-1 by in situ hybridization. Finally, the lesion was diagnosed as GCLS associated with EB virus. Thus, EUS-FNA is advantageous for diagnosing GCLS associated with EB virus.

Signet Ring Cell Carcinoma Mimicking Gastric Gastrointestinal Stromal Tumor: A Case Report

The presentation of submucosal gastric cancer, especially signet ring cell carcinoma, is rare. The submucosal tumor (SMT) is covered with normal mucosa, and confirmation is difficult through endoscopic biopsy; thus, histologic diagnosis is important to determine the appropriate treatment method. Here, we report a case of gastric signet ring cell carcinoma mimicking gastrointestinal stromal tumor (GIST). A 2-cm-sized SMT suspected of being a GIST on preoperative endoscopic ultrasonography and computed tomography was suspected to be cancerous during surgery. The frozen diagnosis of the resected mass (obtained via wedge resection) showed a carcinoma with signet ring feature, and additional frozen diagnosis of one enlarged lymph node revealed metastatic cancer. Therefore, subtotal gastrectomy with lymph node dissection was performed. This case report suggests that preoperative histologic diagnosis of high-risk SMT might be useful, although the tumor had typical features of GIST on preoperative imaging. Overall, if a tumor is suspected of being a gastric carcinoma during surgery and the differential diagnosis between gastric carcinoma and GIST is uncertain, a careful surgical approach should be considered to account for the possibility of adenocarcinoma.

In vivo real-time diagnosis of endoscopic ultrasound-guided needle-based confocal laser endomicroscopy in gastric subepithelial lesions

BACKGROUND AND AIM

The effect of real-time analysis of needle-based confocal laser endomicroscopy (nCLE) for gastric subepithelial lesions (SELs) on the diagnostic value is unclear. The study aimed to investigate the diagnostic efficacy of real-time nCLE for gastric SELs and to assess the technical aspects and safety of real-time nCLE.

METHODS

Consecutive patients with gastric SELs ≥ 1 cm were prospectively investigated by endoscopic ultrasound (EUS), followed by nCLE. During EUS-nCLE, real-time nCLE diagnosis was made by an expert endoscopist. The procedure-relative adverse events were assessed and recorded. One-month washout period later, nCLE videos were reviewed off-line by the same endoscopist. The nCLE diagnoses were compared with corresponding pathological results. Additionally, image quality and interobserver agreements for the criteria were evaluated by three experienced endomicroscopists.

RESULTS

Except for one failing to be punctured, 60 patients completed EUS-nCLE procedures successfully. Real-time nCLE had high diagnostic accuracies of ≥ 88.3% for gastric SELs. There were no significant differences between real-time and off-line nCLE diagnoses for gastric SELs (P > 0.05). The overall accuracy of real-time nCLE for diagnosis of gastric SELs was 86.7%. There were no procedure-relative adverse events occurred. In addition, the mean image quality score was 3.6 (1 = poor and 5 = excellent). The interobserver agreement was "almost perfect" for ectopic pancreas and "substantial" for gastrointestinal stromal tumor, leiomyoma, and carcinoma.

CONCLUSIONS

Endoscopic ultrasound-nCLE could provide in vivo real-time diagnostic imaging with a high diagnostic accuracy. Meanwhile, real-time nCLE was feasible and had a satisfactory safety profile.

Reasons for Diagnostic Failure in Forty-Five Consecutive Mucosal Cutting Biopsy Examinations of Gastric Subepithelial Tumors

BACKGROUND/AIMS

Mucosal cutting biopsy (MCB) is useful for the histopathological diagnosis of gastric subepithelial tumors (SETs). However, there is little information on cases in which MCB did not establish a diagnosis. In the current study, we aimed to investigate the characteristics of cases in which MCB was unsuccessful.

METHODS

Cases in which MCB was used to histopathologically diagnose gastric SETs at Kobe University Hospital between August 2012 and October 2018 were retrospectively reviewed.

RESULTS

Forty-five cases in which MCB was used to diagnose 43 gastric SETs in 43 patients were analyzed. The median tumor size was 20 mm (range, 8-50 mm). Pathological examinations resulted in definitive and suspected diagnoses and no diagnosis in 29 (gastrointestinal stromal tumor: n=17, leiomyoma: n=7, aberrant pancreas: n=3, others: n=2), 6, and 10 cases, respectively. Failure to expose the tumor according to retrospective examinations of endoscopic images was significantly associated with no diagnosis. Other possible explanations included a less elevated tumor, biopsy of the surrounding field instead of the tumor due to the mobility, and poor endoscope maneuverability due to the tumor being close to the cardia.

CONCLUSION

Clear exposure of gastric SETs during MCB may improve the diagnostic rate of such examinations.

Superiority of mucosal incision-assisted biopsy over ultrasound-guided fine needle aspiration biopsy in diagnosing small gastric subepithelial lesions: a propensity score matching analysis

BACKGROUND

Gastric subepithelial lesions, including gastrointestinal stromal tumors, are often found during routine gastroscopy. While endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) has been the gold standard for diagnosing gastric subepithelial lesions, alternative open biopsy procedures, such as mucosal incision-assisted biopsy (MIAB) has been reported useful. The aim of this study is to evaluate the efficacy of MIAB for the diagnosis of gastric SELs compared with EUS-FNAB.

METHODS

We retrospectively analyzed medical records of 177 consecutive patients with gastric SELs who underwent either MIAB or EUS-FNAB at five hospitals in Japan between January 2010 and January 2018. Diagnostic yield, procedural time, and adverse event rates for the two procedures were evaluated before and after propensity-score matching.

RESULTS

No major procedure-related adverse events were observed in either group. Both procedures yielded highly-accurate diagnoses once large enough samples were obtained; however, such successful sampling was more often accomplished by MIAB than by EUS-FNAB, especially for small SELs. As a result, MIAB provided better diagnostic yields for SELs smaller than 20-mm diameter. The diagnostic yields of both procedures were comparable for SELs larger than 20-mm diameter; however, MIAB required significantly longer procedural time (approximately 13 min) compared with EUS-FNAB.

CONCLUSIONS

Although MIAB required longer procedural time, it outperformed EUS-FNAB when diagnosing gastric SELs smaller than 20-mm diameter.

Endoscopic ultrasound-guided fine-needle aspiration biopsy - Recent topics and technical tips

Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNA) is a useful procedure that enables reliable pathological diagnoses of pancreatobiliary diseases, subepithelial lesions, and swollen lymph nodes. In recent years, a pathological diagnosis based on EUS-FNA has made it possible to provide accurate treatment methods not only in these fields, but also in respiratory organs and otorhinolaryngology. This review discusses the latest topics pertaining to EUS-FNA as well as procedural tips.

Mucosal incision-assisted biopsy versus endoscopic ultrasound-guided fine-needle aspiration with a rapid on-site evaluation for gastric subepithelial lesions: A randomized cross-over study

OBJECTIVES

This study aimed to compare the diagnostic yield of mucosal incision-assisted biopsy (MIAB) and endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) with a rapid on-site evaluation (ROSE) for gastric subepithelial lesions (SEL) suspected of being gastrointestinal stromal tumors (GIST) with an intraluminal growth pattern.

METHODS

This was a prospective randomized, cross-over multicenter study. The primary outcome was the diagnostic yield of EUS-FNA and MIAB. The secondary outcomes were the technical success rate, complication rate, procedure time and biopsy frequency.

RESULTS

A total of 47 patients were randomized to the MIAB group (n = 23) and EUS-FNA group (n = 24). There was no significant difference in the diagnostic yield of MIAB and EUS-FNA (91.3% vs 70.8%, P = 0.0746). The complication rates of MIAB and EUS-FNA did not differ to a statistically significant extent. The mean procedure time in the MIAB group was significantly longer than that in the EUS-FNA group (34 vs 26 min, P = 0.0011).

CONCLUSIONS

The diagnostic yield of MIAB was satisfactorily as high as EUS-FNA with ROSE for gastric SEL with an intraluminal growth pattern.

Prospective comparative study of endoscopic ultrasonography-guided fine-needle biopsy and unroofing biopsy

BACKGROUND AND AIM

Adequate tissue acquisition is important in making treatment decisions for patients with upper gastrointestinal subepithelial tumors (SETs). This study aimed to compare the outcomes of endoscopic ultrasonography-guided fine-needle biopsy (EUS-FNB) with those of the unroofing biopsy technique.

METHODS

This study was a single-center, prospective comparative study conducted at Severance Hospital, Yonsei University College of Medicine. A total of 39 patients with SETs ≥15 mm were enrolled between January 2016 and August 2017.

RESULTS

Of the 39 patients, 28 underwent biopsy with both techniques (4 underwent only unroofing and 7 underwent only EUS-FNB). Histological diagnosis was made with EUS-FNB in 64.3% and unroofing biopsy in 78.6% (p = 0.344), and immunohistochemical diagnosis was made with EUS-FNB in 46.4% and unroofing biopsy in 67.9% (p = 0.180). In the subgroup analysis (28 patients), there was no significant difference in diagnostic yield between the 2 methods The mean procedural time with EUS-FNB was shorter than that with unroofing biopsy (p < 0.001). The larger SET (≥ 20 mm) (p = 0.035) and satisfaction of procedure (p = 0.019) were positively associated with successful histological diagnosis by EUS-FNB.

CONCLUSIONS

There was no significant difference in the histological diagnostic yield for SETs between the EUS-FNB and unroofing biopsy techniques (CinicalTrials.gov. identifier NCT02646241).

Current clinical management of gastrointestinal stromal tumor

Gastrointestinal stromal tumors (GISTs) are the most common malignant subepithelial lesions (SELs) of the gastrointestinal tract. They originate from the interstitial cells of Cajal located within the muscle layer and are characterized by over-expression of the tyrosine kinase receptor KIT. Pathologically, diagnosis of a GIST relies on morphology and immunohistochemistry [KIT and/or discovered on gastrointestinal stromal tumor 1 (DOG1) is generally positive]. The prognosis of this disease is associated with the tumor size and mitotic index. The standard treatment of a GIST without metastasis is surgical resection. A GIST with metastasis is usually only treated by tyrosine kinase inhibitors without radical cure; thus, early diagnosis is the only way to improve its prognosis. However, a GIST is usually detected as a SEL during endoscopy, and many benign and malignant conditions may manifest as SELs. Conventional endoscopic biopsy is difficult for tumors without ulceration. Most SELs have therefore been managed without a histological diagnosis. However, a favorable prognosis of a GIST is associated with early histological diagnosis and R0 resection. Endoscopic ultrasonography (EUS) and EUS-guided fine needle aspiration (EUS-FNA) are critical for an accurate diagnosis of SELs. EUS-FNA is safe and effective in enabling an early histological diagnosis and adequate treatment. This review outlines the current evidence for the diagnosis and management of GISTs, with an emphasis on early management of small SELs.

Canalization technique to obtain deep tissue biopsy of gastrointestinal subepithelial tumors as an alternative to conventional known techniques

Background and Objectives

The most accurate technology to detect and diagnose subepithelial tumors (SETs) is the endoscopic ultrasonography (EUS) combined with puncture techniques, such as the endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) or the endoscopic ultrasonography-guided fine-needle biopsy. Going further in the improvement of the results of tumor samples obtained endoscopically to diagnose the SETs, the canalization technique guided by miniprobes (MPs) to obtain biopsies of SET could be an alternative to EUS-FNA. The objective of this study is to analyze the results of samples obtained by this procedure.

Materials and Methods

A multicenter, retrospective study of a review of a database of 32 consecutive patients with a SET in the digestive tract, from 2000 to 2015 was conducted. All patients underwent EUS-performed by MP, to define the size, internal echostructure, and layer of origin of tumor. Once the echostructure was defined, it proceeded to the canalization technique to arrive to the tumor tissue.

Results

The average diameter of SETs in this series (32 patients) was about 21.6±11 mm (range: 5-41 mm). The diagnostic accuracy was 28/32, 87.50% (Confidence interval 95%: 76.04%-98.99%), and there were no major complications. All procedures were performed on outpatients, none of which required additional hospitalization. The 50% of patients were operated or endoscopically resected and in all cases, the previous pathological diagnosis was confirmed.

Conclusions

This is a feasible, safe, and effective procedure that allows to access to inside of SET to obtain deep biopsies. Tumor samples obtained by deep biopsy, with prior performing of the canalization technique guided by MP, were sufficient for histopathological and immunohistochemical diagnosis and similar to those obtained with other known methods (FNA Trucut, ProCore^®, etc.). However, more prospective comparative studies with a larger number of patients and different specialists carrying out the procedure to reach a higher statistical significance are necessary.

Oval mucosal opening bloc biopsy after incision and widening by ring thread traction for submucosal tumor

Gastric submucosal tumors (SMTs) less than 2 cm are generally considered benign neoplasms, and endoscopic observation is recommended, but SMTs over 2 cm, 40% of which are gastrointestinal stromal tumors (GISTs), have malignant potential. Although the Japanese Guidelines for GIST recommend partial surgical resection for GIST over 2 cm with malignant potential as well as en bloc large tissue sample to obtain appropriate and large specimens of SMTs, several reports have been published on tissue sampling of SMTs, such as with endoscopic ultrasound sound fine needle aspiration, submucosal tunneling bloc biopsy, and the combination of bite biopsy and endoscopic mucosal resection. Because a simpler, more accurate method is needed for appropriate treatment, we developed oval mucosal opening bloc biopsy after incision and widening by ring thread traction for submucosal tumor (OMOB) approach. OMOB was simple and enabled us to obtain large samples under direct procedure view as well as allowed us to restore to original mucosa.

Direct endoscopic biopsy for subepithelial tumor larger than 20 mm after removal of overlying mucosa

OBJECTIVE

An accurate diagnosis of a subepithelial tumor (SET) using endoscopic ultrasound (EUS) without tissue acquisition is difficult. Treatment plan for a SET may be influenced by endoscopic tissue diagnosis. We aimed to clarify the clinical outcomes of direct endoscopic biopsy for SET after removal of the overlying mucosa.

METHODS

We evaluated the medical records of 15 patients. All patients underwent direct endoscopic biopsy for a SET larger than 20 mm (involving proper muscle layer) after removal of the overlying mucosa. The rate of achieving an accurate diagnosis and the treatment decision after the procedure were evaluated.

RESULTS

The patients' mean age was 55.1 ± 14.7 years. The patient population predominantly comprised men (9/15, 60%). The mean tumor size was 24.3 ± 7.8 mm. The mean biopsy number was 3.5 ± 1.7. No major complications occurred with the procedure. The mean procedure time was 15 ± 7.4 min. An accurate diagnosis was achieved in 93.3% of patients (14/15). The main pathological diagnoses after direct endoscopic SET biopsy were leiomyoma (33.3%, 5/15) and ectopic pancreas (33.3%, 5/15) followed by gastrointestinal stromal tumor (GIST) (13.3%, 2/15) and schwannoma (13.3%, 2/15). The treatment plan was influenced by the result of biopsy in 80% of patients (9/15), and unnecessary surgical resection was avoided.

CONCLUSIONS

Direct endoscopic SET biopsy after removal of the overlying mucosa using an endoscopic conventional snare was a useful diagnostic tool with high diagnostic accuracy and low risk of complications.

Efficacy of single-incision needle-knife biopsy for sampling subepithelial lesions

Background and study aims Single-incision needle-knife (SINK) biopsy is a diagnostic method for acquiring tissue samples for subepithelial lesions (SELs). A single linear incision is made in the overlying mucosa and tissue samples are obtained by passing conventional biopsy forceps through the opening and deep into the lesion. The aim of this study was to describe the efficacy and safety of this technique. Patients and methods Consecutive patients who underwent SINK biopsy for an upper gastrointestinal SEL between October 2013 and September 2015 were retrospectively reviewed. Results Forty-nine patients underwent 50 SINK biopsies. Sufficient sampling for a definite pathologic diagnosis was obtained in 42 (86 %) cases, with 91 % (40/44) having sufficient sample to perform immunohistochemistry when deemed clinically relevant. Of the 26 patients with prior non-diagnostic biopsies or FNA, a specific diagnosis was obtained in 85 % (22/26). There were no significant adverse events. Conclusions SINK biopsy is a safe and feasible strategy for obtaining a definitive tissue diagnosis with immunohistochemistry for SELs.

A retrospective study on the safety, diagnostic yield, and therapeutic effects of endoscopic unroofing for small gastric subepithelial tumors

BACKGROUND AND AIMS

Accurate diagnosis of small gastric subepithelial tumors (SETs) is essential to assess their malignant potential. Endoscopic unroofing has been reported to yield sufficient tissue samples for histologic evaluation. This study aimed to evaluate the safety, diagnostic yield, and potential therapeutic effects of this technique over time.

METHODS

This retrospective analysis of prospectively collected clinical data identified patients who underwent endoscopic unroofing at the Medical University of Vienna from January 2003 to December 2012. Demographic data, indications for endoscopic unroofing, intraprocedural adverse events, hospital stay, histologic results, and follow-up procedures were reviewed.

RESULTS

A total of 14 patients (7 men; 7 women; median age, 70 years; range, 51-95 years) underwent endoscopic unroofing of 14 gastric SETs with a mean diameter of 26 ± 13 mm at EUS. In 9 of 14 cases, endoscopic unroofing was done exclusively for diagnostic purposes; in the remaining cases, it was performed with therapeutic intent because of bleeding from the gastric SETs. Unroofing was technically successful in 13 of 14 cases and revealed 8 cases of GI stromal tumor (GIST) and 1 case each of leiomyoma, fibroid polyp, glomus tumor, pancreatic rest, and nondiagnostic material at histology. Intraprocedural bleeding was the only adverse event (4 cases) and could be managed endoscopically. A follow-up EUS was available (median, 8 months) for 10 of the 14 patients. Notably, most patients showed complete regression of their gastric SETs after unroofing (on white light and EUS), including the glomus tumor, the leiomyoma, and 6 of the 8 cases of GIST.

CONCLUSIONS

Endoscopic unroofing was safe and had a very favorable diagnostic yield in this study. Unexpectedly, it led to complete regression in most gastric SETs. Although it is not an oncologically curative treatment, endoscopic unroofing can be a valuable option to treat local adverse events in patients unfit for surgical therapy. (Clinical trial registration number: NCT02587923.).

Efficacy of deep biopsy for subepithelial lesions in the upper gastrointestinal tract

Introduction

Accurate diagnosis of subepithelial lesions (SELs) in the gastrointestinal tract depends on a variety of methods: endoscopy, endoscopic ultrasound and different types of biopsy. Making an error-free diagnosis is vital for the subsequent application of an appropriate treatment.

Aim

To evaluate the efficacy of deep biopsy via the endoscopic submucosal dissection (ESD) technique for SELs in the upper gastrointestinal tract.

Material and methods

It was a case series study. Deep biopsy via the ESD technique was completed in 38 patients between November 2012 and October 2014. Thirty-eight SELs in the upper gastrointestinal tract of varying size (very small ≤ 1 cm, small 1–2 cm and large ≥ 2 cm) by means of the ESD technique after an incision with an electrosurgical knife of the overlying layers and revealing a small part of the lesion were biopsied under direct endoscopic view.

Results

Deep biopsy via the ESD technique was diagnostic in 28 of 38 patients (73.3%; 95% CI: 59.7–89.7%). The diagnostic yield for SELs with a clear endophytic shape increased to 91.3%. An evident endophytic appearance of a subepithelial lesion, the mean number of biopsied samples (6.65 ±1.36) and the total size in length of all samples per case (19.88 ±8.07 mm) were the main criteria influencing the positiveness of deep biopsy in the diagnostic group compared to the nondiagnostic one (p = 0.001; p = 0.025; p = 0.008).

Conclusions

Deep biopsy via the ESD technique is an effective and safe method for the diagnosis of SELs especially with a clear endophytic appearance in a large number of biopsied samples.

Endoscopic ultrasound without tissue acquisition has poor accuracy for diagnosing gastric subepithelial tumors

Incidental gastric subepithelial tumor (SET) is frequently found during endoscopy. Although endoscopic ultrasonography (EUS) can provide useful information, its diagnostic accuracy varies. Most of the potentially malignant tumors observed on EUS are hypoechoic lesions. Therefore, we aimed to investigate the diagnostic accuracy of EUS for hypoechoic lesions located in the submucosa or proper muscle layer. We also evaluated various characteristics for potential associations with diagnostic accuracy.A retrospective review was conducted of the medical records of 99 patients who were diagnosed with gastric SET and who underwent EUS with pathologic confirmation between March 2008 and April 2015. After reviewing the endoscopic and pathologic findings, we attempted to analyze factors that were associated with the diagnostic accuracy of EUS.The mean ± standard deviation size of the lesions was 20.0 ± 12.7 mm. The most common location was the upper third of the stomach (43.4%). The overall accuracy of EUS was 66.7%. No statistically significant difference in EUS accuracy was observed according to the location, size, or layer of the lesion. The following pathologic diagnostic methods were used: EUS-guided fine needle aspiration (3.0%), forceps biopsy (16.2%), deep tissue biopsy using cap-assisted mucosal resection (8.1%), endoscopic submucosal dissection (25.2%), and operation (47.5%). The accuracy of EUS according to the expected diagnosis of the lesion was 77.1% for gastrointestinal stromal tumor, 50% for neuroendocrine tumor, and 50% for ectopic pancreas.Although EUS is a useful tool for gastric SET in clinical practice, the accuracy of diagnostic EUS is suboptimal. When considering whether to treat gastric SET, the decision should be made based on the pathologic diagnosis.

Using Forceps Biopsy after Small Submucosal Dissection in the Diagnosis of Gastric Subepithelial Tumors

The current tissue sampling techniques for subepithelial tumors (SETs) of the gastrointestinal (GI) tract have limited diagnostic efficacy. We evaluated the diagnostic yield and safety of forceps biopsies after small endoscopic submucosal dissection (SESD biopsies) in the diagnosis of gastric SETs. A total of 42 patients with gastric SETs > 10 mm were prospectively enrolled between May 2013 and October 2014. A dual knife was used to incise the mucosa and submucosa and forceps biopsies were then introduced deep into the lesion. To compare SESD biopsies with EUS-FNA, we used the retrospective data of 30 EUS-FNA cases. The diagnostic yield of SESD biopsies was comparable to that of EUS-FNA (35/42, 83.3% vs. 24/30, 80.0%, P = 0.717). The mean procedure time of SESD biopsies was shorter than that of EUS-FNA (10 vs. 37 minutes, P < 0.001). There were no procedure-related adverse events in the both group. The pathological diagnoses in SESD biopsies group included 15 leiomyomas, 7 GISTs, 10 heterotopic pancreases, 2 lipomas, and one other lesion. SESD biopsies are an easy, effective and safe technique for the diagnosis of gastric SETs and its diagnostic yield is comparable to that of EUS-FNA. This technique may be a reliable alternative to conventional EUS-FNA (Clinical trial registration No. KCT0000730).

Two Patients with Large Colonic Lipomas for which Endoscopic Unroofing was Ineffective

Endoscopic unroofing is effective for treating large colonic lipomas. However, additional endoscopic resection is occasionally required when the outcomes of initial unroofing are incomplete. The colonoscopy of an 82-year-old woman with abdominal pain revealed a yellowish lipoma of about 20 mm in the transverse colon. The mass was treated by unroofing, but a follow-up colonoscopy 5 days later revealed residual lipoma. One month later, the regenerated surface had become covered with mucosa, and the status of the lipoma had returned to that before unroofing. The colonoscopy of a 74-year-old man with abdominal pain and melena revealed a 50-mm-wide protruding lipoma in the transverse colon. The mucosa of the upper third of the lipoma was excised using an electric knife and snare, which allowed the immediate partial drainage of adipose tissue. Unroofing proceeded, but 7 days later, the unroofed surface had become coated with a white substance, and the residual lipoma required additional endoscopic resection. Colonic lipomas are often asymptomatic. However, patients with abdominal pain and hemorrhage should be treated in consideration of complete resection, but not by unroofing, which could leave a residual tumor. Drainage should be confirmed after unroofing and any residual lipoma should be treated by additional resection.

Effectiveness of Endoscopic Ultrasonography during Double Balloon Enteroscopy for characterization and management of small bowel submucosal tumours

BACKGROUND

Characterization of small bowel submucosal tumours is challenging, requiring additional investigations. Endoscopic Ultrasonography performed during Double Balloon Enteroscopy, appeared a promising technique although it has not been fully evaluated. The aim was to determine the effectiveness of this technique for characterization and management of sub mucosal tumours in a large cohort of patients.

METHODS

Patients with suspected small bowel tumours, who underwent Endoscopic Ultrasonography performed during Double Balloon Enteroscopy in our Institution between 2005 and 2013, were reviewed. Demographic data, clinical, endoscopic and radiological findings, therapeutic management, final diagnosis and follow-up were analyzed.

RESULTS

30 patients (19 male; median age 61.5) affected by submucosal tumours were included in the study. Endoscopic Ultrasonography performed during Double Balloon Enteroscopy was successfully performed in all cases providing a correct characterization of 19 submucosal tumours (63%). Based on the ultrasonographic characteristics 8 patients were treated endoscopically, 16 were referred to surgery, and 6 were managed conservatively.

CONCLUSION

Our results suggest that Endoscopic Ultrasonography performed during Double Balloon Enteroscopy is a safe and useful technique for submucosal tumours characterization. This procedure may be applied in clinical practice when small bowel tumours are encountered, to confirm the diagnosis and provide the most appropriate management.

Esophageal insufflation computed tomography for the diagnosis and management of esophageal submucosal tumors

BACKGROUND

The selection of therapy for benign esophageal lesions depends in part on whether the lesion extends to or through the esophageal muscle wall. The advent of endoscopic dissection of deep lesions has made this distinction important in the choice between different forms of advanced endoscopic therapy. The goal of this study was to evaluate esophageal insufflation computed tomography (EICT) for the diagnosis and management of esophageal submucosal tumors (SMTs).

METHODS

Between April 2011 and May 2013 at the Second Affiliated Hospital of Harbin Medical University, 27 patients with esophageal SMTs diagnosed by gastroscopy were studied observationally. Entry criteria included tumors larger than 0.5 cm. We compared endoscopic ultrasound (EUS) and EICT to assess lesion depth and the relationship between the submucosal lesion and the esophageal wall using the resected lesion as the gold standard.

RESULTS

Twenty-seven esophageal SMTs were evaluated. EUS and EICT accurately identified nine as superficial to the muscularis propria. EICT correctly identified the relation of the tumor extension and the outer esophageal wall in all 18 lesions that originated from the muscularis propria; only nine were correctly assessed by EUS (P < 0.001).

CONCLUSIONS

EICT enables improved judgment of the relation of esophageal lesions and the esophageal-mediastinal border. We propose EICT as a new, safe, effective, useful, simple and high-tolerance method for assessing the depth and relationships of esophageal submucosal lesions.

Endoscopic ultrasound-guided forceps biopsy from upper gastrointestinal subepithelial lesions using a forward-viewing echoendoscope

BACKGROUND AND STUDY AIMS

Endoscopic tissue acquisition techniques using needle-knife and biopsy forceps allow abundant tissue acquisition from upper gastrointestinal subepithelial lesions; however, these techniques cannot capture real-time intratumor information. The aim of this study was to evaluate the feasibility of endoscopic ultrasound-guided forceps biopsy (EUS-FB) from upper gastrointestinal subepithelial lesions using a forward-viewing echoendoscope.

PATIENTS AND METHODS

This study was a prospective case series. After mucosal cuts, several specimens were taken using a hot biopsy forceps under real-time EUS visualization. The incision was closed using hemoclips. Diagnostic yield, rate of diagnosable samples obtained under EUS visualization, procedure time, and adverse events were assessed.

RESULTS

Ten patients (median lesion size 16 mm, range 15 - 44 mm) underwent EUS-FB. The overall rate of histological diagnosis by EUS-FB was 100 % (10/10). The rate of diagnosable samples among all cases was 97.6 % (41/42). The median procedure times for EUS-FB and complete closure were 28.5 and 4.5 minutes, respectively. No adverse events occurred.

CONCLUSIONS

This newly developed EUS-FB is feasible and allowed forceps biopsy from upper gastrointestinal subepithelial lesions.

STUDY REGISTRATION

UMIN000015364.

Mucosal Incision and Forceps Biopsy for Reliable Tissue Sampling of Gastric Subepithelial Tumors

Background/Aims

The diagnostic efficacy of current tissue sampling techniques for gastric subepithelial tumors (SETs) is limited. Better tissue sampling techniques are needed to improve pathological diagnosis. The aim of this study was to evaluate the safety and efficacy of a new technique, mucosal incision and forceps biopsy, for reliable tissue sampling of gastric SETs.

Methods

This study enrolled 12 consecutive patients who underwent mucosal incision and forceps biopsy of gastric SETs between November 2011 and September 2014 at Gangneung Asan Hospital. The medical records of patients were reviewed retrospectively. The safety and diagnostic yield of this method were evaluated.

Results

By performing mucosal incision and forceps biopsy, we were able to provide a definitive histological diagnosis for 11 out of 12 cases. The pathological diagnoses were leiomyoma (3/11), gastrointestinal stromal tumor (GIST; 2/11), lipoma (2/11), schwannoma (1/11), and ectopic pancreas (3/11). In cases of leiomyoma (n=3) and GIST (n=2), tissue samples were of sufficient size to allow immunohistochemical staining. In addition, the mitotic index was evaluated in two cases of GIST. There were no procedure-related complications.

Conclusions

Mucosal incision and forceps biopsy can be used as one of several methods to obtain adequate tissue samples from gastric SETs.

Submucosal tunnel endoscopy: Peroral endoscopic myotomy and peroral endoscopic tumor resection

Peroral endoscopic myotomy (POEM) is an innovative, minimally invasive, endoscopic treatment for esophageal achalasia and other esophageal motility disorders, emerged from the natural orifice transluminal endoscopic surgery procedures, and since the first human case performed by Inoue in 2008, showed exciting results in international level, with more than 4000 cases globally up to now. POEM showed superior characteristics than the standard 100-year-old surgical or laparoscopic Heller myotomy (LHM), not only for all types of esophageal achalasia [classical (I), vigorous (II), spastic (III), Chicago Classification], but also for advanced sigmoid type achalasia (S1 and S2), failed LHM, or other esophageal motility disorders (diffuse esophageal spasm, nutcracker esophagus or Jackhammer esophagus). POEM starts with a mucosal incision, followed by submucosal tunnel creation crossing the esophagogastric junction (EGJ) and myotomy. Finally the mucosal entry is closed with endoscopic clip placement. POEM permitted relatively free choice of myotomy length and localization. Although it is technically demanding procedure, POEM can be performed safely and achieves very good control of dysphagia and chest pain. Gastroesophageal reflux is the most common troublesome side effect, and is well controllable with proton pump inhibitors. Furthermore, POEM opened the era of submucosal tunnel endoscopy, with many other applications. Based on the same principles with POEM, in combination with new technological developments, such as endoscopic suturing, peroral endoscopic tumor resection (POET), is safely and effectively applied for challenging submucosal esophageal, EGJ and gastric cardia tumors (submucosal tumors), emerged from muscularis propria. POET showed up to know promising results, however, it is restricted to specialized centers. The present article reviews the recent data of POEM and POET and discussed controversial issues that need further study and future perspectives.

Histological diagnosis of gastric submucosal tumors: A pilot study of endoscopic ultrasonography-guided fine-needle aspiration biopsy vs mucosal cutting biopsy

AIM: To compare the usefulness of endoscopic ultrasonography-guided fine-needle aspiration biopsy (EUS-FNAB) without cytology and mucosal cutting biopsy (MCB) in the histological diagnosis of gastric submucosal tumor (SMT).

METHODS: We prospectively compared the diagnostic yield, feasibility, and safety of EUS-FNAB and those of MCB based on endoscopic submucosal dissection. The cases of 20 consecutive patients with gastric SMT ≥ 1 cm in diameter. who underwent both EUS-FNAB and MCB were investigated.

RESULTS: The histological diagnoses were gastrointestinal stromal tumors (n = 7), leiomyoma (n = 6), schwannoma (n = 2), aberrant pancreas (n = 2), and one case each of glomus tumor, metastatic hepatocellular carcinoma, and no-diagnosis. The tumors’ mean size was 23.6 mm. Histological diagnosis was made in 65.0% of the EUS-FNABs and 60.0% of the MCBs, a nonsignificant difference. There were no significant differences in the diagnostic yield concerning the tumor location or tumor size between the two methods. However, diagnostic specimens were significantly more frequently obtained in lesions with intraluminal growth than in those with extraluminal growth by the MCB method (P = 0.01). All four SMTs with extraluminal growth were diagnosed only by EUS-FNAB (P = 0.03). No complications were found in either method.

CONCLUSION: MCB may be chosen as an alternative diagnostic modality in tumors showing the intraluminal growth pattern regardless of tumor size, whereas EUS-FNAB should be performed for SMTs with extraluminal growth.

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.

Diagnostic efficacy of endoscopic ultrasound-guided needle sampling for upper gastrointestinal subepithelial lesions: a meta-analysis

BACKGROUND

An increasing number of studies have been conducted on the use of endoscopic ultrasound (EUS)-guided needle sampling for upper gastrointestinal subepithelial lesions (SEL). However, reported diagnostic efficacy varies greatly.

OBJECTIVE

To summarize up current evidences on the diagnostic efficacy of EUS-guided needle sampling for upper GI SEL.

METHOD

A reproducible strategy was used to search four databases. Search results were evaluated for eligibility, and the quality of eligible studies was assessed by QUADAS-2. Pooled efficacy of EUS-guided needle sampling in upper GI SEL was calculated. Procedure-related complications, diagnostic errors, and independent factors related to a higher success rate were also recorded and analyzed.

RESULTS

Seventeen studies, comprising 978 attempts of EUS-guided needle sampling, were included in a meta-analysis. Pooled diagnostic rate of EUS-guided needle sampling was 59.9 %, with a heterogeneity I (2) of 55.2 %. Subgroup analysis showed no difference in diagnostic rate among fine needle aspiration (FNA), trucut needle biopsy (TCB), and fine needle biopsy (FNB), or among 19-, 22-, and 25-G needles. Subgroup analysis and meta-regression suggested that the cell block method might be correlated with a higher diagnostic rate. Few severe complications were reported. Diagnosis errors were rare.

CONCLUSION

EUS-guided needle sampling is a safe, but only moderately effective method for pathology diagnosis of upper GI SEL. Choice of FNA/TCB/FNB, or 19 G/22 G/25 G does not seem to alter the overall diagnostic rate.

Endoscopic Submucosal Dissection for Gastric Subepithelial Tumors: A Single-Center Experience

Background and Aims. Endoscopic submucosal dissection (ESD) has been accepted as a treatment modality for gastrointestinal epithelial tumors. Recently, ESD has been applied to resect subepithelial tumors (SETs) in the gastrointestinal tract, but clinical evidence on its efficacy and safety is limited. The aim of this study was to investigate the efficacy and safety of ESD for gastric SETs and to assess possible predictive factors for incomplete resection. Patients and Methods. Between January 2006 and December 2013, a total of 49 patients with gastric SET underwent ESD at our hospital. Clinicopathologic characteristics of patients and SETs, therapeutic outcomes, complications, and follow-up outcomes were evaluated. Results. The overall rates of en bloc resection and complete resection were 88% (43/49) and 84% (43/49), respectively. Complete resection rates in tumors originating from the submucosal layer were significantly higher than those in tumors originating from the muscularis propria layer (90% versus 56%, P = 0.028). In multivariate logistic regression analyses, tumor location (upper third: odds ratio [OR] 12.639, 95% confidence interval [CI] 1.087–146.996, P = 0.043) and layer of tumor origin (muscularis propria: OR 8.174, 95% CI 1.059–63.091, P = 0.044) were independently associated with incomplete resection. Procedure-related bleeding and perforation rates were both 4%. No recurrence was observed in patients with complete resection at a median follow-up period of 29 months (range: 7–83 months). Conclusions. ESD is an effective, safe, and feasible treatment for gastric SETs. The frequency of incomplete resection increases in tumors located in the upper third of the stomach and in those originating from the muscularis propria layer.

Forward-viewing versus oblique-viewing echoendoscopes in the diagnosis of upper GI subepithelial lesions with EUS-guided FNA: a prospective, randomized, crossover study

BACKGROUND

The role of the forward-viewing echoendoscope compared with the oblique-viewing echoendoscope for EUS-guided FNA (EUS-FNA) of upper GI subepithelial lesions has not been defined.

OBJECTIVE

To compare the diagnostic yield and clinical efficacy of EUS-FNA by using the 2 echoendoscopes in the same upper GI subepithelial lesion.

DESIGN

Prospective, randomized, crossover study.

SETTING

Tertiary-care medical center.

PATIENTS

Forty-one patients with an upper GI subepithelial lesion.

INTERVENTIONS

All patients first underwent EUS-FNA with a 19-gauge needle by using both echoendoscopes, based on random selection. When required, 22-gauge or 25-gauge needles were used additionally.

MAIN OUTCOME MEASUREMENTS

Comparison of diagnostic yield, tissue sample area, puncture success rates, procedure time, and adverse events.

RESULTS

Forty-one patients (median lesion size 22 mm, range 15-63 mm) were enrolled. Rates of histologic diagnosis were 80.5% (33/41) and 73.2% (30/41) (P=.453) by using forward-viewing and oblique-viewing echoendoscopes, respectively. Median tissue sample area in GI stromal tumors (n=22) obtained with the forward-viewing echoendoscope was larger than with the oblique-viewing echoendoscope (2.46 mm2 vs 1.00 mm2; P=.046). Puncture success rates were 39 of 41 (95.1%) and 35 of 41 (85.4%; P=.289) with forward-viewing and oblique-viewing echoendoscopes, respectively. Median procedure time was 21 minutes with the forward-viewing echoendoscope and 27 minutes with the oblique-viewing echoendoscope (P=.009). An infectious adverse event occurred in a patient and was treated with antibiotics.

LIMITATIONS

Small sample size.

CONCLUSION

Diagnostic yield did not differ between the 2 echoendoscopes. However, tissue sample area and procedure time were superior with the forward-viewing echoendoscope.

Minimally invasive surgeries for submucosal tumors of the stomach

Submucosal tumors (SMTs) of the gastrointestinal tract, which may be an occasional finding on routine upper gastrointestinal (GI) endoscopy, represent a diagnostic and therapeutic challenge. Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract and have the potential to progress to malignancy. The primary treatment goal for localized GISTs is surgical resection with achievement of a negative margin (R0 resection). This is the effective way to achieve complete treatment. Minimally invasive surgery has become common in the surgical resection of gastrointestinal SMTs. Recent advances in endoscopic technology provide various treatment modalities for gastric SMTs. Moreover, investigators have developed laparoscopic and endoscopic cooperative procedures. In addition, robotic surgery for SMTs is another choice. The purpose of this article is to review recent trends in minimally invasive surgery for gastric SMTs.

Diagnosis of ectopic pancreas by endoscopic ultrasound with fine-needle aspiration

AIM: To study the clinical, endoscopic, sonographic, and cytologic features of ectopic pancreas (EP).

METHODS: This was a retrospective study performed at an academic referral center including two hospitals. Institutional review board approval was obtained. Patients referred to the University Hospital or Denver Health Medical Center Gastrointestinal Endoscopy Lab for gastroduodenal subepithelial lesions (SEL) with a final diagnosis of EP between January 2009 and December 2013 were identified. Patients in this group were selected for the study if they underwent endoscopic ultrasound (EUS) with fine-needle aspiration (FNA) or deep biopsy. A review of the medical record was performed specifically to review the following information: presenting symptoms, endoscopic and EUS findings, computed tomography or magnetic resonance imaging findings, pathology results, procedure-related adverse events, and subsequent treatments after EUS-FNA. EUS with FNA or deep submucosal biopsy was performed in all patients on an outpatient basais by one of two physicians (Attwell A, Fukami N). Review of all subsequent clinic notes and operative reports was performed in order to determine follow-up and final diagnoses.

RESULTS: Between July 2009 and December 2013, 10 patients [3 males, 7 females, median age 52 (26-64) years] underwent EUS for a gastroduodenal SEL and were diagnosed with EP. One patient was symptomatic. Six (60%) lesions were in the antrum, 3 (30%) in the body, and 1 (10%) in the duodenum. A mucosal dimple was noted in 6 (60%). Mean lesion size was 17 (8-25) mm. Gastrointestinal wall involvement: muscularis mucosae, 10%; submucosa, 70%; muscularis propria, 60%; and serosa, 10%. Nine (90%) lesions were hypoechoic and 5 (50%) were homogenous. A duct was seen in 5 (50%). FNA was attempted in 9 (90%) and successful in 8 (80%) patients after 4 (2-6) passes. Cytology showed acini or ducts in 7 of 8 (88%). Superficial biopsies in 7 patients (70%) showed normal gastric mucosa. Deep endoscopic biopsies were taken in 2 patients and diagnostic in one. One patient (10%) developed pancreatitis after EUS-FNA. Two patients (20%) underwent surgery to relieve symptoms or confirm the diagnosis. The main limitation of the study was the fact that it was retrospective and performed at a single medical center.

CONCLUSION: EUS features of EP include antral location, mucosal dimple, location in layers 3-4, and lesional duct, and FNA or biopsy is accurate and effective.

The incidence of colon cancer among patients diagnosed with left colonic or sigmoid acute diverticulitis is higher than in the general population

BACKGROUND

Considering the low incidence of colon cancer after an initial episode of colonic diverticulitis in some categories of patients, some authors suggested to exempt them from colonoscopy. However, this incidence has never been compared to that of a reference population, and predictors of cancer are still poorly investigated. We aimed to determine the 1-year incidence of colon cancer at the site of diverticulitis in patients diagnosed with left colonic or sigmoid acute diverticulitis, to compare this incidence to a reference population to state whether endoscopy is required or not, and to identify predicting factors of cancer to better target subpopulations needing that examination.

METHODS

All patients admitted at the University Hospitals of Geneva for left colonic or sigmoid acute diverticulitis were included. Patients with a previous history of colon cancer or non-available for follow-up were excluded. Demographic data, haemoglobin values, and the Hinchey score were documented. This cohort was matched with the Geneva Cancer Registry to look for cancer occurrence at the site of diverticulitis within 1 year. Predictors of cancer were assessed using univariate logistic regression and the risk of cancer by comparing observed cases to a reference population using standardized incidence ratios.

RESULTS

The final cohort included 506 patients. Eleven (2.2 %) had a diagnosis of cancer at the site of diverticulitis within 1 year. The mean age was significantly different between patients with cancer and others. No predictor of cancer could be identified, except a trend for an increased risk with advancing age (p = 0.067). The standardized incidence ratios showed a 44-fold increased risk of cancer among the cohort compared to the reference population.

CONCLUSIONS

Colonoscopy should be continued after an initial diagnosis of left colonic or sigmoid acute diverticulitis, irrespective of the clinical or radiological presentations.

Unroofing Technique as an Option for the Endoscopic Treatment of Giant Gastrointestinal Lipomas

Gastrointestinal lipomas are usually asymptomatic, detected incidentally. However, they can cause severe symptoms such as obstruction, invagination, and bleeding. The transsection of an infarcted or large lipoma by needle sphincterotome (needle knife) and/or snare polypectomy of the upper part of the tumour is an option for the endoscopy treatment of giant infarcted lipomas. Cutting a top of lipoma (unroofing technique) allowed flow out of adipose tissue from the lipoma.

Minimally invasive surgery for submucosal (subepithelial) tumors of the stomach

Minimally invasive surgery has become common in the surgical resection of gastrointestinal submucosal tumors (SMTs). The purpose of this article is to review recent trends in minimally invasive surgery for gastric SMTs. Although laparoscopic resection has been main stream of minimally invasive surgery for gastrointestinal SMTs, recent advances in endoscopic procedures now provide various treatment modalities for gastric SMTs. Moreover, investigators have developed several hybrid techniques that include the advantages of both laparoscopic and endoscopic procedure. In addition, several types of reduced port surgeries, modification of conventional laparoscopic procedures, have been recently applied to the surgical resection of SMTs. Meanwhile, robotic surgery for SMTs requires further evidence and improvement.

When to puncture, when not to puncture: Submucosal tumors

Subepithelial masses of the gastrointestinal (GI) tract are a frequent source of referral for endosonographic evaluation. Subepithelial tumors most often appear as protuberances in the GI tract with normal overlying mucosa. When there is a need to obtain a sample of the mass for diagnosis, endoscopic ultrasound (EUS) - guided fine-needle aspiration (FNA) is superior to other studies and should be the first choice to investigate any subepithelial lesion. When the decision is made to perform EUS-guided FNA several technical factors must be considered. The type and size of the needle chosen can affect diagnostic accuracy, adequacy of sample size and number of passes needed. The use of a stylet or suction and a fanning or standard technique during EUS-guided FNA are other factors that must be considered. Another method proposed to improve the efficacy of EUS-guided FNA is having an on-site cytopathologist or cytotechnician. Large or well-differentiated tumors may be more difficult to diagnose by standard EUS-FNA and the use of a biopsy needle can be used to acquire a histopathology sample. This can allow preservation of tissue architecture and cellularity of the lesion and may lead to a more definitive diagnosis. Alternatives to FNA such as taking bite-on-bite samples and endoscopic submucosal resection (ESMR) have been studied. Comparison of these two techniques found that ESMR has a significantly higher diagnostic yield. Most complications associated with EUS-FNA such as perforation, infection and pancreatitis are rare and the severity and incidence of these adverse events is not known. Controversy exists as to the optimal method in which to perform EUS-FNA and larger prospective trials are needed.

Evaluation of gastric submucosal tumors using endoscopically visualized features with submucosal endoscopy

Although the macroscopic characteristics of submucosal tumors (SMTs), such as gastrointestinal stromal tumors (GISTs), have been characterized, the assessment of SMTs by their endoscopically visualized features (EVF; which are observed by endoscopic imaging under direct view) remains unevaluated. The aim of the present study was to investigate the potential of endoscopic diagnostics for SMTs using EVF. The EVF of 26 gastric SMT cases, in which the final pathological diagnosis was obtained by core biopsy using the submucosal endoscopy with mucosal flap method, were retrospectively reviewed. Each type of SMT was classified according to the following five EVF: Color, clarity, shape, tumor coating and solidity. Additionally, the EVF of 13 low-risk GISTs and 13 benign submucosal tumors (BSTs) were comparatively evaluated for the five abovementioned EVF. Similar trends were identified between the low-risk GISTs, granular cell tumors and the schwannoma with regard to EVF. However, while these tumors exhibited cloudy EVF, the leiomyomas tended to exhibit clear EVF. Among SMTs of the heterotopic pancreas type, the EVF demonstrated particularly small nodules of the pancreatic tissue itself. Although the sample size included in the present study is small, a classification system for gastric SMTs was proposed according to the EVF. When compared with the BST group, the GIST group demonstrated a significantly higher frequency of tumors that exhibited a combination of three EVF (white, cloudy and rigid) that are consistent with all gastric GISTs (P<0.05). Gastric SMTs may be classified based on the EVF, which indicates that the EVF possess potential diagnostic value for the differentiation of GISTs from BSTs.

Suck-ligate-unroof-biopsy by using a detachable 20-mm loop for the diagnosis and therapy of small subepithelial tumors (with video)

BACKGROUND

The diagnosis and therapy of subepithelial tumors (SETs) can be challenging.

OBJECTIVE

Proof-of-concept evaluation of the suck-ligate-unroof-biopsy (SLUB) technique for small (<2 cm), non-pedunculated SETs.

DESIGN

Pilot feasibility study.

SETTING

Tertiary-care referral center.

PATIENTS

Twenty-three patients (median age 60 years) meeting the inclusion criteria after preliminary EUS.

INTERVENTION

SET ligation was performed with a detachable 20-mm loop deployed through an 18-mm diameter, soft, oblique, transparent, cap attachment. The SLUB technique comprised (1) suction to draw the SET into the cap; (2) ligation below the SET, confirmation by repeat EUS; (3) unroofing of the overlying mucosa with a needle-knife; and (4) biopsy specimens taken from the exposed tumor.

MAIN OUTCOME MEASUREMENTS

Technical success, histology and/or immunohistochemistry yield, adverse events, completeness of resection.

RESULTS

SLUB was attempted on 24 SETs and was technically successful in all. Location was the stomach (n = 19), small bowel (n = 1), colon (n = 2), and rectum (n = 2). Median size by EUS was 10 mm (range 6-15 mm). Biopsy specimens provided an immunohistologic diagnosis in all cases: GI stromal tumor (n = 5), leiomyoma (n = 8), carcinoid tumor (n = 5), Vanek's tumor (n = 2), granuloma (n =1), and pancreatic heterotopia (n = 3). Follow-up endoscopy and EUS in 13 patients showed well-healed scars with no residual tumor, including all 9 patients with premalignant neoplastic lesions. The only adverse event was self-limited pain in 2 patients.

LIMITATIONS

Single center, single operator, small sample size.

CONCLUSIONS

Loop ligation of small, non-pedunculated SETs is feasible by using a cap attachment for suction. Unroofing after ligation is safe and provides sufficient tissue for immunohistochemistry. Ligation combined with unroofing appears to lead to complete ablation by ischemia and tumor enucleation.

Submucosal tunneling techniques: current perspectives

Advances in endoscopic submucosal dissection include a submucosal tunneling technique, involving the introduction of tunnels into the submucosa. These tunnels permit safer offset entry into the peritoneal cavity for natural orifice transluminal endoscopic surgery. Technical advantages include the visual identification of the layers of the gut, blood vessels, and subepithelial tumors. The creation of a mucosal flap that minimizes air and fluid leakage into the extraluminal cavity can enhance the safety and efficacy of surgery. This submucosal tunneling technique was adapted for esophageal myotomy, culminating in its application to patients with achalasia. This method, known as per oral endoscopic myotomy, has opened up the new discipline of submucosal endoscopic surgery. Other clinical applications of the submucosal tunneling technique include its use in the removal of gastrointestinal subepithelial tumors and endomicroscopy for the diagnosis of functional and motility disorders. This review suggests that the submucosal tunneling technique, involving a mucosal safety flap, can have potential values for future endoscopic developments.

Ligation-assisted endoscopic enucleation for treatment of esophageal subepithelial lesions originating from the muscularis propria: a preliminary study

An innovative ligation-assisted endoscopic enucleation (EE-L) technique was developed for the diagnosis and treatment of esophageal subepithelial lesions (smaller than 12 mm) originating from muscularis propria by combining endoscopic band ligation and endoscopic enucleation techniques. The aim of the study was to evaluate efficacy and safety of EE-L technique in the treatment of esophageal subepithelial lesions (smaller than 12 mm) originating from muscularis propria. Forty-seven esophageal subepithelial lesions (smaller than 12 mm) originating from the muscularis propria in 44 patients were treated with EE-L between September 2010 and September 2012. The lesion was first aspirated into the transparent cap attached to the tip of endoscope. The elastic band was then released around its base. The purpose of ligation was to force the lesion to assume a polypoid form with a pseudostalk. Endoscopic enucleation was then performed until the tumor was completely enucleated from muscularis propria using a hook knife and forceps. All tumors (median diameter: 8.2 ± 2.3 mm, range: 4-12 mm) were enucleated completely. Histopathology identified 45 tumors (95.7%) as leiomyoma, 2 (4.3%) tumors as gastrointestinal stromal tumor with very low risk. The mean time of the EE-L procedure was 12.5 ± 4.6 minutes (range: 6-23 minutes). Two patients experienced self-limiting, non-life-threatening hemorrhage after EE-L. No perforation and massive hemorrhage requiring further endoscopic or surgical intervention occurred. There were no recurrences during the 6-24 months follow-up period. EE-L offers the option of localized treatment of small esophageal muscularis propria tumors (smaller than 12 mm) with relatively few complications and low mortality, and provides the advantage of allowing a histopathological diagnosis. All the resected lesions in this study had a benign pathology.

Hybrid natural orifice transluminal endoscopic surgery in gastric subepithelial tumors

Diagnosis of gastric subepithelial tumor (SET) has shown a rapid increase worldwide. Although, until now, endoscopic ultrasound guided procedures such as fine needle aspiration have shown relatively high accuracy in diagnosis of SET, the most important modality for diagnosis and treatment of SETs is complete resection such as endoscopic or surgical resection. However, endoscopic resection or laparoscopic wedge resection alone also has some limitations. Endoscopic resection is difficult to perform in cases of gastric SET located within deep portion of the gastric layer or a relatively large (larger than 25 mm diameter). On the other hand, gastric SET in a difficult location, such as the gastroesophageal junction or pyloric ring is challenging for laparoscopic surgical resection. The hybrid natural orifice transluminal endoscopic surgery (NOTES) technique is a combined method, including the advantages of both laparoscopic resection and endoscopic resection for gastric SETs. This method may be performed safely with reasonable operation times, less bleeding, and adequate resection margin and regardless of tumor size. In particular, in the case of a difficult location for resection, such as the esophagogastric junction or pyloric ring, hybrid NOTES is currently believed to be an ideal treatment method.

A feasible modified biopsy method for tissue diagnosis of gastric subepithelial tumors

AIM: To evaluate the diagnostic yield and safety of a modified technique for the histological diagnosis of subepithelial tumors (SETs).

METHODS: A retrospective review of patients who underwent a modified technique for the histological diagnosis of gastric SETs, consisting of a mucosal incision with a fixed flexible snare (MIF) and deep-tissue biopsy under conventional endoscopic view, from January 2012 to January 2013 was performed. Eleven patients with gastric SETs 10-30 mm in diameter and originating from the third or fourth layer on endoscopic ultrasonography were included.

RESULTS: The mean age was 59.8 (range, 45-76) years, and 5 patients were male. The mean size of the SETs was 21.8 (range, 11-30) mm. The number of biopsy specimens was 6.3 (range 5-8). The mean procedure time was 9.0 min (range, 4-17 min). The diagnostic yield of MIF biopsies was 90.9% (10/11). The histological diagnoses were leiomyoma (4/11, 36.4%), aberrant pancreas (3/11, 27.3%), gastrointestinal stromal tumors (2/11, 18.2%), an inflammatory fibrinoid tumor (1/11, 9.1%); one result was non-diagnostic (1/11, 9.1%). There were six mesenchymal tumors; the specimens obtained in each case were sufficient for an immunohistochemical diagnosis. There was no major bleeding, but one perforation occurred that was successfully controlled by endoscopic clipping.

CONCLUSION: The MIF biopsy was simple to perform, safe, and required a shorter procedure time, with a high diagnostic yield for small SETs.