Assessment of a Real-world Learning Curve for the Endoscopic Resection of Gastric Gastrointestinal Stromal Tumors

BACKGROUND

Endoscopic resection (ER) is a proven treatment for gastric gastrointestinal stromal tumors (gGISTs). We aimed to assess the learning curve (LC) associated with ER for gGISTs and identify determinants.

METHODS

We conducted an analysis of 289 patients who underwent the ER of gGISTs by an experienced endoscopist. To characterize the LC, we employed cumulative sum analysis of the duration of surgery. The participants were divided into an early phase (cases 1-50) and a later phase (case 51-289), which were compared. Furthermore, we identified risk factors for the conversion from endoscopic to laparoscopic resection (LR).

RESULTS

The durations of surgery and hospitalization were shorter, and there were fewer complications and fasting days in the later phase. The conversion rates to LR were 6.0% and 2.5% in the early and later phases, respectively. The tumor diameter (≥3.0 cm) and invasion beyond the muscularis propria were significant risk factors for conversion to LR (odds ratio 17.92, 95% confidence interval 2.66-120.87; and 58.03, 6.40-525.84; respectively).

CONCLUSIONS

The LC for ER of gGISTs lasts for approximately 50 cases. In addition, tumors ≥3.0 cm in diameter and those that invade beyond the muscularis propria are more likely to require conversion to LR.

A novel technique for endoscope progression in gastroscopy resection: forward-return way for dissection of stromal tumor in the muscularis propria of the gastric fundus

Background

The fundus of the stomach is a challenging region for endoscopic resection of gastrointestinal stromal tumors (GISTs), especially in the anterior wall of the fornix at the side of the greater curvature. This study aimed to introduce the Forward-Return Way (FRW) technique in gastric fundus operations and provide evidence of its advantages. The FRW technique allows the gastroscope to access the stomach fornix without entering the gastric antrum after passing through the gastric cardia. Using FRW, the gastroscope body makes a forward return along the wall of the posterior wall of the upper gastric body and the wall of the greater curvature.

Methods

The clinical data of patients with stromal tumors in muscularis propria at the gastric fundus (STMF) at the Fourth Hospital of China Medical University between May 2020- March 2021 were reviewed. The novel FRW technique was used in the procedures, and the beneficial effects, suitability, applicable lesion site, and success rates of FRW were analyzed.

Results

A total of 10 cases were reviewed, and the FRW technique was successfully performed in 7 cases (70%). The gastroscope's tip reached the area just below the gastric cardia, allowing endoscopists to successfully access all angles and sites of the stomach's fundus in all seven patients. The lesion was easily accessed, and the gastroscope was stable with good left-right and forward-backwards movements.

Conclusion

The FRW technique significantly facilitates the resection of the GISTs by aligning the endoscopy body movement direction with the observation direction. Gastrointestinal Stromal Tumor; forward-return of gastroscopy along the gastric body wall; muscularis propria; gastric fundus.

Efficacy and safety of endoscopic "calabash" ligation and resection for small gastric stromal tumors originating from the muscularis propria

AIM

We compared endoscopic "calabash" ligation and resection (ECLR) and endoscopic submucosal excision (ESE) in treating endophytic gastric stromal tumors (GSTs) ≤15 mm in diameter originating from the muscularis propria.

METHODS

We performed a retrospective study and included patients who visited our hospital for removal of small endophytic GSTs (diameter ≤ 15 mm) confirmed by postoperative pathological reports between February 2019 and December 2020. Patients were assigned to the study (received ECLR) or control (accepted ESE) groups, and their medical records were reviewed. Age, sex, GST size, resection outcomes, procedure measurements, lengths of hospital stays, medical expenses, intraoperative and postoperative complications, and follow-up outcomes were documented and compared between the two groups. Propensity score matching was used to avoid retrospective biases.

RESULTS

A total of 277 patients were included in the analysis, with 135 in the study group and 142 in the control group. After propensity score matching, 119 cases in each group were finally included in the study. Compared to the control group, the study group had significantly shorter procedure durations and lengths of hospital stays, as well as reduced medical expenses. Compared to the control group, the study group also had significantly lower incidence rates of intraoperative stomach perforation, postoperative intraperitoneal infection, and postoperative electrocoagulation syndrome, as well as a lower intensity of postoperative pain. There were no significant differences in the other measurements between the two groups.

CONCLUSION

ECLR is an effective and safe procedure for treating patients with endophytic GSTs ≤15 mm in diameter originating from the muscularis propria.

Gastric Schwannoma: A Case Report and Literature Review

Gastric schwannomas (GS) are very rare spindle cell, submucosal mesenchymal tumors that arise from Schwann cells of nerve plexuses in the stomach wall. They are usually benign but can become malignant and metastasize to other organs. Surgical resection with biopsy is the gold standard for diagnosis and management of GS. In this article, we present a 68-year-old female patient who presented with abdominal pain, nausea, vomiting, and belching for a couple of months. Upon further evaluation, she was found to have a 4.2 cm gastric mass, which was consistent with gastric schwannoma through biopsy and immunohistochemistry. The patient underwent complete surgical resection of the tumor without any complications. In this article, we will discuss the literature about GS including its clinical presentation, diagnosis, and management options.

Analysis of Tumor Depth Invasion With Anti-Smoothelin Antibody in Equivocal Transurethral Resection of Urinary Bladder Tumor Surgical Specimens

OBJECTIVE

To examine the expression and value of the smoothelin marker in control cases, to standardize the working method, and to analyze its application in pathologic staging process of problematic transurethral resection of bladder tumor (TURBT) cases.

MATERIAL AND METHODS

Immunohistochemical (IHC) staining was performed on tumor-free bladder wall sections, tumor-free large bowel sections, TURBTs with unequivocal tumor stage, and TURBTs with equivocal stage. The IHC staining of muscularis mucosa (MM), muscularis propria (MP), and blood vessels was evaluated semiquantitatively.

RESULTS

Smoothelin IHC staining pattern ranged from negative (30% to 67% cases) to 2+ (0% to 15% cases) in MM and from 1+ (10% to 50% cases) to 3+ (9% to 48% cases) in MP. When compared on the same slide, the smoothelin expression of MP showed a stronger staining intensity than the one of the MM in all the analyzed cases. Blood vessel muscle cells stained in a constant intensity as the MM (r = 0.9808; r = 0.9604). Smoothelin determined restaging of 33% of the problematic TURBT cases.

CONCLUSION

Smoothelin is an IHC marker that shows differential staining between coexistent MM and MP; however, variations in staining intensity and pattern may occur, aspects that can be influenced by different technique variables. We recommend using this marker as a diagnostic tool in problematic TURBT cases only when there is sufficient experience in control cases with this antibody.

Segmental Ileal Dilatation Presenting with Neonatal Intestinal Obstruction

Segmental ileal dilatation is an uncommon cause of neonatal intestinal obstruction. This report highlights a rare combination of abnormal distribution of muscles in the muscularis propria and partial loss of interstitial cells of Cajal as causative factors for segmental intestinal dilatation.

Challenges surrounding postoperative adjuvant chemotherapy for T2N0 gastric cancer

Determining the requirement for adjuvant chemotherapy in patients with stage IB gastric cancer (GC), and particularly for those with stage T2N0 (muscularis propria) disease, remains challenging. Patients with stage II/III disease benefit from postoperative adjuvant therapy; however, the randomized trials examining whether such therapy affords any survival benefit to patients with T2N0 disease are not sufficient. Current evidence suggests that not all patients with T2N0 disease should undergo such treatment, but only those with a high risk. To date, a number of retrospective studies have attempted to identify factors that are predictive of increased risk in an effort to guide adjuvant therapy-related clinical decision making. The National Comprehensive Cancer Network and the Chinese Society of Clinical Oncology have published guidelines regarding factors associated with increased patient risk. As a result, treatment decisions for patients with stage T2N0 disease are currently determined on an individualized basis, in light of risk factors and the potential benefits of treatment. The present review surveyed current evidence related to the treatment of patients with high-risk GC and highlighted the potential avenues for future investigated.

Clinical Implication of Tumor-invasive Status into the Muscularis Propria in T2 Gastric Cancer

BACKGROUND/AIM

Several studies have investigated prognostic factors in patients with T2 gastric cancer, but no consensus has been reached to date. The aim was to investigate the clinicopathological significance of the status of tumor invasion into the muscularis propria (MP) in T2 gastric cancer patients.

PATIENTS AND METHODS

A total of 113 patients with T2 cancer were enrolled. The status of caner invasion was analyzed according to width (extent of horizontal invasion) and depth (extent of vertical invasion).

RESULTS

The prognosis of the group with wide width of invasion (≥1.5 cm) was significantly poorer than that of the group with narrow width of invasion (<1.5 cm) (p=0.001). Multivariate analysis identified the width, and not the depth, as an independent prognostic factor. The analysis according to AJCC N stage showed that the width, and not the nodal status, was an independent prognostic factor in the N2-N3 patients (p=0.005).

CONCLUSION

Measurement of the width of tumor invasion into the MP was useful to understand the malignant potential of T2 gastric cancer.

Submucosal Tunneling Endoscopic Resection for Large and Irregular Submucosal Tumors Originating from Muscularis Propria Layer in Upper Gastrointestinal Tract

BACKGROUND

The majority of submucosal tumors (SMTs) are benign. However, large SMTs with irregular outer shapes are proved to harbor a higher risk for malignancy. Submucosal tunneling endoscopic resection (STER) has emerged as a feasible technique for resecting SMTs.

OBJECTIVE

To evaluate the safety and efficacy of STER for large and irregular SMTs with a diameter no <35 mm originating from the muscularis propria layer, and to share the technical skills of STER for complete and en bloc resection.

PATIENTS AND METHODS

We retrospectively reported 10 cases in which the new technique of STER was performed to remove large and irregular SMTs with a diameter no <35 mm of upper gastrointestinal tract in our hospital between April 2014 and April 2017.

RESULTS

All 10 (100%) patients underwent STER successfully, with a mean operation time of 156 minutes. Among the 10 SMTs, 3 (30%) were located in the esophagus, 7 (70%) were in the cardia. All the SMTs had a maximum diameter no <35 mm, ranging from 35 to 100 mm. The mean size was 57.2 mm. En bloc resection was achieved in 8 (80%) of the tumors. Only two (20%) of the SMTs were resected into more than one piece. Complication occurred in 1 (10%) of the patients as a representation of pneumothorax. No recurrence was noted during a median follow-up of 15 months.

CONCLUSION

In this retrospective study, STER may be an effective and safe technique resecting large and irregular SMTs with a diameter no >40 mm in transverse diameter and no >100 mm in longitudinal diameter.

Submucosal tunneling endoscopic resection of upper gastrointestinal tract tumors arising from muscularis propria

The management of incidentally discovered small upper gastrointestinal (GI) tract submucosal tumors (SMT) remains debatable. In this review, we summarize the evolving experience with submucosal tunneling endoscopic resection (STER) of upper GI SMTs originating from the muscularis propria. From 16 original studies, we reviewed a total of 703 patients with 736 lesions. Of these, 436 were located in the esophagus, 146 in the esophagogastric junction (EGJ) and 154 in the stomach. The composite complete resection rate (CRR) for STER of upper GI tumors arising from the muscularis propria layer was 99.8% (445/446). The composite CRR for STER of esophageal, EGJ and gastric SMTs arising from the muscularis propria layer was 100% (208/208),100% (78/78)and 100% (115/115), respectively. The composite en bloc resection rate (EBRR) for STER of upper GI tumors arising from the muscularis propria layer was 94.6% (679/718). The composite EBRR for STER of esophageal, EGJ and gastric SMTs arising from the muscularis propria layer was 98.6% (205/208), 96.2% (75/78) and 97.9% (95/97), respectively. Tumor recurrence rate was 0%. The reported complication rate for STER was high but the majority responded to conservative management. STER is a minimally invasive and efficacious alternative to surgery, especially for patients with small tumors (<3 cm). Careful selection of candidates remains crucial for excluding potentially malignant tumors.

Myofibroblasts of the muscle layer stimulate the malignant potential of colorectal cancer

Myofibroblasts of colorectal cancer (CRC) have been associated with histopathological factors such as lymph node metastasis, liver metastasis and local recurrence. However, few studies have assessed the association between these malignant potentials and the myofibroblast distribution in CRC. We aimed to evaluate the relationship between clinical factors and myofibroblast distribution around CRC invasive lesions. The study included 121 cases of pT3 CRC that were diagnosed at stage II or III. Myofibroblast density of the following three histological layers was measured: the submucosa (SM), muscularis propria (MP) and subserosa (SS). We analyzed the relationship between the clinicopathological factors and myofibroblast density by studying the histopathological features of the three layers. The myofibroblast density of the MP layer was significantly higher in the groups with high-frequency lymphatic and venous invasion than the groups with low-frequency lymphatic (P<0.001) and venous (P<0.01) invasion, respectively. In the positive lymph node metastasis group, the myofibroblast density at the MP layer was significantly higher than that in the negative lymph node metastasis group (P<0.001). The high myofibroblast density group at the MP layer was significantly associated with poor overall survival (P<0.003). Our study indicated that myofibroblasts are a type of cancer-associated fibroblasts and that the myofibroblast distribution contributes to the malignant potential of CRC. Furthermore, we demonstrated that myofibroblasts present at the MP layer play an important role in the malignant potential and poor prognosis of patients with CRC.

Cap-aspiration lumpectomy for small submucosal tumors originating from the muscularis propria of the gastric fundus: a preliminary study (with videos)

OBJECTIVE

Small fundal submucosal tumors (SMTs) originated from the muscularis propria pose great difficulties to conventional therapies. We aimed to evaluate the feasibility and safety of endoscopic cap-aspiration lumpectomy (CASL) as a new and simple full-thickness resection for the treatment of small fundal SMTs.

METHODS

From July 2013 to February 2014, patients with small fundal SMTs of ≤10 mm in diameter that were originated from muscularis propria were included in the study. CASL was performed by suctioning SMTs into a transparent cap, ligating with a metal snare and resecting the tumors. The wall deficit was closed by using endoclips.

RESULTS

Altogether 28 patients were included in the study. CASL achieved an en bloc resection rate of 100%, with a mean total procedure time of 23.9 min. Active perforation was found in 20 (71.4%) patients, and endoclips closed the wall defect in all 20 cases. One patient developed pneumoperitoneum and self-limited peritonitis was found in two patients, all of whom were managed successfully. Pathological examination showed that 71.4% (20/28) of the tumors were gastrointestinal stromal tumors. No tumor recurrence was observed during the follow-up.

CONCLUSIONS

CASL may be a feasible and safe full-thickness resection modality for the treatment of small fundal SMTs arising from the muscularis propria. Further randomized studies are needed to confirm the results.

Submucosal tunnelling endoscopic resection (STER) for the treatment of a case of huge esophageal tumor arising in the muscularis propria: a case report and review of literature

BACKGROUND AND AIMS

Endoscopic Interventional Treatment is of little trauma and less complications in the treatment of esophageal tumor and leads to faster recovery and fewer days of hospitalization. This study was aimed to investigate the safety and efficacy of endoscopic interventional therapy for huge esophageal tumor arising in the muscularis propria.

METHODS

The patient was treated by submucosal tunneling endoscopic resection (STER).

RESULTS

The huge esophageal tumor was resected completely by STER technique, with little trauma and less complications. The size of the resected tumor was 5.5×3.5×3.0 cm.

CONCLUSION

Submucosal tunneling endoscopic resection is a safe and efficient technique for treating Huge Esophageal Tumor originating from muscularis propria layer.

Circular and longitudinal muscles shortening indicates sliding patterns during peristalsis and transient lower esophageal sphincter relaxation

Esophageal axial shortening is caused by longitudinal muscle (LM) contraction, but circular muscle (CM) may also contribute to axial shortening because of its spiral morphology. The goal of our study was to show patterns of contraction of CM and LM layers during peristalsis and transient lower esophageal sphincter (LES) relaxation (TLESR). In rats, esophageal and LES morphology was assessed by histology and immunohistochemistry, and function with the use of piezo-electric crystals and manometry. Electrical stimulation of the vagus nerve was used to induce esophageal contractions. In 18 healthy subjects, manometry and high frequency intraluminal ultrasound imaging during swallow-induced esophageal contractions and TLESR were evaluated. CM and LM thicknesses were measured (40 swallows and 30 TLESRs) as markers of axial shortening, before and at peak contraction, as well as during TLESRs. Animal studies revealed muscular connections between the LM and CM layers of the LES but not in the esophagus. During vagal stimulated esophageal contraction there was relative movement between the LM and CM. Human studies show that LM-to-CM (LM/CM) thickness ratio at baseline was 1. At the peak of swallow-induced contraction LM/CM ratio decreased significantly (<1), whereas the reverse was the case during TLESR (>2). The pattern of contraction of CM and LM suggests sliding of the two muscles. Furthermore, the sliding patterns are in the opposite direction during peristalsis and TLESR.

Ligation-assisted endoscopic enucleation for the treatment of colorectal submucosal tumours originating in the muscularis propria

AIM

A ligation-assisted endoscopic enucleation (EE-L) technique was developed and was evaluated to determine its efficacy and safety for treating colorectal submucosal tumours (< 10 mm) originating in the muscularis propria.

METHOD

EE-L was used to treat 13 patients between January 2011 and January 2014. The tumour was sucked into a transparent cap and ligated at its base by a rubber band ligature attached to the tip of the endoscope. With the creation of a pseudo-stalk, the tumour was then enucleated using endoscopic dissection and the wound was closed with clips.

RESULTS

All tumours [median diameter 6.8 (4-10) mm] were successfully enucleated [procedure time 19 (11-27) min]. Histopathological examination identified 11 (84.6%) to be leiomyoma and 2 (15.4%) low-risk gastrointestinal stromal tumours. No perforations or massive haemorrhage occurred and there were no recurrences during a follow-up of 3-39 months.

CONCLUSION

EE-L is a successful technique for the removal of small colorectal tumours in the muscularis propria with few complications and enables a histopathological diagnosis. In this study, all the resected lesions had a benign pathology.

Submucosal tunneling endoscopic resection for simultaneous esophageal and cardia submucosal tumors originating from the muscularis propria layer (with video)

Submucosal tunneling endoscopic resection (STER) is a new treatment technique for upper gastrointestinal submucosal tumors (SMT) originating from the muscularis propria (MP) layer. In contrast to conventional endoscopic resection, the new therapy can maintain the mucosal integrity of the digestive tract, which effectively prevents mediastinitis and peritonitis. STER, although a known method, has not been widely adopted because of technical difficulties. Here, we describe the case of a 30-year-old patient presenting with two separate SMT originating from the esophageal and cardia MP layer. A 2-cm longitudinal mucosal incision was made approximately 5 cm proximal to the esophageal SMT, and the esophageal and cardia SMT were dissected successively in the same submucosal tunnel. In the relevant literature, this is the first case of STER for resecting esophageal and cardia SMT using the same submucosal tunnel.

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.

Mast cells expressing interleukin 17 in the muscularis propria predict a favorable prognosis in esophageal squamous cell carcinoma

The proinflammatory cytokine interleukin 17 (IL-17) is considered to play a crucial role in diverse human tumors; however, its role in disease progression remains controversial. This study investigated the cellular source and distribution of IL-17 in esophageal squamous cell carcinoma (ESCC) in situ and determined its prognostic value. Immunohistochemistry, immunofluorescence and immunoelectron microscopy were used to identify IL-17-expressing cells in ESCC tissues, paying particular attention to their anatomic localization. Kaplan-Meier analysis and Cox proportional hazards regression models were applied to estimate overall survival in 215 ESCC patients with long-term follow-up (>10 years). The results showed that mast cells, but not T cells or macrophages, were the predominant cell type expressing IL-17 in ESCC tissues. Unexpectedly, these IL-17(+) cells were highly enriched in the muscularis propria rather than the corresponding tumor nest (p < 0.0001). The density of IL-17(+) cells in muscularis propria was inversely associated with tumor invasion (p = 0.016) and served as an independent predictor of favorable survival (p = 0.007). Moreover, the levels of IL-17(+) cells in muscularis propria were positively associated with the density of effector CD8(+) T cells and activated macrophages in the same area (both p < 0.0001). This finding suggested that mast cells may play a significant role in tumor immunity by releasing IL-17 at a previously unappreciated location, the muscularis propria, in ESCC tissues, which could serve as a potential prognostic marker and a novel therapeutic target for ESCC.

Endoscopic submucosal dissection of gastric fundus subepithelial tumors originating from the muscularis propria

Endoscopic resection of gastric subepithelial tumors (SETs) carries a high risk of perforation, particularly for tumors located at the gastric fundus and originating from the muscularis propria. Based on our experience with endoscopic submucosal dissection (ESD) and a novel endoscopic device, namely the ‘Resolution clip’ for the endoscopic closure of iatrogenic upper gastrointestinal (upper GI) perforations, we evaluated the clinical feasibility and safety of ESD for gastric fundus subepithelial tumors originating from the muscularis propria. In this prospective study, 11 consecutive patients who presented with gastric SETs ≤3 cm in diameter were enrolled. Regardless of whether perforation occurred, the gastric wall defect was closed with clips. The patients were followed up after the surgery. Endoscopic resection was successfully performed in 10 patients; however, in one patient a pure endoscopic approach was impossible as the lesion was severely adhered to surrounding tissue, and a switch to laparoscopic wedge resection was necessary. The mean resected tumor size was 18.8×17.2 mm and the mean surgery time of the 10 patients with ESD was 81 min (range 45–130 min). Histological diagnosis was gastrointestinal stromal tumor (GIST) in eight lesions [very low risk according to the National Institutes of Health (NIH) risk classification] and leiomyoma in three lesions. Perforation occurred in 3/10 patients. Gastric closure with the Resolution clips was performed successfully in all cases. Early post-ESD bleeding (EPEB) occurred in one patient. Basic ferric sulfate solution was sprayed during the upper GI endoscopy examination and the bleeding stopped. No complications occurred and the follow-up was unremarkable. In this early study, ESD using the Resolution clip was demonstrated to be a feasible and minimally invasive treatment for gastric fundus subepithelial tumors originating from the muscularis propria.