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.

Preoperative diagnosis of gastrointestinal stromal tumor by endoscopic ultrasound-guided fine needle aspiration

AIM: To evaluate the role of endoscopic ultrasonography-guided fine needle aspiration (EUS-FNA) in the preoperative diagnosis of gastrointestinal stromal tumor (GIST).

METHODS: From September 2002 to June 2006, Fifty-three consecutive EUS-FNAs of GI tract subepithelial hypoechoic tumors with continuity to proper muscle layer suspected as GIST by standard EUS were evaluated prospectively. The reference standards for the final diagnosis were surgery (n = 31), or clinical follow-up (n = 22). Additionally, immunophenotyping of specimens obtained by EUS-FNA and surgical resection specimens were compared.

RESULTS: In 2 cases puncture was not performed because of anatomical problems. The collection rate of adequate specimens from the GI tract subepithelial hypoechoic tumor with continuity to proper muscle layer was 82% (42/51). The diagnostic rate for the tumor less than 2 cm, 2 to 4 cm, and 4 cm or more were 71% (15/21), 86% (18/21), and 100% (9/9), respectively. In 29 surgically resected cases, the sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of EUS-FNA using immunohistochemical analysis of GIST were 100% (24/24), 80% (4/5), 96% (24/25), 100% (4/4), and 97% (28/29), respectively. No major complications were encountered.

CONCLUSION: EUS-FNA with immunohistochemical analysis is a safe and accurate method in the prethera-peutic diagnosis of GIST. It should be taken into consideration in decision making, especially in early diagnosis following minimal invasive surgery for GIST.

Intraductal papillary-mucinous tumors of the pancreas: differential diagnosis between benign and malignant tumors by endoscopic ultrasonography

OBJECTIVES

Recently, intraductal papillary-mucinous tumor (IPMT) of the pancreas has increasingly been recognized. However, differential diagnosis between benign and malignant IPMT is often difficult using conventional imaging modalities. The purpose of this study was to retrospectively investigate the value of endoscopic ultrasonography (EUS) for differentiating malignant from benign IPMT.

METHODS

A total of 51 patients with IPMT were preoperatively examined by EUS. The endosonograhic findings were compared with histopathological findings of the resected specimens.

RESULTS

In main duct type IPMT, the diameter of the main pancreatic duct (MPD) was > or =10 mm in seven of the eight malignant tumors, compared with two of the seven benign tumors (p < 0.05). In branch duct type IPMT, three of the four large tumors (>40 mm) with irregular thick septa were malignant lesions. In both main duct type IPMT and branch duct IPMT, eight patients had large mural nodules (>10 mm); seven of the eight tumors were malignant and one of the eight tumors was benign. When the tumor was diagnosed as malignant according to above three findings, EUS was able to differentiate between malignant and benign IPMT with an accuracy of 86%.

CONCLUSIONS

Main duct type tumors with > or =10 mm dilated MPD, branch duct type tumors (>40 mm) with irregular septa, and large mural nodules (>10 mm) strongly suggest malignancy on EUS. EUS would be a useful modality for differentiating between benign and malignant IPMT.

Pretreatment staging of endoscopically early gastric cancer with a 15 MHz ultrasound catheter probe

BACKGROUND

The usefulness of and problems associated with an ultrasound catheter probe in the pretreatment staging of endoscopically early gastric cancer remain unexplored.

METHODS

Endoscopic ultrasonography using a 15 MHz catheter probe of 2.6 mm diameter was performed in a prospective study to determine the pretherapy staging of endoscopically early gastric cancer in 78 patients. The results of the ultrasound images were compared with the histologic findings of the specimens obtained by endoscopic mucosal resection or surgical resection.

RESULTS

The accuracy of the catheter probe for depth of invasion of endoscopically early gastric cancers was 67% (52 of 78 patients). The accuracy in determining depth of invasion in relation to endoscopic type was significantly higher for the elevated type (91%) than for the depressed type of early cancer (56%) (p < 0.01). The staging accuracy classified by histologic type was significantly higher for differentiated (86%) than for undifferentiated (18%) cancer (p < 0.01). Staging accuracy decreased as tumor size increased. The accuracy, sensitivity, and specificity for nodal staging were 80%, 17%, and 90%, respectively.

CONCLUSIONS

A 15 MHz ultrasound catheter probe is most useful for determining depth of invasion when the tumor is histologically differentiated and endoscopically of the small elevated type early gastric cancer, but it is unreliable in the diagnosis of metastatic lymph nodes.

Preoperative evaluation of gastric cancer by endoscopic ultrasound

The preoperative use of endoscopic ultrasound was evaluated in 74 patients with confirmed gastric cancer. It was used in diagnosing the depth of invasion in the gastric wall, the infiltration to the adjacent organs, and the involvement of the perigastric lymph nodes. Results were compared with histological findings in resected specimens. Accuracy in staging gastric cancer using the T grade of the 1987 TNM system was 81.1% (60 of 74 patients). Endoscopic ultrasound provided excellent results compared with computed tomography and conventional ultrasound, particularly in evaluating perigastric lymph node metastasis and direct infiltration to the adjacent organs. The success rate in detecting lymph node metastasis was 50% (11 of 22 patients); the accuracy in diagnosing direct infiltration to the adjacent organs was 60% (three of five patients). This technique is useful in diagnosing malignant invasion and lymph node metastasis of gastric carcinomas but requires further refinement for use in diagnosing the disease itself. Its preoperative use is recommended for establishing surgical and other treatment plans, as well as in predicting the prognosis of gastric cancer.

Clinical usefulness of endoscopic ultrasound-guided fine needle aspiration for gastric subepithelial lesions smaller than 2 cm

BACKGROUND AND AIMS

There is no evidence of postoperative metastasis of gastric gastrointestinal stromal tumors (GISTs) smaller than 2 cm. The aim of this study was to evaluate the clinical usefulness of endoscopic ultrasound guided fine needle aspiration (EUS-FNA) for gastric subepithelial lesions (SELs) smaller than 2 cm.

PATIENTS AND METHODS

Using a prospectively maintained EUS-FNA database, 90 consecutive EUS-FNAs of gastric hypoechoic solid SELs smaller than 2 cm diagnosed by EUS were evaluated retrospectively. The reference standards for the final diagnosis were surgery (n=44) and/or clinical follow-up (n=46) using esophagogastroduodenoscopy (EGD), CT, and/or ultrasonography (US). Additionally, immunophenotyping of specimens obtained by EUS-FNA and surgical resection specimens were compared.

RESULTS

The diagnostic rate of EUS-FNA for gastric hypoechoic solid SELs smaller than 2 cm was 73% (66/90). Histological diagnosis of EUS-FNA showed 47 (52%) malignant SELs (44 GISTs, 1 glomus tumor, 1 SEL like cancer, and 1 malignant lymphoma), 19 (21%) benign SELs (14 leiomyomas, 4 ectopic pancreas, and 1 neurinoma), and 24 (27%) indeterminate SELs. In 44 surgically resected cases, the diagnostic accuracy of EUS-FNA using immunohistochemical analysis was 98% (43/44). There were no complications. Appropriate management was performed in 65 out of 66 SELs (98%) diagnosed by definitive EUS-FNA. After surgery, there was no recurrence of malignant SELs.

CONCLUSIONS

EUS-FNA is an accurate and safe method in the pre-therapeutic diagnosis of gastric SELs smaller than 2 cm. EUS-FNA for gastric SELs smaller than 2 cm is a promising way to permit early management of patients with gastric SELs including GIST.

Pre-operative staging of ampullary tumours by endoscopic ultrasound

Ampullary carcinomas have a significantly higher resectability rate and better prognosis than other periampullary carcinomas, although the prognosis is poor with advanced disease. Accurate tumour staging is therefore important in surgical planning. Our objective was to evaluate the usefulness of, and problems associated with, endoscopic ultrasound (EUS) in the pre-operative staging of ampullary tumours. 35 patients with ampullary tumours were pre-operatively examined with EUS. The imaging results were compared with histopathological findings of the resected specimen according to the TNM staging classification. The overall accuracy of tumour (T) staging was 74% (26/35) for all tumours, and 67% (6/9), 71% (10/14) and 83% (10/12) respectively for T1, T2 and T3 tumours. The overall accuracy of nodal (N) staging was 63%. In diagnosing pancreatic invasion, EUS had an accuracy of 86% (30/35), a sensitivity of 83% (10/12), and a specificity of 87% (20/23). In conclusion, EUS provides an accurate method of evaluating the stage of ampullary tumours, especially infiltration into the pancreas. This modality is useful to surgeons in deciding on an appropriate therapeutic approach and in giving a prognosis.

Regional lymph node metastasis in gastric cancer: evaluation with endoscopic US

Endoscopic ultrasound (EUS) was performed in 83 patients with gastric cancer to evaluate regional lymph node metastasis. Histopathologic findings were compared with preoperative EUS findings in a total of 1,519 resected lymph nodes. In lymph node staging, the prevalence of metastatic adenopathy was 31.3% (26 of 83 patients); EUS had an accuracy of 83.1% (69 of 83 patients), sensitivity of 53.8% (14 of 26 patients), specificity of 96.5% (55 of 57 patients), positive predictive value of 87.5% (14 of 16 patients), and negative predictive value of 82.1% (55 of 67 patients). The greater the maximum diameter of the node with metastasis, or the larger the ratio of the metastatic area to the cross-sectional area of the node, the higher the detection rate. In tumors classified on the basis of depth of invasion according to the 1987 TNM system, the rate of detection of metastasis in individual nodes was 0% in pT1 tumors (none of five nodes), 20% in pT2 tumors (17 of 85 nodes), 29% in pT3 tumors (20 of 70 nodes), and 10% in pT4 tumors (three of 31 nodes). It is concluded that the most important use of EUS will be in diagnosis of regional lymph node metastasis.

Endoscopic ultrasonography: a promising method for assessing the prospects of endoscopic mucosal resection in early gastric cancer

BACKGROUND AND STUDY AIMS

A recent challenge that is increasingly being faced in endoscopy is the use of endoscopic mucosal resection (EMR) to treat differentiated intramucosal gastric cancers smaller than 2 cm. The usefulness of pretherapeutic endoscopic ultrasonography (EUS) in assessing whether this form of treatment is possible remains controversial.

PATIENTS AND METHODS

We retrospectively investigated the value of pretherapeutic EUS evaluation in 58 patients with macroscopically early gastric cancer that was histologically differentiated and less than 2 cm in diameter. The patients were classified as negative for endoscopic mucosal resection if EUS showed modifications of the third layer, and as positive if such modifications were not seen. All patients underwent radical surgery and the preoperative EUS findings were compared with the histological findings.

RESULTS

The prevalence of metastatic adenopathy was 3% (two of 58). In the lymph-node staging, endosonography had a sensitivity of 0% (neither of two cases), and a specificity of 93% (52 of 56). In assessing the indication for EMR, EUS had a sensitivity of 93% (27 of 29), and a specificity of 86% (25 of 29).

CONCLUSIONS

These results suggest that EUS is a promising method of evaluating the indication for endoscopic mucosal resection in early gastric cancer. EUS may improve pretherapeutic prediction of tumor curability by EMR, and may reduce the need for standard gastrectomy.

Prospective randomized trial of transnasal versus peroral endoscopy using an ultrathin videoendoscope in unsedated patients

AIM

The aim of this study was to compare the acceptance and tolerance of transnasal and peroral esophagogastroduodenoscopy (EGD) using an ultrathin videoendoscope in unsedated patients.

METHODS

A total of 124 patients referred for diagnostic endoscopy were assigned randomly to have an unsedated transnasal EGD (n = 64) or peroral EGD (n = 60) with local anesthesia. An ultrathin videoendoscope with a diameter of 5.9 mm was used in this study. A questionnaire for tolerance was completed by the patient (a validated 0-10 scale where '0' represents no discomfort/well tolerated and '10' represents severe discomfort/poorly tolerated).

RESULTS

Of the 64 transnasal EGD patients, 60 patients (94%) had a complete examination. Four transnasal EGD examinations failed for anatomical reasons; all four patients were successfully examined when switched to the peroral EGD. All 60 peroral EGD patients had a complete examination. Between the transnasal and peroral groups, there was a statistically significant difference in scores for discomfort during local anesthesia (1.5 +/- 0.2 vs 2.6 +/- 0.3, P = 0.003), discomfort during insertion (2.3 +/- 0.3 vs 4.3 +/- 0.3, P = 0.001), and overall tolerance during procedure (1.6 +/- 0.2 vs 3.8 +/- 0.2, P = 0.001). In all, 95% of transnasal EGD patients and 75% of peroral EGD patients (P = 0.002) were willing to undergo the same procedure in the future. Four patients in the transnasal EGD group experienced mild epistaxis.

CONCLUSION

For unsedated endoscopy using an ultrathin videoendoscope, transnasal EGD is well tolerated and considerably reduces patient discomfort compared with peroral EGD.

Improved techniques for double-balloon-enteroscopy-assisted endoscopic retrograde cholangiopancreatography

AIM: To investigate the clinical outcome of double balloon enteroscopy (DBE)-assisted endoscopic retrograde cholangiopancreatography (DB-ERCP) in patients with altered gastrointestinal anatomy.

METHODS: Between September 2006 and April 2011, 47 procedures of DB-ERCP were performed in 28 patients with a Roux-en-Y total gastrectomy (n = 11), Billroth II gastrectomy (n = 15), or Roux-en-Y anastomosis with hepaticojejunostomy (n = 2). DB-ERCP was performed using a short-type DBE combined with several technical innovations such as using an endoscope attachment, marking by submucosal tattooing, selectively applying contrast medium, and CO₂ insufflations.

RESULTS: The papilla of Vater or hepaticojejunostomy site was reached in its entirety with a 96% success rate (45/47 procedures). There were no significant differences in the success rate of reaching the blind end with a DBE among Roux-en-Y total gastrectomy (96%), Billroth II reconstruction (94%), or pancreatoduodenectomy (100%), respectively (P = 0.91). The total successful rate of cannulation and contrast enhancement of the target bile duct in patients whom the blind end was reached with a DBE was 40/45 procedures (89%). Again, there were no significant differences in the success rate of cannulation and contrast enhancement of the target bile duct with a DBE among Roux-en-Y total gastrectomy (88 %), Billroth II reconstruction (89%), or pancreatoduodenectomy (100%), respectively (P = 0.67). Treatment was achieved in all 40 procedures (100%) in patients whom the contrast enhancement of the bile duct was successful. Common endoscopic treatments were endoscopic biliary drainage (24 procedures) and extraction of stones (14 procedures). Biliary drainage was done by placement of plastic stents. Stones extraction was done by lithotomy with the mechanical lithotripter followed by extraction with a basket or by the balloon pull-through method. Endoscopic sphincterotomy was performed in 14 procedures with a needle precutting knife using a guidewire. The mean total duration of the procedure was 93.6 ± 6.8 min and the mean time required to reach the papilla was 30.5 ± 3.7 min. The mean time required to reach the papilla tended to be shorter in Billroth II reconstruction (20.9 ± 5.8 min) than that in Roux-en-Y total gastrectomy (37.1 ± 4.9 min) but there was no significant difference (P = 0.09). A major complication occurred in one patient (3.5%); perforation of the long limb in a patient with Billroth II anastomosis.

CONCLUSION: Short-type DBE combined with several technical innovations enabled us to perform ERCP in most patients with altered gastrointestinal anatomy.

Diagnosis and staging of pancreatic cancer by endoscopic ultrasound

The aim of this study was to evaluate the usefulness of and problems associated with endoscopic ultrasonography (EUS) in the diagnosis and pre-operative staging of pancreatic cancer. 96 patients suspected of having pancreatic cancer were pre-operatively examined with EUS. 37 of these 96 patients had pancreatic cancer. Results of the EUS imaging were compared with findings of histology and/or surgery, and the patient's clinical course. The sensitivity and specificity of EUS for diagnosing pancreatic cancer were 89% and 97%, respectively. EUS had excellent sensitivity regardless of tumour size or location. EUS was accurate (90%) in determining tumour size in pancreatic cancers less than 3 cm in maximum diameter, but not for tumours greater than 3 cm (30%). The accuracy of tumour (T) and nodal (N) staging were 64% and 50%, respectively. EUS is a promising method for the early diagnosis and pre-operative staging of pancreatic cancers, but requires further refinement.

Preoperative evaluation of submucosal invasive colorectal cancer using a 15-MHz ultrasound miniprobe

BACKGROUND AND STUDY AIMS

Recently, it was reported that focal submucosal invasive colorectal cancer could be treated by polypectomy or endoscopic mucosal resection (EMR) because of the rarity of lymph-node metastasis. Our objective was to examine the accuracy and efficacy of a 15-MHz ultrasound miniprobe in the preoperative evaluation of the degree of submucosal invasion in colorectal cancer.

PATIENTS AND METHODS

A total of 35 patients with submucosal invasive colorectal cancer who underwent ultrasonography with a miniprobe were studied prospectively. The results of this imaging were compared with the histologic findings in resected specimens.

RESULTS

Although the accuracy of the miniprobe in categorizing submucosal invasion into three subclasses (SM1, invasion limited to the upper third; SM2, limited to the middle third; SM3, limited to the lower third) was low (37.1%; 13/35), the accuracy in differentiation between < or = SMI (M and SMI) and > or = SM2 (SM2, SM3, MP, and S) was 85.7 % (30/35).

CONCLUSIONS

The miniprobe can be useful for therapeutic decision-making in submucosal invasive colorectal cancer.

Endoscopic submucosal dissection using a novel grasping type scissors forceps

Endoscopic submucosal dissection (ESD) with a knife is a technically demanding procedure that is associated with a high complication rate. The shortcoming of this method is the difficulty in fixing the knife to the target lesion. This difficulty can lead to unexpected incision, resulting in major complications such as perforation and bleeding. To reduce the risk of complications related to ESD, we developed a new grasping type scissors forceps (GSF), which can grasp and incise the targeted tissue using an electrosurgical current. The ESD procedure using the GSF was carried out in an animal model (resected porcine stomachs in vitro). After marking the lesion and injecting a solution into the submucosa, the lesion was separated from the surrounding normal mucosa following complete incision around the lesion using the GSF. A piece of submucosal tissue was grasped and cut with the GSF using an electrosurgical current to achieve submucosal exfoliation. ESD using the GSF was carried out safely and easily without unintentional incision. ESD using GSF appears to be an easy, safe, and technically efficient method for resecting gastrointestinal neoplasms.

Pre-operative TN staging of gastric cancer using a 15 MHz ultrasound miniprobe

The aim of the study was to evaluate the usefulness of and problems associated with a new endoscopically guided ultrasound miniprobe, used for pre-operative staging of gastric cancers. 59 cases of gastric cancer were prospectively examined with a 15 MHz ultrasound miniprobe. The results of the ultrasound imaging were compared with the histological findings of the resected specimens. The accuracy of the miniprobe for depth of invasion (T category) was 61% for all tumours, and 72% and 40%, respectively, for T1 and T2 to T4 lesions. If indeterminate cases due to ultrasound attenuation were excluded, the accuracy was improved to 82% for T1 and 57% for T2 to T4 tumours, respectively. The accuracy of the miniprobe for nodal staging (N category) was 69% overall, and 86%, 25% and 14% for stages N0, N1 and N2, respectively. In tumours classified on the basis of endoscopic types, the miniprobe staged early type gastric cancers (T category = 73%, N category = 80%) significantly (p < 0.01) more accurately than advanced ones (T category = 21%, N category = 36%). This study suggests that the miniprobe is indicated for pre-operative TN staging when endoscopy reveals an early gastric cancer.

Double-balloon endoscopy in the diagnosis and management of GI tract diseases: Methodology, indications, safety, and clinical impact

AIM: To prospectively evaluate the indications, methodology, safety, and clinical impact of double-balloon endoscopy.

METHODS: A total of 60 patients with suspected or documented small- or large-bowel diseases were investigated by double balloon endoscopy. A total of 103 procedures were performed (42 from the oral route, 60 from the anal route, and 1 from the stoma route). The main outcome measurements were the time of insertion and the entire examination, complications, diagnostic yields, and the ability to successfully perform treatment.

RESULTS: Observation of the entire small intestine was possible in 10 (40%) of 25 patients with total enteroscopy. The median insertion time was 122 min (range, 74-199 min). Observation of the entire colon was possible in 13 (93%) of 14 patients after failure of total colonoscopy using a conventional colonoscope. Small-intestine abnormalities were found in 20 (43%) of 46 patients with indications of suspected or documented small bowel diseases, obscure GI tract bleeding, or a history of ileus. Endoscopic procedures including tattooing (n = 33), bite biopsy (n = 17), radiographic examination (n = 7), EUS (n = 5), hemostasis (n = 1), polypectomy (n = 5), balloon dilatation (n = 1), endoscopic mucosal resection (n = 1) and lithotripsy (n = 1) were all successfully performed. No relevant technical problems or severe complications were encountered.

CONCLUSION: Double balloon endoscopy is a feasible technique that allows adequate small and large bowel examination and potentially various endoscopic procedures of small-intestinal lesions. It is safe, useful, and also provides a high clinical impact.

Predictive factors for colonic diverticular rebleeding: a retrospective analysis of the clinical and colonoscopic features of 111 patients

Background/Aims

Colonic diverticular bleeding can stop spontaneously or be stopped by endoscopic hemostasis. We analyzed the clinical and colonoscopic features of patients with colonic diverticular bleeding to establish the predictive factors for rebleeding.

Methods

A total of 111 patients (median age, 72 years) with colonic diverticular bleeding in Aso Iizuka Hospital between April 2007 and July 2010 were enrolled. Age, sex, body mass index (BMI), comorbidity, medication, location of bleeding, colonoscopic findings and hemostatic methods were analyzed retrospectively from the hospital records.

Results

The most common sites of bleeding were the ascending (39.6%) and sigmoid (29.7%) colon. Overt rebleeding occurred in 30 patients (27.0%). Spontaneous hemostasis was seen in 81 patients (73.0%), and endoscopic hemostatic treatment was performed in 30 patients. The BMI in the patients with colonic diverticular rebleeding was significantly higher than in patients without rebleeding. Colonoscopic findings of actively bleeding or nonbleeding visible vessels in the responsible diverticula were more frequent in the group with rebleeding.

Conclusions

A higher BMI and colonoscopic findings of actively bleeding or nonbleeding visible vessels can be used as predictive factors for colonic diverticular rebleeding. Patients with such findings should be carefully followed up after hemostasis of the initial colonic diverticular bleeding.

Scirrhous carcinoma of the stomach versus hypertrophic gastritis: findings at endoscopic US

To differentiate scirrhous carcinoma from hypertrophic gastritis, 16 patients with scirrhous carcinoma of the stomach and seven patients with hypertrophic gastritis were examined with endoscopic ultrasonography (US) between August 1987 and October 1990. US images of the normal gastric walls of 16 patients with gastric ulcers served as controls. Characteristic features of scirrhous carcinoma included an irregular hypoechoic enlargement of the third (submucosa) and fourth (muscularis propria) layers. The mean thickness of the third and fourth layers was increased sixfold and threefold, respectively, compared with thickness in healthy subjects. In the patients with scirrhous carcinoma, the mucosal layer remained normal in appearance at US, and it was possible to distinguish the five-layer structure of the gastric wall. These findings were prospectively correlated with histopathologic findings in the resected specimens. In contrast, only the mucosal layer was thickened in cases of hypertrophic gastritis. Recognition of these patterns at US can aid in the differential diagnosis of scirrhous carcinoma and such benign diseases as hypertrophic gastritis with a thickened gastric wall.

Endoscopic submucosal dissection for removal of superficial gastrointestinal neoplasms: A technical review

Endoscopic submucosal dissection (ESD) is now the most common endoscopic treatment in Japan for intramucosal gastrointestinal neoplasms (non-metastatic). ESD is an invasive endoscopic surgical procedure, requiring extensive knowledge, skill, and specialized equipment. ESD starts with evaluation of the lesion, as accurate assessment of the depth and margin of the lesion is essential. The devices and strategies used in ESD vary, depending on the nature of the lesion. Prior to the procedure, the operator must be knowledgeable about the treatment strategy(ies), the device(s) to use, the electrocautery machine settings, the substances to inject, and other aspects. In addition, the operator must be able to manage complications, should they arise, including immediate recognition of the complication(s) and its treatment. Finally, in case the ESD treatment is not successful, the operator should be prepared to apply alternative treatments. Thus, adequate knowledge and training are essential to successfully perform ESD.

Suitability of the expanded indication criteria for the treatment of early gastric cancer by endoscopic submucosal dissection: Japanese multicenter large-scale retrospective analysis of short- and long-term outcomes

OBJECTIVE

The criteria for endoscopic resection for early gastric cancer include absolute and expanded indications. Consensus already exists for the absolute indications. However, the suitability of the expanded indications must be validated by long-term outcome analyses since such lesions have only recently become resectable with the development of endoscopic submucosal dissection. The aim of this study is to clarify the suitability of the expanded indications for the treatment of early gastric cancer with endoscopic submucosal dissection.

MATERIALS AND METHODS

The medical records of 1161 patients with early gastric cancers (1332 lesions) treated by endoscopic submucosal dissection and meeting the criteria for absolute or expanded indications without additional treatment with gastrectomy were divided into absolute indication group or expanded indication group.

RESULTS

Complete resection rates were 96.4% and 93.4% in absolute and expanded indication groups, respectively, with no significant differences between the groups. Delayed bleeding rates were significantly higher in the expanded indication group, whereas all cases were successfully managed conservatively. The 5-year overall survival and recurrence-free rates were 93.7%/99.77% and 90.49%/98.90% in the absolute and the expanded indication groups, respectively, with no significant differences between the groups for either measure. Multivariate analyses revealed that affected horizontal margin and tumor location were independent predictive factors for recurrence.

CONCLUSION

The expanded indication group showed excellent post-endoscopic submucosal dissection short-term and long-term outcomes compared with the absolute indications group, demonstrating that expanded indications are suitable for endoscopic submucosal dissection for early gastric cancer.

Gastrointestinal stromal tumor of the stomach: How to manage?

Gastrointestinal stromal tumor (GIST) is one of the most common malignant mesenchymal tumors of the stomach. Prognosis of this disease is related to tumor size and mitotic activity and early diagnosis is the only way to improve it. Diagnosis of GIST always requires histological and immunohistochemical confirmation as no imaging modalities can diagnose it conclusively. Endoscopic forceps biopsy results are frequently negative. Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is a technique which allows tissue samples to be obtained with minimal risks and is accurate in the diagnosis of GIST. From the point of view of the endoscopist, aggressive use of EUS-FNA is the only promising way to allow early diagnosis and early treatment of this disease.

Endoscopic submucosal dissection by using a grasping-type scissors forceps: a preliminary clinical study (with video)

BACKGROUND

Endoscopic submucosal dissection (ESD) with a knife is a technically demanding procedure associated with a high complication rate. The shortcoming of this method is the difficulty of fixing the knife to the target lesion. It can lead to an unexpected incision and result in major complications, such as perforation and bleeding. To reduce the risk of complications related to ESD, we developed a new grasping-type scissors forceps (GSF), which can grasp and incise the targeted tissue by using electrosurgical current.

OBJECTIVE

To evaluate the efficacy and safety of ESD by using GSF for the removal of gastric neoplasms in human beings.

DESIGN

Prospective, uncontrolled, single center.

SETTING

Department of Gastroenterology, Aso Iizuka Hospital, Iizuka, Japan.

PATIENTS

Four patients with early gastric neoplastic lesions.

INTERVENTIONS

After marking and injection of a solution into the submucosa, the lesion was separated from the surrounding normal mucosa by complete incision around the lesion by using the GSF. A piece of submucosal tissue was grasped and cut with the GSF by using electrosurgical current to achieve submucosal excision.

MAIN OUTCOME MEASUREMENT

Technical success and complications.

RESULTS

All lesions were treated easily and safely, without any unexpected incisions. No delayed hemorrhage and perforation occurred. An en bloc resection and a negative resection margin was obtained in all cases.

LIMITATIONS

The small number of patients and an uncontrolled study.

CONCLUSIONS

ESD with GSF appeared to be an easy, safe, and technically efficient method for resecting GI neoplasms.

Endoscopic submucosal dissection using a grasping-type scissors forceps for early gastric cancers and adenomas

AIM

To reduce the risk of complications related to endoscopic submucosal dissection (ESD) using knives, we developed a new grasping-type scissors forceps (GSF) that can grasp and incise the target tissue using electrosurgical current. The aim of the present study was to evaluate the efficacy and safety of ESD using GSF for the removal of early gastric cancers and adenomas.

METHODS

ESD using GSF was carried out on 35 consecutive patients with early gastric cancers or adenomas who had preoperative EUS diagnoses of mucosal tumor without lymph node involvement. Therapeutic efficacy and safety were assessed.

RESULTS

All lesions were treated easily and safely without unexpected incision. The mean size of epithelial tumors and resected specimens was 15.6mm and 32.7mm, respectively. Curative en-bloc resection rates according to tumor size and location were 96% (26/27) in tumors ≤20mm, 100% (8/8) in tumors >20mm, 100% (18/18) of tumors in the lower portion, 100% (8/8) of tumors in the middle portion, 89% (8/9) of tumors in the upper portion, and 97% (34/35) overall. The mean operating time according to tumor size and location was 93.4min in tumors ≤20mm, 140min in tumors >20mm, 77.6min for tumors in the lower portion, 113.4min for tumors in the middle portion, 148.6min for tumors in the upper portion, and 104.1min overall. No intraoperative complication occurred, and postoperative bleeding was seen in 3% (1/35).

CONCLUSIONS

ESD using GSF allows simple and safe en-bloc resection of early gastric cancer or adenoma irrespective of tumor size and location.

Short- and long-term outcomes of endoscopic resection of rectal neuroendocrine tumours: analyses according to the WHO 2010 classification

OBJECTIVE

Although the World Health Organisation (WHO) defined a novel classification of gastroenteropancreatic neuroendocrine tumours (NETs) in 2010, indications for endoscopic resection of rectal NETs in the guidelines were based on evidence accumulated for carcinoid tumours defined by a previous classification. This study was designed to clarify indications for endoscopic resection of rectal NETs corresponding to the new WHO classifications.

MATERIAL AND METHODS

One hundred-seventy rectal NETs resected endoscopically from April 2001 to March 2012 were histologically re-classified according to the WHO 2010 criteria. The clinicopathological features of these lesions were analysed, and the short- and long-term outcomes of endoscopic resection were evaluated.

RESULTS

Of the 170 rectal NETs, 166 were histopathologically diagnosed as NET G1 and four as NET G2. Thirty-eight tumours (22.4%) were positive for lymphovascular invasion, a percentage higher than expected. Although the curative resection rate was low (65.3%), en bloc (98.8%) and complete (85.9%) resection rates were high. Modified endoscopic mucosal resection (88.0%) and endoscopic submucosal dissection (92.2%) resulted in significantly higher complete resection rates than conventional endoscopic mucosal resection (36.4%). No patient experienced tumour recurrence, despite the low curative resection rate.

CONCLUSION

Despite the low curative resection rate, prognosis after endoscopic resection of rectal NETs was excellent. Prospective large-scale, long-term studies are required to determine whether NET G2 and tumours >1 cm should be included in the indication for endoscopic resection and whether tumours with lymphovascular invasion can be followed up without additional surgery.