Kazuya Akahoshi

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

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

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.

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.

Preoperative staging of colorectal cancer by a 15 MHz ultrasound miniprobe

BACKGROUND Our objective was to examine the accuracy of a 15 MHz ultrasound miniprobe in the pre-operative staging of colorectal cancer by assessing the depth of tumor infiltration and involvement of pericolonic lymph nodes. METHODS Thirty-three patients with colorectal cancer who underwent ultrasonography with a miniprobe were studied prospectively. The results of this imaging were compared with the histologic findings of the resected specimens. RESULTS The accuracy of the miniprobe for depth of invasion (T category) was 82% (27 of 33) for all tumors, 76% (13 of 17) in pT1 cases, and 88% (14 of 16) in pT2 to pT4 cases. The accuracy of the miniprobe for nodal staging (N category) was 87% (26 of 30) overall. The sensitivity was 63% (5 of 8), the specificity was 95% (21 of 22), the positive predictive value was 83% (5 of 6), and the negative predictive value was 88% (21 of 24). CONCLUSIONS The miniprobe is an accurate method for the preoperative TN staging of colorectal cancer. We recommend its preoperative use because the results may influence the surgical approach.

Endosonography probe-guided endoscopic mucosal resection of gastric neoplasms

the stomach following endoscopic volvulus reduction in a poor surgical candidate. This novel approach resulted in persistence of normal gastric position as documented by UGI series 1 year later. Further data is needed on the long-term follow-up of patients with various types of symptomatic volvulus managed endoscopically in regards to the significance and frequency of recurrence. In conclusion, we have described a new maneuver, the alpha-loop technique, for endoscopic reduction of gastric volvulus. We used this technique to successfully reduce gastric volvulus in 7 out of 8 patients with no procedural complications. The major benefit of endoscopic volvulus reduction was to allow time for elective surgical repair of abdominal pathology (paraesophageal hernia) predisposing to volvulus formation. The role of the alpha-loop technique as a definitive therapy in poor surgical candidates and in patients with idiopathic volvulus requires further evaluation.

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.

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 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.

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.

A new approach: endoscopic submucosal dissection using the Clutch Cutter® for early stage digestive tract tumors.

Endoscopic submucosal dissection (ESD) is accepted as minimally invasive therapy for early stage digestive tract tumors. It has allowed the achievement of histologically curative en-bloc resection of early stage digestive tract tumors regardless of size, including the resection of previously non-resectable tumors. Although numerous electrosurgical knives have been developed for ESD, technical difficulties and high complication rates (bleeding and perforation) have limited their use worldwide. Furthermore, conventional ESD usually needs several devices for each session. We developed the Clutch Cutter® (CC), which can grasp and incise the targeted tissue using electrosurgical current, to resolve such ESD-related problems. The ESD procedure using the CC is as follows: after marking using the CC and the injection of a solution into the submucosa, the lesion is separated from the surrounding normal mucosa by complete incision around the lesion using the CC. A piece of submucosal tissue is grasped and cut with the CC using electrosurgical current to achieve submucosal exfoliation. Intraoperative bleeding is also treated by the CC. Reported clinical studies showed that ESD using the CC is a safe, simple, easy-to-learn, technically efficient (en-bloc resection rate 100%), and a single-device method for the dissection of early stage digestive tract tumors. This new approach is promising to become the worldwide method of choice for early stage digestive tract tumors because it is technically simple and safe to perform.