Role of endoscopic ultrasonography

[Clinical and Technical Guideline for Endoscopic Ultrasound-guided Tissue Acquisition of Pancreatic Solid Tumor: Korean Society of Gastrointestinal Endoscopy]

Endoscopic ultrasound (EUS)-guided tissue acquisition of pancreatic solid tumor requires a strict recommendation for its proper use in clinical practice because of its technical difficulty and invasiveness. The Korean Society of Gastrointestinal Endoscopy appointed a Task Force to draft clinical practice guidelines for EUS-guided tissue acquisition of pancreatic solid tumor. The strength of recommendation and the level of evidence for each statement were graded according to the Minds Handbook for Clinical Practice Guideline Development 2014. The committee, comprising a development panel of 16 endosonographers and an expert on guideline development methodology, developed 12 evidence-based recommendations in eight categories intended to help physicians make evidence- based clinical judgments with regard to the diagnosis of pancreatic solid tumor. This clinical practice guideline discusses EUS-guided sampling in pancreatic solid tumor and makes recommendations on circumstances that warrant its use, technical issues related to maximizing the diagnostic yield (e.g., needle type, needle diameter, adequate number of needle passes, sample obtaining techniques, and methods of specimen processing), adverse events of EUS-guided tissue acquisition, and learning-related issues. This guideline was reviewed by external experts and suggests best practices recommended based on the evidence available at the time of preparation. This guideline may not be applicable for all clinical situations and should be interpreted in light of specific situations and the availability of resources. It will be revised as necessary to cover progress and changes in technology and evidence from clinical practice.

Clinical and Technical Guideline for Endoscopic Ultrasound (EUS)-Guided Tissue Acquisition of Pancreatic Solid Tumor: Korean Society of Gastrointestinal Endoscopy (KSGE)

Endoscopic ultrasound (EUS)-guided tissue acquisition of pancreatic solid tumor requires a strict recommendation for its proper use in clinical practice because of its technical difficulty and invasiveness. The Korean Society of Gastrointestinal Endoscopy (KSGE) appointed a task force to draft clinical practice guidelines for EUS-guided tissue acquisition of pancreatic solid tumor. The strength of recommendation and the level of evidence for each statement were graded according to the Minds Handbook for Clinical Practice Guideline Development 2014. The committee, comprising a development panel of 16 endosonographers and an expert on guideline development methodology, developed 12 evidence-based recommendations in eight categories intended to help physicians make evidence-based clinical judgments with regard to the diagnosis of pancreatic solid tumor. This clinical practice guideline discusses EUS-guided sampling in pancreatic solid tumor and makes recommendations on circumstances that warrant its use, technical issues related to maximizing the diagnostic yield (e.g., needle type, needle diameter, adequate number of needle passes, sample obtaining techniques, and methods of specimen processing), adverse events of EUS-guided tissue acquisition, and learning-related issues. This guideline was reviewed by external experts and suggests best practices recommended based on the evidence available at the time of preparation. This guideline may not be applicable for all clinical situations and should be interpreted in light of specific situations and the availability of resources. It will be revised as necessary to cover progress and changes in technology and evidence from clinical practice.

Clinical and Technical Guideline for Endoscopic Ultrasound (EUS)-Guided Tissue Acquisition of Pancreatic Solid Tumor: Korean Society of Gastrointestinal Endoscopy (KSGE)

Endoscopic ultrasound (EUS)-guided tissue acquisition of pancreatic solid tumor requires a strict recommendation for its proper use in clinical practice because of its technical difficulty and invasiveness. The Korean Society of Gastrointestinal Endoscopy (KSGE) appointed a task force to draft clinical practice guidelines for EUS-guided tissue acquisition of pancreatic solid tumor. The strength of recommendation and the level of evidence for each statement were graded according to the Minds Handbook for Clinical Practice Guideline Development 2014. The committee, comprising a development panel of 16 endosonographers and an expert on guideline development methodology, developed 12 evidence-based recommendations in eight categories intended to help physicians make evidence-based clinical judgments with regard to the diagnosis of pancreatic solid tumor. This clinical practice guideline discusses EUS-guided sampling in pancreatic solid tumor and makes recommendations on circumstances that warrant its use, technical issues related to maximizing the diagnostic yield (e.g., needle type, needle diameter, adequate number of needle passes, sample obtaining techniques, and methods of specimen processing), adverse events of EUS-guided tissue acquisition, and learning-related issues. This guideline was reviewed by external experts and suggests best practices recommended based on the evidence available at the time of preparation. This guideline may not be applicable for all clinical situations and should be interpreted in light of specific situations and the availability of resources. It will be revised as necessary to cover progress and changes in technology and evidence from clinical practice.

Factors influencing diagnostic accuracy of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) in pancreatic and biliary tumors

BACKGROUND AND AIM

Diagnostic accuracy of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is influenced by several factors, primarily operator expertise. Formal training in EUS-FNA, as suggested by the European Society of Gastrointestinal Endoscopy and the American Society for Gastrointestinal Endoscopy guidelines, is not always available and is often expensive and time-consuming. In this study we evaluate factors influencing the diagnostic accuracy of pancreatic EUS-FNA.

METHODS

In a retrospective study, 557 consecutive EUS-FNAs were evaluated. Several variables relating to the procedures were considered to calculate the EUS-FNA performance over eight years.

RESULTS

A total of 308 out of 557 EUS-FNAs were selected. Overall sensitivity of EUS-FNA was 66% (95% CI: 60.8-71.8), specificity 100%, and diagnostic accuracy 69% (95% CI: 64.0-74.4). An increase in diagnostic accuracy was observed to >90% using a new fine-needle biopsy (FNB) needle and in the case of simultaneous sampling of primary and metastatic lesions. Diagnostic accuracy >80% was observed after 250 procedures, in the absence of rapid on-site cytopathological examination (ROSE). Multivariate logistic regression analysis confirmed that the FNB needle, operator skill, and double EUS-FNA sampling are associated with high diagnostic accuracy.

CONCLUSIONS

The learning curve for EUS-FNA may be longer and a considerable number of procedures are needed to achieve high diagnostic accuracy in the absence of ROSE. However, the use of FNB needles and the simultaneous sampling of primary and metastatic lesions can rapidly improve the diagnostic accuracy of the procedure.

Endoscopic submucosal dissection for treatment of gastric submucosal tumors originating from the muscularis propria layer

BACKGROUND AND AIMS

We aimed to study the feasibility of endoscopic submucosal dissection (ESD) for the removal of gastric muscularis propria tumors and to evaluate the efficacy and safety of ESD for this treatment.

METHODS

Eighteen patients with gastric SMTs originating from the muscularis propria were treated by ESD between July 2008 and July 2011. Tumor characteristics, complications, en bloc resection rate, and local recurrence rate were evaluated.

RESULTS

Among the 18 patients, 11 were women (61.1 %). The median age was 65.3 ± 6.3 years old (range 30-71 years old). Seventeen tumors were resected completely by ESD (success rate 94.4 %). The mean tumor size as determined by endoscopic ultrasound was 2.6 ± 1.2 cm (range 1.0-3.5 cm). The histological diagnosis was gastrointestinal stromal tumor for 13 lesions and leiomyoma for four tumors. The mean operation time was 90 ± 38 min (range 50-120 min), and the average blood loss was 20 ml. Two patients developed perforation, which was closed by endoscopic methods with metallic clips. The tumor was closely adhered to the muscularis propria and was convex to the enterocoelia in one case. No single case had severe complications, such as GI bleeding, peritonitis, or abdominal abscess, and there were no other immediate post-procedure complications.

CONCLUSIONS

ESD is a safe, effective, well-tolerated, and minimally invasive therapy for the intraluminal SMTs originating from gastric muscularis propria with relatively few complications. Although there is a risk of perforation which has become manageable endoscopically.

Effect of dedicated and supervised training on achieving competence in EUS-FNA of solid pancreatic lesions

BACKGROUND AND AIM

The diagnostic accuracy of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has been suggested as a benchmark of quality performance in EUS. However, there is paucity of data on the training requirement for competency in EUS-FNA of the pancreas. KO commenced the service without prior formal training in EUS-FNA. A formally trained colleague (MN) who underwent a fellowship in the same unit was appointed to a substantive post in 2007. The aims of the study were to assess if a dedicated training program in pancreaticobiliary (PB) EUS-FNA of solid lesions: (1) produced better results at the outset of independent practice than produced at the initiation of service without formal training and (2) produced results comparable with those of an experienced endosonographer.

MATERIAL AND METHODS

This is a retrospective review comparing the first 80 consecutive cases at the onset of practice of operator KO1 (2003/2004) and MN (2007/2008) as well as consecutive cases of operator KO2 (2007/2008) in the same time frame as the initial cases of operator MN.

RESULTS

There was a significant difference in EUS-FNA sensitivity for pancreatic malignancy between operator KO1 (56%) and operator MN (77%) p < 0.05. There was no significant difference in test performance between operator KO2 (82%) and MN (77%) (p > 0.05).

CONCLUSION

Our data show that formal training in PB EUS produces test performance at the outset of independent practice that is comparable with an experienced endosonographer, in line with the published standards for EUS-FNA of the pancreas and significantly better than that achieved without training.

Factors Associated with Inadequate Tissue Yield in EUS-FNA for Gastric SMT

Aims. Our aim was to identify the factors that made the specimens inadequate and nondiagnostic in endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) biopsy of suspected submucosal tumors (SMTs). Methods. From August 2001 to October 2009, 47 consecutive patients with subepithelial hypoechoic tumors originating in the fourth sonographic layer of the gastric wall suspected as GIST by standard EUS in Chiba University hospital underwent EUS-FNA for histologic diagnosis. We evaluated patient age, sex, location of lesion, size, pattern of growth in a stomach, and pattern of echography retrospectively. We defined a case of gaining no material or an insufficient material for immunohistological diagnosis as nondiagnostic. Results. The diagnostic yield of EUS-FNA for the diagnosis of gastric SMTs was 74.5%. Multivariate logistic regression analysis identified that age of under 60 years (compared with patients older than 60 years: odds ratio [OR] = 11.91, 95% confidence interval [CI] = 1.761-80.48) and location of SMT at lower third area (compared with upper or middle third area: OR = 10.62, 95% CI = 1.290-87.42) were the predictive factors for inadequate tissue yield in EUS-FNA. Conclusions. The factors associated with inadequate tissue yield in EUS-FNA were younger age and the location of lesion at lower third area in stomach.

Appropriate use of endoscopy in the diagnosis and treatment of gastrointestinal diseases: up-to-date indications for primary care providers

The field of endoscopy has revolutionized the diagnosis and treatment of gastrointestinal (GI) diseases in recent years. Besides the ‘traditional’ endoscopic procedures (esophagogastroduodenoscopy, colonoscopy, flexible sigmoidoscopy, and endoscopic retrograde cholangiopancreatography), advances in imaging technology (endoscopic ultrasonography, wireless capsule endoscopy, and double balloon enteroscopy) have allowed GI specialists to detect and manage disorders throughout the digestive system. This article reviews various endoscopic procedures and provides up-to-date endoscopic indications based on the recommendations of American Society for Gastrointestinal Endoscopy and American Cancer Society for primary care providers in order to achieve high-quality and cost-effective care.

A-mode ultrasound-based intra-femoral bone cement detection and 3D reconstruction in RTHR

Due to the difficulty of determining the 3D boundary of the cement-bone interface in Revision Total Hip Replacement (RTHR), the removal of the distal intra-femoral bone cement can be a time-consuming and risky operation. Within the framework of computer- and robot-assisted cement removal, the principles and first results of an automatic detection and 3D surface reconstruction of the cement-bone boundary using A-mode ultrasound are described. Sound propagation time and attenuation of cement were determined considering different techniques for the preparation of bone cement, such as the use of a vacuum system (Optivac, Biomet). A laboratory setup using a rotating, standard 5-MHz transducer was developed. The prototype enables scanning of bisected cement-prepared femur samples in a 90 degrees rotation range along their rotation axis. For system evaluation ex vivo, the distal femur of a human cadaver was prepared with bone cement and drilled (Ø 10 mm) to simulate the prosthesis cavity in a first approximation. The sample was cut in half and CT scanned (0.24 mm resolution; 0.5 mm distance; 0.5 mm thickness), and 3D voxel models of the manually segmented bone cement were reconstructed, providing the ground truth. Afterwards, 90 degrees segments of each ex-vivo sample were scanned by the A-mode ultrasound system. To obtain better ultrasound penetration, we used coded signal excitation and pulse compression filtering. A-mode ultrasound signal detection, filtering and segmentation were accomplished fully automatically. Subsequently, 3D voxel models of each sample were calculated. Accuracy evaluation of the measured ultrasound data was performed by ICP matching of each ultrasound dataset ( approximately 8000 points) to the corresponding CT dataset and calculation of the residual median distance error between the corresponding datasets. Prior to each ICP matching, an initial pre-registration was calculated using prominent landmarks in the corresponding datasets. This method yielded a median distance error in the region of 0.25 mm for the cement-bone interface in both femur halves.

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.

Gastric cancer

Gastric cancer is one of the most common cancers and one of the most frequent causes of cancer-related deaths. The incidence, diagnostic studies, and therapeutic options have undergone important changes in the last decades, but the prognosis for gastric cancer patients remains poor, especially in more advanced stages. Surgery is the mainstay of treatment of this disease, even if it is associated with a high rate of locoregional and distant recurrence. There is ongoing debate regarding the role of adjuvant treatment In advanced disease, palliation of symptoms, rather than cure, is the primary goal of patient management. Several combination therapies have been developed and have been examined in phase III trials; however, in most cases, they have failed to demonstrate a survival advantage over the reference arm. This review summarizes the most important recommendations for the management of patients with gastric cancer.

Endoscopic ultrasonographic appearance of gastric emphysema

Emphysematous gastritis (or phlegmonous gastritis) and gastric emphysema (or gastric pneumatosis) are variations of conditions associated with the presence of intramural air in the stomach. The presence of air in the gastric wall is a very rare clinical condition, associated with bacterial infection, increased intragastric pressure from gastric outlet obstruction, gastric mucosal disruption or air dissection from the mediastinum. In adults, this can occur in the setting of instrumentation-related injury, gastric outlet obstruction by gastric, duodenal or pancreatic malignancies or bowel ischemia. Here we describe a case of gastric emphysema related to repeated biliary stenting and partial duodenal obstruction in a patient with inoperable periampullary cancer, and provide the first description of the endoscopic ultrasonographic findings of gastric emphysema in the literature. In our case, endoscopic ultrasound showed a band of bright echogenicity arising from the submucosa layer, representing air in the gastric wall.

Role of endoscopy in the staging of esophageal and gastric cancer

Progress in instrumentation and clinical research continues to expand the potential utility of endoscopic ultrasound (EUS) in the treatment of esophageal and gastric cancer. This review focuses on the role of EUS in the staging and treatment planning of patients with esophageal and gastric cancer.