Interventional endoscopic ultrasound in pancreatic disease

Rapid On-Site Evaluation by Endosonographers during Endoscopic Ultrasonography-Guided Fine-Needle Aspiration for Diagnosis of Gastrointestinal Stromal Tumors

BACKGROUND/AIMS

Endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) has been used to diagnose gastrointestinal submucosal tumors (SMTs). Although rapid on-site evaluation (ROSE) has been reported to improve the diagnostic accuracy of EUS-FNA for pancreatic lesions, on-site cytopathologists are not routinely available. Given this background, the usefulness of ROSE by endosonographers themselves for pancreatic tumors has also been reported. However, ROSE by endosonographers for diagnosis of SMT has not been reported. The aim of this study was to evaluate the diagnostic accuracy of EUS-FNA with ROSE by endosonographers for SMT, focusing on diagnosis of gastrointestinal stromal tumor (GIST), compared with that of EUS-FNA alone.

METHODS

Twenty-two consecutive patients who underwent EUS-FNA with ROSE by endosonographers for SMT followed by surgical resection were identified. Ten historical control subjects who underwent EUS-FNA without ROSE were used for comparison.

RESULTS

The overall diagnostic accuracy for SMT was significantly higher in cases with than without ROSE (100% vs. 80%, p=0.03). The number of needle passes by FNA with ROSE by endosonographers tended to be fewer, although accuracy was increased (3.3±1.3 vs. 5.9±3.8, p=0.06).

CONCLUSIONS

ROSE by endosonographers during EUS-FNA for SMT is useful for definitive diagnosis, particularly for GIST.

Yields and Utility of Endoscopic Ultrasonography-Guided 19-Gauge Trucut Biopsy versus 22-Gauge Fine Needle Aspiration for Diagnosing Gastric Subepithelial Tumors

Background/Aims

To evaluate the yields and utility of 19-gauge (G) Trucut biopsy (TCB) versus 22 G fine needle aspiration (FNA) for diagnosing gastric subepithelial tumors (SETs).

Methods

We retrieved data for 152 patients with a gastric SET larger than 2 cm who had undergone endoscopic ultrasonography (EUS)-guided 19 G TCB (n=90) or 22 G FNA (n=62). Relevant clinical, tumor-specific, and EUS procedural information was reviewed retrospectively.

Results

A specific diagnosis was made for 76 gastrointestinal stromal tumors (GISTs) and 51 non-GIST SETs. The diagnostic yield of TCB was greater than that of FNA (77.8% vs. 38.7%, p<0.001). The percentage of non-diagnostic specimens (suspicious and insufficient) was significantly lower in the TCB group (6.7% and 15.5%, respectively) than in the FNA group (22.6% and 38.7%, respectively; both p<0.001). TCB accurately diagnosed 90.9% of GISTs and 81.1% of non-GIST SETs, whereas FNA accurately diagnosed 68.8% of GISTs and 14.3% of non-GIST SETs. There were nine technical failures with TCB, and the rate of adverse events did not differ between the groups (TCB vs. FNA, 3.3% vs. 8.1%; p=0.27).

Conclusions

Nineteen-gauge TCB is safe and highly valuable for diagnosing gastric SETs larger than 2 cm if technical failure can be avoided.

Ultrasound-guided direct delivery of 3-bromopyruvate blocks tumor progression in an orthotopic mouse model of human pancreatic cancer

Studies in animal models of cancer have demonstrated that targeting tumor metabolism can be an effective anticancer strategy. Previously, we showed that inhibition of glucose metabolism by the pyruvate analog, 3-bromopyruvate (3-BrPA), induces anticancer effects both in vitro and in vivo. We have also documented that intratumoral delivery of 3-BrPA affects tumor growth in a subcutaneous tumor model of human liver cancer. However, the efficacy of such an approach in a clinically relevant orthotopic tumor model has not been reported. Here, we investigated the feasibility of ultrasound (US) image-guided delivery of 3-BrPA in an orthotopic mouse model of human pancreatic cancer and evaluated its therapeutic efficacy. In vitro, treatment of Panc-1 cells with 3-BrPA resulted in a dose-dependent decrease in cell viability. The loss of viability correlated with a dose-dependent decrease in the intracellular ATP level and lactate production confirming that disruption of energy metabolism underlies these 3-BrPA-mediated effects. In vivo, US-guided delivery of 3-BrPA was feasible and effective as demonstrated by a marked decrease in tumor size on imaging. Further, the antitumor effect was confirmed by (1) a decrease in the proliferative potential by Ki-67 immunohistochemical staining and (2) the induction of apoptosis by terminal deoxynucleotidyl transferase-mediated deoxyuridine 5-triphospate nick end labeling staining. We therefore demonstrate the technical feasibility of US-guided intratumoral injection of 3-BrPA in a mouse model of human pancreatic cancer as well as its therapeutic efficacy. Our data suggest that this new therapeutic approach consisting of a direct intratumoral injection of antiglycolytic agents may represent an exciting opportunity to treat patients with pancreas cancer.

Endoscopic ultrasound-guided biliary drainage

Endoscopic ultrasound (EUS)-guided biliary drainage has emerged as a minimally invasive alternative to percutaneous and surgical interventions for patients with biliary obstruction who had failed endoscopic retrograde cholangiopancreatography (ERCP). EUS-guided biliary drainage has become feasible due to the development of large channel curvilinear therapeutic echo-endoscopes and the use of real-time ultrasound and fluoroscopy imaging in addition to standard ERCP devices and techniques. EUS-guided biliary drainage is an attractive option because of its minimally invasive, single step procedure which provides internal biliary decompression. Multiple investigators have reported high success and low complication rates. Unfortunately, high quality prospective data are still lacking. We provide detailed review of the use of EUS for biliary drainage from the perspective of practicing endoscopists with specific focus on the technical aspects of the procedure.

[Chronic pancreatitis as a risk factor for the development of pancreatic cancer--diagnostic challenges]

Patients with chronic pancreatitis are burdened with an increased risk of developing pancreatic cancer. Strategies or guidelines for the surveillance and early detection of pancreatic adenocarcinoma in patients with chronic pancreatitis are not established, because available clinical, serologic or imaging techniques are still of limited sensitivity and specificity. Despite these limitations do patients with chronic pancreatitis and suspected pancreatic cancer need a careful and sometimes repeated diagnostic work-up. A clear benefit of surveillance programs outside of clinical trials for the early detection of pancreatic cancer has not been demonstrated. A 51-year-old patient with chronic pancreatitis is reported who developed cancer of the pancreatic head while undergoing repeated imaging studies.

Endoscopic ultrasound-guided intratumoural therapy for pancreatic cancer

Pancreatic cancer is the second most frequent gastrointestinal malignancy and carries a dismal prognosis. The current standard of care includes resection, if possible, as well as systemic chemoradiation therapy. Endoscopic ultrasound (EUS) is an established technique for the diagnosis and staging of pancreatic adenocarcinoma. Interventional EUS via fine needle injection (FNI) for the treatment of pancreatic cancer is a rapidly expanding field. The present article reviews the up-to-date developments in EUS FNI for intratumoural pancreatic cancer therapy, including antitumoural agents, immunotherapy, ablative techniques and new delivery systems. The therapeutic modalities discussed are currently under development and will hopefully reach clinical practice if benefit is demonstrated through clinical trials. EUS FNI may be an exciting new technique for the delivery of desperately needed novel therapies for pancreatic cancer.

The multidisciplinary management of gastrointestinal cancer. Pancreatic cancer: from pathogenesis to cure

Pancreatic cancer is the fourth leading cause of cancer-related death in the USA. The disease has a high mortality rate and the 5-year survival rate is estimated to be 4%. Currently, surgical resection is only possible in 20% of patients; even then, the overall 5-year survival rate is only 25%. As such, surgical therapy alone is not sufficient for pancreatic carcinoma, and prospective investigation of additional modalities is crucial. Numerous negative trials have shown that chemotherapy alone is the standard of care after resection of pancreatic carcinoma. However, results remain poor and progress with new drugs is needed in this setting. For locally advanced disease, the situation is more complicated; the ideal chemoradiation schedule has not been clearly defined, and improvements could come in the near future from the use of new radiotherapy tools and targeted therapies. For advanced disease, chemotherapy alone has given very disappointing results. A multidisciplinary approach combining biological assessment of targets with clinical trials to evaluate new targeted drugs should be considered.

Changing trends in endosonography: linear imaging and tissue are increasingly the issue

The indications and uses of endoscopic ultrasound (EUS) are expanding. The role of EUS-guided fine needle aspiration (EUS-FNA) is considered an essential aspect of EUS practice. A significant change in the indications and technology used for EUS has occurred. This study was designed to compare the use of radial, linear, and miniprobe endosonography equipment during a 10-year period in a single, large, EUS practice. A retrospective review of an EUS experience at a single high-volume center was performed. In this single-center experience, there has been an increase in the volume of EUS and EUS-FNA. For luminal cancer-staging cases, the radial echoendoscope is the predominant scope used for examination and has not changed significantly. In contrast, for pancreaticobiliary and mediastinal indications, the use of the linear array echoendoscope alone has increased and currently is the preferred scope for examination (33% vs. 76%, P < 0.001; 46% vs. 96%, P < 0.001). In these cases requiring EUS-FNA, the use of the linear array scope alone has increased from 17% to 73%. In this single-center experience, EUS has shifted from an imaging technology to an image-guided biopsy and therapeutic technology. The use of the linear array EUS alone has increased, especially in the evaluation of pancreatobiliary and mediastinal disease and when fine-needle aspiration is performed.

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