Prospective, Multi-Institutional, Real-Time Next-Generation Sequencing of Pancreatic Cyst Fluid Reveals Diverse Genomic Alterations That Improve the Clinical Management of Pancreatic Cysts.

BACKGROUND & AIMS: Next-generation sequencing (NGS) of pancreatic cyst fluid is a useful adjunct in the assessment of patients with pancreatic cyst. However, previous studies have been retrospective or single institutional experiences. The aim of this study was to prospectively evaluate NGS on a multi-institutional cohort of patients with pancreatic cyst in real time. METHODS: The performance of a 22-gene NGS panel (PancreaSeq) was first retrospectively confirmed and then within a 2-year timeframe, PancreaSeq testing was prospectively used to evaluate endoscopic ultrasound-guided fine-needle aspiration pancreatic cyst fluid from 31 institutions. PancreaSeq results were correlated with endoscopic ultrasound findings, ancillary studies, current pancreatic cyst guidelines, follow-up, and expanded testing (Oncomine) of postoperative specimens. RESULTS: Among 1933 PCs prospectively tested, 1887 (98%) specimens from 1832 patients were satisfactory for PancreaSeq testing. Follow-up was available for 1216 (66%) patients (median, 23 months). Based on 251 (21%) patients with surgical pathology, mitogen-activated protein kinase/GNAS mutations had 90% sensitivity and 100% specificity for a mucinous cyst (positive predictive value [PPV], 100%; negative predictive value [NPV], 77%). On exclusion of low-level variants, the combination of mitogen-activated protein kinase/GNAS and TP53/SMAD4/CTNNB1/mammalian target of rapamycin alterations had 88% sensitivity and 98% specificity for advanced neoplasia (PPV, 97%; NPV, 93%). Inclusion of cytopathologic evaluation to PancreaSeq testing improved the sensitivity to 93% and maintained a high specificity of 95% (PPV, 92%; NPV, 95%). In comparison, other modalities and current pancreatic cyst guidelines, such as the American Gastroenterology Association and International Association of Pancreatology/Fukuoka guidelines, show inferior diagnostic performance. The sensitivities and specificities of VHL and MEN1/loss of heterozygosity alterations were 71% and 100% for serous cystadenomas (PPV, 100%; NPV, 98%), and 68% and 98% for pancreatic neuroendocrine tumors (PPV, 85%; NPV, 95%), respectively. On follow-up, serous cystadenomas with TP53/TERT mutations exhibited interval growth, whereas pancreatic neuroendocrine tumors with loss of heterozygosity of ≥3 genes tended to have distant metastasis. None of the 965 patients who did not undergo surgery developed malignancy. Postoperative Oncomine testing identified mucinous cysts with BRAF fusions and ERBB2 amplification, and advanced neoplasia with CDKN2A alterations. CONCLUSIONS: PancreaSeq was not only sensitive and specific for various pancreatic cyst types and advanced neoplasia arising from mucinous cysts, but also reveals the diversity of genomic alterations seen in pancreatic cysts and their clinical significance.

Endoscopic retrieval of magnetic foreign body ingestions with a nasal bridle: description of a novel technique (with video).

BACKGROUND AND AIMS: Accidental and intentional foreign body ingestions are common and frequently require endoscopic intervention. Sharp metallic objects pose a risk of perforation to the entire GI tract and are often difficult to visualize among food and other matter in the stomach. METHODS: Three patients with histories of multiple ingestions are considered. Metallic foreign bodies can be easily removed using a nasal bridle. A snare and magnetic catheter are used as endoscopic tools to extract various metallic items. RESULTS: The bridle technique was used in 68 endoscopies in 3 patients who presented numerous times for foreign body ingestions. The technique was successful in 66 of the 68 procedures, with no adverse events. CONCLUSIONS: The bridle technique is an easy and effective way to remove metallic foreign bodies and has many advantages over traditional, mechanical modes of foreign body retrieval.

A Randomized Controlled Trial Comparing the Depth of Maximal Insertion Between Anterograde Single-Balloon Versus Spiral Enteroscopy.

BACKGROUND: Three device-assisted deep endoscopic platforms presently exist and are available for clinical use: double-balloon enteroscopy, single-balloon enteroscopy (SBE), and spiral enteroscopy (SE). In a retrospective study, SE was associated with a greater depth of maximal insertion (DMI) with similar diagnostic yields and procedure time as compared with SBE. AIMS: This was a prospective, randomized comparison of SE and SBE with respect to DMI, diagnostic yield, procedure time, and rate of adverse events. METHODS: Patients were prospectively randomized to undergo either anterograde SE or SBE. Patient demographics, indication for procedure, DMI, procedure time, therapeutic procedure time, adverse event, diagnostic findings, and therapeutic interventions were prospectively recorded. The primary outcome was DMI. Secondary outcomes included: procedure time; diagnostic yield; therapeutic yield and adverse event rates. RESULTS: During the study period, 30 patients underwent deep enteroscopy (SE 13, SBE 17). The most common indication was gastrointestinal bleeding in both groups. There was no significant difference in the DMI between SE and SBE (330.0 ± 88.2 cm vs 285.3 ± 80.8 cm, P = .16). There was no difference between SE and SBE in procedure time (37.0 ± 10.5 vs 38.3 ± 12.4, P = .76), diagnostic yield (SE = 9 [69%] vs SBE = 7 [41%], P = .16), or therapeutic yield (SE = 6 [46%] vs SBE = 4 [24%], P = .26). There were no major adverse events in either group. CONCLUSIONS: Spiral enteroscopy and SBE are similar with respect to DMI, diagnostic yield, therapeutic yield, procedure time, and rate of adverse events. Small numbers prevent giving a definitive judgment and future adequately powered prospective study is required to confirm these findings.

Mutational spectrum of Barrett's stem cells suggests paths to initiation of a precancerous lesion.

The precancerous lesion known as Barrett's oesophagus can evolve to oesophageal adenocarcinoma in decades-long processes of regenerative growth. Here we report the isolation and propagation of distinct, patient-matched stem cells of Barrett's, gastric and oesophageal epithelia that yield divergent tumour types following in vitro transformation and xenografting. Genomic analyses reveal a broad mutational spectrum unique to Barrett's stem cells that likely reflects their risk for oncogenesis. Remarkably, 25% of cases show no cancer-related genomic changes, suggesting that Barrett's initiates without driver mutations. Most cases, however, sustain patterns of deletions almost identical to adenocarcinoma though tumour-associated gene amplifications were absent. Notably, those suspected of low-grade dysplasia have p53 mutations or undergo amplifications of proto-oncogenes and receptor tyrosine kinases, implicating these events in lethal transitions. Our findings suggest paths for the initiation and progression of Barrett's and define a discrete stem cell underlying its regenerative growth whose eradication could prevent oesophageal adenocarcinoma.

Pancreatic necrosectomy using covered esophageal stents: a novel approach.

BACKGROUND: Endoscopic necrosectomy for necrotizing pancreatitis has been increasingly used as an alternative to surgical or percutaneous interventions. The use of fully covered esophageal self-expandable metallic stents may provide a safer and more efficient route for internal drainage. The aim of this study was to evaluate the safety and efficacy of endoscopic treatment of pancreatic necrosis with these stents. METHODS: A retrospective study at 2 US academic hospitals included patients with infected pancreatic necrosis from July 2009 to November 2012. These patients underwent transgastric placement of fully covered esophageal metallic stents draining the necrosis. After necrosectomy, patients underwent regular sessions of endoscopic irrigation and debridement of cystic contents. The efficacy endpoint was successful resolution of infected pancreatic necrosis without the need for surgical or percutaneous interventions. RESULTS: Seventeen patients were included with the mean age of 41±12 years. A mean of 5.3±3.4 sessions were required for complete drainage and the follow-up period was 237.6±165 days. Etiology included gallstone pancreatitis (6), alcohol abuse (6), s/p distal pancreatectomy (2), postendoscopic retrograde cholangiopancreatography pancreatitis (1), medication-induced pancreatitis (1), and hyperlipidemia (1). Mean size of the necrosis was 14.8 cm (SD 5.6 cm), ranging from 8 to 19 cm. Two patients failed endoscopic intervention and required surgery. The only complication was a perforation during tract dilation, which was managed conservatively. Fifteen patients (88%) achieved complete resolution. CONCLUSIONS: Endoscopic necrosectomy with covered esophageal metal stents is a safe and successful treatment option for infected pancreatic necrosis.

Dose-dependent depth of tissue injury with carbon dioxide cryotherapy in porcine GI tract.

BACKGROUND: Cryotherapy is a method of endoscopic mucosal ablation that involves delivery of a cryogen to result in tissue destruction by extreme low temperature. Its effects are influenced by the dosage of cryogen and thawing of ice. There are limited data on the tissue effects of multiple freeze and thaw cycles of carbon dioxide (CO(2)) cryotherapy on GI tissues. OBJECTIVE: To investigate the extent of tissue injury due to escalating doses of CO(2) cryotherapy on the esophagus, stomach, and colon of pigs. DESIGN: Animal experiment. INTERVENTION: Varying doses of CO(2) cryotherapy with increasing number of freeze-thaw cycles were applied to each site. The animals were allowed to survive for 48 hours. MAIN OUTCOME MEASUREMENTS: Depth of tissue injury assessed in blinded fashion by varying doses of cryotherapy on a defined area of porcine esophagus, stomach, and colon. RESULTS: There was a dose-dependent relationship of CO(2) cryogen and depth of injury (P = .0001 and P = .002, respectively). In the stomach, the dose-response relationship was significant (P = .007), but the average grades of injury across the various doses were lower when compared with the esophagus at comparable cryogen doses (P = .0004). The estimated depth of tissue injury from the mucosal surface in the porcine esophagus and colon tissue ranged from 1.2 to 2.5 mm and 1.3 to 2.5 mm, respectively. LIMITATIONS: The study was performed in a normal porcine model. CONCLUSION: There was a dose-dependent relationship between the dose of CO(2) cryotherapy and the depth of tissue injury in the porcine esophagus, stomach, and colon.

Morphological alterations in neurons forming corticocortical projections in the neocortex of aged Patas monkeys.

Recent studies indicate that the cognitive processes mediated by the prefrontal cortex, such as working memory, are impaired during normal aging. These disturbances in cortical function may be a consequence of abnormalities in neocortical circuits, even though the numbers of cortical neurons are preserved in normal aging. We performed retrograde tract-tracing of cortical projections connecting the temporal cortex to the prefrontal cortex in combination with dye-filling and three-dimensional neuronal reconstructions in aged patas monkeys. Age-related changes affected the apparent complexity of the apical dendrites of projection neurons and caused a significant loss of dendritic spines at all levels of their dendritic trees. These results indicate that normal aging is accompanied by neuronal changes that are quite subtle, and possibly involves discrete cellular components of certain cortical neurons selectively rather than inducing major alterations such as cell death.