Artificial intelligence-assisted optical diagnosis for the resect-and-discard strategy in clinical practice: the Artificial intelligence BLI Characterization (ABC) study.

BACKGROUND: Optical diagnosis of colonic polyps is poorly reproducible outside of high volume referral centers. The present study aimed to assess whether real-time artificial intelligence (AI)-assisted optical diagnosis is accurate enough to implement the leave-in-situ strategy for diminutive (≤ 5 mm) rectosigmoid polyps (DRSPs). METHODS: Consecutive colonoscopy outpatients with ≥ 1 DRSP were included. DRSPs were categorized as adenomas or nonadenomas by the endoscopists, who had differing expertise in optical diagnosis, with the assistance of a real-time AI system (CAD-EYE). The primary end point was ≥ 90 % negative predictive value (NPV) for adenomatous histology in high confidence AI-assisted optical diagnosis of DRSPs (Preservation and Incorporation of Valuable endoscopic Innovations [PIVI-1] threshold), with histopathology as the reference standard. The agreement between optical- and histology-based post-polypectomy surveillance intervals (≥ 90 %; PIVI-2 threshold) was also calculated according to European Society of Gastrointestinal Endoscopy (ESGE) and United States Multi-Society Task Force (USMSTF) guidelines. RESULTS: Overall 596 DRSPs were retrieved for histology in 389 patients; an AI-assisted high confidence optical diagnosis was made in 92.3 %. The NPV of AI-assisted optical diagnosis for DRSPs (PIVI-1) was 91.0 % (95 %CI 87.1 %-93.9 %). The PIVI-2 threshold was met with 97.4 % (95 %CI 95.7 %-98.9 %) and 92.6 % (95 %CI 90.0 %-95.2 %) of patients according to ESGE and USMSTF, respectively. AI-assisted optical diagnosis accuracy was significantly lower for nonexperts (82.3 %, 95 %CI 76.4 %-87.3 %) than for experts (91.9 %, 95 %CI 88.5 %-94.5 %); however, nonexperts quickly approached the performance levels of experts over time. CONCLUSION: AI-assisted optical diagnosis matches the required PIVI thresholds. This does not however offset the need for endoscopists' high level confidence and expertise. The AI system seems to be useful, especially for nonexperts.

Efficacy of a computer-aided detection system in a fecal immunochemical test-based organized colorectal cancer screening program: a randomized controlled trial (AIFIT study).

BACKGROUND: Computer-aided detection (CADe) increases adenoma detection in primary screening colonoscopy. The potential benefit of CADe in a fecal immunochemical test (FIT)-based colorectal cancer (CRC) screening program is unknown. This study assessed whether use of CADe increases the adenoma detection rate (ADR) in a FIT-based CRC screening program. METHODS: In a multicenter, randomized trial, FIT-positive individuals aged 50-74 years undergoing colonoscopy, were randomized (1:1) to receive high definition white-light (HDWL) colonoscopy, with or without a real-time deep-learning CADe by endoscopists with baseline ADR > 25 %. The primary outcome was ADR. Secondary outcomes were mean number of adenomas per colonoscopy (APC) and advanced adenoma detection rate (advanced-ADR). Subgroup analysis according to baseline endoscopists' ADR (≤ 40 %, 41 %-45 %, ≥ 46 %) was also performed. RESULTS: 800 individuals (median age 61.0 years [interquartile range 55-67]; 409 men) were included: 405 underwent CADe-assisted colonoscopy and 395 underwent HDWL colonoscopy alone. ADR and APC were significantly higher in the CADe group than in the HDWL arm: ADR 53.6 % (95 %CI 48.6 %-58.5 %) vs. 45.3 % (95 %CI 40.3 %-50.45 %; RR 1.18; 95 %CI 1.03-1.36); APC 1.13 (SD 1.54) vs. 0.90 (SD 1.32; P  = 0.03). No significant difference in advanced-ADR was found (18.5 % [95 %CI 14.8 %-22.6 %] vs. 15.9 % [95 %CI 12.5 %-19.9 %], respectively). An increase in ADR was observed in all endoscopist groups regardless of baseline ADR. CONCLUSIONS: Incorporating CADe significantly increased ADR and APC in the framework of a FIT-based CRC screening program. The impact of CADe appeared to be consistent regardless of endoscopist baseline ADR.

Endoscopic ultrasound assessment and tissue acquisition of mediastinal and abdominal lymph nodes.

The differential diagnosis between benign and malignant lymph nodes (LNs) has a fundamental role in the characterization and staging of malignant conditions, as well as in subsequent patients' management. All imaging modalities (i.e. computed tomography and magnetic resonance imaging) rely mainly on size; endoscopic ultrasound (EUS) criteria based on B-mode evaluation and Doppler features fail to adequately characterize with high specificity LNs nature. The introduction of EUS-elastography and contrast-enhanced harmonic EUS are useful techniques to increase the diagnostic yield in identifying metastatic LNs, to identify which suspicious LN should require pathological characterization and, finally, to target tissue acquisition. EUS-guided tissue acquisition (EUS-TA) is increasingly being used for diagnosing lymphadenopathy whenever the characterization modifies patients' subsequent management and when no superficial LN is accessible. Since target therapy are currently available (i.e. lung cancer, breast cancer), EUS-TA of malignant LNs could be required to identify tumor biology. In this field, both fine needle aspiration and biopsy needles are able to guarantee accurate results with almost perfect specificity and sub-optimal sensitivity. We finally propose a diagnostic algorithm based on most recent, high-level evidence for the diagnostic approach to suspected LNs assessment.

Conservative management of malignant gastric outlet obstruction syndrome-evidence based evaluation of endoscopic ultrasound-guided gastroentero-anastomosis.

Gastric outlet obstruction (GOO) is a clinical syndrome characterized by postprandial vomiting, abdominal pain, bloating and, in advanced cases, by weight loss secondary to inadequate oral intake. This clinical entity may be caused by mechanical obstruction, either benign or malignant, or by motility disorders. In this review we will focus on malignant GOO and on its endoscopic ultrasound (EUS)-guided palliative treatment. The most frequent malignant causes of this syndrome are gastric and locally advanced pancreatic carcinomas; other causes include duodenal or ampullary neoplasms, gastric lymphomas, retroperitoneal lymphadenopathies and, more infrequently, gallbladder and bile duct cancers. Surgery represents the treatment of choice when radical and curative resection is potentially feasible; if the malignant cause is not likely to be completely resected, palliative treatments should be proposed. Palliative treatments for malignant GOO are primarily based on surgical gastro-jejunostomy and endoscopic placement of an enteral self-expanding metal stent. Both treatments are effective; however, endoscopic stent placement is less invasive and it is associated with good short-term results, while surgery provides longer-lasting effects with a lower frequency of reintervention. In the last few years, EUS-guided gastroenterostomy (GE) has been proposed as palliative treatment for malignant GOO. This novel technique consists of the creation of an anastomosis between the gastric lumen and a small bowel loop distal to the malignant obstruction, through the deployment of a lumen-apposing metal stent under EUS-view. EUS-GE has the advantage of being as minimally invasive as enteral stent placement, and of guaranteeing long-term results similar to those of surgery.