Colonoscopic Ultrasound-Guided Fine-Needle Aspiration Using a Curvilinear Array Transducer: A Single-Center Retrospective Cohort Study

Endoscopic ultrasound-guided fine-needle aspiration for gastrointestinal subepithelial lesions

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is the first-choice procedure for obtaining pathological tissue samples from gastrointestinal (GI) subepithelial lesions (SELs). However, its diagnostic accuracy is lower than that for pancreatic masses owing to puncture difficulty and the need for immunostaining for definitive diagnosis. The advent of fine-needle biopsy needles, which have become well known in recent years, improves the diagnostic accuracy of EUS-FNA for GI SELs. The forward-viewing echoendoscope and rapid on-site evaluation (ROSE) have also helped to improve diagnostic accuracy. Furthermore, in facilities where ROSE is not available, endosonographers perform a macroscopic on-site evaluation. With these procedural innovations, EUS-FNA is now performed aggressively even for SELs smaller than 20 mm. The incidence of procedure-related adverse events such as bleeding and infection is low, and thus, EUS-FNA can be safely performed to diagnose SELs.

Diagnosis by Endoscopic Ultrasonography-Guided Sampling through the Lower Gastrointestinal Tract

Endoscopic ultrasound-guided fine-needle aspiration/biopsy (EUS-FNA/FNB) is very safe and has a high diagnostic rate for upper gastrointestinal lesions, especially pancreatic lesions, but its application in the lower gastrointestinal tract has rarely been reported. Due to the tortuous course of the colorectum, with the sigmoid colon particularly prone to perforation, most endoscopists are reluctant to perform lateral-sector endoscopic ultrasound scanning without a water-bag protection for the puncture. The ultrasonic endoscopy and flexible puncture needle techniques recently introduced into clinical practice have made ultrasound-guided puncture safer and more convenient. In addition, endoscopists have carefully tested various protective measures to improve the safety of the lower gastrointestinal puncture, substantially increasing its clinical feasibility. In this article, we review the iterations of endoscopic ultrasound equipment introduced in recent years and the many ingenious ideas proposed by endoscopists regarding lower gastrointestinal puncture.

Endoscopic ultrasound artificial intelligence-assisted for prediction of gastrointestinal stromal tumors diagnosis: A systematic review and meta-analysis

BACKGROUND

Subepithelial lesions (SELs) are gastrointestinal tumors with heterogeneous malignant potential. Endoscopic ultrasonography (EUS) is the leading method for evaluation, but without histopathological analysis, precise differentiation of SEL risk is limited. Artificial intelligence (AI) is a promising aid for the diagnosis of gastrointestinal lesions in the absence of histopathology.

AIM

To determine the diagnostic accuracy of AI-assisted EUS in diagnosing SELs, especially lesions originating from the muscularis propria layer.

METHODS

Electronic databases including PubMed, EMBASE, and Cochrane Library were searched. Patients of any sex and > 18 years, with SELs assessed by EUS AI-assisted, with previous histopathological diagnosis, and presented sufficient data values which were extracted to construct a 2 × 2 table. The reference standard was histopathology. The primary outcome was the accuracy of AI for gastrointestinal stromal tumor (GIST). Secondary outcomes were AI-assisted EUS diagnosis for GIST vs gastrointestinal leiomyoma (GIL), the diagnostic performance of experienced endoscopists for GIST, and GIST vs GIL. Pooled sensitivity, specificity, positive, and negative predictive values were calculated. The corresponding summary receiver operating characteristic curve and post-test probability were also analyzed.

RESULTS

Eight retrospective studies with a total of 2355 patients and 44154 images were included in this meta-analysis. The AI-assisted EUS for GIST diagnosis showed a sensitivity of 92% [95% confidence interval (CI): 0.89-0.95; P < 0.01), specificity of 80% (95%CI: 0.75-0.85; P < 0.01), and area under the curve (AUC) of 0.949. For diagnosis of GIST vs GIL by AI-assisted EUS, specificity was 90% (95%CI: 0.88-0.95; P = 0.02) and AUC of 0.966. The experienced endoscopists' values were sensitivity of 72% (95%CI: 0.67-0.76; P < 0.01), specificity of 70% (95%CI: 0.64-0.76; P < 0.01), and AUC of 0.777 for GIST. Evaluating GIST vs GIL, the experts achieved a sensitivity of 73% (95%CI: 0.65-0.80; P < 0.01) and an AUC of 0.819.

CONCLUSION

AI-assisted EUS has high diagnostic accuracy for fourth-layer SELs, especially for GIST, demonstrating superiority compared to experienced endoscopists' and improving their diagnostic performance in the absence of invasive procedures.

Endoscopic Ultrasound View of Pneumatosis Cystoides Intestinalis

Pneumatosis cystoid intestinalis (PCI) is a rare condition, with a worldwide incidence of 0.3-1.2%. PCI is classified into primary (idiopathic) and secondary forms, with 15% and 85% of presentations, respectively. This pathology was associated with a wide variety of underlining etiologies to explain the abnormal accumulation of gas within the submucosa (69.9%), subserosa (25.5%), or both layers (4.6%). Many patients endure misdiagnosis, mistreatment, or even inadequate surgical exploration. In this case, a patient presented acute diverticulitis, after treatment, a control colonoscopy was performed that found multiple rounds and elevated lesions. To further study the subepithelial lesion (SEL), a colorectal endoscopic ultrasound (EUS) was performed with an overtube in the same procedure. For safe insertion of the curvilinear array EUS, an overtube with colonoscopy was positioned through the sigmoid as described by Cheng et al. The EUS evaluation evidenced air reverberation in the submucosal layer. The pathological analysis was consistent with PCI's diagnosis. The diagnosis of PCI is usually made by colonoscopy (51.9%), surgery (40.6%), and radiological findings (10.9%). Although the diagnosis can be made by radiological studies, a colorectal EUS and colonoscopy can be made in the same section without radiation and with high precision. As it is a rare disease, there are not enough studies to define the best approach, although colorectal EUS should be preferred for a reliable diagnosis.

The use of ultrasound in colonic and perianal diseases

PURPOSE OF REVIEW

To revise recent literature findings regarding the use of ultrasound in colonic and perianal diseases by focusing particularly on its feasibility in inflammatory bowel diseases (IBD), colorectal neoplastic lesions, and perineal diseases, with further highlight on interventional capabilities.

RECENT FINDINGS

Treat-to-target approach in IBD raised an interest in intestinal ultrasound (IUS) for monitoring bowel activity considering its noninvasive nature, low costs, and well tolerability. New IUS indices have been developed with ever better methodologies and are at various stage of validation. A standardized over-the-wire technique for colonic US using a flexible overtube enables endoscopic ultrasound (EUS)-guided tissue sampling beyond the rectum, and forward-viewing radial-array echoendoscopes can assist identification of early neoplastic lesions in proximal colon. Intraoperative ultrasound and contrast-enhanced ultrasound carry an additional diagnostic value compared to conventional preoperative imaging modalities in detecting colorectal cancer liver metastases (CRLM).

SUMMARY

The feasibility of IUS in monitoring IBD activity is supported by growing evidence, but uniform IUS indices are still lacking. Recent advancements in EUS are expanding capabilities for determining depth of invasion of colorectal neoplasms, tissue sampling, and EUS-guided interventions to the entire colon. Ultrasonography can be a valuable tool in CRLM diagnostics as well.

AGA Clinical Practice Update on Management of Subepithelial Lesions Encountered During Routine Endoscopy: Expert Review

BEST PRACTICE ADVICE 1: Forceps bite-on-bite or deep-well biopsies or tunnel biopsies can sometimes establish a pathologic diagnosis of SEL. BEST PRACTICE ADVICE 2: EUS is the modality of choice to evaluate indeterminate SEL of the GI track and/or if non-diagnostic tissue by forceps biopsies. BEST PRACTICE ADVICE 3: SEL arising from the submucosa can be sampled using tunnel biopsies (or deep-well biopsies), EUS guided fine-needle aspiration (FNA), EUS guided fine-needle biopsy (FNB), or advanced endoscopic techniques (unroofing or endoscopic submucosal resection). BEST PRACTICE ADVICE 4: SEL arising from muscularis propria should be sampled (preferably using FNB or FNA) to determine whether the lesion is a GIST or leiomyoma. Structural assessment and staining will allow differentiation of mesenchymal tumors and assessing their malignant potential. BEST PRACTICE ADVICE 5: Endoscopic resection techniques have been described for removal of SEL and should be limited to endoscopists skilled in advanced tissue resection techniques. BEST PRACTICE ADVICE 6: Management of each SEL depends on the size of the lesion, histopathology, their malignant potential, and presence of symptoms. BEST PRACTICE ADVICE 7: SEL that have an endoscopic appearance consistent with a lipoma or pancreatic rest and normal mucosal biopsies do not need further evaluation or surveillance. BEST PRACTICE ADVICE 8: For SEL arising from muscularis propria that are less than 2 cm in size, surveillance using EUS should be considered. BEST PRACTICE ADVICE 9: Gastric GIST larger than 2 cm should be considered for resection. BEST PRACTICE ADVICE 10: Subepithelial lesions that are ulcerated, bleeding, or causing symptoms should be considered for resection.