Utility of an upper echoendoscope for endoscopic ultrasonography of malignant and benign conditions of the sigmoid/left colon and the rectum

Evaluation of appendiceal mucinous neoplasms by curved linear-array echoendoscope: A preliminary study

BACKGROUND

Preoperative diagnosis of appendiceal mucinous neoplasms is challenging, and there are few reports regarding the endosonographic characteristics of these neoplasms.

AIM

To provide a retrospective assessment of the imaging features of appendiceal mucinous neoplasms using endoscopic ultrasound (EUS) by curved linear-array echoendoscope.

METHODS

A database of all patients with appendiceal mucinous neoplasms who had received EUS examination at our hospital between January 2018 and July 2023 was retrospectively analyzed. The EUS characteristics and patients’ clinical data were reviewed.

RESULTS

Twenty-two patients were included in the study. The linear-array echoendoscope successfully reached the ileocecal region in every patient. In the endoscopic view, we could observe the protrusion in the appendiceal orifice in all patients. A volcano sign was observed in two patients, and an atypical volcano sign was seen in two patients. EUS showed that all 22 lesions were submucosal cystic hypoechoic lesions with clear boundaries. No wall nodules were observed, but an onion-peeling sign was observed in 17 cases.

CONCLUSION

Linear-array echoendoscope is safe to reach the ileocecal region under the guidance of EUS. Image features on endoscopic and echoendosonograhic views could be used to diagnose appendiceal mucinous neoplasms.

Endoscopic Ultrasound Elastography as a Novel Diagnostic Method for the Assessment of Hardness and Depth of Invasion in Colorectal Neoplasms

INTRODUCTION

We aimed to compare the efficacy of endoscopic ultrasound elastography (EUS-EG) with that of magnifying chromoendoscopy (MCE) and endoscopic ultrasonography (EUS) for the diagnosis of the depth of invasion in colorectal neoplasms. This is an important clinical issue as the depth of invasion is associated with the risk of metastasis.

METHODS

Consecutive patients with suspected superficial colorectal neoplasms, evaluated by MCE, EUS, and EUS-EG, for whom endoscopic submucosal dissection was considered, were enrolled in 2018 (derivation study) and in 2019-2020 (validation study). The primary clinical endpoint was the diagnostic yield differentiating intramucosal and shallow submucosal neoplasms from deep submucosal (dSM) and advanced colorectal cancers. In addition, inter- and intra-observer agreements of the elastic score of colorectal neoplasm (ES-CRN) were evaluated by 2 expert and 2 non-expert endoscopists.

RESULTS

Thirty-one (33 lesions) and 50 (55 lesions) patients were enrolled in the derivation and validation studies, respectively. Sensitivity, specificity, positive, and negative predictive values, and accuracy of assessment of the depth of submucosal or deeper invasion in the derivation and validation groups were as follows: EUS-EG, 100/88.2/86.7/100/93.3% and 77.8/86.1/73.7/88.6/83.3%; MCE, 66.7/94.4/90.9/77.3/81.8% and 84.2/91.4/84.2/91.4/88.9%; and EUS, 93.3/77.8/77.8/93.3/84.8% and 89.5/65.7/58.6/92.0/74.1%, respectively. For the 2 expert endoscopists, interobserver agreement for the ES-CRN (first and second assessments) in the derivation group was 0.84 and 0.78, respectively; these values were 0.73 and 0.49, respectively, for the 2 non-expert endoscopists.

DISCUSSION/CONCLUSION

All 3 modalities presented similar diagnostic yield. Inter- and intra-observer agreements of the ES-CRN were substantial, even for non-expert endoscopists. Therefore, EUS-EG may be a useful modality in determining the depth of invasion in colorectal neoplasms.

A forward-viewing radial-array echoendoscope is useful for diagnosing the depth of colorectal neoplasia invasion

BACKGROUND

It is important to accurately diagnose the depth of colorectal neoplasia invasion. We aimed to evaluate the usefulness of a new forward-viewing radial-array echoendoscope (FRE), relative to the pit pattern method.

METHODS

In this prospective study, the invasion depth of suspected early-stage carcinoma was diagnosed using the pit pattern and FRE methods. The diagnoses were classified as T1a (submucosal invasion distance < 1,000 μm) or shallower and T1b (≥ 1,000 μm) or deeper. Pathological diagnoses were used to compare the diagnostic capabilities of the two methods.

RESULTS

The final analyses included 110 lesions. The FRE was successfully inserted to the lesion in all cases. There were no significant differences between the two methods regarding the correct prediction rate (79.1% vs. 75.5%, P = 0.57), accuracy (81.3% vs. 79.0%, P = 0.68), specificity (81.3% vs. 70.8%, P = 0.135), positive predictive value (65.0% vs. 60.4%, P = 0.649), negative predictive value (91.0% vs. 98.1%, P = 0.108), or frequency of unevaluable cases (2.7% vs. 4.5%, P = 0.471). The correct prediction rate was calculated by adding the number of unevaluable cases to the denominator of accuracy. Relative to the pit pattern method, the FRE method offered significantly higher sensitivity for predicting T1b or deeper invasion (81.3% vs. 97.0%, P = 0.048). The pit pattern method had significantly poorer accuracy for large lesions (> 36 mm) than for smaller lesions (≤ 36 mm). In contrast, the accuracy of the FRE method did not differ significantly with lesion size. When using the FRE method, no cases were unevaluable because of attenuation. The FRE method provided correct diagnoses in 2 of 3 cases that were unevaluable using the pit pattern method.

CONCLUSIONS

The pit pattern and FRE methods offered similar diagnostic performance for invasion depth. Furthermore, the FRE method may be used to correctly diagnose cases that are unevaluable using the pit pattern method.

Present status and perspectives of endosonography 2017 in gastroenterology

Endoscopic ultrasound has become an essential tool in modern gastroenterology and abdominal surgery. Compared with all other endoscopic methods, it has the most potential for innovation and its future looks bright. Thus, we compiled this summary of established and novel applications of endoscopic ultrasound methods to inform the reader about what is already possible and where future developments will lead in improving patient care further. This review is structured in four parts. The first section reports on developments in diagnostic endoscopic ultrasound, the second looks at semi-invasive endoscopic ultrasound, and the third discusses advances in therapeutic endoscopic ultrasound. An overview on the future prospects of endoscopic ultrasound methods concludes this article.

Endoscopic ultrasound for staging of colonic cancer proximal to the rectum: A systematic review and meta-analysis

Background and Objectives:

Treatment of colonic cancer patients is highly dependent on the depth of tumor invasion (T-stage) as well as the extension of lymph node involvement (N-stage). We aimed to systematically review the accuracy of endoscopic ultrasound (EUS) for staging of colonic cancer proximal to the rectum.

Patients and Methods:

Men and women with colonic adenocarcinomas were included in the study. EUS staging was compared to histopathology as the gold standard. Outcome measures were T- and N-staging accuracies. Articles were searched in PubMed, Web of Science, The Cochrane Library, and EMBASE.

Results:

Six studies were identified comparing EUS staging of colonic cancer to histopathology. The pooled-staging sensitivity and specificity were 0.90 and 0.98 for T1 tumors, 0.67 and 0.96 for T2 tumors, and 0.97 and 0.83 for T3/T4 tumors, respectively. Sensitivity and specificity for N + disease were 0.59 and 0.78, respectively.

Conclusions:

EUS is a feasible method for T-staging of cancers of the colon proximal to the rectum. The accuracy of lymph node staging needs to be verified by prospective multicenter studies including larger patient populations.

Forward-viewing linear echoendoscope: a new option in the endoscopic ultrasound armamentarium (with video)

The forward-viewing linear echoendoscope (FV-EUS) has been developed with the aim of overcoming limitations of standard curved linear-array echoendoscopes (CLA-EUS) and to further expand interventional applications of EUS. The main characteristic of the FV-EUS is a shifting in the orientation of both endoscopic and ultrasound views from oblique to forward, with the exit of the working channel at the tip of the instrument. This allows exit of the devices parallel to the longitudinal axis of the endoscope, thus resulting in a more direct and stable access to the lesion while increasing the precision and force applied to the target. Accumulating evidence has shown that the FV-EUS can be used instead of the standard CLA-EUS scope for routine fine needle aspiration, with extremely good performance for subepithelial lesions and for difficult to reach locations. Several areas of use of this echoendoscope are yet to be better defined, such as its potential for therapeutic and interventional procedures, as well as for natural orifice transluminal endoscopic surgery. The current report provides an updated overview of the available evidence for both diagnostic and interventional uses of the FV-EUS.

Forward-viewing radial-array echoendoscope for staging of colon cancer beyond the rectum

AIM: To evaluate feasibility of the novel forward-viewing radial-array echoendoscope for staging of colon cancer beyond rectum as the first series.

METHODS: A retrospective study with prospectively entered database. From March 2012 to February 2013, a total of 21 patients (11 men) (mean age 64.2 years) with colon cancer beyond the rectum were recruited. The novel forward-viewing radial-array echoendoscope was used for ultrasonographic staging of colon cancer beyond rectum. Ultrasonographic T and N staging were recorded when surgical pathology was used as a gold standard.

RESULTS: The mean time to reach the lesion and the mean time to complete the procedure were 3.5 and 7.1 min, respectively. The echoendoscope passed through the lesions in 13 patients (61.9%) and reached the cecum in 10 of 13 patients (76.9%). No adverse events were found. The lesions were located in the cecum (n = 2), ascending colon (n = 1), transverse colon (n = 2), descending colon (n = 2), and sigmoid colon (n = 14). The accuracy rate for T1 (n = 3), T2 (n = 4), T3 (n = 13) and T4 (n = 1) were 100%, 60.0%, 84.6% and 100%, respectively. The overall accuracy rates for the T and N staging of colon cancer were 81.0% and 52.4%, respectively. The accuracy rates among traversable lesions (n = 13) and obstructive lesions (n = 8) were 61.5% and 100%, respectively. Endoscopic ultrasound and computed tomography had overall accuracy rates of 81.0% and 68.4%, respectively.

CONCLUSION: The echoendoscope is a feasible staging tool for colon cancer beyond rectum. However, accuracy of the echoendoscope needs to be verified by larger systematic studies.

Endoscopic management of portal hypertension

Cirrhosis is the leading cause of portal hypertension worldwide, with the development of bleeding gastroesophageal varices being one of the most life-threatening consequences. Endoscopy plays an indispensible role in the diagnosis, staging, and prophylactic or active management of varices. With the expected future refinements in endoscopic technology, capsule endoscopy may one day replace traditional gastroscopy as a diagnostic modality, whereas endoscopic ultrasound may more precisely guide interventional therapy for gastric varices.

Successful endoscopic ultrasound-guided fine-needle aspiration of the pelvic lesion through the sigmoid colon

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is a useful modality when the target is a lymph node located in the mediastinum, perigastric area or perirectum. Although it is difficult to carry out EUS-FNA of the colon using an oblique view linear scope, we report two cases of successful EUS-FNA of the lesions via the proximal sigmoid colon using a recently available new convex type EUS scope. Case 1 was a 77-year-old Japanese woman noted to have multiple lymph node swelling in the para-aortic area and in the pelvis. Case 2 was a 60-year-old Japanese woman noted to have a large mass in the left lower abdomen. In case 1, oral EUS showed no lymph node swelling. In both cases, EUS with forward-viewing radial echoendoscope was carried out via the anus, and multiple lymph-node swelling or a large mass was observed near the proximal sigmoid colon. In the EUS-FNA for these cases, we used a new convex-type EUS scope that has an oblique view, but with a wide-angled optical device giving a view similar to a forward one. EUS-FNA was successfully carried out on the lesions. The pathological specimen revealed diffuse large B-cell lymphoma in case 1 and gastrointestinal stromal tumor (GIST) in case 2.

Use of the front-view forward-array echoendoscope to evaluate right colonic subepithelial lesions

BACKGROUND

Endosonographic evaluation and sampling of right colonic subepithelial lesions is technically difficult.

OBJECTIVE

To evaluate the feasibility, safety, and tissue yield of a prototype front-view, forward-array, curved linear array echoendoscope in the evaluation and sampling of right colonic subepithelial lesions.

SETTING

Tertiary referral center.

DESIGN

Procedural and outcome data on all patients undergoing EUS evaluation of right-sided colonic and pericolonic lesions were collected during a 1-year study period.

MAIN OUTCOME MEASUREMENTS

Patient demographics, clinical indication, EUS findings, EUS-FNA yield, technical success, and procedural complications.

RESULTS

A total of 15 patients underwent EUS examination of right-sided colonic lesions with the prototype echoendoscope. The lesions were located in the cecum (n = 12) and the ascending colon (n = 3). The cecum was reached in all examinations within 10 minutes. Twelve patients had subepithelial lesions detected during colonoscopy. Findings included 6 extrinsic compressions from an adjacent normal structure, 1 calcified lymph node, 1 ovarian cyst, 1 prolapsed appendiceal orifice, 1 GI stromal tumor, 1 appendiceal mucocele, and 1 lymphoma. Two patients were evaluated for a pericolonic lesion seen on CT; findings included focal diverticulitis and a metastatic lymph node. In the patient evaluated for an infiltrative mass with previous nondiagnostic biopsies, colonic histoplasmosis was diagnosed. FNA was performed in 6 patients and provided diagnostic samples in 5 (83%). No procedure- or FNA-related complications were reported.

CONCLUSIONS

Endosonographic evaluation and sampling of right-sided colonic subepithelial lesions with the prototype front-view, forward-array, curved linear array echoendoscope is feasible and safe. The yield of FNA is high, consistent with applications in the upper GI tract.

Endoscopic ultrasound in the diagnosis, staging and management of colorectal tumors

Endoscopic ultrasound (EUS) has evolved as a useful technique for imaging and intervention in the colon and rectum. This article reviews the clinical applications of EUS for imaging and intervention in colorectal cancer, with an emphasis on the most recent clinical studies.

Recent developments in the role of endoscopic ultrasonography in diseases of the colon and rectum

PURPOSE OF REVIEW

Endoscopic ultrasound has evolved as a useful technique for imaging and intervention in a variety of gastrointestinal and extraintestinal diseases including diseases of the colon and rectum. This paper will review recent developments in endoscopic ultrasound for colorectal diseases.

RECENT FINDINGS

Recent studies have shown significant clinical impact of endoscopic ultrasound in rectal cancer staging. Iliac lymph node evaluation by endoscopic ultrasound-guided fine needle aspiration may further expand the role of endoscopic ultrasound in rectal cancer. Three-dimensional endoscopic ultrasound may help decrease some of the errors of staging with two-dimensional endoscopic ultrasound and may further improve staging accuracy. Recent studies have confirmed continued problems with re-staging rectal cancer after chemoradiation. Endoscopic ultrasound-fine needle aspiration can be helpful in detecting local recurrence of rectal cancer and has been shown to be useful in evaluation of subepithelial masses of the colon and rectum and evaluation of rectosigmoid endometriosis.

SUMMARY

Endoscopic ultrasound continues to be useful for a variety of conditions of the colon and rectum with recent studies confirming its clinical impact as well as expanding its role into newer indications. Assessment for residual cancer after chemoradiation is still problematic and hopefully technological developments in ultrasound in the future may help in improving the accuracy of endoscopic ultrasound in this situation.

Role of endoscopic miniprobe ultrasonography in diagnosis of submucosal tumor of large intestine

AIM: To evaluate the role of miniprobe ultrasonography under colonoscope in the diagnosis of submucosal tumor of the large intestine, and to determine its imaging characteristics.

METHODS: Thirty-five patients with submucosal tumors of the large intestine underwent miniprobe ultrasonography under colonoscope. The diagnostic results of miniprobe ultrasonography were compared with pathological findings of specimens by biopsy and surgical resection.

RESULTS: Lipomas were visualized as hyperechoic homogeneous masses located in the submucosa with a distinct border. Leiomyomas were visualized as hypoechoic homogeneous mass originated from the muscularis propria. Leiomyosarcomas were shown with inhomogeneous echo and irregular border. Carcinoids were presented as submucosal hypoechoic masses with homogenous echo and distinct border. Lymphangiomas were shown as submocosal hypoechoic masses with cystic septal structures. Malignant lymphomas displayed as hypoechoic masses from mucosa to muscularis propria, while pneumatosis cystoids intestinalis originated from submucosa with a special sonic shadow. One large leiomyoma was misdiagnosed as leiomyosarcoma.

CONCLUSION: Endoscopic miniprobe ultrasonography can provide precise information about the size, layer of origin, border of submucosal tumor of the large intestine and has a high accuracy in the diagnosis of submucosal tumor of the large intestine. Pre-operative miniprobe ultrasonography under colonoscope may play an important role in the choice of therapy for submucosal tumor of the large intestine.

Comparison of hydrocolonic sonograpy accuracy in preoperative staging between colon and rectal cancer

AIM

To compare the accuracy of hydrocolonic sonography (HUS) in determining the depth of invasion (T stage) in colon and rectal cancer.

METHODS

A total of 1 000-2 000 mL of saline was instilled per rectum using a system for barium enemas, and then ultrasonography was conducted by a SSA-270A (Toshiba Co, Japan) sonolayer unit with a 3.75 MHz for 17 patients with colon cancer and 13 patients with rectal cancer before operation. After operation, T stage in HUS was compared with postoperative histological findings.

RESULTS

Overall, the accuracy of T stage was 70%. It was 88% in colon cancer and 46% in rectal cancer. In evaluating nodal state, the accuracy of HUS was low in both colon (71%) and rectal cancers (46%) compared with conventional CT or MRI. The overall accuracy of N staging was 60%.

CONCLUSION

HUS is valuable to evaluate the depth of invasion in colon cancer, but is less valuable in rectal cancer. Because HUS is low-cost, noninvasive, and readily available at any place, this technique seems to be useful to determine the preoperative staging in colon cancer, but not in rectal cancer.

Staging of colonic neoplasms by colonoscopic miniprobe ultrasonography

BACKGROUND AND AIMS

In contrast to the situation in the upper gastrointestinal tract staging of colonic neoplasm by endoscopic ultrasonography (EUS) has not gained importance because until yet preoperative staging is without any clinical consequences. This may change with the introduction of minimally invasive surgical procedures and endoscopic resection techniques as an alternative to conventional (open) surgery.

PATIENTS AND METHODS

We performed EUS with a miniprobe in 54 consecutive patients with colonic tumors who had been referred to our hospital for endoscopic resection or for laparoscopic resection of their lesions. Therefore patients with locally advanced tumors or systemic tumor spread were not included. After detection of the lesion during colonoscopy miniprobe EUS was performed with water-filling of the colonic lumen. The depth of invasion (T classification) and the local lymph node status (positive or negative) was ascertained. Lymph node-negative lesions staged as T1 underwent endoscopic resection whenever this was technically possible. In lymph node-negative T2-3 tumors laparoscopic resection was planned if they were localized at least 10 cm apart from the flexuras. All other lesions were resected by open surgery. The EUS findings were later compared with the final pathological results (pTN classification) of the resected specimen.

RESULTS

In 50 patients (93%) a sufficient EUS evaluation of the colonic tumor was possible. In one patient with a tumor at the left flexura the lesion could not be completely visualized, and in three patients a sufficient water filling of the colon was impossible. The infiltration depth was correctly classified in 17 adenomas, 16 T1, 8 T2, 5 T3, and one T4-carcinoma (EUS accuracy for T staging: 94%). Two T2 and one T3 carcinoma were overstaged by EUS while no understaging was recorded. The lymph node status was correctly classified in 42/50 patients (84%), and a false-negative lymph node status was found in only 4/50 cases (8%). The overall accuracy of EUS was 80%.

CONCLUSION

Miniprobe EUS is suitable and has a sufficient but not optimal accuracy for staging of colonic neoplasm. Its employment makes sense if minimally invasive resection techniques in patients with high-risk for open surgery are planned.

The role of sigmoidoscopy and colonoscopy in the diagnosis and management of lower gastrointestinal disorders: technique, indications, and contraindications

Flexible sigmoidoscopy and colonoscopy have revolutionized the clinical management of colonic diseases. Colonoscopy has a broad range of indications, including evaluating lower GI symptoms such as lower GI bleeding, evaluating abnormal radiographic findings, and screening and surveillance for colon cancer. Colonoscopy is increasingly being used therapeutically. Patient evaluation, patient instructions, and colonic preparation before colonoscopy are essential for safe and efficient colonoscopy. Intravenous sedation reduces patient pain and anxiety during colonoscopy, but requires monitoring by pulse oximetry and automated measurements of vital signs. An experienced colonoscopist can complete colonoscopy in 90% or more of cases, using maneuvers to maintain the colonic lumen in view, straighten the colonoscope, and avoid looping during colonic intubation.

The role of sigmoidoscopy and colonoscopy in the diagnosis and management of lower gastrointestinal disorders: endoscopic findings, therapy, and complications

Flexible sigmoidoscopy and colonoscopy have revolutionized the clinical management of colonic diseases. Colonoscopy is a highly sensitive and specific test. Colonic diseases often produce characteristic colonoscopic findings, as well as characteristic histologic findings, as identified in colonoscopic biopsy or polypectomy specimens. Colonoscopy is relatively safe, with a low incidence of serious complications, such as colonic perforation, hemorrhage, cardiopulmonary arrest, or sepsis. Colonoscopy is becoming more important clinically because of more widespread use of screening colonoscopy for colon cancer, application of therapeutic colonoscopy, and exciting new technical improvements.