Provocative mesenteric angiography for occult gastrointestinal bleeding: a systematic review

Occult gastrointestinal bleeding (GIB) is a challenge for physicians to diagnose and treat. A systematic literature search of the PubMed and Embase databases was conducted up to January 1, 2023. Eligible studies included primary research studies with patients undergoing provocative mesenteric angiography (PMA) for diagnosis or localization of occult GIB. Twenty-seven articles (230 patients) were included in the review. Most patients (64.8%) presented with lower GIB. The average positivity rate for provocative angiography was 48.7% (58% with heparin and 46.7% in thrombolytics). Embolization was performed in 46.4% of patients, and surgical management was performed in 37.5%. Complications were rare. PMA can be an important diagnostic and treatment tool but studies with high-level evidence and standardized protocols are needed to establish its safety and optimal use.

Adding non-contrast and delayed phases increases the diagnostic performance of arterial CTA for suspected active lower gastrointestinal bleeding

OBJECTIVES

When assessing for lower gastrointestinal bleed (LGIB) using CTA, many advocate for acquiring non-contrast and delayed phases in addition to an arterial phase to improve diagnostic performance though the potential benefit of this approach has not been fully characterized. We evaluate diagnostic accuracy among radiologists when using single-phase, biphasic, and triphasic CTA in active LGIB detection.

METHOD AND MATERIALS

A random experimental block design was used where 3 blinded radiologists specialty trained in interventional radiology retrospectively interpreted 96 CTA examinations completed between Oct 2012 and Oct 2017 using (1) arterial only, (2) arterial/non-contrast, and (3) arterial/non-contrast/delayed phase configurations. Confirmed positive and negative LGIB studies were matched, balanced, and randomly ordered. Sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, positive and negative predictive values, and time to identify the presence/absence of active bleeding were examined using generalized estimating equations (GEE) with sandwich estimation assuming a binary distribution to estimate relative benefit of diagnostic performance between phase configurations.

RESULTS

Specificity increased with additional contrast phases (arterial 72.2; arterial/non-contrast 86.1; arterial/non-contrast/delayed 95.1; p < 0.001) without changes in sensitivity (arterial 77.1; arterial/non-contrast 70.2; arterial/non-contrast/delayed 73.1; p = 0.11) or mean time required to identify bleeding per study (s, arterial 34.8; arterial/non-contrast 33.1; arterial/non-contrast/delayed 36.0; p = 0.99). Overall agreement among readers (Kappa) similarly increased (arterial 0.47; arterial/non-contrast 0.65; arterial/non-contrast/delayed 0.79).

CONCLUSION

The addition of non-contrast and delayed phases to arterial phase CTA increased specificity and inter-reader agreement for the detection of lower gastrointestinal bleeding without increasing reading times.

KEY POINTS

• A triphasic CTA including non-contrast, arterial, and delayed phase has higher specificity for the detection of lower gastrointestinal bleeding than arterial-phase-only protocols. • Inter-reader agreement increases with additional contrast phases relative to single-phase CTA. • Increasing the number of contrast phases did not increase reading times.

Provocative Angiography, Followed by Therapeutic Interventions, in the Management of Hard-To-Diagnose Gastrointestinal Bleeding

BACKGROUND

Despite significant advances in imaging and endoscopic diagnostic techniques, adequate localization of gastrointestinal bleeding (GIB) can be challenging. Provocative angiography (PROVANGIO) has not been part of the standard diagnostic algorithms yet. We sought to examine the ability of PROVANGIO to identify the bleeding source when conventional radiography fails.

METHODS

Patients undergoing PROVANGIO for GIB during 2008-2014 were retrospectively included. Demographics and periprocedural patient characteristics were recorded. PROVANGIO was performed in a multidisciplinary setting, involving interventional radiology, surgery and anesthesiology teams, ready to intervene in case of uncontrolled bleeding. The procedure included conventional angiography of the celiac, superior and inferior mesenteric arteries (SMA, IMA) followed by a stepwise bleeding provocation with anticoagulating, vasodilating and/or thrombolytic agent administration, combined with angiography.

RESULTS

Twenty-three PROVANGIO were performed. Patients were predominantly male (15, 65.2%), and hematochezia was the most common presenting symptom (12, 52.2%). Patients with a positive PROVANGIO had lower Charlson comorbidity index (1 vs. 7, p = 0.009) and were less likely to have a prior history of GIB (14.3% vs. 87.5%, p = 0.001). PROVANGIO localized bleeding in 7 (30%) patients. In 6 out of 7 patients, the bleeding source was identified in the SMA and, in one case, in the IMA distribution. The bleeding was controlled angiographically in four cases, endoscopically in one case and surgically in the remaining two. No complications related to PROVANGIO were detected.

CONCLUSIONS

In our series, PROVANGIO safely identified the bleeding source, and provided that necessary safeguards are put into place, we recommend incorporating it in the diagnostic algorithms for GIB management.

The role of imaging in gastrointestinal bleed

Gastrointestinal (GI) bleed accounts for approximately 20% of emergency visits; 2% of hospital admissions and its incidence has been increasing. In patients where the GI bleed does not stop spontaneously, intervention is required to identify the source of bleeding and stop the hemorrhage. Although identifying the source of bleeding can be challenging due to the vast number of underlying etiologies, radiology plays a vital role in patients where endoscopy and/or medical management fail. Radiology offers both non-invasive and invasive options for the diagnosis as well as management of GI bleeds. Scintigraphy and computed tomography angiography (CTA) are the most important non-invasive imaging tests that can identify presence of and help locate the site of bleeding and are used when the patient is hemodynamically stable. If the patient is hemodynamically unstable, conventional angiography (CA) allows diagnosis of the presence, site of bleeding as well as the means of treating the bleed by embolization. Our review article focuses on the various etiologies of GI bleed, the role of imaging in diagnosis as well as treatment of these patients based on the underlying etiologies, the merits and disadvantages of each of these modalities with emphasis on triaging patients for the most appropriate imaging test to guide the most suitable management.

The Role of Transcatheter Arterial Embolization in the Management of Nonvariceal Upper Gastrointestinal Bleeding

Nearly 50 years ago, catheter angiography was introduced as a means of both diagnosing and treating nonvariceal upper gastrointestinal bleeding. Technological advances and innovations have resulted in the introduction of microcatheters that, using a coaxial technique, are capable of selecting third-order arterial branches and of delivering a wide array of embolic agents. This article reviews the imaging diagnosis of nonvariceal upper gastrointestinal bleeding, the techniques of diagnostic and therapeutic angiography, the angiographic appearance of the various etiologies of nonvariceal upper gastrointestinal bleeding, the rationale behind case-specific selection of embolic agents as well as the anticipated outcome of transcatheter arterial embolization.

Post-pancreaticoduodenectomy hemorrhage: DSA diagnosis and endovascular treatment

Objective

To explore the diagnostic value of digital subtraction angiography (DSA) and the effectiveness of endovascular treatment for a post-pancreaticoduodenectomy hemorrhage (PPH).

Results

During the DSA examination, positive results were found in 29 patients, yielding a positive rate of 69.0%. The manifestations of the DSA examination included contrast medium extravasation, pseudoaneurysm, and artery walls coarse. All 29 patients with positive results underwent endovascular treatment, including transartery embolization (TAE) in 28 patients and covered stents placement in one patient. The technical success and clinical success rates were 100% and 72.4%, respectively. Re-bleeding occurred in 8 of the 29 patients after the first treatment (27.6%). The mortality of PPH was 17.2% (5 of 29). Two of the five PPH patients died following severe infections, and three died from multiple organ failure.

Materials and Methods

A DSA examination was conducted using clinical and imaging data of 42 patients, and endovascular treatment for delayed PPH was retrospectively analyzed.

Conclusions

DSA examination is a minimally invasive and rapid method for the diagnosis of delayed PPH. For patients with positive DSA results, endovascular treatment can be performed rapidly, safely, and effectively. Therefore, the DSA examination and endovascular treatment could be considered a preferred treatment approach for delayed PPH.