Provocative angiography for lower gastrointestinal bleeding

Carbon dioxide angiography during angioembolization for trauma patients increases the detection of active bleeding and leads to reliable hemostasis: a retrospective, observational study

BACKGROUND

Angiography with carbon dioxide (CO2) has long been used as an alternative when iodine contrast media (ICM) cannot be used due to allergy to iodine or renal dysfunction. Conversely, CO2 angiography is also known as a provocation method for active bleeding. In this study, we examined the efficacy of CO2 angiography in angioembolization (AE) for trauma patients.

METHODS

This was a single-center, retrospective, observational study of trauma patients who underwent AE at our facility between January 2012 and April 2023.

RESULTS

Within this period, 335 AEs were performed. CO2 angiography was performed in 102 patients (30.4%), and in 113 procedures. CO2angiography was used to provoke active bleeding which went undetected using ICM in 83 procedures, and to confirm hemostasis after embolization in 30 procedures. Of the 80 procedures wherein, active bleeding was not detected on ICM, 35 procedures (43.8%) were detected using CO2. The spleen had the highest detection rate of active bleeding by CO2 angiography among the organs. There were 4/102 (1.9%) patients with CO2 contrast who underwent some form of reintervention. Two patients were re-embolized with n-butyl-2-cyanoacrylate because of recanalization after embolization with gelatin sponge. The other two patients had pseudoaneurysm formation which required reintervention, and CO2 angiography was not used. Vomiting was the most common complication of CO2 angiography in 10 patients (9.8%), whereas all were transient and did not require treatment.

CONCLUSIONS

CO2 angiography of trauma patients may have a better detection rate of active bleeding compared with ICM, leading to reliable hemostasis.

Carbon dioxide-enhanced angiography for detection of colonic diverticular bleeding and clinical outcomes

PURPOSE

To determine the ability of CO2-enhanced angiography to detect active diverticular bleeding that is not detected by iodinated contrast medium (ICM)-enhanced angiography and its impact on clinical outcomes when used to confirm embolization, particularly the risks of rebleeding and ischemic complications.

MATERIALS AND METHODS

We retrospectively identified a cohort of patients with colonic diverticular bleeding who underwent catheter angiography between August 2008 and May 2023 at our institution. We divided them according to whether they underwent CO2 angiography following a negative ICM angiography study or to confirm hemostasis post-embolization (the CO2 angiography group) or ICM angiography alone in the absence of active bleeding or for confirmation of hemostasis post-embolization (the ICM angiography group). The ability to detect active colonic diverticular bleeding and clinical outcomes were compared between the two groups.

RESULTS

There were 31 patients in the ICM angiography group and 29 in the CO2 angiography group. The rate of detection of active bleeding by CO2 angiography that was not identified by ICM angiography was 48%. The rebleeding rate was 23% in the ICM angiography group and 6.9% in the CO2 angiography group. Among the patients who underwent TAE, the ischemic complications rate was 7.1% in the ICM angiography group and 4.5% in the CO2 angiography group.

CONCLUSIONS

CO2 angiography may detect active diverticular bleeding that is not detectable by ICM angiography and appears to be associated with a lower rebleeding rate.

LEVEL OF EVIDENCE

IV.

Twenty years of embolization for acute lower gastrointestinal bleeding: a meta-analysis of rebleeding and ischaemia rates

BACKGROUND

Transarterial embolization (TAE) for acute lower gastrointestinal bleeding (LGIB) can be technically challenging due to the compromise between achieving haemostasis and causing tissue ischaemia. The goal of the present study is to determine its technical success, rebleeding, and post-embolization ischaemia rates through meta-analysis of published literature in the last twenty years.

METHODS

PubMed, Embase, and Cochrane Library databases were queried. Technical success, rebleeding, and ischaemia rates were extracted. Baseline characteristics such as author, publication year, region, study design, embolization material, percentage of superselective embolization were retrieved. Subgroup analysis was performed based on publication time and embolization agent.

RESULTS

A total of 66 studies including 2121 patients who underwent embolization for acute LGIB were included. Endoscopic management was attempted in 34.5%. The pooled overall technical success, rebleeding, post-embolization ischaemia rates were 97.0%, 20.7%, and 7.5%, respectively. Studies published after 2010 showed higher technical success rates (97.8% vs 95.2%), lower rebleeding rates (18.6% vs 23.4%), and lower ischaemia rates (7.3% vs 9.7%). Compared to microcoils, NBCA was associated with a lower rebleeding rate (9.3% vs 20.8%) at the expense of a higher post-embolization ischaemia rate (9.7% vs 4.0%). Coagulopathy (P = .034), inotropic use (P = .040), and malignancy (P = .002) were predictors of post-embolization rebleeding. Haemorrhagic shock (P < .001), inotropic use (P = .026), malignancy (P < .001), coagulopathy (P = .002), blood transfusion (P < .001), and enteritis (P = .023) were predictors of mortality. Empiric embolization achieved a similarly durable haemostasis rate compared to targeted embolization (23.6% vs 21.1%) but a higher risk of post-embolization ischaemia (14.3% vs 4.7%).

CONCLUSION

For LGIB, TAE has a favourable technical success rate and low risk of post-embolization ischaemia. Its safety and efficacy profile has increased over the last decade. Compared to microcoils, NBCA seemed to offer a more durable haemostasis rate at the expense of higher ischaemia risk. Due to the heterogeneity of currently available evidence, future prospective and comparative studies are warranted.

ADVANCES IN KNOWLEDGE

(1) Acute LGIB embolization demonstrate a high technical success rate with acceptable rate of rebleeding and symptomatic ischaemia rates. Most ischaemic stigmata discovered during routine post-embolization colonoscopy were minor. (2) Although NBCA seemed to offer a more durable haemostasis rate, it was also associated with a higher risk of ischaemia compared to microcoils. (3) Coagulopathy, malignant aetiology, and inotropic use were predictors of rebleeding and mortality. (4) Routine post-embolization endoscopy to assess for ischaemia is not indicated.

Review article: Advances in the management of lower gastrointestinal bleeding

BACKGROUND

Lower gastrointestinal bleeding (LGIB) is a common emergency with substantial associated morbidity and mortality. Elective colonoscopy plays an essential role in management, with an even more important role for radiology in the acute setting. Recent advances in the management of patients with LGIB warrant review as the management has recently evolved.

AIMS

To provide a comprehensive and updated overview of advances in the approach to patients with LGIB METHODS: We performed a comprehensive literature search to examine the current data for this narrative review supplemented by expert opinion.

RESULTS

The incidence of LGIB is increasing worldwide, partly related to an ageing population and the increasing use of antithrombotics. Diverticulosis continues to be the most common aetiology of LGIB. Pre-endoscopic risk stratification tools, especially the Oakland score, can aid appropriate patient triage. Adequate resuscitation continues to form the basis of management, while appropriate management of antithrombotics is crucial to balance the risk of worsening bleeding against increased cardiovascular risk. Radiological imaging plays an essential role in the diagnosis and treatment of acute LGIB, especially among unstable patients. Colonoscopy remains the gold-standard test for the elective management of stable patients.

CONCLUSIONS

The management of LGIB has evolved significantly in recent years, with a shift towards radiological interventions for unstable patients while reserving elective colonoscopy for stable patients. A multidisciplinary approach is essential to optimise the outcomes of patients with LGIB.

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.

Management of Patients With Acute Lower Gastrointestinal Bleeding: An Updated ACG Guideline

Acute lower gastrointestinal bleeding (LGIB) is a common reason for hospitalization in the United States and is associated with significant utilization of hospital resources, as well as considerable morbidity and mortality. These revised guidelines implement the Grading of Recommendations, Assessment, Development, and Evaluation methodology to propose recommendations for the use of risk stratification tools, thresholds for red blood cell transfusion, reversal agents for patients on anticoagulants, diagnostic testing including colonoscopy and computed tomography angiography (CTA), endoscopic therapeutic options, and management of antithrombotic medications after hospital discharge. Important changes since the previous iteration of this guideline include recommendations for the use of risk stratification tools to identify patients with LGIB at low risk of a hospital-based intervention, the role for reversal agents in patients with life-threatening LGIB on vitamin K antagonists and direct oral anticoagulants, the increasing role for CTA in patients with severe LGIB, and the management of patients who have a positive CTA. We recommend that most patients requiring inpatient colonoscopy undergo a nonurgent colonoscopy because performing an urgent colonoscopy within 24 hours of presentation has not been shown to improve important clinical outcomes such as rebleeding. Finally, we provide updated recommendations regarding resumption of antiplatelet and anticoagulant medications after cessation of LGIB.

Carbon Dioxide Angiography for the Detection of Lower Gastrointestinal Arterial Bleeding Initially Occult to Angiography with Iodinated Contrast Media

This study evaluated the utility of carbon dioxide (CO₂) in angiography for the detection of lower gastrointestinal arterial bleeding initially occult to angiography with iodinated contrast media. Fourteen patients underwent CO₂-enhanced angiography. In all patients, extravasation was identified by contrast-enhanced computed tomography but not by initial iodinated contrast-enhanced angiography. After iodinated contrast-enhanced angiography, CO₂-enhanced angiography was performed from the same catheter position. The detection capability for extravasation on CO₂-enhanced angiography was evaluated. CO₂-enhanced angiography allowed for the visualization of extravasation and subsequent transcatheter arterial embolization in 11 of 14 (79%) cases, with extravasation seen during either CO₂-enhanced angiography (n = 8) or subsequent repeat iodinated contrast-enhanced angiography immediately after negative CO₂-enhanced angiography (n = 3). Conservative treatment was performed in the remaining 3 cases. In conclusion, CO₂-enhanced angiography appears useful for identifying occult lower gastrointestinal bleeding.

Clinical factors associated with successful embolization of lower gastrointestinal bleeding

AIM

To develop a model of clinical factors that may predict: (1) technically and clinically successful embolization of a bleeding vessel at digital subtraction angiography (DSA) for lower gastrointestinal bleed (LGIB); (2) a negative DSA in the presence of positive CT-mesenteric angiography (CTMA) for LGIB.

METHODS

A retrospective cohort study of all DSAs conducted with intent for embolization for acute LGIB over a 10-year period was undertaken. Pre-procedural and intra-procedural clinical variables were evaluated using uni- and multi-variate analysis.

RESULTS

One hundred and twenty-three DSAs were evaluated. Technical success was 81% and clinical success 78% where DSA was positive. Technical success was associated with super-selective approach, contrast extravasation on CT, haemoglobin drop, anatomical source and time from CT to DSA on univariate analysis. On multivariate analysis, time from CT to DSA was significant with a higher success probability within 120 min with different factors being salient depending on degree of delay. Clinical success was only associated with activated partial thromboplastin time (<27.5 s). A negative DSA was associated with anatomical source, haemodynamic stability, platelet count and time from CT to DSA on univariate analysis. The latter three remained so on multivariate analysis.

CONCLUSION

A triaging approach to utilizing emergency DSA may be helpful. If prolonged delay between CT and DSA is anticipated, with haemodynamic stability and a near-normal platelet count, the DSA may not be fruitful. Technical success may be more likely if DSA occurs within 120 min. Clinical success may be more likely if activated partial thromboplastin time is within normal range.

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.

Transcatheter Arterial Embolization Using Cone-beam Computed Tomography during Angiography and Automated Vessel Detection Software for Obscure Colonic Diverticular Hemorrhage after Unsuccessful Endoscopic Clipping: A Report of Two Cases

We report the usefulness of cone-beam computed tomography angiography (CBCTA) and automated vessel detection (AVD) software in transcatheter arterial embolization in two cases of obscure ascending colonic diverticular hemorrhage after unsuccessful endoscopic clipping. Arteriography of the superior mesenteric artery demonstrated no active bleeding. Considering the positional relationship of the clips, we could narrow the responsible vessel down to two candidates but could not definitively identify the responsible vessel. We performed CBCTA at the marginal artery of the right colic artery, and the responsible branch was identified using AVD. The responsible vessel could be embolized, and hemostasis was achieved with no ischemic complications. CBCTA and AVD software for colonic diverticular hemorrhage after endoscopic clipping were useful for identifying the responsible vessel and in performing selective embolization.