Recurrent gastrointestinal bleeding: use of thrombolysis with anticoagulation in diagnosis

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.

Unmasking lower gastrointestinal bleeding under administration of norepinephrine

BACKGROUND

Bleeding in the gastrointestinal tract is common and transarterial embolization enables the clinician to control gastrointestinal bleeding. Contrast extravasation is a prerequisite for successful embolization. Provocative angiography is helpful in the detection of elusive bleeding.

AIM

We performed a retrospective analysis of angiographic treatment in patients with lower gastrointestinal hemorrhage and initially negative angiographies, as well as the role of norepinephrine (NE) in unmasking bleeding.

METHODS

We analyzed 41 patients with lower gastrointestinal bleeding after angiography who had undergone treatment over a period of 10 years. All patients had a positive shock index and needed intensive care.

RESULTS

In three of four patients, angiography disclosed the site of bleeding when NE was used during the procedure for hemodynamic stabilization.

CONCLUSION

We suggest that angiography performed after the administration of NE in unstable patients with gastrointestinal bleeding and an initially negative angiography has the potential to unmask bleeding sites for successful embolization. However, this statement must be confirmed in prospective studies.

The Role of Provocative Testing and Localization of the Video Capsule Endoscope in the Management of Small Intestinal Bleeding

The cause of small intestinal bleeding (SIB) may be elusive despite exhaustive testing. This article describes the current understanding of SIB regarding evaluation, with emphasis on the use of video capsule endoscopy (VCE) as a diagnostic procedure. This article addresses the utility of provocative testing in challenging cases and the performance of endoscopic procedures on active antithrombotic therapy. Specific recommendations accompany this article, including use of antithrombotic agents to stimulate bleeding when clearly indicated; performance of endoscopic procedures on active antithrombotic therapy; and progressive adoption of VCE and device-assisted enteroscopy in the inpatient setting.

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.

Empiric cone-beam CT-guided embolization in acute lower gastrointestinal bleeding

OBJECTIVES

To evaluate the clinical effect and safety of cone-beam CT (CBCT)-guided empirical embolization for acute lower gastrointestinal bleeding (LGIB) in patients with a positive CT angiography (CTA) but subsequent negative digital subtraction angiography (DSA).

METHODS

A retrospective study of consecutive LGIB patients with a positive CTA who received a DSA within 24 h from January 2008 to July 2019. Patients with a positive DSA were treated with targeted embolization (TE group). Patients with a negative DSA underwent an empiric CBCT-guided embolization of the assumed ruptured vas rectum (EE group) or no embolization (NE group). Recurrent bleeding, major ischemic complications, and in-hospital mortality were compared by means of Fisher's exact test. Further subgroup analysis was performed on hemodynamic instability.

RESULTS

Eighty-five patients (67.6 years ± 15.7, 52 men) were included (TE group, n = 47; EE group, n = 19; NE group, n = 19). If DSA was positive, technical success of targeted embolization was 100% (47/47). If DSA was negative and the intention to treat by empiric CBCT-guided embolization, technical success was 100% (19/19). Recurrent bleeding rates in the TE group, EE group, and NE group were 17.0% (8/47), 21.1% (4/19), and 52.6% (10/19) respectively. Empiric CBCT-guided embolization reduced rebleeding significantly in patients with a negative DSA and hemodynamic instability (EE group, 3/10 vs NE group, 10/12, p = .027). Major ischemic complications occurred in one patient (TE group). Overall, the in-hospital mortality rate was 7.1% (6/85).

CONCLUSION

Empiric cone-beam CT-guided embolization proved to be a feasible, effective, and safe treatment strategy to reduce rebleeding and improve clinical success in hemodynamically unstable patients with acute LGIB, positive CTA but negative DSA.

KEY POINTS

• A novel transarterial embolization technique guided by cone-beam CT could be developed extending the "empiric" embolization strategy to lower gastrointestinal bleeding. • By implementing the empiric treatment strategy, nearly all patients with an active lower gastrointestinal bleeding on CTA will be eligible for a superselective empiric embolization, even if subsequent catheter angiography is negative. • In patients with a negative catheter angiography, empiric embolization reduces the rebleeding rate and, particularly in hemodynamically unstable patients, improves clinical success compared with a conservative "wait-and-see" management.

Localization and Definitive Control of Lower Gastrointestinal Bleeding with Angiography and Embolization

Angiography has long been a mainstay of lower gastrointestinal bleeding localization. More recently, angioembolism has been used therapeutically for bleeding control, but there are limited data on its efficacy. This study was designed to evaluate the efficacy of angiography and embolization for localizing and treating lower gastrointestinal bleeding as well evaluate the occurrence of bowel ischemia after embolization. This study is a retrospective descriptive review of all patients undergoing mesenteric angiography at a tertiary hospital over an eight-year period. Clinical data were recorded including patient demographics, causes of bleeding, procedures, and outcomes. Patients were excluded if the cause of bleeding was upper gastrointestinal bleeding or the medical record was missing data. Localization and definitive control of bleeding was the primary end point. One hundred fifty-nine angiograms were performed on 152 patients. Mean age was 72 years. Angiographic localization was successful in 23.7 per cent of patients. Although embolization after angiographic localization achieved definitive control of bleeding in 50 per cent of patients, the success rate was only 8.6 per cent of all patients who had angiography. One patient developed postembolization ischemia requiring laparotomy. Angiographic localization of lower gastrointestinal bleeding is successful in only 23.7 per cent of patients. Definitive hemostasis through embolization was successful in only 8.6 per cent of patients who underwent angiography for lower gastrointestinal bleeding.

The Clinician's Guide to Suspected Small Bowel Bleeding

Small bowel bleeding accounts for 5-10% of gastrointestinal bleeding. With the advent of capsule endoscopy, device-assisted enteroscopy, and multiphase CT scanning, a small bowel source can now be found in many instances of what has previously been described as obscure gastrointestinal bleeding. We present a practical review on the evaluation and management of small bowel bleeding for the practicing clinician.

Pharmacologic provocation combined with endoscopy in refractory cases of GI bleeding

BACKGROUND AND AIMS

The source of GI bleeding may elude us despite exhaustive testing in some cases. Bleeding in these cases is often related to a vascular lesion that is discernible only when actively bleeding. The objective of this study was to determine the efficacy and safety of endoscopy combined with the administration of antiplatelet and/or anticoagulant agents to stimulate bleeding in order to define a source.

METHODS

A retrospective review of a database of device-assisted enteroscopy (DAE) procedures was completed to identify cases in which provocation with antiplatelet or anticoagulant agents was used as part of a GI bleeding evaluation. Procedures were divided into 3 groups based on the method of provocation: patients with a history of bleeding associated with an antiplatelet/anticoagulant (provocation-experienced); patients naïve to these medications (provocation-naïve); and cases of recurrent, overt GI bleeding in which a combination of clopidogrel and intravenous heparin was administered for provocation (Lousiana State University [LSU] protocol).

RESULTS

A review of 824 DAE procedures was completed to identify a total of 38 instances in which provocation was attempted in 27 patients. These cases were subdivided into 13 provocation-experienced procedures, 18 provocation-naïve procedures, and 7 LSU protocol procedures. The diagnostic yield of provocative testing per procedure was 53% in the provocation-experienced group, 27% in the provocation-naïve group, and 71% in the full protocol group. Provocative testing was revealing in 15 of 27 patients; angioectasias and Dieulafoy lesions were the most common pathologies. Provocative testing was not beneficial in 4 patients who were eventually diagnosed with bleeding caused by intestinal angioectasias (3) and an aorto-enteric fistula (1). There were no adverse events.

CONCLUSIONS

Provocative testing combined with endoscopy can be justified as an option in the diagnostic algorithm of complex cases of GI bleeding when intermittent bleeding related to a vascular lesion, such as an angioectasia or Dieulafoy, is suspected. However, this novel technique should be considered only after standard management has failed to define a bleeding source, and bleeding continues to recur. This is the first reported case series of provocative testing combined with endoscopy.

Video capsule endoscopy for previous overt obscure gastrointestinal bleeding in patients using anti-thrombotic drugs

BACKGROUND AND AIM

Little is known about the causes of overt obscure gastrointestinal bleeding (OGIB) in patients using anti-thrombotic therapy. We aimed to describe video capsule endoscopy (VCE) findings and to identify factors associated with positive findings in these patients.

METHODS

We carried out a retrospective study of 56 patients who underwent VCE for evaluation of previous overt OGIB during anti-thrombotic therapy. VCE studies were re-evaluated by a gastroenterologist blinded to clinical details. Clinical data included in the multivariate analysis were sex, age, indication for and type of anti-thrombotic therapy, hemodynamic instability on admission, type of blood loss, hemoglobin on admission, use of a proton pump inhibitor, NSAID use, time between bleeding episodes and VCE, and whether or not anti-thrombotic therapy was resumed before the VCE study.

RESULTS

A probable cause for gastrointestinal bleeding was identified in 28 (50%) of the 56 studies. Angiodysplasia was found in 19 patients. Twenty-two studies showed a possible cause in the small bowel. Multivariate logistic regression analysis showed that reinstitution of anti-thrombotic therapy before VCE was carried out was the only independent predictor of positive VCE findings (OR: 8.61, 95% CI: 1.20-60.42, P=0.032).

CONCLUSIONS

Small intestinal angiodysplasia was the most common cause for overt OGIB. Reinstitution of withdrawn anti-thrombotic drugs before the VCE examination was carried out was associated with positive VCE findings in multivariate analysis.

Thrombolysis for acute occlusion of the superior mesenteric artery

BACKGROUND

This study evaluated the incidence, complications, and outcome of local intra-arterial thrombolytic therapy for acute superior mesenteric artery (SMA) occlusion in Sweden.

METHODS

Patients undergoing local intra-arterial thrombolytic therapy for acute SMA occlusion were identified in the Swedish Vascular Registry (SWEDVASC) between 1987 and 2009. Patient data were retrieved in a structured protocol by local vascular surgeons at each participating hospital.

RESULTS

Included were 34 patients (20 women) from 12 hospitals. Median age was 78 years. The first patient was treated in 1997, and the annual number of patients undergoing thrombolysis increased continuously from 2004 to 2009. Twenty-eight patients (82%) had embolic occlusion. No patients (0%) had acute peritonitis, and one (3%) had bloody stools at admission. Thirty-two patients (94%) were diagnosed by computed tomography with intravenous contrast enhancement. The median dose of alteplase was 20 mg (interquartile range, 11.6-34.0). Successful thrombolysis was achieved in 30 patients (88%). Initial adjunctive aspiration thromboembolectomy was performed in 10 patients. There were six self-limiting bleeding complications; one from the gastrointestinal tract. Thirteen explorative laparotomies, 10 repeat laparotomies, and eight bowel resections were performed. The in-hospital mortality rate was 26% (9 of 34). Age was not associated with in-hospital death (P = .42). Successful thrombolysis was associated with decreased mortality (P = .048).

CONCLUSION

Local thrombolysis for acute SMA occlusion is a minimally invasive and effective treatment alternative in a select group of patients without peritonitis. The few technique-related complications were mild.

Recent advances in endovascular techniques for management of acute nonvariceal upper gastrointestinal bleeding

Over the past two decades, transcatheter arterial embolization has become the first-line therapy for the management of upper gastrointestinal bleeding that is refractory to endoscopic hemostasis. Advances in catheter-based techniques and newer embolic agents, as well as recognition of the effectiveness of minimally invasive treatment options, have expanded the role of interventional radiology in the management of hemorrhage for a variety of indications, such as peptic ulcer bleeding, malignant disease, hemorrhagic Dieulafoy lesions and iatrogenic or trauma bleeding. Transcatheter interventions include the following: selective embolization of the feeding artery, sandwich coil occlusion of the gastroduodenal artery, blind or empiric embolization of the supposed bleeding vessel based on endoscopic findings and coil pseudoaneurysm or aneurysm embolization by three-dimensional sac packing with preservation of the parent artery. Transcatheter embolization is a fast, safe and effective, minimally invasive alternative to surgery when endoscopic treatment fails to control bleeding from the upper gastrointestinal tract. This article reviews the various transcatheter endovascular techniques and devices that are used in a variety of clinical scenarios for the management of hemorrhagic gastrointestinal emergencies.

Nonvariceal upper gastrointestinal bleeding: the usefulness of rotational angiography after endoscopic marking with a metallic clip

Objective

We wanted to assess the usefulness of rotational angiography after endoscopic marking with a metallic clip in upper gastrointestinal bleeding patients with no extravasation of contrast medium on conventional angiography.

Materials and Methods

In 16 patients (mean age, 59.4 years) with acute bleeding ulcers (13 gastric ulcers, 2 duodenal ulcers, 1 malignant ulcer), a metallic clip was placed via gastroscopy and this had been preceded by routine endoscopic treatment. The metallic clip was placed in the fibrous edge of the ulcer adjacent to the bleeding point. All patients had negative results from their angiographic studies. To localize the bleeding focus, rotational angiography and high pressure angiography as close as possible to the clip were used.

Results

Of the 16 patients, seven (44%) had positive results after high pressure angiography as close as possible to the clip and they underwent transcatheter arterial embolization (TAE) with microcoils. Nine patients without extravasation of contrast medium underwent TAE with microcoils as close as possible to the clip. The bleeding was stopped initially in all patients after treatment of the feeding artery. Two patients experienced a repeat episode of bleeding two days later. Of the two patients, one had subtle oozing from the ulcer margin and that patient underwent endoscopic treatment. One patient with malignant ulcer died due to disseminated intravascular coagulation one month after embolization. Complete clinical success was achieved in 14 of 16 (88%) patients. Delayed bleeding or major/minor complications were not noted.

Conclusion

Rotational angiography after marking with a metallic clip helps to localize accurately the bleeding focus and thus to embolize the vessel correctly.

Occult and obscure gastrointestinal bleeding: causes and clinical management

Occult gastrointestinal bleeding, defined as bleeding that is unknown to the patient, is the most common form of gastrointestinal bleeding and can be caused by virtually any lesion in the gastrointestinal tract. Patients with occult gastrointestinal bleeding include those with fecal occult blood and iron-deficiency anemia (IDA). In men and postmenopausal women, IDA should be considered to be the result of gastrointestinal bleeding until proven otherwise. Indeed, the possibility of gastrointestinal tract malignancy in these patients means that gastrointestinal evaluation is nearly always indicated. Obscure gastrointestinal bleeding is defined as obvious bleeding from a difficult to identify source and is always recurrent. This form of bleeding accounts for approximately 5% of all cases of clinically evident gastrointestinal bleeding and is most commonly caused by bleeding from the small intestine. Capsule endoscopy and deep enteroscopy have had a major impact on the way that patients with occult and, in particular, obscure bleeding are managed. In this Review the causes, diagnostic evaluation and treatment of occult and obscure gastrointestinal bleeding are discussed.

The role of colonoscopy and radiological procedures in the management of acute lower intestinal bleeding

There are multiple strategies for evaluating and treating lower intestinal bleeding (LIB). Colonoscopy has become the preferred initial test for most patients with LIB because of its diagnostic and therapeutic capabilities and its safety. However, few studies have directly compared colonoscopy with other techniques and there are controversies regarding the optimal timing of colonoscopy, the importance of colon preparation, the prevalence of stigmata of hemorrhage, and the efficacy of endoscopic hemostasis. Angiography, radionuclide scintigraphy, and multidetector computed tomography scanning are complementary modalities, but the requirement of active bleeding at the time of the examination limits their routine use. In addition, angiography can result in serious complications. This review summarizes the available evidence regarding colonoscopy and radiographic studies in the management of acute LIB.

Upper endoscopy in patients with acute myocardial infarction and upper gastrointestinal bleeding: results of a decision analysis

BACKGROUND

The management of patients with acute myocardial infarction (AMI) and upper gastrointestinal bleeding (UGIB) can present a challenge. The utility of upper endoscopy (esophagogastroduodenoscopy, EGD) and endoscopic therapy must be weighed against safety considerations.

AIM

To assess the utility and safety of EGD in patients with UGIB and AMI.

METHODS

Using decision analysis, patients with UGIB and AMI were assigned to one of two strategies: (1) EGD prior to cardiac catheterization (EGD strategy) and (2) cardiac catheterization without EGD (CATH strategy).

RESULTS

In patients with overt UGIB, the EGD strategy resulted in 97 deaths per 10,000 patients, compared with 600 deaths in the CATH strategy. The EGD strategy resulted in fewer non-fatal complications (1,271 vs. 6,000 per 10,000 patients). In patients with occult blood loss, the EGD strategy resulted in more deaths (59 vs. 16 per 10,000) and more non-fatal complications (888 vs. 160 per 10,000) than the CATH strategy.

CONCLUSIONS

Our analysis supports EGD prior to cardiac catheterization in patients with AMI and overt UGIB. This strategy results in fewer deaths and complications compared with a strategy of proceeding directly to catheterization. Our analysis does not support routine EGD prior to cardiac catheterization in patients with fecal occult blood.

Use of provocative angiography to localize site in recurrent gastrointestinal bleeding

BACKGROUND

While the source of most cases of lower gastrointestinal bleeding may be diagnosed with modern radiological and endoscopic techniques, approximately 5% of patients remain who have negative endoscopic and radiological investigations [1].

CLINICAL PROBLEM

These patients require repeated hospital admissions and blood transfusions, and may proceed to exploratory laparotomy and intraoperative endoscopy. The personal and financial costs are significant.

METHOD OF DIAGNOSIS AND DECISION MAKING

The technique of adding pharmacologic agents (anticoagulants, vasodilators, fibrinolytics) during standard angiographic protocols to induce a prohemorrhagic state is termed provocative angiography. It is best employed when significant bleeding would otherwise necessitate emergency surgery.

TREATMENT

This practice frequently identifies a bleeding source (reported success rates range from 29 to 80%), which may then be treated at the same session. We report the case of a patient with chronic lower gastrointestinal hemorrhage with consistently negative endoscopic and radiological workup, who had an occult source of bleeding identified only after a provocative angiographic protocol was instituted, and who underwent succeeding therapeutic coil embolization of the bleeding vessel.

Interventional management of lower gastrointestinal bleeding

Lower gastrointestinal bleeding (LGIB) arises from a number of sources and is a significant cause of hospitalization and mortality in elderly patients. Whereas most episodes of acute LGIB resolve spontaneously with conservative management, an important subset of patients requires further diagnostic workup and therapeutic intervention. Endovascular techniques such as microcatheter embolization are now recognized as safe, effective methods for controlling LGIB that is refractory to endoscopic intervention. In addition, multidetector CT has shown the ability to identify areas of active bleeding in a non-invasive fashion, enabling more focused intervention. Given the relative strengths and weaknesses of various diagnostic and treatment modalities, a close working relationship between interventional radiologists, gastroenterologists and diagnostic radiologists is necessary for the optimal management of LGIB patients.

Nonvariceal upper gastrointestinal bleeding

Nonvariceal upper gastrointestinal bleeding (NUGB) remains a major medical problem even after advances in medical therapy with gastric acid suppression and cyclooxygenase (COX-2) inhibitors. Although the incidence of upper gastrointestinal bleeding presenting to the emergency room has slightly decreased, similar decreases in overall mortality and rebleeding rate have not been experienced over the last few decades. Many causes of upper gastrointestinal bleeding have been identified and will be reviewed. Endoscopic, radiographic and angiographic modalities continue to form the basis of the diagnosis of upper gastrointestinal bleeding with new research in the field of CT angiography to diagnose gastrointestinal bleeding. Endoscopic and angiographic treatment modalities will be highlighted, emphasizing a multi-modality treatment plan for upper gastrointestinal bleeding.

Angiographic diagnosis and endovascular management of nonvariceal gastrointestinal hemorrhage

Diagnostic angiography still plays an essential role in the diagnosis of patients,particularly those with acute lower GI bleeding. Transcatheter therapy appears to be a viable treatment alternative in selected patients with GI bleeding. Many interventionists today believe embolotherapy to be more effective initially and to have better long-term results, specifically less rebleeding, than vasopressin infusion with at least equal complication rates. Unfortunately, direct comparison of the two techniques in a randomized, controlled fashion has not been performed. Small patient series, such as those summarized here, suggest that the results of the two techniques are essentially equal, and ischemic complications appear more prevalent with embolotherapy. The use of embolotherapy--either empirically based on endoscopic or surgical findings or directed against a site found to have contrast extravasation-represents the current intervention of choice in the case of upper GI bleeding refractory to endoscopic intervention. Head-to-head studies directly comparing the efficacy, morbidity, and mortality associated with endovascular or surgical correction of bleeding from the upper GI tract is needed. Although the current tide favors embolotherapy in the lower GI tract, infusion of vasoconstricting agents deserves more attention. To that end, there is a great need for scientific data regarding the safety and efficacy of transcatheter therapy for upper and lower GI bleeding.

Obscure gastrointestinal bleeding

Obscure GI bleeding is a relatively common problem facing internists, gastroenterologists, and surgeons in a typical clinical practice. The etiology is occasionally suggested by the patient's age, history, and medications. Management is complicated and typically requires a team-oriented approach, with input from the internist, gastroenterologist, radiologist, and surgeon alike. SBFT and enteroclysis seem to have a limited role, unless there is a high suspicion of a small bowel mass lesion or Crohn's disease. Scintigraphy may be performed in patients with active bleeding in whom endoscopy has failed oris contraindicated. Angiography may be used in patients with an early positive nuclear imaging or failed endoscopic therapy. Provocative angiography probably has a lower diagnostic yield than previously reported, and should be performed only in experienced centers. Helical CT is a new and potentially important option in patients with obscure bleeding, but is currently considered experimental. All patients with obscure GI bleeding should undergo repeat upper endoscopy and perhaps colonoscopy to rule out missed lesions. SBE seems to be complementary to capsule endoscopy, and it is unknown whether this should be performed before capsule endoscopy or only if capsule endoscopy yields a positive proximal small bowel finding. Double balloon enteroscopy seems promising, but the technique requires further study. Surgery should be reserved for patients who have a positive capsule endoscopy requiring surgical therapy or patients who have persistent GI bleeding requiring recurrent blood transfusions in whom all other modalities have failed. Treatment for vascularectasias, the most common cause of obscure GI bleeding, is currently inadequate,and typically requires a combination of multiple management approaches.

Laparoendoscopic Techniques for Occult Gastrointestinal Bleeding

Up to 5% of gastrointestinal bleeds occur between the ligament of Treitz and the ileocecal valve. These patients present with occult bleeding and pose diagnostic and therapeutic challenges. Currently, an array of technology exists for diagnostic purposes, including upper and lower endoscopies, capsule endoscopy, nuclear scans, angiography, and intraoperative endoscopy. All of these modalities have advantages and disadvantages. However, the diagnostic gold standard for occult gastrointestinal bleeding does not exist. We present a case of an 18-year-old male with occult gastrointestinal bleeding to illustrate the variety of available modalities. Initially, the patient underwent upper, lower, and push endoscopies. Subsequently, he had a nuclear bleeding scan, video capsule endoscopy, and an angiogram. Ultimately, the patient had a diagnostic laparoscopy with mobilization of the terminal ileum and right colon. The bowel was exteriorized and an intraoperative endoscopy was performed through a small bowel enterotomy. Multiple arteriovenous malformations (AVMs) were ascertained and resected. This case is presented in detail and the technique of intraoperative endscopy is reviewed. The diagnostic literature regarding AVMs is also reviewed.

Transcatheter treatment for lower gastrointestinal hemorrhage

Modern transcatheter embolization has emerged as a viable option for the treatment of lower gastrointestinal (LGI) hemorrhage. Over the last decade, steady data has accumulated showing the safety and effectiveness of superselective microcoil embolization within the colon. In light of such results, the application of microcatheter-based skills has become more important in an algorithm for managing LGI bleeding. The purpose of this article is to discuss the modern embolization technique while also reviewing traditional and experimental transcatheter methods that may prove useful in the appropriate clinical settings. While recognizing that transcatheter therapy continues to evolve, the proposed indications for these current treatments are reviewed.

The management of lower gastrointestinal hemorrhage

PURPOSE

Gastrointestinal hemorrhage is a common clinical problem, which accounts for approximately 1 to 2 percent of acute hospital admissions. The colon is responsible for approximately 87 to 95 percent of all cases of lower gastrointestinal bleeding, with the remaining cases arising in the small bowel. The etiology, diagnostic evaluation, management, and treatment options available for lower gastrointestinal hemorrhage were reviewed.

METHODS

A review of lower gastrointestinal bleeding was performed, which discussed the most common etiologies with a few rare and unusual causes. The current literature about different diagnostic techniques, management problems, and therapeutic options was reviewed. Current management strategies and treatment options for the many causes of lower gastrointestinal bleeding will be reviewed.

RESULTS

A review of the different causes of lower gastrointestinal hemorrhage and available diagnostic studies was performed. Management strategies based on the etiology of the bleeding and results of the diagnostic studies were discussed. An algorithm was provided to develop a diagnostic and therapeutic treatment strategy for lower gastrointestinal hemorrhage.

CONCLUSIONS

Lower gastrointestinal hemorrhage can be a difficult and frustrating problem to both the clinician and the patient. Knowledge of the available diagnostic tests to help identify the source of bleeding is essential to the practicing clinician. Once the source is identified, management strategies and available treatment options need to be specific for each individual case. This review will aid the practicing physician in developing an algorithm for lower gastrointestinal hemorrhage.

Acute gastrointestinal bleeding

Radionuclide bleeding scintigraphy remains a simple yet powerful method of localizing sites of gastrointestinal hemorrhage and is most commonly performed today using the red blood cell technique. Radionuclide techniques for detecting bleeding remain safe, sensitive, and noninvasive. Based on several simple concepts, including the use of cine-mode imaging over the abdomen, it is possible to achieve excellent accuracy in localizing the site of bleeding. Studies often contain additional ancillary information, which is helpful for diagnosis and patient treatment.

Nonlocalized lower gastrointestinal bleeding: provocative bleeding studies with intraarterial tPA, heparin, and tolazoline

PURPOSE

The purpose of this study was to assess the efficacy and safety of provocative mesenteric angiography with tissue plasminogen activator (tPA), heparin, and tolazoline in patients with nonlocalized lower gastrointestinal (LGI) bleeding. Results were examined to assess the clinical impact of the study on patients who had positive or negative results from elective provocative bleeding studies.

MATERIALS AND METHODS

Seventeen provocative bleeding studies for occult LGI bleeding were performed in 16 patients, nine of whom were women, aged 44-79 years. All patients had negative results from previous endoscopic and angiographic studies. Patients' requirements for blood transfusion ranged from 6 to 69 units. Studies were performed electively. Blood group matching and cross-matching were performed for all patients. To provoke bleeding, a combination of intravenous heparin, intraarterial tolazoline, and intraarterial tPA was used. Doses used included 3,000-10,000 U heparin, 25-100 mg intraarterial tolazoline, and 10-50 mg intraarterial tPA (mean, 20.3 mg). Duration of follow-up was 3-34 months.

RESULTS

Seventeen elective provocative studies were performed in 16 patients with occult LGI bleeding, leading to provoked bleeding in six patients (37.5%). In addition, two previously undiagnosed vascular abnormalities were diagnosed, which did not bleed during provocation. Therefore, an abnormality was identified in eight of 16 patients (50%) overall. There were no procedural complications encountered during or after any of the 17 procedures. In six patients in whom bleeding was successfully provoked, four bleeding episodes occurred in the large bowel and two occurred in the small bowel. Five of the positively provoked patients had a previously positive tagged red cell scintigraphic study. Three patients had superselective embolization at the time of provoked bleeding. Two were treated with estrogen therapy, and one patient was treated palliatively. Five of these six patients required no further therapy for LGI bleeding. Ten patients (including two with vascular abnormalities) did not bleed during the provoked study with tPA. Follow-up of the group of eight patients with completely normal study results ranged from 3 to 34 months in duration, and during the follow-up period, five patients experienced repeated bleeding and one had no further bleeding. One patient was diagnosed with an ileal vascular lesion during subsequent intraoperative enteroscopy and underwent surgical resection. One patient was lost to follow-up.

CONCLUSION

Intraarterial provocative mesenteric angiography with heparin, vasodilator, and tPA identified the site of bleeding in 37.5% of patients in our study group and contributed to treatment in 50%. This small study indicates that the procedure appears to be safe, with no complications encountered in this series. Larger prospective studies are needed to fully assess the safety and efficacy of the technique and to optimize the pharmacologic protocol and patient selection.

Obscure digestive bleeding

Obscure digestive bleeding is defined as recurrent bleeding for which no definite source has been identified by routine endoscopic or barium studies. Mucosal vascular abnormality or 'angioectasia' is the most common course of obscure bleeding, especially in elderly patients. Small bowel tumours are more frequent in patients younger than 50 years. However, missed or underestimated upper and lower gastrointestinal lesions at the initial endoscopic investigation may be the source of a so-called obscure intestinal bleeding. The various radiological procedures, including enteroclysis, visceral angiography and CT scan as well as radioisotope bleeding scans have limitations in the case of obscure gastrointestinal bleeding. Recent developments in magnetic resonance imaging are promising. The different methods of enteroscopy have a similar diagnostic yield, reaching approximately 40-65%. Endoscopic cauterization of small bowel angioectasias seems to be efficacious but randomized trials are needed. Efficacy of hormonal therapy is very controversial. The extent of diagnostic and therapeutic strategies must be based on a number of factors including the patient's parameters, bleeding characteristics and also the result of previous work-up.

Initial failure of angiography to demonstrate a bleeding pancreatic cancer: a case for provocative agents

BACKGROUND

Mesenteric angiography is commonly employed in the modern-day investigation of gastro-intestinal bleeding if the bleeding sites cannot be identified by endoscopic means. Angiography is optimally sensitive in the presence of active bleeding. However, vasospasm may occasionally account for a negative study shortly after bleeding.

CASE OUTLINE

A 70-year-old lady with inoperable carcinoma of the pancreas presented with gastro-intestinal bleeding. Although upper endoscopy visualised active bleeding from the tumour, which had invaded into the duodenum, haemostasis could not be achieved endoscopically. Therefore, mesenteric angiography was arranged.

RESULTS

The initial angiography failed to demonstrate the bleeding site, which only became obvious on a repeat study, when embolisation was performed to achieve haemostasis.

DISCUSSION

Vasospasm probably accounted for the initial negative study, as the second angiography was able to demonstrate contrast extravasation without the use of any anticoagulant or thrombolytic agent. It is not our routine to give pharmacological agents to provoke bleeding after a negative angiography, but for selected patients this manoeuvre may turn out to be more cost-effective.

Provocative angiography in patients with gastrointestinal hemorrhage of obscure origin

OBJECTIVE

A standard diagnostic evaluation including upper and/or lower endoscopy, tagged red blood cell scintigraphy, and visceral angiography identifies the source of GI bleeding in the majority of patients who present with acute GI hemorrhage. However, in a small group of patients the source of bleeding remains obscure; this form of GI hemorrhage is uncommon but represents a considerable diagnostic challenge. Some investigators have advocated provocation of bleeding with vasodilators, anticoagulants, and/or thrombolytics in association with tagged red blood cell scans or angiography. Unfortunately, the available literature on this topic is limited. Therefore, the purpose of this study is to report our experience with provocative GI bleeding studies.

METHODS

The radiology databases at Duke University Medical Center and the Durham Veterans Administration Medical Center were reviewed from 1994 to 1999. Any patient who received a vasodilator, anticoagulant, or thrombolytic to induce bleeding during a tagged red blood cell scan or visceral angiogram was included.

RESULTS

Seven provocative bleeding studies were performed on seven patients. All patients underwent a visceral angiogram with intra-arterial administration of tolazoline (a vasodilator), heparin (an anticoagulant), and/or urokinase (a thrombolytic). Of the seven provocative studies, only two induced angiographically identifiable bleeding. Both of these patients underwent surgical therapy. There were no complications attributed to the provocative bleeding studies.

CONCLUSIONS

These results suggest that provocative GI bleeding studies can be performed safely. However, because an active bleeding source was identified in only a small proportion of patients, we believe that further study is required to optimize patient selection and to clarify the cost-effectiveness of this approach in patients with GI hemorrhage of obscure origin.

Diagnosis and management of lower gastrointestinal bleeding

There are few randomized, prospective trials evaluating the optimal diagnostic and therapeutic strategies in the management of lower gastrointestinal bleeding. However, recent data suggest that urgent colonoscopy represents a safe and effective initial diagnostic approach. The role of tagged erythrocyte scintigraphy is yet to be defined, but it may be of utility as a screening test for visceral angiography. Colonoscopy and angiography both offer substantial therapeutic options but remain of unproved benefit from a treatment standpoint; surgery continues to play an important role in the management of lower gastrointestinal bleeding. Obscure gastrointestinal bleeding, which often presents as lower gastrointestinal bleeding, continues to be one of the most challenging diagnostic and therapeutic problems in gastroenterology. Occult gastrointestinal bleeding, often arising from the lower gastrointestinal tract, usually mandates gastrointestinal evaluation.

Detection of bleeding due to small bowel cholesterol emboli using helical CT examination in gastrointestinal bleeding of obscure origin

Chronic, intermittent GI bleeding is defined as obscure when routine diagnostic examinations of the GI tract, including barium and endoscopic studies, fail to reveal the cause of bleeding. Our patient had significant bleeding and extensive evaluation including upper endoscopy, small bowel enteroscopy, enteroclysis, colonoscopy, and provocative angiography with urokinase, without the source of bleeding detected. This report describes a noninvasive novel approach using helical CT scanning with water as oral contrast and rapid injection of intravenous iodinated contrast material and thin slices obtained to diagnose the site of recurrent, obscure GI bleeding related to cholesterol crystal embolization to the small intestine.