Octreotide lowers gastric mucosal blood flow in normal and portal hypertensive stomachs

Bevacizumab in combination with octreotide rescues a patient with liver cirrhosis, GAVE syndrome and refractory hemorrhage - a case report

Gastric antral vascular ectasia (GAVE) syndrome is a rare but often challenging etiology of upper gastrointestinal bleeding (UGIB).We report on a 60-year-old patient with liver cirrhosis, GAVE syndrome and recurrent and refractory GAVE-related UGIB. During a 5-month hospital stay, the patient required a total of 82 packed red blood cells (pRBCs) and 23 gastroscopies. All endoscopic approaches, including multiple argon plasma coagulation and band ligation sessions, remained unsuccessful. Antrectomy was waived because of the high perioperative mortality risk in Child-Pugh B liver cirrhosis. TIPS insertion also failed to control the bleeding. Only continuous intravenous octreotide infusion slowed the bleeding, but this forced the patient to be hospitalized. After 144 inpatient days, administration of subcutaneous octreotide allowed the patient to be discharged. However, the patient continued to require two pRBCs every 2-3 weeks. Based on recently published data, we treated the patient with bevacizumab (anti-VEGF antibody) off-label at a dose of 7.5 mg/kg body weight every three weeks in nine single doses over six months. Since the first administration, the patient has remained transfusion-free, has not required hospitalization, and leads an active life, working full-time. He remains on octreotide, which has been reduced but not yet discontinued. Additionally, no adverse events were observed.Thus, in patients with liver cirrhosis and refractory GAVE-related hemorrhage, bevacizumab combined with subcutaneous octreotide should be considered as an effective and durable pharmacological treatment option.

Pharmacotherapy for the Treatment of Gastric Antral Vascular Ectasia: A Narrative Review

Gastric antral vascular ectasia (GAVE) is an uncommon clinical entity leading to recurrent gastrointestinal bleeding. There is no consensus regarding treatment of GAVE. Endoscopic therapy is the preferred treatment option, but has a fairly high recurrence rate. Surgical resection can completely resolve GAVE, but is invasive with a relatively high risk of postoperative complications. Recently, the role of pharmacotherapy for GAVE has been recognized. However, the evidence is limited to scattered case reports or small case series. This review comprehensively summarizes the efficacy and side effects of drugs commonly used for the treatment of GAVE, including octreotide, cyproheptadine, cyclophosphamide, prednisolone, estrogen-progesterone, thalidomide, bevacizumab, and tranexamic acid.

Clinical treatment strategy for post pancreatectomy hemorrhage

Hemorrhage is the most serious complication after pancreatic surgery and is also the main cause of clinical death. With the progress of surgical methods and the rapid development of minimally invasive techniques, surgeons have more technical means to deal with postoperative hemorrhage. It is still inconsistent in terms of taking effective therapeutic measures according to different causes of bleeding. And this has long plagued every pancreatic surgeon. This article reviews the location, causes, preventive measures, and treatment of hemorrhage after pancreatectomy, in order to provide some guidance to clinicians.

Role of splanchnic constriction in governing the hemodynamic responses to gravitational stress in conscious dogs

Octreotide is a somatostatin analog that constricts the splanchnic circulation, thereby improving orthostatic tolerance. We tested the hypotheses that octreotide improves orthostatic tolerance by 1)increasing cardiac filling (right atrial) pressure via reductions in vascular capacity; 2) by causing an upward (i.e., cranial) shift of the hydrostatic indifferent point; and 3) by increasing arterial pressure via a reduction in total vascular conductance. Studies were carried out in acepromazine-sedated, hexamethonium-treated atrioventricular-blocked conscious dogs lightly restrained in lateral recumbency. Beat-by-beat cardiac output was held constant via computer-controlled ventricular pacing at rest and during 30 s of 30° head-up tilt. Octreotide (1.5 μg/kg iv) raised right atrial pressure by 0.5 mmHg and raised mean arterial pressure by 11 mmHg by reducing total vascular conductance (all P < 0.05). Right atrial pressure fell by a similar amount in response to tilting before and after octreotide, thus there was no difference in location of the hydrostatic indifferent point. These data indicate that octreotide improves orthostatic tolerance by decreasing total vascular conductance and by increasing cardiac filling pressure via a reduction in unstressed vascular volume and not by eliciting a cranial shift of the location of the hydrostatic indifferent point.

Assessment of splanchnic blood flow using magnetic resonance imaging

BACKGROUND AND AIMS

The splanchnic circulation has an important function in the body under both physiological and pathophysiological conditions. Despite its importance, no reliable noninvasive procedures for estimating splanchnic circulation have been established. The aim of this study was to evaluate MRI as a tool for assessing intra-abdominal blood flows of the aorta, portal vein (VPO) and the major intestinal and hepatic vessels.

METHODS

In nine healthy volunteers, the proximal aorta (AOP) and distal abdominal aorta (AOD), superior mesenteric artery (SAM), celiac trunk (CTR), hepatic arteries (common and proper hepatic arteries, AHC and AHP, respectively), and VPO were localized on contrast-enhanced magnetic resonance angiography images. Volumetric flow was measured using a two-dimensional cine echocardiogram-gated phase contrast technique. Measurements were taken before and 30 min after continuous intravenous infusion of somatostatin (250 microg/h) and were independently evaluated by two investigators.

RESULTS

Blood flow measured by MRI in the VPO, SAM, AOP, AHP, and CTR significantly decreased after drug infusion. Flows in the AOD and AHC showed a tendency to decrease (P>0.05). Interrater agreement on flows in MRI was very good for large vessels (VPO, AOP, and AOD), with a concordance correlation coefficient of 0.94, as well as for smaller vessels such as the CTR, AHC, AHP, and SAM (concordance correlation coefficient =0.78).

CONCLUSION

Somatostatin-induced blood flow changes in the splanchnic region were reliably detected by MRI. MRI may be useful for the noninvasive assessment of blood flow changes in the splanchnic region.

Mucosal blood flow measurements using laser Doppler perfusion monitoring

Perfusion of individual tissues is a basic physiological process that is necessary to sustain oxygenation and nutrition at a cellular level. Ischemia, or the insufficiency of perfusion, is a common mechanism for tissue death or degeneration, and at a lower threshold, a mechanism for the generation of sensory signalling including pain. It is of considerable interest to study perfusion of peripheral abdominal tissues in a variety of circumstances. Microvascular disease of the abdominal organs has been implicated in the pathogenesis of a variety of disorders, including peptic ulcer disease, inflammatory bowel disease and chest pain. The basic principle of laser Doppler perfusion monitoring (LDPM) is to analyze changes in the spectrum of light reflected from tissues as a response to a beam of monochromatic laser light emitted. It reflects the total local microcirculatory blood perfusion, including perfusion in capillaries, arterioles, venules and shunts. During the last 20-25 years, numerous studies have been performed in different parts of the gastrointestinal (GI) tract using LDPM. In recent years we have developed a multi-modal catheter device which includes a laser Doppler probe, with the intent primarily to investigate patients suffering from functional chest pain of presumed oesophageal origin. Preliminary studies show the feasibility of incorporating LDPM into such catheters for performing physiological studies in the GI tract. LDPM has emerged as a research and clinical tool in preference to other methods; but, it is important to be aware of its limitations and account for them when reporting results.

Pro/con debate: octreotide has an important role in the treatment of gastrointestinal bleeding of unknown origin?

Whether it is the primary reason for admission or a complication of critical illness, upper gastrointestinal bleeding is commonly encountered in the intensive care unit. In this setting, in the absence of endoscopy, intensivists generally provide supportive care (transfusion of blood products) and acid suppression (such as proton pump inhibitors). More recently, octreotide (a somatostatin analogue) has been used in such patients. However, its precise role in patients with upper gastrointestinal bleeding is not necessarily clear and the drug is associated with significant costs. In this issue of Critical Care, two expert teams debate the merits of using octreotide in non-variceal upper gastrointestinal bleeding.