Celiac-mesenteric insufficiency. Apropos of a case of aorto-hepatic bypass

The Authors report a case of coeliac axis atheromatous obstruction, with superior mesenteric artery steal. The coeliac axis, stopped up the origin was indirectly revascularized by hepatic artery. The early diagnosis of chronic intestinal ischaemia should avoid the intestinal infarction. The development of intravenous digital angiography will certainly help an early diagnosis.     

Mesenteric ischemia

Mesenteric ischemia secondary to vascular disease remains a significant problem in patients presenting with acute abdominal conditions, especially if they are elderly. Although rare, it is nevertheless an important and perhaps increasing cause of death or significant morbidity. Occasionally, it may be a mode of dying, but more often, it is the reason for death. Individual cases can manifest an almost overwhelming spectrum from chronic to acute, mild to catastrophic, arterial to venous, occlusive to hemodynamic, extensive to limited, or precisely diagnosed to accidentally found. Treatment principles are well defined, but continued refinement of supportive therapies of several types is occurring. In contrast, improved screening tests that can lead to early specific etiologic diagnosis remain at the experimental stage. Thus, good "clinical suspicion" is foremost and essential.     

缺血预处理对肺缺血再灌注损伤的影响

目的观察缺血预处理（ＩＰＣ）对肺缺血再灌注（Ｉ／Ｒ）损伤的影响。方法建立兔单肺原位热缺血再灌注损伤模型。３０只兔分Ｉ／Ｒ组、ＩＰＣ组和对照组。对比观察各组平均动脉压、动脉血氧分压、肺组织１２５Ｉ标记牛血清白蛋白漏出量、肺湿干重比、髓过氧化物酶活性。结果经９０分钟缺血１８０分钟再灌注后,ＩＰＣ组肺组织１２５Ｉ标记牛血清白蛋白漏出量、肺湿干重比、髓过氧化物酶活性低于Ｉ／Ｒ组（Ｐ＜０．０５）,平均动脉压、动脉血氧分压高于Ｉ／Ｒ组（Ｐ＜０．０５）。结论ＩＰＣ能减轻肺Ｉ／Ｒ导致的肺毛细血管通透性增高、中性粒细胞浸润,减轻肺Ｉ／Ｒ引起的平均动脉压和动脉血氧分压的下降程度,表明ＩＰＣ能减轻肺Ｉ／Ｒ损伤。     

Chronic mesenteric ischemia

Although chronic mesenteric ischemia is an infrequent, even rare, condition and a busy vascular surgeon may encounter only one such patient in a year, the associated morbidity and mortality are high, especially if the condition is not recognized. General and vascular surgeons must bear in mind the triad of postprandial pain, weight loss and diarrhea. Patients with mesenteric ischemia are at high risk and generally have diffuse peripheral vascular disease. Although surgery is hazardous, successful repair can result in long-term survival without morbidity. The author favours antegrade supraceliac bypass grafting over infrarenal grafting which is technically more difficult.     

Acute mesenteric ischemia

Acute mesenteric ischemia is not an isolated clinical entity, but a complex of diseases, including acute mesenteric arterial embolus and thrombus, mesenteric venous thrombus, and nonocclusive mesenteric ischemia. These diseases have common clinical features caused by impaired blood perfusion to the intestine, bacterial translocation, and systemic inflammatory response syndrome. There is substantial evidence that the mortality associated with acute mesenteric ischemia varies according to its trigger cause. Nonocclusive mesenteric ischemia is the most lethal form of the acute mesenteric ischemia, because of the poor understanding of its pathophysiology and its mild and nonspecific symptoms, which often delay its diagnosis. Mesenteric venous thrombosis is much less lethal than acute thromboembolism of the superior mesenteric artery and nonocclusive mesenteric ischemia. In this articles we presents an overview of acute mesenteric ischemia, based on the research. Although the mortality rates, in acute mesenteric ischemia, have remained high over the last few decades, accumulated knowledge on this condition is expected to improve its prognosis.     

Acute limb ischemia

Although there is little information on the incidence of acute limb ischemia (ALI) in the general population, it is estimated to be 14 per 100,000 and to compose 10% to 16% of the vascular workload. Also, as surgical intervention has become an option for ALI, the numbers actually referred appear to be increasing. The two main causes of ALI are either an embolism or a thrombosis, and differentiation based on history and clinical examination alone may be clinically impossible in 10% to 15% of cases. However, with the advent of thrombolysis, the distinction between emboli and thrombotic occlusions has become less important from the point of view of management. The natural history of ALI has remained largely unchanged despite the advent of the Fogarty catheter and thrombolysis. Patients presenting with ALI continue to have a particularly severe short-term outlook both in terms of loss of the leg and mortality, with 30-day amputation rates of between 10% and 30% and a mortality rate of around 15%. A patient with an embolic cause for an ischemic leg is at a higher risk of death because of the associated underlying cardiac disease, whereas patients with a thrombotic cause are more likely to lose a limb. The fact that overall mortality rates after intervention for acute ischemia have not improved dramatically over the past 20 years no doubt reflects the severity of the underlying diseases in these high-risk patients.     

Platelet-mediated cardiac ischemia

Although platelets have been associated with angina pectoris, myocardial infarction, and sudden death, the platelet's capacity for induction and propagation of cardiac ischemia remains incompletely defined. We therefore evaluated the effects of platelet activation occurring within the coronary circulation and tested the hypothesis that inhibition of platelet function would prevent platelet-induced cardiac ischemia. Human platelets were isolated from blood obtained from normal donors by Sepharose 2B column chromatography, resuspended in Hepes buffer, and added to the perfusate of a Langendorff rabbit heart (platelet counts > 10,000/μl). Without, and with low dose (10 μM) prostaglandin E₁ (PGE₁), a reversible inhibitor of platelet function, immediate and irreversible global cardiac ischemia, as monitored by NADH fluorescent photography, ensued (N = 4) following platelet activation with thrombin (0.1 to 1 U/ml). Higher concentrations of PGE₁ (0.1 to 1 mM, N = 2) or aspirin ingestion (1000 mg taken approximately 12, 4, and 1 hr prior to experiment, N = 2) completely prevented this platelet-induced myocardial ischemia. Aspirin, unlike PGE₁, was effective despite its inability to block thrombin-induced platelet aggregation in our in vitro gel-filtered system. We conclude that activation of platelets within the coronary circulation is sufficient for induction of irreversible cardiac ischemia. The efficacy of aspirin, a cyclooxygenase inhibitor, further suggests that the products of arachidonate metabolism (e.g., thromboxanes) have a fundamental role in the genesis of platelet-mediated myocardial ischemia.     

Colonic ischemia.

Our understanding of ischemia and the importance of this disease in the elderly have increased dramatically over the past 30 years. Moreover, the number of patients found to have colonic ischemia can be expected to increase over the next several decades as that portion of our population older than 65 years grows and the many forms of ischemic injury to the colon are better appreciated. Earlier diagnosis should follow the wider use of colonoscopy, and recognition of the ischemic nature of the varied disease manifestations and identification of patients at high risk for this disease should result in better management.