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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Much of the morbidity and mortality in sickle cell disease (SCD) is caused by tissue ischemia and infarction resulting from vascular occlusion. Research in this area has been dominated by the hypothesis that vascular occlusion in SCD is due primarily to microvascular obstruction by sickle erythrocytes (SS RBC), yet there is no direct evidence that microvascular occlusion is responsible for any of the vasocclusive complications of SCD. In this paper an alternate hypothesis is proposed: that thrombotic occlusion of larger arteries and veins is an important factor in many of the vasocclusive complications of SCD. Large-vessel cerebral arterial disease (intimal hyperplasia with superimposed thrombosis) has clearly been established as the most important cause of stroke in SCD, and considerable evidence suggests that pulmonary arterial thrombosis/embolism is a major cause of pulmonary infarction and hypertension. The involvement of large-vessel thrombosis in painful crisis, aseptic necrosis of bone, priapism, leg ulcers, retinopathy, and miscarriage has not been adequately investigated. Large-vessel occlusion in SCD is probably a consequence of the abnormal adhesive and procoagulant properties of SS RBC, which produce endothelial damage, secondary intimal proliferation, and thrombosis. Techniques currently used to treat large-vessel occlusion in other disorders (antiplatelet and anticoagulant agents, thrombolytic therapy, angioplasty, endarterectomy, and vascular bypass surgery) should be considered in sickle cell subjects with large-vessel occlusion, especially in the cerebral vasculature.
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PMID:Large-vessel occlusion in sickle cell disease: pathogenesis, clinical consequences, and therapeutic implications. 189 Sep 82

Veno-occlusive priapism may be associated with prolonged corporeal ischemia, subsequent fibrosis of the corpora and impotence. We report on 6 patients who presented with an unusual sequela of veno-occlusive priapism, recurrent episodes of prolonged erections or priapism. In all cases the subsequent episodes were idiopathic and veno-occlusive, occurred with a frequency ranging from several times per day to once per month and were symptomatically disabling. Pharmacocavernosometry ruled out mechanical occlusion of corporeal venous drainage by demonstrating elevated flows to maintain intracavernosal pressures following smooth muscle contraction and markedly decreased flow rates following smooth muscle relaxation. Treatment of the recurrent episodes with intracavernous self-injection of phenylephrine resulted in successful detumescence. The use of oral phenylpropanolamine reduced the frequency and duration of the recurrences, and markedly reduced the need for adrenergic self-injection. It is proposed that this syndrome may develop secondary to the initial ischemic episode, resulting in a functional alteration of the adrenergic and/or endothelial-mediated mechanisms that control penile tumescence and maintain penile flaccidity.
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PMID:Recurrent prolonged erections and priapism as a sequela of priapism: pathophysiology and management. 200 96

The frequency of the iatrogenic priapism complicating the intracavernous injections of drugs for impotence has greatly improved the conceptions about priapism resulting in several novelties: a. definition: priapism may be defined as a pathological erection provoked by various anomalies of the erectile hemodynamics; a. pathogeny: at first, priapism is only the penile symptom of various diseases. Secondary and inconstantly, the priapism symptom become a priapism disease featured by an acute cavernous ischemia; c. physiopathology with two different priapisms: an unusual high flow priapism due to an acquired arteriocavernous fistula. A most usual stasis priapism due to a neuromuscular or hematological blockade of the cavernous detumescence of several origin; d. treatment: the stasis priapism alone is an genuine emergency. Puncture must be always the first treatment. If unsuccessful, the choice between pharmacological detumescence (new treatment for priapism) and surgery depends from both the physiopathological mechanisms and mainly the severity of the cavernous tissular suffering.
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PMID:[Physiopathologic aspects of priapism. Disease or symptom?]. 218 30

Two forms of priapism are known to occur. The more common type, veno-occlusive priapism, presents with a prolonged painful erection, and it is characterized by ischemia and pooling of blood within the corpora cavernosa. The less common form, high flow priapism, is characterized by lack of pain and ischemia. The pathophysiology of this disorder is poorly understood and the treatment is unclear. We report 2 cases of nonischemic priapism, one of which occurred after blunt perineal trauma and the other after intracavernosal self-injection with papaverine and phentolamine. Based on our 2 cases as well as a review of the literature (5 cases), we propose that the pathophysiological mechanism of this disorder is unregulated arterial inflow into the corpora, classify it as arterial priapism, and describe a diagnostic and therapeutic algorithm for its management.
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PMID:Traumatic laceration of intracavernosal arteries: the pathophysiology of nonischemic, high flow, arterial priapism. 229 41

Renal vein thrombosis in early infancy is a complication of dehydration and prolonged hypotension. The onset is usually acute and the most common clinical signs are uni- or bilateral frank masses, hematuria, proteinuria and thrombocytopenia. In most cases, with conservative management, the late outcome is favorable. In the adult, renal vein thrombosis is often a silent complication of the nephrotic syndrome, the hypercoagulability of which may be an important factor in the pathogenesis of the thrombosis. Clinically, the presentation of a sudden complete occlusion is that of severe abdominal and lumbar pain with hematuria and loss of function of the kidney that suffers hemorrhagic infarction. Physical examination often reveals an enlarged kidney. With gradual occlusion, renal function is preserved. The initial diagnostic approach is with ultrasound studies and computed tomography; definitive diagnosis is established by renal venography or by selective renal arteriography. In general, a conservative approach including the use of anticoagulant treatment is preferred to surgical intervention. Priapism is a persistent painful penile erection due to ischemic or non-ischemic causes; therapeutic intracavernosal injection of papaverine is becoming the most common cause. In early and mild stages, aspiration of blood from the corpora cavernosa supplemented with intracavernosal irrigation with alpha-stimulating agents is the procedure of first choice; in late and severe ischemia, a shunt procedure may become necessary. Hepatic vein thrombosis occurs in association with a number of conditions considered predisposing factors including the use of oral contraceptives. The clinical picture may be that of an acute illness with abdominal pain, hepatomegaly, ascites and hepatic failure as well as early death. More often, the onset is insidious with slowly developing ascites and wasting. For the diagnosis, hepatic scintigraphy may be helpful but, at present, ultrasonography, computed tomography and magnetic resonance scanning are procedures of choice. There is, as yet, no adequate treatment. A fatal outcome may be prevented by surgical decompression of the congested liver and, in recent years, liver transplantation has been employed. Portal vein thrombosis, in children, is usually considered a complication of umbilical sepsis or a result of a congenital abnormality of the portal vein. In adults, the most frequent causes are hepatic cirrhosis and neoplasia. Clinically, there may be a sudden appearance of ascites with resolution in a symptom-free interval until the onset of other features of portal hypertension occur. Currently, ultrasound real-time imaging supplemented with Doppler capability, computed tomography and magnetic resonance scanning provide the necessary diagnostic information. Variceal hemorrhage is often the first major complication requiring treatment.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Thrombosis in particular organ veins. 268 Aug 53

The recent introduction of intracorporeal injections of papaverine and phentolamine for the diagnosis and treatment of impotence has resulted in an increased incidence of iatrogenic priapism. Based on our research into penile hemodynamics we propose a refined approach to all types of priapism. Intracorporeal blood gas and pressure monitoring should be used to differentiate ischemic (low flow) from nonischemic (high flow) types. Most cases of papaverine-induced or phentolamine-induced priapism will respond to aspiration alone or in combination with intracorporeal instillation of a diluted alpha-adrenergic agent. In spontaneous priapism alpha-adrenergic agents can be tried first if patients have only mild or no ischemia. In patients with severe ischemia stagnant blood should be evacuated and a shunt procedure should be performed to allow metabolic replenishment of tissue. Intracorporeal pressure monitoring will help to determine the size and number of shunts needed to re-establish corporeal circulation.
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PMID:Priapism: a refined approach to diagnosis and treatment. 371 92

Of 239 patients with erectile dysfunction (aged 36 to 70 years) who were evaluated with dynamic infusion cavernosometry-cavernosography, 32 (13.4%) developed priapism after the procedure and were successfully managed with immediate intracorporal injection of phenylephrine. No single risk factor for the development of priapism was identified in this group. Early pharmacologic intervention for priapism induced by dynamic infusion cavernosometry-cavernosography is a simple, safe, and time-saving measure to achieve detumescence and prevent potential sequelae such as corporal ischemia or fibrosis.
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PMID:Incidence and simple management of priapism following dynamic infusion cavernosometry-cavernosography. 823 80

This study is a prospective multicenter cooperative survey of the evaluation and treatment of erectile dysfunction in men with spinal cord injury (SCI). Uniform database questionnaires were completed prospectively by patients seeking therapy for erectile dysfunction. Eighty-five SCI men aged 17-68 years (mean age = 26 +/- 17) were enrolled. Mean duration of traumatic SCI was 3 +/- 3.2 years (Range = 0.3-18 years). The level of injury was cervical in 20 patients, thoracic in 31, lumbar in 29 and sacral in five. Patients were fully evaluated and then counseled as to their therapeutic options. Twenty-eight chose to use a vacuum erection device (VED), 26 preferred pharmacological penile injection and five used both intracorporeal therapy and VED. The remainder were managed with marriage and sexual counseling in 10 patients, three underwent penile prosthesis placement and two used topical pharmacotherapy. Four patients used other forms of treatment and in nine no therapy was recommended. Of the patients that used pharmacologic injection only, 74 percent used papaverine as a single agent, 20 percent used papaverine with phentolamine, five percent used prostaglandin E (PGE1) alone and one percent used a mixture. Patients using injection therapy report sexual intercourse a mean of 3 +/- 3.4 times per month as compared with 5 +/- 3.2 times per month in those using VED. Five intracorporeal injection patients developed priapism while two patients using the VED developed subcutaneous bleeding and one developed penile ischemia. We conclude that although a spectrum of erectile dysfunction treatment is present among SCI centers, VED and pharmacological penile injection are by far the two most popular methods of treatment and papaverine is the most common drug. The incidence of complications is small in the model centers.
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PMID:Epidemiology of current treatment for sexual dysfunction in spinal cord injured men in the USA model spinal cord injury centers. 881 27

Priapism is a condition of prolonged penile erection which often causes pain and is unrelated to sexual desire. There is a high risk of impotence despite immediate intervention. The incidence has doubled since the introduction of intracorporeal injection therapy for impotence. Two subtypes of priapism have been described, depending on the underlying cause. The more common type, termed low flow, is characterised by inadequate venous outflow, leading to a hypoxic painful prolonged erection. The etiology is either idiopathic or related to intracorporeal injection therapy. Treatment consists of aspiration and instillation of a diluted alpha-adrenergic agent, or surgery, depending on the degree of hypoxia. The less common subtype, high flow, is arteriogenic, and causes less pain and no ischemia. Injury to a cavernous artery leads to a fistula between the artery and the corpora cavernosa. Treatment is either conservative with immediate ice pack and compression, or delayed selective embolization of the fistula.
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PMID:[Priapism. Etiology, diagnosis and treatment]. 901 77

Priapism is a prolonged, painful, penile erection that fails to subside despite orgasm. An erection lasting longer than 4-6 h is considered to be priapic; nevertheless, pain does not usually ensue until 6-8 h have elapsed. Priapism is considered a failure of the detumescence mechanism, which may be due to excess release of contractile neurotransmitters, obstruction of draining venules, malfunction of the intrinsic detumescence mechanism, or prolonged relaxation of intracavernosal smooth muscle. There are essentially two main types of priapism: high flow (non-ischemic) and low flow (ischemic). Low flow priapism is the more common form, and it is associated with a decrease in venous outflow and vascular stasis that, in turn, cause tissue hypoxia and acidosis. This form of priapism is usually quite painful because of tissue ischemia. Penile blood aspirated from cavernous spaces appears dark in color. Immediate treatment is necessary or penile fibrosis will ensue. High flow priapism is usually due to trauma, although, on rare occasions it has been idiopathic or due to sickle cell disease. The hallmark of this type of priapism is an increase in arterial inflow in the setting of normal venous outflow. Aspirated penile blood is noted to be bright red and has a high pO(2). This form of priapism is not usually painful because it is non-ischemic. Treatment is dependent on the wishes of the patient but is not mandatory. International Journal of Impotence Research (2000) 12, Suppl 4, S133-S139.
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PMID:Priapism. 1103 1


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