Multilevel occlusive vascular disease presenting with gangrene

The medical records of all patients subjected to lower extremity amputations during a 3-year period were reviewed. It was shown that advanced age and the presence of multiple medical problems do not predispose to higher levels of limb loss. Although diabetic patients more frequently undergo amputation because of sepsis than their nondiabetic counterparts, the diabetic state was not found to be associated with a greater likelihood of above knee (AK) procedures. Prior arterial surgery was not shown to make AK amputation more likely, but it was disconcerting to note that limb salvage was not achieved in many individuals despite patent proximal inflow revascularization procedures. This initial study showed that several presumed risk factors were not predictors of amputation level. Those patients requiring AK amputations had a greater frequency of combined segment (aortoiliac and femoropopliteal) occlusive disease than those who had successful amputations at more distal levels. A follow-up study of 41 consecutive patients presenting with tissue loss due to combined segment occlusive disease was performed. Eighteen (Group I) underwent inflow procedures only, while 23 (Group II) also underwent distal revascularization. The groups were similar with respect to age, risk factors, extent of tissue loss and sepsis. At 1 year 10 (56%) Group I and only 3 (13%) Group II patients required major amputation (P = 0.01). Distal bypass, in addition to an inflow procedure, is recommended for those who present with tissue loss due to multilevel arterial occlusion.     

Carotid occlusive disease: an electrophysiological macular investigation

Thirteen patients with carotid stenosis were studied by the authors by the measuring the Visual Evoked Potentials (VEPs) before and after thromboendarterectomy. This test of retinal function measures the recovery time of the amplitude of the major positive peak (P100) after photostress. When compared to that we observed in controls, we found, a significant increase of the P100 recovery time in patients suffering from carotid disease with severe stenosis. The method proved suitable for the functional evaluation of the vascular reconstruction of the carotid area, since four weeks after surgery a physiological recovery of the amplitude of VEP was observed. This method is proposed by the authors for the long-term functional evaluation of patients subjected to carotid thromboendarterectomy for tight stenosis of the carotid bifurcation.     

颈动脉内膜剥脱术治疗动脉粥样硬化性颈内动脉闭塞症

目的 探讨颈动脉内膜剥脱术治疗颈内动脉闭塞症的疗效.方法 回顾分析2004年6月至2005年10月手术治疗的32例动脉粥样硬化性颈内动脉闭塞症的临床资料,探讨外科治疗适应证、手术要点和围手术期并发症的预防.所有患者明确颈内动脉狭窄率＞70%,术中放置颈动脉转流管和选择性应用补片修补成形,围手术期给予抗血小板药物和降纤药物治疗,双功DUPLEX超声随访.结果 本组无围手术期死亡及脑梗塞等严重合并症发生,1例患者术后出现右侧舌下神经损伤表现.术后随访5～20个月.随访期间患者无脑梗塞发生,双功DUPLEX超声检查提示颈内动脉通畅,未发现≥50%的颈内动脉术后再狭窄,2例患者发现≥50%颈内动脉扩张.结论 颈动脉内膜剥脱术是治疗动脉粥样硬化性颈内动脉闭塞症的有效而安全的手术.术中精细操作,合理应用转流管、补片,以及合理的血管开放顺序是预防围手术期并发症的关键.     

Carotid plaque morphology correlates with presenting symptomatology

Purpose: In carotid artery disease, correlation of carotid plaque morphology with the patient's presenting symptoms has drawn conflicting conclusions. The purpose of this series was to correlate carotid plaque characteristics with the presenting symptoms from a large cohort of patients who underwent operation for carotid artery disease. Methods: From a series of 1252 consecutive patients who underwent carotid endarterectomy, presenting symptoms were divided into three groups: transiently symptomatic (transient ischemic attack [TIA] or amaurosis fugax), prior stroke, and asymptomatic. Plaque characteristics, including ulceration, intraplaque hemorrhage, and degree of stenosis, were recorded prospectively for 1008 procedures. All endarterectomy specimens were inspected during the procedure, and plaque characteristics were recorded immediately after operation. Results: There was a higher incidence of plaque ulceration in the transiently symptomatic and prior stroke groups (391 of 508 [77%] and 91 of 115 [79%]) than in the asymptomatic cohort (231 of 385 [60%]; p< 0.0001, χ² test). There was no significant difference in the incidence of plaque hemorrhage between the transiently symptomatic and prior stroke patients compared with the asymptomatic patients. There was no statistical difference for ulcerated plaque or plaque hemorrhage between the transiently symptomatic and prior stroke groups. Intraplaque hemorrhage occurred more frequently in patients with high-grade stenosis (90% to 99%) than in those with less than 90% stenosis (202 of 299 [68%] versus 97 of 299 [32%]; p = 0.01, χ² test). Conclusions: On gross examination of the carotid specimen in the operating room, plaque ulceration correlates with an initial presentation of amaurosis fugax, TIA, or prior stroke compared with patients operated on for asymptomatic disease. The presence of intraplaque hemorrhage is associated with more advanced stenosis of the internal carotid artery. These findings suggest that plaque morphology does play an important role in the presentation of carotid artery disease. (J Vasc Surg 1998;27:872-9.)     

Aortic-iliac occlusive disease

This article is divided into 4 sections which deal with changes in the management of short stenoses in the iliac arteries, the management of aorto-iliac disease and the effects of concomitant myocardial ischemia, changes in the design of prostheses, and multisegmental disease. Myocardial ischemia may be apparent from clinical or electrocardiogram evidence, or it may be covert. The mortality rate after aortic bifurcation grafting may improve if patients with severe coronary artery disease are either refused operation or have a coronary bypass first. It was postulated over 10 years ago that increased porosity would encourage the formation of a functioning intima on the inner surface of a prosthesis. Since then, the fashion has been to use porous prostheses, and recent developments to offset the loss of blood at implantation are described. Methods of predicting which patients with multisegmental disease will require combined aorto-iliac and femoropopliteal reconstructions are discussed in the light of the problem of early occlusion of aortobifemoral grafts.

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Resumen El presente artículo está dividido en 4 secciones relativas al manejo de las estenosis cortas de las arterias iliacas, al manejo de la enfermedad aortoiliaca con isquemia miocárdica concomitante, a los cambios en el diseño de las prótesis vasculares, y a la enfermedad arterial multisegmentaria. La isquemia miocárdica puede resultar aparente por evidencia clínica o electrocardiográfica, o puede permanecer inadvertida. La tasa de mortalidad de los injertos de la bifurcación aórtica puede ser mejorada si aquellos pacientes con enfermedad coronaria severa son rechazados para operación, o bien sometidos primero a una derivacíon coronaria. Hace más de 10 años fue postulado que la mayor porosidad de una prótesis estimula la formación de una íntima funcional en la superficie interna. Desde entonces se ha preferido utilizar prótesis porosas; aquí se describen recientes avances para lograr la pérdida de sangre en el momento de la implantation del injerto. Se discuten métodos para predecir qué pacientes habrán de requerir reconstrucciones aortoiliacas y femoropoplíteas una vez que se presenta el problema de la oclusión temprana de un injerto aortobifemoral.

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Résumé Dans cet article nous envisageons 4 sujets: les tendances therapeutiques actuelles des sténoses courtes des artères iliaques, celles des arteriopathies aorto-iliaques lorsqu'existe une ischémie myocardique concomitante, les changements dans la fabrication des prothèses, et le traitement en cas de maladie artérielle multisegmentaire. Une ischémie du myocarde peut être évidente à partir des données de la clinique ou d'après l'électrocardiogramme; ailleurs elle est latente. Pour réduire la mortalité après remplacement du carrefour aortique chez le patient présentant une maladie ischémique du coeur, on peut soit refuser d'opérer ces patients, soit les faire opérer au préalable de leurs artères coronaires. Il y a plus de 10 ans on a supposé que si on augmentait la porosité, on favoriserait la formation d'une couche d'intima fonctionnelle à l'intérieur de la prothèse. Depuis qu'on utilise des prothèses poreuses, les pertes sanguines au niveau des anastomoses tendent à se minimiser. Les méthodes destinées à choisir quels patients avec une maladie multisegmentaire pourront bénéficier d'une recontruction aorto-iliaque et fémoropoplitée combinée sont discutées à la lumière du problème que pose la thrombose précoce des prothèses aortobifémorales.

     

Aortoiliac occlusive disease

Aortoiliac occlusive disease, or peripheral artery disease affecting the suprainguinal vessels, can lead to a range of clinical symptoms from claudication to more severe, chronic limb-threatening ischemia. Although open surgical reconstruction has traditionally been the reference standard, endovascular options have become significantly more robust in recent years, owing to both improved devices and increasing experience with advanced techniques. This review will discuss the demographics, presentation, and evaluation of chronic aortoiliac occlusive disease, as well as explore the options, both open and endovascular, for revascularization.     

Intestinal strictures presenting with gastrointestinal blood loss

The typical manifestations of intestinal strictures include abdominal distention, bilious vomiting, hematochezia, diarrhea, disaccharide intolerance, and occasional growth failure. However, chronic gastrointestinal (GI) blood loss from ulcers at the site of the stricture has not been noted as a major feature. We report three patients in whom an intestinal stricture presented with minimal evidence of obstruction, but with GI bleeding and anemia. Our experience indicates that intestinal strictures with ulcers must be considered in the differential diagnosis of blood loss, and that surgical intervention may be required if GI blood loss is chronic and laboratory results are negative.     

Experience with fibrinolytic therapy of vascular occlusive disease

1. There may well be a place for streptokinase therapy in selected patients with chronic arterial occlusion, but the emphasis should be on developing information on selection criteria. 2. Efficacy and safety have been established for the use of streptokinase in occluded AV cannulae, but this may be more of historical than contemporary importance. 3. Although more investigation is required to define the role of lytic therapy in retinal vascular occlusion and in the hemolytic uremic syndrome, the preliminary results are encouraging and merit further attention.     

全麻意识消失的神经生理机制

目前的研究表明,全麻药引起的意识消失是一种发生在中枢不同水平、由多个环节组成的级联反应,包括全麻药对脑干的抑制而减少网状结构上行激活系统对丘脑和皮层的影响;全麻药对中脑边缘环路和丘脑皮层丘脑环的阻断和抑制作用;全麻药对顶额叶之间联系的解耦联作用;全麻药对额前皮质的抑制作用等环节.其中丘脑结构是此级联反应的中心环节,而各环节相关中枢结构之间还可通过神经元细胞群的同步化活动或神经振荡等模式进行耦联或整合.各种全麻药均可通过对其中不同环节及相应的耦联或整合活动的阻断而引发级联反应、并最终导致机体意识的消失.     

下肢动脉硬化性闭塞症腔内治疗

随着人口老龄化，生活质量水平的提高，下肢多节段动脉硬化性闭塞症发病率逐年升高。据统计，60岁以下发病率为2．5％，60～69岁为8．3％，≥70岁发病率为18．8％。下肢多节段动脉硬化性闭塞症已成为血管外科常见疾病，是临床上导致肢体严重缺血的主要原因，也是治疗的难点。     

Laboratory evaluation of patients with vascular occlusive disease

In addition to the determination of the presenting symptom of patients with peripheral vascular occlusive disease, evaluation of these patients may include the noninvasive measurements of ankle/arm pressure ratio, limb blood flow, and treadmill testing to evaluate the severity of the reduction in blood flow. We have included metabolic studies to assess the effect of this reduced blood flow in patients with stable intermittent claudication (n = 20), and with end-stage ischemia (night and rest pain) (n = 11), and in a control group without vascular disease (n = 8). No correlations were found between the resting limb blood flow, ankle/arm pressure ratios, maximum walking distance, and stated walking distance for the patients with stable claudication. Although the oxygen consumption was reduced only in the patients with end-stage ischemia, the percent oxygen extraction was increased to the same level in the patients with stable claudication and those with end-stage ischemia. Intramuscular stores of high-energy phosphates and glycogen were maintained in all groups with the lactate/pyruvate ratio increased only in the patients with end-stage ischemia. The complex interrelationships between the rate and distribution of blood flow with exercise and enzyme adaptation in patients with vascular disease make current resting hemodynamic and metabolic evaluations a poor reflection of the severity of the clinical condition within each patient group. Therefore laboratory testing may offer no advantage over clinical presentation in the overall evaluation of these patients.     

Carotid stent-assisted angioplasty: the newest addition to the surgeons' armamentarium in the management of carotid occlusive disease

Carotid artery angioplasty and stenting (CAS) has been accomplished in multiple centers with short-term and midterm results similar to carotid endarterectomy (CEA). Until completion of multicentered prospective evaluation of the benefit of CAS versus established therapy (CEA) clinical judgment must be used to determine whether an individual patient with unusual technical challenges and/or risks might be best suited for CEA or CAS. We report our experience with 41 CAS procedures in 39 patients treated from November 1996 through November 2001. Six patients had primary lesions (three symptomatic and three asymptomatic). Thirty-three patients had 35 procedures for recurrent carotid stenosis (11 symptomatic and 24 asymptomatic). Technical success was achieved in 40 of 41 procedures. No deaths occurred. The 30-day major stroke rate was one in 41 (2.4%), and the overall 30-day stroke/transient ischemic attack rate was three in 41 (7.3%). No recurrence or late neurologic events were seen in patients treated for primary carotid stenosis. A 23 per cent recurrence rate was observed in patients treated for recurrent carotid stenosis, after one or more CEAs, with mean follow-up of 18 +/- 14 months. Recurrence requiring operative correction with carotid resection and interposition grafts occurred in three patients treated with CAS in this group. Late deaths occurred in six patients; one of these was due to stroke. Overall freedom from late stroke and/or need for reintervention (by Kaplan-Meier analysis) was 64 +/- 13 per cent at 48 months in the group treated by CAS for post-CEA recurrence. CAS represents a technically simplistic means of providing carotid revascularization. However, its role remains undefined and benefits unproven. Surgical revascularization remains appropriate for patients with operable carotid lesions. However, surgical revascularization is not always an ideal option when we are faced with difficult carotid lesions and risks. For this reason we advocate that all surgeons who intend to remain specialists in the management of carotid disease should attain, master, and maintain the skills necessary for CAS.