Acute ischemia of the upper and lower limbs: Tailoring the treatment to the underlying etiology

Acute limb ischemia (ALI) can be a devastating clinical emergency with potentially limb- or life-threatening consequences. It is defined as a quickly developing or sudden decrease in limb perfusion producing new or worsening symptoms and signs, often threatening limb viability. ALI is commonly related to an acute arterial occlusion. Rarely, extensive venous occlusion can lead to upper and lower extremities ischemia (ie, phlegmasia). The incidence of acute peripheral arterial occlusion causing ALI is approximately 1.5 cases per 10,000 people per year. The clinical presentation depends on the etiology and whether the patient has underlying peripheral artery disease. Except for traumas, the most common etiologies are embolic or thrombotic events. Peripheral embolism, likely related to embolic heart disease, is the most common cause of acute upper extremity ischemia. However, an acute thrombotic event may occur in native arteries, at the site of a pre-existing atherosclerotic plaque, or as a failure of previous vascular interventions. The presence of an aneurysm may predispose to ALI for both embolic and thrombotic mechanisms. Immediate diagnosis, accurate assessment of limb viability, and prompt intervention, when needed, play important roles in salvaging the affected limb and preventing major amputation. Severity of symptoms is usually dependent on the amount of surrounding arterial collateralization, which may often reflect a pre-existing chronic vascular disease. For this reason, early recognition of the underlying etiology is crucial for choice of best management and definitely for treatment success. Any error in the initial evaluation may negatively affect the functional prognosis of the limb and endanger the patient's life. The aim of this article was to discuss diagnosis, etiology, pathophysiology, and treatment of patients with acute ischemia of the upper and lower limbs.

Acute Upper Extremity Arterial Occlusion Diagnosed on POCUS in the Emergency Department

Upper extremity acute limb ischemia (ALI) is a limb-threatening and potentially lethal pathology that is most commonly caused by vascular embolization. Outcomes of limb ischemia are time-sensitive due to the correlation between a longer time from symptom onset to intervention with a vastly higher risk of amputation. In this report, point of care ultrasound (POCUS) was utilized to rapidly diagnose a patient with a proximal right brachial artery embolic occlusion, prompting expedited surgical consultation and successful embolectomy. POCUS can provide a focused vascular examination of the limbs to expedite diagnosis of time-sensitive ALI and facilitate timely medical intervention and surgical consultation.

Acute limb ischaemia due to vasospasm: a rare presentation

A 30-year-old woman with active intravenous drug use presented with pain, blue discolouration, paresthesia and lack of grip strength of left hand for 1 week. Physical examination revealed blue discolouration, decreased sensation and cold to touch in the left hand. She had no palpable radial pulse. She admitted Heroin use only but the urine drug screen was also positive for amphetamine. CT angiogram of the left upper extremity was concerning for acute ischaemia due to arterial occlusion. The initial plan was for amputation. However, to salvage the limb with thrombolysis, an interventional radiology angiogram was performed. The angiogram demonstrated diffuse arterial spasm and response to nitroglycerin. She was treated with nitroglycerin drip and transitioned to a calcium channel blocker. She did improve significantly. To ensure no embolic sequelae, the patient was discharged with a month of oral anticoagulation.

A retrospective analysis of the investigative practices of acute limb ischaemia presenting with an unknown aetiology

BACKGROUND

Acute limb ischaemia (ALI) is a limb and life-threatening condition with significant morbidity. There are currently no consensus recommendations for the investigative practices to determine the aetiology of ALI presenting without a known aetiology. We undertook a detailed analysis of all investigations performed to identify an underlying precipitant in those with unexplained ALI and formulated a suggested diagnostic algorithm for the evaluation of unexplained ALI.

METHODS

ALI cases presenting to a tertiary referral centre over a 3-year period were reviewed, and known aetiologies, and investigations undertaken to determine the underlying aetiology of unexplained ALI were obtained.

RESULTS

Unexplained ALI was found in 27 of 222 patients (12%), of which 21 (78%) had a cause for ALI established after further investigations. Six patients had no cause identified despite extensive work-up. Most patients with unexplained ALI had a cardioembolic source identified as the underlying cause (62%), and this included atrial fibrillation, infective endocarditis, cardiac myxoma and intra-cardiac thrombus. Other causes of unexplained ALI were detected by computed tomography (CT) imaging and included newly diagnosed significant atherosclerotic disease (19%), embolism from isolated proximal large vessel thrombus (10%) and metastatic malignancy (10%). There were no cases attributed to inherited thrombophilias, myeloproliferative neoplasms or anti-phospholipid syndrome.

CONCLUSION

Among patients with unexplained ALI, the majority had a cardioembolic source highlighting the importance of comprehensive cardiac investigations. A subset of patients had alternative causes identified on CT imaging. These data support the use of a collaborative and integrative diagnostic algorithm in the evaluation of unexplained ALI.

Digital ischaemia aetiologies and mid-term follow-up: A cohort study of 323 patients

Upper extremity digital ischaemia (UEDI) is a rare heterogeneous condition whose frequency is 40 times less than that of toe ischaemia. Using a large cohort, the aim of this study was to evaluate aetiologies, prognosis and midterm clinical outcomes of UEDI.All patients with UEDI with or without cutaneous necrosis in a university hospital setting between January 2000 to December 2016 were included. Aetiologies, recurrence of UEDI, digital amputation and survival were analyzed retrospectively.Three hundred twenty three patients were included. UEDI due to cardio-embolic disease (DICE) was the highest occurring aetiology with 59 patients (18.3%), followed by DI due to Systemic Sclerosis (SSc) (16.1%), idiopathic causes (11.7%), Thromboangiitis obliterans (TAO) (9.3%), iatrogenic causes (9.3%), and cancer (6.2%). DICE patients tended to be older and featured more cases with arterial hypertension whereas TAO patients smoked more tobacco and cannabis. During follow-up, recurrences were significantly more frequent in SSc than in all other tested groups (P < .0001 vs idiopathic and DICE, P = .003 vs TAO) and among TAO patients when compared to DICE patients (P = .005). The cumulated rate of digital amputation was higher in the SSc group (n = 18) (P = .02) and the TAO group (n = 7) (P = .03) than in DICE (n = 2).This retrospective study suggests that main aetiologies of UEDI are DICE, SSc and idiopathic. This study highlights higher frequency of iatrogenic UEDI than previous studies. UEDI associated with SSc has a poor local prognosis (amputations and recurrences) and DICE a poor survival. UEDI with SSc and TAO are frequently recurrent.

MDCT angiography of emergent, non-traumatic, upper extremity vascular lesions

Timely, accurate diagnosis of upper extremity vascular pathology is critical for successful clinical and surgical management. Although the vast majority of upper extremity vascular injury is due to trauma, physicians in the emergency setting, including radiologists, must be familiar with vascular lesions from iatrogenic injury, thromboembolic disease, vascular malformations, and vasculitis. Non-invasive diagnostic imaging with multidetector CT (MDCT) angiography is often employed in the emergency department to evaluate patients with suspected vascular pathology of the upper extremity. Maximum intensity projection and volume rendering technique are two methods that are useful for evaluating vasculature. In addition, dual-energy MDCT is useful in that it allows for the generation of iodine-selective images and bone subtracted images. These techniques can be used to create images that simulate catheter angiograms. In this article, we will discuss the role of MDCT angiography in the diagnosis and management of emergent non-traumatic vascular lesions of the upper extremity.

A Population-Based Study of Incidence, Presentation, Management and Outcome of Primary Thromboembolic Ischemia in the Upper Extremity

OBJECTIVES

To investigate the epidemiology of acute upper limb thromboembolism in a well-defined Norwegian population.

METHODS

This study was a retrospective, single-center, observational population-based cohort study of acute upper limb thromboembolism. The study included all patients from the hospital's primary catchment area from January 2000 to December 2015. Age- and gender-adjusted incidence rates were calculated using population demographics from Statistics Norway.

RESULTS

A total of 54 patients were identified, of which 49 were included in the analyses: 27 (55%) females (median age 83 years, range 40-96) and 22 (45%) males (median age 70 years, range 42-95) (P = .053). The adjusted incidence rate for the period was 1.6 patients per 100,000 inhabitants per year (95% confidence interval 1.2-2.2) and did not change significantly during the period studied. Atrial fibrillation was detected by electrocardiography in 30 (61%) patients; in this group, 10 patients were on warfarin but only two had an international normalized ratio > 1.9 and the remaining 20 were not anticoagulated. Altogether, 38 (78%) patients underwent surgery, 1 (2%) was treated with thrombolysis, and the remaining patients were treated conservatively; no amputations were performed. Four patients (8%) died within 30 days, and 12 of the surviving 45 patients (27%) had recurrent thromboembolism.

CONCLUSION

The incidence rate was stable during the study period. Patients with upper limb thromboembolism due to atrial fibrillation were inadequately anticoagulated. One in four patients experienced a recurrent thromboembolic event. Lifelong anticoagulation should be considered in all patients with upper limb thromboembolism.

Vascular Surgery in Japan: 2011 Annual Report by the Japanese Society for Vascular Surgery

This is an annual report indicating the number and early clinical results of annual vascular treatments performed by vascular surgeons in Japan during 2011, as analyzed by database management committee (DBC) members of the Japanese Society for Vascular Surgery (JSVS). Materials and Methods: To survey the current status of vascular treatments performed by vascular surgeons in Japan, the DBC members of the JSVS analyzed the vascular treatment data provided from National Clinical Database (NCD), including the number of treatments and early clinical results such as operative and in-hospital mortality. Given that NCD data were prospectively built by a nationwide registration, this annual report reports prospective clinical data. Results: In total 71,707 vascular treatments including open repairs and endovascular treatments were registered by 992 institutions in 2011. This database is composed of 7 fields including treatment of aneurysms, chronic arterial occlusive disease, acute arterial occlusive disease, vascular injury, complication of vascular reconstruction, venous diseases, and other vascular treatments. The number of vascular treatments in each field was 17,524, 11,278, 3,799, 1,030, 1,615, 19,371, and 17,510, respectively. In the field of aneurysm treatment, 13,218 cases with abdominal aortic aneurysms (AAA) including iliac aneurysms were registered, including 1,253 ruptured cases. Forty-five percent of AAA cases were treated by stent graft. The operative mortality of ruptured and non-ruptured AAA was 18.8% and 0.8%, respectively. Regarding chronic arterial occlusive disease, open repair was performed in 7,115 cases including 984 distal bypasses to the crural or pedal artery, whereas endovascular procedures were performed in 4,163 cases. For acute arterial occlusive disease, more than 90% of cases were treated with open repair. Vascular injury treatment included 81 venous injury cases and 949 arterial injury cases, and 60% of arterial injuries were iatrogenic. Treatment for complication of previous vascular treatment included 445 cases of graft infections, 240 cases of anastomotic aneurysms, and 811 cases of graft revision operations. The venous treatment included 18,864 varicose vein treatments, 343 cases with lower limb deep venous thrombosis, and 67 cases with vena cava reconstructions. Regarding other vascular operations, 16,296 cases of vascular access operations and 1,037 amputation surgeries are included. Conclusions: This vascular surgery database indicates not only the number of vascular treatments but also the early clinical outcomes for each treatment procedure, thereby representing a useful source for researching the clinical background of poor outcomes and for finding improvements in the quality of treatment. Continuing this work will provide information regarding changing the treatment modality in response to the changing structure of disease and societal needs. (This is a translation of Jpn J Vasc Surg 2017; 26: 45-64.).

Earliest effects of sudden occlusions on pressure profiles in selected locations of the human systemic arterial system

We have developed a numerical simulation method for predicting the time dependence (wave form) of pressure at any location in the systemic arterial system in humans. The method uses the matlab-Simulink environment. The input data include explicitly the geometry of the arterial tree, treated up to an arbitrary bifurcation level, and the elastic properties of arteries as well as rheological parameters of blood. Thus, the impact of anatomic details of an individual subject can be studied. The method is applied here to reveal the earliest stages of mechanical reaction of the pressure profiles to sudden local blockages (thromboses or embolisms) of selected arteries. The results obtained with a purely passive model provide reference data indispensable for studies of longer-term effects due to neural and humoral mechanisms. The reliability of the results has been checked by comparison of two available sets of anatomic, elastic, and rheological data involving (i) 55 and (ii) 138 arterial segments. The remaining arteries have been replaced with the appropriate resistive elements. Both models are efficient in predicting an overall shift of pressure, whereas the accuracy of the 55-segment model in reproducing the detailed wave forms and stabilization times turns out dependent on the location of the blockage and the observation point.