History: A 32-year-old woman was admitted to the emergency department because of acute dyspnea and syncope. A few minutes before the onset of symptoms, she had self-administered an intravenous injection of one gram of heroin combined with grinded flunitrazepam tablets.Investigations: Signs of acute cor pulmonale were detected on transthoracic echocardiography despite lack of pulmonary embolism in computed tomography. It was assumed that microembolisms were the cause of acute pulmonary hypertension after intravenous injection of heroin and flunitrazepam.Treatment and course: Because of lack of thrombus in CT scan therapeutic anticoagulation with unfractionated heparin and oxygen insufflation was initiated resulting in rapid improvement of oxygen saturation and blood pressure. On the following day pulmonary pressure in transthoracic echocardiography was already decreased significantly. Without signs of deep venous thrombosis in duplex scan and only a marginal sub segmental perfusion deficit in ventilation-perfusion-scintigraphy therapeutic anticoagulation was recommended for three months.

Conclusion:

The most likely cause of micro embolisms in this case are particles of talc, which are often used to cut heroin, or the microcrystalline cellulose used in tablets. There have been reports of tissue necrosis due to arterial embolism/vasospasm by crystalloid or oily substances (embolia cutis medicamentosa) in the extremities after intraarterial injection of grinded flunitrazepam tablets. Therefore it seems plausible that intravenous application may cause a serve but transient deficit of perfusion in pulmonary circulation.

Acute limb ischemia may manifest by ischemic rest pain, ischemic ulcers, or gangrene. Acute arterial occlusion can be the result of emboli from a distant source, acute thrombosis of a previously patent artery, or direct trauma to an artery. Toe necrosis resulting from norepinephrine bitartrate (Levophed; Hospira Inc, Lake Forest, Illinois) is a rare case.

Abstract

Purpose:

(1) Investigate the acute effects of whole body vibration (WBV) on central hemodynamic responses, muscle oxygenation and oxygen consumption ([Formula: see text]) in individuals with spinal cord injury (SCI) versus sex, age and activity-matched able-bodied (AB) individuals. (2) Assess the effects of three WBV frequencies on all outcome measures.

Methods:

Eleven males with SCI and 10 AB individuals were recruited. Subjects completed three WBV exercise sessions at 30, 40 and 50 Hz. Heart rate (HR), mean arterial blood pressure (MAP), stroke volume (SV), cardiac output (CO), [Formula: see text] and relative changes in oxygenated (Δ[HbMbO2]), deoxygenated (Δ[HHbMb]) and total (Δ[HbMbtot]) heme groups were obtained when [Formula: see text] steady state was achieved for: pre-WBV sitting, pre-WBV standing, WBV and post-WBV standing.

Results:

Both groups demonstrated small but significant increases in [Formula: see text], Δ[HbMbO2] and Δ[HbMbtot]; but the increases were larger in the SCI group. A significant decrease Δ[HHbMb] was observed in the SCI group. No frequency effect was observed.

Conclusion:

The WBV responses do not appear sufficient to induce cardiovascular benefits in the SCI population. WBV may be helpful for individuals with SCI in improving lower limb peripheral blood flow and coping with orthostatic hypotension symptoms earlier in their rehabilitation programs. Implications for Rehabilitation Increased muscle oxygenation and blood flow observations in response to WBV suggest a possible application of WBV for increasing lower extremity blood flow and/or oxygen saturation in individuals with SCI. WBV may be incorporated into the rehabilitation programs for reducing thrombosis susceptibility in individuals with SCI. Blood pressure in individuals with SCI appeared to be maintained much better in the upright position when WBV is applied. This could be helpful in the rehabilitation of SCI patients by allowing them to avoid the difficulties of orthostatic hypotension earlier in their rehabilitation programs.

REASONS FOR PERFORMING STUDY: Intralesional (i.l.) injection is currently the most commonly used technique for stem cell therapy in equine tendon injury. A comparison of different techniques of injection of mesenchymal stem cells for the treatment of tendon lesions is required.

OBJECTIVES:

We hypothesised that vascular perfusion of the equine distal limb with mesenchymal stem cells (MSCs) would result in preferential distribution of MSCs to acute tendon injuries.

STUDY DESIGN:

In vivo experimental study.

METHODS:

Lesions were surgically induced in forelimb superficial digital flexor tendons of 8 horses. Three or 10 days after lesion induction, technetium-99 hexamethyl propylene amine oxime-labelled MSCs were injected via i.v. or intra-arterial (i.a.) regional limb perfusion (RLP) at the level of the distal antebrachium and compared to i.l. injection. Mesenchymal stem cell persistence and distribution within the forelimb and tendon lesions was assessed with scintigraphy for 24 h.

RESULTS:

Lesion uptake was higher with i.l. injection than with RLP, but MSC persistence decreased similarly over time in all 3 techniques. Intra-arterial RLP resulted in a better distribution of MSCs and a higher uptake at the lesion site than i.v. RLP. Limbs perfused i.a. on Day 10 showed greater accumulation of MSCs in the lesion than limbs perfused on Day 3. Arterial thrombosis occurred in 50% of the i.v. RLP limbs and in 100% of the i.a. RLP limbs, which led to clinical complications in one horse.

CONCLUSIONS

AND POTENTIAL RELEVANCE: Compared with i.l. injection, RLP results in lower uptake but similar persistence of MSCs at the site of tendon lesions. A time dependent accumulation of MSCs was identified with i.a. RLP. The i.a. RLP appears more advantageous than the i.v. RLP in terms of distribution and uptake. However, the described i.a. technique produced arterial thrombosis and thus cannot currently be recommended for clinical use. The Summary is available in Chinese - see Supporting information.

Hypercoagulability is a well-documented and prominent risk factor for venous thromboembolism. The role of thrombophilia in arterial thrombotic events is less well defined. A 52-year-old male patient with multiple atherogenic risk factors was admitted for non-healing pedal ulcer and absent distal pulses. Based on the clinical presentation, Doppler ultrasound and angiography findings, the patient underwent elective in situ bypass arterial reconstruction. The saphenous vein graft was of satisfactory quality and the procedure went routinely. Acute graft thrombosis on postoperative day 0 was recognized immediately and prompted an emergent surgical revision. No technical errors or anatomical/mechanical causes for failed reconstruction were found and the graft was successfully thrombectomized using a Fogarty balloon-catheter. Graft rethrombosis, however, ensued after several hours. Considering the absence of threatening limb ischemia and the idiopathic recurrent thrombosis, raising suspicion of prothrombotic state, conservative treatment was pursued. Postoperative thrombophilia testing proved positive for activated protein C resistance, mandating introduction of chronic oral anticoagulation. Six months later, the operated extremity is viable. Inexplicable vascular graft thrombosis, particularly if early and recurrent, should raise suspicion of underlying thrombophilia. If confirmed by laboratory testing, long-term secondary antithrombotic prophylaxis may be required.

Acute critical lower limb ischemia refers to the state of severely impaired vitality of lower limbs due to acute occlusion of arterial blood vessel by a thrombus or emboli. Surgical revascularization in the first 6-12 hours after the onset of symptoms gives the best results. However, a high mortality rate and probability of limb loss make this problem more debatable, and can be related with associated diseases.This research included 95 patients who had been operated within the first 12 hours after the onset of symptoms of critical limb ischemia We collected the following data: age and sex of patients, etiology of limb ischemia, type of operation, associated diseases and outcome of treatment.Most of the patients were 70 to 80 years old, both sexes being equally represented. There was significantly more arterial embolism (70%) than thrombosis on the prior arterial lesion. Most of the embolizations were treated with Fogarty balloon catheter embolectomy (98%); however, a great number ofarterial thrombosis demanded more complex "inflow" and "outflow" ensuring procedures such as thromboendarterectomy and bypass (33%). The performed surgical procedures showed no statistical differences when final outcome was analyzed. Amputation had to be performed in about 3% of the patients and all of them were diabetics. Mortality rate in this research was 10.5% and 7/10 with this outcome had severe form of chronic myocardiopathy and metabolic decompensation.Acute critical lower limb ischemia should be treated surgically as soon as possible. Negative outcomes are associated with comorbidity and general condition of the patient.

Heparin-induced thrombocytopenia type II (HIT) is a clinicopathologic syndrome in which one or more clinical events are temporally related to heparin administration and caused by HIT antibodies. There are at least five different types of clinical events that are associated with HIT: thrombocytopenia; thrombosis; skin necrosis at heparin injection site, venous limb gangrene; and an acute systemic reaction that occurs 5-30 min after intravenous bolus of heparin. HIT typically presents 5-14 days after initiation of heparin therapy, later onset is unusual. Heparin is a routine anticoagulant in hemodialysis but administration is different than in surgical and other medical population. Doses are lower and administered every other day, yet hemodialysis patients receive heparin for years. Relationship between dialysis vintage and HIT-antibody positivity has been analyzed in two studies. In national survey of HIT in hemodialysis population of the United Kingdom mean time between starting hemodialysis and development of HIT was 61 days (5-390 days). Japanese authors also found greatest incidence of HIT antibody positivity in patients who were on hemodialysis for less than 1 year, none of patients on hemodialysis for more than 10 years was HIT-antibody positive. We present a case of 70-years old female who developed HIT after 24 years of hemodialysis and exposure to heparin. First 22 years she was receiving unfractionated heparin for anticoagulation during hemodialysis sessions. Afterwards her therapy was changed to low molecular weight heparin. Last 12 years she has tunneled cuffed catheter which was also filled with unfractionated heparin. She had a history of severe renal osteodistrophy and severe aortal valve stenosis, hypothyreosis, thrombosis of both subclavian veins and partial colon resection due to mesenterial artery thrombosis. Her thrombocyte count was low, but despite extensive work-up which included HIT antibody detection, no cause could be identified. She started complaining of flushing, dyspnea and chest pain that developed several minutes after start of hemodialysis and stopped spontaneously during or after hemodialysis. Symptoms were attributed to her heart disease and she was hospitalized for cardiac reevaluation. Thrombosis of right superficial and commune femoral vein was diagnosed as well as further worsening of thrombocytopenia. HIT antibodies were assessed again and they were positive. Anticoagulation during hemodialysis was changed to fondaparinux and catheter filling to citrate. Afterwards symptoms during hemodialysis disappeared and thrombocyte count recovered. HIT type II is a rare but potentially fatal syndrome that can develop years after start of heparin therapy. To our knowledge, this is the patient with longest hemodialysis vintage and newly diagnosed HIT. This is also the first case of patient on hemodialysis that developed HIT in Croatia published to date.

Thrombotic or embolic arterial occlusive disease can lead to profound ischemia and, without emergent revascularization, is associated with significant morbidity and mortality. Significant advances in the management of arterial occlusive disease range from newer thrombolytic agents to innovative catheter designs to enhance thrombolysis and thrombectomy. Most of these advances have been directed toward the management of acute limb ischemia; therefore, we review the management of limb ischemia with emphasis on endovascular interventions.

Aortoiliac thrombosis is rare in infants and neonates. Protein C deficiency is frequently observed with venous thromboembolism, but off-late report of arterial thrombosis is increasingly common. We report a case of large infrarenal aortoiliac saddle and right popliteal artery thrombosis in a 7-month-old infant, with 3-mm atrial septal defect without clinical and Doppler evidence of deep vein thrombosis, presented with acute bilateral lower limb ischemic attack. Diagnosis was made by computed tomographic (C T) angiography of aorta and bilateral lower limbs. Patient operated on in emergency by transperitoneal route. Aortoiliac and right popliteal artery thromboembolectomy with closure of aortotomy with polytetraflouroethylene patch was performed.

Pheochromocytoma is a rare cause of hypertension in the general population. Only isolated reports show an association with acute obstructive arterial thrombosis. A 50-year-old chronically noncompliant woman with a known unresected pheochromocytoma presented to the emergency department with ataxia. Imaging confirmed a right-sided ischemic stroke. During her hospital stay, the patient developed signs consistent with acute right upper extremity ischemia resulting from occlusion in the distal right subclavian, axillary, and proximal brachial arteries. Emergent open thrombectomy was successfully performed. In patients with an unresected pheochromocytoma, one must consider acute arterial thrombosis as a rare but potentially limb-threatening and even life-threatening complication.