Diffusion-Weighted Imaging in Stroke
Andrei I. Holodny in Functional Neuroimaging, 2019
TGA is a syndrome characterized by sudden onset of severe memory impairment associated with both retrograde and anterograde amnesia without other neurologic deficits. The symptoms typically resolve in three to four hours. Many patients with TGA have no acute abnormality on conventional or DW images (102), but others have reported punctate lesions with decreased diffusion in the medial hippocampus, the parahippocampal gyrus, and the splenium of the corpus callosum (Fig. 12) (103–106). Follow-up T2-weighted sequences have shown persistence of some of these lesions, which, the authors concluded, were small infarctions. Another study, however, reported more diffuse and subtle DWI hyperintense lesions in the hippocampus that resolved on follow-up imaging, which were thought to be secondary to spreading depression rather than reversible ischemia (107). One more recent study demonstrated that the detection of DWI changes in TGA is delayed (108); the authors observed DWI abnormalities in only 2 of 31 patients with TGA in the acute phase, but at 48 hours, 26 of 31 patients had DWI hyperintense foci in the hippocampus. The authors speculate that this phenomenon may result from venous congestion. It is currently unclear whether the TGA patients with DWI abnormalities have a different prognosis or a different etiologie mechanism, or whether they should be managed differently compared with TGA patients without DWI abnormalities.
Open surgical reconstructions for non-malignant occlusion of large veins
Peter Gloviczki, Michael C. Dalsing, Bo Eklöf, Fedor Lurie, Thomas W. Wakefield, Monika L. Gloviczki in Handbook of Venous and Lymphatic Disorders, 2017
History and physical examination, complemented by a hand-held Doppler examination, should reveal signs and symptoms typical of venous congestion. Patients with venous occlusion have swelling and develop exercise-induced pain in the thigh or calf, known as venous claudication. This pain is described as a bursting pain in the thigh, and sometimes in the calf, that develops after exercise and is relieved by rest and leg elevation. The swollen leg has a cyanotic hue with distended varicose veins even in the supine position. Bilateral swelling indicates bilateral iliofemoral or caval occlusion or systemic disease. Collateral veins in the suprapubic and abdominal wall usually indicate pelvic venous occlusion. Bleeding from high-pressure varicosities is not infrequent. In some patients, venous congestion results in hyperhidrosis and significant fluid loss through the skin. Associated chronic lymphedema may also develop. Advanced disease presents with stasis skin changes and venous ulcerations. Patients with membranous occlusion of the IVC frequently will have evidence of hepatic failure and portal hypertension as well.17 For details of the clinical and diagnostic evaluation of the patients with chronic venous insufficiency, the readers are referred to Chapters 13, 14, and 29.
Cerebral perfusion pressure
Hemanshu Prabhakar, Charu Mahajan, Indu Kapoor in Manual of Neuroanesthesia, 2017
Finally, venous drainage should be assessed in the patient receiving intracranial intervention, especially in the surgical suite. Positioning of the head for prone and lateral approaches to the cranium can result in significant occlusion of the internal jugular vein as well as regional nerve injuries. While ultrasound can be used to judge flow (and take note of dominant vasculature) prior to sterile preparation of the field, often a visual survey of the eyes, face, and head is sufficient to determine whether there is venous congestion. When in doubt, discuss repositioning of the head with the surgeon sooner rather than later; it is almost impossible to alter the arrangement after the cranium is open. As already discussed, if there are concerns for high CVP (ICP must be greater than CVP to allow for adequate drainage, especially when supine or prone), efforts should be made to lower this value (i.e., fluid restriction, cardiac optimization, minimizing/eliminating positive end-expiratory pressure [PEEP], decreasing pulmonary hypertension).
High field structural MRI in the management of degenerative cervical myelopathy
Published in British Journal of Neurosurgery, 2018
Dan Wright, Sean Martin, Erlick AC Pereira, Yazhuo Kong, Irene Tracey, Thomas Cadoux-Hudson
Cervical radiculopathy can be acute and if so is often caused by disc herniation. This often occurs in younger patients. The cytokine mediated milieu that ensues predominately effects large diameter myelinated axons causing motor symptoms. Chronic radiculopathy more often presents with sensory disturbances. Compression of the nerve root causes local dural and arachnoid thickening and alteration to the blood-nerve barrier leading to nerve root dysfunction.12 The clinical findings often point to the affected cervical level. Cervical myelopathy is a form of chronic spinal cord injury. The resultant compression of neural structures causes hypoperfusion injury. The anterior and posterior spinal arteries are compromised, and in turn the pial and intramedullary arterioles.13 Venous congestion causes venous infarction. Hypoxia damaged oligodendrocytes and neurons cause an inflammatory response which along with ischaemic endothelial cell damage causes compromise of the blood-spinal cord barrier (BSCB). Inflammatory Fas ligand (FasL) signalling then leads to neuronal loss and axonal damage.11
Effects of negative pressure wound therapy on an axial congested rabbit skin flap model without any bare surface
Published in Journal of Plastic Surgery and Hand Surgery, 2022
Uğur Şahin, Anıl Demiröz, Songül Şahin, Hakan Arslan
Reconstruction with pedicled (local, regional, or distant) or free flaps is a common procedure in plastic surgery. Simple venous insufficiency causing venous congestion is common in daily practice. Studies have shown that venous congestion is more detrimental for the flap compared to arterial ischemia. Surgical exploration is the gold standard treatment for venous congestion; but if surgical correction fails, alternative techniques such as releasing sutures, pricking a flap, chemical leeching, medicinal leeching, or venous cannulation could be employed [1–8]. Usually medicinal leech therapy (MLT) is considered to be one of the first choices for the management of venous congested flaps not otherwise salvageable by surgical interventions [3,5,6] and some authors used subcutaneous heparin injections or venous cannulation as the alternatives of MLT [2,4,7,8]. However excessive blood loss and requirement for blood transfusions are the main and frequent complications of these methods [4]. With the purpose of overcoming these drawbacks, we planned to employ NPWT therapy for the treatment of flap with venous congestion.
Adventitial cystic disease of the popliteal artery
Published in Baylor University Medical Center Proceedings, 2019
Rachel Rendon, Kristyn Mannoia, William Shutze
In Patient 1, there was significant venous congestion with some dilated superficial veins. The popliteal vein was densely adherent to the mass, which was carefully dissected out. The mass was completely mobilized circumferentially. The patient was systemically heparinized, and the artery and vein were occluded proximally and distally. The mass was then incised, and some gelatinous material slowly leaked out, confirming that it was a popliteal adventitial cyst (Figure 1b). The entire cyst was then segmentally resected, and the artery was skeletonized of any cyst wall. We opened up the artery where the cyst was adherent to it. The artery was healthy both proximally and distally. The interior of the artery was normal. A bovine pericardial patch was cut to the appropriate length and sewn in with running 6.0 Prolene suture (Figure 3). Flow was restored. The patient had excellent pulses and a strong palpable posterior tibial pulse at the ankle. The patient’s postoperative convalescence was remarkable only for immediate symptom relief, and he was discharged on postoperative day 2. The patient continues to be asymptomatic in follow-up with good pedal pulses after 15 months.
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