Idiopathic myointimal hyperplasia of the mesenteric veins

Idiopathic myointimal hyperplasia of the mesenteric veins (IMHMV) is caused by proliferation of smooth muscle cells in the wall of small mesenteric veins and venules with accumulation of a proteoglycan matrix leading to a non-thrombotic, non-inflammatory venous occlusion resulting in venous ischemia. IMHMV is a rare and poorly understood disease, with <20 case reports in the literature. The purpose of this report is to describe the case of a 63-year-old man who presented with this condition that resulted in colonic ischemia necessitating surgical resection. The cause of IMHMV in this patient was attributed to a Chinese herbal supplement used for degenerative osteoarthritis of the knees. A brief review of the literature is provided along with the case report.

Faster Detection of Ischemia in Free Muscle Transfer When Using Microdialysis

Background Microdialysis is a clinical method used to detect ischemia after microvascular surgery. Microdialysis is easy to use and reliable, but its value in most clinical settings is hampered by a 1- to 2-h delay in the delivery of patient data. This study evaluated the effectiveness of an increase in the microdialysis perfusion rate from 0.3 to 1.0 µL/min on the diagnostic delay in the detection of ischemia. Methods In eight pigs, two symmetric pure muscle transfers were dissected based on one vascular pedicle each. In each muscle, two microdialysis catheters were placed. The two microdialysis catheters were randomized to a perfusion rate of 0.3 or 1.0 µL/min, and the two muscle transfers were randomized to arterial or venous ischemia, respectively. After baseline monitoring, arterial and venous ischemia was introduced by the application of vessel clamps. Microdialysis sampling was performed throughout the experiment. The ischemic cutoff values were based on clinical experience set as follows: CGlucose < 0.2 mmol/L, CLactate > 7 mmol/L, and the lactate/pyruvate ratio > 50. Results The delay for the detection of 50% of arterial ischemia was reduced from 60 to 25 minutes, and for the detection of all cases of arterial ischemia, the delay was reduced from 75 to 40 minutes when the perfusion rate was increased from 0.3 to 1.0 µL/min. After the same increase in perfusion, the detection of 50% of venous ischemia was reduced from 75 to 40 minutes, and for all cases of venous ischemia, a reduction from 135 to 95 minutes was found. Conclusion When using microdialysis for the detection of ischemia in pure muscle transfers, an increase in the perfusion rate from 0.3 to 1.0 µL/min can reduce the detection delay of ischemia.

Parametric Features of Regional Cerebral Blood Flow in Venous Ischemic Stroke

The lecture is devoted to the peculiarities of changes in tissue and cell perfusion of the brain with a rare pathology – venous ischemic stroke. Venous stroke, being a “relatively unknown cerebrovascular disease”, occurs up to 5 % of all cases of stroke. The terms “venous ischemia” and “venous stroke” have long been used in the literature and the definition of the venous nature of stroke should lead to a change in therapeutic tactics. Neuroimaging should ensure the verification of stroke and cerebral venous sinus thrombosis, which are the main cause of such a stroke. A certain “alertness” to the venous nature of the stroke with the expansion of the volume of radiologic methods of investigation and the performance of angiographic and perfusion CT and MR techniques, diffusion MRI allowed to increase the number of diagnosed and verified venous strokes from 0.4 % of the total number of stroke patients to 2.4 %. A distinctive feature of venous ischemic stroke from the arterial is moderate hyperemia in the central part in cases where necrosis does not develop and perifocal hyperperfusion in the development of necrosis. Moderate plethora, defined by perfusion parameters (up to 30 % CBF, CBV, MTT) of CT, MRI and SPECT techniques, and not oligemia is the primary damaging factor of the pathogenesis of venous stroke in contrast to the arterial and hyperemia patterns should be the reference points in emergency diagnosis venous stroke along with tomoangiographic symptoms of cerebral venous sinustrombosis.

Spontaneous Subdural Hematoma and Behavioral Changes Due to a Dural Arteriovenous Fistula. A Case Report and Literature Review

Dural arteriovenous fistulas (DAVFs) represent 10–15% of intracranial arteriovenous malformations. Of these, only 12–29% cause intracranial hemorrhage. The presentation of DAVF as a subdural hematoma (SDH) and intraparenchymal hemorrhage (IPH) is infrequent; additionally, behavioral changes are not common among these patients. We report, for the first time in our country, the case of a 23-year-old man with no history of head injury, in which a brain computed tomography (CT) scan revealed SDH and IPH with behavioral disturbances. The angiotomography showed ecstatic venous vessels, indicating the presence of a DAVF, which was later confirmed by cerebral angiography. Endovascular therapy, which followed the clinical diagnosis, resulted in satisfactory evolution two years after treatment. A review of the literature concerning cases with DAVF and behavioral disturbances is presented. DAVF may lead to cognitive impairment, behavioral changes, and dementia as a result of diffuse white matter and thalamus modifications related to venous ischemia, and it should be considered as a reversible cause of vascular dementia.

Restrictive cerebral cortical venopathy: A new clinicopathological entity

We present a case of a novel restrictive cerebral venopathy in a child, consisting of a bilateral network of small to medium cortical veins without evidence of arteriovenous shunting, absence of the deep venous system, venous ischemia, elevated intracranial pressure, and intracranial calcifications. The condition is unlike other diseases characterized by networks of small veins, including cerebral proliferative angiopathy, Sturge-Weber syndrome, or developmental venous anomaly. While this case may be the result of an anatomic variation leading to the congenital absence of or early occlusion of the deep venous system, the insidious nature over many years argues against this. The absence of large cortical veins suggests a congenital abnormality of the venous structure. The child’s presentation with a seizure-like event followed by protracted hemiparesis is consistent with venous ischemia. We propose that this is likely to represent a new clinicopathological entity.

Monitoring of Free Flaps with Combined Tissue Spectrophotometry and Laser Doppler Flowmetry in an Animal Experimental Model

Background When mobilizing free flaps, postoperative monitoring of perfusion is crucial to detect ischemia. Continuous monitoring may be feasible by applying a combination of tissue spectrophotometry and laser Doppler flowmetry (oxygen-2-see [O2C]). Material and Methods On 10 pigs, two symmetrical myocutaneous flaps were mobilized on each side of the abdomen based on the deep inferior epigastric vessels. Flaps were randomized to clamp either the artery or the vein and measurements using O2C were performed before, during, and after the intervention yielding information on blood flow, saturation (sat), and relative tissue hemoglobin (rHgb) concentration. Results Baseline values were similar in all groups. Introduction of ischemia caused a rapid decline in arterial ischemic flaps which all reached threshold levels in 3 minutes, whereas that was only the case for three of six venous ischemic flaps. Venous clamping resulted in a decline in sat, while the response to arterial clamping was an initial decline followed by an increase in sat. In all arterial ischemic flaps, rHgb concentration either decreased or remained at baseline levels but increased in all venous ischemic flaps. The median time to a 30% rise was 1 minute at an 8-mm depth. The rate of decreasing flow along with the rHgb measurements made it possible to distinguish the arterial ischemia (AI) from the venous ischemia (VI) within the first few minutes. Conclusion In this animal experimental model, O2C measurements of blood flow reliably detected ischemia. By adding information about rHgb, it was possible to distinguish between AI and VI.