Intramural mesenteric venulitis

Venous damage is an uncommon cause of intestinal ischaemia. We report on a 44-year-old woman who presented signs and symptoms of acute intestinal ischaemia requiring surgical treatment. Histological examination of the resected right colon showed features of an intramural lymphocytic venulitis with no other demonstrable causes of ischaemic injury of the bowel. Extramural mesenteric veins appeared dilated and congested, without evidence of thrombotic occlusion or of inflammatory involvement. The patient, who was not taking any long-term medication and had no clinical evidence of collagen-vascular disease, promptly recovered after surgery. Follow-up for 7 months with no recurrences suggested a self-limited or indolent process. We propose the name intramural mesenteric venulitis for this condition and believe that it could represent one extreme (the microscopic variant or intramural phase) of the spectrum comprising entero-colic phlebitis and mesenteric inflammatory veno-occlusive disease. The immunohistochemical evidence of a marked preponderance of T phenotype in the perivenular lymphocytes suggests lymphocyte-mediated vascular damage as the pathogenesis of the lesion.     

Focal myointimal hyperplasia of mesenteric veins is associated with previous trauma in surgical specimens

Idiopathic myointimal hyperplasia of mesenteric veins (IMHMV) is a rare and poorly understood disease that occurs in the rectosigmoid colon of predominantly young, previously healthy, male patients. This disease is often confused with chronic idiopathic inflammatory bowel disease clinically, and pathologists may miss the diagnosis unless elastin stains are performed because diseased veins may readily be mistaken for arteries. The etiology of IMHMV is unclear, but a traumatic pathomechanism resulting in arterialization of the veins has been proposed. Review of bowel resection specimens (n=68) for non-neoplastic disease within a 1-year period in patients younger than 50 years of age revealed 10 cases with focal mesenteric vein myointimal hyperplasia. Significantly more cases with focal myointimal hyperplasia of mesenteric veins (MHMV) were associated with pre-resection trauma to the involved bowel segment (5/11 vs. 5/57; p=0.0016). A significant association of MHMV with pre-resection trauma supports the hypothesis that idiopathic myointimal hyperplasia of the mesenteric veins may be the result of trauma through torsion/stretching of the sigmoid colon and, subsequently, increased mesenteric venous pressure through arterialization.     

Giant-cell vasculitides

Although many of the vasculitides within the classification of the American College of Rheumatology can have a component of granulomatous inflammation with giant cells, two (ie, giant-cell [temporal] arteritis and Takayasu arteritis) are characterized by infiltrates that are dominated by granulomatous and/or giant-cell-containing inflammation. Furthermore, granulomatous and/or giant-cell dominant infiltrates can characterize disseminated giant-cell arteritis, granulomatous vasculitis of the central nervous system, localized giant-cell arteritis, mesenteric inflammatory veno-occlusive disease, primary cutaneous phlebitis, and giant-cell phlebitis of mesenteric veins and/or omentum. Like the other systemic vasculitides, there is considerable clinicopathologic overlap between these giant-cell vasculitides. Indeed, they are likely closely related, but how they specifically relate to each other is not clear. Their accurate diagnosis is important; because serious morbidity and even death may occur, if proper treatment is delayed or if excessive immunotherapy is given.     

肠系膜静脉病变导致的缺血性肠病的临床病理分析

目的探讨肠系膜静脉病变导致的缺血性肠病的临床及病理特征。方法对2003—2004年间收集到的肠系膜血管病变导致的缺血性肠病3例进行临床病理的系统分析。结果肠系膜静脉炎继发静脉血栓导致缺血性肠病,临床上以急性腹痛起病,可并发腹膜炎,急诊剖腹探查术中发现有坏死的病变肠段,切除后组织学检查在肠壁的黏膜下层和肠系膜的小到中等大小的静脉壁中有以淋巴细胞为主的炎细胞浸润,血管壁纤维素样坏死,血栓形成;但动脉未受累及。1例缺血性肠病在2年多的随访过程中没有局部的复发或发展成系统性的静脉炎。结论肠系膜静脉炎导致的缺血性肠病是一种罕见的疾病,是静脉的炎症病变,可逐渐导致血栓的形成,最后导致肠道的充血、缺血和坏死。该病可能有自限性,病变肠段的外科切除可以治愈。     

Mechanical, morphological and pharmacological properties of oesophageal varices and small mesenteric veins in portal hypertensive rabbits

The properties of isolated small oesophageal and mesenteric veins were investigated in a rabbit model subjected to a 4-week period of portal vein stenosis. The animals developed oesophageal varices and these together with the small mesenteric veins were mounted on a myograph. Compared with sham-operated controls portal hypertension resulted in an increased normalized inner radius and media thickness of the oesophageal veins resulting in a non-significant increase in the media to lumen ratio, while the inner radius decreased as media thickness increased in mesenteric veins resulting in a significant (P less than 0.01) increase in the media to lumen ratio. When activated, the active wall tension of both the oesophageal and mesenteric veins was increased following portal hypertension, but the active media stress was unchanged. The EC50 for noradrenaline and angiotensin II did not change in portal hypertensive vessels compared with controls and was equal in oesophageal and mesenteric vessels. The ability of isoprenaline and serotonin to relax pre-contracted vessels of both types was reduced by the portal hypertension. The results of these studies suggest that the development of oesophageal varices is not only due to increased portal venous pressure.     

Hepatic lipogranulomatosis simulating veno-occlusive disease of the liver

Two cases of unsuspected veno-occlusive disease of the liver were discovered at autopsy. Nearly all central veins and sublobular venules were occluded by lipogranulomas consisting of lipid-laden macrophages, epithelioid histiocytes, giant cells, fibroblasts, lymphocytes, and deposits of collagen. The process extended into the sublobular hepatic venules. Large hepatic veins were uninvolved. Known causes of veno-occlusive disease were ruled out, and the cause of the present cases is unknown.     

Pulmonary veno-occlusive disease: involvement of pulmonary arteries and review of the literature

Pulmonary vessels from 26 patients with pulmonary veno-occlusive disease were studied histologically and morphometrically. In addition to the well-known obstruction of veins and venules, pulmonary arteries were also narrowed or obliterated in approximately half of the patients. It is unlikely that the arterial intimal fibrosis, which was sometimes as severe as the fibrosis in the veins, was secondary to the venous obstruction; rather, like the venous alterations, it probably resulted from organization of thrombi. It is possible that primary damage to the vascular wall elicited thrombosis. Such an injury may also have caused the arterialization of the venous walls, a common finding that cannot always be explained by distal narrowing of larger veins. Although the etiology of pulmonary veno-occlusive disease is obscure, it seems increasingly likely that multiple noxious agents may induce this condition. In children no predilection for either sex has been observed, but in adults, men are affected twice as often as women.     

Isolation and culture of endothelial cells from the mesenteric vascular bed

Methods are described for the enzymatic isolation of endothelial cells from rat and rabbit mesenteric arteries and veins. The mesenteric vascular bed is incubated with an enzyme solution containing collagenase, deoxyribonuclease, papain, dithiothreitol and bovine serum albumin for 45 min at 37 °C in a shaking waterbath. After the 45 min digestion, cells are centrifuged and plated. This method yields an endothelial cell population with a high plating efficiency which is relatively free of smooth muscle contamination.     

Pulmonary veno-occlusive disease in a patient with HIV infection. A case report with autopsy findings

We relate the autopsy findings of a case of pulmonary veno-occlusive disease which occurred in an HIV-infected intravenous drug abuser. This exceedingly rare disease, of unknown cause, is responsible for 10% of primary pulmonary hypertension. Histologically, the disease is characterized by a fibrous intimal thickening of small and medium sized pulmonary veins associated with congestive and dilated capillary network and alveolar haemorrhage. The occurrence of primary pulmonary hypertension in HIV positive patients is 25 times more frequent than in the general population. This is the third reported case of pulmonary veno-occlusive disease occurring in a HIV positive patient. It suggests the role of HIV in the pathogenesis of these vascular lesions.     

Pulmonary veno-occlusive disease. A report of four cases

Four cases of pulmonary veno-occlusive disease are described. Two patients, who were brothers, had respiratory tract infections. The third patient had chronic active hepatitis and coeliac disease suggesting an abnormality of the immune system; the fourth patient had no obvious cause but presented initially with systemic hypertension. Three of the cases had been diagnosed initially as primary pulmonary hypertension either on open lung biopsy or clinically. In all cases the pulmonary arteries were abnormal with medial hypertrophy, intimal fibrosis and, in some cases, thrombosis in elastic pulmonary arteries. These findings suggest that pulmonary veno-occlusive disease is not confined to veins and should be considered as a widespread pulmonary vascular disease. The range of aetiological factors indicate that it should not be considered as a single disease entity.     

The nodular mesenteric pseudoxanthomatosis (Schaefer) (author's transl)

A casus of so-called nodular mesenteric pseudoxanthomatosis (Schaefer) was investigated by a 73 years old woman. This special findings in the mesenteric lymphnodes were interpreted as changes after inflammatory or infectious diseases in the alimentary tract. For the exact designation was proposed the term lymphonodular mesenteric pseudoxanthomatosis.     

Primary mesenteritis, mesenteric fibrosis and mesenteric fibromatosis. Report of four cases, pathology, and classification

Primary mesenteritis is a rare disease. Two cases and two additional patients with mesenteric fibrosis/fibromatosis are reported. A classification of primary and secondary mesenteritis is suggested in order to replace the confusing variety of terms used for the same disease process. Differential diagnosis of mesenteric fibrosis versus mesenteric fibromatosis may be difficult, and some criteria for the separation of these two entities are discussed. Among the clinical symptoms, transmission of aortic pulsations to the anterior abdominal wall is a rare but important aid for diagnosis. Associated diseases are malignant lymphoma, colonic adenomatosis (Gardner's syndrome) and retroperitoneal fibrosis. Microscopically, mesenteric lipomatosis and Whipple's disease must be ruled out. Usually, surgical treatment is not necessary. Prednisone and azathioprine may be helpful in severe cases. Fatal outcome of primary mesenteritis is extremely rare.     

Hepatic vein lesions in alcoholic liver disease: retrospective biopsy and necropsy study.

Obliteration of the terminal hepatic venules with perivenular fibrosis (phlebosclerosis) is a well recognised feature in alcoholic liver disease. Veno-occlusive lesions with intimal obliteration of hepatic veins and a lymphocytic phlebitis of hepatic veins may also be present. We looked for these lesions in 256 liver biopsies and 50 livers obtained at necropsy from patients with alcoholic liver disease. Phlebosclerosis was a universal finding in alcoholic hepatitis and cirrhosis and showed increasing severity with progressive liver injury. Veno-occlusive lesions, however, were found in only 25 of 256 (9.8%) of biopsies and 11 of 50 (22%) of livers obtained at necropsy, showing alcoholic hepatitis or cirrhosis: lymphocytic phlebitis was found in 10 of 256 (3.9%) and two of 50 (4%), respectively. Moreover, veno-occlusive lesions were generally mild. The prevalence of veno-occlusive lesions and lymphocytic phlebitis was considerably less than has been previously documented. Phlebosclerosis may have a different mechanism and be a more important contributory factor in progressive liver injury.     

Morphological and mechanical properties of small mesenteric arteries and veins in spontaneously hypertensive rats

Segments of small mesenteric arteries (—150 μm lumen diameter) and of corresponding veins were taken from 5-month-old spontaneously hypertensive rats (SHR) and from age matched Wistar Kyoto (WKY) controls. The segments were mounted on a myograph which enabled their mechanical and morphological parameters to be investigated simultaneously. Compared with the WKY arteries the lumen diameter of the SHR arteries was smaller while the media thickness and active wall tension response were greater. On the other hand there were no differences between the corresponding veins from SHR and WKY animals although, compared with the arteries, the veins had a greater lumen diameter, a smaller media thickness and a smaller tension response. The findings suggest that the morphological and mechanical differences seen in arteries from SHR are not found on the venous side.     

A light and scanning electron microscopic study of hepatic veno-occlusive disease

Hepatic veno-occlusive disease, which was observed in a patient with hepatic coma, was examined by scanning electron microscopy (SEM), and correlated with its histology. Postmortem examination disclosed microscopic occlusion of the centrilobular and sublobular veins in the liver. These veins were occluded, partially or completely, by intimal and medial thickening of their walls due to proliferation of collagen and reticulin fibers. In addition to venous obliteration, which had not been demonstrated by other techniques, frequent occlusion of the sinusoidal opening into the central veins was observed by SEM. The size and distribution of the openings were irregular in comparison with those in normal controls. There was no evidence of fibrin thrombus formation in the veins. This case exemplified the usefulness of the application of SEM to autopsy material.     

A LIGHT AND SCANNING ELECTRON MICROSCOPIC STUDY OF HEPATIC VENO-OCCLUSIVE DISEASE

Hepatic veno-occlusive disease, which was observed in a patient with hepatic coma, was examined by scanning electron microscopy (SEM), and correlated with its histology. Postmortem examination disclosed microscopic occlusion of the centrilobular and sublobular veins in the liver. These veins were occluded, partially or completely, by intimal and medial thickening of their walls due to proliferation of collagen and reticulin fibers. In addition to venous obliteration, which had not been demonstrated by other techniques, frequent occlusion of the sinusoidal opening into the central veins was observed by SEM. The size and distribution of the openings were irregular in comparison with those in normal controls. There was no evidence of fibrin thrombus formation in the veins. This case exemplified the usefulness of the application of SEM to autopsy material.     

The origin and distribution of 5-hydroxytryptamine-like immunoreactive nerve fibres to major mesenteric blood vessels of the rat

5-Hydroxytryptamine-like immunoreactive nerve plexuses were demonstrated by indirect immunofluorescence histochemistry in whole-mount preparations and cryostat sections of blood vessels from the mesenteric vasculature of the adult rat. The major veins showed a density of innervation greater than that of the accompanying arteries. Removal of the coeliac-superior mesenteric ganglion complex resulted in almost total loss of 5-hydroxytryptamine-like immunoreactive nerves from superior mesenteric blood vessels. The results of crush lesions applied to distal vessels of the superior mesentery indicate that there were no 5-hydroxytryptamine-like immunoreactive nerve fibres extending from the enteric nervous system to these vessels. The administration of 6-hydroxydopamine resulted in a large reduction in the noradrenergic innervation, accompanied by a similar fall in the number of 5-hydroxytryptamine-like immunoreactive nerve fibres. It is suggested that the cell bodies of the 5-hydroxytryptamine-like immunoreactive nerve fibres demonstrated in the superior mesenteric vasculature are located within the sympathetic ganglia which supply the noradrenergic innervation to the same region and that the 5-hydroxytryptamine-like immunoreactivity may be co-localized with noradrenaline within sympathetic nerve fibres.     

Transport of serotonin from the rat jejunal lumen into mesenteric veins in vivo

The transport of labelled (hot) and non-labelled (cold) serotonin (5-HT) into the mesenteric venous circulation was studied after instillation of test solutions into an isolated jejunal loop of anaesthetized rats. After instillation of [3H]H2O and [14C]5-HT there was an almost parallel appearance of the isotopes in mesenteric venous blood. After instillation of 5-HT a marked early increase of the total amounts of cold 5-HT was observed in mesenteric veins compared with animals instilled with saline only. In a third type of experiment the label was detected in mesenteric venous whole blood after instillation of [3H]5-HT into the gut lumen. After hydrolysis of blood cells and protein precipitation the samples were fractionated and determined for 5-HT and metabolites. Only 5-HT was detected in these fractions. The label was present within 5-HT peaks in three out of eight animals. The experiments indicate rapid transport of 5-HT (or metabolites) across the rat jejunal mucosa. These substances may be bound to a binding protein in platelets since the isotope was detected in whole blood but more seldom in supernatants after hydrolysis and precipitation.     

Pathology of passive mesenteric anaphylaxis in the chicken

Passive mesenteric anaphylaxis (PMA) was produced on intravenous challenge by bovine serum albumin in chickens which had received two hours earlier an intraperitoneal injection of anti‐BSA chicken serum. Sequential study of permeability and cellular responses, using colloidal carbon, revealed a biphasic pattern of increased permeability which was confined to venules and small veins only. The cell population comprised an infiltration of heterophils, monocytes and baso‐phils. Marked degranulation and disruption of mast cells accompanied by a significant decrease in their number suggested their active participation. There was strong evidence that the activated mediator cells were both mast cells and basophils. It is suggested that PMA may offer an excellent experimental model in avian anaphylaxis research.     

多层螺旋CT肠系膜动脉造影的三维解剖学研

目的:评价多层螺旋CT血管造影(MSCTA)对肠系膜动脉的显示能力,研究肠系膜动脉的三维影像学解剖。方法:54例患者行腹部MSCT薄层增强扫描获得原始图像,用容积再现(VR)、最大密度投影(MIP)、薄层最大密度投影(TSMIP)、多平面重组(MPR)进行血管三维重建,分析肠系膜动脉的空间解剖特征,比较不同重建方法对肠系膜动脉、特别是交通支的显示。结果:54例肠系膜动脉均清晰显示。VR及MIP图像可显示4～5级分支,TSMIP可显示6～7级分支至肠壁周围血管网。MSCTA可清晰显示肠系膜动脉位置、起源、管径、走向、分布及变异情况。腹腔干(CA)和肠系膜上动脉(SMA)间、SMA内部分支间均可见吻合支,仅59.2%病例显示肠系膜上下动脉间吻合。在显示吻合支的能力方面,TSMIP优于MIP和VR。结论:MSCTA三维成像能很好的显示肠系膜动脉解剖学特征,为临床诊断和治疗提供依据。