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Altered expression of vascular endothelial growth factor and its receptors in normal saphenous vein and in arterialized and stenotic vein grafts.

BACKGROUND: Myointimal thickening is a major cause saphenous vein graft failure. The prominence of medial and adventitial microvessels in stenotic vein grafts and the known angiogenic effects of vascular endothelial growth factor (VEGF) lead us to investigate the expression of VEGF and its receptors in vein graft arterialization and stenosis. METHODS: Normal and arterialized vein graft segments were evaluated by reverse transcription-polymerase chain reaction (RT-PCR) for expression of VEGF-R1 (flt), VEGF-R2 (KDR), and neuropilin-1. The cells expressing VEGF, VEGF-R1, VEGF-R2, and neuropilin-1 were identified in normal, stenotic, and arterialized vein graft segments by immunohistochemistry. RESULTS: Vascular endothelial growth factor, detected in the wall in endothelial cells and adventitial microvessels in normal vein, localized to smooth muscle cells, endothelial cells and adventitial microvessels in arterialized and stenotic vein. VEGF-R1 and VEGF-R2 were expressed infrequently on endothelial cells, macrophages, and smooth muscle cells in arterialized and stenotic vein. Neuropilin-1 was detected in all specimens. RT-PCR demonstrated significantly greater expression of neuropilin-1 in normal vein compared with arterialized vein (P <0.05). CONCLUSIONS: The differential expression of VEGF and its receptors in normal, arterialized, and stenotic vein grafts suggests that alterations in VEGF/VEGF-R2/neuropilin-1 interactions may be important determinants of the adaptive response of vein grafts to arterialization.

Graft Occlusion, Vascular↗

Perivenous support reduces early changes in human vein grafts: studies in whole blood perfused human vein segments.

BACKGROUND: Patency of vein grafts in coronary artery bypass grafting procedures is generally less favorable than those of selected arterial grafts. However, vein grafts still are needed in cardiac operations. It would be desirable to find measures to improve the patency of vein grafts next to antithrombotic regimens. Animal studies demonstrated that arterial pressure induces overdistention of the thin-walled vein grafts and that prevention of this overdistention with extravascular support ameliorates the arterialization process with, subsequently, more favorable patency. To evaluate whether perivenous stenting of the rather muscular human vein grafts is also beneficial, we designed an in vitro model to study the early effects of perivenous support in human vein grafts. METHODS: Seven paired segments of human vein graft obtained during coronary artery bypass grafting procedures were placed in a perfusion circuit and perfused simultaneously with autologous whole blood, with a pressure of 60 mm Hg (nonpulsatile flow). After 30 minutes of perfusion, one segment, and after 60 minutes of perfusion, the remaining segment were taken for histologic and immunohistochemical examination. In the next experiments 7 segments of human vein graft were placed in the circuit and supported with a polytetrafluoroethylene graft to prevent overdistention with 7 unstented segments as controls. RESULTS: In unsupported vein grafts perfused with autologous blood under a pressure of 60 mm Hg, a complete de-endothelialization was shown after 1 hour of perfusion. In the study vein grafts, with a perivenous polytetrafluoroethylene graft preventing overdistention (n = 7), the endothelium remained intact. Electron microscopic investigation of the media showed severe damage in the circular smooth muscle layer in the unstented group, whereas in the stented group almost no injury was found. CONCLUSION: In our in vitro closed-loop model, reproducible vessel wall changes were observed in all human vein graft specimens studied. The beneficial effect of perivenous support could also be established for the human greater saphenous vein, providing a basis for clinical application.

Blood Pressure↗

Prediction of a small internal jugular vein by external jugular vein diameter.

The relationship between internal jugular vein diameter as measured with an ultrasound imaging machine (SiteRite, Dymax) and external jugular vein diameter was studied in 50 anaesthetised patients undergoing elective cardiac surgery. There was an inverse correlation between external jugular vein diameter and internal jugular vein diameter (r = -0.47, p < 0.001). All patients with an external jugular vein diameter of 7 mm or greater had an internal jugular vein diameter of less than 15 mm. No patient with an external jugular vein diameter of less than 7 mm had an internal jugular vein diameter of less than 20 mm. No other patient dimension (height, weight, body mass index, neck circumference) predicted internal jugular vein size. These results suggest that a large external jugular vein (i.e. 7 mm or greater in external diameter) may be associated with a small internal jugular vein. A size 5.0-mm internal diameter tracheal tube may be used to provide a rapid assessment of external jugular vein diameter.

Adult↗

Sonographic guidance when using the right internal jugular vein for central vein access.

OBJECTIVE: The intent of this study was to substantiate the advantages of the use of sonographic guidance for central venous access via the right internal jugular vein. SUBJECTS AND METHODS: Eighty sequential patients requiring central vein access were examined with a hand-held sonography transducer to determine the size, patency, and location of the right internal jugular vein before puncture. Access to the right internal jugular vein was subsequently performed, under sterile conditions, using sonographic guidance. Periprocedural complications were prospectively recorded. Subsequently, we compared our findings with published reports of complications when visible and palpable anatomic landmarks were used for guidance during cannulation of the internal jugular vein. RESULTS: Among these 80 patients, the anatomy of the right internal jugular vein was typical in only 57 (71%). In another 13 patients (16%), sonography showed a medial position of the right internal jugular vein, anterior to the common carotid artery. In three other patients (4%), the right internal jugular vein was positioned laterally by more than 1 cm. In the remaining seven patients (9%), the vein was thrombosed. Its diameter, measured without use of the Valsalva maneuver, also varied, measuring 0.5-2.0 cm. Cannulation was achieved in all 73 patients with a patent right internal jugular vein. One puncture was required in 68 patients (93%); two punctures in three other patients (4%); and three punctures in the remaining two patients (3%). In no case was the common carotid artery inadvertently punctured. Only one periprocedural complication occurred, and it was unrelated to the use of sonographic guidance. CONCLUSION: Sonographic guidance for central vein access via the right internal jugular vein is safer and more efficient than the traditional landmark approach.

Adolescent↗

Remarkable hepatic vein-to-vein anastomoses in giant cavernous hemangioma of the liver: a case report.

Intrahepatic venous collaterals develop in Budd-Chiari syndrome, hepatomas, and other tumors if the hepatic veins are obstructed. In portal hypertension hepatic vein-to-vein anastomoses develop without obstruction of the hepatic veins. In a 53-year-old woman with giant cavernous hemangioma of the liver, hepatic venography demonstrated remarkable hepatic vein-to-vein anastomoses in the periphery of the hepatic veins without venous obstruction, accompanied with low wedged hepatic vein pressure. The hemodynamic change of the liver may cause this abnormality because of the large blood space of the hemangioma. Pathological examination of the resected liver apart from the tumor confirmed numerous deformations and dilatations of the central veins not found in the normal liver, in the area of hepatic vein-to-vein anastomoses shown by venography. Clinically, atypical hepatic resection is possible by maintaining a drainage vein to preserve as much of the normal liver as possible. Hepatic venography, as well as hepatic angiography, gives important information about the liver.

Female↗

Peripheral veins: influence of gender, body mass index, age and varicose veins on cross-sectional area.

To investigate changes in the size of the deep and superficial venous systems associated with gender, age, body mass index and varicose veins, changes to the cross-sectional area of the femoral and the long saphenous veins were analysed in the Duesseldorf/Essen civil servant study population. Between December 1989 and July 1993 a total of 9935 employees were recruited; 9261 were then evaluated for this analysis. Diameters of the long saphenous and femoral veins were determined 2-3 cm distal to the confluence in lying (after 15 min rest) and standing (after 5 min) positions. Cross-sectional areas (CSA) were calculated. A total of 63% of all people were assigned to CEAP (clinical, etiological, anatomical pathophysiological) class 0, 27% to class 1, 8.5% to class 2, while 1.5% belonged to higher CEAP classes. In people without varicose veins (CEAP class 0) the CSA of the femoral and long saphenous veins were smaller in females than in males. In people with a normal body mass index (BMI) (20-25) the mean CSA of the femoral and long saphenous veins in a standing position was similar from the third up to the sixth decade of life. The volume increase due to a standing position expressed as the absolute increase in CSA of the femoral and long saphenous veins was not age-related, either. The relative volume increase expressed as a ratio remained unchanged with age. There was a strong relationship between the CSA of both veins and increasing BMI. In a lying position, the CSA of the femoral and long saphenous veins increased only slightly with increasing CEAP classes. In a standing position, the CSA of both veins increased even in CEAP class 1 (p < 0.001). In a stepwise multivariate regression analysis, the CSA of both veins in a standing position was not age-related but associated with BMI, CEAP classes and gender. The absolute increase in CSA was influenced by all four variables, but BMI and gender were most important. In Conclusion, this study shows that aging is not necessarily associated with an increase in venous CSA of the deep and superficial venous system. BMI is the most important determinant for an increase in CSA in standing position. Varicosity of the superficial venous system is always associated with similar changes in the deep venous system.

Adult↗

[125 reinterventions for recurrent popliteal varicose veins after excision of the short saphenous vein. Anatomical and physiological hypotheses of the mechanism of recurrence].

Recurrence of popliteal varicose veins has long been attributed to insufficient excision of an incompetent short saphenous vein. Indeed, recurrence is still frequent after surgery of the short saphenous. In order to assess the risk of insufficient excision and study the mechanism of recurrence, we reviewed 125 popliteal procedures for recurrence after excision of an incompetent short saphenous vein. Among this series, 48 were personal procedures and among these, 43 had been performed without preoperative ultrasound explorations prior to 1991. Recurrences were classified into five categories (table I) according to the anatomic presentation at reoperation. Type 1) 17 patients had an intact short saphenous (13.6%) with either an inadequate incision or a simple recanalized suture. Type 2) 53 patients had a long stump (42.4%) with new superficial varicose communications. Type 3) 4 patients had a small residual and incompetent short saphenous trunk (3.2%), 20 patients had both a long stump and an incompetent residual trunk (16%). Type 4) 29 patients had incompetent popliteal perforating veins (23.2%). Type 5) 2 patients developed recurrence on a new varicose communication which followed the posterior nerves of the thigh. Among our personal series, 43 reoperations for recurrence were performed without preoperative duplex Doppler exploration. Among them, excision was insufficient in 38 (table II). The 5 patients reoperated after preoperative ultrasound exploration had a popliteal perforating vein. Recurrence with a popliteal perforator was significantly more frequent in men than in women (table III). The delay to reoperation for popliteal recurrence after surgery of the short saphenous (50% at 6 years) was significantly shorter than the delay to reoperation for inguinal recurrence after surgery of the greater saphenous (50% at 12 years) (table V). Insufficient excision was observed in 75.2% of the cases, but 23.2% of the recurrences were due to the development of an incompetent popliteal perforating veins. These perforating veins were residual stumps of the short saphenous with complex pathways, unrecognized perforating veins associated with the short saphenous at the first operation, or a new popliteal incompetence. Ces perforantes de la fosse poplitée pourraient être des moignons résiduels de petites saphènes à trajet complexe, des perforantes méconnues associées à la petite saphène developing in several perforating vessels described in the popliteal fossa. The lack of preoperative ultrasound data made it difficult to interpret these recurrences. The development of perforating veins in the popliteal fossa is a type of recurrence which is probably the expression of particular hemodynamic phenomena in the popliteal venous circulation. These phenomena probably involve the flexion of the popliteal vein, the contraction of the calf muscles, and also popliteal valvular incompetence frequently demonstrated in patients who develop short saphenous vein insufficiency.

Female↗

Retrobronchial vertical vein in totally anomalous pulmonary venous connection to the innominate vein and its specific occurrence in right isomerism.

Recently, a case of right isomerism with totally anomalous pulmonary venous connection (TAPVC) to the innominate vein through a vertical vein that ascended in the mediastinum posterior to the left-sided main bronchus was encountered. This retrobronchial vertical vein that has not been described previously in patients with TAPVC to the innominate vein prompted the performance of a retrospective analysis of 44 cases with TAPVC to the innominate vein in which angiography had been performed. The 44 cases consisted of 36 patients with situs solitus, 7 with right isomerism, and 1 with left isomerism. The spatial relation of the vertical vein to the adjacent pulmonary artery and main bronchus could be defined in 41 cases. The vertical vein was retrobronchial in 4 of 5 cases with right isomerism in which the location of the vertical vein could be defined with certainty. No case with situs solitus or left isomerism was associated with a retrobronchial vertical vein. In all 4 patients with a retrobronchial vertical vein, angiographic evidence of obstruction of pulmonary venous drainage was present, and was due to an extrinsic bronchial compression in 2 and to an intrinsic narrowing of the vertical vein in 2.

Abnormalities, Multiple↗

Causes of varicose vein recurrence: late results of a randomized controlled trial of stripping the long saphenous vein.

BACKGROUND: The purpose of this study was to investigate the long-term outcomes following stripping of the long saphenous vein during primary varicose vein surgery and to identify factors which may predict recurrence and the need for reoperation. METHODS: The original study was designed as a randomized trial of 100 patients (133 legs) who underwent saphenofemoral ligation with or without long saphenous vein stripping. After invitation 11 years later, 51 patients (74 legs) underwent clinical review and duplex imaging and completed an Aberdeen Varicose Vein Symptom Severity Score (AVVSSS). The hospital notes of the original cohort of patients were used to compile cumulative data and assess predictive factors. RESULTS: A cumulative total of 83 legs had developed clinically recurrent varicose veins by 11 years (62%). There was no statistically significant difference between the ligation-only and the stripping groups. Reoperation was required for 20 of 69 legs that underwent ligation alone compared with 7 of 64 legs that had additional long saphenous vein stripping (relative risk [RR], 2.65; 95% confidence interval, 1.20 to 5.84; P = .012). By life table analysis, freedom from reoperation at 11 years was 70% after ligation, compared with 86% after stripping ( P = .01). The presence of neovascularization (RR, 2.88; P = .15) , an incompetent superficial vessel in the thigh (RR, 3.24; P = .03) or an incompetent saphenofemoral junction on duplex imaging at 2 years postoperatively (RR, 4.89; P = .0001) increased the risk of a patient's developing clinically recurrent veins. Patients with visible recurrent varicose veins had a significantly worse AVVSSS ( P = .001). CONCLUSION: Stripping the long saphenous vein is recommended as part of routine varicose vein surgery as it reduced the risk of reoperation by 60% after 11 years, although it did not reduce the rate of visible recurrent veins.

Adult↗

Cephalic vein cutdown at the wrist: comparison to the standard saphenous vein ankle cutdown.

We first developed a technique for cutdown of the cephalic vein at the wrist. We then conducted a prospective cross-over cadaver study comparing the ability of medical students to perform this technique with that of the standard saphenous vein cutdown at the ankle. All students had a previous course in anatomy but had never performed a cutdown. Before testing, the students were given written material and a ten-minute lecture describing both approaches. Seventeen students performed 34 cutdowns; nine students attempted the cephalic cutdown followed by the saphenous cutdown; the remaining eight used the reverse order. The mean time (+/- SD) to isolation of the cephalic vein was 85 +/- 70 seconds; for the saphenous vein, mean time was 70 +/- 89 seconds (P = NS). There was one failure (inability to isolate the vein within five minutes) in 17 attempts at the cephalic vein and two failures in 17 attempts at the saphenous (P = NS). There were no complications (nerve, artery, or tendon injury) with either technique. The mean external vein diameter (+/- SD) of the cephalic vein and the saphenous vein were 3.2 +/- 1.0 mm and 3.6 +/- 0.7 mm, respectively (P = NS). We conclude that relatively inexperienced providers can learn to perform the cephalic vein cutdown at the wrist on fresh cadavers with similar speed and success as that for the saphenous vein cutdown at the ankle. Cutdown at this site may provide a useful alternative to the saphenous cutdown in certain clinical situations.

Humans↗

Comparison of extracellular matrix in skin and saphenous veins from patients with varicose veins: does the skin reflect venous matrix changes?

Varicose vein disease is a frequently occurring pathology with multifactorial causes and a genetic component. An intense remodelling of the varicose vein wall has been described and could be at the origin of its weakness and altered elasticity. We have described previously a dysregulation of collagen synthesis in cultured smooth muscle cells from saphenous veins and in dermal fibroblasts from the skin of patients with varicose veins, suggesting a systemic defect in their connective tissue. The present study describes comparative morphological and immunohistochemical data in both the skin and saphenous veins of eight control subjects (undergoing coronary bypass surgery) and eight patients with varicose veins. Histological staining of glycoproteins, the elastic fibre network and collagen bundles showed that the remodelling and fragmentation of elastic fibres observed in varicose veins were also present in the skin of the patients. When compared with control subjects, we observed in both the veins and skin of patients with varicose veins (i) an increase in the elastic network, as quantified by image analysis; (ii) an accumulation of collagen type I, fibrillin-1 and laminin; and (iii) an overproduction of MMP (matrix metalloproteinase)-1, MMP-2 and MMP-3, analysed by immunohistochemistry, but normal levels of other MMPs (MMP-7 and MMP-9) and their inhibitors (TIMP-1, TIMP-2 and TIMP-3). An imbalance of extracellular matrix production/degradation was thus observed in veins as well as in the skin of the patients with varicose veins and, taken together, these findings show that remodelling is present in different organs, confirming systemic alterations of connective tissues.

Adult↗

Abdominal CT findings when the superior vena cava, brachiocephalic vein, or subclavian vein is obstructed.

OBJECTIVE: We evaluated findings on contrast-enhanced abdominal CT scans that suggest obstruction of the superior vena cava, brachiocephalic vein, or subclavian vein. SUBJECTS AND METHODS: We conducted a retrospective review of 22 patients with superior vena caval, brachiocephalic vein, or subclavian vein obstruction and analyzed the upper abdominal images on a chest CT scan or an abdominal CT scan. We assessed collateral vessels in the upper abdomen to answer the following question: Did enhancement approach undiluted IV contrast or were there other findings? In the second part of our study, we conducted a prospective review of abdominal CT scans of 200 patients without known mediastinal disease or known upper extremity venous occlusion to determine the frequency of abnormal enhancement of these vessels in a healthy population. RESULTS: The groups of collateral vessels revealed on abdominal CT scans were azygos or hemiazygos veins, internal mammary veins, lateral thoracic and superficial thoracoabdominal veins, vertebral venous plexus veins, and small mediastinal collateral veins. In the retrospective series, one patient had focal enhancement of the liver and early inferior vena caval enhancement due to collateral vessels. In the prospective series, abdominal CT scans of two patients (1%) revealed dense undiluted enhancement of one or more groups of collateral vessels: One patient had an ipsilateral pacemaker, and the other patient had an anterior neck phlegmon to the upper mediastinum. Both conditions may have been factors in the revealing of the collateral vessels. Two other patients (1%) in the prospective series had mild to moderate vessel enhancement that was less than that from undiluted contrast material. In one of these patients, the enhancement was related to abdominal wall hyperemia after surgery. In the other patient, enhancement may have been the result of ipsilateral axillary nodes. CONCLUSION: On upper abdominal CT scans, dense undiluted contrast material in the collateral vessel groups that we studied suggests possible obstruction of the superior vena cava, brachiocephalic vein, or subclavian vein.

Abdomen↗

Aberrant right gastric vein directly communicating with left portal vein system. Incidence and implications.

In 3 patients with primary hepatic malignancies, a communication between the right gastric vein and the left portal vein system was recognized at angiography. The right gastric vein entered directly into the left lateral portal veins in 2 patients and into the left medial portal veins in one. Portal angio-CT performed in one patient demonstrated a specific defect only in the left lateral superior area of the liver, consistent with the segmental opacification of the portal vein branch recognized on the angiogram. This rare communication was seen in 3 (1.5%) of 200 consecutive patients who underwent celiac angiography and is most likely an anomaly in which the right gastric vein directly enters the left portal vein instead of the portal vein trunk. When interpreting a filling defect not associated with a mass lesion on portal angio-CT for hepatic neoplasms or the right gastric vein communicating with the left portal vein system on the angiogram, this particular anomaly should be considered.

Adult↗

Detailed anatomy of the internal spermatic vein and the ovarian vein. Human cadaver study and operative spermatic venography: clinical aspects.

The exact anatomical course of the spermatic vein and the ovarian vein (gonadal) has not been described in detail previously. To determine the precise anatomy of the gonadal veins an autopsy study of 70 fresh human cadavers (40 men, 10 women, 10 male stillborns and 10 female stillborns) was performed by making a resin cast of both gonadal veins which then was carefully dissected. The study showed absence of valves in the spermatic vein, cross-communications between the right and left spermatic veins, and communication between the spermatic and renal capsular veins, spermatic and ipsilateral ureteral veins, and spermatic ipsilateral colonic veins. For clarification of the presence of valves intraoperative antegrade spermatic venography was done in 6 men with and 5 without varicocele. In both groups valves were not detected. These observations regarding the anatomy of the spermatic vein and the ovarian vein may help to explain related clinical conditions.

Adult↗

Anatomic study of anterior frontal cortical bridging veins with special reference to the frontopolar vein.

Anatomic variations of the frontopolar vein were investigated in 21 cadaver brains to improve the preservation rate of this vein in interhemispheric surgery for anterior communicating aneurysms. Most of the frontopolar vein has been considered to drain the outer convex side of the frontal lobe, but in reality, the area of its venous drainage was found to cover a large part of the frontal lobe, including its medial and basal surfaces. This observation suggests that sacrifice of the vein during surgery carries a risk of venous infarction. Therefore, care must be taken to not injure the vein during surgery. The mean distance between the frontopolar vein and the most anterior point of the frontal lobe was 31.1 mm. Although the vein became smaller close to the frontal tip, the mean diameter of the vein was 1.9 mm. Morphologically, approximately two-thirds of the frontopolar veins was found to have a "main trunk." The frontopolar vein can be spared during surgery by using a flexible surgical technique incorporating vein dissection or additional craniotomy.

Aged↗

Correlation between preoperative and postoperative duplex vein measurements of the greater saphenous vein used for infrainguinal arterial reconstruction.

Vein diameter measurements using B-mode Doppler ultrasound (US) are used to assess the greater saphenous vein (GSV) for bypass operations; a 2.5-3.0 mm diameter is suggested as a minimum. Preoperative measurements are made while the vein is in the low-pressure venous system. This may not reflect the distended diameter of a vein after placement in the arterial system. This study compares preoperative and postoperative GSV diameters to identify the degree of dilatation and the minimal size adequate for use in arterial bypass operations. The GSV of 11 patients undergoing an infrainguinal arterial bypass were assessed by utilizing Doppler US. Measurements were taken every 10 cm, for 70 cm, along the course of the GSV before and 4 weeks after operation. All segments showed a percent increase in diameter from the preoperative to postoperative time points; 10 cm, 38+/-; 20 cm, 31+/-; 30 cm, 16+/-; 40 cm, 26+/-; 50 cm, 23+/-; 60 cm, 28+/-; and 70 cm, 22+/-. A Bonferroni post hoc analysis between the 2 time point means showed a significant increase in means for the 2 time points of 9.49 units (Bonf p value < 0.001). Preoperative vein segments were divided into 3 categories: </= 3.0 mm, 3.1-4.0 mm, and > 4.1 mm. All showed a significant increase over time. Preoperative diameter measurements of the vein may not reflect the final distended diameter after bypass. Preoperative vein diameters </= 3.0 mm showed a significant increase of 33+/- to nearly 4.0 mm. This was the largest increase observed in any segment measured. A potential 16-33+/- increase in vein diameter should be considered in vein mapping. The rejection of small veins (</= 3.0 mm) in preoperative vein-mapping studies may not be warranted given the potential for a substantial increase in size when placed in the arterial system.

Aged↗

Expression of functional luteinizing hormone (LH) receptor and its messenger ribonucleic acid in bovine uterine veins: LH induction of cyclooxygenase and augmentation of prostaglandin production in bovine uterine veins.

We have previously reported that bovine endometrium contains LH/human CG binding receptors and LH induces cyclooxygenase and prostaglandin production in the bovine endometrium. The present study investigated 1) whether bovine uterine vein and artery contain LH receptor messenger RNA (mRNA) and receptor protein and 2) whether LH can regulate the formation of vasoactive eicosanoids by the uterine vein. The uterine vein endothelium, but not the uterine artery, contained LH receptor mRNA transcript essentially identical to that found in the bovine corpus luteum. The uterine vein endothelium also contained a 95-kDa immunoreactive receptor protein that bound to rat anti-LH receptor antibody in Western blots. The LH receptor mRNA and LH receptor were maximally expressed in the uterine vein from cows in proestrus/estrus compared with cows in luteal or postovulatory phases. Incubation of endothelial minces of uterine vein with LH resulted in a 2-fold increase in cyclooxygenase concentration as determined by Western blot using an antibody to ram seminal vesicle cyclooxygenase. The increase in cyclooxygenase was maximal in cows in proestrus/estrus compared with postovulatory and luteal phase cows. Incubation of proestrous/estrous uterine vein or artery minces with LH or mellitin (a phospholipase A2 stimulator) caused increased production of eicosanoids. In the uterine vein, LH caused a significant increase in both PGF2alpha (basal 4.1 +/- 0.4 vs. 5.7 +/- 0.4 ng/100 mg x 6 h, P < 0.01; N = 9 cows) and PGE2 (basal 5.7 +/- 0.3 vs. 7.7 +/- 0.8 ng/100 mg x 6 h, P < 0.01; N = 6 cows) but had no effect on prostaglandin production by the artery. Mellitin increased PGF2alpha production by both uterine vein and artery minces but had no effect on PGE2 production in either tissue. Addition of steroids (progesterone, estradiol) or cytokines (tumor necrosis factor-alpha, IL-6) to the uterine vascular tissues had essentially no effect on prostanoid production. In summary, bovine uterine vein from proestrous/estrous cows expressed the LH receptor and its mRNA. Expression of the receptor may have physiological significance as LH induces cyclooxygenase and increases prostaglandin release in the uterine vein. The maximal stimulation of the receptor and its mRNA at proestrus/ estrus may serve to increase the amounts of prostanoids reaching the regressing corpus luteum either directly by increasing prostanoid production or indirectly by increasing the blood flow to the ovary.

Animals↗

Combined liver vein and spleen pulp pressure measurements in patients with portal or splenic vein thrombosis.

BACKGROUND: Patients with thrombosis of the portal or splenic vein may develop portal hypertension with bleeding from oesophageal or gastric varices. The relevant portal pressure cannot be measured by liver vein catheterization or transhepatic puncture of the portal vein because the obstruction is peripheral to the accessible part of the portal system. METHODS: Liver vein catheterization was combined with percutaneous splenic pressure measurement in 10 patients with portal or splenic vein thrombosis and no cirrhosis, and 10 cirrhotic patients without thrombosis. The splenic pressure was measured by percutaneous puncture below the curvature of the ribs with an angle of the needle to skin of 30 degrees in order to minimize the risk of cutting the spleen if the patient took a deep breath. RESULTS: None of the patients in whom the described procedure was followed had complications. Pressure measurements in the spleen pulp and splenic vein were concordant. The pressure gradient across the portal venous system (splenic-to-wedged hepatic vein pressure) was -1.3 to 8.5 mmHg (median, 2.8 mmHg) in cirrhosis patients and 0-44 mmHg (median, 18 mmHg) in thrombosis patients, the variation reflecting various degrees of obstruction to flow in the portal venous system. Peripheral portal pressure (splenic-to-free liver vein pressure gradient) was 1.1-28 mmHg (median, 17 mmHg) in cirrhotic patients and 11-52 mmHg (median, 23 mmHg) in thrombosis patients. CONCLUSIONS: Liver vein catheterization combined with percutaneous splenic pressure measurement is feasible in quantifying pressure gradient across a thrombosis of the portal/splenic vein and in quantifying portal pressure peripheral to this kind of thrombosis.

Adult↗