A Case of Idiopathic Severe Acute Pancreatitis following Cesarean Section Delivery.

Acute pancreatitis rarely occurs in the postpartum period. Furthermore, there are very few reports of it after cesarean section delivery. A 35-year-old woman presented with dyspnea and abdominal distension on the third day after cesarean section delivery. Under a suspicion of acute pancreatitis, she was initially managed with conservative treatment. However, she developed intra-abdominal fluid collections and gastric bleeding, which were managed with percutaneous drainage, endoscopic hemostasis, and angiographic embolization. She was discharged with good clinical recovery. Postpartum pancreatitis, especially after cesarean section, is rare; however, its management is not different from that for usual pancreatitis.

The fetal splenic vein flow pattern and fetal inflammatory response in the preterm prelabor rupture of membranes.

OBJECTIVE: To evaluate the intensity of the fetal inflammatory response, characterized by umbilical cord blood IL-6 levels, and neonatal outcome in the preterm prelabor rupture of membranes (PPROM) pregnancies using the pulsatile fetal splenic vein flow pattern. METHODS: Women with singleton pregnancies complicated by PPROM at a gestational age between 24 + 0 and 36 + 6 weeks were included in the study. Doppler evaluation of the fetal splenic vein flow was performed. The flow-velocity waveform pattern was evaluated qualitatively as continuous or pulsatile. The umbilical cord blood interleukin-6 (IL-6) levels were evaluated after delivery. The fetal inflammatory response was defined as IL-6 >11 pg/mL. RESULTS: In total, 129 women were included. The fetuses with pulsatile splenic vein flow exhibited higher IL-6 levels in umbilical cord blood (median: 56.7 pg/mL versus 5.6 pg/mL; p < 0.0001) and had a higher rate of fetal inflammatory response syndrome (71% versus 35%; p = 0.0005) than fetuses with continuous flow. The pulsatile flow pattern was related to a higher rate of early onset neonatal sepsis (odds ratio 4.2; 95% confidence interval: 1.3-13.5). CONCLUSION: The presence of pulsatile fetal splenic vein flow in PPROM pregnancies is associated with fetal inflammatory response and neonatal morbidity.

Optimal management of the splenic vein at the time of venous resection for pancreatic cancer: importance of the inferior mesenteric vein.

BACKGROUND: Resection of the superior mesenteric vein (SMV)-portal vein (PV)-splenic vein (SV) confluence during pancreatectomy for pancreatic cancer requires management of the SV. DISCUSSION: Simple SV ligation can result in sinistral portal hypertension if the inferior mesenteric vein (IMV) enters the confluence and is thereby resected, or if the IMV is insufficient to drain the SV. We describe herein three patients whose clinical course confirms the importance of the IMV decompressing the SV to avoid sinistral hypertension.

Ultrasonographic scoring system score versus liver stiffness measurement in prediction of cirrhosis.

BACKGROUND/AIMS: We compared the cirrhosis-prediction accuracy of an ultrasonographic scoring system (USSS) combining six representative sonographic indices with that of liver stiffness measurement (LSM) by transient elastography, and prospectively investigated the correlation between the USSS score and LSM in predicting cirrhosis. METHODS: Two hundred and thirty patients with chronic liver diseases (187 men, 43 women; age, 50.4±9.5 y, mean±SD) were enrolled in this prospective study. The USSS produces a combined score for nodularity of the liver surface and edge, parenchyma echogenicity, presence of right-lobe atrophy, spleen size, splenic vein diameter, and abnormality of the hepatic vein waveform. The correlations of the USSS score and LSM with that of a pathological liver biopsy (METAVIR scoring system: F0-F4) were evaluated. RESULTS: The mean USSS score and LSM were 7.2 and 38.0 kPa, respectively, in patients with histologically overt cirrhosis (F4, P=0.017) and 4.3 and 22.1 kPa in patients with fibrotic change without overt cirrhosis (F0-F3) (P=0.025). The areas under the receiver operating characteristic (ROC) curves of the USSS score and LSM for F4 patients were 0.849 and 0.729, respectively. On the basis of ROC curves, criteria of USSS ≥6: LSM ≥17.4 had a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 89.2%:77.6%, 69.4%:61.4%, 86.5%:83.7%, 74.6%:51.9% and 0.83:0.73, respectively, in predicting F4. CONCLUSIONS: The results indicate that this USSS has comparable efficacy to LSM in the diagnosis of cirrhosis.

Revisiting vascular patency after spleen-preserving laparoscopic distal pancreatectomy with conservation of splenic vessels.

BACKGROUND: We evaluated vascular patency and potential changes in preserved spleens after laparoscopic spleen-preserving distal pancreatectomy (SPDP) with conservation of both splenic vessels. METHODS: We retrospectively analyzed the patency of conserved splenic vessels in patients who underwent laparoscopic or robotic splenic vessel-conserving SPDP from January 2006 to August 2010. The patency of the conserved splenic vessels was evaluated by abdominal computed tomography and classified into three grades according to the degree of severity. RESULTS: Among 30 patients with splenic vessel-conserving laparoscopic SPDP, 29 patients with complete follow-up data were included in this study. During the follow-up period (median: 13.2 months), grades 1 and 2 splenic arterial obliteration were observed in one patient each. A total of five patients (17.2%) showed grade 1 or 2 obliteration in conserved splenic veins. Most patients (82.8%) had patent conserved splenic vein. Four patients (13.8%) eventually developed collateral venous vessels around gastric fundus and reserved spleen, but no spleen infarction was found, and none presented clinical relevant symptoms, such as variceal bleeding. There was no statistical difference in vascular patency between the laparoscopic and robotic groups (P > 0.05). CONCLUSIONS: Most patients showed intact vascular patency in conserved splenic vessels and no secondary changes in the preserved spleen after laparoscopic splenic vessel-conserving SPDP.

Venous drainage from the tail of the pancreas to the lienal vein and its relationship with the distal splenorenal shunt selectivity.

PURPOSE: To identify the veins draining from the pancreatic tail to the lienal vein and its possible relationship with the loss of the distal splenorenal shunt selectivity. METHODS: Thirty eight human blocks including stomach, duodenum, spleen, colon and pancreas, removed from fresh corpses, were studied with the replenish and corrosion technique, using vinilic resin and posterior corrosion of the organic tissue with commercial hydrochloric acid, in order to study the lienal vein and its tributaries. RESULTS: The number of veins flowing directly to the splenic vein varied from seven to twenty two (14.52 + or - 3.53). Pancreatic branches of the pancreatic tail flowing to the segmentary veins of the spleen were found in 25 of the anatomical pieces studied (65.79%). These branches varied from one to four, predominating one branch (60%) and two branches (24%). CONCLUSIONS: In 65.79% of the anatomical pieces studied, the veins of the pancreatic tail flowed in segmentary branches of the splenic vein. These branches could be responsible for the loss of distal splenorenal shunt selectivity. The complete disconnection of the pancreatic tail could increase the selectivity in this procedure.

Venous drainage from the tail of the pancreas to the lienal vein and its relationship with the distal splenorenal shunt selectivity / Drenagem venosa da cauda do pâncreas para a veia lienal e sua relação com a seletividade da anastomose esplenorrenal

PURPOSE: To identify the veins draining from the pancreatic tail to the lienal vein and its possible relationship with the loss of the distal splenorenal shunt selectivity. METHODS: Thirty eight human blocks including stomach, duodenum, spleen, colon and pancreas, removed from fresh corpses, were studied with the replenish and corrosion technique, using vinilic resin and posterior corrosion of the organic tissue with commercial hydrochloric acid, in order to study the lienal vein and its tributaries. RESULTS: The number of veins flowing directly to the splenic vein varied from seven to twenty two (14.52 ± 3.53). Pancreatic branches of the pancreatic tail flowing to the segmentary veins of the spleen were found in 25 of the anatomical pieces studied (65.79 percent). These branches varied from one to four, predominating one branch (60 percent) and two branches (24 percent). CONCLUSIONS: In 65.79 percent of the anatomical pieces studied, the veins of the pancreatic tail flowed in segmentary branches of the splenic vein. These branches could be responsible for the loss of distal splenorenal shunt selectivity. The complete disconnection of the pancreatic tail could increase the selectivity in this procedure.

OBJETIVO: Identificar as veias da cauda do pâncreas afluentes da veia lienal e a possível relação destes ramos com a perda de seletividade da derivação esplenorrenal distal. MÉTODOS: Foram estudadas 38 peças humanas, retiradas de cadáveres, contendo estômago, duodeno, baço, cólon e pâncreas, utilizando-se a técnica de repleção vascular com resina vinílica e posterior corrosão do tecido orgânico com o objetivo de se estudar o molde vascular da veia lienal e seus afluentes. RESULTADOS: O número de veias afluindo diretamente para a veia esplênica variou de sete a vinte dois (MA 14.52±3.53). Ramos pancreáticos da cauda do pâncreas afluindo para as veias segmentares do baço estavam presentes em 25 das peças estudadas (65,79 por cento). Estes ramos variaram de um a quatro, predominando um ramo (60 por cento) e dois ramos (24 por cento). CONCLUSÕES: Em 65,79 por cento das peças veias da cauda do pâncreas desembocavam em ramos segmentares da veia esplênica. Estes ramos poderiam ser responsáveis pela perda de seletividade da derivação esplenorrenal distal e a esqueletização completa da cauda do pâncreas poderia aumentar a seletividade neste procedimento.

Patency of splenic vessels after laparoscopic spleen and splenic vessel-preserving distal pancreatectomy.

BACKGROUND: This study evaluated the short- and long-term patency of preserved splenic vessels after laparoscopic spleen-preserving distal pancreatectomy (SPDP) with preservation of the splenic vessels. METHODS: This single-centre retrospective study included all patients who had undergone splenic vessel-preserving laparoscopic SPDP between 2004 and 2007. The patency of the splenic vessels was assessed by abdominal computed tomography and classified into three grades according to the degree of stenosis. RESULTS: Twenty-two patients were included. The preoperative patency of the splenic artery and vein was normal in 20 and 19 patients respectively. Normal patency of the splenic artery and vein was observed in 16 and five patients respectively within 1 month of surgery, and in 19 and nine patients 6 months or more after operation. Nine of ten patients with complete splenic vein occlusion developed a collateral circulation in the late postoperative phase. Splenic perfusion was well preserved in all patients. CONCLUSION: Splenic vessel-preserving laparoscopic SPDP has the short-term benefit of good perfusion to the spleen. In the long term, there is a risk of left-sided portal hypertension if the splenic vein becomes occluded after surgery. (c) 2009 British Journal of Surgery Society Ltd.

Splenic reflex modulation of central cardiovascular regulatory pathways.

The splenorenal reflex induces changes in mean arterial pressure (MAP) and renal function. We hypothesized that, in addition to spinal pathways previously identified, these effects are also mediated through central pathways. We investigated the effect of elevated splenic venous pressure on central neural activation in intact, renal-denervated, and renal + splenic-denervated rats. Fos-labeled neurons were quantified in the nucleus of the tractus solitarius (NTS), paraventricular nucleus (PVN), supraoptic nucleus (SON), and subfornical organ (SFO) after 1-h partial splenic vein occlusion (SVO) in conscious rats bearing balloon occluders around the splenic vein, telemetric pressure transducers in the gastric vein (splenic venous pressure), and abdominal aorta catheters (MAP). SVO stimulated Fos expression in the PVN and SON, but not NTS or SFO of intact rats. Renal denervation abolished this response in the parvocellular PVN, while renal + splenic denervation abolished activation in the magnocellular PVN and the SON. In renal-denervated animals, SVO depressed Fos expression in the NTS and increased expression in the SFO, responses that were abolished by renal + splenic denervation. In intact rats, SVO also induced a fall in right atrial pressure, an increase in renal afferent nerve activity, and an increase in MAP. We conclude that elevated splenic venous pressure does induce hypothalamic activation and that this is mediated through both splenic and renal afferent nerves. However, in the absence of renal afferent input, SVO depressed NTS activation, probably as a result of the accompanying fall in cardiac preload and reduced afferent signaling from the cardiopulmonary receptors.

Subtotal splenectomy preserving the lower pole in rats: technical, morphological and functional aspects / Esplenectomia subtotal com preservação do pólo inferior em ratos: aspectos técnicos, morfológicos e funcionais

PURPOSE: To assess the possibility of preserving the lower pole of the spleen, supplied by the inferior lobar vessels and segmental vessels, or by vessels of the gastrosplenic ligament, in subtotal splenectomy; to study the viability and function of the lower pole of the spleen. METHODS: Thirty-six male Wistar rats were used in this study. Said animals weighed 273-390 g ( 355.2 ± 30.5 g ), and were randomly distributed into three groups. Group 1 comprised ten animals which were submitted to exploratory laparotomy with spleen manipulation (sham operation). Group 2 comprised 16 animals which were submitted to total splenectomy. Group 3 comprised ten animals which were submitted to subtotal splenectomy, preserving the lower pole of the spleen. Blood was collected from all animals before and 90 days after surgery to measure the levels of cholesterol and triglycerides. The animals were sacrificed 90 days after surgery. Spleens and remaining spleens were removed for macroscopic and microscopic examination. RESULTS: Surgery was performed with no complications in all groups. Six animals died in group 2. Spleens of groups 1 and 2, and lower poles of group 3 were macroscopically viable. Apparent white pulp hyperplasia was observed in group 1. In group 3, slight inflammation and capsular fibrosis were observed at the incision site, as well as diffuse hemosiderosis in the red pulp. Average mass of remaining spleen was 35.84 percent ± 4.31 percent. No significant difference was observed between preoperative and late postoperative lipid levels in groups 1 and 3 (p > 0.05). Late postoperative lipid levels significantly increased in group 2. CONCLUSIONS: Preservation of the lower pole of the spleen (supplied by gastrosplenic vessels or inferior lobar vessels and segmental vessels) was possible with subtotal splenectomy. The lower pole was macroscopically and microscopically viable in all cases. Subtotal splenectomy preserving the lower pole prevented changes in...

OBJETIVO: Avaliar a exequibilidade de preservação do pólo inferior suprido por vasos lobares inferiores e segmentares ou por vasos no ligamento esplenogástrico, na esplenectomia subtotal, e estudar a viabilidade e a função desse pólo. MÉTODOS: Foram utilizados 36 ratos machos, Wistar, com peso entre 273 gramas e 390 gramas (M.A 355,2 ±30,5), distribuídos aleatoriamente em 3 grupos : grupo 1- 10 animais submetidos à laparotomia com manipulação do baço (operação simulada); grupo 2- 16 animais submetidos à esplenectomia total ; grupo 3- 10 animais submetidos à esplenectomia subtotal com preservação do pólo inferior. Em todos os animais foi colhido sangue no pré-operatório e no 90° P.O para dosagem do colesterol e frações e triglicérides. Os animais foram mortos após 90 dias e o baço e o remanescente esplênico foram retirados para estudo macro e microscópico. RESULTADOS: As operações nos três grupos foram realizadas sem dificuldades. Houve 6 óbitos no grupo da esplenectomia total. Os baços dos grupos 1 e 2 e os pólos inferiores do grupo 3 estavam macroscopicamente viáveis. Houve uma aparente hiperplasia da polpa branca no grupo simulação O pólo inferior apresentou áreas discretas de inflamação e fibrose capsular na área da incisão e hemossiderose difusa na polpa vermelha. O percentual médio de massa remanescente do pólo inferior foi 35,84 por cento ± 4,31 por cento. Não houve alterações significantes nos níveis de colesterol e frações e triglicérides no pós-operatório tardio em relação ao pré-operatório (P>0,05) nos grupos 1 e 3. No grupo 2 houve aumento significante do colesterol e frações e triglicérides no pós-operatório tardio. CONCLUSÕES: A preservação do pólo inferior suprido por vasos lobares inferiores e segmentares ou vasos no ligamento esplenogástrico foi exeqüível na esplenectomia subtotal. Esse pólo manteve-se macro e microscopicamente viável em todos os casos. A esplenectomia subtotal com preservação do pólo inferior previne contra as alterações...

Subtotal splenectomy preserving the lower pole in rats: technical, morphological and functional aspects.

PURPOSE: To assess the possibility of preserving the lower pole of the spleen, supplied by the inferior lobar vessels and segmental vessels, or by vessels of the gastrosplenic ligament, in subtotal splenectomy; to study the viability and function of the lower pole of the spleen. METHODS: Thirty-six male Wistar rats were used in this study. Said animals weighed 273-390 g ( 355.2 +/- 30.5 g ), and were randomly distributed into three groups. Group 1 comprised ten animals which were submitted to exploratory laparotomy with spleen manipulation (sham operation). Group 2 comprised 16 animals which were submitted to total splenectomy. Group 3 comprised ten animals which were submitted to subtotal splenectomy, preserving the lower pole of the spleen. Blood was collected from all animals before and 90 days after surgery to measure the levels of cholesterol and triglycerides. The animals were sacrificed 90 days after surgery. Spleens and remaining spleens were removed for macroscopic and microscopic examination. RESULTS: Surgery was performed with no complications in all groups. Six animals died in group 2. Spleens of groups 1 and 2, and lower poles of group 3 were macroscopically viable. Apparent white pulp hyperplasia was observed in group 1. In group 3, slight inflammation and capsular fibrosis were observed at the incision site, as well as diffuse hemosiderosis in the red pulp. Average mass of remaining spleen was 35.84% +/- 4.31%. No significant difference was observed between preoperative and late postoperative lipid levels in groups 1 and 3 (p > 0.05). Late postoperative lipid levels significantly increased in group 2. CONCLUSIONS: Preservation of the lower pole of the spleen (supplied by gastrosplenic vessels or inferior lobar vessels and segmental vessels) was possible with subtotal splenectomy. The lower pole was macroscopically and microscopically viable in all cases. Subtotal splenectomy preserving the lower pole prevented changes in lipid levels, which were observed in rats submitted to total splenectomy. Plasma lipid levels in rats submitted to subtotal splenectomy were similar to those observed in sham operated rats.

Prostacyclin causes splenic dilation and haematological change in dogs.

1. The effect of vasodilators on spleen volume and the blood storage function is not yet well elucidated. To this end, in the present study the effects of prostacyclin, a potent vasodilator, on splenic diameter and blood cell concentrations in arterial and splenic venous blood were evaluated in anaesthetized dogs. 2. The main splenic artery and vein were dissected for measurement of splenic arterial blood flow and intra-arterial administration and for sampling of splenic venous blood, respectively. The diameter of the spleen was measured continuously by sonomicrometry. Counts of white blood cells (WBC), red blood cells (RBC) and platelets in blood sampling from the aorta and splenic vein were estimated by an automatic blood cell counter. 3. Bolus injections of prostacyclin (1-100 ng/kg) into the splenic artery produced dose-dependent increases in splenic arterial blood flow and splenic diameter associated with significant decreases in splenic venous concentrations of WBC, RBC and platelets. When splenic blood flow was kept constant, similar changes in splenic diameter and blood cell counts were observed with prostacyclin injection. 4. Splenic dilation and haematological changes induced by prostacyclin were relatively more potent than those induced by prostaglandin E(2), acetylcholine, nitroglycerin or isoproterenol when doses producing a comparable increase in splenic blood flow were compared. 5. Infusion of prostacyclin (100 ng/kg per min) into the splenic artery caused a marked increase in splenic diameter, with immediate reductions in splenic venous concentrations of WBC, RBC and platelets, followed by significant reductions in these cell counts in the general circulation. 6. These results indicate that prostacyclin produces potent and flow-independent splenic dilation that may contribute to a decrease in circulating blood cell concentrations.

Doppler hemodynamic study in portal hypertension and hepatic encephalopathy.

BACKGROUND/AIMS: The aim of our study was to evaluate and compare the differences in the parameters of portal hypertension in two groups of patients with liver cirrhosis, with and without hepatic encephalopathy (HE). METHODOLOGY: 30 patients with liver cirrhosis, 17 (56.7%) of them with HE, were investigated by clinical, neurological, laboratory, endoscopic methods and with color Doppler ultrasonography (CDU) at the Institute for Digestive Diseases, Clinical Center of Serbia, Beograde. RESULTS: Significant correlation was found between the diameters of the right liver lobe and the portal vein (p=0.01), and also between the diameters of the spleen and splenic vein (p=0.0002), in both groups of patients. Mean portal vein diameter significantly increases (p=0.01) in patients with HE (14.87 +/- 1.86mm), compared to those without HE (13.2 +/- 2.31mm), while mean splenic vein diameter was not significantly different in the two groups. In patients with ascites, CDU showed significantly lower (p=0.03) portal flow velocity (11.87 +/- 6.25cm/ sec), compared to those without ascites (14.33 +/- 4.41cm/sec). Splenic flow velocity was not significantly different (16.00 +/- 6.60cm/sec with ascites and 14.61 +/- 5.29cm/sec without ascites). In patients with HE, portal flow velocity was significantly lower (9.00 +/- 5.41cm/sec) compared to those without HE (14.0 +/- 7.03cm/sec) (p=0.04). Mean splenic flow velocity was significantly lower (p=0.03) in patients with HE (12.60 +/- 4.16cm/sec), compared to those without HE (17.77 +/- 5.91cm/sec). Portal flow velocity shows linear decrease, related to the increase of the liver damage (Child-Pugh score), while splenic velocity was not related to this parameter. CONCLUSIONS: Ultrasonographic parameters of portal hypertension show significant correlation between the diameters of liver/portal vein and spleen/splenic vein. Portal hemodynamic parameter (blood flow velocity) is significantly related to the stages of liver damage, presence of ascites and HE, while splenic hemodynamics is specific and not directly related to these parameters.

Splenorenal reflex modulates renal blood flow in the rat.

We have previously shown that the splenorenal reflex controls renin release through splenic afferent and renal sympathetic nerves. We proposed that this reflex would also affect renal blood flow (RBF). RBF was measured in male Long Evans rats using transit-time flow probes. There were no significant differences between any of the experimental groups with respect to baseline values of RBF (8.9 +/- 0.4 ml min(-1), n= 25) or mean arterial pressure (MAP, 98.7 +/- 2.5 mmHg, n= 25). Splenic venous pressure was selectively raised (from 7.9 +/- 0.6 to 21.6 +/- 0.3 mmHg, n= 25) in anaesthetized rats by partial ligation of the splenic vein. This caused an immediate fall in RBF (-2.1 +/- 0.2 ml min(-1), n= 7) and in MAP (-12.4 +/- 2.8 mmHg, n= 7). The fall in RBF, but not the fall in blood pressure, was attenuated by renal denervation (DeltaRBF: - 0.7 +/- 0.1 ml min(-1), n= 6), splenic denervation (DeltaRBF: -0.8 +/- 0.1 ml min(-1), n= 6) and close renal arterial injection of the alpha1-adrenergic blocker phenoxybenzamine (12.5 microg; DeltaRBF: -0.8 +/- 0.1 ml min(-1), n= 6). Renal conductance fell only in the intact control group, i.e. the residual fall in RBF in the denervated and phenoxybenzamine-treated animals could be attributed to the fall in MAP. We also showed that splenic vein occlusion increased both splenic afferent (from 3.0 +/- 0.3 to 6.6 +/- 0.6 spikes s(-1), n= 5) and renal efferent (from 24.8 +/- 2.0 to 50.2 +/- 4.9 spikes s(-1), n= 9) nerve activity. We conclude that obstruction to splenic venous outflow, such as would occur in portal hypertension, initiates increased splenic afferent nerve activity and renal vasoconstriction through the splenorenal reflex, as well as a fall in blood pressure. We propose that this contributes to the renal and cardiovascular dysfunction observed in portal hypertension.

Guanylyl cyclase mediates ANP-induced vasoconstriction of murine splenic vessels.

We have previously shown that ANP causes differential constriction of the splenic vasculature of the rat (veins greater than arteries), which may be inhibited by blocking the production of cGMP with A7195. In this paper, we report experiments done on vessels derived from guanylyl cyclase (GC)-A knockout mice. Small splenic arteries ( approximately 150-microm diameter) and veins ( approximately 250-microm diameter) were dissected from male GC-A-deficient 129sv mice or age-matched wild-type controls and mounted in a wire myograph. In the wild-type mice, ANP exhibited higher potency in the veins than in the arteries (EC(50) values wild-type mice: artery, 8 +/- 3 x 10(-9) M, n = 5 vs. vein, 6 +/- 4 x 10(-10) M, n = 5; P < 0.05). The concentration-response curve for ANP-induced vasoconstriction was also shifted leftward in denuded compared with intact arteries (EC(50) values: denuded artery: 5 +/- 3 x 10(-10) M, n = 5 vs. intact artery, 8 +/- 3 x 10(-9) M, n = 5; P < 0.05), i.e., the denuded vessels were more reactive. By contrast, ANP caused no significant change in tension from baseline in intact splenic arteries, intact splenic veins, or denuded splenic arteries derived from the GC-A-deficient mice, although these vessels did show normal concentration-dependent increases in tension to phenylephrine. We conclude that ANP causes vasoconstriction in the splenic vasculature by an endothelium-independent mechanism, mediated via guanylyl cyclase.

Intraportal venous flow distribution: evaluation with single breath-hold ECG-triggered three-dimensional half-Fourier fast spin-echo MR imaging and a selective inversion-recovery tagging pulse.

OBJECTIVE: The purpose of this study was to evaluate the intraportal blood flow distribution from splenic and superior mesenteric veins with an unenhanced MR angiographic technique using single breath-hold ECG-triggered three-dimensional (3D) half-Fourier fast spin-echo sequence and selective inversion-recovery tagging pulse. SUBJECTS AND METHODS: Seventeen healthy volunteers were included in this prospective study. After obtaining regular single breath-hold ECG-triggered 3D half-Fourier fast spin-echo images without applying a tagging pulse, we placed the selective inversion-recovery tagging pulse on the superior mesenteric vein (TAG-A), the splenic vein (TAG-B), or on both (TAG-C) to study the inflow correlation of tagged or marked blood into the portal vein. MR images were evaluated subjectively by three reviewers. RESULTS: On MR images obtained using the TAG-A pulse to suppress the signal flow from the superior mesenteric vein into the portal vein, the most common pattern of signal loss was observed on the right half of the main portal vein (8/17 subjects). Conversely, on the MR images obtained using the TAG-B pulse, signal loss of the left half of the main portal vein was the most common pattern (11/17 subjects). Signal reduction from the splenic venous flow in the left portal vein was significantly greater than that from the superior mesenteric venous flow (p<0.05). CONCLUSION: The unenhanced MR angiographic technique using single breath-hold ECG-triggered 3D half-Fourier fast spin echo with selective inversion-recovery tagging pulse has the potential to assess the intraportal blood flow distribution from the splenic and superior mesenteric veins.

Increased splenic capacity in response to transdermal application of nitroglycerine in the dog.

This study was conducted to determine if application of transdermal 2% nitroglycerine ointment (TDNG) to dogs anesthetized with alpha chloralose would produce splenic dilatation by relaxation of venous smooth muscle. Sonomicrometer crystals were applied to the spleen in each of 15 dogs, and a pressure-measuring catheter was inserted into a splenic vein. The sonomicrometer crystals permitted measurement of splenic dimension, which is known to correlate with splenic volume. Ten dogs were given 2.5 cm TDNG/10 kg, and 5 dogs (vehicle controls) were given only petrolatum, both applied to the inner surface of the auricular pinna. Splenic dimension in all dogs receiving TDNG increased significantly (P < .05) by 7.0 +/- 4.8%, whereas splenic dimension in dogs receiving petrolatum did not increase. Splenic venous pressures did not change significantly in either group. Spleens began to dilate 482 +/- 652 seconds after application of TDNG and achieved maximal dilatation at 861 +/- 632 seconds. Splenic dilatation occurred in the absence of elevation of splenic venous pressure, indicating that the dilatation probably resulted from relaxation of splenic smooth muscle. TDNG was absorbed transdermally and produced splenic dilatation in health dogs anesthetized with alpha chloralose. If the spleen is a sentinel for peripheral veins, then TDNG may increase venous capacity, retaining blood from the lungs and thereby functioning to reduce pulmonary congestion and edema in dogs with left-sided heart failure.

Effects of adrenergic-receptor blockade and ligation of spleen vessels on the hemodynamics of dogs injected with scorpion venom.

OBJECTIVE: In dogs, scorpion venom evokes a rapid increase in cardiac output (CO) that decreases below baseline level in 1 hr. The changes in CO have recently been shown to be related to the effect of the venom on venous return. In the present study, we tested the hypothesis that changes in determinants of venous return are secondary to sympathoadrenal stimulation evoked by the venom, which causes splenic contracture in the first stage of envenomation leading to increased mean circulatory pressure (MCP) and CO. Persistence of adrenergic response is the main factor leading to the second stage of envenomation, characterized by an increase in resistance to venous return (Rv) and a decrease in CO. DESIGN: Repeated measures, prospective study in dogs. SETTING: University-affiliated research laboratory. SUBJECTS: Mixed-breed dogs injected with scorpion venom. INTERVENTIONS: The effects of alpha- and beta-adrenergic-receptor blockade (blockade group, n = 9 dogs) and effects of ligation of spleen vessels (spleen ligation group, n = 11 dogs) following intravenous injection of scorpion venom from Leiurus quinquestriatus (0.05 mg/kg) were tested on the determinants of venous return and compared with the effects of scorpion venom alone (control group, n = 6 dogs). MEASUREMENTS AND MAIN RESULTS: Scorpion venom in the control group caused a marked increase in CO from 2.9+/-0.2 SD L/min to 6.5+/-2.2 L/min (p<.001) and MCP from 8.7+/-2.7 torr (1.2+/-0.35 kPa) to 21.6+/-1.4 torr (2.9+/-0.19 kPa) (p<.001) within 5 mins after venom injection. Cardiac output and MCP markedly decreased at 60 mins to 1.8+/-0.3 L/min (p<.001) and 7.3+/-3.8 torr (1.0+/-0.5 kPa) (p<.05), respectively. Rv did not change at 5 mins but increased from 196+/-50 dyne x sec/cm5 to 335+/-102 dyne x sec/cm5 (p<.01) at 60 mins. Adrenergic-receptor blockade attenuated the increase of CO and MCP at 5 mins, from 2.1+/-0.5 L/min to 2.7+/-1 L/min (p<.001) and from 5.6+/-2.0 torr (0.8+/-0.27 kPa) to 7.5+/-2.3 torr (1.0+/-0.31 kPa) (p<.05), respectively. By 60 mins, both CO and MCP returned to baseline, while Rv was not affected and was maintained at 204+/-158 dyne x sec/cm5. Ligation of spleen vessels prevented a CO increase at 5 mins and it was maintained at baseline value (2.5+/-0.6 L/min). However, MCP increased from 7.9+/-0.5 torr to 12+/-1.3 torr (p<.05). At 60 mins, CO decreased to 1.6+/-0.7 L/min (p<.01) while MCP returned to baseline. The changes in MCP were accompanied by significant increases of Rv from 152+/-24 dyne x sec/cm5 to 383+/-93 dyne x sec/cm5 (p<.001) at 5 mins, and 510+/-175 dyne x sec/cm5 (p<.01) at 60 mins. CONCLUSIONS: The changes in CO and MCP following scorpion venom injection in dogs are in part related to sympathetic stimulation. Adrenergic-receptor blockade attenuated the initial inotropic effect of the venom and completely prevented a late decrease in CO and MCP. The increase in Rv is the most important factor for late decrease in CO, and results from persistent adrenergic-receptor stimulation. In addition, an Rv increase apparently expresses vasoconstriction and redistribution of blood flow. The initial increase in CO and MCP is explained mainly by adrenergic-receptor effects on the spleen leading to augmented circulatory blood volume.

Contrast-enhanced three-dimensional magnetic resonance angiography of the splanchnic vasculature before and after caloric stimulation. Original investigation.

RATIONALE AND OBJECTIVES: To develop a comprehensive noninvasive magnetic resonance angiography (MRA) strategy for the morphologic and functional assessment of the splanchnic arteries, based on a combination of breath-held contrast-enhanced 3D MRA and segmented k-space 2D phase-contrast acquisitions acquired before and after caloric stimulation. METHODS: Ten healthy volunteers were examined twice: once in the fasting state (6 hours with no food intake) and a second time following caloric stimulation with a standard 475-kcal meal. Flow in the superior mesenteric artery (SMA) and vein (SMV) was quantitated using a 2D breath-held, segmented k-space phase-contrast (PC) acquisition in a plane perpendicular to the axis of the vessels, while vascular morphology was displayed with a contrast-enhanced 3D MRA acquisition consisting of 44 contiguous 2-mm sections, acquired in apnea (28 seconds). For comparative analysis, the splanchnic vasculature was divided into 11 segments and evaluated on a 2-point scale (cannot exclude pathology, can exclude pathology). RESULTS: Flow volume in the SMA increased from 2.3 ml/min/kg (+/- 0.9 ml/min kg) to 7.3 ml/min kg (+/- 4.7 ml/min kg) following caloric stimulation (P < 0.05). Flow in the SMV exceeded flow in the SMA and increased from 3.4 ml/min/kg (+/- 0.3 ml/min kg) to 9.1 ml/min/kg (+/- 4.8 ml/min/kg) following stimulation. Flow volume of SMV correlated better with SMA flow after stimulation. Caloric stimulation significantly improved visualization of the splanchnic arterial vasculature (P < 0.05). Only 5 of 110 evaluated arterial segments (4.5%) remained inadequately seen to exclude vascular pathology. CONCLUSION: Magnetic resonance imaging offers a comprehensive assessment of the splanchnic arterial vasculature based on 3D display of vessel morphology and analysis of flow function. While the most relevant proximal vessel segments are visible even under fasting conditions, caloric stimulation enhances visualization of small vessels.