Early perioperative mortality in a multidisciplinary hospital

To clear the efficacy of treatment for large porto-systemic shunts, changes of liver function and portal hemodynamics after obliteration of gastric-renal shunt (GRS) or gastric-inferior phrenic vein shunt (GIS) communicated with gastric fundic varies in 24 patients treated with balloon-occluded retrograde transvenous obliteration (B-RTO) were studied. 1) The wedged hepatic venous pressure and the hepatic venous pressure gradient were statistically not significant changed after obliteration of GRS or GIS. 2) Serum albumin value was significantly increased (p < 0.005) and ICGR15 was significantly improved (p < 0.005) at one year after treatment in patients that, not only whose GRS or GIS were larger than 10mm in diameter, but also whose superior mesenteric arterial venography before treatment showed hepatofugal flow. 3) At a mean follow-up abdominal angiography of 23.3 months in 20 cases, GRS or GIS was yet obliterated respectively. And more, superior mesenteric arterial venography revealed hepatopetal flow alone in 43% of patients that, whose superior mesenteric arterial venography before treatment showed hepatofugal flow. 4) During a mean follow-up of 32.5 months, gastric fundic varies were not recurrent in all patients, but the other hand, cumulative red color sign positive esophageal varies apparent rates were high (16.7% at before treatment, 38.4% at 2-years, 54.4% at 4-years). According to their hemodynamic characteristics, cumulative red color sign positive esophageal varies apparent rates in patients with another collaterals besides GRS or GIS before treatment (26.7% at before treatment, 61.1% at 2-years, 74.1% at 4-years) were significantly higher (p < 0.05) than those in patients without another collateral except GRS or GIS (0% at 2-years, 16.7% at 4-years). We conclude that, 1) Increment of portal flom and improvement of liver function can be expected by obliteration of GRS or GIS in patients that, whose superior mesenteric venous blood flow into large GRS or GIS. 2) After obliteration of GRS or GIS, the incidence of aggravation of esophageal varies in patients with another collaterals besides GRS or GIS before treatment is high, while that in cases without another collateral is low.     

MR imaging in the evaluation of the therapeutic effect of B-RTO for gastric varices

BACKGROUNDS/AIMS: Balloon-occluded retrograde transvenous obliteration (B-RTO) has become a new treatment option for gastric varices. In the present study, mid-term follow-up data after B-RTO were presented, and the role of magnetic resonance imaging (MRI) and MR-portography in the assessment of therapeutic effect was evaluated. METHODOLOGY: Twelve patients with gastric varices were treated with up to three sessions of B-RTO. The patients were followed up with MRI, MR-portography, and endoscopy for a mean of 12.3 months. RESULTS: In ten patients, one (n = 8) or two (n = 2) sessions of B-RTO were effective to produce immediate (< 2 weeks) variceal obliteration on MRI and MR-portography. Endoscopic confirmation of variceal eradication was obtained within three (n = 9) or six (n = 1) months after B-RTO in these patients. The remaining two patients who underwent three sessions of B-RTO showed only a significant reduction in variceal size immediately after B-RTO, but variceal obliteration was observed within three months with subsequent variceal eradication. There were no signs of exacerbation of gastric varices on MRI and endoscopy in any patient during the follow-up period. CONCLUSIONS: The results suggest that B-RTO is effective for the treatment of gastric varices. MRI and MR-portography may provide accurate assessment of therapeutic effect.     

Injection sclerotherapy for gastric varices using N-butyl-2-cyanoacrylate and ethanolamine oleate

BACKGROUND/AIMS: Tissue adhesive agents, such as the cyanoacrylates, have been used as an alternative to conventional sclerotherapy to treat gastric varices, but the long-term efficacy of this approach has not been determined. We evaluated the efficacy and long-term outcome of injection sclerotherapy with n-butyl-2-cyanoacrylate and ethanolamine oleate in 16 patients with gastric varices. METHODOLOGY: We evaluated the effect of injection sclerotherapy in 16 Japanese patients with gastric varices. Injection sclerotherapy was performed on an emergency basis in 6 patients, an elective basis in 5 patients, and as prophylaxis in 5 patients. RESULTS: No bleeding was observed in the 7 patients in whom gastric varices disappeared during the 51 month follow-up period. The non-bleeding rate after treatment was significantly higher in this group than in the 9 patients in whom gastric varices did not disappear (p<0.05). Acute bleeding was stopped in 5 (83.3%) of 6 patients. The single failure was a patient in whom the sclerosant could not be injected into the gastric varices. No serious complications, such as emboli in other organs, were observed. CONCLUSION: The results suggest that this therapy is a safe and useful treatment for gastric varices and that the goal of injection sclerotherapy should be the disappearance of gastric varices.     

Progressive genu valgum secondary to a fibrous tether at the distal aspect of the femur. A case report

We describe a technique for the treatment of hepatic encephalopathy in a cirrhotic patient with a large spontaneous splenorenal shunt. This large shunt was successfully occluded without severe complications by retrograde transrenal venous obliteration with ethanolamine oleate after balloon occlusion. This procedure may be an effective method to occlude a large spontaneous splenorenal shunt for the treatment of hepatic encephalopathy.     

A novel therapeutic approach for rectal varices: a case report of rectal varices treated with double balloon-occluded embolotherapy

We present a patient with continuous melena, diagnosed as rectal varices bleeding. She had a history of esophageal varices, which was treated by endoscopic ligation therapy. Eight years after the treatment of esophageal varices, the continuous melena began. Colonoscopic examination showed that the melena was caused by rectal varices, which were so severe that they could not be treated by either endoscopic sclerotherapy or surgical devascularization. Taking into considering the overall risk of treating rectal varices, we chose the approach of double balloon-occluded embolotherapy (DBOE) with 5% ethanolamine oleate with iopamodol as a liquid embolic material. DBOE is one of the interventional radiology techniques (Morita et al., Acta Hepatol Jpn 1994;35:109-120), but in this case was a completely new and novel clinical procedure for rectal varices. After the DBOE therapy, the condition of rectal varices was markedly improved. Thus, DBOE might be a new tool for treating inoperable rectal varices.     

Influence of extravariceal collateral channel pattern on recurrence of esophageal varices after sclerotherapy

We investigated the influence of extravariceal collateral channel pattern on the recurrence of esophageal varices after sclerotherapy. One hundred and fifteen patients with cirrhosis and esophageal varices were studied. They were divided into four groups according to extravariceal collateral pattern on portal venography. Group 1 patients had neither paraesophageal veins nor gastrorenal veins (n = 49); group 2 patients had paraesophageal veins only (n = 30); group 3 patients had gastrorenal veins only (n = 25); and group 4 patients had paraesophageal veins plus gastrorenal veins (n = 11). Sclerotherapy was repeated to eradicate esophageal varices and follow-up endoscopic examination were performed. The overall recurrence-free rate at 36 months was 68%. The log-rank test showed the recurrence-free rate to be significantly higher in group 3 (76%) and group 4 patients (89%) than in group 1 patients (51%; P < 0.05 and P < 0.05, respectively). Although the recurrence-free rate was higher in group 4 than in group 2 patients (59%), this did not reach the level of significance (P = 0.10). No significant differences were found between other pairs of groups. These results suggest that gastrorenal veins play an important role in the protection against recurrent esophageal varices after sclerotherapy, while the protective role of paraesophageal veins appears to be small.     

Estrogen alleviates cognitive dysfunction following transient brain ischemia in ovariectomized gerbils

Acute hepatic failure models with extensive hepatic necrosis and hyperammonemia were developed in small animals. One model is bases on the retrograde infusion of ethanolamine oleate into the common bile duct of guinea pigs and another is based on the infusion of TNF-lipiodol emulsion into the portal tract of rats.     

Sevoflurane selectively increases coronary collateral blood flow independent of KATP channels in vivo

BACKGROUND: Volatile anesthetic agents produce coronary vasodilation via activation of adenosine triphosphate-sensitive potassium (KATP) channels. The authors tested the hypothesis that sevoflurane selectively increases coronary collateral blood flow and assessed the role of KATP channel activation in this process. METHODS: Experiments were conducted in dogs 8 weeks after long-term implantation of a left anterior descending coronary artery (LAD) ameroid constrictor to stimulate coronary collateral growth. Dogs were instrumented for measurement of retrograde LAD blood flow (an index of large coronary collateral blood flow) and LAD tissue flow (via radioactive microspheres; an index of small collateral blood flow). Coronary collateral perfusion and normal (left circumflex coronary artery [LCCA]) zone tissue blood flow were determined in four groups of dogs pretreated with intracoronary glyburide (50 microg/kg) or vehicle in the presence or absence of sevoflurane (1 minimum alveolar concentration). Dose-response relationships to the KATP channel agonist nicorandil were established in each dog using doses (25, 50, and 100 microg/min) previously shown to increase coronary collateral blood flow. RESULTS: Sevoflurane increased blood flow through large and small collaterals and increased collateral vascular conductance in the presence of glyburide but did not affect LCCA blood flow or conductance. In contrast, nicorandil increased blood flow through small but not large collaterals. Nicorandil also increased LCCA blood flow and conductance, actions that were attenuated by glyburide. CONCLUSIONS: The results demonstrate that sevoflurane selectively increases large and small coronary collateral blood flow via mechanism(s) independent of KATP channel activation.     

Echocardiographic evidence of aortopulmonary collaterals in premature infants after closure of ductus arteriosus

Aortopulmonary collaterals occur in a variety of congenital heart diseases, in chronic pulmonary infection and abscesses, in association with lung tumors, and after multiple pulmonary emboli. In patients with congenital cyanotic heart disease aortopulmonary collaterals mainly occur in conditions with reduced pulmonary blood flow. We investigated 12 preterm low-birth-weight infants, gestational age 29.3+/-3.3 weeks, with respiratory failure who suffered from moderate to severe chronic lung disease after a period of mechanical ventilation. All patients developed aortopulmonary collaterals after closure of a patent ductus arteriosus. Aortopulmonary collaterals could be displayed clearly by color Doppler echocardiography and originated mainly from the descending aorta or the aortic arch. Hypoxic and hypercapnic episodes favored the development of aortopulmonary collaterals, which disappeared after pulmonary hemodynamics and respiratory function had improved. In only one patient coiling of a large col lateral vessel had to be performed. Systemic-to-pulmonary collateral vessels potentially aggravate chronic lung disease by increasing collateral pulmonary blood flow and reducing lung compliance. We conclude that aortopulmonary collaterals occur in bronchopulmonary dysplasia and can cause major problems in ventilated premature infants. Echocardiographic evaluation is important to prevent aggravation of chronic lung disease of infants at risk.     

Effects of endoscopic variceal sclerotherapy on azygos vein blood flow and systemic haemodynamics

The present study was designed to determine the systemic haemodynamic effects of obliterating oesophageal varices by endoscopic sclerotherapy. We evaluated systemic and splanchnic haemodynamics before and after the first course of sclerotherapy in cirrhotic patients. The baseline cardiac index was significantly correlated with baseline azygos vein blood flow (r = 0.64; P < 0.01) and the azygos vein blood flow and cardiac index significantly decreased (-33% and -16%, respectively; P < 0.01) following sclerotherapy. The systemic vascular resistance index was also increased significantly (+ 20%; P < 0.01) in these patients. Moreover, the per cent change in azygos vein blood flow was directly correlated with that of the cardiac index (r = 0.51; P < 0.03). We conclude from these findings that the obliteration of portosystemic collaterals by sclerotherapy significantly reverses hyperdynamic circulation in such patients via a decrease in cardiac preload. The blood flow of the portosystemic shunt per se is a leading contributor to the hyperdynamic circulation observed in patients with well-developed portal systemic collateral vessels.     

Significance of radioisotope bone marrow uptake on 99m technetium sulphocolloid scan in portal hypertension

A prospective study of 101 consecutive patients of portal hypertension was carried out to study the possible relationships between bone marrow activity on 99m technetium labelled sulphocolloid scan and severity of liver disease, etiology of portal hypertension and cirrhosis, as well as presence and extent of collateral circulation, including esophageal varices. The patients were divided into 4 etiological groups: alcoholic cirrhosis (ALD), (38) non-alcoholic cirrhosis (NALD) (35) non-cirrhotic portal fibrosis (NCPF) (14) and extrahepatic portal vein obstruction (EHPVO) (14). Patients of cirrhosis were categorised according to modified Child-Pugh's classification. Esophageal varices were graded endoscopically as (1) no varix (2) small varices (< 5mm) (3) large varices (> 5mm). All patients underwent radionuclide imaging using 99m Technetium labelled sulphocolloid and bone marrow activity was studied. Evaluation of portasystemic collaterals was done ultrasonically. We found that 16.6%, 44.6% and 72.72% patients with Child A, B and C cirrhosis respectively, had increased marrow activity (p < 0.05). There was no significant difference between marrow activity of patients with ALD (52.6%) and NALD (40%). None of the non-cirrhotic patients demonstrated bone marrow uptake of radioisotope. There was no significant difference between bone marrow uptake presence of lienorenal collaterals and presence or size of esophageal varices. We thus conclude the bone marrow activity on radioisotope scanning depends only on the severity of liver disease and does not vary a according to the etiology of cirrhosis, or presence and extent of portasystemic collaterals, including esophageal varices.     

Development of extrahepatic arterial blood supply to the liver during hepatic arterial infusion chemotherapy

The aim of this study was to evaluate the correlation of development of the collateral circulation to the liver during hepatic arterial infusion chemotherapy (HAIC) with the presence of hepatic tumours adjacent to the hepatic surface, and with pretreatment occlusion of aberrant hepatic arteries. In 102 patients with unresectable malignant hepatic tumours treated with HAIC using an implantable port system, development of collaterals to the liver was assessed with CT arteriography using the implantable port and pre- and postoperative angiography. Aberrant hepatic arteries, if present, were occluded prior to treatment for hepatic arterial redistribution. Collaterals to the liver were seen in 29 patients, who had 35 areas with collateral perfusion: 22 areas were in the right posterosuperior area, 6 in the left peripheral area and 7 in the right or left lobar area. Collaterals were revealed more frequently in patients with hepatic tumours adjacent to the hepatic surface than in those without hepatic tumours in peripheral areas in the liver (p < 0.0001). In addition, collaterals developed more frequently in patients with an aberrant hepatic arterial anatomy compared with those with conventional anatomy (p = 0.0007). Our results indicated that patients with hepatic tumours adjacent to the hepatic surface and with pretreatment occlusion of aberrant hepatic arteries had the potential to develop collaterals to the liver during HAIC.     

Collateral circulation to an ischemic kidney

A review of 301 consecutive abdominal arteriograms given to patients suspected of having occlusive arterial diseases was conducted. In 99 patients, 35% or more stenosis of the renal artery was demonstrated; of these, 40 showed demonstrable collaterals to the ischemic kidney. The adrenal and lumbar arteries contributed four times more frequently than the periureteric arteries to the collateral circulation. Characteristic ureteral notching from the periureteric artery collateral was noted in only 50% of the cases. Intrarenal collaterals were observed and appeared to contribute to the preservation of the size and function of the affected kidney.     

Alteration of serotonergic innervation in the suprachiasmatic nucleus of the rat following removal of input fibers from retina and lateral geniculate nucleus

We report the results of sclerotherapy in 20 patients with bleeding gastric varices due to hepatic schistosomiasis. In an endemic area, patients with hepatic schistosomiasis, and bleeding gastric varices seen on endoscopy to be inferior extension of esophageal varices, were treated with emergency endoscopic injection just proximal to the cardia. Hemostasis was achieved in 17. Obliteration of varices was achieved in all patients with sclerotherapy, combined with surgery. Thirteen patients who had not been operated on in the past and consented to surgery underwent esophagogastric devascularization with splenectomy. Surgery was carried out as an emergency in the three patients who did not respond to sclerotherapy and electively in 10 patients after control of bleeding. After surgery, sclerotherapy was required for remnant varices. One patient with Child-Pugh grade C cirrhosis died of hepatic encephalopathy after control of the bleed. During a median follow-up of 9 months (range, 1-25 months), recurrence of bleeding in one patient and recurrent varices in two others were controlled with sclerotherapy. One patient had a fatal hemorrhage at home. We conclude that sclerotherapy effectively controls acutely bleeding type 1 gastric varices. Combined with esophagogastric devascularization and splenectomy, long-term results may be encouraging in patients with hepatic schistosomiasis.     

Application of ultrasound method for hemorrhagic digestive disease]

Ultrasonography for the digestive diseases are consisted of abdominal ultrasonography (US), endoscopic ultrasonography (EUS) and color Doppler endoscopic ultrasonography (CDEUS). These play a supplementary role in comparison with the roentgenography and endoscopy. The information of the ultrasonography is different from these examinations. By US the collateral shunts of esophago-gastric varices are observed. EUS is useful for diagnosis of the properties of esophago-gastric varices and judgement of effects of treatment for these varices, gastric ulcer and vessels in ulcer base and hemorrhagic bowel diseases. CDEUS can show blood streams of esophago-gastric varices and hemorrhagic ulcer.     

Doppler-duplex ultrasonography in the diagnosis of cavernous portal vein

Prehepatic portal hypertension caused by cavernous transformation of the portal vein has been more and more considered as a multiorgan disease with circulatory changes in numerous organs related to systemic and splanchnic vascular network [1]. Honeycomb-like, spongy, cavernous portal vein is a rare clinical and pathoanatomical entity which usually results from portal vein thrombosis. Recanalization and neovascularization processes lead to cavernomatous transformation of the portal vein lumen and formation of periportal collateral hepatopetal venous varices (Petren's veins) [5, 6]. Recently, with Doppler ultrasonography and angiography cavernous portal vein has been identified as the cause of prehepatic portal hypertension. Usage of color Doppler and duplex Doppler ultrasonography has greatly contributed to diagnostic efficiency, while therapeutically, the disease remains a serious and controversial problem. METHODS: At the Institute of Digestive Diseases, Clinical Centre of Serbia, 8 patients with cavernous portal vein were studied in the period 1995-1997. Real-time duplex and color Doppler ultrasonography (Toshiba-SSA 100A with sector duplex probe 3.75 MHz, and 9 ATL with color Doppler convex duplex probe 3.5 MHz) were used. Indirect (arterial) portography was used for imaging of lienoportal system in the venous phase of angiography as follows: catheterization (Seldinger's technique) of the coeliac trunk or lienal artery, and catheterization of the superior mesenteric artery. Indirect portography was performed by injection of 60-80 ml of the contrast medium by an automatic pump, at 10-14 ml/sec, i.e. 8-10 ml/sec by the digital technique [7]. Peroral fiberendoscopy was performed in all patients by Olympus GIF-XQ 10 endoscope. RESULTS: In our study the conventional ultrasonographic examination failed to provide an appropriate image of the normal portal vein. In hepatoduodenal ligament multiple tubular and round structures were seen, revealing an atypical honeycomb or spongycavernous shape of the venous lumen (Figs. 1 and 2). Doppler ultrasonography of the lumen of these venous collateral structures revealed a continuous, hypokinetic flow, mid-rate 7.4 cm/sec, which was always hepatopetally directed (to the liver). Color Doppler ultrasonography detected extensive portosystemic collateralls in all patients, and varices in the gallbladder wall in 1 patient. The results of indirect portography correlated well with Doppler ultrasonographic findings. In all patients hepatopetal flow was found (Figs. 3 and 4). The aetiology was diverse: idiopathic, liver cirrhosis, haematological diseases, Crohn's disease and Marfan's syndrome. Two patients had IV degree varices in the distal third of the oesophagus, and 4 patients had II/III degree varices. Patients with posthepatic liver cirrhosis and Crohn's disease had no varices in the distal third of the oesophagus and gastric fornix. DISCUSSION: Since Pick (1909) described this malformation as the hepatopetal collateral, the haemodynamic concept of this entity has not been changed. Doppler ultrasonography and angiography confirm that the blood flow in cavernomas is hepatopetal, i.e. compensated and functional. Cavernous transformation of the portal vein is clinically manifested by bleeding from oesophagogastric varices. Haemathemesis is the most alarming complication and may be the first clinical sign. The haemorrhage is usually recurrent and profuse, but in most cases it is tolerated well owing to preserved hepatic function in patients without liver cirrhosis [19]. Portosystemic collateral circulation may take place via retroperitoneal and other spontaneous venous shunts, not involving the left gastric vein or vv. gastricae breves, when oesophagogastric varices are absent (our patient with Crohn's disease and posthepatitic B cirrhosis). Splenomegaly with hypersplenism is always present with cavernous transformation of the portal vein, and usually precedes the occurrence of gastrointestinal hae     

Transjugular obliteration of the gastric coronary vein

The feasibility of transjugular entry into the portal vein for catheterization and obliteration of the left gastric vein is demonstrated in a human. This technique may play a significant role in the nonsurgical management of bleeding esophageal varices.     

Computed radiography of the chest in patients with paraesophageal varices: diagnostic accuracy and characteristic findings

OBJECTIVE: The purpose of our study was to determine the diagnostic accuracy of computed radiography of the chest in the detection of paraesophageal varices and to describe the characteristic radiographic findings. SUBJECTS AND METHODS: From June 1995 through May 1997, in 100 consecutive patients, portal hypertension was diagnosed through both clinical and radiologic evidence. Computed radiographs of the chest and hepatic helical CT scans of these 100 patients with portal hypertension and 20 control subjects were analyzed by two chest radiologists and one abdominal radiologist, who were not aware of the results of the other study. RESULTS: On CT, paraesophageal varices were seen in 38 (38%) of 100 patients with portal hypertension. Overall, the sensitivity, specificity, and accuracy of chest computed radiography in the detection of paraesophageal varices were 53% (20/38), 90% (74/82), and 78% (94/120), respectively. In the patients with paraesophageal varices, splenomegaly (29/38, 76%), lateral displacement or obliteration of the inferior portion of the azygoesophageal interface (18/38, 47%), obliteration or nodularity of the inferior portion of the descending thoracic aorta interface (9/38, 24%), lateral displacement of the right inferior paraspinal interface (6/38, 16%), lateral displacement of the left inferior paraspinal interface (4/38, 11%), and varices in the left inferior pulmonary ligament (1/38, 3%) were seen on chest computed radiographs. Paraesophageal varices smaller than the diameter of the descending thoracic aorta (usually <2.5 cm) were not detected. CONCLUSION: Although chest computed radiography is only moderately sensitive for paraesophageal varices, the findings are characteristic when well developed, with a limited differential diagnosis. Splenomegaly, whether detected clinically or radiographically, eliminates most other diagnostic possibilities.     

Influence of nitroglycerin on portal pressure and gastric mucosal hemodynamics in patients with cirrhosis

We studied 30 patients with cirrhosis to determine the effect of nitroglycerin on portal and gastric mucosal hemodynamics. Systemic hemodynamics, portal venous pressure (PVP), the hemoglobin index (IHB), and the oxygen saturation index (ISO2) of the gastric mucosa were measured before and after a continuous infusion of nitroglycerin. The patients were divided into two groups according to the presence or absence of major portal-systemic collateral routes on portograms. Nitroglycerin caused a reduction in PVP in all patients. Although there was no significant difference in systemic hemodynamic changes between the two groups, the reduction in PVP in patients with major portal-systemic collaterals was significantly higher than in those without major collaterals. A nitroglycerin infusion, at a dose of 1.0 micrograms/kg per min for 10 min, produced a reduction in both IHB (-16%, P < 0.001) and ISO2 (-13%, P < 0.001) in the gastric mucosa, indicating gastric mucosal ischemia secondary to splanchnic vasoconstriction. These findings suggest that the continuous infusion of nitroglycerin reduces PVP in cirrhotic patients, particularly in those with major portal-systemic collaterals, and reduces the congestion of the gastric mucosa in patients with portal hypertension.     

Endothelium-dependent relaxation of collateral microvessels after intramuscular gene transfer of vascular endothelial growth factor in a rat model of hindlimb ischemia

BACKGROUND: Recent investigations have demonstrated the ability of vascular endothelial growth factor (VEGF) to augment the development of collateral arteries in vivo. In vitro studies have suggested that the use of VEGF also improves the endothelium-dependent relaxation of collaterals at the microvascular level. The purpose of this study was to determine in vivo the extent to which vasomotor responses of collateral microvessels are altered after VEGF treatment. METHODS AND RESULTS:Ischemia was induced in the hindlimb of 35 rats by excision of the femoral artery. Immediately thereafter, 400 microg of a plasmid encoding VEGF or ss-galactosidase (control) was transfected into limb muscles. Four weeks later, synchrotron radiation microangiography, with a spatial resolution of 30 microm, was performed to document the reactivity of collateral microvessels. Administration of the endothelium-dependent vasodilator acetylcholine failed to induce dilation of collateral microvessels in control animals. By contrast, profound dilation of collaterals was observed after acetylcholine in VEGF-treated animals. This response was evident in vessels with a linear appearance but not in those with an undulating appearance. The resulting blood flow in the ischemic limb after administration of acetylcholine in the control animals was only 64.6+/-17.0% of that of the contralateral normal limb, whereas blood flow was augmented to 106.1+/-8.4% in VEGF-treated animals (P<0.05). CONCLUSIONS: These results demonstrate in vivo that the use of VEGF restores impaired vasomotor responses in some types of collateral microvessels, which may help to provide a basis for understanding the microcirculation after therapeutic angiogenesis with VEGF.