HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Marc A Ruel Frank W Sellke Tanveer A Khan William E Cohn Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Ruel, M. A. Articles by Cohn, W. E. Search for Related Content PubMed PubMed Citation Articles by Ruel, M. A. Articles by Cohn, W. E.

Ann Thorac Surg 2003;75:1443-1449
© 2003 The Society of Thoracic Surgeons

---

Original article: cardiovascular

Endogenous myocardial angiogenesis and revascularization using a gastric submucosal patch

^a Center for Minimally Invasive Surgery, Harvard Medical School, Boston, MA, USA
^b Division of Cardiothoracic Surgery, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, Boston, MA, USA

Accepted for publication October 24, 2002.

^* Address reprint requests to Dr Cohn, Division of Cardiothoracic Surgery, Beth Israel Deaconess Medical Center, 110 Francis St, Suite 2A, Boston, MA 02215, USA (Email: wcohn{at}caregroup.harvard.edu).

	Abstract

Top Abstract Introduction Material and methods Results Comment Acknowledgments References

 
Background: The gastrointestinal submucosa physiologically produces angiogenic proteins. We examined whether these properties could lead to endogenous myocardial angiogenesis in a swine model of chronic ischemia.

Methods: Fifteen Yorkshire swine underwent ameroid constrictor placement around the circumflex artery and either lateral epicardial abrasion, creation of a gastroepiploic artery (GEA) based gastric patch, mucosal avulsion, transdiaphragmatic transfer, and apposition of the patch against the circumflex myocardial territory (number = 8; test animals), or lateral epicardial abrasion alone (number = 7; controls). Seven weeks later, lateral myocardial perfusion, endothelial cell density, and expression of VEGFR-1 and VE-cadherin were determined using isotope-labeled microsphere assays, immunohistochemistry, and immunoblotting, respectively.

Results: Microsphere assays showed equivalent lateral/anterior myocardial perfusion indices at rest (1.10 ± 0.49 vs 0.95 ± 0.23, test vs control animals; p = 0.54), but higher perfusion in test animals versus controls during pacing (1.05 ± 0.29 vs 0.69 ± 0.09, test vs controls; p = 0.02). Increased myocardial endothelial cell density (42.6 ± 8.5 vs 26.1 ± 11.6 cells per 3850 µm², test vs controls; p = 0.02) and expression of VE-cadherin (3.10 ± 0.60-fold change, test vs controls; p = 0.001) were also observed in the lateral territory of test animals versus controls. Reconstitution of the proximally occluded circumflex artery from patch collaterals was demonstrated on gastroepiploic arteriography in a subset of test animals.

Conclusions: This model results in an angiogenic process of significantly greater magnitude than that resulting from chronic myocardial ischemia alone, without the need for exogenous angiogenic agents.

	Introduction

Top Abstract Introduction Material and methods Results Comment Acknowledgments References

 
Angiogenesis is an incompletely understood process which involves a multitude of steps, signals, and substances [1]. Therapeutic regimens have been largely based on the administration of a single growth factor, and limited by efficacy and safety issues that are likely to persist until the angiogenic cascade and the role of exogenous substances are better understood [2–4]. In the meantime, the use of modalities or tissues that stimulate physiologic angiogenesis could constitute a more controlled and effective approach to angiogenic therapy.

Multiple growth factors have been identified from the gastrointestinal mucosa and submucosa, including epidermal, transforming, vascular endothelial, and fibroblast growth factors [5, 6], whose expression as well as that of their receptors have been reported to be upregulated after mucosal injury [7–10]. Aiming at developing a method to enhance endogenous myocardial angiogenesis without the use of growth factors, we examined whether the properties of the gastric submucosa could be surgically modulated to accomplish myocardial revascularization in a swine model of chronic ischemia.

	Material and methods

Top Abstract Introduction Material and methods Results Comment Acknowledgments References

 
Animal protocol
General experimental sequence
Fifteen 18- to 23-kg female Yorkshire pigs were randomized for the study, which consisted of two separate procedures on each animal. The first stage involved the placement of an ameroid constrictor around the proximal circumflex artery in all swine. Test animals (n = 8) also had a gastric submucosal patch constructed and apposed against the lateral surface of the heart after abrasion of the overlying epicardium. Control animals (n = 7) underwent ameroid placement and abrasion of the lateral epicardium only.

The animals were brought back 7 weeks later for a second procedure that involved sternotomy, upper laparotomy and selective angiography of the gastroepiploic artery in test animals, complete dissection of the heart including removal of the gastric submucosal patch in test animals, visual determination of the ischemic zone supplied by branches of the circumflex artery 1- to 3-cm caudal to the left atrioventricular groove, microsphere blood flow determinations at rest and during pacing, euthanasia, and cardiac harvest for myocardial microsphere analyses, immunohistochemistry, and immunoblotting.

Animal preparation
Anesthesia was induced with telazol 4.4 mg/kg intramuscularly and xylazine 2.2 mg/kg intramuscularly, and maintained with 1.0% to 2.0% isoflurane in a 60% O₂/room air mixture for all procedures. Cefazolin 30 mg/kg was intravenously administered at induction and narcotic analgesics (buprenorphine 0.02 mg/kg intramuscularly b.i.d.) were given for a minimum of 24 hours postoperatively. Euthanasia was carried out with 10 ml/kg of a saturated KCl solution administered intravenously. All animals received humane care in compliance with the Harvard Medical Area Institutional Animal Care and Use Committee and the National Research Council’s Guide for the Care and Use of Laboratory Animals, prepared by the Institute of Laboratory Animals and published by the National Institutes of Health (National Institutes of Health publication No. 86-23, revised 1985).

Details of the first-stage procedure
In test animals, a 7-cm upper midline laparotomy was performed and the stomach was partially exteriorized. The right gastroepiploic artery (GEA) and veins were mobilized from the antrum and distal body of the stomach up to a site on the midportion of the greater curvature. The gastroepiploic arcade was doubly ligated 8-cm cephalad to this site, and a TA-90 was used to resect a wedge of stomach between these two points without damaging the arteriovenous pedicle. The pedicled wedge segment was wrapped in iodine-soaked sponges and allowed to bleed freely while the gastric staple line was oversewn. The mucosa was avulsed from the wedge segment using a sponge, with care taken at preserving blood vessels on its submucosal aspect.

A small left anterolateral thoracotomy was performed and a 1.75-mm ameroid constrictor (Research Instruments SW, Escondido, CA) was inserted around the left circumflex artery. After placement, the ameroid was visually confirmed to not acutely constrict the artery and the electrocardiogram was allowed to normalize before proceeding. The lateral epicardial surface of the heart corresponding to the circumflex distribution was abraded with an electrocautery scratch pad mounted on a clamp. The anteroinferior pericardium was incised and a 1-cm opening was created in the diaphragm. The pedicled gastric wedge was passed through the diaphragm into the pericardial cavity, apposed directly onto the lateral myocardium, and secured in position with interrupted 5-0 polypropylene stitches (Fig 1). The abdominal and thoracic incisions were closed in a routine fashion.

View larger version (3K): [in this window] [in a new window]   Fig 1. Experimental model. In test animals, a submucosal gastric patch based on a gastroepiploic arteriovenous pedicle (GEA) was transferred through the diaphragm and apposed directly against the lateral myocardium, made ischemic by the placement of an ameroid constrictor (A) around the left circumflex artery (LCx). Control animals underwent circumflex ameroid placement and abrasion of the lateral epicardium, but did not receive a submucosal gastric patch.

Myocardial blood flow determinations
Myocardial perfusion was assessed at the time of the second procedure with isotope-labeled microspheres (ILM) (BioPAL, Worcester, MA). Under normovolemic rest conditions, 15 million (6 ml) ILM were injected into the left atrium more than 30 seconds while a reference arterial sample was drawn from the femoral artery at a rate of 8 ml/min for 2 minutes. The right ventricle was then paced at a rate of 145 beats/min, cardiac performance allowed to stabilize for 2 minutes, and a second injection performed using ILM of a different isotopic mass. The sequence was repeated in test animals with ILM of different isotopic mass after clamping of the gastroepiploic pedicle at the level of the diaphragm. Following euthanasia, the heart was harvested and the gastric patch dissected off the myocardial surface. Blood samples and seven circumferential, transmural left ventricular sections were collected from each animal, weighed, and dried. Each sample was subsequently exposed to a neutron beam and its microsphere density counted in a gamma counter. Myocardial blood flow was determined by the following equation: Blood Flow (myocardial sample) = [Reference blood sample withdrawal rate (ml/min) ÷ Weight (myocardial sample; g)] x [Isotope counts (myocardial sample) ÷ Isotope counts (reference blood sample)]; and expressed as absolute flows and relative perfusion indices of lateral (collateral-dependent) over anterior (normally perfused) myocardium, at rest as well as during pacing (Table 1).

Immunohistochemistry
After visual determination of the ischemic zone, myocardial samples corresponding to the center of the circumflex and left anterior territories were obtained from circumferential transmural left ventricular slices. Samples were frozen, sectioned at 6-µm thickness on a Leica CM1850 cryomicrotome, placed on Fisher Superfrost slides, fixed for 1 minute in acetone, washed in TBS, blocked for endogenous avidin and biotin, and incubated overnight at 4°C in biotin-labeled lectin from Bandeiraea Simplicifolia BS-1 (Sigma-Aldrich, St. Louis, MO). Sections were rewashed and incubated for one hour at room temperature in Vector ABC-AP avidin-alkaline phosphate complex (Vector Laboratories, Burlingame, CA) and color was developed using Vector Red as a substrate. The sections were counterstained with methyl green and coverslipped in Permount before viewing. Endothelial cells were counted in a triplicate (i.e., three separate areas per slide), blinded fashion from 700 x 550 µm (0.385 mm²) cross-sectional fields randomly selected from the center of the lateral and anterior myocardial territories of test and control animals.

Immunoblotting
Total lysate from lateral myocardial samples of test and control animals was obtained by 30-second homogenization on ice in lysis buffer containing 1% NP-40, 0.5% sodium deoxycholate, 0.1% SDS, and protease inhibitors (Complete, Roche, Nutley, NJ), and centrifuged at 12,000g for 10 minutes at 4°C to separate soluble from insoluble proteins. The supernatant protein concentration was measured spectrophotometrically at 595-nm wavelength with a BCA protein assay kit. Total protein was fractionated on 10% SDS-PAGE and transferred to a polyvinylidene difluoride membrane (Immobilon-P, Millipore, Bedford, MA) with a semidry transfer apparatus. Membranes were stained with Ponceau S, and incubated with 5% nonfat dry milk in 50 mmol/L Tris-HCL at pH 8.0, 100 mmol/L NaCl, and 0.1% Tween 20 (TBST) buffer for 1 hour at room temperature to block nonspecific binding. Membranes were individually incubated with antivascular endothelial growth factor receptor-1 (VEGFR-1) and anti-VE cadherin goat polyclonal antibodies (Santa Cruz Biotechnology, Santa Cruz, CA) at 1:1000 (vol/vol) dilution for 2 hours. After washing with TBST, the membranes were incubated for 24 hours in 2.5% bovine serum albumin in TBST diluted with a rabbit antigoat IgG secondary antibody at 1:4000 (vol/vol) dilution conjugated to horseradish peroxidase. Peroxidase activity was visualized using an enhanced chemiluminescence substrate system and exposed to roentgenogram films.

Data analysis
Data are expressed as mean ± SD. Isotope-labeled microspheres and endothelial cell density data were analyzed with a two-tailed, unpaired Student’s t-test or with an analysis of variance as appropriate. Immunoblots were analyzed after digitization of roentgenogram films with a scanner using NIH Image 1.62 software (National Institutes of Health, Bethesda, MD). Blots were compared to base line values, expressed as mean fold changes ± SD, and analyzed by a two-tailed, one-way analysis of variance. Ponceau S staining was used to determine proper protein fractionation and equivalent loading. The optical density ratio of the bands was compared to Ponceau S and corrected for small uneven loading. Only samples with similar protein fractionation and protein loading with less than 20% differences were analyzed further. A p value of less than 0.05 was considered statistically significant.

	Results

Top Abstract Introduction Material and methods Results Comment Acknowledgments References

 
Feasibility
There was no periprocedural mortality. An oval shaped gastric submucosal patch of 5.2 ± 0.6 cm by 6.5 ± 0.9 cm was successfully created in all test animals. Two swine in the control group died 3 and 4 weeks after the first procedure with evidence of lateral myocardial infarction at autopsy. The procedures were otherwise well tolerated, and weight gain during the 7-week interval was similar between the two groups (18.2 ± 3.8 vs 16.4 ± 2.2 kg, control vs test animals, respectively; p = 0.30). The ameroid constrictor was confirmed to have completely occluded the circumflex artery at the time of the second procedure in all animals. Herniation of abdominal contents through the diaphragmatic opening constructed for transfer of the patch was observed in the first four test swine at the time of the second procedure, but did not adversely affect the animals’ general status. However, herniation interfered with the injection and distribution of contrast agent to supradiaphragmatic structures during gastroepiploic angiography. Transdiaphragmatic herniation was prevented in subsequent animals by reinforcing the diaphragmatic opening with polypropylene mesh, and gastroepiploic angiography was successfully performed in these animals.

Myocardial perfusion
Results of isotope-labeled microsphere assays are reported in Table 1 and Figure 2. There was no difference in relative myocardial perfusion indices between control and test animals at rest; however, test animals had significantly higher lateral territory perfusion during pacing. The relative myocardial perfusion indices of test animals remained above 1.0 during pacing, indicating that their lateral blood flow increased during stress on par with that of the normally perfused anterior myocardial territory. In contrast, a significantly lower perfusion index of 0.69 was found during pacing in control animals, indicative of decreased myocardial perfusion in the lateral territory. A significant increase in relative circumflex territory perfusion compared to controls was no longer observed after the GEA pedicle was clamped in test animals (Table 1).

View larger version (3K): [in this window] [in a new window]   Fig 2. Relative indices of myocardial perfusion determined with isotope-labeled microspheres. The perfusion ratios of collateral-dependent (LCx) over normal (LAD) myocardial territories were equivalent in the two groups at rest (1.10 ± 0.49 versus 0.95 ± 0.23, test [white bars] versus control [black bars] animals; p = 0.54), but were higher in test animals versus controls during pacing (1.05 ± 0.29 versus 0.69 ± 0.09, test versus controls; *p = 0.02).

View larger version (8K): [in this window] [in a new window]   Fig 3. Gastroepiploic (GEA) arteriogram of a test animal at seven weeks. Patch contour (P), circumflex artery occlusion at the ameroid constrictor (A) level and reconstitution (LCx) from the patch, and drainage of contrast through the coronary sinus (CS) were observed.

View larger version (10K): [in this window] [in a new window]   Fig 4. Lectin-positive endothelial cells (arrows) in the left circumflex territory at 7 weeks. Increased endothelial cell density was observed in test (T) animals (left) versus controls (C) (right).

View larger version (5K): [in this window] [in a new window]   Fig 5. Representative immunoblots of VEGFR-1 and VE-Cadherin expression in collateral-dependent myocardial territories at 7 weeks. Expression of the endothelial cell marker VE-Cadherin was significantly increased in test (T) animals versus controls (C).

	Comment

Top Abstract Introduction Material and methods Results Comment Acknowledgments References

The experimental model used in this study involved a gastric submucosal patch based on a gastroepiploic arteriovenous pedicle. This approach was elected not only to ensure viability of the patch after transfer into the chest, but also to provide arterial inflow to submucosal-myocardial collaterals. Although arterial collateralization between the gastroepiploic artery and the coronary circulation was demonstrated on angiography, no firm conclusion can however be drawn with respect to this finding due to its sporadic occurrence in the study, possibly related to the development of transdiaphragmatic hernias in a large proportion of test animals.

Microsphere blood flow determinations revealed differences in relative circumflex territory perfusion between test and control groups only during pacing and after controlling for perfusion to the normal LAD territory. Our inability to observe an absolute myocardial perfusion difference may be have been due to the consistently longer and more extensive dissection before proceeding to microsphere injections in test versus control animals, which may have resulted in exacerbated fluid shifts, temperature loss, and myocardial depression in the former. The absence of a significant perfusion difference at rest may also have resulted from spontaneous myocardial collateralization, which can occur in control swine in response to chronic ischemia and result in the preservation of adequate myocardial perfusion at rest with inability to increase collateral-dependent coronary flow during pacing [11, 12]. The lack of a significant perfusion difference at rest may also have been substantiated by the inherent variability associated with microsphere assays [13, 14].

Functional increases in relative myocardial perfusion during pacing were anatomically corroborated by the demonstration of increased endothelial cell density in the lateral territory of test animals. In this respect, lectin-positive endothelial cell density was used as a morphometric end-point in lieu of capillary density, since capillary counting can prove unreliable in planar sections and be altered by the variety of orientations and circumvolutions that capillaries display in tissues [15]. The circumflex myocardium of test animals also expressed significantly more VE-cadherin than controls, but the expression of VEGFR-1 was not significantly changed. Although the two proteins constitute endothelial markers, expression of VEGFR-1 in replicating endothelial cells likely occurs at an earlier stage than that of VE-cadherin, which is involved in the spatial organization and joining of functionally competent endothelial cells [16, 17]. Together these findings suggest that a later stage of endothelial differentiation was found in the lateral myocardium of test animals versus controls.

Historically, efforts at performing myocardial revascularization using autologous tissue transfer have been mostly unsuccessful. The Vineberg procedure [18], in which the left mammary artery was tunneled intramyocardially, provided arterial inflow but graft angiography suggested in most cases that only modest collateralization had developed between the systemic and coronary circulation, with many patients experiencing little or no benefit [19]. The Beck II procedure [20], in which the ischemic heart was wrapped in the omentum, has also been long abandoned. Although now recognized as a source of angiogenic proteins [21], the omentum consists mostly of adipose tissue with a modest arterial supply. In contrast, the gastric submucosal patch model studied provides major arterial inflow, has a capillary density several orders of magnitude greater than that of the omentum, and constitutes a physiologic source of angiogenic proteins [5, 6].

Limitations of the study
Although functional, histologic, and molecular data suggest that a significant angiogenic process took place in test animals, the results of this study must nevertheless be interpreted with caution. Confounding factors such as development of pericardial or myocardial inflammation after surgery may have played a role in eliciting or enhancing an endogenous angiogenic response in these experiments. However, potential discrepancies between the two experimental groups were minimized by abrading the lateral epicardial surface of control swine to the same extent as test animals, a necessary step in the test group to appose the submucosal patch directly against the ischemic circumflex myocardium. The occurrence of a true angiogenic process rather than a nonspecific wound-healing response to injury in the test group is supported by the increased myocardial expression of VE-cadherin in these animals, a protein which is believed to undergo sequestration in inflammatory states [22].

Another potential limitation of this study relates to the use of ameroid constrictors. Although all animals had ameroid occlusion confirmed following the second procedure, the time-course of ameroid closure, which typically occurs over a period of 2 to 3 weeks, could have differed between animals and influenced the stimulation of capillary development by ischemia. Such variability is however expected to have distributed randomly between the two groups. The exact myocardial territory subtended by occlusion of the ameroid on the proximal circumflex artery may also have displayed random variation between animals; however, this shortcoming was minimized by the standardized sampling of circumferential, transmural left ventricular sections for microsphere flow determinations, and by triplicate endothelial cell density assessments of each myocardial territory.

In summary, the present study indicates that the use of a gastric submucosal patch can stimulate endogenous myocardial angiogenesis and thereby lead to revascularization of a territory rendered chronically ischemic by the placement of an ameroid constrictor without the need for exogenous angiogenic agents. The findings of this study may help define how endogenous angiogenesis can be surgically modulated for therapeutic purposes, and potentially lead to new approaches for angiogenic therapy.

	Acknowledgments

Top Abstract Introduction Material and methods Results Comment Acknowledgments References

 
This work was funded by the Center for Minimally Invasive Surgery at Harvard Medical School and by grant HL-46716 from the National Institutes of Health (Dr Sellke). Doctor Ruel is a fellow of the Heart and Stroke Foundation of Canada in partnership with the Canadian Institutes of Health Research.

	References

Top Abstract Introduction Material and methods Results Comment Acknowledgments References

 

1. Sellke FW, Simons M. Angiogenesis in cardiovascular disease. current status and therapeutic potential. Drugs 1999;58:391-396.[Medline]
2. Simons M, Bonow RO, Chronos NA, et al. Clinical trials in coronary angiogenesis. issues, problems, consensus: an expert panel summary. Circulation 2000;102:E73-E86.[Medline]
3. Simons M. Therapeutic coronary angiogenesis. a fronte praecipitium a tergo lupi?. Am J Physiol Heart Circ Physiol 2001;280:H1923-H1927.[Free Full Text]
4. Ruel M, Laham RJ, Parker JA, et al. Long-term effects of surgical angiogenic therapy with FGF-2 protein. J Thorac Cardiovasc Surg 2002 (in press).
5. Jones MK, Tomikawa M, Mohajer B, Tarnawski AS. Gastrointestinal mucosal regeneration. role of growth factors. Front Biosci 1999;4:D303-D309.[Medline]
6. Turley H, Scott PA, Watts VM, Bicknell R, Harris AL, Gatter KC. Expression of VEGF in routinely fixed material using a new monoclonal antibody VG1 J Pathol 1998;186:313-318.[Medline]
7. Polk Jr WH, Dempsey PJ, Russell WE, et al. Increased production of transforming growth factor alpha following acute gastric injury Gastroenterology 1992;102:1467-1474.[Medline]
8. Majumdar AP, Fligiel SE, Jaszewski R, Tureaud J, Dutta S, Chelluderai B. Inhibition of gastric mucosal regeneration by tyrphostin. evaluation of the role of epidermal growth factor receptor tyrosine kinase. J Lab Clin Med 1996;128:173-180.[Medline]
9. Akimoto M, Hashimoto H, Shigemoto M, Yamashita K, Yokoyama I. Changes of nitric oxide and growth factors during gastric ulcer healing J Cardiovasc Pharmacol 2000;36:S282-S285.[Medline]
10. Hull MA, Brough JL, Powe DG, Carter GI, Jenkins D, Hawkey CJ. Expression of basic fibroblast growth factor in intact and ulcerated human gastric mucosa Gut 1998;43:525-536.[Abstract/Free Full Text]
11. Sellke FW, Kagaya Y, Johnson RG, et al. Endothelial modulation of porcine coronary microcirculation perfused via immature collaterals Am J Physiol 1992;262:H1669-H1675.[Medline]
12. Harada K, Grossman W, Friedman M, et al. Basic fibroblast growth factor improves myocardial function in chronically ischemic porcine hearts J Clin Invest 1994;94:623-630.[Medline]
13. Austin Jr RE, Hauck WW, Aldea GS, Flynn AE, Coggins DL, Hoffman JI. Quantitating error in blood flow measurements with radioactive microspheres Am J Physiol 1989;257:H280-H288.[Medline]
14. Prinzen FW, Bassingthwaighte JB. Blood flow distributions by microsphere deposition methods Cardiovasc Res 2000;45:13-21.[Abstract/Free Full Text]
15. Rakusan K, Korecky B, Sarkar K, Turek Z. Merits and pitfalls in morphological assessment of cardiac growth Fed Proc 1986;45:2580-2584.[Medline]
16. Esser S, Lampugnani MG, Corada M, Dejana E, Risau W. Vascular endothelial growth factor induces VE-cadherin tyrosine phosphorylation in endothelial cells J Cell Sci 1998;111:1853-1865.[Abstract/Free Full Text]
17. Hirashima M, Kataoka H, Nishikawa S, Matsuyoshi N. Maturation of embryonic stem cells into endothelial cells in an in vitro model of vasculogenesis Blood 1999;93:1253-1263.[Abstract/Free Full Text]
18. Vineberg AM. Development of an anastomosis between the coronary vessels and a transplanted internal mammary artery Can Med Assoc J 1946;55:117-119.[Medline]
19. Ochsner JL, Moseley PW, Mills NL, Bower PJ. Long-term follow-up of internal mammary artery myocardial implantation Ann Thorac Surg 1977;23:118-121.[Abstract/Free Full Text]
20. Beck CS, Leighninger DS. Scientific basis of the surgical treatment of coronary artery disease JAMA 1954;159:1264-1271.
21. Zhang QX, Magovern CJ, Mack CA, Budenbender KT, Ko W, Rosengart TK. Vascular endothelial growth factor is the major angiogenic factor in omentum. mechanism of the omentum-mediated angiogenesis. J Surg Res 1997;67:147-154.[Medline]
22. Alexander JS, Alexander BC, Eppihimer LA, et al. Inflammatory mediators induce sequestration of VE-cadherin in cultured human endothelial cells Inflammation 2000;24:99-113.[Medline]

This article has been cited by other articles:

				Y. Shudo, S. Miyagawa, S. Fukushima, A. Saito, T. Shimizu, T. Okano, and Y. Sawa Novel regenerative therapy using cell-sheet covered with omentum flap delivers a huge number of cells in a porcine myocardial infarction model J. Thorac. Cardiovasc. Surg., November 1, 2011; 142(5): 1188 - 1196. [Abstract] [Full Text] [PDF]

				K. Takaba, C. Jiang, S. Nemoto, Y. Saji, T. Ikeda, S. Urayama, T. Azuma, A. Hokugo, S. Tsutsumi, Y. Tabata, et al. A combination of omental flap and growth factor therapy induces arteriogenesis and increases myocardial perfusion in chronic myocardial ischemia: Evolving concept of biologic coronary artery bypass grafting J. Thorac. Cardiovasc. Surg., October 1, 2006; 132(4): 891 - 899. [Abstract] [Full Text] [PDF]

				T. Kanamori, G. Watanabe, T. Yasuda, H. Nagamine, H. Kamiya, and Y. Koshida Hybrid Surgical Angiogenesis: Omentopexy Can Enhance Myocardial Angiogenesis Induced by Cell Therapy Ann. Thorac. Surg., January 1, 2006; 81(1): 160 - 167. [Abstract] [Full Text] [PDF]

				P. Voisine, J. Li, C. Bianchi, T. A. Khan, M. Ruel, S.-H. Xu, J. Feng, A. Rosinberg, T. Malik, Y. Nakai, et al. Effects of L-Arginine on Fibroblast Growth Factor 2-Induced Angiogenesis in a Model of Endothelial Dysfunction Circulation, August 30, 2005; 112(9_suppl): I-202 - I-207. [Abstract] [Full Text] [PDF]

				P. Voisine, C. Bianchi, T. A. Khan, M. Ruel, S.-H. Xu, J. Feng, J. Li, T. Malik, A. Rosinberg, and F. W. Sellke Normalization of coronary microvascular reactivity and improvement in myocardial perfusion by surgical vascular endothelial growth factor therapy combined with oral supplementation of L-arginine in a porcine model of endothelial dysfunction J. Thorac. Cardiovasc. Surg., June 1, 2005; 129(6): 1414 - 1420. [Abstract] [Full Text] [PDF]

				M. Ruel, G. F. Wu, T. A. Khan, P. Voisine, C. Bianchi, J. Li, J. Li, R. J. Laham, and F. W. Sellke Inhibition of the Cardiac Angiogenic Response to Surgical FGF-2 Therapy in a Swine Endothelial Dysfunction Model Circulation, September 9, 2003; 108(2011): II-335 - II-340. [Abstract] [Full Text] [PDF]

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Marc A Ruel Frank W Sellke Tanveer A Khan William E Cohn Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Ruel, M. A. Articles by Cohn, W. E. Search for Related Content PubMed PubMed Citation Articles by Ruel, M. A. Articles by Cohn, W. E.