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The peritoneum as a natural scaffold for vascular regeneration.

Bonvini S, Albiero M, Ferretto L, Angelini A, Battocchio P, Fedrigo M, Piazza M, Thiene G, Avogaro A, Fadini GP, Grego F - PLoS ONE (2012)

Bottom Line: In rats, immunostaining for human mitochondri revealed that endothelial cells and smooth muscle cells rarely were of human origin.Remodeling of the graft was mainly attributable to local cells with no clear evidence of c-kit+ endothelial progenitor cells or c-kit+ resident perivascular progenitor cells.The parietal peritoneum can be feasibly used as a scaffold to sustain the regeneration of blood vessels, which appears to occur through the contribution of host-derived resident mature cells.

View Article: PubMed Central - PubMed

Affiliation: Department of Cardiac, Thoracic and Vascular Sciences, University of Padova, Padova, Italy. stefanobonvini@yahoo.it

ABSTRACT

Objective: The peritoneum has the same developmental origin as blood vessels, is highly reactive and poorly thrombogenic. We hypothesize that parietal peritoneum can sustain development and regeneration of new vessels.

Methods and results: The study comprised two experimental approaches. First, to test surgical feasibility and efficacy of the peritoneal vascular autograft, we set up an autologous transplantation procedure in pigs, where a tubularized parietal peritoneal graft was covered with a metal mesh and anastomosed end-to-end in the infrarenal aorta. Second, to dissect the contribution of graft vs host cells to the newly developed vessel wall, we performed human-to-rat peritoneal patch grafting in the abdominal aorta and examined the origin of endothelial and smooth muscle cells. In pig experiments, the graft remodeled to an apparently normal blood vessel, without thrombosis. Histology confirmed arterialization of the graft with complete endothelial coverage and neointimal hyperplasia in the absence of erosion, inflammation or thrombosis. In rats, immunostaining for human mitochondri revealed that endothelial cells and smooth muscle cells rarely were of human origin. Remodeling of the graft was mainly attributable to local cells with no clear evidence of c-kit+ endothelial progenitor cells or c-kit+ resident perivascular progenitor cells.

Conclusions: The parietal peritoneum can be feasibly used as a scaffold to sustain the regeneration of blood vessels, which appears to occur through the contribution of host-derived resident mature cells.

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Related in: MedlinePlus

Graphic representation of the two types of experiments.A) A pig autologous end-to-end peritoneal implant was used to study patency, eventual thrombosis, endothelization and arterializations of the graft, 2 weeks after surgery. B) A human-to-rat peritoneal graft approach was set up to study remodeling of the peritoneum and to determine the host vs donor origin of cells that contributed to the process of endothelization and eventual arterialization.
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pone-0033557-g001: Graphic representation of the two types of experiments.A) A pig autologous end-to-end peritoneal implant was used to study patency, eventual thrombosis, endothelization and arterializations of the graft, 2 weeks after surgery. B) A human-to-rat peritoneal graft approach was set up to study remodeling of the peritoneum and to determine the host vs donor origin of cells that contributed to the process of endothelization and eventual arterialization.

Mentions: Two types of experiments were set up to study the patency, eventual thrombosis, endothelization and arterialization of the graft, as well as the origin of cells that contributed to its remodeling (Figure 1). Five 30 days old female pigs underwent induction with sodium thiopental and general anesthesia (1 mg/kg Xilazine plus 0.5 mg/kg Tiletamine chlorhydrate) with endotracheal intubation. The abdominal cavity was accessed with a midline incision. A 5×3 cm rectangular layer of the abdominal peritoneum was collected, leaving in situ the posterior rectus aponeurosis. The peritoneum was tubularized on a plastic tutor by a continuous 6/0 polypropylene suture, creating a 10 mm diameter, 5 cm length vascular graft. The intra-abdominal surface of the peritoneum was used as the internal sheath of the graft. Then, the peritoneum tubularized on the tutor was covered with a stainless steel mesh (Biocompound Shunt® - Alpha Research Switzerland). After dissection of the infrarenal aorta, intravenous sodium heparin (150 IU/kg) was administrated, and the aorta was clamped. A 4 cm portion of the infrarenal aorta was removed and the mesh/peritoneal autograft was inserted by end-to-end surgical anastomosis, performed with 6/0 polypropylene thread. The removed aortic portion must be 1 cm shorter than the vascular autograft because the aorta is very elastic and retracts. Patency and resistance of the graft was confirmed by the visual intra-operative inspection and pulse-checking of the proximal and distal aorta. Then, optimal hemostasis was verified and the abdomen was closed by layers. During the post-operative period, each animal received analgesic medication (fentanyl 0.1 mg/day), antibiotics and a daily subcutaneous injection of 6000 IU of low-molecular-weight-heparin (enoxaparin). Animals were observed for 2 weeks, evaluating clinical parameters and eventual development of arterial insufficiency (intensity of pulse, temperature, trophism and functional changes of the hind limbs). One week after surgery, an echo-color-Doppler scan was performed under pharmacological sedation to confirm patency of the graft. Two weeks after surgery, animals were sacrificed under general anesthesia. A re-do open transperitoneal approach to the aorta was performed and autografts, including the whole proximal and distal anastomosis, were harvested.


The peritoneum as a natural scaffold for vascular regeneration.

Bonvini S, Albiero M, Ferretto L, Angelini A, Battocchio P, Fedrigo M, Piazza M, Thiene G, Avogaro A, Fadini GP, Grego F - PLoS ONE (2012)

Graphic representation of the two types of experiments.A) A pig autologous end-to-end peritoneal implant was used to study patency, eventual thrombosis, endothelization and arterializations of the graft, 2 weeks after surgery. B) A human-to-rat peritoneal graft approach was set up to study remodeling of the peritoneum and to determine the host vs donor origin of cells that contributed to the process of endothelization and eventual arterialization.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3306415&req=5

pone-0033557-g001: Graphic representation of the two types of experiments.A) A pig autologous end-to-end peritoneal implant was used to study patency, eventual thrombosis, endothelization and arterializations of the graft, 2 weeks after surgery. B) A human-to-rat peritoneal graft approach was set up to study remodeling of the peritoneum and to determine the host vs donor origin of cells that contributed to the process of endothelization and eventual arterialization.
Mentions: Two types of experiments were set up to study the patency, eventual thrombosis, endothelization and arterialization of the graft, as well as the origin of cells that contributed to its remodeling (Figure 1). Five 30 days old female pigs underwent induction with sodium thiopental and general anesthesia (1 mg/kg Xilazine plus 0.5 mg/kg Tiletamine chlorhydrate) with endotracheal intubation. The abdominal cavity was accessed with a midline incision. A 5×3 cm rectangular layer of the abdominal peritoneum was collected, leaving in situ the posterior rectus aponeurosis. The peritoneum was tubularized on a plastic tutor by a continuous 6/0 polypropylene suture, creating a 10 mm diameter, 5 cm length vascular graft. The intra-abdominal surface of the peritoneum was used as the internal sheath of the graft. Then, the peritoneum tubularized on the tutor was covered with a stainless steel mesh (Biocompound Shunt® - Alpha Research Switzerland). After dissection of the infrarenal aorta, intravenous sodium heparin (150 IU/kg) was administrated, and the aorta was clamped. A 4 cm portion of the infrarenal aorta was removed and the mesh/peritoneal autograft was inserted by end-to-end surgical anastomosis, performed with 6/0 polypropylene thread. The removed aortic portion must be 1 cm shorter than the vascular autograft because the aorta is very elastic and retracts. Patency and resistance of the graft was confirmed by the visual intra-operative inspection and pulse-checking of the proximal and distal aorta. Then, optimal hemostasis was verified and the abdomen was closed by layers. During the post-operative period, each animal received analgesic medication (fentanyl 0.1 mg/day), antibiotics and a daily subcutaneous injection of 6000 IU of low-molecular-weight-heparin (enoxaparin). Animals were observed for 2 weeks, evaluating clinical parameters and eventual development of arterial insufficiency (intensity of pulse, temperature, trophism and functional changes of the hind limbs). One week after surgery, an echo-color-Doppler scan was performed under pharmacological sedation to confirm patency of the graft. Two weeks after surgery, animals were sacrificed under general anesthesia. A re-do open transperitoneal approach to the aorta was performed and autografts, including the whole proximal and distal anastomosis, were harvested.

Bottom Line: In rats, immunostaining for human mitochondri revealed that endothelial cells and smooth muscle cells rarely were of human origin.Remodeling of the graft was mainly attributable to local cells with no clear evidence of c-kit+ endothelial progenitor cells or c-kit+ resident perivascular progenitor cells.The parietal peritoneum can be feasibly used as a scaffold to sustain the regeneration of blood vessels, which appears to occur through the contribution of host-derived resident mature cells.

View Article: PubMed Central - PubMed

Affiliation: Department of Cardiac, Thoracic and Vascular Sciences, University of Padova, Padova, Italy. stefanobonvini@yahoo.it

ABSTRACT

Objective: The peritoneum has the same developmental origin as blood vessels, is highly reactive and poorly thrombogenic. We hypothesize that parietal peritoneum can sustain development and regeneration of new vessels.

Methods and results: The study comprised two experimental approaches. First, to test surgical feasibility and efficacy of the peritoneal vascular autograft, we set up an autologous transplantation procedure in pigs, where a tubularized parietal peritoneal graft was covered with a metal mesh and anastomosed end-to-end in the infrarenal aorta. Second, to dissect the contribution of graft vs host cells to the newly developed vessel wall, we performed human-to-rat peritoneal patch grafting in the abdominal aorta and examined the origin of endothelial and smooth muscle cells. In pig experiments, the graft remodeled to an apparently normal blood vessel, without thrombosis. Histology confirmed arterialization of the graft with complete endothelial coverage and neointimal hyperplasia in the absence of erosion, inflammation or thrombosis. In rats, immunostaining for human mitochondri revealed that endothelial cells and smooth muscle cells rarely were of human origin. Remodeling of the graft was mainly attributable to local cells with no clear evidence of c-kit+ endothelial progenitor cells or c-kit+ resident perivascular progenitor cells.

Conclusions: The parietal peritoneum can be feasibly used as a scaffold to sustain the regeneration of blood vessels, which appears to occur through the contribution of host-derived resident mature cells.

Show MeSH
Related in: MedlinePlus