The neuropeptide catestatin acts as a novel angiogenic cytokine via a basic fibroblast growth factor-dependent mechanism.

RATIONALE: The neuropeptide catestatin is an endogenous nicotinic cholinergic antagonist that acts as a pleiotropic hormone. OBJECTIVE: Catestatin shares several functions with angiogenic factors. We therefore reasoned that catestatin induces growth of new blood vessels. METHODS AND RESULTS: Catestatin induced migration, proliferation, and antiapoptosis in endothelial cells and exerted capillary tube formation in vitro in a Matrigel assay, and such effects were mediated via G protein, mitogen-activated protein kinase, and Akt. Catestatin-induced endothelial cell functions are further mediated by basic fibroblast growth factor, as shown by blockade of effects by a neutralizing fibroblast growth factor antibody. Furthermore, catestatin released basic fibroblast growth factor from endothelial cells and stimulated fibroblast growth factor signaling. In addition to its function on endothelial cells, catestatin also exerted effects on endothelial progenitor cells and vascular smooth muscle cells. In vivo, catestatin induced angiogenesis in the mouse cornea neovascularization assay and increased blood perfusion and number of capillaries in the hindlimb ischemia model. In addition to angiogenesis, catestatin increased density of arterioles/arteries and incorporation of endothelial progenitor cells in the hindlimb ischemia model, indicating induction of arteriogenesis and postnatal vasculogenesis. CONCLUSION: We conclude that catestatin acts as a novel angiogenic cytokine via a basic fibroblast growth factor-dependent mechanism.

Gene therapy with the angiogenic cytokine secretoneurin induces therapeutic angiogenesis by a nitric oxide-dependent mechanism.

RATIONALE: The neuropeptide secretoneurin induces angiogenesis and postnatal vasculogenesis and is upregulated by hypoxia in skeletal muscle cells. OBJECTIVE: We sought to investigate the effects of secretoneurin on therapeutic angiogenesis. METHODS AND RESULTS: We generated a secretoneurin gene therapy vector. In the mouse hindlimb ischemia model secretoneurin gene therapy by intramuscular plasmid injection significantly increased secretoneurin content of injected muscles, improved functional parameters, reduced tissue necrosis, and restored blood perfusion. Increased muscular density of capillaries and arterioles/arteries demonstrates the capability of secretoneurin gene therapy to induce therapeutic angiogenesis and arteriogenesis. Furthermore, recruitment of endothelial progenitor cells was enhanced by secretoneurin gene therapy consistent with induction of postnatal vasculogenesis. Additionally, secretoneurin was able to activate nitric oxide synthase in endothelial cells and inhibition of nitric oxide inhibited secretoneurin-induced effects on chemotaxis and capillary tube formation in vitro. In vivo, secretoneurin induced nitric oxide production and inhibition of nitric oxide attenuated secretoneurin-induced effects on blood perfusion, angiogenesis, arteriogenesis, and vasculogenesis. Secretoneurin also induced upregulation of basic fibroblast growth factor and platelet-derived growth factor-B in endothelial cells. CONCLUSIONS: In summary, our data indicate that gene therapy with secretoneurin induces therapeutic angiogenesis, arteriogenesis, and vasculogenesis in the hindlimb ischemia model by a nitric oxide-dependent mechanism.

Reduction of Phantom Limb Pain and Improved Proprioception through a TSR-Based Surgical Technique: A Case Series of Four Patients with Lower Limb Amputation.

Four patients underwent targeted sensory reinnervation (TSR), a surgical technique in which a defined skin area is first selectively denervated and then surgically reinnervated by another sensory nerve. In our case, either the area of the lateral femoral cutaneous nerve or the saphenous nerve was reinnervated by the sural nerve. Patients were then fitted with a special prosthetic device capable of transferring the sense of pressure from the sole of the prosthesis to the newly wired skin area. Pain reduction after TSR was highly significant in all patients. In three patients, permanent pain medication could even be discontinued, in one patient the pain medication has been significantly reduced. Two of the four patients were completely pain-free after the surgical intervention. Surgical rewiring of existing sensory nerves by TSR can provide the brain with new afferent signals seeming to originate from the missing limb. These signals help to reduce phantom limb pain and to restore a more normal body image. In combination with special prosthetic devices, the amputee can be provided with sensory feedback from the prosthesis, thus improving gait and balance.

Hypoxia up-regulates the angiogenic cytokine secretoneurin via an HIF-1alpha- and basic FGF-dependent pathway in muscle cells.

Expression of angiogenic cytokines like vascular endothelial growth factor is enhanced by hypoxia. We tested the hypothesis that decreased oxygen levels up-regulate the angiogenic factor secretoneurin. In vivo, muscle cells of mouse ischemic hind limbs showed increased secretoneurin expression, and inhibition of secretoneurin by a neutralizing antibody impaired the angiogenic response in this ischemia model. In a mouse soft tissue model of hypoxia, secretoneurin was increased in subcutaneous muscle fibers. In vitro, secretoneurin mRNA and protein were up-regulated in L6 myoblast cells after exposure to low oxygen levels. The hypoxia-dependent regulation of secretoneurin was tissue specific and was not observed in endothelial cells, vascular smooth muscle cells, or AtT20 pituitary tumor cells. The hypoxia-dependent induction of secretoneurin in L6 myoblasts is regulated by hypoxia-inducible factor-1alpha, since inhibition of this factor using si-RNA inhibited up-regulation of secretoneurin. Induction of secretoneurin by hypoxia was dependent on basic fibroblast growth factor in vivo and in vitro, and inhibition of this regulation by heparinase suggests an involvement of low-affinity basic fibroblast growth factor binding sites. In summary, our data show that the angiogenic cytokine secretoneurin is up-regulated by hypoxia in muscle cells by hypoxia-inducible factor-1alpha- and basic fibroblast growth factor-dependent mechanisms.

Stabilization of microvascular pedicles in intricate locations using fibrin glue.

In reconstructive microsurgery, it is occasionally advantageous to use long recipient or donor vessels for optimal flap inset. These long vessels are prone to kinking or torsion along their longitudinal axis from vessel distension during blood inflow and rising blood pressure. More often than arteries, the veins can also be compressed by overlying tissue sutured under tension or by developing edema. Reanastomosis can no longer be feasible or desirable for several reasons, and the elongated vessels may have to be shifted to a curved course. To avoid detrimental kinking or torsion, fibrin glue can be administered along this new vessel course in order to ensure stabilization. In 20 such cases, we successfully avoided complications when the danger of kinking, torsion, or vein compression was evident after successful anastomosis. On the basis of this experience, we recommend the use of fibrin glue in microsurgical procedures, especially for vessels in intricate geometrical locations.

Effect of extracorporeal shock wave treatment on deep partial-thickness burn injury in rats: a pilot study.

Extracorporeal shock wave therapy (ESWT) enhances tissue vascularization and neoangiogenesis. Recent animal studies showed improved soft tissue regeneration using ESWT. In most cases, deep partial-thickness burns require skin grafting; the outcome is often unsatisfactory in function and aesthetic appearance. The aim of this study was to demonstrate the effect of ESWT on skin regeneration after deep partial-thickness burns. Under general anesthesia, two standardized deep partial-thickness burns were induced on the back of 30 male Wistar rats. Immediately after the burn, ESWT was given to rats of group 1 (N = 15), but not to group 2 (N = 15). On days 5, 10, and 15, five rats of each group were analyzed. Reepithelialization rate was defined, perfusion units were measured, and histological analysis was performed. Digital photography was used for visual documentation. A wound score system was used. ESWT enhanced the percentage of wound closure in group 1 as compared to group 2 (P < 0.05). The reepithelialization rate was improved significantly on day 15 (P < 0.05). The wound score showed a significant increase in the ESWT group. ESWT improves skin regeneration of deep partial-thickness burns in rats. It may be a suitable and cost effective treatment alternative in this type of burn wounds in the future.

Anatomic study on the transverse cervical vessels perforators in the lateral triangle of the neck and harvest of a new flap: the free supraclavicular transverse cervical artery perforator flap.

BACKGROUND: Vessels in the supraclavicular area and their contribution to skin vascularization have always been studied for flaps planning in head and neck reconstruction and many pedicled flaps have been described based on those vessels. Little has been written instead about the vascularization of the supraclavicular skin itself for the use as a free flap. The purpose of this anatomical study was to assess the vascularization of the supraclavicular skin and the possibility of finding an adequate pedicle to harvest it as a free flap in order to close the donor site directly. METHODS: A total of 25 cadavers, 10 formalin fixed and 15 fresh, have been studied in cooperation with the Division for Clinical-Functional Anatomy, Department of Anatomy, Histology and Embryology, Innsbruck Medical University, Innsbruck, Austria and the Laboratoire d'Anatomie, Universiteé R. Descartes, Paris, France. RESULTS: The supraclavicular skin was nourished by perforators coming from the transverse cervical artery and constantly present in an average number of four. Venous drainage was accomplished through the superficial cervical vein, and not through the venae comitantes of the transverse cervical artery. CONCLUSIONS: Based on the results of this investigation, a free supraclavicular transverse cervical artery perforator (STCAP) flap seems to be feasible pedicled on perforators from the transverse cervical artery and drained by the superficial cervical vein. Due to its thickness and skin texture, it can be indicated for facial and intraoral defects, with the limitations of a relatively short pedicle. Primary closure of the donor site can be accomplished concealing the scar in the neck crease.

Refinements in pectus carinatum correction: the pectoralis muscle split technique.

BACKGROUND: The standard approach for correction of pectus carinatum deformity includes elevation of the pectoralis major and rectus abdominis muscle from the sternum and adjacent ribs. A postoperative restriction of shoulder activity for several weeks is necessary to allow stable healing of the elevated muscles. To reduce postoperative immobilization, we present a modified approach to the parasternal ribs using a pectoralis muscle split technique. METHODS: At each level of rib cartilage resection, the pectoralis muscle is split along the direction of its fibers instead of elevating the entire muscle as performed with the standard technique. From July 2000 to May 2007, we successfully used this technique in 33 patients with pectus carinatum deformity. RESULTS: After the muscle split approach, patients returned to full unrestricted shoulder activity as early as 3 weeks postoperatively, compared to 6 weeks in patients treated with muscle flap elevation. Postoperative pain was reduced and the patients were discharged earlier from the hospital than following the conventional approach. CONCLUSIONS: The muscle split technique is a modified surgical approach to the parasternal ribs in patients with pectus carinatum deformity. It helps to maintain pectoralis muscle vascularization and function and can reduce postoperative pain, hospitalization, and rehabilitation period.

Vascular anatomy of the supraclavicular area revisited: feasibility of the free supraclavicular perforator flap.

BACKGROUND: The supraclavicular skin has been studied extensively and used as a pedicled flap for face and neck reconstruction. Its use as a free flap has not paralleled its use as a pedicled flap. The authors performed an anatomical investigation to assess the possibility of harvesting a free supraclavicular flap with the donor-site scar lying in the supraclavicular crease. In this article, the authors present the results of their anatomical study together with the preliminary clinical applications. METHODS: Skin vascularization and feasibility of a free supraclavicular perforator flap were studied on 25 cadavers (15 fresh cadavers injected with colored latex at the Universiteé René Descartes in Paris; and 10 formalin-fixed, noninjected cadavers at the Innsbruck Medical University). The flap was used in two patients at the Plastic Surgery Department of the University of Palermo for a cutaneous facial reconstruction and intraoral reconstruction after cancer excision. RESULTS: An average of four perforators were consistently found in the supraclavicular area coming from the transverse cervical artery. Venous perforators drain into the superficial venous plexus rather than into the venae comitantes of the transverse cervical artery. Two flaps were successfully used based on these vessels. CONCLUSIONS: The vascularization of the supraclavicular skin depends on skin perforators coming from the transverse cervical artery and draining into the superficial venous plexus. Based on these vessels, a reliable free supraclavicular flap seems to be safe to harvest, with the scar hidden in the supraclavicular crease. The preliminary clinical applications of such a flap gave promising results, suggesting its potential applications.