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Flap Perfusion (flap + perfusion)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Non-viral VEGF165 gene therapy , magnetofection of acoustically active magnetic lipospheres (,magnetobubbles') increases tissue survival in an oversized skin flap model

JOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 3 2010
Thomas Holzbach
Abstract Adenoviral transduction of the VEGF gene in an oversized skin flap increases flap survival and perfusion. In this study, we investigated the potential of magnetofection of magnetic lipospheres containing VEGF165 -cDNA on survival and perfusion of ischemic skin flaps and evaluated the method with respect to the significance of applied magnetic field and ultrasound. We prepared perfluoropropane-filled magnetic lipospheres (,magnetobubbles') from Tween60-coated magnetic nanoparticles, Metafectene, soybean-oil and cDNA and studied the effect in an oversized random-pattern-flap model in the rats (n= 46). VEGF-cDNA-magnetobubbles were administered under a magnetic field with simultaneously applied ultrasound, under magnetic field alone and with applied ultrasound alone. Therapy was conducted 7 days pre-operative. Flap survival and necrosis were measured 7 days post-operatively. Flap perfusion, VEGF-protein concentration in target and surrounding tissue, formation and appearance of new vessels were analysed additionally. Magnetofection with VEGF-cDNA-magnetobubbles presented an increased flap survival of 50% and increased flap perfusion (P < 0.05). Without ultrasound and without magnetic field, the effect is weakened. VEGF concentration in target tissue was elevated (P < 0.05), while underlying muscle was not affected. Our results demonstrate the successful VEGF gene therapy by means of magnetobubble magnetofection. Here, the method of magnetofection of magnetic lipospheres is equally efficient as adenoviral transduction, but has a presumable superior safety profile. [source]

Efficacy of the Flashlamp-Pumped Pulsed-Dye Laser in Nonsurgical Delay of Skin Flaps

DERMATOLOGIC SURGERY, Issue 7 2003
Ali Riza Erçöçen MD
Objective. The purpose of this article was to determine the effectiveness of laser delay by use of the flashlamp-pumped pulsed-dye laser operating at a wavelength of 585 nm; to elucidate the comparable or dissimilar macroscopic, microscopic, and hemodynamic changes between laser and surgical delay methods; and to clarify the possible mechanisms underlying the delay effect of laser. Methods. A standardized caudally based random dorsal rat flap model was used in this study: Acute random skin flaps served as control subjects (group 1). Surgical delay was employed by incision of lateral longitudinal borders both without (group 2) and with (group 3) undermining, and laser delay methods were performed by laser irradiation of both lateral longitudinal borders (group 4) and the entire surface (group 5) of the proposed flap. Evaluation was done by histologic examination, India ink injection, laser Doppler perfusion imaging, and measurement of flap survival. Results. Histologically, dilation and hypertrophy of subpapillary and subdermal vessels were evident in groups 2, 3, and 4; on the other hand, degranulation of mast cells in the vicinity of occluded vessels at the 1st hour of laser delay and a striking mast cell proliferation and degranulation in association with newly formed vessels (angiogenesis) at the 14th day of laser delay were prominent in group 5. India ink injections revealed longitudinally arranged large-caliber vessels and cross-filling between the vessels of adjacent territories in groups, 2, 3, and 4, but only small-caliber vessels in group 5. Compared with the acute flaps, both surgical and laser delay significantly increased the mean flap perfusion to the maximal levels after a 14-day delay period, and all delay procedures improved flap survival; the most significant increase in surviving area was observed in group 3, whereas the less significant increase in surviving area was in group 5. Conclusion. This study demonstrates that laser delay is as effective as surgical delay and that laser delay by lasering lateral borders leads to dilation and longitudinal rearrangement of the existing vessels rather than angiogenesis, whereas laser delay by lasering the entire surface results in delay effect by inducing angiogenesis due to activation and degranulation of the mast cells. [source]

Non-viral VEGF165 gene therapy , magnetofection of acoustically active magnetic lipospheres (,magnetobubbles') increases tissue survival in an oversized skin flap model

Postoperative monitoring of lower limb free flaps with the Cook,Swartz implantable Doppler probe: A clinical trial

MICROSURGERY, Issue 5 2010
B.Med.Sc., P.G.Dip.Surg.Anat., Ph.D., Warren M. Rozen M.B.B.S.
Background: Free flaps to the lower limb have inherently high venous pressures, potentially impairing flap viability, which may lead to limb amputation if flap failure ensues. Adequate monitoring of flap perfusion is thus essential, with timely detection of flap compromise able to potentiate flap salvage. While clinical monitoring has been popularized, recent use of the implantable Doppler probe has been used with success in other free flap settings. Methods: A comparative study of 40 consecutive patients undergoing microvascular free flap reconstruction of lower limb defects was undertaken, with postoperative monitoring achieved with either clinical monitoring alone or the use of the Cook-Swartz implantable Doppler probe. Results: The use of the implantable Doppler probe was associated with salvage of 2/2 compromised flaps compared to salvage of 2/5 compromised flaps in the group undergoing clinical monitoring alone (salvage rate 100% vs. 40%, P = 0.28). While not statistically significant, this was a strong trend toward an improved flap salvage rate with the use of the implantable Doppler probe. There were no false positives or negatives in either group. One flap loss in the clinically monitored group resulted in limb amputation (the only amputation in the cohort). Conclusion: A trend toward early detection and salvage of flaps with anastomotic insufficiency was seen with the use of the Cook,Swartz implantable Doppler probe. These findings suggest a possible benefit of this technique as a stand-alone or adjunctive tool in the clinical monitoring of free flaps, with further investigation warranted into the broader application of these devices. © 2009 Wiley-Liss, Inc. Microsurgery 30:354,360, 2010. [source]

Perfusion, viability, and pedicle dependence in acute and delayed rat island skin flaps

MICROSURGERY, Issue 2 2007
Ewa Komorowska-Timek M.D.
Purpose: Although surgical delay phenomenon has been widely investigated, its pathophysiology has not been fully elucidated. Methods: In 25 Spraque,Dawley rats, an 8 × 8 cm2 epigastric skin flap consisting of 4 vertical zones A through D (farthest from vascular pedicle) was outlined. All animals were perfused twice with colored fluorescent microspheres: immediately before and after flap elevation (Acute, n = 10) and before and after pedicle ligation on POD 8 (Delayed, n = 15). Results: After acute flap elevation, peripheral perfusion dropped significantly in zone C (0.29 ± 0.01 vs. 0.19 ± 0.04 ml g,1 min,1; P < 0.01) and zone D (0.33 ± 0.09 vs 0.01 ± 0.01 ml g,1 min,1; P < 0.01), while global flap perfusion remained unchanged. Total and regional blood flow did not change in the Delayed group after pedicle ligation. Conclusions: Elevation of a pedicled flap caused significant decrease in distal flap perfusion while maintaining proximal and total flap perfusion. Eight-day delay was adequate to establish sufficient flap perfusion independent of the vascular pedicle. © 2007 Wiley-Liss, Inc. Microsurgery, 2007. [source]

The effect of dobutamine on blood flow of free tissue transfer flaps during head and neck reconstructive surgery*

ANAESTHESIA, Issue 10 2009
A. Scholz
Summary In view of the controversy over the use of inotropes in free tissue transfer surgery, we assessed the effect of different intra-operative dobutamine infusion rates on blood flow in the anastomosed recipient artery. Twenty patients undergoing head and neck tumour resection and immediate reconstructive surgery with free tissue transfer were recruited. After completion of the microvascular anastomoses, patients received dobutamine infusions of 2, 4 and 6 ,g.kg,1.min,1 in a randomised order. After steady state dobutamine concentration was achieved, mean and maximum blood flow in the arterial anastomosis was measured at each concentration, using the Medi-Stim Butterfly Flowmeter system. Systemic haemodynamic parameters were simultaneously recorded using a pulse contour cardiac output system. Both mean and maximum blood flow increased significantly in the anastomosed artery at dobutamine infusions of 4 and 6 ,g.kg,1.min,1 and this was accompanied by increased cardiac output. This may improve free flap perfusion. [source]