scholarly journals Patterns of Reinnervation and Blood Flow in Split-Skin Grafts

2005 ◽  
Vol 13 (3) ◽  
pp. 133-137
Author(s):  
A Juma ◽  
D Oudit ◽  
M Ellabban

One of the most important functions of skin is thermoregulation. The alterations in the patterns of blood flow in skin is one of the main physiological processes responsible for thermoregulatory control. The mechanisms governing the thermoregulatory control of cutaneous blood flow are mainly neural and chemical in nature. At present, there is a lack of studies in the literature looking at the relationship between reinnervation and the blood flow pattern of skin grafts. The present study uses Laser Doppler flowmetry and the immunohistochemical stains protein gene product 9.5, calcitonin gene-related peptide and substance P to identify nerve fibres, and antibodies to CD31 and von Willebrand factor to identify endothelial tissues. The aim of the present study was to investigate the patterns of blood flow and nerve tissue regeneration in split-skin grafts up to 15 years following the original procedure. Thirty-two split-skin grafts were studied and these were placed into two groups based on the nature of the bed of excision: group I consisted of patients who underwent tangential excision and split-skin grafting (n=17), and group II consisted of patients with split-skin grafts placed onto fascial beds (n=15). Each subpopulation of patients was further divided into three groups based on the length of time following grafting: one to three years, four to six years and seven to 15 years. These divisions were arbitrarily chosen and called A1, A2 and A3, respectively. In the Laser Doppler flowmetry arm of the study, the grafts were assessed at various stages after heating, cooling and further reheating. The Laser Doppler flowmetry studies showed that, on subjecting the skin grafts in both groups I and II to heating and cooling followed by reheating, the overall response of the blood flow to changes in the temperature was slower. The immunohistochemical analysis showed that in all graft types and graft ages, protein gene product 9.5, calcitonin gene-related peptide and substance P stains demonstrated a relative lack of the presence of nerve fibres in the split-skin grafts compared with the control (‘normal’ skin). However, von Willebrand factor and CD31 immunological staining demonstrated that vessels were present in the split-skin grafts, with no significant difference in size or quantity from the control samples. It was found that the blood flow in the split-skin graft in response to thermal challenge, although present, was slower than that of normal skin, a finding which was independent of the age of the skin graft. It is thought that this was related to a lack of regeneration of nerve fibres and, hence, a deficiency in the neurally mediated reflexes of the blood vessels within the split-skin grafts.

2005 ◽  
Vol 13 (1) ◽  
pp. 16-22
Author(s):  
A Juma ◽  
D Oudit ◽  
M Ellabban

Background: There is a paucity of reports in the literature examining the pattern of sensory and autonomic neural recovery of myocutaneous microvascular flaps and skin grafts to the lower limbs after a prolonged period of time. Objectives: To investigate the recovery of sensation and autonomic nerve activity in long-standing split-skin grafts applied to fascial beds and in myocutaneous microvascular flaps. Methods: The patients were divided into two groups: group a consisted of patients with a split-skin graft applied to a fascial bed (n=11) and group B consisted of patients with free microvascular flaps (n=4). Patients in both groups underwent various clinical subjective and objective tests, including the measurement of electrical resistance and thermal sensory analysis. Laser Doppler flowmetry was used to investigate the blood flow patterns. Results: Patients in both groups showed significantly reduced sensory modalities. However, the findings of both the electrical resistance and laser Doppler flowmetry were significantly different among the patients in group a compared with controls. In contrast, electrical resistance and laser Doppler flowmetry test results were similar in group B and controls. Conclusions: Both split-skin grafts applied to fascial beds and microvascular flaps on the lower limb had poor sensory recovery. However, after 15 years, the microvascular flaps regained the ability to sweat and some degree of thermoregulatory function. This may imply that the long-standing myocutaneous free flaps regained some aspects of their autonomic innervation, whereas the split-skin grafts had not.


2019 ◽  
Vol 24 (2) ◽  
pp. 108-119 ◽  
Author(s):  
B. N. Davydov ◽  
D. A. Domenyuk ◽  
S. V. Dmitrienko

Relevance. Morpho-functional changes in peripheral circulation established in type 1 diabetes mellitus correlate with changes in central hemodynamics, allowing the use of microcirculation indicators as diagnostic and prognostic criteria for assessing the degree of functional vascular disorders. Identifcation of microcirculation features of the blood by the method of laser Doppler flowmetry in children with different experience of type 1 diabetes in key age categories.Materials and methods. The study included 67 children with type 1 diabetes mellitus aged 12-15 years with an experience of the disease from six months to ten years. The comparison group consisted of 38 healthy children. The state of the microvasculature was assessed by laser Doppler flowmetry using a laser analyzer for capillary blood flow LAKK-OP.Results. In children with an experience of type 1 diabetes of less than two years, microcirculation disorders in periodontal tissues correspond to the hyperemic form, accompanied by increased perfusion, a decrease in the amplitude of low-frequency oscillations, increased heart rate, high blood flling, and blood flow bypass. For children with an endocrinopathy experience of more than three years, microcirculation disorders correspond to a stagnant form, combined with a decrease in perfusion due to stagnation of blood in the venular link, endothelial domination with suppression of neurogenic and cardiac fluctuations, low efciency and redistribution of blood flow in favor of the nutritive link.Conclusions. With the increase in experience, the degree of compensation of type 1 diabetes, the progression of diabetic microangiopathy, it is advisable to designate two stages of development of microcirculatory disorders. Early – compensatory with active adaptation, including neurogenic and endothelial regulation mechanisms. Late – decompensation with passive adaptation, supporting the effectiveness of microcirculation due to myogenic control of regulation, shunting and increasing the rate of blood outflow.


1991 ◽  
Vol 261 (6) ◽  
pp. F998-F1006 ◽  
Author(s):  
M. S. Nobes ◽  
P. J. Harris ◽  
H. Yamada ◽  
F. A. Mendelsohn

The effects of angiotensin II (ANG II) or angiotensin III (ANG III) on renal cortical blood flow (CBF) or papillary blood flow (PBF) were investigated in Inactin-anesthetized young rats with the use of laser-Doppler flowmetry. Infusion of equimolar pressor doses of ANG II (300 ng.kg-1.min-1 iv) or ANG III (267 ng.kg-1.min-1) decreased CBF by 31 +/- 2.6% (P less than 0.001) and 20.3 +/- 3.2% (P less than 0.01), respectively but increased PBF by 19 +/- 6.1% (P less than 0.05) and 14.6 +/- 4.4% (P less than 0.05). The ANG II-induced increase in PBF was not prevented by aortic clamping to maintain constant renal perfusion pressure or pretreatment with the prostaglandin synthase inhibitor, indomethacin. The nonpeptide ANG II receptor antagonist, DuP 753 completely abolished the systemic and intrarenal effects of ANG II. After pretreatment with a kallikrein inhibitor, aprotinin, ANG II infusion increased mean arterial pressure but did not affect PBF, suggesting that kinins, but not prostaglandins, modulate the action of systemic ANG II on PBF. We conclude that circulating ANG II induces vasoconstriction in the cortex and also promotes the intrarenal production of kinins, which act to enhance papillary blood flow.


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