The isotope clearance technique for measuring skin blood flow

Young, Craig; Hopewell, J. W.

doi:10.1016/0007-1226(83)90097-8

Cited by 20 publications

(6 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It turned out that the border of fluorescein penetration appeared closer to the flap base than the border of clinical necrosis. This observation confirms findings reported previously by others, 3 and implies that vascular patterns determining survival are not completely established in the early hours after the creation of a flap. 12 The reason for this is still not fully understood, but vascular adaptation may be part of the explanation.…”

Section: Discussionsupporting

confidence: 92%

“…However, even physicians with long clinical experience sometimes find it difficult to detect the early signs of tissue ischemia. Therefore, various tests have been designed to evaluate either tissue vascularity [1][2][3][4][5] or changes in tissue metabolism typical of ischemia. [6][7][8] None of these tests has proved to be totally reliable in predicting the fate of a newly-raised flap, and none is widely used in clinical routine.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Prediction of Border Necrosis in Skin Flaps of Pigs with Microdialysis

Röjdmark¹,

Hedén²,

Ungerstedt³

2000

J reconstr Microsurg

View full text Add to dashboard Cite

Metabolic changes were studied in newly-raised pedicled skin flaps of pigs. These flaps were constructed so that their distal parts were predestined to necrotize. The objective was to find new ways of making early postoperative prognostications about future flap viability. For that purpose, the fluorescein penetration technique was compared with microdialysis monitoring of interstitial tissue concentrations of glucose, lactate, and glycerol. These parameters were measured 6 to 24 hr postoperatively, and collected at five different sites, ranging from base to end of the flap. The fluorescein penetration border appeared closer to the flap base than a subsequent necrotic border, thereby confirming that this technique--when applied early in the postoperative period--underestimates flap viability. The authors also observed that glucose concentration in the flap declined at an early stage close to the border of fluorescein penetration. No further change was seen in more distal parts of the flap. Consequently, glucose concentration underestimates the viable flap area just as fluorescein does. In contrast, both glycerol and lactate concentrations began to increase closer to the necrotic border. Both increased significantly on passing the border between viable tissue and tissue which later on would become necrotic, and reached levels in the necrotic portion which were never seen in the viable parts. These results were obtained within the first postoperative hours. They suggest that microdialysis monitoring of lactate and glycerol concentrations in skin flaps of pigs can be used to estimate at an early stage where the necrotic border will appear later on. If these results hold true in humans, they may have important clinical applications.

show abstract

Section: Discussionsupporting

confidence: 92%

mentioning

confidence: 99%

Prediction of Border Necrosis in Skin Flaps of Pigs with Microdialysis

Röjdmark¹,

Hedén²,

Ungerstedt³

2000

J reconstr Microsurg

View full text Add to dashboard Cite

show abstract

“…Radioactive microsphere distribution gives consistent results, but allows only a few measurements per flap (Guba et al 1978). Intradermal 133xenon clearance has also yielded good results (Palmer et al 1972, Young 1982, Young & Hopewell 1983, but this is an invasive method, the results of the injection alone increasing flow dramatically (Holloway 1980). Four noninvasive methods of measurement have been described: (1) atraumatic epicutaneous xenon clearance, a development of the intradermal technique (Englehart & Kristensen 1983); (2) photoplethysmography (Harrison et al 1981, McCaffrey et al 1980; (3) dermatofluorimetry, possibly the most reliable method ofassessment of immediate skin flap viability (Graham et al 1983, Silverman et al 1980, Wiseman et al 1982; (4) laser Doppler velocimetry (Bonner et al 1981, Holloway & Watkins 1977, Stern et al 1977, Watkins & Holloway 1982), a recently developed technique which has now become commercially available.…”

Section: Discussionmentioning

confidence: 99%

Quantitative Analysis of Skin Flap Blood Flow in the Rat Using Laser Doppler Velocimetry

Marks

1985

J R Soc Med

View full text Add to dashboard Cite

Summary: Two experiments carried out on rat skin flaps are described, where microvascular flow has been measured noninvasively by a laser Doppler velocimeter. Using this technique it is possible to define the limits of an axial pattern flap in terms of microvascular flow; this was found to increase when the flap is elevated. 'Random-pattern' perfusion is defined by a fall in flow. This recovers sequentially along the flap, and at a constant rate at all sites. A differential in microvascular perfusion is thus maintained along a random-pattern flap for at least the first postoperative week. In a second experiment it is shown that there appears to be a linear relationship between the reduction in skin blood flow in a random-pattern flap and the distance from the base at which the measurements are made.It is suggested that these data support the view that the blood flow in a skin flap recovers primarily from its base rather than via peripheral neovascularization, and that this is due to vascular collaterals opening within the flap rather than to a relaxation of sympathetic tone. IntroductionThe use of pedicled skin flaps in head and neck surgery has recently declined in favour of myocutaneous flaps. The latter seem to offer flaps that are bigger, more robust and reliable and more adaptable. However, our understanding of both in terms of the physiology of their blood flow remains incomplete. In particular, there is little detailed data on what happens to microvascular flow. To date, methods available have tended to assess this indirectly, assuming it is related to the surviving length of a skin flap. More acutely, their perfusion has been assessed by dyes like fluorescein. However, these are not fully accurate visually until 24 hours (Sasaki & Pang 1980) and only give one measurement -where effective microvascular flow stops. Input/output flows in island flaps have been able to demonstrate some aspects of whole flap flow, i.e., pressure-flow functions, but reveal nothing as to how the blood is distributed (Cutting et al. 1981).This report describes how data acquired using laser Doppler velocimetry (LDV), a newly available technique, can give some insight into the physiological changes in microvascular flow in skin flaps.

show abstract

“…The clearance of the isotope was estimated from counts obtained each 15 s by a NaI crystal attached to a ratemeter (Model SR7, Nuclear Enterprises Ltd., Reading, UK). The clearance constant (K) was calculated as the slope of the regression line fitted to the logarithm of the number of counts recorded (Young & Hopewell, 1983).…”

Section: Calculation Of Sbfmentioning

confidence: 98%

The veno‐arteriolar reflex in free skin flaps

Zoltie

Young

Faris

et al. 1989

Clinical Physiology

View full text Add to dashboard Cite

The veno-arteriolar reflex was measured in 10 subjects in whom an area of denervated skin was present in the lower limb following free flap transfer of skin and subcutaneous tissue 3 weeks to 2 years previously. The vasoconstrictor response to dependency was measured in the skin of the flap, in adjacent innervated skin and after chemical dilatation of cutaneous vessels in the skin of the flap. This veno-arteriolar reflex resulting in a reduction of blood flow of 30-40% was present and equal in both normal and denervated skin. The response was abolished by chemical vasodilatation. The results indicate that sympathetic innervation is not essential for the veno-arteriolar reflex, and suggest that myogenic mechanisms may be more important than previously believed.

show abstract

The isotope clearance technique for measuring skin blood flow

Cited by 20 publications

References 30 publications

Prediction of Border Necrosis in Skin Flaps of Pigs with Microdialysis

Prediction of Border Necrosis in Skin Flaps of Pigs with Microdialysis

Quantitative Analysis of Skin Flap Blood Flow in the Rat Using Laser Doppler Velocimetry

The veno‐arteriolar reflex in free skin flaps

Contact Info

Product

Resources

About