Laser and Light Treatment of Acquired and Congenital Vascular Lesions Flashcards Preview

Surgical MCQs > Laser and Light Treatment of Acquired and Congenital Vascular Lesions > Flashcards

Flashcards in Laser and Light Treatment of Acquired and Congenital Vascular Lesions Deck (141):
1

Lasers produce selective photocoagulation of vessels using wavelengths of light that are well absorbed by haemoglobin.

T

2

Lasers produce selective photocoagulation of vessels using pulse durations equal to or longer than the thermal relaxation time (or cooling time) of the vessels.

F Equal to or shorter than thermal relaxation time.

3

Larger-diameter and deeper vessels require shorter wavelengths of light and shorter pulse durations.

F Longer wavelength and longer pulse durations.

4

Lasers and light devices used to treat vascular lesions include KTP, pulsed-dye, alexandrite, diodie and Nd:YAG lasers, in addition to IPL.

T

5

Laser stands for Light Amplification by the Stimulated Emission of Radiation.

T

6

Fluence is measured in J/cm2.

T

7

The major chromophores in skin are haemoglobin and melanin.

F And water.

8

When targeting a vascular lesion, the wavelength of light chosen should be well absorbed by haemoglobin and poorly absorbed by melanin.

T

9

Selective heating of the laser target is produced when the energy is deposited at a rate faster than the rate for cooling of the target structure.

T

10

Pulsed KTP laser has a wavelength of 532nm.

T

11

Pulsed dye laser has a wavelength of 595nm.

F 585nm (long-pulsed dye is 585-600nm).

12

Long-pulsed alexandrite laser has a wavelength of 755nm.

T

13

Diode laser uses 800, 810 or 840nm wavelength.

F 800, 810 or 940nm.

14

Long-pulsed Nd:YAG laser has a wavelength of 1064nm.

T

15

IPL uses a wavelength of 515-920nm.

F 515-1200nm.

16

For a given wavelength of light, the optical penetration into skin depends on absorption and scattering.

T

17

The most penetrating wavelengths are in the 650-1200nm red and near-infrared region.

T

18

Longer wavelengths (600-1200nm) penetrate deeper, but with more scattering

F Deeper with less scattering

19

The least penetrating wavelengths are in the far UV, where protein absorption dominates, and the far-infrared, where water absorption dominates.

T

20

The depth of penetration gradually decreases with longer wavelengths.

F Increases with longer wavelengths.

21

With smaller spot sizes, a greater fraction of photons scatter outside the beam area and are rendered ineffective.

T

22

Cooling the skin does not effect tissue injury caused by laser procedures.

F Cooling before/during/after reduces tissue injury.

23

Cooling can be achieved by using a liquid cryogen spray during treatments

T

24

Pulsed-dye laser produces transient blue-black purpura due to haemorrhage and a delayed vasculitis.

T

25

For v essels 10-50microm in diameter, the thermal relaxation time would be 0.1-10ms, with an average of 1.2ms

T

26

Pulsed-KTP lasers emit in the green light spectrum.

T

27

Longer pulse durations increase photomechanical injury and post-treatment purpura.

F Reduce.

28

Lasers with near-infrared wavelengths are not suitable for treating larger vascular anomalies or larger leg veins.

F Alexandrite, diode and Nd:YAG used for this.

29

Vascular lasers can be used for capillary malformations, haemangiomas, venous malformations, telangiectasias, facial erythema, cherry angiomas, venous lakes and poikiloderma of Civatte.

T

30

Striae distensae cannot be treated with vascular laser.

F Striae rubra shows best response.

31

The hypopigmentation of striae distensae responds well to vascular laser.

F No effect.

32

Port wine stains can regress.

F Never regress.

33

Port wine stains darken in colour and become increasingly nodular with age.

T

34

The hypertrophy or nodularity of a PWS are associated with a risk of spontaneous bleeding or haemorrhage with injury to the site.

T

35

PWS should not be treated ideally until adulthood.

F Childhood better.

36

Treatment of PWS in early life enables more rapid clearing, however there may be partial return of the PWS 5-10 years after treatment.

T

37

Greater PWS clearance in children is attributed to thinner skin allowing better laser penetration, smaller vessel diameter, and smaller lesional surface area.

T

38

Gradual clearing of PWS is produced with successive PDL treatments usually performed at 2-4 week intervals.

F 4-6 week intervals.

39

PDL can be safely used in skin types I-IV.

T

40

With PDL, longer wavelengths and longer durations improve PWS clearance.

T Longer wavelengths provide more deeply penetrating light to target deeper vessels.

41

The response of a PWS to PDL treatment depends on its size, anatomic location and the types of vessels that comprise the lesion

T

42

PWS that are present in the central facial area or in a V2 dermatomal distribution respond faster than PWSs located elsewhere on the head and neck.

F More slowly.

43

PWS on extremities respond more slowly to laser therapy than lesions on the trunk, and lesions on the distal extremity respond the slowest.

T

44

Smaller PWSs respond better to PDL.

T

45

The best response to PDL is seen in PWSs located deeper, with smaller diameter vessels.

F Superficially located, larger-diameter vessels

46

Vessel morphology does not correlate with PWS colour.

F Pink = smaller vessel, purple = larger vessel.

47

Red PWS lesions are composed of more superficially located vessels than pink or purple ones.

T

48

Red coloured PWSs respond poorly to laser, while pink coloured PWSs respond better.

F Red better, pink worse.

49

Even slowly responsive PWSs continue to clear with repetitive PDL treatment with no increased risk of adverse effects.

T

50

PDL treatment for PWS during infancy is not recommended.

F Safe and rapid clearance possible.

51

Treatment of PWS with PDL is usually performed with the smallest spot size available to prevent reticulation.

F Largest spot size.

52

PDL treatment of PWS should be performed with the lowest fluence possible that produces purpura without tissue graying or whitening.

T

53

Improved technology in skin cooling has been a major advancement in treatment of PWS

T

54

Appropriate cooling can be achieved by applying millisecond-duration cryogen spurts, preceding each laser pulse with maintenance of the temperature of the laser-heated dermal vessels

T

55

There may be a delayed final tissue reaction after PDL, so the patient should be observed for several minutes after treatment.

T

56

Intense purpura develops 7-10 days after PDL.

F Immediately.

57

The post-treatment purpura associated with PDL takes 2-4 weeks to resolve.

F 7-10 days.

58

Following resolution of purpura after PDL, lesional lightening takes place over 4-8 weeks, when repeat treatments are performed.

T

59

Subsequent treatment sessions with PDL should be delayed until all traces of relative erythema have subsided.

T

60

Treatment should be performed with the lowest possible fluence that produces purpure without tissue graying or whitening

T

61

When tissue graying is encountered, skin should be cooling immediately with ice-packs to avoid epidermal necrosis, crusting and potential scarring

T

62

Subsequent treatment sessions for PWS can continue despite the development of reactive erythema

F Should be delayed until all traces of reactive erythema have subsided

63

IPL devices are broadband filtered xenon flashlamps that work on the principles of selective photothermolysis.

T

64

The IPL emission spectrum of 515-1200nm is adjusted with the use of a series of cut-off filters.

T

65

The pulse duration of IPL ranges from approximately 100 to 200ms.

F 0.5 to 100ms

66

IPL is the treatment of choice for PWS.

F PDL.

67

IPL can be used to treat PDL-resistant PWS.

T

68

KTP laser provides relatively equal absorption and depth of penetration to the PDL, but the overall rate of side effects is higher due to its higher absorption by melanin.

T

69

Long-pulsed alexandrite and Nd:YAG lasers are effective in treating hypertrophic or nodular PWS.

T

70

The alexandrite laser can produce bulk heating and necrosis if used too aggressively for the treatment of PWS.

F This is true for Nd:YAG.

71

The Nd:YAG laser has a higher incidence of post-inflammatory hyperpigmentation compared to the PDL.

F This is true for the alexandrite laser.

72

Haemangiomas occur in females three times as often as males.

T

73

60-70% of haemangiomas occur on the trunk.

F Head and neck.

74

Haemangiomas are composed of numerous small blood vessels and infiltrating vascular endothelial cells that express GLUT1.

T

75

Infantile haemangiomas initially appear as white or pink macules, or telangiectasia with surrounding vasoconstriction.

T

76

Approximately 5% of patients with haemangiomas have incomplete involution.

F 50%

77

Superficial haemangiomas appear as bright red vascular papules or plaques when fully developed.

T

78

Deep haemangiomas appear as bluish-coloured nodules within the skin with only a subcutaneous component.

T

79

Haemangiomas may be only either superficial or deeply located.

F Compound haemangiomas occur.

80

Focal haemangiomas account for 85% of lesions.

T

81

Focal haemangiomas occur on any site in random distribution.

F Occur along lines of embryological fusion.

82

Diffuse hamangiomas occur on any body site in random distribution.

F Segmental distribution.

83

Diffuse haemangiomas tend to be deep lesions.

F Superficial or compound.

84

Diffuse haemangiomas carry a high risk of ulceration.

T

85

Laser therapy for haemangiomas can only be performed once the lesion has involuted.

F Perform during both proliferation and involution.

86

PDL prevent haemangioma enlargement, promote involution, induce re-epithelialisation of ulcerations, and reduce ectasia.

T

87

Thin haemangiomas (

T

88

Haemangiomas treated early in the prodromal phase respond better than those treated during active proliferation.

T

89

Laser treatment usually slows the proliferation of the superficial component of haemangiomas and promotes early regression.

T

90

Haemangiomas should be treated using the same laser parameters as for PWS.

F Lower fluence, larger spot size.

91

Ulceration is not a common complication of haemangiomas.

F Most common complication.

92

Approximately 12% of diffuse haemangiomas and 65% of focal haemangiomas ulcerate.

F 12% focal, 65% diffuse.

93

Ulcerated haemangiomas usually result in a scar.

T

94

Ulcerated haemangiomas respond well to PDL if the ulceration is limited and the haemangioma is not undergoing rapid proliferation.

T

95

Segmental haemangioms are best treated in the early growth phase with PDL.

F Laser can cause ulceration in this context.

96

Pulsed-dye lasers can greatly effect the subcutaneous component of haemangiomas.

F Little effect due limited depth of penetration.

97

CO2 lasers and long-/short-pulsed Er:YAG lasers produce excellent improvement in the atrophic scarring and textural change that accompany haemangioma involution.

T

98

The peak incidence of spider angiomata between the ages of 30 and 40 years old.

F 7-10yo.

99

Treatment of telangiectasiae with PDL is performed by applying contiguous laser pulses with no overlap.

F Approx. 10% overlap.

100

Nd:YAG can be very safely used around the nasal ala to treat telangiectasiae.

F Need proper skin cooling and avoidance of pulse stacking to prevent epidermal damage.

101

Long-pulsed Nd:YAG lasers are particularly useful for the treatment of larger-calibre paranasal vessels.

T

102

Nd:YAG treatment of visible facial veins is limited to those outside the orbital rim.

T Risk of damage to eye with this deeply penetrating wavelength.

103

IPL cannot be used to treat facial telangiectasiae.

F

104

Laser treatment of poikiloderma should be delayed for a minimum of 4 weeks following sun exposure.

T

105

Compared to the treatment of telangiectasia, fluences for poikiloderma should be lowered by approximately 50-70% to avoid adverse effects.

F 25-30%.

106

IPL systems for the treatment of poikiloderma generally use 515-550nm cut-off filters.

T

107

During IPL treatment, a thin layer of gel is applied to the skin surface to aid in skin cooling.

T

108

Erythema and oedema may be present for 2-3 weeks following laser or IPL treatment of poikiloderma.

F 2-3 days.

109

PDL is not suitable for the treatment of scars.

F Use for erythematous and hypertrophic scars.

110

PDL treatment for scars reduces erythema, scar height and surface texture changes.

T

111

Multiple PDL treatment sessions are often necessary for scars.

T

112

Scars should be treated with lasers in intervals of 6-8 weeks.

T

113

PDL are not very effective in treating condyloma acuminata, plantar warts, periungual wart, flat warts and verrucae vulgaris.

T

114

Recalcitrant warts post-laser treatment are best treated with a different method.

F Require 3-4 treatments at 3-4 week intervals.

115

Laser and IPL beams should always be directed away from the orbit when treating in the eye region.

T

116

PDL is capable of igniting a fire in the presence of oxygen and nitrous oxide.

T

117

Topical anaesthetic cannot be used with vascular lasers and light sources.

F

118

With PDL, larger spot sizes are less efficacious and increase the potential for reticulation.

F Greater efficacy, reduce potential for reticulation between Rx sessions.

119

With PDL, post-treatment purpura is most intense with the 0.45ms pulse duration and requires approx. 10 days for resolution.

T

120

With epidermal cooling techniques, blistering or crusting after PDL occurs rarely.

T

121

At pulse durations greater than 6ms, purpura is not produced with PDL.

T Urticarial papules  resolve over several hrs.

122

Most vascular lesions only require one treatment session.

F Multiple Rx sessions.

123

Suntanned individuals can be treated with PDL and KTP laser.

F Risk of absorption by epidermal pigment.

124

Facial telangiectasia and erythema respond well to millisecond-duration KTP lasers.

T

125

Patients with skin types V and VI can be treated with KTP laser.

F

126

Following treatment with KTP laser, there may be erythema and urticarial oedema of the treated skin lasting up to 24 hours.

T

127

Scarring can occur after KTP laser due to excessive fluence, overlapping of laser pulses, or in adequate skin cooling, which results in non-selective thermal damage to the epidermis/dermis.

T

128

Nd:YAG laser is the first-line device for treatment of superficial telangiectasia-

F

129

Larger paranasal and periauricular telangiectasia and venulectasia, that may not clear with green and yellow light, don’t respond well to Nd:YAG laser.

F Do respond well due to its greater depth of penetration.

130

The Nd:YAG laser produces bulk tissue heating.

T

131

Nd:YAG laser pulses can be safely stacked.

F Never – leads to ulceration and necrosis.

132

IPL uses a large rectangular footprint.

T

133

With IPL, shorter wavelength filters (515nm) and the single pulse mode are used on skin type I with fine superficial vessels.

T

134

With IPL, larger and deeper vessels are treated with longer cut-off filters (570 and 590nm) and double or triple pulse modes.

T

135

With IPL, shorter wavelength and shorter interpulse delays are used for darker skin types.

F Longer wavelength and interpulse delay.

136

Gel is not needed when treating with IPL.

F

137

Pulse durations of 10ms or higher are generally required to avoid purpura formation.

T

138

In contrast to treatment for telangiectasia, fluences should be lowered by 25-30% to avoid adverse effects in treating poikiloderma

T

139

PDL can be applied to treat hypertrophic scars but have a poor response

T good response (57-83%)

140

Pulsed dye lasers are very effective in treating the cutaneous lesions of HPV

T Via thermal alteration of the virally infected tissue

141

Low fluence pulsed-dye laser therapy also improves the appearance of striae

T