Smoking

1.
2.
3.
4.
5.
Over 4000 toxic substances including
nicotine
carbon monoxide
hydrogen cyanide
acrolein
polonium (radioactive)
 biologically active, toxic, mutagenic and carcinogenic
 acute perioperative effects are a concern in plastic surgery
Acute molecular effects
Characterised by
1. vasoconstriction
2. abnormal cellular function
3. thrombogenesis
4. hypoxia
Vasoconstriction
 Direct and indirect
 Direct
i. Mediated by nicotine.
ii. Mechanisms
a. amplification of noradrenaline-induced skin vasoconstriction
b. impairment of endothelium-dependent skin vasorelaxation.
 Indirect
i. Augmentation of thromboxane A2 and stimulation of catecholamine release
from adrenal medulla, sympathetic ganglia and nerve endings
 Cutaneous tissue beds have the highest sympathetic innervation and the least
autoregulatory control – their blood flow is mediated through alpha receptor
activation (noradrenaline)
 Because of the vasoconstrictive effects of cigarette smoke (sympathetic innervation
through alpha receptors), the effect on digits and other cutaneous tissues is greater
than that in, for example, free muscle flaps, which are under less sympathetic
nervous control and rely more on local autoregulation.
Cellular dysfunction
 Inhibits leucocyte function
 Reduced proliferation of macrophages and fibroblasts
 Reduced collagen deposition and retard reepithelialisation
 Direct injury to endothelial cells increases thrombogenic potential
Thrombogenesis
 Nicotine interferes with PGI2, a potent vasodilator
 Carboxyhemoglobin also increases platelet adhesiveness, leading to
microangiopathic thrombosis resulting in total or partial flap loss.
 Increased serum levels of fibrinogen and haemoglobin(polycythemia) have been
documented in smokers.
Hypoxia
 increases the serum level of carboxyhemoglobin, which leads to a reduced oxygencarrying capacity of the blood
 hydrogen cyanide inhibits oxidative pathways for oxidative metabolism
Clinical effects
Cardiovascular
 increased HR and BP
 Peripheral vasoconstriction
i. Direct and indirect mechanisms
ii. Worse with cutaneous and digital supply
 Negative inotropic and arrthymic
 Endothelial damage
 Impairs vasorelaxation
Respiratory
Hypersecretion
Impaired tracheobronchial clearance
Narrowing small airways
Hematopoietic
Polycythemia and increased blood viscosity
Increased platelet adhesion
Reduced oxygen carrying capacity (carboxyhemoglobin)
Immunologic
Decreased cellular and humoral immunity
Mucosal
Increased oral ulcers and duodenal ulcers
Intraoral/upper aerodigestive
Field carcinogenesis
Leucoplakia, erythroplasia
Point DNA mutation
Impaired dental hygiene
Musculoskeletal
Increased time to achieve union
Increased incidence of delayed union/nonunion
 Smoking is strongly associated with failure of union after screw fixation and
non-vascularized bone grafting of the scaphoid. (Little, J Hand Surg [Br]. 2006
Feb 17)
 In dental procedures (ie implants/bone grafts), a higher degree of complication,
or implant failure rates, were found in smokers with and without bone grafts.
 Smoking is associated with an increased risk of complications in patients with
open tibial fractures. There is an increased rate of flap failure, delayed union and
non-union. (Adams CI; Injury 2001)
Reduced strength of bones
Wound healing
Inhibitory effect on Inflammatory and proliferative phases
Decreased collagen deposition
Decreased epithelialisation
Tissue hypoxia
Analgesia
Increased requirements
Increased tolerance (increased enzyme production)
Perioperative effects
Cardiovascular
Vasoconstriction
Direct
1 cigarette
Digital artery blood flow
Indirect
50-90mins
reduced by 24-42%
12-24 hours
Increased heart rate and blood pressure
Respiratory
10mins smoking reduces oxygen tension
Hypoxia – carboxyhemoglobin
Sputum production
Chest infection
Reduced if smoking ceased preop
Returns to non-smoking level
12-24hours
for 60 minutes
12 hours (1/2 life is 4 hours)
declines over 6 weeks
2 months
over 6 months
Hematopoietic
Polycythemia and increased viscocity
up to 4 months
Immunological
Immune system depressed
over 6 months
Wound hypoxia
Tissue hypoxia
Wound healing mechanisms
Epithelialisation and collagen
days-weeks
2-4 weeks
3-4 months
Applications in Plastic Surgery
General complications
 Delayed wound healing and wound breakdown
 Increased infection, seroma and hematoma
 Poor scar formation
 Increased secondary procedures and reoperation rate
 DVT and PE increased (small risk)
Random Pattern flaps
 Reduced viability
 Reduced healing
Free Flaps
 Increased recipient bed complication
o Skin viability and bone healing
 Increased intraoral dehiscence and infection
 No increase in anastomotic thrombosis rate
Replantation
 Failure rate 80-90% if smoke up to 2 months prior to replantation
 Vascular spasm postoperative if continue to smoke
Postmastectomy TRAM flap reconstruction
 Increased (Chang, Kroll PRS Jun 2000)
o Mastectomy flap necrosis
5x




o Abdominal skin necrosis
8x
o Hernia
3x
Reduced complications if stop 4 weeks prior
Patients with a smoking history of greater than 10 pack-years were at especially
high risk for perioperative complications
Not increased
o Free flap loss
o Vessel thrombosis
o Fat necrosis
Spears Ann Plast Surg Dec 2005 found that
o both active and former smokers had a statistically significant higher
incidence of multiple flap complications.
o Compared with nonsmokers, active smoking carries an odds ratio of 5.1 for
having at least 2 flap complications, while former smokers have a 4.9 times
greater risk for multiple flap complications.
o active smokers had a significantly higher rate of TRAM infection when
compared with nonsmokers.
o former smokers had a significantly higher rate of delayed wound healing.
Postmastectomy tissue expander/implant breast reconstruction
Goldwin SJ: Ann Plast Surg. 2005 Jul; Complications in smokers after
postmastectomy tissue expander/implant breast reconstruction.
 Overall complications (OR 3.07)
 mastectomy skin flap necrosis (OR 3.13)
 positive relationship found between number of cigarettes smoked per day and
duration of smoking history to overall complications
 the results of the current series suggest that ex-smokers (those who quit at least 4
weeks prior to surgery) have complication rates more similar to active smokers
rather than nonsmokers.
Abdominoplasties
 Delayed wound healing and dehiscence 3x
 Hospital stay – increased 2-3days
 Reduced complications if stop 4 weeks pre and post
Face lift
 Skin slough and necrosis rate increased 4-12.5%
 Incidence reduced if limit undermining to 2-3cm margin
 Surgery deferred for 4-6 weeks
Nicotine patches
 No effect from CO, cyanide but nicotine will increase HR/BP and increased digital
vasospasm
 Ie need to go off nicotine patches for 6 weeks prior to elective microsurgery