non surgical intervention for palliation in tof

2.  A female baby was born at 40 weeks of gestation and with
3200 g of birth weight had cyanosis and a heart murmur.
Echocardiogram revealed enlargement of the right ventricle,
large ventricular septal defect (8.4 mm), dextroposition of the
aorta (50%), and severe RVOT stenosis (PG 70 mm Hg) with
pulmonary hypoplasia. Pulmonary blood flow was secured
mainly by small ductus arteriosus. The patient started on
continuous prostaglandin infusion and was stabilised with
oxygen saturation approaching 80%.

3.  Early surgical repair
 Surgical shunts
 PDA stenting
 RVOT balloon dilatation
 RVOT stent

4.  Degree of cyanosis depends on
 degree of right ventricular outflow tract obstruction
 degree of pulmonary artery development
 Favorable anatomy – good size confluent PA’s – Total
correction
 In infancy and even in neonatal life, age is no BAR

5. Advantages of primary repair include
 early abolishment of cyanosis,
 minimisation of right ventricular hypertrophy and
fibrosis,
 avoidance of left ventricular volume-loading from
palliative shunts and
 potential reduction in dysrhythmias.
Major disadvantage : the neonatal brain may be more
prone to surgery-related neurological injury

6. Early primary repair : Preferred but not possible
when
 Unsuitable anatomy – small PAs
 Critically ill child
 Very small infant, LBW, Preterm

7. McGoon ratio: (Diameter of RPA + Diameter of LPA/DAo)
 Normal ≥ 2
 Adequate for primary repair 1.2
 Inadequate <0.8
Nakata Index: (CSA of RPA + CSA of LPA)/BSA
 Normal value > 200 mm2/m2
 > 150 mm2/m2 is adequate
 Not usable preoperatively when MAPCAs are the major source of PBF &
one-stage unifocalization + full repair is planned

8.  Surgical shunts
 PDA stenting
 RVOT balloon dilatation
 RVOT stent

9.  Neonatal shunt – high mortality and morbidity
 25- 30% neonatal mortality
Ann Card Anaesth 2014;17:191-7
 Overburdened surgical lists, Long stay (5-6 days post
surgery) and so bed occupancy in ICU!!
 Complication of CPB, Second surgery difficult, blockage in
not rare…
 PA growth and distortion of Pas.

10. CLSSICAL BT SHUNT
MODIFIED BT SHUNT
THE WATERSTON SHUNT
THE POTTS SHUNT

12.  Performed under general anaesthesia or deep
conscious sedation
 Preferable to have a mildly constricted duct (enough
to allow the stent to be secured)
 Recommended to stop prostaglandin infusion 6 - 12
hours before the procedure.

13.  To confirm ductal size - echocardiography before catheterisation
laboratory
 Delay the procedure if duct does not show a degree of constriction.
 If ductal diameter is large as a result of prostaglandin therapy it may
be of benefit to administer a prostaglandin inhibitor (ibuprofen 5 -
10mg/kg intravenously)
 Prefer to ensure good guide wire position before administering a
prostaglandin inhibitor as a protective measure

14.  Retrograde femoral arterial access is most commonly used
 Carotid and axillary routes have been described. The latter
requires cut down by a vascular surgeon
 Smaller sheath sizes preferred to avoid vascular
complications
 Patients heparinised (50 - 100U/kg iv) and routine
prophylactic antibiotics are given according to local
protocols

15.  Various catheters may be utilized for angiography and
stent.
 Routine angiography is usually performed with a pigtail
catheter
 In the majority of cases, the configuration of a right
coronary artery catheter should enable one to cross the
duct safely
 Sometimes a cut-off pigtail may be useful to cross the PDA.
 In difficult cases a coaxial system may be extremely helpful

16.  The following should be clearly demonstrated before stenting:
 Origin from the aortic arch,
 Diameter at pulmonary artery (most often the narrowest),
 Ampulla diameter and
 Ductal length
 Ductal length can be misleading as ducts are often convoluted
or angled, thus difficult to measure accurately.
 Measure the length of the PDA with the guide wire in position;
this tends to straighten the ductus and allows an improved
estimation of ductal length

17.  Standard bare metal coronary stents used
 Stents with the lowest profile are preferred
 It is of the utmost importance to stent the entire
length of the duct as any unstented segment
will soon become constricted and may be
extremely difficult to recannulate

18.  Stent sizes as recommended:
 3.5 mm diameter in those patients weighing <3kg
 4mm in those weighing 3 - 5kg, and
 4.5mm stents in those patients weighing 5kg and above.
 Heparin infusion is continued at a dose of 25U/kg/hr
for 24 - 48 hours.
 Aspirin is simultaneously initiated at 2 - 3mg/kg/day
and patients are discharged on this dose.

22.  Complicated duct anatomy
 Branch pulmonary artery stenosis

23.  Peri-procedural complications include
 Acute stent thrombosis (2 - 3%),
 Pre-stent ductal spasm (<1%),
 Stent dislodgement and migration,
 Vessel or chamber perforation
 Long term complications resemble those of surgical shunts
and consist of
 Progressive stent stenosis,
 Pulmonary overflow with pulmonary hypertension and
 Branch pulmonary artery distortion

24.  Reduced waiting period before intervention
 Avoids the side-effects of continuous prostaglandin
infusion
 Rapid post-procedure Recovery and short hospital stay
 Can be performed on relatively small and premature
newborns that are often critically ill.

31.  Adequate for valvular PS
 Inadequate for Infundibular or Supravalvular PS
 Most TOF pts  combined PS
 Unreliable results

33.  Small babies,
 With co morbidities,
 Small PAs ,
 Ostial stenosis of PAs,
 Need palliation, significant blue
RVOT stent

34. First described by Gibbs & Colleagues in 1997
Advantages of RVOT stenting –
 Physiological direction of pulsating flow
 Symmetric growth of MPA & both PAs
 Decreased morbidity as compared to surgical
shunt

35. FV – 5F - Small babies
6F – Can use guide catheter
RCA – BMW – Branch PA
Long sheath – useful – Injection – stent

37.  Diameter - on the pulmonary valve annulus – 1 – 2 mm
higher.
 Length - RVOT infundibular length
 Positioning equally important
 Consider preserving Pulmonary valve

38.  Peripheral Vascular stent
 BMS
 Express vascular stent
 Ballon expandable.
 ParaMount Mini GPS Balloon-Expandable - biliary
 Coronary stent – small babies.

39.  To preserved pulmonary valve
 If pulmonary valve not preserved, will needed  TAP;
 Most patient undergoing RVOT stenting, needed TAP
– usually small annulus
 Not to entrap the tricuspid valve with placement of the
stent

40. Take care to prevent stent embolization : too small
a stent  Inc risk of stent instability and
embolization
 Avoid entrapping Tricuspid valve
 Diuretics may be needed post stenting to prevent
reperfusion lung injury

44.  Case series and case reports from worldwide
 Not more than 200 cases reported
 RCT not possible,
 TC, PDA stenting and RVOT stenting had different
subjects.

45.  52 pts. Mean age – 63 days. Mean weight – 3.8 kg.
 Surgical intervention deemed high risk in all
 Only 1 procedural death and 1 emergency surgery
 Saturations increased from 71% (52-83%)  92% (81-100%)
Heart Online First, published on July 11, 2013 as 10.1136/heartjnl-2013-304155

46. Chesney D. Castleberry et al Pediatr Cardiol (2014) 35:423–430

47. Cardiol J 2008;15;376-9

52. ICR after RVOT stenting

53. D.J. Barron et al. / European Journal of Cardio-Thoracic Surgery 2013

54.  Most patient needed TAP – (Trans annular patch)
 RVOT stenting – very severe cyanosis – very tight PS –
small annulus – will also need patch in ICR.
 More bypass time and cross clamp time
 The average bypass time was 109 ± 42 min and cross-
clamp time 68 ± 29 min V/S 88 ± 36 min and 63 ± 22
min
Karl TR. Tetralogy of Fallot: current surgical perspective. Ann Pediatr Cardiol
2008;1:93–100

55.  Complete removal of the stent is not always possible.
 Often, remnants of the stent are embedded into the
myocardium and close to the VSD margins.
 Retained stent - focus for future ventricular
arrhythmias or infections ???
 The small retained portions of the stent- not prevent
satisfactory anatomical repair,  need close
surveillance in the future.

56.  RVOT stenting is a logical palliative procedure to augment
pulmonary blood flow
 It is feasible and generally safe
 Life saving in a critically ill patient who is unfit for surgical
palliation

57.  Small babies,
 With co morbidities,
 Small PAs ,
 Ostial stenosis of PAs,
 Need palliation, significant blue
RVOT stent

58.  Primary repair is treatment of choice whenever feasible
 Non surgical interventions such as PDA stenting, RVOT
stenting, and RVOT ballooning emerging as equally
effective and safe method of palliation as compared with
surgical shunts

59. Thank You