Blalock-Taussig Shunt

Blalock-Taussig Shunt

Cite this article as:
Marc Anders. Blalock-Taussig Shunt, Don't Forget the Bubbles, 2013. Available at:
https://doi.org/10.31440/DFTB.3598

Definition: Modified Blalock-Taussig shunt: Gortex graft from subclavian or innominate artery to the ipsilateral PA to augment PBF. Blalock-Taussig shunt: direct anastomosis between the transected subclavian artery (or the innominate artery) and the pulmonary artery.


Indication:

To provide adequate (but not excessive) pulmonary blood flow, hence minimising the risk of congestive cardiac failure and pulmonary hypertension: TOF, TA, PA with IVS, Ebstein’s anomaly, HLHS.


Physiology:

Aiming for a balanced circulation (SpO2 75-85%), aiming for a Qp:Qs = 1:1.


Postoperative management:

  • Commence heparin 10U/kg/hr once no major bleeding
  • Start aspirin (5 mg/kg) on first postoperative day. Once feeds are tolerated, cease heparin if no CVL in situ
  • Commence morphine sedation, paralyse with cisatracurium for 12 hours until the pulmonary and systemic blood flow have balanced
  • Respiratory: SpO2 75-85%; may need some time to settle pulmonary blood flow and achieve stable saturations
  • Inotropes: usually not required
  • Haemodynamics: SBP >60 mmHg, MAP >40 mmHg (increasing over time), LAP 8-12 mmHg, CVP 8-12 mmHg
  • Fluid restriction: 3ml/kg/hr, avoid hypovolaemia, trophic feeds
  • Haemostasis: Hb 130-150 g/l

Specific problems:

  • Prostaglandin infusion should be weaned slowly, especially if infant was on it for more than 48 hours
  • Low diastolic BP usually indicates good shunt flow (diastolic run off), but also lower coronary artery perfusion pressure and risk of splanchnic hypoperfusion
  • If low SpO2, exclude shunt occlusion (change in murmur ?): ECHO, heparin 50 U/kg, inform surgeons; hypovolaemia (give volume bolus); hypotension (volume bolus and/or inotropes); inadequate CO (inotropes)
  • If high SpO2 with pulmonary overcirculation leading to pulmonary oedema (unilateral) may indicate a too large shunt or PDA, which was not ligated. If still intubated: decrease FiO2 to 0.21; allow mild hypercapnoea; correct hypovolaemia; increase Hb; PDA ligation if necessary; try to extubate if feasible; non-invasive ventilation to support CO

References:

[1] Critical Heart Disease in Infants and Children; 2nd ed, Nichols et al: Tricuspid Atresia

[2] J Card Surg 2009;24: 101-108: Yuan et al: The Blalock-Taussig Shunt

[3] Ann Thorac Surg 2011;92:642-52: Petrucci et al: Risk Factors for Mortality and Morbidity After the Neonatal Blalock-Taussig Shunt Procedure

[3] Partners of the Heart: Vivien Thomas and His Work with Alfred Blalock, by Vivien T. Thomas (originally published as Pioneering Research in Surgical Shock and Cardiovascular Surgery: Vivien Thomas and His Work with Alfred Blalock), University of Pennsylvania Press, 1985


CENTRAL SHUNT

Definition: anastomosis between the ascending aorta and the main pulmonary artery made of PTFE.

[1] Ann Thorac Surg. Nov 1991;52(5):1132-7: Watterson et al: Very small pulmonary arteries: central end-to-side shunt.


SANO SHUNT

Definition: right ventricle-to-pulmonary artery shunt in an attempt to overcome the obstacles noted with a systemic-to-pulmonary artery shunt (diastolic runoff and low coronary artery perfusion pressure); disadvantages: Sano Shunt becomes obstructive over time.

[1] J Thorac Cardiovasc Surg. Aug 2003;126(2):504-9; discussion 509-10: Sano et al: Right ventricle-pulmonary artery shunt in first-stage palliation of hypoplastic left heart syndrome

[2] J Card Surg. 2009 Mar-Apr;24(2):101-8: Yuan et al: The Blalock-Taussig shunt


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About Marc Anders

AvatarMarc Anders is a paediatric intensivist.

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Author: Marc Anders Marc Anders is a paediatric intensivist.

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