Glenn Shunts Revisited

Transcription

1 Glenn Shunts Revisited What is a Super Glenn Patricia O Brien, MSN, CPNP-AC Nurse Practitioner, Pediatric Cardiology

2 No Disclosures

3 Single Ventricle Anatomy

4 Glenn Shunt Cavopulmonary Anastomosis Anastomosis of the Superior Vena Cava to the Right Pulmonary Artery PA s in continuity Performed at 3-6 months Usually 2 nd Stage

5 Glenn Shunts Revisited Review Glenn shunts Classic Glenn Bidirectional Glenn Bilateral Bidirectional Glenn Physiology of Glenn shunts Super Glenn modification Case Study

6 Classic Glenn Dr. William Glenn, 1958 Patients with Tri Atresia SVC attached to Right lung Right lung not in continuity with left lung Decreased volume load on ventricle Relieved cyanosis Meant as a final stage repair

7 Classic Glenn Long Term Results: Median survival was 43 years of age - Post Glenn survival 31 years - Long Term Complications: - Pulmonary AVM s 30% - (Cyanosis, hemoptysis, stroke) - Arrhythmias 30% - (SVT, Sinus node dysfunction) (Zahr, RA et al, Ann Thor Surg, 101(1),2016)

8 Pulmonary AVM s Abnormal connection between arteries and veins bypassing capillary system Right to left shunt - cyanosis Risk for embolic events, hemoptysis Treatment: coil embolization

9 Pulmonary AVM s

10 Pulmonary AVM s Keep coming back, difficult to treat

11 Pulmonary AVM s Classic Glenn excluded hepatic blood flow (from IVC) from reaching right lung PAVM s also seen with liver disease (hepatopulmonary syndrome) Srivastava (1995) identified link that normal hepatic blood flow may prevent or reverse PAVM s in congenital heart disease (Circulation, 92(5), 1995)

12 Bidirectional Glenn Shunt Decreases volume load on single ventricle Relieves cyanosis, correct amount of PBF in infancy All natural tissue, will grow with child PA s in continuity Flow to both lungs

13 Bidirectional Glenn Shunt

14 Bilateral Bidirectional Glenn Both Right and Left SVC s Complex anatomy Heterotaxy syndromes Concerns: PA distortion Clot formation

15 Bidirectional Glenn Older infants Half of C.O. through upper body - adequate PBF Gravity helps move blood through lungs IVC pressure low - protects liver and gut Reduces pressure and volume load on ventricle

16 Bidirectional Glenn Preschooler As they grow: More C.O. goes through lower body and IVC - increasing cyanosis Exercise decreases IVC saturation - increased cyanosis with exercise Risk of Pulmonary AVM s increases with time

17 Normal Cardiac Pressures

18 Glenn Physiology Transpulmonary Gradient: Pulmonary artery pressure minus pulmonary vein pressure Normal is less than 4 Measure of resistance across pulmonary bed

19 Blood ALWAYS follows the path of least resistance

20 Glenn Physiology Glenn relies on non-pulsatile flow Normal PA vasculature is critical Blood flow equally to both lungs Blood flow at low pressure and resistance No obstructions in pulmonary artery or vein Need blood flow for continued PA growth

21 Pulmonary and Collateral Circulation

22 Aortopulmonary Collaterals Arise from systemic arteries: Aorta and bronchial arteries Supply blood to pulmonary circulation Collateral Flow: High pressure blood flow Improves saturations BUT : Competes with normal PA flow Increases volume load on ventricle Increases PAp Can lead to hemoptysis

23 Systemic Venous Collaterals

24 Venovenous Collaterals Connections between SVC and IVC venous systems, pulmonary veins, other veins Post Glenn: SVC pressure rises to overcome PVR, LAp IVC pressure remains low With high SVC pressure: Venous collateral connections develop Can cause severe desaturation

25 Collateral Management Coil embolization

26 Collaterals Keep coming back, difficult to treat

27 Super Glenn Designed for complex single ventricle patients with abnormal pulmonary arteries or pulmonary veins to one lung which increases pressure to that lung so usual bidirectional Glenn not working well or poor Fontan candidate

28 What is a Super Glenn - Bidirectional Glenn to one lung (low pressure) - Small shunt to diseased lung (high pressure) - PA Band between Glenn insertion and shunt

29 Additional Pulmonary Blood Flow PROS: -Might promote PA growth -Improved saturations -Prevent PAVM s (hepatic blood flow from other source) CONS: -Volume load on ventricle remains -Still cyanotic - incidence of pleural effusions and chylothorax - PA p = SVC p venovenous collaterals For most SV pts, additional PBF NOT an advantage (Alghamdi, AA, J Card Surg, 30(9),2015)

30 Super Glenn Poor Glenn or Fontan patients: - More often HLHS or Heterotaxy pts - Hypoplastic or stenotic pulmonary arteries - Unilateral pulmonary vein stenosis / atresia Almost always involves left lung

31 Super Glenn Used a smaller shunt than usual for pt size Controlled PBF Avoid significant increase in SVC pressure Avoid volume load on ventricle Band between BD Glenn to right / shunt to left Protect SVC from high pressure Drive flow to lung that needs it

32 Catheter Interventions Pulmonary Artery Dilations Pulmonary Vein Dilations Coil collaterals: - aortopulmonary - venovenous Multiple interventions common

33 Case Study Boy with (SLL) DILV, L-TGA, PA, ASD, VSD, anomalous LUPV

34 Case Study PDA stent as newborn BD Glenn/repair of anom LUPV at 4 months ARDS, I month on ventilator Chylous effusions- pleurodesis DVT- stroke, hemiparesis, seizures 4 caths over next 8 months Coiled collaterals at every cath, BD ASD

35 Case Study Referred to BCH at 2 years At cath: Glenn pressures 16 5 mm ASD gradient No flow to left lung from Glenn (competing flow) Multiple APC s to left lung, coiled Venovenous collaterals coiled (high SVC press) OR: Super Glenn (5 months later) 5 mm shunt from innominate to LPA Band PA between Glenn and LPA

36 Case Study Cath: 3 weeks post op: SVC pressure 19 (was 16) LPA pressure 21 (was 10) Unobstructed blood flow to left lung Cath: 4 months later Stable pressures and LPA flow Coiled collaterals OR: 5 months after Super Glenn Fenestrated Fontan, LPA plasty, Tricuspid valve repair, takedown shunt

37 Case Study Now 2 years Post Fontan Doing well, O2 sat 92% Cathed twice: Fontan pressures 15, LPA stented Other medical problems have improved Growing well

38 Thank you

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