1. Risk factors for late pulmonary homograft stenosis after the Ross procedure 
Ehud Raanani, MD, Terrence M Yau, MD, Tirone E David, MD, Goran Dellgren, MD, Brian D Sonnenberg, MD, Ahmed Omran, MD 
The Annals of Thoracic Surgery 
Volume 70, Issue 6, Pages (December 2000)
DOI: /S (00)

2. Fig 1
Early and late postoperative gradients across the pulmonary homograft in 105 patients undergoing the Ross procedure. No Doppler gradient across the homograft was noted in any patient 1 week postoperatively, but late peak Doppler gradients were 20 mm Hg or more in 30 of 105 patients (29%) and 40 mm Hg or more in 4 of 105 patients (3.8%).
The Annals of Thoracic Surgery  , DOI: ( /S (00) )

3. Fig 2
Univariate relationship of risk factors previously associated with increased homograft viability on mean gradients across the pulmonary homograft. Younger donor age (p = 0.002), shorter length of cryopreservation (p = 0.02), and beating heart donor status (p = 0.059) were most significant, but all factors associated with greater viability demonstrated at least a trend toward increased gradients.
The Annals of Thoracic Surgery  , DOI: ( /S (00) )

4. Fig 3
Effect of risk factors previously associated with increased homograft viability on late pulmonary homograft gradients. These putative risk factors included donor age less than 30 years, ABO mismatch, beating heart donor status, warm ischemic time less than 2 hours, amphotericin usage, and length of cryopreservation less than 20 months. Mean Doppler gradients across the pulmonary homograft increased from 6 ± 4 mm Hg in homografts with none of these risk factors to 26 ± 3 mm Hg in homografts with all six of these risk factors (p = 0.002).
The Annals of Thoracic Surgery  , DOI: ( /S (00) )