Congenital Diaphragmatic Hernia: What will the Successes be Like as Adults? Allan L Coates, MDCM, B Eng(elect) With a big thanks to Dr Priscilla Chiu Dr Desmond Bohn Dr Daniel Trachsel No conflict of Interest Introduction ¾ Relatively common with estimated incidence of 1 in 3000 live births ¾ 85% are left sided, the classic posterolateral Bochdalek hernia ¾ Antenatal diagnosis is common but does not appear to affect outcome dramatically ¾ Associated abnormalities, (40-50%) particularly congenital heart disease are affect mortality Early Respiratory Challenges ¾ Pulmonary hypoplasia Bilateral but almost always worse on side of hernia ¾ Pulmonary hypertension One of the main reasons for NO and/or ECMO ¾ Reflux and aspiration Usually a problem as soon as feeding begins and often a problem for many years Historical Milestone in Treatment ¾ ExtraCorporeal Membrane Oxygenation (circa 70’s and 80’s) ¾ Stabilization before surgery (circa late 80’s) ¾ High Frequency Oscillation Ventilation (circa 80’s) ¾ “Gentle” Ventilation or passive hypercapnea (circa mid 90”s) ¾ Inhaled Nitric Oxide (90’s) The CDH ECMO Controversy ¾ Sickkids vs Boston Children’s Hospital 19811994 > 400 cases ¾ Boston used ECMO as primary method of resuscitation with 50% receiving ECMO and a 53% survival vs 1% at Sickkids and a 55% survival ¾ Retrospective Study Bohn Am J Respir Crit Care Med 2002 Azarow et al J Pediatr Surgery 1997 Wilson et al J Pediatr Surgery 1997 Changing Mortality at Sickkids ¾ Conventional Ventilation (CV) n=77 1985-1989 Survival 51% HFOV 15% ECMO 0% Need for gastrostomy feeding 8% ¾ Gentle Ventilation (GV) n=66 1996-2000 Survival 80% (p<0.05 Chi squared) HFOV 36% ECMO 4% Need for gastrostomy feeding 34% (p<0.05) ¾ No mention is made of associate abnormalities such as congenital heart disease Chui et al J Pediatric Surgery 2006 Late Respiratory Challenges ¾ Airway Hyperractivity with asthma like symptoms In previous study 50% of “Gentle Ventilation” group were prescribed bronchodilators ¾ Musculoskeletal abnormalities (about 25%) Scoliosis, pectus excavatum, chest wall asymmetry ¾ Recurrence of hernia, especially with patch repairs ¾ Long term gastrostomy feeding and GERD AT BIRTH and 8 YEARS OLD V/Q Scan Right Lung 63% Left Lung 37% Pulmonary Function at Seven ¾ TLC 131% RV/TLC 45% ¾ FEV1 63% FVC ¾ FEV1/FVC 60% ¾ No response to bronchodilators 90% Long Term Follow Up (Sickkids) ¾ 1985–1991 Conventional Ventilation n=23 with age and gender matched controls ¾ Echocardiography ¾ Pulmonary Function Testing ¾ Cycle Ergometer Exercise Testing (progressive 2 min intervals) with Cardiac Output at each end of each interval (CO2) exponential – Lands et al) Trachsel et al Pediatric Pulmonology 2006 Long Term Follow Up (Sickkids) ¾ Echocardiography Good myocardial function but smaller pulmonary artery on affected side (p<0.01) ¾ Pulmonary function Cases vs Controls FEV1 (% pred) 83±15% vs 98±10% (p<0.02) RV/TLC 31±10% vs 22±6% (p<0.001) ¾ Exercise Wmax (% pred) 77±12% vs 91±16% (p<0.01) Wmax correlated with FEV1 and RV/TLC in cases All cardiac indices were normal Long Term Follow Up (Netherlands) ¾ Survivors from 1987-1999 ECMO excluded n=53 ¾ Case Control Study matching sex, age and height ¾ Pulmonary Function Measurements Spirometry Lung volume (FRC by washout technique) ¾ Exercise Testing Treadmill, Bruce Protocol, 3 minute stages Peetsold et al Eur J Respir 2009 Results PFTs ¾ Pre bronchodilatation, the FEV1 was < Lower Limit of Normal (LLN defined as Z score < 1.64) in 46% CDH but in no controls. Mean 1.63±1.78 vs 0.08±0.90. p<0.001 ¾ Positive response to BD in 28% in CDH vs 6% in controls (p=0.007) ¾ RV/TLC > ULN in 52% CDH vs 0 controls (p<0.001) ¾ Abnormal PFTs associated with GERD and length of ventilation Peetsold et al Eur J Respir 2009 Results ¾ Exercise performance did not differ from control subjects ¾ Changes with age The CDH survivors ranged from 6-17 years FEV1 Z-scores showed a trend to be lower in the older subjects, p=0.06 but not controls It is unclear whether this was due to improved therapy eg less ventilator induced injury or other factors Issues Not Addressed In Both Studies ¾ Effects of type of surgery Patch repairs have a higher incidence of recurrence At Sickkids, VATS has high much higher incidence of recurrence ¾ Effects of recurrence ¾ Effects of musculoskeletal abnormalities ¾ Mentioned but not addressed is that there was a subset of the population that has neurological sequellae Common Follow Up Themes ¾ There is a significant degree of obstructive findings ¾ There is a high incidence of asthma like symptoms and findings ¾ Exercise abnormalities tend to be mild ¾ Despite early pulmonary hypertension and decreased size of the affected pulmonary artery, cardiac function becomes normal Conclusions ¾ Despite increasing survival of those who would not have survived 25 years ago, this new group of survivors does not appear to have much greater sequellae ¾ Some degree of obstructive disease, usually responsive to brochodilators is common and likely lasting well into adulthood ¾ CDH is another neonatal disease like pre term birth with bronchopulmonary dysplasia that will give rise to airway obstruction in young adults