Reversal of Cardiopulmonary Failure by Mandibular Distraction PURPOSE: To demonstrate the improvement in multiple cardiopulmonary functions after mandibular distraction.
MATERIALS AND METHODS: Thirty-three patients with symptomatic micrognathia underwent mandibular distraction using the �No Vector� Technique.� Preoperative and postoperative echocardiograms (1, 3 and 12 months) were performed and several parameters were evaluated, including: right and left ventricular (RV, LV) dimensions, LV mass index, LV geometry, pulmonary artery pressure (PAP) and total pulmonary vascular resistance (TPVR) as calculated using standard methods.� At each interval, the echocardiogram was used to calculate: LV mass (0.891.04[IVS+PWT+LVED]3-[LVED]3)+0.06); LV geometry (Normal, Concentric remodeling, Eccentric hypertrophy, Concentric hypertrophy); RV structure; PA pressure (Velocity/ Baseline frequency x2xcos0); and Pressure gradient (4 x maximal flow velocity2).
RESULTS: Preoperatively, both LV indices were increased when compared to age matched controls (P < .001).� Those patients with severe OSAS had pathologic increases in both RV dimension and LV mass indices (P < .001). �There was a change in LV geometry in over half of the patients preoperatively and these changes were severe enough to be associated with an increased risk of cardiac events in later life(P < .001).� PA pressures were also calculated to be elevated in more than half of patients preoperatively and normalized postoperatively.� Total PVR was also normalized after surgery.�
Postoperative echocardiogram revealed normalization of RV and LV dimensions, with a significant decrease in both LV thickness and LV mass index.� �These parameters were compared using repeated measures analysis (MANOVA), and post-hoc testing was performed using standard methods.
CONCLUSION: Pathologic cardiopulmonary changes that are seen in patients with severe micrognathia and obstructive sleep apnea include increases in ventricular thickness, PA pressures, and PVR.� These changes may have significant implications for future cardiac disease.� Mandibular distraction can improve or normalize many of these changes, supporting early intervention for airway as a means to minimize later cardiac risk factors.� These data merit futher evaluation in a larger series to evaluate more subtle degrees of obstruction and establish criteria for functional intervention.