Surgery for chronic thromboembolic pulmonary hypertension--inclusive experience from a national referral center.

BACKGROUND: Chronic thromboembolic pulmonary hypertension represents a unique form of pulmonary hypertension amenable to curative intervention with a pulmonary thromboendarterectomy (PTE). Canada's first successful and sustainable program for PTE surgery was established at the University of Ottawa Heart Institute in 1995. Inclusive results from similarly sized programs are not readily available owing to selective reporting, therefore making it difficult to benchmark outcomes. The purpose of this report is to provide a review of the inclusive results from our moderately sized national program for all PTE, with a particular emphasize on the aspects of the learning curve in terms of patient management.
METHODS: Since 1995, 180 patients have been referred for consideration of PTE, and 106 patients have undergone surgery with a perioperative 30-day mortality rate of 9.4%.
RESULTS: There was a significant improvement in all hemodynamic parameters except right ventricular ejection fraction in nonsurvivors (mean pulmonary artery pressure pre 47 +/- 12 mm Hg versus post 28 +/- 9 mm Hg, p < 0.0001; pulmonary vascular resistance pre 814 +/- 429 dynes x sec(-1) x cm(-5), post 224 +/- 145 dynes x sec(-1) x cm(-5), p < 0.0001; cardiac index pre 2.0 +/- 0.7 L x min(-1) x m(-2), post 3.2 +/- 0.7 L x min(-1) x m(-2), p < 0.0001). A postoperative pulmonary vascular resistance of 500 dynes x sec(-1) x cm(-5) or more was associated with increased perioperative mortality (odds ratio, 12 +/- 8.7; p = 0.001). On average, these procedures were associated with significant resource use involving operating room time (610 +/- 243 minutes), intensive care unit and hospital days (11.2 +/- 13.7 and 19.5 +/- 15.6 days), and ventilation time (7.8 +/- 10.0 days). There was no significant change in hospital or intensive care unit length of stay, or the mortality rate during this first decade.
CONCLUSIONS: PTE programs are resource-intensive surgical specialty services that demand excellence in cardiothoracic expertise. The initial decade reflected an expanding referral basis and likely parallel increases in patient complexity and expertise. The current results at a national referral center have emphasized the importance of centralization of resources to optimize patient outcome.