Intraoperative and Perioperative Mortality Risk Factors for Dogs Undergoing Surgical Correction of a Patent Ductus Arteriosus. McNamara KL1, Regier PJ1, Toth D1, Mickelson M2, Luther J3, Pyne C3, Wallace M4, Sturkie C4, Dugat D5, Marvel S6, Sumner J7, Scharf V8, Clark J8. 1University of Florida, Gainesville, FL; 2Iowa State University, Ames, IA; 3University of Missouri, Columbia, MO; 4University of Georgia, Athens, GA; 5Oklahoma State University, Stillwater, OK; 6Colorado State University, Fort Collins, CO; 7Cornell University, Ithaca, NY; 8North Carolina State University, Raleigh, NC.
There has been no recent literature in veterinary medicine evaluating preoperative patient factors to identify risk factors for intraoperative hemorrhage during patent ductus arteriosus (PDA) ligation and the effect of intraoperative complications on outcome. The objective of this study is to identify risk factors for perioperative complications, mortality rates, and long-term survival in dogs undergoing surgical PDA ligation. We hypothesized that older age and a larger PDA size would have a higher risk for intraoperative hemorrhage; mitral valve disease would not impact survival; and intraoperative hemorrhage would be associated with a higher mortality rate. Medical records of 417 dogs were reviewed. Data related to signalment, clinical signs, diagnostics, perioperative complications, and mortality were recorded. There was no association between age and risk of intraoperative hemorrhage (P = 0.7); type of PDA and risk of intraoperative hemorrhage (P = 0.28); between type of PDA and location of intraoperative hemorrhage (P = 0.7); or between increasing La:Ao ratio and intraoperative hemorrhage (P = 0.08). Intraoperative mortality was 2%. Intraoperative hemorrhage was not associated with a higher mortality rate. Survival to discharge was 97%. The one- and five-year survival rates were 96.4% and 87%. Mitral valve disease did not impact survival. The La:Ao ratio and risk of intraoperative hemorrhage may be clinically significant. The main limitation is the retrospective nature. This study shows an improvement in the perioperative survival of patients experiencing intraoperative hemorrhage, as well as the long-term management of patients with a surgically corrected PDA and other concurrent heart disease. Older age and lower weight should not preclude surgical treatment.