INCIDENCE OF VOCAL FOLD PARALYSIS IN INFANTS UNDERGOING LIGATION OF PATENT DUCTUS-ARTERIOSUS

Background. Left-sided, iatrogenic vocal fold paralysis (IVFP) seconda ry to recurrent laryngeal nerve injury is a potential complication of ligation of patent ductus arteriosus (PDA). This study investigates sp ecific risk factors associated with IVFP. Methods. A retrospective cha rt review was performed for all infants 12 months of age or younger wh o underwent operative PDA closure at the University of Iowa from Janua ry 1, 1991, to January 1, 1994. Results. Six cases of IVFP were diagno sed in 68 infants who underwent PDA ligation using clips (52.9%), sutu re ligatures (41.2%), or both (5.9%). Compared with infants without po stoperative IVFP, infants with IVFP were smaller at birth (0.9 versus 2.3 kg; p < 0.001) and more premature (gestational age, 26.3 versus 33 .8 weeks; p < 0.001), and were smaller (1.1 versus 3.4 kg; p < 0.001) and younger (31.9 versus 88.4 days; p < 0.001) at operation. Weight ga in from birth to operation was significant only in infants without pos toperative IVFP (p < 0.05). Although the overall incidence of IVFP in all infants undergoing PDA closure was 8.8%, five of the six cases (83 .3%) of IVFP occurred in extremely low birth weight infants, ie, those weighing 1 kg or less at birth. Among the cohort of extremely low bir th weight babies undergoing operation, the incidence of IVFP was 22.7% . Iatrogenic vocal fold paralysis was associated only with the use of surgical clips; however, because clips were used in 90.9% of the prema ture infants requiring PDA ligation, it was not possible to establish whether suture ligature is a safer technique. Conclusions. This study demonstrates that the single major risk factor for IVFP after ligation of PDA is birth weight less than 1 kg.