Mortality Following Major Spinal Deformity Corrective Surgery in Adults

OBJECTIVE: To determine the incidence of mortality following major spinal deformity corrective surgery in adults and factors which may contribute to postoperative mortality.

INTRODUCTION: Incidence of mortality following major spinal deformity corrective surgery has reportedly ranged from 1.4-20%. Few studies assess mortality in a large series. We report our experience in 417 patients.

MATERIAL AND METHODS: From 1992-1999, 417 patients (F 347, M 70) aged 20-87 (avg. 51) underwent spinal deformity corrective surgery (146 primary, 271 revision). Surgical approaches include 23 anterior, 155 posterior, 167 same-day combined, and 72 staged combined. Average introperative blood loss was 3100. Comorbiditiy risk was assessed by ASA score (1 – 28, 2 – 233, 3 – 143, 4 – 3; avg. – 2.3). Fusion levels varied as follows: <5 – 108; 5-10 – 192; >10 – 107. We retrospectively reviewed the patients who died on our service and identified factors that may have contributed to their
demise.

RESULTS: The incidence of mortality was 2.4% (10/417; M 2, F 8; aged 35-70, avg. 52). One death was intraoperative. Death occurred on average on post-op day 9. Average intraoperative blood loss was 3600cc (1300-9000). Average number of levels was 10.1 (5-15). Of the 10, 2 were anterior approaches, 5 were posterior alone, and 3 were combined; 5 were revisions. Pedicle subtraction osteotomies were performed in 6 of 8 posterior approaches. ASA scores averaged 3 (range 2 – 4);( 4 – 2, 3 – 5, 2 – 2, 1 – 0). Causes of death included pulmonary embolus (3), MI, shock, abdominal hemorrhage, seizures, multisystem organ failure, cerebral edema/brain death, and ARDS.

CONCLUSION: The incidence of mortality following major spinal corrective surgery in adults is significant. Sex, age, blood loss, and revision status were not factors affecting mortality. Patients who died tended to have higher ASA scores/comorbidities (3 vs. 2.3) and were more likely to have had osteotomies. The high incidence of pulmonary embolus as cause of death makes it imperative to further investigate PE in this patient population.