Thirty-day readmission and reoperation after surgery for spinal tumors: a National Surgical Quality Improvement Program analysis

Abstract

OBJECTIVE The goal of this study was to use a large national registry to evaluate the 30-day cumulative incidence and predictors of adverse events, readmissions, and reoperations after surgery for primary and secondary spinal tumors. METHODS Data from adult patients who underwent surgery for spinal tumors (2011-2014) were extracted from the prospective National Surgical Quality Improvement Program (NSQIP) registry. Multivariable logistic regression was used to evaluate predictors of reoperation, readmission, and major complications (death, neurological, cardiopulmonary, venous thromboembolism [VTE], surgical site infection [SSI], and sepsis). Variables screened included patient age, sex, tumor location, American Society of Anesthesiologists (ASA) physical classification, preoperative functional status, comorbidities, preoperative laboratory values, case urgency, and operative time. Additional variables that were evaluated when analyzing readmission included complications during the surgical hospitalization, hospital length of stay (LOS), and discharge disposition. RESULTS Among the 2207 patients evaluated, 51.4% had extradural tumors, 36.4% had intradural extramedullary tumors, and 12.3% had intramedullary tumors. By spinal level, 20.7% were cervical lesions, 47.4% were thoracic lesions, 29.1% were lumbar lesions, and 2.8% were sacral lesions. Readmission occurred in 10.2% of patients at a median of 18 days (interquartile range [IQR] 12-23 days); the most common reasons for readmission were SSIs (23.7%), systemic infections (17.8%), VTE (12.7%), and CNS complications (11.9%). Predictors of readmission were comorbidities (dyspnea, hypertension, and anemia), disseminated cancer, preoperative steroid use, and an extended hospitalization. Reoperation occurred in 5.3% of patients at a median of 13 days (IQR 8-20 days) postoperatively and was associated with preoperative steroid use and ASA Class 4-5 designation. Major complications occurred in 14.4% of patients: the most common complications and their median time to occurrence were VTE (4.5%) at 9 days (IQR 4-19 days) postoperatively, SSIs (3.6%) at 18 days (IQR 14-25 days), and sepsis (2.9%) at 13 days (IQR 7-21 days). Predictors of major complications included dependent functional status, emergency case status, male sex, comorbidities (dyspnea, bleeding disorders, preoperative systemic inflammatory response syndrome, preoperative leukocytosis), and ASA Class 3-5 designation (p < 0.05). The median hospital LOS was 5 days (IQR 3-9 days), the 30-day mortality rate was 3.3%, and the median time to death was 20 days (IQR 12.5-26 days). CONCLUSIONS In this NSQIP analysis, 10.2% of patients undergoing surgery for spinal tumors were readmitted within 30 days, 5.3% underwent a reoperation, and 14.4% experienced a major complication. The most common complications were SSIs, systemic infections, and VTE, which often occurred late (after discharge from the surgical hospitalization). Patients were primarily readmitted for new complications that developed following discharge rather than exacerbation of complications from the surgical hospital stay. The strongest predictors of adverse events were comorbidities, preoperative steroid use, and higher ASA classification. These models can be used by surgeons to risk-stratify patients preoperatively and identify those who may benefit from increased surveillance following hospital discharge.

Keywords: ACS = American College of Surgeons; ASA = American Society of Anesthesiologists; AUROC = area under the receiver operating curve; BMI = body mass index; CI = confidence interval; COPD = chronic obstructive pulmonary disease; CPT = Current Procedural Terminology; GI = gastrointestinal; GU = genitourinary; ICD-9-CM = International Classification of Diseases, Ninth Revision, Clinical Modification; INR = international normalized ratio; IQR = interquartile range; LOS = length of stay; NSQIP = National Surgical Quality Improvement Program; PTT = partial thromboplastin time; SIRS = systemic inflammatory response syndrome; SSI = surgical site infection; UTI = urinary tract infection; VTE = venous thromboembolism; WBC = white blood cell; complication; metastases; readmission; reoperation; spinal tumor; surgical site infection; venous thromboembolism.