149. Increased risk of medical complications in patients with normal pressure hydrocephalus undergoing decompression for cervical myelopathy

Abstract

BACKGROUND CONTEXT Normal pressure hydrocephalus (NPH) is a rare condition more commonly seen in elderly populations that are prone to degenerative spine pathologies, specifically those that predispose them to cervical myelopathy (CM). While symptomatic presentation can mimic CM, there is limited information about this population in the perioperative setting. Prior studies have demonstrated that patients with NPH have increased complications following orthopedic procedures; however, to date no study has examined the impact of NPH in spine surgery. PURPOSE The aim of this study was to examine if a concomitant diagnosis of NPH increased risk of postoperative complications following elective cervical decompression for CM. STUDY DESIGN/SETTING Retrospective cohort study. PATIENT SAMPLE This study included 5,399 Medicare beneficiaries undergoing elective cervical decompression. OUTCOME MEASURES Initial inpatient length of stay (LOS), 90-day medical complications, 90-day readmissions. METHODS Medicare patients under the age of 85 undergoing elective decompression for CM between the years of 2006-2013 were queried using International Classification of Diseases (ICD) coding. Exclusion criteria included any patients with a prior diagnosis of noncervical myelopathy, spinal infection, spinal trauma, or spinal malignancy 5 years prior to decompression. Patients who met study criteria were then separated into those with preexisting NPH prior to index surgery and those without (controls). NPH patients where then matched in a 1:20 ratio to controls using age, sex, and preexisting comorbidities. All postoperative outcomes of interest between the two populations were evaluated using multivariate logistic regression. Significance was defined as p RESULTS Following application of study criteria and matching, 5,399 patients were identified for the study, of these 266 had a diagnosis of NPH. Within 90 days of index surgery, NPH patients had significantly higher risk of cerebrovascular accident (OR 2.61 [1.19-5.08] p=0.008), pulmonary embolism (OR: 2.73 [1.03-6.03] p=0.024), and urinary tract infection (OR 2.1 [1.44-2.98] p CONCLUSIONS Myelopathic patients with preoperative NPH had an increased risk 90-day medical complications following decompression surgery. Likewise, this population had a protracted initial LOS and higher readmission rates following index surgery. Patients and physicians should be aware of these risks and care should be taken to optimize these patients prior to surgery to mitigate future postoperative complications. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.