Rani Nasser

Comparison of ICD-9–based, retrospective, and prospective assessments of perioperative complications: assessment of accuracy in reporting

OBJECT large studies of ICD-9-based complication and hospital-acquired condition (HAC) chart reviews have not been validated through a comparison with prospective assessments of perioperative adverse event occurrence. Retrospective chart review, while generally assumed to underreport complication occurrence, has not been subjected to prospective study. It is unclear whether ICD-9-based population studies are more accurate than retrospective reviews or are perhaps equally susceptible to bias. To determine the validity of an ICD-9-based assessment of perioperative complications, the authors compared a prospective independent evaluation of such complications with ICD-9-based HAC data in a cohort of patients who underwent spine surgery. For further comparison, a separate retrospective review of the same cohort of patients was completed as well. METHODS a prospective assessment of complications in spine surgery over a 6-month period (May to December 2008) was completed using an independent auditor and a validated definition of perioperative complications. The auditor maintained a prospective database, which included complications occurring in the initial 30 days after surgery. All medical adverse events were included in the assessment. All patients undergoing spine surgery during the study period were eligible for inclusion; the only exclusionary criterion used was the availability of the auditor for patient assessment. From the overall patient database, 100 patients were randomly extracted for further review; in these patients ICD-9-based HAC data were obtained from coder data. Separately, a retrospective assessment of complication incidence was completed using chart and electronic medical record review. The same definition of perioperative adverse events and the inclusion of medical adverse events were applied in the prospective, ICD-9-based, and retrospective assessments. RESULTS ninety-two patients had adequate records for the ICD-9 assessment, whereas 98 patients had adequate chart information for retrospective review. The overall complication incidence among the groups was similar (major complications: ICD-9 17.4%, retrospective 19.4%, and prospective 22.4%; minor complications: ICD-9 43.8%, retrospective 31.6%, and prospective 42.9%). However, the ICD-9-based assessment included many minor medical events not deemed complications by the auditor. Rates of specific complications were consistently underreported in both the ICD-9 and the retrospective assessments. The ICD-9 assessment underreported infection, the need for reoperation, deep wound infection, deep venous thrombosis, and new neurological deficits (p = 0.003, p < 0.0001, p < 0.0001, p = 0.0025, and p = 0.04, respectively). The retrospective review underestimated incidences of infection, the need for revision, and deep wound infection (p < 0.0001 for each). Only in the capture of new cardiac events was ICD-9-based reporting more accurate than prospective data accrual (p = 0.04). The most sensitive measure for the appreciation of complication occurrence was the prospective review, followed by the ICD-9-based assessment (p = 0.05). CONCLUSIONS an ICD-9-based coding of perioperative adverse events and major complications in a cohort of spine surgery patients revealed an overall complication incidence similar to that in a prospectively executed measure. In contrast, a retrospective review underestimated complication incidence. The ICD-9-based review captured many medical events of limited clinical import, inflating the overall incidence of adverse events demonstrated by this approach. In multiple categories of major, clinically significant perioperative complications, ICD-9-based and retrospective assessments significantly underestimated complication incidence. These findings illustrate a significant potential weakness and source of inaccuracy in the use of population-based ICD-9 and retrospective complication recording.

Nerve injury during the transpsoas approach for lumbar fusion

A lateral transpsoas approach to achieve interbody fusion in the lumbar spine using either the extreme lateral interbody fusion or direct lateral interbody fusion technique is an increasingly popular method to treat spinal disease. Dissection and dilation through the iliopsoas muscle places the lumbosacral plexus at risk for injury, but there is very limited information in the published literature about adverse clinical events resulting in postoperative motor deficits or reports of failure of electrophysiological monitoring to detect nerve injury. The authors present 2 cases of postoperative motor deficits following the transpsoas approach not detected by intraoperative monitoring, review the medical literature, and discuss strategies for complication avoidance.

Clinical Assessment of Percutaneous Lumbar Pedicle Screw Placement Using the O-Arm Multidimensional Surgical Imaging System

BACKGROUND: Increasing popularity of minimally invasive surgery for lumbar fusion has led to dependence upon intraoperative fluoroscopy for pedicle screw placement, because limited muscle dissection does not expose the bony anatomy necessary for traditional, freehand techniques nor for registration steps in image-guidance techniques. This has raised concerns about cumulative radiation exposure for both surgeon and operating room staff. The recent introduction of the O-arm Multidimensional Surgical Imaging System allows for percutaneous placement of pedicle screws, but there is limited clinical experience with the technique and data examining its accuracy. OBJECTIVE: We present the first large clinical series of percutaneous screw placement using navigation of O-arm imaging and compare the results with the fluoroscopy-guided method. METHODS: A retrospective review of a 24-month period identified patients undergoing minimally invasive lumbar interbody fusion. The O-arm was introduced in the middle of this period and was used for all subsequent patients. Accuracy of screw placement was assessed by examination of axial computed tomography or O-arm scans. RESULTS: The fluoroscopy group included 141 screws in 42 patients, and the O-arm group included 205 screws in 52 patients. The perforation rate was 12.8% in the fluoroscopy group and 3% in the O-arm group (P < .001). Single-level O-arm procedures took a mean 200 (153-241) minutes, whereas fluoroscopy took 221 (178-302) minutes (P < .03). CONCLUSION: Percutaneous pedicle screw placement with the O-arm Multidimensional Intraoperative Imaging System is a safe and effective technique and provided improved overall accuracy and reduced operative time compared with conventional fluoroscopic techniques.

Patient comorbidity score predicting the incidence of perioperative complications: assessing the impact of comorbidities on complications in spine surgery

OBJECT Present attempts to control health care costs focus on reducing the incidence of complications and hospital-acquired conditions (HACs). One approach uses restriction or elimination of hospital payments for HACs. Present approaches assume that all HACs are created equal and that payment restrictions should be applied uniformly. Patient factors, and especially patient comorbidities, likely impact complication incidence. The relationship of patient comorbidities and complication incidence in spine surgery has not been prospectively reported. METHODS The authors conducted a prospective assessment of complications in spine surgery during a 6-month period; an independent auditor and a validated definition of perioperative complications were used. Initial demographics captured relevant patient comorbidities. The authors constructed a model of relative risk assessment based on the presence of a variety of comorbidities. They examined the impact of specific comorbidities and the cumulative effect of multiple comorbidities on complication incidence. RESULTS Two hundred forty-nine patients undergoing 259 procedures at a tertiary care facility were evaluated during the 6-month duration of the study. Eighty percent of the patients underwent fusion procedures. One hundred thirty patients (52.2%) experienced at least 1 complication, with major complications occurring in 21.4% and minor complications in 46.4% of the cohort. Major complications doubled the median duration of hospital stay, from 6 to 12 days in cervical spine patients and from 7 to 14 days in thoracolumbar spine patients. At least 1 comorbid condition was present in 86% of the patients. An increasing number of comorbidities strongly correlated with increased risk of major, minor, and any complications (p = 0.017, p < 0.0001, and p < 0.0001, respectively). Patient factors correlating with increased risk of specific complications included systemic malignancy and cardiac conditions other than hypertension. CONCLUSIONS Comorbidities significantly increase the risk of perioperative complications. An increasing number of comorbidities in an individual patient significantly increases the risk of a perioperative adverse event. Patient factors significantly impact the relative risk of HACs and perioperative complications.

Incidence of early complications in cervical spine surgery and relation to preoperative diagnosis: a single-center prospective study.

Study Design Prospective observational cohort study. Objective To determine the incidence of early postoperative complications in patients undergoing cervical spine surgery and its correlation with preoperative diagnosis. Summary of Background Data The reported incidence of complications and adverse events in cervical spine surgery is highly variable. Inconsistent definitions and varying methodologies have made the interpretation of earlier reports difficult. No large study has analyzed the overall early morbidity of cervical spine surgery in a prospective fashion or attempted to correlate preoperative diagnosis and comorbidities with perioperative complications. Methods Data on 121 consecutive patients, who underwent cervical spine surgery at the Thomas Jefferson University Hospital from May to December 2008, was prospectively collected. Complication definition and gradations of complication severity were validated by a survey of spine surgeons and spine surgery patients. An independent assessor prospectively audited complication incidence in the patient cohort. Data on diagnosis, comorbidities, BMI, complications, and length of stay were prospectively collected and assessed using stepwise multivariate analysis. Results The overall incidence of early complications was 47.1% with a 40.5% incidence of minor complications and an 18.2% incidence of major complications. Major complication incidence was greater in cases of infection (20.0%) and spinal oncologic procedures (30.0%), although this difference was not of statistical significance (P=0.07). Total number of complications recorded was greater in cases of infection and neoplasm (P=0.05). Conclusions Complications in cervical spine procedures occurred most frequently in cases involving trauma and spinal oncologic procedures. This study illustrates that the incidence of early complications in cervical spine procedures is greater than appreciated earlier. This difference likely arises owing to the use of a broad definition of perioperative complications, elimination of recall bias through use of a prospective assessment, and overall case complexity. Accurate assessment of the incidence of early complications in cervical spine surgery is important for patient counseling and in design of prospective quality improvement programs.

Symptomatic progression of degenerative scoliosis after decompression and limited fusion surgery for lumbar spinal stenosis

Significant degenerative scoliosis together with lumbar spinal stenosis increases the complexity of planning a surgical intervention for iatrogenic instability may be introduced by decompression in the midst of the curve, especially at or near the curve apex, that may lead to more rapid progression of a deformity, especially if surgery is at, or is near, the apex of the curve and a listhesis is present. Surgical options include simple laminectomy, a laminectomy with limited fusion, or an extensive fusion that addresses the overall curve, but there is no consensus as to the best approach. There is scant information in the literature about specific instances of failure of a limited surgical approach from which any instructive lessons may be learned. We report a surgical failure in a 59-year-old woman with degenerative lumbar stenosis and scoliosis from L3-5 and L3-4 disc herniation treated with a simple hemilaminectomy and discectomy, a subsequent fusion for symptomatic progression of deformity, and a third surgery to fuse the entire scoliotic curve after development of severe deformity, pain, and neurological deficits. We conclude that surgical decision-making should take into consideration any risk factors for deformity progression as well as overall sagittal and coronal balance and advise that similar patients be followed for a lengthy period following surgery to monitor for stability.

Postoperative urinary retention in patients undergoing elective spinal surgery

OBJECTIVE Postoperative urinary retention (POUR) is a common problem leading to morbidity and an increased hospital stay. There are limited data regarding its baseline incidence in patients undergoing spinal surgery and the risk factors with which it may be associated. The purpose of this study was to evaluate the incidence of POUR in elective spine surgery patients and determine the factors associated with its occurrence. METHODS The authors retrospectively reviewed the records of patients who had undergone elective spine surgery and had been prospectively monitored for POUR during an 18-month period. Collected data included operative positioning, surgery duration, volume of intraoperative fluid, length of hospital stay, and patient characteristics such as age, sex, and medical comorbidities. Dialysis patients or those with complete urinary retention preoperatively were excluded from analysis. RESULTS Of the 397 patients meeting the study inclusion criteria, 35 (8.8%) developed POUR. An increased incidence of POUR was noted in those who underwent posterior lumbar surgery, those with benign prostatic hypertrophy (BPH), those with chronic constipation or prior urinary retention, and those using a patient-controlled analgesia pump postoperatively. An increased incidence of POUR was seen with a longer operative time but not with intraoperative intravenous fluid administration. A significant relationship between the female sex and POUR was noted after controlling for BPH, yet there was no association between POUR and diabetes or intraoperative instrumentation. Postoperative retention significantly prolonged the hospital stay. Three patients developed epidural hematomas necessitating operative reexploration, and while they experienced POUR, they also developed the full constellation of cauda equina syndrome. CONCLUSIONS Awareness of the risk factors for POUR may be useful in perioperative Foley catheter management and in identifying patients who need particular vigilance when they are due to void postprocedure. A greater understanding of POUR may also prevent longer hospital stays in select at-risk patients. Postoperative retention is rarely caused by a postoperative cauda equina syndrome due to epidural hematoma, which is also associated with saddle anesthesia, leg pain, and weakness, yet the delineation of isolated POUR from this urgent complication is necessary for optimal patient care.

Resection of spinal column tumors utilizing image-guided navigation: a multicenter analysis.

OBJECTIVE The use of intraoperative stereotactic navigation has become more available in spine surgery. The authors undertook this study to assess the utility of intraoperative CT navigation in the localization of spinal lesions and as an intraoperative tool to guide resection in patients with spinal lesions. METHODS This was a retrospective multicenter study including 50 patients from 2 different institutions who underwent biopsy and/or resection of spinal column tumors using image-guided navigation. Of the 50 cases reviewed, 4 illustrative cases are presented. In addition, the authors provide a description of surgical technique with image guidance. RESULTS The patient group included 27 male patients and 23 female patients. Their average age was 61 ± 17 years (range 14-87 years). The average operative time (incision to closure) was 311 ± 188 minutes (range 62-865 minutes). The average intraoperative blood loss was 882 ± 1194 ml (range 5-7000 ml). The average length of hospitalization was 10 ± 8.9 days (range 1-36 days). The postoperative complications included 2 deaths (4.0%) and 4 radiculopathies (8%) secondary to tumor burden. CONCLUSIONS O-arm 3D imaging with stereotactic navigation may be used to localize lesions intraoperatively with real-time dynamic feedback of tumor resection. Stereotactic guidance may augment resection or biopsy of primary and metastatic spinal tumors. It offers reduced radiation exposure to operating room personnel and the ability to use minimally invasive approaches that limit tissue injury. In addition, acquisition of intraoperative CT scans with real-time tracking allows for precise targeting of spinal lesions with minimal dissection.

Ruptured anterior spinal artery aneurysm from a herniated cervical disc. A case report and review of the literature.

Background: Subarachnoid hemorrhage (SAH) caused by a ruptured cervical anterior spinal artery aneurysm is extremely rare and in the setting of cervical spondylosis. This case presentation reviews the diagnosis, management, and treatment of such aneurysms. Case Presentation: An 88-year-old female presented with the worst headache of her life without focal deficits. She was found to have diffuse SAH in the basal cisterns extending inferiorly down the spinal canal. Review of the neurodiagnostic images revealed an anterior spinal artery aneurysm in the setting of cervical spondylosis. Conclusions: Clinicians should be suspicious of cervical spondylosis as a rare etiology for an SAH when cerebral angiograms prove negative for intracranial aneurysms.

Thirty-day readmission and reoperation rates after single-level anterior cervical discectomy and fusion versus those after cervical disc replacement

OBJECTIVE The goal of this study was to compare 30-day readmission and reoperation rates after single-level anterior cervical discectomy and fusion (ACDF) versus those after cervical disc replacement (CDR). METHODS The authors used the 2013-2014 American College of Surgeons National Surgical Quality Improvement Program database. Included were adult patients who underwent first-time single-level ACDF or CDR for cervical spondylosis or disc herniation. Primary outcome measures were readmission and/or reoperation within 30 days of the original surgery. Logistic regression analysis was used to assess the independent effect of the procedure (ACDF or CDR) on outcome, and results are presented as odds ratios with 95% confidence intervals. RESULTS A total of 6077 patients met the inclusion criteria; 5590 (92.0%) patients underwent single-level ACDF, and 487 (8.0%) patients underwent CDR. The readmission rates were 2.6% for ACDF and 0.4% for CDR (p = 0.003). When stratified according to age groups, only patients between the ages of 41 and 60 years who underwent ACDF had a significantly higher readmission rate than those who underwent CDR (2.5% vs 0.7%, respectively; p = 0.028). After controlling for patient age, sex, body mass index, smoking status, history of chronic obstructive pulmonary disease (COPD), diabetes, hypertension, steroid use, and American Society of Anesthesiologists (ASA) class, patients who underwent CDR were significantly less likely to undergo readmission within 30 days than patients who underwent ACDF (OR 0.23 [95% CI 0.06-0.95]; p = 0.041). Patients with a history of COPD (OR 1.97 [95% CI 1.08-3.57]; p = 0.026) or hypertension (OR 1.62 [95% CI 1.10-2.38]; p = 0.013) and those at ASA Class IV (OR 14.6 [95% CI 1.69-125.75]; p = 0.015) were significantly more likely to require readmission within 30 days. The reoperation rates were 1.2% for ACDF and 0.4% for CDR (p = 0.086), and multivariate analysis revealed that CDR was not associated with lower odds of reoperation (OR 0.60 [95% CI 0.14-2.55]; p = 0.492). However, increasing age was associated with a higher risk (OR 1.02 [95% CI 1.00-1.05]; p = 0.031) of reoperation; a 2% increase in risk per year of age was found. CONCLUSIONS Patients who underwent single-level ACDF had a higher readmission rate than those who underwent single-level CDR in this study. When stratified according to age, this effect was seen only in the 41- to 60-year age group. No significant difference in the 30-day single-level ACDF and single-level CDR reoperation rates was found. Although patients in the ACDF group were older and sicker, other unmeasured covariates might have accounted for the increased rate of readmission in this group, and further investigation is encouraged.