Merritt D. Kinon

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.

Use of Google Glass to Enhance Surgical Education of Neurosurgery Residents: “Proof-of-Concept” Study

BACKGROUND The relatively decreased time spent in the operating room and overall reduction in cases performed by neurosurgical trainees as a result of duty-hour restrictions demands that the pedagogical content within each surgical encounter be maximized and crafted toward the specific talents and shortcomings of the individual. It is imperative to future generations that the quality of training adapts to the changing administrative infrastructures and compensates for anything that may compromise the technical abilities of trainees. Neurosurgeons in teaching hospitals continue to experiment with various emerging technologies-such as simulators and virtual presence-to supplement and improve surgical training. METHODS The authors participated in the Google Glass Explorer Program in order to assess the applicability of Google Glass as a tool to enhance the operative education of neurosurgical residents. Google Glass is a type of wearable technology in the form of eyeglasses that employs a high-definition camera and allows the user to interact using voice commands. RESULTS Google Glass was able to effectively capture video segments of various lengths for residents to review in a variety of clinical settings within a large, tertiary care university hospital, as well as during a surgical mission to a developing country. The resolution and quality of the video were adequate to review and use as a teaching tool. CONCLUSION While Google Glass harbors the potential to dramatically improve both neurosurgical education and practice in a variety of ways, certain technical drawbacks of the current model limit its effectiveness as a teaching tool.

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.

Effect of body mass index on surgical outcomes after posterior spinal fusion for adolescent idiopathic scoliosis

OBJECTIVE Obesity is an increasing public health concern in the pediatric population. The purpose of this investigation was to examine the impact of body mass index (BMI) on 30-day outcomes after posterior spinal fusion for adolescent idiopathic scoliosis (AIS). METHODS The American College of Surgeons National Surgical Quality Improvement Program Pediatric database (2013 and 2014) was reviewed. Patients 10-18 years of age who had undergone fusion of 7 or more spinal levels for AIS were included. Thirty-day outcomes (complications, readmissions, and reoperations) were compared based on patient BMI per age- and sex-adjusted growth charts as follows: normal weight (NW; BMI < 85th percentile), overweight (OW; BMI 85th-95th percentile), and obese (OB; BMI > 95th percentile). RESULTS Patients eligible for study numbered 2712 (80.1% female and 19.9% male) and had a mean age of 14.4 ± 1.8 years. Average BMI for the entire cohort was 21.9 ± 5.0 kg/m2; 2010 patients (74.1%) were classified as NW, 345 (12.7%) as OW, and 357 (13.2%) as OB. The overall complication rate was 1.3% (36/2712). For NW and OW patients, the complication rate was 0.9% in each group; for OB patients, the rate was 4.2% (p < 0.001). The 30-day readmission rate was 2.0% (55/2712) for all patients, 1.6% for NW patients, 1.2% for OW patients, and 5.0% for OB patients (p < 0.001). The 30-day reoperation rate was 1.4% (39/2712). Based on BMI, this reoperation rate corresponded to 0.9%, 1.2%, and 4.8% for NW, OW, and OB patients, respectively (p < 0.001). After controlling for patient age, number of spinal levels fused, and operative/anesthesia time on multiple logistic regression analysis, obesity remained a significant risk factor for complications (OR 4.61), readmissions (OR 3.16), and reoperations (OR 5.33; all p < 0.001). CONCLUSIONS Body mass index may be significantly associated with short-term outcomes after long-segment fusion procedures for AIS. Although NW and OW patients may have similar 30-day outcomes, OB patients had significantly higher wound complication, readmission, and reoperation rates and longer hospital stays than the NW patients. The findings of this study may help spine surgeons and patients in terms of preoperative risk stratification and perioperative expectations.

Image-guided percutaneous internal fixation of sacral fracture

Percutaneous iliosacral screw placement is a technically challenging procedure with a significant complication profile for misplaced screws. The use of stereotactic image guidance has been shown to provide superior accuracy in the placement of spinal instrumentation. Here, the authors describe a novel application of O-arm technology (Medtronic Sofamor Danek, Memphis, TN, USA) to help safely place iliosacral screws for the treatment of a traumatic sacral fracture.

Traumatic atlanto-occipital dissociation presenting as locked-in syndrome

We present an unusual presentation of unstable atlanto-occipital dissociation as locked-in syndrome. Traumatic atlanto-occipital dissociation is a severe injury that accounts for 15-20% of all fatal cervical spinal injuries. A disruption occurs between the tectorial ligaments connecting the occipital condyle to the superior articulating facets of the atlas, resulting in anterior, longitudinal, or posterior translation, and it may be associated with Type III odontoid fractures. Furthermore, the dissociation may be complete (atlanto-occipital dislocation) or incomplete (atlanto-occipital subluxation), with neurologic findings ranging from normal to complete quadriplegia with respiratory compromise.

Minimally Invasive Separation Surgery with Intraoperative Stereotactic Guidance: A Feasibility Study

BACKGROUND The treatment of spinal metastasis consists of algorithms combining surgical and radiation modalities. Recently the concept of separation surgery followed by stereotactic radiosurgery was shown to be a safe and effective treatment to achieve local tumor control. OBJECTIVE We examined a minimally invasive approach to separation surgery in a cadaveric study followed by a patient cohort with spinal metastasis using navigation to discuss our results and provide a technical note. METHODS A cadaveric study using minimally invasive access systems examined the feasibility of spinal cord decompression. Subsequently, 17 patients with spinal metastasis underwent minimally invasive separation surgery and instrumentation using navigation. All patients were at least 3/5 and pre- and post-operative CT scans were used to evaluate the decompression. Endpoints included neurologic function, operative time, estimated blood loss, duration of hospital stay, and complications. RESULTS The cadaveric study demonstrated adequate decompression of the spinal cord. For the operative cases, the post-operative imaging demonstrated excellent separation for safe stereotactic radiosurgery. The mean incision length was 4.9 cm. The average operative time was 6 hours and 48 minutes, the mean length of stay was 12.8 days and the mean surgical blood loss was 458 mL. The median Spine Instability Neoplastic Score score was 10 with a range of 6-16. All patients remained or improved their neurologic baseline with excellent pain control. One patient incurred a perioperative complication. CONCLUSIONS Minimally invasive separation surgery for spinal metastasis allows for circumferential decompression of the spinal cord and safe post-operative stereotactic radiosurgery. In addition, we demonstrated the efficacy of intra-operative navigation in guiding the resection.

Predicting critical care unit-level complications after long-segment fusion procedures for adult spinal deformity

Background To identify predictive factors for critical care unit-level complications (CCU complication) after long-segment fusion procedures for adult spinal deformity (ASD). Methods The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database [2010-2014] was reviewed. Only adult patients who underwent fusion of 7 or more spinal levels for ASD were included. CCU complications included intraoperative arrest/infarction, ventilation >48 hours, pulmonary embolism, renal failure requiring dialysis, cardiac arrest, myocardial infarction, unplanned intubation, septic shock, stroke, coma, or new neurological deficit. A stepwise multivariate regression was used to identify independent predictors of CCU complications. Results Among 826 patients, the rate of CCU complications was 6.4%. On multivariate regression analysis, dependent functional status (P=0.004), combined approach (P=0.023), age (P=0.044), diabetes (P=0.048), and surgery for over 8 hours (P=0.080) were significantly associated with complication development. A simple scoring system was developed to predict complications with 0 points for patients aged <50, 1 point for patients between 50-70, 2 points for patients 70 or over, 1 point for diabetes, 2 points dependent functional status, 1 point for combined approach, and 1 point for surgery over 8 hours. The rate of CCU complications was 0.7%, 3.2%, 9.0%, and 12.6% for patients with 0, 1, 2, and 3+ points, respectively (P<0.001). Conclusions The findings in this study suggest that older patients, patients with diabetes, patients who depend on others for activities of daily living, and patients who undergo combined approaches or surgery for over 8 hours may be at a significantly increased risk of developing a CCU-level complication after ASD surgery.

Large central lumbar disc herniation causing acute cauda equina syndrome with loss of evoked potentials during prone positioning for surgery

Background: Few studies in the literature discuss operative positioning for lumbar surgery precipitating acute cauda equina syndromes (CES). Case Description: A 56-year-old male with a large L2-3-disc herniation was placed prone on a Jackson table. He immediately lost all motor and sensory evoked potentials. Signals returned to the baseline when surgery was aborted, and he was returned to the supine position. However, potentials were again lost when he was repositioned prone, following which the surgeons proceeded with surgical decompression with a good outcome. Conclusion: This case highlights the risk for patients with large acute lumbar disc herniation/stenosis and CES undergoing prone positioning for lumbar decompression. Here, despite the secondary loss of both sensory and motor evoked potentials, the patient successfully underwent lumbar decompressive surgery/discectomy performed on a Jackson table, resulting in full postoperative neurological recovery.

Minimally invasive transpedicular approach for the treatment of central calcified thoracic disc disease: a technical note

PurposeTo assess the utility of stereotactic navigation for the surgical treatment of ossified, paracentral thoracic discs via a minimally invasive (MI) transpedicular approach.MethodsThe authors performed a retrospective review of cases with paracentral thoracic disc herniation resulting in myelopathy where a traditional MI approach would be difficult, who underwent a stereotactic assisted MI transpedicular approach via a tubular retractor system between 2011 and 2016. Five cases of patients over the age of 18 were selected. Collected data included patient age at surgery, sex, preoperative Nurick grade, number of levels treated, calcified disc presence, length of surgery, estimated blood loss (EBL), length of stay (LOS), complication rate, postoperative Nurick grade, and length of follow-up.ResultsFive patients had a stereotaxic assisted MI transpedicular thoracic discectomy for paracentrally located calcified disc herniation. Intraoperative navigational images were acquired using intraoperative CT scans (O-arm) to plan and guide the surgical procedure, and real-time navigation was used for precise navigation around the cord to access and remove all fragments. MIS surgery was successfully performed in these otherwise contraindicated cases due to the use of intraoperative real-time stereotactic navigation. All patients had a successful decompression around the anterior aspect of the cord.ConclusionThe traditional MI transpedicular thoracic discectomy approach can be further refined and enhanced by stereotactic navigation to expand the limitations of the MIS technique allowing for an increased number and types of patients eligible for minimally invasive surgery. Therefore, MIS via a tubular retractor system with stereotactic navigation is a novel, safe, and effective improvement in feasibility from the traditional minimally invasive transpedicular thoracic discectomy technique.