Postoperative Visual Loss Following Lumbar Spine Surgery: A Review of Risk Factors by Diagnosis

Agreement between non-invasive and invasive arterial blood pressure during surgery in the prone position: an error grid analysis

PURPOSE

Prone position has recently gained renewed importance as a treatment for acute respiratory distress syndrome and spine and brain surgeries. Our study aimed to perform an error grid analysis to examine the clinical discrepancies between arterial blood pressure (ABP) and non-invasive blood pressure (NIBP) in the prone position and to investigate the risk factors influencing these differences.

METHODS

Error grid analysis was performed retrospectively on 1389 pairs of 100 consecutive prone positioning cases. This analysis classifies the difference between the two methods into five clinically relevant zones, from "no risk" to "dangerous risk". Additionally, multivariable ordinal logistic regression analysis was conducted to evaluate the relationship between the risk zones of mean blood pressure (MBP), as classified by error grid analysis and the covariate of interest.

RESULTS

Error grid analysis showed that the proportions of measurement pairs in risk zones A-E for systolic blood pressure were 96.8%, 3.2%, 0.1%, 0%, and 0%, respectively. In contrast, the MBP proportions were 74.0%, 25.1%, 0.9%, 0.1%, and 0%. Multivariable ordinal logistic regression analysis revealed that the position of arms (next to the head) was a significant factor (adjusted odds ratio: 4.35, 95% CI: 2.38-8.33, P < 0.001).

CONCLUSION

Error grid analysis revealed a clinically unacceptable discrepancy between ABP and NIBP for MBP during prone positioning surgery. The position of the arms next to the head was associated with increased clinical discrepancy between the two MBP measurement methods.

Perioperative vision loss after sequential lower extremity fracture surgery: a case report

Perioperative vision loss (POVL) is a rare but serious complication, most frequently reported after cardiac and prone spinal surgeries. POVL following lower extremity surgery is uncommon. We herein report a case of POVL in a man in his mid-thirties after a third surgery to repair a lower extremity fracture. The patient developed vision loss 3 hours postoperatively following sequential surgeries for a lower extremity fracture. Before the third surgery, he was in a hypercoagulable state, and tranexamic acid was administered to reduce intraoperative blood loss. After POVL occurred, anticoagulant and antithrombotic agents, as well as high-dose steroid pulse therapy, were promptly administered. The patient's vision recovered 3 days later, with no abnormalities found during follow-up visits over the next 6 months. For patients at high risk of thrombosis, POVL warrants careful attention. The coagulation system should be kept as stable as possible, and medications that may promote thrombosis, such as tranexamic acid, should be used cautiously.

Postoperative Glaucoma Decompensation Following Spine Surgery: The Importance of Proper Patient Positioning

Transforaminal lumbar interbody fusion (TLIF) is a widely utilized surgical procedure for the treatment of degenerative lumbar spinal conditions, including lumbar disc herniations, spinal stenosis, and spondylolisthesis. One such rare and underreported complication is vision loss following spinal surgery. Postoperative vision loss (POVL) is an extremely uncommon complication, occurring in approximately 0.002% to 0.2% of all non-ocular surgeries, including spinal procedures. We presented a 70-year-old male with complaints of left-sided cruralgia, lumbar radicular pain (sciatica-type L5), and right-sided weakness who underwent L4-S1 TLIF and who reported complete vision loss in his left eye, accompanied by persistent tearing from the affected eye whenever he attempted to focus his vision. The patient's vision in the left eye, which had been stable and functional prior to surgery, was permanently affected by the intraoperative complication. At the three-month follow-up, ophthalmological assessments confirmed that the optic nerve damage was irreversible, and the patient's vision in the left eye remained completely blurred. Postoperative vision loss (POVL) is a rare but devastating complication associated with various types of surgeries, including spinal procedures like transforaminal lumbar interbody fusion (TLIF). The present case of a 70-year-old patient developing permanent vision loss in his left eye due to glaucoma decompensation after TLIF underscores the importance of proper intraoperative positioning, especially in patients with pre-existing ocular conditions.

Perioperative Vision Loss Following Prone Spine Surgery: A Case-Control Study

PURPOSE

Perioperative vision loss (POVL) is a rare and devastating complication following prone spine surgery. Due to the rare nature of this complication, there is limited research available about patient and surgical risk factors that increase the risk of POVL. The objective of this study was to investigate associated risk factors for POVL with use of the National Surgical Quality Improvement Program (NSQIP) database.

DESIGN

This study used a case-control secondary data analysis methodology that included five cases of POVL and 250 controls from the American College of Surgeons National Surgical Quality Improvement Program database who all underwent prone spine surgery between 2010 and 2020.

METHODS

Each POVL case was matched to 50 randomly selected controls (n = 250) based on type and year of surgery. Demographics and variables of interest were compared among the POVL cases, among POVL cases and the aggregate control group (n = 250), and POVL cases against their matched control group. Univariate and multivariate conditional logistic regression were then used to estimate the odds of developing POVL in relation to potential patient and surgical risk factors.

FINDINGS

When POVL cases were compared to the 250 control cases using univariate analysis, patients who developed POVL were more likely to have received a blood transfusion within 72 hours of surgery (P < .0001). and have longer operative times (odds ratio = 1.01, 95% CI [1.003, 1.017], P = .003).

CONCLUSIONS

Two surgical risk factors were determined to be statistically significant, including the need for perioperative blood transfusion and prolonged operative time. These findings support previous research on POVL which often identified blood loss and prolonged operative times as surgical risk factors. The narrow patient population used in this project may have limited the ability to perform a more robust study on POVL. Therefore, further research on POVL using the National Surgical Quality Improvement Program database is strongly encouraged.

A Case Report on Acute Visual Loss With Ophthalmoplegia Following Spine Surgery

Postoperative vision loss is an unusual but serious side effect that can occur after nonocular surgeries, particularly those involving the heart or spine. Various causes, including ischemic optic neuropathy, central retinal artery occlusion, central retinal vein occlusion, and ischemic orbital compartment syndrome, can cause this condition. Here, we present a case of a 28-year-old male patient who underwent spine surgery for cervicodorsal spine injury and experienced sudden, painless vision loss in his left eye following the surgery. On examination, his right eye had a bedside vision of >3/60, while his left eye could only perceive light. The patient's left eye showed mild axial proptosis, supraorbital edema, conjunctival congestion, chemosis, relative afferent papillary defect, and restricted eye movements in all gazes. Fundus examination of the left eye showed pale retina, optic disc pallor, severely attenuated retinal vessels, and an absent cherry red spot suggesting ophthalmic artery occlusion. The right eye anterior segment and fundus findings were normal. Magnetic resonance imaging of the brain and orbit showed mild preseptal thickening in the left orbit, and magnetic resonance venography was normal. This case report is noteworthy in that an ophthalmic artery occlusion has been identified as the cause of sudden, unilateral, painless vision loss associated with ophthalmoplegia subsequent to a spinal surgical procedure.

Dynamic Arterial Elastance as a Predictor of Supine-to-Prone Hypotension (SuProne Study): An Observational Study

Background and Objectives: Supine-to-prone hypotension is caused by increased intrathoracic pressure and decreased venous return in the prone position. Dynamic arterial elastance (Eadyn) indicates fluid responsiveness and can be used to predict hypotension. This study aimed to investigate whether Eadyn can predict supine-to-prone hypotension. Materials and Methods: In this prospective, observational study, 47 patients who underwent elective spine surgery in the prone position were enrolled. Supine-to-prone hypotension is defined as a decrease in Mean Arterial Pressure (MAP) by more than 20% in the prone position compared to the supine position. Hemodynamic parameters, including systolic blood pressure (SAP), diastolic blood pressure, MAP, stroke volume variation (SVV), pulse pressure variation (PPV), stroke volume index, cardiac index, dP/dt, and hypotension prediction index (HPI), were collected in the supine and prone positions. Supine-to-prone hypotension was also assessed using two different definitions: MAPprone < 65 mmHg and SAPprone < 100 mmHg. Hemodynamic parameters were analyzed to determine the predictability of supine-to-prone hypotension. Results: Supine-to-prone hypotension occurred in 13 (27.7%) patients. Eadyn did not predict supine-to-prone hypotension [Area under the curve (AUC), 0.569; p = 0.440]. SAPsupine > 139 mmHg (AUC, 0.760; p = 0.003) and dP/dtsupine > 981 mmHg/s (AUC, 0.765; p = 0.002) predicted supine-to-prone hypotension. MAPsupine, SAPsupine, PPVsupine, and HPIsupine predicted MAPprone <65 mm Hg. MAPsupine, SAPsupine, SVVsupine, PPVsupine, and HPIsupine predicted SAPprone < 100 mm Hg. Conclusions: Dynamic arterial elastance did not predict supine-to-prone hypotension in patients undergoing spine surgery. Systolic arterial pressure > 139 mmHg and dP/dt > 981 mmHg/s in the supine position were predictors for supine-to-prone hypotension. When different definitions were employed (mean arterial pressure < 65 mmHg in the prone position or systolic arterial pressure < 100 mmHg in the prone position), low blood pressures in the supine position were related to supine-to-prone hypotension.

Study on the relationship between scoliosis and vision problems: A narrative review

Adolescent scoliosis is one of the most common surgical disorders of the pediatric spine. With timely detection and early treatment, most scoliotic children can avoid major and expensive surgery. Vision problems are also frequently found at an early age and can take a toll on individuals quality of life. However, scoliosis, a severe health hazard to adolescents, is often accompanied by vision problems clinically, including myopia, astigmatism, strabismus, amblyopia, horizontal paralysis, and blindness. And people with genetic defects have a higher probability of suffering both spinal problems and vision problems than those with nongenetic defects. However, many individuals viewed scoliosis and vision problems as 2 irrelevant diseases. This review searched PubMed, China National Knowledge Infrastructure, and Web of Science for studies on adolescent, scoliosis, eye diseases, myopia, strabismus, spinal disorders, and vision problems for almost 3 decades, and thus confirmed the potential relationship between adolescent scoliosis and vision problems.

The effect of restrictive vs. liberal fluid protocols on ocular parameters in patients undergoing prone spine surgery: a randomized controlled trial

BACKGROUND

Elevated intraocular pressure (IOP) and optic nerve edema occurring during prone surgeries may cause ocular and optic nerve ischaemia injury. We hypothesized that a liberal fluid protocol might further increase IOP and optic nerve sheath diameter (ONSD) than a restrictive fluid protocol for patients in the prone position.

METHODS

A single-centre, prospective and randomized trial was conducted. Patients were randomly allocated into 2 groups: the liberal fluid infusion group, in which repeated bolus doses of Ringer's lactate solution were given to maintain pulse pressure variation (PPV) within 6~9%, and the restrictive fluid infusion group, where PPV was maintained within 13-16%. IOP and ONSD were measured in both eyes at 10min after the anaesthesia induction in the supine position, 10min after the prone position placement, and 1h and 2h since the prone position was placed, at the conclusion of surgery, and returned to the supine position.

RESULTS

A total of 97 patients were recruited and completed the study. IOP increased significantly from 12±3mmHg in the supine position to 31±5 mmHg (p<0.001) at the end of surgery in the liberal fluid infusion group and from 12±2 to 28±4 mmHg (p<0.001) in the restrictive fluid infusion group. There was a statistically significant difference in the change of IOP over time between the two groups (p=0.019). ONSD increased significantly from 5.3±0.3mm in the supine position to 5.5±0.3mm (p<0.001) at the end of surgery in both groups (both p<0.001). There was no statistically significant difference in the change of ONSD over time between the two groups (p>0.05).

CONCLUSIONS

Compared to the restrictive fluid protocol, the liberal fluid protocol increased IOP but not ONSD in patients undergoing prone spine surgery.

TRIAL REGISTRATION

The study was registered in ClinicalTrials.gov ( https://clinicaltrials.gov ) prior to patient enrollment, ID: NCT03890510, on March 26, 2019. The principal investigator was Xiao-Yu Yang.

Hypoalbuminemia and Elevated CRP are Risk Factors for Deep Infections and Urinary Tract Infections After Lumbar Spine Surgery in a Large Retrospective Patient Population

STUDY DESIGN

Retrospective cross-sectional study.

OBJECTIVES

To determine if pre-operative albumin and CRP can predict post-operative infections after lumbar surgery.

METHODS

Patients who underwent an anterior lumbar interbody fusion (ALIF), posterior lumbar interbody fusion (PLIF), or lumbar discectomy were identified using a patient record database (PearlDiver) and were included in this retrospective study. Patients were stratified by Charlson Comorbidity Index (CCI) scores and pre-operative albumin and CRP status. Post-operative complications included deep infections and urinary tract infections within 3 months of the surgery and revisions within 1 year of the surgery.

RESULTS

74,280 patients were included in this study. 21,903 had pre-operative albumin or CRP lab values. 7,191 (33%), 12,183 (56%), and 2,529 (12%) patients underwent an ALIF, PLIF, and a lumbar discectomy, respectively. 16,191 did not have any complication (74%). The most common complication was UTI (16%). Among all patients, hypoalbuminemia was a significant risk factor for deep infection and UTI after ALIF, deep infection, UTI, and surgical revision after PLIF, and deep infection after lumbar discectomy. Elevated CRP was a significant risk factor for deep infection after ALIF, UTI after PLIF, and deep infection after lumbar discectomy in patients with a CCI ≤ 3.

CONCLUSIONS

Pre-operative hypoalbuminemia and elevated CRP were significant risk factors for deep infection, UTI, and/or revision, after ALIF, PLIT, and/or lumbar discectomy. Future studies with a larger population of patients with low albumin and high CRP values are needed to further elaborate on the current findings.

Perioperative management of spinal cord injury: the anesthesiologist's point of view

BACKGROUND

Traumatic spinal cord injury (SCI) is one of the most devastating events a person can experience. It may be life-threatening or result in long-term disability. This narrative review aims to delineate a systematic step-wise airways, breathing, circulation and disability (ABCD) approach to perioperative patient management during spinal cord surgery in order to fill some of the gaps in our current knowledge.

METHODS

We performed a comprehensive review of the literature regarding the perioperative management of traumatic spinal injuries from May 15, 2020, to December 13, 2020. We consulted the PubMed and Embase database libraries.

RESULTS

Videolaryngoscopy supplements the armamentarium available for airway management. Optical fiberscope use should be evaluated when intubating awake patients. Respiratory complications are frequent in the acute phase of traumatic spinal injury, with an estimated incidence of 36-83%. Early tracheostomy can be considered for expected difficult weaning from mechanical ventilation. Careful intraoperative management of administered fluids should be pursued to avoid complications from volume overload. Neuromonitoring requires investments in staff training and cooperation, but better outcomes have been obtained in centers where it is routinely applied. The prone position can cause rare but devastating complications, such as ischemic optic neuropathy; thus, the anesthetist should take the utmost care in positioning the patient.

CONCLUSIONS

A one-size fit all approach to spinal surgery patients is not applicable due to patient heterogeneity and the complexity of the procedures involved. The neurologic outcome of spinal surgery can be improved, and the incidence of complications reduced with better knowledge of patient-specific aspects and individualized perioperative management.

Corneal Abrasions in Total Joint Arthroplasty

Introduction

Corneal abrasion (CA) is the most common ocular complication in patients undergoing nonocular surgery. Corneal abrasions can be caused by a variety of mechanisms, the most common being drying of the cornea due to reduced tear secretions, loss of eyelid reflex, and the loss of pain recognition during surgery. Though CA heals well with eye lubricants, it can result in significant ocular pain and some cases may go on to develop ocular complications. With the current switch to outpatient total joint replacement, CA could potentially lead to discharge delays.

Materials and Methods

We examined the results of a quality improvement project to reduce CA during general anesthesia to determine the rates of CA during hip and knee total joint replacement. We compared rates of CA for 6 months before and 6 months after the intervention.

Results

A total of 670 hip and knee arthroplasty procedures were performed during this period. Two events of CA occurred, one occurred before and one after the intervention to decrease eye injuries. Both incidences occurred during total hip arthroplasty (THA) procedures with the patient in the lateral decubitus position and recovered without long-term deficit.

Discussion

Surgeons and anesthesiologists alike should be cognizant of this avoidable complication and take precaution to protect the eyes during surgery, especially during THA when the patient is placed in the lateral decubitus position.

Conclusion

Corneal abrasion during total joint arthroplasty is a rare complication and is infrequently addressed in the literature. CA is mostly self-limiting, however, but may lead to patient dissatisfaction and to delays if same-day discharge is attempted. Preventative measures and attentive care may help reduce the incidence of CA in patients undergoing total joint arthroplasty. The lateral decubitus position and longer surgeries times are risk factors for CA.

A practical guide to patient position and complication management in neurosurgery: a systematic qualitative review

PURPOSE

Adequate patient positioning is of paramount importance in neurosurgery. Complications related to the position are common and make up for more than 16% of the claims towards anaesthesiologists and neurosurgeons. This paper aims to provide the anaesthesiologist with a practical guide to avoid common pitfalls related to the patient positioning process.

METHOD

We performed a systematic review of the medical literature for the identification, screening, and inclusion of articles. The bibliographic search was conducted on June 1st, 2021 by two of the authors. In this review, we included articles indexed by MEDLINE, Cochrane Library, or Google Scholar.

RESULTS

We retrieved a total of 5706 unique papers from our initial search. However, after the initial screening, 5363 papers were removed is not related to our research leaving a total of 343 papers. We examined the full text of all the 343 articles including 68 of them in the final qualitative analysis.

DISCUSSION

In this review we examine the most common neurosurgical positions: supine, sitting, lateral, park-bench, prone, jack-knife, and knee-chest. For each of them, the proper positioning and related complications are described. Particular attention is given to the prevention and management of these complications, providing a practical guide for clinicians.

Effects of Sevoflurane-Propofol-Balanced Anesthesia on Flash Visual Evoked Potential Monitoring in Spine Surgery: A Randomized Noninferiority Trial

BACKGROUND

Intraoperative flash visual evoked potential (FVEP) can be used to monitor visual function during spine surgery. However, it is limited due to the previous perception of its sensitivity to inhalation anesthesia. We conducted this trial to test the noninferiority of sevoflurane-propofol-balanced anesthesia (BA) versus popular propofol-based total intravenous anesthesia (TIVA) on the amplitude of FVEP during spine surgery.

METHODS

A total of 60 patients undergoing spine surgery were randomized to receive either sevoflurane-propofol-balanced anesthesia (BA group) or propofol-based total intravenous anesthesia (TIVA group) for anesthesia maintenance. We titrated the propofol plasma concentration to keep the bispectral index (BIS) values between 40 and 50. The primary outcome was the P100-N145 amplitudes of FVEP at 120 minutes after induction of anesthesia. The noninferiority margin (δ) was defined as 10% of the P100-N145 amplitude at 120 minutes after induction in the TIVA group. If the confidence interval (CI) for mean differences of P100-N145 amplitude at 120 minutes after induction between BA and TIVA groups lied above the lower limit of -δ with P < .025, we defined BA group was noninferior to TIVA group.

RESULTS

Fifty-nine patients were included in the final analysis. The amplitude of P100-N145 at 120 minutes after anesthesia induction in group BA was noninferior to group TIVA (3.8 [1.3] µV vs 3.2 [1.6] µV, -δ = -0.32, mean difference, 0.57, 95% CI, -0.18 to 1.33, P for noninferiority = .015).

CONCLUSIONS

The effect of 0.5 minimum alveolar concentration (MAC) of sevoflurane-propofol-balanced anesthesia on the P100-N145 amplitude of FVEP was noninferior to that of propofol-based TIVA under comparable BIS range.

Intraoperative Fluid Management in Patients Undergoing Spine Surgery: A Narrative Review

Fluid management has been widely recognized as an important component of the perioperative care in patients undergoing major procedures including spine surgeries. Patient- and surgery-related factors such as age, length of the surgery, massive intraoperative blood loss, and prone positioning, may impact the intraoperative administration of fluids. In addition, the type of fluid administered may also affect post-operative outcomes. Published literature describing intraoperative fluid management in patients undergoing major spine surgeries is limited and remains controversial. Therefore, we reviewed current literature on intraoperative fluid management and its association with post-operative complications in spine surgery.

Systematic Review and Meta-Analysis of Prone Position on Intraocular Pressure in Adults Undergoing Surgery

BACKGROUND

Patients undergoing surgery in the prone position may be at risk for postoperative vision loss associated with increased intraocular pressure. The purpose of this systematic review and meta-analysis is to estimate the magnitude of the increase in intraocular pressure at specific perioperative time points in adult patients. The research question to be addressed is "What is the magnitude of the increase in intraocular pressure at specific perioperative time points in adults undergoing surgery in the prone position?"

METHODS

Comprehensive search strategies were used to identify nine eligible studies (N = 229). Standardized mean difference effect sizes were calculated for two intraoperative time points.Time points for meta-analysis were selected to achieve the greatest number of comparisons for analysis at each time point. Prediction intervals for each time point were also calculated to show the dispersion of true effect sizes around the mean.

RESULTS

Meta-analysis showed that intraocular pressure increased significantly between induction of anesthesia and up to 10 minutes of prone position (T1: standardized mean difference [d] = 2.55; P < .001) and continued to increase significantly until the end of the prone position (T2: d = 3.44; P = .002).

CONCLUSIONS

Intraocular pressure increases of this magnitude demonstrate the need for implementing interventions to reduce the risk for postoperative vision loss in patients undergoing surgery in the prone position.

CLINICAL RELEVANCE

Implementing preoperative ophthalmologic examinations for patients undergoing surgery in the prone position may help to reduce the risk for ocular injury. Intraoperative interventions that can be implemented to reduce or mitigate the increase in intraocular pressure include implementing a 5- to 10-degree reverse Trendelenburg prone position, reducing the amount of time the patient is in the prone position, considering staged procedures, monitoring intraocular pressure, providing periodic position changes or rest periods, preventing pressure on the eye, and administering specific medications or anesthetics.

Iatrogenic ophthalmic artery occlusion and retinal artery occlusion

Iatrogenic ophthalmic artery occlusion (IOAO) is a rare but devastating ophthalmic disease that may cause sudden and permanent visual loss. Understanding the possible etiologic modalities and pathogenic mechanisms of IOAO may prevent its occurrence. There are numerous medical etiologies of IOAO, including cosmetic facial filler injection, intravascular procedures, intravitreal gas or drug injection, retrobulbar anesthesia, intraarterial chemotherapy in retinoblastoma. Non-ocular surgeries and vascular events in arteries that are not directly associated with the ophthalmic artery, can also cause IOAO. Since IOAO has a limited number of treatment modalities, which lead to poor final visual prognosis, it is imperative to acknowledge the information regarding medical procedures that are etiologically associated with IOAO. We accumulated all searchable and available IOAO case reports (our cases and previous reported cases from the literature), classified them according to their mechanisms of pathogenesis, and summarized treatment options and responses of each of the causes. Various sporadic cases of IOAO can be categorized into three mechanisms as follows: intravascular event, orbital compartment syndrome, and increased intraocular pressure. Embolic IOAO, which is considered the primary cause of the condition, was classified into three subgroups according to the pathway of embolic movement (retrograde pathway, anterograde pathway, pathway through collateral channels). Despite the practical limitations of treating spontaneous (non-iatrogenic) retinal artery occlusion, this article will contribute in predicting and improving the prognosis of IOAO by recognizing the treatable factors. Furthermore, it is expected to provide clues to future research associated with the treatment of retinal artery occlusion.

Tarik Syndrome: Reversible Postoperative Blindness Secondary to Occipital Seizures

BACKGROUND

Postoperative blindness is a devastating surgical complication. Although usually associated with prolonged cardiac and prone spinal operations, it may follow other procedures as well. Postoperative blindness is most commonly caused by a vascular etiology, but it can more rarely be caused by status epilepticus. We have previously reported a case of this phenomenon following a staged spinal deformity surgery.

CASE DESCRIPTION

Here we report 2 additional cases following a skull base procedure and a single stage lumbar spine surgery. In all instances, rapid recognition that the patients' blindness was due to occipital seizures resulted in acute antiepileptiform treatment and full restoration of vision.

CONCLUSIONS

Although a rare phenomenon, this syndrome, first recognized and described by Tarik F. Ibrahim, should be considered in any patient with postoperative visual impairment.

OPHTHALMOLOGIC COMPLICATIONS IN SPINAL SURGERIES: LITERATURE REVIEW

ABSTRACT Literature review using PubMed, relating ophthalmologic complications in spinal surgery. Ischemic optic neuropathy (ION), central retinal artery occlusion (CRAO) and cortical blindness (CB) constitute the majority of cases. These are rare complications and have a poor prognosis. Post-operative visual loss (POVL) occurs most often in surgical procedures performed in the prone position. Being male, anemia, blood transfusion, and prolonged surgery time are related to ION, while malposition and direct compression of the eyeball are related to the development of CRAO. Level of Evidence III; Systematic reviewbof level III studies.

Single position versus lateral-then-prone positioning for lateral interbody fusion and pedicle screw fixation

Background

To compare perioperative and radiographic outcomes following lateral lumbar interbody fusions in two cohorts of patients who either underwent single position or dual position surgery.

Methods

Patients over the age of 18 with degenerative lumbar pathology who underwent a lumbar interbody fusion via lateral access from 2012-2015 from a single surgeon met inclusion criteria. Patients who underwent combined procedures, had a history of retroperitoneal surgery, or had inadequate preoperative imaging were excluded. Patients who remained in the lateral decubitus position for pedicle screw fixation [single-position (SP)] were compared to those turned prone [dual-position (DP)]. Demographics, surgical details, and perioperative outcomes were compared between groups.

Results

A total of 42 SP and 24 DP patients were analyzed. The DP group had a 44.4-minute longer operating room time compared to the SP group (P<0.001) after adjusting for the number of levels operated (P<0.001) and unilateral versus bilateral screw placement (P=0.048). Otherwise, no differences were observed in peri-operative outcomes. Lordosis was not different between groups pre-operatively (P>0.999) or post-operatively (P=0.479), and neither was the pre- to post-operative change (P=0.283).

Conclusions

Lateral pedicle screw fixation following lateral interbody fusion decreases operating room time without compromising post-operative lordosis, complication rates, or perioperative outcomes.

Revisiting Postoperative Vision Loss following Non-Ocular Surgery: A Short Review of Etiology and Legal Considerations

Postoperative vision loss (POVL) following non-ocular surgery is a serious complication where the causes are not fully understood. Studies have identified several causes of POVL as well as risk factors and prevention strategies. POVL research is made difficult by the fact that cases are often subject to malpractice claims, resulting in a lack of public access to case reports. This literature review was conducted in order to identify legal issues as a major barrier to studying POVL and address how this affects current knowledge. Informed consent provides an opportunity to overcome legal challenges by reducing malpractice litigation through educating the patient on this outcome. Providing pertinent information regarding POVL during the informed consent process has potential to reduce malpractice claims and increase available clinical information.

Demographic, Systemic, and Ocular Factors Associated with Nonarteritic Anterior Ischemic Optic Neuropathy

OBJECTIVE

Nonarteritic anterior ischemic optic neuropathy (NAION) is a devastating ocular condition causing permanent vision loss. Little is known about risk factors for developing this disease. We assessed demographic, systemic, and ocular factors associated with NAION.

DESIGN

Retrospective longitudinal cohort study.

PARTICIPANTS

Beneficiaries between 40 and 75 years old without NAION at baseline enrolled in a large U.S. managed care network.

METHODS

Enrollees were monitored continuously for ≥2 years between 2001 and 2014 to identify those newly diagnosed with NAION (International Classification of Diseases, 9th Revision, Clinical Modification [ICD-9-CM] code 377.41). All persons were under ophthalmic surveillance and all cases had ≥1 confirmatory ICD-9-CM code for NAION during follow-up.

MAIN OUTCOME MEASURES

Multivariable Cox regression modeling was used to generate hazard ratios (HRs) with 95% confidence intervals (CIs) to describe the statistical relationship between selected demographic characteristics, systemic and ocular conditions, and the hazard of developing NAION.

RESULTS

Of 1 381 477 eligible enrollees, 977 (0.1%) developed NAION during a mean ± standard deviation (SD) follow-up of 7.8±3.1 years. The mean ± SD age for NAION cases at the index date was 64.0±9.2 years vs. 58.4±9.4 years for the remainder of the beneficiaries. After adjustment for confounding factors, each additional year older was associated with a 2% increased hazard of NAION (HR = 1.02; 95% CI: 1.01-1.03). Female subjects had a 36% decreased hazard of developing NAION (HR = 0.64; 95% CI: 0.55-0.74) compared with male subjects. Compared with whites, Latinos had a 46% decreased hazard of developing NAION (HR = 0.54; 95% CI: 0.36-0.82), whereas African ancestry was not significantly associated with NAION (HR = 0.91; 95% CI: 0.72-1.15). Systemic diseases associated with NAION included hypertension (HR = 1.62; 95% CI: 1.26-2.07) and hypercoagulable states (HR = 2.46; 95% CI: 1.51-4.00). Although diabetes mellitus (DM) was not significantly associated with NAION compared with those without DM (P = 0.45), patients with end-organ involvement from DM had a 27% increased hazard of NAION relative to those with uncomplicated DM (HR = 1.27; 95% CI: 1.01-1.59). Ocular diseases associated with NAION were age-related macular degeneration (HR = 1.29; 95% CI: 1.08-1.54) and retinal vein occlusion (HR = 3.94; 95% CI: 3.11-4.99).

CONCLUSIONS

Our study identified several modifiable risk factors that may be associated with NAION. Should future studies confirm these findings, they may offer opportunities to prevent or treat this debilitating condition.

Tirofiban as treatment for acute retinal artery occlusion following internal carotid artery flow diverter implantation

PURPOSE

To report a favorable outcome of branch retinal artery occlusion (BRAO) treated by means of early administration of tirofiban, a glycoprotein IIb-IIIa platelet receptor inhibitor.

METHODS

Case report.

RESULTS

A 65-year-old woman developed dramatic visual impairment in her left eye secondary to BRAO after left internal carotid artery endovascular reconstruction with flow diverter stent implant; visual acuity was hand motion. A dose of intravenous tirofiban was injected 10 minutes after symptoms onset. Fourteen hours after drug infusion, retinal fluorescein angiography revealed a well-perfused macula with a partial reperfusion of the inferior temporal branch of the central retinal artery; visual acuity was 20/20 in both eyes.

CONCLUSIONS

This case supports the effectiveness of tirofiban in secondary BRAO in neurosurgery and may open its usage to further research.

Perioperative visual loss following prone spinal surgery: A review

Background:

Postoperative visual loss (POVL) following prone spine surgery occurs in from 0.013% to 1% of cases and is variously attributed to ischemic optic neuropathy (ION: anterior ION or posterior ION [reported in 1.9/10,000 cases: constitutes 89% of all POVL cases], central retinal artery occlusion [CRAO], central retinal vein occlusion [CRVO], cortical blindness [CB], direct compression [horseshoe, prone pillows, and eye protectors Dupaco Opti-Gard]), and acute angle closure glaucoma (AACG).

Methods:

Risk factors for ION include prolonged operative times, long-segment spinal instrumentation, anemia, intraoperative hypotension, diabetes, obesity, male sex, using the Wilson frame, microvascular pathology, decreased the percent of colloid administration, and extensive intraoperative blood loss. Risk factors for CRAO more typically include improper positioning during the surgery (e.g., cervical rotation), while those for CB included prone positioning and obesity.

Results:

POVL may be avoided by greater utilization of crystalloids versus colloids, administration of α-2 agonists (e.g., decreases intraocular pressure), avoidance of catecholamines (e.g., avoid vasoconstrictors), avoiding intraoperative hypotension, and averting anemia. Patients with glaucoma or glaucoma suspects may undergo preoperative evaluation by ophthalmologists to determine whether they require prophylactic treatment prior to prone spinal surgery and whether and if prophylactic treatment is warranted.

Conclusions:

The best way to avoid POVL is to recognize its multiple etiologies and limit the various risk factors that contribute to this devastating complication of prone spinal surgery. Furthermore, routinely utilizing a 3-pin head holder will completely avoid ophthalmic compression, while maintaining the neck in a neutral posture, largely avoiding the risk of jugular vein and/or carotid artery compromise and thus avoiding increasing IOP.

Postoperative complications of spine surgery

A variety of surgical approaches are available for the treatment of spine diseases. Complications can arise intraoperatively, in the immediate postoperative period, or in a delayed fashion. These complications may lead to severe or even permanent morbidity if left unrecognized and untreated [1-4]. Here we review a range of complications in the early postoperative period from more benign complications such as postoperative nausea and vomiting (PONV) to more feared complications leading to permanent loss of neurological function or death [5]. Perioperative pain management is covered in a separate review (Chapter 8).