Improving Surgical Triage in Spine Clinic: Predicting Likelihood of Surgery Using Machine Learning.

BACKGROUND: Correctly triaging patients to a surgeon or a nonoperative provider is an important part of the referral process. Clinics typically triage new patients based on simple intake questions. This is time-consuming and does not incorporate objective data. Our goal was to use machine learning to more accurately screen surgical candidates seen in a spine clinic. METHODS: Using questionnaire data and magnetic resonance imaging reports, a set of artificial neural networks was trained to predict whether a patient would be recommended for spine surgery. Questionnaire responses included demographics, chief complaint, and pain characteristics. The primary end point was the surgeon's determination of whether a patient was an operative candidate. Model accuracy in predicting this end point was assessed using a separate subset of patients. RESULTS: The retrospective dataset included 1663 patients in cervical and lumbar cohorts. Questionnaire data were available for all participants, and magnetic resonance imaging reports were available for 242 patients. Within 6 months of initial evaluation, 717 (43.1%) patients were deemed surgical candidates by the surgeon. Our models predicted surgeons' recommendations with area under the curve scores of 0.686 for lumbar (positive predictive value 66%, negative predictive value 80%) and 0.821 for cervical (positive predictive value 83%, negative predictive value 85%) patients. CONCLUSIONS: Our models used patient data to accurately predict whether patients will receive a surgical recommendation. The high negative predictive value demonstrates that this approach can reduce the burden of nonsurgical patients in surgery clinic without losing many surgical candidates. This could reduce unnecessary visits for patients, increase the proportion of operative candidates seen by surgeons, and improve quality of patient care.

Risk factors for the development of DJK in AIS patients undergoing posterior spinal instrumentation and fusion.

PURPOSE: Typically, selection of lowest instrumented vertebra (LIV) in Adolescent Idiopathic Scoliosis (AIS) is based on the coronal radiograph; however, increasing evidence suggests that fusions proximal to the stable sagittal vertebrae (SSV) on the lateral radiograph can result in distal junctional kyphosis (DJK). The purpose of this study is to compare rates of DJK in patients with AIS that have a discordance between the Lowest Touched Vertebra (LTV) and the SSV and to identify risk factors for developing DJK. METHODS: Patients with AIS Lenke type 1, 2 and 3 curves treated with a posterior spinal fusion were separated into two groups. Group 1 had SSV that was proximal to the LTV whereas group 2 had SSV that was distal to the LTV. Comparisons were made for patients that were fused to the SSV(a), LTV(b) or between(c). Distal junctional angle (DJA) > 5° and increasing kyphosis at the end of the fusion construct were evaluated as risk factors for DJK. RESULTS: The rate of DJK was 0.0% in group 1a, 1b, and 1c compared to 4.3%, 18.5% and 10.0% in groups 2a, 2b and 2c, respectively(p < 0.001). The rate of DJK was 22.9% when the distal junctional angle(DJA) > 5° versus 1.4% when the DJA < 5°(p < 0.001). CONCLUSION: There was a low risk for progression of DJK when the SSV was proximal to the LTV, however, those with SSV distal to the LTV represent a high-risk group. Importantly, the development of DJK occurred almost exclusively in patients with LIV at the thoracolumbar junction which demonstrates that surgeons need to be cautious when ending fusions at T11, T12, and L1 in patients at high risk for DJK. Furthermore, having a distal junctional angle 5° or greater increased the risk of developing DJK by roughly 16-fold. At a minimum of 5-year follow-up, the development of DJK did not appear to adversely impact SRS outcomes or revision rates.

Bleeding Risk and Mortality Associated With Uninterrupted Antithrombotic Therapy During Percutaneous Endoscopic Gastrostomy Tube Placement.

INTRODUCTION: Antithrombotic therapy is often interrupted before the placement of a percutaneous endoscopic gastrostomy (PEG) tube because of potentially increased risk of hemorrhagic events. The aim of our study was to evaluate the risk of bleeding events and overall complication rates after PEG in patients on uninterrupted antiplatelet and anticoagulation therapy in a high-volume center. METHODS: Data regarding demographics, diagnoses, comorbidities, and clinical outcomes pertinent to PEG were collected from 2010 to 2016. Furthermore, data regarding antithrombotic therapy along with the rate of minor or major complications including bleeding associated with this procedure were analyzed. Significant bleeding was defined as postprocedure bleeding from PEG site requiring a blood transfusion and/or surgical/endoscopic intervention. RESULTS: We included 1,613 consecutive PEG procedures in this study, of which 1,540 patients (95.5%) received some form of uninterrupted antithrombotic therapy. Of those patients, 535 (34.7%) were on aspirin, 256 (16.6%) on clopidogrel, and 119 (7.7%) on both aspirin and clopidogrel. Subcutaneous heparin was uninterrupted in 980 (63.6%), intravenous heparin in 34 (2.1%), warfarin in 168 (10.9%), and direct-acting oral anticoagulation in 82 (5.3%) patients who overlapped on multiple drugs. We observed 6 significant bleeding events in the entire cohort (0.39%), and all were in subcutaneous heparin groups either alone or in combination with aspirin. No clinically significant bleeding was noted in patients on uninterrupted aspirin, warfarin, clopidogrel, or direct-acting oral anticoagulation groups. Only 5 patients (0.31%) had PEG-related mortality. DISCUSSION: The risk of significant bleeding associated with the PEG placement was minimal in patients on uninterrupted periprocedural antithrombotic therapy.

Fusions ending above the sagittal stable vertebrae in adolescent idiopathic scoliosis: does it matter?

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To validate whether fusions that end proximal to the sagittal stable vertebrae are at risk for developing distal junctional kyphosis in adolescent idiopathic scoliosis. BACKGROUND: Posterior spinal fusion is routinely used for the treatment of patients with adolescent idiopathic scoliosis. Fusions that end in either the lower thoracic or upper lumbar spine have the advantage of preserving motion segments. However, fusions ending proximal to the sagittal stable vertebrae has been shown to be at higher risk for developing distal junctional kyphosis. METHODS: A multi-center database of prospectively enrolled subjects was queried for patients with adolescent idiopathic scoliosis that had Lenke type 1, 2 and 3 curves treated with posterior pedicle screw instrumentation. PA (posterior-anterior) and lateral full-length scoliosis films were obtained on each patient. PA radiographs were viewed to determine the coronal deformity and lateral radiographs to determine the sagittal deformity. Distal junctional kyphosis was defined as a greater than 10° increase in segmental kyphosis between the LIV and the LIV + 1 vertebra. RESULTS: 346 patients were included with 85% being female and mean age of cohort 14.2 [Formula: see text] 2.08 years. At 5 years postoperatively, there was significant difference occurrence of distal junctional kyphosis dependent on whether the LIV relative to SSV with only 2.2% of fusions below the SSV developing DJK compared to 6.5% for fusions ending at the SSV and 15% for fusions with LIV above the SSV (p < 0.001). There was no statistical difference in revision rates based on the relationship of LIV to SSV. CONCLUSION: There is an increased risk for development of DJK in patients with AIS treated with posterior fusion where the LIV was chosen proximal to the SSV. LEVEL EVIDENCE: Level III.

Fusions ending at the thoracolumbar junction in adolescent idiopathic scoliosis: comparison of lower instrumented vertebrae.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To compare clinical outcomes and radiographic parameters between patients treated with a posterior spinal fusion that had a lower instrumented vertebra at T11, T12, and L1. BACKGROUND: Posterior instrumented fusions are well established for treating patients with adolescent idiopathic scoliosis (AIS). Fusions limited to the thoracic spine can adequately correct a spinal deformity while preserving lumbar segmental mobility. However, fusions that end at the thoracolumbar junction have been proposed to cause adjacent segment complications. Studies comparing outcomes between patients who were treated with fusions that end at the thoracolumbar junction with varying LIVs are limited. METHODS: A multicenter database was queried for patients with AIS that had Lenke Type 1 and 2 curves treated with a fusion that had an LIV at T11, T12, or L1. Coronal curve magnitude, degree of junctional kyphosis, C7-central sacral line, thoracic apical translation, and sagittal stable vertebrae were measured. Clinical and functional outcomes were assessed using the Scoliosis Research Society-22 (SRS-22) questionnaire and lumbar flexibility testing. RESULTS: The lower instrumented level was below the sagittal stable vertebrae in 22.7%, 40%, and 66.2% of patients in the LIV-T11, T12, and L1 groups, respectively (p < 0.001). The 5-year postoperative lumbar curve magnitudes were 20.3°, 16.3°, and 14.0° for T11, T12, and L1-LIV, respectively (p < 0.001). No patients in the T11 group (0%), two patients in the T12 group (2.5%), and one patient in the L1 (0.8%) group developed distal junctional kyphosis (p = 0.5). The 5-year postoperative total SRS-22 scores were 4.21, 4.50, and 4.38 (p = 0.029). Lumbar flexion decreased by 0.78 cm in the T11-LIV group, increased by 0.01 cm in the T12-LIV group, and decreased by 0.15 cm in the L1-LIV group (p = 0.434). CONCLUSION: There was no significant difference in SRS-22 scores, development of distal junctional kyphosis or loss of lumbar mobility between patients treated with a spinal fusion that had an LIV at T11, T12, or L1. LEVEL OF EVIDENCE: Level III.

An Entirely Atypical Presentation of Esophageal Squamous Cell Cancer with Pancreatic and Bone Metastases.

Few cases of solitary pancreatic metastases from esophageal cancer have been reported; however, these previous cases all describe a solid pancreatic mass. We present a unique case of a 67-year-old man with squamous cell carcinoma detected within a pancreatic cystic lesion that was sampled with endoscopic ultrasound-guided fine needle aspiration. Esophagogastroduodenoscopy identified a friable and fungating partially obstructing mass in the distal esophagus with features of fistulization into the lung. Pathology showed esophageal squamous cell cancer. An isolated bone lesion was also biopsied and revealed squamous cell cancer. The patient tolerated oral intake and a multidisciplinary decision was made for palliative care with home hospices given his comorbidities portending poor operative candidacy and overall poor prognosis secondary to multiple sites of metastases from his esophageal squamous cell cancer.

Off label use of lumen-apposing metal stent for persistent gastro-jejunal anastomotic stricture.

We are reporting a novel "off-label" use of lumen apposing metal stent (LAMS) for management of refractory gastro-jejunal (GJ) anastomotic stricture after Roux-en-y gastric bypass (RYGB). With increasing prevalence of obesity, bariatric surgery is performed more frequently than ever. RYGB is one of the most commonly performed bariatric procedures. GJ anastomotic stricture is a late complication of this procedure. Our patient, seven years after RYGB developed GJ anastomotic ulcer and subsequently a stricture not amendable to repeated pneumatic dilations. Instead of using the conventional fully covered self-expanding metal stent (fcSEMS) we deployed the relatively new LAMS keeping in mind its novel dumbbell shaped design. Our patient's symptoms were controlled successfully and she remained asymptomatic on follow-up. Despite initial approval for pancreatic pseudocyst drainage, LAMS has been used with increased frequency at various locations within gastrointestinal tract including GJ anastomotic strictures. Future randomized control trials are warranted to compare the efficacy of fcSEMS to LAMS.

Acetaminophen-Induced Hepatotoxicity: a Comprehensive Update.

Hepatic injury and subsequent hepatic failure due to both intentional and non-intentional overdose of acetaminophen (APAP) has affected patients for decades, and involves the cornerstone metabolic pathways which take place in the microsomes within hepatocytes. APAP hepatotoxicity remains a global issue; in the United States, in particular, it accounts for more than 50% of overdose-related acute liver failure and approximately 20% of the liver transplant cases. The pathophysiology, disease course and management of acute liver failure secondary to APAP toxicity remain to be precisely elucidated, and adverse patient outcomes with increased morbidity and mortality continue to occur. Although APAP hepatotoxicity follows a predictable timeline of hepatic failure, its clinical presentation might vary. N-acetylcysteine (NAC) therapy is considered as the mainstay therapy, but liver transplantation might represent a life-saving procedure for selected patients. Future research focus in this field may benefit from shifting towards obtaining antidotal knowledge at the molecular level, with focus on the underlying molecular signaling pathways.

New diamino-diheterophenol ligands coordinate iron(III) to make structural and functional models of protocatechuate 3,4-dioxygenase.

Three diamino, dihetero-phenol ligands were synthesized by sequential Mannich condensations. These ligands were combined with FeCl3 to produce three five-coordinate Fe(III) complexes that are structural models for the enzyme 3,4-PCD. The three Fe(III) complexes were characterized by elemental analysis, single crystal X-ray diffraction studies, UV-vis spectroscopy, and cyclic voltammetry. Combining the Fe(III) complexes with 3,5-di-t-butylcatechol and O2 resulted in oxidative cleavage similar to the function of 3,4-PCD.

Postoperative changes in intraocular pressure and corneal biomechanical metrics Laser in situ keratomileusis versus laser-assisted subepithelial keratectomy.

PURPOSE: To compare intraocular pressure (IOP) and corneal biomechanical metric changes after myopic laser in situ keratomileusis and laser-assisted subepithelial keratectomy (LASEK). SETTING: Private practice, St. Louis, Missouri, USA. METHODS: The IOP, corneal biomechanical markers, and Ocular Response Analyzer (ORA) waveform parameters were prospectively measured preoperatively and after 6 months in ablation-matched myopic LASIK eyes (mLASIK group) and LASEK eyes (mLASEK group). A retrospectively identified cohort of low myopia LASIK eyes (lmLASIK group) and fellow unoperated eyes (control) were tested at a single postoperative visit. Statistical analysis compared the percentage change in parameters between groups. RESULTS: The mean postoperative Goldmann tonometry and Goldmann-correlated IOPs were statistically significant reduced in the mLASIK and mLASEK groups (P<.03). Corneal-compensated IOP, but not Pascal dynamic contour tonometry, was significantly reduced in the mLASIK group. The percentage change in corneal hysteresis (CH) and the corneal resistance factor (CRF) was greater in the mLASIK and mLASEK groups than in the lmLASIK group. The greatest percentage change in ORA signal parameters was in the mLASIK group and the smallest change, in the mLASEK group. On multivariate linear regression, the residual stromal bed was predictive of the percentage change in CH and CRF (P<.001). CONCLUSIONS: Microkeratome flap creation combined with deeper stromal ablation had the greatest effect on the ORA applanation signal, indicating corneas that are more readily deformable. The smallest change in the signal was in the group without a stromal flap (LASEK). There was a complex interaction between ablation location and depth that affected corneal biomechanical properties.