A novel endoscope-port unit for lumbar microendoscopic surgery: a single-center case series review.

Minimally invasive spinal surgery has shown benefits not only from a clinical standpoint but also in some cost-effectiveness metrics. Microendoscopic procedures combine optical advantages of endoscopy with the preservation of bimanual surgical maneuvers that are not feasible with full percutaneous endoscopic procedures. TELIGEN is a new endoscopic platform designed to optimize these operations. Our aim was to present a retrospective review of surgical data from the first consecutive cases applying this device in our institution and describe some of its technical details. 25 patients have underwent procedures using this device at our institution to the date, with a mean follow-up of 341.7 ± 45.1 days. 17 decompression-only procedures, including microendoscopic discectomies (MED) and decompression of stenosis (MEDS), with or without foraminotomies (± MEF) and 8 microendoscopic transforaminal lumbar interbody fusions (ME-TLIF) were performed. Mean age and body mass index (BMI) were respectively 58.8 ± 17.4 years and 27.6 ± 5.3 kg/m2. Estimated blood loss (13 ± 4.8, 12.8 ± 6.98 and 76.3 ± 35.02 mL), postoperative length of hospital stay (11.2 ± 21.74, 22.1 ± 26.85 and 80.7 ± 44.60 h), operative time (130.3 ± 58.53, 121 ± 33.90 and 241.5 ± 45.27 min) and cumulative intraprocedural radiation dose (14.2 ± 6.36, 15.4 ± 12.17 and 72.8 ± 12.26 mGy) are reported in this paper for MED ± MEF, MEDS ± MEF and ME-TLIF, respectively. TELIGEN affords an expanded surgical field of view with unique engineered benefits that provide a promissing platform to enhance minimally invasive spine surgery.

The Impact of L4-L5 Minimally Invasive Transforaminal Lumbar Interbody Fusion on 2-Year Adjacent-level Parameters.

OBJECTIVE: This study evaluates the impact of L4-L5 minimally invasive surgery (MIS)- transforaminal lumbar interbody fusion (TLIF) on adjacent-level parameters. METHODS: This is a retrospective study performed on consecutive patients between January 2015 and December 2019. The index- and adjacent-level segmental lordosis (SL) and disc angle (DA) were measured. Patient-reported outcomes (PROs) were collected preoperatively and at 3-24 months postoperatively. Factors influencing changes in adjacent-level parameters and the occurrence of adjacent segment degeneration (ASDeg) were assessed. RESULTS: A total of 117 adult patients, averaging 65.5 years of age and slight preponderance of female (56.4%), were analyzed. L4-L5 SL decreased at 2 years (P < 0.05), but L4-L5 DA significantly increased at all timepoints (P < 0.05). While L3-L4 SL and DA significantly decreased at all timepoints (P < 0.05), L5-S1 SL decreased at 3 and 12 months (P < 0.05) and L5-S1 DA only significantly decreased at 2 years (P < 0.05). All PROs improved significantly (P < 0.0001). The ASDeg rate was 19.7% at 2.2 years. Cephalad and caudal ASDeg rates were 12.0% and 10.3%, respectively. Eight patients (6.8%) required adjacent-level reoperations, mainly at L3-L4 (6 cases). The use of expandable cage significantly reduced the odds of caudal ASDeg (OR 0.15, P = 0.037), but had no significant effect on cephalad ASDeg. CONCLUSIONS: L4-L5 MIS-TLIF had a more consistent effect on L3-L4 than L5-S1. Although adjacent-level SL and DA decreased over time, their association with ASDeg appears limited, suggesting a multifactorial etiology. L4-L5 MIS-TLIF provides demonstrable clinical benefits with lasting PRO improvements and low adjacent-level reoperations.

Microendoscopic Posterior Cervical Foraminotomy Using TELIGEN: 2-Dimensional Operative Video.

This operative video details the treatment of cervical radiculopathy caused by unilateral cervical foraminal stenosis through a microendoscopic posterior cervical foraminotomy in the sitting position using the TELIGEN system. A 67-year-old male patient presented with a unilateral C6-7 radiculopathy with imaging corroborating severe foraminal stenosis. Therefore, a microendoscopic posterior cervical foraminotomy was recommended rather than an anterior cervical diskectomy and fusion or arthroplasty to preserve segmental motion and minimize hardware-related complications. This video reviews the nuances of this approach and key surgical steps. Emphasis is given to the patient positioning and ergonomic favorability and enhanced visualization afforded by the TELIGEN endoscopic platform. The patient tolerated the procedure well and reported significant improvement of radiculopathy after surgery. At 2-week follow-up, the patient reported resolution of his preoperative symptoms and returned to normal activity without restrictions. The patient consented to the procedure, and the participants and any identifiable individuals consented to publication of his/her image.

Extra-Axial Cavernous Angioma: A Case Report and Review of the Literature.

Cavernous angiomas (CAs) are benign vascular malformations predominantly seen in the brain parenchyma and therefore referred to as intra-axial. Extra-axial dural-based cavernous angiomas, on the other hand, are rare vascular lesions found outside of the brain parenchyma. They occur in the middle fossa and may be easily misdiagnosed as meningiomas due to their extra-axial location. In addition, CAs that are located outside the middle fossa, such as in the convexity, have a better prognosis since they are more surgically accessible. Surgical resection is the main treatment of choice in CAs. However, other options, such as embolization and radiotherapy, may also be considered therapeutic choices or additive treatment options. The pathogenesis of CA and the involvement of other factors (genetics or environmental factors) are still unknown and require further investigation. We are presenting a young man who presented for evaluation of seizure-like events without any family history of neurologic conditions. The physical examination was unremarkable except for a slightly antalgic gait. Imaging studies showed an extra-axial left tentorial mass suggestive of a meningioma, hemangiopericytoma, or other extra-axial lesions. The lesion was resected where its vascular nature was mentioned initially, and the histology proved the diagnosis of cavernous angioma. Here we give an overview of the known pathogenesis, causes, clinical features, and diagnostic and therapeutic options in CA. Better knowledge about CA, its causes, clinical features, and treatment options would help clinicians in early diagnosis and patient management.

Advances in computational and translational approaches for malignant glioma.

Gliomas are the most common primary brain tumors in adults and carry a dismal prognosis for patients. Current standard-of-care for gliomas is comprised of maximal safe surgical resection following by a combination of chemotherapy and radiation therapy depending on the grade and type of tumor. Despite decades of research efforts directed towards identifying effective therapies, curative treatments have been largely elusive in the majority of cases. The development and refinement of novel methodologies over recent years that integrate computational techniques with translational paradigms have begun to shed light on features of glioma, previously difficult to study. These methodologies have enabled a number of point-of-care approaches that can provide real-time, patient-specific and tumor-specific diagnostics that may guide the selection and development of therapies including decision-making surrounding surgical resection. Novel methodologies have also demonstrated utility in characterizing glioma-brain network dynamics and in turn early investigations into glioma plasticity and influence on surgical planning at a systems level. Similarly, application of such techniques in the laboratory setting have enhanced the ability to accurately model glioma disease processes and interrogate mechanisms of resistance to therapy. In this review, we highlight representative trends in the integration of computational methodologies including artificial intelligence and modeling with translational approaches in the study and treatment of malignant gliomas both at the point-of-care and outside the operative theater in silico as well as in the laboratory setting.

Effects of the 2016 CDC opioid prescription guidelines on opioid use and worker compensation case length in patients with back pain.

BACKGROUND: Narcotic consumption in the workers' compensation population contributes to prolonged case duration, worse clinical outcomes, and opioid dependence. In 2016, the CDC provided recommendations guiding clinicians on prescribing opioids to adult patients with chronic pain. The objective of our study was to evaluate a cause-and-effect relationship between narcotic consumption and worker compensation claim length before and following guideline revision. METHODS: An administration database was retrospectively queried to identify patients evaluated for spine-related workers' compensation claimants from 2011 to 2021. Data was recorded for age, sex, BMI, case length, narcotic usage, and injury location. Cases were grouped together by exam date before (2011-2016) and after (2017-2021) the 2016 CDC opioid guideline revision. RESULTS: Six hundred twenty-five patients were evaluated. Males composed 58% of the study population. From 2011 to 2016, narcotic consumption was reported in 54% of subjects versus no narcotic consumption in 46% of subjects (135 cases). From 2017 to 2021, narcotic consumption decreased to 37% (P = 0.00298). Prior to the guideline revision, mean case length was 635 days. Following CDC guideline revision, there was a significant decline in mean case length duration to 438 days (31% reduction) (P = 0.000868). CONCLUSION: This study demonstrates that following revised opioid prescription recommendations by the CDC in 2016, there was a statistically significant decline in opioid consumption and workers' compensation case length duration. Opioid use may influence prolonged worker disability and delayed return to work.

Feasibility of outpatient robot assisted minimally invasive transforaminal lumbar interbody fusion.

Introduction: Lumbar interbody fusion is a common spine procedure. 199,140 elective lumbar fusions were performed in the United States in 2015. Robot assisted (RA) pedicle screw placement has advanced minimally invasive spine surgery (MIS) making short stay transforaminal lumbar interbody fusions (TLIF) with same day or next day discharge a possibility for select patients. Methods: This study is a retrospective case series of a single surgeon's experience with RA MIS TLIF using the Globus ExcelsiusGPS system. Patients undergoing RA MIS TLIF at an outpatient surgery center between August 2020 and February 2021 were included in the study. Results: Twenty-three patients met inclusion criteria. Ninety-six RA pedicle screws and 25 interbody cages were placed. 96/96 (100%) pedicle screws and 25/25 (100%) interbodies were found to be in satisfactory position using intraoperative x-ray. None of the instrumentation required re-placement or revision intraoperatively. 20/23 (87%) patients were able to discharge within 24 hours of the procedure. 2/23 (8.7%) patients discharged on the day of surgery. One patient of 23 (4.3%) required discharge to an inpatient rehabilitation facility post operatively. 0/23 (0%) patients required readmission for pain control. Conclusions: Our study demonstrates the safety and feasibility of outpatient RA MIS TLIF for select patients. Future directions include a larger study to elucidate characteristics of the best candidates for outpatient RA MIS TLIF.

Cervical syringomyelia with caudal thoracic epidural lipomatosis: case report and literature review.

Syringomyelia associated with epidural lipomatosis is a rare finding. Only three published cases of epidural lipomatosis associated with syringomyelia exist in the literature.We report the case of a 46-year-old woman who presented with progressive myelopathy over an 18-month period. Imaging revealed significant thoracic spinal cord compression secondary to epidural lipomatosis from T3 to T8 with cephalad cervical syringomyelia extending from C7 to T1. Imaging was unremarkable for Chiari malformation or a craniospinal space-occupying lesion. A T2 to T8 laminoplasty was performed, removing excessive epidural adipose tissue to decompress the thoracic spinal cord. Postoperatively, the patient reported symptom improvement with complete symptom resolution at 3 months. Follow-up imaging at 3-months demonstrated thoracic spinal cord decompression with mild syrinx reduction. At two-year follow-up the patient remained asymptomatic with unchanged imaging.Syringomyelia in the setting epidural lipomatosis is a rare finding.

Phrenic Nerve Dysfunction Secondary to Cervical Neuroforaminal Stenosis: A Literature Review.

BACKGROUND: Phrenic nerve dysfunction has been associated with cervical neuroforaminal stenosis in limited case reports and case-controlled studies. It is unclear if magnetic resonance imaging of the cervical spine should be included in the workup of patients with pulmonary dysfunction. A systematic review of the current literature was conducted on the topic to provide an outline of the body of knowledge and some guidance for neurosurgeons that receive these patient referrals. METHODS: A systematic literature review was conducted through the PubMed database to identify articles related to phrenic nerve dysfunction secondary to cervical stenosis. RESULTS: A total of 12 case reports were found. The median subject age was 64 years, 11 were male. Presenting symptoms included shortness of breath (n = 9), radiculopathy (n = 7), myelopathy (n = 5), reduced pulmonary function (n = 6), weakness (n = 4), and neck pain (n = 5). Ten of these patients underwent surgical intervention, all having improvements in their pulmonary and neurological symptoms at follow-up ranging from 10 days to 2 years. CONCLUSIONS: Cervical stenosis, resulting in neuroforaminal stenosis, may be related to phrenic nerve dysfunction in select patients with idiopathic diaphragmatic paralysis or pulmonary dysfunction. Surgical decompression improves pulmonary and neurological symptoms.

Stent-assisted coiling of dural sinus diverticula: a case series.

BACKGROUND: Dural sinus diverticula are a rare vascular etiology of pulsatile tinnitus. Patients typically present with disabling symptoms and undergo an extensive workup for common causes of pulsatile tinnitus. Endovascular treatment has been shown to be effective in several case reports. We present the largest case series of eight patients treated with endovascular therapy using stent-assisted coiling and describe the unique details of intervention. METHODS: A retrospective chart review was performed on all patients who underwent endovascular dural sinus stenting. RESULTS: One-hundred-twenty patients underwent dural sinus stetnting from August 2012 to February 2020. Eight of these had symptomatic pulsatile tinnitus secondary to a dural sinus diverticulum and were successfully treated with stent-assisted coil embolization. No complications occurred. CONCLUSION: Our case series demonstrates that endovascular dural sinus stent-assisted coil embolization for symptomatic dural sinus diverticula is a safe and effective treatment.

Cost-Effectiveness of Adult Spinal Deformity Surgery.

STUDY DESIGN: Review article. OBJECTIVE: A review of the literature evaluating the cost-effectiveness of undergoing adult spinal deformity surgery and potential avenues for reducing costs. METHODS: A review of the current literature and synthesis of data to provide an update on the cost effectiveness of undergoing adult spinal deformity surgery. RESULTS: Compared with nonoperative management, operative management for adult spinal deformity is associated with improved patient-reported outcomes and quality of life; however, it is associated with significant financial and resource use. CONCLUSION: Operative management for adult spinal deformity has been shown to be effective but is associated with significant cost and resource utilization. The optimal operative treatment is highly dependent on the patients' symptomatology and is surgeon dependent. Maximizing preoperative surgical health and minimizing postoperative complications are key measures in reducing the cost and resource utilization of adult spinal deformity surgery. Future studies are needed to evaluate how to optimize the cost-effectiveness.

Unique variant of idiopathic intracranial hypertension dural sinus stenting.

PURPOSE/AIM OF THE STUDY: To report on the successful treatment of idiopathic intracranial hypertension (IIH) in a patient with venous sinus stenosis secondary to a persistent occipital-marginal sinus (POMS) utilizing venous sinus stenting. MATERIALS/METHODS: A 55-year-old female presented with headaches and blurry vision. Ophthalmologic examination demonstrated papilledema. Two lumbar punctures demonstrated opening pressures of 31 and 38 cmH2O and provided temporary symptom relief. Cerebral venography demonstrated hypoplastic bilateral transverse-sigmoid sinuses with dominant drainage through a persistent occipital-marginal sinus (POMS). Multiple enlarged arachnoid granulations resulted in stenosis in the marginal sinus with an 18 mmHg mean pressure gradient across the stenosis. RESULTS: The decision was made for venous sinus stenting of the POMS. Immediate post-stenting venography demonstrated resolution of the POMS stenosis with flow only into the POMS and a mean pressure gradient across the stenosis normalized to 2 mmHg. Six-month follow-up venography demonstrated continued stent patency and clinical symptoms remained resolved. She has remained symptom free at 18 months. CONCLUSION: This writing summarizes the utility of endovascular dural sinus stenting and the importance of recognizing the dominant dural sinus drainage route in the treatment of IIH.

Orbital myxoma: A case report.

BACKGROUND: Myxomas are rare, locally infiltrative, benign neoplasms of mesenchymal origin. Although benign, these tumors are locally aggressive with a high rate of recurrence following conservative resection. Their relative infrequency, variable location, and insidious growth present a diagnostic challenge to clinicians. Cases of myxomas have been described throughout the body, but intraosseous myxomas of the orbit are exceedingly rare. CASE DESCRIPTION: We report a case of a 53-year-old male with a history of chronic sinusitis and symptoms of hyposmia and bifrontal headaches refractory medical management who presented for neurosurgical evaluation after radiographic findings of an orbital lesion. Physical examination was unremarkable with intact extraocular movements. Prior radiographic workup demonstrated a 2.4 × 2.7 × 2.2 cm expansile lesion involving the bony left superior and lateral orbit. A prior open biopsy was performed which demonstrated a low-grade spindle cell neoplasm consistent with intraosseous myxoma. Definitive resection was recommended through the left orbitozygomatic craniotomy. The patient tolerated the procedure well without complications. Gross total resection was achieved. Reconstruction of the orbital roof and lateral orbital wall was performed with a frontal bone autograft and titanium plating. Postoperative course was uneventful, and the patient was discharged home postoperative day 2. At 1-month follow-up visit, the patient remained neurologically intact. Surveillance imaging at 6 months and 1 year remained stable without signs of recurrence. CONCLUSION: Intraosseous orbital myxomas are exceedingly rare entities. Although they are considered benign neoplasms, myxomas demonstrate high recurrence rates. The authors report a unique case of an orbital myxoma that was successfully treated through an orbitozygomatic approach achieving gross total resection.

Treatment of pediatric unstable os odontoideum with adjacent degenerative cyst: case presentation and literature review.

Degenerative cysts associated with an unstable os odontoideum in pediatric patients are uncommon lesions. Reported treatments of such lesions have varied and yielded mixed results with the optimal surgical strategy remaining unclear. The authors report the clinical and surgical outcome of a 13-year-old patient presenting with degenerative cyst adjacent to an abnormal os odontoideum motion segment. The patient was asymptomatic from this lesion which was an incidental finding while undergoing workup for atypical headaches. Clinical and radiologic findings, operative details, and postoperative outcome are described. The patient was successfully treated with posterior cervical fusion without direct cyst decompression. Complete resolution of the cyst was demonstrated on magnetic resonance imaging at 6 months. Computed tomography 8 months postoperatively showed solid bony fusion and normal alignment. Regarding treatment goals in pediatric patients with os odontoideum degenerative cysts, the current case and literature review supports posterior instrumented fusion without direct surgical cyst resection.

Anticoagulation and Spine Surgery.

STUDY DESIGN: Literature review. OBJECTIVE: Preoperative management of therapeutic anticoagulation in spine surgery is critical to minimize risk of thromboembolic events yet prevent postsurgical complications. Limited research is available, and most guidelines are based on drug half-lives. We aim to clarify current guidelines and available evidence for safe practice of spine surgery in this patient population. METHODS: A literature search in PubMed was done encompassing comprehensive search terms to locate published literature on anticoagulation and spine surgery. Predefined inclusion and exclusion criteria were applied and data extraction was performed. RESULTS: A total of 17 articles met the final inclusion criteria. Of these, 12 articles were retrospective chart reviews, 3 were prospective observational studies, and 2 were systematic reviews. Current practice suggests holding warfarin until international normalized ratio <1.4, anti-Xa drugs for 48 to 72 hours, 12 to 24 hours for low-molecular-weight heparin, and 4 to 24 hours for heparin, before surgery. Antiplatelet agents can be stopped for 1 to 3 days prior to operation (81-500 mg) but must be stopped for 1 week for doses >1 g/d. For Plavix, 5 to 7 days of discontinuation advised to prevent complications. CONCLUSIONS: This review provides an overview of main anticoagulation agents seen in preoperative setting for spine patients. Although data is mixed and no true randomized control trials are available, there is growing evidence suggesting the aforementioned guidelines are needed to optimize anticoagulation in setting of spine surgery. Further studies are needed to elucidate risk of complications while operating under therapeutic levels of anticoagulation for a variety of comorbid conditions.

Venous Thromboprophylaxis in Spine Surgery.

STUDY DESIGN: Review article. OBJECTIVE: A review of the literature on postoperative initiation of thrombophylactic agents following spine surgery. METHODS: A review of the literature and synthesis of the data to provide an update on venous thromboprophylaxis following spine surgery. RESULTS: Postoperative regimens of venous thromboprophylaxis measures following spine surgery remain a controversial issue. Recommendations regarding mechanical versus chemical prophylaxis vary greatly among institutions. CONCLUSION: Postoperative spine surgery initiation of thromboprophylaxis remains controversial regarding optimal timing and agent selection. The benefits of deep vein thrombosis/pulmonary embolism prophylaxis must be weighed against the possible postoperative complications associated with spine surgery.

Neuroendoscopic fenestration of glioependymal cysts to the ventricle: report of 3 cases.

Glioependymal cysts are rare congenital lesions of the central nervous system. Reported surgical treatments of these lesions have varied and yielded mixed results, and the optimal surgical strategy is still controversial. The authors here report the clinical and surgical outcomes for three adult patients successfully treated with neuroendoscopic fenestration into the ventricular system. The patients had presented with symptomatic glioependymal cysts in the period from 2013 to 2016 at the authors' institution. All underwent minimally invasive neuroendoscopic fenestration of the glioependymal cyst into the lateral ventricle via a stereotactically guided burr hole. Presenting clinical and radiological findings, operative courses, and postintervention outcomes were evaluated.All three patients initially presented with symptoms related to regional mass effect of the underlying glioependymal cyst, including headaches, visual disturbances, and hemiparesis. All patients were successfully treated with endoscopic fenestration of the cyst wall into the lateral ventricle, where the wall was thinnest. Postoperatively, all patients reported improvement in their presenting symptoms, and neuroimaging demonstrated decompression of the cyst. Clinical follow-up ranged from 4 months to 5 years without evidence of reexpansion of the cyst or shunt requirement.Compared to open resection and shunting of the cyst contents, minimally invasive endoscopic fenestration of a glioependymal cyst into the ventricular system is a safe and effective surgical option. This approach is practical, is less invasive than open resection, and appears to provide a long-term solution.

Very Large Metastases to the Brain: Retrospective Study on Outcomes of Surgical Management.

BACKGROUND: The incidence of brain metastases is rising. To our knowledge, no published study focuses exclusively on brain metastases larger than 4 cm. We present our surgical outcomes for patients with brain metastases larger than 4 cm. METHODS: This is a retrospective chart review of inpatient data at our institution from January 2006 to September 2015. Primary end points included overall survival, progression-free survival, and local recurrence rate. RESULTS: Sixty-one patients had a total of 67 brain metastases larger than 4 cm: 52 were supratentorial and 15 were infratentorial. Forty-three patients underwent surgical resection. Average duration of disease freedom after resection was 4.79 months (range, 0-30 months). Excluding patients with residual on immediate postoperative magnetic resonance imaging, the average rate of local recurrence was 7 months (range, 1-14 months). Overall survival after surgery excluding patients who chose palliation in the immediate postoperative period averaged 8.76 months (range, 1-37 months). Thirty-five of 43 patients (81.4%) had stable or improved neurologic examinations postoperatively. Six patients (13.95%) developed surgical complications. There were 3 major complications (6.98%): 2 pseudomeningoceles required intervention and 1 postoperative hematoma required external ventricular drain placement. There were 3 minor complications (6.98%): 1 self-limited pseudomeningocele, 1 subgaleal fluid collection, and 1 postoperative seizure. CONCLUSIONS: Surgery resulted in stable or improved neurologic examination in 81.4% of cases. On statistical analysis, significantly increased overall survival was noted in patients undergoing surgical resection, and those with higher Karnofsky Performance Scale and lower number of brain metastases at presentation. There is a need for further studies to evaluate management of brain metastases larger than 4 cm.

Necessity of Repeat Computed Tomography Imaging in Isolated Mild Traumatic Subarachnoid Hemorrhage.

BACKGROUND: The standard of care for mild isolated traumatic subarachnoid hemorrhage (itSAH) involves serial head computed tomography (CT) examinations at dedicated time intervals to monitor neurologic status and hemorrhagic progression. Considering recent evidence questioning such an aggressive monitoring protocol, this study aimed to assess the necessity of repeat head CT imaging in managing itSAH. METHODS: All patients who presented to our academic institution with mild traumatic brain injury were evaluated. Patients ≥18 years of age presenting with mild, blunt itSAH (Glasgow Coma Scale [GCS] score 13-15) were included. Patients with significant polytrauma or coagulopathy were excluded. Patient demographics (age and sex), imaging results (CT progression), and outcomes (final GCS score, discharge status, interventions, and 30-day readmission) were all recorded. RESULTS: Of 190 cases identified for inclusion, 58 (30.5%) met all study criteria (age, 59.5 ± 18.0 y; 30 men). Five (8.6%) patients presented with repeat CT progression, with none reporting 30-day readmission or adverse event on follow-up. Comparison of cases with and without CT progression found no meaningful differences in age or sex. Of the 3 patients readmitted, none demonstrated CT progression, and cause of readmission was unrelated to head trauma in all cases. Two patients demonstrated clinical deterioration (final GCS score <14), and neither case showed progression on CT, was readmitted, or received neurosurgical intervention of any kind. CONCLUSIONS: Our findings suggest that serial CT imaging has little efficacy in changing mild itSAH management and is poorly correlated with clinical progression. A less aggressive management protocol may be more appropriate for managing this patient population.

Location of glomerular immune deposits, not codeposition of immunoglobulin G, influences definitive renal outcomes in immunoglobulin A nephropathy.

Background: It has been suggested that the prognosis of immunoglobulin (IgA) nephropathy (IgAN) is adversely affected if there is codeposition of IgG in the glomeruli or if immune deposits are present in the glomerular capillary walls. We sought to understand how these variables affect clinical outcome. Methods: A total of 80 IgAN biopsies were retrospectively divided into groups: (i) IgA without IgG deposition versus IgA + IgG and (ii) immune deposits restricted to the mesangium versus mesangium and peripheral capillary walls (PCWs). The association of these groups with the composite primary outcome of renal replacement therapy, renal transplant, death or doubling of serum creatinine (SCr) concentration was determined. The change in estimated glomerular filtration rate (eGFR) was also assessed. Covariates examined were age, sex, race, SCr and proteinuria level at biopsy and at follow-up, duration of follow-up, treatment, Oxford score and presence of crescents. Results: IgG codeposition showed a trend toward endocapillary hypercellularity (P = 0.082); there were no other baseline differences between the IgA (n = 55) and IgA + IgG (n = 25) groups. At a median follow-up time of 29 months, the combined primary outcome was reached in 24 patients, 16 with IgA and 8 with IgA + IgG (P = 0.82). Patients with immune deposits in the PCWs (n = 21) presented with higher baseline proteinuria than those with deposits limited to the mesangium (n = 59; P = 0.025), were more likely to have crescents/segmental glomerular necrosis on biopsy (P = 0.047) and were more likely to reach the combined primary outcome (P = 0.026). Biopsies with crescents/segmental glomerular necrosis were associated with endocapillary hypercellularity (P < 0.001). Conclusions: In this multicenter IgAN cohort, IgG co-deposition and the location of glomerular immune deposits in the PCWs were both associated with greater histologic activity on renal biopsy, but only the location of glomerular immune deposits in the PCWs was associated with a significantly increased risk for end-stage renal disease, transplant, death and/or doubling of SCr.