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Ambati, Vardhaan

https://orcid.org/0000-0003-0074-9217

Mayo Clinic

University of California, San Francisco

Citations 6

Predicting therapeutic clinical trial enrollment for adult patients with low- and high-grade glioma using supervised machine learning
Mehari, Mulki , Warrier, Gayathri , Dada, Abraham , Kabir, Aymen , Haskell-Mendoza, Aden , Tripathy, Arushi , Jha, Rohan , Nieblas‐Bedolla, Edwin , Jackson, Joshua , Gonzalez, Ariel T , Reason, Ellery , Flusché, Ann Marie , Reihl, Sheantel , Dalton, Tara , Negussie, Mikias , Gonzales, Cesar Nava, Ambati, Vardhaan , Desjardins, Annick , Krishna, Saritha, Chang, Susan M. , Porter, Alyx B. , Fecci, Peter E. , Hollon, Todd , Chukwueke, Ugonma , Badal, Kimberly , Molinaro, Annette M. , Hervey‐Jumper, Shawn L. , Haskell-Mendoza, Aden P , Reason, Ellery H , Ambati, Vardhaan , Krishna, Saritha , Porter, Alyx , Hollon, Todd , Chukwueke, Ugonma N , Badal, Kimberly , Molinaro, Annette M. , Hervey-Jumper, Shawn L , Reihl, Sheantel J , Fecci, Peter E , Desjardins, Annick , Daniel, Andy G. S.

Science Advances | June 11, 2025 | Volume: 11 | Issue: 23 | Pages: No page available

10.1126/sciadv.adt5708 Get It

Therapeutic clinical trial enrollment does not match glioma incidence across demographics. Traditional statistical methods have identified independent predictors of trial enrollment; however, our understanding of the interactions between these factors remains limited. To test the interactive effects of demographic, socioeconomic, and oncologic variables on trial enrollment, we designed boosted neural networks (BNNs) for all glioma patients ( n = 1042), women ( n = 445, 42.7%), and minorities ( n = 151, 14.5%) and externally validated these models [whole cohort, n = 230; women, n = 89 (38.7%); minority, n = 66 (28.7%)]. For the whole-cohort BNN, the most influential variables on enrollment were oncologic variables, including KPS [total effect (TE), 0.327], chemotherapy (TE, 0.326), tumor location (TE, 0.322), and seizures (TE, 0.239). The women-only BNN exhibited a similar trend. Conversely, for the minority-only BNN, socioeconomic variables [insurance status (TE, 0.213), occupation classification (TE, 0.204), and employment status (TE, 0.150)] were most influential. These results may help prioritize patient-specific initiatives to increase accrual.
Do Patients With High ASA Grades Benefit From CSM Surgery?
Ambati, Vardhaan , Patel, Arati , Dada, Abraham , Macki, Mohamed, Chan, Andrew K. , Chou, Dean , Bisson, Erica F. , Bydon, Mohamad , Coric, Domagoj , Potts, Eric A. , Foley, Kevin T. , Wang, Michael, Fu, Kai-Ming, Virk, Michael, Knightly, John J. , Meyer, Scott A., Upadhyaya, Cheerag D., Tumialán, Luis M. , Turner, Jay D. , Uribe, Juan S. , Gottfried, Oren N., Shaffrey, Christopher I. , Haid, Regis W., DiGiorgio, Anthony M. , Mummaneni, Praveen V., Ambati, Vardhaan , Asher, Anthony, Wang, Michael, Fu, Kai-Ming, Virk, Michael, Park, Paul , Mummaneni, Praveen V.

Clinical Spine Surgery | April 21, 2025 | Volume: 38 | Issue: 4 | Pages: 197-203

10.1097/bsd.0000000000001774 Get It

Study Design: Analysis of prospectively collected data. Objective: To assess if systemic illness severity affects cervical spondylotic myelopathy (CSM) surgery outcomes. Summary of Background Data: It remains unclear if CSM patients with poor physical status/severe systemic illness benefit as much from surgery as those in good condition. Methods: Using the Quality Outcomes Database CSM cohort and the American Association of Anesthesiology (ASA) grade as a surrogate for illness burden, we compared patients with (ASA 3–4) and without (ASA 1–2) severe systemic illness, including rates of readmission and 24-month minimal clinically important differences (MCID) achievement for patient-reported outcomes (PROs)—numerical rating score (NRS) arm and neck pain, neck pain-related disability (NDI), and quality of life (EQ-5D). Results: Of 1141 CSM patients, 1062 had ASA grades recorded. Of these 1062 patients, 70.2% had a 2-year follow-up for mJOA, and 81%–84% had a follow-up for NRS arm and neck, NDI, and EQ-5D. Five hundred twenty-one patients (49.1%) had mild (ASA 1–2) and 541 (50.9%) had severe systemic illness (ASA 3–4). The severe disease cohort was older (63.3±11.0 vs. 57.4±11.7), had higher BMI (31.4±7.0 vs. 28.9±5.6), had more comorbidities (diabetes, coronary artery disease, depression), and had less independent ambulation (71.3% vs. 90.6%) ( P <0.05). At baseline, severe disease patients had worse NRS arm (5.2±3.5 vs. 4.7±3.4) and neck (5.5±3.2 vs. 5.1±3.3) pain, NDI (40.5±20.1 vs. 36.8±21.0), and EQ-5D (0.53±0.22 vs. 0.59±0.22) scores ( P <0.05). Perioperatively, the severe disease cohort had longer hospitalizations (2.4±2.6 vs. 1.7±2.0 days) and increased nonhome discharges (17% vs. 5%) ( P <0.05). The severe disease cohort had higher 90-day readmissions (7.6% vs. 2.5%), including surgery-related (3.7% vs. 1.5%) and non–surgery-related reasons (3.9% vs. 1.0%) ( P <0.05). On multivariate analysis, increased ASA grade was significantly associated with 90-day readmissions (OR: 2.55 per 1-grade increase, 95% CI: 1.38–4.83). However, both severe and mild disease cohorts had similarly high rates of achieving 2-year MCID for mJOA (67.5% vs. 66.0%), NRS arm (72.0% vs. 74.1%), neck (69.5% vs. 69.4%) pain, NDI (63.1% vs. 68.1%), and EQ-5D (67.9% vs. 66.9%) ( P >0.05). Conclusion: Patients with severe systemic illness (higher ASA) have worse baseline PROs and higher 90-day readmissions. However, they achieve similar MCID rates for mJOA and all measured PROs 2 years postoperatively.
Spatial synaptic connectivity underlies oligodendroglioma evolution and recurrence
Raleigh, David R. , Mirchia, Kanish , Oten, Sena, Ambati, Vardhaan , Vasudevan, Harish N. , Young, Jacob, Taylor, Jennie , Krishna, Saritha, Brang, David , Phillips, Joanna J. , Chang, Susan M. , Hervey‐Jumper, Shawn L. , Raleigh, David , Ambati, Vardhaan , Vasudevan, Harish , Taylor, Jennie W , Phillips, Joanna , Perry, Arie , de Groot, John , Hervey-Jumper, Shawn L , Picart, Thiébaud , Nguyen, Minh, Perry, Arie , Berger, Mitchel S. , Groot, John de

No container title available | April 4, 2025 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.21203/rs.3.rs-6299872/v1 Get It

Abstract Oligodendrogliomas are initially slow-growing brain tumors that are prone to malignant transformation despite surgery and cytotoxic therapy. Understanding of oligodendroglioma evolution and new treatments for patients have been encumbered by a paucity of patient-matched newly diagnosed and recurrent tumor samples for multiplatform analyses, and by a lack of preclinical models for interrogation of therapeutic vulnerabilities that drive oligodendroglioma growth. Here we integrate spatial and functional analyses of tumor samples and patient-derived organoid co-cultures to show that synaptic connectivity is a hallmark of oligodendroglioma evolution and recurrence. We find that patient-matched recurrent oligodendrogliomas are enriched in synaptic gene expression programs irrespective of previous therapy or histologic grade. Analyses of spatial, single-cell, and clinical data reveal epigenetic misactivation of synaptic genes that are concentrated in regions of cortical infiltration and can be used to predict eventual oligodendroglioma recurrence. To translate these findings to patients, we show that local field potentials from tumor-infiltrated cortex at the time of resection and neuronal hyperexcitability and synchrony in patient-derived organoid co-cultures are associated with oligodendroglioma proliferation and recurrence. In preclinical models, we find that neurophysiologic drugs block oligodendroglioma growth and pathologic electrophysiology. These results elucidate mechanisms underlying oligodendroglioma evolution from an indolent tumor to a fatal disease and shed light on new biomarkers and new treatments for patients.
Do obese patients undergoing surgery for grade 1 spondylolisthesis have worse outcomes at 5 years’ follow-up? A QOD study
Zammar, Samer G. , Yee, Timothy J., Patel, Arati , Le, Vivian , Alan, Nima , Coric, Domagoj , Potts, Eric A. , Bisson, Erica F. , Knightly, Jack, Fu, Kai-Ming, Foley, Kevin T. , Shaffrey, Mark E., Bydon, Mohamad , Chou, Dean , Chan, Andrew K. , Meyer, Scott A., Shaffrey, Christopher I. , Slotkin, Jonathan R., Haid, Regis W., Glassman, Steven D. , Virk, Michael S. , Mummaneni, Praveen V. , Ambati, Vardhaan , Fu, Kai-Ming, Asher, Anthony L., Wang, Michael , Park, Paul

Journal of Neurosurgery: Spine | September 14, 2024 | Volume: 41 | Issue: 5 | Pages: 564-571

10.3171/2024.5.spine24125 Get It

OBJECTIVE The long-term effects of increased body mass index (BMI) on surgical outcomes are unknown for patients who undergo surgery for low-grade lumbar spondylolisthesis. The goal of this study was to assess long-term outcomes in obese versus nonobese patients after surgery for grade 1 spondylolisthesis. METHODS Patients who underwent surgery for grade 1 spondylolisthesis at the Quality Outcomes Database’s 12 highest enrolling sites (SpineCORe group) were identified. Long-term (5-year) outcomes were compared for patients with BMI ≥ 35 versus BMI < 35. RESULTS In total, 608 patients (57.6% female) were included. Follow-up was 81% (excluding patients who had died) at 5 years. The BMI ≥ 35 cohort (130 patients, 21.4%) was compared to the BMI < 35 cohort (478 patients, 78.6%). At baseline, patients with BMI ≥ 35 were more likely to be younger (58.5 ± 11.4 vs 63.2 ± 12.0 years old, p < 0.001), to present with both back and leg pain (53.8% vs 37.0%, p = 0.002), and to require ambulation assistance (20.8% vs 9.2%, p < 0.001). Furthermore, the cohort with BMI ≥ 35 had worse baseline patient-reported outcomes including visual analog scale (VAS) back (7.6 ± 2.3 vs 6.5 ± 2.8, p < 0.001) and leg (7.1 ± 2.6 vs 6.4 ± 2.9, p = 0.031) pain, disability measured by the Oswestry Disability Index (ODI) (53.7 ± 15.7 vs 44.8 ± 17.0, p < 0.001), and quality of life on EuroQol-5D (EQ-5D) questionnaire (0.47 ± 0.22 vs 0.56 ± 0.22, p < 0.001). Patients with BMI ≥ 35 were more likely to undergo fusion (85.4% vs 74.7%, p = 0.01). There were no significant differences in 30- and 90-day readmission rates (p > 0.05). Five years postoperatively, there were no differences in reoperation rates or the development of adjacent-segment disease for patients in either BMI < 35 or ≥ 35 cohorts who underwent fusion (p > 0.05). On multivariate analysis, BMI ≥ 35 was a significant risk factor for not achieving minimal clinically important differences (MCIDs) for VAS leg pain (OR 0.429, 95% CI 0.209–0.876, p = 0.020), but BMI ≥ 35 was not a predictor for achieving MCID for VAS back pain, ODI, or EQ-5D at 5 years postoperatively. CONCLUSIONS Both obese and nonobese patients benefit from surgery for grade 1 spondylolisthesis. At the 5-year time point, patients with BMI ≥ 35 have similarly low reoperation rates and achieve rates of satisfaction and MCID for back pain (but not leg pain), disability (ODI), and quality of life (EQ-5D) that are similar to those in patients with a BMI < 35.
Cost-effectiveness of posterior lumbar interbody fusion and/or transforaminal lumbar interbody fusion for grade 1 lumbar spondylolisthesis: a 5-year Quality Outcomes Database study
Yee, Timothy J., Liles, Campbell, Johnson, Sarah E. , DiGiorgio, Anthony M. , Alan, Nima , Coric, Domagoj , Potts, Eric A. , Bisson, Erica F. , Knightly, John J. , Fu, Kai-Ming, Foley, Kevin T. , Shaffrey, Mark E., Bydon, Mohamad , Chou, Dean , Chan, Andrew K. , Meyer, Scott A., Shaffrey, Christopher I. , Slotkin, Jonathan R., Wang, Michael Y. , Haid, Regis W., Glassman, Steven D. , Virk, Michael S., Mummaneni, Praveen V., Ambati, Vardhaan , Asher, Anthony L., Virk, Michael S., Mummaneni, Praveen V. , Park, Paul

Journal of Neurosurgery: Spine | August 17, 2024 | Volume: 41 | Issue: 5 | Pages: 596-603

10.3171/2024.5.spine24112 Get It

OBJECTIVE Posterior lumbar interbody fusion (PLIF) and/or transforaminal lumbar interbody fusion (TLIF), referred to as "PLIF/TLIF," is a commonly performed operation for lumbar spondylolisthesis. Its long-term cost-effectiveness has not been well described. The aim of this study was to determine the 5-year cost-effectiveness of PLIF/TLIF for grade 1 degenerative lumbar spondylolisthesis using prospective data collected from the multicenter Quality Outcomes Database (QOD). METHODS Patients enrolled in the prospective, multicenter QOD grade 1 lumbar spondylolisthesis module were included if they underwent single-stage PLIF/TLIF. EQ-5D scores at baseline, 3 months, 12 months, 24 months, 36 months, and 60 months were used to calculate gains in quality-adjusted life years (QALYs) associated with surgery relative to preoperative baseline. Healthcare-related costs associated with the index surgery and related reoperations were calculated using Medicare reimbursement–based cost estimates and validated using price transparency diagnosis-related group (DRG) charges and Medicare charge-to-cost ratios (CCRs). Cost per QALY gained over 60 months postoperatively was assessed. RESULTS Across 12 surgical centers, 385 patients were identified. The mean patient age was 60.2 (95% CI 59.1–61.3) years, and 38% of patients were male. The reoperation rate was 5.7%. DRG 460 cost estimates were stable between our Medicare reimbursement–based models and the CCR-based model, validating the focus on Medicare reimbursement. Across the entire cohort, the mean QALY gain at 60 months postoperatively was 1.07 (95% CI 0.97–1.18), and the mean cost of PLIF/TLIF was $31,634. PLIF/TLIF was associated with a mean 60-month cost per QALY gained of $29,511. Among patients who did not undergo reoperation (n = 363), the mean 60-month QALY gain was 1.10 (95% CI 0.99–1.20), and cost per QALY gained was $27,591. Among those who underwent reoperation (n = 22), the mean 60-month QALY gain was 0.68 (95% CI 0.21–1.15), and the cost per QALY gained was $80,580. CONCLUSIONS PLIF/TLIF for degenerative grade 1 lumbar spondylolisthesis was associated with a mean 60-month cost per QALY gained of $29,511 with Medicare fees. This is far below the well-established societal willingness-to-pay threshold of $100,000, suggesting long-term cost-effectiveness. PLIF/TLIF remains cost-effective for patients who undergo reoperation.
Three-level ACDF versus 3-level laminectomy and fusion: are there differences in outcomes? An analysis of the Quality Outcomes Database cervical spondylotic myelopathy cohort
Ambati, Vardhaan , Macki, Mohamed, Chan, Andrew K. , Michalopoulos, Giorgos D. , Le, Vivian , Jamieson, Alysha, Chou, Dean , Shaffrey, Christopher I. , Gottfried, Oren N., Bisson, Erica F. , Asher, Anthony L. , Coric, Domagoj , Potts, Eric A. , Foley, Kevin T. , Wang, Michael Y. , Fu, Kai-Ming, Virk, Michael S. , Knightly, John J. , Meyer, Scott A., Park, Paul , Upadhyaya, Cheerag D., Shaffrey, Mark E., Buchholz, Avery L., Tumialán, Luis M. , Turner, Jay D. , Sherrod, Brandon A. , Haid, Regis W., Bydon, Mohamad , Mummaneni, Praveen V. , Michalopoulos, Giorgos , Ambati, Vardhaan

Neurosurgical Focus | September 1, 2023 | Volume: 55 | Issue: 3 | Pages: E2

10.3171/2023.6.focus23295 Get It

OBJECTIVE The authors sought to compare 3-level anterior with posterior fusion surgical procedures for the treatment of multilevel cervical spondylotic myelopathy (CSM). METHODS The authors analyzed prospective data from the 14 highest enrolling sites of the Quality Outcomes Database CSM module. They compared 3-level anterior cervical discectomy and fusion (ACDF) and posterior cervical laminectomy and fusion (PCF) surgical procedures, excluding surgical procedures crossing the cervicothoracic junction. Rates of reaching the minimal clinically important difference (MCID) in patient-reported outcomes (PROs) were compared at 24 months postoperatively. Multivariable analyses adjusted for potential confounders elucidated in univariable analysis. RESULTS Overall, 199 patients met the inclusion criteria: 123 ACDF (61.8%) and 76 PCF (38.2%) patients. The 24-month follow-up rates were similar (ACDF 90.2% vs PCF 92.1%, p = 0.67). Preoperatively, ACDF patients were younger (60.8 ± 10.2 vs 65.0 ± 10.3 years, p < 0.01), and greater proportions were privately insured (56.1% vs 36.8%, p = 0.02), actively employed (39.8% vs 22.8%, p = 0.04), and independently ambulatory (14.6% vs 31.6%, p < 0.01). Otherwise, the cohorts had equivalent baseline modified Japanese Orthopaedic Association (mJOA), Neck Disability Index (NDI), numeric rating scale (NRS)–arm pain, NRS–neck pain, and EQ-5D scores (p > 0.05). ACDF patients had reduced hospitalization length (1.6 vs 3.9 days, p < 0.01) and a greater proportion had nonroutine discharge (7.3% vs 22.8%, p < 0.01), but they had a higher rate of postoperative dysphagia (13.5% vs 3.5%, p = 0.049). Compared with baseline values, both groups demonstrated improvements in all outcomes at 24 months (p < 0.05). In multivariable analyses, after controlling for age, insurance payor, employment status, ambulation status, and other potential clinically relevant confounders, ACDF was associated with a greater proportion of patients with maximum satisfaction on the North American Spine Society Patient Satisfaction Index (NASS) (NASS score of 1) at 24 months (69.4% vs 53.7%, OR 2.44, 95% CI 1.17–5.09, adjusted p = 0.02). Otherwise, the cohorts shared similar 24-month outcomes in terms of reaching the MCID for mJOA, NDI, NRS–arm pain, NRS–neck pain, and EQ-5D score (adjusted p > 0.05). There were no differences in the 3-month readmission (ACDF 4.1% vs PCF 3.9%, p = 0.97) and 24-month reoperation (ACDF 13.5% vs PCF 18.6%, p = 0.36) rates. CONCLUSIONS In a cohort limited to 3-level fusion surgical procedures, ACDF was associated with reduced blood loss, shorter hospitalization length, and higher routine home discharge rates; however, PCF resulted in lower rates of postoperative dysphagia. The procedures yielded comparably significant improvements in functional status (mJOA score), neck and arm pain, neck pain–related disability, and quality of life at 3, 12, and 24 months. ACDF patients had significantly higher odds of maximum satisfaction (NASS score 1). Given comparable outcomes, patients should be counseled on each approach’s complication profile to aid in surgical decision-making.