Bio

Clinical Focus


  • Nephrology
  • Kidney Stones

Academic Appointments


Honors & Awards


  • Ben J. Lipps Research Fellowship Award, American Society of Nephrology (2017-2019)

Professional Education


  • Board Certification, Nephrology, American Board of Internal Medicine (2019)
  • Master of Science, Stanford University, EPIDM-MS (2019)
  • Fellowship:Stanford University Nephrology Fellowship (2018) CA
  • Board Certification: Internal Medicine, American Board of Internal Medicine (2017)
  • Residency:UCSD Internal Medicine Residency (2016) CA
  • Medical Education:UCLA David Geffen School Of Medicine Registrar (2013) CA
  • Bachelor of Science, Caltech, Biology (2009)

Publications

All Publications


  • Prevalence of twenty-four hour urine testing in Veterans with urinary stone disease. PloS one Ganesan, C., Thomas, I. C., Song, S., Sun, A. J., Sohlberg, E. M., Kurella Tamura, M., Chertow, G. M., Liao, J. C., Conti, S., Elliott, C. S., Leppert, J. T., Pao, A. C. 2019; 14 (8): e0220768

    Abstract

    The American Urological Association guidelines recommend 24-hour urine testing in patients with urinary stone disease to decrease the risk of stone recurrence; however, national practice patterns for 24-hour urine testing are not well characterized. Our objective is to determine the prevalence of 24-hour urine testing in patients with urinary stone disease in the Veterans Health Administration and examine patient-specific and facility-level factors associated with 24-hour urine testing. Identifying variations in clinical practice can inform future quality improvement efforts in the management of urinary stone disease in integrated healthcare systems.We accessed national Veterans Health Administration data through the Corporate Data Warehouse (CDW), hosted by the Veterans Affairs Informatics and Computing Infrastructure (VINCI), to identify patients with urinary stone disease. We defined stone formers as Veterans with one inpatient ICD-9 code for kidney or ureteral stones, two or more outpatient ICD-9 codes for kidney or ureteral stones, or one or more CPT codes for kidney or ureteral stone procedures from 2007 through 2013. We defined a 24-hour urine test as a 24-hour collection for calcium, oxalate, citrate or sulfate. We used multivariable regression to assess demographic, geographic, and selected clinical factors associated with 24-hour urine testing.We identified 130,489 Veterans with urinary stone disease; 19,288 (14.8%) underwent 24-hour urine testing. Patients who completed 24-hour urine testing were younger, had fewer comorbidities, and were more likely to be White. Utilization of 24-hour urine testing varied widely by geography and facility, the latter ranging from 1 to 40%.Fewer than one in six patients with urinary stone disease complete 24-hour urine testing in the Veterans Health Administration. In addition, utilization of 24-hour urine testing varies widely by facility identifying a target area for improvement in the care of patients with urinary stone disease. Future efforts to increase utilization of 24-hour urine testing and improve clinician awareness of targeted approaches to stone prevention may be warranted to reduce the morbidity and cost of urinary stone disease.

    View details for DOI 10.1371/journal.pone.0220768

    View details for PubMedID 31393935

  • Urinary Stone Disease in Pregnancy: A Claims-Based Analysis of 1.4 Million Patients. The Journal of urology Sohlberg, E. M., Brubaker, W. D., Zhang, C. A., Anderegg, L. D., Dallas, K., Song, S., Ganesan, C., Chertow, G., Pao, A., Liao, J., Leppert, J. T., Elliott, C. S., Conti, S. L. 2019: 101097JU0000000000000657

    Abstract

    PURPOSE: Urinary stone disease during pregnancy is poorly understood but is thought to be associated with increased maternal and fetal morbidity. We sought to determine the prevalence of urinary stone disease in pregnancy and whether urinary stone disease during pregnancy is associated with adverse pregnancy outcomes.MATERIALS AND METHODS: We identified all pregnant women from 2003 through 2017 in the Optum national insurance claims database. We used diagnosis claims to identify urinary stone disease and assess medical comorbidity. We established the prevalence of urinary stone disease during pregnancy, stratified by week of pregnancy. We further evaluated associations among urinary stone disease and maternal complications and pregnancy outcomes in both univariable and multivariable analyses.RESULTS: Urinary stone disease affects 8/1000 pregnancies and is more common in white women and women with more comorbid conditions. In fully adjusted models, pregnancies complicated by urinary stone disease had higher rates of adverse fetal outcomes, including prematurity and spontaneous abortions. This analysis is limited by its retrospective administrative claims design.CONCLUSIONS: The rate of urinary stone disease during pregnancy is higher than previously reported. Urinary stone disease is associated with adverse pregnancy outcomes.

    View details for DOI 10.1097/JU.0000000000000657

    View details for PubMedID 31738114

  • Ultra-low-dose CT: An Effective Follow-up Imaging Modality for Ureterolithiasis. Journal of endourology Cheng, R. Z., Shkolyar, E., Chang, T. C., Spradling, K., Ganesan, C., Song, S., Pao, A. C., Leppert, J. T., Elliott, C. S., To'o, K., Conti, S. L. 2019

    Abstract

    BACKGROUND AND PURPOSE: Classically, abdominal X-ray (KUB), ultrasound or a combination of both have been routinely used for ureteral stone surveillance after initial diagnosis. More recently, ultra-low-dose CT (ULD CT) has emerged as a CT technique that reduces radiation dose while maintaining high sensitivity and specificity for urinary stone detection. We aim to evaluate our initial experience with ULD CT for patients with ureterolithiasis, measuring real-world radiation doses and stone detection performance.METHODS: We reviewed all ULD CT scans performed at the Veterans Affairs Palo Alto Health Care System between 2016 and 2018. We included patients with ureteral stones and calculated the mean effective radiation dose per scan. We determined stone location and size, if the stone was visible on the associated KUB or CT scout film, and if hydronephrosis was present. We performed logistic regression to identify variables associated with visibility on KUB or CT scout film and hydronephrosis.RESULTS: One-hundred and eighteen ULD scans were reviewed, of which 50 detected ureteral stones. The mean effective radiation dose was 1.04 0.41 mSv. Of the ULD CTs that detected ureterolithiasis, 38% lacked visibility on KUB/CT scout film and had no associated hydronephrosis, suggesting they would be missed with a combination of KUB and ultrasound. Larger stones (OR: 1.40, 95% CI: 1.08-1.96 for every 1mm increase in stone size) were more likely to be detected by KUB/CT scout or ultrasound, while stones in the distal ureter (OR: 0.18, 95% CI: 0.03-0.81) were more likely to be missed by KUB/CT scout or hydronephrosis.CONCLUSION: Based on our institutions' initial experience with ULD CT, ULD CT detects small and distal ureteral stones that would likely be missed by KUB or ultrasound, while maintaining a low effective radiation dose. An ULD CT protocol should be considered when re-imaging for ureteral stones is necessary.

    View details for DOI 10.1089/end.2019.0574

    View details for PubMedID 31663371

  • Spironolactone plus patiromer: proceed with caution LANCET Ganesan, C., Pao, A. C. 2019; 394 (10208): 1486?88
  • Twenty-Four Hour Urine Testing and Prescriptions for Urinary Stone Disease-Related Medications in Veterans. Clinical journal of the American Society of Nephrology : CJASN Song, S., Thomas, I. C., Ganesan, C., Sohlberg, E. M., Chertow, G. M., Liao, J. C., Conti, S., Elliott, C. S., Pao, A. C., Leppert, J. T. 2019

    Abstract

    Current guidelines recommend 24-hour urine testing in the evaluation and treatment of persons with high-risk urinary stone disease. However, how much clinicians use information from 24-hour urine testing to guide secondary prevention strategies is unknown. We sought to determine the degree to which clinicians initiate or continue stone disease-related medications in response to 24-hour urine testing.We examined a national cohort of 130,489 patients with incident urinary stone disease in the Veterans Health Administration between 2007 and 2013 to determine whether prescription patterns for thiazide diuretics, alkali therapy, and allopurinol changed in response to 24-hour urine testing.Stone formers who completed 24-hour urine testing (n=17,303; 13%) were significantly more likely to be prescribed thiazide diuretics, alkali therapy, and allopurinol compared with those who did not complete a 24-hour urine test (n=113,186; 87%). Prescription of thiazide diuretics increased in patients with hypercalciuria (9% absolute increase if urine calcium 201-400 mg/d; 21% absolute increase if urine calcium >400 mg/d, P<0.001). Prescription of alkali therapy increased in patients with hypocitraturia (24% absolute increase if urine citrate 201-400 mg/d; 34% absolute increase if urine citrate ?200 mg/d, P<0.001). Prescription of allopurinol increased in patients with hyperuricosuria (18% absolute increase if urine uric acid >800 mg/d, P<0.001). Patients who had visited both a urologist and a nephrologist within 6 months of 24-hour urine testing were more likely to have been prescribed stone-related medications than patients who visited one, the other, or neither.Clinicians adjust their treatment regimens in response to 24-hour urine testing by increasing the prescription of medications thought to reduce risk for urinary stone disease. Most patients who might benefit from targeted medications remain untreated.

    View details for DOI 10.2215/CJN.03580319

    View details for PubMedID 31712387

  • Regarding the possibility of anterior vascular injury from the posterior approach to the lumbar disc space: an anatomical study. Spine Ganesan, C., Petrus, L., Ross, I. B. 2012; 37 (22): E1371?5

    Abstract

    Anatomical study with magnetic resonance imaging data.To document the distances between the major retroperitoneal vessels and the anterior lumbar disc spaces; to determine the effect of patient positioning on these relationships; and to discuss ways to deal with vascular injury.It is well known that there are major vascular structures anterior to the lower lumbar spine. Vascular injury during posterior approaches, however, remains a problem. These anatomical relationships have not been determined in vivo, and there are no data on the effect of turning the patient prone, and onto bolsters.A random sampling of 49 women and 48 men was made. All examinations were performed in magnetic resonance scanners operating at 1.5 T. Measurements were made using electronic calipers on axial T2-weighted images. Post hoc studies were done on a smaller number of patients, to determine the effect of prone positioning.At the L4-L5 level, 66% of the common iliac arteries in women and 49% of those in men were within 5 mm of the anterior aspect of the disc space. At L5-S1, these numbers dropped to 23% for women and 19% for men. No relationship between the age of the patient and the distance from disc space to blood vessel was found. There was little change in these measurements between the supine and prone positions. The use of bolsters to decompress the abdominal contents in the prone position did not significantly alter the disc-artery distances. Venous relationships were also documented.The lower lumbar spine is confirmed to frequently be very close to the major retroperitoneal vessels. Turning the patient prone and placing the patient on bolsters does not change this relationship. This is part of the reason why vascular injuries may occur during routine lumbar spine surgery. Spine surgeons should be able to recognize and initiate treatment of such injuries.

    View details for DOI 10.1097/BRS.0b013e318267fb36

    View details for PubMedID 22781009

Footer Links:

Stanford Medicine Resources: