Back to Authors

Tyson, Mark D.

0009-0001-5346-1404

Mayo Clinic

Mayo Clinic

Citations 77

Effect of intracorporeal urinary diversion on the incidence of benign ureteroenteric stricture after cystectomy
Faraj, Kassem , Navaratnam, Anojan , Abdul-Muhsin, Haidar , Eversman, Sarah, Singh, Vijay Kumar , Tyson, Mark D. , Faraj, Kassem S , Rose, Kyle M., Navaratnam, Anojan K, Abdul-Muhsin, Haidar M , Singh, Vijay , Rose, Kyle

International Journal of Urology | February 20, 2021 | Volume: 28 | Issue: 5 | Pages: 593-597

10.1111/iju.14521 Get It

ObjectivesTo compare ureteroenteric stricture rates after radical cystectomy in patients who undergo an intracorporeal urinary diversion versus other surgical approaches.MethodsWe retrospectively reviewed health records of all patients who underwent cystectomy with urinary diversion at Mayo Clinic Hospital (Phoenix, AZ, USA) from 1 January 2007 through 1 January 2018. Ureteroenteric stricture was identified by surveillance imaging. Patients were stratified by surgical approach: open radical cystectomy, robot‐assisted radical cystectomy with extracorporeal urinary diversion and robot‐assisted radical cystectomy‐intracorporeal urinary diversion. A Cox proportional hazards model was fitted that included independent predictors of stricture development.ResultsOf the 573 cystectomies assessed, 236 (41.2%) were carried out robotically. In the robot‐assisted radical cystectomy cohort, 39 patients (16.5%) underwent intracorporeal urinary diversion. The median follow‐up period was 55, 70 and 71 months for the open radical cystectomy, robot‐assisted radical cystectomy‐extracorporeal urinary diversion and robot‐assisted radical cystectomy‐intracorporeal urinary diversion groups, respectively. Subgroup stricture rates were as follows: open radical cystectomy, 8.0%; robot‐assisted radical cystectomy‐extracorporeal urinary diversion, 9.6%; and robot‐assisted radical cystectomy‐intracorporeal urinary diversion, 2.6% (P = 0.33). The median time to stricture was 5 months (interquartile range 3.3–11.5 months). In the bivariable analysis, factors that were associated with the development of ureteroenteric stricture were postoperative urinary leak (hazard ratio 3.177, 95% confidence interval 1.129–8.935; P = 0.03) and body mass index (hazard ratio 1.078, 95% confidence interval 1.027–1.132; P = 0.002). On multivariable logistic regression analysis, intracorporeal urinary diversion approach was not associated with the development of ureteroenteric stricture (hazard ratio 0.272, 95% confidence interval 0.036–2.066; P = 0.21).ConclusionsUreteroenteric stricture is a complication that typically occurs within the first postoperative year. Although our results did not support major differences in outcomes between intracorporeal urinary diversion and extracorporeal urinary diversion, the small sample size did not exclude the possibility of a type 2 statistical error.
Declining Medicare Reimbursement for Urologists: An Opportunity for Informed Advocacy
Edmonds, Victoria S. , Haglin, Jack M. , Tyson, Mark D.

Journal of Urology | February 3, 2021 | Volume: 206 | Issue: 1 | Pages: 10-12

10.1097/ju.0000000000001655 Get It

Variation in Lymph Node Yield After Radical Cystectomy
Faraj, Kassem , Judge, Nathanael, Blodgett, Gail, Stanton, Melissa, Tyson, Mark D. , Faraj, Kassem S , Stanton, Melissa L, Chang, Yu‐Hui

American Journal of Clinical Pathology | October 29, 2020 | Volume: 156 | Issue: 3 | Pages: 391-398

10.1093/ajcp/aqaa247 Get It

Abstract Objectives To test the hypothesis that lymph node yield will vary by pathology assistant (PA) in patients undergoing radical cystectomy (RC) with pelvic lymph node dissection (PLND). Methods This is a single-institution retrospective review that included patients who underwent an RC with PLND for bladder cancer from January 1, 2007, to January 1, 2018. Predicted mean lymph node counts were generated using multivariable regression analysis. Results In a total of 430 patients who underwent RC with PLND, the median lymph node count (interquartile range) was 15.0 (11.0-21.0). The frequency of the limits of lymphadenectomy was as follows: external iliac, internal iliac, and obturator (true pelvis) (33.3%); true pelvis plus common iliac to the level of the aortic bifurcation (47.9%); and inferior mesenteric artery (18.8%). On descriptive analysis, there were differences in lymph node yield when evaluating the following variables: level of dissection, clinical stage, neoadjuvant chemotherapy, surgical approach, surgeon, pathologist, and PA (P < .05). On multivariable analysis, adjusted lymph node counts varied between surgeons, pathologists, clinical stage, and level of dissection but not by PA (P = .18). Conclusions Lymph node yield after RC varies on several known levels, including surgeon, extent of lymphadenectomy, clinical stage, and pathologist. This study found no significant variation in lymph node yield according to PA.
Editorial Comment
Tyson, Mark D.

Journal of Urology | July 27, 2020 | Volume: 204 | Issue: 4 | Pages: 724-725

10.1097/ju.0000000000001089.01 Get It

GEMINI: An open-label, single-arm, phase II trial of intraoperative gemcitabine intravesical instillation in patients undergoing radical nephroureterectomy for upper tract urothelial carcinoma.
Leibovich, Bradley C. , Thompson, R. Houston, Potretzke, Aaron M. , Chow, George K. , Tollefson, Matthew K. , Schulte, Phillip J. , Tyson, Mark D. , Boorjian, Stephen A. , Packiam, Vignesh T. , Lyon, Timothy D.

Journal of Clinical Oncology | February 19, 2020 | Volume: 38 | Issue: 6_suppl | Pages: TPS594-TPS594

10.1200/jco.2020.38.6_suppl.tps594 Get It

TPS594 Background: The standard treatment for upper tract urothelial carcinoma (UTUC) is radical nephroureterectomy (RNU) with bladder cuff resection. Subsequent intravesical recurrence is common and results in patient morbidity and increased healthcare cost. Level 1 evidence has demonstrated reduction of intravesical recurrence with instillation of intravesical Mitomycin C at 10 days following RNU. However, there has been limited adoption of Mitomycin C due to concerns for toxicity and logistics of postoperative drug delivery. Meanwhile, immediate intravesical gemcitabine has been shown to reduce intravesical recurrence following transurethral resection of bladder cancers without increasing toxicity compared to placebo. Moreover, small series have suggested improved efficacy of intraoperative intravesical chemotherapy for RNU. The purpose of the GEMINI trial, therefore, is to prospectively establish the safety and efficacy of intraoperative instillation of intravesical gemcitabine in patients undergoing RNU for UTUC. Methods: GEMINI is a multi-center open-label, single-arm, Phase II study that aims to enroll 90 patients with cTa-T4N0M0 UTUC. Patients receive intraoperative intravesical instillation of gemcitabine at the beginning of RNU, to be held in the bladder for at least 1 hour. The instilled drug will be drained prior to resection of the bladder cuff. Patients will undergo standard of care postoperative surveillance, including cystoscopy at 3, 6, 12, 18, and 24 months. The primary endpoint is 1-year intravesical recurrence-free survival. The historical event rate for no treatment is 30%, and we estimated a 40% relative reduction in event rate with gemcitabine. The study is powered to provide 80% power to detect this difference based on a one-sided exact test of proportions with alpha level 0.05. Secondary endpoints include time to recurrence and stratification of recurrence free survival by tumor grade, tumor stage, neoadjuvant chemotherapy, ureteral tumor location, and history of bladder cancer. Safety and adverse event endpoints will be evaluated. Complete accrual is expected within 3 years.
Comparison of Magnetic Resonance Imaging and Transrectal Ultrasound Informed Prostate Biopsy for Prostate Cancer Diagnosis in Biopsy Naïve Men: A Systematic Review and Meta-Analysis
Chandrasekar, Thenappan , Klotz, Laurence , Emberton, Mark , Haider, Masoom A. , Taneja, Samir S. , Fleshner, Neil , Finelli, Antonio , Perlis, Nathan , Tyson, Mark D. , Klaassen, Zachary , Arora, Karan, Goldberg, Hanan , Ahmad, Ardalan E. , Arora, Karan , Wallis, Christopher J D

Journal of Urology | October 14, 2019 | Volume: 203 | Issue: 6 | Pages: 1085-1093

10.1097/ju.0000000000000595 Get It

Assessment of treatment patterns of nonmuscle invasive bladder cancer patients in privately insured patients.
Tyson, Mark D. , Guo, Amy , Papademetriou, Eros , Spigelman, Samuel, Rotter, David , Potluri, Ravi C.

Journal of Clinical Oncology | May 27, 2019 | Volume: 37 | Issue: 15_suppl | Pages: e16012-e16012

10.1200/jco.2019.37.15_suppl.e16012 Get It

e16012 Background: 75–85% of bladder cancer patients present with non-muscle invasive disease (NMIBC). While transurethral resection of bladder tumors (TURBT) is the initial standard treatment for visible lesions, there is variation in the utilization of adjuvant intravesical treatments in the real world. This study aims to assess current treatment patterns in privately insured NMIBC patients. Methods: Bladder cancer patients were identified from Truven MarketScan Commercial and Medicare Supplemental databases using ICD-9/ICD-10 codes. In the absence of tumor staging information, patients were considered to have NMIBC based on diagnosis of CIS or an algorithm centered on the use of TURBT, intravesical treatments and absence of immediate progression to muscle invasive disease. Patients were included in the final cohort if they had one year of continuous insurance coverage prior to index diagnosis, and were without any bladder cancer treatment during this period. Results: 18,683 patients met the eligibility criteria and had a median follow-up of 23 months; the mean age was 68.6 years and 75% were male. The median time from diagnosis to TURBT was 8 days. 54% of the cohort had an intravesical treatment (35% specifically with Bacillus Calmette–Guérin (BCG), with median time from TURBT of 69 days). 77% of BCG-treated patients received 5 or more administrations during induction. However, only 22% of patients received maintenance BCG after induction. 16% of the total cohort developed a recurrence or progression during the available follow-up; five percent underwent a cystectomy, while seven percent were diagnosed with metastatic disease. Only 4% of patients with 5 or more BCG administrations during induction met the definition for being BCG-unresponsive; this is influenced by the low adherence to BCG maintenance protocol. Conclusions: Only a third of NMIBC patients are given intravesical BCG treatment. Adherence to BCG maintenance protocols is suboptimal. Rates of cystectomy/ exenteration are low, suggesting patients’ preference of bladder preservation and the unmet need for new bladder-sparing alternatives.
063 Wide Variation in Postoperative Urologic Surgery Opioid Prescribing in Tertiary Care Centers
Ziegelmann, M., Glasgow, Amy E. , Tyson, Mark D. , Pak, Raymond , Gettman, Matthew T., Joseph, Jason , Habermann, Elizabeth B.

The Journal of Sexual Medicine | March 29, 2019 | Volume: 16 | Issue: Supplement_1 | Pages: S34-S35

10.1016/j.jsxm.2019.01.074 Get It

062 Evidence-Based Opioid Prescribing Guidelines for the Postoperative Urologic Surgery Patient at Discharge
Ziegelmann, M., Glasgow, Amy E. , Tyson, Mark D. , Pak, Raymond , Gettman, Matthew T., Joseph, Jason , Gazelka, Halena M. , Habermann, Elizabeth B.

The Journal of Sexual Medicine | March 29, 2019 | Volume: 16 | Issue: Supplement_1 | Pages: S33-S34

10.1016/j.jsxm.2019.01.073 Get It