Endourology & Laparoscopy Fellowship

Program Overview

Endourological SocietyThe Endourology Fellowship at UCSF under the joint direction of Drs. Marshall Stoller and Thomas Chi aims to train innovative, superb clinicians and researchers and provide them with the tools to pursue careers in academic urology and research. The program seeks to attract bright, committed, and compassionate applicants from diverse backgrounds, who aspire to become future leaders in this specialty. They should possess a genuine desire to serve culturally diverse and medically underserved populations while being dedicated to addressing issues related to diversity, equity, and inclusion. The program has trained fellows since 1989 and was accredited with the Endourological Society starting in 2018. The recruitment goal of the training program is to recruit one fellow each year committed to two years of fellowship training. If an appropriate two-year candidate is not available in the candidate pool, the option exists for a one year training program, where the fellow would spend time with primarily Dr. Stoller or Chi for their fellowship year. In the two year track, fellows’ time is divided into one year spent primarily with Dr. Stoller where there is a heavier dedication to clinical skills with 20-30% research incorporated and the other year spent primarily with Dr. Chi where there is a heavier dedication to developing advanced skills in research and grantsmanship with 20-30% clinical time. Overlap in both clinical and research activities exists between Dr. Stoller’s and Dr. Chi’s practices, providing fellows a collaborative environment for training in a dynamic team atmosphere.

Clinical Training Opportunities

UCSF Parnassus CampusThe fellows’ clinical training includes exposure to all aspects of medical treatment of urinary stone disease, surgical endourologic techniques, and mastery of laparoscopic and minimally invasive surgery before completing their fellowship. Graduating fellows will be proficient in both fluoroscopic and ultrasound guided percutaneous renal access techniques from both the supine and prone positions. They also will gain proficiency in advanced ureteroscopy and holmium laser enucleation of the prostate (HoLEP) as well as advanced laparoscopy. Typical fellows complete at minimum 200 ureteroscopy, 180 percutaneous nephrolithotomy (PCNL), and 50 HoLEP cases in addition to 150 laparoscopy cases. While fellows have the opportunity to participate in robotic cases, robotics is not part of the core training curriculum.

Research Training Opportunities

For the research aspect of fellowship training, fellows are exposed to a broad range of basic, clinical, and translational research work. They have ample opportunity to be productive, publishing manuscripts as well as presenting their findings at national and regional scientific meetings. Their training will include mastering strategies to optimize study design and the basics of grantsmanship.

Multiple federally funded projects are currently ongoing that provide fellows with a vast array of areas on which to focus, whether it be clinical, basic, translational, or device development research. Examples include an ongoing prospective research study funded by the NIH currently establishing a high quality novel registry in urinary stone disease called ReSKU (The Registry for Stones of the Kidney and Ureter) to understand the natural history of kidney stones and their recurrence. This registry has supported clinical research projects focused on advancing our implementation of disposable ureteroscopes, ultrasound guidance for stone surgery, and novel therapeutics. In addition, an open randomized placebo-controlled clinical trial for cystinurics is currently underway. Multiple studies in the novel uses of ultrasound in urinary stone disease treatment and diagnosis are also being undertaken. Current fellows are engaged in data analysis and manuscript preparation related to all of these projects from a clinical research perspective. An active laboratory experience also exists supporting a Drosophila fruit fly model for urinary stone disease as well as innovations in papillary imaging to understand the microscopic architecture of the kidney that contributes to kidney stone formation. In addition, translational work in genomic and microbiomic analysis of kidney stone patients is underway. These projects are performed under the joint mentorship of all key faculty, including basic science as well as clinical faculty. Depending on the fellows’ own area of interest, they will be encouraged to engage in a main project as a framework in which to learn research skills. In this core area, fellows are expected to participate in designing research protocols, learning new laboratory techniques, performing experiments, and/or analyzing data in addition to preparing manuscripts and oral presentations related to their research work. The goal for graduating fellows is to build the foundation of a fundable research program to support their academic careers that they will be able to carry forward leaving fellowship. Fellows are expected to publish in peer-reviewed journals and present their work at regional, national, and international meetings.

This combined approach to fellowship training utilizing both rich clinical and research experiences will provide graduating fellows with the tools to pursue long and productive careers in endourology.

Application Process

We participate in the Endourological Society process administered by the American Urological Association (AUA).

Program Prerequisites/ Preferences

  • Candidate must have completed an ACGME or RCPSC Urology Residency Training Program
  • Candidate must be a United States or Canadian citizen 
  • Special interest in future academic and scholarly activities is considered highly favorable
  • Preferably be a candidate for the American Board of Urology
  • Candidate must be eligible to obtain a California medical license (please refer to the CA Medical Board for eligibility requirements)

Applications are due March 1st of each year, 16 months prior to beginning fellowship.

Application Packets should include:

Submit application packets via email to Marshall Stoller, MD and Thomas Chi, MD Endourology Fellowship Program Director c/o Katherine Jung, [email protected]

2024 Match Information

As of May 2023, in adherence to the UC Policy, UCSF OGME and in support of the AAMC, virtual interviews only will be conducted for the next match cycle.

Two Virtual Interview Dates

  • Thursday, April 11, 2024 
  • Thursday, May 16, 2024

Current Fellows

Maria Camila Velasquez Escobar, MD     Maria Camila Velasquez Escobar, MD
7/1/2023 - 6/30/2025
2023, University of Miami Miller School of Medicine, Desai Sethi Urology Institute
Medical School: 
2012, Universidad CES School of Medicine



Wilson Sui, MD    

Wilson Sui, MD
7/1/2022 - 6/30/2024
2020, Vanderbilt University Medical Center
Medical School:
2017, Columbia University Medical Center



Heiko Yang, MD, PhD
7/1/2022 - 6/30/2024
2022, University of California, San Francisco
Medical School:
2016, University of Michigan


Alumni Spotlight

Fadl Hamouche, MD  

Fadl Hamouche, MD
Endourology Fellow 2020-2022
Faculty, McGill University Health Center,
Montreal, Quebec, Canada

Greg Hosier, MD, MSc  

Greg Hosier, MD, MSc
Endourology Fellow 2021-2022
Attending, Faculty University of Manitoba/Health Sciences Centre,
Winnipeg, Manitoba, Canada


Justin Ahn, MD


Justin Ahn, MD
Endourology & Laparoscopy Fellow 2019-2021
Assistant Professor, Department of Urology,
University of California, San Francisco

David Bayne, MD, MPH   David Bayne, MD, MPH
Clinical Instructor 2018-2020
Assistant Professor, Department of Urology, University of California, San Francisco, CA
Scott Wiener, MD   Scott Wiener, MD
Endourology Fellow 2017-2019
Faculty and Director, Kidney Stone Program, SUNY Upstate Medical University, Syracuse, NY
David Tzou, MD   David Tzou, MD
Endourology Fellow  2017-2018
Faculty, University of Arizona, Tucson, AZ
Benjamin Sherer, MD   Benjamin Sherer, MD
Endourology Fellow 2016-2017
Attending, Colorado Permanente Medical Group, Denver, CO

To view past clinical/research fellows trained, click here.