Category: Clinical Stones: Pediatrics
Introduction & Objective : Patients with urologic congenital disease, especially those with severe scoliosis, present obstacles to renal access. Stone-free rates are known to be low. DynaCT acts as a conventional fluoroscopic c-arm, but can also perform intraoperative cone-beam CT. The two images are fused to allow for mapping of the puncture onto a real-time fluoroscopic image. It also acts as an angiography system, should this be required. We began a program of DynaCT PCNL, in which for select patients renal access is performed under combined CT and fluoroscopic guidance, with endoscopic and CT confirmation of stone clearance.
Renal access and PCNL were conducted under one anesthetic with the patients prone. All staff, including anesthesiologists, exit to a shielded portion of the IR suite during CT acquisition. PCNL was performed with 24 and 30Fr sheaths. Radiation dose was estimated from dose-length products.
Results : Two women, aged 28 and 26 years old, with bladder augmentation and extensive pediatric GU reconstruction underwent DynaCT-PCNL for renal stone Guy’s Stone Score of 4 (Fig 1). Both patients had severe scoliosis (Fig 2). No residual fragments remained in either kidney (Fig 3), and there were no infectious or bleeding complications. One patient had undergone a PCNL the year prior complicated by large hydrothorax – this did not recur. Effective dose from each cone beam CT run ranged from 1.8 - 10.3 mSv. There was moderate beam-hardening artifact around sheath and wire, but small stone fragments remained visible.
Conclusions : For patients at highest risk of PCNL complication, single-stage DynaCT PCNL may offer a safe and effective alternative. It requires coordination of radiologists, urologists, and anesthesiologists.
Caleb Nelson– Associate Professor of Surgery (Urology) and Pediatrics, Boston Children's Hospital / Harvard Medical School, Boston, Massachusetts
Harry Padua– Boston, Massachusetts
Robert MacDougall– Boston, Massachusetts
Mary Landrigan-Ossar– Boston, Massachusetts
Bartley Cilento– Boston, Massachusetts
Michael Kurtz– Boston, Massachusetts
Associate Professor of Surgery (Urology) and Pediatrics
Boston Children's Hospital / Harvard Medical School
Dr. Caleb P. Nelson, MD, MPH is Associate Professor of Surgery (Urology) and Pediatrics at Harvard Medical School and since 2006 has been on the staff of Boston Children’s Hospital. He attended Dartmouth College and the Duke University School of Medicine. He did his urology training at the University of Michigan, and also completed a Clinical Research Training Program and received his MPH from the University of Michigan School of Public Health. He then completed a 2-year fellowship in pediatric urology at the Johns Hopkins Hospital. His research interests focus on clinical effectiveness research in pediatric urology and in pediatric urolithiasis, as well as quality of care and patient safety.