Left Ureterocalycostomy With Ileal Interposition for Retroperitoneal Fibrosis in Patient With Erdheim-Chester Disease

BACKGROUND Erdheim-Chester disease (ECD) is a rare progressive non -Langerhans' cell histiocytic multisystem disorder with a broad spectrum of clinical manifestations, including infiltrative perinephric with ureteral involvement resulting in hydronephrosis, renal atrophy, and eventual renal failure. OBJECTIVE To present a patient with ECD with bilateral renal/ureteral involvement managed with bilateral percutaneous nephrostomy tubes (PCNT) and trametinib who underwent bilateral robotic upper tract reconstruction, the first such published report. The video demonstrates only the left -sided repair, which posed specific challenges and demonstrates reconstructive techniques useful in complex upper tract repairs with limited tissue availability. MATERIALS AND METHODS A 35 -year -old male initially presented with baseline creatinine of 1.62 and split renal function; 30% right and 70% left by Lasix renogram. Extra -genitourinary manifestations of disease included cardiac hypertrophy and skin ulcers/lesions. Bilateral retrograde pyeloureterography showed proximal ureteral obliteration -4 cm bilaterally. Multiple management options were discussed including PCNTs, but patient elected for definitive repair. He was seen by Cardiology and Anesthesia and deemed to be optimized. He held his trametinib for 1 week before surgery. We demonstrate a difficult ureteral dissection with fibrotic hilum preventing separation. Simultaneous ureteroscopy identified the distal extent of stricture which was excised, leaving a -15 cm gap. Downward nephropexy was performed with ultrasound guidance to identify an inferior calyx. Partial nephrectomy was then performed without vascular control due to hilar fibrosis. Ileal interposition was chosen to bridge the remaining -8 cm gap. Proximal ileo-calyceal and distal ileo-ureteral anastomoses were performed. We then placed a 30 cm x 7 Fr double -J ureteral stent in standard fashion. The ileum was secured to the renal pelvis to maintain a straight lie and an omental flap was secured in place. RESULTS Immediate postoperative course was complicated by partial small bowel obstruction leading to a negative exploratory laparotomy and a subsequent episode of urosepsis. The patient is now voiding well without stents or PCNTs, without infections and with improving renal function, now with GFR (glomerular filtration rate) of 62 from 43 preoperatively. With aggressive hydration, patient has had no obstruction of the distal ureter with mucus. MRI Abdomen/Pelvis 6 months later showed irregularity of the calyces with stable mild hydronephrosis. The patient continues to be medically managed on trametinib for his underlying disease, with surveillance for recurrent fibrosis and obstruction which has not yet occurred. CONCLUSION Robotic ureterolysis and ureterocalycostomy with possible bowel interposition is a reasonable option for upper tract reconstruction in select patients with ECD. UROLOGY 184: e253- e255, 2024. Published by Elsevier Inc.