2.1 Clinical history and diagnosis
A 27-year-old woman presented to the Emergency Department complaining of asthenia, adynamia and weight loss associated with lower urinary tract symptoms and subfebrile temperature. Ten years before, she had undergone a pediatric en-bloc kidney transplant because of end-stage kidney disease secondary to perinatal asphyxia syndrome. Asphyxia can lead to multi-organ dysfunction and a redistribution of cardiac output to maintain cerebral, cardiac and adrenal perfusion while potentially compromising renal, gastrointestinal and skin perfusion as circulatory response.
One allograft was located in the right iliac fossa (upside-down implantation with ureteric anastomosis following Lich-Gregoir technique, violet in Fig. 1) and the other in the right flank (end-to-side uretero-ureteral anastomosis with native right kidney, blue and orange in Fig. 1). The en-bloc graft was made to rest on the right psoas muscle, and the graft vena cava was anastomosed terminolaterally to the recipient external iliac vein using 6–0 polypropylene suture. The graft aorta was also anastomosed terminolaterally to the right external iliac artery using 7–0 polypropylene suture.
Our patient presented other comorbidities as well such as hypertension, asymptomatic, bilateral cataracts, intellectual disability, sensorineural hearing loss and Wolff–Parkinson–White syndrome (WPW pattern or preexcitation consisting of a short PR interval and prolonged QRS with an initial slurring upstroke—“delta” wave—in the presence of sinus rhythm) with episodic palpitations and lightheadedness. Anthropometric features are : height 125 cm, weight 25 kg, BMI = 14.2. She reported 10 kg weight loss in the last 5 months due to depression symptoms associated with COVID-19 (coronavirus disease) quarantine. Her daily medication was: prednisone 4 mg, amlodipine 5 mg, atenolol 25 mg, enalapril 2.5 mg, mycophenolic acid 250 mg/250 mg and tacrolimus 2 mg/2 mg.
The main abnormalities in the laboratory data were white blood cells count 15,654/mm3, serum creatinine level 1 mg/dl (baseline: 0.6 mg/dl), lactate 3.6 mmol/l and pH 7.39.
Non-contrast computed tomography (NCCT) scan showed staghorn calculi in the kidney allograft implanted in the right iliac fossa composed of at least 3 stones of 12.5 mm, 13.7 mm and 10 mm located in superior, medium and inferior calyx, respectively (530 Hounsfield Units) (Fig. 2). Moreover, both the right flank transplanted kidney and the right native kidney had severe pelvicalyceal dilation because of two ureteral stones of 6.7 mm and 5.9 mm impacted in the uretero-ureteral anastomosis (450 to 510 HU). Finally, a 7.2-mm stone was reported in the lower calyx of her right native kidney (457 HU).
Initial management consisted in hospital admission and empiric treatment with ceftriaxone. After 24 h of empiric ceftriaxone and following our COVID19 protocol, an attempt to perform primary URS of the ureteral stones was carried out. Nevertheless, once the guidewire (Sensor™ PTFE-Nitinol Guidewire with Hydrophilic Tip, Boston Scientific®) passed through the ureteral stones, purulent material came out from the ureteral meatus. Due to this finding, we decided to take an upper urinary tract urine sample for culture, place a double pig-tail stent and a bladder catheter, and stop the procedure. She stayed 9 days in-hospital for management of postobstructive polyuria and was discharged with oral antimicrobial agents (ciprofloxacin and fluconazole) and without the bladder catheter.
2.2 Surgical technique and operative results
Definitive operative treatment of urolithiasis was performed three weeks thereafter. The traditional lithotomy position, in this unprecedented patient, allowed both antegrade and retrograde access. After removing ureteral stent, semirigid ureteroscopy (8Fr, Richard Wolf, Germany®) and Holmium-YAG laser lithotripsy of the ureteral stones (120 W, Lumenis®) were carried out. Retrograde intrarenal surgery (RIRS) (Flex X2, Karl Storz®) was required to treat the stone located in the inferior calyx of the native kidney. Fragmentation of the stones was executed using these laser settings: 0.8 J and 10 Hz. Fragments were removed using a nitinol stone-retrieval frontal basket (NGage, Cook Medical®).
At the meantime, upper pole puncture of the right iliac fossa allograft was performed under ultrasound (US) guidance by a second endourologist. Endovision puncture was not attempted in order to protect the reusable flexible ureteroscope from an extreme proximal ureteral kinking loop (Fig. 3B).
Tract dilation was accomplished using one-shot dilator to establish a 21-Fr working channel over the guidewire. Mini-PNL (MIP Storz 12 Fr Nephroscope ®) was performed with Holmium-YAG laser dusting of the stones (settings: 0.5 J and 50 Hz). Stone fragments and dust were flushed out through the sheath by vortex effect. After most of the stone fragments had been removed, antegrade flexible nephroscopy (Flexible Fiber-Cystoscope 15Fr, Richard Wolf, Germany®) was conducted to search for residual stones in locations that were inaccessible with the rigid nephroscope (Fig. 3C). A 14-Fr 100% silicon nephrostomy tube and a bladder catheter were left in place. Operating time was 120 min. Estimated blood loss was approximately 50 cc.
Postoperative NCCT scan, performed 12 h postoperatively, showed neither residual fragments nor suggestive signs of immediate postoperative complications (Fig. 4). Both the nephrostomy and the bladder catheter were removed the following day. The patient remained in hospital for 3 days because of tacrolimus blood levels fluctuation. Neither early nor late onset postoperative complications occurred.
After 10 months from discharge, the patient remains stone-free. She is now under magnesium supplement and nitrofurantoin 100 mg daily prophylaxis since crystallographic analysis showed ammonium magnesium phosphate as the main component of the stones. Every six months ultrasound will be performed as follow-up.
