ENDOUROLOGY AND STONE DISEASE Flexible Ureterorenoscopy Management of Calyceal Diverticular Calculi Houmeng Yang, Xuping Yao, Chunbo Tang, Yuxi Shan, Guobin Weng* Objective: To introduce flexible ureterorenoscopy with holmium laser lithotripsy in the management of sympto- matic caliceal diverticular calculi. Materials and Methods: The records of 26 patients who underwent flexible ureterorenoscopy and lithotripsy with holmium laser to manage symptomatic caliceal diverticular calculi from January 2012 to June 2016 were retrospectively reviewed. Result: Flexible ureterorenoscopy lithotripsy was successfully placed in all 26 patients. Twenty-two cases accept- ed lithotripsy at the same time, and the success rate was 84.6%. The stone-free rate was 76.9%.The mean operative time was 48 ± 16 minutes. The mean hospital stay was 4.8 ± 1.6 days. There was no evidence of stone regrowth or recurrence at a mean follow-up of 11.5 months. Conclusion: Flexible ureterorenoscopy with holmium laser lithotripsy is safe and effective, and it can be offered as a first line therapy for symptomatic caliceal diverticular calculi. Keywords: flexible ureterorenoscopy; stone disease; caliceal diverticula; ultrasound; puncture INTRODUCTION Calyceal diverticula are rare renal anomalies in the renal parenchyma that result in nonsecreto-ry, urothelial-lined cavities that are filled with urine refluxing from an adjacent collecting system(1,2). The connection between diverticula and the collecting system may be often very small and has limited drain- age, resulting in infection and stone formation. Diver- ticula are more commonly associated with the upper and mid-calyceal systems. Although mostly asymptomatic, the indications for treatment of the calyceal diverticu- lar calculi are related to flank pain, hematuria, and recurrent infection(3). Current treatment options for the stone-bearing diverticula include extracorporeal shock wave lithotripsy (SWL)(4,5),percutaneous nephrolitho- tomy (PNL)(6,7), flexible ureterorenoscopy lithotripsy (F-URSL)(7,8), and laparoscopic approaches(9). In recent years, F-URSL has been most commonly accepted by urologists for treating the stone-bearing diverticula be- cause it iss less invasive and more efficient. MATERIALS AND METHODS The records of 26 patients who underwent flexible uret- erorenoscopy (7.5F Storz) with holmium laser lithotrip- sy to manage symptomatic calyceal diverticular calculi from January 2012 to June 2016 were retrospectively reviewed. The demographic data and medical informa- tion were obtained from their medical records and charts (Table 1). All patients were evaluated by medical histo- ry, physical examination, complete blood count, plasma urea and creatinine values, coagulation profiles, urinal- Department of Urology, Ningbo Urologic and Nephrotic Hospital, Ningbo 315000, China. *Correspondence: Department of Urology, Ningbo Urologic and Nephrotic Hospital, Qianhe Road 1, Ningbo 315000, China. Tel: +86 0574 55662999. Fax: +86 13732112880. E-mail: 511538235@qq.com. Received June 2017 & Accepted August 2017 ysis and urine cultures. Urinary infection was treated with appropriate antibiotics before the operations. Six patients received a JJ stent through cystoscopy outpa- tient two weeks before F-URSL, but the other patients refused the procedure. For 5 patients, prior treatment with SWL was unsuccessful. All patients underwent CT urography before the operation (Figure 1). F-URSL procedures were best performed under gener- al anesthesia with the patient placed in the lithotomy position. Rigid ureteroscopy (8/9.8F Wolf) was rou- tinely performed before flexible ureterorenoscopy in all patients to dilate the ureter and place a hydrophilic guidewire into the renal pelvis. Thereafter, a ureteral access sheath (12-14F Cook) was passed over the hy- drophilic guidewire as far as the ureteropelvic junction. When the access sheath could not be advanced easily, the stent was remained for 2 weeks before repeating the procedure. The flexible ureterorenoscopy was inserted through the ureteral access sheath to identify the diver- ticular neck. If necessary, it was guided by ultrasound (Figure 2)or used the Blue Spritz technique. The diver- ticular neck was gradually incised with a 200μm hol- mium laser probe and the stones were fragmented until they were deemed small enough to be passed sponta- neously (Figure 3). The small fragments were flushed out of the diverticulum or extracted using Nitinol stone baskets (1.7 F Cook). A JJ stent was placed at the end of the procedure, if possible, it was placed with the upper segment within the diverticulum or the calyces, which was removed approximately 2-4 weeks postoperatively. A KUB was obtained to observe the position of the JJ stent．Renal ultrasound was conducted to observe per Endourology and Stone Diseases 12 Vol 16 No 01 January-February 2019 13 inephric effusion or hematoma two days after surgery. A spiral CT was performed 1 month postoperatively to evaluate the status of the stones. Symptom-free status was assessed at 2 months postoperatively. Evaluation and scoring of complications were based on the modi- fied Clavien-Dindo classification(10). RESULTS The 26 patients included 11 males and 15 females, the average patients’ age was 35.2 ± 13.6 years (range, 25- 62). All patients had unilateral calyceal diverticulum calculi, with 12, 9,and 5 cases having calyceal diver- ticular calculi in the upper pole, middle pole and lower pole of the kidney respectively. Sand-like stones were observed in some calyceal diverticula. The average di- ameter of the stone was 12.3 ± 4.8mm. The presenting symptoms were flank pain (80.8%), recurrent infec- tion(34.6%) ,and hematuria(19.2%) F-URSL was successfully placed in all 26 patients. Twenty-two cases accepted lithotripsy at the same time, and the success rate was 84.6%. The stone-free rate was 76.9%. Twenty-two patients were symptom free after the operation. The mean operative time was 48 ± 16 minutes. The mean hospital stay was 4.8 ± 1.6 days. Caliceal diverticula were not found in 4 cases under flexible ureterorenoscopy. Two cases accepted mi- ni-PNL while 2 cases refused further treatment. There was no evidence of stone regrowth or recurrence at a mean follow-up of 11.5 months. Four patients suffered from complications (Clavien I-II). Three patients had postoperative fever, which was treated medically. One patient suffered from urine leak for the JJ stent bend, the perirenal effusion was absorbed 2 weeks later after repositioning of the JJ stent. DISCUSSION The pathogenesis of calculi within calyceal diverticu- la remains controversial and appears to be multifacto- rial. Although the most common hypotheses include urinary stasis and metabolic derangements, the exact mechanisms of stone development in diverticula are unknown(11,12). Most asymptomatic calyceal diverticu- lar calculi do not require treatment. The indications for treatment of the calyceal diverticular calculi are related to flank pain, hematuria, and recurrent infection. Cur- rent treatment options of the stone-bearing divertic- ula include SWL,PNL,F-URSL and laparoscopic ap- proaches. Although technically simpler and potentially safer, stone-free rates with SWL have not been com- parable with PNL and F-URSL methods(13). Batter and Dretler utilized F-URSL in 26 patients with symptomat- ic calyceal diverticula, and, 18(70%) of the cases were treated successfully(1). In recent years, more and more urologists have chosen to use F-URSL because it is less invasive and more efficient. Before performing F-UR- SL, urinary infection must be treated with appropriate antibiotics. Perioperatively, broad-spectrum antibiotic prophylaxis should be instituted. Imaging information (IVP or CTU) should be available to provide a road map Table 1. Demographic characteristics and surgical statistics Variable Value Gender(n) Male 11 Female 15 Age (years) 35.2 ± 13.6 (25-62) Stone burden(mm) 12.3 ± 4.8 (0.8-18.6) Location of diverticula (n) Upper pole 12 Middle pole 9 Lower pole 5 Surgery time (min) 48 ± 16 ± (37~84) Success rate 84.6% Symptomatic success 84.6% Stone-free rate 76.9% Hospitalization time (day) 4.8 ± 1.6 (4~9) Complications(Clavien I-II) (n) 4 Fever 3 urine leak 1 Figure 1. Left upper pole diverticulum . Figure 2. Look for the diverticular neck guided by ultrasound. Management of calyceal diverticular calculi-Yang et al. inephric effusion or hematoma two days after surgery. A spiral CT was performed 1 month postoperatively to evaluate the status of the stones. Symptom-free status was assessed at 2 months postoperatively. Evaluation and scoring of complications were based on the modi- fied Clavien-Dindo classification(10). RESULTS The 26 patients included 11 males and 15 females, the average patients’ age was 35.2 ± 13.6 years (range, 25- 62). All patients had unilateral calyceal diverticulum calculi, with 12, 9,and 5 cases having calyceal diver- ticular calculi in the upper pole, middle pole and lower pole of the kidney respectively. Sand-like stones were observed in some calyceal diverticula. The average di- ameter of the stone was 12.3 ± 4.8mm. The presenting symptoms were flank pain (80.8%), recurrent infec- tion(34.6%) ,and hematuria(19.2%) F-URSL was successfully placed in all 26 patients. Twenty-two cases accepted lithotripsy at the same time, and the success rate was 84.6%. The stone-free rate was 76.9%. Twenty-two patients were symptom free after the operation. The mean operative time was 48 ± 16 minutes. The mean hospital stay was 4.8 ± 1.6 days. Caliceal diverticula were not found in 4 cases under flexible ureterorenoscopy. Two cases accepted mi- ni-PNL while 2 cases refused further treatment. There was no evidence of stone regrowth or recurrence at a mean follow-up of 11.5 months. Four patients suffered from complications (Clavien I-II). Three patients had postoperative fever, which was treated medically. One patient suffered from urine leak for the JJ stent bend, the perirenal effusion was absorbed 2 weeks later after repositioning of the JJ stent. DISCUSSION The pathogenesis of calculi within calyceal diverticu- la remains controversial and appears to be multifacto- rial. Although the most common hypotheses include urinary stasis and metabolic derangements, the exact mechanisms of stone development in diverticula are unknown(11,12). Most asymptomatic calyceal diverticu- lar calculi do not require treatment. The indications for treatment of the calyceal diverticular calculi are related to flank pain, hematuria, and recurrent infection. Cur- rent treatment options of the stone-bearing divertic- ula include SWL,PNL,F-URSL and laparoscopic ap- proaches. Although technically simpler and potentially safer, stone-free rates with SWL have not been com- parable with PNL and F-URSL methods(13). Batter and Dretler utilized F-URSL in 26 patients with symptomat- ic calyceal diverticula, and, 18(70%) of the cases were treated successfully(1). In recent years, more and more urologists have chosen to use F-URSL because it is less invasive and more efficient. Before performing F-UR- SL, urinary infection must be treated with appropriate antibiotics. Perioperatively, broad-spectrum antibiotic prophylaxis should be instituted. Imaging information (IVP or CTU) should be available to provide a road map Table 1. Demographic characteristics and surgical statistics Variable Value Gender(n) Male 11 Female 15 Age (years) 35.2 ± 13.6 (25-62) Stone burden(mm) 12.3 ± 4.8 (0.8-18.6) Location of diverticula (n) Upper pole 12 Middle pole 9 Lower pole 5 Surgery time (min) 48 ± 16 ± (37~84) Success rate 84.6% Symptomatic success 84.6% Stone-free rate 76.9% Hospitalization time (day) 4.8 ± 1.6 (4~9) Complications(Clavien I-II) (n) 4 Fever 3 urine leak 1 Figure 1. Left upper pole diverticulum . Figure 2. Look for the diverticular neck guided by ultrasound. Management of calyceal diverticular calculi-Yang et al. Endourology and Stone Diseases 14 Vol 16 No 01 January-February 2019 15 Management of calyceal diverticular calculi-Yang et al. 1. Batter SJ, Dretler SP: Ureteroscopic approach to the symptomatic caliceal diverticulum. J Urol .1997;158:709-713, 2. Gross AJ, Fisher M. Management of stones in patients with anomalously sited kidneys. Curr Opin Urol. 2006; 16:100-105. 3. Jr M A, Pfister R C. Stone-containing pyelocaliceal diverticulum: embryogenic, anatomic, radiologic and clinical characteristics.J Urol, 1974;111:2-6. 4. Hayashi M, Kobayashi K, Tanaka G, et al. Treatment of caliceal diverticular calculi with extracorporeal shock wave lithotripsy. Nishinihon Journal of Urology, 2002;64:141- 5. 5. Psihramis KE, Dretler SP.Extracorporeal shock wave lithotripsy of caliceal diverticula calculi. J Urol .1987;138:707-711. 6. ELshal A M, Shoma A M, Shokeir A A. Percutaneous Nephrolithotomy (PCNL) for Calyceal Diverticulum: An Egyptian Experience[M]// Difficult Cases in Endourology. Springer London, 2013:161- 168. 7. Bas O, Ozyuvali E, Aydogmus Y, et al. Management of calyceal diverticular calculi: a comparison of percutaneous nephrolithotomy and flexible ureterorenoscopy[J]. Urolithiasis, 2015, 43(2):155-61. 8. Sejiny M, Alqahtani S, Elhaous A, Molimard B, Traxer O . Efficacy of flexible ureterorenoscopy with holmium laser in the management of stone-bearing caliceal diverticula.[J]. J Endourol, 2010, 24:961-7. 9. Miller SD, Ng CS, Streem SB, Gill IS. Laparoscopic management of caliceal diverticular calculi. J Urol.2002;167:1248- 1252. 10. Dindo D. Demartines N. Clavien PA. Classification of surgical complications: A new Proposal with evaluation in a cohort of 6336 patients and results of a survey. Ann Surg 2004; 240:205-213. 11. Auge BK, Maloney ME, Mathias BJ ,Pietrow PK．Preminger GM. Metabolic abnormalities associated with calyceal diverticular stones. BJU Int,2006;97:1053- 1056. 12. Matlaga BR, Miller NL, Terry C et al. The pathogenesis of calyceal diverticular calculi. Urol Res.2007; 35:35-40. 13. Jones J A, Lingeman J E, Steidle C P. The roles of extracorporeal shock wave lithotripsy and percutaneous nephrostolithotomy in the management of pyelocaliceal diverticula. J Urol, 1991, 146:724-7. 14. Long C J, Weiss D A, Kolon T F, Srinivasan AK, Shukla. Pediatric calyceal diverticulum treatment: An experience with endoscopic and laparoscopic approaches. Journal of Ped Urol, 2015,11:172.e1-172.e6. 15. Gross A J, Herrmann T R. Management of stones in calyceal diverticulum. Curr Opin Urol, 2007, 17:136-40.