Urolithiasis DOI 10.1007/s00240-014-0672-1
Original Paper
Is retrograde flexible nephrolithotripsy feasible for calyceal diverticular stone? Bulent Erkurt · Murat Can Kiremit · Bulent Altay · Vahit Guzelburc · Mustafa Soytas · Firat Erdogan · Cem Cahit Barisik · Selami Albayrak
Received: 3 March 2014 / Accepted: 2 June 2014 © Springer-Verlag Berlin Heidelberg 2014
Abstract The aim of this study is to manage the calyceal diverticular (CD) stone, several treatment options were applied but it is still a challenging condition of endourology. In this retrospective study, we aim to report the results of our patients with CD stones treated with retrograde flexible nephrolithotripsy (RFNL). A total of 47 patients (55 procedures) who underwent RFNL by a single surgeon for CD stones from January 2004 to March 2013 were evaluated retrospectively. The demographic properties and initial complaints of those patients have been recorded along with
B. Erkurt · M. C. Kiremit (*) · B. Altay · V. Guzelburc · M. Soytas · S. Albayrak Department of Urology, Medical Faculty of Medipol University, TEM Avrupa Otoyolu Goztepe Cikisi No: 1 Bagcilar, 34214 Istanbul, Turkey e-mail: [email protected] B. Erkurt e-mail: [email protected] B. Altay e-mail: [email protected] V. Guzelburc e-mail: [email protected] M. Soytas e-mail: [email protected] S. Albayrak e-mail: [email protected] F. Erdogan Department of Pediatrics, Medical Faculty of Medipol University, Istanbul, Turkey e-mail: [email protected] C. C. Barisik Department of Radiology, Medical Faculty of Medipol University, Istanbul, Turkey e-mail: [email protected]
their comorbidities and previous history of stone management. Moreover, the size and number of the stones, the duration of the surgery, fluoroscopy time, stone-free rate (SFR) and postoperative complications of the patients have been evaluated. The mean age was 41.8 years (range 16– 71). Of the study population, 31 (65.9 %) were male. Mean stone size was 21.1 (7–52) mm whereas in 3 (6.4 %) of the cases the stones could not be reached. Mean duration of the surgery was 92.8 (57–163) min whereas mean fluoroscopy time was 35.9 (14–103) s. After 3 months of followup period, the SFR was 85.1 %. No major complications occurred. RFNL with holmium laser and nitinol basket catheter application is a feasible and successful procedure in the management of CD stones. With its high success rates, low incidence of complications and minimal morbidity when compared with other treatment options, RFNL has the potential of becoming the preferred treatment option in the minimally invasive management of patients with CD stones. Keywords Calyceal diverticulum · Kidney · Stone · Ureterorenoscopy
Introduction Calyceal diverticulum (CD) is a congenital or acquired abnormality characterized by a urine-containing cystic cavity within the renal parenchyma lined by transitional epithelium and surrounding the muscularis mucosae [1]. Although its incidence on radiological work-up [intravenous urography (IVU)] is estimated to be 2.1–4.5 per 1,000 evaluations, the true incidence of this anomaly is thought to be much higher [1–3]. The pathology is unilateral in the majority of the cases (97 %), and the upper pole of the
13
Urolithiasis
kidney is the most commonly involved part (70 %) [4]. While varying in size, the vast majority of these diverticula are less than 1 cm in diameter, and they tend to develop more frequently from the posterior rather than anterior aspect of the renal collecting system [5]. Published data have clearly shown that although the clinical course of CD is often asymptomatic, stone(s) [6] could be detected in 9.5–50 % of the involved cases due to a combination of metabolic abnormalities with evident urinary stasis [7–9]. At present, there are no well-established standards in the treatment of these cases, and percutaneous nephrolithotomy (PNL) is commonly performed for a pathology as well as to achieve a stone-free status [10]. However, with recent technological advancements and the experience gained in ureteroscopy, retrograde flexible nephrolithotripsy (RFNL), with its minimally invasive nature, is increasingly being utilized for the endoscopic disintegration as well as removal of kidney stones [11]. Although this option has proven itself in the practical and safe management of calculi located in different parts of the kidney, there are only limited data in the literature regarding its efficacy and safety in the removal of stones located in a CD [12]. In the present study, we aimed to evaluate the efficacy of RFNL in the management of stones located in a CD.
Patients and methods Between January 1998 and March 2013, 1,810 cases were treated for kidney stones with RFNL in our institution. Of these, a total of 47 cases (2.5 %) managed with RFNL for stone(s) in a CD were included in the study. Data related to patient history, other demographic characteristics, comorbidities, as well as previous history of stone management were all well recorded. Moreover, in addition to the stone (size and number of stones) and procedure-related factors (duration of the surgery, fluoroscopy time), final outcome of the procedures (stone-free rate (SFR) and postoperative surgical complications according to Clavien classification) [13] were well evaluated. Preoperative diagnostic procedures included urine analysis, urine culture antibiogram test and routine blood biochemistry tests. In case of a urinary tract infection, appropriate antibiotic treatment was applied before the procedure. Additionally, radiologic evaluation of the cases was performed using either IVU or computed tomography (CT) depending on the clinical features of the case on an individualized basis. All RFNL procedures were performed by a single urologist (BE). Between 2004 and 2013, five different flexible ureterorenoscopes (Flex-X, Flex-X2 and Flex-XC, Karl Storz, Tuttlingen, Germany; and URF-P3 and URF-P5,
13
Olympus Surgical, Orangeburg, NY) were used for the disintegration and/or removal of CD stones. Patients were placed in a modified lithotomy position under general anesthesia. After draping, an 8 F rigid ureteroscope was used to inspect the urethra and bladder. After visualization of the orifice, a 0.038 inch 145 cm safety guide wire was introduced gently into the ureter up to the involved kidney. Then, depending on the type of ureteroscope, an appropriate-sized access sheath (9.5–11.5 F and 12–14 F Flexor, Cook Medical Inc., Bloomington, IN, USA and 11–13 F Navigator, Boston Scientific, Natick, MA, USA) was placed up to the proximal ureteral portion under fluoroscopic guidance. If this attempt was unsuccessful, a diagnostic ureteroscopy was performed in order to dilate the ureter and rule out a possible ureteral pathology (e.g., ureteral stricture or stone). If the access sheath could not be placed despite ureteroscopic examination, an additional second 0.025 inch 150 cm safety guide wire was inserted to straighten the ureter and ease the passage of a flexible ureterorenoscope over the guide wire. Once the renal cavity was reached by the ureterorenoscope, all major and minor calices were inspected to identify the orifice of the diverticular neck (Fig. 1). In case of any difficulty in identifying the orifice of the CD neck, a contrast medium was injected under biplanar fluoroscopic guidance. Irrespective of the type of CD, holmium laser fibers (StoneLight, AMS, MN, USA and Sphinx, LISA, Katlenburg-Lindau, Germany) of varying size (150, 200 or 272 µm) were used to incise the narrow diverticular neck and/or to ablate the tissue between the CD and the collecting system, with the settings of 10 Hz and 0.6 J (Fig. 2), to remove all stones and prevent the recurrence of diverticular neck stenosis, if needed. Following the opening of the diverticular neck after laser incision, the stones were either evacuated using the manual pump to flush them out of the diverticulum or fragmented into small pieces for extraction with a basket catheter. Double-J stents were placed in all patients, and a special effort was given to insert them into the diverticulum, if possible. All patients were discharged within 24 h if there were no major complications. The double-J stents were removed in 2–6 weeks after the operation. The patients were re-evaluated 3 months later with urine analysis, urine culture sensitivity tests, serum biochemistry (creatinine, hemoglobin levels) and radio-sonographic evaluation [kidney–ureter– bladder ultrasonography (KUB-USG), IVU or non-contrast CT].
Results A total of 47 patients with CD stones were treated with RFNL in our institution. The mean age of the patients were
Urolithiasis Table 1 Patient characteristics
Fig. 1 Identification of calyceal diverticulum under direct vision
Age (years) Gender Female Male BMI Clinical presentation Lomber pain Urinary tract infection Hematuria Stone size (mm) Stone number Single Multiple Side Left Right
Fig. 2 Incision of narrowing calyceal diverticular neck by holmium laser
41.8 years (range 16–71), and 31 of them (65.9 %) were male (Table 1). Although chronic lumbar pain was the most common symptom upon hospitalization, urinary tract infection and hematuria were the other symptoms diagnosed in 9 (19.1 %) and 2 (4.3 %) patients, respectively. The preoperative above-mentioned radiological evaluation was successful in detecting all calculi located in the kidney; however, in 8 (17 %) patients, the stones in CD could only be diagnosed by direct vision or retrograde pyelography during the procedure. While previous renal stone management history revealed shock wave lithotripsy (SWL) in 32 (68 %) patients, PNL and open stone surgery were performed in 4 (8.6 %) and 2 (4.3 %) patients, respectively. In the remaining 9 patients (19.1 %), however, there was no previous surgery history. The stones were multiple in 36 (76.5 %) patients, and the majority of the calculi were located in the right kidney
41.8 ± 12.78 (16–71) 16 (34.1 %) 31 (65.9 %) 27.8 ± 4.55 (18–37) 47 (100 %) 9 (19.1 %) 2 (4.3 %) 21.1 ± 8.47 (7–52) 11 (23.5 %) 36 (76.5 %) 21 (44.7 %) 26 (55.3 %)
(26/47, 55.3 %). None of the patients had bilateral CD stones. The mean size of the stones was 21.1 mm (range 7–52) measured at the longest diameter. A total of 55 procedures were performed in 47 patients, and the results are summarized in Table 2. The procedure was unsuccessful in 3 (6.4 %) cases in which stones could not be reached by retrograde approach due to undetectable (either under direct vision or biplanar fluoroscopy) ostium of the CD. A mini PNL procedure to remove the stones was planned for these patients, but they were all lost to followup. The mean duration of the surgery was 92.8 min (range 57–63), with a mean fluoroscopy time of 35.9 s (range 14–103). Following the procedures, the patients were discharged uneventfully after a mean hospitalization of 1.3 days (range 1–6). No major complication was noted, and no blood transfusion was necessary in any of the patients. Minor complications requiring no intervention occurred in 14.8 % of the procedures. Acute pyelonephritis and cystitis, which were treated with appropriate antibiotics, were seen in 1 (2.1 %) and 4 (8.5 %) patients, respectively. Persistent hematuria resolving spontaneously after the removal of the double-J stent occurred in 1 (2.1 %) patient. Additionally, urinoma formation was detected in 1 (2.1 %) patient, and healed spontaneously with conservative management. After 9 months of follow-up, the SFR was 85.1 %, while the remainder of the patients had residual stones in the CD.
Discussion Calyceal diverticula (CD) are generally asymptomatic and detected incidentally during routine imaging studies [5].
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Urolithiasis Table 2 Outcomes of surgery Number of patients Diverticulotomy Diverticulotomy + stone fragmentation by Holmium laser and/or basket catheter Unsuccessful procedure Number of procedure Single session RFNL 2nd session RFNL 3rd session RFNL Stone-free rate Duration of operation (min) Duration of fluoroscopy (sec) Duration of hospitalisation (day) Access sheath Postoperative double-J stent (day) Complication rate Location Upper Mid Low Type of previous management
47 8 (18.2 %) 36 (81.2 %) 3 (6.4 %) 37 (84.1 %) 6 (13.7 %) 1 (2.2 %) 40 (85.1 %) 92.8 ± 22.72 (57–163) 35.9 ± 14.28 (14–103) 1.3 ± 0.83 (1–6) 45 (95.7 %) 19.6 ± 6.58 (14–45) 7 (14.8 %) 31 (65.9 %) 9 (19.2 %) 7 (14.9 %)
SWL PNL Open surgery
32 (68 %) 4 (8.6 %) 2 (4.3 %)
Primary
9 (19.1 %)
However, urinary stasis and increased pressure in the diverticulum may result in an increased risk of infection or stone formation, along with the compression and/or progressive damage to the adjacent renal parenchyma [2]. Patients with these CD-induced renal pathologic alterations may refer with complaints of hematuria, lumbar–abdominal pain, recurrent urinary tract infections, and arterial hypertension [13]. Due to the rare incidence of this pathology in clinical practice, specific management principles have not been established to date. With respect to the surgical management of stones in CD, a number of approaches have been performed; namely, open surgery, SWL, PNL, RFNL, and laparoscopic surgery, with varying success as well as recurrence rates [14]. Prior to the development of minimally invasive technologies, open nephrolithotomy and partial nephrectomy were among the treatment alternatives for stones in CD. Although SWL is considered as the first choice in the minimally invasive treatment of these calculi [6, 15], the reported SFRs are relatively low, and most importantly, as a non-surgical alternative, this approach does not widen the diverticular neck to enable spontaneous discharge of stone fragments after their disintegration. In their original study, Turna et al. [16] reported 21 % stone-free and 61 % symptom-free status after SWL.
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However, 12 of these 38 patients (31.5 %) required a further intervention (PNL and RFNL to achieve a stone-free status. Studies have clearly demonstrated that although favorable SFR results [5, 16, 17] could be obtained in such stones with PNL, higher complication rates could be anticipated [5]. As the majority of these stones are usually located in the upper pole of the kidney, a direct access to the diverticulum supracostally may cause certain major pulmonary complications. Mendez-Probst et al. [12] reported that 27.6 % of the 76 patients with CD stones undergoing PNL developed pulmonary complications such as pleural effusion, pneumothorax, atelectasis, or pneumonia, and the overall minor (Clavien I and II) and major (Clavien IIIa) complication rates were 30.2 and 9 %, respectively. Additionally, anterior location of a CD, in which more renal parenchyma may be affected during such an access, is another drawback for PNL [18]. Last but not least, the mean hospital stay after PNL in patients with CD stones has been reported to range between 2.8 and 5 days [5, 12]. Laparoscopic removal of CD stone(s) has been reported as another minimally invasive option to PNL, RFNL and SWL for achieving higher success rates in terms of stonefree status [19]. However, over the past 20 years, only limited data have been reported in the English literature as a case series, including the results of 39 patients undergoing this procedure for the removal of CD stones [19]. Laparoscopic management of CD stones is an invasive alternative when compared with the other endoscopic modalities [19]. In addition to the limited experience, the relatively deep location of the diverticulum surrounded by a thick layer of overlying parenchyma constitutes the main technical difficulty of this approach, even in experienced hands. Thus, an anteriorly located thin-walled diverticulum is the best candidate for laparoscopic approach [18]. The ongoing developments in instrument technology coupled with the experience in ureteroscopic procedures both in adults and children have made flexible retrograde ureteroscopic approach a valuable treatment option in the diagnosis as well as management of several upper urinary tract pathologies. Today, this approach is commonly applied in the minimally invasive treatment of renal stones up to 20 mm, with highly successful outcomes [20]. As a result of the accumulated experience, treatment of CD stones with this technique was first described by Fuchs et al. [21], in which they first dilated the narrow diverticular neck and removed the stone(s) directly via endoscopy or SWL applied during the same session. Access to the diverticulum could be accomplished in all patients, and the SFR was 73.3 % (11/15). Recently, by performing the same technique in CD stones, Sejiny and associates [22] reported a SFR of 55.3 %, where 90 % of the treated cases became symptom- free.
Urolithiasis
Although other published studies and our data clearly show that RFNL can result in a SFR similar to that achieved with PNL, with meaningfully less morbidity, Auge and coworkers [5] reported lower SFR after RFNL when compared with PNL (19 vs 78 %). In the same study, the authors stated that ureteroscopic access to lower pole infundibula is difficult due to the limited deflection capacity of the ureteroscope. Sejiny et al. [22] stated that the CD localization may not be a critical factor affecting the final outcome of this procedure. However, advances in flexible ureterorenoscope technology (active deflectable) have enabled endourologists to reach the diverticula located in the lower pole. As surgeons gain experience with RFNL, success rates with this procedure in patients with CD stones may improve. The major limitations of our study were the retrospective analysis of our data and the absence of long-term follow-up. Moreover, the lack of patients with CD stones undergoing other treatment alternatives (i.e., PNL, SWL, laparoscopy) could be considered another limitation, and their inclusion might have increased the scientific quality of our paper. However, taking into account the rare occurrence of CD and also the limited published data concerning the efficacy of retrograde flexible ureteroscopic approach in the management of stones formed in these diverticula, we can suggest that our present short-term data will contribute to the existing information concerning the place as well as the efficacy of RFN in these cases.
Conclusion In light of the previously published and our present data, we suggest that RFNLwith holmium laser and nitinol basket catheter application is a feasible and successful procedure in the management of CD stones. With its high success rates, low incidence of complications and minimal morbidity when compared with other treatment options, RFNL has the potential of becoming the preferred treatment option in the minimally invasive management of patients with CD stones. Acknowledgments We would like to thank to Ege Can Serefoglu MD, and Abdulkadir Tepeler MD, for their contributions to this study. Conflict of interest No conflict of interests exists.
References
3. Ellis JH, Patterson SK, Sonda LP, Platt JF, Sheffner SE, Woolsey EJ (1991) Stones and infection in renal caliceal diverticula: treatment with percutaneous procedures. Am J Roentgenol 156(5):995–1000 4. Timmons JW Jr, Malek RS, Hattery RR, Deweerd JH (1975) Caliceal diverticulum. J Urol 114(1):6–9 5. Auge BK, Munver R, Kourambas J, Newman GE, Wu NZ, Preminger GM (2002) Neoinfundibulotomy for the management of symptomatic caliceal diverticula. J Urol 167(4):1616–1620 6. Jones JA, Lingeman JE, Steidle CP (1991) The roles of extracorporeal shock wave lithotripsy and percutaneous nephrostolithotomy in the management of pyelocaliceal diverticula. J Urol 146(3):724–727 7. Matlaga BR, Miller NL, Terry C, Kim SC, Kuo RL, Coe FL et al (2007) The pathogenesis of calyceal diverticular calculi. Urol Res 35(1):35–40 8. Hsu TH, Streem SB (1998) Metabolic abnormalities in patients with caliceal diverticular calculi. J Urol 160(5):1640–1642 9. Liatsikos EN, Bernardo NO, Dinlenc CZ, Kapoor R, Smith AD (2000) Caliceal diverticular calculi: is there a role for metabolic evaluation? J Urol 164(1):18–20 10. Monga M, Smith R, Ferral H, Thomas R (2000) Percutaneous ablation of caliceal diverticulum: long-term followup. J Urol 163(1):28–32 11. Grasso M, Loisides P, Beaghler M, Bagley D (1995) The case for primary endoscopic management of upper urinary tract calculi: I. A critical review of 121 extracorporeal shock wave lithotripsy failures. Urology 45(3):363–371 12. Mendez-Probst CE, Fuller A, Nott L, Denstedt JD, Razvi H (2011) Percutaneous nephrolithotomy of caliceal diverticular calculi: a single center experience. J Endourol 25(11):1741–1745 13. Dindo D, Demartines N, Clavien PA (2004) Classification of surgical complications: a new proposal with evaluation in a cohort of 6336 patients and results of a survey. Ann Surg 240:205–213 14. Canales B, Monga M (2003) Surgical management of the calyceal diverticulum. Curr Opin Urol 13(3):255–260 15. Psihramis KE, Dretler SP (1987) Extracorporeal shock wave lithotripsy of caliceal diverticula calculi. J Urol 138(4):707–711 16. Turna B, Raza A, Moussa S, Smith G, Tolley DA (2007) Management of calyceal diverticular stones with extracorporeal shock wave lithotripsy and percutaneous nephrolithotomy: long-term outcome. BJU Int. 100(1):151–156 17. Kim SC, Kuo RL, Tinmouth WW, Watkins S, Lingeman JE (2005) Percutaneous nephrolithotomy for caliceal diverticular calculi: a novel single stage approach. J Urol 173(4):1194–1198 18. Gross AJ, Herrmann TR (2007) Management of stones in calyceal diverticulum. Curr Opin Urol 17(2):136–140 19. Basiri A, Radfar MH, Lashay A (2013) Laparoscopic management of caliceal diverticulum: our experience, literature review, and pooling analysis. J Endourol 27(5):583–586 20. Turk C, Knoll T, Petrik A, Sarica K, Skolarikos A, Straub M et al (2013) Members of the European Association of Urology (EAU) Guidelines Office. Guidelines on urolithiasis. In: EAU guidelines, edition presented at the 28th EAU Annual Congress, Milan 21. Fuchs GJ, David R (1989) Flexible ureterorenoscopy, dilatation of narrow caliceal neck, and ESWL: a new, minimally invasive approach to stones in caliceal diverticula. J Endourol 3:255–263 22. Sejiny M, Al-Qahtani S, Elhaous A, Molimard B, Traxer O (2010) Efficacy of flexible ureterorenoscopy with holmium laser in the management of stone-bearing caliceal diverticula. J Endourol 24(6):961–967
1. Wulfsohn MA (1980) Pyelocaliceal diverticula. J Urol 123(1):1–8 2. Middleton AW Jr, Pfister RC (1974) Stone-containing pyelocaliceal diverticulum: embryogenic, anatomic, radiologic and clinical characteristics. J Urol 111(1):2–6
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Original Paper
Is retrograde flexible nephrolithotripsy feasible for calyceal diverticular stone? Bulent Erkurt · Murat Can Kiremit · Bulent Altay · Vahit Guzelburc · Mustafa Soytas · Firat Erdogan · Cem Cahit Barisik · Selami Albayrak
Received: 3 March 2014 / Accepted: 2 June 2014 © Springer-Verlag Berlin Heidelberg 2014
Abstract The aim of this study is to manage the calyceal diverticular (CD) stone, several treatment options were applied but it is still a challenging condition of endourology. In this retrospective study, we aim to report the results of our patients with CD stones treated with retrograde flexible nephrolithotripsy (RFNL). A total of 47 patients (55 procedures) who underwent RFNL by a single surgeon for CD stones from January 2004 to March 2013 were evaluated retrospectively. The demographic properties and initial complaints of those patients have been recorded along with
B. Erkurt · M. C. Kiremit (*) · B. Altay · V. Guzelburc · M. Soytas · S. Albayrak Department of Urology, Medical Faculty of Medipol University, TEM Avrupa Otoyolu Goztepe Cikisi No: 1 Bagcilar, 34214 Istanbul, Turkey e-mail: [email protected] B. Erkurt e-mail: [email protected] B. Altay e-mail: [email protected] V. Guzelburc e-mail: [email protected] M. Soytas e-mail: [email protected] S. Albayrak e-mail: [email protected] F. Erdogan Department of Pediatrics, Medical Faculty of Medipol University, Istanbul, Turkey e-mail: [email protected] C. C. Barisik Department of Radiology, Medical Faculty of Medipol University, Istanbul, Turkey e-mail: [email protected]
their comorbidities and previous history of stone management. Moreover, the size and number of the stones, the duration of the surgery, fluoroscopy time, stone-free rate (SFR) and postoperative complications of the patients have been evaluated. The mean age was 41.8 years (range 16– 71). Of the study population, 31 (65.9 %) were male. Mean stone size was 21.1 (7–52) mm whereas in 3 (6.4 %) of the cases the stones could not be reached. Mean duration of the surgery was 92.8 (57–163) min whereas mean fluoroscopy time was 35.9 (14–103) s. After 3 months of followup period, the SFR was 85.1 %. No major complications occurred. RFNL with holmium laser and nitinol basket catheter application is a feasible and successful procedure in the management of CD stones. With its high success rates, low incidence of complications and minimal morbidity when compared with other treatment options, RFNL has the potential of becoming the preferred treatment option in the minimally invasive management of patients with CD stones. Keywords Calyceal diverticulum · Kidney · Stone · Ureterorenoscopy
Introduction Calyceal diverticulum (CD) is a congenital or acquired abnormality characterized by a urine-containing cystic cavity within the renal parenchyma lined by transitional epithelium and surrounding the muscularis mucosae [1]. Although its incidence on radiological work-up [intravenous urography (IVU)] is estimated to be 2.1–4.5 per 1,000 evaluations, the true incidence of this anomaly is thought to be much higher [1–3]. The pathology is unilateral in the majority of the cases (97 %), and the upper pole of the
13
Urolithiasis
kidney is the most commonly involved part (70 %) [4]. While varying in size, the vast majority of these diverticula are less than 1 cm in diameter, and they tend to develop more frequently from the posterior rather than anterior aspect of the renal collecting system [5]. Published data have clearly shown that although the clinical course of CD is often asymptomatic, stone(s) [6] could be detected in 9.5–50 % of the involved cases due to a combination of metabolic abnormalities with evident urinary stasis [7–9]. At present, there are no well-established standards in the treatment of these cases, and percutaneous nephrolithotomy (PNL) is commonly performed for a pathology as well as to achieve a stone-free status [10]. However, with recent technological advancements and the experience gained in ureteroscopy, retrograde flexible nephrolithotripsy (RFNL), with its minimally invasive nature, is increasingly being utilized for the endoscopic disintegration as well as removal of kidney stones [11]. Although this option has proven itself in the practical and safe management of calculi located in different parts of the kidney, there are only limited data in the literature regarding its efficacy and safety in the removal of stones located in a CD [12]. In the present study, we aimed to evaluate the efficacy of RFNL in the management of stones located in a CD.
Patients and methods Between January 1998 and March 2013, 1,810 cases were treated for kidney stones with RFNL in our institution. Of these, a total of 47 cases (2.5 %) managed with RFNL for stone(s) in a CD were included in the study. Data related to patient history, other demographic characteristics, comorbidities, as well as previous history of stone management were all well recorded. Moreover, in addition to the stone (size and number of stones) and procedure-related factors (duration of the surgery, fluoroscopy time), final outcome of the procedures (stone-free rate (SFR) and postoperative surgical complications according to Clavien classification) [13] were well evaluated. Preoperative diagnostic procedures included urine analysis, urine culture antibiogram test and routine blood biochemistry tests. In case of a urinary tract infection, appropriate antibiotic treatment was applied before the procedure. Additionally, radiologic evaluation of the cases was performed using either IVU or computed tomography (CT) depending on the clinical features of the case on an individualized basis. All RFNL procedures were performed by a single urologist (BE). Between 2004 and 2013, five different flexible ureterorenoscopes (Flex-X, Flex-X2 and Flex-XC, Karl Storz, Tuttlingen, Germany; and URF-P3 and URF-P5,
13
Olympus Surgical, Orangeburg, NY) were used for the disintegration and/or removal of CD stones. Patients were placed in a modified lithotomy position under general anesthesia. After draping, an 8 F rigid ureteroscope was used to inspect the urethra and bladder. After visualization of the orifice, a 0.038 inch 145 cm safety guide wire was introduced gently into the ureter up to the involved kidney. Then, depending on the type of ureteroscope, an appropriate-sized access sheath (9.5–11.5 F and 12–14 F Flexor, Cook Medical Inc., Bloomington, IN, USA and 11–13 F Navigator, Boston Scientific, Natick, MA, USA) was placed up to the proximal ureteral portion under fluoroscopic guidance. If this attempt was unsuccessful, a diagnostic ureteroscopy was performed in order to dilate the ureter and rule out a possible ureteral pathology (e.g., ureteral stricture or stone). If the access sheath could not be placed despite ureteroscopic examination, an additional second 0.025 inch 150 cm safety guide wire was inserted to straighten the ureter and ease the passage of a flexible ureterorenoscope over the guide wire. Once the renal cavity was reached by the ureterorenoscope, all major and minor calices were inspected to identify the orifice of the diverticular neck (Fig. 1). In case of any difficulty in identifying the orifice of the CD neck, a contrast medium was injected under biplanar fluoroscopic guidance. Irrespective of the type of CD, holmium laser fibers (StoneLight, AMS, MN, USA and Sphinx, LISA, Katlenburg-Lindau, Germany) of varying size (150, 200 or 272 µm) were used to incise the narrow diverticular neck and/or to ablate the tissue between the CD and the collecting system, with the settings of 10 Hz and 0.6 J (Fig. 2), to remove all stones and prevent the recurrence of diverticular neck stenosis, if needed. Following the opening of the diverticular neck after laser incision, the stones were either evacuated using the manual pump to flush them out of the diverticulum or fragmented into small pieces for extraction with a basket catheter. Double-J stents were placed in all patients, and a special effort was given to insert them into the diverticulum, if possible. All patients were discharged within 24 h if there were no major complications. The double-J stents were removed in 2–6 weeks after the operation. The patients were re-evaluated 3 months later with urine analysis, urine culture sensitivity tests, serum biochemistry (creatinine, hemoglobin levels) and radio-sonographic evaluation [kidney–ureter– bladder ultrasonography (KUB-USG), IVU or non-contrast CT].
Results A total of 47 patients with CD stones were treated with RFNL in our institution. The mean age of the patients were
Urolithiasis Table 1 Patient characteristics
Fig. 1 Identification of calyceal diverticulum under direct vision
Age (years) Gender Female Male BMI Clinical presentation Lomber pain Urinary tract infection Hematuria Stone size (mm) Stone number Single Multiple Side Left Right
Fig. 2 Incision of narrowing calyceal diverticular neck by holmium laser
41.8 years (range 16–71), and 31 of them (65.9 %) were male (Table 1). Although chronic lumbar pain was the most common symptom upon hospitalization, urinary tract infection and hematuria were the other symptoms diagnosed in 9 (19.1 %) and 2 (4.3 %) patients, respectively. The preoperative above-mentioned radiological evaluation was successful in detecting all calculi located in the kidney; however, in 8 (17 %) patients, the stones in CD could only be diagnosed by direct vision or retrograde pyelography during the procedure. While previous renal stone management history revealed shock wave lithotripsy (SWL) in 32 (68 %) patients, PNL and open stone surgery were performed in 4 (8.6 %) and 2 (4.3 %) patients, respectively. In the remaining 9 patients (19.1 %), however, there was no previous surgery history. The stones were multiple in 36 (76.5 %) patients, and the majority of the calculi were located in the right kidney
41.8 ± 12.78 (16–71) 16 (34.1 %) 31 (65.9 %) 27.8 ± 4.55 (18–37) 47 (100 %) 9 (19.1 %) 2 (4.3 %) 21.1 ± 8.47 (7–52) 11 (23.5 %) 36 (76.5 %) 21 (44.7 %) 26 (55.3 %)
(26/47, 55.3 %). None of the patients had bilateral CD stones. The mean size of the stones was 21.1 mm (range 7–52) measured at the longest diameter. A total of 55 procedures were performed in 47 patients, and the results are summarized in Table 2. The procedure was unsuccessful in 3 (6.4 %) cases in which stones could not be reached by retrograde approach due to undetectable (either under direct vision or biplanar fluoroscopy) ostium of the CD. A mini PNL procedure to remove the stones was planned for these patients, but they were all lost to followup. The mean duration of the surgery was 92.8 min (range 57–63), with a mean fluoroscopy time of 35.9 s (range 14–103). Following the procedures, the patients were discharged uneventfully after a mean hospitalization of 1.3 days (range 1–6). No major complication was noted, and no blood transfusion was necessary in any of the patients. Minor complications requiring no intervention occurred in 14.8 % of the procedures. Acute pyelonephritis and cystitis, which were treated with appropriate antibiotics, were seen in 1 (2.1 %) and 4 (8.5 %) patients, respectively. Persistent hematuria resolving spontaneously after the removal of the double-J stent occurred in 1 (2.1 %) patient. Additionally, urinoma formation was detected in 1 (2.1 %) patient, and healed spontaneously with conservative management. After 9 months of follow-up, the SFR was 85.1 %, while the remainder of the patients had residual stones in the CD.
Discussion Calyceal diverticula (CD) are generally asymptomatic and detected incidentally during routine imaging studies [5].
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Urolithiasis Table 2 Outcomes of surgery Number of patients Diverticulotomy Diverticulotomy + stone fragmentation by Holmium laser and/or basket catheter Unsuccessful procedure Number of procedure Single session RFNL 2nd session RFNL 3rd session RFNL Stone-free rate Duration of operation (min) Duration of fluoroscopy (sec) Duration of hospitalisation (day) Access sheath Postoperative double-J stent (day) Complication rate Location Upper Mid Low Type of previous management
47 8 (18.2 %) 36 (81.2 %) 3 (6.4 %) 37 (84.1 %) 6 (13.7 %) 1 (2.2 %) 40 (85.1 %) 92.8 ± 22.72 (57–163) 35.9 ± 14.28 (14–103) 1.3 ± 0.83 (1–6) 45 (95.7 %) 19.6 ± 6.58 (14–45) 7 (14.8 %) 31 (65.9 %) 9 (19.2 %) 7 (14.9 %)
SWL PNL Open surgery
32 (68 %) 4 (8.6 %) 2 (4.3 %)
Primary
9 (19.1 %)
However, urinary stasis and increased pressure in the diverticulum may result in an increased risk of infection or stone formation, along with the compression and/or progressive damage to the adjacent renal parenchyma [2]. Patients with these CD-induced renal pathologic alterations may refer with complaints of hematuria, lumbar–abdominal pain, recurrent urinary tract infections, and arterial hypertension [13]. Due to the rare incidence of this pathology in clinical practice, specific management principles have not been established to date. With respect to the surgical management of stones in CD, a number of approaches have been performed; namely, open surgery, SWL, PNL, RFNL, and laparoscopic surgery, with varying success as well as recurrence rates [14]. Prior to the development of minimally invasive technologies, open nephrolithotomy and partial nephrectomy were among the treatment alternatives for stones in CD. Although SWL is considered as the first choice in the minimally invasive treatment of these calculi [6, 15], the reported SFRs are relatively low, and most importantly, as a non-surgical alternative, this approach does not widen the diverticular neck to enable spontaneous discharge of stone fragments after their disintegration. In their original study, Turna et al. [16] reported 21 % stone-free and 61 % symptom-free status after SWL.
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However, 12 of these 38 patients (31.5 %) required a further intervention (PNL and RFNL to achieve a stone-free status. Studies have clearly demonstrated that although favorable SFR results [5, 16, 17] could be obtained in such stones with PNL, higher complication rates could be anticipated [5]. As the majority of these stones are usually located in the upper pole of the kidney, a direct access to the diverticulum supracostally may cause certain major pulmonary complications. Mendez-Probst et al. [12] reported that 27.6 % of the 76 patients with CD stones undergoing PNL developed pulmonary complications such as pleural effusion, pneumothorax, atelectasis, or pneumonia, and the overall minor (Clavien I and II) and major (Clavien IIIa) complication rates were 30.2 and 9 %, respectively. Additionally, anterior location of a CD, in which more renal parenchyma may be affected during such an access, is another drawback for PNL [18]. Last but not least, the mean hospital stay after PNL in patients with CD stones has been reported to range between 2.8 and 5 days [5, 12]. Laparoscopic removal of CD stone(s) has been reported as another minimally invasive option to PNL, RFNL and SWL for achieving higher success rates in terms of stonefree status [19]. However, over the past 20 years, only limited data have been reported in the English literature as a case series, including the results of 39 patients undergoing this procedure for the removal of CD stones [19]. Laparoscopic management of CD stones is an invasive alternative when compared with the other endoscopic modalities [19]. In addition to the limited experience, the relatively deep location of the diverticulum surrounded by a thick layer of overlying parenchyma constitutes the main technical difficulty of this approach, even in experienced hands. Thus, an anteriorly located thin-walled diverticulum is the best candidate for laparoscopic approach [18]. The ongoing developments in instrument technology coupled with the experience in ureteroscopic procedures both in adults and children have made flexible retrograde ureteroscopic approach a valuable treatment option in the diagnosis as well as management of several upper urinary tract pathologies. Today, this approach is commonly applied in the minimally invasive treatment of renal stones up to 20 mm, with highly successful outcomes [20]. As a result of the accumulated experience, treatment of CD stones with this technique was first described by Fuchs et al. [21], in which they first dilated the narrow diverticular neck and removed the stone(s) directly via endoscopy or SWL applied during the same session. Access to the diverticulum could be accomplished in all patients, and the SFR was 73.3 % (11/15). Recently, by performing the same technique in CD stones, Sejiny and associates [22] reported a SFR of 55.3 %, where 90 % of the treated cases became symptom- free.
Urolithiasis
Although other published studies and our data clearly show that RFNL can result in a SFR similar to that achieved with PNL, with meaningfully less morbidity, Auge and coworkers [5] reported lower SFR after RFNL when compared with PNL (19 vs 78 %). In the same study, the authors stated that ureteroscopic access to lower pole infundibula is difficult due to the limited deflection capacity of the ureteroscope. Sejiny et al. [22] stated that the CD localization may not be a critical factor affecting the final outcome of this procedure. However, advances in flexible ureterorenoscope technology (active deflectable) have enabled endourologists to reach the diverticula located in the lower pole. As surgeons gain experience with RFNL, success rates with this procedure in patients with CD stones may improve. The major limitations of our study were the retrospective analysis of our data and the absence of long-term follow-up. Moreover, the lack of patients with CD stones undergoing other treatment alternatives (i.e., PNL, SWL, laparoscopy) could be considered another limitation, and their inclusion might have increased the scientific quality of our paper. However, taking into account the rare occurrence of CD and also the limited published data concerning the efficacy of retrograde flexible ureteroscopic approach in the management of stones formed in these diverticula, we can suggest that our present short-term data will contribute to the existing information concerning the place as well as the efficacy of RFN in these cases.
Conclusion In light of the previously published and our present data, we suggest that RFNLwith holmium laser and nitinol basket catheter application is a feasible and successful procedure in the management of CD stones. With its high success rates, low incidence of complications and minimal morbidity when compared with other treatment options, RFNL has the potential of becoming the preferred treatment option in the minimally invasive management of patients with CD stones. Acknowledgments We would like to thank to Ege Can Serefoglu MD, and Abdulkadir Tepeler MD, for their contributions to this study. Conflict of interest No conflict of interests exists.
References
3. Ellis JH, Patterson SK, Sonda LP, Platt JF, Sheffner SE, Woolsey EJ (1991) Stones and infection in renal caliceal diverticula: treatment with percutaneous procedures. Am J Roentgenol 156(5):995–1000 4. Timmons JW Jr, Malek RS, Hattery RR, Deweerd JH (1975) Caliceal diverticulum. J Urol 114(1):6–9 5. Auge BK, Munver R, Kourambas J, Newman GE, Wu NZ, Preminger GM (2002) Neoinfundibulotomy for the management of symptomatic caliceal diverticula. J Urol 167(4):1616–1620 6. Jones JA, Lingeman JE, Steidle CP (1991) The roles of extracorporeal shock wave lithotripsy and percutaneous nephrostolithotomy in the management of pyelocaliceal diverticula. J Urol 146(3):724–727 7. Matlaga BR, Miller NL, Terry C, Kim SC, Kuo RL, Coe FL et al (2007) The pathogenesis of calyceal diverticular calculi. Urol Res 35(1):35–40 8. Hsu TH, Streem SB (1998) Metabolic abnormalities in patients with caliceal diverticular calculi. J Urol 160(5):1640–1642 9. Liatsikos EN, Bernardo NO, Dinlenc CZ, Kapoor R, Smith AD (2000) Caliceal diverticular calculi: is there a role for metabolic evaluation? J Urol 164(1):18–20 10. Monga M, Smith R, Ferral H, Thomas R (2000) Percutaneous ablation of caliceal diverticulum: long-term followup. J Urol 163(1):28–32 11. Grasso M, Loisides P, Beaghler M, Bagley D (1995) The case for primary endoscopic management of upper urinary tract calculi: I. A critical review of 121 extracorporeal shock wave lithotripsy failures. Urology 45(3):363–371 12. Mendez-Probst CE, Fuller A, Nott L, Denstedt JD, Razvi H (2011) Percutaneous nephrolithotomy of caliceal diverticular calculi: a single center experience. J Endourol 25(11):1741–1745 13. Dindo D, Demartines N, Clavien PA (2004) Classification of surgical complications: a new proposal with evaluation in a cohort of 6336 patients and results of a survey. Ann Surg 240:205–213 14. Canales B, Monga M (2003) Surgical management of the calyceal diverticulum. Curr Opin Urol 13(3):255–260 15. Psihramis KE, Dretler SP (1987) Extracorporeal shock wave lithotripsy of caliceal diverticula calculi. J Urol 138(4):707–711 16. Turna B, Raza A, Moussa S, Smith G, Tolley DA (2007) Management of calyceal diverticular stones with extracorporeal shock wave lithotripsy and percutaneous nephrolithotomy: long-term outcome. BJU Int. 100(1):151–156 17. Kim SC, Kuo RL, Tinmouth WW, Watkins S, Lingeman JE (2005) Percutaneous nephrolithotomy for caliceal diverticular calculi: a novel single stage approach. J Urol 173(4):1194–1198 18. Gross AJ, Herrmann TR (2007) Management of stones in calyceal diverticulum. Curr Opin Urol 17(2):136–140 19. Basiri A, Radfar MH, Lashay A (2013) Laparoscopic management of caliceal diverticulum: our experience, literature review, and pooling analysis. J Endourol 27(5):583–586 20. Turk C, Knoll T, Petrik A, Sarica K, Skolarikos A, Straub M et al (2013) Members of the European Association of Urology (EAU) Guidelines Office. Guidelines on urolithiasis. In: EAU guidelines, edition presented at the 28th EAU Annual Congress, Milan 21. Fuchs GJ, David R (1989) Flexible ureterorenoscopy, dilatation of narrow caliceal neck, and ESWL: a new, minimally invasive approach to stones in caliceal diverticula. J Endourol 3:255–263 22. Sejiny M, Al-Qahtani S, Elhaous A, Molimard B, Traxer O (2010) Efficacy of flexible ureterorenoscopy with holmium laser in the management of stone-bearing caliceal diverticula. J Endourol 24(6):961–967
1. Wulfsohn MA (1980) Pyelocaliceal diverticula. J Urol 123(1):1–8 2. Middleton AW Jr, Pfister RC (1974) Stone-containing pyelocaliceal diverticulum: embryogenic, anatomic, radiologic and clinical characteristics. J Urol 111(1):2–6
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