Urolithiasis DOI 10.1007/s00240-013-0625-0
ORIGINAL PAPER
Retrograde intrarenal surgery in patients with isolated anomaly of kidney rotation Ural Og˘uz • Melih Balci • Gokhan Atis • Omer Faruk Bozkurt • Altug Tuncel Fikret Halis • Yilmaz Aslan • Ismail Okan Yildirim • Cagri Senocak • Mustafa Yordam • Ali Atan • Turhan Caskurlu • Ali Unsal
•
Received: 6 August 2013 / Accepted: 6 November 2013 Ó Springer-Verlag Berlin Heidelberg 2013
Abstract The purpose of the study was to investigate feasibility of retrograde intrarenal surgery (RIRS) in patients with isolated anomaly of kidney rotation with kidney stones. We retrospectively reviewed the medical records of patients who underwent RIRS due to kidney stones in three referral hospitals. Twenty-four patients who had kidney rotation were included in this study. The patients with horseshoe kidney or pelvic kidney were not included in the study. The patients were evaluated for final success 1 month after surgery. Success was defined as stone-free or fragment smaller than 3 mm. Mean age of patients was 39.5 years (1–71 years) and male/female ratio was 3:1. Mean stone size was 13.46 mm (5–30 mm). Twelve (50 %) patients had the operation on the right side and other 12 (50 %) patients had on the left side. Eighteen (75 %) patients were stone-free after single procedure. And stone-free rate increased to 83.3 % after additional treatment procedures.
U. Og˘uz (&) O. F. Bozkurt F. Halis C. Senocak M. Yordam Department of Urology, Kecioren Training and Research Hospital, Ankara, Turkey e-mail: [email protected] M. Balci A. Tuncel Y. Aslan Department of Urology, Numune Training and Research Hospital, Ankara, Turkey G. Atis T. Caskurlu Department of Urology, Goztepe Training and Research Hospital, Istanbul Medeniyet University, Istanbul, Turkey I. O. Yildirim Department of Radiology, Kecioren Training and Research Hospital, Ankara, Turkey A. Atan A. Unsal Department of Urology, Gazi University School of Medicine, Ankara, Turkey
When we compared the successful and failed procedures, gender, stone side and size, preoperative hydronephrosis, access sheet usage, ureteral double-J stent insertion were not statistically significant in two groups. We did not confront major complication. RIRS seems to be an effective and safe treatment option for renal stones in patients with isolated anomaly of kidney rotation. Keywords Retrograde intrarenal surgery Isolated anomaly of kidney rotation Kidney stones
Introduction Retrograde intrarenal surgery (RIRS) has greatly improved since it was first described and performed in the 1990s [1–3]. The potential indications for RIRS have dramatically increased with advances in the technology of flexible ureteroscopy [4–6]. RIRS in patients with spinal deformities or high body mass index has been described [7–9], and results with this technique in patients with kidney abnormalities have been reported in the literature [10, 11]. However, there have not been any studies investigating RIRS in the isolated anomaly of kidney rotation. In the present study, we investigated the feasibility of RIRS in patients with the isolated anomaly of kidney rotation with kidney stones.
Materials and methods Patients We performed a retrospective analysis of patients who underwent RIRS due to kidney stones in three referral
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Urolithiasis
Fig. 1 Isolated anomaly of kidney rotation on the right side with a kidney stone
preoperatively, a semirigid ureteroscope was not used, and a hydrophilic guide wire was placed with a rigid cystoscope. Then, ureteral access sheath (UAS) was placed with the guidance of the guide wire. In some cases, the UAS was not placed, based on the discretion of surgeon. Ureteral orifice dilation with a balloon dilator was necessary in some patients, when the ureteral access could not be advanced easily. To avoid ureteral injury, surgery was stopped when a difficulty was encountered while placing UAS or when extensive strictures were detected. In such cases, the procedure was postponed to the other session for 1–2 weeks by placing a ureteral double-J stent. We observed that this approach facilitated the procedure without the complication of ureteral injury. All the procedures were performed using a 7.5 flexible ureteroscope (Karl Storz FLEX-X2, Tuttlingen, Germany). Holmium:YAG laser with a 273-lm fiber was used for lithotripsy, and stones were fragmented until they were sufficiently small to pass spontaneously. A ureteral stent was placed at the end of the surgery based on the surgeon’s decision. Postoperative follow-up
hospitals. We detected that 24 of the patients had the isolated anomaly of kidney rotation, and were included in this study. Patients with horseshoe kidney or pelvic kidney were excluded from the study. We identified the patients with the isolated anomaly of kidney rotation using intravenous urography (IVU) or computerized tomography (CT) in this retrospective research. We standardized the rotation degree and only included kidneys with a ventral position of 90° which was the most common presentation (Fig. 1). Then, we defined the results of RIRS in these patients. Before surgery, patients were evaluated with abdominal X-ray, ultrasonography (USG), IVU and/or CT. Blood samples were analyzed for serum biochemistry, complete blood count and coagulation tests. Urinalysis and urine culture were analyzed routinely and an appropriate antibiotic was administered before the surgery according to urine culture. Antithrombotic or antiaggregant agents, such as aspirin, were stopped at least 1 week before the procedure. Surgical technique All the operations were performed following the standard procedures, starting with insertion of a hydrophilic guide wire with fluoroscopic imaging capability in the lithotomy position under general anesthesia. Fluoroscopic screening was performed using a mobile C-arm fluoroscopy unit, with an under the couch X-ray tube and an over-the-couch image intensifier. Semirigid ureteroscopy for visualization and dilation of the ureter was mostly performed. However, in some cases, especially in patients with ureteral stents
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A plain film and USG were preferred for determining stone clearance the day after surgery in all the patients. The patients were evaluated for final success 1 month after surgery with X-ray/IVU and USG. CT was used in patients with non-opaque stones or residual fragments. Children were not checked with CT if their stones were radiopaque, to avoid radiation exposure. Success was defined as stonefree or residual fragments smaller than 3 mm. Statistical analysis All the statistical analyses were performed using SPSS software, version 20.0. Statistical significance was assumed at p \ 0.05. As a supplementary statistic, frequencies (percentages) for the variables, obtained by counting, and mediums ± standard deviations and median (minimum and maximum) values for the variables, obtained by measurement, were used. Chi-square analysis was used for the variables obtained by counting. The Mann–Whitney U test was used for comparing two independent groups.
Results A total of 24 patients with the isolated anomaly of kidney rotation and kidney stones were included this study. The male-to-female ratio was 3:1. The mean patient age was 39.8 (1–71) years. While there were two children with ages of 1 and 9 years old, the other patients were adults. The mean stone size was 13.46 (5–30) mm. Four (16.7 %)
Urolithiasis Table 1 Patient, stone and operative characteristics Mean age (range)
39.8 years (1–71 years)
Gender Male (%)
18 (75 %)
Female (%)
6 (25 %)
Mean stone size (range)
13.46 mm (5–30 mm)
Location of stone Renal pelvis (%) Middle pole calyces (%)
10 (41.7 %) 3 (12.5 %)
Upper pole calyces (%)
2 (8.3 %)
Lower pole calyces (%)
9 (37.5 %)
Side Left (%)
12 (50 %)
Right (%)
12 (50 %)
No. of patients with non-opaque stones
5 (20.8 %)
Preoperative hydronephrosis (%)
6 (25 %)
Ureteral access sheath (%)
20 (83.3 %)
No. of postoperative double-J stents
17 (70.8 %)
Success rates (%)
18 (75 %)
Mean postoperative hospitalization time, days (range)
1.5 days (1–5 days)
Mean operation time, min (range)
48.7 min (18–135 min)
Mean fluoroscopy time, s (range)
27.4 s (0–91 s)
Major complication (Clavien III–IV)
–
patients had a history of previous ureteroscopy, and 12 (50 %) patients had a history of extracorporeal shock wave lithotripsy (SWL). Stones were located in the renal pelvis in 10 (41.7 %) patients, middle pole calyces in 3 (12.5 %) patients, upper pole calyces in 2 (8.3 %) patients and lower pole calyces in 9 (37.5 %) patients. Twelve (50 %) patients underwent surgery on the right side and other 12 (50 %) patients on the left side. Preoperative hydronephrosis was detected in 6 (25 %) patients. In total, 5 (20.8 %) patients had non-opaque kidney stones, and we performed followup procedures using CT (Table 1). The mean operative and fluoroscopy times were 48.7 (18–135) min and 27.4 (0–91) s, respectively. Ureteral orifice dilation was performed in only one patient, a 1 year old child. Ureteral access was not possible due to narrow ureteral orifice in 2 (8.3 %) patients. After ureteral stent insertion for passive dilation, the procedures were performed successfully 2 weeks later in these two patients. A UAS was not placed in 4 (16.7 %) patients based on the discretion of the surgeon. Double-J stents were placed in 17 (70.8 %) patients at the end of surgery, and the stents were removed 2–3 weeks after the procedure (Table 1). The mean postoperative hospitalization time was 1.5 (1–5) days. Two (8.3 %) patients had minor postoperative
hematuria, which self-limited in 1–2 days. Bleeding that was prolonged or that required intervention did not occur in any of the patients. We also did not detect high-grade (Grades 2–4) ureteral wall injuries. Although we did not have longterm follow-up results for all the patients, we did not detect any hydronephrosis or ureteral stricture due to RIRS in their follow-ups. Medical complications were not experienced perhaps because the patients constituted a young population. Nine (37.5 %) patients experienced renal colic after surgery within the first 24 h, and 1 (4.1 %) patient required re-hospitalization 5 days after the operation due to renal colic. Two (8.3 %) patients required additional surgical interventions (one rigid ureteroscopy for lower ureteral calculus and one flexible ureteroscopy for residual renal calculus). Fever less than 38.5 °C was detected in two (8.3 %) patients immediately after surgery, disappearing the day after surgery without medication. We did not experience any major complications, classified as Clavien III–V. We defined our success rate as stone-free or residual fragments smaller than 3 mm. Eighteen (75 %) patients underwent successful RIRS procedures. Of 18 patients, 15 patients were completely stone-free, and 3 patients had clinically insignificant fragments smaller than 3 mm 1 month after the procedure. Six (25 %) of the 24 patients had failed procedures. Of these six patients, one required reoperation for a residual fragment 5 mm in diameter. The stone was located in the lower calyx and caused significant renal colic. Because it was resistant to SWL, a second RIRS procedure was performed, and she was completely stone-free after the second procedure. One patient underwent SWL for a residual fragment, which was 10 mm in diameter and was located in renal pelvis. He was stone-free after SWL. Four patients who had residual fragments larger than 3 mm were asymptomatic, and they are in the follow-up program without additional interventions. In total, the success rate after the additional procedures increased to 83.3 %. The final success rate after the initial procedures was 75 % in our study. When we compared the successful procedures (n = 18) and failed procedures (n = 6), the stone sizes were 15.5 (10–30) and 13.5 (5–30) mm, respectively (p [ 0.05). Stone location was not comparable because of the small number of failed procedures. Sex, stone side and size, previous intervention history (ureteroscopy, SWL) and, the existence of preoperative hydronephrosis were not statistically significantly different between the successful and failed procedures (p [ 0.05). The characteristics of the two groups are summarized in Tables 2 and 3.
Discussion Rotation of the kidney is a rare anomaly caused by dystopia and abnormal blood circulation [12]. Anterior rotation of
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Urolithiasis Table 2 Distribution of characteristics in two success and failed groups Group
Statistical analysis
Success n
Failure %
All
n
%
n
%
Chi-square
p
Fisher’s exact
1.000
Fisher’s exact
1.000
Fisher’s exact
1.000
Fisher’s exact
0.539
Fisher’s exact
1.000
Fisher’s exact
0.568
Fisher’s exact
1.000
Gender Female
5
27.78
1
16.67
6
25.00
13 18
72.22 100.00
5 6
83.33 100.00
18 24
75.00 100.00
Right
9
50.00
3
50.00
12
50.00
Left
9
50.00
3
50.00
12
50.00
All
18
100.00
6
100.00
24
100.00
Absent
9
50.00
3
50.00
12
50.00
Existence
9
50.00
3
50.00
12
50.00
18
100.00
6
100.00
24
100.00
20
83.33
4
16.67
Male All Side
Preoperative SWL
All Pre-surgery Absent Existence All
14
77.78
6
100.00
4
22.22
0
0.00
18
100.00
6
100.00
24
100.00
Preoperative hydronephrosis Absent Existence
13 5
72.22 27.78
5 1
83.33 16.67
18 6
75.00 25.00
All
18
100.00
6
100.00
24
100.00
Non-opaque Opaque
15
83.33
4
66.67
19
79.17
Nonopaque
3
16.67
2
33.33
5
20.83
18
100.00
6
100.00
24
100.00
5
27.78
2
33.33
7
29.17
All DJ stent placing Absent Existence
13
72.22
4
66.67
17
70.83
All
18
100.00
6
100.00
24
100.00
the kidney is most often accompanied by horseshoe kidneys and ectopic kidneys. An isolated rotation anomaly in a normal location is extremely rare, and the real incidence is unknown because malrotations with minor degrees have not been reported. Normal kidneys have a ventral position by the sixth week of gestation. Then, rotation 90° toward the midline occurs during the renal migration to the renal fossa, as a result of the branching of the budding ureteral tree. Finally, while the calyces face the lateral side, the renal pelvis faces the medial side by the end of ninth week of intrauterine life. If this final position is not ensured in gestation, rotation anomalies occur. Although there have been different descriptions of malrotation according to degrees of rotation, we only included patients with kidneys in the ventral position (Fig. 1). This position is the most common presentation, and it describes the primitive ventral
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position of the kidney. This anteroposterior position indicates that the kidney did not undergo any rotation or rarely underwent extensive rotation with a 360° turn during gestation [13]. There have not been many articles about treatment alternatives for patients with an isolated anomaly of kidney rotation for renal calculus. Mosavi-Bahar et al. [14] presented their percutaneous nephrolithotomy (PNL) series in 16 patients with kidney malformations. In their series, 5 (31.2 %) patients had rotation anomalies, and the authors reported high success rates (81 %) with PNL without major complications. Binbay et al. [15] presented the largest series of PNL for malrotated kidneys. Their study was a matched-pair analysis of 44 malrotated and 44 non-malrotated kidneys at six institutions. The success rates for the two groups were reported as 77.3 and 79.5 %, respectively
Urolithiasis Table 3 Distribution of gender, stone size, duration of operation and fluoroscopy Group n
Mann–Whitney U Mean
Median
Min
Max
SS
Mean rank
U
p
36
0.229
43.5
0.482
44
0.938
34.5
0.888
Age Success
18
36.83
35.5
1
62
16.19
11.50
Failure
6
47.83
46
25
71
15.43
15.50
24
39.58
42
1
71
16.41
Success
18
12.78
13
5
25
4.65
11.92
Failure All
6 24
15.50 13.46
13 13
10 5
30 30
7.66 5.49
14.25
Success
18
46.53
40
18
90
22.42
10.93
Failure
6
54.17
42
20
135
41.33
11.17
24
48.71
40
18
135
28.13
Success
18
23.17
23.5
3
74
19.85
9.38
Failure
6
35.83
20.5
0
91
38.83
9.75
24
27.39
22
0
91
27.13
All Stone size
Operation time
All Fluoroscopy time
All
(p [ 0.05). Although the success rate seemed to be low, the stone burden was 5.9 cm2, and the authors claimed that it was the largest stone burden in the literature. A unique difference between the two groups in their series was a decrease in hemoglobin of 1.9 and 1.3 g/dl, respectively (p \ 0.05). They explained the difficulties in surgery and the factors affecting this decrease in hemoglobin after PNL in three ways. First, percutaneous access might not have been optimally achieved because of altered caliceal anatomy. Second, the length of the parenchyma passed to reach the calyx could have been greater in malrotated kidneys. And third, more torque might have been necessary during routine manipulation with a rigid nephroscope. As mentioned above, rotation anomalies occur during the branching of the budding ureteral tree. Excessive fibrous tissue around the ureteropelvic junction and upper ureter can cause upper urinary tract obstruction and stasis to varying degrees [13]. In patients with an isolated anomaly of kidney rotation, clearance of stone fragments after SWL can also be impaired without urinary obstruction due to stasis. Compression of the renal artery or accessory artery and distortion of the upper ureter are the primary causes of urinary stasis in these patients. As a result of these causes, these patients are prone to stone formation, and there is difficulty in the spontaneous passage of stone fragments after SWL [13, 15]. Tunc et al. [16] presented 150 patients who had anomalous kidneys and who underwent SWL. Thirty of these patients had rotation anomalies. They presented a stone-free rate of 56.7 % for malrotated kidneys, and this rate was lower than that for kidneys
without rotation. In another study, Ku¨peli et al. [17] reported in their series a success rate with SWL of 54 % in kidneys with malrotation. Prior reports have revealed the effects of kidney rotation on PNL and SWL for the treatment of renal calculi. To our knowledge, there have been no articles in the international literature on the efficacy of RIRS in this patient group. The present study is the first article investigating the efficacy of RIRS in a series of 24 patients with a rotated anomaly of the kidney. Because there have not been large and prospective series regarding the treatment of calculus in rotated kidneys, the current recommendations for calculus in normal kidneys are considered acceptable for rotated kidneys. The EAU guidelines [18] recommend that PNL be the first-line treatment for kidney stones larger than 2 cm. For kidney stones smaller than 2 cm, SWL is recommended as the first-line treatment in the guidelines. In contrast, RIRS has greatly improved since it was first performed, as a result of advances in the technology of flexible ureteroscopy [4–6]. Furthermore, the potential indications have increased because it is a safe and effective method for kidney stones, with high stone-free rates [19]. Stone-free rates with this surgery have varied between 69.7 and 97 % in the international literature [20–23]. Two recent studies [8, 9] reported the results of RIRS in obese patients. Both studies demonstrated that RIRS is an effective method, with low complication rates, in obese patients. Moreover, Atis and co-workers [10] published their RIRS experiences in patients with horseshoe kidneys.
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Urolithiasis
They presented 20 patients with horseshoe kidneys in two institutions, with a success rate of 70 % and with a minor complication rate of 25 %. They concluded that this procedure was also effective in horseshoe kidneys, without major complications. In our study, we retrospectively reviewed the medical records of 24 patients who had the isolated anomaly of kidney rotation and who underwent RIRS due to kidney stones. The initial success rate was 75 %, and the final success was 83.3 %, after additional procedures. Compared with the stone-free rates with RIRS in the normal population, our results were similar. When we compared our outcomes with the stone-free rates in kidneys with rotation anomalies, our outcomes seemed superior to those following PNL and SWL. We did not experience any major intraoperative or postoperative complications. When we compared the successful and failed procedures, we could not find any differences between the characteristic findings in these patients. As we mentioned above, there have not been any previous studies investigating the results of RIRS in rotated kidneys. Therefore, we could not compare our findings with the results of other studies. We acknowledge several limitations of this study. The first limitation was that the study was retrospective, without a control group. The second limitation was that CT was not used routinely for detecting residual fragments. The patients were assessed for final success with plain X-ray graph/IVU and USG 1 month after surgery. CT was used in patients with non-opaque stones or residual fragments. The third limitation was that hydronephrosis and ureteral stricture were not detected 1 month after surgery, and longterm follow-up results could be necessary for the evaluation of ureteral strictures after RIRS due to the procedure.
Conclusion According to our results, RIRS seems to be an effective treatment option without major complications in patients with the isolated anomaly of kidney rotation with kidney stones. We believe that our findings must be confirmed by further prospective, randomized studies. Conflict of interest The authors declare that they have no conflicts of interest.
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ORIGINAL PAPER
Retrograde intrarenal surgery in patients with isolated anomaly of kidney rotation Ural Og˘uz • Melih Balci • Gokhan Atis • Omer Faruk Bozkurt • Altug Tuncel Fikret Halis • Yilmaz Aslan • Ismail Okan Yildirim • Cagri Senocak • Mustafa Yordam • Ali Atan • Turhan Caskurlu • Ali Unsal
•
Received: 6 August 2013 / Accepted: 6 November 2013 Ó Springer-Verlag Berlin Heidelberg 2013
Abstract The purpose of the study was to investigate feasibility of retrograde intrarenal surgery (RIRS) in patients with isolated anomaly of kidney rotation with kidney stones. We retrospectively reviewed the medical records of patients who underwent RIRS due to kidney stones in three referral hospitals. Twenty-four patients who had kidney rotation were included in this study. The patients with horseshoe kidney or pelvic kidney were not included in the study. The patients were evaluated for final success 1 month after surgery. Success was defined as stone-free or fragment smaller than 3 mm. Mean age of patients was 39.5 years (1–71 years) and male/female ratio was 3:1. Mean stone size was 13.46 mm (5–30 mm). Twelve (50 %) patients had the operation on the right side and other 12 (50 %) patients had on the left side. Eighteen (75 %) patients were stone-free after single procedure. And stone-free rate increased to 83.3 % after additional treatment procedures.
U. Og˘uz (&) O. F. Bozkurt F. Halis C. Senocak M. Yordam Department of Urology, Kecioren Training and Research Hospital, Ankara, Turkey e-mail: [email protected] M. Balci A. Tuncel Y. Aslan Department of Urology, Numune Training and Research Hospital, Ankara, Turkey G. Atis T. Caskurlu Department of Urology, Goztepe Training and Research Hospital, Istanbul Medeniyet University, Istanbul, Turkey I. O. Yildirim Department of Radiology, Kecioren Training and Research Hospital, Ankara, Turkey A. Atan A. Unsal Department of Urology, Gazi University School of Medicine, Ankara, Turkey
When we compared the successful and failed procedures, gender, stone side and size, preoperative hydronephrosis, access sheet usage, ureteral double-J stent insertion were not statistically significant in two groups. We did not confront major complication. RIRS seems to be an effective and safe treatment option for renal stones in patients with isolated anomaly of kidney rotation. Keywords Retrograde intrarenal surgery Isolated anomaly of kidney rotation Kidney stones
Introduction Retrograde intrarenal surgery (RIRS) has greatly improved since it was first described and performed in the 1990s [1–3]. The potential indications for RIRS have dramatically increased with advances in the technology of flexible ureteroscopy [4–6]. RIRS in patients with spinal deformities or high body mass index has been described [7–9], and results with this technique in patients with kidney abnormalities have been reported in the literature [10, 11]. However, there have not been any studies investigating RIRS in the isolated anomaly of kidney rotation. In the present study, we investigated the feasibility of RIRS in patients with the isolated anomaly of kidney rotation with kidney stones.
Materials and methods Patients We performed a retrospective analysis of patients who underwent RIRS due to kidney stones in three referral
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Urolithiasis
Fig. 1 Isolated anomaly of kidney rotation on the right side with a kidney stone
preoperatively, a semirigid ureteroscope was not used, and a hydrophilic guide wire was placed with a rigid cystoscope. Then, ureteral access sheath (UAS) was placed with the guidance of the guide wire. In some cases, the UAS was not placed, based on the discretion of surgeon. Ureteral orifice dilation with a balloon dilator was necessary in some patients, when the ureteral access could not be advanced easily. To avoid ureteral injury, surgery was stopped when a difficulty was encountered while placing UAS or when extensive strictures were detected. In such cases, the procedure was postponed to the other session for 1–2 weeks by placing a ureteral double-J stent. We observed that this approach facilitated the procedure without the complication of ureteral injury. All the procedures were performed using a 7.5 flexible ureteroscope (Karl Storz FLEX-X2, Tuttlingen, Germany). Holmium:YAG laser with a 273-lm fiber was used for lithotripsy, and stones were fragmented until they were sufficiently small to pass spontaneously. A ureteral stent was placed at the end of the surgery based on the surgeon’s decision. Postoperative follow-up
hospitals. We detected that 24 of the patients had the isolated anomaly of kidney rotation, and were included in this study. Patients with horseshoe kidney or pelvic kidney were excluded from the study. We identified the patients with the isolated anomaly of kidney rotation using intravenous urography (IVU) or computerized tomography (CT) in this retrospective research. We standardized the rotation degree and only included kidneys with a ventral position of 90° which was the most common presentation (Fig. 1). Then, we defined the results of RIRS in these patients. Before surgery, patients were evaluated with abdominal X-ray, ultrasonography (USG), IVU and/or CT. Blood samples were analyzed for serum biochemistry, complete blood count and coagulation tests. Urinalysis and urine culture were analyzed routinely and an appropriate antibiotic was administered before the surgery according to urine culture. Antithrombotic or antiaggregant agents, such as aspirin, were stopped at least 1 week before the procedure. Surgical technique All the operations were performed following the standard procedures, starting with insertion of a hydrophilic guide wire with fluoroscopic imaging capability in the lithotomy position under general anesthesia. Fluoroscopic screening was performed using a mobile C-arm fluoroscopy unit, with an under the couch X-ray tube and an over-the-couch image intensifier. Semirigid ureteroscopy for visualization and dilation of the ureter was mostly performed. However, in some cases, especially in patients with ureteral stents
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A plain film and USG were preferred for determining stone clearance the day after surgery in all the patients. The patients were evaluated for final success 1 month after surgery with X-ray/IVU and USG. CT was used in patients with non-opaque stones or residual fragments. Children were not checked with CT if their stones were radiopaque, to avoid radiation exposure. Success was defined as stonefree or residual fragments smaller than 3 mm. Statistical analysis All the statistical analyses were performed using SPSS software, version 20.0. Statistical significance was assumed at p \ 0.05. As a supplementary statistic, frequencies (percentages) for the variables, obtained by counting, and mediums ± standard deviations and median (minimum and maximum) values for the variables, obtained by measurement, were used. Chi-square analysis was used for the variables obtained by counting. The Mann–Whitney U test was used for comparing two independent groups.
Results A total of 24 patients with the isolated anomaly of kidney rotation and kidney stones were included this study. The male-to-female ratio was 3:1. The mean patient age was 39.8 (1–71) years. While there were two children with ages of 1 and 9 years old, the other patients were adults. The mean stone size was 13.46 (5–30) mm. Four (16.7 %)
Urolithiasis Table 1 Patient, stone and operative characteristics Mean age (range)
39.8 years (1–71 years)
Gender Male (%)
18 (75 %)
Female (%)
6 (25 %)
Mean stone size (range)
13.46 mm (5–30 mm)
Location of stone Renal pelvis (%) Middle pole calyces (%)
10 (41.7 %) 3 (12.5 %)
Upper pole calyces (%)
2 (8.3 %)
Lower pole calyces (%)
9 (37.5 %)
Side Left (%)
12 (50 %)
Right (%)
12 (50 %)
No. of patients with non-opaque stones
5 (20.8 %)
Preoperative hydronephrosis (%)
6 (25 %)
Ureteral access sheath (%)
20 (83.3 %)
No. of postoperative double-J stents
17 (70.8 %)
Success rates (%)
18 (75 %)
Mean postoperative hospitalization time, days (range)
1.5 days (1–5 days)
Mean operation time, min (range)
48.7 min (18–135 min)
Mean fluoroscopy time, s (range)
27.4 s (0–91 s)
Major complication (Clavien III–IV)
–
patients had a history of previous ureteroscopy, and 12 (50 %) patients had a history of extracorporeal shock wave lithotripsy (SWL). Stones were located in the renal pelvis in 10 (41.7 %) patients, middle pole calyces in 3 (12.5 %) patients, upper pole calyces in 2 (8.3 %) patients and lower pole calyces in 9 (37.5 %) patients. Twelve (50 %) patients underwent surgery on the right side and other 12 (50 %) patients on the left side. Preoperative hydronephrosis was detected in 6 (25 %) patients. In total, 5 (20.8 %) patients had non-opaque kidney stones, and we performed followup procedures using CT (Table 1). The mean operative and fluoroscopy times were 48.7 (18–135) min and 27.4 (0–91) s, respectively. Ureteral orifice dilation was performed in only one patient, a 1 year old child. Ureteral access was not possible due to narrow ureteral orifice in 2 (8.3 %) patients. After ureteral stent insertion for passive dilation, the procedures were performed successfully 2 weeks later in these two patients. A UAS was not placed in 4 (16.7 %) patients based on the discretion of the surgeon. Double-J stents were placed in 17 (70.8 %) patients at the end of surgery, and the stents were removed 2–3 weeks after the procedure (Table 1). The mean postoperative hospitalization time was 1.5 (1–5) days. Two (8.3 %) patients had minor postoperative
hematuria, which self-limited in 1–2 days. Bleeding that was prolonged or that required intervention did not occur in any of the patients. We also did not detect high-grade (Grades 2–4) ureteral wall injuries. Although we did not have longterm follow-up results for all the patients, we did not detect any hydronephrosis or ureteral stricture due to RIRS in their follow-ups. Medical complications were not experienced perhaps because the patients constituted a young population. Nine (37.5 %) patients experienced renal colic after surgery within the first 24 h, and 1 (4.1 %) patient required re-hospitalization 5 days after the operation due to renal colic. Two (8.3 %) patients required additional surgical interventions (one rigid ureteroscopy for lower ureteral calculus and one flexible ureteroscopy for residual renal calculus). Fever less than 38.5 °C was detected in two (8.3 %) patients immediately after surgery, disappearing the day after surgery without medication. We did not experience any major complications, classified as Clavien III–V. We defined our success rate as stone-free or residual fragments smaller than 3 mm. Eighteen (75 %) patients underwent successful RIRS procedures. Of 18 patients, 15 patients were completely stone-free, and 3 patients had clinically insignificant fragments smaller than 3 mm 1 month after the procedure. Six (25 %) of the 24 patients had failed procedures. Of these six patients, one required reoperation for a residual fragment 5 mm in diameter. The stone was located in the lower calyx and caused significant renal colic. Because it was resistant to SWL, a second RIRS procedure was performed, and she was completely stone-free after the second procedure. One patient underwent SWL for a residual fragment, which was 10 mm in diameter and was located in renal pelvis. He was stone-free after SWL. Four patients who had residual fragments larger than 3 mm were asymptomatic, and they are in the follow-up program without additional interventions. In total, the success rate after the additional procedures increased to 83.3 %. The final success rate after the initial procedures was 75 % in our study. When we compared the successful procedures (n = 18) and failed procedures (n = 6), the stone sizes were 15.5 (10–30) and 13.5 (5–30) mm, respectively (p [ 0.05). Stone location was not comparable because of the small number of failed procedures. Sex, stone side and size, previous intervention history (ureteroscopy, SWL) and, the existence of preoperative hydronephrosis were not statistically significantly different between the successful and failed procedures (p [ 0.05). The characteristics of the two groups are summarized in Tables 2 and 3.
Discussion Rotation of the kidney is a rare anomaly caused by dystopia and abnormal blood circulation [12]. Anterior rotation of
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Urolithiasis Table 2 Distribution of characteristics in two success and failed groups Group
Statistical analysis
Success n
Failure %
All
n
%
n
%
Chi-square
p
Fisher’s exact
1.000
Fisher’s exact
1.000
Fisher’s exact
1.000
Fisher’s exact
0.539
Fisher’s exact
1.000
Fisher’s exact
0.568
Fisher’s exact
1.000
Gender Female
5
27.78
1
16.67
6
25.00
13 18
72.22 100.00
5 6
83.33 100.00
18 24
75.00 100.00
Right
9
50.00
3
50.00
12
50.00
Left
9
50.00
3
50.00
12
50.00
All
18
100.00
6
100.00
24
100.00
Absent
9
50.00
3
50.00
12
50.00
Existence
9
50.00
3
50.00
12
50.00
18
100.00
6
100.00
24
100.00
20
83.33
4
16.67
Male All Side
Preoperative SWL
All Pre-surgery Absent Existence All
14
77.78
6
100.00
4
22.22
0
0.00
18
100.00
6
100.00
24
100.00
Preoperative hydronephrosis Absent Existence
13 5
72.22 27.78
5 1
83.33 16.67
18 6
75.00 25.00
All
18
100.00
6
100.00
24
100.00
Non-opaque Opaque
15
83.33
4
66.67
19
79.17
Nonopaque
3
16.67
2
33.33
5
20.83
18
100.00
6
100.00
24
100.00
5
27.78
2
33.33
7
29.17
All DJ stent placing Absent Existence
13
72.22
4
66.67
17
70.83
All
18
100.00
6
100.00
24
100.00
the kidney is most often accompanied by horseshoe kidneys and ectopic kidneys. An isolated rotation anomaly in a normal location is extremely rare, and the real incidence is unknown because malrotations with minor degrees have not been reported. Normal kidneys have a ventral position by the sixth week of gestation. Then, rotation 90° toward the midline occurs during the renal migration to the renal fossa, as a result of the branching of the budding ureteral tree. Finally, while the calyces face the lateral side, the renal pelvis faces the medial side by the end of ninth week of intrauterine life. If this final position is not ensured in gestation, rotation anomalies occur. Although there have been different descriptions of malrotation according to degrees of rotation, we only included patients with kidneys in the ventral position (Fig. 1). This position is the most common presentation, and it describes the primitive ventral
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position of the kidney. This anteroposterior position indicates that the kidney did not undergo any rotation or rarely underwent extensive rotation with a 360° turn during gestation [13]. There have not been many articles about treatment alternatives for patients with an isolated anomaly of kidney rotation for renal calculus. Mosavi-Bahar et al. [14] presented their percutaneous nephrolithotomy (PNL) series in 16 patients with kidney malformations. In their series, 5 (31.2 %) patients had rotation anomalies, and the authors reported high success rates (81 %) with PNL without major complications. Binbay et al. [15] presented the largest series of PNL for malrotated kidneys. Their study was a matched-pair analysis of 44 malrotated and 44 non-malrotated kidneys at six institutions. The success rates for the two groups were reported as 77.3 and 79.5 %, respectively
Urolithiasis Table 3 Distribution of gender, stone size, duration of operation and fluoroscopy Group n
Mann–Whitney U Mean
Median
Min
Max
SS
Mean rank
U
p
36
0.229
43.5
0.482
44
0.938
34.5
0.888
Age Success
18
36.83
35.5
1
62
16.19
11.50
Failure
6
47.83
46
25
71
15.43
15.50
24
39.58
42
1
71
16.41
Success
18
12.78
13
5
25
4.65
11.92
Failure All
6 24
15.50 13.46
13 13
10 5
30 30
7.66 5.49
14.25
Success
18
46.53
40
18
90
22.42
10.93
Failure
6
54.17
42
20
135
41.33
11.17
24
48.71
40
18
135
28.13
Success
18
23.17
23.5
3
74
19.85
9.38
Failure
6
35.83
20.5
0
91
38.83
9.75
24
27.39
22
0
91
27.13
All Stone size
Operation time
All Fluoroscopy time
All
(p [ 0.05). Although the success rate seemed to be low, the stone burden was 5.9 cm2, and the authors claimed that it was the largest stone burden in the literature. A unique difference between the two groups in their series was a decrease in hemoglobin of 1.9 and 1.3 g/dl, respectively (p \ 0.05). They explained the difficulties in surgery and the factors affecting this decrease in hemoglobin after PNL in three ways. First, percutaneous access might not have been optimally achieved because of altered caliceal anatomy. Second, the length of the parenchyma passed to reach the calyx could have been greater in malrotated kidneys. And third, more torque might have been necessary during routine manipulation with a rigid nephroscope. As mentioned above, rotation anomalies occur during the branching of the budding ureteral tree. Excessive fibrous tissue around the ureteropelvic junction and upper ureter can cause upper urinary tract obstruction and stasis to varying degrees [13]. In patients with an isolated anomaly of kidney rotation, clearance of stone fragments after SWL can also be impaired without urinary obstruction due to stasis. Compression of the renal artery or accessory artery and distortion of the upper ureter are the primary causes of urinary stasis in these patients. As a result of these causes, these patients are prone to stone formation, and there is difficulty in the spontaneous passage of stone fragments after SWL [13, 15]. Tunc et al. [16] presented 150 patients who had anomalous kidneys and who underwent SWL. Thirty of these patients had rotation anomalies. They presented a stone-free rate of 56.7 % for malrotated kidneys, and this rate was lower than that for kidneys
without rotation. In another study, Ku¨peli et al. [17] reported in their series a success rate with SWL of 54 % in kidneys with malrotation. Prior reports have revealed the effects of kidney rotation on PNL and SWL for the treatment of renal calculi. To our knowledge, there have been no articles in the international literature on the efficacy of RIRS in this patient group. The present study is the first article investigating the efficacy of RIRS in a series of 24 patients with a rotated anomaly of the kidney. Because there have not been large and prospective series regarding the treatment of calculus in rotated kidneys, the current recommendations for calculus in normal kidneys are considered acceptable for rotated kidneys. The EAU guidelines [18] recommend that PNL be the first-line treatment for kidney stones larger than 2 cm. For kidney stones smaller than 2 cm, SWL is recommended as the first-line treatment in the guidelines. In contrast, RIRS has greatly improved since it was first performed, as a result of advances in the technology of flexible ureteroscopy [4–6]. Furthermore, the potential indications have increased because it is a safe and effective method for kidney stones, with high stone-free rates [19]. Stone-free rates with this surgery have varied between 69.7 and 97 % in the international literature [20–23]. Two recent studies [8, 9] reported the results of RIRS in obese patients. Both studies demonstrated that RIRS is an effective method, with low complication rates, in obese patients. Moreover, Atis and co-workers [10] published their RIRS experiences in patients with horseshoe kidneys.
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Urolithiasis
They presented 20 patients with horseshoe kidneys in two institutions, with a success rate of 70 % and with a minor complication rate of 25 %. They concluded that this procedure was also effective in horseshoe kidneys, without major complications. In our study, we retrospectively reviewed the medical records of 24 patients who had the isolated anomaly of kidney rotation and who underwent RIRS due to kidney stones. The initial success rate was 75 %, and the final success was 83.3 %, after additional procedures. Compared with the stone-free rates with RIRS in the normal population, our results were similar. When we compared our outcomes with the stone-free rates in kidneys with rotation anomalies, our outcomes seemed superior to those following PNL and SWL. We did not experience any major intraoperative or postoperative complications. When we compared the successful and failed procedures, we could not find any differences between the characteristic findings in these patients. As we mentioned above, there have not been any previous studies investigating the results of RIRS in rotated kidneys. Therefore, we could not compare our findings with the results of other studies. We acknowledge several limitations of this study. The first limitation was that the study was retrospective, without a control group. The second limitation was that CT was not used routinely for detecting residual fragments. The patients were assessed for final success with plain X-ray graph/IVU and USG 1 month after surgery. CT was used in patients with non-opaque stones or residual fragments. The third limitation was that hydronephrosis and ureteral stricture were not detected 1 month after surgery, and longterm follow-up results could be necessary for the evaluation of ureteral strictures after RIRS due to the procedure.
Conclusion According to our results, RIRS seems to be an effective treatment option without major complications in patients with the isolated anomaly of kidney rotation with kidney stones. We believe that our findings must be confirmed by further prospective, randomized studies. Conflict of interest The authors declare that they have no conflicts of interest.
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