Kidney collecting system anatomy applied to endourology - a narrative review.

OBJECTIVE: To evaluate the surgical anatomy of the kidney collecting system through a narrative review of the literature, highlighting its importance during diagnosis and its approach during surgical procedures for the treatment of renal stones. MATERIAL AND METHODS: We carried out a review about the anatomy of the kidney collecting system. We analyzed papers published in the past 40 years in the databases Pubmed, Embase and Scielo, and we included only papers in English and excluded case reports, editorials and opinions of specialists. RESULTS: Renal collecting system could be divided in four groups: A1 - kidney midzone (KM), drained by minor calyx that are dependent on the superior or the inferior caliceal groups; A2 - KM drained by crossed calyx, one draining into the superior caliceal group and another draining into the inferior caliceal group; B1 - KM drained by a major caliceal group independent of both the superior and inferior groups; and B2 - KM drained by minor calyx entering directly into the renal pelvis. Some details and anatomic variations of the collecting system are related to clinical and radiological aspects, particularly perpendicular calyces, interpyelocalyx space, position of calyces in relation to renal border, classification of the renal collecting system, infundibular diameter and the angle between the lower infundibulum and renal pelvis. CONCLUSION: The knowledge of intra-renal collecting system divisions and variations as the angle between the renal pelvis and lower infundibula, position of the calices in relationship with renal edge and the diameter and position of the calyces are important for the planning of minimally invasive renal surgeries.

A case report of renal calyceal diverticulum with hypertension in children and review of literature.

BACKGROUND: Renal calyx diverticulum refers to a cystic lesion covered with the transitional epithelium in the renal parenchyma. Although there is no clear evidence that calyx diverticulum can cause hypertension, there exists a close association between the two, and there are few related reports. Herein, we reported the case of a child with renal calyx diverticulum complicated with hypertension and summarized the diagnosis and treatment. CASE PRESENTATION: Physical examination of the patient, an 11-year-old child, revealed a left renal cyst with hypertension (155/116 mmHg). There were no related symptoms. Routine urine and blood biochemical examinations showed no abnormalities. Imaging revealed left renal cyst compression causing the hypertension. She underwent renal cyst fluid aspiration and injection of a sclerosing agent into the capsule, but her blood pressure increased again 3 days postoperatively. Color Doppler ultrasonography showed that the size of the left renal cyst was the same as that preoperatively. To further confirm the diagnosis, cystoscopic retrograde ureteropyelography was performed to confirm the diagnosis of renal calyx diverticulum. Subsequently, renal calyceal diverticulum resection and calyx neck enlargement were performed. The operation went smoothly and the blood pressure returned to normal postoperatively. No abnormalities were noted at the 7-month postoperative follow-up. CONCLUSION: There exists an association between renal calyx diverticulum and hypertension. Therefore, hypertension can be considered a surgical indication for renal calyx diverticulum. Moreover, renal calyceal diverticulum in children can be easily misdiagnosed as a renal cyst. Therefore, it is important to be vigilant to prevent a series of complications, such as postoperative urine leakage, in such cases.

Calyceal Diverticula Disease: Diagnosis and Management Options in the Era of Non-Contrast CT Scan.

INTRODUCTION: Calyceal diverticula (CD) are traditionally diagnosed by contrast studies. However, non-contrast CT is the standard imaging modality for kidney stones. Therefore, we aimed to determine if the lack of contrast imaging affected outcomes of the management of symptomatic CD with stone. MATERIALS AND METHODS: This is a retrospective study of patients diagnosed with CD with intracalyceal stone from 2000 to 2017 analyzing demographics, clinical data, and success of different treatment options. The timing of CD diagnosis is correlated to the success of the first treatment. RESULTS: Forty-eight patients were found. CD was diagnosed prior to intervention in 20 (42%) cases and intraoperatively during flexible ureteroscopy in 17 (35%) and 11 (23%) cases were diagnosed after failed intervention, mainly ESWL. We found that the success rate of treatment was highly affected by the timing and modality of diagnosis. Preoperative diagnosis of CD was associated with 69% success rate of the first intervention. In contrast, there was a 0% success rate of first treatment if CD was not diagnosed with contrast imaging. Furthermore, univariate analysis showed no significant association between sociodemographics and clinical variables and success treatment (p > 0.05). CONCLUSIONS: The delay in diagnosing CD with stone contributes significantly to the success rate and the number of treatments.

Calyceal diverticula: Clinical, radiological and histopathological findings of an uncommon entity with presumed congenital origin.

Calyceal diverticula (CD) are relatively uncommon urologic conditions that generally follow an asymptomatic course and rarely require medical intervention. CD are thought to have a congenital origin due to abnormalities during the process of ureteral bud formation. Clinically and radiologically, they can mimic multiple neoplastic and non-neoplastic renal processes, with potentially relevant differences in the management of these patients. Symptoms are usually associated with the presence of stones, obstruction to the drainage of the diverticulum, large size, or secondary infection. In chronic cases, surgery might become necessary, creating an opportunity to examine the histopathological characteristics of this condition. Although these are benign in the majority of patients, some rare instances of malignancy arising from the CD have been reported. In this series, we addressed the clinical, radiological, and histopathological findings of CD.

Lower pole anatomy of horseshoe kidney and complete ureteral duplication: Anatomic and radiologic study applied to endourology.

PURPOSE: To analyze the 3-dimensional intrarenal anatomy of horseshoe kidneys (HK) and kidney with complete ureteral duplication (CUD), in polyester resin endocasts of the collecting system and in patients submitted to 3D computerized tomography scan (CT-scan). MATERIALS AND METHODS: We analyzed seven 3-dimensional polyester resin endocasts of the kidney collecting system obtained from 6 fresh adult cadavers (4 with unilateral CUD and 2 with horseshoe kidney) and CT-scan reconstruction images of kidneys from 24 patients: 6 patients with HK, 8 with CUD and 10 patients without renal anomalies that were used as controls. We analyzed the spatial distribution of the calices, the infundibula diameters, the angle between the lower infundibulum and the renal pelvis (LIP) and the angle between the lower infundibulum and the inferior minor calyces (LIICA). Measurements of the width and length of the inferior infundibulum and the infundibula of the minor calyces, as well as the angles (LIP and LIICA) were made with the aid of the LibreOffice 6.3 software. The data were analyzed with the IBM® SPSS® Statistics. RESULTS: There was no statistical difference in the inferior pole measurements between the groups with anomalies and the control group, both in polyester resin endocasts and CT-scan reconstruction images for LIP. When we compared the LIP in the CT-scan between HK versus CUD (p= 0.003), and HK versus the control group (p= 0.035), we observed statistical difference. CONCLUSIONS: The knowledge of spatial anatomy of lower pole is of utmost importance during endourologic procedures in patients with kidney anomalies. In the present study we observed that horseshoe kidneys had more restrictive anatomic factors in lower pole than the complete ureteral duplication.

[A Case of Calyceal Diverticula with Stones Treated by Ureteroscopic Management].

Most patients with calyceal diverticula stones are asymptomatic, but some patients experience fever and low back pain. Here we report a case of calyceal diverticula stones treated by ureteroscopic management. A 41-year-old woman with backache visited a local doctor. She was diagnosed with a urinary tract infection, and prescribed an antibiotic. Her symptoms began to improve, but the ultrasonography showed she had a left renal cystic lesion, so she visited our hospital. Abdominal contrast-enhanced computed tomography (CT) showing in-flow of a contrast agent into the left renal calyceal diverticula located stones in the upper pole. We performed ureteroscopic management of the calyceal diverticula stones in two stages. First, we expanded the neck of the calyceal diverticula by indwelling the ureteral stent at the calyceal diverticula. Then, using a ureteral dilator, we expanded the neck of the calyceal diverticula further and removed the stones in the calyceal diverticula. Treatment with ureteroscopic management was possible due to the location of the calyceal diverticula stones and the success rate was increased by performing the treatment in two stages.

The left ureterocele and stone of calyceal diverticulum in the patient with bilateral incomplete duplex kidneys managed by flexible ureteroscopy: a case report and literature review.

BACKGROUND: Duplex kidneys are one of the most common renal congenital abnormalities, mostly asymptomatic and of no clinical significance. There are little reports about the left ureterocele and stone of calyceal diverticulum in patients with bilateral incomplete duplex kidneys managed by flexible ureteroscopy. CASE PRESENTATION: A 69-year-old Chinese woman was presented with left waist pain for 1 month. A preoperative computed tomography (CT) scan and intravenous pyelogram revealed the left ureterocele which located in the left ureterovesical junction, and stone of calyceal diverticulum which located in the upper kidney of left incomplete duplex kidneys. The ureterocele was confirmed in view of ureteroscopy and the holmium laser was used for the resection of ureterocele. It took us a lot of efforts to find out the stone because of diverticular neck stenosis. Fortunately, when diverticular neck stenosis was incised internally by holmium laser, the stone was discovered clearly and removed using the holmium laser and nitinol stone basket through flexible ureteroscopy. A double-J ureteral stent was inserted and remained in place for 1 month. The symptom disappeared postoperatively and no complications were developed during the placement of the stent. There were no stone residents observed on CT scan before removing the ureteral stent 1 month later. CONCLUSIONS: Flexible ureteroscopy with holmium laser is feasible to manage the ureterocele and calyceal diverticulum stones in patients with bilateral incomplete duplex kidneys in one operation.

Challenges in the diagnosis of calyceal diverticulum: A report of two cases and review of the literature.

BACKGROUND: Calyceal diverticula outpouchings that occur rarely in the upper collecting system of the kidney and is often difficult to detect. In this study, we present two cases of calyceal diverticula and discuss their clinical characteristics and radiologic features. PATIENTS AND METHODS: In the presented two cases, we applied several imaging examinations, including delayed intravenous pyelography, retrograde pyelography and axial computerized tomographic (CT) scanning of the kidneys with and without contrast. Serum creatinine levels in fluid withdrawn from the diverticula were found to be significantly higher than the simultaneous serum creatinine levels. Intravenous injection of methylene blue through a ureteral catheter was also aided in the diagnosis. Calyceal diverticulum neck dilatation was performed through a percutaneous nephroscope.ResultsThe two cases were diagnosed preoperatively and the operation was successful performed. The nephrostomy tube was removed seven days after surgery without complications. CT scans of the kidney after six months showed that the size of the calyceal diverticulum of two patients were considerably smaller than pre-surgery. There were no reports of pain in the lumbar region or other discomfort. COMMENTS: Diagnosis of calyceal diverticulum mainly depend on a variety of imaging examinations, including the delayed intravenous pyelography, retrograde pyelography, and kidney CT plain scan plus enhanced scan. If the patient cannot be diagnosed by above methods, cyst fluid can be aspirated percutaneously to measure the preoperative creatinine level. If it is significantly higher than the serum creatinine level, the cyst fluid is considered urine, which can assist in the diagnosis of calyceal diverticulum. A ureteral catheter should also be inserted before operation namely, intravenous injection of methylene blue through a ureteral catheter is helpful for diagnosis. The choice of surgical treatment is based on the size and location of calyceal diverticulum and clinical manifestations.

Incorporation of the fluoroless C-Arm Trainer at the American Urological Association hands on training percutaneous renal access.

OBJECTIVES: To assess for usefulness and validity evidence for incorporating the C-Arm Trainer (CAT) simulator into the annual AUA hands on course for training percutaneous nephrolithotomy (PCNL). MATERIALS AND METHODS: The course started with a didactic session followed by four stations for training the "bull's eye" technique using the CAT simulator. Each station included a pre-test, 30-min practice on the simulator, and post-test. All participants were assessed using a 4-item checklist. All participants were asked to fill in a qualitative self-assessment questionnaire after the pre- and the post-test, and respond to a course evaluation questionnaire and post-course survey. RESULTS: A total of 38 physicians, who attended the hands on course, voluntarily participated in the study. Only 21.1% had previous practice on PCNL simulators. Compared with the results of the checklist total score and the qualitative self-assessment questionnaire scores after the pre-test, there was significant improvement in the checklist total score (p < 0.001), temporal demands (p = 0.003), situational stress (p = 0.003, and performance (0.003) after the post-test. A total of 14 (36%) participants responded to the course evaluation questionnaire, 50% evaluated the course as excellent, 28.6% as very good, and 21.4% as good. Unfortunately, only five (13%) participants responded to the post-course survey, 4/5 implemented the new competencies and knowledge into their practice, and 3/5 have attempted to obtain fluoroscopic guided PCA without assistance. CONCLUSION: The CAT simulator was considered useful for training the percutaneous renal access procedure. There was significant improvement in the qualitative and quantitative assessment parameters after the post-test compared with the pre-test.

Prediction of Intraoperative Urinary Collecting System Entry in Patients with Peripheral Renal Tumors Undergoing Partial Nephrectomy: Usefulness of Tumor-Centered Multiplanar Reconstruction.

OBJECTIVE: To assess the usefulness of tumor-centered multiplanar reconstruction (TC-MPR) for predicting intraoperative urinary collecting system (UCS) entry in patients with peripheral renal tumors undergoing partial nephrectomy (PN). METHODS: Dynamic computed tomography images of 50 peripheral cT1 renal tumors treated with laparoendoscopic PN were analyzed. TC-MPR generated a digital cross-sectional image showing the tumor center and the closest calyx on a same plane. Patients and tumor characteristics including the distance from the tumor margin to the closest calyx (MPR-distance), and the angle formed by 2 tangent lines from the closest calyx to the tumor (MPR-angle) were assessed. RESULTS: Intraoperative UCS entry was observed in 15 patients (30%). The patients who experienced intraoperative UCS entry had a higher RENAL score, wider MPR-angle, and shorter MPR-distance than those who did not (p = 0.04, p = 0.001, p < 0.001, respectively). Multivariate analysis identified MPR-angle as an independent factor for intraoperative UCS entry (p < 0.001). CONCLUSIONS: The spatial information assessed using TC-MPR serves as a predictive factor for intraoperative UCS entry during PN.

[Congenital megacalycosis in a girl with unilateral renal agenesis]. / Wrodzone kielichonercze u dziewczynki z jednostronna agenezja nerki.

Renal agenesis occurs in pediatric population with the incidence 1:500- 2000 children. It is more often diagnosed in boys and on the left side of the body. Renal agenesis may be isolated or it may be a part of complex malformation syndrome. Megacalycosis is a very rare anomaly of urinary tract associated with abnormal structure of the kidney pyramids. AIM: The aim of the study was to present for the first time in the medical literature the case of a girl with unilateral renal agenesis and megacalycosis. CASE REPORT: A girl, born at term in good general medical condition, and with normal birth weight was admitted to the hospital because of urinary tract infection caused by E.coli. Antenatal abdominal ultrasounds were normal. In a diagnostic, repeated ultrasound studies, unilateral, left renal agenesis and the righ-sided megacalycosis were found. The right kidney had dilated collecting system, with normal size of renal pelvis and enlarged calyces up to 26 mm. The kidney function was normal. Voiding cystourethrography excluded vesicoureteral reflux. Dynamic scintigraphy 99mTc-EC showed the lack of function of the left kidney, postinflammatory changes and dilation of collecting system without signs of obstruction. During two-years follow up we didn't observe clinical relapse of urinary tract infection. Blood pressure and kidney function were normal. CONCLUSIONS: Complex congenital anomalies of the kidney and the urinary tract (CAKUT) can be diagnosed at any age. Normal antenatal abdominal ultrasound does not exclude CAKUT. Every patient with congenital abnormalities of the kidney and the urinary tract requires long-term follow up, because of increased risk of chronic kidney disease.

Skin to calyx distance is not a predictive factor for miniaturized percutaneous nephrolithotomy outcomes.

OBJECTIVE: To evaluate the predictive value of the distance from skin to calyx (SCD) on the outcome and complication rates of patients undergoing mPNL. MATERIALS AND METHODS: Patient's charts, who had undergone mPNL between June 2012 and June 2015, were analyzed retrospectively. Patients who had a preoperative computerized tomography (CT) were enrolled into the study. Two separateurologists evaluated the CT scans and calculated the SCD defined as the distance between the skin and surface/lateral edge of the calyx, which was the preferred site of entry for percutaneous access. The average value of the two measurements was included inthe final analysis to avoid bias. The mean SCD was 75mm. According to the median SCD value, patients were divided into two groups: group 1 (SCD ≤75) and group 2 (SCD >75). RESULTS: A total of 140 patients and 130 patients were enrolled in groups 1 and 2, respectively. The mean operation time and the mean fluoroscopy time was significantly longer in group 2 (p:0.004 vs. p:0.021). The rate of blood transfusion was significantly higher in group 1 (6 patients). None of patientsin group 2required blood transfusion (p:0.017). Stone-free status after a single session of mPNL was 67.1% in group 1 and 75.4% in group 2 (p:0.112). After additional procedures, stone-free rates increased to 84.3% and 85.4% in group 1 and group 2, respectively (p:0.802). CONCLUSION: Our study demonstrated that longer SCD was not a predictive factor for stone-free rates after mPNL. However, SCD over 75mm was associated with longer operation time and fluoroscopy time with lower rates of transfusion.

Upper Calyx Approachability through a Lower Calyx Access for Prone Versus Supine Percutaneous Nephrolithotomy.

PURPOSE: We assessed the approachability of the upper calyx through lower calyx access for prone and supine percutaneous nephrolithotomy and used computerized tomography to analyze anatomical factors that may influence it. MATERIALS AND METHODS: A prospective series of 45 patients treated with percutaneous nephrolithotomy were operated on in the prone (20) and supine (25) positions. Computerized tomography simulated access to the lower and upper calyx longitudinal axes were used to measure skin-to-lower calyx distance, thickness of the body wall, muscle and fat, the muscle-to-fat thickness ratio and the angle between the lower calyx tract and the upper calyx axis. Intraoperative approachability to the upper calyx was also evaluated. RESULTS: The upper calyx was successfully approached in 20% of prone and 80% of supine percutaneous nephrolithotomies (p <0.0001). The average skin-to-lower calyx distance was 98.4 mm (range 65.3 to 128.6) in the prone position and 98.7 mm (range 60.8 to 150) in the supine position (p = 0.99). Body wall and muscular thickness, and the muscle-to-fat thickness ratio were significantly lower in supine than prone nephrolithotomy (p <0.001, <0.0005 and <0.05, respectively). The average angle between the lower and upper calyces axes was wide in the supine position (141 degrees, range 90 to 170) and acute in the prone position (84 degrees, range 65 to 110, p <0.05(E-10)). CONCLUSIONS: Upper calyx endoscopic approachability through the lower calyx is significantly higher in supine than in prone percutaneous nephrolithotomies, possibly due to a thinner body wall, a thinner muscular layer, a lower muscle-to-fat thickness ratio and a wider angle between the lower and upper calyx axes.

Use of Volume Rendered, Maximum Intensity Projection Images to Assess Whether the Medial Calyx Synonymous with the Posterior Calyx.

INTRODUCTION: This paper attempts to verify the anatomical veracity of the belief that in order to enter into a posterior calyx one must aim for the medial calyx during a percutaneous nephrolithotomy (PCNL). METHODS: Volume rendered and maximum intensity projection reconstructions of normal pelvicalyceal systems were assessed in various rotational planes. An experienced urologist decided the appropriate access for PCNL in the upper, interpole and lower calyx on each side. The selected calyx was then viewed on anteroposterior sections to decide whether they were projecting laterally or medially. RESULTS: Of the 508 calyces studied, the posterior calyx was projecting laterally in 72% and medially in 28%. In the upper calyx, the posterior calyx was projecting laterally in a majority of cases, 94% on the right and 89% on the left. In the right lower calyx, the posterior calyx was pointing laterally in 86%, whereas the distribution on the left was 64%. CONCLUSION: Our results refute the belief that the medial calyx is always synonymous with the lateral calyx.

SUBSTANTIATION OF THE METHOD OF TREATMENT CHOICE FOR PATIENTS, SUFFERING CALCULI OF THE LOWER CALICES RENALES.

Results of treatment of 276 patients, suffering the lower renalis calyx (LRC) calculi, hav' ing size (1.14 ± 0.35) сm, were analyzed. Depending on acuteness of іnfundibulo­ pelvic angle (ІPA) the examined persons were divided on groups with blunt (n=118) and acute (n=158) IPA; 8 аnatomic parameters of the LRC were in total determined. There was established, that еxtracorporal shock­wave lithotripsy, in accordance to the cal' culated index of a LRC calculis elimination, is expedient to apply in a bigger ІPA, lesser іnfundibulo­lumbar angle, lesser length of the LRC neck; transcutaneous nephrolithotripsy is effective not depending from a calculi dimensions, length of the LRC neck, value of ІPA and infundibulo­lumbar angle.

Rupture of the maternal renal calyx secondary to fetal malpresentation: a case report.

BACKGROUND: Rupture of the renal collecting system is a potentially life-threatening condition in pregnancy. Most cases are associated with obstruction from nephrolithiasis or diseased renal parenchyma. CASE: A 24-year-old, nulliparous, African American woman at 38 weeks + 3 days' gestation presented with left flank pain refractory to conservative pain management. Computed tomography was negative for a stone but significant for infrarenal fluid and rupture of a left renal calyx. The fetal head was not flexed and appeared to be compressing the left ureter. A face presentation became apparent during her labor course, and she underwent a cesarean delivery when labor did not progress. CONCLUSION: This represents the first reported case of a ruptured renal collecting system secondary to fetal malpresentation. A high index of suspicion is essential to diagnose collecting system rupture, and it may occur in the absence of parenchymal disease or stones.

Ultrasound evaluation of obstructive uropathy and its hemodynamic responses in southwest Nigeria.

PURPOSE: To determine the renal arterial hemodynamic changes induced by obstructive uropathy using Doppler ultrasonography. MATERIALS AND METHODS: 60 adult subjects with suspected obstructive uropathy and 60 asymptomatic apparently healthy controls with normal renal ultrasound features were evaluated. B-mode sonography of the kidneys and spectral Doppler examination of the renal interlobar arteries of all the participants were performed. The mean resistive indices (mRI) of both interlobar arteries were obtained and compared to that of the controls. The mRI of bilaterally obstructed kidneys were also compared with the mRI of unilaterally obstructed kidneys. RESULTS: The mRI of the right and left kidneys of subjects were 0.72±0.04 and 0.69±0.06 while those of the controls were 0.64±0.04 and 0.63±0.03 respectively. The mRI for the grades of caliectasis increased from grade I (0.72±0.03) to grade II (0.73±0.03) and grade III (0.73±0.02) but fell within the most severe levels of obstruction (0.69±0.07). There was no statistically significant relationship between the grades of caliectasis and unilateral or bilateral obstruction for both kidneys. The results show a sensitivity and specificity of 86.7% and 90% respectively when mRI≥0.7 was used to determine presence of obstruction. CONCLUSION: Renal duplex sonography is highly sensitive and specific for diagnosis of obstructive uropathy. Increased resistive index of the obstructed kidney may be a useful diagnostic tool in situations where intravenous urography cannot be done or is contraindicated.

The Welsh study of mothers and babies: protocol for a population-based cohort study to investigate the clinical significance of defined ultrasound findings of uncertain significance.

BACKGROUND: Improvement in ultrasound imaging has led to the identification of subtle non-structural markers during the 18 - 20 week fetal anomaly scan, such as echogenic bowel, mild cerebral ventriculomegaly, renal pelvicalyceal dilatation, and nuchal thickening. These markers are estimated to occur in between 0.6% and 4.3% of pregnancies. Their clinical significance, for pregnancy outcomes or childhood morbidity, is largely unknown. The aim of this study is to estimate the prevalence of seven markers in the general obstetric population and establish a cohort of children for longer terms follow-up to assess the clinical significance of these markers. METHODS/DESIGN: All women receiving antenatal care within six of seven Welsh Health Boards who had an 18 to 20 week ultrasound scan in Welsh NHS Trusts between July 2008 and March 2011 were eligible for inclusion. Data were collected on seven markers (echogenic bowel, cerebral ventriculomegaly, renal pelvicalyceal dilatation, nuchal thickening, cardiac echogenic foci, choroid plexus cysts, and short femur) at the time of 18 - 20 week fetal anomaly scan. Ultrasound records were linked to routinely collected data on pregnancy outcomes (work completed during 2012 and 2013). Images were stored and reviewed by an expert panel.The prevalence of each marker (reported and validated) will be estimated. A projected sample size of 23,000 will allow the prevalence of each marker to be estimated with the following precision: a marker with 0.50% prevalence to within 0.10%; a marker with 1.00% prevalence to within 0.13%; and a marker with 4.50% prevalence to within 0.27%. The relative risk of major congenital abnormalities, stillbirths, pre-term birth and small for gestational age, given the presence of a validated marker, will be reported. DISCUSSION: This is a large, prospective study designed to estimate the prevalence of markers in a population-based cohort of pregnant women and to investigate associations with adverse pregnancy outcomes. The study will also establish a cohort of children that can be followed-up to explore associations between specific markers and longer-term health and social outcomes.

Pyocalycosis: a report of two cases of complicated hydrocalycosis.

Hydrocalycosis is defined as cystic dilatation of a major calyx with a demonstrable connection to the renal pelvis and an epithelial lining of the cyst wall. Although this condition has long been known, there are no sufficient data concerning this pathology in the literature. In this study, we present two complicated hydrocalycosis--'pyocalycosis'--and discussed the therapeutic approaches.