Stone-containing pyelocaliceal diverticulum: embryogenic, anatomic, radiologic and clinical characteristics

Efficacy of flexible ureterorenoscopy with holmium laser in the management of calyceal diverticular calculi

The purpose of this study was to evaluate the efficacy and safety of flexible ureteroscopy with holmium laser lithotripsy in the management of calyceal diverticular calculi. In this study, we retrospectively analyzed the clinical data of 27 patients with calyceal diverticular calculi admitted to the Department of Urology of the Zigong First People's Hospital from May 2018 to May 2021. Intraoperatively, the diverticular neck was found in all 27 patients, but flexible ureterorenoscopy lithotripsy was not performed in 2 cases because of the slender diverticular neck, and the success rate of the operation was 92.6%. Of the 25 patients with successful lithotripsy, the mean operative time was 76.9 ± 35.5 (43-200) min. There were no serious intraoperative complications such as ureteral perforation, mucosal avulsion, or hemorrhage. Postoperative minor complications (Clavien classification I-II) occurred in 4 (16%) patients. The mean hospital stay was 4.4 ± 1.7 (3-12) days. The stone-free rate was 80% at the 1-month postoperative follow-up. After the second-stage treatment, the stone-free rate was 88%. In 22 cases with complete stone clearance, no stone recurrence was observed at 5.3 ± 2.6 (3-12) months follow-up. This retrospective study demonstrated that flexible ureterorenoscopy with holmium laser is a safe and effective choice for the treatment of calyceal diverticular calculi, because it utilizes the natural lumen of the human body and has the advantages of less trauma, fewer complications, and a higher stone-free rate.

Retrograde intrarenal surgery for stones associated with renal anomalies: caliceal diverticulum, horseshoe kidney, medullary sponge kidney, megacalycosis, pelvic kidney, uretero-pelvic junction obstruction

PURPOSE OF REVIEW

Nowadays, due to the increase of imaging diagnosis, we identify easily renal anomalies, and we can choose between a wide range of armamentarium to treat symptomatic stones in those challenging cases. However, there is a lack of evidence and consensus on its use. The aim of this narrative review is to collect all the available data about safety and efficacity of retrograde intrarenal surgery (RIRS) in the treatment of kidney stones associated to a renal anomaly.

RECENT FINDINGS

Renal anomalies are uncommon findings and even more if it has to be associated with renal stones. After a literature review of the past 2 years, there are a small number of studies that compare the outcomes in patients who have been treated with minimally invasive modalities and they are mainly focus on RIRS.

SUMMARY

It is of extreme importance to know the advances on the stone treatment in anomalous kidneys. With the development of new laser technologies, RIRS is becoming a more interesting technique with high success rate and safety. Further studies are needed to make an accurate statement about the adequate surgical technique for each renal anomaly and also, clinical trials using new laser technologies.

Percutaneous management of caliceal diverticula: a narrative review

PURPOSE OF REVIEW

Caliceal diverticula are relatively uncommon within urologic practice and may be difficult to diagnose and treat. We aim to highlight contemporary studies examining surgical interventions for patients with caliceal diverticula, with a focus on percutaneous intervention, and provide updated practical recommendations for the management of these patients.

RECENT FINDINGS

Studies within the last 3 years examining surgical treatment options for caliceal diverticular calculi are limited. When flexible ureteroscopy (f-URS) and percutaneous nephrolithotomy (PCNL) are examined within the same observational cohorts, PCNL is associated with improved stone-free rates (SFRs), lower requirement for re-intervention, and longer lengths of stay (LOS). Retrograde f-URS for the treatment of caliceal diverticula and diverticular calculi is associated with satisfactory safety and efficacy outcomes. There are no studies in the last 3 years that provide supporting evidence to use shock wave lithotripsy to treat caliceal diverticular calculi.

SUMMARY

Recent studies examining surgical interventions for patients with caliceal diverticula are limited to small observational studies. Heterogeneity in LOS and follow-up protocol limits comparisons between series. Despite technological advancements in f-URS, PCNL appears to be associated with more favorable and definitive outcomes. PCNL continues to be the preferred treatment strategy for patients with symptomatic caliceal diverticula when deemed technically feasible.

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 Diverticulum: A Case Report

Calyceal diverticulums are often benign and asymptomatic. On the other hand, some interventions are necessary in several symptoms. Radiological imaging is performed to made dianoses, but somehow can pose misinterpretation of radiological imaging results and mistreatment from the urologist. To present a case of a calyceal diverticulum treated with open diverticulectomy. This study reported a case of a calyceal diverticulum in a 30-year-old man with an almost 1-month history of left flank pain. The patient undergone several imaging diagnostics, before finally diagnosed calyceal diverticulum with a stone inside it. The patient had underwent open diverticulectomy. Initially, cystoscopy and insertion of Double J Stent (DJ Stent) were done, and then using the lumbotomy approach the incision that had been made. This case demonstrated the use of imaging combined with urologist interpretation and surgical management which was successfully treated the patient’s clinical problems.

Congenital Anomalies of the Upper Urinary Tract: A Comprehensive Review

The upper urinary tract is the most common human system affected by congenital anomalies. Congenital anomalies of the kidneys and ureters comprise a wide spectrum of disorders ranging from simple variants with no clinical significance to complex anomalies that may lead to severe complications and end-stage renal disease. They may be classified as anomalies of renal form, which are subclassified as structural anomalies (eg, persistent fetal lobulation, hypertrophied column of Bertin, and dromedary hump) and fusion anomalies (eg, horseshoe kidney and pancake kidney); anomalies of renal position (eg, renal malrotation, simple renal ectopia, and crossed renal ectopia) and renal number (eg, renal agenesis and supernumerary kidney); and abnormalities in development of the urinary collecting system (eg, pyelocaliceal diverticulum, megacalycosis, ureteropelvic junction obstruction, duplex collecting system, megaureter, ectopic ureter, and ureterocele). US is usually the first imaging modality used because of its low cost, wide availability, and absence of ionizing radiation. Intravenous urography and voiding cystourethrography are also useful, mainly for characterization of the collecting system and vesicoureteral reflux. However, intravenous urography has been replaced by CT urography and MR urography. These imaging methods not only allow direct visualization of the collecting system but also demonstrate the function of the kidneys, the vascular anatomy, adjacent structures, and complications. Comprehension of congenital anomalies of the upper urinary tract is crucial for an accurate diagnosis and correct management. The authors discuss the spectrum of these anomalies, with emphasis on embryologic development, imaging findings, clinical manifestations, and complications. Online supplemental material is available for this article. ^©RSNA, 2021.

Caliceal diverticulum with ureteropelvic junction obstruction in a dysplastic kidney: a pediatric case report

A caliceal diverticulum is a rare entity in children. Its etiology is closely associated with that of ureteropelvic junction malformations and renal dysplasia. We herein present a case of these complex disorders in an infant. A renal cyst and hydronephrosis were found in the left kidney during the fetal period. The postnatal diagnosis was hydronephrosis due to ureteropelvic junction obstruction and a caliceal diverticulum in the left dysplastic kidney. Although left renal function was severely decreased, the patient had no symptoms. Therefore, we did not perform surgical treatment. At the time of this writing, the patient was 3 years 8 months old and had developed no symptoms.

Identification and characterization of calyceal diverticula with MR urography (MRU) in children

PURPOSE

To determine the MRU imaging findings of calyceal diverticula in a large cohort of children and to compare the frequency of calyceal diverticula in our cohort with what has been previously reported.

METHODS

This was a HIPAA-compliant, IRB-approved retrospective study of all patients with suspected CD based on their medical records. All patients in this study underwent MRU at our institution between 2010 and 2017. Two pediatric radiologists reviewed each MRU blinded to clinical information and other urologic imaging regarding the presence, size, location, and morphology of the cyst and presence/absence of contrast within it. The time when contrast first appeared within the cystic mass was recorded, and a χ² test was used to determine significance on differences between the different characteristics of renal cysts and diverticula.

RESULTS

Fifty children (29 girls and 21 boys; median age of 11.5 years, IQR 7-16) with a total of 66 individual cystic masses were included. 21 (21/66, 31.8%) Cystic masses demonstrated contrast filling and were characterized as diverticula, resulting in a frequency of 26.6 cases per 1000 patients (21/787). The remaining 45 cystic masses (45/66, 68.1%) were cysts. The median diameter of CD was 2.5 cm (IQR 1.5-3.7). Contrast was observed within the cystic mass on average at 4.6 min (SD ± 2.4; range 1.5-13 min). The agreement between both radiologists was 91% (k = 0.78). 6 Cysts and 18 CD were confirmed surgically, MRU demonstrated accurate diagnosis in 100% of those cases.

CONCLUSION

Magnetic resonance urography is reliable in differentiating calyceal diverticula from renal cysts. On MRU, all diverticula were identified within 15 min of contrast administration; hence longer delays in imaging are unnecessary.

Factors Impacting Stone-Free Rate After Retrograde Intrarenal Surgery for Calyceal Diverticular Calculi

Objective

To evaluate the outcomes of retrograde intrarenal surgery (RIRS) treatment of calyceal diverticular calculi and identify the associated factors affecting post-operative stone-free rate.

Materials and Methods

From August 2015 to May 2019, data of 32 patients with calyceal diverticular calculi who were treated by RIRS in a Siriraj Hospital were retrospectively studied. All operations were performed by the same surgeon using flexible ureterorenoscopy (f-URS) and holmium YAG laser lithotripsy. Calyceal diverticula were identified by our refluxing technique and from the collected demographic, diverticular and stone data. Operative outcomes were retrospectively evaluated. Data were analysed to identify the factors associated with stone-free outcomes. Stone-free was defined as no residual stones remaining after surgery.

Results

Mean age of the patients was 55.7 years. Stone locations were non-lower pole in 81.2% of cases and lower pole for the remaining 18.8% of cases. Median stone size was 1.2 cm with three as the median number of stones per patient. Calcium oxalate was the most common stone composition (56.3%). Positions of the diverticulum were anterior calyx (34.4%) and posterior calyx (50%), while the remainder were undetermined (incomplete data). Average length of the diverticular neck was 0.4 cm. Mean operative time was 46 minutes and mean hospital stay was 2.9 days. Complications included fever in three patients (9.3%) and sepsis in two patients (6.3%), with overall post-operative stone-free rate at 75%. Factors significantly affecting stone-free status were stone size (P=0.003) and length of diverticular neck (P=0.038). Multivariate analysis determined that only stone size had a statistically significant effect on post-operative stone-free status (P=0.015). Cut off point for stone size that increased the chances of a post-operative stone-free outcome was less than 1.5 cm, as determined by the ROC curve.

Conclusion

RIRS was found to be an effective and safe treatment option for the removal of calyceal diverticular calculi. Stone size of less than 1.5 cm offered a better chance of post-operative stone-free condition.

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.

Robotic renal cyst decortication with calyceal diverticulectomy in a toddler - technical practicalities: a case report

Background

Incidence of simultaneous renal cyst with calyceal diverticula in contralateral kidney is rare in children. A minimally invasive procedure in different sittings is often recommended.

Case presentation

A Chinese 15-month-old boy presented to the Urology department of a tertiary care center with right flank pain. He was subjected to magnetic resonance urography and was diagnosed as having right renal cyst and contralateral calyceal diverticula. He underwent robotic cyst decortication and calyceal diverticulectomy using da Vinci robot. His postoperative period was uneventful. He was discharged on fifth postoperative day. Histopathology was consistent with simple renal cyst.

Conclusions

Robotic combined cyst decortication and contralateral diverticulectomy is feasible in selected small children. However, it demands adequate technical skill and experience.

Rupture of a Calyceal Diverticulum Secondary to Ureteroscopy: A Rare Complication

We present a case of a 45-year-old female who experienced rupture of a right calyceal diverticulum caused by ureteroscopy. Fifteen hours after the operation, she had severe right flank pain and a high fever (38.9°C). Computed tomography revealed perinephric extravasation of urine and bleeding inside the diverticulum. We diagnosed rupture of a calyceal diverticulum; therefore, we continued antibiotic administration and pain relief medication. She became afebrile on postoperative day 4 and was discharged from the hospital on postoperative day 7. Owing to renal cortex thinning in the diverticula, ureteroscopy is associated with a risk of rupture of calyceal diverticula.

Systematic Review of Caliceal Diverticulum

PURPOSE

We performed a systematic review of the literature regarding the diagnosis and treatment of caliceal diverticulum (CD).

METHODS

The search strategy was conducted according to the Cochrane review guidelines for systematic reviews and Preferred Reporting Items for Systematic reviews and Meta-Analyses checklist.

RESULTS

In total 1189 titles and abstracts were reviewed, of which 101 were selected for article evaluation. Of these 101 articles, 40 were selected for inclusion after full article evaluations. In the extracted article, intravenous urography (IVU), rather than CT urography, was the main imaging tool for diagnosis, although many articles had failed to provide any imaging modality information. The extracted articles included 88, 153, and 487 patients who underwent shock wave lithotripsy (SWL), flexible ureteroscopy/retrograde intrarenal surgery (fURS/RIRS), and percutaneous nephrolithotomy (PCNL), respectively. Stone-free rates were 21.3% (SWL), 61.4% (fURS/RIRS), and 83.0% (PCNL). The complication rates were 8.0% (SWL), 3.3% (fURS/RIRS), and 11.9% (PCNL). There was incomplete and inconsistent reporting of even basic clinical parameters, such as the size and location of the CD, number of stones, outcomes, and complications. There was a striking lack of follow-up data, despite a known high recurrence rate. The literature on laparoscopic management was too sparse to analyze.

CONCLUSIONS

This meta-analysis revealed that there are not enough high-quality studies to evaluate the ideal strategy for the diagnosis and treatment of CDs. This systematic review emphasizes (a) the importance of contrast imaging for CD diagnosis, (b) higher success rates but also higher complication rates in PCNL compared with SWL and FURS, and (c) the need for standardized reporting of outcomes to include complications, number of interventions, symptom resolution, stone clearance, and CD ablation.

Management of renal caliceal diverticular stones: A decade of experience

Objective:

The objective of this study is to evaluate our methods for management of renal caliceal diverticular stones (CDS).

Materials and Methods:

We conducted a retrospective study from January 2005 to July 2015 and included patients who were treated for renal CDS. Patients were evaluated for treatment modality, puncture site (in case percutaneous nephrolithotomy [PCNL] attempted), operative time, stone clearance rate, and complications. During PCNL, if the infundibulum was found to connect the diverticulum to the calyx, then a double J stent was placed. No attempt was made to dilate the diverticular neck or to create a neoinfundibulum.

Results:

Twenty-four patients were treated for CDS during the study period. Two patients underwent shockwave lithotripsy, and 22 were managed by PCNL. Mean stone size was 16.37 mm (range: 6–35 mm) and mean diverticulum size was 20.62 mm (range: 12–37 mm). No fulguration was done in initial 17 patients, while fulguration by Holmium Laser was performed in the last five cases treated with PCNL. Mean operative time was 70.31 min (range: 47–90 min). Mean follow-up was 34 months, diverticulum resolved in 14 patients and reduced in size in 7 patients.

Conclusion:

Caliceal diverticular calculi can be treated most efficiently by PCNL. Stone-guided puncture and no attempt to dilate or create neoinfundibulum reduces operative time and morbidity while yielding high stone-free rate.

Detailed evaluation of the upper urinary tract in patients with prune belly syndrome using magnetic resonance urography

INTRODUCTION

Magnetic resonance urography (MRU) has proven to be useful in the setting of complex urologic anatomy. Prune belly syndrome (PBS) patients are known to have malformed and highly variable urinary tract anatomy due to significant dilation and renal dysplasia.

OBJECTIVE

To further characterize the renal and ureteral anatomy and renal function in patients with PBS via MRU.

STUDY DESIGN

Children with PBS undergoing MRU (2006-2011) were identified. Studies were performed to evaluate severe hydronephrosis in all patients. Demographics, previous imaging, and MRU findings were collected. A single radiologist reviewed all studies.

RESULTS

MRU was performed on 13 boys, with a median age of 29.3 months (IQR 6-97). Two patients underwent >1 study for ureteropelvic junction obstruction (UPJ obstruction) and calyceal diverticulum with a solitary kidney, respectively. Hydroureteronephrosis (HUN) was identified in 12 boys (92%), while one (8%) did not have ureteral dilation. All patients demonstrated morphologic abnormalities beyond HUN as follows: five (38%) renal dysplasia; five (38%) scarring; four (31%) calyceal diverticula; and three (23%) thickened bladder. The median renal transit time (RTT) was 6 min (IQR 3.5-10.5), and >8 min (range 8.5-35) in six patients; one patient was ultimately diagnosed with obstruction. The mean serum creatinine was 0.5 ± 0.3 mg/dl. This summary figure is a coronal excretory phase T1 MRU image demonstrating absence of well-defined calyces and a 5-cm calyceal diverticulum (white arrow).

DISCUSSION

This study reports significant anatomic and functional findings on MRU that were not readily apparent when using standard imaging for children with PBS. The high-resolution images and functional data obtained with MRU allowed for visualization of calyceal diverticula and abnormal renal pelvic anatomy not previously described in PBS. In addition, renal dysplasia could be identified with MRU, which is badly characterized in the PBS population outside of renal biopsy studies. Potential limitations of the study included its nature as a small retrospective case series, which limited the ability to compare imaging modalities. Imaging modalities were based on individual clinical needs; therefore, comparison with diuretic renal scintigraphy was limited.

CONCLUSION

MRU provided anatomic and functional details of the urinary tract in children with PBS that allowed for characterization of new renal anatomic abnormalities, including the incidence of calyceal diverticula and renal dysplasia, which have not been previously described. While renal scarring, dysplasia and calyceal diverticula were easily discerned on MRU in ten patients, their clinical significance requires longer follow-up in a larger patient population.

Pediatric calyceal diverticulum treatment: An experience with endoscopic and laparoscopic approaches

INTRODUCTION

The symptomatic calyceal diverticulum is a rare event in the pediatric population. In adults, surgical options include ureteroscopy, percutaneous ablation, and laparoscopic decortication but there is a lack of experience in the literature with these techniques.

OBJECTIVE

We present our experience with both the ureteroscopic and laparoscopic approach to treating the pediatric calyceal diverticulum.

STUDY DESIGN

We performed a retrospective case series looking at patients who underwent treatment for calyceal diverticulum at our institution from January 2009 to May 2014. We reviewed patient demographics, indications for intervention, radiographic appearance, type of intervention, and perioperative outcomes. Ureteroscopic approach included dilation of infundibulum and ablation of diverticular cavity. Laparoscopic approach included ablation of the diverticulum with argon diathermy with or without surgical closure of the ostium.

RESULTS

There were 13 patients who underwent 15 procedures for symptomatic calyceal diverticulum (Table). Median age was 11 years. Indications for intervention were: pain and increasing size of diverticulum (8/15, 55%), hematuria (3/15, 20%), UTI (3/15, 20%), and calculi (1/15, 5%). 11/15 (73%) procedures were managed endoscopically and 4/15 (27%) were managed with laparoscopic decortication. Ureteral stent was left in all patients for a mean duration of 51 days (15-120 days). Follow up imaging at median of 2.1 years (0.5-4 years) revealed an initial success rate of 85% (11/13 patients). Two patients failed initial intervention (persistent pain/increasing size) necessitating successful secondary minimally invasive procedures. There were 2 (13%) complications: a perinephric hematoma post endoscopic ablation which resolved spontaneously and a deep venous thrombosis in a patient with a coagulation disorder in the laparoscopic group.

DISCUSSION

Limitations of our study include its retrospective design, lack of standardization of the treatment approach amongst the four treating surgeons, and the small number of patients requiring intervention for this relatively rare diagnosis. Our study is the largest to date in the pediatric population and is the first to report outcomes with ureteroscopic management of the calyceal diverticulum.

CONCLUSIONS

We found that the pediatric calyceal diverticulum can be successfully treated in a minimally invasive manner. The endoscopic approach should be the first line option for patients with small, endophytic diverticula, particularly those located in the upper and mid pole. The laparoscopic approach is more invasive but should be considered for large diverticula that are exophytic with thin overlying parenchyma.

Retrograde intrarenal surgery in the management of symptomatic calyceal diverticular stones: a single center experience

To evaluate the outcome of RIRS in managing symptomatic calyceal diverticular as a minimally invasive option, we retrospectively reviewed the records of 43 patients who underwent RIRS from 2005 to 2014 for symptomatic calyceal diverticular stones. A month after the initial operation, the success rate was (81.4%, 35 patients) of which 21 (48.83%) patients were stone free and 14 (32.6%) patients had clinically insignificant residual fragments (CIRFs), and 90% patients were symptom free. Eight patients (16.6%) had significant residual fragments (>3 mm), five of them became completely stone free after the second procedure, other three patients were symptom free and underwent a routine follow-up. The final treatment success rate was 93.0%. The initial success rate in the lower calyx was significantly lower than the other calices (P = 0.040). In addition, the association between the stone size and the initial treatment success was significant (P = 0.036). There was no association between any of our other variables and the success rate. The mean first operative time was 60.95 ± 12.43 min (range 34-92). No major complication (Clavien III-V) occurred, although there were five minor complications (11.6%) (Clavien I-II). There were no admissions to intensive care or deaths in our series, the mean hospitalization time was 1.77 ± 0.80 days. The management of calyceal diverticular calculus with RIRS is highly effective and can be accomplished with low morbidity.

Calyceal diverticulum mimicking simple parapelvic cyst: a case report

Calyceal diverticulum is a cystic intrarenal cavity lined by nonsecretory transitional epithelium that communicates with the collecting system via a narrow isthmus or infundibulum. It is a rare anatomic anomaly with an incidence of 0.2% to 0.6% in the patients undergoing renal imaging.1 Single imaging modality usually cannot differentiate calyceal diverticulum from other cystic renal diseases.2 Here, we report a 60-year-old male who was reliably diagnosed with calyceal diverticulum by retrograde urography combined with non-enhanced computed tomography (CT) and magnetic resonance urography (MRU).

Clinical manifestation of a calyceal diverticular abscess in a pregnant woman

Calyceal diverticula are congenital, nonsecretory abnormalities in which the transitional cell-lined cavity communicates with the renal collecting system. Here we present the case of a calyceal diverticular abscess during pregnancy. A 40-year-old primiparous woman developed the abscess at 23 weeks of gestation, with right flank pain and a 37.8°C fever. A transabdominal ultrasound revealed a 12 × 10 cm cystic mass in the right kidney. She was initially diagnosed with a simple renal cyst infection, and intravenous antibiotics were initiated. Percutaneous drainage was started at 26 weeks of gestation. When urine excretion from the cyst was confirmed by dye test using indigotindisulfonate sodium, the patient was diagnosed with a calyceal diverticular abscess. She gave birth to a 2,870 g healthy male at 38 weeks of gestation. Percutaneous drainage with low-dose antimicrobial therapy could thus allow for the continued pregnancy of women with a calyceal diverticular abscess until full term.

Robotic-assisted laparoscopic management of a caliceal diverticular calculus

PURPOSE

To report the first case of robotic-assisted laparoscopic management of a symptomatic caliceal diverticular calculus and review the literature on laparoscopic treatment for this condition.

CASE REPORT

A 33-year-old obese woman with a 2×1 cm calculus within an anterior caliceal diverticulum located in the middle pole of the left kidney was referred to our service. She had already undergone two flexible ureterorenoscopies without success. We considered that a percutaneous approach would be very challenging due to stone location, thus we elected to perform a robotic-assisted laparoscopic procedure for stone removal and diverticulum fulguration. The procedure was uneventfully performed with no intraoperative or postoperative complications. The patient was discharged from the hospital on the second postoperative day and after 1.5 years of follow-up she is asymptomatic with no recurrence.

CONCLUSIONS

The robotic-assisted laparoscopic approach to caliceal diverticular calculi is feasible and safe, providing one more option for treatment of stones in challenging locations.

Is retrograde flexible nephrolithotripsy feasible for calyceal diverticular stone?

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 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 follow-up 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.

Urothelial carcinoma in a pyelocaliceal diverticulum discovered by magnetic resonance urography

Neither computed tomography (CT) nor intravenous pyelography (IVP) alone can diagnose tumors of renal pelvic diverticula, but magnetic resonance urography (MRU) can obtain accurate preoperative information.

Robotic partial nephrectomy for caliceal diverticulum: a single-center case series

The aim of this study is to examine the role of robotic partial nephrectomy (RPN) in the management of caliceal diverticula by assessing our single-center outcomes. Between July 2007 and July 2013, 7 of 670 patients underwent RPN procedures as a reason of caliceal diverticula. The indications for RPN in all cases were recurrent urinary tract infection and pain attributed to the diverticulum in addition to failed management by endourologic or extracorporeal shockwave lithotripsy (SWL) treatments. One patient with a calcified diverticulum and another with an unsuccessful SWL treatment underwent RPN without further endourologic intervention. The other five patients had a history of unsuccessful percutaneous nephrolithotomy (one case), ureteroscopy (URS) (two cases), and a combination of SWL+URS (two cases). No intraoperative or postoperative complications were observed. No patient was readmitted postoperatively. Unique features of the robotic platform facilitate the excision of diverticulum and subsequent kidney reconstruction for this benign, but complex pathology.

Management of stones associated with intrarenal stenosis: infundibular stenosis and caliceal diverticulum

PURPOSE

To review our experience with retrograde intrarenal surgery (RIRS) for management of conditions associated with intrarenal stricture and present a treatment algorithm based on the series.

PATIENTS AND METHODS

RIRS was offered to all patients with symptomatic intrarenal stenosis regardless of location if stone burden was 2 cm or less. With a combined endourology and lithotripsy table, patients with stones between 2 and 3 cm were also offered RIRS using a combined approach of RIRS and shockwave lithotripsy (SWL). A total of 108 patients with symptomatic stones and caliceal diverticulum or infundibular stenosis were included in the data analysis. A standard technique was used in all cases. Failures or patients not suitable for RIRS were treated with either percutaneous nephrolithotomy (PCNL) or laparoscopic surgery.

RESULTS

Successful identification and dilation/incision of the stenotic opening was accomplished in 94% of cases. Seventy-five percent of stones were managed with basketing and/or holmium laser ablation. In these patients, 90% were stone free (<2 mm stone fragments). For stones between 2 and 3 cm, the use of holmium laser in combination with SWL provided stone-free rates of 75%. Five percent of patients needed PCNL because of larger stone burden and posterior location.

CONCLUSIONS

With the appropriate equipment, RIRS provides a valid treatment option for patients with intrarenal strictures. While upper pole and midrenal lesions are ideal, lower pole segments may be approached as well. A treatment algorithm based on the results provides a simplified approach for the minimally invasive management of intrarenal stenosis.

Urology patients in the nephrology practice

Urologists and nephrologists provide care to many mutual patients. This review addresses the initial management of upper urinary tract issues commonly seen in nephrology practice. Patients with hematuria without clear benign causes should be referred to urologists for workup to rule out urologic malignancies. Asymptomatic microscopic hematuria after negative workup should be followed with annual urinalysis with repeat urologic evaluation if it persists after 5 years. Hydronephrosis is another commonly encountered diagnosis. Functional urinary obstruction should be excluded using a diuretic nuclear renography in the appropriate population. Asymptomatic, stable hydronephrosis can be observed, but those with acute, symptomatic obstruction, or patients with suspected obstruction with signs of infection, should seek urologic care for intervention. Hydronephrosis is common in pregnant women; symptomatic patients merit intervention similar to nonpregnant patients. The management of patients with an acute stone episode is similar to that for those with hydronephrosis. Patients with first stone episodes need evaluation for risk factors for stone formation, whereas patients with identified risk factors or recurrent stones need comprehensive metabolic workup. Patients with incidentally found kidney masses should be referred to urology for possible intervention when they have solid kidney masses or cystic masses that need further evaluation.

Percutaneous Holmium Laser Fulguration of Calyceal Diverticula

Introduction. Calyceal diverticular stones are uncommon findings that represent a challenge in their treatment, due to the technical difficulty in accessing the diverticulum, and the high risk of their recurrence. Current percutaneous technique for calyceal diverticular stones involves establishing a renal access, clearing the stone, and fulguration of the diverticular lining with a roller-ball cautery electrode using hypotonic irrigation solution such as sterile water or glycine solution which may be associated with the absorption of hypotonic fluids with its inherent electrolyte disturbances.Case Report. In this paper, we present for the first time percutaneous holmium laser fulguration of calyceal diverticula in 2 patients using normal saline. Their immediate postoperative sodium was unchanged and their follow-up imaging showed absence of stones. Both patients remain asymptomatic at 30 months post-operatively.Conclusion. This demonstrates that holmium laser is a safe alternative method to fulgurate the calyceal diverticulum after clearing the stone percutaneously.

Laparoscopic calyceal diverticulectomy: video review of techniques and outcomes

Calyceal diverticula are cystic dilations within renal parenchyma prone to urinary stasis, stone formation, and recurrent infection. Using ICD-9 code 55.39 and CPT code 50549, we identified five women and two men (mean age 42 years) who underwent laparoscopic calyceal diverticulectomy at our center from August 2007 to July 2010. Patient videos that highlight basic and advanced laparoscopic techniques (retroperitoneal approach and partial nephrectomy) were selected from an Institutional Review Board-approved video library. Because few published case series exist in the literature, we include equipment used and outcomes for all patients. Posterior diverticula (4/7) were ablated by balloon-assisted retroperitoneal approach. One patient required concomitant partial nephrectomy for a solid renal mass, and laparoscopic ultrasound probe was required for diverticular identification in two patients. No complications were noted with reasonable mean blood loss (40 mL), operating times (160 minutes), and hospital stay (2 days). All diverticula were resolved at 3-month follow-up computed tomography imaging.

The imaging appearances of calyceal diverticula complicated by uroliathasis

The presence of diverticula arising from the calyceal system is a relatively uncommon urological problem, occurring with an incidence of 2.1-4.5 per 1000 intravenous urogram (IVU) examinations. While the incidence of calyceal diverticula is low, the frequency of stone formation within them is high. We describe the aetiology and clinical presentation and describe the role of imaging with ultrasound, intravenous and retrograde pyelography and CT in diagnosis and planning treatment. We also describe the potential of fluid-sensitive magnetic resonance imaging techniques as a radiation-free alternative to the use of more conventional modalities, such as intravenous urography and retrograde pyelography, in delineating the anatomy of calyceal diverticula before surgical and radiological intervention especially in young patients and pregnant women.

Percutaneous management of caliceal diverticuli

BACKGROUND AND PURPOSE

Caliceal diverticula are rare congenital abnormalities that can become symptomatic if associated with a calculus or infection. We review percutaneous management of caliceal diverticula.

METHODS

Pathogenesis, clinical evaluation, management options, and recommended follow-up for symptomatic caliceal diverticula are reviewed. We present our single-stage and prepercutaneous nephrolithotomy opacification techniques for the management of caliceal diverticula. This involves complete extraction of all stone particles and ablation of the diverticular cavity without infundibular identification or dilation. Comparison of outcomes between our current ablative technique and our previous dilation technique is evaluated.

RESULTS

Percutaneous management of caliceal diverticula offers the highest symptomatic relief and stone-free rate of available management options. We identified 106 patients with caliceal diverticula who were treated with a percutaneous approach. Review of 85 of these patients demonstrated that most procedures can be performed with a small nephrostomy tube in place for 24 hours and an overnight hospital stay. Minimal complication and stone recurrence rates were observed. Patients treated with caliceal diverticular ablation experienced a shorter hospital stay, fewer complications, and a higher stone-free status than those patients who were treated with dilation of the diverticular infundibulum.

CONCLUSIONS

Percutaneous management of caliceal diverticula using cavity ablation is a minimally invasive technique that offers long-term symptomatic relief with minimal complications.

Preoperative indications for percutaneous nephrolithotripsy in 2009

Abstract Since the first description of percutaneous nephrolithotripsy (PNL) over 30 years ago, the indications for this procedure in the management of upper tract urinary stones has greatly expanded. Despite recent advances in shock wave lithotripsy and ureteroscopic technologies, PNL maintains a dominant role in the management of complex and large volume upper tract stones. The contemporary indications for PNL are reviewed herein.

Management of calyceal diverticular stones with extracorporeal shock wave lithotripsy and percutaneous nephrolithotomy: long-term outcome

OBJECTIVE

To review patients with an extended follow-up after extracorporeal shock wave lithotripsy (ESWL) or percutaneous nephrolithotomy (PCNL) for calyceal diverticular stones (CDS), over a 15-year period, assessing the long-term outcome.

PATIENTS AND METHODS

In all, 56 patients were treated for symptomatic CDS disease by ESWL (38) or PCNL (18). The stone-bearing diverticula were in the upper calyces in 26, middle calyces in 24 and lower calyces in six patients, and in the right kidney in 22 and in the left in 34. The most frequent symptom was ipsilateral flank pain (84%) and 32% of patients presented with associated chronic urinary tract infections. In a retrospective analysis, we assessed stone size, diverticulum location, stone-free rate, symptom-free rate, complications and extended follow-up.

RESULTS

In the short-term in the ESWL group, 21% of patients were stone-free and 61% were asymptomatic; 8% developed symptoms and 8% developed recurrence or stone-growth in the long term. There were six minor complications. In the PCNL group, 15 patients (83%) were stone-free in the short term; two had a recurrence (11%) and two had stone growth (11) in the long term. There were three complications after PCNL.

CONCLUSIONS

This series shows that PCNL is an effective and durable means of treating CDS, regardless of stone size or location of the diverticulum. Despite low stone-free rates with ESWL, most patients were rendered symptom-free with minimal complications. The long-term recurrence rates, 8% for ESWL and 11% for PCNL, were comparable.

Pre-percutaneous nephrolithotomy opacification for caliceal diverticular calculi

Caliceal diverticula harbor calculi in as many as 50% of cases. Such stones rarely pass spontaneously. Various stone-removal techniques have been used, with percutaneous techniques generally having the best results. In patients with nonradiopaque stones or in whom the diverticulum does not opacify when contrast is instilled retrograde or by intravenous urogram, contrast can be instilled directly into the cavity with CT or ultrasound guidance. Three such cases are described, with good results.

Renal cystic diseases: a review

This review aims to assist in the categorization of inherited, developmental, and acquired cystic disease of the kidney as well as to provide a pertinent, up-to-date bibliography. The conditions included are autosomal-dominant polycystic kidney disease, autosomal-recessive polycystic kidney disease, unilateral renal cystic disease (localized cystic disease), renal simple cysts, multicystic dysplastic kidney, pluricystic kidney of the multiple malformation syndromes, juvenile nephronophthisis and medullary cystic disease, medullary sponge kidney, primary glomerulocystic kidney disease, and glomerulocystic kidney associated with several systemic disorders mainly of genetic or chromosomal etiology, cystic kidney in tuberous sclerosis, and in von Hippel-Lindau syndrome, cystic nephroma, cystic variant of congenital mesoblastic nephroma, mixed epithelial stromal tumor of the kidney, renal lymphangioma, pyelocalyceal cyst, peripylic cyst and perinephric pseudocyst, acquired renal cystic disease of long-term dialysis, and cystic renal cell carcinoma and sarcoma. Whereas the gross and histologic appearance of some of these conditions may be diagnostic, clinical and sometimes molecular studies may be necessary to define other types.

Laparoscopy in the management of stone disease of urinary tract

As in other fields of urology, the use of minimally invasive techniques has helped decrease the morbidity and convalescence associated with the management of urolithiasis. Laparoscopy has also been used as one of the minimally invasive techniques. This has developed particularly with the increasing experience and use of intracorporeal suturing techniques. However, in comparison with other surgeries, laparoscopy for stone removal is relatively uncommon and we review the current indications, technical limitation and results.

Percutaneous endoscopic treatment for calyceal diverticular calculi

A 29-year-old man complaining of gross hematuria was referred to our department. DIP demonstrated calyceal diverticular calculi of the left kidney. The patient requested ESWL, but the stone had not been discharged after two treatments. He then underwent PNL with dilation of the narrow neck of the calyceal diverticulum under fluoroscope. The neck of the diverticulum was dilated using an amplats dilator. Three months after the surgery, DIP demonstrated that the diverticulum was completely free from calculi and the size of the diverticulum was reduced. He was doing well 24 months after the operation. Calyceal diverticular calculi should be managed not only with ESWL and PNL but also with dilation of the narrow neck of the calyceal diverticulum.

Laparoscopy-Assisted Transperitoneal Percutaneous Nephrolithotomy for Renal Caliceal Diverticular Calculi

BACKGROUND AND PURPOSE

There are a variety of options for the management of symptomatic calculi in caliceal diverticula, each with utility in particular situations. Herein, we describe a laparoscopy-assisted transperitoneal percutaneous nephrolithotomy (PCNL) technique to address the unusual combination of an anterior caliceal diverticulum together with multiple branched calculi having segments both within and proximal to the diverticulum.

TECHNIQUE

With the patient in a modified lithotomy position, standard transperitoneal laparoscopy was performed utilizing three 10-mm trocars. After mobilization of the colon medially, the cystic diverticulum was opened. An additional 12-mm trocar was placed to allow transperitoneal PCNL within the diverticulum. Rigid nephroscopy, holmium laser lithotripsy, and stone extraction were performed, including laser enlargement of the diverticular neck and removal of the stone burden proximal to the neck. A double-pigtail ureteral stent and Jackson-Pratt drain were placed.

RESULTS

This procedure was successful in the only patient in whom it has been used to date. As far as we know, this is the first report of laparoscopy-assisted transperitoneal PCNL for the management of caliceal diverticular calculi.

CONCLUSION

Laparoscopy-assisted transperitoneal PCNL is a safe and effective alternative for the management of symptomatic stones in anterior cystic caliceal diverticula with a narrow neck and complex branched calculi.

PERCUTANEOUS NEPHROLITHOTOMY FOR CALICEAL DIVERTICULAR CALCULI: A NOVEL SINGLE STAGE APPROACH

PURPOSE

Current percutaneous treatment of symptomatic caliceal diverticular calculi involves renal access, stone removal, dilation of the diverticular communication, fulguration of the cavity and placement of a nephrostomy tube. We reviewed the outcomes of patients undergoing a novel single stage percutaneous nephrolithotomy technique for radiopaque caliceal diverticular stones that eliminates ureteral catheterization and entry into the renal collecting system.

MATERIALS AND METHODS

A total of 21 patients (8 male and 13 female including 1 bilateral) with a mean age of 42.4 years underwent percutaneous nephrolithotomy for caliceal diverticular stones from February 2001 to May 2003. Of the diverticula 12 were upper pole, 4 were interpolar and 6 were lower pole. Infracostal access was established by the urologist directly onto the radiopaque stones without the aid of a ureteral catheter. After balloon tract dilation a 30Fr Amplatz sheath was placed and following stone removal the diverticulum was fulgurated. The infundibulum was neither cannulated nor dilated. A 20Fr red rubber catheter or an 8.5Fr Cope loop was placed into the diverticulum. Stone-free status was assessed by noncontrast computerized tomography on postoperative day 1 (POD1). The drainage tube was removed if there was no urine drainage and the kidney was stone-free. Excretory urography was performed at 3 months to evaluate diverticular resolution.

RESULTS

Of 21 patients 20 were discharged home tubeless on POD1 and 18 of 21 (85.7%) renal units were stone- free on POD1 noncontrast computerized tomography. Mean operative time was 58.5 minutes and mean stone burden was 138.9 mm. Mean stone diameter was 11.6 mm and mean diverticular diameter was 15.3 mm. Of 22 renal units 16 had followup excretory urography. All diverticula decreased in size and 14 (87.5%) had complete resolution.

CONCLUSIONS

In patients with symptomatic radiopaque caliceal diverticular stones, a single stage procedure without the need for ureteral catheterization combined with direct infracostal diverticular puncture allows for a rapid procedure with little morbidity.

A large renal pelvic diverticulum, presenting incomplete excretion during tc-99m mag-3 scintigraphy and tracer accumulation on tc-99m dmsa scintigraphy; a case report

This case report illustrates the dynamic and static renal scintigraphic images of a patient with an unusual large diverticulum of the renal pelvis. The initial diagnosis by intravenous pyelography (IVP) and ultrasonographic (US) examination was a renal pelvic diverticulum of the left kidney, and the patient was referred to the nuclear medicine department for exploration of the effect of the pelvic diverticulum on renal functions. We performed dynamic renal scintigraphy with technetium-99m (Tc-99m) labeled mercaptoacetyl triglycine (MAG-3) and static renal scintigraphy with Tc-99m labeled dimercaptosuccinic acid (DMSA). In dynamic renal scintigraphy, bilaterally normal concentration function was observed. While right kidney excretion function was normal, an incomplete excretion pattern was seen on the left side. Complete urinary flow obstruction occurred approximately at the 10th minute of the acquisition, which did not seem to respond to the i.v. furosemide application. However, when only the renal cortex was included in the region of interest, the obstructive pattern disappeared. In static renal scintigraphy, a large renal pelvic diverticulum localized antero-medially was clearly visualized in the left-anterior oblique projection, most probably due to accumulation of radiopharmaceutical inside it. This case showed that a renal pelvic diverticulum should be thought of when an incomplete excretion pattern is seen on dynamic renal scintigraphy. Using only a cortical region of interest may also help to distinguish other types of obstructive pattern from diverticulum. Additionally, Tc-99m DMSA scintigraphy may show diverticulum localization with antero-oblique projections in addition to routine projections.

Expression of laminin and fibronectin in renal dysplasia

The pathogenesis of renal dysplasia is a matter of debate. Recent theories have conceptualized the role of extracellular matrix proteins in the genesis of renal dysplasia. During normal nephrogenesis, collagen type I and III and fibronectins are lost and laminin and syndecan appear once proper induction has occurred. Any deviation from the normal pattern is said to lead to dysplasia. In this study, the expressions of adhesive glycoproteins, laminin, and fibronectin were studied immunohistochemically in 25 autopsy cases of renal dysplasia and normal age-matched control cases. These cases of renal dysplasia were categorized into 3 groups based on the period of gestation: 20 to 26 weeks, 27 to 33 weeks, and 34 to 40 weeks. The immunohistochemical findings were graded from 0 to 4+ based on the visual intensity. Chi-square analysis was used to calculate the difference in expressions of laminin and fibronectin in cases and controls as a whole and within and between age groups. Immunostaining for laminin in all age groups showed a significant difference in expression between dysplastic kidneys (less expression) and normal controls (greater expression). In the case of fibronectin expression, all but 1 group showed a significant difference, with dysplastic kidneys showing more and normal controls showing less expression. The inference derived is that laminin expression decreases and fibronectin expression increases in renal dysplasia compared with normal nephrogenesis.

Erect and supine radiographs to assess effectiveness of SWL for stones in a caliceal diverticulum or dilated calix

BACKGROUND AND PURPOSE

There are patients who have been treated with shockwave lithotripsy (SWL) for stones in a caliceal diverticulum (CD) or a dilated calix in whom the degree of fragmentation is difficult to assess. The aim of this study was to see if adequate fragmentation could be confirmed by the demonstration of layering of fine fragments on an erect radiograph.

PATIENTS AND METHODS

Over a period of 9 months, 13 patients with stones in a CD or a dilated calix with a stenosed infundibulum were studied 2 weeks after SWL with erect and supine radiographs.

RESULTS

One of eight patients with a CD cleared all fragments. Two patients showed no change in the appearance of the stone on either the supine or the erect film, and of the remaining five patients, three demonstrated layering of sand at the base of the CD. Five patients with a dilated calix and a narrow infundibulum were also studied: two of these patients became stone free, two demonstrated complete fragmentation with layering of the sand, and in one patient, a 4-mm fragment, hidden within the sand, was revealed only on the erect film.

CONCLUSION

There are patients who have been treated with SWL for stones in a CD or a dilated calix in whom adequate fragmentation is difficult to demonstrate. An erect radiograph in these patients may demonstrate layering of the fragments to confirm fragmentation and obviate repeat SWL.

Endoscopic management of symptomatic caliceal diverticula: a retrospective comparison of percutaneous nephrolithotripsy and ureteroscopy

BACKGROUND AND PURPOSE

A myriad of minimally invasive options exist for managing symptomatic caliceal diverticula, including shockwave lithotripsy, percutaneous surgery, retrograde ureteroscopy, and laparoscopy. Yet no direct comparisons have been made in the literature of the relative treatment efficacy of ureteroscopy (URS) and percutaneous nephrolithotripsy (PNL). A retrospective review of our patients was performed to determine the most appropriate endoscopic management option for patients with symptomatic caliceal diverticula.

PATIENTS AND METHODS

Between November of 1994 and April 2001, 39 patients presented with symptomatic caliceal diverticula, 37 of which contained calculi. Twenty-two patients (56%) underwent PNL, and 17 patients (44%) were managed by URS. Of the PNL group, 82% required the creation of a neoinfundibulotomy. The stone burden in the PNL group averaged 11.4 x 12.0 mm and that in the URS group 12.7 x 13.0 mm (p > 0.05). Pain, recurrent urinary tract infections, and nausea and vomiting were the presenting complaints in both subgroups of patients, with pain being by far the most common symptom. The average hospital stay was 2.8 days for the PNL group. All the URS procedures were performed on a same-day-surgery basis. Results, including stone-free, symptom-free, and complication rates, were compared for the two groups.

RESULTS

Thirty-five percent of the URS group were symptom free at 6 weeks' follow-up, with an additional 29% reporting an improvement in pain, whereas 86% of the PNL group was completely symptom free at 6 weeks' follow-up. Only 19% of the URS group were stone free on follow-up intravenous urography v 78% of those undergoing PNL (three patients failed to return for follow-up imaging). It was not possible to identify the ostium of the stenotic infundibulum in 4 patients (24%) undergoing URS, and 7 patients (41%) eventually went on to PNL with ultimate success. The PNL was statistically better than URS in producing stone-free results for diverticula located in the upper pole and for stones <11 mm (p < 0.05). No complications occurred in the URS group; however, complications were identified in four patients after PNL. One patient developed clot urinary retention necessitating Foley catheterization and manual bladder irrigation; one patient experienced significant bleeding necessitating early cessation of the procedure. Two patients sustained intrathoracic complications, one a pneumothorax and the other a pneumohemothorax after supra-11(th) rib access. Both were managed successfully with tube thoracostomy.

CONCLUSIONS

Our review clearly suggests an advantage of percutaneous management over ureteroscopy for complex posterior symptomatic caliceal diverticula, although with a slightly increased risk of complications. Therefore, PNL should be considered the primary modality for managing these difficult processes. In cases where the stenotic infundibulum cannot be traversed with a guidewire, creation of a neoinfundibulotomy permitted secure access to the collecting system while providing effective results.

Pyelocalyceal diverticulum: an unusual cause of acute renal colic

The differential diagnosis of acute flank pain includes kidney stones, urinary tract infection, dissecting abdominal aortic aneurysm (AAA), arterial or venous compromise of the kidney, renal abscess, renal carcinoma, and papillary necrosis. This is a report of an unusual cause of renal colic: pyelocalyceal diverticulum. Stasis of urine within a diverticulum promotes both calculus formation and urinary tract infection, either of which can lead to colic. Several radiographic findings may suggest a calyceal diverticulum, including, on plain X-ray, a very peripheral or mobile renal calculus, or on intravenous pyelogram, an early filling-defect and delayed or retained filing of a circular or ovoid mass.

Pyelocalyceal diverticulum: the imaging spectrum with emphasis on the ultrasound features

Clinical and imaging data of 11 patients with pyelocalyceal diverticulum were retrospectively examined. Four patients suffered from ipsilateral flank pain, one from recurrent urinary tract infection and the other six from unrelated symptoms. All patients underwent ultrasound as the initial imaging study. In two cases ultrasound was the only examination performed. Additional imaging studies were obtained in the other nine patients (abdominal radiography in six cases, intravenous urography (IVU) in five and CT in four). Ultrasound suggested the diagnosis of pyelocalyceal diverticulum in eight cases owing to the presence of echogenic and mobile material within the cyst-like lesion. In three cases the ultrasound appearance was similar and indistinguishable from a simple cyst and the diagnosis was made by another imaging study IVU in two cases and CT in one). We suggest that ultrasound examination is the best imaging method for the diagnosis of a pyelocalyceal diverticulum, and no further imaging modalities are required when mobile echogenic material is seen. In uncertain cases, another relatively inexpensive imaging study should be added such as abdominal radiography or IVU.