Calyceal diverticula. Ureteroscopic management

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.

Treatment Options for Calyceal Diverticula

PURPOSE OF REVIEW

Calyceal diverticula are rare entities that can pose a significant challenge when it comes to their management. We analyse and summarise the literature with a focus on recent advances in the management of calyceal diverticula and discuss the advantages and disadvantages of each surgical technique.

RECENT FINDINGS

The identification of calyceal diverticula requires a certain level of suspicion and contrast-enhanced imaging. Conventional techniques of imaging the renal collecting system such as the classic intravenous urography are now superseded by the ease of access to contrast-enhanced CT imaging. Conventional surgical techniques for managing calyceal diverticula are not being superseded by new techniques but rather being progressively enhanced and improved through the amelioration of existing technology. Debate still exists over the best treatment approach for the management of symptomatic calyceal diverticula, the choice of which still very much depends on the location and anatomy of the diverticulum itself. The most significant advance in the management of calyceal diverticula and indeed stones, in general, seems to be the progressive miniaturisation of percutaneous nephrolithotomy (PCNL) equipment allowing effective treatment with a reduction in associated risks of conventional PCNL. The increasing accessibility of robotics has a role to play in the management of this condition but is not likely surpass flexible ureteroscopic (fURS) or percutaneous approaches. The future of surgical management for this condition lies in striking a balance between treatment efficacy and invasiveness. More recent identification of metabolic disturbances in patients with calyceal diverticular stones may provide further insights into the underlying pathology of this condition and is likely to play a role in future research of diverticular stones.

Retrospective Analysis of Ultrasound-guided Flexible Ureteroscopy in the Management of Calyceal Diverticular Calculi

Background:

Percutaneous nephrolithotomy (PCNL) is the most widely recommended treatment for calyceal diverticular calculi, providing excellent stone-free results. However, its invasiveness is not negligible considering its major complication rates. Flexible ureteroscopy (FURS) is currently used to treat calyceal diverticula. However, the greatest drawback of FURS is locating the diverticulum since its neck is narrow and concealed. In such a case, the FURS procedure must be converted to PCNL. The aim of this study was to evaluate ultrasound-guided flexible ureteroscopy (UFURS) identifying diverticulum and the management of calyceal diverticular calculi.

Methods:

A retrospective analysis was conducted on 24 patients who had calyceal diverticular calculi. In all 12 patients in the UFURS group, direct FURS failed to find evidence of calyceal diverticula but were confirmed with imaging. The other 12 patients in the PCNL group received PCNL plus fulguration of the diverticular walls.

Results:

Puncture of calyceal diverticulum was successful in all 12 UFURS patients. Two patients in this group had postoperative residual calculi and two patients developed fever. In the PCNL group, percutaneous renal access and lithotomy were successful in all 12 patients. One patient in this group had residual calculi, one had perirenal hematoma, and two patients developed fever. No significant difference was found in the operating time (UFURS vs. PCNL, 91.8 ± 24.2 vs. 86.3 ± 18.7 min), stone-free rate (UFURS vs. PCNL, 9/12 vs. 10/12), and rate of successful lithotripsy (UFURS vs. PCNL, 10/12 vs. 11/12) between the two groups (all P > 0.05). Postoperative pain scores in the FURS group were significantly lower than that in the PCNL group (2.7 ± 1.2 vs. 6.2 ± 1.5, P < 0.05). Hospital stay in the UFURS group was significantly shorter than that in the PCNL group (3.4 ± 0.8 vs. 5.4 ± 1.0 days, P < 0.05). All patients were symptom-free following surgery (UFURS vs. PCNL, 10/10 vs. 12/12).

Conclusion:

Ultrasound-guided puncture facilitates identification of calyceal diverticula during FURS and improves the success rate of FURS surgery.

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.

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.

Lasers in percutaneous renal procedures

INTRODUCTION

Since the invention of lasers in 1960, they have been increasingly used in medicine. In this review paper, the types of lasers used in urology, in addition to their applications to percutaneous renal surgery will be reviewed. Specifically, use of lasers in the percutaneous management of renal stones, upper tract transitional cell carcinoma and stricture will be reviewed.

MATERIALS AND METHODS

Pubmed was searched for citations since 1966. The following terms were used: "lasers", "calculi", "endopyelotomy", and "transitional cell carcinoma".

RESULTS

Due to its minimal depth of penetration, holmium laser has proven to be safe and efficacious. It is currently the primary energy source for flexible instrumentation, and also has demonstrated efficacy in percutaneous lithotripsy (faster than ultrasonic lithotripsy and safer than electrohydraulic lithotripsy). Holmium laser been used for antegrade endopyelotomy and percutaneous resection of upper tract transitional cell carcinoma.

CONCLUSIONS

Holmium laser is safer than other lasers and has become the gold standard for laser lithotripsy for flexible instrumentation. It has been used successfully in the percutaneous management of renal stones, ureteropelvic junction obstruction, and upper tract transitional cell carcinoma. Holmium laser is an alternative energy source to conventional lithotripters and electrocautery for endopyelotomy and resection of upper tract transitional cell carcinoma.

Treatment of Symptomatic Caliceal Diverticula Using a Mini-Percutaneous Technique with Greater Than 3-Year Follow-Up

BACKGROUND AND PURPOSE

Caliceal diverticula can be treated with a variety of techniques. Traditional percutaneous techniques utilize nephrostomy-tract dilation to between 26F and 32F. Identification of a small diverticulum can be difficult after such dilation. The mini-percutaneous nephrolithotomy technique has been described for the treatment of nephrolithiasis. We report on two patients with caliceal diverticula treated using a mini-perc technique with long-term follow-up.

PATIENTS AND METHODS

Two symptomatic patients underwent treatment of posterior caliceal diverticula using a mini-perc technique. An interventional radiologist placed an 8F nephrostomy tube for access to the diverticulum. The following day, a 12F/14F ureteral access sheath was placed over a guidewire. Through the sheath, we identified the diverticulum and its neck with a 7F semirigid ureteroscope. The diverticular neck was balloon dilated to 18F, followed by fulguration with a 3F Bugbee electrode. A Double-J ureteral stent was placed antegrade from the diverticulum to the bladder, and an 8F nephrostomy tube provided external drainage.

RESULTS

The mean operative time was 138.5 minutes, and the mean estimated blood loss was 10 mL. Neither of the diverticula contained calculi. The mean length of stay was 2.5 days, and there were no complications. The hemoglobin and creatinine values showed no significant change. Both patients remained asymptomatic at a mean follow-up of 38 months.

CONCLUSION

Treatment of a caliceal diverticulum via a mini-perc technique is safe, effective technique with durable long-term results. It offers a less-invasive alternative to standard percutaneous treatment with larger access sheaths.

Treatment Selection and Outcomes: Renal Calculi

This article summarizes the history of how renal stones have been treated over the centuries and reviews current treatments and outcomes for renal stones. The authors provide an algorithm based on available outcome data for shock wave lithotripsy, ureteroscopy, and percutaneous nephrolithotomy.

Retrograde intra-renal surgery for stone extraction

OBJECTIVE

To assess various clinical parameters affecting the efficacy and safety profile of retrograde intra-renal surgery (RIRS) for stone extraction.

MATERIAL AND METHODS

Between the years 2001 and 2003, 63 patients underwent RIRS in our department for renal calculi, including 25 who had stones >/=20mm in size.

RESULTS

Among the 63 patients who underwent the operation, 19 (30%) had infectious complications postoperatively. Although neither preoperative stenting nor stone burden were found to have any direct implication on postoperative course, a trend was seen as 64% of the infected patients had initially had large renal stones (>/=20mm in diameter) and 59% had been preoperatively drained.

CONCLUSIONS

RIRS is currently considered to be a safe standard retrograde endoscopic procedure for treating renal calculi. However, patients with stones>20 mm in diameter or multiple small calculi, especially in the presence of pre-existing tubes or following prior urinary tract infections, represent a subgroup of patients that are, in general, at higher risk of remarkable infectious complication rates and are likely to experience less satisfying stone-free rates when RIRS surgery is performed.

Management of stones in calyceal diverticulum

PURPOSE OF REVIEW

Congenital abnormities in urology are very common. These abnormalities include calyceal diverticula, which are frequently diagnosed as an incidental finding. Once symptomatic, calyceal diverticula have to be located by accurate imaging and then treated in an appropriate manner.

RECENT FINDINGS

Possible methods of treatment in calyceal diverticula are generally the same as in other abnormalities of the kidney: extracorporeal shock-wave lithotripsy, endoscopic procedures, percutaneous procedures, laparoscopy and open surgery. It is important to find the exact location of the stone-bearing diverticulum and various imaging techniques may be used for this purpose. Metabolic work-up remains important.

SUMMARY

There is a strong trend towards endoscopical and laparoscopical treatment in renal abnormalities such as calyceal diverticula. A combination of these two methods seems to be appropriate in some cases.

Lasers in the upper urinary tract for non-stone disease

Though the most common use for lasers in the genitourinary tract is for urolithiasis, a number of other urologic conditions can be treated with lasers because of their unique ablative, destructive and hemostatic properties. This paper reviews the advantages and disadvantages of laser technology for a number of non-stone indications.

Ureteroscopy for Symptomatic Hydrocalices: A Case Series

BACKGROUND

Hydrocalix is an uncommon condition that typically is treated with percutaneous dilation of the stenotic infundibulum. Ureteroscopy has the advantage of minimizing invasiveness.

METHODS

We reviewed our experience with 12 retrograde ureteroscopies for hydrocalix in 10 patients.

RESULTS

Access to the hydrocalix could not be achieved in one. Of the remaining 11, the original infundibulum was dilated in all but one, in whom neoinfundibulotomy was performed with a laser. The laser was used in eight cases, balloon dilation with cautery in two, and cautery alone in one. Of the seven hydrocalices bearing stones, four were rendered stone free. Immediate symptomatic success was achieved after 6 of the 11 evaluable procedures (one patient was lost to follow-up after a technically successful procedure). Of the five symptomatic failures, three went on to additional treatment (one ureteroscopy and two percutaneous), one elected against treatment despite recurrence of stenosis, and one had persistent pain owing to stones even though the hydrocalix was cured. Of the six symptomatic successes, three were without symptoms at a mean 25 months of follow-up, two have had recurrences necessitating additional treatment (both percutaneous) a mean of 51 months later, and one did not have adequate imaging follow-up.

CONCLUSION

Ureteroscopy for hydrocalix achieved technical success in most patients, but relief of symptoms followed only about half of the procedures. A trial of ureteroscopy does not preclude subsequent success with a percutaneous approach. Ureteroscopy is a reasonable option for hydrocalix for patients who wish to avoid percutaneous surgery.

Advanced intrarenal ureteroscopic procedures

The role of flexible ureteroscopy in the management of intrarenal pathology has undergone a dramatic evolution, powered by improvements in flexible ureteroscope design; deflection and image quality; diversification of small, disposable instrumentation; and the use of holmium laser lithotripsy. This article reviews the application of flexible ureteroscopy for advanced intrarenal procedures.

Surgical management of urolithiasis

The surgical management of urinary calculus disease has changed dramatically in the past two decades. Minimally invasive options have made open stone surgery nearly obsolete. The development of shock wave lithotripsy, percutaneous nephrostolithotomy techniques and intracorporeal lithotripsy devices has conferred unprecedented management tools for upper tract stones. Moreover, transfusion rates, hospital costs, and convalescence periods have been markedly reduced when compared to open surgery. Likewise, the advent of fiberoptic technology has resulted in miniaturization of ureteroscopes making access to the entire collecting system possible from either a retrograde or antegrade approach. With experience, successful stone retrieval has occurred in upwards of 90% of cases, again with minimal complications. The subspecialty of Endourology has emerged over the past 20 years and significantly changed the management of urinary tract calculi within this short period of time. Further advancements in shock wave and laser technology, training modules and the development of more durable endoscopes may prove beneficial in providing even better stone treatments with a reduction in morbidity.

Childhood infundibular stenosis

Infundibular stenosis is a rare condition marked by dilation of one or more calices proximal to a stenotic infundibulum. Contrary to older reports, more recent information suggests that progressive renal dysfunction occurs in a significant number of these patients. We present a case of incidentally discovered infundibular stenosis. On the basis of the existing published reports, we make several recommendations. Close monitoring for a decline in renal function secondary to hyperfiltration injury is essential, and a worsening should prompt referral to a pediatric nephrologist. Progressive hydronephrosis should be corrected surgically, although proof of effect on the disease process is lacking in the evidence-based reports.