Nephrolithiasis in patients with urinary diversion

The Saudi urological association guidelines on urolithiasis

Aims

The Saudi Urolithiasis Guidelines are a set of recommendations for diagnosing, evaluating, and treating urolithiasis in the Saudi population. These guidelines are based on the latest evidence and expert consensus to improve patient outcomes and optimize care delivery. They cover the various aspects of urolithiasis, including risk factors, diagnosis, medical and surgical treatments, and prevention strategies. By following these guidelines, health-care professionals can improve care quality for individuals with urolithiasis in Saudi Arabia.

Panel

The Saudi Urolithiasis Guidelines Panel consists of urologists specialized in endourology with expertise in urolithiasis and consultation with a guideline methodologist. All panelists involved in this document have submitted statements disclosing any potential conflicts of interest.

Methods

The Saudi Guidelines on Urolithiasis were developed by relying primarily on established international guidelines to adopt or adapt the most appropriate guidance for the Saudi context. When necessary, the panel modified the phrasing of recommendations from different sources to ensure consistency within the document. To address areas less well covered in existing guidelines, the panel conducted a directed literature search for high quality evidence published in English, including meta analyses, randomized controlled trials, and prospective nonrandomized comparative studies. The panel also searched for locally relevant studies containing information unique to the Saudi Arabian population. The recommendations are formulated with a direction and strength of recommendation based on GRADE terminology and interpretation while relying on existing summaries of evidence from the existing guidelines.

Retrograde intrarenal surgery: An expanding role in treatment of urolithiasis

During the past 3 decades, the surgical management of kidney stones has undergone many technological advances and one is the development of the flexible ureteroscopy. The development of this instrument as well as ancillary equipment such as baskets, graspers, and others, and improvements in lithotripsy with Holmium: YAG laser have led to expand its indications with diagnostic and therapeutic management of medical issues of the upper urinary tract such as urolithiasis and urothelial tumors. The objective of this review is to describe its indications and results in the different scenarios for the treatment of urinary stones.

Kidney Stone in a Patient with an Ileal Conduit

The advantage of a retrograde over an antegrade approach in ileal conduit diversion is the lower morbidity. Furthermore, in cases in which there are bone deformities and no ureteral reflux from the reservoir into the upper tract, percutaneous access can be challenging. Thus, a retrograde approach should be considered as the first-line option for the treatment of renal stones in patients with an ileal conduit, but the urologist should keep in mind that an antegrade or combined approach may be possible in the case of failure.

Retrograde Endourological Management of Upper Urinary Tract Abnormalities in Patients with Ileal Conduit Urinary Diversion: A Dual-Center Experience

INTRODUCTION

Patients with ileal conduit urinary diversions are at an increased risk of long-term upper urinary tract (UUT) complications, including anastomotic strictures, infections, and urolithiasis. The reconstructed urinary system poses challenges for endoscopic manipulation. We present and describe our dual-center experience in performing retrograde ureteroscopy to treat or diagnose UUT abnormalities in patients with ileal conduit incontinent diversion.

PATIENT AND METHODS

We performed a retrospective analysis of medical records for all patients with previous urinary diversion who underwent retrograde ureteroscopic procedures via the ileal loop in our institutions over a 9 year period (between June 2007 and August 2016).

RESULTS

Fifty-four procedures were performed in 36 patients. Mean age was 61 (28-90) years. Average time from diversion to ureteroscopic procedure was 13.0 (0.08-53) years. Stone disease was the most common indication for intervention in 35.2% (19/54) of cases, with a stone-free rate of 78.9% (15/19). Other indications included surveillance of transitional-cell carcinoma in 22.2% (12/54), diagnostic flexible ureteroscopy (fURS) in 20.4% (11/54), stricture management in 11.1% (6/54), removal of encrusted stent/nephrostomy in 7.4% (4/54), urine leak after diversion in 1.9% (1/54), and miscellaneous in 1.9% (1/54). Successful retrograde access was possible in 74% (40/54) of cases. A long and tortuous ileal segment, too difficult to negotiate, was the most common cause of failure to access the UUT. In 13 out of 54 (24.1%) cases, retrograde fURS was combined with simultaneous percutaneous antegrade access. Six patients (11.1%) developed postprocedural pyrexia requiring additional antibiotic therapy, and one (1.9%) patient required embolization of the renal artery for ongoing bleeding. Median length of stay was 1 day (0-55), with 13 (24%) being performed as day-case procedures.

CONCLUSIONS

Retrograde ureteroscopy in patients with ileal conduits can be technically challenging due to distorted anatomy. This procedure can be safely performed in experienced hands with standard endourological equipment. An antegrade approach can be carried out simultaneously, which may be required in a small number of patients.

Stones in special situations

There are several special situations in which urinary lithiasis presents management challenges to the urologist. An in-depth knowledge of the pathophysiology, unique anatomy, and treatment options is crucial in order to maintain good health in these patients. In this review, we summarize the current literature on the management of the following scenarios: bladder stones, stones in bowel disease, during pregnancy, in association with renal anomalies, with skeletal deformities, in urinary diversions, and in children.

[Multiple stones in atypical heterotopic reservoir in a patient with renal transplant: endourologic resolution]

BACKGROUND

Urolithiasis is a frequent complication in a heterotopic reservoir and the surgical management could be a difficult problem. Open surgery is not recommended in patients with multiple previous surgeries. A less invasive technique, such as the endourologic procedures, would allow high stone-free rate and low surgical morbidity.

INTRODUCTION

Stone formation in the reservoir is a well-known complication of urinary diversion. The incidence of lithiasis in patients with continent urinary diversion is reported as 12-52.5%. Most patients will have multiple physical factors, such as immobility, need for self-catheterization and poor urine drainage, so that it is not certain that an intestinal reservoir is the cause of stones on its own. The management of urolithiasis in continent urinary diversion can be challenging and could be a difficult problem to solve. A less invasive technique, such as the endourologic procedures, is desiderable, especially in patients with kidney transplant and low immune defence.

MATERIALS AND METHODS

We present the case of a 59-year-old woman with previous history of spina bifida and with neurogenic bladder. At a pediatric age, she underwent incontinent urinary diversion using a sigmo-colic conduit. For several years she had been suffering from kidney stones and recurrent urinary infections, which led to a left nephrectomy for pyonephrosis, subsequent deterioration of renal function and dialysis. In 2004, we performed an atypical continent and self-catheterizable reservoir using the previous colic conduit detubularized and ileum-cecal tract with Mitrofanoff system conduit of 14 Fr size. Finally, kidney transplant was carried out as last surgical procedure. Recently she has come to our attention for multiple and large reservoir stones.

SURGICAL TECHNIQUE

preliminary exploration of the continent pouch with flexible cystoscope. Percutaneous access with Endovision° direct control through the afferent conduit with 8 Fr flexible ureteroscope. Dilation of percutaneous tract with pneumatic balloon and positioning 30 Fr Amplats sheet. Lithotripsy, with ultrasound and ballistic sources, was performed and the residual fragments were removed with grasping. At the end of the procedure, after controlling the complete clearance with flexible nephroscope and X-ray, a percutanous 12 Fr catheter and a 12 Fr Foley in the Mitrofanoff conduit were inserted.

RESULTS

No fever or increase serum creatinine were observed in the post-operative time. On day 3, we removed the percutaneous foley and after 7 days we performed a cystography with a normal pouch configuration; no leakage or residual fragments were observed. The woman was discarge and returned to usual self-catheterization. The first 3-month post-operative control was regular; no infections or pain were reported.

CONCLUSIONS

In special cases, like this one, the percutaneous procedure is preferred to open surgery for a best control of the pouch and a simple complete clearence of the fragments.

Large orthotopic reservoir stone burden: Role of open surgery

PURPOSE

To present our experience in open poucholithotomy as a primary management of large orthotopic reservoir stone burden and discuss different management options.

MATERIALS AND METHODS

Records of men underwent radical cystectomy and orthotopic urinary diversion were retrospectively reviewed as regards pouch stone formation. Patients with large reservoir stone burden managed by open poucholithotomy were further selected.

RESULTS

Large reservoir stone burden was encountered in 12 post radical cystectomy men. All underwent open poucholithotomy as a primary management of their reservoir stones. Median age at cystectomy was 46 (range: 32-55) years with a median total follow up period of 214.15 (range: 147-257) months and a median interval to stone detection of 99 (range: 63-132) months. The median stone burden was 5260 (range: 3179-20410) mm(2). All patients were continent during the day while 5 showed nocturnal enuresis; 2 of them became continent after removal of the stones. Post poucholithotomy, all patients had sterile urine cultures except one who showed occasional colonization. None of the 12 patients showed stone recurrence after poucholithotomy. Two patients underwent revision of a dessuscepted nipple valve in association with stone removal.

CONCLUSIONS

Open poucholithotomy for large reservoir stone burden is a feasible and safe option. It saves the reservoir mesentery and adjacent bowel. It allows complete removal of the stone(s) leaving no residual fragments. Furthermore, it permits correction of concomitant reservoir abnormalities.

Percutaneous treatment of large upper tract stones after urinary diversion

OBJECTIVES

To present our experience in percutaneous management of large upper tract stones after urinary diversion.

METHODS

From October 1984 to March 2005, 20 percutaneous nephrolithotomy and 4 antegrade ureteroscopy procedures were performed in 17 men and 7 women, with a mean age of 53.5 years. The urinary diversions were an ileal W neobladder, hemi-Kock pouch, ileal conduit, and rectal bladder in 10, 7, 4, and 3 patients, respectively. The median interval between diversion and stone management was 1.5 years. Success was defined as a stone-free, nonobstructed renal unit at 3 months after the intervention. Follow-up was performed every 6 months with intravenous urography or noncontrast computed tomography for diagnosis of stone recurrence and evaluation of renal morphology.

RESULTS

Renal punctures were guided with ultrasonography in 18 patients (75%) and fluoroscopy in 6 patients. One intraoperative complication (4.16%) and two postoperative complications (8.3%) occurred. All patients with ureteral stones became stone free after one procedure. Auxiliary procedures were needed in 5 patients after percutaneous nephrolithotomy; 2 patients required a second session and 3 needed extracorporeal shock wave lithotripsy. The overall success rate was 87.5% (21 patients). One patient with treatment failure underwent open surgery, and two with small residual fragments were followed up. Long-term follow-up data were available for 15 patients. The stone recurrence rate was 33.3% (5 patients) after a median follow-up of 40 months (range 14 to 132). Recurrent stones were treated with extracorporeal shock wave lithotripsy.

CONCLUSIONS

The results of our study have demonstrated that percutaneous treatment of large upper tract stones after urinary diversion offers a high success rate with minimal morbidity. However, regular follow-up after treatment is recommended.

The surgical management of stones in patients with urinary diversions

PURPOSE OF REVIEW

Stones in patients with urinary diversions present unique challenges. Anatomical knowledge of the type of diversion is essential to adequately and safely treat the patient. We will review the anatomical differences between the forms of diversion and helpful maneuvers for successful management of urinary lithiasis in this patient population.

RECENT FINDINGS

Urology has recently seen a shift toward continent diversion with the most common forms being continent-cutaneous or orthotopic reservoirs. In patients with these forms of diversions, stone management is challenging. In continent cutaneous diversion, for example, trauma to the continence mechanism during stone manipulation can occur. Recently, percutaneous pouch access to facilitate the treatment of upper/lower tract stones has become popular. In patients with upper tract stones, knowledge of ureteral anatomy is essential. There is controversy not only on non-refluxing versus refluxing anastomoses, but also on the mechanism of formation of non-refluxing anastomoses. At the same time, some stone centers have gone back to attempting retrograde management of upper tract stones. In some types of anastomoses, however, this is not possible.

SUMMARY

Percutaneous pouch access for large stone burden has become the treatment of choice for most urologists. Percutaneous access may involve placement of an Amplatz sheath or laparoscopic trocars into the pouch, allowing for stone entrapment or intracorporeal lithotripsy. With upper tract stones, retrograde management can be attempted in the setting of a refluxing-ureteral-anastomosis. Laparoscopic management of stones may be on the rise, however, like open stone surgery, the indications are narrow.

[Giant stone in a Bricker urinary diversion. Obstruction uropathy as the presenting form]

Bowel is used in urological surgery to replace the bladder, either as a conduit to drain urine to the abdominal wall as a urinary stoma or refashioned to form a substitute bladder. Many factors contribute to stone formation, being urinary stasis, mucus production and bacteriuria the most important. Metabolic changes induced by exposure of segments of the alimentary tract to urine promote struvite, calcium oxalate and calcium phosphate stone formation. Generally, the majority of patients with stones in a urinary diversion can be treated with minimally invasive techniques. Open surgical removal is considered when other modality of treatments cannot be accomplished safely and expeditiously.

Stone risk after bladder substitution with the ileal-urethral Kock reservoir

OBJECTIVE

The study was carried out to compare urinary biochemical and physicochemical environments in patients who had undergone bladder substitution with the ileal-urethral Kock reservoir, and who had no actual urinary infection, with those of healthy subjects.

MATERIAL AND METHODS

The participants were 23 male patients who had undergone bladder substitution with the ileal-urethral Kock reservoir and 25 healthy men. All subjects had sterile urine at the time of urine collection. Concentrations of calcium, magnesium, phosphorus, creatinine, citrate, oxalate, and ammonia in 24-h urine samples were measured. Estimates of ion activity products of calcium oxalate (CaOx), calcium phosphate (CaP), brushite (Bru), and magnesium ammonium phosphate (MAP) in urine were calculated according to Tiselius.

RESULTS

There was no significant difference in 24-h urinary volume between patients with a bladder substitute and the healthy controls. For most of the other measured values the results for patients differed significantly from those for controls. The most striking findings were markedly lower urinary excretion rates of citrate (p < 0.0001) and higher urine pH (p < 0.0001) in patients compared with controls. These findings were reflected in significantly higher levels of urinary supersaturation with respect to CaOx (p < 0.0001), CaP (p <0.0001), Bru (p < 0.0001) and MAP (stuvite) (p < 0.0001) in patients with a bladder substitute compared with healthy subjects.

CONCLUSIONS

Hypocitraturia seems to be the main risk factor for calcium stone formation in non-infected Kock reservoir patients, and citrate supplementation appears to be the most obvious choice for stone prophylaxis in patients with intestinal urinary diversion and recurrent renal stone formation.

A prospective randomized study comparing absorbable and nonabsorbable staples in constructing antireflux valves of urethral hemi-Kock pouches

OBJECTIVE

To determine the long-term complications associated with constructing an antireflux nipple valve using absorbable or nonabsorbable staples in the urethral hemi-Kock pouch.

PATIENTS AND METHODS

Fifty patients (all men, median age 47 years, range 28-73) undergoing construction of a urethral hemi-Kock pouch were randomized prospectively into two equal groups. In group 1, absorbable (polyglyconate) staples were used for the construction, and in group 2 nonabsorbable (metal) staples were used but omitting the staples applied at the tip of nipple valve. Assessment during the follow-up of 6-88 months comprised urine analysis, culture and sensitivity, measurement of serum creatinine, electrolytes and blood gases, and plain abdominal radiography, intravenous urography and micturating pouchography.

RESULTS

In group 1, 21 patients were evaluable; a pouch stone was detected in one, extussusception of the valve in one and valve stenosis in one. In group 2, 20 patients were evaluable; pouch stones were detected in six, extussusception of the valve in three and valve stenosis in one.

CONCLUSION

Compared with nonabsorbable (metal) staples, the use of absorbable (polyglyconate) staples significantly decreased the incidence of pouch stone formation and improved valve stability in patients with a urethral hemi-Kock pouch.