Endoscopic management of ureteral calculus in a patient with ureterosigmoidostomy diversion

ARTICLE INFO _________________________________________________________ ___________________ Vol. 39 (4): 593-596, July August, 2013 doi: 10.1590/S1677-5538.IBJU.2013.04.19 IBJu | endoscopic management of ureteral calculus 594 An abdominal radiograph could not show the stone confirming it as radiolucent. Serum creatinine was 1.6 mg/ dL. A percutaneous nephrostomy-ultrasound guided was emergently performed to relieve obstruction. While waiting for the definitive treatment the patient lost the nephrostomy and underwent a new percutaneous nephrostomy. The initial treatment plan was to perform an anterograde holmium LASER flexible ureterolitotripsy. Under fluoroscopic guidance a middle calyx was punctured which allowed adequate access to the ureteropelvic junction (UPJ). Dilation was carried out with axial ureteral dilators over a 0.035” guidewire and a 9.5Fr access sheath was introduced until close to the UPJ entry. When the flexible ureteroscope was introduced distal migration of the stone was noticed. Because of ureteral tortuosity we were unable to perform LASER lithotripsy and retrieve the stone (Figure-2). In this procedure a retrograde access was tried, however, we were unable to catheterize the ostium. A retrograde approach with a side view endoscope was then carried. During sigmoidoscopy, right ureteral ostium was located at a distance of approximately 15 cm from the anal verge. The ureteral ostium was catheterized with a cholangiopancreatography catheter (Figure-3). A retrograde pyelogram confirmed the 2 cm stone in the distal ureter. A 0.035’’ hydrophilic guide wire was inserted and dilation of the uretero-sigmoid junction was carried with a balloon catheter (Figure-4). After dilation it was possible to see the calculus protruding through the ostium and a biliary balloon catheter was used to pull it down (Figure-5). The Figure 1 Pre-operative CT scan.


INTRODuCTION
Ureterosigmoidostomy has been used as a form of urinary diversion for either benign or malignant conditions.Urinary lithiasis has been reported as ureterosigmoidostomy complication in 3-10% of the cases in recent series (1,2).Bacterial colonization and diversion-associated metabolic derangements are main risk factors (3) in this situation.
Treatment of urinary stones depends on clinical, anatomic and stone factors and there are many therapeutic options that might be considered when evaluating uncommon cases.Nevertheless, the choice for the best approach depends on the availability of equipment and expertise of the surgeon.

CASE REPORT
We report the case of a 62 years old woman submitted to cystectomy and ureterosigmodostomy 35 years ago due to bladder endometriosis.Potassium citrate was used to prevent hyperchloremic metabolic acidosis.The follow-up was unremarkable until the patient's current presentation with acute right flank pain.A CT scan showed left kidney agenesis and right kidney hydronephrosis.A 2 cm stone with 580HU was located in the proximal right ureter (Figure -1).

Endoscopic management of ureteral calculus in a patient with ureterosigmoidostomy diversion _______________________________________________
An abdominal radiograph could not show the stone confirming it as radiolucent.Serum creatinine was 1.6 mg/ dL.A percutaneous nephrostomy--ultrasound guided was emergently performed to relieve obstruction.While waiting for the definitive treatment the patient lost the nephrostomy and underwent a new percutaneous nephrostomy.
The initial treatment plan was to perform an anterograde holmium LASER flexible ureterolitotripsy.Under fluoroscopic guidance a middle calyx was punctured which allowed adequate access to the ureteropelvic junction (UPJ).Dilation was carried out with axial ureteral dilators over a 0.035" guidewire and a 9.5Fr access sheath was introduced until close to the UPJ entry.When the flexible ureteroscope was introduced distal migration of the stone was noticed.Because of ureteral tortuosity we were unable to perform LASER lithotripsy and retrieve the stone (Figure-2).In this procedure a retrograde access was tried, however, we were unable to catheterize the ostium.
A retrograde approach with a side view endoscope was then carried.During sigmoidoscopy, right ureteral ostium was located at a distance of approximately 15 cm from the anal verge.The ureteral ostium was catheterized with a cholangiopancreatography catheter (Figure -3).A retrograde pyelogram confirmed the 2 cm stone in the distal ureter.A 0.035'' hydrophilic guide wire was inserted and dilation of the uretero-sigmoid junction was carried with a balloon catheter (Figure -4).After dilation it was possible to see the calculus protruding through the ostium and a biliary balloon catheter was used to pull it down (Figure -5).The  calculus had a soft appearance, however, we were unable to recover it for further composition analysis.A CT scan confirmed that the patient was stone free postoperatively and the nephrostomy was removed.Renal function returned to baseline after treatment and the patient was well until the last follow-up 1 year after the procedure.

DISCuSSION
Treatment options for ureteral stones in patients with urinary diversion range from minimally invasive procedures such as extracorporeal shock-wave lithotripsy (ESWL) to conventional open surgery.
Open surgery may be a definitive option, however, morbidity associated with a reoperation and the risks of complications must be considered.ESWL may be a good option for proximal ureteral stones but for radiolucent or distal stones the results may not be optimal (4,5).
Chemolytic dissolution of stones or residual stone fragments is a useful adjunct to conventional treatment.Although uric acid stones have good response to chemolytic therapy, oral chemolysis may take several days for complete dissolution (6).Moreover, urinary alcalinization may be difficult in patients with chronic metabolic acidosis.Direct chemolysis can also be done through the nephrostomy tube.Nevertheless, the risks of infection and metabolic complications may be increased in this particular situation.
Choosing a retrograde or anterograde approach will depend on location of the stone.For stones located in medium or proximal ureter an anterograde approach is feasible.Renal access should be carried out in medium or upper calix to allow passage of the flexible ureteroscope without angulation as described by Lackmichi et al. (7).However, urologists must be aware that more than one flexible ureteroscope may be necessary to accomplish the procedure as was emphasized by the authors.In the reported case anterograde ureterolithotripsy was unsuccessfully because of distal migration of the stone and tortuosity of the ureter.
For stones located in the distal ureter retrograde approach may be necessary.Fitzgerald et al. ( 8) described ureterolithotripsy with a semirigid ureteroscope of a large ureteral stone.A guide wire was passed through a previously placed nephrostomy down the sigmoid/rectum which helped to locate and dilate the ureterointestinal junction.Mosler et al. (9) were the first to report the use of a side view duodenoscope for retrograde approach.Insufflation with air during endoscopy helped to locate the ureterointestinal junction allowing dilation of the anastomosis and removal of calculus with basket without lithotripsy.Hyams et al. (10) reported successful retrograde access in 21 of 28 attempts without the aid of previous renal percutaneous access.A flexible ureteroscope was also used to retrieve ureteral stones.In the reported case a side view duodenoscope was used for retrograde access and we also found that air insufflation helped location and dilation of the ureterointestinal junction.Lesion of ureterosigmoid junction during dilation for retrograde access might be of concern.Nevertheless, complications were not reported on Hyams' series, as well as in our case.
In the reported case lithotripsy was unnecessary.Nevertheless, flexible or semirigid ureteroscopes with the aid of LASER or other lithotripters may be used whenever necessary.

CONCLuSIONS
Endoscopic management of ureteral stones after urinary diversion is feasible and can be achieved with little morbidity.The use of retrograde or anterograde approach for ureteral stones after urinary diversions should combine endoscopic and endourologic technics in a multidisciplinary environment.

Figure 4 -Figure 5 -
Figure 4 -Dilation of the ostium with a balloon catheter.Figure5-Extraction of the stone with the balloon catheter.