Ureteroscopic Injuries to the Upper Urinary Tract

Management of iatrogenic ureteric injury with retrograde ureteric stenting: an analysis of factors affecting technical success and long-term outcome

Background Iatrogenic ureteral injuries arise as serious complication following obstetrics, gynecological, general, and urological surgery with incidence in the range of 0.5-10%. Retrograde placement of double-J ureteric stent is a possible treatment option if the injury is not recognized at the time of surgery. Purpose To assess technical success and long-term outcome associated with retrograde ureteric stent insertion for iatrogenic ureteric injury. Material and Methods Between 1999 and 2011, 26 patients with initially unrecognized iatrogenic ureteric injury underwent initial management with retrograde ureteric stenting. Full case-notes were available for review in 25 patients. Results The mean interval from injury to attempted stenting was 19.4 days. Successful retrograde ureteric stenting was achieved in 21/25 patients (81%). Retrograde stenting failed in four patients, and nephrostomy followed by alternative procedures were performed instead. At a median follow-up interval of 9.7 months, normal anatomy was demonstrated on 12/21 patients (57%) and a stricture was observed in 6/21 patients (28%) with three requiring surgical intervention. Conclusion Retrograde stenting is a safe and efficient initial management in patients with iatrogenic ureteric injuries.

Significance of Extraction Forces in Kidney Stone Basketing

INTRODUCTION

Ureteroscopic stone extraction devices are effective tools in the management of urolithiasis, but on occasion, their improper use can cause injury to the ureter. Avulsion and perforation of the ureter as a result of excessive forces on the extraction device are some of the more serious complications of this treatment.

MATERIALS AND METHODS

In this article, avulsion and perforation forces were measured by two different test setups. Eleven clinicians were asked to apply three ranges of forces (safe, cautious, and dangerous).

RESULTS

The output force measurements were recorded and plotted for further analysis. The maximal average perforation forces were 7.13±2.36 N in the benchtop tests and 7.07±2.20 N in the ex-vivo porcine tests (P=0.54). The maximal average avulsion forces were measured to be 10.14±2.01 N in the benchtop tests. Although the average forces were similar in the proximal and distal parts of the ureter (P=0.27), higher values were recorded for the distal part. The operative time was noted to be significantly different in the safe and cautious force regions (P=0.006). The average forces were higher in the benchtop tests compared with the porcine ureter tests. The extraction forces were measured and were noted to be significantly different for attending physicians and residents. The results suggest the need for force feedback training for residents.

CONCLUSION

The findings can be used to design a "smart device" that can provide visual force feedback to clinicians while they are operating, leading to improved patient outcome.

Ureteric injury: a challenging condition to diagnose and manage

Although ureteric injury is relatively uncommon, it is a serious event that can result in intra-abdominal sepsis, renal failure, and loss of the ipsilateral renal unit. Most injuries are iatrogenic and remain undiagnosed until the patient presents with symptoms postoperatively. In addition to compromising patient safety, missed ureteric injuries frequently result in litigation. Over the past 20 years, there has been a rapid uptake of laparoscopic and robotic techniques within urology and other surgical specialties. This trend, coupled with increased use of ureteroscopy, has increased the risk of injury to the ureter. The key to diagnosing and managing a ureteric injury is to have a low threshold for suspecting its presence. Diagnosis can be achieved using retrograde pyelography, ureteroscopy, CT, or intravenous urography. Initial management should involve ureteric stent placement or percutaneous nephrostomy drainage. In selected patients, surgical reconstruction might be the optimal approach. Decisions regarding surgical technique (open, laparoscopic, or robotic) are guided by the clinical situation and surgical expertise available.

Acute postoperative pain after ureteroscopic removal of stone: incidence and risk factors

Purpose

Ureteroscopic removal of stones (URS) has been widely used to treat ureteral stones because it is comparatively safe, has a high success rate, and enables patients to rapidly return to their daily routines. However, some patients experience pain after URS, but the incidence of acute post-URS pain remains largely unknown. This study aimed to investigate the incidence of acute postoperative pain after URS and the associated risk factors.

Materials and Methods

Data for 143 consecutive patients who underwent URS from June 2008 to December 2010 were collected. After excluding 8 patients who developed intraoperative complications, the patients were divided into two groups according to postoperative pain on the first postoperative day. Acute postoperative pain was defined as a pain score greater than 4 on a visual analogue pain scale (normal range, 0 to 10). Various factors were analyzed to identify the risk factors that could predict acute postoperative pain after URS.

Results

The stone-free rate without URS intraoperative complications was 95.5%. A total of 21 (14.6%) patients experienced postoperative pain on the first postoperative day. Young age, psychiatric illness, history of urinary tract infection, use of a stone basket, large stone size, and prolonged operation time were identified as risk factors for acute postoperative pain.

Conclusions

The incidence of acute postoperative pain is not that low and should not be overlooked, because it is associated with postoperative complications that could result in an unscheduled hospital admission or visit. Active pain control should be contemplated after URS in young patients and in those with a history of urinary tract infection, psychiatric illness, large stone size, and prolonged operation time.

Ureteroscopic ultrasound technology to size kidney stone fragments: proof of principle using a miniaturized probe in a porcine model

PURPOSE

A prototype ultrasound-based probe for use in ureteroscopy was used for in vitro measurements of stone fragments in a porcine kidney.

METHODS

Fifteen human stones consisting of three different compositions were placed deep in the collecting system of a porcine kidney. A 2 MHz, 1.2 mm (3.6F) needle hydrophone was used to send and receive ultrasound pulses for stone sizing. Calculated stone thicknesses were compared with caliper measurements.

RESULTS

Correlation between ultrasound-determined thickness and caliper measurements was excellent in all three stone types (r(2) = 0.90, p < 0.0001). All 15 ultrasound measurements were accurate to within 1 mm, and 10 measurements were accurate within 0.5 mm.

CONCLUSION

A 3.6F ultrasound probe can be used to accurately size stone fragments to within 1 mm in a porcine kidney.

Percutaneous management of ureteral injuries that are diagnosed late after cesarean section

Objective

We wanted to present the results of percutaneous management of ureteral injuries that were diagnosed late after cesarean sections (CS).

Materials and Methods

Twenty-two cases with 24 ureteral injuries that were diagnosed late after CS underwent percutaneous nephrostomy (PN), antegrade double J (DJ) catheter placement and balloon dilatation or a combination of these. The time for making the diagnosis was 21 ± 50.1 days. The injury site was the distal ureter in all cases (the left ureter: 13, the right ureter: 7 and bilateral: 2). Fifteen complete ureteral obstructions were detected in 13 cases. Ureteral leakage due to partial (n = 4) or complete (n = 3) rupture was noted in seven cases. Two cases had ureterovaginal fistula. All the cases were initially confirmed with antegrade pyelography and afterwards they underwent percutaneous nephrostomy. Balloon dilatation was needed in three cases. Antegrade DJ stents were placed in 10 cases, including the three cases with balloon dilatation. Repetititon of percutaneous nephrostomy with balloon dilatation and DJ stent placement was needed in one case with complete obstruction. All the cases were followed-up with US in their first week and then monthly thereafter for up to two years.

Results

Eighteen ureters (75%) were managed by percutaneous procedures alone. A total of six ureter injuries had to undergo surgery (25%).

Conclusion

Percutaneous management is a good alternative for the treatment of post-CS ureteral injuries that are diagnosed late after CS. Percutaneous management is at least preparatory for a quarter of the cases where surgery is unavoidable.

Handling and prevention of complications in stone basketing

OBJECTIVE

To review the incidence, risk factors, and treatment options of intraoperative and postoperative complications of stone basketing in urology with emphasis on certain principles that must be upheld to prevent those complications.

METHODS

A literature search was performed using the MEDLINE database on stone basketing between 1970 and 2005.

RESULTS

Iatrogenic trauma due to retrieval of a stone is well known but the exact incidence is difficult to ascertain. Rarely, stone basketing can cause major trauma to the ureter, such as avulsion or intussusception, requiring open or laparoscopic intervention for ureteral continuity restoration. Mucosal abrasion, ureteral perforation, and stricture formation have also been described as complications of stone basketing. Occasionally, the engaged or broken basket can provoke anxiety even for experienced urologists. Factors that increase the risk of complications, strategies for repair, and techniques for prevention are discussed extensively.

CONCLUSION

Infrequent, surgical misadventures during stone basketing can occur and must be treated appropriately. Careful attention to instrument selection and surgical techniques and awareness of risk factors and type and site of potential injury are essential to reduce these complications.

Complications of ureteroscopy

Ureteroscopy has undergone a dramatic evolution over the last two decades. Although ureteroscopic injury is the most common cause of ureteral trauma because of the large number of ureteroscopic procedures performed, improvements in instrumentation and technique have resulted in a reduced incidence of serious complications. Despite significant technologic advances, however, surgical misadventures still occur, some of which have lasting consequences. Careful attention to instrument selection and surgical technique are critical to reduce untoward events related to ureteroscopy. As such, adverse sequelae associated with ureteroscopy should be related to the underlying pathology itself rather than to the treatment.

[Endoscopic treatment of ureteral lithiasis. Our experience with 360 retrograde uretero-renal endoscopies in the last ten years]

Presentation of results and complications obtained in 360 procedures of transuretral ureterorenoscopy (URS) in ureteral lithiasis performed in our unit from january 1990 to august 2000 in 354 patients: 55% female and 45% male. A rigid ureteroscopy Storz 10.5 Ch. was used and intracorporeal lithotripsy was necessary in 17.31% of cases. URS indications were always treatment of ureteral lithiasis, pelvic ureter localization in most cases (70.33%) being 93.05% the percentage of overall success and with a significant decrease when the calculus was located in the upper third of the ureter. Serious complications were only 3.05% of cases and endoscopic surgery was necessary in three cases of ureteral stenosis. In our experience, URS is our technique of choice for treatment of lower and medium third of the ureter where the percentage of success we have obtained were 98.99% and 95.83% respectively.

Surgical management of a ureteral defect with ureterorrhaphy and of ureteritis with ureteroneocystostomy in a foal

A 2-day-old male foal developed uroperitoneum. Initial exploration of the abdomen via ventral midline celiotomy failed to localize the source of uroperitoneum. Bilateral nephropyelocentesis and antegrade urography were performed, and a defect in the right ureter and stenosis of the left ureter were identified. With the foal in dorsal recumbency in the Trendelenburg position, ureterorrhaphy was performed on the right ureter. After ureterorrhaphy, a ureteral catheter was maintained as a stent. The stenotic left ureter was transected, and ureteroneocystostomy was performed using a drop-in mucosal apposition technique. The ureteral catheter was removed 26 days after surgery. Histopathologic findings suggested that ureteritis of unknown origin was a possible initiating factor for stenosis of the left ureter. The drop-in technique for ureteroneocystostomy may be used successfully for ureteral transposition in horses. Ureterorrhaphy combined with the use of a ureteral stent may be used to repair ureteral defects in foals.

To stent or not to stent? That is still the question

BACKGROUND AND PURPOSE

Most patients are stented after ureteroscopy for stone extraction. This practice necessitates a second procedure to remove the stent, with its inherent morbidity. The aim of our study was to determine whether routine stenting of the ureter is really necessary after ureteroscopy.

PATIENTS AND METHODS

This prospective study evaluated 26 men and 18 women admitted for elective distal ureteral stone fragmentation. The stones ranged in size from 6 mm to 1 cm. Of the series, 16 patients (10 men) had been stented prior to ureteroscopy. A 9F semirigid ureteroscope was used in 31 cases, and a 7.5F semirigid ureteroscope was used in the other 11 cases; there was no need for ureteral orifice dilatation with either ureteroscope. Ballistic intracorporeal lithotripsy was performed in all cases with the Swiss Lithoclast; all stone fragments were retrieved with a 3F helical basket. The patients were followed up as inpatients for 24 hours and reviewed in the clinic 1 week later with a request to report if they felt significant discomfort or loin pain or became feverish.

RESULTS

Only one patient (male) had to be readmitted with loin pain. Two others (both women) complained when they attended for follow-up of having had dull lower abdominal pain and some frequency.

CONCLUSIONS

The low incidence of complications in this preliminary study suggests that routine stenting is not necessary after ureteroscopy. The chief exception to this statement is patients who had a difficult and prolonged stone fragmentation.

Routine radiologic surveillance for obstruction is not required in asymptomatic patients after ureteroscopy

OBJECTIVE

A retrospective medical record review was performed with the goal of determining the need for radiologic evaluation after ureteroscopy.

PATIENTS AND METHODS

Of 183 patients undergoing ureteroscopic procedures at our institution between 1989 and 1993, 131 underwent postoperative radiologic studies capable of diagnosing ureteral obstruction. Of these patients, 110 (84%) were asymptomatic after the procedure, and radiologic procedures capable of displaying obstruction were performed at a median of 60 days (mean 73 days; standard deviation 189 days) after ureteroscopy.

RESULTS

None of these asymptomatic patients displayed obstruction at the time of the routine follow-up radiologic procedure. Of those 21 patients (16%) who experienced flank pain subsequent to ureteroscopy, 13 were found to have ureteral obstruction secondary to ureteral calculus. One patient (1/131 or 0.8%) was found to have a ureteral stricture, which occurred after a full-thickness ureteral injury. All cases of postoperative obstruction were heralded by a concomitant display of flank pain.

CONCLUSION

Routine postoperative radiologic studies are not necessary in surveillance for obstruction in the asymptomatic postureteroscopy patient, as obstruction should become evident by virtue of flank pain. The exception to this practice may be in patients experiencing a ureteral perforation intraoperatively, who may be at greater risk of stricture.

Ureteroscopic lithotripsy using mini-endoscope and Swiss lithoclast: experience in 147 cases

To evaluate the efficacy of a semirigid mini-endoscope and the Swiss Lithoclast compared with a conventional rigid endoscope and ultrasound, the results of transurethral ureteroscopic lithotripsy in 147 patients over a period of 30 months were analyzed according to the type of ureteroscope (rigid v semirigid) and energy (ultrasound v Lithoclast) used. In the initial 25 cases (Group I), a conventional rigid ureteroscope and ultrasound were used. The latter 122 patients (Group II) were subjected to ureteroscopic lithotripsy using a miniscope and the Lithoclast. The results were superior in Group II with respect to the overall success rate (p = 1.6 x 10[-2]), first-attempt success rate (p = 2.9 x 10[-4]), and the need for ureteral dilation (P = 1.0 x 10[-6]) compared with Group I. There were no major complications. Overall, minor complications (hematuria and urinary tract infection) were observed in 25% of the cases. Further, the results of ureteroscopic lithotripsy in Group II were comparable to those of SWL in situ for upper ureteral calculi and better than for those located in the iliac and lower ureter as reported previously. Our results demonstrate that the Swiss Lithoclast provides effective fragmentation of even hard and smooth stones without increasing the complication rate. This lithotripter is reliable, safe, and simple to operate. In addition, the cost of maintenance is almost nil.

Changing incidence and etiology of iatrogenic ureteral injuries

In the last decade there have been major advances in endoscopic surgery including ureteroscopy and laparoscopy, both of which may cause ureteral injury. We sought to determine if increased use of these procedures affected the frequency and nature of major iatrogenic ureteral injuries managed at our medical center. From 1980 to 1984 we treated 8 patients with such injuries compared to 19 patients treated from 1985 to 1989. The most recent period corresponded to the institution of ureteroscopy and the use of more aggressive laparoscopic procedures. Of the patients 14 sustained injuries at our center while 13 were referred from other institutions. Between 1985 and 1989 the incidence of injuries per total hospital admissions at risk increased from 4 to 11 per 10,000 (p = 0.0067), the incidence of urological injuries increased from 4 to 23 per 10,000 (p = 0.0071) and the incidence of injuries occurring in gynecologic patients increased from 13 to 41 per 10,000 admissions (p = 0.0385). There was no difference in the incidence of injuries in the general surgical population. From 1980 to 1984 no laparoscopic or ureteroscopic injuries occurred. However, from 1985 to 1989, 25% of gynecologic injuries occurred during laparoscopy and 70% of urological injuries were sustained during ureteroscopic procedures. Depending on the extent of the injury, patients were initially treated with either endourological or open surgical procedures. Good results were obtained in the majority of cases. Contemporary therapeutic strategies for treating patients sustaining ureteral injuries are discussed.

The fate of the iatrogenic retroperitoneal stone

Ureteral perforation with resultant retroperitoneal stone expulsion is a recognized complication of ureteroscopy. In a 5-year retrospective review of 400 cases we identified a 1.3% incidence of iatrogenic retroperitoneal stone dislodgment. Average followup was 21 months. Four cases were managed with observation and 1 required surgical correction of a ureteropelvic junction stricture. We discuss the management of this problem, which begins with thorough radiographic documentation in the perioperative period. Aggressive ureteroscopic manipulation and attempted stone retrieval are not warranted, and a ureteral stent should be placed. Radiographic followup and clinical observation confirm the low morbidity associated with retroperitoneal urinary stones. Patient understanding of the extra-ureteral stone location is essential to avoid misdiagnosis and mismanagement by uninformed physicians in the future.