Ureteroscopy 

Updated: Jun 18, 2018
Author: Michael Grasso, III, MD; Chief Editor: Bradley Fields Schwartz, DO, FACS 

Overview

Background

Ureteroscopy is defined as upper urinary tract endoscopy performed most commonly with an endoscope passed through the urethra, bladder, and then directly into the upper urinary tract. Indications for ureteroscopy have broadened from diagnostic endoscopy to various minimally invasive therapies. Technological advancements have led to broader indications while minimizing peri-operative complications resulting in efficacious access to the upper tract.

See image below.

Flexible fiberoptic ureteropyeloscope. Flexible fiberoptic ureteropyeloscope.

Endoscopic lithotripsy, treatment of upper urinary tract urothelial malignancies, stricture incisions, and ureteropelvic junction obstruction repair are all current treatments facilitated by contemporary ureteroscopic techniques. Because the application of ureteroscopic procedures has evolved from a diagnostic tool to a facilitator in complex therapeutic interventions, a proportional increase in the rate and severity of complications would be expected. However, with improved instrumentation and evolution of surgical technique, the complication rate associated with ureteropyeloscopy has actually decreased significantly.

History of the Procedure

The progression from cystoscopy to upper urinary tract endoscopy was natural, with pediatric cystoscopes being used as the first rigid rod-lens ureteroscopes. Relatively large rod-lens endoscopes, averaging 12F (3F = 1 mm) in diameter, combined with ultrasonic and electrohydraulic lithotripsy probes became the first commonly accepted ureteroscopic equipment combination used to treat distal ureteral calculi.

Ureteroscopic treatment of calculi and, in particular, distal ureteral stones was the first common application of upper urinary tract endoscopy. Early in this evolution, smaller and more precise instrumentation was obviously found to cause less trauma to normal tissues. Rigid ureteroscopes progressed from rod-lens imaging to fiberoptic imaging with outer-diameter miniaturization. The narrow and delicate distal ureter once required vigorous balloon dilation for ureteroscopic access; however, by 1989, the fiberoptic-based rigid endoscopes were small enough (averaging 7F in diameter) for frequent placement in the distal ureter under direct vision. The small rigid ureteroscopes combined with both laser and pneumatic lithotriptors are currently used to treat distal ureteral calculi in both university and community settings.

Flexible ureteroscopy was an attractive alternative to rigid ureteroscopy in that the more proximal ureter and intrarenal collecting system were theoretically more easily accessible with this type of instrument. The application of flexible ureteroscopy was first reported by Marshall in 1964.[1] He described the passage of a 9F endoscope manufactured by American Cystoscope Makers (Pelham Manor, NY) into the ureter to visualize an impacted ureteral calculus. These first flexible ureteroscopes were not capable of being directed and did not have a working channel, thus permitting only the most primitive diagnostic maneuvers. The subsequent addition of a cystoscopically placed “guide tube” facilitated placement of the first flexible ureteroscopes. In addition, irrigant then could be passed through the guide tube to displace the ureteral mucosa and debris from the distal endoscopic lens.

In the early 1980s, Bagley, Huffman, and Lyon began work at the University of Chicago to develop an improved flexible fiberoptic ureteropyeloscope.[2] Three major design changes improved the potential of the flexible ureteroscope. First, the addition of a working channel allowed irrigant and endoscopic accessories to be passed directly through the endoscope rather than through an operating sheath. Second, active tip deflection allowed the endoscope to be directed or steered to areas of interest. Finally, by altering the stiffness (ie, based on durometer measurements) of the endoscope shaft, the actively deflecting portion could be combined with passive buckling of the endoscope (ie, secondary deflection), which facilitated lower-pole intrarenal access as depicted below.

Secondary endoscope deflection that allows lower-p Secondary endoscope deflection that allows lower-pole intrarenal access.

The first steerable, actively deflectable, flexible ureteropyeloscopes were equipped with relatively large fiberoptic bundles for imaging and illumination. The addition of the working channel and a cable-and-pulley system used for active tip deflection required on outer diameter of 3.6 mm. By the late 1980s, optical fiber miniaturization and improved geometrical pixel packing produced a smaller fiberoptic bundle and thus, a smaller-diameter endoscope. Flexible ureteroscope specifications in 1990 included a 10F outer diameter, a standard 3.6F working channel, and unidirectional active tip deflection. Guide tubes were no longer required as direct guidewire endoscope placement became mainstream. Intramural ureteral dilation was often required for placement of this flexible ureteroscope into the upper urinary tract. These endoscopes allowed inspection of the entire intrarenal collecting system and became part of the standard evaluation of filling defects within the upper urinary tract defined on contrast-enhanced imaging studies and pyelograms.

The introduction of small diameter (< 8F) flexible ureteroscopes in 2001 offered greater active tip deflection and significantly advanced the therapeutic and diagnostic efficacy of ureteroscopy. These endoscopes maintained a standard 3.6F working channel for irrigation and accessory use while offering a greater deflection radius. In addition, the stiff shaft allowed for atraumatic direct endoscope placement often without a guidewire.

In 2014, digital imaging replaced fiberoptics for the small diameter flexible ureteroscope. This addition provides greater clarity with digital enhancement that improves the sensitivity of tumor mapping. The digital imager removes the round “insect eye” appearance of the quartz bundles providing a bright clear rectangular image that has twenty times the resolution of the fiberoptic and can be enhanced to accentuate malignant lesions and other urothelial anomalies. The tiny CMOS chip imager has been incorporated with the now standard specifications of small shaft diameter, exaggerated tip deflection, standard 3.6F working channel, etc.[3]  Integrated digital ureteroscopes are lighter, with integrated L.E.D.s at the end of the device. Without the need for an attached camera head and light cord, there are fewer potential points for device failure, and are also ergonomically superior to its predecessor.[4]

Currently, rigid and flexible ureteroscopes average 8F in tip diameter and are commonly passed atraumatically into the upper urinary tract without intramural dilation. These endoscopes are used to diagnose and treat various upper urinary tract disorders including calculi, urothelial malignancies, stricture disease, and bleeding lesions. The addition of laser energy applied through optical quartz fibers passed through the working channel of the endoscope has facilitated these treatments. Specific treatments are discussed further in subsequent sections of this article.

Problem

Ureteroscopy is used as a diagnostic tool in situations such as investigating abnormal imaging findings, assessing obstruction or unilateral essential hematuria, or localizing the source of positive urinary cytology results.

Therapeutic uses of ureteroscopy have broadened to include various minimally invasive therapies. Endoscopic lithotripsy (treating stones), treatment of upper urinary tract urothelial malignancies, stricture incisions, and ureteropelvic junction obstruction repair are all current treatments facilitated by contemporary ureteroscopic techniques.

Epidemiology

Frequency

Ureteroscopy is a routine procedure performed by urologists. The most common indication is to treat upper urinary tract calculi, particularly those that are either unsuitable for extracorporeal shockwave lithotripsy or are refractory to that form of treatment. Other common indications include evaluation of an abnormal lesion revealed by less invasive imaging tools (eg, intravenous pyelography [IVP], MRI, CT scanning) or localization of the source of positive urine culture or cytology results. Thus, ureteroscopy is often an essential part of the diagnostic algorithm and can also be used to treat the underlying disorder.

Indications

Diagnostic indications for ureteropyeloscopy are as follows:

  • Abnormal imaging findings - Filling defect

  • Obstruction - Determination of etiology

  • Unilateral essential hematuria

  • Localizing source of positive urinary cytology results, culture results, or other test results

  • Evaluation of ureteral injury

  • Surveillance with known history of urothelial malignancy

Therapeutic indications for ureteropyeloscopy are as follows:

  • Endoscopic lithotripsy

  • Retrograde endopyelotomy

  • Incision of ureteral strictures

  • Improvement of calyceal drainage

  • Treatment of calyceal diverticular lesions

  • Treatment of malignant urothelial tumors

  • Treatment of benign tumors and bleeding lesions

Relevant Anatomy

The ureter has 3 physiologic narrowings: (1) the ureteropelvic junction, (2) the crossing over the iliac vessels, and (3) the ureterovesical junction. This is crucial in the manifestations of calculus disease. These narrowings may result in ureteral stones becoming trapped and obstructing at these specific levels. For more information about the relevant anatomy, see Ureter Anatomy.

The segments of the ureter in which calculi can become lodged are also natural barriers for the ureteroscope. The intramural ureter is the narrowest segment and can prohibit endoscope passage. Guidewires are frequently passed into the ureteral orifice cystoscopically and are then directed into the renal pelvis with fluoroscopic assistance. Guidewires straighten the ureter and can facilitate (1) dilation of obstructed segments with balloon or graduated dilators, (2) advancement of endoscopes over the wires into the proximal collecting system, and (3) placement of internal stents and drainage catheters.

The intramural ureter once required balloon dilation for endoscope access. Small diameter semirigid ureteroscopes commonly employed in the lower ureter have graduated shafts with an oval or triangular 7.5F tip (see image below). This facilitates direct tip access, and when advanced the intramural segment is also modestly dilated (ie, dilation under direct vision). Use of a working sheath to facilitate passage of the ureteroscope beyond the intramural ureter can be employed when repeated access to the ureter is expected or if the intramural ureter is unusually tight or restrictive. The use of operative sheaths is optional, and is generally not required. Furthermore, recent literature has suggested that the use of such sheaths may have detrimental effects[5] .

Comparison of the semi-rigid Karl Storz ureterosco Comparison of the semi-rigid Karl Storz ureteroscope and tip (above) with that of the ACMI MR6 endoscope (below).

Operative ureteral access sheaths have, in general, a relatively large outer diameter ranging from 12F to 16F, often significantly greater than the normal diameter of the ureteral lumen with the obvious risk of wall trauma during insertion. Traxer and colleagues in Paris recently underscored this concern by evaluating ureters immediately after sheath removal.[5] Ureteral trauma with wall damage was found in almost one-half of patients (46.5%), with high grade full thickness injury identified in 13.3%. Similar findings were confirmed by Guzelburc et al with low-grade injuries found in 41.5% of patients,[6] and a meta-analysis by Huang et al demonstrated a higher incidence of post-operative complications with the use of ureteral access sheaths (OR 1.46), including persistent post-operative hematuria, increased need for post-operative ureteral stents and ureteral strictures.[7]  These high rates of trauma are exponentially greater than noted in series where small diameter endoscopes were placed directly into the ureter, thus questioning the long term risk of subsequent stricture disease associated with routine operative sheath use. For these reasons access sheaths should be employed judiciously.

As the fiberoptic-based rigid ureteroscope continues proximally past the ureteral orifice, it then is inhibited by the natural curvature of the ureter as it crosses the iliac vessels, psoas muscle, and the ureteropelvic junction. If the ureter is dilated, the rigid endoscope may be safely passed proximally. If not, then conversion to an actively deflectable flexible endoscope is indicated.

Flexible ureteroscopes are passed into the upper urinary tract with a wireless technique or over a guidewire. The flexible ureteroscope is a particularly useful instrument, especially when a rigid endoscope cannot be placed safely into the more proximal ureter or if intrarenal inspection is required. In these cases, endoscope tip deflection is essential to completely inspect the calyces.

Lower pole intrarenal access performed with a flexible ureteroscope can be challenging and may require both active tip and passive shaft deflection. Design improvements of the small diameter flexible ureteroscopes include two-way logical or “intuitive” active endoscope tip deflection (i.e. thumb lever down causes tip to go down and vice versa), a large radius of deflection, and incorporation of a standard passive secondary deflecting segment of the more proximal shaft (which buckles to produce greater deflectability for the most dependent lower pole intrarenal access).

To place the tip of the endoscope into the lower pole, the instrument must first be actively deflected and then advanced to allow the proximal shaft to buckle as depicted below. This maneuver, termed secondary deflection, was historically required in 60% of traditional flexible ureteroscopies for a complete inspection. The increased active deflection offered by new-generation flexible ureteroscopes significantly decreases the need for secondary deflection and enhances the surgeon’s ability to inspect all aspects of the renal collecting system.

Using secondary deflection, access to this lower p Using secondary deflection, access to this lower pole stone burden is made possible.
The use of dilute contrast injected through the ur The use of dilute contrast injected through the ureteroscope ensures adequate mapping and inspection of all calyces

Contraindications

Diagnostic ureteroscopy has few contraindications. Untreated urinary tract infection, endoscopy without appropriate antibiotic coverage, and uncorrected bleeding diathesis are relative contraindications.

Contraindications to therapeutic ureteroscopy (eg, lithotripsy, endopyelotomy, tumor therapy) are more numerous and can mirror those associated with the corresponding more invasive open surgical intervention. In general, the major contraindications are related to untreated infections and uncorrected bleeding diathesis prior to therapeutic endoscopy.

 

Workup

Laboratory Studies

Useful pre-operative laboratory stories include:

  • Coagulation factors

    • Prothrombin time

    • Activated partial thromboplastin time

    • Platelet count

  • Urinalysis and urine culture

  • Standard preoperative laboratory workup

    • CBC count

    • Electrolyte levels

    • Serum creatinine and BUN determination

Imaging Studies

Useful preoperative imaging studies depending on the clinical presentation may include the following:

  • Renal ultrasonography

  • IVP (once ubiquitous, now increasingly being phased out)

  • CT scan

    • non-contrast (i.e. stone protocol)
    • IV contrast with delay (i.e. Hematuria, Mass protocol)
  • MRI

 

Treatment

Surgical Therapy

Ureteroscopy can be divided into diagnostic endoscopy and therapeutic treatments.

Diagnostic Ureteroscopy

Atraumatic diagnostic endoscopy minimizes mucosal distortion, allowing for complete mapping of the upper urinary tract. Ureteroscopic access is obtained with a wireless technique, if possible. The ureteral orifice is visualized and intubated without the assistance of a guidewire. The intramural ureter is traversed employing a "no-touch" technique, and the more proximal ureter and renal collecting system are then mapped. In a recent prospective study of 460 consecutive upper-tract endoscopies, no-touch ureteroscopy was successfully performed in most patients without prior stenting or ureteral dilation.[8] This wireless form of flexible ureteroscopy eliminates the potential trauma, mucosal irritation, and inadvertent manipulation of stones or tumors caused by guidewires and is particularly helpful when the collecting system is evaluated for mucosal/intra-luminal lesions.

Fluid irrigation facilitates passage of the ureteroscope while simultaneously clearing the optical field. Sterile saline is the preferred irrigant. Although automatic pumps are available for this purpose, hand irrigation is preferred for its precise control of volume dispensed.

When wireless flexible ureteroscopy is not feasible, a small-diameter rigid ureteroscope can be employed first to inspect and map the ureter. A guidewire is then placed only to the area that already has been inspected, and then a flexible instrument is the passed over it in a monorail fashion, under fluoroscopic guidance, to complete the mapping. The flexible ureteroscope is directed from calyx to calyx, and frequently dilute contrast material is injected through the working channel of the endoscope to help ensure the entire collecting system is inspected as depicted below.

Therapeutic Ureteroscopy

Therapeutic ureteroscopy is used in varied applications, including in the treatment of stones, urothelial tumors, and stricture disease.

Management of Stone Disease

Ureteroscopy is a safe and minimally invasive method of treating stone disease in the kidneys and ureter as shown below. It can be used either as primary therapy or as salvage therapy for residual stones following treatment with other modalities such as extracorporeal shockwave lithotripsy (ESWL) and/or percutaneous nephrolithotomy (PCNL). Compared with ESWL, ureteroscopic lithotripsy achieves a greater stone-free state.[9] Success rates following ureteroscopy are shown in Table 2 and Table 3 in the Outcome and Prognosis section below.

Furthermore, in select cases, ureteroscopy has been shown to be a viable and effective means of treating stone disease where ESWL may be contraindicated, such as in pregnant women and pediatric patients. In fact, a study by Freton et al indicated that in pediatric patients with stones of the upper ureter or kidney, the achievement of stone-free status in a single session was more likely with flexible ureteroscopy than with ESWL. The investigators found that after a single procedure, 37% of patients who had undergone flexible ureteroscopy were stone free, compared to 21% of patients who were treated with ESWL, even though there was more complexity to the urinary stones (a higher rate of multiple stones and lower-pole calculi) in the ureteroscopy group.[10]  Prattley and colleagues have demonstrated the efficacy of this modality in the elderly population, with significant initial and final stone-free states (88%; 97%), with 73% of cases performed as day surgery procedures.[11]

Ureteroscopic image of an impacted jack stone in t Ureteroscopic image of an impacted jack stone in the ureter. These calculi are composed of calcium oxalate monohydrate.

Urothelial Malignancy

Ureteroscopy is also a powerful tool in the diagnosis, treatment, and surveillance of transitional cell tumors of the upper tracts.[12, 13]

See image below.

Ureteroscopic image of a papillary transitional ce Ureteroscopic image of a papillary transitional cell carcinoma of the ureter.

Stricture Disease/Obstruction

In addition, ureteroscopy can be employed to treat ureteral stenosis/stricture and ureteropelvic junction obstruction. In each setting, an energy source is delivered through the working channel of the endoscope to fragment, ablate, and/or incise. Additional accessories can also be passed through the standard 3.6F working channel to remove stone fragments or to obtain biopsy samples (see Intraoperative details).

Preoperative Details

Prior to ureteroscopic examination, the surgeon must have the appropriate instrumentation available. This includes endoscopes, accessories, appropriate energy sources, and fluoroscopy.

Rigid ureteroscope specifications include the following:

  • Tip diameter - 4.5-9.5F (6.9F most common)

  • Optics - Fiberoptic bundles or digital imager

  • Working channels - One, 2, or 3 (2 channels preferred)

  • Accessory length - 40 - 60 cm

Flexible ureteroscope specifications include the following:

  • Tip diameter - 6.9-9.8F (7.5F most common)

  • Optics - Fiberoptic bundles or digital imager

  • Working channel - Single, 3.6F

  • Access - Guidewire (0.035 in nitinol or 0.038 in stainless steel)

  • Accessory length - 100 - 120 cm

Energy sources include the following:

  • Holmium:yttrium-aluminum-garnet (Ho:YAG) laser

  • Neodymium:yttrium-aluminum-garnet (Nd:YAG) laser

  • Thulium laser

  • Electrocautery

  • Electrohydraulic lithotripsy

  • Mechanical impactor (ie, Lithoclast)

Prophylaxis is as follows:

  • All patients receive a preoperative dose of a broad-spectrum parenteral antibiotic.

  • Patients with positive cultures should receive appropriate treatment course, based on sensitivity panel

Intraoperative Details

When therapeutic ureteroscopy is performed, a guidewire can be useful. It can help facilitate multiple passes of the instrument while maintaining access to the upper urinary tract. For example, during treatment of a distal ureteral stone, a rigid ureteroscope is passed up the ureter beside the guidewire and laser energy is delivered through a small quartz fiber to fragment the stone. An accessory such as a wire prong grasper or basket then can be used to extract fragments with multiple passes of the endoscope (see video below). A ureteral sheath can be employed, but its relatively large diameter may potentiate ureteral wall trauma as described earlier.[5]

Wireless ("no touch") ureteroscopy, laser lithotripsy and stone extraction technique performed with the digital ureteroscope.

There are a variety of stone extraction devices available. Those composed of nitinol, which maintains its shape and rarely kinks, are preferred- as depicted in the video above.

If electrocautery is to be employed, special attention to the guidewire choice helps minimize energy scatter. If a standard stainless steel guidewire is used, electrical current may inadvertently arc to the wire and result in thermal injury. This can be prevented by using an insulated guidewire such as a Teflon-sheathed nitinol guidewire (eg, Zebra wire, Boston Scientific, Natick, Mass).

Intraluminal ultrasonography has been used in various applications. It offers enhanced diagnostic yield in the evaluation of disease processes such as ureteropelvic junction obstruction, tumors of the upper tract, and anatomic anomalies (eg, crossing renal vessels). It has also improved treatment of hidden or submucosal ureteral calculi.

Special Consideration: The Impacted Distal Calculus/The Tight Intramural Ureter

A particular therapeutic quandary can be the impacted distal ureteral stone. When a guidewire cannot be passed cystoscopically, employing a small diameter semi-rigid ureteroscope is useful in gaining access to the proximal ureter. The tip of the endoscope is placed into the edema and a guidewire is passed proximally beyond the obstruction under direct vision.

In the case of a tight intramural ureteral tunnel, after a guide wire is passed into the proximal collecting system, a two wire access technique is often helpful. In this setting a small caliber, two-channel semi-rigid ureteroscope is passed just to the ureteral orifice beside the pre-placed safety guide wire. A second guide wire is passed through the working channel proximally under direct endoscopic and fluoroscopic guidance. Irrigation is administered thru the second endoscopic working channel to clear the optical field and the endoscope rotated placing its tip between the two guide wires. The semi-rigid ureteroscope is then gently passed proximally between the two wires, compressing the edema and gently dilating the distal segment until the calculus is encountered. Once at the level of the calculus the second wire is removed and lithotripsy can commence.

Postoperative Details

When the ureteroscopy is completed, internal ureteral stents are commonly placed to facilitate healing and to ensure drainage, particularly if vigorous therapeutic maneuvers were performed and/or the ureter required dilation for access. However, simple diagnostic ureteroscopy without ureteral dilation does not routinely require postoperative ureteral stenting.

Internal ureteral stents are associated with lower urinary tract symptomatology, including urinary frequency, urgency, and mild-to-moderate hematuria, which is transient. Ureteral stents are removed after a period of healing that can range from a few days to 6-8 weeks, depending on the complexity of the treatment. Stents are usually removed in the office with either an attached nylon trailor or cystoscopically.

Most ureteroscopic procedures are performed as day surgery outpatient procedures. On discharge prophylactic oral (quinolone-based) antibiotics and analgesics are frequently prescribed. Anticholinergic medications and alpha-blockers can be used to minimize frequency, urgency, and discomfort often associated with ureteral stents; however, individual patient tolerance varies widely. Careful selection of the best stent length and optimal positioning help to minimize these unpleasant symptoms.

Follow-up

Most patients are return after 1-2 weeks following the ureteroscopic procedure for stent removal and surgical follow-up. If endoscopic lithotripsy was performed, serial imaging (eg, plain radiography or ultrasonography) is performed to define residual stone burden.

Subsequent imaging is required and tailored to the clinical presentation and underlying disease process. If, for example, a ureteral stricture is incised ureteroscopically, serial follow-up imaging studies defining drainage and renal function (eg, IVP or CT urography and nuclear medicine renal scan) are performed periodically, particularly during the first year to ensure an acceptable surgical outcome.

Complications

Minor intraoperative complications

Minor ureteroscopic complications are those that have no long-term deleterious effects and, if treated promptly, cause only minimal or transient postoperative problems. Table 1 (below) chronologically lists 5 studies spanning the almost 20-year evaluation of ureteroscopic equipment and technique. In the initial series from the Mayo Clinic, large-diameter endoscopes were used,[14] while, in the last two series, the smallest-diameter ureteropyeloscopes were used, with a noticeable decrease in complication rates.[15, 16]

In general, the minor complication rate associated with ureteropyeloscopy was decreased based on refined technique, experience of the operators, and prompt treatment or prevention of intraoperative problems. Prophylactic parenteral antibiotics, careful guidewire placement, endoscope minimization preventing excessive ureteral dilation, and postoperative ureteral stenting all have decreased the rate of postoperative problems. This, combined with better surgical training and improved instrumentation, has resulted in this very positive trend.

Major intraoperative complications

Major intraoperative problems associated with ureteroscopy include trauma to tissues leading to significant ureteral wall perforations, avulsions, or foreign body (eg, stone) migration into the ureteral wall. The major complication rate has markedly decreased (now occurring in less than 1% of all ureteroscopic procedures). As with the minor problems, major complications are less common for basically the same reasons. However, when they do occur, treatment is more complex.

Major ureteral wall perforations can be the product of improper application of an endoscope, dilator, or sheath. The forceful positioning of any device, particularly in young patients with a small caliber ureter, can lead to ureteral wall trauma. Pre-operative placement of a double-J stent is often unnecessary, but is recommended when unusual difficulty in access is encountered, or when a strictures is found. Pre-stenting greatly facilitates complex ureteroscopy.

Ureteral wall trauma may lead to stone migration into the wall or outside the urinary tract. Subsequently, this may result in the formation of a stone granuloma and ureteral wall strictures. Meticulous clearance of stone fragments in this setting and stent drainage will minimize the risk of subsequent stricture.

When a minor problem is encountered during ureteroscopy, taking appropriate measures to prevent progression is essential. Additionally, the inappropriate application of endoscopes, lithotrities, and accessories can lead to surgical misadventure. An example would be basketing a relatively large renal stone with a retrograde-placed ureteroscope and attempting extraction rather than fragmentation.

A basic concern is that, if the stone was too large to pass, how does engagement in a basket and application of tension along the long axis of the ureter have merit? Surgeons can find themselves in a tenuous situation in which extraction is impossible; stone disengagement is difficult, and, with a single endoscopic working channel, simultaneous placement of an endoscopic lithotrite is difficult or impossible. Excessive tension on the ureter can lead to an avulsion, with disastrous complications.

Allowances or contingencies should be made for stone fragmentation if extraction is deemed too difficult or dangerous. If treatment is challenging and/or access difficult, placing a stent and returning another day is a better plan, or consider an alternative technique such as percutaneous access or extracorporeal shockwave lithotripsy. Such planning can prevent complications and poor outcomes.

Recent case reports in the literature defined an issue with a specific flexible endoscope, where the outer jacket accordioned intraoperatively, resulting in a distal tip that was too large to extract. Consequently, the endoscope could not be removed. While the manufacturer in question performed a recall of this particular model, practitioners are nonetheless cautioned to perform careful inspection of their equipment prior to insertion to confirm stability of the device.[17]

If ureteral avulsion occurs in the distal segment, repair is based on standard open or laparoscopic surgical technique of ureteral reimplantation. Ureteroneocystostomy can be performed for most distal ureteral avulsions, with a psoas bladder hitch used if necessary, to create a tension-free anastomosis. A Boari bladder wall flap can increase the proximal extent of the repair to the middle third of the ureter. These repairs are usually performed over a ureteral catheter with perianastomotic drainage. This can be performed at the time of the injury or in a staged fashion after proximal percutaneous drainage is obtained.

The more proximal ureteral avulsion requires the most complex surgical repair. If a proximal ureteral avulsion is encountered intraoperatively and most of the ureter is intact, primary repair over a ureteral catheter can be performed. Unfortunately, in this setting the ureter is often devitalized. If the entire devitalized ureteral segment is brought into the bladder, it is of no value in subsequent repair. Percutaneous renal drainage should be obtained immediately for this type of ureteral injury. Subsequent therapy is based on either bowel interposition (ie, ileal ureter) or renal autotransplantation to a pelvic position. Both procedures are highly complex and have their own inherent risks.

Table 1. Comparison of Complication Rates Associated With Ureteroscopy, Emphasizing the Noticeable Decrease in the Major Complication Rate With Greater Experience and Endoscope Miniaturization (Open Table in a new window)

 

Blute, et al.[14]

Abdel-Razzak and Bagley[18]

Harmon, et al.[19]

Grasso[15]

Jiang, et al.[16]

Year

1988

1992

1997

2000

2007

Number of Procedures

346

290

209

1000

697

Minor Complications

(%)

(%)

(%)

(%)

(%)

Colic/pain

--

9.0

3.5

4.2

--

Fever

6.2

6.9

2.0

1.3

--

False passage

0.9

--

--

0.4

0.4

Hematuria

Minor

Prolonged

0.5

0.3

2.1

1.0

0

0

0.8

0.2

 

Extravasation

0.6

1.0

--

--

--

UTI

--

1.0

--

1.7

--

Pyelonephritis

--

--

--

1.0

--

 

 

 

 

 

 

Major Complications

(%)

(%)

(%)

(%)

(%)

Major perforation

4.6

1.7

1.0

0

0.3

Stricture

1.4

0.7

0.5

0.4

0.3

Avulsion

0.6

0

0

0

0

Urinoma

0.6

--

0

0

--

Urosepsis

0.3

0

0

0

--

CVA

--

--

0.5

0.1

--

DVT

--

--

--

0.1

--

MI

--

--

--

0.1

--

 

UTI= urinary tract infection; CVA= cerebrovascular accident; DVT= deep vein thrombosis; MI= myocardial infarction

Outcome and Prognosis

The outcome of a ureteroscopic procedure is based on the underlying disorder and whether a diagnostic or therapeutic endoscopy was performed. In diagnostic ureteroscopy, finding the source of bleeding, or defining the nature of a filling defect (with tissue sampling for biopsy) is usually the end point.

Therapeutic ureteroscopy for the treatment of upper urinary tract calculi should resolve ureteral obstruction and decrease the stone burden. Endoscopic treatment of stricture disease should improve drainage. Treatment of urothelial tumors has the same goals and end points as endoscopic treatment of bladder tumors. Thus, ureteroscopy is a surgical platform from which various disease processes can be treated, each with their own specific postoperative expectations and outcomes.

The following tables show success rates of ureteroscopic lithotripsy.

Table 2. New York University Experience With Ureteroscopic Treatment of Ureteral Calculi Using the Holmium:YAG Laser (Open Table in a new window)

Segment

Number of Cases

Mean Diameter,

mm (range, mm)

Success Rate,

First-Stage Treatment

and Second -Stage Treatment

Proximal third

75

11.3 (30-5)

95% and 96%

Middle third

45

10.7 (60-5)

98% and 100%

Distal third

91

10.3 (50-4)

99% and 100%

Totals

211

 

97% and 99%

Table 3. New York University Experience With Ureteropyeloscopic Treatment of Intrarenal Calculi Using the Holmium:YAG Laser (Open Table in a new window)

Location

Number of Cases

Mean Diameter,

mm (range, mm)

Success Rate, Treatment

and Multistage Treatment

Upper pole

58

10.6 (35-4)

90% and 97%

Middle pole

30

11.1 (23-4)

90% and 93%

Lower pole

103

14.8 (40-3)

79% and 85%

Renal pelvic

37

20.5 (60-6)

78% and 95%

Totals

228

 

81% and 90%

 

Advances in technology and surgical technique have paved the way for the endoscopic treatment of larger stone burdens. The ureteroscopic treatment of large upper urinary tract calculi was first described in patients with comorbidities prohibiting percutaneous nephrostolithotomy in 1998.[20] Over the last 15 years multiple centers have presented their experience with similar large stones treated ureteroscopically with excellent stone free rates and minimal morbidity as exhibited in Table 4.[21]

Table 4. Review of Studies on Ureteroscopic Management of Upper Urinary Tract Calculi > 2 cm (Open Table in a new window)

STUDY

Date

Number of Patients

Mean Stone Diameter (mm)

Mean number of procedures

Stone Free (%)

Complications number (%)

Grasso et al.[20]

1998

51

24.9

1.3

93

3 (3)

El-Anany et al.[22]

2001

30

>20

1

77

3 (10)

Ricchiuti et al.[23]

2007

23

30.9

1.4

74

0 (0)

Breda et al.[24]

2008

15

22

2.3

93

3 (9)

Riley et al.[25]

2009

22

30

1.8

91

4 (10)

Hyams et al.[26]

2010

120

24

1.2

83

8 (6)

Takazawa et al.[27]

2011

20

31

1.4

90

3 (5)

Cohen et al.[21]

2012

145

29

1.6

87

5 (2)

 

Future and Controversies

Miniaturization of ureteroscopic instrumentation will continue, with smaller fiberoptics and enhanced digital imagers, improved accessories, and new energy sources. As the instrumentation becomes smaller and more refined, it also will become more delicate. Thus, manufacturers are challenged to develop new, smaller instruments that will also survive the rigors of surgical therapy.