Ureteroscopy

Anatomy and Physiology

The ureters course downward and medially, connecting the ipsilateral renal collecting system to the bladder and propelling urine toward the bladder through peristaltic contractions.  In adults, the ureter typically measures 22 to 30 cm in length, with variations often correlating with body height.[2]

For descriptive purposes, the ureters may be divided as follows: 

• Abdominal: Renal pelvis to the iliac vessels
• Pelvic: Iliac vessels to the bladder 

Alternatively, the ureters may be divided into 3 segments: 

• Upper: Renal pelvis to the upper border of the sacrum
• Middle: Upper border to the lower border of the sacrum, along the iliac vessels 
• Lower: Lower border of the sacrum to the bladder

There are three clinically significant sites of anatomical narrowing along the course of the ureter, which are the most common locations for ureteral calculi obstruction. From proximal to distal, these sites include: [3] 

• The ureteropelvic junction
• The crossing of the ureter over the bifurcation of the iliac vessels
• The intramural ureter at the ureterovesical junction is the narrowest part of the ureter, which may require dilation before the introduction of larger-caliber instruments

Blood supply to the ureter stems from multiple vessels. The upper ureter receives its blood supply medially, whereas the pelvic ureter receives it laterally. Branches of the renal, gonadal, renal polar, capsular, and adrenal arteries supply the upper ureter. In contrast, branches of the common iliac, external iliac, gluteal, superior vesical, deferential, vaginal, and middle rectal arteries supply the pelvic ureter. The most significant portion of the arterial supply originates from the renal pelvis for the upper or proximal ureter and the bladder for the pelvic or distal ureter. The venous drainage system mirrors the arterial distribution. 

Clinically, the iliac region of the ureter is poorly vascularized. An incision or ureteral injury in this area may result in poor healing. All the vessels that supply the ureter anastomose to form a plexus that runs within the ureteral adventitia. Therefore, the ureter can generally be mobilized from surrounding tissues without compromising its blood supply as long as the adventitia remains intact.[4]

The muscularis layer of the ureter was traditionally thought to consist of three layers—two longitudinal layers separated by a circular layer. However, more recent studies indicate a spiral arrangement of muscle fibers that generate the peristalsis. Muscle fibers along the ureter terminate over the bladder's detrusor muscles to form the trigone.[5] The muscularis layer gradually increases in thickness from the kidney to the bladder. Consequently, complete perforations occur at a higher frequency in the proximal ureter compared to the distal ureter.[5][6] 

Ureteral peristalsis appears to function independently of autonomic input, instead originating from intrinsic smooth muscle pacemaker sites in the renal calyces and propagating in an antegrade fashion. Sympathetic nerves transmit nociceptive signals generated from mucosal irritation, tension, or distension, resulting in visceral-type pain, which may be referred to as the flank, groin, or scrotal/labial regions. 

A duplicated urinary collecting system is the most common urological congenital anomaly, occurring in approximately every 1 in 125 live births. Duplication of the ureters is bilateral in 20% of cases, frequently asymptomatic, and might be complete or incomplete.

Duplicated ureters originate in a kidney pole. An incomplete duplication terminates in the adjacent ipsilateral ureter, making a Y-shaped juncture at some point. Navigating this fork in the ureter with the ureteroscope entering only the selected renal unit can sometimes be challenging. This navigation can be accomplished using an angle tip guidewire to guide entry into the selected proximal ureteral segment.

In cases of complete ureteral duplication, the duplicated ureter typically terminates in the bladder but can be inserted in different locations along the urinary tract. In boys, it may terminate between the trigone and the ejaculatory duct, whereas in girls, it may insert into the vagina, leading to continuous, uncontrollable incontinence.[7] Only females can develop incontinence from the ectopic insertion of a duplicated ureter. The distal insertion point of the duplicated ureter is a potential site for calculus obstruction. The challenge of visualizing the orifice in the bladder of a duplex ureter may be overcome using various guidewires or intravenous agents that change the color of expelled urine.

In a completely duplicated system, the proximal ureteral orifice (more lateral and cephalad)  typically drains the lower renal pole moiety and tends to reflux. The distal ureteral orifice (more medial and caudal) tends to obstruct and usually drains the upper pole renal moiety. This phenomenon is known as the Weigert-Meyer law. 

Indications

Ureteroscopy has applications in both diagnostic and therapeutic interventions. Generally, a rigid or semi-rigid ureteroscope is preferred for examining or treating conditions in the distal ureter. In contrast, the flexible ureteroscope is better suited for navigating the tortuosity of the upper ureter, renal pelvis, and calyces. Ureteroscopy can be performed using a retrograde approach through urethral access or an antegrade approach through percutaneous nephrostomy access.[8] 

Antegrade access is particularly valuable for patients with an ectopic ureteral orifice after ureteral reimplantation, renal transplant, ileal conduit, or neobladder. Strong evidence suggests that ureteroscopy does not cause significant long-term harm to the kidneys or renal function.[9][10] For example, the overall risk of ureteral stricture is only about 1%.

The most common indication for ureteroscopy is the management of renal and ureteral calculi. For patients with nephrolithiasis and clinically significant stones who do not respond to conservative or medical expulsive therapy, surgical intervention is necessary.

Indications for ureteroscopy include the diagnosis and treatment of the following: [11]

• Ureteral calculi that have not responded to conservative therapy remained unchanged for 4 to 6 weeks or continue to cause symptoms
• Nephrolithiasis
• Filling defects observed in excretory computed tomography (CT) urography, including radiolucent calculi, strictures, post-inflammatory changes, sloughed papilla, blood clots, fungus balls, and ureteral and renal pelvic tumors
• Lateralizing essential hematuria, including hemangiomas, minute venous rupture, varices, arteriovenous malformations, and neoplasms
• Foreign bodies, most commonly migrated or fragmented double J catheters and broken accessory devices
• Upper-tract neoplasms, including biopsy, surveillance, laser ablation, and palliative measures
• Fistulas, particularly diagnostic modality of choice for definitive diagnosis of ureterovaginal fistula

Ureteroscopy, in conjunction with endoluminal ultrasonography, can assist in identifying extraluminal causes of filling defects and further evaluate the intramural extension of malignant lesions.[12]

The American Urological Association (AUA) guidelines recommend ureteroscopy over alternatives such as extracorporeal shockwave lithotripsy and percutaneous nephrolithotomy for the treatment of calculi in the following instances: [13]

• Mid or distal ureteral calculi, regardless of size (may also be used for proximal ureteral calculi, though extracorporeal shockwave lithotripsy has similar efficacy and is considered a first-line therapy).
• Suspected cystine or uric acid ureteral stones due to their radiolucency (uric acid) or resistance to extracorporeal shockwave lithotripsy (cystine).
• Renal calculi <20 mm in size (>20 mm, percutaneous nephrolithotomy is generally preferred, but flexible ureteroscopy with laser lithotripsy is now a reasonable alternative except for stones in the lower pole).[14]
• Removal of residual renal calculi fragments following extracorporeal shockwave lithotripsy or percutaneous nephrolithotomy, including steinstrasse.
• Patients who are not candidates for percutaneous nephrolithotomy may be offered staged ureteroscopy with or without extracorporeal shockwave lithotripsy, sometimes called sandwich therapy.
• Anatomic or functional obstruction distal to the calculi that is treated using ureteroscopy.
• Patients with uncorrected bleeding diathesis or those who require continuous anticoagulation/antiplatelet therapy, where extracorporeal shockwave lithotripsy is contraindicated.
• Failure or anticipated failure of extracorporeal shockwave lithotripsy. Extracorporeal shockwave lithotripsy is considered a failure after two treatment sessions. Failure is more likely in patients with a large body habitus, a skin-to-stone distance >10 cm, stones larger than 15 to 20 mm, and resistant stone compositions such as cystine, brushite, and calcium oxalate monohydrate.[13]

Although ureteroscopy is more invasive and has slightly higher morbidity compared to extracorporeal shockwave lithotripsy, it offers a more favorable stone-free rate.[13] Ureteroscopy also appears relatively harmless to the kidneys, with a minimal lasting effect on renal function.[9] A recent study of over 3000 patients with nephrolithiasis suggested that early intervention, such as ureteroscopy or extracorporeal shockwave lithotripsy, should be considered for all stones >7 mm and calculi 5 to 7 mm in the mid or proximal ureter.[15] As ureteroscopy technology and equipment advancements continue, its clinical applications are expected to expand.

Contraindications

Contraindications to ureteroscopy are limited. An active UTI must be treated and resolved before proceeding with the procedure. Management typically involves placing a percutaneous nephrostomy or a double J ureteral stent to establish urinary drainage on the affected side and using appropriate culture-specific antibiotics. Contraindications to general or spinal anesthesia typically prohibit ureteroscopy. Uncorrected bleeding diatheses, ongoing anticoagulation, or antiplatelet therapy are relative contraindications and should be assessed on a case-by-case basis.[16] However, ureteroscopy can often be performed safely in patients on anticoagulant therapy.

Other contraindications include ureteral kinking or narrowing, typically treatable using double J stent, and impassable anatomy involving the ureteral orifice, prostate, trigone, or distal ureter due to cancer or other disorders. If a guidewire cannot be passed due to an impassable stricture, stone, or other obstruction, an antegrade approach may be considered.  This approach passes a guidewire through a percutaneous nephrostomy and down the ureter, often succeeding where the retrograde approach has failed. If successful, this enables subsequent stenting, dilation, and ureteroscopy.

Flexible ureteroscopy is considered safe during pregnancy, unlike extracorporeal shockwave lithotripsy, which is contraindicated. However, anesthesia considerations and the potential for early labor induction should be carefully evaluated.[17] The alternative during pregnancy involves using double J stents or percutaneous nephrostomy tubes; however, these require very frequent changes, typically every 3 to 6 weeks, necessitating additional operating room procedures and anesthesia.  

The single most important predictor of postoperative urinary tract infectious complications is the presence of a preoperative urinary infection. Other risk factors include female gender, pre- or postoperative stenting, diabetes mellitus, positive nitrites on preoperative urinalysis, and longer operative time.[18][19] Ureteroscopy patients with larger calculi (>13 mm) and mid-ureteral stone locations tend to have more postoperative emergency room visits.[20]

Equipment

Modern ureteroscopes can be semi-rigid or flexible. The semi-rigid ureteroscopes are primarily used for distal ureteral interventions. These ureteroscopes range in size from 7 to 12 French and have large, often dual, 3 to 6 French working channels for better irrigation and larger accessory instruments such as baskets and lasers. Compared to the flexible instrument, the semi-rigid ureteroscope offers lower cost, greater durability, larger or dual working channels, and easier maneuverability, leading to shorter operating times.[21] 

Semi-rigid and flexible ureteroscopes are generally available from 6 to 9 French, with the smallest sizes intended for diagnostic use only. Flexible ureteroscopes now have digital video imaging and a wide angulation range at the tip of up to 275°, compared to <10° in semi-rigid ureteroscopes. This enhanced flexibility allows them to access the renal pelvis and calyces through the kidney, including the lower pole, which presents the greatest tortuosity.

An important accessory for flexible ureteroscopy is the ureteral access sheath. These sheaths are available in sizes ranging from 9 to 16 French and facilitate multiple passages of the ureteroscope into the ureter and kidney without requiring a guidewire or the risk of distal ureteral injury from repeated insertions. The benefits of the sheaths are 2-fold—repetitive trauma to the distal ureter and ureteral meatus is avoided, and irrigation fluid is better drained, enabling enhanced visualization and lower intraluminal pressures. There is a small risk of ureteral wall ischemia, urothelial mucosal tears, subsequent strictures, and ureteral and renal pelvic perforations; however, the placement of ureteral double J stents in the postoperative period minimizes these risks to levels comparable to flexible ureteroscopy without access sheaths.[22][23]

Instruments that can be inserted through the ureteroscope's working channel include wire baskets, biopsy forceps, balloon catheters, cold knives, and electrocautery. Instruments specifically designed for ureteroscopic lithotripsy include ultrasound, electrohydraulic, pneumatic probes, and laser fibers. The ultrasound probe allows continuous, simultaneous suction with stone ablation to reduce calculi retropulsion but is considered the least effective option overall. Pneumatic probes may only be used through rigid and semi-rigid ureteroscopes, and while effective, they must be in direct contact with the stones to work.

The most significant advances in ureteroscopy over the past 2 decades have been related to the miniaturization of the scopes and accessories. A key development contributing to miniaturization is the evolution from fiberoptic to digital video optical systems. Unlike fiberoptics with direct-viewing lenses, the digital video optical system uses a charge-coupled device (CCD) camera chip mounted to the tip of the ureteroscope and connected to a monitor display through a single cable. This technology provides a higher quality image, enhanced durability, and greater flexibility compared to fiberoptic cables. In addition, the thinner design allows for a larger working channel. Future developments may incorporate a second CCD camera chip to allow for three-dimensional imaging, similar to robotic surgery.[1]

Another significant advance is the commercial introduction of disposable flexible ureteroscopes by several manufacturers. These devices provide improved or alternative mechanics while preventing wear and tear on more expensive, reusable ureteroscopes. However, their optical quality is not yet equivalent to the standard, reusable, digital video ureteroscopes. Disposable ureteroscopes are ideal for emergencies where demand for ureteroscopes exceeds the available supply and may be cost-effective.[24][25]

These advances have contributed to the development of ureteroscopes with multiple working channels. Dual working channels allow for simultaneous visualization, accessory function, and continuous irrigation. These advanced features were first developed in rigid and semi-rigid ureteroscopes, whose larger caliber channels allowed additional functionality. Eventually, these features become incorporated into flexible scopes as well. As optical systems, accessories, and lasers continue to evolve and become more compact, commercially available flexible dual-channel ureteroscopes are now available in sizes under 10 French.

Laser Lithotripsy of Urinary Calculi

Laser fibers are the most versatile and have the smallest diameter (<1 French). These fibers are available in various sizes, typically ranging from 150 to 360 μ, with larger sizes designed for use in the bladder. Smaller laser fibers are more flexible and typically preferred for use in the renal pelvis.

Lasers are highly effective for lithotripsy of all stone types and are used for tissue ablation, coagulation, excision, incision, and vaporization.[1][26] For stone fragmentation, the laser can be set to initial frequency settings of 5 to 10 Hz (low frequency) with a power range of 5 to 9 W (relatively high power).[27] 

For ureteral stones and stone vaporization ("dusting"), lower power settings with a higher frequency are recommended, such as a power level of 0.2 W with a frequency of 25 to 50 Hz. Some lasers provide dual settings so the surgeon can quickly go from one power setup to another. Unfortunately, there is no consensus regarding the optimal power, frequency, and modulation settings for fragmentation, popcorn, and dusting.[28][29] Even new model lasers lack safety presets.[30] 

There is also significant variability in the understanding of laser technological principles and ureteral biomechanics among urological trainees and even experienced practicing urologists.[31] While individual lasers require specific settings, the fundamental principle remains the same—higher power and slower frequency promote stone fragmentation. In comparison, lower power with higher frequency settings optimizes vaporization and tends to minimize stone migration.[32][33][34][35]

Unlike stone fragmentation, laser vaporization or dusting is typically most effective when the laser fiber is not in direct contact with the target. For dusting, it is generally only necessary to approach the stone closely with the laser fiber. The main issue with laser dusting of urinary calculi is that it takes longer and may limit the amount of stone material available for chemical analysis. In some cases, a harder, more resistant central nidus at the core may be best managed by fragmentation and stone basket extraction rather than dusting. A combination of dusting and fragmentation techniques may also be used.

All modern lasers work reasonably well, and the choice of which one to use is often based on availability and convenience rather than clinician preference or the clinical situation. A lack of head-to-head studies makes comparisons difficult, but some general conclusions can be made.[28] 

The 3 basic types of lasers available for treating urinary calculi include:

Holmium:YAG lasers: These lasers have long been the gold standard technology for laser lithotripsy of urinary calculi since their introduction in 1992.[28][36] The main advantages include high peak power, extensive clinical experience, low stone carbonization, and a large variety of power, frequency, and modulated pulse settings, making them highly versatile.[28][37][38][39]

• The new pulse-modulated high-power holmium:YAG (Ho:YAG) lasers, including micro-pulses, offer reduced retropulsion, improved efficacy, better stone-free rates, and shorter operating times.[37][40][41][42] These lasers have also proven to be particularly useful for percutaneous stone laser ablation.[43][44][45] The future development and use of artificial intelligence to optimize settings and minimize tissue damage hold great potential to improve outcomes.[46]

• Disadvantages include the generation of high tissue temperatures, which can lead to thermal injuries.[28][47][48][49] This issue is being addressed by proposed laser tip temperature sensors and various cooling methodologies, including chilled or open irrigation systems, modified ureteral access sheaths, preset laser power limits (<40 W suggested), and continuous laser activity.[50][51][52][53] Safety presets are lacking even in new model lasers.[30]

• Newer pulse-modulated Ho:YAG systems tend to be relatively expensive and may not be cost-effective.[54]

Thulium lasers: These lasers, introduced in 2018, are significantly quieter and far more energy-efficient compared to Ho:YAG lasers, using only about 10% of the power to achieve comparable stone ablation, fragmentation, and dusting.[55]

• Similar to Ho:YAG lasers, thulium lasers allow for a wide range of power and frequency settings, up to a theoretical 2000 Hz.[28][56] Short pulses are generally recommended for lithotripsy.

• Thulium is a pulsed laser and uses a smaller delivery fiber. The lower power settings allow for reduced retropulsion and backburn, whereas the smaller laser fibers resist bending and breakage better.[57][58][59]

• Thulium lasers are more effective at stone ablation for both hard and soft calculi than Ho:YAG lasers, achieving stone fragmentation twice as quickly and dusting up to 5 times faster while leaving even smaller particles, sometimes referred to as micro-dusting.[55][56][60] However, overly aggressive dusting in larger stones can interfere with vision from the dense particle cloud.[28]

• Thulium energy is more rapidly absorbed by water, making it a safer laser. The lower peak power required reduces possible tissue damage and improves its coagulation properties.[55]

• Disadvantages include the lack of consensus on power and frequency settings and the need for the laser fiber to be in direct contact with the stone.[30][61] While the laser can be used with any stone type, cystine and calcium phosphate stones have reportedly caused a flashing and burning effect.[28] Ureteroscopic visualization is improved if the laser fiber is moved slightly further away (proximal) from the scope's tip.

Pulsed thulium-YAG lasers: Pulsed thulium-YAG is the latest laser available for urinary stone fragmentation, ablation, and lithotripsy.[62] A wavelength between the Ho:YAG and the thulium laser is used because this provides high peak power closer to the Ho:YAG for better fragmentation of urinary calculi while still maintaining low-power efficacy for stone dusting.[39][63] 

• In vitro studies indicate that pulsed thulium-YAG can perform fragmentation similar to Ho:YAG and dusting comparable to thulium.[39][62][63][64]

• The pulsed thulium-YAG laser was significantly better at dusting stones compared to Ho:YAG.[63][64][65]

• The only disadvantage of this new laser is the lack of clinical studies. The pulsed thulium-YAG laser appears promising, with unsurpassed urinary calculus fragmentation and dusting capability. However, there is insufficient evidence or adequate published studies to indicate its true functionality and clinical applicability.[66][67]

Personnel

The personnel required for ureteroscopy include the surgeon and an assistant—such as a resident, scrub tech, nurse practitioner, or physician assistant—to assist in holding the wires, passing instruments, and operating the various baskets. When fluoroscopy with a radiological C-arm is necessary, a radiology technician is also required.[68] However, dedicated cystoscopy tables may not require a radiology technician. The operating room should also have anesthesia staff and a circulating nurse present.

Preparation

Planning is crucial for ureteroscopy to avoid unnecessary complications and minimize operating time. Imaging, such as a noncontrast CT and an abdominal x-ray (kidney, ureter, and bladder (KUB)), should be reviewed preoperatively for urolithiasis. Preoperative urinalysis and urine cultures are critical to ensure there is no evidence of urinary tract infection (UTI).

After shared decision-making and obtaining informed consent, the patient should be anesthetized and positioned, prepped, and draped, typically in the dorsal lithotomy position using stirrups, with accurate side marking and prophylactic antibiotics according to AUA guidelines.[69][70][71] Although meta-analyses have shown that prophylactic antibiotics do not significantly reduce postoperative febrile UTIs, they have been associated with a lower risk of postoperative pyuria and bacteriuria.[72][73]

Patients should be advised preoperatively about the possibility of a two-stage procedure if ureteral narrowing, excessive bleeding, or other technical challenges are encountered, necessitating the placement of a double J stent. This preparedness helps ensure they are not unexpectedly faced with the necessity of an additional procedure after surgery. Such procedures are optimally scheduled about 2 weeks later.

The 2019 AUA guidelines for antibiotic prophylaxis recommend tailoring the prophylactic agent towards the individual patient, considering prior urine culture results, the hospital's antibiogram, and any additional risk factors. The choice of antimicrobial is a single dose of a first- or second-generation cephalosporin or trimethoprim-sulfamethoxazole (TMP-SMX).[71] Alternatively, a combination of ampicillin and gentamicin or amoxicillin/clavulanate can be used.

If a parenteral antibiotic is selected, it should be administered within 1 hour before the introduction of the cystoscope so that an appropriate perioperative tissue concentration is established. If an oral agent, such as TMP-SMX or amoxicillin/clavulanate, is selected, certain factors must be taken into account, such as the variable amount of time it takes to reach adequate tissue levels and the fact that patients may be under a nothing by mouth dietary restriction before the procedure. For these reasons, an intravenous agent may be preferred.

A single preoperative dose of gentamicin, in addition to standard prophylactic antibiotics, may help control postoperative infections when performing procedures on infected systems or in patients deemed highly susceptible to infection.[74][75] Gentamicin is readily absorbed into renal tissue and provides additional, long-lasting renal antibiotic prophylaxis even from a single preoperative dose. The standard dose of gentamicin is 3 mg/kg body weight.

Although general anesthesia is recommended, combined spinal-epidural anesthesia is an adequate alternative.[76] However, the urologist may prefer or even require the patient to be under full general anesthesia as there is less patient movement, which is particularly important for semi-rigid ureteroscopy.[77] In addition, it is essential to ensure that the operating table can handle the patient's weight, especially when the patient is moved to the end of the table for cystoscopy in the dorsal lithotomy position.

Before starting the procedure, all equipment and supplies mentioned earlier should be prepped and readily available, including a selection of guidewires, baskets, laser fibers, connectors, double J stents, dual-lumen catheters, high-pressure irrigation systems, retrograde catheters, diluted contrast, a torque vise, an Albarran bridge, urethral mechanical and balloon dilators, a variety of ureteral access sheaths (in different lengths and diameters), and other appropriate supplies based on the individual case, as this is ultimately the surgeon's responsibility.

If a dedicated cystoscopy fluoroscopy table and suite are unavailable, the ureteroscopic video tower should be positioned on the side of the patient's stone and the C-arm (x-ray) on the opposite (contralateral) side. The optimal arrangement is often to have the C-arm monitor more cephalad (closer to the patient's head) but on the same side as the C-arm. Viewing the C-arm monitor is then achieved by looking through the vacant, open center arc of the C-arm.

Pre-stenting with a double J stent is not routinely required before ureteroscopy, but it does help facilitate the procedure, particularly flexible ureteroscopy of the proximal ureter and kidneys. Pre-stenting may be electively performed if narrowed ureters are expected for symptomatic relief or infection control. Double J stent placement is also recommended when ureteroscopy is attempted, but adequate ureteral access is difficult, or ureteral access sheath placement requires significant dilation or substantial force. In such situations, it is recommended to cancel the ureteroscopy, place a double J stent, and return another day for the definitive ureteroscopic procedure.

Technique or Treatment

Cystoscopy is essential immediately before any ureteroscopy to better understand the patient's individual anatomy, visualize the bladder and ureteric orifice, perform retrograde pyelography, and place the initial guidewire.[68][69] In male patients, the penis should initially be held vertically to keep the pendulous urethra straight to facilitate the insertion of the cystoscope. The cystoscope tip is then angled upwards (anteriorly) in the deep bulbous urethra, under vision, to enter and pass through the external sphincter, prostatic urethra, and bladder neck to enter the urinary bladder.

Once the cystoscope is in the bladder, a comprehensive visual examination of the bladder should be performed. A scout x-ray film or noncontrast image is obtained. A small ureteral catheter is then flushed to remove any air bubbles and inserted into the ureteral orifice through the cystoscope.

If there is trouble negotiating the ureteral orifice, an angled-tip, stiff hydrophilic guidewire can be introduced through an open-ended catheter to help stabilize the wire and provide support close to the obstruction to prevent bowing. The cystoscope tip should be placed as close as possible to the ureteral orifice to avoid bowing of the guidewire. A torque vise attached to the distal end of the wire can help control the guidewire while gently twisting and advancing. An Albarran bridge can help cannulate an awkwardly oriented ureteral orifice.

Sometimes, changing the orientation of the cystoscope by 90° to 180° may facilitate guidewire entry and passage. f entry through the ureteral orifice remains challenging, a retrograde pyelogram using a cone-tip ureteral catheter can help visualize the distal ureter. If these measures fail, a semi-rigid ureteroscope is positioned directly at the ureteral orifice, passing the guidewire through the scope. A retrograde pyelogram can also be performed in the same manner.[78]

A small volume, typically around 3 mL, of diluted fluoroscopic contrast, typically 50/50, is gently injected into the distal ureter through the ureteric catheter for a retrograde ureteropyelogram to visualize the ureteral anatomy and identify the size, shape, and exact location of any stones. A safety guidewire is then placed through the ureteral catheter into the renal pelvis.[79] 

If cloudy or purulent urine drains from the ureter or renal pelvis before ureteroscope placement, it is a presumptive sign of infection, even if the preoperative urinalysis was negative. A urine culture should be obtained from the abnormal urine, the ureteroscopy should be postponed, and a double J stent should be immediately placed. The procedure should be rescheduled for a later date after completing a full course of appropriate antibiotics and subsequent negative urine culture. If the follow-up urinalysis is clear, the procedure may continue.

The bladder should be drained before inserting the ureteroscope to facilitate advancement through the orifice without causing undue intramural ureteral compression.[68][79] A second working guidewire may be used to navigate and railroad the ureteroscope through the ureter. Caution is required when advancing the ureteroscope, as the wire coating can sometimes be stripped, resulting in a nidus for future stone development. This second wire can be placed either through the cystoscope alongside the previous wire or after the removal of the cystoscope through a dual-lumen catheter.

There are several advantages to using the dual-lumen catheter. A retrograde pyelogram can be conducted through the second channel for better visualization. Passing the dual-lumen catheter can act as a ureteral dilator. As it has a relatively large lumen, lidocaine jelly can also be injected to help reduce spasms. Difficulty in catheter entry or advancement suggests ureteral narrowing. In such cases, leaving a double J stent for a few weeks is prudent and advisable to allow for passive ureteral dilation and return a few weeks later to complete the ureteroscopy. At the very least, a smaller caliber ureteral access sheath should be used, but the likelihood of intimal ureteral injury and scarring increases. 

The handle of the ureteroscope should be held with the dominant hand while the scope is advanced with the non-dominant hand. The scope should be advanced slowly and easily, keeping the distal tip straight, into the renal pelvis. Pressurized irrigation with normal saline—preferred due to the reduced risk of tissue damage if the fluid is absorbed or extravasates—assists in dilating the more proximal ureter and filling the renal pelvis to allow for better visualization.

Although ureteroscopy has multiple diagnostic and therapeutic indications, it is most commonly performed for the management of ureteric or renal stones. The decision to use a semi-rigid or flexible ureteroscope depends on multiple factors—location, size, and shape of stone; cost and availability of equipment; and the individual surgeon's preference and experience.[68] For example, lower pole calculi are likely to necessitate a flexible ureteroscopy.

Ureteral Access Sheaths

A ureteral access sheath may be inserted over the working guidewire, extending to the point of the stone location or ureteropelvic junction, depending on the patient's clinical presentation, to allow for repeated ureteroscope passage.[69] The dilator portion of the ureteroscopic sheath can be inserted over the guidewire first, or the dual-lumen catheter can be used as an initial ureteral dilator.

If either or both of these encounters significant resistance, a smaller sheath should be considered. Alternatively, the ureteroscopic procedure can be postponed with the immediate placement of a double J stent. This stent gently dilates the ureter over the next several weeks, making it easier to perform the ureteroscopy later on. This approach reduces the risk of severe ureteral damage that could result from overly aggressive or forced dilation.[80]

The smallest diameter sheath that comfortably fits and is adequate for the procedure should be used. For multiple or larger stones, a larger diameter sheath is helpful if safe placement is possible. Knowing the stone's location is essential to ensure the ureteral access sheath is not advanced beyond that point, as this can push the calculus through the wall of the ureter.

Forceful advancement of the ureteroscopic sheath, its dilator, or the dual-lumen catheter should be avoided if considerable ureteral resistance is encountered. The dilator and sheath should be advanced only to the level required for the ureteroscopy. Advancing the sheath or dilators too far can easily occur, increasing the risk of mucosal injury, ureteral disruption, or renal pelvic perforation. Therefore, advancing an inch at a time with full fluoroscopic guidance as the tip of the sheath or dilator approaches its expected final position is recommended.

Despite these precautions, using two guidewires—one working and one safety guidewire—and ureteroscopic access sheaths is generally recommended. Overall, ureteral access sheaths are safe and do not appear to substantially increase the risk of ureteral strictures compared to ureteroscopy without sheaths.[81]

Up to 20% of patients undergoing ureteroscopy have narrow ureters that require substantial effort to dilate sufficiently to pass a ureteral access sheath.[82] A retrograde pyelogram can indicate the relative diameter of the ureter. In such cases, it is recommended to abandon the ureteroscopic procedure, leave a double J stent, and reschedule the ureteroscopy.

A dual-lumen catheter is often used for a retrograde pyelogram and to place a second guidewire. If the dual-lumen catheter does not pass easily, this almost certainly means that the ureteral lumen is too narrow for a ureteral access sheath, and consideration should be given to leaving a double J stent and rescheduling the surgery for a later date. When choosing a ureteral access sheath, the smallest feasible diameter should be used to minimize ureteral trauma.

Using an access sheath is optional, as it has both pros and cons. The main benefit is that it facilitates repeated introductions of the ureteroscope into the ureter and, particularly, the renal pelvis. The main disadvantage is that placement is not always simple or uncomplicated, as it can easily cause intimal tearing of the ureter, hematuria, and even ureteral perforation.

Leaving a double J stent is highly advisable and recommended whenever a ureteroscopic sheath is used unless the ureter has been previously stented.

When the decision is made to use a ureteral access sheath, the correct lengths are generally as follows:

• A 35- to 36-cm long ureteral access sheath or shorter is used for all semi-rigid ureteroscopy in both male and female patients and flexible ureteroscopy in female patients.        
• In males, a 45- to 46-cm length ureteral access sheath is used for flexible ureteroscopy.

Semi-Rigid Ureteroscopy

Semi-rigid ureteroscopy is typically reserved for the distal ureter, which avoids the angulation necessary to advance into the mid and upper ureters. Although semi-rigid scopes can be advanced further, as a general rule, a flexible ureteroscope is preferred in these situations. When using a semi-rigid scope, it is prudent to remember that this is an inflexible, sharp-ended instrument that can easily cause considerable damage if not handled properly.

The ureteroscope can be advanced into the bladder by itself, over a guidewire, through a short ureteral access sheath, or even through an empty cystoscope sheath, but using sheaths limits the potential proximal advancement of the scope. Advancing the ureteroscope over a guidewire is advisable to minimize urethral trauma in complicated urethras.

Careful adjustment of the irrigation fluid flow can aid in advancing the scope; however, improper regulation may push the stone retrograde and out of reach. To facilitate the initial entry of semi-rigid ureteroscopes, it is preferable to dilate at least the intramural portion of the ureter using the dilator portion of a ureteral access sheath or a dual-lumen catheter.

Stones removed without an access sheath can be deposited in the urinary bladder to facilitate the reintroduction of the ureteroscope into the ureter without the need to remove it completely from the bladder each time.[8] 

When advancing the ureteroscope, the ureteral mucosa should appear to pass the scope. If there is much resistance and the mucosa is not moving, excessive force should be avoided. Instead, the scope should be gently pulled back and then reattempted for advancement. If there is obvious mucosal damage or injury, removing the ureteroscope and leaving a double J stent is prudent.

The ureteroscopy can be rescheduled for a later date, typically around 2 weeks.[78] When advancing semi-rigid ureteroscopes, it is important to remember that the ureter is not straight. If the ureter develops spasms and hugs the scope, withdrawal should be performed slowly and cautiously. If no safety guidewire is present, it may be prudent to have a wire pre-loaded in the scope in case of passed stones or significant mucosal injury found on examination during withdrawal.

Flexible Ureteroscopy

Once the ureteroscope is inserted into the renal pelvis, the working guidewire, which assisted in navigating the ureter, should be removed while keeping the safety guidewire in place. The distal end of the safety guidewire should be securely positioned in its holder or clamped to the drapes to prevent interference with the ureteroscopy procedure.

A small basket, such as a zero-tip basket, or a small laser fiber may then be placed within the working channel of the ureteroscope.[69] Normal saline irrigation, either with a pressure bag at 300 lbs pressure or a hand-operated pressure syringe, should be attached to the ureteroscope. In rigid ureteroscopy, where there is often a dual channel, the irrigation is attached to the smaller port.

If there is only a single channel, then a dual-channel adapter, such as a Tuohy-Borst Y adaptor, should be used. This setup allows the irrigation to be attached to the channel using the offset port, leaving the adjustable diaphragmatic port available for the basket, laser fiber, or guidewire. 

There is no significant difference in complication rate between the use of a continuous high-pressure irrigation bag and a hand-operated pressure syringe, although there are slightly fewer complications with the pressure bag, most likely from the avoidance of overly high irrigation pressures.[83] 

The safety guidewire should be used as a reference to aid in orientation while inspecting the renal pelvis. A quick fluoroscopic image of the ureteroscope in each calyx can help verify a complete inspection and facilitate reentry to a specific calyx.

In longer cases, the lubricious coating to the lumen of the ureteral access sheath may wear off. To minimize this, adding a little lubricant to the scope each time it is removed before its reinsertion helps maintain the easy passage of the ureteroscope through the sheath's lumen.

Laser Lithotripsy Technique

Once the stone is visualized ureteroscopically, the surgeon can begin to fragment it into basketable-sized pieces. The pieces can then be captured using a stone basket and removed along with the ureteroscope through the ureteral access sheath. If the stone fragment is too large to enter the access sheath, it can be repositioned inside the basket by pushing it back into the dilated proximal ureter or renal pelvis, then carefully opening and closing the basket slowly to allow the stone to reorient in a more favorable, longitudinal position. Laser treatment is repeated until the stone is small enough to pass through the access sheath.

If a stone is already in a basket but is too large to extract, it is possible to use a laser on it while it is engaged. The basket should be opened, and a small laser fiber should be used to break up or vaporize the stone until it is small enough to extract. Care should be taken to avoid lasering the wires of the basket.

Another technique involves pulling the stone as much as possible into the proximal end of the ureteral access sheath and then removing the sheath, ureteroscope, basket, and stone all together while keeping traction on the stone basket. This technique allows the access sheath to act as a dilator or leader and facilitate the stone's removal, but there is a real risk that the stone may still get stuck. Therefore, it should only be performed when the stone's size closely matches the diameter of the access sheath.

The ureteral access sheath should be replaced after the extraction of the stone with the sheath, which takes additional time. This maneuver becomes increasingly risky as the stone's location becomes more proximal and is generally not recommended for larger or borderline calculi in the renal pelvis. In such cases, additional lasering of the stone is preferred. If this maneuver fails and the stone gets stuck, overly aggressive pulling on the stone, sheath, or ureteroscope should be avoided. Instead, the stone should be disengaged by releasing it from the basket, and laser lithotripsy should be used to reduce its size until it fits through the access sheath.

There is also the risk of getting a piece of the ureter jammed between the stone and the sheath, which could cause a rent, perforation, or even complete disruption of the ureter. Therefore, this advanced technique is not recommended routinely and only by experienced practitioners.

The dual-lumen catheter is the ideal tool for replacing the second guidewire, assuming the safety guidewire is still in place, allowing the ureteral access sheath to be easily replaced. The ureteral access sheath should never be advanced without the dilator in place and only over a guidewire.

The ureteral access sheath should never be advanced except with the inner dilator in place.

The inner dilator should never be placed or advanced except over a guidewire due to the very significant risk of a perforation of the ureter or renal pelvis. 

All stone fragments removed should be sent for chemical analysis.[84]

Once all the stones have been removed, the ureteroscope and ureteral access sheath may be slowly extracted together to inspect the ureter for any passed stones and any intimal or mucosal injury.[69][79] An alternative technique involves replacing the guidewire through the scope and then withdrawing the access sheath until the end is at the scope's handle. The ureteroscope and sheath can then be slowly withdrawn together to inspect the ureter while still leaving a wire in place. This technique is particularly useful if the operator works alone or with inexperienced or unskilled help.

Double J stents are generally recommended after ureteroscopy, especially when ureteral access sheaths are used, and for impacted stones, longer operating times, larger stone size or burden, older patient age, solitary kidneys, ureteral trauma/damage, and increased intrarenal complexity or complications.[85]

The finding of any significant ureteral mucosal or intimal damage should suggest the need to leave a double J stent, typically for 2 to 4 weeks. If a bilateral procedure is performed, at least one side should be stented. If in doubt about leaving a stent or not, it is always safer to leave the stent. Leaving a double J stent is strongly recommended if a ureteral access sheath was used unless the ureter was pre-stented.

A  double J ureteral stent may be placed over the remaining safety guidewire and inspected for good curl both within the renal pelvis and distally in the bladder. This decision is up to the individual surgeon but is strongly recommended for patients with ureteral damage on ureteroscopic inspection and those with an increased risk of bleeding, perforation, UTIs, or significant residual fragments.[70] Leaving a stent in such situations significantly reduces postoperative complications but can lead to stent discomfort.[85]

In uncomplicated cases where stones can be easily removed and there is minimal resistance to ureteral dilation or the placement of an access sheath, patients who previously had a double J stent before ureteroscopy may not require a stent after the procedure.[86]

Guidelines from the AUA and European Association of Urology now allow the omission of postoperative double J stents after uncomplicated ureteroscopies.[13][70][86][87]

Uncomplicated ureteroscopy is defined as follows: [87]

• American Society of Anesthesiologists score of 1 or 2
• A unilateral procedure
• No balloon ureteral dilation
• No mechanical dilation was performed, but if used, not greater than 10 French
• Patient not immunocompromised or pregnant
• Patient does not have a solitary kidney
• No anatomical or structural urinary tract abnormalities, such as horseshoe kidney and ureteropelvic junction obstruction
• Patient with no uncorrected or untreated coagulopathies
• Patient with no untreated UTIs
• Patient with no history of urinary tract reconstruction
• No stones treated in multiple locations
• No plan or likely need for a second-look ureteroscopic procedure
• No ureteral perforations, extravasation, or significant ureteral trauma
• No large stones (>10 mm) treated
• No substantial stone residue or significant removable fragments remaining
• No ureteral access sheath used
• Pre-stenting used (preferred but not required)

The recommended technique for double J stent placement is well-described elsewhere, but key recommendations are summarized below.[84]

• The dangler thread should not be removed until the stent is optimally positioned, as it allows for easy removal if an exchange is desired and helps stabilize placement.
• Stiffer guidewires aid placement but increase the risk of perforation, requiring careful handling.
• Measuring the ureteral length with an appropriately marked ureteral catheter is a more reliable method for selecting a double J stent length than relying solely on patient height.
• A stiffer stent should be used if it resists compression better, as it often has a tighter curl for the renal pelvis.
• A dangler thread should not be left on any critical stent, as it may be accidentally pulled out.
• Placement is optimized by pulling the guidewire back enough to allow the proximal tip of the stent to curl while maintaining traction on the dangler thread and the pusher.
• The stent, pusher, and guidewire can be moved as a unit slightly into and out of the ureteral orifice just enough to allow the proximal tip of the stent to curl properly, which can be confirmed fluoroscopically.
• The thread can be cut and removed, as the pusher and guidewire prevent the stent from moving as the wire is extracted.
• Once the guidewire has been removed and all aspects of the genitourinary tract have been inspected for any iatrogenic injury, the patient may be safely extubated and transferred to the postoperative care unit.

The double J ureteral stent can be left with or without a dangler thread. If the thread is left on the stent, it can be easily removed at the bedside, in the clinic, or even by the patient themselves at home. If the thread is removed, a flexible cystoscopy is required to extract the stent with a flexible grasper.

Stents are typically removed 5 to 7 days after a successful ureteroscopy. After the stent is removed, a follow-up ultrasound or an x-ray (KUB) should be performed between 4 and 6 weeks later to rule out any residual fragments or silent hydronephrosis. 

Stent discomfort is best managed by optimizing the stent size and length during placement, along with the use of alpha-blockers, possibly in combination with mirabegron 50 mg daily.[84][88][89][90][91][92][93][94] In a single study, pregabalin showed a beneficial effect on stent discomfort but did not affect associated urinary symptoms.[93][95]

The AUA guidelines on stones recommend that all patients with ureteroscopic stone surgery be informed about the potential benefits and availability of 24-hour urine testing and prophylactic medical therapy for nephrolithiasis.[96] Interpretation of 24-hour urine tests has become much easier and is now routinely performed by many urologists, nephrologists, and primary care physicians using published guides.[97]

Bilateral ureteroscopic procedures can be performed with good success rates and only slightly higher complication rates. Individual patient circumstances and the necessary extra anesthesia time should be considered.[98][99]

Alpha-blockers: The use of alpha-blockers for at least 1 week preoperatively is recommended before ureteroscopy, although the optimal medication or duration of pretreatment remains uncertain.[100] Alpha-blockers have been shown to minimize the need for mechanical dilation of the ureteral orifice, improve successful ureteroscopic access, reduce ureteral spasms and contractions, and shorten overall operating time.[100][101][102][103][104]

Tricks of the trade are as follows: [68][78][79][105][106]

• Always take a scout (KUB) film before injecting any contrast. Stones can move, and the film serves as a good reference, especially for renal calculi in various calyces.
• A retrograde ureterogram or pyelogram using diluted contrast is also recommended, as it outlines the ureteral and internal renal anatomy for later reference and orientation.
• Some experts recommend performing a semi-rigid ureteroscopy immediately before all flexible ureteroscopies for distal ureteral inspection and dilation. Semi-rigid ureteroscopy can also help identify any stones that have unexpectedly relocated to the distal ureter.
• Every ureteroscopy is different and unique. Avoid assuming that any ureteroscopic procedure is routine, as this can lead to unintended consequences.
• Have a wide variety of stents, guidewires, connectors, clamps, baskets, and scopes available.
• A safety guidewire is recommended to be placed in the renal pelvis for access in case of unexpected difficulty. Secure it carefully so it is not accidentally lost, pulled, or removed.
• Be mindful of your assistants' skills and experience, as errors such as accidentally removing the safety wire, cutting the dangler, or opening instead of closing the basket can be disruptive. To prevent such issues, review procedures with your assistants before starting the surgery.
• Always use normal saline for irrigation during ureteroscopies. In the event of unexpected complications, perforation, or extravasation, normal saline is the safest fluid to avoid osmotic cellular and tissue damage.
• Stiffer guidewires facilitate ureteral access sheath placement and double J stent advancement easier. However, they are also less likely to buckle but may increase the risk of perforation, so extra caution is required.
• The dual-lumen catheter is an extremely important accessory. This catheter can be used as a ureteral dilator or a stone pusher to inject diluted contrast for retrogrades, to place a second guidewire, or to replace a guidewire.
• If a particular guidewire type cannot bypass a stricture, impacted stone, or other blockages, try a different one (brand). Hydrophilic and angled-tip wires generally work best in these situations.
• When performing retrograde pyelograms, mixing diluted contrast with lidocaine jelly or plain lubricant increases its viscosity while keeping its radiopacity and helps keep the contrast in the renal pelvis longer, if desired. Stir the mixture slowly and carefully to avoid air bubbles.
• If ureteral strictures are found, it is better to leave a double J stent and return another day rather than using mechanical or balloon ureteral dilators.
• To minimize radiation toxicity, static, pulsed x-ray images are used instead of live, continuous exposures. The use of the last image hold feature is also recommended.
• Always use the minimum amount of radiation exposure necessary.
• Remember to flush the ureteral catheters before insertion to eliminate air bubbles, which can interfere with visualization.
• Avoid blind basketing, as it is both dangerous and unnecessary. 
• The dangler thread on double J stents should not be cut or removed until the stent is in its final position. Once the thread is cut, further positional adjustments and replacement become much more difficult.
• Never vigorously pull, push, or twist any instrument in the ureter or renal pelvis, as any resulting damage may be irreparable.
• Avoid aspiration through the ureteroscope, as it can cause more bleeding.
• If visibility is impaired due to bleeding, use the high-pressure irrigation flow and be patient.
• If the stone size has been misjudged when basketing, do not hesitate to use the laser to fragment or vaporize it.
• A laser should always be available during ureteroscopy for urinary stones.
• Avoid spending time basketing very small stones. Stones smaller than the shaft of the basket or guidewire can typically be left behind. However, in the case of infectious stones, attempt to basket and remove as much infected stone material as possible.
• If contrast bypasses an obstructing stone, it should be possible to pass a guidewire beyond it.
• Very distal stones may not require initial retrograde pyelography that can inadvertently push stones further proximal.
• Impacted stones can sometimes be gently nudged proximally using a catheter or the tip of the ureteroscope, but this must be done carefully. If unsuccessful, limited laser lithotripsy can be performed but only sufficiently to place a guidewire.
• Exercise caution when advancing the ureteral access sheath, as it can easily damage the ureter or renal pelvis. Without careful monitoring, it may advance further proximally than anticipated. Use fluoroscopy for optimal positioning; never advance the ureteral access sheath without the dilator inserted and only with a guidewire in place.
• Be familiar with all the controls on the ureteroscope and use them effectively. Most flexible ureteroscopes flex the tip upwards and down when the calyces and stones are generally left or right. Reusable scopes typically have an adjustment so the shaft can be rotated 90° right or left to facilitate caliceal examination and entry. Disposable ureteroscopes typically lack this adjustment and require more manual rotation to the left or right as needed, which can be somewhat awkward.
• High-pressure irrigation is one of the most important and useful tools. High flow rates promote visualization, ureteroscope advancement, and ureteral dilation but may also push the stone proximally. High pressure can also cause a calyceal rupture and increase the risk of bacteremia.
• In the renal pelvis, excessive irrigation flow can cause the stone to jump around and move from one calyx to another. Therefore, use the lowest irrigation flow necessary to maintain adequate visualization in the kidney.
• The brief use of higher irrigation flow rates can be used to jiggle a stone around so the stone basket can more easily capture it.
• Lasering of stones creates a dust cloud. To ensure visibility, use irrigation at the lowest flow rate necessary to maintain clear vision.
• Most stone baskets retract toward the ureteroscope when being closed. To avoid this, advance the stone basket at the same rate as the assistant closes it. This technique closes the basket around the stone without retracting the basket.
• Regardless of how damaged the ureter appears after ureteroscopy, it almost certainly heals with the placement of a double J stent and sufficient time, typically 4 to 6 weeks. A follow-up ultrasound is recommended in such cases to identify silent hydronephrosis.
• Tracking of all double J stented patients is important, as their removal remains the responsibility of the urologist, even if patients do not return for their postoperative visit.

Surgeons are reminded of the immortal words attributed to renowned endourologist Dr Arthur Smith, who famously said When the going gets tough, the tough leave a double J stent and go home! 

Nothing is as bad as dealing with a serious, avoidable complication such as a complete ureteral avulsion from the renal pelvis. Experienced surgeons do not hesitate to leave a double J stent and return another day to finish a ureteroscopy in which they encounter difficulty with ureteral narrowing, poor visualization, unexpected pus or infection, excessive bleeding, or other significant difficulties. This approach is a prudent strategy for all who perform ureteroscopy.

The availability of 24-hour urine testing for stone prophylaxis should always be discussed with the patient and documented in the medical record, especially for those with high surgical or anesthesia risk. Only highly motivated patients are likely to benefit substantially from prophylactic treatment as it requires long-term compliance. Guidelines recommend discussing the pros and cons of 24-hour urine testing with all urolithiasis patients, especially those who have already undergone ureteroscopic surgery.

24-hour urine testing is particularly recommended in the following situations: [97][107][108]

• Anatomical abnormalities of the urinary tract
• Chronic diarrhea and irritable bowel syndrome
• Cystine, calcium phosphate, or uric acid as primary stone chemical composition
• Family history of urolithiasis
• Gastrointestinal bypass surgery
• Known high surgical or anesthesia risk factors
• Morbid obesity
• Multiple or recurrent UTIs
• Nephrocalcinosis
• Reconstructive urinary tract surgery (reimplanted ureters)
• Significant renal failure
• Solitary functional kidney
• Ureteropelvic junction obstruction
• Young age (<21 years) at first kidney stone

Complications

Ureteroscopy has significantly evolved over the past few decades with new scopes and various accessories to help increase the procedure's safety. However, complications, both minor and severe, still exist.

Minor complications include hematuria, mild UTI, double J stent discomfort, and transient creatinine elevation. Severe complications, though rare, include severe urosepsis, extra-ureteral or submucosal stone migration, ureteral perforation, ureteral stricture, and ureteral avulsion.[109][110][111]

Risk factors for postoperative septic shock following ureteroscopy include positive preoperative urine cultures, higher body weight (body mass index), and older patient age.[112]

There is concern among experts that increased intrarenal pressure during ureteroscopy may increase the risk of complications. Generally, any pressure above 61 to 80 cm of water is considered high. However, further research is needed to better define increased intrarenal pressure and its effect on patient outcomes.[113]

Clinical Significance

Ureteroscopy has been a revolutionary tool within the armamentarium of the endourologist. This technique is effective, safe, outpatient, and minimally invasive for both diagnostic and therapeutic purposes. However, this procedure requires proper training and care to prevent avoidable complications. The rapid design of newer, more advanced scopes and ancillary equipment gives greater access to treat even more complex cases in the future.[68][69]

Comparison of Ureteroscopy and Extracorporeal Shockwave Lithotripsy

Ureteroscopy has improved immediate stone-free rates and reduced the likelihood of requiring a second procedure compared to extracorporeal shockwave lithotripsy. This technique can reach lower pole renal stones that are fragmented by extracorporeal shockwave lithotripsy treatment but often fail to clear. Ureteroscopy is particularly effective for small, distal ureteral stones but can reach anywhere in the lower, middle, or upper urinary tracts.[114][115][116]

Ureteroscopy with laser lithotripsy can be performed on stones not easily treated by extracorporeal shockwave lithotripsy, such as brushite, calcium oxalate monohydrate, cystine, and uric acid. Small distal stones can typically be removed easily and quickly using ureteroscopy. Ureteroscopy can be performed selectively during pregnancy and in patients actively receiving anticoagulation or with coagulation disorders.

However, ureteroscopy is an invasive procedure that requires general anesthesia, takes longer operating time, and has a higher risk of complications compared to extracorporeal shockwave lithotripsy. Ureteroscopy typically takes a substantially longer time for larger proximal ureteral and renal stones compared to extracorporeal shockwave lithotripsy. The procedure frequently requires a double J stent, which can be uncomfortable for the patient and become calcified or lead to stone buildup if forgotten and not removed promptly. If ureteral access is challenging, a double J stent can be placed, allowing the ureters to dilate before rescheduling the procedure. However, this approach necessitates a second surgical intervention.

Ureteroscopy used as salvage therapy after failed extracorporeal shockwave lithotripsy has a lower success rate for renal stones and an increased risk of postoperative complications when used for ureteral calculi.[117]

Extracorporeal shockwave lithotripsy is a much less invasive surgical procedure compared to ureteroscopy, with an extremely low complication rate.[115] Extracorporeal shockwave lithotripsy uses relatively minimal anesthesia, such as intravenous sedation, and offers roughly similar overall stone-free rates comparable to ureteroscopy. However, it may require a second extracorporeal shockwave lithotripsy treatment and a longer time to pass all the stone fragments.[115] Uncomfortable double J stents are not typically needed.[115]

Unusually hard or radiolucent stones, such as brushite, calcium oxalate monohydrate, cystine, and uric acid; stones larger than 20 mm in size; and calculi that have failed to fragment after two extracorporeal shockwave lithotripsy procedures are best treated with ureteroscopy.[115] Extracorporeal shockwave lithotripsy cannot be safely performed during pregnancy or in patients with untreated coagulopathies, severe hypertension, or those actively taking anticoagulants.[115]

Enhancing Healthcare Team Outcomes

Proper ureteroscopy is best performed by an experienced team. Enhancing patient-centered care, outcomes, safety, and team performance in ureteroscopy involves a multidisciplinary approach that leverages the skills, strategies, and collaborative efforts of various healthcare professionals, including clinicians, advanced care practitioners, pharmacists, and other healthcare providers.

Clinicians, particularly urologists, play a central role in performing ureteroscopy. They must possess the technical skills necessary for the procedure and a deep understanding of the underlying conditions and potential complications. Advanced care practitioners, such as physician assistants or nurse practitioners, can assist in patient assessment, preoperative preparation, intraoperative assistance, and postoperative care under the clinician's supervision.

Nurses play various roles, including preoperative assessment, intraoperative assistance, and postoperative care. Nurses must possess excellent communication skills to ensure effective collaboration among team members and provide comprehensive patient education regarding pre- and post-procedural care.

Pharmacists review medication orders, provide information on drug interactions and contraindications, and offer guidance on pain management and antibiotic prophylaxis. Pharmacists also play a crucial role in preventing medication errors and promoting adherence to evidence-based guidelines.

Other healthcare professionals, such as radiologic technologists, anesthesiologists, and surgical technologists, also play essential roles in supporting ureteroscopy procedures. Radiologic technologists assist with imaging studies, whereas anesthesiologists administer anesthesia and monitor patients during the procedure. Surgical technologists provide the surgical team with sterile instruments and equipment, ensuring a safe and efficient operating environment.

The initial strategy and plan should be discussed with staff immediately before starting the procedure to ensure that all personnel understand their roles. The radiology technologist and surgeon should communicate clearly about using live or static images, how to move the imaging fields, when to use magnification, and which terms to use. Close cooperation between the surgical assistants, nursing staff, and surgeons ensures better outcomes and more efficient, safer ureteroscopic procedures. All healthcare team members should contribute to patient education about the procedure and preventive strategies, such as 24-hour urine testing for patients who are interested and motivated to significantly reduce their risk of urolithiasis.

In addition to individual skills and responsibilities, effective interprofessional communication and care coordination are essential for optimizing patient-centered care and outcomes in ureteroscopy. Effective teamwork involves clear communication among team members, sharing relevant patient information, and coordinating care across different phases of the procedure, from preoperative evaluation to postoperative follow-up. By collaborating and supporting each other's expertise, healthcare professionals can enhance patient safety, improve treatment outcomes, and optimize team performance in ureteroscopic procedures.