Diagnostic Ureteroscopy






Generalities


In selected cases in which clinical, laboratory, and/or imagistic data are equivocal, establishing a correct diagnosis may require the endoscopic exploration of the upper urinary tract. Due to the complexity of the spatial distribution of the renal pelvis and the calyces, rigid or semirigid ureteroscopy does not allow for the exploration of the entire upper urinary tract in the vast majority of cases.


The use of flexible ureteroscopes has made possible, at least in theory, the minimally invasive approach of the upper urinary tract and its systematic exploration at any level, becoming not just an efficient therapeutic instrument, but also a very useful component of the investigation protocol.


Still, in our current phase of technological development, flexible ureteroscopes present a series of limitations regarding maneuverability and visibility. Although their utility in evaluating the pyelocaliceal system is indisputable, the balance is still in favor of rigid and semirigid endoscopes with regard to inspecting the ureter (especially its distal segment). Therefore, the standard diagnostic ureteroscopy protocol includes two stages: an initial stage for ureteral evaluation, which is performed with rigid instruments, and a second, pyelocaliceal stage, which uses flexible ureteroscopes.





Indications and contraindications


Ureteroscopy represents an extremely important part of the diagnostic armamentarium for the pathology of the upper urinary tract. However, endoscopic exploration is an invasive method, despite the reduction in aggressiveness of modern endoscopes as a result of technological progress. It is for this reason that the choice of performing ureteroscopy must be made based on clear criteria, when the other, less invasive explorations do not provide sufficient information for determining the diagnosis or therapeutic attitude ( ).


The indications for flexible diagnostic ureteroscopy can be systematized as follows ( ):




  • establishing the etiology of a lacunar image at the level of the upper urinary tract, detected by imaging exams



  • determining the etiology of hematuria originating in the upper urinary tract, which cannot be diagnosed through other methods



  • localizing the source of modifications of the urinary cytological tests in patients with normal cystoscopy



  • follow-up of patients with conservatively treated upper urinary tract urothelial tumors, within the postoperative protocol



  • determining the etiology of an obstacle at the level of the upper urinary tract




Lacunar Images at the Level of the Upper Urinary Tract


Ureteroscopy may allow the determination of the nature of upper urinary tract lesions: malignant (transitional cell carcinoma, etc.) ( Fig. 4.1 ) or benign (calculi, polyps, hemangiomas, tuberculous lesions, cellular detritus, or blood clots, etc.) ( Fig. 4.2 ).




Figure 4.1


Diagnostic ureteroscopy in a patient with upper caliceal lacunar image.

Retrograde pyelography highlighting the lacunar image at the level of the upper calyx (a), flexible ureteroscopic inspection of the upper calyx (intraoperative fluoroscopy) (b), upper caliceal urothelial carcinoma (c, d).



Figure 4.2


Diagnostic ureteroscopy in a patient with upper caliceal lacunar image.

Retrograde pyelography highlighting the lacunar image at the level of the upper calyx (a), flexible ureteroscopic inspection of the upper calyx (intraoperative fluoroscopy) (b), old clot at the upper caliceal level (c), extracting the upper caliceal clot (d), normal aspect of the caliceal mucosa under the clot fragments (e).


The ureteroscopic evaluation must not be stopped after identifying a lesion, but must continue with the systematic exploration of the entire upper urinary tract ( Fig. 4.3 ).




Figure 4.3


The systematic inspection of the other caliceal groups, without detecting tumoral masses.


Evaluation is performed by gradually using the diagnostic methods, from the least invasive to the more aggressive ones.


Anamnesis may provide clues that can guide the diagnosis:




  • a history of lithiasis or of bladder tumors may guide the diagnosis toward the same type of conditions



  • in patients with a history of diabetes, recurrent urinary infections, abuse of analgesics or blood disorders, the filling defect may be more frequently determined by papillary necrosis or by a blood clot



  • uretero-enteric fistulas may be suspected in patients with inflammatory bowel diseases



  • recurrent Escherichia coli infections may be associated with malakoplakia



  • pneumaturia may appear due to a communication between the colon and the upper or, more frequently, lower urinary tract



Complete urine analysis is also a mandatory component of the diagnostic protocol:




  • pH over 6.5 is frequently associated with uric lithiasis



  • in hematuria, the filling defect may be caused by a clot



  • urinary cytology is useful for detecting urothelial tumors, but is encumbered by a significant rate of false positive or negative results, depending on the tumor grade



  • the presence of aerobic and anaerobic germs detected in the urine culture raises the suspicion of a uretero-intestinal fistula



The next step in evaluating a filling defect discovered by intravenous urography (IVU) is comprised of other imaging explorations (CT, MRI, etc.).


If a diagnosis cannot be established following these exams ( Table 4.1 ), the next step is represented by ureteropyelography and ureteroscopy.



Table 4.1

Upper Urinary Tract Filling Defects: Differential Diagnosis


































































































Common entities
Tumors Transitional cell carcinoma
Lithiasis Uric acid calculus
Blood clot Trauma/tumors ( Fig. 4.4 )
Air Iatrogenic (RUP)
Infection/inflammation Papillary necrosis
Ball of fungi
Rare causes
Tumors Leukemic infiltrate
Angiolipoma
Multiple myeloma
Lymphoma
Wilms’ tumor
Cysts
Polyps ( Fig. 4.5 )
Squamous cell cancer
Adenocarcinoma
Leukoplasia
Amyloidosis
Sarcoma
Connective tissue tumors
Metastatic tumors
Urinary lithiasis Soft (matrix)
Xanthine
Blood clot Coagulopathy
Nephritis
Anticoagulants
Air Enteric fistulas
Congenital Vessels
Ectopic papillae
Hypertrophic papillae ( Figs 4.6 and 4.7 )
Vascular Renal artery aneurysm
Vascular impressions (vessels that cross the renal pelvis, lower renal pole vessel, ovarian vein)
Arteriovenous fistulas
Infection/inflammation Cystic pyelitis
Cystic ureteritis
Tuberculosis
Malakoplakia
Helminths
Fistula
Foreign bodies Iatrogenic ( Fig. 4.8 )



Figure 4.4


Upper calyx clot determining a lacunar image on pyelography.



Figure 4.5


Pseudotumoral polypoid masses at the renal pelvis level (retrograde semirigid ureteroscopy).





Figure 4.6


Endoscopic aspects of hypertrophic caliceal papillae.



Figure 4.7


Hypertrophic caliceal papillae, without tumoral characteristics in white light (a, c) or NBI (b, d).



Figure 4.8


Unabsorbed sutures at the pyelocaliceal level in a patient with a history of pyeloplasty.


Any lacunar image with an origin not determined through imaging investigations must be explored ureteroscopically ( Fig. 4.9 ).




Figure 4.9


Management of upper urinary tract filling defects.

Source: Modified after Resnick.


Endoscopic exploration can be included in the diagnostic algorithm of patients with upper urinary tract urothelial tumors, allowing visualization and evaluation of tumor dimensions, as well as harvesting of tissue for histopathological confirmation. Uretero-pyeloscopic exploration associated with tissue biopsy is a standard investigation for all patients with upper urinary tract lesions, excepting those in whom ultrasonography is suggestive of lithiasic disease ( ).



Unilateral Hematuria


The endoscopic approach may contribute to the establishment of the etiological diagnosis of hematuria originating in the upper urinary tract ( Table 4.2 ).



Table 4.2

Causes of Unilateral Hematuria

















































Urinary lithiasis
Vascular causes Hemangiomas
Arteriovenous aneurysm
Venous ectasia
Infection/inflammation Nonspecific infections
Tuberculosis
Papillary necrosis
Reno-ureteral trauma
Tumors Transitional cell carcinoma
Multiple myeloma
Lymphoma
Wilms’ tumor
Cysts
Squamous cell cancer
Adenocarcinoma
Sarcoma
Connective tissue tumors
Metastatic tumors
Systemic causes Coagulopathy
Hemoglobinopathies
Nephritis
Anticoagulants


For patients with macroscopic hematuria, the investigation protocol includes anamnesis and a thorough physical exam, laboratory exams (urinary cytology, determining proteinuria, coagulation tests), and imaging exams (IVU, CT, arteriography), as well as endoscopic evaluation of the urinary tract ( Fig. 4.10 ).




Figure 4.10


Management of patients with unilateral hematuria.


The physical exam can detect cutaneous or oral mucosal hemangiomas, which may indicate the presence of similar lesions at the kidney level.


The examination of the morphology of red blood cells in the urine may differentiate bleeding caused by glomerular affections (red blood cells with modified morphology) from an anatomical lesion (cells with normal morphology). In 1987, Tomita described five different types of red blood cells indicating the glomerular or nonglomerular source of bleeding. This test has a good accuracy, studies showing a 73–90% sensitivity and a 60–98% specificity.


In patients with unilateral hematuria of undetermined cause, detailed analysis of urinary proteins may have a diagnostic role. Thus, a nonglomerular source of hematuria determines an increase in high molecular weight urinary proteins. When urinary albumin is greater than 100 mg/L, it is recommended to determine alpha2-macroglobulin from the second morning urine. If this is also increased (alpha2-macroglobulin/albumin > 2/100), the bleeding source is probably nonglomerular, postrenal.


Besides the previously described tests, the diagnostic protocol also includes ultrasonography, IVU, and cystoscopy. Urography must clearly visualize all of the calyces and the entire length of the ureter, which most often requires performing multiple radiological imagings and repositioning of the patient. If satisfactory images are not obtained at urography, retrograde ureteropyelography, a more invasive diagnostic method, may be performed.


If urography and retrograde ureteropyelography do not detect a cause for hematuria (filling defects, calculi, kidney tumors) and bleeding through a ureteral orifice is visualized on cystoscopy, a CT exam is indicated. Some authors recommend CT before retrograde ureteropyelography.


If these explorations do not provide significant data, renal arteriography may be performed in the next diagnostic step, which may detect an arteriovenous malformation or another vascular affection. This method sometimes resolves the respective cause by embolization. There is no unanimously accepted indication for performing this type of paraclinical exam.


Some authors recommend performing angiography only if there is a history of punctures, surgical interventions, trauma, or kidney tumors ( ).


Angiography may be replaced by the more modern angio-MRI.


The last diagnostic step is ureteroscopy ( Fig. 4.11 ). It is recommended to perform the endoscopic exploration in case of active hematuria because the detection of lesions is difficult, if not impossible, after its cessation.




Figure 4.11


Flexible ureteroscopic exploration in a patient with unilateral hematuria.

Bleeding at the level of the left ureteral orifice (a), inspection with the help of the semirigid ureteroscope up to the level of the left renal pelvis (intraoperatory fluoroscopy) (b), normal aspect at the flexible ureteroscopic inspection of the upper calyx (c, d), hemorrhagic vascular lesions at the level of the secondary upper calyx papilla (e, f), hemorrhagic vascular lesions at the level of the middle calyx papilla (g, h), blood clot at the level of the middle caliceal infundibulum (i), flexible ureteroscopic approach of the lower caliceal group (j, k), vascular lesions at the level of the lower calyx papilla (l, m).




In the etiological diagnosis of hematuria originating in the upper urinary tract, it is essential to determine the malignant or benign nature of the cause. This is even more important due to the fact that for well-differentiated upper urinary tract urothelial carcinomas, the cytological exam can provide false negative results in up to 80% of cases ( ).


A cause of chronic unilateral hematuria, especially in young patients, may be represented by renal hemangiomas ( ) ( Fig. 4.12 ).




Figure 4.12


Bleeding papillary hemangioma.


These are solitary or multiple venous malformations, localized most often at the level of the papilla. Hematuria determined by this condition is most frequently spontaneous and intermittent, being triggered by the thrombosis and infarction of the hemangioma or by the erosion of the mucosa on its surface ( ).


In most cases, vascular lesions such as ruptured hemangiomas or venous ectasias can only be detected endoscopically ( ; ).


Other causes of unilateral total hematuria are represented by calculi ( Fig. 4.13 ), tumors ( Figs 4.14 and 4.15 ), stenoses, specific ureteral or pyelocaliceal inflammatory lesions (tuberculosis) ( Fig. 4.16 ), or nonspecific ones ( Fig. 4.17 ).




Figure 4.13


Flexible ureteroscopic aspects of caliceal calculi.



Figure 4.14


Flexible ureteroscopic aspects of pyelocaliceal urothelial tumors.



Figure 4.15


Carcinoma in situ lesions at the pyelocaliceal level.



Figure 4.16


Flexible ureteroscopy in a patient with total hematuria determined by renal tuberculosis opened into the urinary tract.

Disorganized aspect of the pyelocaliceal system, with inhomogeneous opacification and lacunar images (intraoperatory fluoroscopy) (a), systematic exploration of all caliceal groups, with the detection of papilla ulcerations, white deposits and false exudate membranes (b–j), Koster follicle in the renal medulla (HE staining, 20×) (k, l).





Figure 4.17


Flexible ureteroscopic aspect suggestive of papillary necrosis.


There are situations in which ureteroscopic exploration can only detect nonspecific lesions, such as congestion of the ureteral, caliceal or pelvic mucosa ( Fig. 4.18 ), calcareous encrustations ( Figs 4.19 and 4.20 ), etc., or even the absence of pathological modifications ( ).




Figure 4.18


Intensely hyperemic pyelocaliceal mucosa in a patient with total hematuria.



Figure 4.19


Papillary calcifications detected by flexible ureteroscopy in patients with unilateral total hematuria.



Figure 4.20


Endoscopic aspect in a patient with nephrocalcinosis and hematuria.


The use of flexible ureteroscopes, by thoroughly exploring areas of the upper urinary tract that used to be inaccessible to rigid and semirigid endoscopes, has reduced the number of cases diagnosed as “essential” hematuria ( ; ).


When determining the malignant or benign nature of lesions is difficult under white light, the NBI mode available in the case of the Olympus URF-Vo ureteroscope may provide additional visual information in order to decide on the course of action (biopsy or not) ( Figs 4.21–4.24 ). This mode also allows for a better surface characterization of tumors when conservative treatment is chosen.




Figure 4.21


Edema of the pyelocaliceal system (a), without tumoral characteristics in NBI (b).



Figure 4.22


Superficial lesions (a, c), having tumoral characteristics in NBI (b, d).



Figure 4.23


Flat lesion, suspected for CIS (a), without tumoral aspect in NBI (b).



Figure 4.24


Caliceal mucosal lesions (a), without NBI tumor characteristics (b).



Abnormal Results of Cytological Tests


Another indication for ureteroscopic evaluation is represented by patients with abnormal urinary cytology ( ), with normal urethrocystoscopy and, eventually, with negative bladder and prostatic urethra biopsies.


Due to the theoretical possibility of visualizing the entire upper urinary tract, eventually with sampling of bioptic material, ureteroscopy has a 93% sensitivity, compared to only 72% for imaging methods ( ).



Follow-Up of Conservatively Treated Upper Urinary Tract Urothelial Tumors


In selected cases, patients with upper urinary tract urothelial tumors have an indication for conservative endourological treatment: tumor on the solitary kidney, patients with kidney failure, bilateral synchronous tumors, and important surgical risk.


Due to the high risk of tumor recurrence, the follow-up protocol for these patients must be very strict, the periodic endoscopic exploration of the entire upper urinary tract also being necessary ( Fig. 4.25 ).




Figure 4.25


Recurrent urothelial tumor after conservative treatment.


In a study performed on a group of 10 patients (12 renal units) with conservatively treated upper urinary tract urothelial tumors, Amon Sesmero and Estebanez Zarranz performed 42 ureteroscopies (31 with flexible instruments and 11 with rigid endoscopes) in a mean follow-up period of 31.9 months. Two patients presented ureteroscopically identified tumor recurrences and two patients died, one from distant progression and the other due to a metachronous bladder tumor, chronologically previous to the ureteral one ( ). In the opinion of the authors, flexible ureteroscopy is the most efficient follow-up method for these patients.



Other Indications for Diagnostic Ureteroscopy


Ureteroscopy may also contribute to the etiological diagnosis of obstructions at the ureteral or uretero-pelvic junction level. As in the case of the diagnosis of filling defects, ureteroscopic approach allows for direct visualization of lesions (calculus, tumor, ureteral, or uretero-pelvic junction stenosis), eventually with sampling of bioptic material and, very frequently, with their conservative treatment.


In selected cases, with certain anatomical particularities (such as important ureteral curves, urinary derivations, and malformations of the urinary tract), the use of flexible ureteroscopes may be absolutely necessary for the diagnosis of the upper urinary tract obstruction’s etiology.


Incomplete pathological pyeloureteral duplicity represents an entity that benefits, in selected cases, from ureteroscopic evaluation and treatment ( ).


The use of flexible ureteroscopes allows for the visualization, in good conditions, of the bifurcation areas and for the direct exploration of all pelvises, in order to determine the type of obstruction and any associated conditions.


The effects of lesions located outside the urinary tract (retroperitoneal diseases, digestive, or gynecological cancers, kidney cysts, Grawitz tumors, etc.) on the urinary tract can be evaluated or confirmed by retrograde ureteroscopic approach ( Fig. 4.26 ).




Figure 4.26


Kidney cyst visualized through the transparency of the caliceal wall.



Contraindications


The contraindications of diagnostic ureteroscopy are few, all of them being considered as relative:




  • hemorrhagic disorders



  • neglected urinary tract infections



  • lack of appropriate antibiotic prophylaxis



Adequate preoperatory preparation (correction of coagulation, antibiotic treatment, or prophylaxis, etc.) may allow for performing the ureteroscopic exploration in good conditions in these cases as well.


The introduction of flexible ureteroscopes into current urological practice allows one to perform this investigation also in patients in whom semirigid ureteroscopic approach used to be difficult or even impossible (skeletal deformities, voluminous prostate adenomas, etc.)





Lacunar Images at the Level of the Upper Urinary Tract


Ureteroscopy may allow the determination of the nature of upper urinary tract lesions: malignant (transitional cell carcinoma, etc.) ( Fig. 4.1 ) or benign (calculi, polyps, hemangiomas, tuberculous lesions, cellular detritus, or blood clots, etc.) ( Fig. 4.2 ).




Figure 4.1


Diagnostic ureteroscopy in a patient with upper caliceal lacunar image.

Retrograde pyelography highlighting the lacunar image at the level of the upper calyx (a), flexible ureteroscopic inspection of the upper calyx (intraoperative fluoroscopy) (b), upper caliceal urothelial carcinoma (c, d).



Figure 4.2


Diagnostic ureteroscopy in a patient with upper caliceal lacunar image.

Retrograde pyelography highlighting the lacunar image at the level of the upper calyx (a), flexible ureteroscopic inspection of the upper calyx (intraoperative fluoroscopy) (b), old clot at the upper caliceal level (c), extracting the upper caliceal clot (d), normal aspect of the caliceal mucosa under the clot fragments (e).


The ureteroscopic evaluation must not be stopped after identifying a lesion, but must continue with the systematic exploration of the entire upper urinary tract ( Fig. 4.3 ).




Figure 4.3


The systematic inspection of the other caliceal groups, without detecting tumoral masses.


Evaluation is performed by gradually using the diagnostic methods, from the least invasive to the more aggressive ones.


Anamnesis may provide clues that can guide the diagnosis:




  • a history of lithiasis or of bladder tumors may guide the diagnosis toward the same type of conditions



  • in patients with a history of diabetes, recurrent urinary infections, abuse of analgesics or blood disorders, the filling defect may be more frequently determined by papillary necrosis or by a blood clot



  • uretero-enteric fistulas may be suspected in patients with inflammatory bowel diseases



  • recurrent Escherichia coli infections may be associated with malakoplakia



  • pneumaturia may appear due to a communication between the colon and the upper or, more frequently, lower urinary tract



Complete urine analysis is also a mandatory component of the diagnostic protocol:




  • pH over 6.5 is frequently associated with uric lithiasis



  • in hematuria, the filling defect may be caused by a clot



  • urinary cytology is useful for detecting urothelial tumors, but is encumbered by a significant rate of false positive or negative results, depending on the tumor grade



  • the presence of aerobic and anaerobic germs detected in the urine culture raises the suspicion of a uretero-intestinal fistula



The next step in evaluating a filling defect discovered by intravenous urography (IVU) is comprised of other imaging explorations (CT, MRI, etc.).


If a diagnosis cannot be established following these exams ( Table 4.1 ), the next step is represented by ureteropyelography and ureteroscopy.



Table 4.1

Upper Urinary Tract Filling Defects: Differential Diagnosis


































































































Common entities
Tumors Transitional cell carcinoma
Lithiasis Uric acid calculus
Blood clot Trauma/tumors ( Fig. 4.4 )
Air Iatrogenic (RUP)
Infection/inflammation Papillary necrosis
Ball of fungi
Rare causes
Tumors Leukemic infiltrate
Angiolipoma
Multiple myeloma
Lymphoma
Wilms’ tumor
Cysts
Polyps ( Fig. 4.5 )
Squamous cell cancer
Adenocarcinoma
Leukoplasia
Amyloidosis
Sarcoma
Connective tissue tumors
Metastatic tumors
Urinary lithiasis Soft (matrix)
Xanthine
Blood clot Coagulopathy
Nephritis
Anticoagulants
Air Enteric fistulas
Congenital Vessels
Ectopic papillae
Hypertrophic papillae ( Figs 4.6 and 4.7 )
Vascular Renal artery aneurysm
Vascular impressions (vessels that cross the renal pelvis, lower renal pole vessel, ovarian vein)
Arteriovenous fistulas
Infection/inflammation Cystic pyelitis
Cystic ureteritis
Tuberculosis
Malakoplakia
Helminths
Fistula
Foreign bodies Iatrogenic ( Fig. 4.8 )

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Oct 10, 2019 | Posted by in UROLOGY | Comments Off on Diagnostic Ureteroscopy
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