endourology and other urologic ancillary procedures department of urosurgery

Dellosa, MiguelLeeChuy, Katherine

Lee, Sidney AlbertLegaspi, Roberto JoseLerma, Daniel Joseph

Li, Henry Winston

Jerry Santos, MDFacilitator

The use of closed procedures via needle and guidewire access to visualize and manipulate the kidneys and upper urinary tract.

Patient in prone position Local anesthesia – lidocaine

hydrochloride Ultrasonographic or

fluoroscopic guidance Standard puncture site –

posterior axillary line, midway between 12th rib and iliac crest into a dorsal calyx

Fluoroscopic guidance after successful puncture

Place transducer cephalad to the puncture site Incise skin and fascia Shift transducer over incision to measure distance to the

target Blind insertion of 16-18 gauge needle through abdominal

wall Visualize both target and needle in same plane before

puncturing collecting system

Intravenous or retrograde administration of contrast dye

Insert 16-18 gauge needle through abdominal wall

Insert fine needle through larger needle to the collecting system

Advance larger needle over fine needle Remove fine needle and insert guidewire

Diagnostic Antegrade pyelography Pressure/perfusion study (Whitaker test)Therapeutic Nephrostomy catheter drainage Antegrade ureteral stenting Dilation of ureteral strictures Perfusion chemolysis of renal stones Percutaneous nephrolithotomy Percutaneous resection and coagulation of

urothelial tumors

Blood clotting anomalies

Obtaining radiograph after antegrade injection of contrast dye (20-30% diluted)

Simultaneously done with Whitaker’s test

Assess pyeloureteral resistance by differentiating an obstructed from non-obstructed dilated system

Simultaneous measurements of intrapelvic and intravesical pressures during antegrade perfusion at 5, 10, 15, and 20mL/min flow rates via a manometer

Differential pressure = renal pelvic – bladder pressure◦ Flow rate 10mL/min: normal < 13 cmH2O; mild

obstruction 14-22 cmH2O; moderate to severe obstruction > 22 cmH2O

◦ Flow rate 15mL/min: normal < 18 cmH2O◦ Flow rate 20mL/min: normal < 21 cmH2O

Drainage and decompression of upper urinary tract if retrograde ureteral catheterization cannot be done

Insertion of guidewire, dilator, then nephrostomy catheter

Can do antegrade ureteral stenting and balloon dilation through catheter

Adjunct treatment for residual stones after surgery, PNL, or ESWL

Use of double-catheter system for simultaneous irrigation and drainage

Flow rate 100-120mL/hr Uric acid: Na+ or K+ bicarbonate Cystine: D-penicillamine, acetylcysteine,

tromethamine-E Struvite/apatitie: Suby’s solution G or M or

hemiacidrin

Complications: pyelotubular/pyelovenous reflux of chemolytic agent; infected urine; hypermagnesemia; sepsis

Endoscopic Intrarenal Endoscopic Intrarenal InstrumentationInstrumentation Nephroscopes – endoscopic instruments,

15-26F sheaths, inserted percutaneously◦ Standard rigid instruments available in sizes 24-

26F, have telescopes with offset eyepieces Smaller working channel allows insertion of

flexible intruments Instrumentation through flexile

nephroscopes is limited by size and flexibility of working instruments

NephroscopyNephroscopy Rarely indicated for diagnostic purpose Mostly performed for percutaneous

lithotripsy ESWL has gradually replaced PNL for renal

stone treatment PNL used in:

◦ Urinary obstruction not caused by stone itself◦ Large volume stones◦ Stones that cannot be positioned within SW focus

Renal StonesRenal Stones PNL is limited to specific stone diseases Large stones must be disintegrated using

mechanical, ultrasonic, electrohydraulic, or laser energy

For soft stones - continuous disintegration and evacuation of fragments

Hard stones – broken up into largest possible fragments that can be extracted

Ureteropelvic StenosisUreteropelvic Stenosis Direct-vision internal incision (pyelolysis,

endopyelotomy, endopyeloplasty)◦ Offers advantage of an incision under direct vision

Renal Pelvis TumorRenal Pelvis Tumor Electroresection, electrocoagulation,

electrovaporization, neodymium:YAG laser coagulation

Percutaneous management may be an alternative to nephroureterectomy for patients with grade I disease, and for palliative tratment

Percutaneous Aspiration & Percutaneous Aspiration & BiopsyBiopsy Usually perfomed for diagnostic purposes In combination with therapeutic intentions Ultrasound and CT are imaging techniques

of choice

Renal CystsRenal Cysts Indications of diagnostic puncture of cystic

lesion:◦ Irregular, thick wall, internal echoes on ultrasound

exam◦ Density numbers on CT higher than serous fluid◦ Hematuria

Indications of puncture for therapy:◦ Cyst causes compression

Renal BiopsyRenal Biopsy Performed percutaneously or open surgery Bleeding is expected due to vascularity of

parenchyma Open surgical biopsy rather than

percutaneous biopsy is indicated in patients with solitary kidneys or uncontrolled hypertension

• The normal kidneys are bean-shaped• Located between the upper border of T11

and lower border of L3• The right kidney lies approximately 2 cm

lower than the left.• The normal range of renal length in adults is

11 to 15 cm.• The increased radiolucency of the fat makes

the outline of the kidney standout from the soft tissues

• The kidneys are contained within the renal capsule and surrounded perirenal fat, which is enclosed within Gerota’s fascia.

• There are 3 anatomic spaces around each kidney:

1. Perirenal2. Anterior pararenal3. Posterior pararenal

Left Kidney

Anterior Layer of the renal fascia

Posterior Layer of the renal fascia

Fibrous capsule of the kidney

Perirenal fat

The leaves of the Gerota’s fascia fuse superiorly, medially and laterally, enclosing the kidney, adrenal gland, renal vasculature and emerging portion of the proximal ureter.

In theory fluid collections are more likely to collect in spaces between tissue planes rather than in the perirenal and pararenal spaces.

The ureters cannot be defined on plain KUB film however radioopaque calculi may be detected along the course of the ureter.

3 areas of normal narrowinga. Ureteropelvic junctionb. Ureterovesical junctionc. Bifurcation of the iliac vessels

These are sites where calculi often lodge in the course of passage

The shadow of the urinary bladder can often be identified.

The urinary bladder is a muscular hollow viscus which lies in the pelvis but balloons upward when distended.

The psoas muscle shadows are usually well outlined.

Assymmetry or other abnormalities are noted.

In perirenal abscess, the psoas muscle shadow is enlarged and its margin is indistinct adjacent to the area of infection.

Psoas abscess may displace the kidney and ureter

Vesical calculi can be outlined. Vascular calcifications, including phleboliths

and arterial plaques are frequently seen.

• Assessment of GUT requiring IV injection of contrast to visualize renal collecting systems, ureters and UB

• Indications:– Urinary stones– Neoplasia– Urinary inflammations– Urinary trauma and obstruction– Miscellaneous: congenital anomalies, GUT fistula

formation, patent urachus, etc.

◦ NPO◦ Bowel cleansing◦ Some cases: adequate hydration (MM, IDDM and

renal failure)

Contrast material◦ Organic iodides: radiopacity depends on its iodine

content◦ 2 types:

Ionic Non-ionic: lower osmolality

Advantages: less toxicity and less reactions Disadvantage: more expensive

◦ Mechanism of exretion: Almost entirely by glomerular filtration little or no

tubular resorption

• hypersensitivity to contrast• combined hepatic and renal disease• oliguria• serum creatinine >2.5-3.0 mg/dl• IDD with renal insufficiency (serum crea > 1.5

mg/dl)• Multiple myeloma• Hx of severe allergy• Use of metformin (within previous 48hrs)• ++ value of INFORMATION obtained must be

weighed against the risk

◦Adverse contrast reactions Minor: urticaria, sweating , nausea, vomiting

Major: laryngeal edema, hypotension, bradycardia, shock, seizure, anaphylactoid rxn, such as cardio-respi arrest

-minimally invasive procedure that requires cystoscopy and the placement of catheters in the ureters

-radiopaque contrast medium is introduced into the ureters or renal collecting structures through the ureteral catheters, and radiographs of the abdomen are taken.

Retrograde Urogram

INDICATIONS: a.)excretory urograms or CT urogram

(CTU) are unsatisfactoryb.) history of adverse reaction to

intravenouscontrast media

Nephrogram• Diffuse opacification of the renal parenchyma• Reflects the ability of proximal tubules to reabsorb

water and concentrate the contrast • Visualize renal outline

Pyelogram• Visualization of the pelvocalyceal complex and ureters• Contrast has reached the collecting tubules and

excretory passages• Information on architecture and function of kidney

Cystogram-Visualization of the lower part of ureters and

UB

• Visualization of the UB wherein a urethral catheter is inserted and the UB is filled with contrast

usually instilled via a transurethral catheter, but when necessary can be administered via percutaneous suprapubic bladder puncture

suspected UB rupture in trauma patients suspected UB tumors diverticula calculi

imaged radiographically by retrograde injection of radiopaque fluid or in antegrade fashion with voiding cystourethrography, or with voiding following EU.

antegrade technique is required when lesions of the posterior urethra, for example, posterior urethral valves, are suspected.

retrograde technique is more useful for examining the anterior (penile) urethra

A wave frequency of 1 cycle/s (cps) is called a hertz (Hz). Sound frequencies greater than 20 kHz are beyond the range of human hearing and are called ultrasound.

Medical sonography uses ultrasound to produce images. The frequencies commonly used in medical sonography are between 3.5and 15 MHz.

Ultrasound images are reflection images formed when part of the sound that was emitted by the transducer bounces back from tissue interfaces to the transducer.

A more sensitive method of detecting flow, called power mode Doppler, is available on modern equipment. This technique displays the integrated power of the Doppler signal rather than the mean Doppler frequency shift

Sonography of the kidney. Upper: Normalkidney. Renal cortex (C), normal renal sinus echoes(S). Middle: Moderate hydronephrosis and hydroureter;dilated renal pelvis (P). Dilated proximal ureter (proxure). Lower: Severe hydronephrosis of the transplantedkidney, compound sagittal scans, dilated clubbed calices(C), dilated renal pelvis (P).

Ultrasound is commonly used for the evaluation of the kidney, urinary bladder, prostate, testis, and penis.

Assessment of renal size and growth.

Triaging patients with renal failure, e.g. small echogenic kidneys suggest renal parenchymal(medical) disease, whereas a dilated pelvocaliceal system indicates an obstructive, and potentially reversible, cause of renal failure. Useful in detection and characterization of renal masses. It provides an effective method of distinguishing benign cortical cysts from potentially malignant solid renal lesions.

Ultrasound may also be used to follow up mildly complicated cysts detected on CT, e.g. hyperdense cysts or cysts with thin septations.

The differential diagnosis for echogenic renal masses includes renal stones, angiomyolipomas, renal cortical neoplasms (including carcinoma), and, less commonly,abscesses and hematomas.

All echogenic renal masses should be correlated with clinical history and, if necessary, confirmed with another imaging modality or follow-up ultrasound.

Echogenic lesions smaller than 1 cm are more difficult to characterize by CT owing

to partial volume averaging; in the correct clinical setting, follow-up ultrasound rather than repeat CT may be more useful.

Doppler sonography is useful for the evaluation of renal vessels, vascularity of renal masses, and complications following renal transplant. It can detect renal vein thrombosis, renal artery stenosis, and ureteral obstruction prior to the development of hydronephrosis, arteriovenous fistulas, and pseudoaneurysms.

Perinephric fluid collections following renal transplantation, extracorporeal shockwave lithotripsy, or acute obstructions are reliably detected by ultrasound.

Developments in other imaging modalities have decreased the use of ultrasound in several clinical scenarios.

Most patients with suspected renovascular hypertension are evaluated with CTA or MRA rather than Doppler sonography

ease of use, High patient tolerance noninvasiveness lack of ionizing radiation low relative cost wide availability. include a relatively low signal-to-noise level,

tissue nonspecificity, limited field of view, and dependence

relatively low signal-to-noise level tissue nonspecificity, limited field of view Dependence on the operator’s skill and the

patient’s habitus.

Acute flank pain Hematuria Renal infection

(search for abscess) Renal trauma Staging renal

neoplasm Solid or cystic mass

Contrast scans◦ IV iodinated contrast media◦ Anatomy and pathology

Noncontrast scans◦ Renal or perirenal calcification◦ Hemorrhage◦ Urine extravasation

• Contrast media • rapid intravenous bolus for assessment of renal anatomy

or measurement of aortorenal transit time. • Using a bolus injection and rapid sequence scanning,

renal arterial opacification is followed immediately by enhancement of the cortex.

• Nephrogram phase with medullary enhancement is reached within 60 seconds.

• Excretion of contrast material into the collecting structures can be expected within 2–3 minutes after initiation of contrast administration.

Detect ureteral tumors◦ Tumor staging and evaluation of the cause and

level of obstruction. intravenous contrast is the preferred imaging modality

• Helical CT without oral or intravenous contrast is the preferred imaging modality for patients with renal colic or suspected urolithiasis

Primarily in staging bladder tumors Bladder rupture following trauma Increased sensitivity in bladder filled with

dilute contrast medium (CT cystography)

Prostatic CT◦ Lymphadenopathy◦ Prostatic abscessess

Testis◦ Undescended testis◦ Testicular tumors◦ Nodal distant metastases

Wide field of view, Detect subtle differences in the x-ray

attenuation properties of various tissues, good spatial resolution, anatomical cross-sectional images, and operator independence.

Reformatted planes in 3D

Limitations to the transaxial plane for direct imaging

Tissue nonspecificity Low soft-tissue contrast resolution, Need for contrast media (both oral and

intravenous). Radiation exposure

Clinical Applications:• Congenital anomalies

• Diagnosis of renal vein thrombosis

• Diagnosis and staging of renal cell carcinoma

MR angiography◦ renal transplant vessels◦ renal vein tumor thrombosis◦ renal artery stenosis

Gadolinium

◦ obstruction (renal artery stenosis)

T1-weighted conventional spin-echo image -Higher signal intensity cortex (C) -lower signal intensity medulla (M)-Left renal vein (arrow) -Inferior vena cava (I)

LEFT- large renal cell carcinoma (T) arising from the inferior pole of the right kidney

RIGHT- Coronal image of a large renal cell carcinoma (T) replacing almost entire parenchyma of the left kidney (K). Superior displacement of the pancreas (arrows).

Gadolinium-enhanced renal magnetic resonance angiography

LEFT- renal arteries are normal

RIGHT- atrophic left kidney with an occluded left renal artery

severely stenotic right renal artery

Advantages-Direct imaging in any plane desired-Choice of large or small field of view- Excellent soft-tissue contrast- No exposure to ionizing radiation- Less operator dependence

Disadvantages◦ scanning time is relatively slow

Absolute contraindications◦ intracranial aneurysm clips◦ intraorbital metal fragments◦ any electrically,magnetically, or mechanically

activated implants Eg. Cardiac pacemakers, biostimulators,

neurostimulators, cochlear implants, and hearing aids

Most useful in:

Evaluation renal masses in pxs with contraindication to IV contrast

Contrast enhanced CT has been inadequate for diagnosis and staging

Detection renal vascular disorder

• ++appearance of specific structures varies with the IMAGING SEQUENCE