Ureteroscopes and ancillary equipment Mohan Arianayagam ...

Ureteroscopes and ancillary equipment Mohan Arianayagam ... Ureteroscopes and ancillary equipment Mohan Arianayagam ...

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Ureteroscopes and ancillary equipment Mohan Arianayagam Trainees week 2007 Rigid ureteroscopes Rigid ureteroscopy was first introduced in 1979. The instruments were large (14F) with a single 5F working channel. They required dilatation of the ureteric orifice and were used primarily for distal ureteric stones. There was a high incidence of perforation, rupture and stricture and the treatment was sometimes worse than the disease. Over the last 20 years there has been an impressive improvement in the technology and the scopes are now much smaller. This has led to increased usage as there has been a significant decrease in complications. This is particularly the case with the advent of the holmium laser for stone fragmentation and the treatment of upper tract tumours. Most modern rigid scopes are fibre optic and have a maximal shaft diameter of 9F with one or two working channels. They may have off centre or in line eye pieces. The two channel scopes can be advantageous as a single channel can be dedicated to irrigation or allow passage of a second instrument with greater ease. Flexible ureteroscopes Flexible ureteroscopes allow access to the upper ureter and renal collecting system for investigation or treatment of upper tract tumours or stones. They are about 6F at the tip and increase up to 9F at the shaft. The have a primary deflection function that allows movement of the tip from 180 to 270 degrees. The amount of deflection varies between the different manufacturers. Some have a secondary passive deflection mechanism that allows the scope to be passed into the lower pole while the DUR8 (Gyrus ACMI) actually has an active secondary deflector. Unfortunately the latter has reduced primary deflection. The flexible scopes are made up of bundles of optical fibres clad in a second kind of glass with a different refractive index. This increases flexibility and durability. As the technology has improved this has allowed better images as the cladding has become finer, reducing the grain of the picture. Flexible ureteroscopes are very delicate and need to be handled with care, particularly at the most distal part of the shaft where the fibre optics join the handle. Stress on this area can lead to damage of the fibre optics. In addition, passing instruments down the working channels while deflected can also result in damage to the working channels. This is particularly the case with laser fibres. As the technology improves there will soon be digital scopes where the image capture system is in the tip obviating the need for fibre optics. This should again improve the image as well as durability. Ancillary equipment There are a wide variety of devices used to snare calculi post fragmentation. The key feature is the ability to disengage a stone that is too large. The device need to have sufficient radial force to open in the ureter. The smaller calibre devices also allow better irrigation while nitinol is essential to maintain basket shape. Ureteric access sheaths are also available and these allow improved irrigation and ease of fragment removal. The newer sheaths also have a second irrigation channel and some have an active deflection mechanism. A variety of wires are available including the urowire and sensor wire. These combine a hydrophilic floppy tip attached to a stiffer metal wire. These improve access and safety during difficult access cases as it is not necessary to change the slipper glide wire over a catheter for better safety.

<strong>Ureteroscopes</strong> <strong>and</strong> <strong>ancillary</strong> <strong>equipment</strong><br />

<strong>Mohan</strong> <strong>Arianayagam</strong><br />

Trainees week 2007<br />

Rigid ureteroscopes<br />

Rigid ureteroscopy was first introduced in 1979. The instruments were large (14F) with a single 5F<br />

working channel. They required dilatation of the ureteric orifice <strong>and</strong> were used primarily for distal<br />

ureteric stones. There was a high incidence of perforation, rupture <strong>and</strong> stricture <strong>and</strong> the treatment was<br />

sometimes worse than the disease. Over the last 20 years there has been an impressive improvement in<br />

the technology <strong>and</strong> the scopes are now much smaller. This has led to increased usage as there has been<br />

a significant decrease in complications. This is particularly the case with the advent of the holmium<br />

laser for stone fragmentation <strong>and</strong> the treatment of upper tract tumours.<br />

Most modern rigid scopes are fibre optic <strong>and</strong> have a maximal shaft diameter of 9F with one or two<br />

working channels. They may have off centre or in line eye pieces. The two channel scopes can be<br />

advantageous as a single channel can be dedicated to irrigation or allow passage of a second<br />

instrument with greater ease.<br />

Flexible ureteroscopes<br />

Flexible ureteroscopes allow access to the upper ureter <strong>and</strong> renal collecting system for investigation or<br />

treatment of upper tract tumours or stones. They are about 6F at the tip <strong>and</strong> increase up to 9F at the<br />

shaft. The have a primary deflection function that allows movement of the tip from 180 to 270 degrees.<br />

The amount of deflection varies between the different manufacturers. Some have a secondary passive<br />

deflection mechanism that allows the scope to be passed into the lower pole while the DUR8 (Gyrus<br />

ACMI) actually has an active secondary deflector. Unfortunately the latter has reduced primary<br />

deflection.<br />

The flexible scopes are made up of bundles of optical fibres clad in a second kind of glass with a<br />

different refractive index. This increases flexibility <strong>and</strong> durability. As the technology has improved<br />

this has allowed better images as the cladding has become finer, reducing the grain of the picture.<br />

Flexible ureteroscopes are very delicate <strong>and</strong> need to be h<strong>and</strong>led with care, particularly at the most<br />

distal part of the shaft where the fibre optics join the h<strong>and</strong>le. Stress on this area can lead to damage of<br />

the fibre optics. In addition, passing instruments down the working channels while deflected can also<br />

result in damage to the working channels. This is particularly the case with laser fibres. As the<br />

technology improves there will soon be digital scopes where the image capture system is in the tip<br />

obviating the need for fibre optics. This should again improve the image as well as durability.<br />

Ancillary <strong>equipment</strong><br />

There are a wide variety of devices used to snare calculi post fragmentation. The key feature is the<br />

ability to disengage a stone that is too large. The device need to have sufficient radial force to open in<br />

the ureter. The smaller calibre devices also allow better irrigation while nitinol is essential to maintain<br />

basket shape. Ureteric access sheaths are also available <strong>and</strong> these allow improved irrigation <strong>and</strong> ease<br />

of fragment removal. The newer sheaths also have a second irrigation channel <strong>and</strong> some have an<br />

active deflection mechanism. A variety of wires are available including the urowire <strong>and</strong> sensor wire.<br />

These combine a hydrophilic floppy tip attached to a stiffer metal wire. These improve access <strong>and</strong><br />

safety during difficult access cases as it is not necessary to change the slipper glide wire over a<br />

catheter for better safety.


Complications Of Ureteroscopy<br />

1988 major complication rate (10-14 Fr scope) 7.5%<br />

1998 major complication rate (7 Fr scope) 0.9%<br />

Specific complications<br />

–Perforation 0-1%<br />

–Stricture 0.5-1%<br />

–False passage 0.5%<br />

–Avulsion 0-0.5%<br />

–Sepsis<br />

–Bleeding<br />

–Colic 5%<br />

•Bleeding<br />

–If blood obscures vision do not proceed blindly<br />

–Use Guide wire to perform retrograde pyelogram to ascertain integrity of system the stent.<br />

•Pyonephrosis<br />

–Stent <strong>and</strong> ab<strong>and</strong>on with ABx 2/52<br />

•False passage with safety wire<br />

–Retrograde pyelogram<br />

–Do not remove guide wire, place another wire next to the wire (this way the wire closes off the false<br />

passage)<br />

–If unable to pass guide wire ab<strong>and</strong>on, consider nephrostomy +/- anterograde stent<br />

•“kinked” ureter<br />

–May use PUJ occluding catheter<br />

–Inflate at level below kink <strong>and</strong> apply gentle traction <strong>and</strong> place guide wire up catheter<br />

•Basket that won’t disengage<br />

–Dismantle h<strong>and</strong> piece, loose wire.<br />

–If unable to remove still place ureteroscope next to basket <strong>and</strong> laser stone.<br />

•Ureteric Perforation<br />

–Stent <strong>and</strong> return on another day<br />

–If very large may need open repair<br />

•Ureteric Stricture<br />

–Delayed complication<br />

–Confirm diagnosis on retrograde pyelogram<br />

CT/IVU may not show distal strictures in multiple stricture disease<br />

–Short Consider primary excision<br />

–Long Prox – Ureterocalycostomy/ pyeloplasty<br />

Mid – Trans ureteroureterostomy, ileal substitute<br />

Distal - Reimplantation +/- boari or psoas hitch<br />

•Ureteric Avulsion<br />

–Dreaded complication<br />

–Confirm diagnosis on retrograde pyelogram<br />

–Distal à consider primary repair<br />

–Proximal/Mid à consider nephrostomy <strong>and</strong> delayed repair<br />

Distal<br />

Mid<br />

Proximal<br />

- Primary reimplantation +/- boari flap or psoas hitch<br />

–Boari Flap/Psoas hitch<br />

–Trans uretero-ureterostomy<br />

–Ileal transposition<br />

–Ileal transposition<br />

–Auto transplantation


Energy sources for<br />

Endourology<br />

Trainee Week 2007<br />

Janelle Brennan


Overview<br />

• 4 types of intracorporeal lithotripsy<br />

• Flexible<br />

• Laser (Holmium)<br />

• Electrohydraulic (EHL)<br />

• Rigid<br />

• Ballistic (Lithoclast)<br />

• Ultrasonic<br />

• Mechanism, advantages, disadvantages & surgical<br />

technique<br />

• Summary


Which lithotripter is the best?<br />

• Depends on stone location & size<br />

• Large volume calculus at PCN - ultrasonic &/or pneumatic<br />

• Ureter/small intrarenal - holmium laser as flexible, small<br />

diameter <strong>and</strong> can fragment all stone types<br />

• Balance between 3 factors:<br />

• Efficiency<br />

• Size of probe<br />

• Flexibility


Electrohydraulic (EHL) -<br />

Mechanism<br />

• Underwater spark plug<br />

• Spark discharge causes explosive formation of plasma<br />

channel & vaporization of water around electrode<br />

• Subsequent expansion & collapse of gas bubble generates a<br />

shock wave<br />

• Shock wave is not focused so EHL probe needs to applied ~1mm<br />

from stone to optimize fragmentation<br />

• vs. >3mm which results in high speed microjets<br />

• Functions equally well in N saline (vs.. 1/6 saline)


EHL - Advantages<br />

• Successfully fragment 90% stones<br />

• Average 3/12 stone-free rate only 84% because some<br />

fragments not removed<br />

• Decreased ureteral stone free rates if >15mm<br />

• 67% EHL vs. 100% Holmium:YAG<br />

• Probe flexibility<br />

• 1.6 to 5Fr; can be passed up flex URS<br />

• Only probe equivalent to 200um laser fibre<br />

• Low cost<br />

• Inexpensive generator <strong>and</strong> probes<br />

• Average 1-1.3 probes/case<br />

• Little difference in efficiency b/w probe size but better<br />

durability if larger size


EHL - Disadvantages<br />

• High rates of ureteral mucosal damage <strong>and</strong> ureteral<br />

perforation<br />

• Mean perforation rate 8.5%<br />

• Damage caused by cavitation bubble so may occur even if probe<br />

not in direct contact with mucosa<br />

• Increased perforation risk - higher energies (e.g. hard stone),<br />

impacted stones (poor vision from blood, mucosal edema)<br />

• Retrograde propulsion of calculi (> laser)<br />

• Production of large number & sized fragments (esp. if stone<br />

>15mm)<br />

• Repeated URS passage exacerbates mucosal irritation


EHL - Technique<br />

• Fibre tip 2-5mm from distal end of URS to protect lens<br />

from emitted spar<br />

• Probe ~1mm from stone surface<br />

• Allows maximal shock wave emission<br />

• Start with low voltage (50-60V) & short intermediate or<br />

single pulses<br />

• Goal is to create fragments that can be removed with<br />

basket or pass spontaneously<br />

• Do not attempt to reduce stone fragments


EHL - Summary<br />

• Underwater spark discharge<br />

• 1st lithotripsy technique developed<br />

• Effective & flexible probes BUT narrow safety<br />

margin<br />

• High risk ureteric perforation<br />

• May be used in bladder stones (wider safety<br />

margin) but largely surpassed by newer<br />

techniques


LASER - Mechanism<br />

• Light Amplification by Stimulated Emission of Radiation<br />

• Atom is stimulated by an external energy source which creates a<br />

population of excited electrons<br />

• Excited (or high energy) electrons release their excess energy in<br />

form of photons (light energy)<br />

• Laser light has 3 properties<br />

• Coherent (all photons in phase with one another)<br />

• Collimated (photons travel parallel to each other)<br />

• Monochromatic (all photons have same wavelength)<br />

• Allow considerable energy to be transmitted in highly concentrated<br />

manner<br />

• Lasers names after laser medium generating specific<br />

wavelength


Holmium:YAG - Mechanism<br />

• Wavelength 2140nm in pulsed mode<br />

• Highly absorbed by water so majority of holmium energy is<br />

absorbed superficially (tissue mainly water)<br />

• Superficial cutting or ablation<br />

• Zone of thermal injury 0.5-1mm<br />

• Long pulse duration (250-350us)<br />

• Results in elongated cavitation bubble that generates only<br />

weak shock wave<br />

• Lithotripsy primarily through a photothermal mechanism<br />

that causes stone vaporization


Holmium:YAG - Advantages<br />

• Flexible fibre (200, 365 <strong>and</strong> 500 um)<br />

• Fragment all stones regardless of composition<br />

• Mean stone free rates >95% (failures usually secondary to<br />

migration)<br />

• Produces small fragments (avoid extraction)<br />

• Weak shockwave so less retropulsion<br />

• Excellent safety profile<br />

• Safely activated 0.5-1mm from ureteric wall<br />

• Mean perforation rate (1.1%) <strong>and</strong> stricture rate (1.2%)<br />

• Required eye protection does not compromise view<br />

• Requires minimal maintenance <strong>and</strong> ready for use within 1<br />

minute of turning machine on


Holmium:YAG - Disadvantages<br />

• High cost of device <strong>and</strong> laser fibres but . . .<br />

• Laser fibres are reusable<br />

• Multiple soft tissue applications e.g. BPH, strictures, urothelial<br />

tumours<br />

• Cyanide production with uric acid stones<br />

• In vitro studies<br />

• No clinical evidence of significant cyanide toxicity<br />

• Not particularly fast for larger stones<br />

• Can easily damage ureteroscope (lens or working<br />

channel)<br />

• Visualization may be difficult if laser damage to<br />

epithelium causing bleeding


Holmium:YAG - Technique<br />

• Keep the fibre tip in view at all times<br />

• Place fibre on stone surface before activation<br />

• Short pause after initiation due to “snowstorm effect<br />

• Clear vision is need to avoid mucosal perforation (need good<br />

irrigation)<br />

• Keep the fibre tip >1mm from urothelium<br />

• Care with basket as cuts through metal<br />

• Work from inside of the stone outward moving in a<br />

“painting fashion”<br />

• Vaporize rather than fragment<br />

• Avoid drilling into stone (# fibre) or drilling past stone (damage<br />

urothelium)


Holmium:YAG - Settings<br />

• Lithotripsy depends on pulse energy output <strong>and</strong><br />

diameter of optical delivery fibre<br />

• Energy density increases with decreasing fibre diameter so<br />

200um fibre more likely to drill<br />

• Start at low settings<br />

• Pulse energy of 0.6J to 1.2J<br />

• Pulse rates of 5Hz to 15Hz<br />

• High pulse energy narrows the safety margin <strong>and</strong><br />

increases stone retropulsion <strong>and</strong> fibre damage<br />

• Increase pulse frequency in preference to pulse energy to<br />

speed fragmentation


Holmium:YAG - Summary<br />

• Photothermal mechanism causing vaporization<br />

• Paint the stone surface; results in small fragments<br />

• Minimal shock wave so less stone migration<br />

• Excellent safety profile<br />

• Highly absorbed in water, zone thermal injury 0.5-1mm<br />

• Keep fibre tip in view at all times<br />

• Very effective (all stone types) <strong>and</strong> versatile BUT high cost<br />

& takes time<br />

• Start with low settings e.g 0.6J & 6Hz<br />

• Uses - ureteric & small intrarenal stones (flex URS)


Ballistic - Mechanism<br />

• Relies on energy generated by movement of projectile<br />

• Once projectile is in contact with another object the ballistic<br />

energy is transferred<br />

• Flexible objects preserve momentum of energy<br />

• Inflexible objects e.g. stone, fragment on impact (Jackhammer effect)<br />

• Swiss LithoClast (early 1990s)<br />

• Metal projectile in h<strong>and</strong>piece is propelled by bursts of compressed<br />

air (12 cycles/second)<br />

• Discharged probe brought back to former position by rubber<br />

bushing around base of probe<br />

• Probes 0.8 to 2.5mm<br />

• New devices - electrokinetic (heavier h<strong>and</strong>piece), suction device, flexible nitinol<br />

probe


Ballistic - Advantages<br />

• Effective in entire urinary tract for all stone types<br />

• Mean successful fragmentation rate 89%<br />

• Rapid <strong>and</strong> efficient fragmentation if stone can be pinned<br />

down<br />

• Can be combined with ultrasound (LithoClast<br />

Master/Ultra)<br />

• Wide safety margin<br />

• No heat produced so no risk of thermal injury to urothelium<br />

• Ureteral perforation rate


Ballistic - Disadvantages<br />

• Rigid probe so require straight working channel<br />

• Bowing of probe e.g. 30 degree channel results in significant<br />

reduced efficiency<br />

• High rate of stone retropulsion<br />

• Mean stone migration rate 7.3%<br />

• Higher rate if proximal ureteric stone (more capacious ureter)<br />

• Hard to treat fragments


Ballistic - Technique<br />

• Need clear view of stone <strong>and</strong> probe<br />

• Fixation of stone<br />

• Easy in kidney or bladder but may need proximal<br />

basket/ureteral occlusion device in ureter<br />

• Goal is to generate fragments


Ballistic - Summary<br />

• Shock waves transmitted to probe via<br />

movement of projectile - jackhammer<br />

• Excellent safety <strong>and</strong> low cost BUT rigid probe<br />

so can’t be used with flexible URS<br />

• High rate proximal stone migration<br />

• Uses - ureteric stones <strong>and</strong> large, hard calculi at<br />

PCNL


Ultrasonic - Mechanism<br />

• Application of electrical energy to excite a piezoceramic<br />

plate in U/S transducer<br />

• Plate resonates at a specific frequency & generates ultrasonic<br />

waves at frequency of 23000-25000Hz<br />

• Ultrasound energy is transformed into longitudinal <strong>and</strong> transverse<br />

vibrations of hollow steel probe --> transmits energy to calculus<br />

• Probe tip causes stone to resonate at high frequency <strong>and</strong> break<br />

• Heat does develop at end of probe so irrigation needed<br />

• Irrigation 30ml/min - temperature increase only 1.4 o C<br />

• Combined with suction device


Ultrasonic - Advantages<br />

• Efficient combination of stone fragmentation<br />

& simultaneous fragment removal (


Ultrasonic - Disadvantages<br />

• High suction can draw air bubbles into the system<br />

impeding vision<br />

• Straight instrument<br />

• Bending can result in energy loss at convexity of bend,<br />

with energy transformed to heat (thermal injury)<br />

• Smaller diameter probes (2.5Fr) for ureter don’t have<br />

irrigation so overheat & cause thermal damage (therefore<br />

need larger probes)<br />

• Slower fragmentation with smooth-surfaced, large<br />

stones <strong>and</strong> cystine, calcium oxalate monohydrate &<br />

uric acid


Ultrasonic - Technique<br />

• Trap stone between probe <strong>and</strong> urothelium<br />

• Apply gentle pressure to the stone to enhance<br />

fragmentation<br />

• Avoid pushing too hard as can push calculi through the<br />

urothelium<br />

• Increased risk of perforation with smaller <strong>and</strong> more<br />

ruggedly surfaced stones<br />

• Force applied to stone is transferred to a smaller surface area of<br />

urothelium<br />

• Higher risk thin walled renal pelvis or ureter (vs. calyx backed by<br />

renal parenchyma)


Ultrasonic - Summary<br />

• Ultrasound energy transmitted to stone causing it to<br />

resonate at high frequency <strong>and</strong> break<br />

• Fragments are then sucked out through the centre of the<br />

hollow probe<br />

• Can only be passed down straight instruments <strong>and</strong><br />

needs large diameter probe<br />

• Good safety profile<br />

• Uses - fragmentation of renal calculi during PCNL


Overall summary<br />

• Electrohydraulic<br />

• High risk ureteric perforation<br />

• Holmium:YAG Laser<br />

• Mainstay of ureterorenoscopic lithotripsy<br />

• Excellent safety profile<br />

• Ballistic<br />

• Good for ureteric & large renal stones & excellent safety<br />

• High rate of proximal stone migration<br />

• Ultrasonic<br />

• Ideal for complex, large-volume calculi at PCNL


References<br />

• Campbell-Walsh Urology 9th Ed<br />

• p. 1458-1465<br />

• Oxford H<strong>and</strong>book of Urology<br />

• P. 368-370<br />

• Complications of Urologic Surgery <strong>and</strong><br />

Practice<br />

• K Loughlin, Ch. 23


Radiation safety – including safe use of the image intensifier <strong>and</strong> tips to minimise exposure; Clair Whelan<br />

Why does it matter?<br />

‐ Radiation does have an effect on human tissues<br />

‐ Radiation sickness/ poisoning in acute setting<br />

‐ Late effects include fatal cancers, incidence relating to dose received; Germ cell damage can manifest as hereditary<br />

disorders; Cataracts<br />

However, perspective is needed:<br />

Cancer is a common disease <strong>and</strong> 20% of the population will die of it<br />

Genetic abnormalities occur in 3% of normal population<br />

So there is a difficulty in really establishing risk of low level exposure<br />

? Thyroid cancer increase in Chernobyl screening bias only...<br />

Public dose limit is 1mSv/y = death risk 1 in 20000 (per year)<br />

Occupational limit is 20mSv/y; most receive far less (Study on endovascular surgeons showed exposure with precautions around<br />

5‐8% of this)<br />

Annual death risks – smoking 1 in 200, road accidents 1 in 10000<br />

And medical imaging can save lives <strong>and</strong> decrease morbidity (think of the road accident) so aim for rational approach<br />

So ALARA principle – As Low As Reasonably Achievable – for all interactions, patients <strong>and</strong> staff<br />

Factors which contributes to total exposure for patient <strong>and</strong> staff can be considered in terms of these 3 – time, distance,<br />

shielding.<br />

Remember there are 2 sources – direct beam <strong>and</strong> scatter – <strong>and</strong> 2 recipients ‐ patients <strong>and</strong> staff.<br />

Time:<br />

‐ Improving operator training, more experience<br />

‐ Less “foot on pedal” operating<br />

‐ “Dry runs” – position then confirm, don’t screen to look for anatomy<br />

‐ Pulsed fluoroscopy<br />

‐ Communicate – establish clear language to signal when single shot or screening required<br />

Distance:<br />

‐ Inverse square law – double the distance to reduce dose by a quarter<br />

‐ Extend your fingers by using an instrument to h<strong>and</strong>le items in the field<br />

‐ Tilt body even 30cm away<br />

‐ Shoot with the source below <strong>and</strong> the patient close to the II<br />

‐ Remote operating stations<br />

Shielding:<br />

‐ Attenuates radiation to reduce exposure to more acceptable level<br />

‐ Of rooms; thick walls, Lead screens <strong>and</strong> glass<br />

‐ Personal – aprons (95%+ reduction), glasses, include the thyroid <strong>and</strong> your back<br />

‐ Monitors to be worn under for retrospective assessment<br />

‐ Collimate fields – shields closest to source most effective<br />

‐ Shield patient (thyroid, gonads) if able<br />

‐ Test gowns yearly<br />

‐ 0.25 to 0.5 mm in thickness for lead aprons – actually lead equivalent material, thyroid collars <strong>and</strong> eye shields 0.5mm.<br />

‐ The HVL (half‐value layer) may be used as a guide to the thickness of the shielding necessary to block the radiation. The<br />

HVL is the thickness of the shielding necessary to reduce the radiation dose rate to half of the original or unshielded<br />

dose rate<br />

Equipment considerations:<br />

‐ Use of lock‐out systems to stop misuse<br />

‐ Timer lock‐out alarm as reminder<br />

‐ Audible means of indicating screening<br />

‐ Suitable table <strong>and</strong> avoiding bars, etc by planning<br />

‐ Adjustable lighting<br />

‐ Greater FSD best, source below table<br />

‐ Store images (so to review without repeating)<br />

‐ Minimise people in theatre<br />

References:<br />

Lipsitz EC, Veith FJ, Ohki T, et al: Does endovascular repair of aortoiliac aneurysms pose a radiation safety hazard to vascular<br />

surgeons? J Vasc Surg 32:702, 2000<br />

Course notes Radiation Protection for Non Radiologist Physicians Involved with Fluoroscopic Xray procedures


Lower Pole Renal Stone<br />

Options for management of 1cm lower pole stone<br />

• ESWL<br />

• Flexible Ureteroscopy <strong>and</strong> Holmium laser<br />

• PCNL<br />

• Observation<br />

ESWL<br />

• Shock waves generated extracorporeally which fragment stone due to a change in<br />

acoustic impedance<br />

• Contraindications – AAA, bleeding diathesis, UTI, Morbid obesity (skin to stone distance<br />

>10cm), Pregnancy<br />

• Outcomes of ESWL in context of lower pole stone treatment<br />

• Pearle et al 2005 – ESWL vs Flexible Ureteroscopy<br />

• Albala et al 2001 – ESWL vs PCNL<br />

• Stone free rates (SFR) for lower pole stones 2cm in size<br />

• Role less well defined in 1cm lower pole stone<br />

• Albala et al – SFR 1cm – 100%, 1-2cm – 93%, 2-3cm – 86%<br />

• Major morbidity in 4-8% of all cases – mainly visceral injury (colon, spleen), significant<br />

bleeding, urosepsis, hydrothorax, pneumothorax. Risk of colon injury higher with intra<br />

abdominal adhesions, retrorenal colon<br />

• Contraindications – bleeding diathesis, hydatid cyst, UTI, comorbidity precluding prone<br />

GA, body habitus<br />

Ureterorenoscopy/ Laser<br />

• More viable option with improved scopes, increased deflection, holmium laser, nitinol<br />

baskets<br />

• SFR – 50% in lower pole stones


PUJ stone <strong>and</strong> acute management:<br />

• 55 year old man presents with 12 hour history of classic renal colic.<br />

• No past medical history.<br />

• No previous stone<br />

• MSU shows large WCC <strong>and</strong> bacteria seen.<br />

• Temperature 39 C<br />

• CT shows 12 mm stone<br />

Management:<br />

1. Medical expulsive therapy / Watchful waiting<br />

‣ For patients without associated signs of infection, uncontrollable pain, or renal<br />

failure, conservative management is a viable option.<br />

‣ Morbidity less.<br />

‣ Cheaper.<br />

‣ Proven efficacy for stones in the distal ureter, efficacy unproven for proximal <strong>and</strong><br />

PUJ stones. Probably only good for small stones.<br />

2. Stenting +/- ureteroscopy<br />

‣ Decompress system, drainage of urine.<br />

‣ Potential if infected of causing urosepsis.<br />

‣ Ureteroscopy contra-indicated if patient septic.<br />

‣ If stone impacted may causes ureteric damage.<br />

3. Nephrostomy tube<br />

‣ Decompress kidney.<br />

‣ Drain urine.<br />

‣ Temporizing procedure.<br />

‣ Have access for PCNL subsequently.<br />

PUJ stones need more active management because they are less likely to pass<br />

spontaneously. Acutely decompress infected systems<br />

Treatment subsequently:<br />

Dissolution therapy<br />

ESWL<br />

Ureteroscopy<br />

(flexi or rigid)<br />

PCNL<br />

– small stones only<br />

– small stones only. High failure rate. Very high in larger stones<br />

– Good for smaller stones. Larger stones have higher failure rate.<br />

– Gold st<strong>and</strong>ard. Only real choice for large stones. Some morbidity<br />

associated. Access may be difficult in JJ stent previously inserted<br />

<strong>and</strong> decompressed system.


Distal Ureteric Stones in Pregnancy, by Andrew Hadley<br />

Pregnancy Physiology<br />

Hydronephrosis<br />

-90% by K6-10<br />

-Resolves 4-6/52 post-partum<br />

-Mechanisms thought to be increased progesterone early, <strong>and</strong> compression factors late<br />

-Right side more common than left, my be due to gas-filled sigmoid colon shielding,<br />

or right ovarian vein syndrome<br />

Blood Volume increases 25-40%, plasma volume by 50% <strong>and</strong> red cell volume by<br />

15%, causing a relative anaemia. GFR increases 30-50%<br />

Calcium levels double secondary to elevated Vit D levels. The increases are well<br />

above those required for foetal skeletal development<br />

There are also increases in stone inhibitors, stabilizing the stone formation rate<br />

Increased uric acid also<br />

Bacteruria 2.5 - 11% in pregnancy, similar to non-pregnant women, but a lot are<br />

asympomatic decreasing the likelihood of treatment.<br />

Stones in pregnancy<br />

Incidence 1:1500, same as non-pregnant<br />

80-90% occur in the 2 nd <strong>and</strong> 3rd trimesters<br />

50-80% spontaneous passage rate, so most are observed<br />

Equal incidence on right <strong>and</strong> left sides<br />

Imaging<br />

USS -St<strong>and</strong>ard – >poor sensitivity of 30-60%, specificity 80%<br />

-resistive index is better, but change in resistive index is very good. RI’s >0.7<br />

sensitivity 45% <strong>and</strong> 91% specificity, but a change in RI of 0.06 gives 95% sensitivity<br />

<strong>and</strong> 100% specificity.<br />

Transvaginal ultrasound is not frequently done but appears to be highly sensitive <strong>and</strong><br />

specific for distal stones (approaching 100%)<br />

Plain KUB sensitivity 60-80%. 0.14cGy exposure<br />

Limited IVP, 0.17cGy for a scout <strong>and</strong> single 20 minute film, sensitivty >95%<br />

-CT exposure of 2.5cGy thought too high a risk for teratogenesis – RR 2.4 for all<br />

childhood malignancies for exposure 0.16 to 4 cGy (avg 1 cGy)<br />

MRI- doesn’t show stone, but can see associated changes <strong>and</strong> stone/fluid transition<br />

point quite well. Not yet routine investigation.<br />

Management<br />

-50-80% pass spontaneously<br />

MET not tested in pregnancy. Tamsulosin Class B pregnancy drug<br />

Stent-risk of encrustation - 12 weeks 76.3%<br />

-therefore should change stents every 4 to 6 weeks<br />

PCN, for drainage or antegrade stent<br />

Ureteroscopy with lasertripsy due to tortuosity. Cyanide from uric acid stones not<br />

proven to be harmful<br />

ESWL – contraindicated in pregnancy, but inadvertent treatments not detrimental<br />

Open surgery – rare<br />

References<br />

Loughlin KR, McAleer SJ. Management of urological problems in pregnancy: A rationale <strong>and</strong> strategy.<br />

AUA updates 2005 Vol 4, Lesson 5<br />

Watterson et al. Ureteroscopy <strong>and</strong> Holmium:YAG laser lithotripsy… Urology 60(3) 2002<br />

Spencer et al. Evaluation of painful hydronephrosis in pregnancy:MRI… J.Urol Vol 171, pg 256-260.<br />

2004


Case Presentation: Large mid ureteric stone.<br />

Mr DH<br />

86yo<br />

Cotton, cattle, sheep farmer<br />

Resident of Roma<br />

Father of 4 cattle dogs<br />

Intermittent flank pain for 24/12<br />

PMedHx<br />

- IHD (CABGx4, CABG x2), CVA, HTN, CRF, Smoker<br />

- EF 15% 64kg<br />

PUrolHx<br />

- Recurrent stone former – 2x ESWL<br />

- 2x UTI in 18/12, Minimal LUTS<br />

Cr 220<br />

MSU 100/200/10 NG<br />

CT(NC)/KUB<br />

- Atrophic kidneys<br />

- Moderate Right hydronephrosis<br />

- Right 1.5cm mid ureteric calculus<br />

Anaesthetic Review<br />

‐ “one anaesthetic only”<br />

Defintion<br />

Within ureter overlying the sacrum – approximately at iliac vessels<br />

Passage rates (6/52)<br />

6mm


- Degree of obstruction<br />

- Length of time calculus has been present<br />

Surgeon Factors<br />

- Familiarity<br />

- Equipment available<br />

Options<br />

- Conservative – regular imaging<br />

- Ureteroscopy <strong>and</strong> basket<br />

- Ureteroscopic lithotripsy ‐ ultrasonic<br />

- ‐ electrohyraulic<br />

- ‐ lithoclast<br />

- ‐ laser<br />

- ESWL<br />

- Chemolysis – uric acid (struvite, cystine)<br />

- Ureterolithotomy<br />

URETEROSCOPY<br />

- Rigid, semirigid, flexible scopes<br />

- First line treatment<br />

- Superior stone free rates > 90%<br />

- Fragmentation via ultrasound/EHL/Pneumatic/Laser<br />

- Low complication rates: haematuria, infection, perforation, avulsion, stricture, reflux, failure<br />

ESWL<br />

- Performed in prone position<br />

- Single treatment, less discomfort, day case, no instrumentation, low complication rate<br />

- Higher retreatment rates, especially if > 1cm, impacted<br />

- Better results with stent<br />

- Contraindications: pregnancy, bleeding disorder, body habitus, distal obstruction, size > 3cm,<br />

cystine stones, AAA, splenomegaly<br />

URETEROLITHOTOMY<br />

Indications:<br />

- Extensive stone disease<br />

- Very hard stones<br />

- Impacted stones<br />

- Failed ESWL, Ureteroscopy<br />

- Medical Comorbidities<br />

Principles:<br />

- Immediately preop KUB, consider II<br />

- Expose ureter <strong>and</strong> secure stone with extraperitoneal approach<br />

- Limit dissection to prevent ischaemia<br />

- Longitudinal incision<br />

- JJ stent <strong>and</strong> exclude distal obstruction<br />

- Close ureterotomy<br />

- Peri ureteric drain without suction<br />

Complications:<br />

- Loss of stone<br />

- Prolonged extravasation/ urinoma<br />

- Ureterocutaneous fistula<br />

- Stricture


- Extended ureteric loss<br />

- Longer hospital stay<br />

- General: pain, pneumonia, DVT/PE<br />

CASE<br />

- Failed access with rigid URS<br />

- Large impacted stone on flexible URS<br />

- Ureterolithotomy via 8cm oblique incision<br />

- Discharged day 5 stone free<br />

- Follow up at 6/52 for R/o stent<br />

CONCLUSION<br />

The modern management of ureteric calculus disease is focused upon minimally invasive<br />

techniques of endourology<br />

These options can result in the patient requiring multiple anaesthetics <strong>and</strong> procedures to<br />

produce a stone free state<br />

Open ureterolithotomy should not be forgotten as a reasonable option in certain patients. Stone<br />

free rates are ~99%<br />

It does however, have increased morbidity <strong>and</strong> hospital stay as attendant risks


CALICEAL DIVERTICULUM – A BRIEF OVERVIEW (HANS GOOSSEN)<br />

Definition:<br />

A cystic cavity, lined by transitional non-secretory epithelium, encased within the renal substance, <strong>and</strong><br />

situated peripheral to a minor calyx, to which it is connected by a narrow channel.<br />

- Rayer, 1841 (“kystes urinairies”)<br />

- Uncommon: 0.2 – 0.6 % (30x less for bilateral)<br />

- Male:female = 1:1<br />

- Right:left = 1:1<br />

- Predominance for upper pole (60 - 80%); exclude TB<br />

Pathogenesis:<br />

- Developmental / congenital<br />

- Persistent ureteral branches<br />

- Acquired<br />

- Cortical abscess<br />

- Obstruction / blow-out<br />

- Fibrosis infundibulum<br />

- Renal injury<br />

- Achalasia<br />

- Spasm / dysfunction sphincter minor calyx<br />

- Reflux<br />

Diagnosis:<br />

- AXR – KUB (different positions to demonstrate mild of calcium)<br />

- USS – KUB (up to 80% sensitivity)<br />

- CT – triple phase<br />

- IVP with delayed films<br />

- MRI (rarely indicated)<br />

- Retrograde pyelogram (N.B. no visualization if neck of diverticulum is obstructed)<br />

Complications / Indications for intervention:<br />

- Stones (common: 10 – 50 %)<br />

- asymptomatic<br />

- pain<br />

- haematuria<br />

- infection<br />

- Infection<br />

- Rupture<br />

- Milk of calcium +/- Micro-calculi<br />

Main Treatment Options<br />

- None (if asymptomatic, no calculus, etc)<br />

- PCNL + marsupialisation diverticulum<br />

- Direct puncture into diverticulum<br />

- Avoid perforation<br />

- Ureteroscopy + enlargement neck of diverticulum<br />

- Unable to find / access opening in 30%<br />

- Upper pole / anterior calyces / small stone burden<br />

- Laparoscopy<br />

- Anterior caliceal diverticulum / large stone burden / thin cortex<br />

N.B. Diverticulum fulguration <strong>and</strong>/or canal dilatation should be part of the treatment.<br />

N.B. ESWL has a high failure rate.<br />

N.B. Nephrectomy (partial or complete) should nowadays only be reserved for rare cases, e.g. complex<br />

anatomy or complication from any of the other procedures.


Upper Tract TCC – Can Huynh<br />

Trainee’s Week, Mornington Peninsula 2007<br />

Case Summary<br />

History<br />

• 85yo male<br />

• haematuria with oliguria<br />

• fatigue, nausea, <strong>and</strong> vomiting<br />

• K+ 5, urea 150, creat 720<br />

• Hb 105 coags N<br />

Past History<br />

• Left nephrectomy 20 years ago (T1 RCC)<br />

• 2004 TURBT - 1.2cm TaG2 bladder TCC<br />

• Follow up missed<br />

Examination<br />

• afebrile, HR 87, BP 150<br />

• JVP raised, widespread pulmonary crepitations<br />

• no abdominal masses or tenderness<br />

Immediate Management<br />

• Resuscitation with nephrology involvement<br />

• G+H, CSU<br />

• 22Fr 3-way irrigating catheter<br />

• CT-KUB<br />

• HDU<br />

What Now?<br />

• haemodialysis<br />

• PCN or DJS<br />

Stabilisation<br />

• Renal function improved over 7 days<br />

• Haemodialysis ceased<br />

• Haematuria ceased<br />

Management<br />

• Anterograde laser ablation<br />

• Patient discharged home with conservative follow-up<br />

Upper Tract TCC<br />

• 5% of TCCs<br />

• 10% of renal tumours<br />

• Risk Factors<br />

o Analgesic / Phenacetin nephropathy<br />

o Balkan nephropathy (interstitial nephritis)<br />

o Chinese herbs (a. fangchi)<br />

Indications for Conservative Treatment<br />

• Anatomic or functional solitary kidneys<br />

• Bilateral disease<br />

• Significant comorbid disease<br />

• Low risk disease<br />

Outcomes<br />

• 30% recurrence rate<br />

• 80% disease specific survival 5yrs<br />

• Roupret M et al. (2007) Upper urinary tract transitional cell carcinoma: recurrence rate after percutaneous endoscopic<br />

resection. Eur Urol 51: 709–713<br />

Track Seeding?<br />

• Possible but rare event<br />

• Case reports for high grade TCC<br />

• No occurrences in three large series<br />

o Jarrett et al (1995)<br />

o Patel et al (1996)<br />

o Clark et al (1999)

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