Ureteroscopes and ancillary equipment Mohan Arianayagam Trainees week 2007

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.
Complications Of Ureteroscopy
1988 major complication rate (10-14 Fr scope) 7.5%
1998 major complication rate (7 Fr scope) 0.9%
Specific complications
–Perforation 0-1%
–Stricture 0.5-1%
–False passage 0.5%
–Avulsion 0-0.5%
–Sepsis
–Bleeding
–Colic 5%
Bleeding
–If blood obscures vision do not proceed blindly
–Use Guide wire to perform retrograde pyelogram to ascertain integrity of system the stent.
Pyonephrosis
–Stent and abandon with ABx 2/52
False passage with safety wire
–Retrograde pyelogram
–Do not remove guide wire, place another wire next to the wire (this way the wire closes off the false
passage)
–If unable to pass guide wire abandon, consider nephrostomy +/- anterograde stent
“kinked” ureter
–May use PUJ occluding catheter
–Inflate at level below kink and apply gentle traction and place guide wire up catheter
Basket that won’t disengage
–Dismantle hand piece, loose wire.
–If unable to remove still place ureteroscope next to basket and laser stone.
Ureteric Perforation
–Stent and return on another day
–If very large may need open repair
Ureteric Stricture
–Delayed complication
–Confirm diagnosis on retrograde pyelogram
CT/IVU may not show distal strictures in multiple stricture disease
–Short Consider primary excision
–Long Prox – Ureterocalycostomy/ pyeloplasty
Mid – Trans ureteroureterostomy, ileal substitute
Distal - Reimplantation +/- boari or psoas hitch
Ureteric Avulsion
–Dreaded complication
–Confirm diagnosis on retrograde pyelogram
–Distal à consider primary repair
–Proximal/Mid à consider nephrostomy and delayed repair
Distal
- Primary reimplantation +/- boari flap or psoas hitch
Mid
–Boari Flap/Psoas hitch
–Trans uretero-ureterostomy
–Ileal transposition
Proximal
–Ileal transposition
–Auto transplantation
Energy sources for
Endourology
Trainee Week 2007
Janelle Brennan
Overview
• 4 types of intracorporeal lithotripsy
Š Flexible
ƒ Laser (Holmium)
ƒ Electrohydraulic (EHL)
Š Rigid
ƒ Ballistic (Lithoclast)
ƒ Ultrasonic
Š Mechanism, advantages, disadvantages & surgical
technique
Š Summary
Which lithotripter is the best?
• Depends on stone location & size
Š Large volume calculus at PCN - ultrasonic &/or pneumatic
Š Ureter/small intrarenal - holmium laser as flexible, small
diameter and can fragment all stone types
• Balance between 3 factors:
Š Efficiency
Š Size of probe
Š Flexibility
Electrohydraulic (EHL) Mechanism
• Underwater spark plug
Š Spark discharge causes explosive formation of plasma
channel & vaporization of water around electrode
Š Subsequent expansion & collapse of gas bubble generates a
shock wave
ƒ Shock wave is not focused so EHL probe needs to applied ~1mm
from stone to optimize fragmentation
ƒ vs. >3mm which results in high speed microjets
Š Functions equally well in N saline (vs.. 1/6 saline)
EHL - Advantages
• Successfully fragment 90% stones
Š Average 3/12 stone-free rate only 84% because some
fragments not removed
Š Decreased ureteral stone free rates if >15mm
ƒ 67% EHL vs. 100% Holmium:YAG
• Probe flexibility
Š 1.6 to 5Fr; can be passed up flex URS
ƒ Only probe equivalent to 200um laser fibre
• Low cost
Š Inexpensive generator and probes
ƒ Average 1-1.3 probes/case
ƒ Little difference in efficiency b/w probe size but better
durability if larger size
EHL - Disadvantages
• High rates of ureteral mucosal damage and ureteral
perforation
Š Mean perforation rate 8.5%
Š Damage caused by cavitation bubble so may occur even if probe
not in direct contact with mucosa
Š Increased perforation risk - higher energies (e.g. hard stone),
impacted stones (poor vision from blood, mucosal edema)
• Retrograde propulsion of calculi (> laser)
• Production of large number & sized fragments (esp. if stone
>15mm)
Š Repeated URS passage exacerbates mucosal irritation
EHL - Technique
• Fibre tip 2-5mm from distal end of URS to protect lens
from emitted spar
• Probe ~1mm from stone surface
Š Allows maximal shock wave emission
• Start with low voltage (50-60V) & short intermediate or
single pulses
• Goal is to create fragments that can be removed with
basket or pass spontaneously
Š Do not attempt to reduce stone fragments <2mm as high risk of
urothelial damage
• After 50-60 firing, a new probe is often needed as
insulation tip often peels away
EHL - Summary
• Underwater spark discharge
Š 1st lithotripsy technique developed
• Effective & flexible probes BUT narrow safety
margin
Š High risk ureteric perforation
• May be used in bladder stones (wider safety
margin) but largely surpassed by newer
techniques
LASER - Mechanism
• Light Amplification by Stimulated Emission of Radiation
Š Atom is stimulated by an external energy source which creates a
population of excited electrons
Š Excited (or high energy) electrons release their excess energy in
form of photons (light energy)
Š Laser light has 3 properties
ƒ Coherent (all photons in phase with one another)
ƒ Collimated (photons travel parallel to each other)
ƒ Monochromatic (all photons have same wavelength)
Š Allow considerable energy to be transmitted in highly concentrated
manner
• Lasers names after laser medium generating specific
wavelength
Holmium:YAG - Mechanism
• Wavelength 2140nm in pulsed mode
Š Highly absorbed by water so majority of holmium energy is
absorbed superficially (tissue mainly water)
ƒ Superficial cutting or ablation
ƒ Zone of thermal injury 0.5-1mm
• Long pulse duration (250-350us)
Š Results in elongated cavitation bubble that generates only
weak shock wave
Š Lithotripsy primarily through a photothermal mechanism
that causes stone vaporization
Holmium:YAG - Advantages
• Flexible fibre (200, 365 and 500 um)
• Fragment all stones regardless of composition
Š Mean stone free rates >95% (failures usually secondary to
migration)
• Produces small fragments (avoid extraction)
• Weak shockwave so less retropulsion
• Excellent safety profile
Š Safely activated 0.5-1mm from ureteric wall
Š Mean perforation rate (1.1%) and stricture rate (1.2%)
Š Required eye protection does not compromise view
• Requires minimal maintenance and ready for use within 1
minute of turning machine on
Holmium:YAG - Disadvantages
• High cost of device and laser fibres but . . .
Š Laser fibres are reusable
Š Multiple soft tissue applications e.g. BPH, strictures, urothelial
tumours
• Cyanide production with uric acid stones
Š In vitro studies
Š No clinical evidence of significant cyanide toxicity
• Not particularly fast for larger stones
• Can easily damage ureteroscope (lens or working
channel)
• Visualization may be difficult if laser damage to
epithelium causing bleeding
Holmium:YAG - Technique
• Keep the fibre tip in view at all times
Š Place fibre on stone surface before activation
• Short pause after initiation due to “snowstorm effect
Š Clear vision is need to avoid mucosal perforation (need good
irrigation)
Š Keep the fibre tip >1mm from urothelium
• Care with basket as cuts through metal
• Work from inside of the stone outward moving in a
“painting fashion”
Š Vaporize rather than fragment
Š Avoid drilling into stone (# fibre) or drilling past stone (damage
urothelium)
Holmium:YAG - Settings
• Lithotripsy depends on pulse energy output and
diameter of optical delivery fibre
Š Energy density increases with decreasing fibre diameter so
200um fibre more likely to drill
• Start at low settings
Š Pulse energy of 0.6J to 1.2J
Š Pulse rates of 5Hz to 15Hz
• High pulse energy narrows the safety margin and
increases stone retropulsion and fibre damage
Š Increase pulse frequency in preference to pulse energy to
speed fragmentation
Holmium:YAG - Summary
• Photothermal mechanism causing vaporization
Š Paint the stone surface; results in small fragments
Š Minimal shock wave so less stone migration
• Excellent safety profile
Š Highly absorbed in water, zone thermal injury 0.5-1mm
Š Keep fibre tip in view at all times
• Very effective (all stone types) and versatile BUT high cost
& takes time
• Start with low settings e.g 0.6J & 6Hz
• Uses - ureteric & small intrarenal stones (flex URS)
Ballistic - Mechanism
• Relies on energy generated by movement of projectile
Š Once projectile is in contact with another object the ballistic
energy is transferred
ƒ Flexible objects preserve momentum of energy
ƒ Inflexible objects e.g. stone, fragment on impact (Jackhammer effect)
• Swiss LithoClast (early 1990s)
Š Metal projectile in handpiece is propelled by bursts of compressed
air (12 cycles/second)
Š Discharged probe brought back to former position by rubber
bushing around base of probe
Š Probes 0.8 to 2.5mm
•
New devices - electrokinetic (heavier handpiece), suction device, flexible nitinol
probe
Ballistic - Advantages
• Effective in entire urinary tract for all stone types
Š Mean successful fragmentation rate 89%
Š Rapid and efficient fragmentation if stone can be pinned
down
Š Can be combined with ultrasound (LithoClast
Master/Ultra)
• Wide safety margin
Š No heat produced so no risk of thermal injury to urothelium
Š Ureteral perforation rate <1%
• Low cost and maintenance (no disposables)
Ballistic - Disadvantages
• Rigid probe so require straight working channel
Š Bowing of probe e.g. 30 degree channel results in significant
reduced efficiency
• High rate of stone retropulsion
Š Mean stone migration rate 7.3%
Š Higher rate if proximal ureteric stone (more capacious ureter)
• Hard to treat fragments <4mm so often need to use
basket/stone forceps
• Causes backward movement of stone so can push stone
through delicate tissue
Ballistic - Technique
• Need clear view of stone and probe
• Fixation of stone
Š Easy in kidney or bladder but may need proximal
basket/ureteral occlusion device in ureter
• Goal is to generate fragments <2mm that will pass
spontaneously
• Atraumatic so often don’t need stent
Š Unless difficult ureteral access of severe edema/trauma at
site of stone impaction
Ballistic - Summary
• Shock waves transmitted to probe via
movement of projectile - jackhammer
• Excellent safety and low cost BUT rigid probe
so can’t be used with flexible URS
• High rate proximal stone migration
• Uses - ureteric stones and large, hard calculi at
PCNL
Ultrasonic - Mechanism
• Application of electrical energy to excite a piezoceramic
plate in U/S transducer
Š Plate resonates at a specific frequency & generates ultrasonic
waves at frequency of 23000-25000Hz
Š Ultrasound energy is transformed into longitudinal and transverse
vibrations of hollow steel probe --> transmits energy to calculus
Š Probe tip causes stone to resonate at high frequency and break
Š Heat does develop at end of probe so irrigation needed
ƒ Irrigation 30ml/min - temperature increase only 1.4oC
• Combined with suction device
Ultrasonic - Advantages
• Efficient combination of stone fragmentation
& simultaneous fragment removal (<2mm can
be suctioned)
• Minimal risk of serious tissue damage
Š Damage minimal if place on compliant tissue e.g.
urothelium as tissue does not resonate with
vibrational energy
Ultrasonic - Disadvantages
• High suction can draw air bubbles into the system
impeding vision
• Straight instrument
Š Bending can result in energy loss at convexity of bend,
with energy transformed to heat (thermal injury)
Š Smaller diameter probes (2.5Fr) for ureter don’t have
irrigation so overheat & cause thermal damage (therefore
need larger probes)
• Slower fragmentation with smooth-surfaced, large
stones and cystine, calcium oxalate monohydrate &
uric acid
Ultrasonic - Technique
• Trap stone between probe and urothelium
• Apply gentle pressure to the stone to enhance
fragmentation
Š Avoid pushing too hard as can push calculi through the
urothelium
Š Increased risk of perforation with smaller and more
ruggedly surfaced stones
ƒ Force applied to stone is transferred to a smaller surface area of
urothelium
ƒ Higher risk thin walled renal pelvis or ureter (vs. calyx backed by
renal parenchyma)
Ultrasonic - Summary
• Ultrasound energy transmitted to stone causing it to
resonate at high frequency and break
Š Fragments are then sucked out through the centre of the
hollow probe
• Can only be passed down straight instruments and
needs large diameter probe
• Good safety profile
• Uses - fragmentation of renal calculi during PCNL
Overall summary
• Electrohydraulic
Š High risk ureteric perforation
• Holmium:YAG Laser
Š Mainstay of ureterorenoscopic lithotripsy
Š Excellent safety profile
• Ballistic
Š Good for ureteric & large renal stones & excellent safety
Š High rate of proximal stone migration
• Ultrasonic
Š Ideal for complex, large-volume calculi at PCNL
References
• Campbell-Walsh Urology 9th Ed
Š p. 1458-1465
• Oxford Handbook of Urology
Š P. 368-370
• Complications of Urologic Surgery and
Practice
Š K Loughlin, Ch. 23
Radiation safety – including safe use of the image intensifier and tips to minimise exposure; Clair Whelan Why does it matter? ‐ Radiation does have an effect on human tissues ‐ Radiation sickness/ poisoning in acute setting ‐ Late effects include fatal cancers, incidence relating to dose received; Germ cell damage can manifest as hereditary disorders; Cataracts However, perspective is needed: Cancer is a common disease and 20% of the population will die of it Genetic abnormalities occur in 3% of normal population So there is a difficulty in really establishing risk of low level exposure ? Thyroid cancer increase in Chernobyl screening bias only... Public dose limit is 1mSv/y = death risk 1 in 20000 (per year) Occupational limit is 20mSv/y; most receive far less (Study on endovascular surgeons showed exposure with precautions around 5‐8% of this) Annual death risks – smoking 1 in 200, road accidents 1 in 10000 And medical imaging can save lives and decrease morbidity (think of the road accident) so aim for rational approach So ALARA principle – As Low As Reasonably Achievable – for all interactions, patients and staff Factors which contributes to total exposure for patient and staff can be considered in terms of these 3 – time, distance, shielding. Remember there are 2 sources – direct beam and scatter – and 2 recipients ‐ patients and staff. Time: ‐ Improving operator training, more experience ‐ Less “foot on pedal” operating ‐ “Dry runs” – position then confirm, don’t screen to look for anatomy ‐ Pulsed fluoroscopy ‐ Communicate – establish clear language to signal when single shot or screening required Distance: ‐ Inverse square law – double the distance to reduce dose by a quarter ‐ Extend your fingers by using an instrument to handle items in the field ‐ Tilt body even 30cm away ‐ Shoot with the source below and the patient close to the II ‐ Remote operating stations Shielding: ‐ Attenuates radiation to reduce exposure to more acceptable level ‐ Of rooms; thick walls, Lead screens and glass ‐ Personal – aprons (95%+ reduction), glasses, include the thyroid and your back ‐ Monitors to be worn under for retrospective assessment ‐ Collimate fields – shields closest to source most effective ‐ Shield patient (thyroid, gonads) if able ‐ Test gowns yearly ‐ 0.25 to 0.5 mm in thickness for lead aprons – actually lead equivalent material, thyroid collars and eye shields 0.5mm. ‐ The HVL (half‐value layer) may be used as a guide to the thickness of the shielding necessary to block the radiation. The HVL is the thickness of the shielding necessary to reduce the radiation dose rate to half of the original or unshielded dose rate Equipment considerations: ‐ Use of lock‐out systems to stop misuse ‐ Timer lock‐out alarm as reminder ‐ Audible means of indicating screening ‐ Suitable table and avoiding bars, etc by planning ‐ Adjustable lighting ‐ Greater FSD best, source below table ‐ Store images (so to review without repeating) ‐ Minimise people in theatre References: Lipsitz EC, Veith FJ, Ohki T, et al: Does endovascular repair of aortoiliac aneurysms pose a radiation safety hazard to vascular surgeons? J Vasc Surg 32:702, 2000 Course notes Radiation Protection for Non Radiologist Physicians Involved with Fluoroscopic Xray procedures Lower Pole Renal Stone
Options for management of 1cm lower pole stone
• ESWL
• Flexible Ureteroscopy and Holmium laser
• PCNL
• Observation
ESWL
• Shock waves generated extracorporeally which fragment stone due to a change in
acoustic impedance
• Contraindications – AAA, bleeding diathesis, UTI, Morbid obesity (skin to stone distance
>10cm), Pregnancy
• Outcomes of ESWL in context of lower pole stone treatment
ƒ Pearle et al 2005 – ESWL vs Flexible Ureteroscopy
ƒ Albala et al 2001 – ESWL vs PCNL
• Stone free rates (SFR) for lower pole stones <1cm vary in above studies from 35-67%
depending on modality of follow up imaging. Higher SFR when followed with
Nephrotomogram
• Several predictors of success – Sumino et al 2002
o Anatomical
ƒ Infundibulopelivc angle
ƒ Calyceal Pelvic height
ƒ Infundibular length
ƒ Infundibular diameter
o Other
ƒ Stone size/ Composition/ Hounsfield Units/ Location
PCNL
• High stone free rates needs to be considered in the context of increased morbidity
• Stones >2cm in size
• Role less well defined in 1cm lower pole stone
• Albala et al – SFR 1cm – 100%, 1-2cm – 93%, 2-3cm – 86%
• Major morbidity in 4-8% of all cases – mainly visceral injury (colon, spleen), significant
bleeding, urosepsis, hydrothorax, pneumothorax. Risk of colon injury higher with intra
abdominal adhesions, retrorenal colon
• Contraindications – bleeding diathesis, hydatid cyst, UTI, comorbidity precluding prone
GA, body habitus
Ureterorenoscopy/ Laser
• More viable option with improved scopes, increased deflection, holmium laser, nitinol
baskets
• SFR – 50% in lower pole stones<1cm (Pearle et al 2005). CT follow up.
• Indications – ESWL failure, cysteine stones, high CT attenuation, morbid obesity,
musculoskeletal deformity, bleeding diathesis, infundibular stenosis, patient preference
• Overall complication rate 16%. <1% major. Most common – UTI, bleeding obscuring
view, perforation
Lingeman JE, Lifshitz DA, Evan AP. Surgical management of urinary lithiasis. In Walsh PC, Retick AB, Vahghan ED, et al.
Campbell’s Urology 8th Edition. 2002
Pearle MS, Lingeman JE, Leveillee R, Kuo R, Preminger GM et al. Prospective randomised trial comparing shock
wave lithotripsy and ureteroscopy for lower pole caliceal calculi 1cm or less. J.Urol 2005;173, 2005-9
Albala DM, Assimos DG, Cayman RV, et al. Lower Pole I: a prospective randomised trial of extracorporeal shock
wave lithotripsy and percutaneous nephrostolithotomy for lower pole nephrolithiasis – initial results. J.Urol
2001;166(6):2072-80
Lingeman JE, Coury TA, Newman DM, et al. Comparison of resultsand morbidity of percutaneous
nephrostolithotomy and extracorporeal shock wave lithotripsy. J.Urol 1987;138(3):485-90
Elbahnasy AM, Shalhav AL, Hoenig DM et al. Lower calyceal stone clearance after shock wave lithotripsy or
ureteroscopy: the impact of lower pole radiographic anatomy. J.Urol 1998;159:676-82
Tuckey J, Devasia A, Murthy L, Ramsden P, Thomas D. Is there a a simpler method for predicting lower pole stone
clearance after shockwave lithotripsy than measuring infundibulopelvic angle? J.Endourology 2000, 14:475.
Sumino Y, Hiromitsu M, Yoshihisa T, Hitoshi O et al. Predictors of Lower Pole Stone Clearance after Extracorporeal
Shock Wave Lithotripsy. J.Urol 2002; 168: 1344-7
PUJ stone and acute management:
•
•
•
•
•
•
55 year old man presents with 12 hour history of classic renal colic.
No past medical history.
No previous stone
MSU shows large WCC and bacteria seen.
Temperature 39 C
CT shows 12 mm stone
Management:
1. Medical expulsive therapy / Watchful waiting
¾ For patients without associated signs of infection, uncontrollable pain, or renal
failure, conservative management is a viable option.
¾ Morbidity less.
¾ Cheaper.
¾ Proven efficacy for stones in the distal ureter, efficacy unproven for proximal and
PUJ stones. Probably only good for small stones.
2. Stenting +/- ureteroscopy
¾
¾
¾
¾
Decompress system, drainage of urine.
Potential if infected of causing urosepsis.
Ureteroscopy contra-indicated if patient septic.
If stone impacted may causes ureteric damage.
3. Nephrostomy tube
¾
¾
¾
¾
Decompress kidney.
Drain urine.
Temporizing procedure.
Have access for PCNL subsequently.
PUJ stones need more active management because they are less likely to pass
spontaneously. Acutely decompress infected systems
Treatment subsequently:
Dissolution therapy
ESWL
Ureteroscopy
(flexi or rigid)
PCNL
– small stones only
– small stones only. High failure rate. Very high in larger stones
– Good for smaller stones. Larger stones have higher failure rate.
– Gold standard. Only real choice for large stones. Some morbidity
associated. Access may be difficult in JJ stent previously inserted
and decompressed system.
Distal Ureteric Stones in Pregnancy, by Andrew Hadley
Pregnancy Physiology
Hydronephrosis
-90% by K6-10
-Resolves 4-6/52 post-partum
-Mechanisms thought to be increased progesterone early, and compression factors late
-Right side more common than left, my be due to gas-filled sigmoid colon shielding,
or right ovarian vein syndrome
Blood Volume increases 25-40%, plasma volume by 50% and red cell volume by
15%, causing a relative anaemia. GFR increases 30-50%
Calcium levels double secondary to elevated Vit D levels. The increases are well
above those required for foetal skeletal development
There are also increases in stone inhibitors, stabilizing the stone formation rate
Increased uric acid also
Bacteruria 2.5 - 11% in pregnancy, similar to non-pregnant women, but a lot are
asympomatic decreasing the likelihood of treatment.
Stones in pregnancy
Incidence 1:1500, same as non-pregnant
80-90% occur in the 2nd and 3rd trimesters
50-80% spontaneous passage rate, so most are observed
Equal incidence on right and left sides
Imaging
USS -Standard – >poor sensitivity of 30-60%, specificity 80%
-resistive index is better, but change in resistive index is very good. RI’s >0.7
sensitivity 45% and 91% specificity, but a change in RI of 0.06 gives 95% sensitivity
and 100% specificity.
Transvaginal ultrasound is not frequently done but appears to be highly sensitive and
specific for distal stones (approaching 100%)
Plain KUB sensitivity 60-80%. 0.14cGy exposure
Limited IVP, 0.17cGy for a scout and single 20 minute film, sensitivty >95%
-CT exposure of 2.5cGy thought too high a risk for teratogenesis – RR 2.4 for all
childhood malignancies for exposure 0.16 to 4 cGy (avg 1 cGy)
MRI- doesn’t show stone, but can see associated changes and stone/fluid transition
point quite well. Not yet routine investigation.
Management
-50-80% pass spontaneously
MET not tested in pregnancy. Tamsulosin Class B pregnancy drug
Stent-risk of encrustation - <6 weeks 9.2%, 6-12 weeks 47.5%, >12 weeks 76.3%
-therefore should change stents every 4 to 6 weeks
PCN, for drainage or antegrade stent
Ureteroscopy with lasertripsy due to tortuosity. Cyanide from uric acid stones not
proven to be harmful
ESWL – contraindicated in pregnancy, but inadvertent treatments not detrimental
Open surgery – rare
References
Loughlin KR, McAleer SJ. Management of urological problems in pregnancy: A rationale and strategy.
AUA updates 2005 Vol 4, Lesson 5
Watterson et al. Ureteroscopy and Holmium:YAG laser lithotripsy… Urology 60(3) 2002
Spencer et al. Evaluation of painful hydronephrosis in pregnancy:MRI… J.Urol Vol 171, pg 256-260.
2004
Case Presentation: Large mid ureteric stone. Mr DH †
†
†
†
86yo Cotton, cattle, sheep farmer Resident of Roma Father of 4 cattle dogs Intermittent flank pain for 24/12 PMedHx - IHD (CABGx4, CABG x2), CVA, HTN, CRF, Smoker - EF 15% 64kg PUrolHx - Recurrent stone former – 2x ESWL - 2x UTI in 18/12, Minimal LUTS Cr 220 MSU 100/200/10 NG CT(NC)/KUB - Atrophic kidneys - Moderate Right hydronephrosis - Right 1.5cm mid ureteric calculus Anaesthetic Review ‐ “one anaesthetic only” Defintion Within ureter overlying the sacrum – approximately at iliac vessels Passage rates (6/52) <4mm distal 93% prox 80% 4‐6mm 50% >6mm <10% Indications for intervention † High grade obstruction † Uncontrollable pain † Urosepsis † Single kidney † Progressive loss of renal fuction † Lack of progress † Recurrent haematuria Occupation † Patient factors - Body habitus - Place of residence - Patient wishes eg occupation - Clinical status eg urosepsis - Previous stone history Previous urological history † Stone Factors - size, location, composition - Radio opaque vs lucent - Previous treatment - Degree of obstruction - Length of time calculus has been present † Surgeon Factors - Familiarity - Equipment available Options - Conservative – regular imaging - Ureteroscopy and basket - Ureteroscopic lithotripsy ‐ ultrasonic - ‐ electrohyraulic - ‐ lithoclast - ‐ laser - ESWL - Chemolysis – uric acid (struvite, cystine) - Ureterolithotomy URETEROSCOPY - Rigid, semirigid, flexible scopes - First line treatment - Superior stone free rates > 90% - Fragmentation via ultrasound/EHL/Pneumatic/Laser - Low complication rates: haematuria, infection, perforation, avulsion, stricture, reflux, failure ESWL - Performed in prone position - Single treatment, less discomfort, day case, no instrumentation, low complication rate - Higher retreatment rates, especially if > 1cm, impacted - Better results with stent - Contraindications: pregnancy, bleeding disorder, body habitus, distal obstruction, size > 3cm, cystine stones, AAA, splenomegaly URETEROLITHOTOMY Indications: - Extensive stone disease - Very hard stones - Impacted stones - Failed ESWL, Ureteroscopy - Medical Comorbidities Principles: - Immediately preop KUB, consider II - Expose ureter and secure stone with extraperitoneal approach - Limit dissection to prevent ischaemia - Longitudinal incision - JJ stent and exclude distal obstruction - Close ureterotomy - Peri ureteric drain without suction Complications: - Loss of stone - Prolonged extravasation/ urinoma - Ureterocutaneous fistula - Stricture - Extended ureteric loss - Longer hospital stay - General: pain, pneumonia, DVT/PE CASE - Failed access with rigid URS - Large impacted stone on flexible URS - Ureterolithotomy via 8cm oblique incision - Discharged day 5 stone free - Follow up at 6/52 for R/o stent CONCLUSION † The modern management of ureteric calculus disease is focused upon minimally invasive techniques of endourology † These options can result in the patient requiring multiple anaesthetics and procedures to produce a stone free state † Open ureterolithotomy should not be forgotten as a reasonable option in certain patients. Stone free rates are ~99% † It does however, have increased morbidity and hospital stay as attendant risks CALICEAL DIVERTICULUM – A BRIEF OVERVIEW (HANS GOOSSEN)
Definition:
A cystic cavity, lined by transitional non-secretory epithelium, encased within the renal substance, and
situated peripheral to a minor calyx, to which it is connected by a narrow channel.
- Rayer, 1841 (“kystes urinairies”)
- Uncommon: 0.2 – 0.6 % (30x less for bilateral)
- Male:female = 1:1
- Right:left = 1:1
- Predominance for upper pole (60 - 80%); exclude TB
Pathogenesis:
- Developmental / congenital
- Persistent ureteral branches
- Acquired
- Cortical abscess
- Obstruction / blow-out
- Fibrosis infundibulum
- Renal injury
- Achalasia
- Spasm / dysfunction sphincter minor calyx
- Reflux
Diagnosis:
- AXR – KUB (different positions to demonstrate mild of calcium)
- USS – KUB (up to 80% sensitivity)
- CT – triple phase
- IVP with delayed films
- MRI (rarely indicated)
- Retrograde pyelogram (N.B. no visualization if neck of diverticulum is obstructed)
Complications / Indications for intervention:
- Stones (common: 10 – 50 %)
- asymptomatic
- pain
- haematuria
- infection
- Infection
- Rupture
- Milk of calcium +/- Micro-calculi
Main Treatment Options
- None (if asymptomatic, no calculus, etc)
- PCNL + marsupialisation diverticulum
- Direct puncture into diverticulum
- Avoid perforation
- Ureteroscopy + enlargement neck of diverticulum
- Unable to find / access opening in 30%
- Upper pole / anterior calyces / small stone burden
- Laparoscopy
- Anterior caliceal diverticulum / large stone burden / thin cortex
N.B. Diverticulum fulguration and/or canal dilatation should be part of the treatment.
N.B. ESWL has a high failure rate.
N.B. Nephrectomy (partial or complete) should nowadays only be reserved for rare cases, e.g. complex
anatomy or complication from any of the other procedures.
Upper Tract TCC – Can Huynh
Trainee’s Week, Mornington Peninsula 2007
Case Summary
History
•
85yo male
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haematuria with oliguria
•
fatigue, nausea, and vomiting
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K+ 5, urea 150, creat 720
•
Hb 105 coags N
Past History
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Left nephrectomy 20 years ago (T1 RCC)
•
2004 TURBT - 1.2cm TaG2 bladder TCC
•
Follow up missed
Examination
•
afebrile, HR 87, BP 150
•
JVP raised, widespread pulmonary crepitations
•
no abdominal masses or tenderness
Immediate Management
•
Resuscitation with nephrology involvement
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G+H, CSU
•
22Fr 3-way irrigating catheter
•
CT-KUB
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HDU
What Now?
•
haemodialysis
•
PCN or DJS
Stabilisation
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Renal function improved over 7 days
•
Haemodialysis ceased
•
Haematuria ceased
Management
•
Anterograde laser ablation
•
Patient discharged home with conservative follow-up
Upper Tract TCC
•
5% of TCCs
•
10% of renal tumours
•
Risk Factors
o
Analgesic / Phenacetin nephropathy
Balkan nephropathy (interstitial nephritis)
o
o
Chinese herbs (a. fangchi)
Indications for Conservative Treatment
•
Anatomic or functional solitary kidneys
•
Bilateral disease
•
Significant comorbid disease
•
Low risk disease
Outcomes
•
30% recurrence rate
•
80% disease specific survival 5yrs
•
Roupret M et al. (2007) Upper urinary tract transitional cell carcinoma: recurrence rate after percutaneous endoscopic
resection. Eur Urol 51: 709–713
Track Seeding?
•
Possible but rare event
•
Case reports for high grade TCC
•
No occurrences in three large series
o
Jarrett et al (1995)
o
Patel et al (1996)
o
Clark et al (1999)