406

Practical Urology: EssEntial PrinciPlEs and PracticE

Complications of PCNL

with working channels to introduce fragmenta-

tion and retrieval instruments.

Leaving aside failed access, there a number of

X-ray screening in theater is mandatory for

potential complications which warrant mention.

ureteroscopy. Initial placement of a guide wire

PCNL tracts can bleed significantly at the time of

ensures safety and allows placement of a stent if

surgery or in the immediate postoperative period

difficulties ensue. These wires should always be

with a quoted transfusion rate of up to 6%.Acute

placed under x-ray control. This ensures the

bleeding is managed by tamponade of the tract

wire is taking an appropriate course and if the

with a nephrostomy tube. This can be supple-

stone is visible, checks can be made to ensure

mented by clamping the drain if bleeding per-

the stone is not inadvertently pushed proximally.

sists with the intention of promoting clotting

Ideally, the wire should be placed beyond the

within the system.If these conservative measures

stone into the renal pelvis. If the wire cannot be

fail, vascular radiological intervention with a

negotiated past the stone, then a hydrophilic

viewtoembolizationisthenextstep.Nephrectomy

wire may be tried or a hybrid wire with a hydro-

is rare but not unknown. Delayed bleeding

philic tip may be used. If a hydrophilic wire is

(<0.5%) suggests pseudoaneurysm or develop-

used, it is recommended that it is changed for a

ment of an A–V fistula with vascular emboliza-

standard wire as soon as possible using an

tion being the treatment of choice.The possibility

exchange catheter as these wires are notorious

of septicemia should be considered if the patient

for falling out.

is unwell in the immediate postoperative period.

A number of techniques are available for

Other tract-related complications include pleu-

negotiating the ureteric orifice with the uretero-

ral injury with hydrothorax or pneumothorax.

scope. With the wire in situ, it may be relatively

There is a complication rate of up to 16.3% for

straightforward to access the ureter. The config-

upper pole punctures compared to the lower pole

uration of some ureteroscopes allows easier

approach at 4.5% and the rate is strikingly higher

insertion if the ureteroscope is rotated through

after supra 11th rib punctures at 34.6% compared

180 so that the smoother beak glides over the

to 9.7% for the supra 12th rib approach with spe-

trigone. Pushing the ureteroscope against the

cific intrathoracic complication rates being 23.1%

wire can tent the ureteric orifice open, but

and 1.4%, respectively. A chest drain will be

passage of a second wire is extremely useful if

required for most thoracic complications.6

the surgeon is struggling. With one wire within

Other adjacent structures may be at risk with

the instrument channel and the other wire out-

colonic injury being the most prevalent.

side, the ureteroscope is rotated to“separate” the

Fortunately, these tend to settle conservatively

wires and passage is achieved by aiming for the

as the injury is retroperitoneal. The nephros-

gap between them. This technique is also invalu-

tomy drain often acts as a suitable drainage tube

able to safely negotiate difficult areas with the

and if there are concerns that there may be a

ureter. A number of ureteric dilatation devices

higher than usual chance of this injury, using

are available commercially, but they are used

ultrasound at the time of puncture can be help-

infrequently due to the narrow caliber of modern

ful in avoiding bowel. This complication is seen

ureteroscopes. One of the major principles of

most frequently in thin patients and is com-

ureteroscopy is that whenever resistance is

moner on the left side.

noted, the safest course of action is to insert a

Retained fragments of stone can cause prob-

ureteric stent and come back another day. This

lems particularly if they migrate into the ureter

prevents major complications and should never

where they can obviously cause obstruction.

be viewed as a failure. It must be remembered

that some ureteroscopes are graduated with a

Semirigid Ureteroscopy

larger caliber nearer the hilt. In a narrow ureter,

it is therefore possible for there to be no prob-

lem with tightness at the tip of the scope but the

The first retrograde endoscopic examination of

proximal scope can be gripped by ureter. The

the ureter using a specifically designed endo-

ureter in this area can be concertinaed upward

scope was described by Perez-Castro Ellendt

if the ureteroscope is advanced further with the

and Martinez-Pineiro in 1982.7

potential for avulsion of the ureter for the

Modern instruments have evolved with the

unwary. If the operator feels that the scope is not

use of fiber optics allowing finer caliber scopes

moving freely, stenting is strongly advised.

408

Practical Urology: EssEntial PrinciPlEs and PracticE

Laser Lithotripsy

grabbers with a range of configurations such as

tri-radiate forceps.

A number of lasers have been applied to stone

Obviously, it may be tempting to basket a

fragmentation but the most notable is the

stone without any attempt at fragmentation

Holmium YAG device. With a wavelength of

and while this may be appropriate for the small-

2,100 nm, this pulsed dye laser fragments stones

est of stones, it should be remembered that if

efficiently using heat. As the energy is rapidly

stone is too small to pass spontaneously, it may

absorbed in water, it is ideal for endourological

be too large to simply basket. Blind dormia bas-

use. The depth of penetration is of the order of

keting of ureteric stones via a cystoscope is

0.4 mm and although pinpoint damage to the

inappropriate.

urothelium is easily seen, with care, this device

Trying to remove an unrealistic stone with a

is safe. As the laser fibers are flexible, they lend

basket passed runs the potential risk of the

themselves to use with the flexible ureteroscope

major complication of ureteric avulsion which

and the modern prominence of flexi URS is

would require open repair. If a basket having

largely due to its combination with laser tech-

engaged a stone becomes stuck, any thoughts of

nology which has opened up this technique for

pulling hard must be resisted. The situation is

effective stone management within the kidney.

easily resolved by dismantling the basket and

The laser is able to break stones into tiny frag-

removing the ureteroscope. The scope is then

ments within the system and it is entirely rea-

reinserted effectively using the basket as a guide

sonable to avoid the uses of stone retrieval

wire. Any fragmentation device can then be

devices altogether. There is a danger of boring

used to conveniently fragment the stuck stone

holes through larger stones and the technique

with the advantage that the basket’s presence

advised is to allow the fiber to “dance” across

minimizes any chance of retrograde propul-

the stone surface to avoid this. The size of frag-

sion. It should be noted that although laser

ments and relative slowness makes the holmium

technology is very useful in this circumstance,

device less useful with PCNL, unless flexible

the Holmium laser will damage the wires of the

scopes have to be deployed to deal with stones

basket in the same way as it will damage

in less accessible areas.

guidewires.

If there is evidence of injury to the ureter dur-

Endoscopic Management

ing the course of ureteroscopy other than full

avulsion then a stent can be placed over the

of Ureteric Stones

guidewire. If there is doubt about the integrity

of the ureter, then radiographic contrast can be

injected via the irrigation channel of the instru-

The most commonly utilized intracorporeal

ment to check this. Small perforations, trauma

lithotrites used with the ureteroscope are the

to the urothelium, and small laser burns are eas-

Holmium YAG Laser and the lithoclast. Within

ily managed by stenting without any concern for

the ureter, the holmium device (using a 365 mm

long-term sequelae.

fiber) has the advantage of reducing the stone

The flexible ureteroscope is a useful addition

to very small fragments with minimal risk of

to the endourologist’s armamentarium in man-

propulsion of the stone. Effectively this energy

aging ureteric stones. An obvious indication for

source will fragment all calculi. If there is con-

its use is when a ureteric stone is inadvertently

siderable edema or mucosal growth around the

allowed to migrate back into the kidney. When a

CALCULUS, ballistic devices using a 0.8 mm

stone lies within a capacious ureter, there can be

probe may be safer. These tend to fragment

difficulty in deploying the laser onto the stone

the stone into larger fragments and there is a

with the semirigid instrument and going flexible

risk of retrograde propulsion of the stone. A

can help. Other uses include where there has

number of equipment manufacturers market

been significant prior reconstructive surgery to

devices which can be deployed within the ure-

the urinary tract, with resulting anatomy pre-

ter to prevent the stone floating back into the

cluding passage of the semirigid scope. Laser

kidney.

technology is a prerequisite for stone fragmen-

A variety of stone retrieval devices are avail-

tation when the flexible ureteroscopes is

able. These include an array of stone baskets and

deployed using a 200 mm fiber.