**4.1 Patient preparations**

As described, a patient who is about to undergo percutaneous nephrostomy should be thoroughly assessed for current physical status and presence of comorbidities that may affect the risk of developing complications following the procedure. Hyperkalaemia, should be corrected appropriately. Patients who are coagulopathic will have to be managed with plasma or platelet transfusion. Acceptable platelet and INR (International Normalised Ratio) levels vary between institutions, but INR values of less than 1.3 or platelet levels of more than 80,000/dL have been considered acceptable (Ramchandani, Cardella et al. 2003).

Prophylactic antibiotics have been widely used in preparing patients for percutaneous nephrostomy, although no clinical trial has published reports of its benefits to date. A prospective controlled study of patients undergoing percutaneous nephrolithotomy (Mariappan, Smith et al. 2006) reported significant reduction in the risk of upper tract infection and urosepsis following 1 week of prophylactic ciprofloxacin. However this may not be extrapolated in cases of percutaneous nephrostomy not related to underlying calculus or nephrolithotomy, as the presence of calculus is known to be associated with increased risk of infection. On a similar note, McDermott et al regarded the genitourinary tract as being contaminated in the presence of advanced age, diabetes, bladder dysfunction, indwelling urinary catheter, prior manipulation, ureterointestinal anastomosis, bacteriuria and calculi particularly of the struvite variety (McDermott, Schuster et al. 1997). This is particularly so in the presence of clinical signs of infection. It has been recommended that patients with low risk of infection receive a single dose of 1g of intravenous cefazolin or ceftriaxone prior to the procedure (Ramchandani, Cardella et al. 2003). If these patients do not develop continuing signs of infection following the procedure, no further antibiotic treatment is necessary. Patients who are septic or with the above risk factors and at risk of developing infections, are recommended to prophylactically receive 1g of intravenous ceftriaxone 8-hourly or 1g of IV sulbactame 6-hourly, along with 80mg of IV gentamycin 8 hourly (Ramchandani, Cardella et al. 2003). Antibiotics are given for 5-7 days in the periprocedure period, and should be adjusted according to the results of urine culture obtained from the procedure.

Other aspects of patient preparation are common to most other interventional procedures performed in a hospital setting, and this entail obtaining informed consent regarding the procedure as well as adequate fasting if conscious sedation is considered. Certain groups of patients such as young children may have to undergo general anaesthesia, in which case collaboration with an anaesthetist may be necessary.

#### **4.2 Technique**

The patient is traditionally positioned in the prone or prone-oblique position, with the target puncture side elevated by approximately 20-30 degrees. The prone technique was originally adopted by Goodwin probably to avoid the colon and has since gained acceptance. The

Percutaneous Nephrostomy 303

metal cannula may be considered to stabilize the tube during its passage towards the kidney

Smaller-bore catheters (7-8Fr) are sufficient for drainage of non-infected and less viscid urine, while a larger-bore 14Fr catheter may be considered for drainage of infected urine or pus. Once the catheter is placed, its position can be further confirmed by administration of contrast to opacify the collecting system via the tube. The collecting system may be seen to decompress if the catheter is appropriately placed. Care should be taken to avoid over-distension of the collecting system so as to prevent bacteremia and risk of sepsis. To avoid catheter dislocation or dislodgement, self-retaining catheters should be used, and this should be placed as far into the collecting system as possible. Care must however be taken not to obstruct the ureter if a larger-bore catheter is used. Once firmly placed, the catheter is secured externally with retention sutures or other

Further urological intervention may follow the above puncture technique. The tract can be dilated further to allow passage of other instruments such as ureteroscope, balloondilatation system or nephrolithotomy instruments. A ureteral stent may also be placed through the percutaneous puncture. A larger-bore catheter may be considered by the

> Fig. 4. A 0.018 inch guidewire was introduced through the needle into the renal pelvis as distally as possible. The sheath/dilator assembly was then

advanced over the guidewire (not shown). The dilator and the 0.018-inch guidewire were then removed, leaving the sheath (s) in place. More contrast was instilled to delineate the collecting system.

across the perirenal soft tissue.

securing devices such as a skin disc.

urologist to allow for better drainage.

Fig. 3. A lower pole puncture was made with a 21 gauge Accustick needle into the lower pole calyx of the left kidney, with opacification of the collecting system by contrast. The obstructing calculus (c) can be seen along the proximal left ureter, causing upstream

dilatation.

supine anterolateral position has also been recently suggested (Cormio, Annese et al. 2007) as being a safe and effective technique, with the benefits of greater patient comfort as well as causing less respiratory and circulatory difficulties in obese patients. Regardless, the target kidney should be reimaged and reassessed, and this is most commonly performed with ultrasonography. The target renal calyx should be identified and a planned approach should be clearly delineated. The puncture site should then be identified and marked at this stage of the procedure. As described above, the target renal calyx's position relative to the diaphragm during respiration should be observed, and ideally, a subcostal approach targeting Brodel's line should be utilized.

The site of renal puncture is determined by the indication for the procedure. A lower pole posterior calyx for instance, would be best used for simple urinary drainage (Dyer, Regan et al. 2002), while those of the upper and middle poles provide better access to the renal pelvis and ureter, especially if ureteral interventions are being considered. A puncture posterior to a calculus may assist in the treatment of calculus disease. These calyces are best identified by administration of intravenous iodinated contrast with visualization of contrast within the renal collecting system under fluoroscopic guidance. The anterior calyces are usually seen tangentially, while the posterior calyces are seen en face due to the orientation of the kidney about its horizontal axis. This would be contraindicated if the patient has prior history of contrast allergy or an underlying poor renal function, and it is probably not ideal in a severely obstructed system where poor contrast excretion can be expected.

After the patient has been adequately cleaned and draped using sterile methods, the puncture site should be infiltrated with an acceptable local anaesthesia such as 1% xylocaine. Instruction should be given to the patient to breathhold while a 21G diagnostic needle (e.g Accustick System - Boston Scientific, Neff Set - Cook Medical) is used to puncture the skin, which is then advanced posteroanterioly at an angle towards the intended calyx. Alternatively, a three-part co-axial needle may also be used, where there is an outer blunt cannula, an inner 22G needle as well as a stylet. As the renal fibrous capsule of the kidney is punctured, a finer needle may then be introduced via the coaxial needle to puncture the collecting system.

Movement of the needle that follows the kidney as the patient resumes respiration, as well as spontaneous drainage of urine from the needle as the needle stylet is removed, can be used to confirm successful renal entry. Spontaneous urine drainage is particularly seen in an obstructed system. If urine is not spontaneously draining, it may be aspirated from the needle instead. Sampled urine can be sent for culture and further analysis. Renal entry can be further confirmed by administration of contrast medium into the collecting system via the diagnostic needle.

A skin incision at the puncture site may now be performed, appropriately sized according to the catheter width that is to be used. A 0.018-inch guidewire is then passed through the needle to enter the renal pelvis (Figure 3). Over the guidewire, the tract is dilated to an appropriate size with a sheath/dilator assembly to later receive nephrostomy catheters, which can be up to 14Fr (French catheter scale) in size. The dilator and the 0.018 inch guidewire can now be removed, leaving the sheath in place (Figure 4). Subsequently, a 0.038inch guide-wire is advanced through the sheath and placed as distally into the ureter as possible to stabilize the tract (Figure 5). The nephrostomy catheter is then inserted over the guidewire (e.g. an 8Fr Navarre pig-tail catheter - Bard Nordic. Figures 6 and 7). The use of a

supine anterolateral position has also been recently suggested (Cormio, Annese et al. 2007) as being a safe and effective technique, with the benefits of greater patient comfort as well as causing less respiratory and circulatory difficulties in obese patients. Regardless, the target kidney should be reimaged and reassessed, and this is most commonly performed with ultrasonography. The target renal calyx should be identified and a planned approach should be clearly delineated. The puncture site should then be identified and marked at this stage of the procedure. As described above, the target renal calyx's position relative to the diaphragm during respiration should be observed, and ideally, a subcostal approach

The site of renal puncture is determined by the indication for the procedure. A lower pole posterior calyx for instance, would be best used for simple urinary drainage (Dyer, Regan et al. 2002), while those of the upper and middle poles provide better access to the renal pelvis and ureter, especially if ureteral interventions are being considered. A puncture posterior to a calculus may assist in the treatment of calculus disease. These calyces are best identified by administration of intravenous iodinated contrast with visualization of contrast within the renal collecting system under fluoroscopic guidance. The anterior calyces are usually seen tangentially, while the posterior calyces are seen en face due to the orientation of the kidney about its horizontal axis. This would be contraindicated if the patient has prior history of contrast allergy or an underlying poor renal function, and it is probably not ideal in a

After the patient has been adequately cleaned and draped using sterile methods, the puncture site should be infiltrated with an acceptable local anaesthesia such as 1% xylocaine. Instruction should be given to the patient to breathhold while a 21G diagnostic needle (e.g Accustick System - Boston Scientific, Neff Set - Cook Medical) is used to puncture the skin, which is then advanced posteroanterioly at an angle towards the intended calyx. Alternatively, a three-part co-axial needle may also be used, where there is an outer blunt cannula, an inner 22G needle as well as a stylet. As the renal fibrous capsule of the kidney is punctured, a finer needle may then be introduced via the coaxial needle to

Movement of the needle that follows the kidney as the patient resumes respiration, as well as spontaneous drainage of urine from the needle as the needle stylet is removed, can be used to confirm successful renal entry. Spontaneous urine drainage is particularly seen in an obstructed system. If urine is not spontaneously draining, it may be aspirated from the needle instead. Sampled urine can be sent for culture and further analysis. Renal entry can be further confirmed by administration of contrast medium into the collecting system via

A skin incision at the puncture site may now be performed, appropriately sized according to the catheter width that is to be used. A 0.018-inch guidewire is then passed through the needle to enter the renal pelvis (Figure 3). Over the guidewire, the tract is dilated to an appropriate size with a sheath/dilator assembly to later receive nephrostomy catheters, which can be up to 14Fr (French catheter scale) in size. The dilator and the 0.018 inch guidewire can now be removed, leaving the sheath in place (Figure 4). Subsequently, a 0.038inch guide-wire is advanced through the sheath and placed as distally into the ureter as possible to stabilize the tract (Figure 5). The nephrostomy catheter is then inserted over the guidewire (e.g. an 8Fr Navarre pig-tail catheter - Bard Nordic. Figures 6 and 7). The use of a

severely obstructed system where poor contrast excretion can be expected.

targeting Brodel's line should be utilized.

puncture the collecting system.

the diagnostic needle.

metal cannula may be considered to stabilize the tube during its passage towards the kidney across the perirenal soft tissue.

Smaller-bore catheters (7-8Fr) are sufficient for drainage of non-infected and less viscid urine, while a larger-bore 14Fr catheter may be considered for drainage of infected urine or pus. Once the catheter is placed, its position can be further confirmed by administration of contrast to opacify the collecting system via the tube. The collecting system may be seen to decompress if the catheter is appropriately placed. Care should be taken to avoid over-distension of the collecting system so as to prevent bacteremia and risk of sepsis. To avoid catheter dislocation or dislodgement, self-retaining catheters should be used, and this should be placed as far into the collecting system as possible. Care must however be taken not to obstruct the ureter if a larger-bore catheter is used. Once firmly placed, the catheter is secured externally with retention sutures or other securing devices such as a skin disc.

Further urological intervention may follow the above puncture technique. The tract can be dilated further to allow passage of other instruments such as ureteroscope, balloondilatation system or nephrolithotomy instruments. A ureteral stent may also be placed through the percutaneous puncture. A larger-bore catheter may be considered by the urologist to allow for better drainage.

Fig. 3. A lower pole puncture was made with a 21 gauge Accustick needle into the lower pole calyx of the left kidney, with opacification of the collecting system by contrast. The obstructing calculus (c) can be seen along the proximal left ureter, causing upstream dilatation.

Fig. 4. A 0.018 inch guidewire was introduced through the needle into the renal pelvis as distally as possible. The sheath/dilator assembly was then advanced over the guidewire (not shown). The dilator and the 0.018-inch guidewire were then removed, leaving the sheath (s) in place. More contrast was instilled to delineate the collecting system.

Percutaneous Nephrostomy 305

patients may also require hospitalization for adequate monitoring. Frequent monitoring of vital signs should be routinely performed during initial recovery as signs of hemorrhage or sepsis may present suddenly and would require immediate attention. This should be accompanied by routine charting of the catheter output, noting the degree of hematuria as well as the output volume. Although commonly seen in virtually all patients, hematuria should resolve within 24-48 hours (Dyer, Regan et al. 2002). Prolonged hematuria should

Catheter care is useful to reduce rate of catheter dislodgement and clogging, and it should be flushed with normal saline and aspirated routinely. Catheter clogging is a commonly

Antibiotics may be discontinued if there is low-risk of infection, although this should be continued in high-risk patients as described above. This should ideally be adjusted

According to SIR, the reported success rate for percutaneous nephrostomy is 98-99%, and this is defined as successful placement of catheter of sufficient size to allow for adequate drainage of the urinary tract or to allow successful tract dilatation for further interventional procedure. The success rates have been reported to be lower in cases of non-dilated collecting system or complex calculus disease (e.g. staghorn calculus) where a success rate of about 85% was reported (Ramchandani, Cardella et al. 2003). Despite the high success rates however, complications are frequently encountered, be it minor or major, with a reported

Several factors are associated with increased risk of complications. Patients at the extremes of age may develop complications from the procedure itself or even that related to the use of general anaesthesia, should this become necessary particularly in young children. Patient's coexisting comorbidities such as obesity, scoliosis, hepatomegaly and extremely mobile kidneys may necessitate greater manipulation, resulting in a technically challenging and thereby risky procedure. Further, in patients with chronic lung diseases and poor respiratory reserve such as emphysema, particular attention should be paid to the use of a subcostal approach to minimize risk of respiratory complications such as

Minor complications are defined as complications occurring in relation to the procedure that are of no consequence and can be managed conservatively, or those requiring nominal therapy with no consequences (Ramchandani, Cardella et al. 2003). These patients may still require overnight hospitalization for observation. According to published reports, minor complications have been reported to occur in the range of 15-28% of cases (Stables 1982; Lee,

Post-procedure bleeding varies in severity, and may range from simple transient hematuria to severe hemorrhage requiring transfusion or intervention. Minor bleeding complications include transient hematuria, which occurs in virtually all patients, and small perirenal hematomas that can resolve on conservative management. Transient hematuria occurs very

alert the physician to the possibility of persistent bleeding from vascular injury.

incidence of approximately 10% of cases (Ramchandani, Cardella et al. 2003).

according to the urine culture results if available.

**5. Complications** 

pneumothorax.

**5.1 Minor complications** 

Smith et al. 1987; Dyer, Regan et al. 2002).

occurring complication however, and this may even necessitate a change of catheter.

Fig. 5. Subsequently a 0.038 inch guidewire was advanced through the sheath and placed as distally into the ureter as possible for stability.

Fig. 6. An 8Fr Navarre catheter was then inserted over the 0.038 inch guidewire and secured in place.

Fig. 7. The final image showing contrast opacification of the left renal collecting system. Note the reduced caliber of the upper ureter following successful drainage.

#### **4.3 Post-procedure care**

Post-procedure care is essential and may be crucial for early detection as well as reducing the risk of deterioration should complications occur during the procedure. High-risk

Fig. 7. The final image showing contrast opacification of the left renal collecting system.

Post-procedure care is essential and may be crucial for early detection as well as reducing the risk of deterioration should complications occur during the procedure. High-risk

Note the reduced caliber of the upper ureter following successful drainage.

Fig. 6. An 8Fr Navarre catheter was then inserted over the 0.038 inch guidewire

and secured in place.

Fig. 5. Subsequently a 0.038 inch guidewire was advanced through the sheath and placed as distally into the ureter as possible for stability.

**4.3 Post-procedure care** 

patients may also require hospitalization for adequate monitoring. Frequent monitoring of vital signs should be routinely performed during initial recovery as signs of hemorrhage or sepsis may present suddenly and would require immediate attention. This should be accompanied by routine charting of the catheter output, noting the degree of hematuria as well as the output volume. Although commonly seen in virtually all patients, hematuria should resolve within 24-48 hours (Dyer, Regan et al. 2002). Prolonged hematuria should alert the physician to the possibility of persistent bleeding from vascular injury.

Catheter care is useful to reduce rate of catheter dislodgement and clogging, and it should be flushed with normal saline and aspirated routinely. Catheter clogging is a commonly occurring complication however, and this may even necessitate a change of catheter.

Antibiotics may be discontinued if there is low-risk of infection, although this should be continued in high-risk patients as described above. This should ideally be adjusted according to the urine culture results if available.
