**5.2.2 Sepsis**

308 Chronic Kidney Disease

Fig. 9. Nephrogram showing contrast leakage into peripelvic fat due to transgression of the pelvicalyceal system. The patient subsequently

Fig. 11. Successful embolization with micro-

developed flank pain and hypotension, indicating concomitant vascular injury. Sonography confirmed the presence of a peri-

nephric hematoma.

coils (c).

Fig. 8. An 8 Fr Navarre catheter in place with its loop apparently sited within the renal pelvis. Figures 8 to 11 are of the

Fig. 10. Renal angiography demonstrated bleeding from a branch of the inferior segmental artery. Super-selective injection of contrast via a microcatheter (m) into the bleeding artery showed extravasation into the

same patient.

renal pelvis (p).

Significant infection and sepsis following percutaneous nephrostomy is an important and well-recognised complication, with several published reports documenting its occurrence. According to SIR, sepsis related complications have been reported to occur in 1-9% of cases (Ramchandani, Cardella et al. 2003). There is a wide spectrum of severity of infection, but major sepsis may be defined as cases of septicemia requiring escalation in hospital care and longer use of antibiotics therapy, with or without shock. Transient fever is common following the procedure, occurring in almost all patients, the majority of which may settle in less than 6 hours (Lee, Patel et al. 1994). However, persistent fever with chills and signs of hemodynamic instability are worrisome signs and should be identified and treated accordingly. Septic shock is a serious complication, and has been reported to be a contributing factor towards patients mortality in some published case series. In 318 patients who underwent percutaneous nephrostomy, Lewis reported sepsis as the most common major complication, occurring in 2.2% of patients in his published case series, and it is the most severe complication necessitating intensive care (Lewis and Patel 2004). Sepsis was also considered to be a contributing factor in the death of two of these cases. Moskowitz further reported 2 cases of septicemia with shock in 11 cases of severe sepsis in his published case series of patients who underwent percutaneous nephrolithotomy (Moskowitz, Lee et al. 1989). SIR recommended a rate of septic shock of less than 4%, and a rate of less than 10% for cases of septic shock in the setting of pyonephrosis.

Several factors have been found to contribute towards increased risk of sepsis, and this includes the duration of the procedure itself, urine bacterial load, severity of urinary tract obstruction as well as presence of bacteria within the calculus (Mariappan, Smith et al. 2006). Mariappan also reported higher risk of upper urinary tract infections in patients with calculi larger than 20mm or a dilated pelvicalyceal system. Further, the puncture itself, and even the removal of calculus may reactivate underlying pre-existing infection within the urinary tract with release of bacteria into the system. Therefore, care should be taken to avoid over-distension of the renal collecting system during puncture, as this may result in bacterial reflux into the peripapillary plexus. Urine extravasation and absorption of irrigation fluid have also been found to be contributory (Lee, Patel et al. 1994).

The use of prophylactic antibiotics is therefore recommended in high-risk patients, and this has been shown to be of some benefit as reported in a prospective controlled study by Mariappan, who prescribed one week of ciprofloxacin to patients prior to percutaneous nephrolithotomy (Mariappan, Smith et al. 2006). Patients who received prophylactic ciprofloxacin were reported to have significantly reduced incidence of upper urinary tract infection as compared to the control group, with three times less risk of developing systemic inflammatory response syndrome. Antibiotics therapy may be further escalated in patients with evidence of urosepsis following the procedure, and this is best adjusted according to the results of urine culture and sensitivity.

#### **5.2.3 Pleural complications**

Pleural complications such as pneumo-, hydro-, or hemothorax and empyema are uncommon but have been known to occur from percutaneous nephrostomy, with a reported rate of 0.1-0.3% (Dyer, Regan et al. 2002; Ramchandani, Cardella et al. 2003). The risk of

Percutaneous Nephrostomy 311

Fig. 13. Anterograde insertion of a double J stent 3 weeks later on the same patient showed extravasation of contrast through the percutaneous nephrostomy tract into

the descending colon (d).

Injuries to organs adjacent to the kidneys have been reported in less than 1% of cases (M Tan 2010), and of these, splenic injury is the most commonly reported. Liver laceration is less

The risk of splenic injury is increased if a higher supracostal approach (10th-11th ribs) is used, or if the approach is made during inspiration. Should a trans-splenic tract is made, the primary concern is that of hemorrhage with risk of shock, and these may have to be managed surgically. However, conservative management may be considered in selected cases, particularly if the patient is asymptomatic and stable, and this was reported by Carey in a patient who sustained splenic injury that occurred during percutaneous nephrolithotomy (Carey, Siddiq et al. 2006). The patient was managed conservatively, with no serious consequences and the patient was discharged following removal of the

common, and seldom requires intervention (Lee, Smith et al. 1987).

Fig. 12. Delayed phase of an intravenous urogram showing left hydronephrosis (h) due to obstruction at the pelviureteric junction. The gas-distended descending colon is in close proximity to the lateral aspect of the left

**5.2.5 Injury to intra-abdominal viscera** 

nephrostomy catheter.

kidney.

pneumo- and hydrothorax is reported to be in the range of 4-12% if a supracostal approach is used for puncture of the renal upper pole (Carey, Siddiq et al. 2006), although this may be difficult to avoid if it provides the best access to the collecting system. The use of a working sheath is an important consideration in these cases, as it may prevent leakage of fluid into the pleural cavity along the pleural tract during the procedure. Although pleural complications may be treated conservatively (Dyer, Regan et al. 2002), pleural drainage with chest tube insertion may be necessary.

#### **5.2.4 Bowel transgression and colonic perforation**

Bowel transgression is another uncommon but potentially serious complication of percutaneous nephrostomy, and is reported to occur in 0.2-0.3% of cases (Ramchandani, Cardella et al. 2003; M Tan 2010). Several risk factors have been recognized that may contribute to increased risks. Patients with a markedly dilated collecting system, colonic obstruction and patients with scarce perirenal fat are more likely to have a more posteriorly located colon. This increases the risk of colonic transgression when approaching the kidney. An anatomical variant to note is the retrorenal colon which is reported to occur in 1 - 1.9% of supine patients and in up to 10 – 16% of prone patients (Hopper, Sherman et al. 1987; Tuttle, Yeh et al. 2005). This retroperitoneal bowel loop is usually gas-distended and is found mostly around the lower renal poles. Care should thus be taken to visualize this with fluoroscopy or CT before any invasive percutaneous renal procedure. Colonic perforation has also been associated with right upper calyceal punctures in patients with horseshoe kidneys (El-Nahas, Shokeir et al. 2006). Any factor contributing to poor visualization of the kidneys during image-guidance such as gross obesity, abundance of gas-filled bowel loops and mobile kidneys may also result in inadvertent colonic injury. The risk is further increased when too lateral an approach is used to puncture the kidney (Wah, Weston et al. 2004).

Most cases of reported colonic perforation due to percutaneous nephrostomy are retroperitoneal and contained, and these have been managed well conservatively with good recovery (Wah, Weston et al. 2004). However, surgical repair may be required in cases of intraperitoneal colonic perforation, or where there is ensuing hemorrhage with or without shock. M Tan described a case of inadvertent colonic injury during percutaneous nephrostomy that occurred in a thin middle-aged woman with a dilated renal pelvicalyces (M Tan 2010). The patient was asymptomatic and the perforation was only discovered 3 weeks later during a double J stent insertion when contrast was noted in the colon. The patient was managed conservatively and the percutaneous nephrostomy was later withdrawn into the colon, functioning as a percutaneous colostomy. The use of antibiotic cover would be indicated in these cases to prevent infection.

The use of image guidance is important in reducing risk of colonic perforation. The exact location of the colon relative to the kidney should be identified prior to the procedure, and as described above, too lateral an approach should be avoided in high-risk patients. In patients with risk factors leading to poor visualization of the urinary system under ultrasound guidance, CT scan should be used to look for anatomical variants, such as a retrorenal colon or horseshoe kidney, to reduce the chance of inadvertent colonic puncture (M Tan 2010).

pneumo- and hydrothorax is reported to be in the range of 4-12% if a supracostal approach is used for puncture of the renal upper pole (Carey, Siddiq et al. 2006), although this may be difficult to avoid if it provides the best access to the collecting system. The use of a working sheath is an important consideration in these cases, as it may prevent leakage of fluid into the pleural cavity along the pleural tract during the procedure. Although pleural complications may be treated conservatively (Dyer, Regan et al. 2002), pleural drainage with

Bowel transgression is another uncommon but potentially serious complication of percutaneous nephrostomy, and is reported to occur in 0.2-0.3% of cases (Ramchandani, Cardella et al. 2003; M Tan 2010). Several risk factors have been recognized that may contribute to increased risks. Patients with a markedly dilated collecting system, colonic obstruction and patients with scarce perirenal fat are more likely to have a more posteriorly located colon. This increases the risk of colonic transgression when approaching the kidney. An anatomical variant to note is the retrorenal colon which is reported to occur in 1 - 1.9% of supine patients and in up to 10 – 16% of prone patients (Hopper, Sherman et al. 1987; Tuttle, Yeh et al. 2005). This retroperitoneal bowel loop is usually gas-distended and is found mostly around the lower renal poles. Care should thus be taken to visualize this with fluoroscopy or CT before any invasive percutaneous renal procedure. Colonic perforation has also been associated with right upper calyceal punctures in patients with horseshoe kidneys (El-Nahas, Shokeir et al. 2006). Any factor contributing to poor visualization of the kidneys during image-guidance such as gross obesity, abundance of gas-filled bowel loops and mobile kidneys may also result in inadvertent colonic injury. The risk is further increased when too lateral an approach is used to puncture the kidney (Wah, Weston et al.

Most cases of reported colonic perforation due to percutaneous nephrostomy are retroperitoneal and contained, and these have been managed well conservatively with good recovery (Wah, Weston et al. 2004). However, surgical repair may be required in cases of intraperitoneal colonic perforation, or where there is ensuing hemorrhage with or without shock. M Tan described a case of inadvertent colonic injury during percutaneous nephrostomy that occurred in a thin middle-aged woman with a dilated renal pelvicalyces (M Tan 2010). The patient was asymptomatic and the perforation was only discovered 3 weeks later during a double J stent insertion when contrast was noted in the colon. The patient was managed conservatively and the percutaneous nephrostomy was later withdrawn into the colon, functioning as a percutaneous colostomy. The use of antibiotic

The use of image guidance is important in reducing risk of colonic perforation. The exact location of the colon relative to the kidney should be identified prior to the procedure, and as described above, too lateral an approach should be avoided in high-risk patients. In patients with risk factors leading to poor visualization of the urinary system under ultrasound guidance, CT scan should be used to look for anatomical variants, such as a retrorenal colon or horseshoe kidney, to reduce the chance of inadvertent colonic puncture

chest tube insertion may be necessary.

2004).

(M Tan 2010).

**5.2.4 Bowel transgression and colonic perforation** 

cover would be indicated in these cases to prevent infection.

Fig. 12. Delayed phase of an intravenous urogram showing left hydronephrosis (h) due to obstruction at the pelviureteric junction. The gas-distended descending colon is in close proximity to the lateral aspect of the left kidney.

Fig. 13. Anterograde insertion of a double J stent 3 weeks later on the same patient showed extravasation of contrast through the percutaneous nephrostomy tract into the descending colon (d).
