INTRODUCTION
Percutaneous nephrostolithotomy (PCNL) was introduced by Fernström and
Johansson in 1976,1 and it has remained an
important approach for removing kidney stones since its inception. A nephrostomy tube
is
routinely positioned in the renal pelvis in order to tamponade bleeding and drain
the
collecting system. Although PCNL is an established procedure, major complication rates
of up
to 7% have been reported.2 We report two
cases of an uncommon PCNL complication and details of how we managed these cases with
successful outcomes.
CASE REPORT
Case 1 - A 52-year-old male who had previously undergone a right open nephrectomy
of a
non-functioning kidney 10 years prior underwent a left PCNL. Serum creatinine (SCr)
before
surgery was 1.0 mg/dl (normal range 0.6–1.4 mg/dl). Access to the excretory
system was achieved using fascial dilators, and a safety guide wire was used during
the
procedure. Intense bleeding led to a sudden interruption of the procedure; a nephrostomy
tube was inserted and closed in order to control bleeding within the excretory system.
An
antegrade nephrostogram was not performed due to intense bleeding. An arteriography
was
performed and showed no abnormalities. After transfusion of two units of blood, the
patient
remained hemodinamically stable and urine was eliminated only by means of the urethral
catheter. The nephrostomy tube remained closed.
A magnetic resonance scan performed 72 hours later showed the nephrostomy tube in
the left
renal vein (Figure 1). The patient was
transferred to the operating room, and the nephrostomy tube was removed under general
anesthesia with the surgical team on standby ready to intervene. No bleeding occurred
after
removal of the catheter. The patient was discharged with a SCr level of 1.4 mg/dl.
Case 2 - A 35-year-old female underwent a second PCNL for a staghorn stone in the
left
kidney. She had previously lost her right kidney due to kidney stones. The SCr level
before
surgery was 3.0 mg/dl. A PCNL was performed; access to the excretory system was gained
using
coaxial dilators, and a safety guide wire was used during the procedure. An ultrasonic
energy source was used to fragment the stone. Severe venous bleeding was noted during
the
fragmentation process. The procedure was interrupted; a nephrostomy tube was inserted
and
maintained closed. The nephrostomy was reopened on the second postoperative day, and
intense
bleeding was observed through the catheter, which was immediately closed. An antegrade
nephrostogram was performed and showed the presence of iodinated contrast inside the
venous
system. A computed tomography scan showed that the nephrostomy catheter was lodged
inside
the inferior vena cava (Figure 2). The
patient was taken to the operating room, and the nephrostomy tube was repositioned
in the
collecting system under fluoroscopy control with the surgical team on standby ready
to
intervene. The nephrostomy tube was removed 48 hours later. The patient was discharged
three
days later with a SCr level of 3.5 mg/dl.
DISCUSSION
Hemorrhage is the most significant complication of PCNL, and transfusion can be necessary
in up to 10% of procedures.2 Other
complications include sepsis, adjacent organ perforation (such as liver, spleen, and
bowel),
failed renal access, perforation of the excretory system, pneumothorax, and pleural
effusion.2 Placing a nephrostomy tube in
the collecting system following PCNL is a routine practice, and, in addition to its
other
advantages, it is an effective method for stopping venous bleeding.3 Occasionally,
the catheter can pierce the renal parenchyma
and migrate into the renal vein and even to the vena cava.3
In the first case, the nephrostomy tube was removed, and it was relocated under
fluoroscopic guidance in the second. In both cases, the patients were placed under
general
anesthesia, and while the surgical teams were ready to perform emergency open surgery
in the
event of uncontrolled bleeding, this was not necessary.
This study is the second report in the literature regarding misplacement of a nephrostomy
tube into the vascular system and is the first report of such a complication following
PCNL.4 A lesion in a large renal vein
branch caused by the instruments used during percutaneous surgery was the most likely
cause
of the observed bleeding. Furthermore, the proximity of the Amplatz sheath to the
injured
vein could have inadvertently directed the nephrostomy tube inside the venous system.
Although a Doppler ultrasound was not performed after the nephrostomy tubes were removed,
we conclude that no renal or vena cava thrombosis occurred, as these kidneys were
single
organs and renal function was maintained after the procedures in both patients. Thrombotic
phenomena were probably not observed due to the high blood flow and low venous pressure
inside these veins.
Antegrade pyelographies were not performed in either procedure due to the bleeding,
and
this decision was likely a mistake. Antegrade pyelography at the end of a percutaneous
procedure in order to check the exact positioning of the nephrostomy tube should be
mandatory, even in cases of severe bleeding, and must be done routinely. In cases
where
misplacement of the tube is detected, depending on the postoperative time elapsed,
relocation of the nephrostomy tube under fluoroscopy is strongly recommended, and
the
surgical team must stand ready to operate in case an open emergency procedure is
required.