Objective
• To compare micropercutaneous nephrolithotomy
(microperc) and retrograde intrarenal surgery (RIRS) for
the management of renal calculi <1.5 cm with regard to
stone clearance rates and surgical characteristics,
complications and postoperative recovery.
Patients and Methods
• Seventy patients presenting with renal calculi <1.5 cm
were equally randomized to a microperc or a RIRS group
between February 2011 and August 2012 in this
randomized controlled trial. Randomization was based
on centralized computer-generated numbers. Patients
and authors assessing the outcomes were not blinded to
the procedure.
• Microperc was performed using a 4.85-F (16-gauge)
needle with a 272-mm laser fibre. RIRS was performed
using a uretero-renoscope.
• Variables studied were stone clearance rates, operating
time, need for JJ stenting, intra-operative and
postoperative complications (according to the
Clavien–Dindo classification system), surgeon discomfort
score, postoperative pain score, analgesic requirement
and hospital stay.
• Stone clearance was assessed using ultrasonography and
X-ray plain abdominal film of kidney, ureter and bladder
at 3 months.
Results
• There were 35 patients in each group. All the patients
were included in the final analysis.
• The stone clearance rates in the microperc and RIRS
groups were similar (97.1 vs 94.1%, P = 1.0).
• The mean [SD] operating time was similar between the
groups (51.6 [18.5] vs 47.1 [17.5], P = 0.295). JJ stenting
was required in a lower proportion of patients in the
microperc group (20 vs 62.8%, P < 0.001). Intra-operative
complications were a minor pelvic perforation in one
patient and transient haematuria in two patients, all in
the microperc group. One patient in each group required
conversion to miniperc.
• One patient in the microperc group needed RIRS for
small residual calculi 1 day after surgery. The decrease in
haemoglobin was greater in the microperc group (0.96 vs
0.56 g/dL, P < 0.001). The incidence of postoperative
fever (Clavien I) was similar in the two groups (8.6 vs
11.4%, P = 1.0). None of the patients in the study
required blood transfusion.
• The mean [SD] postoperative pain score at 24 h was
slightly higher in the microperc group (1.9 [1.2] vs 1.6
[0.8], P = 0.045). The mean [SD] analgesic requirement
was higher in the microperc group (90 [72] vs 40 [41]
mg tramadol, P < 0.001). The mean [SD] hospital stay was
similar in the two groups (57 [22] vs 48 [18] h, P = 0.08).
Conclusions
• Microperc is a safe and effective alternative to RIRS for
the management of small renal calculi and has similar
stone clearance and complication rates when compared
to RIRS.
• Microperc is associated with higher haemoglobin loss,
increased pain and higher analgesic requirements, while
RIRS is associated with a higher requirement for JJ
stenting.