Microperc is technically feasible, safe and efficacious for small volume renal calculous disease. Further clinical studies and direct comparison with available modalities are required to define the place of microperc in the treatment of nonbulky renal urolithiasis.

Associate Editor Ash Tewari Editorial Board Ralph Clayman, USA Inderbir Gill, USA Roger Kirby, UK Mani Menon, USA OBJECTIVE To report the initial clinical cases of scarless, single port, transumbilical nephrectomy and pyeloplasty. PATIENTS AND METHODS One patient each underwent single port transumbilical nephrectomy and pyeloplasty using the R‐Port (Advanced Surgical Concepts), inserted through a transumbilical incision in both cases. Novel, specialized instruments, curved at the shaft, were used in addition to standard laparoscopic instrumentation. During pyeloplasty, a 2‐mm needle‐port (MiniSite, USSC, Norfolk, CT, USA) was also inserted, with no skin incision, to facilitate suturing. RESULTS Both procedures were technically successful with no extra‐umbilical skin incisions. The total operative duration was 3.4 and 2.7 h, the estimated blood loss 100 and 50 mL, and the hospital stay was 1 and 2 days for the nephrectomy and pyeloplasty, respectively. There were no complications during or after surgery. The total analgesia requirement was 100 and 150 mg of keterolac, and visual analogue pain scores were 8/10 and 2/10 at 1 and 2 days after surgery, respectively. CONCLUSIONS Transumbilical, single port nephrectomy and pyeloplasty are technically feasible. The first initial clinical experience of organ‐ablative and reconstructive renal surgery with this approach is reported.

RESULTS• Mean tract size was 18.2 ± 2 F (15-20) and 26.8 ± 2 F (24-30), P value < 0.0001 in the miniperc and standard PNL, respectively. Holmium LASER and pneumatic lithotripter were the main energy sources used in miniperc and standard PNL, respectively.• Miniperc operative time was longer than that of standard PNL (45.2 ± 12.6 vs 31 ± 16.6 min, P = 0.0008 respectively).• Conversely, there was an advantage of miniperc over standard PNL in terms of a significantly reduced hemoglobin drop (0.8 ± 0.9 vs 1.3 ± 0.4 gram%, P = 0.01), analgesic requirement (55.4 ± 50 vs 70.2 ± 52 mg tramadol, P = 0.29) and hospital stay (3.2 ± 0.8 vs 4.8 ± 0.6 days, P ≤ 0.001), respectively.• Intra-operative conversion of the procedure into a tubeless PNL was significantly more in the miniperc group ( P ≤ 0.001). The miniperc and standard PNL group had clearance rates of 96% and 100%, respectively at 1 month follow up. CONCLUSIONS• This study demonstrated significant advantages of the miniperc procedure in terms of reduced bleeding leading to a tubeless procedure and reduced hospital stay.• The stone free rates and the complications were similar in either group. What's known on the subject? and What does the study add? Standard PNL is known to have higher clearance rates for stones 1-2 cm. However, it is not promoted because of its associated morbidity, especially bleeding. Minitiarization of the PNL has spawned a new interest in this modality for treating small bulk urolithiasis. KEYWORDSThe study adds to a growing body of evidence in a prospective manner that smaller tract PNL "miniperc" is associated with a similiar efficacy of achieving stone-clearance rates while decreasing the invasiveness of the procedure and associated morbidity. OBJECTIVE

Study Type – Therapy (pattern of practice survey) Level of Evidence 2b What's known on the subject? and What does the study add? Miniperc and RIRS are commonly used modality for treating non‐bulky renal urolithiasis. Both the treatment options are invasive and are associated with inherent complications. There are only a few studies that compare these two treatment modalities. Both the modalities are effective to render patient stone free with minimal complications. Immediate stone free rate is higher with miniperc but comparable in both the modalities at 1 month. RIRS is associated with favourable pain scores and lower hemoglobin drop. OBJECTIVE To plan a prospective comparative case–control designed study aiming to compare minipercutaneous (miniperc) and retrograde intrarenal surgery (RIRS) for a renal calculus of size 1–2 cm. PATIENTS AND METHODS A total of 64 cases (32 in each arm) underwent miniperc and RIRS during the study period from March 2009 to April 2011. The primary and secondary outcome objective was stone‐free rate and retreatment rate, complications, operation duration, patient visual pain scores, analgesic requirement, haemoglobin drop and hospital stay, respectively. RESULTS Miniperc and RIRS had stone clearance rates of 100% and 96.88%, respectively. In the RIRS group, one patient required retreatment at 1 month. Hospital stay (0.24) and intra‐operative (0.99) and postoperative complications (0.60) were similar in both groups. Operation duration (P= 0.003) was lower in the miniperc group. Haemoglobin drop (P < 0.001), patient pain and visual analogue scale score (each P < 0.001) at 6, 24 and 48 h, as well as analgesic requirement (P < 0.003), were all lower in the RIRS group. CONCLUSIONS The stone clearances in both modalities are high and complications are low. RIRS requires a larger operation duration, although it is associated with favourable pain scores and a lower haemoglobin drop.