Mini PCNL versus standard PCNL: jury is still out

Fri, 11 Sep 2015 • Joel Vega

Modern technology in stone treatment may provide benefits but the perceived advantages such as in minimally invasive removal techniques require strong evidence in order to minimise complications whilst optimising their effectiveness.

At the 3rd Meeting of the EAU Section of Urolithiasis (EULIS) which opened today in Alicante, Spain, Evangelos Liatsikos (GR) tackled the pros and cons of new versus standard technologies such as in Percutaneous Nephrolithotomy (PCNL).

In his Endourological Society lecture titled “Standard, Mini, Ultra-mini, Super mini, micro PCNL: Do we need all this stuff?”, he examined both the benefits and downsides of minimally invasive technology, and said that doctors should balance their enthusiasm for new techniques with actual and proven evidence.

“Micro PCNL has significantly higher intrarenal pressures in comparison to standard PCNL. The complication rates, however, are similar,” said Liatsikos. “The efficacy of miniatueised seems to be high, but longer operating times apply and benefit compared to standard PCNL for selected patients has yet to be demonstrated.”

“There is some evidence that smaller tracts case less bleedingcomlications, but frther studies need to evaluate this issue,” he said, adding that although his statements may sound provocative there remains the need for evidence-based medicine.

He mentioned that on the issue of lower blood loss, the jury is still out since the studies that looked into this issue were burdened with selection bias.

In his take-home messages, he underscored that standard PCNL ...“should be regarded as the gold standard treatment option for large renal calculi as it combines acceptable morbidity with excellent stone-free rates.”

He also added that flexible ureteroscopy should be preferred over minimally invasive PCNL in small burden stones as it is associated with less morbidity and higher stone-free rates.

But he conceded that there remains a significant role for minimally invasive techniques such as in cases of small stone burden when retrograde intrarenal surgery (RIRS) is less likely to be effective.

“Minimally invasive PCNL can also be considered as a secondary track in complex cases requiring more than one access, in paediatric cases and in Endoscopic Combined Intra Renal Surgery, “ he said.

In the plenary discussion that followed, he further clarified his position and said that a critical eye needs to be cast on new technology since only evidence-based studies can really prove their effectiveness. But achieving this also require a consensus on what consists minimally invasive procedures, a thorny question since there is still no collective agreement on the definitions and scope of minimally invasive treatments.