Intra-renal pressures (IRP)during URS/RIRS/PCNL
Endourology has given gratifying results. Over the period of years we have realised that in PCNL going small has many advantages - so many so called minimally invasive PCNLs have - miniperc, microperc, UMP, MIPXS...etc. However a new factor has emerged - that is IRP during procedures - which increases to significant level during these procedures.
Same way, URS have become slender & slender, FURS has remarkably reduced in size upto 7.5F. All these advances have reduced the channel size & thereby providing less space for irrigation to flow requiring irrigation under pressure. This has led to increase in IRP significantly.
All of us know problems of IRP- causing infections & many other problems. - but what we still do not know is
1) what is cut off limit of IRP beyond which complications will start
2) What is the way in which it can be measured
3) Is IRP increase in every case - can cause same complications -
We are now at this cross road in endourology - where I feel next decade will see huge amount of research in understanding these aspects.
Suction has already come in use along with PCNL - so as to such out fragments but also to keep IRP low.
During RIRS enough methods are advocated so as to reduce IRP - like manual slow irrigation, use of access sheath ...etc However all such methods are at present only experience based & not evidence based.
There are attempts made to measure IRP during procedure - Access sheaths are being develop which will have pressure sensors at the tip & it can show pressures live. However all these are yet in experimental phase. I
we still do not know what is limit. All studies are in lab or in animal model. Unless human studies are done, clarity will not come. & for human study adequate gadgets have to come. So currently in this topic we are still in dark. We still have long way to go before we get definative answer. However one this certain, next decade is going to be interesting wherein lot of physics will occupy our studies. We are going to witness very interesting studies which has potential to change how we look at MIP or RIRS
Interesting article to read https://pubmed.ncbi.nlm.nih.gov/33547026/