PCNL - Initial Puncture Prof Peter Alken

Dear all,

Recently we had an ‘operative workshop’ Organized at Manipal under the aegis of USI and ISU wherein Madhu Agrawal as one of the moderators requested that every step of Initial Puncture be demonstrated emphasizing repeatedly that this part had to be learnt by all indepth to avoid Complications as a proper entry into the collecting system is guided by the appropriateness of the Initial Puncture. Both Operating Surgeons, Ravi and Arun, took special pains to demonstrate each step for initial puncture. Punctures performed by Experts appear very simple but it needs adequate exposure to master and even then at times initial puncture could be difficult.

I had provided an article to SK pal for his commentary on ‘PCNL: Initial Puncture by Prof Peter Alken’. He has provided a Review on initial Puncture for PCNL. I am providing his commentary along with the article of Peter Alken for your reading and understanding.

https://bjui-journals.onlinelibrary.wiley.com/doi/epdf/10.1111/bju.15564 (PDF available)

With warm regards,


Commentary by SK Pal:

Often we make blatant statements like ‘Accurate Initial puncture is the most important step of PCNL’.

We go on to add that if a good puncture has been accomplished, more than 50% of the success has been achieved.

But, do we have robust literature, supporting these statements?  How much is the influence of initial puncture on the success, course, outcome and complications of PCNL?

Haven’t we seen appropriate initial punctures resulting in non-gratifying results or worse- culminating in catastrophic complications and on the other hand, very bad initial punctures, ultimately giving us very satisfactory outcomes.

Most of the published literature on PCNL is silent on the influence of initial puncture.

Prof. Peter Alken has attempted to collect recent published material over the last 5 years on this issue and has summarized outcome of 193 references in an article published on line on August 8th 2021 in BJUI titled – ‘Percutaneous Nephrolithotomy- the puncture’

This Article has extensively studied the influence of various existing imaging modalities and utilized access techniques for initial puncture. Ultimately, no conclusions could be drawn and all imaging modalities and access techniques proved to be equal.

The Article also highlights the technological advances like electromagnetic or optical tracking systems for accurate placement of initial punctures, which might become very useful. 

Paucity of literature on inclusion of details and influence of initial puncture on outcome of PCNL does not authenticate, support or deny the statements against initial puncture being a significant influencer. Thus, the importance attributed to initial puncture remains subjectively high but objectively low. 

This article should prompt the contributors to pay attention and include more relevant details of initial puncture in their publications, so that more detailed assessment and comparison can be made to derive conclusions.

SK Pal


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  • Gyanendra Sharma
    Gyanendra Sharma
    04 Oct 2021 10:54:54 AM

    Respected Teachers, Seniors and Dear Friends

    PCNL is a procedure which is commonly done. Percutaneous renal access is a key step of this procedure. When we say access it is not just access to the calyx but also selecting the right pole and choosing the right calyx.

    Very often these aspects are overlooked. At times the surgeon is not keen for a supracostal access and chooses a lower pole calyx. This results in excessive torque over the renal parenchyma and the resultant difficulties and complications

    Very few articles in literature have emphasized on how to choose the right pole and right calyx. Often the beginner learns what he has seen and perceived and follows the same

    I have always believed that if we objectively define how each step is to be done then the learning curve and subsequently the complications will also come done

    To give a similarity with sports—it does happen with the best of players that some technical flaw creeps in. Because each step is objectively defined—the coach is able to pinpoint the flaw and rectify it

    Arbitariness in deciding the site of skin puncture  and angle of puncture can affect the entire procedure adversely

    Another important issue is the learning surve. Despite nearly 50 years since PCNL come into vogue, there are still articles written on how to make a puncture

    As rightly pointed out by Dr. Alken & Dr. SK Pal –none of the techniques have been properly compared and the comparison validated

    This is possible only if surgeons with the same skill set—possibly newly joined trainees – practice the  various techniques on a trainer and then analysis of various aspects of puncture, like the accuracy, time taken, attempts at accurate puncture , fluoroscopy time etc are estimated and compared

    I had done a similar study but unfortunately attempts to get it published in various journals failed

    For the urologists interested in percutaneous renal access, I am attaching a review article of mine which covers probably every aspect of this surgery

    Hopefully, it would be useful to all and especially the trainees


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  • Ravindra Sabnis
    Ravindra Sabnis
    05 Oct 2021 11:14:27 PM

    Peter Alken is pioneer in PCNL. Anything which comes from him, should be takne with all seriousness. 

    PCNL is very complex procedure. Even after 4 decades of its invention, we still have to organise classes, lectures, workshops to teach puncture. 
    Every person invents his own way to make puncture, dilate the tract & clear the stone. He is right in his article to say that there is no one method which is right or wrong. Lot fo evidences are there to prove that stones can be cleared without complications by multiple ways which are diametrically opposite to each other. 
    For example way SK Pal makes puncture, or someone else makes puncture, we may not agree that it is correct way but that is not true. In same workshop, when I did one case, many in audience including Dr Pal were skeptical about puncture & thought that that is not right way to make puncture but, I could finish case & showed all details in nephroscopy. 
    Big question is what is right puncture & who decided what is right. As peter Alken says, we still have not got answer. There is still dispute about anterior / posterior calyx identification & targeting that. Everyone has their own way of identifying it. PCNL is one operation where practice teaches you, makes you to invent your own way & makes you perfect. You follow one method in your training days & keep following that. After doing few hundred cases you realise what way to go & achieve success. 
    I teach our student - simple way of puncturing & then they have to master it by repeatedly doing same thing. 
    RIRS there are set methods, set movements & you will get results. However in PCNL there are not set methods. People have attempted to give mathematical solution but all have been so far futile. 

  • Venugopal P
    Venugopal P
    18 Oct 2021 10:36:20 AM

    Dear All,

    We in India are the leaders of PCNL and most of our Urologists have performed PCNLs even at remote places with considerable success. The question of Initial Puncture and its importance or otherwise has been discussed by Pal, Gyanendra and Ravi in connection of Alken on ‘PCNL - Initial Puncture’. One can at once make out from the commentaries of the three that there are no Ideal method and most of the times the initial puncture is based on personal experience. Ravi has rightly pointed out that even after 4 decades of Existence of PCNL, Classes, Workshops etc are still needed to make a trainee understand the fundamentals of Initial Puncture. Most often, we pick a technique and follow it implicitly as long as they have given success for the procedure.

    Do we need more accurate methods for guiding us with initial punctures? Alken has mentioned that technological advances like Optical tracking and few others might become useful. Considerable work on various modalities are being undertaken but most of them are in its early stages and time alone will help us to know the real utilities of these technological advances.

    Most of the technological advances that we talk about today, began as tools for Simulation training and some of them progressed to Real Time usage for performing PCNL. Do we need all these advances at our disposal for performing initial puncture when we are able to perform PCNLs regularly with Success most often?

    I am providing an article on ‘Percutaneous puncture during PCNL: new perspective for the future with virtual imaging guidance’ Published by E Checcucci*, F Porpiglia et al, 2021, WJU, Published Online Sept 1st.

    I am sure and hopeful that our experts will provide useful commentaries on the utility of these technological advances in Routine performance of PCNLs in future.

    With warm Regards,



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