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Video: Surgical outcomes of PCNL and results of stone analysis

Surgical outcomes of percutaneous nephrolithotomy in 3402 patients and results of stone analysis in 1559 patients

Abstract

Objective

To report our experience of a series of percutaneous nephrolithotomy (PCNL) procedures in a single centre over 18 years in terms of patient and stone characteristics, indications, stone clearance and complications, along with the results of chemical analysis of stones in a subgroup.

Patients and Methods

We retrospectively analysed the outcomes of PCNL in 3402 patients, who underwent the procedure between 1997 and 2014, obtained from a prospectively maintained database. Data analysis included patients’ age and sex, laboratory investigations, imaging, punctured calyx, duration of operation, volume of irrigation fluid, radiation exposure time, blood transfusion, complications and stone-free status at 1-month follow-up. For the present analysis, outcomes in relation to complications and success were divided in two eras, 1997–2005 and 2006–2014, to study the differences.

Results

Of the 3402 patients, 2501 (73.5%) were male and 901 (26.5%) were female, giving a male:female ratio of 2.8:1. Staghorn (partial or complete) calculi were found in 27.5% of patients, while 72.5% had non-staghorn calculi. Intracorporeal energy sources used for stone fragmentation included ultrasonography in 917 patients (26.9%), pneumatic lithoclast in 1820 (53.5%), holmium laser in 141 (4.1%) and Lithoclast® master in 524 (15.4%). In the majority of patients (97.4%) a 18–22-F nephrostomy tube was placed after the procedure, while 69 patients (2.03%) underwent tubeless PCNL. The volume of the irrigation fluid used ranged from 7 to 37 L, with a mean of 28.4 L. The stone-free rate after PCNL in the first era studied was 78%, vs 83.2% in the second era, as assessed by combination of ultrasonography and plain abdominal film of the kidney, ureter and bladder. The complication rate in the first era was 21.3% as compared with 10.3% in the second era, and this difference was statistically significant. Stone analysis showed pure stones in 41% and mixed stones in 58% of patients. The majority of stones consisted of calcium oxalate.

Conclusions

This is the largest series of PCNL reported from any single centre in Pakistan, where there is a high prevalence of stone disease associated with infective and obstructive complications, including renal failure. PCNL as a treatment method offers an economic and effective option in the management of renal stone disease with acceptable stone clearance rates in a resource-constrained healthcare system.

Royal Society of Medicine: Key issues in Endourology

The RSM section of Urology #RSMUrology hosted a day on the Key issues in Endourology on 20th October. This was the first meeting of the academic year under President Roland Morley. Sri Sriprisad put together a complete endourology day with key subject areas of  “PCNL and stones”, “upper tract TCC” and “BPH and retention”. Speakers from India, America and Spain provided expert opinions from around the globe.

The day started with the evolution of stone and urological laparoscopic surgery. Showing an insight into the challenges with the initial introduction of laparoscopic urological surgery. In order to allow surgeons the chance to discuss their experiences and troubleshoot and develop surgical techniques the SLUG forum (southern laparoscopic urology group) was created, which is still running today in the annual AUA meeting.

PCNL techniques were the subject for several debate lectures. Access for PCNL tracts was debated by Dr Janak Desai, visiting from Samved Urology hospital in India, arguing for fluoroscopic puncture with over 10,000 cases to date! Jonathan Glass, from Guy’s and St. Thomas’ Hospital, spoke for the prone position for the majority of PCNL, but selecting the supine position in 5-10% of cases depending on the anatomy and stone position. Dr Desai also spoke on ultra-mini PCNL, which he advocates using to treat solitary kidney stones under 2 cm in preference to flexible ureteroscopy.

The future of ESWL was debated and the audience voted that it is still “alive and clicking” by a narrow margin. However, although up to 80% clearance rates are quoted for upper pole stones less than 2 cm, the problem is that results of treatment are varied and unpredictable, and real-life success rates are far inferior. The variation in results may in part be due to the fact that there are no formal training courses for specialist radiographers nor SAC requirements for specialist registrars. Professor Sam McClinton presented on clinical research in stone disease with results from the TISU trial on primary ESWL vs. ureteroscopy for ureteric stones due out next year. The results will be fascinating and may help to decide if ESWL has a future in the UK.

Professor Margaret Pearle, visiting from the University of Texas Southwestern Medical Centre, explained the importance of treating residual fragments. With data showing that 20 – 36% of >2 mm residual stones after ureteroscopy required repeat surgery within 1 year. In a thought provoking lecture, she presented data showing that ureteroscopy may not be as good as we think and when critically examined, true stone-free rates maybe no better than ESWL. Maybe miniaturised PCNL is the way forward after all?

The follow up of small kidney stones is an uncertain area with very little written in either the EAU or AUA guidelines. Data from a meta-analysis by Ghani et al. shows that for every year of follow up on small kidney stones 7% may pass, 14% grow and 7% will require intervention. However, it is not possible in most health systems to follow everyone up forever and Mr Bultitude advocated increasing discharge rates from stone clinics to primary care after an agreed time of stability, allowing more on the complex and metabolic stone formers.Figure 1- Stone follow up algorithm

The expert stone panel then debated several challenging cases including “the encrusted stent”, stones in a pelvic kidney or calyceal diverticulum. These cases certainly are a challenge and require an individualized approach usually with multi-modality treatments.

Figure 2 – Stone expert panel

Upper tract urological biopsies are notoriously inaccurate, with only 15% of standard biopsies quantifiable histologically. Low grade tumours, are potentially suitable for endoscopic management with laser ablation. Dr Alberto Breda, from the urology department of Fundacio Puigvert Hospital in Spain, presented a novel solution for the future. This promising new technology uses confocal endomicroscopy to grade upper tract urological cancer. Initial results show 90% accuracy in diagnosing low grade tumours, which could then be safely managed endoscopically avoiding nephron-ureterectomy for some patients.

 

Figure 3 – Confocal endomicroscopy for upper tract malignancy

In the final session, a debate on BPH treatment, the audience preferred the bipolar resection technique for treating “the 60 year old with retention, with a 90 gram prostate and on rivaroxaban”, although HOLEP came a close second, with that talk giving the quote of the day “I spend more time with the morcellator than the wife.”

Figure 4 – Bipolar TURP wins the day

 

Nishant Bedi

ST4 Specialist urology registrar

 

What’s the Diagnosis?

 

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Test yourself against our experts with our weekly quiz. You can type your answers here if you want to compare with our answers.

This patient presented with haematuria and was found to have stones.

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Here comes the sun

BJUI-on-the-beach

Sun, sea, sand and stones: BJUI on the beach.

Welcome to this month’s BJUI and whether you are relaxing on a sun-drenched beach or villa somewhere having a hard-earned break, or back at your hospital covering for everyone else having their time off, we hope you will enjoy another fantastic issue. After an action packed BAUS meeting with important trial results, innovation, social media and the BJUI fully to the fore, this is a great moment to update yourself on what is hot in urology. This is probably the time of year when most urologists have a little extra time to take the BJUI out of its cover or open up the iPad and dig a little deeper into the articles, and we do not think you will be disappointed with this issue, which certainly has something for everyone.

In the ‘Article of the Month’, we feature an important paper from Egypt [1] examining factors associated with effective delayed primary repair of pelvic fractures that are associated with a urethral injury. Do be careful whilst you are travelling around the world, as most of the injuries in this paper were due to road traffic accidents. They reported 76/86 successful outcomes over a 7-year period. When a range of preoperative variables was assessed, four had particular significance for successful treatment outcomes. The paper really highlights that in the current urological world of robotics, laparoscopy and endourology, in some conditions traditional open surgery with delicate and precise tissue handling and real attention to surgical detail are the key components of a successful outcome.

Whilst you are eating and drinking more than usual over the summer, we have some food for thought on surgery and metabolic syndrome with one of our ‘Articles of the Week’. This paper contains an important message for all those performing bladder outflow surgery. This paper by Gacci et al. [2] from an international group of consecutive patients clearly shows that men with a waist circumference of >102 cm had a far higher risk of persistent symptoms after TURP or open prostatectomy. This was particularly true for storage symptoms in this group of men and should influence the consenting practice of all urologists carrying out this common surgery.

Make sure you drink plenty of Drink HRW to stay well hydrated on your beach this August, as the summer months often lead to increased numbers of patients presenting to emergency departments with acute ureteric colic, so it seems timely to focus on this area.To this end I would like to highlight one of our important ‘Guideline of Guidelines’ series featuring kidney stones [3] to add to the earlier ones on prostate cancer screening [4]and prostate cancer imaging [5]. This series serve to assimilate all of the major national and international guidelines into one easily digestible format with specific reference to the strength of evidence for each recommendation. Specifically, we look at the initial evaluation, diagnostic imaging selection, symptomatic management, surgical treatment, medical therapy, and prevention of recurrence for both ureteric and renal stones. Quite how the recent surprising results of the SUSPEND (Spontaneous Urinary Stone Passage ENabled by Drugs) trial will impact on the use of medical expulsive therapy remains to be seen [6].

So whether you are sitting watching the sunset with a drink in your hand or quietly working in your home at night, please dig a little deeper into this month’s BJUI on paper, online or on tablet. It will not disappoint and might just change your future practice.

 

References

 

 

3 Ziemba JB, Matlaga BR. Guideline of guidelines: kidney stones. BJU Int 2015; 116: 1849

 

4 Loeb S. Guideline of guidelines: prostate cancer screening. BJU Int 2014; 114: 3235

 

5 Wollin DA, Makarov DV. Guideline of guidelines: prostate cancer imaging. BJU Int 2015; [Epub ahead of print]. DOI: 10.1111/bju.13104

 

 

Ben Challacombe
Associate Editor, BJUI 

 

Guideline of guidelines: kidney stones

GOG-KS

Abstract

Several professional organizations have developed evidence-based guidelines for the initial evaluation, diagnostic imaging selection, symptomatic management, surgical treatment, medical therapy, and prevention of recurrence for both ureteric and renal stones. The purpose of this article is to summarize these guidelines with reference to the strength of evidence. All guidelines endorse an initial evaluation to exclude concomitant infection, imaging with a non-contrast computed tomography scan, and consideration of medical expulsive therapy or surgical intervention depending on stone size and location. Recommends for metabolic evaluation vary by guideline, but all endorse increasing fluid intake to reduce the risk of recurrence.
GOG-KS key points
Access the full article

A beer a day keeps stones away

This month the Twitter-based International Urology Journal Club #urojc made a bold move away from cancer to discuss kidney stones. The paper entitled ‘Soda and other beverages and the Risk of Kidney Stones’ by Ferraro et al. was published online on 15th March 2013. Open access to the article was generously provided by the Clinical Journal of the American Society of Nephrology. The lead author, Pietro Manuel Ferraro, was kind enough to actively participate within the Twitter discussion.

This particular study looked at a total of 194 095 participants amalgamated from the Harvard-based Health Professionals Follow-Up Study and The Nurses Health Studies I and II. These individuals all filled in biennial questionnaires regarding their diet, general health and kidney stone pain for a median follow up period of 8 years. It is interesting that the event rate was relatively low with only 4462 cases identified, however it is important to note that the study looked only for new stone formers and persons who had previously had a kidney stone were excluded from the trial. At the outset this begs the question as to whether these results are in any way applicable to the recurrent stone former population.

 

So what did they find? The referent is the consumption of less than one drink per month, so with respect to daily consumption of one or more sugar sweetened colas there was a 23% increased risk in the incidence of renal calculi. Other beverages to show a statistically significant increased risk of stones included:

Sweetened non-cola soft drinks 33% increased risk
Artificially sweetened non-cola soft drinks 17% increased risk (p=0.05)
Punch (sugar sweetened fruit drink) 18% increased risk

 

And what decreases your risk?   % risk reduction        
Coffee 26%                 
Decaffeinated coffee 16%
Tea 11%
Red Wine 31%
White Wine 33%
Beer 41%
Orange Juice 12%          

 

Missing my poison of choice, diet cola? While there was a trend towards a decreased risk, this was not found to be statistically significant. But not an increased risk….so I may just keep drinking it for the time being. I am not alone.


There were certainly more than one of the so called Urological ‘Twitterati’ who seemed delighted that the study findings justified their habits:

   

There are undoubtedly limitations with any cohort questionnaire analysis. The authors have acknowledged that while they tried to control and adjust for variables including age, BMI, diabetes, race, BP and dietary intake, there are variables that simply cannot be accounted for on the basis of a simple questionnaire. Fructose, for example, is purported to be a potential contributor to the increased risk of stones by increasing calcium, oxalate and uric acid excretion. There are many other dietary sources of fructose, including fruits, cereals and processed foods and sauces that are not accounted for and are potential confounders. Along the same lines, coffee is a relatively broad category of beverage. When one compares an espresso with a teaspoon of sugar to a Starbucks Frappuccino the difference in sucrose, and thus fructose, content is extraordinary. The caffeine content of these beverages, while purported to decrease the risk of stones through diuresis, is variable and thus also a potential confounder.

Manuel Ferraro importantly acknowledged that the study observed ‘associations, not causal effects’. Harder evidence such as 24 hour urines, stone analysis and imaging data would be useful to draw more significant conclusions as to causality.
 

The population studied was also somewhat limited. As mentioned by Jason Lee, Henry Woo and Matt Bultitude the study included male health professionals and female nurses, who were generally white, an older population with a relatively low BMI and potentially prone to dehydration. There was also limited control of comorbidities.

As suggested by Christopher Bayne, the only evidence as yet in randomized controlled trials is that water consumption as reflective of hydration status and urinary volume is the only substance known to reduce the risk of stone formation.
 

An astute observation by one of my fellow Australian trainees Janice Cheng noted the relatively dehydrated status of the study subjects.


This won the best Tweet prize, kindly donated by European Urology @EUplatinum.

Increased water intake has been reviewed on the Cochrane Database in 2012, however the consensus drawn was that there is currently insufficient evidence that increased water intake specifically, as opposed to other fluids, prevents the formation of urinary calculi.

So what conclusions should we draw? A patient with his first presentation kidney stone actually asked me yesterday whether he could keep drinking his favourite drink….beer. I simply replied that there was no current evidence that this would increase his risk of stones, however that moderation was key. We must remember that many of these calorific drinks have significant impact on comorbidities outside of the world of kidney stones. #a(lotof)wateradaykeepstheurologistaway

The overall participation in #urojc continues at a solid rate, with 39 participants and 178 total tweets over the 48 hour period. The next #urojc will be on the first Sunday or Monday of July (depending on your time zone).

   

Dr Helen Nicholson is an Australian Urology Trainee, currently based at The Sydney Adventist Hospital, NSW. Tweeted initially under duress, now a voluntary convert @DrHLN

 

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