Condition category
Urological and Genital Diseases
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status
Results overdue

Plain English Summary

Background and study aims
Waste products in the blood can occasionally form crystals that collect inside the kidneys.Over time, the crystals may build up to form a hard stone-like lump. Kidney stones are usually found in the kidneys or in the ureter, the tube that connects the kidneys to your bladder. They can be extremely painful, and can lead to kidney infections or the kidney not working properly if left untreated.
The aim of this study is to compare kidney stone laser treatment via miniaturised telescopes through the back versus telescopes via the urinary tract in an Indian population.
Who can participate?
Patients aged 16 years and above with 10 – 30 mm kidney stone(s).

What does the study involve?
Participants will be randomly allocated to receive ultra-mini percutaneous nephrolithotomy (UMP) or Retrograde Internal Surgery (RIRS) for the removal of kidney stones. Participants will be followed-up at one month.

What are the possible benefits and risks of participating?
The benefits of the mini key hole operation was to avoid the need for a second procedure to remove the stent which is needed for the surgical treatment of the kidney stones via the telescope into the urinary tract from below. The other advantages were the ability to remove the maximum stone burden with a single procedure and which is not uncommon with the operation through the urinary tract from below. This operation is less invasive than the standard operation which involves a bigger size of the telescope. The risks were more or less similar in either of the procedure are blood in the urine and urine infection and which extremely rarely can be serious. The risks of the residual stone following the procedures is another factor to consider in either of them.

Where is the study run from?
Samved Hospital (India)

When is the study starting and how long is it expected to run for?
December 2013 to December 2015

Who is funding the study?
Samved Hospital (India)

Who is the main contact?
Ramandeep Chalokia,
Soumendra Nath Datta,
Dr Janak Desai,

Trial website

Contact information



Primary contact

Mr Ramandeep Chalokia


Contact details

5 Duddon Close
CH43 2GL
United Kingdom
+44 (0)7999344144



Additional contact

Mr Soumendra Nath Datta


Contact details

19 Glen Avenue
C03 3SD
United Kingdom
+44 (0)7976971601



Additional contact

Dr Janak Desai


Contact details

Samved Hospital Urology Division
Near Stadium Circle
+91 7926431616

Additional identifiers

EudraCT number

Nil known number

Nil known

Protocol/serial number


Study information

Scientific title

Ultra mini-percutaneous nephrolithotomy versus retrograde intrarenal surgery in the treatment of 10-30 mm calculi: A randomised controlled trial


Study hypothesis

The aims are to investigate the efficacy, cost and safety of ultra mini-percutaneous nephrolithotomy (UMP) versus retrograde intrarenal surgery (RIRS) in renal calculi between 10 - 30mm

Ethics approval

Approved 01/07/2014, Ethics Committee Samved Hospital (2nd Floor Samved Hospital, Near Stadium Circle, Ahmedabad, Gujarat, India, 380009; +91 (0)7926431616;, ref: n/a

Study design

Interventional randomized controlled trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet


Renal calculi


The patients will be randomised using block randomisation software into either the UMP or RIRS group with a ratio of 2:1. Block randomisation design will be used to reduce bias and achieve balance. Block sizes of 6 will be used. The patients will be informed of the procedure after randomisation.

The duration of surgery will be measured (from the visualisation of the stone) and any equipment used during the procedure will be noted to calculate the total cost of the intervention. The requirement and duration of a nephrostomy, DJ stent, and indwelling urinary catheter will be recorded. At the end of each procedure, it will be essential to record the number of patients that will be stone free or had any residual fragments present. Patients will be identified as being stone-free if no identifiable stones can be verified on direct visualization/fluoroscopic. Residual fragments will be defined as those >4 mm.

Deterioration in renal function and bleeding will be assessed by comparing pre-operative haemoglobin (Hb) and creatinine levels with those on the first postoperative day. The need and duration of post-operative opioid Intramuscular/Intravenous analgesia will be recorded, and patients with prolonged pain will be identified. Prolonged pain will be defined as greater than two days in duration requiring anti-spasmodic medication. Post-operative complications will be recognised and classified as per the Clavien-Dindo grading system. The length of hospital stay for each patient and the number of patients that will be required to return (e.g. stent removal) will be recorded. Following discharge, patients will be invited back in one month for a follow-up low dose NCCT scan to identify the presence of residual fragments. Residual fragments will be defined as any calcification ≥ 4 mm present on the NCCT in the kidneys, ureters or bladder.

Intervention type



Drug names

Primary outcome measure

Presence of residual fragments at one month after surgery measured using fluoroscopy

Secondary outcome measures

1. Duration of surgery (minutes) measured using a clock
2. Stone size before surgery measured using fluoroscopy
3. Stent requirement during surgery (yes or no) and duration of stent dwelling measured at one month follow up appointment
4. Nephrostomy requirement and duration
5. Cost of procedure measured using duration and equipment used at the time of surgery
6. Blood Hb and creatinine measured using blood test at baseline and one day post-operatively
7. Duration of hospital stay (hours)
8. Complications and adverse events measured using the Clavien-Dindo Classification of Surgical Complications
9. Presence of haematuria measured by urine analysis during hospital stay

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Age > 16 years
2. 10 - 30mm renal calculi of any position with no history of bleeding diathesis

Participant type


Age group




Target number of participants


Total final enrolment


Participant exclusion criteria

1. Abnormal renal or musculoskeletal anatomy
2. Receiving anticoagulants
3. High anaesthetic risk

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

Samved Hospital
Near Stadium Circle Navrangpura

Sponsor information


Samved Hospital

Sponsor details

Near Stadium Circle
+91 7926420285

Sponsor type

Hospital/treatment centre



Funder type

Hospital/treatment centre

Funder name

Samved Hospital

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

European Urology or another reputed journal.

IPD sharing statement:
The datasets generated during and/or analysed during the current study are available upon request from Dr Janak Desai
The data will be available after peer review publication for meta-analysis. Data will be anonymized. There was no specific patient consent for disclosure of data for metanalysis.

Intention to publish date


Participant level data

Available on request

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes

12/05/2020: Trial’s existence confirmed by Ethics Committee Samved Hospital