Category: Clinical Stones: PCNL

MP7-16 - Supine percutaneous nephrolithotomy in the obese patient

Fri, Sep 21
10:00 AM - 12:00 PM

Introduction & Objective :

Obese patients present a challenge in prone percutaneous nephrolithotomy (PCNL). Supine PCNL (sPCNL) has been shown to have similar stone free rates without increased complications to traditional prone methods. Supine positioning decreases anaesthetic risk for those with high BMI.


Methods :

We describe a series of 111 patients with BMI >30 undergoing sPCNL from 2007-2016 at a single tertiary referral centre for complex nephrolithiasis. Data were collected prospectively and entered in a pre-designed anonymised database.


The cohort comprised 62 male and 49 female patients, median age 60(21-90), median BMI 34(30-70).


Results :

Median operative time was 70 minutes (20-120). 23 staghorns were treated; otherwise, median maximal stone diameter was 18mm (7-41). Median stone density was 964HU (300-1672).


Three cases required multiple access tracts. Single puncture sites: 64 lower pole, 26 interpolar, 17 upper pole.


85 patients (77%) were rendered stone free (residual fragments <2mm on CT 3 months postoperatively). Three cases with residual stone had been planned as staged procedures due to stone burden or position. Seven cases experienced failed access.


Complications were graded according to Clavien-Dindo. 9 Grade II, 2 Grade IIIa, 2 Grade IIIb and 1 Grade IVa were encountered. These included one pseudoaneurym requiring embolization and six cases of UTI/sepsis. No visceral injuries were encountered. Median hospital stay was 3(1-16) days.


Conclusions :

sPCNL promises major advantages in the obese patient. Anaesthesia and positioning are made easier, reducing total operative time.  Stone clearance and complication rates are comparable to national and international standards.

John Withington

Urology Registrar
Royal Free Hospital NHS Trust
London, England, United Kingdom

Masood Moghul

Urology Registrar
Royal Free Hospital NHS Trust
st albans, England, United Kingdom

Masood Moghul MRCS, PgDip, MBBS, BSc (Hons.), AKC
Urology SpR, London

Darrell Allen

Consultant Urologist
Royal Free Hospital NHS Trust
London, England, United Kingdom

Leye Ajayi

Consultant Urologist
Royal Free Hospital NHS Trust
London, England, United Kingdom