Consultant Urological Surgeon
Mr Raison is a prominent consultant urological surgeon at King's College Hospital and a tenured associate professor at King's College London. He is widely recognised for his expertise in benign bladder dysfunction including benign prostate enlargement, overactive bladder syndrome and urinary incontinence and has a subspecialist interest in recurrent urinary tract infection and chronic pelvic, groin and bladder pain
Professional Profile
Mr Raison trained at Imperial College School of Medicine before undertaking specialist urology training in the prestigious London deanery and a dedicated fellowship at Guy's Hospital. He subsequently completed a PhD at King’s College London, earning nomination for the outstanding thesis prize, and holds advanced postgraduate qualifications in medical education with fellowship of the Higher Education Academy.
At the forefront of contemporary surgical research, Mr Raison leads work in data-driven innovation and AI, integrating machine learning with advanced simulation to improve intraoperative guidance, surgical decision-making and predictive modelling. He is chief investigator for several major studies, including a first-in-human trial of intratumoural interleukin-15 for advanced prostate cancer, AI-based prediction of robotic surgical performance, and research into the heritability of overactive bladder syndrome within the TwinsUK biobank. He also serves as the National Institute for Health and Care Research (NIHR) Lead for Surgical Research in South London, promoting regional collaboration and trial development.
Alongside his academic leadership, Mr Raison plays an active role in postgraduate surgical education and simulation training, leading non-technical skills programmes for the European Association of Urology and simulation-based training across the London deanery.
Areas of Clinical Expertise
Mr Gnanappiragasam provides comprehensive care for conditions affecting the kidneys, bladder, prostate, and male genitalia, including:
Benign bladder dysfunction
Non-cancerous conditions affecting how the bladder stores or releases urine, leading to symptoms like urgency, frequency, or poor control.
Benign prostate enlargement (BPH)
Age-related enlargement of the prostate that presses on the urethra, causing weak flow, difficulty starting urination, and frequent trips to the bathroom.
Overactive bladder syndrome
A condition where the bladder contracts too often, creating a sudden, urgent need to urinate, sometimes with leakage.
Urinary incontinence
Loss of bladder control resulting in accidental urine leakage, ranging from occasional drips to more frequent or complete loss of control.
Procedures & Treatments
Kidney & Bladder Stones
Robotic intrarenal stone surgery (RIRS)
Ureteroscopy (for stones and cancer diagnosis)
Percutaneous Nephrolithotomy (PCNL)
Extra corporal shockwave lithotripsy (ESWL)
Bladder stone removal (Laser Endoscopic litholapaxy / Percutaneous cystolithotomy)
Prostate & Bladder Care
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Enlargement (BPH): HoLEP, Rezum, Aquablation, Urolift, Green Light Laser, TURP, and iTIND.
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Cancer Diagnosis: PSA testing, MRI Fusion Transperineal Prostate Biopsy, and TURBT (Bladder).
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Incontinence: Bladder Botox, Autologous Fascial Sling, PTNS, and Urethral Bulking.
Advanced Urological Reconstruction
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Ureteric Stricture: Balloon dilatation and specialized stenting (Resonance, Memokath, Hilzo, Allium).
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Urethral Stricture: Optical urethrectomy and dilatation.
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Scrotal & Penile Surgery: Circumcision, Vasectomy (and Reversal), Varicocele repair, and Orchidectomy.
Practice Locations
King’s College Hospital NHS Foundation Trust
Denmark Hill, London SE5 9RS
