Sacral Root Rhizotomy

1. Concept

  • Neurogenic detrusor overactivity develops because of the lack of suprasacral inhibitory efferent on the pathologic autoexcitatory sacral reflex arcs. For more information, please refer to this
  • Interruption of reflex arcs to denervate the bladder from its afferent and/or efferent pathways may restore bladder storage function.
  • The most representative procedure among many types of denervation procedure for SCI/D is sacral root rhizotomy of S25.
    • Sacral rhizotomy:
      • Converts bladder from hyperreflexic to areflexic
      • Adversely affects anal and urethral sphincters, sexual function, and the lower extremities.
    • Selective sacral rhizotomy
      • In an aim to leave sphincter and sexual function intact
      • Selection of S3 with cystometric and sphincterometric control

2. History

  • In late 1940s to early 1950s, Munro reported an improvement in the overactivity of the spastic paraplegic bladder after extensive anterior rhizotomy [Munro D. Anterior rhizotomy for spastic paraplegia. NEJM 1945;233:453-61]
  • During the early 1950s, much of the denervation surgery was performed.
  • Subsequent clinical results with this technique had been unreliable [Toczek 1975; Lucas 1988], it was not generally accepted into clinical practice.
  • Three major changes have occurred since 1980s in the management of the patients with an overactive detrusor. These have altered the whole pattern of surgery for the overactive bladder [Lucas 1988 ].
  • In 1984, McGuire and Savastano mentioned dorsal root ganglionectomy in patients to increase bladder capacity [McGuire 1984]
  • In late 1980s, both Tanagho and Schmidt [Tanagho 1988] and Brindley [Brindley 1990] conceptualized sensory deafferentation using posterior rhizotomy for the electrical stimulation to alleviate emptying failure.
  • Today, posterior sacral rhizotomies are performed combined with the implantation of an anterior sacral root neurostimulator to achieve micturition. [Sauerwein 1990; Kerrebroeck 1996; Schurch 1997; Egon 1998]
  • Most of the denervation procedures were popular with promising early results for some time but have been gradually abandoned with the poor long-term outcome. Surgical treatment for selective posterior rhizotomy is still performed.

3. Terminology

  • Denervation: extended meaning at any level of nervous pathway involving the urinary bladder  
  • Deafferentiation: when the procedure involves anterior roots

4. Other Types of Denervation Procedure

  • Peripheral or perivesical denervation:
    • Bladder transection
      • open, or endoscopic surgery
      • transvesical phenolization (by injecting substances toxic to nerves)
    • Hyperbaric bladder distension
    • Perivesical denervation of the bladder
  • Transvaginal partial denervation of the bladder (Ingelman-Sundberg procedure)
  • In 1959, originally described by Ingelman-Sundberg [Ingelman-Sundberg 1959].
  • McGuire group modified the technique [Cespedes 1996].
  • Used mostly for the treatment of refractory urge incontinence
  • 2 steps of procedure: Preliminary step of transvaginal local anesthesia and second step of surgical denervation procedure
  • Complete durable resolution of 54% in urge incontinence [Westney 2002]
  • Central denervation: subarachnoid block
      • lack of selectivity
      • causing unintended motor or sensory loss other than related to the bladder.
      • causes decreased compliance, resulting in significant storage problems.

4. Purpose of the Procedure

  • Anterior sacral root rhizotomy:
    • To increase bladder capacity
    • To decrease unstable contractions
    • * No significant change in sphincter activity with voiding
  • Posterior rhizotomy:
    • to eliminate all reflex activities of the detrusor
    • to reduce hyperreflexia of the bladder (increasing bladder capacity and compliance),
    • to eliminate active DSD (which improves urine flow),
    • to reduce reflex incontinence (which protects upper urinary tracts from uteric reflux and hydronephrosis).

5. Indication

  • Refractory detrusor overactivity + DSD

6. Procedure [Madersbacher 2000]

  • Insertion of a suprapubic cystostomy and transurethral placement of an 8F catheter for cystometry.
  • Positioning in prone
  • General anesthesia is used without long-acting muscle relaxants.
  • A laminectomy from L4-5 to S1-2 for the access to the ventral and dorsal sacral roots of the S2-S4-5 segments (bilateral, anterior, posterior). 
  • Intraoperative localization of the ventral sacral roots by intraoperative electrostimulation: eliciting the most significant detrusor contraction (usually S3)
  • The dorsal roots are divided and 2 to 3 mm of their length resected.
  • Closure of the dura and wound closure
  • Other technical considerations:
    • Posterior sacral rhizotomy for sacral deafferentation of the bladder is best achieved by the intradural approach [Madersbacher 2000].
    • Partial or selective procedures are considered only in such patients who retain some sensation or have excellent reflex erections.

7. Clinical Outcomes

Authors (Year)




Koldewijn EL, Van Kerrebroeck PE, Rosier PF, Wijkstra H, Debruyne FM. [J Urol 1994]


27 patients with complete suprasacral SCI in whom intradural posterior sacral root rhizotomies from S2 to S5 in combination with implantation of an intradural Finetech-Brindley bladder stimulator

All patients initially presented with detrusor hyperreflexia.

A majority of these patients had a decreased bladder compliance 5 days postoperatively followed by a rapid increase in bladder compliance thereafter.

All patients showed persistent detrusor areflexia after long-term followup.

Low bladder compliance in 2 patients with incomplete posterior sacral rhizotomies

Intradural rhizotomies of all posterior sacral root components from S2 to S5 in combination with implantation of an anterior sacral root stimulator is a safe and effective procedure in SCI patients.

Gasparini ME, Schmidt RA, Tanagho EA. [J Urol. 1992]

24 patients with cervical or thoracic SCI and a severe reflex neuropathic bladder

selective dorsal sacral rhizotomy with the aid of intraoperative neurostimulation and urodynamic monitoring.

mean 32 months followup

Mean bladder capacity increased significantly after rhizotomy (from 148 to 377ml)

mean volume to first contraction (from 99 to 270ml).

No significant changes in bowel or erectile function

Continence was improved in 94%

The long-term results of selective sacral rhizotomy compare favorably to more aggressive alternatives, such as augmentation cystoplasty or urinary diversion.

Hohenfellner M, Pannek J, Botel U, Dahms S, Pfitzenmaier J, Fichtner J, Hutschenreiter G, Thuroff JW. [Urology 2001] 

9 patients (8 men and 1 woman) between 21 and 58 years old (mean 30.2) with traumatic suprasacral SCI
sacral bladder denervation


Detrusor hyperreflexia and autonomic dysreflexia were eliminated in all cases.

Bladder capacity increased from 177.8 to 668.9mL;

intravesical pressure decreased from 89.3 to 20.2cm H(2)O.

4 patients received a continent vesicostomy in a second-stage procedure

blood pressure lowered from mean 196/114 to 124/76 mm Hg

annual frequency of UTI decreased from 9 to 1.8

In all patients, renal function remained stable.

Sacral rhizotomy as a stand-alone procedure is a valid treatment option for lower urinary tract hyperreflexia and AD.

is an attractive alternative to urinary diversion using intestinal segments.

Madersbacher H [BJU Int. 2000]

posterior sacral rhizotomy for sacral deafferentation of the bladder by the intradural approach

Treated 65 tetraplegic or paraplegic patients with post-SCI reflex urinary incontinence, resistant to all other means of conservative treatment.

Incontinence was abolished in 90% of these patients.


8. Advantages

  • Effects in SCI/D
    • abolishing reflex incontinence [Brindley 1994]
    • reducing detrusor hyperreflexia (increasing bladder capacity and compliance) [Brindley 1994]
    • abolishing DSD without altering resting tone (which improves urinary flow) [Brindley 1994]
  • compared with urinary diversion
    • lower perioperative and postoperative risks
    • the lower long-term morbidity
    • moderately invasive
    • requires neither sophisticated nor expensive medical equipment
    • areflexic bladder is emptied by way of clean intermittent catheterization.

9. Disadvantages

  • Neuroplasticity often results in restoration of neural function, but sometimes with an even less desirable result than was present originally [Madersbacher 2000].
  • It abolishes reflex erection, reflex ejaculation, and reflex defecation [Popovic 2002].
  • Is destructive and irreversible: This point becomes an increasingly important factor as the prospects for spinal cord regeneration improve [Popovic 2002].
  • It may also cause sphincter and pelvic floor weakness, and in a minority of patients, stress incontinence [Barat 1993].

10. Current Significance

  • Sacral de-afferentiation of the bladder by dorsal sacral root rhizotomy of S2-S5 has proved to be an effective procedure for selected patients with SCI and detrusor hyperreflexia, functional low compliance and reflex incontinence, which are refractory to any other means of conservative therapy [Madersbacher 2000].
  • Sacral posterior root rhizotomy is able to abolish detrusor hyperreflexia and therefore recommended for tetra- and paraplegics, however autonomic dysreflexia, if present, can not be totally abolished [Madersbacher 1999]. 

Key Points of This Section

  • These techniques do work but late failures do occur.
  • Neural transaction is not an ideal method.
  • Neural plasticity can obviate the early good results.


  • Barat M, Egon G, Daverat P, Colombel P, Guerin J. Why does continence fail after sacral anterior root stimulator? Neurourol Urodyn. 1993;12(5):507-8. 
  • Brindley GS, Rushton DN. Long-term follow-up of patients with sacral anterior root stimulator implants. Paraplegia. 1990 Oct;28(8):469-75.
  • Brindley GS. The first 500 patients with sacral anterior root stimulator implants: general description. Paraplegia. 1994 Dec;32(12):795-805.
  • Cespedes RD, Cross CA, McGuire EJ. Modified Ingelman-Sundberg bladder denervation procedure for intractable urge incontinence. J Urol. 1996 Nov;156(5):1744-7.
  • Egon G, Barat M, Colombel P, Visentin C, Isambert JL, Guerin J. Implantation of anterior sacral root stimulators combined with posterior sacral rhizotomy in spinal injury patients. World J Urol. 1998;16(5):342-9.
  • Gasparini ME, Schmidt RA, Tanagho EA. Selective sacral rhizotomy in the management of the reflex neuropathic bladder: a report on 17 patients with long-term followup. J Urol. 1992 Oct;148(4):1207-10. 
  • Hohenfellner M, Pannek J, Botel U, Dahms S, Pfitzenmaier J, Fichtner J, Hutschenreiter G, Thuroff JW. Sacral bladder denervation for treatment of detrusor hyperreflexia and autonomic dysreflexia. Urology. 2001 Jul;58(1):28-32. 
  • Ingelman-Sundberg A. Partial denervation of the bladder, A new operation for the treatment of urge incontinence and similar conditions in women. Acta Obstet Gynecol Scand. 1959;38:487-502.
  • Koldewijn EL, Van Kerrebroeck PE, Rosier PF, Wijkstra H, Debruyne FM. Bladder compliance after posterior sacral root rhizotomies and anterior sacral root stimulation. J Urol. 1994 Apr;151(4):955-60.
  • Lucas MG, Thomas DG, Clarke S, Forster DM. Long-term follow-up of selective sacral neurectomy. Br J Urol. 1988 Mar;61(3):218-20.
  • Madersbacher HG. Neurogenic bladder dysfunction. Curr Opin Urol. 1999 Jul;9(4):303-7. 
  • Madersbacher H. Denervation techniques. BJU Int. 2000 May;85 Suppl 3:1-6.
  • McGuire EJ, Savastano JA. Urodynamic findings and clinical status following vesical denervation procedures for control of incontinence. J Urol. 1984 Jul;132(1):87-8.
  • Munro D. Anterior rhizotomy for spastic paraplegia. NEJM 1945;233:453-61.
  • Popovic MR. Sacral root stimulation. Spinal Cord. 2002 Sep;40(9):431.
  • Sauerwein D. urgical treatment of spastic bladder paralysis in paraplegic patients. Sacral deafferentation with implantation of a sacral anterior root stimulator. Urologe A. 1990 Jul;29(4):196-203.
  • Schurch B, Rodic B, Jeanmonod D. Posterior sacral rhizotomy and intradural anterior sacral root stimulation for treatment of the spastic bladder in spinal cord injured patients. J Urol. 1997 Feb;157(2):610-4.
  • Tanagho EA, Schmidt RA. Electrical stimulation in the clinical management of the neurogenic bladder. J Urol. 1988 Dec;140(6):1331-9.
  • Toczek SK, McCullough DC, Gargour GW, Kachman R, Baker R, Luessenhop AJ. Selective sacral rootlet rhizotomy for hypertonic neurogenic bladder.J Neurosurg. 1975 May;42(5):567-74.
  • Van Kerrebroeck PE, Koldewijn EL, Rosier PF, Wijkstra H, Debruyne FM. Results of the treatment of neurogenic bladder dysfunction in spinal cord injury by sacral posterior root rhizotomy and anterior sacral root stimulation. J Urol. 1996 Apr;155(4):1378-81.
  • Westney OL, Lee JT, McGuire EJ, Palmer JL, Cespedes RD, Amundsen CL. Long-term results of Ingelman-Sundberg denervation procedure for urge incontinence refractory to medical therapy. J Urol. 2002 Sep;168(3):1044-7.

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