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Percutaneous radiofrequency sacral rhizotomy in the treatment of neurogenic detrusor overactivity in spinal cord injured patients
Actas Urol Esp. 2011;35(6):325---330
Actas Urológicas Españolas www.elsevier.es/actasuro
ORIGINAL ARTICLE
Percutaneous radiofrequency sacral rhizotomy in the treatment of neurogenic detrusor overactivity in spinal cord injured patients夽 R.S. Ferreira a,b , C.A. Levi d’Ancona c , V.P. Dantas-Filho c , N. Rodrigues Netto Jr. c , R. Miyaoka c,∗ a
Departamento de Urología, Hospital General de Goiânia, Goiânia, GO, Brazil Departamento de Urología, CRER, Centro de Rehabilitación, Goiânia, GO, Brazil c Departamento de Urología, Universidad Estatal de Campinas, UNICAMP, Campinas, SP, Brazil b
Received 15 November 2010; accepted 11 December 2010 Available online 13 October 2011
KEYWORDS Neurogenic bladder; Spinal cord injury; Urodynamics; Sacral rhizotomy; Urinary incontinence; Neurogenic detrusor overactivity; Radiofrequency
Abstract Introduction: To evaluate the effects of percutaneous radiofrequency sacral rhizotomy in spinal cord injured (SCI) patients on urodynamic parameters (maximum cystometric capacity (MCC) and detrusor pressure at maximum cystometric capacity (PdetMCC)). Materials and methods: This prospective study assessed eight patients with SCI (four men and four women) with a mean age of 31.3 years (22---41). Mean interval period between spinal cord lesion and rhizotomy was 53.5 months (20---96). All patients underwent an anesthetic block of the 3rd sacral root bilaterally using 0.5% bupivacaine under fluoroscopic control. Those who responded with an increase on bladder capacity were selected to undergo the percutaneous radiofrequency sacral rhizotomy. All patients underwent urodynamic evaluation at 6 and 12 months following the procedure. MCC and Pdet MCC were recorded. Results: All patients presented a significant improvement on MCC after 12 months. The mean vesical volume increased from 100.2 ± 57.1 to 282.9 ± 133.4 ml (p < 0.05). The Pdet MCC reduced from 82.4 ± 31.7 to 69.9 ± 28.7 cm H2 O (p = 0.2). Three patients with autonomic dysreflexia had complete relief of symptoms after the procedure. At 12 months, recurrence of detrusor hyperactivity was observed in all patients. One patient presented abolishment of reflex erections after the procedure. No major complications related to the rhizotomy were noted. Conclusions: Percutaneous radiofrequency sacral rhizotomy is a minimally invasive technique with low morbidity able to increase MCC. There is a trend towards the reduction of the Pdet MCC in SCI patients at 12 months, although statistical significance was not reached. © 2010 AEU. Published by Elsevier España, S.L. All rights reserved.
夽
Please cite this article as: Ferreira RS, et al. Rizotomía sacra percutánea por radiofrecuencia en el tratamiento de la hiperactividad del detrusor neurogénico en pacientes con lesiones de la médula espinal. Actas Urol Esp. 2011;35:325---30. ∗ Corresponding author. E-mail address: [email protected] (R. Miyaoka). 2173-5786/$ – see front matter © 2010 AEU. Published by Elsevier España, S.L. All rights reserved.
326
PALABRAS CLAVE Vejiga neurógena; Lesión de la médula espinal; Urodinámica; Rizotomía sacral; Incontinencia urinaria; Hiperactividad neutrogénica del detrusor; Radiofrecuencia
R.S. Ferreira et al.
Rizotomía sacra percutánea por radiofrecuencia en el tratamiento de la hiperactividad del detrusor neurogénico en pacientes con lesiones de la médula espinal Resumen Objetivo: Evaluar los efectos de la rizotomía sacral percutánea por radiofrecuencia en pacientes con lesión de la médula espinal sobre parámetros urodinámicos (capacidad cistométrica máxima [CCM] y presión del detrusor a capacidad cistométrica máxima [PdetCCM]). Material y Métodos: En este estudio prospectivo se evaluó a 8 pacientes con LME (4 hombres y 4 mujeres) con una media de edad de 31,3 a˜ nos (de 22 a 41). El intervalo medio entre la lesión de la médula espinal y la rizotomía fue de 53,5 meses (entre 20 y 96). A todos los pacientes se les practicó un bloqueo anestésico bajo control fluoroscópico de la tercera raíz sacral de forma bilateral con bupivacaína 0,5%. Se eligió para rizotomía sacral percutánea por radiofrecuencia a los que respondieron con un aumento en la capacidad vesical. Se procedió a la evaluación urodinámica de todos los pacientes a los 6 y los 12 meses tras la realización del procedimiento. Se consignaron tanto la CCM como la Pdet CCM. Resultados: Todos los pacientes mostraron una mejora significativa en la CCM a los 12 meses. El volumen vesical medio aumentó de los 100,2 ± 57,1 a 282,9 ± 133,4 ml (p < 0,05). La Pdet CCM se redujo de 82,4 ± 31,7 a 69,9 ± 28,7 cm H2 O (p = 0,2). Tres pacientes con disreflexia autonómica experimentaron un alivio total de los síntomas tras el procedimiento. A los 12 meses se observó una reaparición de la hiperactividad del detrusor en todos los pacientes. Un paciente presentó abolición de las erecciones reflejas tras el procedimiento. No se observaron complicaciones de importancia en relación con la rizotomía. Conclusiones: La rizotomía sacral percutánea por radiofrecuencia es una técnica mínimamente invasiva, de baja morbilidad, que puede aumentar la CCM. Existe una tendencia hacia la reducción de la Pdet CCM en pacientes con LME a los 12 meses, a pesar de que no se alcanza un nivel estadísticamente significativo. © 2010 AEU. Publicado por Elsevier España, S.L. Todos los derechos reservados.
Introduction Spinal cord injury (SCI) may impair normal function of the urinary bladder and give rise to neurogenic detrusor hyperactivity (NDH). Urinary incontinence is an important aspect of bladder management in individuals with SCI and represents a most unpleasant complication which may severely impact their social relationships and quality of life.1 The management of lower urinary tract in patients with SCI aims to achieve adequate bladder emptying, maintenance of low intravesical pressures whilst storing proper volume and control of urinary incontinence.2 Treatment options for NDH can be didactically divided into two groups: therapy to facilitate bladder filling or urine storage, and therapy to facilitate bladder emptying.3 A combination of clean intermittent catheterization (CIC) and anticholinergic medication is the first-line treatment for NDH secondary to SCI4 and should be fully optimized before considering any surgical intervention. However, in patients who do not respond to clinical treatment or present intolerable side effects, surgical options become necessary. The ‘‘gold standard’’ surgical approach for treating patients with poor compliance high-pressure bladder includes augmentation cystoplasty and detrusor myomectomy.5,6 Initially presented in the 1950s by Meirowsky et al.,7 sacral rhizotomy lost popularity due to its frequent associated complications --- impotence, urethral and rectal sphincteric dysfunction and lower extremity atrophy.8 However, recent reports have demonstrated that in specific
patient cohorts, selective rhizotomies associated or not with anterior sacral root stimulation, may increase bladder capacity and continence can be improved.9,10 The S3 root seems to be the most important trigger point in subserving bladder control. Root blockade at S4 increases resting sphincter tonus in the urethra. This suggests that it carries an inhibitory nerve supply to the urethral smooth muscle.11 Additionally, in 1978, percutaneous radiofrequency sacral rhizotomy was described in seven patients in order to facilitate intermittent clean catheterization.12 We assessed the effects of percutaneous radiofrequency sacral rhizotomy on urodynamic parameters such as maximum cystometric capacity (MCC) and detrusor pressure at the maximum cystometric capacity (Pdet MCC) in spinal cord injured patients.
Materials and methods Eight patients were selected from our Uroneurology Clinic between July 2003 and December 2004. All subjects underwent complete urological and physical evaluations. Complementary assessment included blood urea nitrogen and creatinine, urine culture, cystogram and urinary tract sonography. Urodynamics were performed according to the recommendations by the International Continence Society (ICS).13 Urodynamic parameters maximum cystometric capacity (MCC) and detrusor pressure at the maximum cystometric capacity (Pdet MCC) were compared before and
Percutaneous Radiofrequency Sacral Rhizotomy in the Treatment of Neurogenic Detrusor Overactivity
Figure 1
327
(A and B) S3 foramen localization.
after treatment. In patients with impaired sensation, MCC was defined as the volume at which urinary leakage was observed.7 This study was approved by our Institutional Ethics Committee for Research in Humans and signed by the patients. The inclusion criterion for percutaneous radiofrequency sacral rhizotomy was an increase in bladder capacity above 100% over the baseline value recorded after an anesthetic sacral blockade. Exclusion criteria included patients who did not accept the proposed treatment or could not perform CIC. The S3 foramen was bilaterally located at the level of the inferior border of the sacroiliac joint. With the patient in prone position and under fluoroscopic guidance a 22 gauge raquianesthesia needle was inserted on the skin surface as a radiopaque marker to orient lining up of the lumbar vertebral spinous processes for accurate localization of the midline. A second line was drawn to connect the most inferior border of the sacroiliac joints, again using the needle as a radiopaque marker. These two landmarks (spinous processes and inferior border of sacroiliac joints) are reliably and clearly visualized under fluoroscopy in every patient regardless of the patient’s weight. The S3 foramen is found just lateral and superior to the intersection of these two imaginary lines (Fig. 1A and B). Because of the angled aspect of the S3 foramen, the needle must be inserted into the skin 1---4 cm above the anticipated location of the S3 foramen, depending on the size of the individual (thickness of the soft tissue above the sacral periosteum).11 Three milliliters of 0.5% bupivacaine chloride were injected into the sacral foramen under fluoroscopic control. Thirty minutes later, a urodynamic study was performed and the effect on MCC and Pdet MCC was recorded. Percutaneous radiofrequency sacral rhizotomy was performed one week after anesthetic blockade. The equipment consisted of a Radiofrequency Lesion Generator (MRFG-01B, MICROMAR, São Paulo, Brazil) (Fig. 2) and a 22G electrode with a 5-mm tip exposure (Fig. 3). Patients were sedated and the procedure began with the percutaneous puncture of the 3rd sacral foramen bilaterally according to the technique previously described. The bilateral S3 sacral root was initially identified through a stimulating pulse of 1.0 ms, 30 Hz and 0.1 V. The voltage was
progressively increased by 0.1 V until detrusor contraction could be registered on urodynamics during the procedure or external signs of S3 stimulation could be seen (such as plantar flexion of the great toe and/or anal sphincteric contraction).12 Thermocoagulation was confirmed by assertion of electric current and comparison of tissue impedance before and after the procedure. The thermolesion was performed for 15 s, after which the electrode was progressively withdrawn 5 mm. The procedure was repeated 3 times in each side. All patients were evaluated at 1, 6 and 12 months following the rhizotomy, and urodynamic parameters were recorded at each visit. Paired Student’s t-test was used for statistical analysis. A significance level of p < 0.05 was considered.
Results Eight SCI patients (4 men, 4 women) with a mean age of 31.3 (22---41) years were initially included in this study (Table 1). The mean interval period between the event of the spinal cord lesion and the date of procedure was 53.5 (20---96) months. Urodynamic parameters of patients who underwent sacral anesthetic block are shown in Table 2. The patients presented a significant increase in MCC from 99.2 ± 57.9 ml to 330.5 ± 139.3 ml (mean ± SD), p < 0.05. Pdet MCC significantly reduced from 90.0 ± 25.0 cm H2 O to 46.0 ± 21.1 cm H2 O (p < 0.05). Urodynamic parameters of patients who underwent percutaneous radiofrequency rhizotomy are shown in Table 3. Twelve months after the procedure patients presented a sustainable significant increase in MCC from 100.2 ± 57.1 ml to 282.9 ± 133.4 ml (p < 0.05) and no significant decrease in Pdet MCC (82.4 ± 31.7 to 69.9 ± 28.7 cm H2 O; p = 0.2). Three out of four patients (75%) who presented autonomic dysreflexia had total relief of symptoms after the procedure. In one patient, complete resolution of unilateral grade II vesicoureteral reflux was observed 6 months after the percutaneous radiofrequency sacral rhizotomy. Another patient presented total abolishment of reflex erections after the procedure.
328
R.S. Ferreira et al.
Figure 2
Radiofrequency Lesion Generator (MRFG-01B, MICROMAR, São Paulo, Brazil).
Figure 3 22G electrode with a 5-mm tip exposure used for S3 foramen puncture and stimulation.
Discussion In the treatment of NDH, the main goal is to preserve the upper urinary tract function. The use of anticholinergic Table 1
drugs to promote stabilization of involuntary contractions is the first-line treatment option.5 However, the striking side effects of anticholinergic therapy, such as dry mouth, constipation, blurred vision, weakness and drowsiness are factors that compromise the patient’s adherence to maintenance therapy. Furthermore, the effects of these drugs on the bladder are frequently not enough to promote a complete improvement on clinical symptoms.14 Meirowsky et al.7 were the first to propose surgical denervation of the urinary bladder with the purpose of improving its function as a reservoir. Nowadays, bladder denervation is accomplished through a dorsal rhizotomy of the sacral nerve roots (S2---S4/5) that is usually performed in combination with the implant of a neurostimulator of the ventral sacral roots.15 In order to evaluate the status of the detrusor before sacral rhizotomy, sacral nerve roots blockade has been performed to select patients. After this procedure, there may be a sufficient increase in bladder capacity, improving its function as a reservoir and allowing the performance of a clean intermittent catheterization at regular intervals.16
Patient demographics.
Patient
Sex
Age (years)
Lesion
Neurological level
ASIA score
Time of lesion (months)
1 2 3 4 5 6 7 8
F M M F M F M F
27 28 40 41 22 37 33 23
Traumatic Traumatic Traumatic Traumatic Traumatic Traumatic Traumatic Traumatic
T8 C6/C7 T9 C5/C6 C5/C6 T12 L1 C5
A A A A A A A A
72 72 60 24 60 96 20 24
Percutaneous Radiofrequency Sacral Rhizotomy in the Treatment of Neurogenic Detrusor Overactivity Table 2
329
Urodynamic parameters of patients that underwent a sacral anesthetic block.
MCC (ml) Pdet MCC (cm H2 O)
Baseline (n = 8)
Post-sacral anesthetic block (n = 8)
p
99.2 (±57.9) 90.0 (±25.0)
330.5 (±139.3) 46.0 (±21.0)
<0.05 <0.05
MCC: maximum cystometric capacity; Pdet MCC: detrusor pressure at the maximum cystometric capacity.
Table 3
Data of patients that underwent a percutaneous radiofrequency sacral rhizotomy.
MCC (ml) Pdet MCC (cm H2 O)
Baseline (n = 8)
6 months (n = 8)
12 months (n = 8)
100.2 (±57.1) 82.4 (±31.7)
313.7 (±103.1), p < 0.05 64.5 (±18.8), p = 0.1
282.9 (±133.4), p < 0.05 69.9 (±28.7), p = 0.2
The sacral anesthetic blockade is a valuable method to select patients for a sacral rhizotomy.16 However, the procedure will not always predict the final outcome of the surgery. The analysis of the changes in bladder capacity after the sacral anesthetic blockade does not always correlate with late rhizotomy postoperative follow-up.17 In the present study, in which only the third sacral root (S3) was bilaterally blocked, a significant increase of the bladder capacity was observed after the procedure in all patients as well as the reduction of detrusor pressure. These data are in accordance with other authors who reported combined blockade of the S2---S4/5 roots.10,16---18 After 1 month, six out of the eight patients (75%) presented significant urodynamic parameters improvement. However, at six months follow-up the patients presented recurrence of detrusor hyperactivity. After total sacral neurectomy, decreased bladder compliance may be found. Some authors suggest the mechanical impact of a stretched wall previously contracted or the effect of some neural component resulting from the denervation as possible causes of the decrease in bladder accommodation.19,20 During follow-up, no change in bladder accommodation was observed in our cohort. After 12 months, all patients presented recurrent detrusor hyperactivity, although all of them maintained a significant increase in their bladder capacity. This problem may have been caused by the development of alternative reflex pathways or due to the proliferation of alpha-adrenergic terminations in the vesical body after the parasympathetic denervation.21,22 On the other hand, Kerrebroeck et al. reported on 52 patients who underwent a posterior sacral rhizotomy and did not show recurrent detrusor hyperactivity after two years.15 After a percutaneous radiofrequency sacral rhizotomy, three patients showed significant improvement in their symptoms of autonomic dysreflexia during the storage phase, but persistent urinary incontinence episodes. Autonomic dysreflexia is an acute potentially lethal complication peculiar to those with spinal injuries above T6.15,19,23 Afferent fibers of the bladder viscero-vascular reflex have been shown to involve the pelvic and hypogastric nerves. Therefore, the preservation of the hypogastric nerves may explain why the autonomic dysreflexia does not disappear after sacral rhizotomy, mainly during the voiding phase.23 One patient presented complete resolution of a low grade vesicoureteral reflux at six months follow-up. No patient
presented worsening of the upper urinary tract status following the procedure. Other investigators have reported that dilation of the upper urinary tract may disappear six weeks after surgery. In three out of six ureters with preoperative vesicoureteral reflux, there was complete resolution at six months follow-up. Other three presented a reduction in reflux grade. Progression of upper urinary tract injuries was not observed in this series.15 Immediately after percutaneous radiofrequency sacral rhizotomy, one patient showed erectile dysfunction which persisted throughout the 12 months follow-up. Some authors report loss of erection after sacral rhizotomy.19 On the other hand, others report preservation of erectile function in all patients submitted to posterior sacral rhizotomy.8,24,25 In the present study, it was possible to note that percutaneous radiofrequency sacral rhizotomy is a simple, minimally invasive procedure associated with a low rate of complications. Its results seem to be temporary nonetheless. This technique may be performed in an outpatient regimen and may even be repeated in cases of recurrent detrusor hyperactivity as well as thermocoagulation of other roots other than S3 (S2 and S4/5 roots).26 We believe that an invasive procedure such as enterocystoplasty must be withheld as the last resource to solve a low compliant high pressure bladder condition. Percutaneous radiofrequency sacral rhizotomy in patients with neurogenic detrusor hyperactivity may not be the end of a therapeutic plan but might be considered a step stage for a definitive treatment.
Conclusion Percutaneous radiofrequency sacral rhizotomy is a simple, effective and safe procedure associated with a low morbidity rate and may be incorporated to the clinical practice. Results at 12 months demonstrate a significant increase in maximum cystometric capacity. Results seem to be temporary and recurrence of detrusor hyperactivity is expected at one year.
Conflict of interest The authors declare that they have no conflict of interest.
330
Acknowledgement This project was funded by the Fundac ¸ão de Apoio à Pesquisa (FAPESP).
References 1. Hansen RB, Biering-Sorensen F, Kristensen JK. Urinary incontinence in spinal cord injured individuals 10---45 years after injury. Spinal Cord. 2010;48:27---33. 2. Sugimura T, Arnold E, English S, Moore J. Chronic suprapubic catheterization in the management of patients with spinal cord injuries: analysis of upper and lower urinary tract complications. BJU Int. 2008;101:1396---400. 3. Ku JH. The management of neurogenic bladder and quality of life in spinal cord injury. BJU Int. 2006;98:739---45. 4. Patki PS, Hamid R, Arumugam K, Shah PJ, Craggs M. Botulinum toxin-type A in the treatment of drug-resistant neurogenic detrusor overactivity secondary to traumatic spinal cord injury. BJU Int. 2006;98:77---82. 5. Elliott DS, Boone TB. Recent advances in the management of the neurogenic bladder. Urology. 2000;56 6 Suppl. 1:76---81. 6. Franco I, Storrs B, Firlit CF, Zebold K, Richards I, Kaplan WE. Selective sacral rhizotomy in children with high pressure neurogenic bladders: preliminary results. J Urol. 1992;148 2 Pt 2:648---50. 7. Meirowsky AM, Scheibert CD, Hinchey TR. Studies on the sacral reflex arc in paraplegia: response of the bladder to surgical elimination of sacral nerve impulses by rhizotomy. J Neurosurg. 1950;7:33---8. 8. 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;148:1207---10. 9. Houle AM, Vernet O, Jednak R, Pippi Salle JL, Farmer JP. Bladder function before and after selective dorsal rhizotomy in children with cerebral palsy. J Urol. 1998;160 3 Pt 2:1088---91. 10. Toczek SK, McCullough DC, Gargour GW, Kachman R, Baker R, Luessenhop AJ. Selective sacral rootlet rhizotomy for hypertonic neurogenic bladder. J Neurosurg. 1975;42:567---74. 11. Chai TC, Mamo GJ. Modified techniques of S3 foramen localization and lead implantation in S3 neuromodulation. Urology. 2001;58:786---90.
R.S. Ferreira et al. 12. Mulcahy JJ, Young AB. Percutaneous radiofrequency sacral rhizotomy in the treatment of the hyperreflexic bladder. J Urol. 1978;120:557---8. 13. Schafer W, Abrams P, Liao L, Mattiasson A, Pesce F, Spangberg A, et al. Good urodynamic practices: uroflowmetry, filling cystometry, and pressure-flow studies. Neurourol Urodyn. 2002;21:261---74. 14. Leippold T, Reitz A, Schurch B. Botulinum toxin as a new therapy option for voiding disorders: current state of the art. Eur Urol. 2003;44:165---74. 15. Van Kerrebroeck EV, Van der Aa HE, Bosch JL, Koldewijn EL, Vorsteveld JH, Debruyne FM. Sacral rhizotomies and electrical bladder stimulation in spinal cord injury. Part I: Clinical and urodynamic analysis. Dutch Study Group on Sacral Anterior Root Stimulation. Eur Urol. 1997;31:263---71. 16. Rockswold GL, Bradley WE, Chou SN. Differential sacral rhizotomy in the treatment of neurogenic bladder dysfunction. Preliminary report of six cases. J Neurosurg. 1973;38:748---54. 17. Diokno AC, Vinson RK, McGillicuddy J. Treatment of the severe uninhibited neurogenic bladder by selective sacral rhizotomy. J Urol. 1977;118:299---301. 18. Young B, Mulcahy JJ. Percutaneous sacral rhizotomy for neurogenic detrusor hyperreflexia. J Neurosurg. 1980;53:85---7. 19. MacDonagh RP, Forster DM, Thomas DG. Urinary continence in spinal injury patients following complete sacral posterior rhizotomy. Br J Urol. 1990;66:618---22. 20. McGuire EJ, Savastano JA. Urodynamic findings and clinical status following vesical denervation procedures for control of incontinence. J Urol. 1984;132:87---8. 21. Opsomer RJ, Klarskov P, Holm-Bentzen M, Hald T. Long term results of superselective sacral nerve resection for motor urge incontinence. Scand J Urol Nephrol. 1984;18:101---5. 22. Torring J, Petersen T, Klemar B, Sogaard I. Selective sacral rootlet neurectomy in the treatment of detrusor hyperreflexia. Technique and long-term results. J Neurosurg. 1988;68:241---5. 23. Schurch B, Knapp PA, Jeanmonod D, Rodic B, Rossier AB. Does sacral posterior rhizotomy suppress autonomic hyper-reflexia in patients with spinal cord injury? Br J Urol. 1998;81:73---82. 24. Clarke SJ, Forster DM, Thomas DG. Selective sacral neurectomy in the management of urinary incontinence due to detrusor instability. Br J Urol. 1979;51:510---4. 25. Torrens MJ, Griffith HB. Management of the uninhibited bladder by selective sacral neurectomy. J Neurosurg. 1976;44:176---85. 26. Mulcahy JJ, Young AB. Long-term follow-up of percutaneous radiofrequency sacral rhizotomy. Urology. 1990;35:76---7.
Actas Urológicas Españolas www.elsevier.es/actasuro
ORIGINAL ARTICLE
Percutaneous radiofrequency sacral rhizotomy in the treatment of neurogenic detrusor overactivity in spinal cord injured patients夽 R.S. Ferreira a,b , C.A. Levi d’Ancona c , V.P. Dantas-Filho c , N. Rodrigues Netto Jr. c , R. Miyaoka c,∗ a
Departamento de Urología, Hospital General de Goiânia, Goiânia, GO, Brazil Departamento de Urología, CRER, Centro de Rehabilitación, Goiânia, GO, Brazil c Departamento de Urología, Universidad Estatal de Campinas, UNICAMP, Campinas, SP, Brazil b
Received 15 November 2010; accepted 11 December 2010 Available online 13 October 2011
KEYWORDS Neurogenic bladder; Spinal cord injury; Urodynamics; Sacral rhizotomy; Urinary incontinence; Neurogenic detrusor overactivity; Radiofrequency
Abstract Introduction: To evaluate the effects of percutaneous radiofrequency sacral rhizotomy in spinal cord injured (SCI) patients on urodynamic parameters (maximum cystometric capacity (MCC) and detrusor pressure at maximum cystometric capacity (PdetMCC)). Materials and methods: This prospective study assessed eight patients with SCI (four men and four women) with a mean age of 31.3 years (22---41). Mean interval period between spinal cord lesion and rhizotomy was 53.5 months (20---96). All patients underwent an anesthetic block of the 3rd sacral root bilaterally using 0.5% bupivacaine under fluoroscopic control. Those who responded with an increase on bladder capacity were selected to undergo the percutaneous radiofrequency sacral rhizotomy. All patients underwent urodynamic evaluation at 6 and 12 months following the procedure. MCC and Pdet MCC were recorded. Results: All patients presented a significant improvement on MCC after 12 months. The mean vesical volume increased from 100.2 ± 57.1 to 282.9 ± 133.4 ml (p < 0.05). The Pdet MCC reduced from 82.4 ± 31.7 to 69.9 ± 28.7 cm H2 O (p = 0.2). Three patients with autonomic dysreflexia had complete relief of symptoms after the procedure. At 12 months, recurrence of detrusor hyperactivity was observed in all patients. One patient presented abolishment of reflex erections after the procedure. No major complications related to the rhizotomy were noted. Conclusions: Percutaneous radiofrequency sacral rhizotomy is a minimally invasive technique with low morbidity able to increase MCC. There is a trend towards the reduction of the Pdet MCC in SCI patients at 12 months, although statistical significance was not reached. © 2010 AEU. Published by Elsevier España, S.L. All rights reserved.
夽
Please cite this article as: Ferreira RS, et al. Rizotomía sacra percutánea por radiofrecuencia en el tratamiento de la hiperactividad del detrusor neurogénico en pacientes con lesiones de la médula espinal. Actas Urol Esp. 2011;35:325---30. ∗ Corresponding author. E-mail address: [email protected] (R. Miyaoka). 2173-5786/$ – see front matter © 2010 AEU. Published by Elsevier España, S.L. All rights reserved.
326
PALABRAS CLAVE Vejiga neurógena; Lesión de la médula espinal; Urodinámica; Rizotomía sacral; Incontinencia urinaria; Hiperactividad neutrogénica del detrusor; Radiofrecuencia
R.S. Ferreira et al.
Rizotomía sacra percutánea por radiofrecuencia en el tratamiento de la hiperactividad del detrusor neurogénico en pacientes con lesiones de la médula espinal Resumen Objetivo: Evaluar los efectos de la rizotomía sacral percutánea por radiofrecuencia en pacientes con lesión de la médula espinal sobre parámetros urodinámicos (capacidad cistométrica máxima [CCM] y presión del detrusor a capacidad cistométrica máxima [PdetCCM]). Material y Métodos: En este estudio prospectivo se evaluó a 8 pacientes con LME (4 hombres y 4 mujeres) con una media de edad de 31,3 a˜ nos (de 22 a 41). El intervalo medio entre la lesión de la médula espinal y la rizotomía fue de 53,5 meses (entre 20 y 96). A todos los pacientes se les practicó un bloqueo anestésico bajo control fluoroscópico de la tercera raíz sacral de forma bilateral con bupivacaína 0,5%. Se eligió para rizotomía sacral percutánea por radiofrecuencia a los que respondieron con un aumento en la capacidad vesical. Se procedió a la evaluación urodinámica de todos los pacientes a los 6 y los 12 meses tras la realización del procedimiento. Se consignaron tanto la CCM como la Pdet CCM. Resultados: Todos los pacientes mostraron una mejora significativa en la CCM a los 12 meses. El volumen vesical medio aumentó de los 100,2 ± 57,1 a 282,9 ± 133,4 ml (p < 0,05). La Pdet CCM se redujo de 82,4 ± 31,7 a 69,9 ± 28,7 cm H2 O (p = 0,2). Tres pacientes con disreflexia autonómica experimentaron un alivio total de los síntomas tras el procedimiento. A los 12 meses se observó una reaparición de la hiperactividad del detrusor en todos los pacientes. Un paciente presentó abolición de las erecciones reflejas tras el procedimiento. No se observaron complicaciones de importancia en relación con la rizotomía. Conclusiones: La rizotomía sacral percutánea por radiofrecuencia es una técnica mínimamente invasiva, de baja morbilidad, que puede aumentar la CCM. Existe una tendencia hacia la reducción de la Pdet CCM en pacientes con LME a los 12 meses, a pesar de que no se alcanza un nivel estadísticamente significativo. © 2010 AEU. Publicado por Elsevier España, S.L. Todos los derechos reservados.
Introduction Spinal cord injury (SCI) may impair normal function of the urinary bladder and give rise to neurogenic detrusor hyperactivity (NDH). Urinary incontinence is an important aspect of bladder management in individuals with SCI and represents a most unpleasant complication which may severely impact their social relationships and quality of life.1 The management of lower urinary tract in patients with SCI aims to achieve adequate bladder emptying, maintenance of low intravesical pressures whilst storing proper volume and control of urinary incontinence.2 Treatment options for NDH can be didactically divided into two groups: therapy to facilitate bladder filling or urine storage, and therapy to facilitate bladder emptying.3 A combination of clean intermittent catheterization (CIC) and anticholinergic medication is the first-line treatment for NDH secondary to SCI4 and should be fully optimized before considering any surgical intervention. However, in patients who do not respond to clinical treatment or present intolerable side effects, surgical options become necessary. The ‘‘gold standard’’ surgical approach for treating patients with poor compliance high-pressure bladder includes augmentation cystoplasty and detrusor myomectomy.5,6 Initially presented in the 1950s by Meirowsky et al.,7 sacral rhizotomy lost popularity due to its frequent associated complications --- impotence, urethral and rectal sphincteric dysfunction and lower extremity atrophy.8 However, recent reports have demonstrated that in specific
patient cohorts, selective rhizotomies associated or not with anterior sacral root stimulation, may increase bladder capacity and continence can be improved.9,10 The S3 root seems to be the most important trigger point in subserving bladder control. Root blockade at S4 increases resting sphincter tonus in the urethra. This suggests that it carries an inhibitory nerve supply to the urethral smooth muscle.11 Additionally, in 1978, percutaneous radiofrequency sacral rhizotomy was described in seven patients in order to facilitate intermittent clean catheterization.12 We assessed the effects of percutaneous radiofrequency sacral rhizotomy on urodynamic parameters such as maximum cystometric capacity (MCC) and detrusor pressure at the maximum cystometric capacity (Pdet MCC) in spinal cord injured patients.
Materials and methods Eight patients were selected from our Uroneurology Clinic between July 2003 and December 2004. All subjects underwent complete urological and physical evaluations. Complementary assessment included blood urea nitrogen and creatinine, urine culture, cystogram and urinary tract sonography. Urodynamics were performed according to the recommendations by the International Continence Society (ICS).13 Urodynamic parameters maximum cystometric capacity (MCC) and detrusor pressure at the maximum cystometric capacity (Pdet MCC) were compared before and
Percutaneous Radiofrequency Sacral Rhizotomy in the Treatment of Neurogenic Detrusor Overactivity
Figure 1
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(A and B) S3 foramen localization.
after treatment. In patients with impaired sensation, MCC was defined as the volume at which urinary leakage was observed.7 This study was approved by our Institutional Ethics Committee for Research in Humans and signed by the patients. The inclusion criterion for percutaneous radiofrequency sacral rhizotomy was an increase in bladder capacity above 100% over the baseline value recorded after an anesthetic sacral blockade. Exclusion criteria included patients who did not accept the proposed treatment or could not perform CIC. The S3 foramen was bilaterally located at the level of the inferior border of the sacroiliac joint. With the patient in prone position and under fluoroscopic guidance a 22 gauge raquianesthesia needle was inserted on the skin surface as a radiopaque marker to orient lining up of the lumbar vertebral spinous processes for accurate localization of the midline. A second line was drawn to connect the most inferior border of the sacroiliac joints, again using the needle as a radiopaque marker. These two landmarks (spinous processes and inferior border of sacroiliac joints) are reliably and clearly visualized under fluoroscopy in every patient regardless of the patient’s weight. The S3 foramen is found just lateral and superior to the intersection of these two imaginary lines (Fig. 1A and B). Because of the angled aspect of the S3 foramen, the needle must be inserted into the skin 1---4 cm above the anticipated location of the S3 foramen, depending on the size of the individual (thickness of the soft tissue above the sacral periosteum).11 Three milliliters of 0.5% bupivacaine chloride were injected into the sacral foramen under fluoroscopic control. Thirty minutes later, a urodynamic study was performed and the effect on MCC and Pdet MCC was recorded. Percutaneous radiofrequency sacral rhizotomy was performed one week after anesthetic blockade. The equipment consisted of a Radiofrequency Lesion Generator (MRFG-01B, MICROMAR, São Paulo, Brazil) (Fig. 2) and a 22G electrode with a 5-mm tip exposure (Fig. 3). Patients were sedated and the procedure began with the percutaneous puncture of the 3rd sacral foramen bilaterally according to the technique previously described. The bilateral S3 sacral root was initially identified through a stimulating pulse of 1.0 ms, 30 Hz and 0.1 V. The voltage was
progressively increased by 0.1 V until detrusor contraction could be registered on urodynamics during the procedure or external signs of S3 stimulation could be seen (such as plantar flexion of the great toe and/or anal sphincteric contraction).12 Thermocoagulation was confirmed by assertion of electric current and comparison of tissue impedance before and after the procedure. The thermolesion was performed for 15 s, after which the electrode was progressively withdrawn 5 mm. The procedure was repeated 3 times in each side. All patients were evaluated at 1, 6 and 12 months following the rhizotomy, and urodynamic parameters were recorded at each visit. Paired Student’s t-test was used for statistical analysis. A significance level of p < 0.05 was considered.
Results Eight SCI patients (4 men, 4 women) with a mean age of 31.3 (22---41) years were initially included in this study (Table 1). The mean interval period between the event of the spinal cord lesion and the date of procedure was 53.5 (20---96) months. Urodynamic parameters of patients who underwent sacral anesthetic block are shown in Table 2. The patients presented a significant increase in MCC from 99.2 ± 57.9 ml to 330.5 ± 139.3 ml (mean ± SD), p < 0.05. Pdet MCC significantly reduced from 90.0 ± 25.0 cm H2 O to 46.0 ± 21.1 cm H2 O (p < 0.05). Urodynamic parameters of patients who underwent percutaneous radiofrequency rhizotomy are shown in Table 3. Twelve months after the procedure patients presented a sustainable significant increase in MCC from 100.2 ± 57.1 ml to 282.9 ± 133.4 ml (p < 0.05) and no significant decrease in Pdet MCC (82.4 ± 31.7 to 69.9 ± 28.7 cm H2 O; p = 0.2). Three out of four patients (75%) who presented autonomic dysreflexia had total relief of symptoms after the procedure. In one patient, complete resolution of unilateral grade II vesicoureteral reflux was observed 6 months after the percutaneous radiofrequency sacral rhizotomy. Another patient presented total abolishment of reflex erections after the procedure.
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R.S. Ferreira et al.
Figure 2
Radiofrequency Lesion Generator (MRFG-01B, MICROMAR, São Paulo, Brazil).
Figure 3 22G electrode with a 5-mm tip exposure used for S3 foramen puncture and stimulation.
Discussion In the treatment of NDH, the main goal is to preserve the upper urinary tract function. The use of anticholinergic Table 1
drugs to promote stabilization of involuntary contractions is the first-line treatment option.5 However, the striking side effects of anticholinergic therapy, such as dry mouth, constipation, blurred vision, weakness and drowsiness are factors that compromise the patient’s adherence to maintenance therapy. Furthermore, the effects of these drugs on the bladder are frequently not enough to promote a complete improvement on clinical symptoms.14 Meirowsky et al.7 were the first to propose surgical denervation of the urinary bladder with the purpose of improving its function as a reservoir. Nowadays, bladder denervation is accomplished through a dorsal rhizotomy of the sacral nerve roots (S2---S4/5) that is usually performed in combination with the implant of a neurostimulator of the ventral sacral roots.15 In order to evaluate the status of the detrusor before sacral rhizotomy, sacral nerve roots blockade has been performed to select patients. After this procedure, there may be a sufficient increase in bladder capacity, improving its function as a reservoir and allowing the performance of a clean intermittent catheterization at regular intervals.16
Patient demographics.
Patient
Sex
Age (years)
Lesion
Neurological level
ASIA score
Time of lesion (months)
1 2 3 4 5 6 7 8
F M M F M F M F
27 28 40 41 22 37 33 23
Traumatic Traumatic Traumatic Traumatic Traumatic Traumatic Traumatic Traumatic
T8 C6/C7 T9 C5/C6 C5/C6 T12 L1 C5
A A A A A A A A
72 72 60 24 60 96 20 24
Percutaneous Radiofrequency Sacral Rhizotomy in the Treatment of Neurogenic Detrusor Overactivity Table 2
329
Urodynamic parameters of patients that underwent a sacral anesthetic block.
MCC (ml) Pdet MCC (cm H2 O)
Baseline (n = 8)
Post-sacral anesthetic block (n = 8)
p
99.2 (±57.9) 90.0 (±25.0)
330.5 (±139.3) 46.0 (±21.0)
<0.05 <0.05
MCC: maximum cystometric capacity; Pdet MCC: detrusor pressure at the maximum cystometric capacity.
Table 3
Data of patients that underwent a percutaneous radiofrequency sacral rhizotomy.
MCC (ml) Pdet MCC (cm H2 O)
Baseline (n = 8)
6 months (n = 8)
12 months (n = 8)
100.2 (±57.1) 82.4 (±31.7)
313.7 (±103.1), p < 0.05 64.5 (±18.8), p = 0.1
282.9 (±133.4), p < 0.05 69.9 (±28.7), p = 0.2
The sacral anesthetic blockade is a valuable method to select patients for a sacral rhizotomy.16 However, the procedure will not always predict the final outcome of the surgery. The analysis of the changes in bladder capacity after the sacral anesthetic blockade does not always correlate with late rhizotomy postoperative follow-up.17 In the present study, in which only the third sacral root (S3) was bilaterally blocked, a significant increase of the bladder capacity was observed after the procedure in all patients as well as the reduction of detrusor pressure. These data are in accordance with other authors who reported combined blockade of the S2---S4/5 roots.10,16---18 After 1 month, six out of the eight patients (75%) presented significant urodynamic parameters improvement. However, at six months follow-up the patients presented recurrence of detrusor hyperactivity. After total sacral neurectomy, decreased bladder compliance may be found. Some authors suggest the mechanical impact of a stretched wall previously contracted or the effect of some neural component resulting from the denervation as possible causes of the decrease in bladder accommodation.19,20 During follow-up, no change in bladder accommodation was observed in our cohort. After 12 months, all patients presented recurrent detrusor hyperactivity, although all of them maintained a significant increase in their bladder capacity. This problem may have been caused by the development of alternative reflex pathways or due to the proliferation of alpha-adrenergic terminations in the vesical body after the parasympathetic denervation.21,22 On the other hand, Kerrebroeck et al. reported on 52 patients who underwent a posterior sacral rhizotomy and did not show recurrent detrusor hyperactivity after two years.15 After a percutaneous radiofrequency sacral rhizotomy, three patients showed significant improvement in their symptoms of autonomic dysreflexia during the storage phase, but persistent urinary incontinence episodes. Autonomic dysreflexia is an acute potentially lethal complication peculiar to those with spinal injuries above T6.15,19,23 Afferent fibers of the bladder viscero-vascular reflex have been shown to involve the pelvic and hypogastric nerves. Therefore, the preservation of the hypogastric nerves may explain why the autonomic dysreflexia does not disappear after sacral rhizotomy, mainly during the voiding phase.23 One patient presented complete resolution of a low grade vesicoureteral reflux at six months follow-up. No patient
presented worsening of the upper urinary tract status following the procedure. Other investigators have reported that dilation of the upper urinary tract may disappear six weeks after surgery. In three out of six ureters with preoperative vesicoureteral reflux, there was complete resolution at six months follow-up. Other three presented a reduction in reflux grade. Progression of upper urinary tract injuries was not observed in this series.15 Immediately after percutaneous radiofrequency sacral rhizotomy, one patient showed erectile dysfunction which persisted throughout the 12 months follow-up. Some authors report loss of erection after sacral rhizotomy.19 On the other hand, others report preservation of erectile function in all patients submitted to posterior sacral rhizotomy.8,24,25 In the present study, it was possible to note that percutaneous radiofrequency sacral rhizotomy is a simple, minimally invasive procedure associated with a low rate of complications. Its results seem to be temporary nonetheless. This technique may be performed in an outpatient regimen and may even be repeated in cases of recurrent detrusor hyperactivity as well as thermocoagulation of other roots other than S3 (S2 and S4/5 roots).26 We believe that an invasive procedure such as enterocystoplasty must be withheld as the last resource to solve a low compliant high pressure bladder condition. Percutaneous radiofrequency sacral rhizotomy in patients with neurogenic detrusor hyperactivity may not be the end of a therapeutic plan but might be considered a step stage for a definitive treatment.
Conclusion Percutaneous radiofrequency sacral rhizotomy is a simple, effective and safe procedure associated with a low morbidity rate and may be incorporated to the clinical practice. Results at 12 months demonstrate a significant increase in maximum cystometric capacity. Results seem to be temporary and recurrence of detrusor hyperactivity is expected at one year.
Conflict of interest The authors declare that they have no conflict of interest.
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Acknowledgement This project was funded by the Fundac ¸ão de Apoio à Pesquisa (FAPESP).
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