Re-evaluation of differential sacral rhizotomy for neurological bladder disease

Transcription

1 J Neurosurg 48: , 1978 Re-evaluation of differential sacral rhizotomy for neurological bladder disease GAYLAN L. ROCKSWOLD, M.D., PH.D., SHELLEY N. CHOU, M.D., PH.D., AND WILLIAM E. BRADLEY, M.D. Departments of Neurosurgery and Neurology, University of Minnesota, Minneapolis, Minnesota o,' The authors describe long-term follow-up results (4 to 6 years) in 13 patients who underwent differential sacral rhizotomy for urgency incontinence. Six patients were originally presented in a preliminary report in In the last seven patients, a highly selective rhizotomy of sacral fascicles innervating only the urinary bladder was performed. Results in the original six patients appear to be superior to those in patients who underwent a more refined rhizotomy. Possible explanations for this as well as alternative approaches to the treatment of urgency incontinence are briefly discussed. KEY WORDS 9 sacral rhizotomy 9 hyperactive neurogenic bladder 9 microsurgery T HF "spastic" or hyperactive neurogenic bladder producing severe urinary frequency and urgency incontinence is not only a source of psychological and social nuisance and embarrassment, but the chronic effects on renal function and general health are often marked and occasionally lethal. Bilateral section of the sacral nerves for improvement of these symptoms has been done since Meirowsky, et al., first proposed the procedure in In 1971, we began performing a more limited sacral rhizotomy, in which only a limited number of fascicles of one or two unilateral sacral roots were cut, so as to restore more physiological voiding by preserving the detrusor reflex and sphincter function, but at the same time increasing bladder capacity? 5 Our initial results with six patients seemed encouraging and demonstrated that the procedure could be done in ambulatory, functional patients without morbidity or mortality. Based on the preliminary work of Toczek, et al., 21 it appeared feasible to make the rhizotomy even more selective by sectioning fibers that innervated the urinary bladder only, thus preserving entirely the efferent fibers to the external urethral and anal sphincters. The purpose of this paper is to relate our experience with refining the differential sacral rhizotomy technique based on experimental data obtained from higher primates (rhesus monkeys and chimpanzees). TM In addition, the long-term results of the rhizotomy in the total group of 13 patients will be presented. Material and Methods Thirteen patients with multiple sclerosis (12 female, one male) have undergone 14 differential sacral rhizotomies (Table 1). All suffered from frequency and urgency incontinence caused by low-threshold detrusor J. Neurosurg. / Volume 48 / May,

2 G. L. Rockswold, S. N. Chou and W. E. Bradley TABLE 1 Clinical summary of 13 patients with differential sacral rhizotomy Case No. Sacral Surgery Residual (cc) Cystometry Nerve Block Date Root Preop Postop Preop Postop Results It S-4 4/71 It S-2, S hyperreflexia same by total at 80 cc 5/72 rt S-4 8/71 1A rt S hyperreflexia same by at 80 cc 5/73 It S-3, 8/71 ~/z It S hyperreflexia same by S-4 at 100 cc 3/72 bilat, ll/71 1/2 It S hyperreflexia no change S-2, S-3 at cc It S-3 11/71 a/~ It S hyperreflexia remains at cc areflexic rt S-3, 2/72 2/3 rt S hyperreflexia increased S-4 1/z rt S-4 at 150 cc capacity to cc It S-4 8/72 1/2 S hyperreflexia same by dorsal & at 150 cc 3/73 ventral fascicles, S-4 total rt S-2, 9/72 1A rt S-2, hypcrreflexia same by S-3 S-3 dorsal at 80 cc 7/74 & ventral fascicles bilat. 1/73 2 ventral hyperreflexia areflexia, S-3, & 1 dorsal at 80 cc bladder S-4 fascicle of capacity S-3 bilat., 480 cc 1/2 S-4 dorsal & ventral fascicles bilat. rt S-3, 11/'72 1 ventral 0 50 hyperreflexia no change S-4 & 2 dorsal at 80 cc fascicles, rt S-3 rt S-3, 5/73 rt S-3, S-4, 0 75 hyperreflexia capacity S-4 S-5 total at 80 cc increased to 320 cc It S-4 2/73 1/2 It S-3 dor sal & ventral fascicles, It S-4 total rt S-3, 4/73 rt S-3:1/ S-4 dorsal & ventral fascicles; rt S-4: all ventral root, 1 dorsal fascicle It S-3, 5/73 S-3, S S-4 total hyperreflexia same by at 80 cc 4/73 hyperreflexia at 80 cc areflexia urge and pain areflexic, with bladder urge at 320 filling to 160 cc without cc, areflexic pain unsatisfactory; recurrent hyperreflexia with incontinence requiring catheter remains nearly asymptomatic remained clinically improved to 12/75 unsatisfactory; no change incontinent without sensation requiring catheter; 10/73 good result until death 1/76 unsatisfactory; symptoms improved for less than 3 mos good result for nearly 2 yrs required catheter because of incontinence without sensation 2 ~ to uninhibited sphincter relaxation unsatisfactory; no change in symptoms; required Foley catheter but leaked around it required catheter because of incontinence without sensation 2 ~ to uninhibited sphincter relaxation; no leakage around catheter unsatisfactory; relief of symptoms for less than 3 mos; required catheter unsatisfactory; recurrent symptoms within 3 mos; status post: prosthetic urinary sphincter status post: prosthetic urinary sphincter, removed 2/74; suprapubic tube, no leaking or pain to present 774 J. Neurosurg. / Volume 48 / May, 1978

3 Differential sacral rhizotomy for neurogenic bladder hyperreflexia. In all but one patient the detrusor hyperreflexia could be abolished and bladder capacity increased by anesthetizing one or two sacral nerves. TM In the first six patients the sacral rhizotomy was performed as described previously. *s Briefly, the sacral nerves were exposed intrathecally under local anesthesia. Stimulation and anesthetization of individual sacral roots with cystometric control and simultaneously questioning the patient as to the sensation of bladder distension or urge to void guided us to the proper nerves for section. A partial rhizotomy was then accomplished by cutting a portion of the anterior and posterior roots, leaving the remainder intact. Experiments were performed in seven rhesus monkeys and two chimpanzees to determine if there was segregation or a localized fascicular pattern of nervous innerration within the sacral roots to the urinary bladder and to the external anal and external urethral sphincters (Fig. 1). TM Stimulating electrodes were placed on the terminal branches of the pelvic nerves to the urinary bladder and the pudendal nerve to the sphincters. Evoked responses produced by stimulation of these terminal nerve branches were recorded in the fascicles and rootlets of the lower thoracic, lumbar, and sacral nerve roots. During identical stimulating and recording conditions, the amplitude and presence or absence of the evoked responses recorded was variable within the various roots, depending on the number of fibers within a particular fascicle that conducted impulses to the urinary bladder or urethral or anal sphincters. Thus, the concept of segregation or compartmentalization of the nervous innervation of these structures within the spinal roots was proven. As these experimental results became evident, the technique for differential sacral rhizotomy was modified. 1. During rhizotomy the dorsal and ventral sacral roots were carefully examined under the operative microscope and found to be composed of three or four fascicles that formed distinct anatomical entities and could be dissected free of each other. The sacral rhizotomy was made more selective by electrostimulation and Pontocaine (tetracaine) anesthetization of individual fascicles within the sacral roots. This permitted precise differentiation be- FIG. I. Schematic diagram of the experimental method used in studying the innervation of the urinary bladder and the external urinary sphincter in seven rhesus monkeys and two chimpanzees. tween anterior and posterior roots, and selection of fibers innervating the detrusor muscle. Further, anal sphincter function was monitored with electromyography (EMG) during the procedure. The effect of stimulating or anesthetizing particular sacral fascicles was noted on the EMG before section. Results In the first six patients previously reported, 15 stimulation of entire ventral roots was performed in five, and anesthetization of ventral and dorsal roots in five. These patients have been followed for a minimum of 5 years (Table 1). Of these six patients, four have experienced significant symptomatic improvement for 2 to 6 years. The fifth patient (Case 4) remained unchanged after the procedure, and the sixth (Case 1) was improved for less than 1 year. Of the two failures, one underwent intraoperative stimulation of roots only and one anesthetization only. J. Neurosurg. / Volume 48 / May,

4 G. L. Rockswold, S. N. Chou and W. E. Bradley A~ _Y! I FIG. 2. A. lntraoperative control cystometrogram showing low-threshold detrusor hyperreflexia. B. Repeat cystometrogram after Pontocaine application to three dorsal fascicles and one ventral fascicle. Bladder capacity was significantly increased while the detrusor reflex was preserved. Horizontal marker = volume (80 cc of air); vertical marker = pressure (20 cm H20). In the seven patients not previously reported, stimulation and/or anesthetization of individual fascicles of the sacral roots was performed during surgery to identify fibers exclusively innervating the bladder. Fascicles were sectioned when an increase in intravesical pressure of 15 cm of water above baseline was obtained on stimulation of the fascicle, and bladder capacity was increased by 50 cc when the fascicle was anesthetized (Fig. 2). Two patients (Cases 11 and 12) underwent intraoperative stimulation of sacral root fascicles without anesthetization. They experienced recurrent symptoms within 3 months of the procedure and are considered failures. The one patient (Case 8) who underwent only intraoperative anesthetization of fascicles had a good result for nearly 2 years. Of the four patients who underwent both stimulation and anesthetization of fascicles intraoperatively, two (Cases 7 and 10) had rapidly recurrent symptoms, and are considered failures. One of these patients (Case 10) had a repeat procedure during which the entire ventral and dorsal roots of S- 3, S-4, and S-5 were sectioned unilaterally. 776 The patient was rendered areflexic but remained incontinent because of uninhibited sphincter relaxation? The third patient (Case 9) was likewise rendered areflexic but remained incontinent because of uninhibited sphincter relaxation. The fourth patient (Case 13) has had a good result for the past 4 years. Thus, of the seven patients undergoing the highly selective rhizotomy, only two were significantly improved for 2 and 4 years. No definite statement can be made regarding the relative value of intraoperative stimulation versus anesthetization for selection of fascicles for section. However, it is our impression that anesthetization correlates more closely to the desired clinical result. There was no operative morbidity or mortality in this group of 13 patients. Discussion Based on our preoperative sacral nerve blocks and intraoperative stimulation and anesthetization of sacral roots, S-3 and S-4 are the predominant nerve roots innervating the urinary bladder. This is in agreement with the reports of other investigators, e,1~ The findings at sacral rhizotomy in humans confirmed the primate experimental results. Stimulation of certain fascicles within the sacral roots in humans produced marked contraction of the detrusor muscle as evidenced by a rise in intravesical pressure while stimulation of other fascicles produced poor or no detrusor contraction. This indicates that the fibers innervating the bladder are compartmentalized or segregated to certain fascicles and not to others. Previous experimental and clinical work would support this conclusion. 2,4,5,8,17,22 In comparing the results of the sacral rhizotomy in the original six patients to those in the later group of seven, it appears that the attempt at a highly selective sacral rhizotomy of fibers innervating the bladder only produced poorer long-term clinical results. Others have reported a similar experience. 22,23 Possible explanations for the development of recurrent symptoms include the development of alternative reflex pathways through the sacral roots, ~2 sprouting of terminal nerve fibers following denervation, 18,19 and denervation supersensitivity to circulating neurotransmitters?,n The development of alternative reflex pathways intuitively seems to occur J. Neurosurg. / Volume 48 / May, 1978

5 Differential sacral rhizotomy for neurogenic bladder more readily in the more selective and limited rhizotomy. One specific problem we have encountered in the postoperative period has been persistent incontinence in two patients despite adequate reduction of detrusor hyperreflexia by cystometry. A third patient developed this problem after 2 years of initial good relief of symptoms. These patients have a sphincter electromyographic pattern of uninhibited sphincter relaxation resulting in incontinence. 1 This pattern is frequently seen in patients with cerebral involvement by the demyelinating process and appears to be a contraindication to sacral rhizotomy. Several alternative approaches to the treatment of detrusor hyperreflexia and secondary urgency incontinence have been attempted. Following initial sacral nerve blocks using a local anesthetic, more permanent sacral blocks with the use of phenol or a percutaneous radiofrequency lesion of the sacral root can be considered, x3 The latter provides the opportunity for stimulation of the nerve root to determine the accuracy of the needle placement. In addition, a graded ablation can be performed with cystometric control. More recently we have sectioned S-3 and S-4 bilaterally in one patient with idiopathic detrusor hyperreflexia and intractihle symptoms. Sphincter function was preserved, presumably by its more rostral origin. TM Also the sympathetically innervated internal sphincter remained functional. TM Possibly recurrence can be at least retarded by more complete obliteration of the roots innervating the urinary bladder. References 1. Bradley WE, Logothetis JL, Timm GW: Cystometric and sphincter abnormalities in multiple sclerosis. Neurology 23: , Downman CBB: Visceratomes and dermatomes: Some comparisons of the inner and outer surfaces of the body, in Curtis DR, Mclntyre AK: Studies in Physiology. New York: Springer-Verlag, Elm6r M: Action of drugs on the innervated and denervated urinary bladder of the rat. Aeta Physiol Scand 91: , Fletcher TF, Kitchell RL: The lumbar, sacral and coccygeal tactile dermatomes of the dog. J Comp Neurol 128: , Gargour GW, Toczek SK, McCullough DC: Selective sacral rootlet section for experimen- J. Neurosurg. / Volume 48 / May, 1978 tal detrusor inhibition. J Neurosurg 38: , Heimburger RF, Freemen LW, Wilde N J: Sacral nerve innervation of the human bladder. J Neurosurg 5: , Kleeman F J: The physiology of the internal urinary sphincter. J Urol 104: , Kuhn RA: Organization of tactile dermatomes in cat and monkey. J Neurophysiol 16: , Meirowsky AM, Scheibert CD, Hinchey TR: Studies on the sacral reflex arc in paraplegia. I. Response of the bladder to surgical elimination of sacral nerve impulses by rhizotomy. J Neurosurg 7:33-38, Nagib A, Leal J, Voris HC: Successful control of selective anterior sacral rhizotomy for treatment of spastic bladder and ureteric reflux in paraplegics. Med Serv J Can 22: , Norlen L, Dahlstrom A, Sundin T, et al: The adrenergic innervation and adrenergic receptor activity of the feline urinary bladder and urethra in the normal state and after hypogastric and/or parasympathetic denervation. Scand J Uroi Nephrol 10: , Rockswold GL: Innervation of the Urinary Bladder In Higher Primates and In Man (Ph.D. Thesis, University of Minnesota) 13. Rockswold GL, Bradley WE: The use of sacral nerve blocks in the evaluation and treatment of neurologic bladder disease. J Urol 118: , Rockswold GL, Bradley WE, Chou SN: Differential sacral rhizotomy. Minn Med 57:586, Rockswold GL, Bradley WE, Chou SN: Differential sacral rhizotomy in the treatment of neurogenic bladder dysfunction. Preliminary report of 6 cases. J Neurosurg 38: , Rockswold GL, Bradley WE, Chou SN: Effect of sacral nerve blocks on the function of the urinary bladder in humans. J Neurosurg 40:83-89, Schnitzlein HN, Hoffman HH, Tucker CC, et al: The pelvic splanchnic nerves in the male rhesus monkey. J Comp Neurol 114:51-58, Sundin T, DahlstrSm A: Sympathetic innervation of the urinary bladder and urethra in the normal state and after parasympathetic denervation at the spinal root level. An experimental study in cats. Scand J Urol Nephrol 7: , Sundin T, Dahlstr~Sm A, Norlen L, et al: The sympathetic innervation and adrenoreceptor function of the human lower urinary tract in the normal state and after parasympathetic denervation. Invest Urol 14: , Tanagho EA, Smith DR: Mechanism of urinary continence. 1. Embryologic, anatomic 777

6 G. L. Rockswold, S. N. Chou and W. E. Bradley and pathologic considerations. J Urol 100: , Toczek SK, McCullough DC, Gargour G, et al: Sacral rootlet rhizotomy for hypertonic neurogenic bladder: a refined technique. Presented at the Annual Meeting of the American Association of Neurological Surgeons, Boston, Massachusetts, April, Toczek SK, McCullough DC, Gargour GW, et al: Selective sacral rootlet rhizotomy for hypertonic neurogenic bladder. J Neurosurg 42: , Torrens M J, Griffith HB: Management of the uninhibited bladder by selective sacral neurectomy. J Neurosurg 44: , 1976 This investigation was supported in part by a research grant from the Minnesota Medical Foundation, University of Minnesota, Minneapolis, Minnesota. Address reprint requests to." Gaylan L. Rockswold, M.D., Division of Neurosurgery, Hennepin County Medical Center, 701 Park Avenue South, Minneapolis, Minnesota J. Neurosurg. / Volume 48 / May, 1978