Occult neurovesical dysfunction with anorectal malformations
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《美国医学杂志》
Department of Pediatric Surgery, All India Institute of Medical Sciences, New Delhi, India
Abstract
Objective. To evaluate for the occurance of occult NVD in children with anorectal malformatons (ARM) using urodynamic evaluation. Methods. This prospective study was carried out on children with ARM prior to and following definitive procedure. Urodynamic studies were performed on the Phoenix Griffon machine (Albyn Medical) using Phonix plus software. Result. Nineteen children in the age range of 3 months to 156 months (mean = 19.2) were included in this study. Among these 19 children 13 underwent re-evaluation after definitive surgery for ARM. There were 11(57.9%) males and 8(42.1%) females. Of the 19 children 14 (73.7%) were cases of high anorectal malformation (HARM) and 5 (26.3%) were cases of low anorectal malformation (LARM). Baseline evaluation done in 19 children revealed seven urodnamci patterns: Normal capacity, compliant without uninhibited contractions (UIC) (21.1%); Normal capacity, compliant with UIC (5.3%); Normal capactity, poorly compliant without UIC (5.3%); Normal capacity, poorly compliant with UIC (10.5%); small capacity, compliant with UIC (5.3%); Small capactity, poorly compliant with UIC (26.3%) and large capacity, complaint with UIC (26.3%). Thirteen patients were evaluated post operativey also and in only 23% (3 of 13) no change in urodynamic pattern were observed. In the remaining 76.9% (10 of 13) some changes in urodynamics pattern were observed. The deleterious changes observed were appearance of UIC in 30.8% (4 of 13), decrease in the bladder capacity in 23% (3 of 13) and decrease in bladder compliance in 15.4% (2 of 13). Conclusion. Only 9 of of the 19 patients had normal urodynamics pre-operatively and post-operatively 3 more patients worsened. Incidence of occult NVD is high in patients with ARM even in the absence of clinical and radiological evidence of vertebral or lower uinary tract abnormalities. Though there seems to be a high incidence of changes in the neurovesical functions of these patients following definitive corrective surgery for ARM only time will show whether this has any deleterious effect on the upper tracts.
Keywords: Anorectal malformation; Occult neurovesical dysfucntion
Association of anorectal malformations (ARM) with structural abnormalities of urinary tract along with variable degrees of vertebral, and urogenhal anomalies is well established.[1],[2],[3],[4],[5] Functional abnormalities of the urinary tract (neurovesical dysfunction, NVD) in children with ARM have recentry been recognized.[6],[7]
Occult spinal dysraphism with tethered cord, lipoma, syrinx and diastematomyelia associated with ARM have also been recognized to be the cause of lower urinary tract dysfunction in such cases.[8],[9] On the other hand no such markers are associated with children suffering from NVD. The importance of NVD in patients of ARM cannot be overemphasized as it alters the management by virtue of therapeutic considerations unique to the condition. Occult NVD may be responsible for added morbidity in the patients and appropriate management of these dysfunction my lead to decrease in morbidity.[6]
NVD may occur in cases of ARM even when clinical and radiological evaluations do not show any abnormality. Also, NVD following definitive procedures for management of ARM can be evaluated and managed appropriately. Moreover, functional urological problems are compounded by associated anatomical Abnormalities.[8],[9],[10],[11]
In cases treated by posterior sagittal anorectoplasty, by virtue of incision being strictly in the midline, it is believed to carry no deleterious effect on functional status of the lower urinary tract.[9],[10],[11] This may be substantiated by an urodynamic evaluation. This study describes the incidence of occult neurovesical dysfunction and the effect of operative interventions for the correction of ARM on the neurovesical function of patients with ARM.
Materials and methods
This prospective study was conducted in the Department of Paediatric Surgery, All India Institute of Medical Sciences from January 2002 to June 2004. Children with ARM were evaluated clinically and radiologically for clinical or radiological evidence of lower urinary tract dysfunction and were subjected to an urodynamic evaluation. Six weeks after definitive surgery the patients were again evaluated for evidence of lower urinary tract dysfunction and were subjected to repeat urodynamic study. Urodynamic evaluation was performed under intravenous Midazolam sedation as most of the cases were below two years of age. Urodynamic studies were performed on the Phoenix Griffon machine (Albyn Medical) using Phoenix plus software. Double lumen (8 F, Albyn Medical) urethral catheter and Mediplus (4.5 F, MED 5400, UK) rectal catheter was used to monitor vesical (Pves) and abdominal pressure (Pabd) and to derive detrusor pressure (Pdet). EMG using two pad electrodes and one ground electrode applied to the thigh was routinely performed, (Bandwidth 0.1 - 20 kHz, input impedence >200 MWt at 50 Hz). A roller peristaltic infusion pump (speed range - 1 to 150 ml/minute) was used and slow filling cystometry with the rate of infusion 5ml per minute was set for all cases. The infusate was normal saline maintained at room temperature. Prior to urodynamic examination urine was cultured routinely. If culture was positive, study was deferred.
The expected bladder capacity was calculated using Berger's (1983)[12] formula (age in years + 2) X 30, for children above 2 yrs of age and Fairhurst's (1991)[13] formula of 7 X weight [Kg] - 1.2, for children below 2 years of age. The patient was observed during the study for first sensation, sense of urgency, pain, leak, and uninhibited contractions. Uninhibited contractions (UIC) were defined as detrusor contractions of greater than 15 centimeters of H 2 O during filling phase. Compliance was defined as the ability of the bladder to expand to capacity with minimal changes in the intravesical pressure and was calculated as compliance = Change in volume/Change in pressure.
Results
Nineteen children in the age range of 3 months to 156 months (mean = 19.2) were included in this study. Among these 19 children, 13 underwent re-evaluation after definitive surgery for ARM. There were 11 (57.9%) males and 8 (42.1%) females. Of the nineteen, 14- (73.7%) were cases of high anorectal malformation (HARM) and 5 (26.3%) were cases of low anorectal malformation (LARM). The definitive procedures performed in the HARM group were either posterior sagittal anorectoplasty (PSARP) in 55.6% (5 of 9) or abdomino perineal posterior sagittal anorectoplasty (APPSARP) in 44.4% (4 of 9) while in the LARM group, Burrow's anoplasty was performed in 25% (1 of 4) and anal transposition in 75% (3 of 4). Eight cases, all with HARM, had associated congenital anomalies. On routine ultrasound examination, none had any demonstrable upper tract dilatation though three patients were found to have solitary kidney, three had cardiac anomaly while two had esophageal atresia with tracheoesophageal fistula. Two patients had vertebral anomalies (absence of the last piece of sacrum in both) while other two patients had complaints of urinary dribbling. Of the two patients who had complaints of dribbling, only one had vertebral, anomaly.
UIC was present in 47.4% (9 of 19) of which 77.8% (7 of 9 cases) had poorly compliant bladders and 66.7% (6 of 9 cases) small capacity bladders table1 Figure1. No UIC were observed in 52.6% (10 of 19 cases) of which 10% (1 to 10) hadpoorly compliant, none had small capacity and 50% (5 of 10 cases) had large capacity bladcleW table1.
Eleven of l9 (57.9%) had compliant bladder. 18.2% (2 of 11) of these had UIC and 81.8% (9 of 11) did not show UIC. In 45.5% (5 of 11) cases bladder capacity was normal, 9.1% (1 of 11) showed small capacity and 45.5% (5 of 11) had large capacity bladde table2. Of the 8 patients (42.1%; 8 of 19) who had poorly compliant bladder, UIC was present in 87.5% (7 of 8). Of these 8 patients bladder capacity was found to be normal in 37.5% (3 of 8) and small in 62.5% (5 of 8) table2.
Of the 8 patients with normal capacity bladder 37.5% (3 of 8) had UIC and an equal number had poorly compliant bladder. Six patients had small capacity bladders and all six had UIC while the compliance was poor in 83.3% (5 of 6) patients. Five of these 19 patients (26.3%) had a large capacity bladder and none of those had UIC or poor compliance table3.
In this baseline urodynamic evaluation seven different urodynamic patterns were observed.
Normal capacity, compliant without UIC - 21.1% (4 of 19)
Normal capacity, compliant with UIC - 5.3% (1 of 19)
Normal capacity, poorly compliant without - 5.3% (1 of 19) UIC
Normal capacity, poorly compliant with UIC - 10.5% (2 of 19)
Small capacity, compliant with UIC - 5.3% (1 of 19)
Small capacity, poorly compliant with UIC - 26.3% (5 of 19)
Large capacity, compliant without UIC - 26.3% (5 of 19)
Thirteen of the nineteen patients with preoperative baseline urodynamic evaluation had also undergone a postoperative evaluation. The results are summarized in table4. Comparing the postoperative with preoperative urodynamic evaluation, of those 6 who had UIC in the preoperative period, 4 (66.7%) persisted to have UIC while in 2 patients (33.3%) the UIC had disappeared. Of the 7 patients who did not have preoperative UIC, 57.1% (4 of 7) developed UIC, white 42.9% (3 of 7) continued not to have UIC.
Of the six patients who had poorly compliant bladders on preoperative evaluations, three (50%) persisted to have poorly compliant bladders in the postoperative period while in the other three, bladders were found to be compliant on postoperative study. Out of 7 preoperatively compliant bladders, 77.4% (5 of 7) remained-compliant while in 28.6% (2 of 7), the bladders became poorly compliant table4.
Of the 6 patients with normal capacity bladders; 4 remained as such while in 2 it became small capacity bladders. Four of the 13 patients who had small capacity bladders preoperatively, 75% (3 of 4) continued to have small capacity bladder postoperatively while 25% (1 of 4) of these acquired normal capacity. Of the 3 patients who had large capacity bladder preoperatively 2 became normal capacity while 1 became small capacity table4.
Discussion
Neurovesical dysfunctions (NVD have been reported in approximately 7 -29% of children with ARM.[14],[15],[16],[17] The presence of vertebral anomalies accompanying ARM may be an indicator for the presence of NVD but such dysfunction may be present even in the absence of vertebral anomalies (Occult NVD).[7],[8],[9] Functional urologic problems are often compounded by associated anatomic urologic abnormalities and these in combination may profoundly alter the course and prognosis of children with ARM. All patients with ARM should be suspected as being at risk for neurovesical dysfunction. These NVD may cause early or late deterioration of the upper urinary tract. Occult spinal dysraphism which includes tethered cord, lipomas, neuroenteric cysts and diastometamyelia are now recognized as important anomalies associated with ARM.[8],[9] The urinary problems in tethered cord syndrome are known to be progressive and have been reported to improve after surgical correction.[18],[19],[20],[21] The same is not known about occult NVD. The early detection of lower tract dysfunction may help in prevention of upper tract deterioration by early intervention.
Neurovesical dysfunction secondary to inadvertent surgical injury of the pelvic nerves and nerve plexus can develop in children with ARM. Pena's posterior sagittal anorectoplasty (PSARP) by virtue of being strictly in midline is believed to have no deleterious effects on lower urinary tract function. However, abdomino-perineal anorectoplasty (APPSARP) may cause some neurogenic dysfunction as the rectal pouch is mobilized close to the urinary tract. The incidence of neurogenic dysfunction developing after 'pull through' procedure is not very high.[10], [11], [12]
In the present study only 21% of the patients (4 of 19) showed no evidence of NVD while in the remaining 79% (15 of 19) some form of NVD was observed. This was in the form of uninhibited contractions, small/large capacity bladders, poor compliance or a combination of these abnormalities. Therefore, irrespective of high or low ARM, presence or absence of vertebral anomalies, presence or absence of clinical or radiological abnormalities of the lower urinary tract, occult neurovesical dysfunction remains a common finding.
Of the two patients who had dribbling, one had UIC with poorly compliant bladder but no vertebral anomaly while the other had normal capacity compliant bladder without UIC but had vertebral anomaly.
In the present study 13 patients were evaluated post-operatively also and in only 23% (3 of 13) no change in urodynamic pattern was observed. In the remaining 76.9% (10 of 13) some changes in urodynamic pattern was observed. The deleterious changes observed were the appearance of UIC in 30.8% (4 of 13), 3 who had undergone PSARP and one APPSARP. Decrease in the bladder capacity was seen in 23% (3 of 13) one of whom had undergone PSARP and two APPSARP. Decrease in bladder compliance was seen in 15.4% (2 of 13), both of whom had undergone PSARP table4.
Amongst the 4 patients who had undergone APPSARP, in only one case no changes were observed while in the remaining three there was appearance of UIC in one and decrease in bladder capacity in two. Amongst the 5 patients who had undergone PSARP no change was observed in only one case, appearance of UIC was seen in three and decrease in bladder capacity in one. In 2 of these 5 patients the bladder became poorly compliant. These changes in the postoperative urodynamic evaluations may progress or resolve. This can only be resolved by repeating the studies at a later date. This means that these patients need to be on regular follow up, clinically, radiologically, and urodynamically for long periods of time.
Neurovesical dysfunction should be suspected in all cases of ARM as patients with NVD are potentially at risk for upper tract dysfunction at a later date. Furthermore, early and late changes have been described after definitive surgery for the correction of ARM in terms of loss of detrusor contractility, large bladder capacities, poor compliance, abdominal (straining during) voiding and high post void residues.[22] Therefore, evaluation of functional as well as structural abnormalities of the lower urinary tract should be completed before anorectoplasty. When possible, neurovesical dysfunction should be managed with clean intermittent catheterization to prevent renal damage and all patients with recto-urinary fistulas and having vesicoureteric reflux or neurovesical dysfunction should be put on cyclical chemoprophylaxis from beginning. Pharmacotherapy for detrusor relaxation so as to take care of UIC may also be required.
Conclusion
Incidence of occult NVD, as documented in this study, is high in patients with ARM even in the absence of clinical and radiological evidence of vertebral or lower urinary tract abnormalities. Only 9 of the 19 patients had normal urodynamics pre-operatively and post-operatively 3 more patients worsened. The baseline NVD as well as deleterious changes due to surgical interventions may be responsible for upper tract deterioration at a later date in these patients. Only time will tell whether this true or not. These observations as well as the progression or resolution of neurovesical abnormalities will need to be studied in these patients with ARM by a linear study and evaluating these patients at a later date also.
References
1. Hall JW, Tank ES, Lapides J. Urogenital anomalies and complications associated with imperforate anus. J Urol 1970; 103 : 810-804.
2. Wiener ES, Kiesewitter WB. Urologic abnormalities associated with imperforate anus. J Pediatr Surg 1973; 8 : 151 -157.
3. Smith ED. Urinary anomalies and complications in imperforate anus and rectum. J Pediatr Surg 1968; 3 : 337-349.
4. Ralph DJ, Woodhouse CR, Ransley PG.The management of the neuropathic bladder in adolescents with imperforate anus. J Urol 1992; 148 : 366-368.
5. Denton JR. The association of congenital spinal anomalies with imperforate anus. Clin Ortho 1982; 162 : 91-98.
6. Boemers TML, de Jong TP, van Gool JD, Bax KM. Urologic problems in anorectal malformations Part2: functional urologic sequelae. J Pediatr Surg 1996: 31 : 634-637.
7. Sheldon C, Cormier M, Crone K, Wacksman. Occult neurovesical dysfunction in children with imperforate anus. J Pediatr Surg 1991; 26 : 49-54.
8. Carson JA, Barnes PD, Tunell WP et al. Imperforate anus: The neurologic implication of sacral abnormalities. J Pediatr Surg 1984; 19 : 838-842.
9. Karrer FM, Flannerg AM, Nelson MD et al. Anorectal malformations: Evaluation of associated spinal dysraphic syndromes. J Pediatr Surg 1988; 23 : 45-48.
10. Kilic N, Emir H, Sander S, Elicevik M, Celayir S, Soylet Y. Comparison of urodynamic investigations before and after posterior sagittal anorectoplasty for anorectal malformations. J Pediatr Surg 1997; 32 : 1724-1727.
11. Hong AR, Acuna MF, Pena A, Chaves L, Rodriguez G. Urologic injuries associated with repair of anorectal malformations in male patients . J pediatr Surg 2002; 37 : 339-344.
12. Berger RM, Maizels M, Moran GC et al. Bladder capacity (ounces) equal age (years) plus 2 predicts normal bladder capacity and aids in diagnosis of voiding patterns. J Urol 1983; 129 : 347-349.
13. Fairhurst JJ, Rubin CME, Hyde I, Freeman NV, Williams JD. Bladder capacity in infants. J Pediatr Surg 1991; 26 : 55-57.
14. Parrott TS. Urologic implications of ARM. Urol Clin N Am 1985; 12 : 13.
15. Belman AH, King LR. Urinary tract abnormalities associated with imperforate anus. J Urol 1972; 108 : 823.
16. Greenfield SP, Fera M. Urodynamic evaluation of the patient with an imperforate anus: a prospective study. J Urol 1991; 146 : 539.
17. Tank ES, Ernst CB, Woolson ST, Lapides J. Urinary tract complications of anorectal surgery. Am J Surg 1972; 123 : 118-125.
18. Curres D. Sacral dysgenesis associate with occult spinal dysraphism causing neurogenic bladder dysfunction. J Urol 1977; 117: 127- 128.
19. Pang D, Hoffinan HJ. Sacral agenesis with progressive neurological deficit. J Neuro Surg 1980; 7 : 118-125.
20. Hellstrom WJ, Edwards MS, Kogan B. Urological aspects of the tethered cord syndrome. J Urol 1985; 135 : 317-320.
21. Boemers TML, Vangool JD, De long TPVM. Urodynamic investigations in children with the caudal regression syndrome. Br J Urol 1991; 64 : 641A
22. Boemers TML, Bax KMA, Rovekamp MH, Van Goo JD. The effect of posterior sagittal anorectoplasty and its variations on lower urinary tract function in children with ARM. J Urol 1995; 153 : 191-193.(Kumar Arun, Agarwala S, M)
Abstract
Objective. To evaluate for the occurance of occult NVD in children with anorectal malformatons (ARM) using urodynamic evaluation. Methods. This prospective study was carried out on children with ARM prior to and following definitive procedure. Urodynamic studies were performed on the Phoenix Griffon machine (Albyn Medical) using Phonix plus software. Result. Nineteen children in the age range of 3 months to 156 months (mean = 19.2) were included in this study. Among these 19 children 13 underwent re-evaluation after definitive surgery for ARM. There were 11(57.9%) males and 8(42.1%) females. Of the 19 children 14 (73.7%) were cases of high anorectal malformation (HARM) and 5 (26.3%) were cases of low anorectal malformation (LARM). Baseline evaluation done in 19 children revealed seven urodnamci patterns: Normal capacity, compliant without uninhibited contractions (UIC) (21.1%); Normal capacity, compliant with UIC (5.3%); Normal capactity, poorly compliant without UIC (5.3%); Normal capacity, poorly compliant with UIC (10.5%); small capacity, compliant with UIC (5.3%); Small capactity, poorly compliant with UIC (26.3%) and large capacity, complaint with UIC (26.3%). Thirteen patients were evaluated post operativey also and in only 23% (3 of 13) no change in urodynamic pattern were observed. In the remaining 76.9% (10 of 13) some changes in urodynamics pattern were observed. The deleterious changes observed were appearance of UIC in 30.8% (4 of 13), decrease in the bladder capacity in 23% (3 of 13) and decrease in bladder compliance in 15.4% (2 of 13). Conclusion. Only 9 of of the 19 patients had normal urodynamics pre-operatively and post-operatively 3 more patients worsened. Incidence of occult NVD is high in patients with ARM even in the absence of clinical and radiological evidence of vertebral or lower uinary tract abnormalities. Though there seems to be a high incidence of changes in the neurovesical functions of these patients following definitive corrective surgery for ARM only time will show whether this has any deleterious effect on the upper tracts.
Keywords: Anorectal malformation; Occult neurovesical dysfucntion
Association of anorectal malformations (ARM) with structural abnormalities of urinary tract along with variable degrees of vertebral, and urogenhal anomalies is well established.[1],[2],[3],[4],[5] Functional abnormalities of the urinary tract (neurovesical dysfunction, NVD) in children with ARM have recentry been recognized.[6],[7]
Occult spinal dysraphism with tethered cord, lipoma, syrinx and diastematomyelia associated with ARM have also been recognized to be the cause of lower urinary tract dysfunction in such cases.[8],[9] On the other hand no such markers are associated with children suffering from NVD. The importance of NVD in patients of ARM cannot be overemphasized as it alters the management by virtue of therapeutic considerations unique to the condition. Occult NVD may be responsible for added morbidity in the patients and appropriate management of these dysfunction my lead to decrease in morbidity.[6]
NVD may occur in cases of ARM even when clinical and radiological evaluations do not show any abnormality. Also, NVD following definitive procedures for management of ARM can be evaluated and managed appropriately. Moreover, functional urological problems are compounded by associated anatomical Abnormalities.[8],[9],[10],[11]
In cases treated by posterior sagittal anorectoplasty, by virtue of incision being strictly in the midline, it is believed to carry no deleterious effect on functional status of the lower urinary tract.[9],[10],[11] This may be substantiated by an urodynamic evaluation. This study describes the incidence of occult neurovesical dysfunction and the effect of operative interventions for the correction of ARM on the neurovesical function of patients with ARM.
Materials and methods
This prospective study was conducted in the Department of Paediatric Surgery, All India Institute of Medical Sciences from January 2002 to June 2004. Children with ARM were evaluated clinically and radiologically for clinical or radiological evidence of lower urinary tract dysfunction and were subjected to an urodynamic evaluation. Six weeks after definitive surgery the patients were again evaluated for evidence of lower urinary tract dysfunction and were subjected to repeat urodynamic study. Urodynamic evaluation was performed under intravenous Midazolam sedation as most of the cases were below two years of age. Urodynamic studies were performed on the Phoenix Griffon machine (Albyn Medical) using Phoenix plus software. Double lumen (8 F, Albyn Medical) urethral catheter and Mediplus (4.5 F, MED 5400, UK) rectal catheter was used to monitor vesical (Pves) and abdominal pressure (Pabd) and to derive detrusor pressure (Pdet). EMG using two pad electrodes and one ground electrode applied to the thigh was routinely performed, (Bandwidth 0.1 - 20 kHz, input impedence >200 MWt at 50 Hz). A roller peristaltic infusion pump (speed range - 1 to 150 ml/minute) was used and slow filling cystometry with the rate of infusion 5ml per minute was set for all cases. The infusate was normal saline maintained at room temperature. Prior to urodynamic examination urine was cultured routinely. If culture was positive, study was deferred.
The expected bladder capacity was calculated using Berger's (1983)[12] formula (age in years + 2) X 30, for children above 2 yrs of age and Fairhurst's (1991)[13] formula of 7 X weight [Kg] - 1.2, for children below 2 years of age. The patient was observed during the study for first sensation, sense of urgency, pain, leak, and uninhibited contractions. Uninhibited contractions (UIC) were defined as detrusor contractions of greater than 15 centimeters of H 2 O during filling phase. Compliance was defined as the ability of the bladder to expand to capacity with minimal changes in the intravesical pressure and was calculated as compliance = Change in volume/Change in pressure.
Results
Nineteen children in the age range of 3 months to 156 months (mean = 19.2) were included in this study. Among these 19 children, 13 underwent re-evaluation after definitive surgery for ARM. There were 11 (57.9%) males and 8 (42.1%) females. Of the nineteen, 14- (73.7%) were cases of high anorectal malformation (HARM) and 5 (26.3%) were cases of low anorectal malformation (LARM). The definitive procedures performed in the HARM group were either posterior sagittal anorectoplasty (PSARP) in 55.6% (5 of 9) or abdomino perineal posterior sagittal anorectoplasty (APPSARP) in 44.4% (4 of 9) while in the LARM group, Burrow's anoplasty was performed in 25% (1 of 4) and anal transposition in 75% (3 of 4). Eight cases, all with HARM, had associated congenital anomalies. On routine ultrasound examination, none had any demonstrable upper tract dilatation though three patients were found to have solitary kidney, three had cardiac anomaly while two had esophageal atresia with tracheoesophageal fistula. Two patients had vertebral anomalies (absence of the last piece of sacrum in both) while other two patients had complaints of urinary dribbling. Of the two patients who had complaints of dribbling, only one had vertebral, anomaly.
UIC was present in 47.4% (9 of 19) of which 77.8% (7 of 9 cases) had poorly compliant bladders and 66.7% (6 of 9 cases) small capacity bladders table1 Figure1. No UIC were observed in 52.6% (10 of 19 cases) of which 10% (1 to 10) hadpoorly compliant, none had small capacity and 50% (5 of 10 cases) had large capacity bladcleW table1.
Eleven of l9 (57.9%) had compliant bladder. 18.2% (2 of 11) of these had UIC and 81.8% (9 of 11) did not show UIC. In 45.5% (5 of 11) cases bladder capacity was normal, 9.1% (1 of 11) showed small capacity and 45.5% (5 of 11) had large capacity bladde table2. Of the 8 patients (42.1%; 8 of 19) who had poorly compliant bladder, UIC was present in 87.5% (7 of 8). Of these 8 patients bladder capacity was found to be normal in 37.5% (3 of 8) and small in 62.5% (5 of 8) table2.
Of the 8 patients with normal capacity bladder 37.5% (3 of 8) had UIC and an equal number had poorly compliant bladder. Six patients had small capacity bladders and all six had UIC while the compliance was poor in 83.3% (5 of 6) patients. Five of these 19 patients (26.3%) had a large capacity bladder and none of those had UIC or poor compliance table3.
In this baseline urodynamic evaluation seven different urodynamic patterns were observed.
Normal capacity, compliant without UIC - 21.1% (4 of 19)
Normal capacity, compliant with UIC - 5.3% (1 of 19)
Normal capacity, poorly compliant without - 5.3% (1 of 19) UIC
Normal capacity, poorly compliant with UIC - 10.5% (2 of 19)
Small capacity, compliant with UIC - 5.3% (1 of 19)
Small capacity, poorly compliant with UIC - 26.3% (5 of 19)
Large capacity, compliant without UIC - 26.3% (5 of 19)
Thirteen of the nineteen patients with preoperative baseline urodynamic evaluation had also undergone a postoperative evaluation. The results are summarized in table4. Comparing the postoperative with preoperative urodynamic evaluation, of those 6 who had UIC in the preoperative period, 4 (66.7%) persisted to have UIC while in 2 patients (33.3%) the UIC had disappeared. Of the 7 patients who did not have preoperative UIC, 57.1% (4 of 7) developed UIC, white 42.9% (3 of 7) continued not to have UIC.
Of the six patients who had poorly compliant bladders on preoperative evaluations, three (50%) persisted to have poorly compliant bladders in the postoperative period while in the other three, bladders were found to be compliant on postoperative study. Out of 7 preoperatively compliant bladders, 77.4% (5 of 7) remained-compliant while in 28.6% (2 of 7), the bladders became poorly compliant table4.
Of the 6 patients with normal capacity bladders; 4 remained as such while in 2 it became small capacity bladders. Four of the 13 patients who had small capacity bladders preoperatively, 75% (3 of 4) continued to have small capacity bladder postoperatively while 25% (1 of 4) of these acquired normal capacity. Of the 3 patients who had large capacity bladder preoperatively 2 became normal capacity while 1 became small capacity table4.
Discussion
Neurovesical dysfunctions (NVD have been reported in approximately 7 -29% of children with ARM.[14],[15],[16],[17] The presence of vertebral anomalies accompanying ARM may be an indicator for the presence of NVD but such dysfunction may be present even in the absence of vertebral anomalies (Occult NVD).[7],[8],[9] Functional urologic problems are often compounded by associated anatomic urologic abnormalities and these in combination may profoundly alter the course and prognosis of children with ARM. All patients with ARM should be suspected as being at risk for neurovesical dysfunction. These NVD may cause early or late deterioration of the upper urinary tract. Occult spinal dysraphism which includes tethered cord, lipomas, neuroenteric cysts and diastometamyelia are now recognized as important anomalies associated with ARM.[8],[9] The urinary problems in tethered cord syndrome are known to be progressive and have been reported to improve after surgical correction.[18],[19],[20],[21] The same is not known about occult NVD. The early detection of lower tract dysfunction may help in prevention of upper tract deterioration by early intervention.
Neurovesical dysfunction secondary to inadvertent surgical injury of the pelvic nerves and nerve plexus can develop in children with ARM. Pena's posterior sagittal anorectoplasty (PSARP) by virtue of being strictly in midline is believed to have no deleterious effects on lower urinary tract function. However, abdomino-perineal anorectoplasty (APPSARP) may cause some neurogenic dysfunction as the rectal pouch is mobilized close to the urinary tract. The incidence of neurogenic dysfunction developing after 'pull through' procedure is not very high.[10], [11], [12]
In the present study only 21% of the patients (4 of 19) showed no evidence of NVD while in the remaining 79% (15 of 19) some form of NVD was observed. This was in the form of uninhibited contractions, small/large capacity bladders, poor compliance or a combination of these abnormalities. Therefore, irrespective of high or low ARM, presence or absence of vertebral anomalies, presence or absence of clinical or radiological abnormalities of the lower urinary tract, occult neurovesical dysfunction remains a common finding.
Of the two patients who had dribbling, one had UIC with poorly compliant bladder but no vertebral anomaly while the other had normal capacity compliant bladder without UIC but had vertebral anomaly.
In the present study 13 patients were evaluated post-operatively also and in only 23% (3 of 13) no change in urodynamic pattern was observed. In the remaining 76.9% (10 of 13) some changes in urodynamic pattern was observed. The deleterious changes observed were the appearance of UIC in 30.8% (4 of 13), 3 who had undergone PSARP and one APPSARP. Decrease in the bladder capacity was seen in 23% (3 of 13) one of whom had undergone PSARP and two APPSARP. Decrease in bladder compliance was seen in 15.4% (2 of 13), both of whom had undergone PSARP table4.
Amongst the 4 patients who had undergone APPSARP, in only one case no changes were observed while in the remaining three there was appearance of UIC in one and decrease in bladder capacity in two. Amongst the 5 patients who had undergone PSARP no change was observed in only one case, appearance of UIC was seen in three and decrease in bladder capacity in one. In 2 of these 5 patients the bladder became poorly compliant. These changes in the postoperative urodynamic evaluations may progress or resolve. This can only be resolved by repeating the studies at a later date. This means that these patients need to be on regular follow up, clinically, radiologically, and urodynamically for long periods of time.
Neurovesical dysfunction should be suspected in all cases of ARM as patients with NVD are potentially at risk for upper tract dysfunction at a later date. Furthermore, early and late changes have been described after definitive surgery for the correction of ARM in terms of loss of detrusor contractility, large bladder capacities, poor compliance, abdominal (straining during) voiding and high post void residues.[22] Therefore, evaluation of functional as well as structural abnormalities of the lower urinary tract should be completed before anorectoplasty. When possible, neurovesical dysfunction should be managed with clean intermittent catheterization to prevent renal damage and all patients with recto-urinary fistulas and having vesicoureteric reflux or neurovesical dysfunction should be put on cyclical chemoprophylaxis from beginning. Pharmacotherapy for detrusor relaxation so as to take care of UIC may also be required.
Conclusion
Incidence of occult NVD, as documented in this study, is high in patients with ARM even in the absence of clinical and radiological evidence of vertebral or lower urinary tract abnormalities. Only 9 of the 19 patients had normal urodynamics pre-operatively and post-operatively 3 more patients worsened. The baseline NVD as well as deleterious changes due to surgical interventions may be responsible for upper tract deterioration at a later date in these patients. Only time will tell whether this true or not. These observations as well as the progression or resolution of neurovesical abnormalities will need to be studied in these patients with ARM by a linear study and evaluating these patients at a later date also.
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