|Year : 2001 | Volume
| Issue : 1 | Page : 42-44
Urodynamic evaluation in bladder exstrophy patients following primary turn-in
S Dave, S Agarwala, VP Grover, DK Mitra, V Bhatnagar
Department of Pediatric Surgery, All India Institute of Medical Sciences, New Delhi, India
Department of Pediatric Surgery, All India Institute of Medical Sciences, New Delhi 110 029
Source of Support: None, Conflict of Interest: None
| Abstract|| |
The staged repair for bladder exstrophy has been established over the last few decades. Bladder neck repair depends on the ability of the closed bladder to increase in capacity with time. Unfortunately, a significant percentage of bladders remain small necessitating a simultaneous bladder augmentation with or after bladder neck reconstruction. We evaluated 12 patients of classical exstrophy after primary turn in using cystometry. In 5 patients the leak point pressure was zero and there was continuous urine leak. The other 7 children demonstrated storage function. There was a high incidence of uninhibited contractions in this group of children (71.4%). The factors influencing the increase in bladder capacity following primary turn-in and the role of urodynamic evaluation is discussed.
Keywords: Bladder Exstrophy; Urodynamics.
|How to cite this article:|
Dave S, Agarwala S, Grover V P, Mitra D K, Bhatnagar V. Urodynamic evaluation in bladder exstrophy patients following primary turn-in. Indian J Urol 2001;18:42-4
|How to cite this URL:|
Dave S, Agarwala S, Grover V P, Mitra D K, Bhatnagar V. Urodynamic evaluation in bladder exstrophy patients following primary turn-in. Indian J Urol [serial online] 2001 [cited 2019 Nov 21];18:42-4. Available from: http://www.indianjurol.com/text.asp?2001/18/1/42/37415
| Introduction|| |
The bladder following primary turn-in was earlier believed to function as a conduit with no storage function. The exstrophied bladder does not behave normally following turn-in and this can be detrimental to the upper tracts as well as the ultimate continence achieved., The bladder capacity achieved prior to bladder neck reconstruction depends on the intrinsic properties of the bladder muscle and the outlet resistance.
| Patients and Methods|| |
Urodynamic evaluation was performed using the Albyn Medical Phoenix and Griffon Computer System, UK, in 12 patients of classical bladder exstrophy who had undergone primary turn-in without osteotomy during the period 1996 to 1998 by a technique described earlier. The mean age at turn-in was 11.9 months, ranging from I to 23 months. There was no dehiscence. The urodynamic study was performed in children older than 2 years of age and at least 1 year following the primary turnin. The cystometry was performed without sedation, using standard slow fill saline infusion (5 ml/minute filling rate) at room temperature. A size 7F double lumen catheter was inserted and used for infusion and simultaneous recording of vesical pressure (Pves). A rectal balloon catheter was inserted to measure the abdominal pressure (Pabd) and to compute the detrusor pressure (Pdet = Pves - Pabd). The study was repeated to ensure accuracy of the results obtained. The following parameters were noted and analyzed: maximum cystometric capacity, leak point pressure and presence of uninhibited contractions. Leak point pressure was defined as the total vesical pressure which resulted in urine leakage. Uninhibited contractions were defined as involuntary detrusor contraction exceeding 15 cm HO. The upper tracts were accessed using ultrasonography and Tc99 m DTPA renogram.
| Results|| |
Of the 12 children evaluated, 5 patients did not retain any saline and leaked continuously without any increase in bladder pressure. The leak point pressure was 0 cm HO in this group of patients. The bladder functioned as a conduit without any outlet resistance. The other 7 children had well defined storage function and could be assessed by cystometry, the details of which are presented in the Table.
The maximum cystometric capacity ranged between 20 and 77 ml but none of the children reached their expected capacity for age as defined by Houle et al. The leak point pressure ranged between 4 and 73 cm HO. A higher leak pressure in general favoured a better capacity but in all cases with leak pressures greater than 30 cm H,0 there was bilateral hydronephrosis on ultrasonography. The renal function and drainage pattern on diuretic renogram was normal and unobstructed.
5 of the 7 patients had uninhibited contractions which persisted on the follow-up study. 3 of these patients had urine leak during, these contractions which subsided with cessation of each contraction. Cases no. 1 and 2 had evidence of bladder outlet obstruction and required dilatation. In all the other patients the 7F catheter could be inserted easily.
| Discussion|| |
A successful early primary turn-in is one of the main factors which determines the ultimate level of continence which can be achieved in patients of urinary bladder exstrophy.,, The final outcome of surgery for continence depends to a great extent on the bladder capacity and the urethral length which can be achieved in these patients by various procedures. Bladder neck reconstruction by tubularisation of the bladder consumes a certain percentage of bladder tissue which contributes to the post turn-in and pre-bladder neck reconstruction capacity. The increase in bladder capacity following primary turn-in depends on the intrinsic properties of the detrusor and the outlet resistance. It has been shown that the exstrophied bladder has a lower smooth muscle to connective tissue ratio and a preponderance of type III collagen., The aim of this study was to evaluate the probable factors responsible for the poor increase in capacity seen in these patients following, turn-in.
Hollowell et al were the first to evaluate lower urinary tract function in exstrophy patients and showed that abnormal bladder function per se could be responsible for upper tract deterioration and incontinence., The age at primary turn-in has an obvious impact on the ultimate bladder capacity achieved and an earlier primary turn-in without dehiscence helps in attaining a better capacity. A low leak point pressure does not allow bladder capacity to increase. 2 of our patients with leak point pressures below 10 cm HO (cases 3 and 4) had leaks associated with uninhibited contractions and had low bladder capacities (16.1 % and 32.2% of expected capacity respectively).
The concept of epispadias repair before bladder neck reconstruction has shown to increase capacity and this would further support the view that a higher leak pressure leads to a better increase in capacity.
The majority of children with exstrophy are born with normal upper tracts. A high leak pressure in the presence of reflux can be detrimental to the upper tracts. All 3 of our patients with leak point pressures greater than 30 cm H2O had upper tract dilatation on ultrasonography.
Of the 7 patients in our study, 5 (71.4%) had evidence of uninhibited contractions and 3 leaked urine only during, these contractions. This can be a significant factor which inhibits the development of bladder capacity following primary turn-in.
We believe that urodynamic assessment is a valuable tool in evaluating, patients of exstrophy bladder following turn-in. A low leak point pressure and uninhibited contractions are the primary reasons for the failure of the bladder to increase in size. Patients with uninhibited contractions can benefit from anticholinergic treatment. An early epispadias repair will also increase outlet resistance and hence the capacity. Also. a high leak point pressure would warrant careful assessment of the upper tracts and dilatation of the bladder outlet if there is any significant narrowing or early re-implantation of the ureters in the presence of vesico-ureteral reflux.
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