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Pressure Measurements in Ileal Conduits
Vol. 114, October Printed in U.SA.
THE JOURNAL OF UROLOGY
Copyright © 1975 by The Williams & Wilkins Co.
PRESSURE MEASUREMENTS IN ILEAL CONDUITS ROBERT M. WEISS, EDWARD J. MCGUIRE
AND
BERNARD LYTTON
From ih,e Department of Surgery, Section of Urology, Yale University School of Medicine, New Haven, Connecticut
ABSTRACT
To study the dynamic properties of ileal conduits and to attempt to diagnose obstruction at an early point in time, that is prior to the development of conduit or upper urinary tract dilatation, a continuously perfused catheter technique was used to measure pressures within the conduit during filling and emptying, and to measure the resistance to flow at the stomal level. The mean values of residual urine, resting pressure, voiding pressure and stomal profile pressure were significantly higher in obstructed than in non-obstructed conduits. However, there was an overlap between values in each parameter, thus necessitating analysis of the entire pressure data in any given case. The data also show that even a small increase in residual urine above normal, 4.0 plus or minus 0.9 cc, may be an indication of early obstruction and that stomal caliber does not necessarily correlate with the degree of obstruction. The ileal conduit is the most commonly used method of supravesical urinary diversion. Its efficacy is predicated on its ability to act as a freely draining conduit rather than as a reservoir that empties periodically. The usual method of end-toside ureteroileal anastomosis permits free reflux of urine from the conduit to the ureters, 1 as can be shown by a loopogram 2 or by the use of cine-fluoroscopic techniques during excretory urography (IVP). 3 The demonstration of ileal ureteral reflux during IVP indicates that reflux of urine to the kidneys occurs during normal activity. Stomal obstruction would be expected to result in a rise in pressure within the conduit and to increase the degree of reflux of infected urine into the kidney, factors which may lead to renal damage. Harbach and associates reviewed their experience with 244 ileal cutaneous urinary diversions and noted a 25 per cent incidence of stenosis of the ileal stoma in children with only a 2.3 per cent incidence in adults. 4 The high incidence of stomal stenosis in children has been described by others.•-• A review of the literature revealed a 25 per cent incidence of stomal stenosis in 500 children who had undergone ileal conduit diversion. 9 We also have observed a higher incidence of stomal obstruction in children than in adults with ileal conduits, which is probably related to the rate of growth of the child with respect to the fixed aperture in the abdominal wall. To study the dynamic properties of ileal conduits in children and to attempt to diagnose stomal obstruction at an early point in time, a continuously perfused catheter technique has been used to measure pressures within the conduit during filling Accepted for publication February 21, 1975. 591
and emptying and to measure resistance to flow at the stomal level. METHODS
A 12F catheter with a single side hole is inserted into the conduit and the residual urine is collected. The catheter is then perfused at a constant rate of 10 cc per minute with a 20 per cent hypaque solution from a large reservoir. The pressure within the loop is monitored with a Statham pressure transducer and recorded on a Grass polygraph. In certain cases simultaneous fluoroscopic monitoring of the loop was performed with the use of an image intensifier. Pressure within the conduit was continuously measured during filling and extrusion of the hypaque solution around the catheter. The quantity of fluid infused that resulted in the onset of extrusion around the catheter was referred to as the capacity and the pressure rise during extrusion was referred to as the voiding pressure. By gradually withdrawing the perfusion aperture of the catheter across the stoma the pressure profile of the stoma or resistance to flow of the perfusate was determined. This pressure rise across the stoma is a function of the increased resistance to flow at the stoma and is a reflection of the relative degree of obstruction. A more practical method for recording these pressure changes, which can be readily used at the bedside or in the office, consists of using a simple venous pressure manometer in place of the transducer and recorder. Thus, the method is readily applicable for routine use. To evaluate the results of the loop dynamicsresidual urine, base line filling pressure (resting pressure), voiding pressure and stomal pressure profile-it is necessary to assess each parameter separately and as a group.
592
WEISS, MCGUIRE AND LYTTON CASE REPORTS
Case 1. C. C., a 4-year-old white girl, who at 5 days of age had an excision of a sacral teratoma, underwent an ileal conduit urinary diversion because of a neurogenic bladder, persistent infection and evidence of chronic pyelonephritis. An IVP 3 years postoperatively showed that the appearance of the upper urinary tract had remained unchanged (fig. 1). The pressure data were characteristic of a well functioning conduit. The residual urine was 3 cc, base line or resting pressure was 2 cm. water, capacity was 15 cc, voiding pressure was low at 7 cm. water and there was a negligible stomal pressure profile. Case 2. J. W., a white boy, had undergone an ileal conduit diversion when he was 2 years old for exstrophy of the bladder. An IVP 2 years after urinary diversion showed mild ureteral dilatation and a distended ileal loop (fig. 2, A). A 28F catheter could be passed easily through the stoma into the loop and the residual urine was 40 cc. The pressure profile across the stoma was elevated to 36 cm. water and with filling there was a gradual rise in the base line pressure. Capacity was 40 cc with an elevated voiding pressure of 48 cm. water.
Because of the pyelographic changes and the obstructive pattern of the pressure data, a revision of the stoma at the skin and fascial levels was performed. An IVP 6 months postoperatively showed improvement and the pressure data returned toward normal (fig. 2, B). Residual was 3 cc, stomal profile was 5 cm. water, capacity was 18 cc and voiding pressure was 12 cm. water. These normal studies were recorded at a time when the stoma, because of acanthosis, would admit only a 16F catheter. Case 3. A. D., a 4-year-old white boy, underwent a high ilea! conduit diversion for massive hydroureteronephrosis associated with prune belly syndrome. An IVP 6 months after diversion showed the dilated pelviocaliceal system and an ileal loop of adequate size. Recurrent abdominal pain developed 6 months later and a loopogram and IVP showed marked dilatation of the conduit (fig. 3). The residual was 250 cc, resting pressure was 2 cm. water and the voiding pressure was slightly elevated to 22 cm. water. The low pressure in the conduit, even after filling with 200 to 300 cc, was indicative of decompensation and was a reflection of the late stage of obstruction. Nine months after an extensive revision of the conduit the pyelogram was improved, the resting pressure was 5 cm. water, voiding pressure was 14 cm. water, stomal profile was 4 cm. water and residual urine was 15 cc. DISCUSSION
C,C. 11;73
RESJDUA L 3 cc CAPACITY 15 cc VOIDING P. 7 cm H2 0 PROFILE 2 cm H20
10 cc
15 cc PROFILE
FIG. 1. Case 1. IVP 3 years after ilea! conduit diversion shows bilateral calicectasis and loss of renal parenchyma. This . represents stable appearance of upper urmary tract smce surgery. Pressure data are characteristic of well functioning conduit. Fluid was extruded around catheter after 15 cc of filling, voiding.
Although ileal conduit diversion is a widely accepted form of supravesical urinary diversion it is associated with frequent early and late complications. A review of 90 children with ileal conduit urinary diversions with a minimum followup of 10 years showed that 87 per cent had complications. 10 Stomal obstruction was the most common complication after the patient was discharged from the hospital, occurring in 38 per cent of the cases. Other complications leading to ileal conduit revision included ureteroileal obstruction (22.2 per cent), elongation of the ileal segment (11.1 per cent), extrinsic loop obstruction (5.6 per cent), stenosis of the ilea! conduit itself (3.3 per cent) and stomal prolapse (3.3 per cent). Some of these complications may have been caused by stomal obstruction. A total of 66.7 per cent of the children in this group required at least 1 revision of the conduit. Comparison of resting pressures in 7 ileal and 4 colonic conduits showed the pressure to be slightly higher in the latter. 11 A non-perfused catheter was used in this study, and the authors did not attempt to use the technique to diagnose stomal obstruction. The perfused catheter provides a more accurate measurement of intraluminal pressure in organs that are not continuously distended with fluid, such as an ilea! conduit. With a non-perfused catheter system, apposition of the conduit wall and t~e catheter lumen results in recording inaccuracies.
593
PRESSURE MEASUREMENTS IN ILEAL CONDUITS
J,W. 11/71
A PROFILE
RESIDUAL 40 cc CAPACITY 40 cc VOIDING P. 48 cm H20 PROFILE 36 cm H20
J.W. 5/72
B
I
24cm H20
--1''---"'""'
40cc VOIDING
PROFILE
RESIDUAL 3 cc CAPACITY 18 cc VOIDING P. 12 cm H2 o PROF! LE 5 cm H2 0
PROFILE
15 cc.
VOIDING
VOIDING
Fm. 2. Case 2. A, IVP shows distended conduit with mild increase of upper urinary tract dilatation. Pressure data are characteristic of stomal obstruction. B, IVP 6 months after stoma revision shows improvement and pressure data have returned toward normal.
A,D, 11/71
RESIDUAL 250 cc CAPACITY 300 cc VOIDING P. 22 cm H20
100 cc
200 cc
300 cc
Fm. 3. Case 3. A, loopogram and B, IVP show markedly dilated conduit in child with prune belly syndrome. Pressure data are indicative of loop decompensation with intraluminal pressure remaining low until voiding occurred, after 300 cc of filling.
594
WEISS, MCGUIRE AND LYTTON
The incidence of infected urine in conduits has been reported to range from 14 to 98 per cent. 5 • 12- 11 However, there is good evidence that the urine in the proximal portion of a well functioning ileal conduit is sterile in the majority of cases and that contamination from the immediate stomal area accounts for the high incidence previously reported. Therefore, any distal obstruction will result in prompt infection of the urine in the proximal portion of the conduit in the majority of cases. In the intact urinary system vesicoureteral reflux in the presence of infection is a well established cause of renal damage. 18 Therefore, any obstruction of the stoma would be likely to result in reflux of infected urine with consequent renal changes. Recently, Richie and associates showed histological changes compatible with pyelonephritis in 83 per cent of dogs with ileal conduit diversions, suggesting that some renal changes might occur even in patients with unobstructed loops. 19 Dogs with colonic conduits in which a non-refluxing ureterocolonic anastomosis had been made had only a 7 per cent incidence of pyelonephritis, suggesting that such an antireflux procedure might afford protection to the kidneys. Minton and associates suggested that physiologic studies may help to predict which patients with ileal conduits are predisposed to urinary infection. 20 Manometric studies using an occlusive catheter showed 3 variations of contractile patterns. Although they recognized that the contractile patterns recorded by occluding the ileal stoma may not be a true representation of the contractile activity of all areas of the segment, they noted a lower incidence of infection in patients with conduits having periodic individual forceful contractions with pressure rises ranging from 10 to 100 mm. Hg than in patients with conduits having irregular, weak contractile patterns of activity. Since the conduit was obstructed when their data were obtained correlation was not made between loop pressures and stomal obstruction, although they did note that an 18F stomal opening represented an adequate outflow tract. Minton and associates furthermore determined emptying curves in ileal segments after instillation of a radioactive substance or dye. 20 They correlated a more rapid clearance of these substances with fewer symptomatic infections. Hinman also emphasized the importance of the relationship of the rate of urinary exchange to the resident volume in the loop in determining the incidence of bacteriuria after ureteroileostomy. 21 He noted that obstruction, by increasing the resident volume and decreasing mixing, lowered the rate of exchange and promoted bacteriuria. In order to determine the dynamic pressure changes during conduit filling and emptying and to attempt to diagnose early stomal obstruction, we used a continuously perfused catheter system. This technique permits a more accurate method of measurement of intraconduit pressure during vari-
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Fm. 4. Pressure data obtained from normal and obstructed conduits. A, residual urine. B, resting pressure. C, voiding pressure. D, stomal profile. Each data point represents individual measurement. Number in parentheses is total number of measurements. To right of each column of data points is mean plus or minus standard error of mean. Mean values for each parameter were significantly higher in obstructed than in non-obstructed conduits (residual urine p less than 0.001, resting pressure p less than 0.05, voiding pressure p less than 0.001 and stomal profile p less than 0.005).
ous stages of distension and provides a method to determine the pressure profile across the ileal stoma. The data obtained from normal and obstructed conduits are shown in figure 4. In these studies a 12F catheter with a 0.5 cm.2 side perfusion aperture was used. Zero base line was arbitrarily accepted as the pressure required to maintain a constant flow of 10 cc per minute with the perfusion aperture at the level of the conduit. The mean of the values of residual urine, resting pressure, voiding pressure and stomal profile pressure was significantly higher in obstructed than in nonobstructed conduits. However, all data must be analyzed in any given case since there was overlap between values in each parameter in the normally and abnormally functioning conduits. For instance, a decompensated conduit may have a high
PRESSURE MEASUREMENTS IN !LEAL CONDUITS
residual and an increased capacity even after correction of any stomal obstruction. Such a conduit would have a normal stomal pressure profile and a normal or elevated pressure. In with stomal obstruction abnormalities in pressure parameters I".lay be noted of the conduit or the in any one of stoma or stomal revision. In ments provide a means without radiation exposure, is not fm evaluation. Our data also show that even increases in residual urine above the 0.9 cc, may be indicative of and that stomal caliber may be unrelated to functional stomal obstruction. REFERENCES 1. Bricker, E. M .. Bladder substitution after pelvic
evisceration. Surg. Clin. N. Amer., 30: 1511, 1950. 2. Smith, E. D.: Follow-up study of 150 ilea] conduits in children. J. Pediat. Surg., 7: 1, 1972. 3. Campbell, J. E., Oliver, J. A. and McKay, D. E.: Dynamics of ilea! conduits. Radiology, 85: 338, 1965. 4. Harbach, L. B., Hall, R. L., Cockett, A. T. K., Kaufman, J. J., Martin, D. C., IV!ims, M. M. and Goodwin, W. E.: Ilea! loop cutaneous urinary diversion: a critical review. ,J. Urol., 105: 511, 1971 5. Retik, A. B., Perlmutter, A. D. and Gross, R. E.: Cutaneous ureteroileostomy in children. New Engl. Med., 277: 217, 1967. 6. Eckstein, H. B.: Urinary diversion in children. A review of 148 with special reference to the neurogenic Develop. Med. Child Neurnl., 7: 167, 1965. 7. Koehler, P.R., Bowles, W. T. and McAlister, W. H.: Roentgenographic evaluation of late results of ilea] loop urinary diversion in infants and children.
595
Amer. J. Roentgen., WO: 177, 1967. 8. Markland, C. and Flocks, R. H.: The ileac conduit stoma. ,J. Urol., 95: 344, 1966. 9. Richie, J. P.: Intestinal loop urinary diversion in children. J. Uro!., Hl: 687, 1974. 10. S. R., Lebowitz, R. and Colodny, A. H.: of 90 children with ilea! conduit urinary diversion a decade later: analysis of complications, pyelography, renal function and bacteriology J. Urol., 114: 289, 1975. 11. Dybner, R.. Jetet, K. and son of intr31t:.minal pressures in conduits in children. ,J. Uro!., Hl8: 477, 1972. 12. Iv!cCoy, R. M. and Rhamy, R. K .. Ilea! conduits m children. J. Urol., HJ3: 491, 1970. B. Holla_nd, J. M., Schirmer, H. K. Gibbons, R. P. and Scott. W. urinary conduit: an 8-year experience m 37 patients. ,J. Urol., 99: 427, 1968. 14. Spence, B., Ireland, G. W. and Cass, A. S.: Bacteriuria in intestinal loop urinary diversion in children. J. Urol., 105: 780, 1971. 15. R. F., Smith, E. D. and Gracey, M.: Bacteflora of urine from ilea! conduit. J. Urol., 105: 452, 1971. 16. Fonkalsrud, E. W. and Smith, J. P.: Permanent urinary diversion in infancy and childhood. J. Urol., 94: 132, 1965. 17. Schmidt, J. D., Hawtrey, C. E., Flocks, R.H. and Culp, D. A.: Complications, results and problems of ilea] conduit diversions. J. Urol., 109: 210, 1973. 18. King, L. R., Kazmi, S. 0. and Belman, A. B.: Natural history of vesicoureteral reflux. Outcome of a trial of nonoperative therapy. Urol. Clin. N. Amer., l: 441, 1974. 19. Richie, ,J. P., Skinner, D. G. and Waisman, J.: The effect of reflux on the development of pyelonephritis in urinary diversion: an experimental study. J. Surg. Res .. 16: 256, 1974. 20. Minton, ,J.P., Kiser, W. S. and Ketcham, A. S.: A study of the functional dynamics of ilea! conduit urinary diversion with relationship to urinary infection. Surg., Gynec. & Obst., 119: 541, 1964. 21. Hinman, F., Jr.. Factors in bacteriuria after urinary diversion. Urol. Int., 23: 164, 1968.
THE JOURNAL OF UROLOGY
Copyright © 1975 by The Williams & Wilkins Co.
PRESSURE MEASUREMENTS IN ILEAL CONDUITS ROBERT M. WEISS, EDWARD J. MCGUIRE
AND
BERNARD LYTTON
From ih,e Department of Surgery, Section of Urology, Yale University School of Medicine, New Haven, Connecticut
ABSTRACT
To study the dynamic properties of ileal conduits and to attempt to diagnose obstruction at an early point in time, that is prior to the development of conduit or upper urinary tract dilatation, a continuously perfused catheter technique was used to measure pressures within the conduit during filling and emptying, and to measure the resistance to flow at the stomal level. The mean values of residual urine, resting pressure, voiding pressure and stomal profile pressure were significantly higher in obstructed than in non-obstructed conduits. However, there was an overlap between values in each parameter, thus necessitating analysis of the entire pressure data in any given case. The data also show that even a small increase in residual urine above normal, 4.0 plus or minus 0.9 cc, may be an indication of early obstruction and that stomal caliber does not necessarily correlate with the degree of obstruction. The ileal conduit is the most commonly used method of supravesical urinary diversion. Its efficacy is predicated on its ability to act as a freely draining conduit rather than as a reservoir that empties periodically. The usual method of end-toside ureteroileal anastomosis permits free reflux of urine from the conduit to the ureters, 1 as can be shown by a loopogram 2 or by the use of cine-fluoroscopic techniques during excretory urography (IVP). 3 The demonstration of ileal ureteral reflux during IVP indicates that reflux of urine to the kidneys occurs during normal activity. Stomal obstruction would be expected to result in a rise in pressure within the conduit and to increase the degree of reflux of infected urine into the kidney, factors which may lead to renal damage. Harbach and associates reviewed their experience with 244 ileal cutaneous urinary diversions and noted a 25 per cent incidence of stenosis of the ileal stoma in children with only a 2.3 per cent incidence in adults. 4 The high incidence of stomal stenosis in children has been described by others.•-• A review of the literature revealed a 25 per cent incidence of stomal stenosis in 500 children who had undergone ileal conduit diversion. 9 We also have observed a higher incidence of stomal obstruction in children than in adults with ileal conduits, which is probably related to the rate of growth of the child with respect to the fixed aperture in the abdominal wall. To study the dynamic properties of ileal conduits in children and to attempt to diagnose stomal obstruction at an early point in time, a continuously perfused catheter technique has been used to measure pressures within the conduit during filling Accepted for publication February 21, 1975. 591
and emptying and to measure resistance to flow at the stomal level. METHODS
A 12F catheter with a single side hole is inserted into the conduit and the residual urine is collected. The catheter is then perfused at a constant rate of 10 cc per minute with a 20 per cent hypaque solution from a large reservoir. The pressure within the loop is monitored with a Statham pressure transducer and recorded on a Grass polygraph. In certain cases simultaneous fluoroscopic monitoring of the loop was performed with the use of an image intensifier. Pressure within the conduit was continuously measured during filling and extrusion of the hypaque solution around the catheter. The quantity of fluid infused that resulted in the onset of extrusion around the catheter was referred to as the capacity and the pressure rise during extrusion was referred to as the voiding pressure. By gradually withdrawing the perfusion aperture of the catheter across the stoma the pressure profile of the stoma or resistance to flow of the perfusate was determined. This pressure rise across the stoma is a function of the increased resistance to flow at the stoma and is a reflection of the relative degree of obstruction. A more practical method for recording these pressure changes, which can be readily used at the bedside or in the office, consists of using a simple venous pressure manometer in place of the transducer and recorder. Thus, the method is readily applicable for routine use. To evaluate the results of the loop dynamicsresidual urine, base line filling pressure (resting pressure), voiding pressure and stomal pressure profile-it is necessary to assess each parameter separately and as a group.
592
WEISS, MCGUIRE AND LYTTON CASE REPORTS
Case 1. C. C., a 4-year-old white girl, who at 5 days of age had an excision of a sacral teratoma, underwent an ileal conduit urinary diversion because of a neurogenic bladder, persistent infection and evidence of chronic pyelonephritis. An IVP 3 years postoperatively showed that the appearance of the upper urinary tract had remained unchanged (fig. 1). The pressure data were characteristic of a well functioning conduit. The residual urine was 3 cc, base line or resting pressure was 2 cm. water, capacity was 15 cc, voiding pressure was low at 7 cm. water and there was a negligible stomal pressure profile. Case 2. J. W., a white boy, had undergone an ileal conduit diversion when he was 2 years old for exstrophy of the bladder. An IVP 2 years after urinary diversion showed mild ureteral dilatation and a distended ileal loop (fig. 2, A). A 28F catheter could be passed easily through the stoma into the loop and the residual urine was 40 cc. The pressure profile across the stoma was elevated to 36 cm. water and with filling there was a gradual rise in the base line pressure. Capacity was 40 cc with an elevated voiding pressure of 48 cm. water.
Because of the pyelographic changes and the obstructive pattern of the pressure data, a revision of the stoma at the skin and fascial levels was performed. An IVP 6 months postoperatively showed improvement and the pressure data returned toward normal (fig. 2, B). Residual was 3 cc, stomal profile was 5 cm. water, capacity was 18 cc and voiding pressure was 12 cm. water. These normal studies were recorded at a time when the stoma, because of acanthosis, would admit only a 16F catheter. Case 3. A. D., a 4-year-old white boy, underwent a high ilea! conduit diversion for massive hydroureteronephrosis associated with prune belly syndrome. An IVP 6 months after diversion showed the dilated pelviocaliceal system and an ileal loop of adequate size. Recurrent abdominal pain developed 6 months later and a loopogram and IVP showed marked dilatation of the conduit (fig. 3). The residual was 250 cc, resting pressure was 2 cm. water and the voiding pressure was slightly elevated to 22 cm. water. The low pressure in the conduit, even after filling with 200 to 300 cc, was indicative of decompensation and was a reflection of the late stage of obstruction. Nine months after an extensive revision of the conduit the pyelogram was improved, the resting pressure was 5 cm. water, voiding pressure was 14 cm. water, stomal profile was 4 cm. water and residual urine was 15 cc. DISCUSSION
C,C. 11;73
RESJDUA L 3 cc CAPACITY 15 cc VOIDING P. 7 cm H2 0 PROFILE 2 cm H20
10 cc
15 cc PROFILE
FIG. 1. Case 1. IVP 3 years after ilea! conduit diversion shows bilateral calicectasis and loss of renal parenchyma. This . represents stable appearance of upper urmary tract smce surgery. Pressure data are characteristic of well functioning conduit. Fluid was extruded around catheter after 15 cc of filling, voiding.
Although ileal conduit diversion is a widely accepted form of supravesical urinary diversion it is associated with frequent early and late complications. A review of 90 children with ileal conduit urinary diversions with a minimum followup of 10 years showed that 87 per cent had complications. 10 Stomal obstruction was the most common complication after the patient was discharged from the hospital, occurring in 38 per cent of the cases. Other complications leading to ileal conduit revision included ureteroileal obstruction (22.2 per cent), elongation of the ileal segment (11.1 per cent), extrinsic loop obstruction (5.6 per cent), stenosis of the ilea! conduit itself (3.3 per cent) and stomal prolapse (3.3 per cent). Some of these complications may have been caused by stomal obstruction. A total of 66.7 per cent of the children in this group required at least 1 revision of the conduit. Comparison of resting pressures in 7 ileal and 4 colonic conduits showed the pressure to be slightly higher in the latter. 11 A non-perfused catheter was used in this study, and the authors did not attempt to use the technique to diagnose stomal obstruction. The perfused catheter provides a more accurate measurement of intraluminal pressure in organs that are not continuously distended with fluid, such as an ilea! conduit. With a non-perfused catheter system, apposition of the conduit wall and t~e catheter lumen results in recording inaccuracies.
593
PRESSURE MEASUREMENTS IN ILEAL CONDUITS
J,W. 11/71
A PROFILE
RESIDUAL 40 cc CAPACITY 40 cc VOIDING P. 48 cm H20 PROFILE 36 cm H20
J.W. 5/72
B
I
24cm H20
--1''---"'""'
40cc VOIDING
PROFILE
RESIDUAL 3 cc CAPACITY 18 cc VOIDING P. 12 cm H2 o PROF! LE 5 cm H2 0
PROFILE
15 cc.
VOIDING
VOIDING
Fm. 2. Case 2. A, IVP shows distended conduit with mild increase of upper urinary tract dilatation. Pressure data are characteristic of stomal obstruction. B, IVP 6 months after stoma revision shows improvement and pressure data have returned toward normal.
A,D, 11/71
RESIDUAL 250 cc CAPACITY 300 cc VOIDING P. 22 cm H20
100 cc
200 cc
300 cc
Fm. 3. Case 3. A, loopogram and B, IVP show markedly dilated conduit in child with prune belly syndrome. Pressure data are indicative of loop decompensation with intraluminal pressure remaining low until voiding occurred, after 300 cc of filling.
594
WEISS, MCGUIRE AND LYTTON
The incidence of infected urine in conduits has been reported to range from 14 to 98 per cent. 5 • 12- 11 However, there is good evidence that the urine in the proximal portion of a well functioning ileal conduit is sterile in the majority of cases and that contamination from the immediate stomal area accounts for the high incidence previously reported. Therefore, any distal obstruction will result in prompt infection of the urine in the proximal portion of the conduit in the majority of cases. In the intact urinary system vesicoureteral reflux in the presence of infection is a well established cause of renal damage. 18 Therefore, any obstruction of the stoma would be likely to result in reflux of infected urine with consequent renal changes. Recently, Richie and associates showed histological changes compatible with pyelonephritis in 83 per cent of dogs with ileal conduit diversions, suggesting that some renal changes might occur even in patients with unobstructed loops. 19 Dogs with colonic conduits in which a non-refluxing ureterocolonic anastomosis had been made had only a 7 per cent incidence of pyelonephritis, suggesting that such an antireflux procedure might afford protection to the kidneys. Minton and associates suggested that physiologic studies may help to predict which patients with ileal conduits are predisposed to urinary infection. 20 Manometric studies using an occlusive catheter showed 3 variations of contractile patterns. Although they recognized that the contractile patterns recorded by occluding the ileal stoma may not be a true representation of the contractile activity of all areas of the segment, they noted a lower incidence of infection in patients with conduits having periodic individual forceful contractions with pressure rises ranging from 10 to 100 mm. Hg than in patients with conduits having irregular, weak contractile patterns of activity. Since the conduit was obstructed when their data were obtained correlation was not made between loop pressures and stomal obstruction, although they did note that an 18F stomal opening represented an adequate outflow tract. Minton and associates furthermore determined emptying curves in ileal segments after instillation of a radioactive substance or dye. 20 They correlated a more rapid clearance of these substances with fewer symptomatic infections. Hinman also emphasized the importance of the relationship of the rate of urinary exchange to the resident volume in the loop in determining the incidence of bacteriuria after ureteroileostomy. 21 He noted that obstruction, by increasing the resident volume and decreasing mixing, lowered the rate of exchange and promoted bacteriuria. In order to determine the dynamic pressure changes during conduit filling and emptying and to attempt to diagnose early stomal obstruction, we used a continuously perfused catheter system. This technique permits a more accurate method of measurement of intraconduit pressure during vari-
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I LEAL CONDUITS
Fm. 4. Pressure data obtained from normal and obstructed conduits. A, residual urine. B, resting pressure. C, voiding pressure. D, stomal profile. Each data point represents individual measurement. Number in parentheses is total number of measurements. To right of each column of data points is mean plus or minus standard error of mean. Mean values for each parameter were significantly higher in obstructed than in non-obstructed conduits (residual urine p less than 0.001, resting pressure p less than 0.05, voiding pressure p less than 0.001 and stomal profile p less than 0.005).
ous stages of distension and provides a method to determine the pressure profile across the ileal stoma. The data obtained from normal and obstructed conduits are shown in figure 4. In these studies a 12F catheter with a 0.5 cm.2 side perfusion aperture was used. Zero base line was arbitrarily accepted as the pressure required to maintain a constant flow of 10 cc per minute with the perfusion aperture at the level of the conduit. The mean of the values of residual urine, resting pressure, voiding pressure and stomal profile pressure was significantly higher in obstructed than in nonobstructed conduits. However, all data must be analyzed in any given case since there was overlap between values in each parameter in the normally and abnormally functioning conduits. For instance, a decompensated conduit may have a high
PRESSURE MEASUREMENTS IN !LEAL CONDUITS
residual and an increased capacity even after correction of any stomal obstruction. Such a conduit would have a normal stomal pressure profile and a normal or elevated pressure. In with stomal obstruction abnormalities in pressure parameters I".lay be noted of the conduit or the in any one of stoma or stomal revision. In ments provide a means without radiation exposure, is not fm evaluation. Our data also show that even increases in residual urine above the 0.9 cc, may be indicative of and that stomal caliber may be unrelated to functional stomal obstruction. REFERENCES 1. Bricker, E. M .. Bladder substitution after pelvic
evisceration. Surg. Clin. N. Amer., 30: 1511, 1950. 2. Smith, E. D.: Follow-up study of 150 ilea] conduits in children. J. Pediat. Surg., 7: 1, 1972. 3. Campbell, J. E., Oliver, J. A. and McKay, D. E.: Dynamics of ilea! conduits. Radiology, 85: 338, 1965. 4. Harbach, L. B., Hall, R. L., Cockett, A. T. K., Kaufman, J. J., Martin, D. C., IV!ims, M. M. and Goodwin, W. E.: Ilea! loop cutaneous urinary diversion: a critical review. ,J. Urol., 105: 511, 1971 5. Retik, A. B., Perlmutter, A. D. and Gross, R. E.: Cutaneous ureteroileostomy in children. New Engl. Med., 277: 217, 1967. 6. Eckstein, H. B.: Urinary diversion in children. A review of 148 with special reference to the neurogenic Develop. Med. Child Neurnl., 7: 167, 1965. 7. Koehler, P.R., Bowles, W. T. and McAlister, W. H.: Roentgenographic evaluation of late results of ilea] loop urinary diversion in infants and children.
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Amer. J. Roentgen., WO: 177, 1967. 8. Markland, C. and Flocks, R. H.: The ileac conduit stoma. ,J. Urol., 95: 344, 1966. 9. Richie, J. P.: Intestinal loop urinary diversion in children. J. Uro!., Hl: 687, 1974. 10. S. R., Lebowitz, R. and Colodny, A. H.: of 90 children with ilea! conduit urinary diversion a decade later: analysis of complications, pyelography, renal function and bacteriology J. Urol., 114: 289, 1975. 11. Dybner, R.. Jetet, K. and son of intr31t:.minal pressures in conduits in children. ,J. Uro!., Hl8: 477, 1972. 12. Iv!cCoy, R. M. and Rhamy, R. K .. Ilea! conduits m children. J. Urol., HJ3: 491, 1970. B. Holla_nd, J. M., Schirmer, H. K. Gibbons, R. P. and Scott. W. urinary conduit: an 8-year experience m 37 patients. ,J. Urol., 99: 427, 1968. 14. Spence, B., Ireland, G. W. and Cass, A. S.: Bacteriuria in intestinal loop urinary diversion in children. J. Urol., 105: 780, 1971. 15. R. F., Smith, E. D. and Gracey, M.: Bacteflora of urine from ilea! conduit. J. Urol., 105: 452, 1971. 16. Fonkalsrud, E. W. and Smith, J. P.: Permanent urinary diversion in infancy and childhood. J. Urol., 94: 132, 1965. 17. Schmidt, J. D., Hawtrey, C. E., Flocks, R.H. and Culp, D. A.: Complications, results and problems of ilea] conduit diversions. J. Urol., 109: 210, 1973. 18. King, L. R., Kazmi, S. 0. and Belman, A. B.: Natural history of vesicoureteral reflux. Outcome of a trial of nonoperative therapy. Urol. Clin. N. Amer., l: 441, 1974. 19. Richie, ,J. P., Skinner, D. G. and Waisman, J.: The effect of reflux on the development of pyelonephritis in urinary diversion: an experimental study. J. Surg. Res .. 16: 256, 1974. 20. Minton, ,J.P., Kiser, W. S. and Ketcham, A. S.: A study of the functional dynamics of ilea! conduit urinary diversion with relationship to urinary infection. Surg., Gynec. & Obst., 119: 541, 1964. 21. Hinman, F., Jr.. Factors in bacteriuria after urinary diversion. Urol. Int., 23: 164, 1968.