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The effect of reflux on the development of pyelonephritis in urinary diversion: An experimental study
JOURNAL
OF SURGlICAL
16, %6-261
RESEARCH
The Effect
of Reflux
in Urinary JEROME
P.
(1974)
on the Development
Diversion: RICHIE, AND
An Experimental
M.D.,
DONALD
JERRY
WAISMAN,
THE NORMAL URINARY TRACT in man provides an effective means of eliminating urinary waste products and protecting against infection. Bladder urine remains sterile in the absence of obstruction, and vesico-ureteral reflux is prevented by oblique intramural tunnels and muscular action of the trigone. The need for an effective bladder substitute in patients whose neurogenic bladders necessitate urinary diversion has spawned a multitude of ingenious operations, including ureterosigmoidostomy, rectal bladder, “wet” colostomy, cutaneous ureterostomy, and cutaneous ureteroileostomy. Ureterosigmoidostomy incorporating a valvelike mechanism, first performed by Mayo and Coffey in 1912 and described by Coffey in 1928 [2], was the procedure of choice for almost 4 decades until complications of electrolyte imbalance as well as recurrent pyelonephritis led to a critical reevaluation of the problem [4]. The cutaneous ureteroileostomy, popularized by Bricker [l] in 1950, has significantly reduced the occurrence of electrolyte imbalance by converting to a conduit system from the reservoir created by the ureterosigmoidostomy. The temporal expoFrom the Department of Surgery, Division of Urology, and the Department of Pathology, UCLA School of Medicine, Los Angeles, California 90024. Presented at the Seventh Annual Meeting of The Association for Academic Surgery, Rochester, New York, November 13, 1973. Submitted for publication November 23, 1973.
0 1974 by Academic of reproduotion in any
Press, Inc. form reserved.
G.
SKINNER,
Study M.D.,
M.D.
sure of urine to bowel mucosa is thus decreased, and the period of reabsorption is reduced. As long-term data become available, however, it is clear that renal deterioration is a problem with this form of diversion [8]. The effect on the kidney of reflux of infected urine from the bladder has been well documented. Ileal conduits are constructed with a freely refluxing uretero-ileal anastomosis, and the long-term results of this continued reflux must remain suspect as an etiologic factor for renal deterioration. Although attempts have been made to create nonrefluxing uretero-ileal anastomoses, no consistent success has been reported. Mogg [7] advocated the use of sigmoid colon as an isolated segment for urinary diversion but made no attempt to prevent reflux. The colon, with its thicker musculature, is readily adaptable to nonrefluxing ureteral anastomoses, as Leadbetter and Clarke [6] have clearly shown. This prevention of reflux may decrease the incidence of the long-term complication of pyelonephritis. Colonic and ileal conduits have been appraised in man [3], and Spence and associates [lo] have compared them in the experimental animal. All studies have, however, compared one entity with another, and individual differences in intra-abdominal pressure, acid-base and electrolyte balance, position, and state of hydration have not been considered. To eliminate these variables and to make an accurate
256 Copyright All rights
of Pyelonephritis
RICHIE,
SKINNER
AND
WAISMAN:
DEVELOPMENT
OI”
PTELONEPHRITIS
2.37
comparison of the two systems, an ileal conduit was created from one kidney and a nonrefluxing colonic conduit from the other kidney in the same animal (Fig. 1). PROCEDURE Sixteen adult mongrel dogs of either sex, weighing 15-30 kg, were anesthetized with sodium pentobarbital. All intravenous operations were performed through an abdominal midline incision. Preoperative serum creatinine levels were normal in all dogs, and bladder urine cultures obtained by aspiration at laparotomy were sterile. Ten centimeter segments of distal ileum and transverse colon were isolated, and entero-enterostomies were performed with two-layer interrupted silk anastomoses. The proximal ends of the conduits were closed with running inverting two-layer chromic suture, reinforced by a row of interrupted silk. The right ureter was spatulated and implanted into the ileal conduit interrupted with a direct one-layer mucosa-to-mucosa anastomosis. The left ureter was implanted into the colonic conduit with a 3-cm tunneled mucosa-tomucosa anastomosis, as described by Leadbetter and Clarke [6]. All conduits were isoperistaltic, and stomas of 2-3 cm in diameter were created in each. Antibiotics were administered routinely for 3 days postoperatively. Five of the 16 dogs had only one kidney connected to a conduit (3 colonic and 2 ileal) ; the remaining kidney, in continuity with the bladder, served as a histologic control. RESULTS Fifteen dogs were available for 3.-month follow-up studies; one control dog with a single ileal conduit died of superficial wound infection and sepsis.Excretory urograms were obtained at 1 and 3 months postoperatively. All studies were normal except the l-month study in three dogs with stoma1 stenosis of the ileal loop. Upper tract dilatation returned to normal after surgical revision of the stoma. -
Fig. 1. Schematic drawing of experimental preparation. Right kidney of dog is connected t,o ileal conduit and left kidney to tunneled colonic conduit.
The presence or absence of reflux was determined by retrograde injection of dye (L’conduitograms”) at 6 weeks postoperatively. These studies were performed by occlusion of each loop with Foley catheters connected to a Y-tube and filled by a common gravity reservoir at a pressure of 35 cm H,O. Free reflux was demonstrated in 11 of the 12 ileal loops, and absence of reflux was seen in all, 14, colonic loops. Serum creatinine levels were normal in all dogs at 3 months postoperatively, and no instances of hyperchloremic acidosis were noted. Urinary excretion of bicarbonate was zero in all loops, and urinary pH showed no significant difference (6.0-6.4). Conduit dynamics were evaluated by the introduction of “?echnetium-DTPA into the loops and collection of serial efflux. Emptying curves for ileal and colonic conduits were parallel, and no differences were noted. Simultaneous resting pressures were obtained with No. 8 French plastic catheters connected to Statham strain gauges (O-75 cm Hg) and a Sanborn polygraph. Pressures were uniformly low (3-4 mm Hg) in both conduits. Ileal conduits tended to have more frequent peristalsis (G/min) and
258
JOURNAL
OF
SURGICAL
Pig. 2. Necropsy specimens enterostomies. Note patency
RESEARCH,
1. Histopathology of Kidneys Connected to Colonic and Ileal Conduits
Colonic conduits (14) Ileal conduits
(12)
16,
NO.
3,
MARCH
of ileal (at left) and colonic (at, right) conduits of both anastomoses as well as length of tunnels.
higher pressure spikes (to 25 mm Hg) with each peristaltic wave than did their colonic counterparts (l/min to 10 mm Hg) After acute occlusion with No. 16 French Foley catheters, simultaneous pressures were recorded as each loop was injected with boli of saline in proportion to its capacity. Pressures rose to 30 mm Hg in both colonic and ileal loops; however, ileal loops continued to have more frequent peristalsis and higher pressure spikes (to 45 mm Hg). All dogs were sacrificed 3 months postoperatively, and urine cultures were collected at necropsy from conduits and both renal pelves. The ureteral anastomosis to Table
VOL.
Normal
Pyelonephritis
Pyelitis
11
1
2
1
10
1
1974
with
uretero-
bowel was clamped prior to manipulation to prevent reflux before cultures could be obtained. At necropsy both kidneys with attached proximal ureters were removed and fixed in formalin for 3 days. The colonic and ileal conduits were examined grossly for obstruction at the uretero-enterostomy ; all ureteral anastomoses were patent (Fig. 2). Each kidney was weighed and bivalved, and cortical thickness was measured; no significant differences were noted. Sections of renal cortex, medulla, pelvis, and upper ureter were embedded in paraffin and stained with hematoxylin and eosin. All sections were reviewed by one of the authors (J. W.), a pathologist, without knowledge of which kidneys were connected to which conduits. Histologic evidence of pyelonephritis was present in 83% of kidneys connected to ileal conduits, as compared to 7% of those connected to colonic conduits (P < 0.001, Table 1). Chronic fibrosis and glomerular
RICHIE,
Fig.
3(A).
Cortex
Fig. 3(B). Tubules tubules (X 100).
atrophy kidneys” pyelitis “colonic
SKINNER
from
from
AND
kidney
same
WAISMAN
connected
kidney.
: DEVELOPMENT
to ileal
Kate
were demonstrated in the “ileal associated with acute and chronic (Fig. 3A,B). Most of the paired kidneys” were histologically nor-
conduit.
acute
OF
Normal
infhmmalory
2.59
PYELONEPHRITIS
area
rcnction
at lower
left
in intrrsti(ium
(X
100
an
ma1 (Fig. 4), as were the control kidneys. No correlation was demonstrate d between urinary infection colo(>lO” nies/ml) and histologic findings (Tab le 2).
260
JOURNAL
Fig.
4. Paired
OF
SURGICAL
kidney
of that
RESEARCH,
shown
in Fig.
DISCUSSION The life-span of patients who undergo urinary diversion for malignant disease is most often determined by the aggressive potential of the malignancy. In patients with urinary diversion for benign disease, however, the most common cause of death is renal failure. Since the majority of patients with benign disease are young, their diversion must function for many decades. Moreover, previous bouts of urinary infection frequently have reduced the number of functioning glomeruli. Thus, a strong argument may be propounded for a method of diversion that will prevent further damage to the kidneys. In children with neurogenic bladders who Table
2. Correlation
of Histologic
Findings
16,
VOL.
3 connected
NO.
3,
to colonic
MARCH
1974
conduit
(X
100).
have normal upper tracts prior to cutaneous ureteroileostomy, 10% will show radiographic evidence of renal deterioration within a &year follow-up period [S, 91. This represents an unacceptably high rate of continuing renal damage. Starr and associates [ll] have reported experimental evidence of a marked decrease in the incidence of pyelonephritis in dogs with the ureter tunneled in the ileal segment; however, 4 of the 14 ureters so implanted demonstrated free reflux. Similar findings have been evinced in a clinical study of uretero-ileal anastomoses with the Leadbetter technique; 60% of the patients showed evidence of reflux [5]. In Spence and associates’ [lo] study of the histologic effects of ileal and colonic with
Injection
in Colonic
and Ileal
Conduits
Infection Colonic Histology Normal Pyelonephritis/Pyelitis Total
(14)
Ileal
(12)
Conduit
Ureter
Conduit
Ureter
7/11 l/3
4/11 l/3
O/l 6/11
O/l 7/11
B/14
5/14
6/12
7/12
RICHIE,
SKINNER
AND
WAISMAN
: DEVELOPMENT
conduits in dogs, all animals had both ureters connected to either an ileal or colonit loop without any antireflux mechanism. At 3 months postoperatively, 25% of the kidneys connected to ileal conduits and 7570 of kidneys connected to colonic conduits had histologic evidence of pyelonephritis. In the present study, with internal controls in the same animal, a statistically significant decrease in the incidence of pyelonephritis has been demonstrated at 3 months in nonrefluxing conduits. Ileal conduits have more frequent peristalsis and higher pressure spikes. In a freely refluxing system, these pressures are transmitted directly to the renal pelvis. Colonic conduits offer several theoretical and actual advantages, including absence of reflux, fewer stoma1 problems, and larger lumen for entero-enterostomies with less chance of obstruction. Since the anastomosis is performed in the left lower quadrant and may be extraperitonealized, fewer problems of late intestinal obstruction should be encountered [12]. Colonic conduits, by denying access of potentially infected urine to the renal pelvis, lessen the likelihood of pyelonephritis and offer a definite advantage over freely refluxing forms of urinary diversion. SUMMARY To make an accurate comparison between ileal and colonic conduits, an ileal conduit was created from one kidney and a nonrefluxing colonic conduit from the other kidney in 16 adult mongrel dogs. The major variable between the two was the presence or absence of reflux. The dogs were studied by excretory urogconduitograms, pressure studies, rwb, and urinary cultures. All dogs were sacrificed at 3 months, and urine cultures were collected at necropsy from conduits and both renal pelves. In each of five control experiments, one kidney was connected to either an ileal or a colonic conduit while the other kidney remained in continuity with the bladder.
OF
PYELONEPHRITIS
261
Although most dogs had significant bacterial growth in both conduit and ureteral urine, histologic sections revealed pyelonephritis in 83% of 12 kidneys connected to ileal conduits as compared to 7% of 14 kidneys connected to colonic conduits. All cont’rol kidneys were histologically normal. This study demonstrates that ureteral reflux from ileal conduits produces histologic evidence of pyelonephritis. Colonic conduits, by preventing reflux of infected urine, reduce the frequency of pyelonephritis and offer definite advantages for long-t’crm urinary diversion. REFERENCES 1. Bricker, E. Bladder substitution after pelvic evisceration. Surg. Clin. North Amer. 30:X11, 1950. 2. Coffey, R. C. Transplantation of the ureters into the large intestine. Surg. Gynecol. Obstet. 47:593, 1928. 3. Dybner, R., Jeter, K., and Lattimer, J. Comparison of intraluminal pressures in ileal and colonic conduits in children. J. Ural. 108:477, 1972. 4. Ferris, D. O., and Odel, H. M. Electrolyte pattern of the blood after bilateral ureteroaigmoidostomy. JAMA 142:634, 1950. 5. Kafetsioulis, A., and Swinney, J. A study of the function of ileal conduits. Brit. J. Ural. 42:33, 1970. 6. Leadbetter, W. F., and Clarke, B. G. Five years experience with uretero-enterostomy by the “combined technique.” J. Ural. 73:67, 1954. 7. Mogg, R. A. The treatment of neurogenic urinary incontinence using the colonic conduit. Brit. J. Ural. 37:681, 1965. 8. Richie, J. P. Intestinal loop urinary diversion in children. J. u?ol. (in press). 9. Smith, E. D. Follow-up studirs of 150 ileal conduits in children. J. Pediat Surg. 7: 1, 1972. 10. Spence, B., E&o, J., and Cass, A. Comparison of iliac and colonic conduit urinary diversions in dogs. J. Ural. 108:712, 1972. 11. Starr, A., Rose, D. H., Cooper, J. F., and Snyder, Y&. N. .Anti-r&x urctero-ileal ‘anastomoses. Two experimental techniques. Presented at the Western Section of American Urological Association, Honolulu, Hawaii, June, 1973. 12. Williams, D. I. Urinary diversion by sigmoid conduit. In R. Scott (Ed.), Current Controversies in Urologic Management, pp. 294-298, W. B. Saunders, Philadelphia, 1972.
OF SURGlICAL
16, %6-261
RESEARCH
The Effect
of Reflux
in Urinary JEROME
P.
(1974)
on the Development
Diversion: RICHIE, AND
An Experimental
M.D.,
DONALD
JERRY
WAISMAN,
THE NORMAL URINARY TRACT in man provides an effective means of eliminating urinary waste products and protecting against infection. Bladder urine remains sterile in the absence of obstruction, and vesico-ureteral reflux is prevented by oblique intramural tunnels and muscular action of the trigone. The need for an effective bladder substitute in patients whose neurogenic bladders necessitate urinary diversion has spawned a multitude of ingenious operations, including ureterosigmoidostomy, rectal bladder, “wet” colostomy, cutaneous ureterostomy, and cutaneous ureteroileostomy. Ureterosigmoidostomy incorporating a valvelike mechanism, first performed by Mayo and Coffey in 1912 and described by Coffey in 1928 [2], was the procedure of choice for almost 4 decades until complications of electrolyte imbalance as well as recurrent pyelonephritis led to a critical reevaluation of the problem [4]. The cutaneous ureteroileostomy, popularized by Bricker [l] in 1950, has significantly reduced the occurrence of electrolyte imbalance by converting to a conduit system from the reservoir created by the ureterosigmoidostomy. The temporal expoFrom the Department of Surgery, Division of Urology, and the Department of Pathology, UCLA School of Medicine, Los Angeles, California 90024. Presented at the Seventh Annual Meeting of The Association for Academic Surgery, Rochester, New York, November 13, 1973. Submitted for publication November 23, 1973.
0 1974 by Academic of reproduotion in any
Press, Inc. form reserved.
G.
SKINNER,
Study M.D.,
M.D.
sure of urine to bowel mucosa is thus decreased, and the period of reabsorption is reduced. As long-term data become available, however, it is clear that renal deterioration is a problem with this form of diversion [8]. The effect on the kidney of reflux of infected urine from the bladder has been well documented. Ileal conduits are constructed with a freely refluxing uretero-ileal anastomosis, and the long-term results of this continued reflux must remain suspect as an etiologic factor for renal deterioration. Although attempts have been made to create nonrefluxing uretero-ileal anastomoses, no consistent success has been reported. Mogg [7] advocated the use of sigmoid colon as an isolated segment for urinary diversion but made no attempt to prevent reflux. The colon, with its thicker musculature, is readily adaptable to nonrefluxing ureteral anastomoses, as Leadbetter and Clarke [6] have clearly shown. This prevention of reflux may decrease the incidence of the long-term complication of pyelonephritis. Colonic and ileal conduits have been appraised in man [3], and Spence and associates [lo] have compared them in the experimental animal. All studies have, however, compared one entity with another, and individual differences in intra-abdominal pressure, acid-base and electrolyte balance, position, and state of hydration have not been considered. To eliminate these variables and to make an accurate
256 Copyright All rights
of Pyelonephritis
RICHIE,
SKINNER
AND
WAISMAN:
DEVELOPMENT
OI”
PTELONEPHRITIS
2.37
comparison of the two systems, an ileal conduit was created from one kidney and a nonrefluxing colonic conduit from the other kidney in the same animal (Fig. 1). PROCEDURE Sixteen adult mongrel dogs of either sex, weighing 15-30 kg, were anesthetized with sodium pentobarbital. All intravenous operations were performed through an abdominal midline incision. Preoperative serum creatinine levels were normal in all dogs, and bladder urine cultures obtained by aspiration at laparotomy were sterile. Ten centimeter segments of distal ileum and transverse colon were isolated, and entero-enterostomies were performed with two-layer interrupted silk anastomoses. The proximal ends of the conduits were closed with running inverting two-layer chromic suture, reinforced by a row of interrupted silk. The right ureter was spatulated and implanted into the ileal conduit interrupted with a direct one-layer mucosa-to-mucosa anastomosis. The left ureter was implanted into the colonic conduit with a 3-cm tunneled mucosa-tomucosa anastomosis, as described by Leadbetter and Clarke [6]. All conduits were isoperistaltic, and stomas of 2-3 cm in diameter were created in each. Antibiotics were administered routinely for 3 days postoperatively. Five of the 16 dogs had only one kidney connected to a conduit (3 colonic and 2 ileal) ; the remaining kidney, in continuity with the bladder, served as a histologic control. RESULTS Fifteen dogs were available for 3.-month follow-up studies; one control dog with a single ileal conduit died of superficial wound infection and sepsis.Excretory urograms were obtained at 1 and 3 months postoperatively. All studies were normal except the l-month study in three dogs with stoma1 stenosis of the ileal loop. Upper tract dilatation returned to normal after surgical revision of the stoma. -
Fig. 1. Schematic drawing of experimental preparation. Right kidney of dog is connected t,o ileal conduit and left kidney to tunneled colonic conduit.
The presence or absence of reflux was determined by retrograde injection of dye (L’conduitograms”) at 6 weeks postoperatively. These studies were performed by occlusion of each loop with Foley catheters connected to a Y-tube and filled by a common gravity reservoir at a pressure of 35 cm H,O. Free reflux was demonstrated in 11 of the 12 ileal loops, and absence of reflux was seen in all, 14, colonic loops. Serum creatinine levels were normal in all dogs at 3 months postoperatively, and no instances of hyperchloremic acidosis were noted. Urinary excretion of bicarbonate was zero in all loops, and urinary pH showed no significant difference (6.0-6.4). Conduit dynamics were evaluated by the introduction of “?echnetium-DTPA into the loops and collection of serial efflux. Emptying curves for ileal and colonic conduits were parallel, and no differences were noted. Simultaneous resting pressures were obtained with No. 8 French plastic catheters connected to Statham strain gauges (O-75 cm Hg) and a Sanborn polygraph. Pressures were uniformly low (3-4 mm Hg) in both conduits. Ileal conduits tended to have more frequent peristalsis (G/min) and
258
JOURNAL
OF
SURGICAL
Pig. 2. Necropsy specimens enterostomies. Note patency
RESEARCH,
1. Histopathology of Kidneys Connected to Colonic and Ileal Conduits
Colonic conduits (14) Ileal conduits
(12)
16,
NO.
3,
MARCH
of ileal (at left) and colonic (at, right) conduits of both anastomoses as well as length of tunnels.
higher pressure spikes (to 25 mm Hg) with each peristaltic wave than did their colonic counterparts (l/min to 10 mm Hg) After acute occlusion with No. 16 French Foley catheters, simultaneous pressures were recorded as each loop was injected with boli of saline in proportion to its capacity. Pressures rose to 30 mm Hg in both colonic and ileal loops; however, ileal loops continued to have more frequent peristalsis and higher pressure spikes (to 45 mm Hg). All dogs were sacrificed 3 months postoperatively, and urine cultures were collected at necropsy from conduits and both renal pelves. The ureteral anastomosis to Table
VOL.
Normal
Pyelonephritis
Pyelitis
11
1
2
1
10
1
1974
with
uretero-
bowel was clamped prior to manipulation to prevent reflux before cultures could be obtained. At necropsy both kidneys with attached proximal ureters were removed and fixed in formalin for 3 days. The colonic and ileal conduits were examined grossly for obstruction at the uretero-enterostomy ; all ureteral anastomoses were patent (Fig. 2). Each kidney was weighed and bivalved, and cortical thickness was measured; no significant differences were noted. Sections of renal cortex, medulla, pelvis, and upper ureter were embedded in paraffin and stained with hematoxylin and eosin. All sections were reviewed by one of the authors (J. W.), a pathologist, without knowledge of which kidneys were connected to which conduits. Histologic evidence of pyelonephritis was present in 83% of kidneys connected to ileal conduits, as compared to 7% of those connected to colonic conduits (P < 0.001, Table 1). Chronic fibrosis and glomerular
RICHIE,
Fig.
3(A).
Cortex
Fig. 3(B). Tubules tubules (X 100).
atrophy kidneys” pyelitis “colonic
SKINNER
from
from
AND
kidney
same
WAISMAN
connected
kidney.
: DEVELOPMENT
to ileal
Kate
were demonstrated in the “ileal associated with acute and chronic (Fig. 3A,B). Most of the paired kidneys” were histologically nor-
conduit.
acute
OF
Normal
infhmmalory
2.59
PYELONEPHRITIS
area
rcnction
at lower
left
in intrrsti(ium
(X
100
an
ma1 (Fig. 4), as were the control kidneys. No correlation was demonstrate d between urinary infection colo(>lO” nies/ml) and histologic findings (Tab le 2).
260
JOURNAL
Fig.
4. Paired
OF
SURGICAL
kidney
of that
RESEARCH,
shown
in Fig.
DISCUSSION The life-span of patients who undergo urinary diversion for malignant disease is most often determined by the aggressive potential of the malignancy. In patients with urinary diversion for benign disease, however, the most common cause of death is renal failure. Since the majority of patients with benign disease are young, their diversion must function for many decades. Moreover, previous bouts of urinary infection frequently have reduced the number of functioning glomeruli. Thus, a strong argument may be propounded for a method of diversion that will prevent further damage to the kidneys. In children with neurogenic bladders who Table
2. Correlation
of Histologic
Findings
16,
VOL.
3 connected
NO.
3,
to colonic
MARCH
1974
conduit
(X
100).
have normal upper tracts prior to cutaneous ureteroileostomy, 10% will show radiographic evidence of renal deterioration within a &year follow-up period [S, 91. This represents an unacceptably high rate of continuing renal damage. Starr and associates [ll] have reported experimental evidence of a marked decrease in the incidence of pyelonephritis in dogs with the ureter tunneled in the ileal segment; however, 4 of the 14 ureters so implanted demonstrated free reflux. Similar findings have been evinced in a clinical study of uretero-ileal anastomoses with the Leadbetter technique; 60% of the patients showed evidence of reflux [5]. In Spence and associates’ [lo] study of the histologic effects of ileal and colonic with
Injection
in Colonic
and Ileal
Conduits
Infection Colonic Histology Normal Pyelonephritis/Pyelitis Total
(14)
Ileal
(12)
Conduit
Ureter
Conduit
Ureter
7/11 l/3
4/11 l/3
O/l 6/11
O/l 7/11
B/14
5/14
6/12
7/12
RICHIE,
SKINNER
AND
WAISMAN
: DEVELOPMENT
conduits in dogs, all animals had both ureters connected to either an ileal or colonit loop without any antireflux mechanism. At 3 months postoperatively, 25% of the kidneys connected to ileal conduits and 7570 of kidneys connected to colonic conduits had histologic evidence of pyelonephritis. In the present study, with internal controls in the same animal, a statistically significant decrease in the incidence of pyelonephritis has been demonstrated at 3 months in nonrefluxing conduits. Ileal conduits have more frequent peristalsis and higher pressure spikes. In a freely refluxing system, these pressures are transmitted directly to the renal pelvis. Colonic conduits offer several theoretical and actual advantages, including absence of reflux, fewer stoma1 problems, and larger lumen for entero-enterostomies with less chance of obstruction. Since the anastomosis is performed in the left lower quadrant and may be extraperitonealized, fewer problems of late intestinal obstruction should be encountered [12]. Colonic conduits, by denying access of potentially infected urine to the renal pelvis, lessen the likelihood of pyelonephritis and offer a definite advantage over freely refluxing forms of urinary diversion. SUMMARY To make an accurate comparison between ileal and colonic conduits, an ileal conduit was created from one kidney and a nonrefluxing colonic conduit from the other kidney in 16 adult mongrel dogs. The major variable between the two was the presence or absence of reflux. The dogs were studied by excretory urogconduitograms, pressure studies, rwb, and urinary cultures. All dogs were sacrificed at 3 months, and urine cultures were collected at necropsy from conduits and both renal pelves. In each of five control experiments, one kidney was connected to either an ileal or a colonic conduit while the other kidney remained in continuity with the bladder.
OF
PYELONEPHRITIS
261
Although most dogs had significant bacterial growth in both conduit and ureteral urine, histologic sections revealed pyelonephritis in 83% of 12 kidneys connected to ileal conduits as compared to 7% of 14 kidneys connected to colonic conduits. All cont’rol kidneys were histologically normal. This study demonstrates that ureteral reflux from ileal conduits produces histologic evidence of pyelonephritis. Colonic conduits, by preventing reflux of infected urine, reduce the frequency of pyelonephritis and offer definite advantages for long-t’crm urinary diversion. REFERENCES 1. Bricker, E. Bladder substitution after pelvic evisceration. Surg. Clin. North Amer. 30:X11, 1950. 2. Coffey, R. C. Transplantation of the ureters into the large intestine. Surg. Gynecol. Obstet. 47:593, 1928. 3. Dybner, R., Jeter, K., and Lattimer, J. Comparison of intraluminal pressures in ileal and colonic conduits in children. J. Ural. 108:477, 1972. 4. Ferris, D. O., and Odel, H. M. Electrolyte pattern of the blood after bilateral ureteroaigmoidostomy. JAMA 142:634, 1950. 5. Kafetsioulis, A., and Swinney, J. A study of the function of ileal conduits. Brit. J. Ural. 42:33, 1970. 6. Leadbetter, W. F., and Clarke, B. G. Five years experience with uretero-enterostomy by the “combined technique.” J. Ural. 73:67, 1954. 7. Mogg, R. A. The treatment of neurogenic urinary incontinence using the colonic conduit. Brit. J. Ural. 37:681, 1965. 8. Richie, J. P. Intestinal loop urinary diversion in children. J. u?ol. (in press). 9. Smith, E. D. Follow-up studirs of 150 ileal conduits in children. J. Pediat Surg. 7: 1, 1972. 10. Spence, B., E&o, J., and Cass, A. Comparison of iliac and colonic conduit urinary diversions in dogs. J. Ural. 108:712, 1972. 11. Starr, A., Rose, D. H., Cooper, J. F., and Snyder, Y&. N. .Anti-r&x urctero-ileal ‘anastomoses. Two experimental techniques. Presented at the Western Section of American Urological Association, Honolulu, Hawaii, June, 1973. 12. Williams, D. I. Urinary diversion by sigmoid conduit. In R. Scott (Ed.), Current Controversies in Urologic Management, pp. 294-298, W. B. Saunders, Philadelphia, 1972.