Physiopathologic aspects of ileal reservoirs

The author reviews some aspects of fecal continence after ileoanal anastomosis with an ileal reservoir. Also, the consequences of fecal stasis on small-bowel absorption and morphologic and bacteriologic features are discussed. Some recommendations for the follow-up of these patients are outlined.     

Radiologic evaluation of ileal reservoirs. Our experience

A radiological investigation was performed in 25 patients subjected to colectomy, mucosal proctectomy and endorectal ileo-anal anastomosis after the creation of an ileal reservoir. The patients had suffered from ulcerative colitis or familial polyposis. Radiology was of great value in the demonstration of post-operative complications.     

Bowel function remains subjectively unchanged after ileal resection for construction of continent ileal reservoirs

Background

Construction of a continent catheterizable urinary reservoir or an orthotopic bladder substitute requires substantial bowel resection, which can cause changes in bowel transit time. The reported incidence of chronic diarrhea after ileocecal resection is about 20%. Studies assessing bowel function after resection of 55-60 cm of ileum without compromising the ileocecal valve are scarce, and long-term results have not been reported.

Objective

Prospective assessment of possible changes in bowel function (eg, stool frequency, diarrhea) and the potential impact on quality of life in patients with resection of small bowel for urinary diversion.

Design, setting, and participants

A total of 82 patients who underwent radical cystectomy, extended lymph node dissection, orthotopic ileal bladder substitution, or heterotopic continent cutaneous urinary diversion with a follow-up >1 yr after surgery were prospectively evaluated. Patients who had a neurogenic bladder disorder, had undergone previous radiotherapy, or had not completed the questionnaire were excluded from the study. The validated Gastrointestinal Quality of Life Index was completed by the patients preoperatively and at 3, 12, and 24 mo postoperatively. Five points concerning bowel function (frequent bowel movement, urgent bowel movement, diarrhea, constipation, or uncontrolled stool loss) were assessed, and the median scores were compared pre- and postoperatively.

Results and limitations

Most patients (≥80%) were rarely or never troubled by frequent or urgent bowel movements, diarrhea, constipation, or uncontrolled stool loss preoperatively. In the case of stool frequency, a remarkable shift from rarely to never was observed postoperatively at 3, 12, and 24 mo. Scores for constipation and uncontrolled stool loss remained unchanged throughout the whole time period. For urgent bowel movements the median preoperative score of 4 decreased to 3 at 3 mo and 12 mo and returned to 4 at 24 mo. For diarrhea the preoperative score of 4 decreased to 3 at 3 mo and 24 mo and remained at 4 after 12 mo.

Conclusions

No relevant changes in bowel movements were found after resection of 55-60 cm of ileum if the terminal ileum and the ileocecal valve were left intact.     

Absorption of L-phenylalanine in human ileal reservoirs exposed to urine

Summary The mucosa of ileal reservoirs exposed to urine undergoes successive structural changes, indicating a loss of absorptive capacity. In patients with urinary diversion via a continent ileal reservoir, the active absorption of L-phenylalanine from the reservoir was studied at different postoperative time intervals. A test solution containing l-phenylalanine was instilled into the resorvoir and samples were taken at intervals during a period of one hour for determination of phenylalanine. In one group of patients, urine from the kidneys by-passed the reservoir via a catheter inserted into the afferent segment. Within three months after construction of the ileal reservoir, the uptake was significantly slower than that in ileostomy reservoirs and the absorption decreased even more with longer observation times. Mixing of urine with the reservoir contents did not influence the uptake of L-phenylalanine to any significant degree. The reduced absorption of L-phenylalanine indicates that the uptake of other substances from this type of ileal reservoirs might be decreased also.     

Changes in mucosal nutrient transport in small and large ileal reservoirs after endorectal ileal pullthrough

It has been hypothesized that, following colectomy and endorectal ileal pullthrough with ileal reservoir (PTR), reservoir tissue might lose some of its normal nutrient transport capacity and assume properties of the colon. Whether reservoir size influences the expected alterations in normal mucosal absorption and thus contributes to changes in intraluminal ecology has not previously been investigated. To study this, the everted intestinal sleeve technique was used to measure uptake of four nutrients in two groups of dogs who underwent PTR: five with a small (5 cm) lateral reservoir and five with a large (18 cm) reservoir. Mucosal samples were taken from normal ileum and colon and from reservoirs 3 months postoperation. Active uptake of carbohydrates (glucose), amino acids (proline), and bile acids (taurocholate) and passive uptake of short chain fatty acids (propionate) were markedly decreased in mucosa of both reservoir sizes compared to normal ileum (P less than 0.05, t test) and more closely approximated that of normal colon. Uptake of glucose, proline, and taurocholate in large reservoirs was significantly less than that in small reservoirs (P less than 0.05). We conclude that (1) ileal reservoir mucosa has a significantly reduced capacity for nutrient uptake, (2) ileal mucosa in small reservoirs shows higher nutrient uptake rates than mucosa in large reservoirs, and (3) short, well-emptying reservoirs appear best suited to optimizing the intraluminal environment and thus enhance reservoir function when performing PTR.     

The urodynamic characteristics of different ileal reservoirs: an experimental study in dogs.

Using adult mongrel dogs, the urodynamic characteristics of three types of ileal reservoirs were studied and compared. Segments of ileum of the same length were utilized to construct simple loop pouches (five dogs), DeKlerk pouches (five dogs) and Kock pouches (five dogs). Six to eight weeks after surgery, urodynamic evaluation was carried out. This included determination of the volume/pressure relationship and measurement of the contractions of the circular and longitudinal muscle fibers. Results indicate that the Kock pouch offers the best features in terms of the volume capacity, the volume/pressure relationship and contractile activity. Detubularization abrogated the muscle tone but it did not affect the phasic contractile activity of the circular muscle layer.     

Quality of life survey of urinary diversion patients: comparison of ileal conduits versus continent Kock ileal reservoirs

There has been a recent marked increase in interest in continent urinary diversions. While considerable time has been spent on the technical aspects of these diversions the psychological impact has not yet been fully explored. We describe an extensive survey that was conducted among 100 consecutive adults (87 respondents) who had undergone urinary diversion via an ileal conduit and 100 consecutive adults (85 respondents) in whom a continent Kock ileal reservoir was created during the last 3 to 5 years at our university by the same surgeons. The Kock pouch patients were stratified further into 63 with primary diversion and 22 who underwent conversion from previous conduit diversions. The survey consisted of a questionnaire that included a social and sexual survey, the Beck Depressive Inventory, the Profile of Mood States and a physical impact study. The results revealed that all patients surveyed generally were satisfied with the diversions and they had adapted reasonably socially, physically and psychologically. The key to adaptation seemed to be a detailed, realistic preoperative education about the type of diversion used. Patients with ileal conduit diversions had the lowest expectations of the form of diversion as defined by the preoperative awareness of the need to wear an external ostomy appliance with its associated inconveniences and change in the external body image. Postoperatively, ileal conduit patients also had the poorest self images as defined by a decrease in sexual desire and in all forms of physical contact (sexual and nonsexual). The subset of patients who underwent conversion from conduit diversions to Kock pouches, however, were statistically the most satisfied, and they were the most physically and sexually active. We conclude that the Kock continent urostomy offers an important alternative to noncontinent forms of diversion.     

Comparison of the myoelectrical activity of the lateral and J-shaped ileal reservoirs

Ileal myoelectrical activity was studied in ten 10-cm J-shaped and ten lateral ileal reservoirs (IR) in rabbits. Electrodes and a strain gauge were placed on both ileal segments of the reservoirs as well as the proximal and distal ileum entering and leaving the reservoirs. In three additional rabbits without reservoirs (controls), electrodes and a strain gauge were sutured to the distal ileum in a similar manner. Myoelectrical activity was recorded as (1) short spike burst complexes (SSBC) lasting greater than 25 seconds but less than three minutes, and (2) long spike burst complexes (LSBC) lasting more than three minutes. SSBC propagated through the lateral IR two weeks after its construction and were synchronous with intestinal contraction. In contrast, SSBC did not become organized or propagate distally through the J-shaped IR until eight weeks after reservoir construction. LSBC occurred infrequently in control rabbits and in those after construction of the J-shaped and lateral IRs. Propagation of LSBC in control rabbits was synchronous with prolonged propulsive intestinal contraction. In both the J-shaped and lateral reservoirs, LSBC occurred randomly and did not propagate from proximal to distal ileum through the IR until three months after reservoir construction. The frequency and duration of LSBC remained diminished for the J-shaped IR at three months when compared with the lateral IR. It is concluded that the return of normal propulsive activity occurs earlier in the lateral iso-peristaltic IR than in the J-shaped IR but that both are effective at three months.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparison of clinical and compliance characteristics between S and W ileal reservoirs

Ileal reservoir reconstruction has become the preferred technique for restoration of bowel continuity in most patients after colectomy for ulcerative colitis or familial adenomatous polyposis. We analyzed and compared compliance characteristics of triple-limb S and quadruple-limb W reservoir designs and correlated changes in capacity with overall function. Fifty patients underwent colectomy and reservoir construction for ulcerative colitis or familial adenomatous polyposis; 12 received S reservoirs and 38 received W reservoirs. Reservoir compliance was assessed by means of a specially designed condom catheter that continuously recorded intrareservoir pressure and changes in perfused volume. During reservoir infusion, volumes and pressures at initial fullness, normal sensation of evacuation, and maximum tolerated volume were noted. Studies were performed at 2 and 12 months after ileostomy takedown. An increase in normal evacuation volume from 218 +/- 9 mL to 310 +/- 12 mL between 2 and 12 months (p less than or equal to 0.05) was observed in patients with W reservoirs. Similar changes were recorded in S reservoir reconstructions (201 +/- 14 mL to 291 +/- 22 mL, p less than or equal to 0.05). No significant differences were observed in the mean pressure at normal evacuation volume between the S and W groups at 2 and 12 months. The 24-hour stool frequency decreased an average of 3 per day for both reservoir designs between the 2- and 12-month study period (p less than or equal to 0.05). This frequency was most directly predicted by normal evacuation volume (r = 0.90 for W and 0.88 for S). The decrease in stool frequency correlated with increased reservoir compliance, as shown by larger tolerated volumes at similar pressures. Restorative proctocolectomies with S or modified W reservoirs are both acceptable alternatives and demonstrate similar compliance characteristics and functional results.     

Immunoglobulins in urine from patients with ileal and colonic conduits and reservoirs

Gel chromatography of proteins in urine from continent cecal urinary reservoirs revealed an abundance of high molecular weight proteins, especially secretory immunoglobulin A. Quantitation of immunoglobulins in urine from ileal and colonic conduits and ileal and cecal reservoirs showed secretory immunoglobulins A, G and M in amounts considerably greater than in urine from normal urinary tracts, whether or not bacteriuria was present. More secretory immunoglobulin A was found in reservoir than in conduit urine, but there was no such difference for immunoglobulin G and immunoglobulin M. In hemagglutination-inhibition tests, immunoglobulin A antibodies from cecal reservoir urine in 1 patient inhibited adherence (mannose-resistant) to human and animal erythrocytes of Escherichia coli obtained from reservoir urine from that same patient. High levels of secretory immunoglobulin A may constitute a host defense mechanism against urinary tract infection in patients with reservoirs and conduits.     

Nitrosamine excretion in patients with continent ileal reservoirs for urinary diversion.

Adenocarcinomas are a recognized complication following ureterosigmoidostomy for which the endogenous formation of N-nitroso compounds may be a risk factor. As an alternative means of urinary diversion, the continent ileal reservoir has recently been developed. Microbiological and chemical investigations on the urine of patients with an ileal reservoir showed the presence of bacteria, nitrate, nitrite and N-nitrosamines formed endogenously in the ileal pouch. The role of nitrosamines in carcinogenesis in these patients as a late stage complication resulting from the use of a continent ileal reservoir is discussed.     

Pelvic ileal reservoirs: experimental assessment of reservoir capacity in three reservoir designs

In order to examine the possible effect of different pouch shape to the capacity of ileal reservoirs three different types of pelvic ileal reservoir (2-, 3- and 4-loop) were compared in piglets, with four animals in each group. The intraoperative volume of all of these reservoirs was 55 ml, measured with saline. A larger (110 ml) 2-loop reservoir was used in a control group of four animals. The animals were kept alive for 6 weeks after which time the capacity and emptying of the reservoirs were studied. The resulting volume increases (ml/kg) were 15.4, 9.2, 8.9 and 8.1 in J-, S-, large-J- and W-shaped reservoirs, respectively. The emptying of the reservoirs was incomplete in all designs. No statistical difference (P greater than 0.5) was found between groups for either of these parameters. If resistance to outflow from the pouch can be avoided, the capacity of the reservoir seems to depend more on its initial size at the time of construction than on the pouch design.     

The physiologic effects of ileal reservoirs and efferent conduits complementing ileoanal anastomosis: an experimental study in dogs

S-shaped ileal reservoirs (SSRs) and double-barreled ileal reservoirs (DBRs) of equal size were placed 6 or 2 cm from the anus and evaluated over 1 year for their ability to improve the functional incontinence noted after an ileoanal anastomosis (IAA). Compared to straight IAA, both reservoirs prolonged intestinal transit (235 minutes versus 135 minutes, P less than 0.001) and alleviated frequency without causing nutritional abnormalities. The capacity of the reservoirs was greater than that of a comparable length of distal ileum in dogs (n = 6) with straight IAA (304 +/- 16 ml versus 102 +/- 2 ml, P less than 0.001). The SSRs (n = 9), in contrast to the DBRs (n = 10), developed excessive volume capacity (360 +/- 30 ml versus 254 +/- 104 ml, P less than 0.01) and obstructive complications. Reservoirs with 6 cm efferent conduits (n = 13), in contrast to those with a 2 cm efferent conduit (n = 6), underwent marked dilatation (334 +/- 24 ml versus 238 +/- 13 ml, P less than 0.005). Electromyography and manometry revealed the DBRs to be more contractile than the SSRs but less than ileum proximal to the anus in dogs with a straight IAA. Ileal reservoirs improve results after IAA. Reservoirs should be complaint and yet contractile (e.g., DBR) so as to discourage excessive dilatation, which is the harbinger of obstruction. Ileal conduits facilitate reservoir placement, but if longer than 2 cm they excessively impeded reservoir emptying, predisposing to excessive reservoir dilatation and obstruction. A DBR with a 2 cm efferent conduit results in continence without obstructive problems.     

The ileal neobladder

We improved the method of Hautmann's operation and an ileal neobladder was created in 7 male patients with bladder carcinoma and 1 female patient with tuberculous contracted bladder. Post-operative urodynamic studies demonstrated that the neobladder capacity was approximate to normal bladder, the maintaining pressure was lower than 25 cmH2O. No reflux and incontinence was noticed during the filling in all the patients. The patients not only could self-control micturate but also had the sensation of distension which was similar to normal bladder.     

The ileal neobladder

Currently we are witnessing an increase of interest in bladder substitution enterocystoplasty. The goal of this presentation is to describe operative technique and first clinical results of a ileal neobladder for total bladder replacement. Creation of a ileal neobladder for total bladder replacement is described in 11 patients. To achieve a low pressure system, disruption of directional bowel peristalsis with a longitudinal incision at the antimesenteric border of a 70 cm ileal segment is performed. A spherical pouch, the neobladder, is fashioned and anastomosed to the urethra. The ureters are implanted according to Le Duc and Camey. Videourodynamic studies during various postoperative phases demonstrate this neobladder to be a urinary reservoir with a capacity approximating that of a normal bladder, good compliance during filling by maintaining pressures lower than 30 cm water and no reflux. Eight of the 11 patients with the neobladder are completely dry day and night. Three are stress incontinent grade I. All 11 patients developed recognizable sensations of bladder distension closely simulating those of their earlier bladders. The use of this ileal neobladder in male patients undergoing radical cystectomy offers a stoma free alternative to urinary diversion resulting in a highly compliant low pressure bladder. A urodynamic comparison between the most recent developments (Kock-pouch, Camey, Mainz-pouch, "Le Bag") is made and this clearly shows the ileal neobladder to have several distinct advantages: the ileocolonic junction and the terminal ileum are saved; the operative technique is safe, simple and reliable (no Kock valve, no 180 degree rotation of the reservoir, simple antireflux technique); development of recognizable sensations of bladder filling in all cases.(ABSTRACT TRUNCATED AT 250 WORDS)     

The ileal neobladder

The ileal neobladder produces a completely detubularized, low pressure, high capacity reservoir constructed from ileum without any valves. Since April 1986, 161 patients underwent this type of surgery at our institution. Of these patients 141 underwent simultaneous radical cystectomy for bladder cancer, and 20 received a bladder augmentation. The mean postoperative follow-up is 23.8 months with a range of 3-52 months. Perioperative mortality was 0.5 percent, 9.5 percent of the patients died later than 2 months postoperatively, 7.5 percent due to tumor progression, 2 percent because of pneumonia, severe metabolic acidosis, myocardial infarction and apoplexy. Day and night continence was preserved in 78% of all patients; severe stress incontinence was found in 4.2 percent of the patients and night time incontinence needing some external device in 7.7%. 10 percent with mild stress incontinence do not require further treatment. Our experience with this relatively simple procedure is excellent: the need for reoperation is low and the high reservoir capacity results in early continence in most cases. This concept offers a genuine alternative to any form of cutaneous urinary diversion with an incidence of complications not higher than after standard supravesical urinary diversion.     

The ileal neobladder

The ileal neobladder in many respects approximates the theoretically ideal continent urinary diversion. The technique, while more technically demanding than the performance of the standard ileal loop diversion, is not difficult, particularly for surgeons used to performing radical retropubic prostatectomies. The ileal neobladder appears to approximate most closely the optimal bladder substitution. Although currently feasible only in males, future considerations could conceivably involve urologists working with their colleagues in gynecology and colorectal surgery to extend the benefits of bladder substitution using the ileal neobladder to selected patients having cystectomy for associated gynecologic or colorectal malignancies.     

The ileal neobladder

An ileal neobladder for total bladder replacement was created in 11 patients. To achieve a low pressure system, disruption of directional bowel peristalsis with a longitudinal incision at the antimesenteric border of a 70 cm. ileal segment is performed. A spherical pouch, the neobladder, is fashioned and anastomosed to the urethra. The ureters are implanted according to the method of Le Duc and Camey. Videourodynamic studies during various postoperative phases demonstrate this neobladder to be a urinary reservoir with a capacity approximating that of a normal bladder, good compliance during filling by maintaining pressure lower than 30 cm. water and no reflux. Of the 11 patients with the neobladder 8 are completely dry day and night, while 3 have grade I stress incontinence. All 11 patients had recognizable sensations of bladder distension closely simulating those of normal bladders. The use of this ileal neobladder in male patients undergoing radical cystectomy offers an alternative free of a stoma to urinary diversion, resulting in a highly compliant, low pressure bladder.