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Keywords:

  • urinary diversion;
  • bowel preparation;
  • gut flora;
  • flora;
  • ileum;
  • complications

Abstract

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. CONFLICT OF INTEREST
  8. REFERENCES

Study Type – Harm (case series)

Level of Evidence 4

What's known on the subject? and What does the study add?

Recent studies show no advantage of bowel preparation before ileal urinary diversion and that avoidance of bowel preparation led to early restoration of intestinal function and shorter hospital stay. However, this was not tested in a prospective comparison.

The current study is a prospective comparison to test for the safety of omitting bowel preparation before ileal urinary diversion. This study also examines simultaneous effects of bowel preparation on the ileal flora and mucosa.

OBJECTIVE

  • To evaluate the safety of no bowel preparation before ileal reconstructive procedures of the lower urinary tract, in comparison to standard 3-day bowel preparation. The present study also examines the effects of bowel preparation on small bowel wall and bacterial flora.

PATIENTS AND METHODS

  • This study enrolled 40 patients scheduled for radical cystectomy and ileal urinary diversion, presenting to the department of urology, Alexandria University, Alexandria, Egypt during the period from January 2009 to September 2010.
  • Patients were prospectively randomized into two groups: Group (I) had standard 3-day bowel preparation. Group (II) had only over-night fasting before surgery.
  • Intra-operatively, one ml of ileal fluid was collected for bacteriological studies and an ileal wall biopsy was taken for histopathological examination.
  • Postoperative complications were reported for all patients using modified Clavien system.

RESULTS

  • Both groups showed insignificant difference regarding the frequency and Clavien grade of postoperative complications (P = 0.30).
  • Under aerobic and anaerobic conditions, 5 cases in group (I) had bacterial overgrowth of E. coli (>105) versus none in group (II) (P = 0.04). Eight patients in group (I) had sterile ileal fluid cultures versus 18 patients (90%) in group (II). No correlation could be made between would infections and the organisms isolated in ileal fluid cultures.
  • Histopathological examination of ileal biopsies revealed mucosal edema and submucosal congestion in 9 cases in group (I) versus 2 cases in group (II) (P = 0.0310).

CONCLUSIONS

  • Omitting bowel preparation before ileal urinary diversion is safe, with no added complications.
  • Non-preparation of the small bowel is not associated with bacterial overgrowth.

Abbreviation
CFU

colony-forming units

INTRODUCTION

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. CONFLICT OF INTEREST
  8. REFERENCES

Many urologists prefer to use small bowel segments for reconstruction of the lower urinary tract. Bowel preparation may add nothing but discomfort for the patient, variable degrees of preoperative dehydration and the possibility of breaking down the normal barrier to bacterial translocation [1]. Nevertheless, there are few prospective studies that recommend the safety of no bowel preparation before the use of ileal segments for urinary diversion.

This study prospectively evaluates the safety of omitting bowel preparation before radical cystectomy and ileal urinary diversion, in comparison with the standard 3-day bowel preparation. The present study also examines the effects of bowel preparation on small bowel wall and bacterial flora.

MATERIALS AND METHODS

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. CONFLICT OF INTEREST
  8. REFERENCES

The present study included 40 consecutive patients who presented to the Urology Department, Alexandria University, Egypt, during the period from January 2009 to December 2010. These patients were scheduled for radical cystectomy and ileal urinary diversion. Exclusion criteria included previous intestinal surgery, previous radiation or chemotherapy, advanced liver or kidney disease and metastatic disease. The study was approved by the ethics committee of the Faculty of Medicine, Alexandria University and all patients signed informed consent. They were randomized into two groups: group I was subjected to a standard 3-day bowel preparation (using laxatives, enemas and antibiotics as shown in Table 1). Group II patients were subjected to overnight fasting before surgery.

Table 1. Three-day bowel preparation protocol
Preoperative dayPreparation protocol
Day – 3Liquid diet
Oral Bisacodyl 15 mg (6 p.m.)
Day – 2Liquid diet
Castor oil 40 g (6 p.m.).
Normal saline enema (9 p.m.)
Day – 1Liquid diet
Erythromycin 1 g twice daily
Metronidazole 1 g twice daily
Castor oil 40 g (6 p.m.).
Normal saline enema (9 p.m.)
Overnight fasting
Day 0Surgery at 8 a.m.

All patients underwent clinical evaluation, metastatic survey, and complete preoperative and postoperative laboratory investigations. All patients in the present study received identical perioperative and postoperative antibiotic regimens: a prophylactic 1 g of third-generation cephalosporine given intravenously 1 h before surgery and continued postoperatively for 7–10 days, guided by culture results. Intraoperatively, surgical towels were used to contain any spillage from the resected ileal segment. One millilitre of ileal fluid was collected intraoperatively for aerobic and anaerobic cultures, before flushing the isolated ileal segment with normal saline. Intestinal integrity was restored using an inverting two-layer technique. Serial 10-fold dilutions of the ileal fluid sample were made using 0.9% sterile saline then, 10 µL was taken from each dilution for culture on the corresponding sector of a blood agar plate. The plates were incubated at 37 °C for 24 h aerobically and anaerobically. The colony count/mL of original sample was calculated as the dilution × 100 × number of colonies = colony-forming units (CFU)/mL. Bacterial overgrowth is diagnosed when the number of bacterial colonies cultured exceeds 105/mL fluid in the small intestine [2]. A tissue specimen from the ileum was taken for histopathology. Postoperative complications concerning wound and tissue healing were reported using a modified Clavien system.

Data were fed to the computer using the Predictive Analytics Software (PASW Statistics 18; SPSS Inc. (An IBM company), SPSS (Hong Kong) Ltd, Quarry Bay, Hong Kong). Qualitative data were described using number and percent. Association between categorical variables was tested using a chi-squared test. When more than 20% of the cells had an expected count <5, correction for chi-squared test was conducted using Fisher's exact test or Monte Carlo correction. Quantitative data were described using median, minimum and maximum as well as mean and standard deviation. The distributions of quantitative variables were tested for normality using Kolmogorov–Smirnov test and Shapiro–Wilk test. The D'Agstino test was used if there was a conflict between the two previous tests. For normally distributed data, comparisons between two independent populations were made using an independent t-test. P value ≤ 0.05 was significant.

RESULTS

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. CONFLICT OF INTEREST
  8. REFERENCES

Both groups were comparable regarding age, gender and comorbid medical conditions (Table 2).

Table 2. Demographic characteristics of both groups showed no significant difference
Demographic parameterGroup IGroup IITest of significance*
  • *

    P is P value for Student's t test; PFE is P value for Fisher exact test.

Age (year)
Range35.0–70.039.0–64.0 P= 0.583
Mean ± SD54.25 ± 8.4552.8 ± 8.12
Gender, n
Female23 P FE= 1.000
Male1817

Ileal urinary diversion procedures used were cutaneous continent reservoir, ileal conduit and ileal orthotopic bladder (Table 3). There was no difference between groups with regard to difference in procedures performed.

Table 3. Types of ileal urinary diversion procedures performed in each group
Type of diversionGroup IGroup II
n n
Cutaneous continent reservoir43
Ileal conduit1210
Orthotopic bladder47
Total2020

Both groups were comparable regarding the results of preoperative and postoperative laboratory investigations (Table 4).

Table 4. Results of preoperative and postoperative laboratory investigations for groups I and II
Laboratory investigationPreoperativePostoperative
Group IGroup II P * Group IGroup II P *
Range Mean ±sdRange Mean ±sdRange Mean ±sdRange Mean ±sd
  • *

    P value for Student's t test.

Haemoglobin (g/dL)8.2–15.38.3–13.70.1618.8–13.18.0–12.60.195
11.76 ± 1.9411.0 ± 1.3710.58 ± 1.2410.09 ± 1.07
WBC (×1000/mm3)3.9–104.5–11.00.4627–137–14.50.254
7.35 ± 2.16.87 ± 1.9810.24 ± 1.5410.98 ± 2.41
Serum creatinine (mg/dL)0.6–2.20.7–1.90.1630.8–2.10.8–2.00.141
1.06 ± 0.441.23 ± 0.291.18 ± 0.351.35 ± 0.36
Na+ (mEq/L)129–150131–1460.361132–147134–1500.143
140.20 ± 4.44139 ± 3.74139.35 ± 4.0140.20 ± 3.83
K+ (mEq/L)3.9–4.83.3–4.70.1614.3–5.14.2–5.20.243
4.21 ± 0.683.9 ± 0.694.5 ± 0.324.62 ± 0.32

There was no difference between groups in the frequency or the severity of postoperative complications. Uneventful postoperative course was observed in nine patients in group I versus 13 patients in group II (P= 0.30). Postoperative urine leak was regarded as a complication if it lasted more than 7 days. It occurred in one case in each group after orthotopic neobladder and stopped within a few days of regular pouch irrigation. Postoperative ileus was labelled prolonged when persisting more than 4 days despite adequate ambulation and normal serum electrolyte levels. Two patients in group I had prolonged ileus compared with only one patient in group II. Superficial wound infections affected seven patients in group I and five patients in group II. One patient in group I needed urgent reoperation for burst wound (Clavien grade III) (Table 5).

Table 5. Postoperative complications reported for groups I and II
Postoperative complicationsGroup IGroup II
Frequency%Frequency%
No complications9451365
Minor complications (Clavien grade I–II)Prolonged ileus21015
Urine leak1515
Superficial wound infection735525
Major complications (Clavien grade III–V)Burst wound1500
Total2010020100

Under aerobic and anaerobic conditions, five cases in group I had bacterial overgrowth of Escherichia coli (>105) versus none in group II (P= 0.04). Eight patients in group I had sterile ileal fluid cultures versus 18 patients in group II. The rest of the patients in each group had insignificant microbial growth: five cultures in group I grew fewer colony counts (<105) of Gram-negative bacteria (E. coli, Klebsiella sp. or Enterococcus faecalis). Pure Candida sp. isolates were found in two cases in each group (Table 6). No correlation could be made between wound infections and the organisms isolated in ileal fluid cultures.

Table 6. Results of aerobic and anaerobic cultures of ileal fluid in groups I and II
Aerobic and anaerobic culturesGroup IGroup II
Frequency%Frequency%
  1. Fisher's exact test, P= 0.0471.

No growth8401890
Bacterial overgrowth (>105) (Escherichia coli)52500
Insignificant microbial growth (<105)53500
Candida alone210210
Total2010020100

Histopathological examination of ileal biopsies revealed mucosal oedema and submucosal congestion in 9 out of 20 specimens in group I versus 2 out of 20 specimens in group II (P= 0.03) (Fig. 1).

image

Figure 1. Histopathological examination of ileal biopsies show submucosal congestion and edema in the prepared ileum (200 × magnification, Hematoxylin and Eosin stain).

Download figure to PowerPoint

DISCUSSION

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. CONFLICT OF INTEREST
  8. REFERENCES

Each method of bowel preparation has some shortcomings. Conventional bowel preparation tends to exhaust the patient and may exacerbate nutritional depletion because it generally requires a 3-day preparation of suboptimal caloric and protein intake. Whole gut irrigation (with lactated Ringer's solution or normal saline) has been found to be no more effective than conventional preparation in reducing wound infections and septic complications [3], even though there is a reduction of aerobic flora compared with the conventional preparation [4]. Also, the usage of whole gut irrigation in the cardiac and elderly is a justified concern. The polyethylene glycol–electrolyte lavage solution was found to be as effective as a conventional preparation but inadequate preparation occurs in 5% of the patients using this modality [5].

The intestinal flora plays an important role in maintenance of mucosal barrier integrity [6] and the influence of antibiotic use over the normal enteric bacterial flora is already known [7]. Still, the value of antibiotics in elective mechanical bowel preparation is controversial. Moreover, antibiotic bowel preparations may result in diarrhoea, pseudomembranous colitis or monilial overgrowth. Some studies showed a reduction in wound infection [8] but others demonstrated no added benefit [9]. Histological studies have revealed the loss of superficial mucus from epithelial cells as well as inflammatory changes within the bowel wall in patients undergoing bowel preparation [10]. Therefore, a number of studies have questioned the efficacy of and even the need for mechanical bowel preparation. Almost all of these studies focused on colonic preparations and few dealt with the effects of small bowel preparation in a prospective manner. Hence, the focus of the present study is to evaluate the safety of no bowel preparation before radical cystectomy and ileal urinary diversion.

In the present study, nine patients in group I had uneventful postoperative courses versus 13 patients in group II (P= 0.30). No significant advantage was observed for bowel-prepared patients over those with non-prepared bowel regarding the frequency or severity of postoperative complications. Most of which were Clavien grade 2 complications: prolonged ileus affected two cases in group I and one patient in group II. All were treated conservatively and improved on nasogastric drainage. Urine leak affected one patient in each group for more than 7 days and both cases dried within a few days on regular pouch irrigation. Superficial wound infections affected seven patients in group I and five patients in group II. All healed well on local care and frequent dressings. Urgent reoperation for wound dehiscence (Clavien grade 3) was needed for one patient in group I (Table 5).

The reported incidence of wound infections (or surgical site infections) following urinary diversions generally varies from 4 to 33% [11,12]. We find our results comparable and our research focuses on improving the preoperative and postoperative care standards in our institution. Many recent studies showed no advantage of bowel preparation before ileal urinary diversion and that avoidance of bowel preparation led to early restoration of intestinal function and shorter hospital stay [13–16]. In the present study, we did not find differences between the two groups in the frequency of postoperative ileus like other series, but a larger cohort would be needed to elucidate subtle differences in resolution of ileus. These series, however, did not examine simultaneous undesirable effects of bowel preparation on the ileal flora and mucosa.

Bacterial density increases in the distal small intestine (duodenum 101–103 CFU/mL, jejunum/ileum 104–107 CFU/mL). Enteric bacteria form a natural defence barrier and have numerous protective, structural and metabolic effects on the epithelium [2]. The bowel is normally inhabited by Gram-negative organisms. Bacterial overgrowth is diagnosed when the number of bacterial colonies cultured exceeds 105/mL fluid in the small intestine [13–16].

In the present study, five patients in group I had bacterial overgrowth of E. coli under aerobic and anaerobic conditions (>105) compared with none in group II (P= 0.04). Eight patients in group I had sterile ileal fluid cultures compared with 18 patients in group II. Five cultures in group I showed insignificant microbial growth (<105) of Gram-negative bacteria (E. coli, Klebsiella sp. or Enterococcus faecalis). Pure Candida isolates were found in two cases in each group (Table 6). No correlation could be made between wound infections and the organisms isolated in ileal fluid cultures.

Bacterial overgrowth could be attributed to antibiotics used for bowel preparation, which in turn alters the mutual balance between small bowel floras. Enemas and laxatives may also lead to anti-peristalsis, which could change the natural gradient of bacterial density along the distal ileum.

Non-preparation of the small intestine before ileal urinary diversion is safe, with no added complications. It is at least equal to mechanical preparation, sparing the patient unnecessary exhaustion before major surgery. Non-preparation of the small bowel is not associated with bacterial overgrowth.

REFERENCES

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. CONFLICT OF INTEREST
  8. REFERENCES
  • 1
    Weist R. Bacterial translocation. Bioscience Microflora 2005; 24: 6190
  • 2
    Blaut M, Collins MD, Welling GW, Doré J, van Loo J, de Vos W. Molecular biological methods for studying the gut microbiota: the EU human gut flora project. Br J Nutr 2002; 87 (Suppl 2): S20311
  • 3
    Christensen PB, Kronborg O. Whole-gut irrigation versus enema in elective colorectal surgery: a prospective, randomized study. Dis Colon Rectum 1981; 24: 5925
  • 4
    Van den Bogaard AE, Weidema W, Hazen MJ, Wesdorp RI. A bacteriological evaluation of three methods of bowel preparation for elective colorectal surgery. Antonie Van Leeuwenhoek 1981; 47: 868
  • 5
    Wolff BG, Beart Jr RW, Dozois RR et al. A new bowel preparation for elective colon and rectal surgery: a prospective, randomized clinical trial. Arch Surg 1988; 123: 895900
  • 6
    O'Hara AM, Shanahan F. The gut flora as a forgotten organ. EMBO Rep 2006; 7: 68893
  • 7
    Brismar B, Edlund C, Malmborg AS, Nord CE. Ecological impact of antimicrobial prophylaxis on intestinal microflora in patients undergoing colorectal surgery. Scand J Infect Dis Suppl 1990; 70: 2530
  • 8
    Clarke JS, Condon RE, Bartlett JG, Gorbach SL, Nichols RL, Ochi S. Preoperative oral antibiotics reduce septic complications of colon operations. Ann Surg 1977; 186: 2519
  • 9
    Menaker GJ, Litvak S, Bendix R et al. Operations on the colon without preoperative oral antibiotic therapy. Surg Gynecol Obstet 1981; 152: 368
  • 10
    Bartlett JG, Condon RE, Gorbach SL, Clarke JS, Nichols RL, Ochi S. Veterans Administration Cooperative Study on bowel preparation for elective colorectal operations: impact of oral antibiotic regimen on colonic flora, wound irrigation cultures, and bacteriology or septic complications. Ann Surg 1978; 188: 24954
  • 11
    Takeyama K, Matsukawa M, Kunishima Y et al. Incidence of and risk factors for surgical site infection in patients with radical cystectomy with urinary diversion. J Infect Chemother 2005; 11: 17781
  • 12
    Ali-el-Dein B, Shaaban AA, Abu-Eideh RH, el-Azab M, Ashamallah A, Ghoneim MA. Surgical complications following radical cystectomy and orthotopic neobladders in women. J Urol 2008; 180: 20610
  • 13
    Shafii M, Murphy DM, Donovan MG, Hickey DP. Is mechanical bowel preparation necessary in patients undergoing cystectomy and urinary diversion? BJU Int 2002; 89: 87981
  • 14
    Gundeti MS, Godbole PP, Wilcox DT. Is bowel preparation required before cystoplasty in children? J Urol 2006; 176: 15746
  • 15
    Tabibi A, Simforoosh N, Basiri A, Ezzatnejad M, Abdi H, Farrokhi F. Bowel preparation versus no preparation before ileal urinary diversion. Urology 2007; 70: 6548
  • 16
    Maffezzini M, Campodonico F, Canepa G, Gerbi G, Parodi D. Current perioperative management of radical cystectomy with intestinal urinary reconstruction for muscle-invasive bladder cancer and reduction of the incidence of postoperative ileus. Surg Oncol 2008; 17: 418