Chapter 6: Elimination
Skip chapter table of contents and go to main content
Surgical urinary diversions
Definition
A urinary diversion is a surgically created system for removing urine from the body when either the bladder or the urethra is non‐existent or no longer viable.
Evidence‐based approaches
Rationale
Muscle‐invasive bladder cancer is the most common condition for which urinary diversions are performed in adults. Other conditions that may lead to urinary diversion include:
- pelvic cancers, for example gynaecological cancers or sarcoma
- congenital abnormalities, for example bladder extrophy
- neuropathic bladder, a condition where the nerve impulses do not reach the bladder as a result of an underlying disease or injury, for example myelomeningocele
- trauma
- irreparable fistula
- interstitial cystitis
- radiation fibrosis
- intractable incontinence (Geng et al. [84]).
There are two main types: incontinent and continent diversions. Incontinent diversions take the form of an ileal conduit or urostomy, where the urine is stored in a body‐worn pouch. Continent urinary diversions differ in that a system is created to collect and store urine, known as a neobladder, before it is removed from the body. Examples of continent urinary diversions include continent cutaneous, orthotopic neobladder and rectal diversion (such as Mainz II) (Geng et al. [85], Spencer et al. [230]).
The main aim in the selection of a urinary diversion is to provide patients with a diversion that gives the lowest potential for complications and the best quality of life and, for those patients with cancer, the best cancer control (Lee et al. [127], Spencer et al. [230]).
Indications
A urinary diversion is formed to:
- eliminate urine from the body if the lower urinary tract is defective or absent (as in cystectomy)
- preserve the upper urinary tract
- avoid metabolic disturbance
- store the urine either internally or externally until convenient to empty.
Continent diversions:
- store an adequate volume of urine at low pressure
- offer patients a choice of urinary diversion
- improve or maintain the individual's body image and their psychological and social wellbeing by removing the necessity of wearing external devices, for example a urostomy pouch or incontinence pads (Geng et al. [85]).
Incontinent diversions
An ileal conduit is the most common form of urostomy; the colon (colonic conduit) may also be used. The word ‘urostomy’ comes from the Greek uros, meaning urine, and stoma, meaning mouth or opening (Nazarko [156]).
A section of bowel is isolated, along with its mesentery vessels, and the remaining ends of the bowel are anastomosed to restore continuity. The isolated section is mobilized, the proximal end is closed and the ureters, once resected from the bladder, are implanted at this end. The distal end is brought out onto the surface of the abdominal wall and everted to form a spout (Figure 6.18). Urine from a urostomy will contain mucus from the bowel used in its construction (Geng et al. [84]).
Figure 6.18 Ileal conduit.
A cutaneous ureterostomy is another form of incontinent diversion where the ureters are brought out onto the abdominal wall together (one stoma) or separately (two stomas). This may be a permanent or temporary procedure, and it may be used for patients with poor renal function and when less extensive abdominal surgery is indicated. Stomas formed in this way are often small and flush to the abdomen. They are prone to stenosis and it is often difficult to maintain a leak‐proof appliance, and they often require permanent stent placement to maintain patency (Rodriguez et al. [214]).
Continent diversions
All continent diversions consist of three components:
- A reservoir to store urine, which may be the bladder itself, an augmented bladder or one made completely of de‐tublarized ileum or colon.
- A continence mechanism to retain urine in the reservoir, which may be an existing valve or sphincter, such as the ileocaecal valve, urethral sphincter or anal sphincter. A valve may also be constructed using the same tissue used to construct the reservoir, such as a flutter valve created by the intussusception of a segment of bowel or a flap valve created by tunnelling a narrow tube between muscle and mucosal layers of the reservoir (Geng et al. [85]).
- A channel or tunnel to let the urine out, which may be formed by using other tube‐ or tunnel‐like structures such as the appendix, ureter, urethra or fallopian tube. Alternatively, a segment of ileum or colon can be used (Geng et al. [85]).
There are three main types of continent diversion: continent cutaneous diversion, rectal bladder and orthotopic neobladder. There are many considerations long and short term that should be factored into decision making (see Table 6.8).
Table 6.8 Long‐ and short‐term risk factors of urinary diversion
| Ileal conduit | Continent cutaneous | Rectal bladder | Orthotopic bladder | |
|---|---|---|---|---|
| Failure to catheterize | ✓ | |||
| Recurrent infection | ✓ | ✓ | ✓ | |
| Hyperchloraemia | ✓ | ✓ | ✓ | |
| Stones | ✓ | ✓ | ✓ | |
| Pouch rupture | ✓ | ✓ | ✓ | |
| Incontinence | ✓ | ✓ | ||
| Inability to empty pouch | ✓ | |||
| Anastomotic stricture | ✓ | |||
| Urine malodour | ✓ | |||
| Risk of colorectal neoplasm | ✓ |
Continent cutaneous diversion
There are a number of different types of continent cutaneous diversion; they differ in construction, using different structures to form the reservoir and the tunnel, and different techniques to create the continence mechanism. The outcomes for patients and the nursing care involved are essentially similar in most cases. The most commonly performed procedure of this type is arguably the Mitrofanoff procedure, which uses the appendix to form the conduit from skin to pouch (Figure 6.19a).
Figure 6.19 A Mitrofanoff urinary diversion. (a) Front view. (b) Side view with a catheter in situ.
In this type of diversion, urine drains into the urinary reservoir (which is constructed from bowel or bladder) through the ureters. One end of the tissue used to construct the channel is buried in a submuscular tunnel in the neobladder, forming an obstructing flap valve. The other end is brought to the surface of the abdominal wall to form a continent stoma. As the bladder fills with urine, more pressure is put on the valve, causing it to become even more obstructed. A catheter is passed into the stoma along the channel, through the valve and into the bladder when the patient wants to empty their bladder (Geng et al. [85]). Patients can self‐catheterize into the continent urinary stoma every 4–6 hours to empty the urine reservoir (Figure 6.19b; see also Procedure guideline 6.17: Continent urinary diversion stoma: self‐catheterization).
Rectal bladder
As with continent cutaneous diversions, there are a number of different surgical techniques that can be used to create a continent rectal bladder; the most commonly used is the sigma rectum pouch known as the Mainz II (Figure 6.20). There are good reported outcomes for continence rates with this technique (Afak et al. [6]). The technique uses a section of de‐tubularized sigmoid to create a pouch that empties rectally, creating a mix of urine and faeces. Continence is tested pre‐operatively using the ‘porridge test’, in which up to 500 mL of loose‐consistency porridge is instilled into the rectum and retention is measured in time (Woodhouse [255]). Patients who fail this test are considered unable to hold sufficiently for this type of urinary diversion.
Figure 6.20 A Mainz II urinary diversion.
Patients must be counselled about the ongoing risk of hyperchloraemia due to reabsorption of urine from the pouch and also the long‐term risk of neoplasm. There is also the risk of incontinence, which may occur immediately or over time. Those with this type of diversion require lifelong careful monitoring.
Orthotopic neobladder
This type of diversion is suitable only for those who have disease suitable for the retention of their native urethra and a functional sphincter. A neobladder is created using a section of de‐tubularized sigmoid and attached to the patient's native urethra (Figure 6.21). The patient will then void per urethra. As the neobladder does not fill under pressure in the same way as a native bladder, the patient is required to perform a Valsalva manoeuvre (which involves forcing expiration against a closed airway by closing the mouth and pinching the nose while trying to forcefully expire) to generate pressure to void and/or perform intermittent self‐catheterization (see Procedure guideline 6.17: Continent urinary diversion stoma: self‐catheterization).
Figure 6.21 (a) Female orthotopic neobladder. (b) Male orthotopic neobladder.
Principles of care
Patient‐reported outcomes relating to physical functioning and quality of life are often higher in patients with continent diversions (Philip et al. [199], Singh et al. [225]). However, the decision making around urinary diversions (particularly for the continent types of diversion) needs to be carried out carefully based on many patient and disease factors (Spencer et al. [230]). Patients’ general levels of health, their co‐morbidities, and their renal and hepatic function are all taken into consideration when deciding on the type of urinary diversion. Intestinal disease (such as inflammatory bowel disease or diverticulitis), stress incontinence, bladder cancer involving the bladder neck or prostatic urethra, concurrent prostate cancer and previous pelvic radiotherapy are contraindications for continent diversion (Hautmann et al. [97], Kwan et al. [116]).
Patients undergoing continent diversions must be motivated towards self‐care, and those needing to self‐catheterize must be dextrous enough to manipulate Nelaton or intermittent catheters (Geng et al. [85]). Good anal sphincter control is essential for those undergoing a rectal bladder; this is tested pre‐operatively using a ‘porridge test’ (Woodhouse [255]).
Encouraging patients’ independence in living with a urinary diversion is a key aim of care. Practical help, advice and support are employed in encouraging patients to continue with all necessary activities of daily living.
It is important to note that surgery for all urinary diversions, and particularly those involving cystectomy, will have an impact on the patient's sexual function. Frequently, sexual function and libido are affected in males and females. The nurse should take time to counsel the patient and their partner on this outcome of surgery. See also the section ‘Sex and the ostomate’ below.
Procedure guideline 6.17
